Snap for 8730993 from 7c9acb6e9ec68ad405374b99209e021959bde0c5 to mainline-tzdata3-releaseaml_tz3_314012070aml_tz3_314012050aml_tz3_314012010aml_tz3_313110000aml_tz3_312511020aml_tz3_312511010aml_tz3_312410020aml_tz3_312410010android12-mainline-tzdata3-releaseaml_tz3_314012010

Change-Id: Ia45eee2fec0da658c76057d3ff6a8955ebcff2e5

40 files changed, 4607 insertions, 7410 deletions

diff --git a/Android.bp b/Android.bp
index 8a1c818..9db5ece 100644
--- a/Android.bp
+++ b/Android.bp
@@ -2,13 +2,30 @@ package {
     default_applicable_licenses: ["external_zopfli_license"],
 }
 
+// Added automatically by a large-scale-change that took the approach of
+// 'apply every license found to every target'. While this makes sure we respect
+// every license restriction, it may not be entirely correct.
+//
+// e.g. GPL in an MIT project might only apply to the contrib/ directory.
+//
+// Please consider splitting the single license below into multiple licenses,
+// taking care not to lose any license_kind information, and overriding the
+// default license using the 'licenses: [...]' property on targets as needed.
+//
+// For unused files, consider creating a 'filegroup' with "//visibility:private"
+// to attach the license to, and including a comment whether the files may be
+// used in the current project.
+//
+// large-scale-change included anything that looked like it might be a license
+// text as a license_text. e.g. LICENSE, NOTICE, COPYING etc.
+//
+// Please consider removing redundant or irrelevant files from 'license_text:'.
+// http://go/android-license-faq
 license {
     name: "external_zopfli_license",
     visibility: [":__subpackages__"],
     license_kinds: [
-        // Most of the code is APL2...
         "SPDX-license-identifier-Apache-2.0",
-        // ...but src/zopflipng/lodepng is zlib instead.
         "SPDX-license-identifier-Zlib",
     ],
     license_text: [
diff --git a/CMakeLists.txt b/CMakeLists.txt
deleted file mode 100644
index e56fd2f..0000000
--- a/CMakeLists.txt
+++ /dev/null
@@ -1,197 +0,0 @@
-cmake_minimum_required(VERSION 2.8.11)
-
-project(Zopfli)
-
-# Check if Zopfli is the top-level project (standalone), or a subproject
-set(zopfli_standalone FALSE)
-get_directory_property(zopfli_parent_directory PARENT_DIRECTORY)
-if(zopfli_parent_directory STREQUAL "")
-  set(zopfli_standalone TRUE)
-endif()
-unset(zopfli_parent_directory)
-
-#
-# Options
-#
-
-# ZOPFLI_BUILD_SHARED controls if Zopfli libraries are built as shared or
-# static
-#
-# It defaults to the value of BUILD_SHARED_LIBS if set, and in most cases
-# that should be used instead. The purpose of ZOPFLI_BUILD_SHARED is to allow
-# overriding it when built as a subproject.
-set(zopfli_shared_default OFF)
-if(DEFINED BUILD_SHARED_LIBS)
-  set(zopfli_shared_default ${BUILD_SHARED_LIBS})
-endif()
-option(ZOPFLI_BUILD_SHARED "Build Zopfli with shared libraries" ${zopfli_shared_default})
-unset(zopfli_shared_default)
-
-# ZOPFLI_BUILD_INSTALL controls if Zopfli adds an install target to the build
-#
-# When built standalone or as a shared library subproject, the default is ON,
-# and for static library subproject the default is OFF.
-if(zopfli_standalone OR ZOPFLI_BUILD_SHARED)
-  option(ZOPFLI_BUILD_INSTALL "Add Zopfli install target" ON)
-else()
-  option(ZOPFLI_BUILD_INSTALL "Add Zopfli install target" OFF)
-endif()
-
-# ZOPFLI_DEFAULT_RELEASE enables changing empty build type to Release
-#
-# Make based single-configuration generators default to an empty build type,
-# which might be surprising, but could be useful if you want full control over
-# compiler and linker flags. When ZOPFLI_DEFAULT_RELEASE is ON, change an
-# empty default build type to Release.
-option(ZOPFLI_DEFAULT_RELEASE "If CMAKE_BUILD_TYPE is empty, default to Release" ON)
-
-if(zopfli_standalone AND ZOPFLI_DEFAULT_RELEASE)
-  if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
-    message(STATUS "CMAKE_BUILD_TYPE empty, defaulting to Release")
-    set(CMAKE_BUILD_TYPE Release)
-  endif()
-endif()
-
-#
-# Library version
-#
-set(ZOPFLI_VERSION_MAJOR 1)
-set(ZOPFLI_VERSION_MINOR 0)
-set(ZOPFLI_VERSION_PATCH 3)
-set(ZOPFLI_VERSION ${ZOPFLI_VERSION_MAJOR}.${ZOPFLI_VERSION_MINOR}.${ZOPFLI_VERSION_PATCH})
-
-if(ZOPFLI_BUILD_SHARED)
-  set(zopfli_library_type SHARED)
-else()
-  set(zopfli_library_type STATIC)
-endif()
-
-include(GNUInstallDirs)
-
-#
-# libzopfli
-#
-add_library(libzopfli ${zopfli_library_type}
-  src/zopfli/blocksplitter.c
-  src/zopfli/cache.c
-  src/zopfli/deflate.c
-  src/zopfli/gzip_container.c
-  src/zopfli/hash.c
-  src/zopfli/katajainen.c
-  src/zopfli/lz77.c
-  src/zopfli/squeeze.c
-  src/zopfli/tree.c
-  src/zopfli/util.c
-  src/zopfli/zlib_container.c
-  src/zopfli/zopfli_lib.c
-)
-target_include_directories(libzopfli
-  INTERFACE
-    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src/zopfli>
-    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
-)
-set_target_properties(libzopfli PROPERTIES
-  OUTPUT_NAME zopfli
-  VERSION ${ZOPFLI_VERSION}
-  SOVERSION ${ZOPFLI_VERSION_MAJOR}
-)
-if(UNIX AND NOT (BEOS OR HAIKU))
-  target_link_libraries(libzopfli m)
-endif()
-
-#
-# libzopflipng
-#
-add_library(libzopflipng ${zopfli_library_type}
-  src/zopflipng/zopflipng_lib.cc
-  src/zopflipng/lodepng/lodepng.cpp
-  src/zopflipng/lodepng/lodepng_util.cpp
-)
-target_link_libraries(libzopflipng libzopfli)
-target_include_directories(libzopflipng
-  INTERFACE
-    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src/zopflipng>
-    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
-)
-set_target_properties(libzopflipng PROPERTIES
-  OUTPUT_NAME zopflipng
-  VERSION ${ZOPFLI_VERSION}
-  SOVERSION ${ZOPFLI_VERSION_MAJOR}
-)
-
-# MSVC does not export symbols by default when building a DLL, this is a
-# workaround for recent versions of CMake
-if(MSVC AND ZOPFLI_BUILD_SHARED)
-  if(CMAKE_VERSION VERSION_LESS 3.4)
-    message(WARNING "Automatic export of all symbols to DLL not supported until CMake 3.4")
-  else()
-    set_target_properties(libzopfli PROPERTIES WINDOWS_EXPORT_ALL_SYMBOLS ON)
-    set_target_properties(libzopflipng PROPERTIES WINDOWS_EXPORT_ALL_SYMBOLS ON)
-  endif()
-endif()
-
-#
-# zopfli
-#
-add_executable(zopfli src/zopfli/zopfli_bin.c)
-target_link_libraries(zopfli libzopfli)
-if(MSVC)
-  target_compile_definitions(zopfli PRIVATE _CRT_SECURE_NO_WARNINGS)
-endif()
-
-#
-# zopflipng
-#
-add_executable(zopflipng src/zopflipng/zopflipng_bin.cc)
-target_link_libraries(zopflipng libzopflipng)
-if(MSVC)
-  target_compile_definitions(zopflipng PRIVATE _CRT_SECURE_NO_WARNINGS)
-endif()
-
-# Create aliases
-#
-# Makes targets available to projects using Zopfli as a subproject using the
-# same names as in the config file package.
-if(NOT CMAKE_VERSION VERSION_LESS 3.0)
-  add_library(Zopfli::libzopfli ALIAS libzopfli)
-  add_library(Zopfli::libzopflipng ALIAS libzopflipng)
-  add_executable(Zopfli::zopfli ALIAS zopfli)
-  add_executable(Zopfli::zopflipng ALIAS zopflipng)
-endif()
-
-#
-# Install
-#
-if(ZOPFLI_BUILD_INSTALL)
-  # Install binaries, libraries, and headers
-  install(TARGETS libzopfli libzopflipng zopfli zopflipng
-    EXPORT ZopfliTargets
-    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
-    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
-  )
-  install(FILES src/zopfli/zopfli.h src/zopflipng/zopflipng_lib.h
-    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
-  )
-
-  # Install config file package
-  #
-  # This allows CMake based projects to use the installed libraries with
-  # find_package(Zopfli).
-  if(NOT CMAKE_VERSION VERSION_LESS 3.0)
-    include(CMakePackageConfigHelpers)
-    write_basic_package_version_file(${CMAKE_CURRENT_BINARY_DIR}/ZopfliConfigVersion.cmake
-      VERSION ${ZOPFLI_VERSION}
-      COMPATIBILITY SameMajorVersion
-    )
-    # Since we have no dependencies, use export file directly as config file
-    install(EXPORT ZopfliTargets
-      DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/Zopfli
-      NAMESPACE Zopfli::
-      FILE ZopfliConfig.cmake
-    )
-    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/ZopfliConfigVersion.cmake
-      DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/Zopfli
-    )
-  endif()
-endif()
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
deleted file mode 100644
index 1ba8539..0000000
--- a/CONTRIBUTING.md
+++ /dev/null
@@ -1,24 +0,0 @@
-Want to contribute? Great! First, read this page (including the small print at the end).
-
-### Before you contribute
-Before we can use your code, you must sign the
-[Google Individual Contributor License Agreement](https://developers.google.com/open-source/cla/individual?csw=1)
-(CLA), which you can do online. The CLA is necessary mainly because you own the
-copyright to your changes, even after your contribution becomes part of our
-codebase, so we need your permission to use and distribute your code. We also
-need to be sure of various other things—for instance that you'll tell us if you
-know that your code infringes on other people's patents. You don't have to sign
-the CLA until after you've submitted your code for review and a member has
-approved it, but you must do it before we can put your code into our codebase.
-Before you start working on a larger contribution, you should get in touch with
-us first through the issue tracker with your idea so that we can help out and
-possibly guide you. Coordinating up front makes it much easier to avoid
-frustration later on.
-
-### Code reviews
-All submissions, including submissions by project members, require review. We
-use Github pull requests for this purpose.
-
-### The small print
-Contributions made by corporations are covered by a different agreement than
-the one above, the Software Grant and Corporate Contributor License Agreement.
diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 6eccb31..a1800be 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -1,9 +1,7 @@
 Mark Adler
 Jyrki Alakuijala
 Frédéric Kayser
-Jeffrey Lim
 Daniel Reed
 Huzaifa Sidhpurwala
 Péter Szabó
 Lode Vandevenne
-Derek Buitenhuis
diff --git a/METADATA b/METADATA
index e8ea873..d97975c 100644
--- a/METADATA
+++ b/METADATA
@@ -1,15 +1,3 @@
-name: "zopfli"
-description: "Zopfli Compression Algorithm is a compression library programmed in C to perform very good, but slow, deflate or zlib compression."
 third_party {
-  url {
-    type: GIT
-    value: "https://github.com/google/zopfli.git"
-  }
-  version: "831773bc28e318b91a3255fa12c9fcde1606058b"
   license_type: NOTICE
-  last_upgrade_date {
-    year: 2021
-    month: 6
-    day: 14
-  }
 }
diff --git a/Makefile b/Makefile
index 5407de8..ef159da 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,8 @@
-CC ?= gcc
-CXX ?= g++
+CC = gcc
+CXX = g++
 
-override CFLAGS := -W -Wall -Wextra -ansi -pedantic -lm -O3 -Wno-unused-function -fPIC $(CFLAGS)
-override CXXFLAGS := -W -Wall -Wextra -ansi -pedantic -O3 -fPIC $(CXXFLAGS)
+CFLAGS = -W -Wall -Wextra -ansi -pedantic -lm -O2
+CXXFLAGS = -W -Wall -Wextra -ansi -pedantic -O2
 
 ZOPFLILIB_SRC = src/zopfli/blocksplitter.c src/zopfli/cache.c\
                 src/zopfli/deflate.c src/zopfli/gzip_container.c\
@@ -10,56 +10,28 @@ ZOPFLILIB_SRC = src/zopfli/blocksplitter.c src/zopfli/cache.c\
                 src/zopfli/lz77.c src/zopfli/squeeze.c\
                 src/zopfli/tree.c src/zopfli/util.c\
                 src/zopfli/zlib_container.c src/zopfli/zopfli_lib.c
-ZOPFLILIB_OBJ := $(patsubst %.c,obj/%.o,$(ZOPFLILIB_SRC))
+ZOPFLILIB_OBJ := $(patsubst src/zopfli/%.c,%.o,$(ZOPFLILIB_SRC))
 ZOPFLIBIN_SRC := src/zopfli/zopfli_bin.c
-ZOPFLIBIN_OBJ := $(patsubst %.c,obj/%.o,$(ZOPFLIBIN_SRC))
 LODEPNG_SRC := src/zopflipng/lodepng/lodepng.cpp src/zopflipng/lodepng/lodepng_util.cpp
-LODEPNG_OBJ := $(patsubst %.cpp,obj/%.o,$(LODEPNG_SRC))
 ZOPFLIPNGLIB_SRC := src/zopflipng/zopflipng_lib.cc
-ZOPFLIPNGLIB_OBJ := $(patsubst %.cc,obj/%.o,$(ZOPFLIPNGLIB_SRC))
 ZOPFLIPNGBIN_SRC := src/zopflipng/zopflipng_bin.cc
-ZOPFLIPNGBIN_OBJ := $(patsubst %.cc,obj/%.o,$(ZOPFLIPNGBIN_SRC))
 
-.PHONY: all libzopfli libzopflipng
-
-all: zopfli libzopfli libzopfli.a zopflipng libzopflipng libzopflipng.a
-
-obj/%.o: %.c
-	@mkdir -p `dirname $@`
-	$(CC) $(CFLAGS) -c $< -o $@
-
-obj/%.o: %.cc
-	@mkdir -p `dirname $@`
-	$(CXX) $(CXXFLAGS) -c $< -o $@
-
-obj/%.o: %.cpp
-	@mkdir -p `dirname $@`
-	$(CXX) $(CXXFLAGS) -c $< -o $@
+.PHONY: zopfli zopflipng
 
 # Zopfli binary
-zopfli: $(ZOPFLILIB_OBJ) $(ZOPFLIBIN_OBJ)
-	$(CC) $^ $(CFLAGS) -o $@ $(LDFLAGS)
+zopfli:
+	$(CC) $(ZOPFLILIB_SRC) $(ZOPFLIBIN_SRC) $(CFLAGS) -o zopfli
 
 # Zopfli shared library
-libzopfli: $(ZOPFLILIB_OBJ)
-	$(CC) $^ $(CFLAGS) -shared -Wl,-soname,libzopfli.so.1 -o libzopfli.so.1.0.3 $(LDFLAGS)
-
-# Zopfli static library
-libzopfli.a: $(ZOPFLILIB_OBJ)
-	ar rcs $@ $^
+libzopfli:
+	$(CC) $(ZOPFLILIB_SRC) $(CFLAGS) -fPIC -c
+	$(CC) $(ZOPFLILIB_OBJ) $(CFLAGS) -shared -Wl,-soname,libzopfli.so.1 -o libzopfli.so.1.0.1
 
 # ZopfliPNG binary
-zopflipng: $(ZOPFLILIB_OBJ) $(LODEPNG_OBJ) $(ZOPFLIPNGLIB_OBJ) $(ZOPFLIPNGBIN_OBJ)
-	$(CXX) $^ $(CFLAGS) -o $@ $(LDFLAGS)
-
-# ZopfliPNG shared library
-libzopflipng: $(ZOPFLILIB_OBJ) $(LODEPNG_OBJ) $(ZOPFLIPNGLIB_OBJ)
-	$(CXX) $^ $(CFLAGS) --shared -Wl,-soname,libzopflipng.so.1 -o libzopflipng.so.1.0.3 $(LDFLAGS)
-
-# ZopfliPNG static library
-libzopflipng.a: $(LODEPNG_OBJ) $(ZOPFLIPNGLIB_OBJ)
-	ar rcs $@ $^
+zopflipng:
+	$(CC) $(ZOPFLILIB_SRC) $(CFLAGS) -c
+	$(CXX) $(ZOPFLILIB_OBJ) $(LODEPNG_SRC) $(ZOPFLIPNGLIB_SRC) $(ZOPFLIPNGBIN_SRC) $(CFLAGS) -o zopflipng
 
 # Remove all libraries and binaries
 clean:
-	rm -f zopflipng zopfli $(ZOPFLILIB_OBJ) $(ZOPFLIBIN_OBJ) $(LODEPNG_OBJ) $(ZOPFLIPNGLIB_OBJ) $(ZOPFLIPNGBIN_OBJ) libzopfli*
+	rm -f zopflipng zopfli $(ZOPFLILIB_OBJ) libzopfli*
diff --git a/README b/README
index 37f6fc3..b28b189 100644
--- a/README
+++ b/README
@@ -25,15 +25,8 @@ zopfli_bin.c is separate from the library and contains an example program to
 create very well compressed gzip files. Currently the makefile builds this
 program with the library statically linked in.
 
-The source code of Zopfli is under src/zopfli. Build instructions:
-
-To build zopfli, compile all .c source files under src/zopfli to a single binary
-with C, and link to the standard C math library, e.g.:
-gcc src/zopfli/*.c -O2 -W -Wall -Wextra -Wno-unused-function -ansi -pedantic -lm -o zopfli
-
-A makefile is provided as well, but only for linux. Use "make" to build the
-binary, "make libzopfli" to build it as a shared library. For other platforms,
-please use the build instructions above instead.
+To build the binary, use "make". To build the library as a shared Linux library,
+use "make libzopfli". The source code of Zopfli is under src/zopfli.
 
 Zopfli Compression Algorithm was created by Lode Vandevenne and Jyrki
 Alakuijala, based on an algorithm by Jyrki Alakuijala.
diff --git a/README.zopflipng b/README.zopflipng
index fc1ced4..84019ee 100644
--- a/README.zopflipng
+++ b/README.zopflipng
@@ -12,27 +12,8 @@ ZopfliPNG is a command line program to optimize the Portable Network Graphics
 This is an alpha-release for testing while improvements, particularly to add
 palette selection, are still being made. Feedback and bug reports are welcome.
 
-Important:
-
-This PNG optimizer removes ancillary chunks (pieces of metadata) from the
-PNG image that normally do not affect rendering. However in special
-circumstances you may wish to keep some. For example for a design using
-custom gamma correction, keeping it may be desired. Visually check in the
-target renderer after using ZopfliPNG. Use --keepchunks to keep chunks, e.g.
---keepchunks=gAMA,pHYs to keep gamma and DPI information. This will increase
-file size. The following page contains a list of ancillary PNG chunks:
-http://www.libpng.org/pub/png/spec/1.2/PNG-Chunks.html
-
-Build instructions:
-
-To build ZopfliPNG, compile all .c, .cc and .cpp files from src/zopfli,
-src/zopflipng and src/zopflipng/lodepng, except src/zopfli/zopfli_bin.c, to a
-single binary with C++, e.g.:
-g++ src/zopfli/{blocksplitter,cache,deflate,gzip_container,hash,katajainen,lz77,squeeze,tree,util,zlib_container,zopfli_lib}.c src/zopflipng/*.cc src/zopflipng/lodepng/*.cpp -O2 -W -Wall -Wextra -Wno-unused-function -ansi -pedantic -o zopflipng
-
-A makefile is provided as well, but only for linux: use "make zopflipng" with
-the Zopfli makefile. For other platforms, please use the build instructions
-above instead.
+To build ZopfliPNG, use "make zopflipng", or compile all the sources except
+zopfli_bin.c.
 
 The main compression algorithm in ZopfliPNG is ported from WebP lossless, but
 naturally cannot give as much compression gain for PNGs as it does for a more
diff --git a/go/zopfli/zopfli.go b/go/zopfli/zopfli.go
deleted file mode 100644
index 0cb78aa..0000000
--- a/go/zopfli/zopfli.go
+++ /dev/null
@@ -1,58 +0,0 @@
-// Copyright 2019 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Package zopfli provides a simple Go interface for Zopfli compression.
-package zopfli
-
-/*
-#cgo LDFLAGS: -lzopfli -lm
-#include <limits.h> // for INT_MAX
-#include <stdlib.h> // for free()
-#include <string.h> // for memmove()
-#include "zopfli.h"
-*/
-import "C"
-import "unsafe"
-
-// Zopfli can't handle empty input, so we use a static result.
-const emptyGzip = "\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\xff\x03\x00\x00\x00\x00\x00\x00\x00\x00\x00"
-
-// Gzip compresses data with Zopfli using default settings and gzip format.
-// The Zopfli library does not return errors, and there are no (detectable)
-// failure cases, hence no error return.
-func Gzip(inputSlice []byte) []byte {
-	var options C.struct_ZopfliOptions
-	C.ZopfliInitOptions(&options)
-
-	inputSize := (C.size_t)(len(inputSlice))
-	if inputSize == 0 {
-		return []byte(emptyGzip)
-	}
-	input := (*C.uchar)(unsafe.Pointer(&inputSlice[0]))
-	var compressed *C.uchar
-	var compressedLength C.size_t
-
-	C.ZopfliCompress(&options, C.ZOPFLI_FORMAT_GZIP,
-		input, inputSize,
-		&compressed, &compressedLength)
-	defer C.free(unsafe.Pointer(compressed))
-
-	// GoBytes only accepts int, not C.size_t. The code below does the same minus
-	// protection against zero-length values, but compressedLength is never 0 due
-	// to headers.
-	result := make([]byte, compressedLength)
-	C.memmove(unsafe.Pointer(&result[0]), unsafe.Pointer(compressed),
-		compressedLength)
-	return result
-}
diff --git a/go/zopfli/zopfli_test.go b/go/zopfli/zopfli_test.go
deleted file mode 100644
index 4d61703..0000000
--- a/go/zopfli/zopfli_test.go
+++ /dev/null
@@ -1,69 +0,0 @@
-// Copyright 2019 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-package zopfli
-
-import (
-	"bytes"
-	"compress/gzip"
-	"io/ioutil"
-	"math/rand"
-	"strings"
-	"testing"
-)
-
-func getRandomBytes(length uint64) []byte {
-	rng := rand.New(rand.NewSource(1)) // Make test repeatable.
-	data := make([]byte, length)
-	for i := uint64(0); i < length; i++ {
-		data[i] = (byte)(rng.Int())
-	}
-	return data
-}
-
-// TestGzip verifies that Gzip compresses data correctly.
-func TestGzip(t *testing.T) {
-	compressibleString := "compressthis" + strings.Repeat("_foobar", 1000) + "$"
-
-	for _, test := range []struct {
-		name    string
-		data    []byte
-		maxSize int
-	}{
-		{"compressible string", []byte(compressibleString), 500},
-		{"random binary data", getRandomBytes(3000), 3100},
-		{"empty string", []byte(""), 20},
-	} {
-		compressed := Gzip(test.data)
-		gzipReader, err := gzip.NewReader(bytes.NewReader(compressed))
-		if err != nil {
-			t.Errorf("%s: gzip.NewReader: got error %v, expected no error",
-				test.name, err)
-			continue
-		}
-		decompressed, err := ioutil.ReadAll(gzipReader)
-		if err != nil {
-			t.Errorf("%s: reading gzip stream: got error %v, expected no error",
-				test.name, err)
-			continue
-		}
-		if bytes.Compare(test.data, decompressed) != 0 {
-			t.Errorf("%s: mismatch between input and decompressed data", test.name)
-			continue
-		}
-		if test.maxSize > 0 && len(compressed) > test.maxSize {
-			t.Errorf("%s: compressed data is %d bytes, expected %d or less",
-				test.name, len(compressed), test.maxSize)
-		}
-	}
-}
diff --git a/go/zopflipng/testdata/zoidberg.png b/go/zopflipng/testdata/zoidberg.png
deleted file mode 100644
index 434d918..0000000
--- a/go/zopflipng/testdata/zoidberg.png
+++ /dev/null
diff --git a/go/zopflipng/zopflipng.go b/go/zopflipng/zopflipng.go
deleted file mode 100644
index f532321..0000000
--- a/go/zopflipng/zopflipng.go
+++ /dev/null
@@ -1,86 +0,0 @@
-// Copyright 2019 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-package zopflipng
-
-import (
-	"fmt"
-)
-
-/*
-#cgo LDFLAGS: -lzopflipng -lzopfli -lstdc++ -lm
-#include <stdlib.h>
-#include <string.h>
-#include "zopflipng_lib.h"
-*/
-import "C"
-import "unsafe"
-
-// Options allows overriding of some internal parameters.
-type Options struct {
-	LossyTransparent   bool
-	Lossy8bit          bool
-	NumIterations      int
-	NumIterationsLarge int
-}
-
-// NewOptions creates an options struct with the default parameters.
-func NewOptions() *Options {
-	ret := &Options{
-		LossyTransparent:   false,
-		Lossy8bit:          false,
-		NumIterations:      15,
-		NumIterationsLarge: 5,
-	}
-	return ret
-}
-
-// Compress recompresses a PNG using Zopfli.
-func Compress(inputSlice []byte) ([]byte, error) {
-	return CompressWithOptions(inputSlice, NewOptions())
-}
-
-// CompressWithOptions allows overriding some internal parameters.
-func CompressWithOptions(inputSlice []byte, options *Options) ([]byte, error) {
-	cOptions := createCOptions(options)
-	input := (*C.uchar)(unsafe.Pointer(&inputSlice[0]))
-	inputSize := (C.size_t)(len(inputSlice))
-	var compressed *C.uchar
-	var compressedLength C.size_t
-	errCode := int(C.CZopfliPNGOptimize(input, inputSize, &cOptions, 0, &compressed, &compressedLength))
-	defer C.free(unsafe.Pointer(compressed))
-	if errCode != 0 {
-		return nil, fmt.Errorf("ZopfliPng failed with code: %d", errCode)
-	}
-
-	result := make([]byte, compressedLength)
-	C.memmove(unsafe.Pointer(&result[0]), unsafe.Pointer(compressed), compressedLength)
-	return result, nil
-}
-
-func createCOptions(options *Options) C.struct_CZopfliPNGOptions {
-	var cOptions C.struct_CZopfliPNGOptions
-	C.CZopfliPNGSetDefaults(&cOptions)
-	cOptions.lossy_transparent = boolToInt(options.LossyTransparent)
-	cOptions.lossy_8bit = boolToInt(options.Lossy8bit)
-	cOptions.num_iterations = C.int(options.NumIterations)
-	cOptions.num_iterations_large = C.int(options.NumIterationsLarge)
-	return cOptions
-}
-
-func boolToInt(b bool) C.int {
-	if b {
-		return C.int(1)
-	}
-	return C.int(0)
-}
diff --git a/go/zopflipng/zopflipng_test.go b/go/zopflipng/zopflipng_test.go
deleted file mode 100644
index 8f3d423..0000000
--- a/go/zopflipng/zopflipng_test.go
+++ /dev/null
@@ -1,35 +0,0 @@
-// Copyright 2019 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-package zopflipng
-
-import (
-	"io/ioutil"
-	"testing"
-)
-
-// TestCompress verifies that ZopfliPng compresses PNGs correctly.
-func TestCompress(t *testing.T) {
-	path := "testdata/zoidberg.png"
-	contents, err := ioutil.ReadFile(path)
-	if err != nil {
-		t.Errorf("Failed to load testdata: %s", path)
-	}
-	compressed, err := Compress(contents)
-	if err != nil {
-		t.Error("ZopfliPNG failed: ", err)
-	}
-	if len(compressed) >= len(contents) {
-		t.Error("ZopfliPNG did not compress png")
-	}
-}
diff --git a/src/zopfli/blocksplitter.c b/src/zopfli/blocksplitter.c
index 161783d..68f5ff3 100644
--- a/src/zopfli/blocksplitter.c
+++ b/src/zopfli/blocksplitter.c
@@ -24,6 +24,7 @@ Author: jyrki.alakuijala@gmail.com (Jyrki Alakuijala)
 #include <stdlib.h>
 
 #include "deflate.h"
+#include "lz77.h"
 #include "squeeze.h"
 #include "tree.h"
 #include "util.h"
@@ -38,10 +39,9 @@ typedef double FindMinimumFun(size_t i, void* context);
 /*
 Finds minimum of function f(i) where is is of type size_t, f(i) is of type
 double, i is in range start-end (excluding end).
-Outputs the minimum value in *smallest and returns the index of this value.
 */
 static size_t FindMinimum(FindMinimumFun f, void* context,
-                          size_t start, size_t end, double* smallest) {
+                          size_t start, size_t end) {
   if (end - start < 1024) {
     double best = ZOPFLI_LARGE_FLOAT;
     size_t result = start;
@@ -53,7 +53,6 @@ static size_t FindMinimum(FindMinimumFun f, void* context,
         result = i;
       }
     }
-    *smallest = best;
     return result;
   } else {
     /* Try to find minimum faster by recursively checking multiple points. */
@@ -89,7 +88,6 @@ static size_t FindMinimum(FindMinimumFun f, void* context,
       pos = p[besti];
       lastbest = best;
     }
-    *smallest = lastbest;
     return pos;
 #undef NUM
   }
@@ -105,13 +103,16 @@ dists: ll77 distances
 lstart: start of block
 lend: end of block (not inclusive)
 */
-static double EstimateCost(const ZopfliLZ77Store* lz77,
+static double EstimateCost(const unsigned short* litlens,
+                           const unsigned short* dists,
                            size_t lstart, size_t lend) {
-  return ZopfliCalculateBlockSizeAutoType(lz77, lstart, lend);
+  return ZopfliCalculateBlockSize(litlens, dists, lstart, lend, 2);
 }
 
 typedef struct SplitCostContext {
-  const ZopfliLZ77Store* lz77;
+  const unsigned short* litlens;
+  const unsigned short* dists;
+  size_t llsize;
   size_t start;
   size_t end;
 } SplitCostContext;
@@ -124,7 +125,8 @@ type: FindMinimumFun
 */
 static double SplitCost(size_t i, void* context) {
   SplitCostContext* c = (SplitCostContext*)context;
-  return EstimateCost(c->lz77, c->start, i) + EstimateCost(c->lz77, i, c->end);
+  return EstimateCost(c->litlens, c->dists, c->start, i) +
+      EstimateCost(c->litlens, c->dists, i, c->end);
 }
 
 static void AddSorted(size_t value, size_t** out, size_t* outsize) {
@@ -145,8 +147,9 @@ static void AddSorted(size_t value, size_t** out, size_t* outsize) {
 /*
 Prints the block split points as decimal and hex values in the terminal.
 */
-static void PrintBlockSplitPoints(const ZopfliLZ77Store* lz77,
-                                  const size_t* lz77splitpoints,
+static void PrintBlockSplitPoints(const unsigned short* litlens,
+                                  const unsigned short* dists,
+                                  size_t llsize, const size_t* lz77splitpoints,
                                   size_t nlz77points) {
   size_t* splitpoints = 0;
   size_t npoints = 0;
@@ -155,8 +158,8 @@ static void PrintBlockSplitPoints(const ZopfliLZ77Store* lz77,
   index values. */
   size_t pos = 0;
   if (nlz77points > 0) {
-    for (i = 0; i < lz77->size; i++) {
-      size_t length = lz77->dists[i] == 0 ? 1 : lz77->litlens[i];
+    for (i = 0; i < llsize; i++) {
+      size_t length = dists[i] == 0 ? 1 : litlens[i];
       if (lz77splitpoints[npoints] == i) {
         ZOPFLI_APPEND_DATA(pos, &splitpoints, &npoints);
         if (npoints == nlz77points) break;
@@ -183,7 +186,7 @@ static void PrintBlockSplitPoints(const ZopfliLZ77Store* lz77,
 Finds next block to try to split, the largest of the available ones.
 The largest is chosen to make sure that if only a limited amount of blocks is
 requested, their sizes are spread evenly.
-lz77size: the size of the LL77 data, which is the size of the done array here.
+llsize: the size of the LL77 data, which is the size of the done array here.
 done: array indicating which blocks starting at that position are no longer
     splittable (splitting them increases rather than decreases cost).
 splitpoints: the splitpoints found so far.
@@ -193,7 +196,7 @@ lend: output variable, giving end of block.
 returns 1 if a block was found, 0 if no block found (all are done).
 */
 static int FindLargestSplittableBlock(
-    size_t lz77size, const unsigned char* done,
+    size_t llsize, const unsigned char* done,
     const size_t* splitpoints, size_t npoints,
     size_t* lstart, size_t* lend) {
   size_t longest = 0;
@@ -201,7 +204,7 @@ static int FindLargestSplittableBlock(
   size_t i;
   for (i = 0; i <= npoints; i++) {
     size_t start = i == 0 ? 0 : splitpoints[i - 1];
-    size_t end = i == npoints ? lz77size - 1 : splitpoints[i];
+    size_t end = i == npoints ? llsize - 1 : splitpoints[i];
     if (!done[start] && end - start > longest) {
       *lstart = start;
       *lend = end;
@@ -213,7 +216,9 @@ static int FindLargestSplittableBlock(
 }
 
 void ZopfliBlockSplitLZ77(const ZopfliOptions* options,
-                          const ZopfliLZ77Store* lz77, size_t maxblocks,
+                          const unsigned short* litlens,
+                          const unsigned short* dists,
+                          size_t llsize, size_t maxblocks,
                           size_t** splitpoints, size_t* npoints) {
   size_t lstart, lend;
   size_t i;
@@ -222,14 +227,14 @@ void ZopfliBlockSplitLZ77(const ZopfliOptions* options,
   unsigned char* done;
   double splitcost, origcost;
 
-  if (lz77->size < 10) return;  /* This code fails on tiny files. */
+  if (llsize < 10) return;  /* This code fails on tiny files. */
 
-  done = (unsigned char*)malloc(lz77->size);
+  done = (unsigned char*)malloc(llsize);
   if (!done) exit(-1); /* Allocation failed. */
-  for (i = 0; i < lz77->size; i++) done[i] = 0;
+  for (i = 0; i < llsize; i++) done[i] = 0;
 
   lstart = 0;
-  lend = lz77->size;
+  lend = llsize;
   for (;;) {
     SplitCostContext c;
 
@@ -237,16 +242,20 @@ void ZopfliBlockSplitLZ77(const ZopfliOptions* options,
       break;
     }
 
-    c.lz77 = lz77;
+    c.litlens = litlens;
+    c.dists = dists;
+    c.llsize = llsize;
     c.start = lstart;
     c.end = lend;
     assert(lstart < lend);
-    llpos = FindMinimum(SplitCost, &c, lstart + 1, lend, &splitcost);
+    llpos = FindMinimum(SplitCost, &c, lstart + 1, lend);
 
     assert(llpos > lstart);
     assert(llpos < lend);
 
-    origcost = EstimateCost(lz77, lstart, lend);
+    splitcost = EstimateCost(litlens, dists, lstart, llpos) +
+        EstimateCost(litlens, dists, llpos, lend);
+    origcost = EstimateCost(litlens, dists, lstart, lend);
 
     if (splitcost > origcost || llpos == lstart + 1 || llpos == lend) {
       done[lstart] = 1;
@@ -256,7 +265,7 @@ void ZopfliBlockSplitLZ77(const ZopfliOptions* options,
     }
 
     if (!FindLargestSplittableBlock(
-        lz77->size, done, *splitpoints, *npoints, &lstart, &lend)) {
+        llsize, done, *splitpoints, *npoints, &lstart, &lend)) {
       break;  /* No further split will probably reduce compression. */
     }
 
@@ -266,7 +275,7 @@ void ZopfliBlockSplitLZ77(const ZopfliOptions* options,
   }
 
   if (options->verbose) {
-    PrintBlockSplitPoints(lz77, *splitpoints, *npoints);
+    PrintBlockSplitPoints(litlens, dists, llsize, *splitpoints, *npoints);
   }
 
   free(done);
@@ -281,22 +290,25 @@ void ZopfliBlockSplit(const ZopfliOptions* options,
   size_t* lz77splitpoints = 0;
   size_t nlz77points = 0;
   ZopfliLZ77Store store;
-  ZopfliHash hash;
-  ZopfliHash* h = &hash;
 
-  ZopfliInitLZ77Store(in, &store);
-  ZopfliInitBlockState(options, instart, inend, 0, &s);
-  ZopfliAllocHash(ZOPFLI_WINDOW_SIZE, h);
+  ZopfliInitLZ77Store(&store);
+
+  s.options = options;
+  s.blockstart = instart;
+  s.blockend = inend;
+#ifdef ZOPFLI_LONGEST_MATCH_CACHE
+  s.lmc = 0;
+#endif
 
   *npoints = 0;
   *splitpoints = 0;
 
   /* Unintuitively, Using a simple LZ77 method here instead of ZopfliLZ77Optimal
   results in better blocks. */
-  ZopfliLZ77Greedy(&s, in, instart, inend, &store, h);
+  ZopfliLZ77Greedy(&s, in, instart, inend, &store);
 
   ZopfliBlockSplitLZ77(options,
-                       &store, maxblocks,
+                       store.litlens, store.dists, store.size, maxblocks,
                        &lz77splitpoints, &nlz77points);
 
   /* Convert LZ77 positions to positions in the uncompressed input. */
@@ -314,9 +326,7 @@ void ZopfliBlockSplit(const ZopfliOptions* options,
   assert(*npoints == nlz77points);
 
   free(lz77splitpoints);
-  ZopfliCleanBlockState(&s);
   ZopfliCleanLZ77Store(&store);
-  ZopfliCleanHash(h);
 }
 
 void ZopfliBlockSplitSimple(const unsigned char* in,
diff --git a/src/zopfli/blocksplitter.h b/src/zopfli/blocksplitter.h
index d1d622f..6791702 100644
--- a/src/zopfli/blocksplitter.h
+++ b/src/zopfli/blocksplitter.h
@@ -30,17 +30,21 @@ ones that enhance it.
 
 #include <stdlib.h>
 
-#include "lz77.h"
 #include "zopfli.h"
 
 
 /*
 Does blocksplitting on LZ77 data.
 The output splitpoints are indices in the LZ77 data.
+litlens: lz77 lit/lengths
+dists: lz77 distances
+llsize: size of litlens and dists
 maxblocks: set a limit to the amount of blocks. Set to 0 to mean no limit.
 */
 void ZopfliBlockSplitLZ77(const ZopfliOptions* options,
-                          const ZopfliLZ77Store* lz77, size_t maxblocks,
+                          const unsigned short* litlens,
+                          const unsigned short* dists,
+                          size_t llsize, size_t maxblocks,
                           size_t** splitpoints, size_t* npoints);
 
 /*
diff --git a/src/zopfli/cache.c b/src/zopfli/cache.c
index 6b9444f..88a49ac 100644
--- a/src/zopfli/cache.c
+++ b/src/zopfli/cache.c
@@ -31,12 +31,6 @@ void ZopfliInitCache(size_t blocksize, ZopfliLongestMatchCache* lmc) {
   lmc->dist = (unsigned short*)malloc(sizeof(unsigned short) * blocksize);
   /* Rather large amount of memory. */
   lmc->sublen = (unsigned char*)malloc(ZOPFLI_CACHE_LENGTH * 3 * blocksize);
-  if(lmc->sublen == NULL) {
-    fprintf(stderr,
-        "Error: Out of memory. Tried allocating %lu bytes of memory.\n",
-        (unsigned long)ZOPFLI_CACHE_LENGTH * 3 * blocksize);
-    exit (EXIT_FAILURE);
-  }
 
   /* length > 0 and dist 0 is invalid combination, which indicates on purpose
   that this cache value is not filled in yet. */
diff --git a/src/zopfli/deflate.c b/src/zopfli/deflate.c
index c5abda9..4b0724b 100644
--- a/src/zopfli/deflate.c
+++ b/src/zopfli/deflate.c
@@ -24,8 +24,8 @@ Author: jyrki.alakuijala@gmail.com (Jyrki Alakuijala)
 #include <stdlib.h>
 
 #include "blocksplitter.h"
+#include "lz77.h"
 #include "squeeze.h"
-#include "symbols.h"
 #include "tree.h"
 
 /*
@@ -294,7 +294,8 @@ Adds all lit/len and dist codes from the lists as huffman symbols. Does not add
 end code 256. expected_data_size is the uncompressed block size, used for
 assert, but you can set it to 0 to not do the assertion.
 */
-static void AddLZ77Data(const ZopfliLZ77Store* lz77,
+static void AddLZ77Data(const unsigned short* litlens,
+                        const unsigned short* dists,
                         size_t lstart, size_t lend,
                         size_t expected_data_size,
                         const unsigned* ll_symbols, const unsigned* ll_lengths,
@@ -305,8 +306,8 @@ static void AddLZ77Data(const ZopfliLZ77Store* lz77,
   size_t i;
 
   for (i = lstart; i < lend; i++) {
-    unsigned dist = lz77->dists[i];
-    unsigned litlen = lz77->litlens[i];
+    unsigned dist = dists[i];
+    unsigned litlen = litlens[i];
     if (dist == 0) {
       assert(litlen < 256);
       assert(ll_lengths[litlen] > 0);
@@ -342,83 +343,29 @@ static void GetFixedTree(unsigned* ll_lengths, unsigned* d_lengths) {
 }
 
 /*
-Same as CalculateBlockSymbolSize, but for block size smaller than histogram
-size.
+Calculates size of the part after the header and tree of an LZ77 block, in bits.
 */
-static size_t CalculateBlockSymbolSizeSmall(const unsigned* ll_lengths,
-                                            const unsigned* d_lengths,
-                                            const ZopfliLZ77Store* lz77,
-                                            size_t lstart, size_t lend) {
+static size_t CalculateBlockSymbolSize(const unsigned* ll_lengths,
+                                       const unsigned* d_lengths,
+                                       const unsigned short* litlens,
+                                       const unsigned short* dists,
+                                       size_t lstart, size_t lend) {
   size_t result = 0;
   size_t i;
   for (i = lstart; i < lend; i++) {
-    assert(i < lz77->size);
-    assert(lz77->litlens[i] < 259);
-    if (lz77->dists[i] == 0) {
-      result += ll_lengths[lz77->litlens[i]];
+    if (dists[i] == 0) {
+      result += ll_lengths[litlens[i]];
     } else {
-      int ll_symbol = ZopfliGetLengthSymbol(lz77->litlens[i]);
-      int d_symbol = ZopfliGetDistSymbol(lz77->dists[i]);
-      result += ll_lengths[ll_symbol];
-      result += d_lengths[d_symbol];
-      result += ZopfliGetLengthSymbolExtraBits(ll_symbol);
-      result += ZopfliGetDistSymbolExtraBits(d_symbol);
+      result += ll_lengths[ZopfliGetLengthSymbol(litlens[i])];
+      result += d_lengths[ZopfliGetDistSymbol(dists[i])];
+      result += ZopfliGetLengthExtraBits(litlens[i]);
+      result += ZopfliGetDistExtraBits(dists[i]);
     }
   }
   result += ll_lengths[256]; /*end symbol*/
   return result;
 }
 
-/*
-Same as CalculateBlockSymbolSize, but with the histogram provided by the caller.
-*/
-static size_t CalculateBlockSymbolSizeGivenCounts(const size_t* ll_counts,
-                                                  const size_t* d_counts,
-                                                  const unsigned* ll_lengths,
-                                                  const unsigned* d_lengths,
-                                                  const ZopfliLZ77Store* lz77,
-                                                  size_t lstart, size_t lend) {
-  size_t result = 0;
-  size_t i;
-  if (lstart + ZOPFLI_NUM_LL * 3 > lend) {
-    return CalculateBlockSymbolSizeSmall(
-        ll_lengths, d_lengths, lz77, lstart, lend);
-  } else {
-    for (i = 0; i < 256; i++) {
-      result += ll_lengths[i] * ll_counts[i];
-    }
-    for (i = 257; i < 286; i++) {
-      result += ll_lengths[i] * ll_counts[i];
-      result += ZopfliGetLengthSymbolExtraBits(i) * ll_counts[i];
-    }
-    for (i = 0; i < 30; i++) {
-      result += d_lengths[i] * d_counts[i];
-      result += ZopfliGetDistSymbolExtraBits(i) * d_counts[i];
-    }
-    result += ll_lengths[256]; /*end symbol*/
-    return result;
-  }
-}
-
-/*
-Calculates size of the part after the header and tree of an LZ77 block, in bits.
-*/
-static size_t CalculateBlockSymbolSize(const unsigned* ll_lengths,
-                                       const unsigned* d_lengths,
-                                       const ZopfliLZ77Store* lz77,
-                                       size_t lstart, size_t lend) {
-  if (lstart + ZOPFLI_NUM_LL * 3 > lend) {
-    return CalculateBlockSymbolSizeSmall(
-        ll_lengths, d_lengths, lz77, lstart, lend);
-  } else {
-    size_t ll_counts[ZOPFLI_NUM_LL];
-    size_t d_counts[ZOPFLI_NUM_D];
-    ZopfliLZ77GetHistogram(lz77, lstart, lend, ll_counts, d_counts);
-    return CalculateBlockSymbolSizeGivenCounts(
-        ll_counts, d_counts, ll_lengths, d_lengths, lz77, lstart, lend);
-  }
-}
-
 static size_t AbsDiff(size_t x, size_t y) {
   if (x > y)
     return x - y;
@@ -427,9 +374,9 @@ static size_t AbsDiff(size_t x, size_t y) {
 }
 
 /*
-Changes the population counts in a way that the consequent Huffman tree
-compression, especially its rle-part, will be more likely to compress this data
-more efficiently. length contains the size of the histogram.
+Change the population counts in a way that the consequent Hufmann tree
+compression, especially its rle-part will be more likely to compress this data
+more efficiently. length containts the size of the histogram.
 */
 void OptimizeHuffmanForRle(int length, size_t* counts) {
   int i, k, stride;
@@ -449,7 +396,7 @@ void OptimizeHuffmanForRle(int length, size_t* counts) {
   }
   /* 2) Let's mark all population counts that already can be encoded
   with an rle code.*/
-  good_for_rle = (int*)malloc((unsigned)length * sizeof(int));
+  good_for_rle = (int*)malloc(length * sizeof(int));
   for (i = 0; i < length; ++i) good_for_rle[i] = 0;
 
   /* Let's not spoil any of the existing good rle codes.
@@ -518,148 +465,47 @@ void OptimizeHuffmanForRle(int length, size_t* counts) {
 }
 
 /*
-Tries out OptimizeHuffmanForRle for this block, if the result is smaller,
-uses it, otherwise keeps the original. Returns size of encoded tree and data in
-bits, not including the 3-bit block header.
-*/
-static double TryOptimizeHuffmanForRle(
-    const ZopfliLZ77Store* lz77, size_t lstart, size_t lend,
-    const size_t* ll_counts, const size_t* d_counts,
-    unsigned* ll_lengths, unsigned* d_lengths) {
-  size_t ll_counts2[ZOPFLI_NUM_LL];
-  size_t d_counts2[ZOPFLI_NUM_D];
-  unsigned ll_lengths2[ZOPFLI_NUM_LL];
-  unsigned d_lengths2[ZOPFLI_NUM_D];
-  double treesize;
-  double datasize;
-  double treesize2;
-  double datasize2;
-
-  treesize = CalculateTreeSize(ll_lengths, d_lengths);
-  datasize = CalculateBlockSymbolSizeGivenCounts(ll_counts, d_counts,
-      ll_lengths, d_lengths, lz77, lstart, lend);
-
-  memcpy(ll_counts2, ll_counts, sizeof(ll_counts2));
-  memcpy(d_counts2, d_counts, sizeof(d_counts2));
-  OptimizeHuffmanForRle(ZOPFLI_NUM_LL, ll_counts2);
-  OptimizeHuffmanForRle(ZOPFLI_NUM_D, d_counts2);
-  ZopfliCalculateBitLengths(ll_counts2, ZOPFLI_NUM_LL, 15, ll_lengths2);
-  ZopfliCalculateBitLengths(d_counts2, ZOPFLI_NUM_D, 15, d_lengths2);
-  PatchDistanceCodesForBuggyDecoders(d_lengths2);
-
-  treesize2 = CalculateTreeSize(ll_lengths2, d_lengths2);
-  datasize2 = CalculateBlockSymbolSizeGivenCounts(ll_counts, d_counts,
-      ll_lengths2, d_lengths2, lz77, lstart, lend);
-
-  if (treesize2 + datasize2 < treesize + datasize) {
-    memcpy(ll_lengths, ll_lengths2, sizeof(ll_lengths2));
-    memcpy(d_lengths, d_lengths2, sizeof(d_lengths2));
-    return treesize2 + datasize2;
-  }
-  return treesize + datasize;
-}
-
-/*
 Calculates the bit lengths for the symbols for dynamic blocks. Chooses bit
 lengths that give the smallest size of tree encoding + encoding of all the
 symbols to have smallest output size. This are not necessarily the ideal Huffman
-bit lengths. Returns size of encoded tree and data in bits, not including the
-3-bit block header.
+bit lengths.
 */
-static double GetDynamicLengths(const ZopfliLZ77Store* lz77,
-                                size_t lstart, size_t lend,
-                                unsigned* ll_lengths, unsigned* d_lengths) {
-  size_t ll_counts[ZOPFLI_NUM_LL];
-  size_t d_counts[ZOPFLI_NUM_D];
-
-  ZopfliLZ77GetHistogram(lz77, lstart, lend, ll_counts, d_counts);
-  ll_counts[256] = 1;  /* End symbol. */
-  ZopfliCalculateBitLengths(ll_counts, ZOPFLI_NUM_LL, 15, ll_lengths);
-  ZopfliCalculateBitLengths(d_counts, ZOPFLI_NUM_D, 15, d_lengths);
+static void GetDynamicLengths(const unsigned short* litlens,
+                              const unsigned short* dists,
+                              size_t lstart, size_t lend,
+                              unsigned* ll_lengths, unsigned* d_lengths) {
+  size_t ll_counts[288];
+  size_t d_counts[32];
+
+  ZopfliLZ77Counts(litlens, dists, lstart, lend, ll_counts, d_counts);
+  OptimizeHuffmanForRle(288, ll_counts);
+  OptimizeHuffmanForRle(32, d_counts);
+  ZopfliCalculateBitLengths(ll_counts, 288, 15, ll_lengths);
+  ZopfliCalculateBitLengths(d_counts, 32, 15, d_lengths);
   PatchDistanceCodesForBuggyDecoders(d_lengths);
-  return TryOptimizeHuffmanForRle(
-      lz77, lstart, lend, ll_counts, d_counts, ll_lengths, d_lengths);
 }
 
-double ZopfliCalculateBlockSize(const ZopfliLZ77Store* lz77,
+double ZopfliCalculateBlockSize(const unsigned short* litlens,
+                                const unsigned short* dists,
                                 size_t lstart, size_t lend, int btype) {
-  unsigned ll_lengths[ZOPFLI_NUM_LL];
-  unsigned d_lengths[ZOPFLI_NUM_D];
+  unsigned ll_lengths[288];
+  unsigned d_lengths[32];
 
   double result = 3; /* bfinal and btype bits */
 
-  if (btype == 0) {
-    size_t length = ZopfliLZ77GetByteRange(lz77, lstart, lend);
-    size_t rem = length % 65535;
-    size_t blocks = length / 65535 + (rem ? 1 : 0);
-    /* An uncompressed block must actually be split into multiple blocks if it's
-       larger than 65535 bytes long. Eeach block header is 5 bytes: 3 bits,
-       padding, LEN and NLEN (potential less padding for first one ignored). */
-    return blocks * 5 * 8 + length * 8;
-  } if (btype == 1) {
+  assert(btype == 1 || btype == 2); /* This is not for uncompressed blocks. */
+
+  if(btype == 1) {
     GetFixedTree(ll_lengths, d_lengths);
-    result += CalculateBlockSymbolSize(
-        ll_lengths, d_lengths, lz77, lstart, lend);
   } else {
-    result += GetDynamicLengths(lz77, lstart, lend, ll_lengths, d_lengths);
+    GetDynamicLengths(litlens, dists, lstart, lend, ll_lengths, d_lengths);
+    result += CalculateTreeSize(ll_lengths, d_lengths);
   }
 
-  return result;
-}
+  result += CalculateBlockSymbolSize(
+      ll_lengths, d_lengths, litlens, dists, lstart, lend);
 
-double ZopfliCalculateBlockSizeAutoType(const ZopfliLZ77Store* lz77,
-                                        size_t lstart, size_t lend) {
-  double uncompressedcost = ZopfliCalculateBlockSize(lz77, lstart, lend, 0);
-  /* Don't do the expensive fixed cost calculation for larger blocks that are
-     unlikely to use it. */
-  double fixedcost = (lz77->size > 1000) ?
-      uncompressedcost : ZopfliCalculateBlockSize(lz77, lstart, lend, 1);
-  double dyncost = ZopfliCalculateBlockSize(lz77, lstart, lend, 2);
-  return (uncompressedcost < fixedcost && uncompressedcost < dyncost)
-      ? uncompressedcost
-      : (fixedcost < dyncost ? fixedcost : dyncost);
-}
-
-/* Since an uncompressed block can be max 65535 in size, it actually adds
-multible blocks if needed. */
-static void AddNonCompressedBlock(const ZopfliOptions* options, int final,
-                                  const unsigned char* in, size_t instart,
-                                  size_t inend,
-                                  unsigned char* bp,
-                                  unsigned char** out, size_t* outsize) {
-  size_t pos = instart;
-  (void)options;
-  for (;;) {
-    size_t i;
-    unsigned short blocksize = 65535;
-    unsigned short nlen;
-    int currentfinal;
-
-    if (pos + blocksize > inend) blocksize = inend - pos;
-    currentfinal = pos + blocksize >= inend;
-
-    nlen = ~blocksize;
-
-    AddBit(final && currentfinal, bp, out, outsize);
-    /* BTYPE 00 */
-    AddBit(0, bp, out, outsize);
-    AddBit(0, bp, out, outsize);
-
-    /* Any bits of input up to the next byte boundary are ignored. */
-    *bp = 0;
-
-    ZOPFLI_APPEND_DATA(blocksize % 256, out, outsize);
-    ZOPFLI_APPEND_DATA((blocksize / 256) % 256, out, outsize);
-    ZOPFLI_APPEND_DATA(nlen % 256, out, outsize);
-    ZOPFLI_APPEND_DATA((nlen / 256) % 256, out, outsize);
-
-    for (i = 0; i < blocksize; i++) {
-      ZOPFLI_APPEND_DATA(in[pos + i], out, outsize);
-    }
-
-    if (currentfinal) break;
-    pos += blocksize;
-  }
+  return result;
 }
 
 /*
@@ -680,27 +526,20 @@ out: dynamic output array to append to
 outsize: dynamic output array size
 */
 static void AddLZ77Block(const ZopfliOptions* options, int btype, int final,
-                         const ZopfliLZ77Store* lz77,
+                         const unsigned short* litlens,
+                         const unsigned short* dists,
                          size_t lstart, size_t lend,
                          size_t expected_data_size,
                          unsigned char* bp,
                          unsigned char** out, size_t* outsize) {
-  unsigned ll_lengths[ZOPFLI_NUM_LL];
-  unsigned d_lengths[ZOPFLI_NUM_D];
-  unsigned ll_symbols[ZOPFLI_NUM_LL];
-  unsigned d_symbols[ZOPFLI_NUM_D];
+  unsigned ll_lengths[288];
+  unsigned d_lengths[32];
+  unsigned ll_symbols[288];
+  unsigned d_symbols[32];
   size_t detect_block_size = *outsize;
   size_t compressed_size;
   size_t uncompressed_size = 0;
   size_t i;
-  if (btype == 0) {
-    size_t length = ZopfliLZ77GetByteRange(lz77, lstart, lend);
-    size_t pos = lstart == lend ? 0 : lz77->pos[lstart];
-    size_t end = pos + length;
-    AddNonCompressedBlock(options, final,
-                          lz77->data, pos, end, bp, out, outsize);
-    return;
-  }
 
   AddBit(final, bp, out, outsize);
   AddBit(btype & 1, bp, out, outsize);
@@ -714,7 +553,7 @@ static void AddLZ77Block(const ZopfliOptions* options, int btype, int final,
     unsigned detect_tree_size;
     assert(btype == 2);
 
-    GetDynamicLengths(lz77, lstart, lend, ll_lengths, d_lengths);
+    GetDynamicLengths(litlens, dists, lstart, lend, ll_lengths, d_lengths);
 
     detect_tree_size = *outsize;
     AddDynamicTree(ll_lengths, d_lengths, bp, out, outsize);
@@ -723,18 +562,18 @@ static void AddLZ77Block(const ZopfliOptions* options, int btype, int final,
     }
   }
 
-  ZopfliLengthsToSymbols(ll_lengths, ZOPFLI_NUM_LL, 15, ll_symbols);
-  ZopfliLengthsToSymbols(d_lengths, ZOPFLI_NUM_D, 15, d_symbols);
+  ZopfliLengthsToSymbols(ll_lengths, 288, 15, ll_symbols);
+  ZopfliLengthsToSymbols(d_lengths, 32, 15, d_symbols);
 
   detect_block_size = *outsize;
-  AddLZ77Data(lz77, lstart, lend, expected_data_size,
+  AddLZ77Data(litlens, dists, lstart, lend, expected_data_size,
               ll_symbols, ll_lengths, d_symbols, d_lengths,
               bp, out, outsize);
   /* End symbol. */
   AddHuffmanBits(ll_symbols[256], ll_lengths[256], bp, out, outsize);
 
   for (i = lstart; i < lend; i++) {
-    uncompressed_size += lz77->dists[i] == 0 ? 1 : lz77->litlens[i];
+    uncompressed_size += dists[i] == 0 ? 1 : litlens[i];
   }
   compressed_size = *outsize - detect_block_size;
   if (options->verbose) {
@@ -744,188 +583,284 @@ static void AddLZ77Block(const ZopfliOptions* options, int btype, int final,
   }
 }
 
-static void AddLZ77BlockAutoType(const ZopfliOptions* options, int final,
-                                 const ZopfliLZ77Store* lz77,
-                                 size_t lstart, size_t lend,
-                                 size_t expected_data_size,
-                                 unsigned char* bp,
-                                 unsigned char** out, size_t* outsize) {
-  double uncompressedcost = ZopfliCalculateBlockSize(lz77, lstart, lend, 0);
-  double fixedcost = ZopfliCalculateBlockSize(lz77, lstart, lend, 1);
-  double dyncost = ZopfliCalculateBlockSize(lz77, lstart, lend, 2);
-
-  /* Whether to perform the expensive calculation of creating an optimal block
-  with fixed huffman tree to check if smaller. Only do this for small blocks or
-  blocks which already are pretty good with fixed huffman tree. */
-  int expensivefixed = (lz77->size < 1000) || fixedcost <= dyncost * 1.1;
-
-  ZopfliLZ77Store fixedstore;
-  if (lstart == lend) {
-    /* Smallest empty block is represented by fixed block */
-    AddBits(final, 1, bp, out, outsize);
-    AddBits(1, 2, bp, out, outsize);  /* btype 01 */
-    AddBits(0, 7, bp, out, outsize);  /* end symbol has code 0000000 */
-    return;
-  }
-  ZopfliInitLZ77Store(lz77->data, &fixedstore);
-  if (expensivefixed) {
-    /* Recalculate the LZ77 with ZopfliLZ77OptimalFixed */
-    size_t instart = lz77->pos[lstart];
-    size_t inend = instart + ZopfliLZ77GetByteRange(lz77, lstart, lend);
-
-    ZopfliBlockState s;
-    ZopfliInitBlockState(options, instart, inend, 1, &s);
-    ZopfliLZ77OptimalFixed(&s, lz77->data, instart, inend, &fixedstore);
-    fixedcost = ZopfliCalculateBlockSize(&fixedstore, 0, fixedstore.size, 1);
-    ZopfliCleanBlockState(&s);
-  }
+static void DeflateDynamicBlock(const ZopfliOptions* options, int final,
+                                const unsigned char* in,
+                                size_t instart, size_t inend,
+                                unsigned char* bp,
+                                unsigned char** out, size_t* outsize) {
+  ZopfliBlockState s;
+  size_t blocksize = inend - instart;
+  ZopfliLZ77Store store;
+  int btype = 2;
+
+  ZopfliInitLZ77Store(&store);
+
+  s.options = options;
+  s.blockstart = instart;
+  s.blockend = inend;
+#ifdef ZOPFLI_LONGEST_MATCH_CACHE
+  s.lmc = (ZopfliLongestMatchCache*)malloc(sizeof(ZopfliLongestMatchCache));
+  ZopfliInitCache(blocksize, s.lmc);
+#endif
 
-  if (uncompressedcost < fixedcost && uncompressedcost < dyncost) {
-    AddLZ77Block(options, 0, final, lz77, lstart, lend,
-                 expected_data_size, bp, out, outsize);
-  } else if (fixedcost < dyncost) {
-    if (expensivefixed) {
-      AddLZ77Block(options, 1, final, &fixedstore, 0, fixedstore.size,
-                   expected_data_size, bp, out, outsize);
+  ZopfliLZ77Optimal(&s, in, instart, inend, &store);
+
+  /* For small block, encoding with fixed tree can be smaller. For large block,
+  don't bother doing this expensive test, dynamic tree will be better.*/
+  if (store.size < 1000) {
+    double dyncost, fixedcost;
+    ZopfliLZ77Store fixedstore;
+    ZopfliInitLZ77Store(&fixedstore);
+    ZopfliLZ77OptimalFixed(&s, in, instart, inend, &fixedstore);
+    dyncost = ZopfliCalculateBlockSize(store.litlens, store.dists,
+        0, store.size, 2);
+    fixedcost = ZopfliCalculateBlockSize(fixedstore.litlens, fixedstore.dists,
+        0, fixedstore.size, 1);
+    if (fixedcost < dyncost) {
+      btype = 1;
+      ZopfliCleanLZ77Store(&store);
+      store = fixedstore;
     } else {
-      AddLZ77Block(options, 1, final, lz77, lstart, lend,
-                   expected_data_size, bp, out, outsize);
+      ZopfliCleanLZ77Store(&fixedstore);
     }
-  } else {
-    AddLZ77Block(options, 2, final, lz77, lstart, lend,
-                 expected_data_size, bp, out, outsize);
   }
 
-  ZopfliCleanLZ77Store(&fixedstore);
+  AddLZ77Block(s.options, btype, final,
+               store.litlens, store.dists, 0, store.size,
+               blocksize, bp, out, outsize);
+
+#ifdef ZOPFLI_LONGEST_MATCH_CACHE
+  ZopfliCleanCache(s.lmc);
+  free(s.lmc);
+#endif
+  ZopfliCleanLZ77Store(&store);
 }
 
-/*
-Deflate a part, to allow ZopfliDeflate() to use multiple master blocks if
-needed.
-It is possible to call this function multiple times in a row, shifting
-instart and inend to next bytes of the data. If instart is larger than 0, then
-previous bytes are used as the initial dictionary for LZ77.
-This function will usually output multiple deflate blocks. If final is 1, then
-the final bit will be set on the last block.
-*/
-void ZopfliDeflatePart(const ZopfliOptions* options, int btype, int final,
-                       const unsigned char* in, size_t instart, size_t inend,
-                       unsigned char* bp, unsigned char** out,
-                       size_t* outsize) {
+static void DeflateFixedBlock(const ZopfliOptions* options, int final,
+                              const unsigned char* in,
+                              size_t instart, size_t inend,
+                              unsigned char* bp,
+                              unsigned char** out, size_t* outsize) {
+  ZopfliBlockState s;
+  size_t blocksize = inend - instart;
+  ZopfliLZ77Store store;
+
+  ZopfliInitLZ77Store(&store);
+
+  s.options = options;
+  s.blockstart = instart;
+  s.blockend = inend;
+#ifdef ZOPFLI_LONGEST_MATCH_CACHE
+  s.lmc = (ZopfliLongestMatchCache*)malloc(sizeof(ZopfliLongestMatchCache));
+  ZopfliInitCache(blocksize, s.lmc);
+#endif
+
+  ZopfliLZ77OptimalFixed(&s, in, instart, inend, &store);
+
+  AddLZ77Block(s.options, 1, final, store.litlens, store.dists, 0, store.size,
+               blocksize, bp, out, outsize);
+
+#ifdef ZOPFLI_LONGEST_MATCH_CACHE
+  ZopfliCleanCache(s.lmc);
+  free(s.lmc);
+#endif
+  ZopfliCleanLZ77Store(&store);
+}
+
+static void DeflateNonCompressedBlock(const ZopfliOptions* options, int final,
+                                      const unsigned char* in, size_t instart,
+                                      size_t inend,
+                                      unsigned char* bp,
+                                      unsigned char** out, size_t* outsize) {
   size_t i;
-  /* byte coordinates rather than lz77 index */
-  size_t* splitpoints_uncompressed = 0;
-  size_t npoints = 0;
-  size_t* splitpoints = 0;
-  double totalcost = 0;
-  ZopfliLZ77Store lz77;
+  size_t blocksize = inend - instart;
+  unsigned short nlen = ~blocksize;
 
-  /* If btype=2 is specified, it tries all block types. If a lesser btype is
-  given, then however it forces that one. Neither of the lesser types needs
-  block splitting as they have no dynamic huffman trees. */
-  if (btype == 0) {
-    AddNonCompressedBlock(options, final, in, instart, inend, bp, out, outsize);
-    return;
-  } else if (btype == 1) {
-    ZopfliLZ77Store store;
-    ZopfliBlockState s;
-    ZopfliInitLZ77Store(in, &store);
-    ZopfliInitBlockState(options, instart, inend, 1, &s);
+  (void)options;
+  assert(blocksize < 65536);  /* Non compressed blocks are max this size. */
 
-    ZopfliLZ77OptimalFixed(&s, in, instart, inend, &store);
-    AddLZ77Block(options, btype, final, &store, 0, store.size, 0,
-                 bp, out, outsize);
+  AddBit(final, bp, out, outsize);
+  /* BTYPE 00 */
+  AddBit(0, bp, out, outsize);
+  AddBit(0, bp, out, outsize);
 
-    ZopfliCleanBlockState(&s);
-    ZopfliCleanLZ77Store(&store);
-    return;
+  /* Any bits of input up to the next byte boundary are ignored. */
+  *bp = 0;
+
+  ZOPFLI_APPEND_DATA(blocksize % 256, out, outsize);
+  ZOPFLI_APPEND_DATA((blocksize / 256) % 256, out, outsize);
+  ZOPFLI_APPEND_DATA(nlen % 256, out, outsize);
+  ZOPFLI_APPEND_DATA((nlen / 256) % 256, out, outsize);
+
+  for (i = instart; i < inend; i++) {
+    ZOPFLI_APPEND_DATA(in[i], out, outsize);
   }
+}
 
+static void DeflateBlock(const ZopfliOptions* options,
+                         int btype, int final,
+                         const unsigned char* in, size_t instart, size_t inend,
+                         unsigned char* bp,
+                         unsigned char** out, size_t* outsize) {
+  if (btype == 0) {
+    DeflateNonCompressedBlock(
+        options, final, in, instart, inend, bp, out, outsize);
+  } else if (btype == 1) {
+     DeflateFixedBlock(options, final, in, instart, inend, bp, out, outsize);
+  } else {
+    assert (btype == 2);
+    DeflateDynamicBlock(options, final, in, instart, inend, bp, out, outsize);
+  }
+}
 
-  if (options->blocksplitting) {
+/*
+Does squeeze strategy where first block splitting is done, then each block is
+squeezed.
+Parameters: see description of the ZopfliDeflate function.
+*/
+static void DeflateSplittingFirst(const ZopfliOptions* options,
+                                  int btype, int final,
+                                  const unsigned char* in,
+                                  size_t instart, size_t inend,
+                                  unsigned char* bp,
+                                  unsigned char** out, size_t* outsize) {
+  size_t i;
+  size_t* splitpoints = 0;
+  size_t npoints = 0;
+  if (btype == 0) {
+    ZopfliBlockSplitSimple(in, instart, inend, 65535, &splitpoints, &npoints);
+  } else if (btype == 1) {
+    /* If all blocks are fixed tree, splitting into separate blocks only
+    increases the total size. Leave npoints at 0, this represents 1 block. */
+  } else {
     ZopfliBlockSplit(options, in, instart, inend,
-                     options->blocksplittingmax,
-                     &splitpoints_uncompressed, &npoints);
-    splitpoints = (size_t*)malloc(sizeof(*splitpoints) * npoints);
+                     options->blocksplittingmax, &splitpoints, &npoints);
   }
 
-  ZopfliInitLZ77Store(in, &lz77);
-
   for (i = 0; i <= npoints; i++) {
-    size_t start = i == 0 ? instart : splitpoints_uncompressed[i - 1];
-    size_t end = i == npoints ? inend : splitpoints_uncompressed[i];
-    ZopfliBlockState s;
-    ZopfliLZ77Store store;
-    ZopfliInitLZ77Store(in, &store);
-    ZopfliInitBlockState(options, start, end, 1, &s);
-    ZopfliLZ77Optimal(&s, in, start, end, options->numiterations, &store);
-    totalcost += ZopfliCalculateBlockSizeAutoType(&store, 0, store.size);
-
-    ZopfliAppendLZ77Store(&store, &lz77);
-    if (i < npoints) splitpoints[i] = lz77.size;
-
-    ZopfliCleanBlockState(&s);
-    ZopfliCleanLZ77Store(&store);
+    size_t start = i == 0 ? instart : splitpoints[i - 1];
+    size_t end = i == npoints ? inend : splitpoints[i];
+    DeflateBlock(options, btype, i == npoints && final, in, start, end,
+                 bp, out, outsize);
   }
 
-  /* Second block splitting attempt */
-  if (options->blocksplitting && npoints > 1) {
-    size_t* splitpoints2 = 0;
-    size_t npoints2 = 0;
-    double totalcost2 = 0;
+  free(splitpoints);
+}
 
-    ZopfliBlockSplitLZ77(options, &lz77,
-                         options->blocksplittingmax, &splitpoints2, &npoints2);
+/*
+Does squeeze strategy where first the best possible lz77 is done, and then based
+on that data, block splitting is done.
+Parameters: see description of the ZopfliDeflate function.
+*/
+static void DeflateSplittingLast(const ZopfliOptions* options,
+                                 int btype, int final,
+                                 const unsigned char* in,
+                                 size_t instart, size_t inend,
+                                 unsigned char* bp,
+                                 unsigned char** out, size_t* outsize) {
+  size_t i;
+  ZopfliBlockState s;
+  ZopfliLZ77Store store;
+  size_t* splitpoints = 0;
+  size_t npoints = 0;
 
-    for (i = 0; i <= npoints2; i++) {
-      size_t start = i == 0 ? 0 : splitpoints2[i - 1];
-      size_t end = i == npoints2 ? lz77.size : splitpoints2[i];
-      totalcost2 += ZopfliCalculateBlockSizeAutoType(&lz77, start, end);
-    }
+  if (btype == 0) {
+    /* This function only supports LZ77 compression. DeflateSplittingFirst
+       supports the special case of noncompressed data. Punt it to that one. */
+    DeflateSplittingFirst(options, btype, final,
+                          in, instart, inend,
+                          bp, out, outsize);
+  }
+  assert(btype == 1 || btype == 2);
+
+  ZopfliInitLZ77Store(&store);
+
+  s.options = options;
+  s.blockstart = instart;
+  s.blockend = inend;
+#ifdef ZOPFLI_LONGEST_MATCH_CACHE
+  s.lmc = (ZopfliLongestMatchCache*)malloc(sizeof(ZopfliLongestMatchCache));
+  ZopfliInitCache(inend - instart, s.lmc);
+#endif
 
-    if (totalcost2 < totalcost) {
-      free(splitpoints);
-      splitpoints = splitpoints2;
-      npoints = npoints2;
-    } else {
-      free(splitpoints2);
-    }
+  if (btype == 2) {
+    ZopfliLZ77Optimal(&s, in, instart, inend, &store);
+  } else {
+    assert (btype == 1);
+    ZopfliLZ77OptimalFixed(&s, in, instart, inend, &store);
+  }
+
+  if (btype == 1) {
+    /* If all blocks are fixed tree, splitting into separate blocks only
+    increases the total size. Leave npoints at 0, this represents 1 block. */
+  } else {
+    ZopfliBlockSplitLZ77(options, store.litlens, store.dists, store.size,
+                         options->blocksplittingmax, &splitpoints, &npoints);
   }
 
   for (i = 0; i <= npoints; i++) {
     size_t start = i == 0 ? 0 : splitpoints[i - 1];
-    size_t end = i == npoints ? lz77.size : splitpoints[i];
-    AddLZ77BlockAutoType(options, i == npoints && final,
-                         &lz77, start, end, 0,
-                         bp, out, outsize);
+    size_t end = i == npoints ? store.size : splitpoints[i];
+    AddLZ77Block(options, btype, i == npoints && final,
+                 store.litlens, store.dists, start, end, 0,
+                 bp, out, outsize);
   }
 
-  ZopfliCleanLZ77Store(&lz77);
+#ifdef ZOPFLI_LONGEST_MATCH_CACHE
+  ZopfliCleanCache(s.lmc);
+  free(s.lmc);
+#endif
+
+  ZopfliCleanLZ77Store(&store);
   free(splitpoints);
-  free(splitpoints_uncompressed);
+}
+
+/*
+Deflate a part, to allow ZopfliDeflate() to use multiple master blocks if
+needed.
+It is possible to call this function multiple times in a row, shifting
+instart and inend to next bytes of the data. If instart is larger than 0, then
+previous bytes are used as the initial dictionary for LZ77.
+This function will usually output multiple deflate blocks. If final is 1, then
+the final bit will be set on the last block.
+*/
+void ZopfliDeflatePart(const ZopfliOptions* options, int btype, int final,
+                       const unsigned char* in, size_t instart, size_t inend,
+                       unsigned char* bp, unsigned char** out,
+                       size_t* outsize) {
+  if (options->blocksplitting) {
+    if (options->blocksplittinglast) {
+      DeflateSplittingLast(options, btype, final, in, instart, inend,
+                           bp, out, outsize);
+    } else {
+      DeflateSplittingFirst(options, btype, final, in, instart, inend,
+                            bp, out, outsize);
+    }
+  } else {
+    DeflateBlock(options, btype, final, in, instart, inend, bp, out, outsize);
+  }
 }
 
 void ZopfliDeflate(const ZopfliOptions* options, int btype, int final,
                    const unsigned char* in, size_t insize,
                    unsigned char* bp, unsigned char** out, size_t* outsize) {
- size_t offset = *outsize;
 #if ZOPFLI_MASTER_BLOCK_SIZE == 0
   ZopfliDeflatePart(options, btype, final, in, 0, insize, bp, out, outsize);
 #else
   size_t i = 0;
-  do {
+  while (i < insize) {
     int masterfinal = (i + ZOPFLI_MASTER_BLOCK_SIZE >= insize);
     int final2 = final && masterfinal;
     size_t size = masterfinal ? insize - i : ZOPFLI_MASTER_BLOCK_SIZE;
     ZopfliDeflatePart(options, btype, final2,
                       in, i, i + size, bp, out, outsize);
     i += size;
-  } while (i < insize);
+  }
 #endif
   if (options->verbose) {
     fprintf(stderr,
-            "Original Size: %lu, Deflate: %lu, Compression: %f%% Removed\n",
-            (unsigned long)insize, (unsigned long)(*outsize - offset),
-            100.0 * (double)(insize - (*outsize - offset)) / (double)insize);
+            "Original Size: %d, Deflate: %d, Compression: %f%% Removed\n",
+            (int)insize, (int)*outsize,
+            100.0 * (double)(insize - *outsize) / (double)insize);
   }
 }
diff --git a/src/zopfli/deflate.h b/src/zopfli/deflate.h
index fcd9ddc..189c77a 100644
--- a/src/zopfli/deflate.h
+++ b/src/zopfli/deflate.h
@@ -25,7 +25,6 @@ Functions to compress according to the DEFLATE specification, using the
 "squeeze" LZ77 compression backend.
 */
 
-#include "lz77.h"
 #include "zopfli.h"
 
 #ifdef __cplusplus
@@ -76,15 +75,10 @@ dists: ll77 distances
 lstart: start of block
 lend: end of block (not inclusive)
 */
-double ZopfliCalculateBlockSize(const ZopfliLZ77Store* lz77,
+double ZopfliCalculateBlockSize(const unsigned short* litlens,
+                                const unsigned short* dists,
                                 size_t lstart, size_t lend, int btype);
 
-/*
-Calculates block size in bits, automatically using the best btype.
-*/
-double ZopfliCalculateBlockSizeAutoType(const ZopfliLZ77Store* lz77,
-                                        size_t lstart, size_t lend);
-
 #ifdef __cplusplus
 }  // extern "C"
 #endif
diff --git a/src/zopfli/gzip_container.c b/src/zopfli/gzip_container.c
index 7615db3..8a062f2 100644
--- a/src/zopfli/gzip_container.c
+++ b/src/zopfli/gzip_container.c
@@ -24,63 +24,56 @@ Author: jyrki.alakuijala@gmail.com (Jyrki Alakuijala)
 
 #include "deflate.h"
 
-/* CRC polynomial: 0xedb88320 */
-static const unsigned long crc32_table[256] = {
-           0u, 1996959894u, 3993919788u, 2567524794u,  124634137u, 1886057615u,
-  3915621685u, 2657392035u,  249268274u, 2044508324u, 3772115230u, 2547177864u,
-   162941995u, 2125561021u, 3887607047u, 2428444049u,  498536548u, 1789927666u,
-  4089016648u, 2227061214u,  450548861u, 1843258603u, 4107580753u, 2211677639u,
-   325883990u, 1684777152u, 4251122042u, 2321926636u,  335633487u, 1661365465u,
-  4195302755u, 2366115317u,  997073096u, 1281953886u, 3579855332u, 2724688242u,
-  1006888145u, 1258607687u, 3524101629u, 2768942443u,  901097722u, 1119000684u,
-  3686517206u, 2898065728u,  853044451u, 1172266101u, 3705015759u, 2882616665u,
-   651767980u, 1373503546u, 3369554304u, 3218104598u,  565507253u, 1454621731u,
-  3485111705u, 3099436303u,  671266974u, 1594198024u, 3322730930u, 2970347812u,
-   795835527u, 1483230225u, 3244367275u, 3060149565u, 1994146192u,   31158534u,
-  2563907772u, 4023717930u, 1907459465u,  112637215u, 2680153253u, 3904427059u,
-  2013776290u,  251722036u, 2517215374u, 3775830040u, 2137656763u,  141376813u,
-  2439277719u, 3865271297u, 1802195444u,  476864866u, 2238001368u, 4066508878u,
-  1812370925u,  453092731u, 2181625025u, 4111451223u, 1706088902u,  314042704u,
-  2344532202u, 4240017532u, 1658658271u,  366619977u, 2362670323u, 4224994405u,
-  1303535960u,  984961486u, 2747007092u, 3569037538u, 1256170817u, 1037604311u,
-  2765210733u, 3554079995u, 1131014506u,  879679996u, 2909243462u, 3663771856u,
-  1141124467u,  855842277u, 2852801631u, 3708648649u, 1342533948u,  654459306u,
-  3188396048u, 3373015174u, 1466479909u,  544179635u, 3110523913u, 3462522015u,
-  1591671054u,  702138776u, 2966460450u, 3352799412u, 1504918807u,  783551873u,
-  3082640443u, 3233442989u, 3988292384u, 2596254646u,   62317068u, 1957810842u,
-  3939845945u, 2647816111u,   81470997u, 1943803523u, 3814918930u, 2489596804u,
-   225274430u, 2053790376u, 3826175755u, 2466906013u,  167816743u, 2097651377u,
-  4027552580u, 2265490386u,  503444072u, 1762050814u, 4150417245u, 2154129355u,
-   426522225u, 1852507879u, 4275313526u, 2312317920u,  282753626u, 1742555852u,
-  4189708143u, 2394877945u,  397917763u, 1622183637u, 3604390888u, 2714866558u,
-   953729732u, 1340076626u, 3518719985u, 2797360999u, 1068828381u, 1219638859u,
-  3624741850u, 2936675148u,  906185462u, 1090812512u, 3747672003u, 2825379669u,
-   829329135u, 1181335161u, 3412177804u, 3160834842u,  628085408u, 1382605366u,
-  3423369109u, 3138078467u,  570562233u, 1426400815u, 3317316542u, 2998733608u,
-   733239954u, 1555261956u, 3268935591u, 3050360625u,  752459403u, 1541320221u,
-  2607071920u, 3965973030u, 1969922972u,   40735498u, 2617837225u, 3943577151u,
-  1913087877u,   83908371u, 2512341634u, 3803740692u, 2075208622u,  213261112u,
-  2463272603u, 3855990285u, 2094854071u,  198958881u, 2262029012u, 4057260610u,
-  1759359992u,  534414190u, 2176718541u, 4139329115u, 1873836001u,  414664567u,
-  2282248934u, 4279200368u, 1711684554u,  285281116u, 2405801727u, 4167216745u,
-  1634467795u,  376229701u, 2685067896u, 3608007406u, 1308918612u,  956543938u,
-  2808555105u, 3495958263u, 1231636301u, 1047427035u, 2932959818u, 3654703836u,
-  1088359270u,  936918000u, 2847714899u, 3736837829u, 1202900863u,  817233897u,
-  3183342108u, 3401237130u, 1404277552u,  615818150u, 3134207493u, 3453421203u,
-  1423857449u,  601450431u, 3009837614u, 3294710456u, 1567103746u,  711928724u,
-  3020668471u, 3272380065u, 1510334235u,  755167117u
-};
-
-/* Returns the CRC32 */
-static unsigned long CRC(const unsigned char* data, size_t size) {
-  unsigned long result = 0xffffffffu;
-  for (; size > 0; size--) {
-    result = crc32_table[(result ^ *(data++)) & 0xff] ^ (result >> 8);
+/* Table of CRCs of all 8-bit messages. */
+static unsigned long crc_table[256];
+
+/* Flag: has the table been computed? Initially false. */
+static int crc_table_computed = 0;
+
+/* Makes the table for a fast CRC. */
+static void MakeCRCTable() {
+  unsigned long c;
+  int n, k;
+  for (n = 0; n < 256; n++) {
+    c = (unsigned long) n;
+    for (k = 0; k < 8; k++) {
+      if (c & 1) {
+        c = 0xedb88320L ^ (c >> 1);
+      } else {
+        c = c >> 1;
+      }
+    }
+    crc_table[n] = c;
   }
-  return result ^ 0xffffffffu;
+  crc_table_computed = 1;
 }
 
-/* Compresses the data according to the gzip specification, RFC 1952. */
+
+/*
+Updates a running crc with the bytes buf[0..len-1] and returns
+the updated crc. The crc should be initialized to zero.
+*/
+static unsigned long UpdateCRC(unsigned long crc,
+                               const unsigned char *buf, size_t len) {
+  unsigned long c = crc ^ 0xffffffffL;
+  unsigned n;
+
+  if (!crc_table_computed)
+    MakeCRCTable();
+  for (n = 0; n < len; n++) {
+    c = crc_table[(c ^ buf[n]) & 0xff] ^ (c >> 8);
+  }
+  return c ^ 0xffffffffL;
+}
+
+/* Returns the CRC of the bytes buf[0..len-1]. */
+static unsigned long CRC(const unsigned char* buf, int len) {
+  return UpdateCRC(0L, buf, len);
+}
+
+/*
+Compresses the data according to the gzip specification.
+*/
 void ZopfliGzipCompress(const ZopfliOptions* options,
                         const unsigned char* in, size_t insize,
                         unsigned char** out, size_t* outsize) {
diff --git a/src/zopfli/hash.c b/src/zopfli/hash.c
index 3025d1e..a3b294f 100644
--- a/src/zopfli/hash.c
+++ b/src/zopfli/hash.c
@@ -26,26 +26,13 @@ Author: jyrki.alakuijala@gmail.com (Jyrki Alakuijala)
 #define HASH_SHIFT 5
 #define HASH_MASK 32767
 
-void ZopfliAllocHash(size_t window_size, ZopfliHash* h) {
-  h->head = (int*)malloc(sizeof(*h->head) * 65536);
-  h->prev = (unsigned short*)malloc(sizeof(*h->prev) * window_size);
-  h->hashval = (int*)malloc(sizeof(*h->hashval) * window_size);
-
-#ifdef ZOPFLI_HASH_SAME
-  h->same = (unsigned short*)malloc(sizeof(*h->same) * window_size);
-#endif
-
-#ifdef ZOPFLI_HASH_SAME_HASH
-  h->head2 = (int*)malloc(sizeof(*h->head2) * 65536);
-  h->prev2 = (unsigned short*)malloc(sizeof(*h->prev2) * window_size);
-  h->hashval2 = (int*)malloc(sizeof(*h->hashval2) * window_size);
-#endif
-}
-
-void ZopfliResetHash(size_t window_size, ZopfliHash* h) {
+void ZopfliInitHash(size_t window_size, ZopfliHash* h) {
   size_t i;
 
   h->val = 0;
+  h->head = (int*)malloc(sizeof(*h->head) * 65536);
+  h->prev = (unsigned short*)malloc(sizeof(*h->prev) * window_size);
+  h->hashval = (int*)malloc(sizeof(*h->hashval) * window_size);
   for (i = 0; i < 65536; i++) {
     h->head[i] = -1;  /* -1 indicates no head so far. */
   }
@@ -55,6 +42,7 @@ void ZopfliResetHash(size_t window_size, ZopfliHash* h) {
   }
 
 #ifdef ZOPFLI_HASH_SAME
+  h->same = (unsigned short*)malloc(sizeof(*h->same) * window_size);
   for (i = 0; i < window_size; i++) {
     h->same[i] = 0;
   }
@@ -62,6 +50,9 @@ void ZopfliResetHash(size_t window_size, ZopfliHash* h) {
 
 #ifdef ZOPFLI_HASH_SAME_HASH
   h->val2 = 0;
+  h->head2 = (int*)malloc(sizeof(*h->head2) * 65536);
+  h->prev2 = (unsigned short*)malloc(sizeof(*h->prev2) * window_size);
+  h->hashval2 = (int*)malloc(sizeof(*h->hashval2) * window_size);
   for (i = 0; i < 65536; i++) {
     h->head2[i] = -1;
   }
@@ -138,6 +129,7 @@ void ZopfliUpdateHash(const unsigned char* array, size_t pos, size_t end,
 
 void ZopfliWarmupHash(const unsigned char* array, size_t pos, size_t end,
                 ZopfliHash* h) {
+  (void)end;
   UpdateHashValue(h, array[pos + 0]);
-  if (pos + 1 < end) UpdateHashValue(h, array[pos + 1]);
+  UpdateHashValue(h, array[pos + 1]);
 }
diff --git a/src/zopfli/hash.h b/src/zopfli/hash.h
index e59c1d4..79c2479 100644
--- a/src/zopfli/hash.h
+++ b/src/zopfli/hash.h
@@ -27,16 +27,16 @@ The hash for ZopfliFindLongestMatch of lz77.c.
 #include "util.h"
 
 typedef struct ZopfliHash {
-  int* head;  /* Hash value to index of its most recent occurrence. */
-  unsigned short* prev;  /* Index to index of prev. occurrence of same hash. */
+  int* head;  /* Hash value to index of its most recent occurance. */
+  unsigned short* prev;  /* Index to index of prev. occurance of same hash. */
   int* hashval;  /* Index to hash value at this index. */
   int val;  /* Current hash value. */
 
 #ifdef ZOPFLI_HASH_SAME_HASH
   /* Fields with similar purpose as the above hash, but for the second hash with
   a value that is calculated differently.  */
-  int* head2;  /* Hash value to index of its most recent occurrence. */
-  unsigned short* prev2;  /* Index to index of prev. occurrence of same hash. */
+  int* head2;  /* Hash value to index of its most recent occurance. */
+  unsigned short* prev2;  /* Index to index of prev. occurance of same hash. */
   int* hashval2;  /* Index to hash value at this index. */
   int val2;  /* Current hash value. */
 #endif
@@ -46,13 +46,10 @@ typedef struct ZopfliHash {
 #endif
 } ZopfliHash;
 
-/* Allocates ZopfliHash memory. */
-void ZopfliAllocHash(size_t window_size, ZopfliHash* h);
+/* Allocates and initializes all fields of ZopfliHash. */
+void ZopfliInitHash(size_t window_size, ZopfliHash* h);
 
-/* Resets all fields of ZopfliHash. */
-void ZopfliResetHash(size_t window_size, ZopfliHash* h);
-
-/* Frees ZopfliHash memory. */
+/* Frees all fields of ZopfliHash. */
 void ZopfliCleanHash(ZopfliHash* h);
 
 /*
diff --git a/src/zopfli/katajainen.c b/src/zopfli/katajainen.c
index 1459017..783ea08 100755..100644
--- a/src/zopfli/katajainen.c
+++ b/src/zopfli/katajainen.c
@@ -26,7 +26,6 @@ Jyrki Katajainen, Alistair Moffat, Andrew Turpin".
 #include "katajainen.h"
 #include <assert.h>
 #include <stdlib.h>
-#include <limits.h>
 
 typedef struct Node Node;
 
@@ -37,13 +36,16 @@ struct Node {
   size_t weight;  /* Total weight (symbol count) of this chain. */
   Node* tail;  /* Previous node(s) of this chain, or 0 if none. */
   int count;  /* Leaf symbol index, or number of leaves before this chain. */
+  char inuse;  /* Tracking for garbage collection. */
 };
 
 /*
 Memory pool for nodes.
 */
 typedef struct NodePool {
-  Node* next;  /* Pointer to a free node in the pool. */
+  Node* nodes;  /* The pool. */
+  Node* next;  /* Pointer to a possibly free node in the pool. */
+  int size;  /* Size of the memory pool. */
 } NodePool;
 
 /*
@@ -53,9 +55,41 @@ static void InitNode(size_t weight, int count, Node* tail, Node* node) {
   node->weight = weight;
   node->count = count;
   node->tail = tail;
+  node->inuse = 1;
 }
 
 /*
+Finds a free location in the memory pool. Performs garbage collection if needed.
+lists: If given, used to mark in-use nodes during garbage collection.
+maxbits: Size of lists.
+pool: Memory pool to get free node from.
+*/
+static Node* GetFreeNode(Node* (*lists)[2], int maxbits, NodePool* pool) {
+  for (;;) {
+    if (pool->next >= &pool->nodes[pool->size]) {
+      /* Garbage collection. */
+      int i;
+      for (i = 0; i < pool->size; i++) {
+        pool->nodes[i].inuse = 0;
+      }
+      if (lists) {
+        for (i = 0; i < maxbits * 2; i++) {
+          Node* node;
+          for (node = lists[i / 2][i % 2]; node; node = node->tail) {
+            node->inuse = 1;
+          }
+        }
+      }
+      pool->next = &pool->nodes[0];
+    }
+    if (!pool->next->inuse) break;  /* Found one. */
+    pool->next++;
+  }
+  return pool->next++;
+}
+
+
+/*
 Performs a Boundary Package-Merge step. Puts a new chain in the given list. The
 new chain is, depending on the weights, a leaf or a combination of two chains
 from the previous list.
@@ -65,16 +99,18 @@ leaves: The leaves, one per symbol.
 numsymbols: Number of leaves.
 pool: the node memory pool.
 index: The index of the list in which a new chain or leaf is required.
+final: Whether this is the last time this function is called. If it is then it
+  is no more needed to recursively call self.
 */
-static void BoundaryPM(Node* (*lists)[2], Node* leaves, int numsymbols,
-                       NodePool* pool, int index) {
+static void BoundaryPM(Node* (*lists)[2], int maxbits,
+    Node* leaves, int numsymbols, NodePool* pool, int index, char final) {
   Node* newchain;
   Node* oldchain;
   int lastcount = lists[index][1]->count;  /* Count of last chain of list. */
 
   if (index == 0 && lastcount >= numsymbols) return;
 
-  newchain = pool->next++;
+  newchain = GetFreeNode(lists, maxbits, pool);
   oldchain = lists[index][1];
 
   /* These are set up before the recursive calls below, so that there is a list
@@ -93,31 +129,15 @@ static void BoundaryPM(Node* (*lists)[2], Node* leaves, int numsymbols,
           newchain);
     } else {
       InitNode(sum, lastcount, lists[index - 1][1], newchain);
-      /* Two lookahead chains of previous list used up, create new ones. */
-      BoundaryPM(lists, leaves, numsymbols, pool, index - 1);
-      BoundaryPM(lists, leaves, numsymbols, pool, index - 1);
+      if (!final) {
+        /* Two lookahead chains of previous list used up, create new ones. */
+        BoundaryPM(lists, maxbits, leaves, numsymbols, pool, index - 1, 0);
+        BoundaryPM(lists, maxbits, leaves, numsymbols, pool, index - 1, 0);
+      }
     }
   }
 }
 
-static void BoundaryPMFinal(Node* (*lists)[2],
-    Node* leaves, int numsymbols, NodePool* pool, int index) {
-  int lastcount = lists[index][1]->count;  /* Count of last chain of list. */
-
-  size_t sum = lists[index - 1][0]->weight + lists[index - 1][1]->weight;
-
-  if (lastcount < numsymbols && sum > leaves[lastcount].weight) {
-    Node* newchain = pool->next;
-    Node* oldchain = lists[index][1]->tail;
-
-    lists[index][1] = newchain;
-    newchain->count = lastcount + 1;
-    newchain->tail = oldchain;
-  } else {
-    lists[index][1]->tail = lists[index - 1][1];
-  }
-}
-
 /*
 Initializes each list with as lookahead chains the two leaves with lowest
 weights.
@@ -125,8 +145,8 @@ weights.
 static void InitLists(
     NodePool* pool, const Node* leaves, int maxbits, Node* (*lists)[2]) {
   int i;
-  Node* node0 = pool->next++;
-  Node* node1 = pool->next++;
+  Node* node0 = GetFreeNode(0, maxbits, pool);
+  Node* node1 = GetFreeNode(0, maxbits, pool);
   InitNode(leaves[0].weight, 1, 0, node0);
   InitNode(leaves[1].weight, 2, 0, node1);
   for (i = 0; i < maxbits; i++) {
@@ -141,24 +161,12 @@ last chain of the last list contains the amount of active leaves in each list.
 chain: Chain to extract the bit length from (last chain from last list).
 */
 static void ExtractBitLengths(Node* chain, Node* leaves, unsigned* bitlengths) {
-  int counts[16] = {0};
-  unsigned end = 16;
-  unsigned ptr = 15;
-  unsigned value = 1;
   Node* node;
-  int val;
-
   for (node = chain; node; node = node->tail) {
-    counts[--end] = node->count;
-  }
-
-  val = counts[15];
-  while (ptr >= end) {
-    for (; val > counts[ptr - 1]; val--) {
-      bitlengths[leaves[val - 1].count] = value;
+    int i;
+    for (i = 0; i < node->count; i++) {
+      bitlengths[leaves[i].count]++;
     }
-    ptr--;
-    value++;
   }
 }
 
@@ -175,7 +183,6 @@ int ZopfliLengthLimitedCodeLengths(
   int i;
   int numsymbols = 0;  /* Amount of symbols with frequency > 0. */
   int numBoundaryPMRuns;
-  Node* nodes;
 
   /* Array of lists of chains. Each list requires only two lookahead chains at
   a time, so each list is a array of two Node*'s. */
@@ -212,35 +219,17 @@ int ZopfliLengthLimitedCodeLengths(
     free(leaves);
     return 0;  /* Only one symbol, give it bitlength 1, not 0. OK. */
   }
-  if (numsymbols == 2) {
-    bitlengths[leaves[0].count]++;
-    bitlengths[leaves[1].count]++;
-    free(leaves);
-    return 0;
-  }
 
-  /* Sort the leaves from lightest to heaviest. Add count into the same
-  variable for stable sorting. */
-  for (i = 0; i < numsymbols; i++) {
-    if (leaves[i].weight >=
-        ((size_t)1 << (sizeof(leaves[0].weight) * CHAR_BIT - 9))) {
-      free(leaves);
-      return 1;  /* Error, we need 9 bits for the count. */
-    }
-    leaves[i].weight = (leaves[i].weight << 9) | leaves[i].count;
-  }
+  /* Sort the leaves from lightest to heaviest. */
   qsort(leaves, numsymbols, sizeof(Node), LeafComparator);
-  for (i = 0; i < numsymbols; i++) {
-    leaves[i].weight >>= 9;
-  }
-
-  if (numsymbols - 1 < maxbits) {
-    maxbits = numsymbols - 1;
-  }
 
   /* Initialize node memory pool. */
-  nodes = (Node*)malloc(maxbits * 2 * numsymbols * sizeof(Node));
-  pool.next = nodes;
+  pool.size = 2 * maxbits * (maxbits + 1);
+  pool.nodes = (Node*)malloc(pool.size * sizeof(*pool.nodes));
+  pool.next = pool.nodes;
+  for (i = 0; i < pool.size; i++) {
+    pool.nodes[i].inuse = 0;
+  }
 
   lists = (Node* (*)[2])malloc(maxbits * sizeof(*lists));
   InitLists(&pool, leaves, maxbits, lists);
@@ -248,15 +237,15 @@ int ZopfliLengthLimitedCodeLengths(
   /* In the last list, 2 * numsymbols - 2 active chains need to be created. Two
   are already created in the initialization. Each BoundaryPM run creates one. */
   numBoundaryPMRuns = 2 * numsymbols - 4;
-  for (i = 0; i < numBoundaryPMRuns - 1; i++) {
-    BoundaryPM(lists, leaves, numsymbols, &pool, maxbits - 1);
+  for (i = 0; i < numBoundaryPMRuns; i++) {
+    char final = i == numBoundaryPMRuns - 1;
+    BoundaryPM(lists, maxbits, leaves, numsymbols, &pool, maxbits - 1, final);
   }
-  BoundaryPMFinal(lists, leaves, numsymbols, &pool, maxbits - 1);
 
   ExtractBitLengths(lists[maxbits - 1][1], leaves, bitlengths);
 
   free(lists);
   free(leaves);
-  free(nodes);
+  free(pool.nodes);
   return 0;  /* OK. */
 }
diff --git a/src/zopfli/katajainen.h b/src/zopfli/katajainen.h
index 5927350..ee8a91e 100644
--- a/src/zopfli/katajainen.h
+++ b/src/zopfli/katajainen.h
@@ -30,7 +30,7 @@ The output is tailored for DEFLATE: symbols that never occur, get a bit length
 of 0, and if only a single symbol occurs at least once, its bitlength will be 1,
 and not 0 as would theoretically be needed for a single symbol.
 
-frequencies: The amount of occurrences of each symbol.
+frequencies: The amount of occurances of each symbol.
 n: The amount of symbols.
 maxbits: Maximum bit length, inclusive.
 bitlengths: Output, the bitlengths for the symbol prefix codes.
diff --git a/src/zopfli/lz77.c b/src/zopfli/lz77.c
index 9df899d..26186b4 100644
--- a/src/zopfli/lz77.c
+++ b/src/zopfli/lz77.c
@@ -18,76 +18,37 @@ Author: jyrki.alakuijala@gmail.com (Jyrki Alakuijala)
 */
 
 #include "lz77.h"
-#include "symbols.h"
 #include "util.h"
 
 #include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 
-void ZopfliInitLZ77Store(const unsigned char* data, ZopfliLZ77Store* store) {
+void ZopfliInitLZ77Store(ZopfliLZ77Store* store) {
   store->size = 0;
   store->litlens = 0;
   store->dists = 0;
-  store->pos = 0;
-  store->data = data;
-  store->ll_symbol = 0;
-  store->d_symbol = 0;
-  store->ll_counts = 0;
-  store->d_counts = 0;
 }
 
 void ZopfliCleanLZ77Store(ZopfliLZ77Store* store) {
   free(store->litlens);
   free(store->dists);
-  free(store->pos);
-  free(store->ll_symbol);
-  free(store->d_symbol);
-  free(store->ll_counts);
-  free(store->d_counts);
-}
-
-static size_t CeilDiv(size_t a, size_t b) {
-  return (a + b - 1) / b;
 }
 
 void ZopfliCopyLZ77Store(
     const ZopfliLZ77Store* source, ZopfliLZ77Store* dest) {
   size_t i;
-  size_t llsize = ZOPFLI_NUM_LL * CeilDiv(source->size, ZOPFLI_NUM_LL);
-  size_t dsize = ZOPFLI_NUM_D * CeilDiv(source->size, ZOPFLI_NUM_D);
   ZopfliCleanLZ77Store(dest);
-  ZopfliInitLZ77Store(source->data, dest);
   dest->litlens =
       (unsigned short*)malloc(sizeof(*dest->litlens) * source->size);
   dest->dists = (unsigned short*)malloc(sizeof(*dest->dists) * source->size);
-  dest->pos = (size_t*)malloc(sizeof(*dest->pos) * source->size);
-  dest->ll_symbol =
-      (unsigned short*)malloc(sizeof(*dest->ll_symbol) * source->size);
-  dest->d_symbol =
-      (unsigned short*)malloc(sizeof(*dest->d_symbol) * source->size);
-  dest->ll_counts = (size_t*)malloc(sizeof(*dest->ll_counts) * llsize);
-  dest->d_counts = (size_t*)malloc(sizeof(*dest->d_counts) * dsize);
-
-  /* Allocation failed. */
-  if (!dest->litlens || !dest->dists) exit(-1);
-  if (!dest->pos) exit(-1);
-  if (!dest->ll_symbol || !dest->d_symbol) exit(-1);
-  if (!dest->ll_counts || !dest->d_counts) exit(-1);
+
+  if (!dest->litlens || !dest->dists) exit(-1); /* Allocation failed. */
 
   dest->size = source->size;
   for (i = 0; i < source->size; i++) {
     dest->litlens[i] = source->litlens[i];
     dest->dists[i] = source->dists[i];
-    dest->pos[i] = source->pos[i];
-    dest->ll_symbol[i] = source->ll_symbol[i];
-    dest->d_symbol[i] = source->d_symbol[i];
-  }
-  for (i = 0; i < llsize; i++) {
-    dest->ll_counts[i] = source->ll_counts[i];
-  }
-  for (i = 0; i < dsize; i++) {
-    dest->d_counts[i] = source->d_counts[i];
   }
 }
 
@@ -96,149 +57,10 @@ Appends the length and distance to the LZ77 arrays of the ZopfliLZ77Store.
 context must be a ZopfliLZ77Store*.
 */
 void ZopfliStoreLitLenDist(unsigned short length, unsigned short dist,
-                           size_t pos, ZopfliLZ77Store* store) {
-  size_t i;
-  /* Needed for using ZOPFLI_APPEND_DATA multiple times. */
-  size_t origsize = store->size;
-  size_t llstart = ZOPFLI_NUM_LL * (origsize / ZOPFLI_NUM_LL);
-  size_t dstart = ZOPFLI_NUM_D * (origsize / ZOPFLI_NUM_D);
-
-  /* Everytime the index wraps around, a new cumulative histogram is made: we're
-  keeping one histogram value per LZ77 symbol rather than a full histogram for
-  each to save memory. */
-  if (origsize % ZOPFLI_NUM_LL == 0) {
-    size_t llsize = origsize;
-    for (i = 0; i < ZOPFLI_NUM_LL; i++) {
-      ZOPFLI_APPEND_DATA(
-          origsize == 0 ? 0 : store->ll_counts[origsize - ZOPFLI_NUM_LL + i],
-          &store->ll_counts, &llsize);
-    }
-  }
-  if (origsize % ZOPFLI_NUM_D == 0) {
-    size_t dsize = origsize;
-    for (i = 0; i < ZOPFLI_NUM_D; i++) {
-      ZOPFLI_APPEND_DATA(
-          origsize == 0 ? 0 : store->d_counts[origsize - ZOPFLI_NUM_D + i],
-          &store->d_counts, &dsize);
-    }
-  }
-
+                           ZopfliLZ77Store* store) {
+  size_t size2 = store->size;  /* Needed for using ZOPFLI_APPEND_DATA twice. */
   ZOPFLI_APPEND_DATA(length, &store->litlens, &store->size);
-  store->size = origsize;
-  ZOPFLI_APPEND_DATA(dist, &store->dists, &store->size);
-  store->size = origsize;
-  ZOPFLI_APPEND_DATA(pos, &store->pos, &store->size);
-  assert(length < 259);
-
-  if (dist == 0) {
-    store->size = origsize;
-    ZOPFLI_APPEND_DATA(length, &store->ll_symbol, &store->size);
-    store->size = origsize;
-    ZOPFLI_APPEND_DATA(0, &store->d_symbol, &store->size);
-    store->ll_counts[llstart + length]++;
-  } else {
-    store->size = origsize;
-    ZOPFLI_APPEND_DATA(ZopfliGetLengthSymbol(length),
-                       &store->ll_symbol, &store->size);
-    store->size = origsize;
-    ZOPFLI_APPEND_DATA(ZopfliGetDistSymbol(dist),
-                       &store->d_symbol, &store->size);
-    store->ll_counts[llstart + ZopfliGetLengthSymbol(length)]++;
-    store->d_counts[dstart + ZopfliGetDistSymbol(dist)]++;
-  }
-}
-
-void ZopfliAppendLZ77Store(const ZopfliLZ77Store* store,
-                           ZopfliLZ77Store* target) {
-  size_t i;
-  for (i = 0; i < store->size; i++) {
-    ZopfliStoreLitLenDist(store->litlens[i], store->dists[i],
-                          store->pos[i], target);
-  }
-}
-
-size_t ZopfliLZ77GetByteRange(const ZopfliLZ77Store* lz77,
-                              size_t lstart, size_t lend) {
-  size_t l = lend - 1;
-  if (lstart == lend) return 0;
-  return lz77->pos[l] + ((lz77->dists[l] == 0) ?
-      1 : lz77->litlens[l]) - lz77->pos[lstart];
-}
-
-static void ZopfliLZ77GetHistogramAt(const ZopfliLZ77Store* lz77, size_t lpos,
-                                     size_t* ll_counts, size_t* d_counts) {
-  /* The real histogram is created by using the histogram for this chunk, but
-  all superfluous values of this chunk subtracted. */
-  size_t llpos = ZOPFLI_NUM_LL * (lpos / ZOPFLI_NUM_LL);
-  size_t dpos = ZOPFLI_NUM_D * (lpos / ZOPFLI_NUM_D);
-  size_t i;
-  for (i = 0; i < ZOPFLI_NUM_LL; i++) {
-    ll_counts[i] = lz77->ll_counts[llpos + i];
-  }
-  for (i = lpos + 1; i < llpos + ZOPFLI_NUM_LL && i < lz77->size; i++) {
-    ll_counts[lz77->ll_symbol[i]]--;
-  }
-  for (i = 0; i < ZOPFLI_NUM_D; i++) {
-    d_counts[i] = lz77->d_counts[dpos + i];
-  }
-  for (i = lpos + 1; i < dpos + ZOPFLI_NUM_D && i < lz77->size; i++) {
-    if (lz77->dists[i] != 0) d_counts[lz77->d_symbol[i]]--;
-  }
-}
-
-void ZopfliLZ77GetHistogram(const ZopfliLZ77Store* lz77,
-                           size_t lstart, size_t lend,
-                           size_t* ll_counts, size_t* d_counts) {
-  size_t i;
-  if (lstart + ZOPFLI_NUM_LL * 3 > lend) {
-    memset(ll_counts, 0, sizeof(*ll_counts) * ZOPFLI_NUM_LL);
-    memset(d_counts, 0, sizeof(*d_counts) * ZOPFLI_NUM_D);
-    for (i = lstart; i < lend; i++) {
-      ll_counts[lz77->ll_symbol[i]]++;
-      if (lz77->dists[i] != 0) d_counts[lz77->d_symbol[i]]++;
-    }
-  } else {
-    /* Subtract the cumulative histograms at the end and the start to get the
-    histogram for this range. */
-    ZopfliLZ77GetHistogramAt(lz77, lend - 1, ll_counts, d_counts);
-    if (lstart > 0) {
-      size_t ll_counts2[ZOPFLI_NUM_LL];
-      size_t d_counts2[ZOPFLI_NUM_D];
-      ZopfliLZ77GetHistogramAt(lz77, lstart - 1, ll_counts2, d_counts2);
-
-      for (i = 0; i < ZOPFLI_NUM_LL; i++) {
-        ll_counts[i] -= ll_counts2[i];
-      }
-      for (i = 0; i < ZOPFLI_NUM_D; i++) {
-        d_counts[i] -= d_counts2[i];
-      }
-    }
-  }
-}
-
-void ZopfliInitBlockState(const ZopfliOptions* options,
-                          size_t blockstart, size_t blockend, int add_lmc,
-                          ZopfliBlockState* s) {
-  s->options = options;
-  s->blockstart = blockstart;
-  s->blockend = blockend;
-#ifdef ZOPFLI_LONGEST_MATCH_CACHE
-  if (add_lmc) {
-    s->lmc = (ZopfliLongestMatchCache*)malloc(sizeof(ZopfliLongestMatchCache));
-    ZopfliInitCache(blockend - blockstart, s->lmc);
-  } else {
-    s->lmc = 0;
-  }
-#endif
-}
-
-void ZopfliCleanBlockState(ZopfliBlockState* s) {
-#ifdef ZOPFLI_LONGEST_MATCH_CACHE
-  if (s->lmc) {
-    ZopfliCleanCache(s->lmc);
-    free(s->lmc);
-  }
-#endif
+  ZOPFLI_APPEND_DATA(dist, &store->dists, &size2);
 }
 
 /*
@@ -543,7 +365,7 @@ void ZopfliFindLongestMatch(ZopfliBlockState* s, const ZopfliHash* h,
 
 void ZopfliLZ77Greedy(ZopfliBlockState* s, const unsigned char* in,
                       size_t instart, size_t inend,
-                      ZopfliLZ77Store* store, ZopfliHash* h) {
+                      ZopfliLZ77Store* store) {
   size_t i = 0, j;
   unsigned short leng;
   unsigned short dist;
@@ -552,6 +374,9 @@ void ZopfliLZ77Greedy(ZopfliBlockState* s, const unsigned char* in,
       ? instart - ZOPFLI_WINDOW_SIZE : 0;
   unsigned short dummysublen[259];
 
+  ZopfliHash hash;
+  ZopfliHash* h = &hash;
+
 #ifdef ZOPFLI_LAZY_MATCHING
   /* Lazy matching. */
   unsigned prev_length = 0;
@@ -562,7 +387,7 @@ void ZopfliLZ77Greedy(ZopfliBlockState* s, const unsigned char* in,
 
   if (instart == inend) return;
 
-  ZopfliResetHash(ZOPFLI_WINDOW_SIZE, h);
+  ZopfliInitHash(ZOPFLI_WINDOW_SIZE, h);
   ZopfliWarmupHash(in, windowstart, inend, h);
   for (i = windowstart; i < instart; i++) {
     ZopfliUpdateHash(in, i, inend, h);
@@ -581,7 +406,7 @@ void ZopfliLZ77Greedy(ZopfliBlockState* s, const unsigned char* in,
     if (match_available) {
       match_available = 0;
       if (lengthscore > prevlengthscore + 1) {
-        ZopfliStoreLitLenDist(in[i - 1], 0, i - 1, store);
+        ZopfliStoreLitLenDist(in[i - 1], 0, store);
         if (lengthscore >= ZOPFLI_MIN_MATCH && leng < ZOPFLI_MAX_MATCH) {
           match_available = 1;
           prev_length = leng;
@@ -595,7 +420,7 @@ void ZopfliLZ77Greedy(ZopfliBlockState* s, const unsigned char* in,
         lengthscore = prevlengthscore;
         /* Add to output. */
         ZopfliVerifyLenDist(in, inend, i - 1, dist, leng);
-        ZopfliStoreLitLenDist(leng, dist, i - 1, store);
+        ZopfliStoreLitLenDist(leng, dist, store);
         for (j = 2; j < leng; j++) {
           assert(i < inend);
           i++;
@@ -616,10 +441,10 @@ void ZopfliLZ77Greedy(ZopfliBlockState* s, const unsigned char* in,
     /* Add to output. */
     if (lengthscore >= ZOPFLI_MIN_MATCH) {
       ZopfliVerifyLenDist(in, inend, i, dist, leng);
-      ZopfliStoreLitLenDist(leng, dist, i, store);
+      ZopfliStoreLitLenDist(leng, dist, store);
     } else {
       leng = 1;
-      ZopfliStoreLitLenDist(in[i], 0, i, store);
+      ZopfliStoreLitLenDist(in[i], 0, store);
     }
     for (j = 1; j < leng; j++) {
       assert(i < inend);
@@ -627,4 +452,31 @@ void ZopfliLZ77Greedy(ZopfliBlockState* s, const unsigned char* in,
       ZopfliUpdateHash(in, i, inend, h);
     }
   }
+
+  ZopfliCleanHash(h);
+}
+
+void ZopfliLZ77Counts(const unsigned short* litlens,
+                      const unsigned short* dists,
+                      size_t start, size_t end,
+                      size_t* ll_count, size_t* d_count) {
+  size_t i;
+
+  for (i = 0; i < 288; i++) {
+    ll_count[i] = 0;
+  }
+  for (i = 0; i < 32; i++) {
+    d_count[i] = 0;
+  }
+
+  for (i = start; i < end; i++) {
+    if (dists[i] == 0) {
+      ll_count[litlens[i]]++;
+    } else {
+      ll_count[ZopfliGetLengthSymbol(litlens[i])]++;
+      d_count[ZopfliGetDistSymbol(dists[i])]++;
+    }
+  }
+
+  ll_count[256] = 1;  /* End symbol. */
 }
diff --git a/src/zopfli/lz77.h b/src/zopfli/lz77.h
index dc8597a..55186a7 100644
--- a/src/zopfli/lz77.h
+++ b/src/zopfli/lz77.h
@@ -46,37 +46,13 @@ typedef struct ZopfliLZ77Store {
   unsigned short* dists;  /* If 0: indicates literal in corresponding litlens,
       if > 0: length in corresponding litlens, this is the distance. */
   size_t size;
-
-  const unsigned char* data;  /* original data */
-  size_t* pos;  /* position in data where this LZ77 command begins */
-
-  unsigned short* ll_symbol;
-  unsigned short* d_symbol;
-
-  /* Cumulative histograms wrapping around per chunk. Each chunk has the amount
-  of distinct symbols as length, so using 1 value per LZ77 symbol, we have a
-  precise histogram at every N symbols, and the rest can be calculated by
-  looping through the actual symbols of this chunk. */
-  size_t* ll_counts;
-  size_t* d_counts;
 } ZopfliLZ77Store;
 
-void ZopfliInitLZ77Store(const unsigned char* data, ZopfliLZ77Store* store);
+void ZopfliInitLZ77Store(ZopfliLZ77Store* store);
 void ZopfliCleanLZ77Store(ZopfliLZ77Store* store);
 void ZopfliCopyLZ77Store(const ZopfliLZ77Store* source, ZopfliLZ77Store* dest);
 void ZopfliStoreLitLenDist(unsigned short length, unsigned short dist,
-                           size_t pos, ZopfliLZ77Store* store);
-void ZopfliAppendLZ77Store(const ZopfliLZ77Store* store,
-                           ZopfliLZ77Store* target);
-/* Gets the amount of raw bytes that this range of LZ77 symbols spans. */
-size_t ZopfliLZ77GetByteRange(const ZopfliLZ77Store* lz77,
-                              size_t lstart, size_t lend);
-/* Gets the histogram of lit/len and dist symbols in the given range, using the
-cumulative histograms, so faster than adding one by one for large range. Does
-not add the one end symbol of value 256. */
-void ZopfliLZ77GetHistogram(const ZopfliLZ77Store* lz77,
-                            size_t lstart, size_t lend,
-                            size_t* ll_counts, size_t* d_counts);
+                           ZopfliLZ77Store* store);
 
 /*
 Some state information for compressing a block.
@@ -96,11 +72,6 @@ typedef struct ZopfliBlockState {
   size_t blockend;
 } ZopfliBlockState;
 
-void ZopfliInitBlockState(const ZopfliOptions* options,
-                          size_t blockstart, size_t blockend, int add_lmc,
-                          ZopfliBlockState* s);
-void ZopfliCleanBlockState(ZopfliBlockState* s);
-
 /*
 Finds the longest match (length and corresponding distance) for LZ77
 compression.
@@ -129,6 +100,22 @@ void ZopfliVerifyLenDist(const unsigned char* data, size_t datasize, size_t pos,
                          unsigned short dist, unsigned short length);
 
 /*
+Counts the number of literal, length and distance symbols in the given lz77
+arrays.
+litlens: lz77 lit/lengths
+dists: ll77 distances
+start: where to begin counting in litlens and dists
+end: where to stop counting in litlens and dists (not inclusive)
+ll_count: count of each lit/len symbol, must have size 288 (see deflate
+    standard)
+d_count: count of each dist symbol, must have size 32 (see deflate standard)
+*/
+void ZopfliLZ77Counts(const unsigned short* litlens,
+                      const unsigned short* dists,
+                      size_t start, size_t end,
+                      size_t* ll_count, size_t* d_count);
+
+/*
 Does LZ77 using an algorithm similar to gzip, with lazy matching, rather than
 with the slow but better "squeeze" implementation.
 The result is placed in the ZopfliLZ77Store.
@@ -137,6 +124,6 @@ dictionary.
 */
 void ZopfliLZ77Greedy(ZopfliBlockState* s, const unsigned char* in,
                       size_t instart, size_t inend,
-                      ZopfliLZ77Store* store, ZopfliHash* h);
+                      ZopfliLZ77Store* store);
 
 #endif  /* ZOPFLI_LZ77_H_ */
diff --git a/src/zopfli/squeeze.c b/src/zopfli/squeeze.c
index a695c18..09e7e2e 100644
--- a/src/zopfli/squeeze.c
+++ b/src/zopfli/squeeze.c
@@ -25,40 +25,35 @@ Author: jyrki.alakuijala@gmail.com (Jyrki Alakuijala)
 
 #include "blocksplitter.h"
 #include "deflate.h"
-#include "symbols.h"
 #include "tree.h"
 #include "util.h"
 
 typedef struct SymbolStats {
   /* The literal and length symbols. */
-  size_t litlens[ZOPFLI_NUM_LL];
+  size_t litlens[288];
   /* The 32 unique dist symbols, not the 32768 possible dists. */
-  size_t dists[ZOPFLI_NUM_D];
+  size_t dists[32];
 
-  /* Length of each lit/len symbol in bits. */
-  double ll_symbols[ZOPFLI_NUM_LL];
-  /* Length of each dist symbol in bits. */
-  double d_symbols[ZOPFLI_NUM_D];
+  double ll_symbols[288];  /* Length of each lit/len symbol in bits. */
+  double d_symbols[32];  /* Length of each dist symbol in bits. */
 } SymbolStats;
 
 /* Sets everything to 0. */
 static void InitStats(SymbolStats* stats) {
-  memset(stats->litlens, 0, ZOPFLI_NUM_LL * sizeof(stats->litlens[0]));
-  memset(stats->dists, 0, ZOPFLI_NUM_D * sizeof(stats->dists[0]));
+  memset(stats->litlens, 0, 288 * sizeof(stats->litlens[0]));
+  memset(stats->dists, 0, 32 * sizeof(stats->dists[0]));
 
-  memset(stats->ll_symbols, 0, ZOPFLI_NUM_LL * sizeof(stats->ll_symbols[0]));
-  memset(stats->d_symbols, 0, ZOPFLI_NUM_D * sizeof(stats->d_symbols[0]));
+  memset(stats->ll_symbols, 0, 288 * sizeof(stats->ll_symbols[0]));
+  memset(stats->d_symbols, 0, 32 * sizeof(stats->d_symbols[0]));
 }
 
 static void CopyStats(SymbolStats* source, SymbolStats* dest) {
-  memcpy(dest->litlens, source->litlens,
-         ZOPFLI_NUM_LL * sizeof(dest->litlens[0]));
-  memcpy(dest->dists, source->dists, ZOPFLI_NUM_D * sizeof(dest->dists[0]));
+  memcpy(dest->litlens, source->litlens, 288 * sizeof(dest->litlens[0]));
+  memcpy(dest->dists, source->dists, 32 * sizeof(dest->dists[0]));
 
   memcpy(dest->ll_symbols, source->ll_symbols,
-         ZOPFLI_NUM_LL * sizeof(dest->ll_symbols[0]));
-  memcpy(dest->d_symbols, source->d_symbols,
-         ZOPFLI_NUM_D * sizeof(dest->d_symbols[0]));
+         288 * sizeof(dest->ll_symbols[0]));
+  memcpy(dest->d_symbols, source->d_symbols, 32 * sizeof(dest->d_symbols[0]));
 }
 
 /* Adds the bit lengths. */
@@ -66,11 +61,11 @@ static void AddWeighedStatFreqs(const SymbolStats* stats1, double w1,
                                 const SymbolStats* stats2, double w2,
                                 SymbolStats* result) {
   size_t i;
-  for (i = 0; i < ZOPFLI_NUM_LL; i++) {
+  for (i = 0; i < 288; i++) {
     result->litlens[i] =
         (size_t) (stats1->litlens[i] * w1 + stats2->litlens[i] * w2);
   }
-  for (i = 0; i < ZOPFLI_NUM_D; i++) {
+  for (i = 0; i < 32; i++) {
     result->dists[i] =
         (size_t) (stats1->dists[i] * w1 + stats2->dists[i] * w2);
   }
@@ -101,15 +96,15 @@ static void RandomizeFreqs(RanState* state, size_t* freqs, int n) {
 }
 
 static void RandomizeStatFreqs(RanState* state, SymbolStats* stats) {
-  RandomizeFreqs(state, stats->litlens, ZOPFLI_NUM_LL);
-  RandomizeFreqs(state, stats->dists, ZOPFLI_NUM_D);
+  RandomizeFreqs(state, stats->litlens, 288);
+  RandomizeFreqs(state, stats->dists, 32);
   stats->litlens[256] = 1;  /* End symbol. */
 }
 
 static void ClearStatFreqs(SymbolStats* stats) {
   size_t i;
-  for (i = 0; i < ZOPFLI_NUM_LL; i++) stats->litlens[i] = 0;
-  for (i = 0; i < ZOPFLI_NUM_D; i++) stats->dists[i] = 0;
+  for (i = 0; i < 288; i++) stats->litlens[i] = 0;
+  for (i = 0; i < 32; i++) stats->dists[i] = 0;
 }
 
 /*
@@ -131,7 +126,7 @@ static double GetCostFixed(unsigned litlen, unsigned dist, void* unused) {
     int dbits = ZopfliGetDistExtraBits(dist);
     int lbits = ZopfliGetLengthExtraBits(litlen);
     int lsym = ZopfliGetLengthSymbol(litlen);
-    int cost = 0;
+    double cost = 0;
     if (lsym <= 279) cost += 7;
     else cost += 8;
     cost += 5;  /* Every dist symbol has length 5. */
@@ -152,7 +147,7 @@ static double GetCostStat(unsigned litlen, unsigned dist, void* context) {
     int lbits = ZopfliGetLengthExtraBits(litlen);
     int dsym = ZopfliGetDistSymbol(dist);
     int dbits = ZopfliGetDistExtraBits(dist);
-    return lbits + dbits + stats->ll_symbols[lsym] + stats->d_symbols[dsym];
+    return stats->ll_symbols[lsym] + lbits + stats->d_symbols[dsym] + dbits;
   }
 }
 
@@ -197,10 +192,6 @@ static double GetCostModelMinCost(CostModelFun* costmodel, void* costcontext) {
   return costmodel(bestlength, bestdist, costcontext);
 }
 
-static size_t zopfli_min(size_t a, size_t b) {
-  return a < b ? a : b;
-}
-
 /*
 Performs the forward pass for "squeeze". Gets the most optimal length to reach
 every byte from a previous byte, using cost calculations.
@@ -218,23 +209,27 @@ static double GetBestLengths(ZopfliBlockState *s,
                              const unsigned char* in,
                              size_t instart, size_t inend,
                              CostModelFun* costmodel, void* costcontext,
-                             unsigned short* length_array,
-                             ZopfliHash* h, float* costs) {
+                             unsigned short* length_array) {
   /* Best cost to get here so far. */
   size_t blocksize = inend - instart;
-  size_t i = 0, k, kend;
+  float* costs;
+  size_t i = 0, k;
   unsigned short leng;
   unsigned short dist;
   unsigned short sublen[259];
   size_t windowstart = instart > ZOPFLI_WINDOW_SIZE
       ? instart - ZOPFLI_WINDOW_SIZE : 0;
+  ZopfliHash hash;
+  ZopfliHash* h = &hash;
   double result;
   double mincost = GetCostModelMinCost(costmodel, costcontext);
-  double mincostaddcostj;
 
   if (instart == inend) return 0;
 
-  ZopfliResetHash(ZOPFLI_WINDOW_SIZE, h);
+  costs = (float*)malloc(sizeof(float) * (blocksize + 1));
+  if (!costs) exit(-1); /* Allocation failed. */
+
+  ZopfliInitHash(ZOPFLI_WINDOW_SIZE, h);
   ZopfliWarmupHash(in, windowstart, inend, h);
   for (i = windowstart; i < instart; i++) {
     ZopfliUpdateHash(in, i, inend, h);
@@ -275,7 +270,7 @@ static double GetBestLengths(ZopfliBlockState *s,
 
     /* Literal. */
     if (i + 1 <= inend) {
-      double newCost = costmodel(in[i], 0, costcontext) + costs[j];
+      double newCost = costs[j] + costmodel(in[i], 0, costcontext);
       assert(newCost >= 0);
       if (newCost < costs[j + 1]) {
         costs[j + 1] = newCost;
@@ -283,16 +278,14 @@ static double GetBestLengths(ZopfliBlockState *s,
       }
     }
     /* Lengths. */
-    kend = zopfli_min(leng, inend-i);
-    mincostaddcostj = mincost + costs[j];
-    for (k = 3; k <= kend; k++) {
+    for (k = 3; k <= leng && i + k <= inend; k++) {
       double newCost;
 
       /* Calling the cost model is expensive, avoid this if we are already at
       the minimum possible cost that it can return. */
-     if (costs[j + k] <= mincostaddcostj) continue;
+     if (costs[j + k] - costs[j] <= mincost) continue;
 
-      newCost = costmodel(k, sublen[k], costcontext) + costs[j];
+      newCost = costs[j] + costmodel(k, sublen[k], costcontext);
       assert(newCost >= 0);
       if (newCost < costs[j + k]) {
         assert(k <= ZOPFLI_MAX_MATCH);
@@ -305,6 +298,9 @@ static double GetBestLengths(ZopfliBlockState *s,
   assert(costs[blocksize] >= 0);
   result = costs[blocksize];
 
+  ZopfliCleanHash(h);
+  free(costs);
+
   return result;
 }
 
@@ -338,16 +334,19 @@ static void TraceBackwards(size_t size, const unsigned short* length_array,
 static void FollowPath(ZopfliBlockState* s,
                        const unsigned char* in, size_t instart, size_t inend,
                        unsigned short* path, size_t pathsize,
-                       ZopfliLZ77Store* store, ZopfliHash *h) {
+                       ZopfliLZ77Store* store) {
   size_t i, j, pos = 0;
   size_t windowstart = instart > ZOPFLI_WINDOW_SIZE
       ? instart - ZOPFLI_WINDOW_SIZE : 0;
 
   size_t total_length_test = 0;
 
+  ZopfliHash hash;
+  ZopfliHash* h = &hash;
+
   if (instart == inend) return;
 
-  ZopfliResetHash(ZOPFLI_WINDOW_SIZE, h);
+  ZopfliInitHash(ZOPFLI_WINDOW_SIZE, h);
   ZopfliWarmupHash(in, windowstart, inend, h);
   for (i = windowstart; i < instart; i++) {
     ZopfliUpdateHash(in, i, inend, h);
@@ -370,11 +369,11 @@ static void FollowPath(ZopfliBlockState* s,
                              &dist, &dummy_length);
       assert(!(dummy_length != length && length > 2 && dummy_length > 2));
       ZopfliVerifyLenDist(in, inend, pos, dist, length);
-      ZopfliStoreLitLenDist(length, dist, pos, store);
+      ZopfliStoreLitLenDist(length, dist, store);
       total_length_test += length;
     } else {
       length = 1;
-      ZopfliStoreLitLenDist(in[pos], 0, pos, store);
+      ZopfliStoreLitLenDist(in[pos], 0, store);
       total_length_test++;
     }
 
@@ -386,12 +385,14 @@ static void FollowPath(ZopfliBlockState* s,
 
     pos += length;
   }
+
+  ZopfliCleanHash(h);
 }
 
 /* Calculates the entropy of the statistics */
 static void CalculateStatistics(SymbolStats* stats) {
-  ZopfliCalculateEntropy(stats->litlens, ZOPFLI_NUM_LL, stats->ll_symbols);
-  ZopfliCalculateEntropy(stats->dists, ZOPFLI_NUM_D, stats->d_symbols);
+  ZopfliCalculateEntropy(stats->litlens, 288, stats->ll_symbols);
+  ZopfliCalculateEntropy(stats->dists, 32, stats->d_symbols);
 }
 
 /* Appends the symbol statistics from the store. */
@@ -413,13 +414,14 @@ static void GetStatistics(const ZopfliLZ77Store* store, SymbolStats* stats) {
 /*
 Does a single run for ZopfliLZ77Optimal. For good compression, repeated runs
 with updated statistics should be performed.
+
 s: the block state
 in: the input data array
 instart: where to start
 inend: where to stop (not inclusive)
 path: pointer to dynamically allocated memory to store the path
 pathsize: pointer to the size of the dynamic path array
-length_array: array of size (inend - instart) used to store lengths
+length_array: array if size (inend - instart) used to store lengths
 costmodel: function to use as the cost model for this squeeze run
 costcontext: abstract context for the costmodel function
 store: place to output the LZ77 data
@@ -430,22 +432,20 @@ static double LZ77OptimalRun(ZopfliBlockState* s,
     const unsigned char* in, size_t instart, size_t inend,
     unsigned short** path, size_t* pathsize,
     unsigned short* length_array, CostModelFun* costmodel,
-    void* costcontext, ZopfliLZ77Store* store,
-    ZopfliHash* h, float* costs) {
-  double cost = GetBestLengths(s, in, instart, inend, costmodel,
-                costcontext, length_array, h, costs);
+    void* costcontext, ZopfliLZ77Store* store) {
+  double cost = GetBestLengths(
+      s, in, instart, inend, costmodel, costcontext, length_array);
   free(*path);
   *path = 0;
   *pathsize = 0;
   TraceBackwards(inend - instart, length_array, path, pathsize);
-  FollowPath(s, in, instart, inend, *path, *pathsize, store, h);
+  FollowPath(s, in, instart, inend, *path, *pathsize, store);
   assert(cost < ZOPFLI_LARGE_FLOAT);
   return cost;
 }
 
 void ZopfliLZ77Optimal(ZopfliBlockState *s,
                        const unsigned char* in, size_t instart, size_t inend,
-                       int numiterations,
                        ZopfliLZ77Store* store) {
   /* Dist to get to here with smallest cost. */
   size_t blocksize = inend - instart;
@@ -454,11 +454,8 @@ void ZopfliLZ77Optimal(ZopfliBlockState *s,
   unsigned short* path = 0;
   size_t pathsize = 0;
   ZopfliLZ77Store currentstore;
-  ZopfliHash hash;
-  ZopfliHash* h = &hash;
   SymbolStats stats, beststats, laststats;
   int i;
-  float* costs = (float*)malloc(sizeof(float) * (blocksize + 1));
   double cost;
   double bestcost = ZOPFLI_LARGE_FLOAT;
   double lastcost = 0;
@@ -466,30 +463,29 @@ void ZopfliLZ77Optimal(ZopfliBlockState *s,
   RanState ran_state;
   int lastrandomstep = -1;
 
-  if (!costs) exit(-1); /* Allocation failed. */
   if (!length_array) exit(-1); /* Allocation failed. */
 
   InitRanState(&ran_state);
   InitStats(&stats);
-  ZopfliInitLZ77Store(in, &currentstore);
-  ZopfliAllocHash(ZOPFLI_WINDOW_SIZE, h);
+  ZopfliInitLZ77Store(&currentstore);
 
   /* Do regular deflate, then loop multiple shortest path runs, each time using
   the statistics of the previous run. */
 
   /* Initial run. */
-  ZopfliLZ77Greedy(s, in, instart, inend, &currentstore, h);
+  ZopfliLZ77Greedy(s, in, instart, inend, &currentstore);
   GetStatistics(&currentstore, &stats);
 
   /* Repeat statistics with each time the cost model from the previous stat
   run. */
-  for (i = 0; i < numiterations; i++) {
+  for (i = 0; i < s->options->numiterations; i++) {
     ZopfliCleanLZ77Store(&currentstore);
-    ZopfliInitLZ77Store(in, &currentstore);
+    ZopfliInitLZ77Store(&currentstore);
     LZ77OptimalRun(s, in, instart, inend, &path, &pathsize,
                    length_array, GetCostStat, (void*)&stats,
-                   &currentstore, h, costs);
-    cost = ZopfliCalculateBlockSize(&currentstore, 0, currentstore.size, 2);
+                   &currentstore);
+    cost = ZopfliCalculateBlockSize(currentstore.litlens, currentstore.dists,
+                                    0, currentstore.size, 2);
     if (s->options->verbose_more || (s->options->verbose && cost < bestcost)) {
       fprintf(stderr, "Iteration %d: %d bit\n", i, (int) cost);
     }
@@ -520,9 +516,7 @@ void ZopfliLZ77Optimal(ZopfliBlockState *s,
 
   free(length_array);
   free(path);
-  free(costs);
   ZopfliCleanLZ77Store(&currentstore);
-  ZopfliCleanHash(h);
 }
 
 void ZopfliLZ77OptimalFixed(ZopfliBlockState *s,
@@ -536,25 +530,17 @@ void ZopfliLZ77OptimalFixed(ZopfliBlockState *s,
       (unsigned short*)malloc(sizeof(unsigned short) * (blocksize + 1));
   unsigned short* path = 0;
   size_t pathsize = 0;
-  ZopfliHash hash;
-  ZopfliHash* h = &hash;
-  float* costs = (float*)malloc(sizeof(float) * (blocksize + 1));
 
-  if (!costs) exit(-1); /* Allocation failed. */
   if (!length_array) exit(-1); /* Allocation failed. */
 
-  ZopfliAllocHash(ZOPFLI_WINDOW_SIZE, h);
-
   s->blockstart = instart;
   s->blockend = inend;
 
   /* Shortest path for fixed tree This one should give the shortest possible
   result for fixed tree, no repeated runs are needed since the tree is known. */
   LZ77OptimalRun(s, in, instart, inend, &path, &pathsize,
-                 length_array, GetCostFixed, 0, store, h, costs);
+                 length_array, GetCostFixed, 0, store);
 
   free(length_array);
   free(path);
-  free(costs);
-  ZopfliCleanHash(h);
 }
diff --git a/src/zopfli/squeeze.h b/src/zopfli/squeeze.h
index 48bb775..e850aaa 100644
--- a/src/zopfli/squeeze.h
+++ b/src/zopfli/squeeze.h
@@ -40,7 +40,6 @@ dictionary.
 */
 void ZopfliLZ77Optimal(ZopfliBlockState *s,
                        const unsigned char* in, size_t instart, size_t inend,
-                       int numiterations,
                        ZopfliLZ77Store* store);
 
 /*
diff --git a/src/zopfli/symbols.h b/src/zopfli/symbols.h
deleted file mode 100644
index b49df06..0000000
--- a/src/zopfli/symbols.h
+++ /dev/null
@@ -1,239 +0,0 @@
-/*
-Copyright 2016 Google Inc. All Rights Reserved.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-
-Author: lode.vandevenne@gmail.com (Lode Vandevenne)
-Author: jyrki.alakuijala@gmail.com (Jyrki Alakuijala)
-*/
-
-/*
-Utilities for using the lz77 symbols of the deflate spec.
-*/
-
-#ifndef ZOPFLI_SYMBOLS_H_
-#define ZOPFLI_SYMBOLS_H_
-
-/* __has_builtin available in clang */
-#ifdef __has_builtin
-# if __has_builtin(__builtin_clz)
-#   define ZOPFLI_HAS_BUILTIN_CLZ
-# endif
-/* __builtin_clz available beginning with GCC 3.4 */
-#elif __GNUC__ * 100 + __GNUC_MINOR__ >= 304
-# define ZOPFLI_HAS_BUILTIN_CLZ
-#endif
-
-/* Gets the amount of extra bits for the given dist, cfr. the DEFLATE spec. */
-static int ZopfliGetDistExtraBits(int dist) {
-#ifdef ZOPFLI_HAS_BUILTIN_CLZ
-  if (dist < 5) return 0;
-  return (31 ^ __builtin_clz(dist - 1)) - 1; /* log2(dist - 1) - 1 */
-#else
-  if (dist < 5) return 0;
-  else if (dist < 9) return 1;
-  else if (dist < 17) return 2;
-  else if (dist < 33) return 3;
-  else if (dist < 65) return 4;
-  else if (dist < 129) return 5;
-  else if (dist < 257) return 6;
-  else if (dist < 513) return 7;
-  else if (dist < 1025) return 8;
-  else if (dist < 2049) return 9;
-  else if (dist < 4097) return 10;
-  else if (dist < 8193) return 11;
-  else if (dist < 16385) return 12;
-  else return 13;
-#endif
-}
-
-/* Gets value of the extra bits for the given dist, cfr. the DEFLATE spec. */
-static int ZopfliGetDistExtraBitsValue(int dist) {
-#ifdef ZOPFLI_HAS_BUILTIN_CLZ
-  if (dist < 5) {
-    return 0;
-  } else {
-    int l = 31 ^ __builtin_clz(dist - 1); /* log2(dist - 1) */
-    return (dist - (1 + (1 << l))) & ((1 << (l - 1)) - 1);
-  }
-#else
-  if (dist < 5) return 0;
-  else if (dist < 9) return (dist - 5) & 1;
-  else if (dist < 17) return (dist - 9) & 3;
-  else if (dist < 33) return (dist - 17) & 7;
-  else if (dist < 65) return (dist - 33) & 15;
-  else if (dist < 129) return (dist - 65) & 31;
-  else if (dist < 257) return (dist - 129) & 63;
-  else if (dist < 513) return (dist - 257) & 127;
-  else if (dist < 1025) return (dist - 513) & 255;
-  else if (dist < 2049) return (dist - 1025) & 511;
-  else if (dist < 4097) return (dist - 2049) & 1023;
-  else if (dist < 8193) return (dist - 4097) & 2047;
-  else if (dist < 16385) return (dist - 8193) & 4095;
-  else return (dist - 16385) & 8191;
-#endif
-}
-
-/* Gets the symbol for the given dist, cfr. the DEFLATE spec. */
-static int ZopfliGetDistSymbol(int dist) {
-#ifdef ZOPFLI_HAS_BUILTIN_CLZ
-  if (dist < 5) {
-    return dist - 1;
-  } else {
-    int l = (31 ^ __builtin_clz(dist - 1)); /* log2(dist - 1) */
-    int r = ((dist - 1) >> (l - 1)) & 1;
-    return l * 2 + r;
-  }
-#else
-  if (dist < 193) {
-    if (dist < 13) {  /* dist 0..13. */
-      if (dist < 5) return dist - 1;
-      else if (dist < 7) return 4;
-      else if (dist < 9) return 5;
-      else return 6;
-    } else {  /* dist 13..193. */
-      if (dist < 17) return 7;
-      else if (dist < 25) return 8;
-      else if (dist < 33) return 9;
-      else if (dist < 49) return 10;
-      else if (dist < 65) return 11;
-      else if (dist < 97) return 12;
-      else if (dist < 129) return 13;
-      else return 14;
-    }
-  } else {
-    if (dist < 2049) {  /* dist 193..2049. */
-      if (dist < 257) return 15;
-      else if (dist < 385) return 16;
-      else if (dist < 513) return 17;
-      else if (dist < 769) return 18;
-      else if (dist < 1025) return 19;
-      else if (dist < 1537) return 20;
-      else return 21;
-    } else {  /* dist 2049..32768. */
-      if (dist < 3073) return 22;
-      else if (dist < 4097) return 23;
-      else if (dist < 6145) return 24;
-      else if (dist < 8193) return 25;
-      else if (dist < 12289) return 26;
-      else if (dist < 16385) return 27;
-      else if (dist < 24577) return 28;
-      else return 29;
-    }
-  }
-#endif
-}
-
-/* Gets the amount of extra bits for the given length, cfr. the DEFLATE spec. */
-static int ZopfliGetLengthExtraBits(int l) {
-  static const int table[259] = {
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,
-    2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
-    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
-    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
-    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
-    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
-    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
-    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
-    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
-    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
-    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
-    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
-    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
-    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
-    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
-    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 0
-  };
-  return table[l];
-}
-
-/* Gets value of the extra bits for the given length, cfr. the DEFLATE spec. */
-static int ZopfliGetLengthExtraBitsValue(int l) {
-  static const int table[259] = {
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 0,
-    1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5,
-    6, 7, 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6,
-    7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
-    13, 14, 15, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 1, 2,
-    3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
-    10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28,
-    29, 30, 31, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
-    18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 0, 1, 2, 3, 4, 5, 6,
-    7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,
-    27, 28, 29, 30, 31, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
-    16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 0
-  };
-  return table[l];
-}
-
-/*
-Gets the symbol for the given length, cfr. the DEFLATE spec.
-Returns the symbol in the range [257-285] (inclusive)
-*/
-static int ZopfliGetLengthSymbol(int l) {
-  static const int table[259] = {
-    0, 0, 0, 257, 258, 259, 260, 261, 262, 263, 264,
-    265, 265, 266, 266, 267, 267, 268, 268,
-    269, 269, 269, 269, 270, 270, 270, 270,
-    271, 271, 271, 271, 272, 272, 272, 272,
-    273, 273, 273, 273, 273, 273, 273, 273,
-    274, 274, 274, 274, 274, 274, 274, 274,
-    275, 275, 275, 275, 275, 275, 275, 275,
-    276, 276, 276, 276, 276, 276, 276, 276,
-    277, 277, 277, 277, 277, 277, 277, 277,
-    277, 277, 277, 277, 277, 277, 277, 277,
-    278, 278, 278, 278, 278, 278, 278, 278,
-    278, 278, 278, 278, 278, 278, 278, 278,
-    279, 279, 279, 279, 279, 279, 279, 279,
-    279, 279, 279, 279, 279, 279, 279, 279,
-    280, 280, 280, 280, 280, 280, 280, 280,
-    280, 280, 280, 280, 280, 280, 280, 280,
-    281, 281, 281, 281, 281, 281, 281, 281,
-    281, 281, 281, 281, 281, 281, 281, 281,
-    281, 281, 281, 281, 281, 281, 281, 281,
-    281, 281, 281, 281, 281, 281, 281, 281,
-    282, 282, 282, 282, 282, 282, 282, 282,
-    282, 282, 282, 282, 282, 282, 282, 282,
-    282, 282, 282, 282, 282, 282, 282, 282,
-    282, 282, 282, 282, 282, 282, 282, 282,
-    283, 283, 283, 283, 283, 283, 283, 283,
-    283, 283, 283, 283, 283, 283, 283, 283,
-    283, 283, 283, 283, 283, 283, 283, 283,
-    283, 283, 283, 283, 283, 283, 283, 283,
-    284, 284, 284, 284, 284, 284, 284, 284,
-    284, 284, 284, 284, 284, 284, 284, 284,
-    284, 284, 284, 284, 284, 284, 284, 284,
-    284, 284, 284, 284, 284, 284, 284, 285
-  };
-  return table[l];
-}
-
-/* Gets the amount of extra bits for the given length symbol. */
-static int ZopfliGetLengthSymbolExtraBits(int s) {
-  static const int table[29] = {
-    0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
-    3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0
-  };
-  return table[s - 257];
-}
-
-/* Gets the amount of extra bits for the given distance symbol. */
-static int ZopfliGetDistSymbolExtraBits(int s) {
-  static const int table[30] = {
-    0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8,
-    9, 9, 10, 10, 11, 11, 12, 12, 13, 13
-  };
-  return table[s];
-}
-
-#endif  /* ZOPFLI_SYMBOLS_H_ */
diff --git a/src/zopfli/util.c b/src/zopfli/util.c
index 428961c..d207145 100644
--- a/src/zopfli/util.c
+++ b/src/zopfli/util.c
@@ -25,6 +25,184 @@ Author: jyrki.alakuijala@gmail.com (Jyrki Alakuijala)
 #include <stdio.h>
 #include <stdlib.h>
 
+int ZopfliGetDistExtraBits(int dist) {
+#ifdef __GNUC__
+  if (dist < 5) return 0;
+  return (31 ^ __builtin_clz(dist - 1)) - 1; /* log2(dist - 1) - 1 */
+#else
+  if (dist < 5) return 0;
+  else if (dist < 9) return 1;
+  else if (dist < 17) return 2;
+  else if (dist < 33) return 3;
+  else if (dist < 65) return 4;
+  else if (dist < 129) return 5;
+  else if (dist < 257) return 6;
+  else if (dist < 513) return 7;
+  else if (dist < 1025) return 8;
+  else if (dist < 2049) return 9;
+  else if (dist < 4097) return 10;
+  else if (dist < 8193) return 11;
+  else if (dist < 16385) return 12;
+  else return 13;
+#endif
+}
+
+int ZopfliGetDistExtraBitsValue(int dist) {
+#ifdef __GNUC__
+  if (dist < 5) {
+    return 0;
+  } else {
+    int l = 31 ^ __builtin_clz(dist - 1); /* log2(dist - 1) */
+    return (dist - (1 + (1 << l))) & ((1 << (l - 1)) - 1);
+  }
+#else
+  if (dist < 5) return 0;
+  else if (dist < 9) return (dist - 5) & 1;
+  else if (dist < 17) return (dist - 9) & 3;
+  else if (dist < 33) return (dist - 17) & 7;
+  else if (dist < 65) return (dist - 33) & 15;
+  else if (dist < 129) return (dist - 65) & 31;
+  else if (dist < 257) return (dist - 129) & 63;
+  else if (dist < 513) return (dist - 257) & 127;
+  else if (dist < 1025) return (dist - 513) & 255;
+  else if (dist < 2049) return (dist - 1025) & 511;
+  else if (dist < 4097) return (dist - 2049) & 1023;
+  else if (dist < 8193) return (dist - 4097) & 2047;
+  else if (dist < 16385) return (dist - 8193) & 4095;
+  else return (dist - 16385) & 8191;
+#endif
+}
+
+int ZopfliGetDistSymbol(int dist) {
+#ifdef __GNUC__
+  if (dist < 5) {
+    return dist - 1;
+  } else {
+    int l = (31 ^ __builtin_clz(dist - 1)); /* log2(dist - 1) */
+    int r = ((dist - 1) >> (l - 1)) & 1;
+    return l * 2 + r;
+  }
+#else
+  if (dist < 193) {
+    if (dist < 13) {  /* dist 0..13. */
+      if (dist < 5) return dist - 1;
+      else if (dist < 7) return 4;
+      else if (dist < 9) return 5;
+      else return 6;
+    } else {  /* dist 13..193. */
+      if (dist < 17) return 7;
+      else if (dist < 25) return 8;
+      else if (dist < 33) return 9;
+      else if (dist < 49) return 10;
+      else if (dist < 65) return 11;
+      else if (dist < 97) return 12;
+      else if (dist < 129) return 13;
+      else return 14;
+    }
+  } else {
+    if (dist < 2049) {  /* dist 193..2049. */
+      if (dist < 257) return 15;
+      else if (dist < 385) return 16;
+      else if (dist < 513) return 17;
+      else if (dist < 769) return 18;
+      else if (dist < 1025) return 19;
+      else if (dist < 1537) return 20;
+      else return 21;
+    } else {  /* dist 2049..32768. */
+      if (dist < 3073) return 22;
+      else if (dist < 4097) return 23;
+      else if (dist < 6145) return 24;
+      else if (dist < 8193) return 25;
+      else if (dist < 12289) return 26;
+      else if (dist < 16385) return 27;
+      else if (dist < 24577) return 28;
+      else return 29;
+    }
+  }
+#endif
+}
+
+int ZopfliGetLengthExtraBits(int l) {
+  static const int table[259] = {
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,
+    2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 0
+  };
+  return table[l];
+}
+
+int ZopfliGetLengthExtraBitsValue(int l) {
+  static const int table[259] = {
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 0,
+    1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5,
+    6, 7, 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6,
+    7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
+    13, 14, 15, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 1, 2,
+    3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
+    10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28,
+    29, 30, 31, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
+    18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 0, 1, 2, 3, 4, 5, 6,
+    7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,
+    27, 28, 29, 30, 31, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+    16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 0
+  };
+  return table[l];
+}
+
+/*
+Returns symbol in range [257-285] (inclusive).
+*/
+int ZopfliGetLengthSymbol(int l) {
+  static const int table[259] = {
+    0, 0, 0, 257, 258, 259, 260, 261, 262, 263, 264,
+    265, 265, 266, 266, 267, 267, 268, 268,
+    269, 269, 269, 269, 270, 270, 270, 270,
+    271, 271, 271, 271, 272, 272, 272, 272,
+    273, 273, 273, 273, 273, 273, 273, 273,
+    274, 274, 274, 274, 274, 274, 274, 274,
+    275, 275, 275, 275, 275, 275, 275, 275,
+    276, 276, 276, 276, 276, 276, 276, 276,
+    277, 277, 277, 277, 277, 277, 277, 277,
+    277, 277, 277, 277, 277, 277, 277, 277,
+    278, 278, 278, 278, 278, 278, 278, 278,
+    278, 278, 278, 278, 278, 278, 278, 278,
+    279, 279, 279, 279, 279, 279, 279, 279,
+    279, 279, 279, 279, 279, 279, 279, 279,
+    280, 280, 280, 280, 280, 280, 280, 280,
+    280, 280, 280, 280, 280, 280, 280, 280,
+    281, 281, 281, 281, 281, 281, 281, 281,
+    281, 281, 281, 281, 281, 281, 281, 281,
+    281, 281, 281, 281, 281, 281, 281, 281,
+    281, 281, 281, 281, 281, 281, 281, 281,
+    282, 282, 282, 282, 282, 282, 282, 282,
+    282, 282, 282, 282, 282, 282, 282, 282,
+    282, 282, 282, 282, 282, 282, 282, 282,
+    282, 282, 282, 282, 282, 282, 282, 282,
+    283, 283, 283, 283, 283, 283, 283, 283,
+    283, 283, 283, 283, 283, 283, 283, 283,
+    283, 283, 283, 283, 283, 283, 283, 283,
+    283, 283, 283, 283, 283, 283, 283, 283,
+    284, 284, 284, 284, 284, 284, 284, 284,
+    284, 284, 284, 284, 284, 284, 284, 284,
+    284, 284, 284, 284, 284, 284, 284, 284,
+    284, 284, 284, 284, 284, 284, 284, 285
+  };
+  return table[l];
+}
+
 void ZopfliInitOptions(ZopfliOptions* options) {
   options->verbose = 0;
   options->verbose_more = 0;
diff --git a/src/zopfli/util.h b/src/zopfli/util.h
index 4b73504..4188f51 100644
--- a/src/zopfli/util.h
+++ b/src/zopfli/util.h
@@ -32,10 +32,6 @@ basic deflate specification values and generic program options.
 #define ZOPFLI_MAX_MATCH 258
 #define ZOPFLI_MIN_MATCH 3
 
-/* Number of distinct literal/length and distance symbols in DEFLATE */
-#define ZOPFLI_NUM_LL 288
-#define ZOPFLI_NUM_D 32
-
 /*
 The window size for deflate. Must be a power of two. This should be 32768, the
 maximum possible by the deflate spec. Anything less hurts compression more than
@@ -55,9 +51,9 @@ operating on huge files without exceeding memory, such as the 1GB wiki9 corpus.
 The whole compression algorithm, including the smarter block splitting, will
 be executed independently on each huge block.
 Dividing into huge blocks hurts compression, but not much relative to the size.
-Set it to 0 to disable master blocks.
+Set this to, for example, 20MB (20000000). Set it to 0 to disable master blocks.
 */
-#define ZOPFLI_MASTER_BLOCK_SIZE 1000000
+#define ZOPFLI_MASTER_BLOCK_SIZE 20000000
 
 /*
 Used to initialize costs for example
@@ -121,6 +117,27 @@ varies from file to file.
 #define ZOPFLI_LAZY_MATCHING
 
 /*
+Gets the symbol for the given length, cfr. the DEFLATE spec.
+Returns the symbol in the range [257-285] (inclusive)
+*/
+int ZopfliGetLengthSymbol(int l);
+
+/* Gets the amount of extra bits for the given length, cfr. the DEFLATE spec. */
+int ZopfliGetLengthExtraBits(int l);
+
+/* Gets value of the extra bits for the given length, cfr. the DEFLATE spec. */
+int ZopfliGetLengthExtraBitsValue(int l);
+
+/* Gets the symbol for the given dist, cfr. the DEFLATE spec. */
+int ZopfliGetDistSymbol(int dist);
+
+/* Gets the amount of extra bits for the given dist, cfr. the DEFLATE spec. */
+int ZopfliGetDistExtraBits(int dist);
+
+/* Gets value of the extra bits for the given dist, cfr. the DEFLATE spec. */
+int ZopfliGetDistExtraBitsValue(int dist);
+
+/*
 Appends value to dynamically allocated memory, doubling its allocation size
 whenever needed.
 
diff --git a/src/zopfli/zlib_container.c b/src/zopfli/zlib_container.c
index 130ffc7..5b7d0aa 100644
--- a/src/zopfli/zlib_container.c
+++ b/src/zopfli/zlib_container.c
@@ -53,7 +53,7 @@ void ZopfliZlibCompress(const ZopfliOptions* options,
   unsigned char bitpointer = 0;
   unsigned checksum = adler32(in, (unsigned)insize);
   unsigned cmf = 120;  /* CM 8, CINFO 7. See zlib spec.*/
-  unsigned flevel = 3;
+  unsigned flevel = 0;
   unsigned fdict = 0;
   unsigned cmfflg = 256 * cmf + fdict * 32 + flevel * 64;
   unsigned fcheck = 31 - cmfflg % 31;
diff --git a/src/zopfli/zopfli.h b/src/zopfli/zopfli.h
index c079662..56512a2 100644
--- a/src/zopfli/zopfli.h
+++ b/src/zopfli/zopfli.h
@@ -52,7 +52,10 @@ typedef struct ZopfliOptions {
   int blocksplitting;
 
   /*
-  No longer used, left for compatibility.
+  If true, chooses the optimal block split points only after doing the iterative
+  LZ77 compression. If false, chooses the block split points first, then does
+  iterative LZ77 on each individual block. Depending on the file, either first
+  or last gives the best compression. Default: false (0).
   */
   int blocksplittinglast;
 
diff --git a/src/zopfli/zopfli_bin.c b/src/zopfli/zopfli_bin.c
index a42bade..8a147ef 100644
--- a/src/zopfli/zopfli_bin.c
+++ b/src/zopfli/zopfli_bin.c
@@ -33,30 +33,20 @@ decompressor.
 #include "gzip_container.h"
 #include "zlib_container.h"
 
-/* Windows workaround for stdout output. */
-#if _WIN32
-#include <fcntl.h>
-#endif
-
 /*
-Loads a file into a memory array. Returns 1 on success, 0 if file doesn't exist
-or couldn't be opened.
+Loads a file into a memory array.
 */
-static int LoadFile(const char* filename,
-                    unsigned char** out, size_t* outsize) {
+static void LoadFile(const char* filename,
+                     unsigned char** out, size_t* outsize) {
   FILE* file;
 
   *out = 0;
   *outsize = 0;
   file = fopen(filename, "rb");
-  if (!file) return 0;
+  if (!file) return;
 
   fseek(file , 0 , SEEK_END);
   *outsize = ftell(file);
-  if(*outsize > 2147483647) {
-    fprintf(stderr,"Files larger than 2GB are not supported.\n");
-    exit(EXIT_FAILURE);
-  }
   rewind(file);
 
   *out = (unsigned char*)malloc(*outsize);
@@ -68,14 +58,11 @@ static int LoadFile(const char* filename,
       free(*out);
       *out = 0;
       *outsize = 0;
-      fclose(file);
-      return 0;
     }
   }
 
   assert(!(*outsize) || out);  /* If size is not zero, out must be allocated. */
   fclose(file);
-  return 1;
 }
 
 /*
@@ -84,10 +71,6 @@ Saves a file from a memory array, overwriting the file if it existed.
 static void SaveFile(const char* filename,
                      const unsigned char* in, size_t insize) {
   FILE* file = fopen(filename, "wb" );
-  if (file == NULL) {
-      fprintf(stderr,"Error: Cannot write to output file, terminating.\n");
-      exit (EXIT_FAILURE);
-  }
   assert(file);
   fwrite((char*)in, 1, insize, file);
   fclose(file);
@@ -104,7 +87,8 @@ static void CompressFile(const ZopfliOptions* options,
   size_t insize;
   unsigned char* out = 0;
   size_t outsize = 0;
-  if (!LoadFile(infilename, &in, &insize)) {
+  LoadFile(infilename, &in, &insize);
+  if (insize == 0) {
     fprintf(stderr, "Invalid filename: %s\n", infilename);
     return;
   }
@@ -114,11 +98,11 @@ static void CompressFile(const ZopfliOptions* options,
   if (outfilename) {
     SaveFile(outfilename, out, outsize);
   } else {
-#if _WIN32
-    /* Windows workaround for stdout output. */
-    _setmode(_fileno(stdout), _O_BINARY);
-#endif
-    fwrite(out, 1, outsize, stdout);
+    size_t i;
+    for (i = 0; i < outsize; i++) {
+      /* Works only if terminal does not convert newlines. */
+      printf("%c", out[i]);
+    }
   }
 
   free(out);
@@ -159,14 +143,14 @@ int main(int argc, char* argv[]) {
     }
     else if (StringsEqual(arg, "--zlib")) output_type = ZOPFLI_FORMAT_ZLIB;
     else if (StringsEqual(arg, "--gzip")) output_type = ZOPFLI_FORMAT_GZIP;
-    else if (StringsEqual(arg, "--splitlast"))  /* Ignore */;
+    else if (StringsEqual(arg, "--splitlast")) options.blocksplittinglast = 1;
     else if (arg[0] == '-' && arg[1] == '-' && arg[2] == 'i'
         && arg[3] >= '0' && arg[3] <= '9') {
       options.numiterations = atoi(arg + 3);
     }
     else if (StringsEqual(arg, "-h")) {
       fprintf(stderr,
-          "Usage: zopfli [OPTION]... FILE...\n"
+          "Usage: zopfli [OPTION]... FILE\n"
           "  -h    gives this help\n"
           "  -c    write the result on standard output, instead of disk"
           " filename + '.gz'\n"
@@ -178,13 +162,13 @@ int main(int argc, char* argv[]) {
           "  --gzip        output to gzip format (default)\n"
           "  --zlib        output to zlib format instead of gzip\n"
           "  --deflate     output to deflate format instead of gzip\n"
-          "  --splitlast   ignored, left for backwards compatibility\n");
+          "  --splitlast   do block splitting last instead of first\n");
       return 0;
     }
   }
 
   if (options.numiterations < 1) {
-    fprintf(stderr, "Error: must have 1 or more iterations\n");
+    fprintf(stderr, "Error: must have 1 or more iterations");
     return 0;
   }
 
diff --git a/src/zopflipng/lodepng/lodepng.cpp b/src/zopflipng/lodepng/lodepng.cpp
index 51492b8..e4f35d7 100644
--- a/src/zopflipng/lodepng/lodepng.cpp
+++ b/src/zopflipng/lodepng/lodepng.cpp
@@ -1,7 +1,7 @@
 /*
-LodePNG version 20201017
+LodePNG version 20131222
 
-Copyright (c) 2005-2020 Lode Vandevenne
+Copyright (c) 2005-2013 Lode Vandevenne
 
 This software is provided 'as-is', without any express or implied
 warranty. In no event will the authors be held liable for any damages
@@ -30,21 +30,14 @@ Rename this file to lodepng.cpp to use it for C++, or to lodepng.c to use it for
 
 #include "lodepng.h"
 
-#ifdef LODEPNG_COMPILE_DISK
-#include <limits.h> /* LONG_MAX */
-#include <stdio.h> /* file handling */
-#endif /* LODEPNG_COMPILE_DISK */
-
-#ifdef LODEPNG_COMPILE_ALLOCATORS
-#include <stdlib.h> /* allocations */
-#endif /* LODEPNG_COMPILE_ALLOCATORS */
+#include <stdio.h>
+#include <stdlib.h>
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1310) /*Visual Studio: A few warning types are not desired here.*/
-#pragma warning( disable : 4244 ) /*implicit conversions: not warned by gcc -Wall -Wextra and requires too much casts*/
-#pragma warning( disable : 4996 ) /*VS does not like fopen, but fopen_s is not standard C so unusable here*/
-#endif /*_MSC_VER */
+#ifdef LODEPNG_COMPILE_CPP
+#include <fstream>
+#endif /*LODEPNG_COMPILE_CPP*/
 
-const char* LODEPNG_VERSION_STRING = "20201017";
+#define VERSION_STRING "20131222"
 
 /*
 This source file is built up in the following large parts. The code sections
@@ -55,12 +48,6 @@ with the "LODEPNG_COMPILE_" #defines divide this up further in an intermixed way
 -The C++ wrapper around all of the above
 */
 
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* // Tools for C, and common code for PNG and Zlib.                       // */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-
 /*The malloc, realloc and free functions defined here with "lodepng_" in front
 of the name, so that you can easily change them to others related to your
 platform if needed. Everything else in the code calls these. Pass
@@ -71,113 +58,41 @@ lodepng source code. Don't forget to remove "static" if you copypaste them
 from here.*/
 
 #ifdef LODEPNG_COMPILE_ALLOCATORS
-static void* lodepng_malloc(size_t size) {
-#ifdef LODEPNG_MAX_ALLOC
-  if(size > LODEPNG_MAX_ALLOC) return 0;
-#endif
+static void* lodepng_malloc(size_t size)
+{
   return malloc(size);
 }
 
-/* NOTE: when realloc returns NULL, it leaves the original memory untouched */
-static void* lodepng_realloc(void* ptr, size_t new_size) {
-#ifdef LODEPNG_MAX_ALLOC
-  if(new_size > LODEPNG_MAX_ALLOC) return 0;
-#endif
+static void* lodepng_realloc(void* ptr, size_t new_size)
+{
   return realloc(ptr, new_size);
 }
 
-static void lodepng_free(void* ptr) {
+static void lodepng_free(void* ptr)
+{
   free(ptr);
 }
 #else /*LODEPNG_COMPILE_ALLOCATORS*/
-/* TODO: support giving additional void* payload to the custom allocators */
 void* lodepng_malloc(size_t size);
 void* lodepng_realloc(void* ptr, size_t new_size);
 void lodepng_free(void* ptr);
 #endif /*LODEPNG_COMPILE_ALLOCATORS*/
 
-/* convince the compiler to inline a function, for use when this measurably improves performance */
-/* inline is not available in C90, but use it when supported by the compiler */
-#if (defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)) || (defined(__cplusplus) && (__cplusplus >= 199711L))
-#define LODEPNG_INLINE inline
-#else
-#define LODEPNG_INLINE /* not available */
-#endif
-
-/* restrict is not available in C90, but use it when supported by the compiler */
-#if (defined(__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))) ||\
-    (defined(_MSC_VER) && (_MSC_VER >= 1400)) || \
-    (defined(__WATCOMC__) && (__WATCOMC__ >= 1250) && !defined(__cplusplus))
-#define LODEPNG_RESTRICT __restrict
-#else
-#define LODEPNG_RESTRICT /* not available */
-#endif
-
-/* Replacements for C library functions such as memcpy and strlen, to support platforms
-where a full C library is not available. The compiler can recognize them and compile
-to something as fast. */
-
-static void lodepng_memcpy(void* LODEPNG_RESTRICT dst,
-                           const void* LODEPNG_RESTRICT src, size_t size) {
-  size_t i;
-  for(i = 0; i < size; i++) ((char*)dst)[i] = ((const char*)src)[i];
-}
-
-static void lodepng_memset(void* LODEPNG_RESTRICT dst,
-                           int value, size_t num) {
-  size_t i;
-  for(i = 0; i < num; i++) ((char*)dst)[i] = (char)value;
-}
-
-/* does not check memory out of bounds, do not use on untrusted data */
-static size_t lodepng_strlen(const char* a) {
-  const char* orig = a;
-  /* avoid warning about unused function in case of disabled COMPILE... macros */
-  (void)(&lodepng_strlen);
-  while(*a) a++;
-  return (size_t)(a - orig);
-}
-
-#define LODEPNG_MAX(a, b) (((a) > (b)) ? (a) : (b))
-#define LODEPNG_MIN(a, b) (((a) < (b)) ? (a) : (b))
-#define LODEPNG_ABS(x) ((x) < 0 ? -(x) : (x))
-
-#if defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_DECODER)
-/* Safely check if adding two integers will overflow (no undefined
-behavior, compiler removing the code, etc...) and output result. */
-static int lodepng_addofl(size_t a, size_t b, size_t* result) {
-  *result = a + b; /* Unsigned addition is well defined and safe in C90 */
-  return *result < a;
-}
-#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_DECODER)*/
-
-#ifdef LODEPNG_COMPILE_DECODER
-/* Safely check if multiplying two integers will overflow (no undefined
-behavior, compiler removing the code, etc...) and output result. */
-static int lodepng_mulofl(size_t a, size_t b, size_t* result) {
-  *result = a * b; /* Unsigned multiplication is well defined and safe in C90 */
-  return (a != 0 && *result / a != b);
-}
-
-#ifdef LODEPNG_COMPILE_ZLIB
-/* Safely check if a + b > c, even if overflow could happen. */
-static int lodepng_gtofl(size_t a, size_t b, size_t c) {
-  size_t d;
-  if(lodepng_addofl(a, b, &d)) return 1;
-  return d > c;
-}
-#endif /*LODEPNG_COMPILE_ZLIB*/
-#endif /*LODEPNG_COMPILE_DECODER*/
-
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // Tools for C, and common code for PNG and Zlib.                       // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
 
 /*
 Often in case of an error a value is assigned to a variable and then it breaks
 out of a loop (to go to the cleanup phase of a function). This macro does that.
 It makes the error handling code shorter and more readable.
 
-Example: if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83);
+Example: if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83);
 */
-#define CERROR_BREAK(errorvar, code){\
+#define CERROR_BREAK(errorvar, code)\
+{\
   errorvar = code;\
   break;\
 }
@@ -186,23 +101,19 @@ Example: if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83);
 #define ERROR_BREAK(code) CERROR_BREAK(error, code)
 
 /*Set error var to the error code, and return it.*/
-#define CERROR_RETURN_ERROR(errorvar, code){\
+#define CERROR_RETURN_ERROR(errorvar, code)\
+{\
   errorvar = code;\
   return code;\
 }
 
 /*Try the code, if it returns error, also return the error.*/
-#define CERROR_TRY_RETURN(call){\
+#define CERROR_TRY_RETURN(call)\
+{\
   unsigned error = call;\
   if(error) return error;\
 }
 
-/*Set error var to the error code, and return from the void function.*/
-#define CERROR_RETURN(errorvar, code){\
-  errorvar = code;\
-  return;\
-}
-
 /*
 About uivector, ucvector and string:
 -All of them wrap dynamic arrays or text strings in a similar way.
@@ -213,121 +124,207 @@ About uivector, ucvector and string:
 */
 
 #ifdef LODEPNG_COMPILE_ZLIB
-#ifdef LODEPNG_COMPILE_ENCODER
 /*dynamic vector of unsigned ints*/
-typedef struct uivector {
+typedef struct uivector
+{
   unsigned* data;
   size_t size; /*size in number of unsigned longs*/
   size_t allocsize; /*allocated size in bytes*/
 } uivector;
 
-static void uivector_cleanup(void* p) {
+static void uivector_cleanup(void* p)
+{
   ((uivector*)p)->size = ((uivector*)p)->allocsize = 0;
   lodepng_free(((uivector*)p)->data);
   ((uivector*)p)->data = NULL;
 }
 
 /*returns 1 if success, 0 if failure ==> nothing done*/
-static unsigned uivector_resize(uivector* p, size_t size) {
-  size_t allocsize = size * sizeof(unsigned);
-  if(allocsize > p->allocsize) {
-    size_t newsize = allocsize + (p->allocsize >> 1u);
+static unsigned uivector_resize(uivector* p, size_t size)
+{
+  if(size * sizeof(unsigned) > p->allocsize)
+  {
+    size_t newsize = size * sizeof(unsigned) * 2;
     void* data = lodepng_realloc(p->data, newsize);
-    if(data) {
+    if(data)
+    {
       p->allocsize = newsize;
       p->data = (unsigned*)data;
+      p->size = size;
     }
-    else return 0; /*error: not enough memory*/
+    else return 0;
   }
-  p->size = size;
-  return 1; /*success*/
+  else p->size = size;
+  return 1;
+}
+
+/*resize and give all new elements the value*/
+static unsigned uivector_resizev(uivector* p, size_t size, unsigned value)
+{
+  size_t oldsize = p->size, i;
+  if(!uivector_resize(p, size)) return 0;
+  for(i = oldsize; i < size; i++) p->data[i] = value;
+  return 1;
 }
 
-static void uivector_init(uivector* p) {
+static void uivector_init(uivector* p)
+{
   p->data = NULL;
   p->size = p->allocsize = 0;
 }
 
+#ifdef LODEPNG_COMPILE_ENCODER
 /*returns 1 if success, 0 if failure ==> nothing done*/
-static unsigned uivector_push_back(uivector* p, unsigned c) {
+static unsigned uivector_push_back(uivector* p, unsigned c)
+{
   if(!uivector_resize(p, p->size + 1)) return 0;
   p->data[p->size - 1] = c;
   return 1;
 }
+
+/*copy q to p, returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned uivector_copy(uivector* p, const uivector* q)
+{
+  size_t i;
+  if(!uivector_resize(p, q->size)) return 0;
+  for(i = 0; i < q->size; i++) p->data[i] = q->data[i];
+  return 1;
+}
 #endif /*LODEPNG_COMPILE_ENCODER*/
 #endif /*LODEPNG_COMPILE_ZLIB*/
 
 /* /////////////////////////////////////////////////////////////////////////// */
 
 /*dynamic vector of unsigned chars*/
-typedef struct ucvector {
+typedef struct ucvector
+{
   unsigned char* data;
   size_t size; /*used size*/
   size_t allocsize; /*allocated size*/
 } ucvector;
 
 /*returns 1 if success, 0 if failure ==> nothing done*/
-static unsigned ucvector_resize(ucvector* p, size_t size) {
-  if(size > p->allocsize) {
-    size_t newsize = size + (p->allocsize >> 1u);
+static unsigned ucvector_resize(ucvector* p, size_t size)
+{
+  if(size * sizeof(unsigned char) > p->allocsize)
+  {
+    size_t newsize = size * sizeof(unsigned char) * 2;
     void* data = lodepng_realloc(p->data, newsize);
-    if(data) {
+    if(data)
+    {
       p->allocsize = newsize;
       p->data = (unsigned char*)data;
+      p->size = size;
     }
     else return 0; /*error: not enough memory*/
   }
-  p->size = size;
-  return 1; /*success*/
+  else p->size = size;
+  return 1;
 }
 
-static ucvector ucvector_init(unsigned char* buffer, size_t size) {
-  ucvector v;
-  v.data = buffer;
-  v.allocsize = v.size = size;
-  return v;
+#ifdef LODEPNG_COMPILE_PNG
+
+static void ucvector_cleanup(void* p)
+{
+  ((ucvector*)p)->size = ((ucvector*)p)->allocsize = 0;
+  lodepng_free(((ucvector*)p)->data);
+  ((ucvector*)p)->data = NULL;
 }
 
+static void ucvector_init(ucvector* p)
+{
+  p->data = NULL;
+  p->size = p->allocsize = 0;
+}
+
+#ifdef LODEPNG_COMPILE_DECODER
+/*resize and give all new elements the value*/
+static unsigned ucvector_resizev(ucvector* p, size_t size, unsigned char value)
+{
+  size_t oldsize = p->size, i;
+  if(!ucvector_resize(p, size)) return 0;
+  for(i = oldsize; i < size; i++) p->data[i] = value;
+  return 1;
+}
+#endif /*LODEPNG_COMPILE_DECODER*/
+#endif /*LODEPNG_COMPILE_PNG*/
+
+#ifdef LODEPNG_COMPILE_ZLIB
+/*you can both convert from vector to buffer&size and vica versa. If you use
+init_buffer to take over a buffer and size, it is not needed to use cleanup*/
+static void ucvector_init_buffer(ucvector* p, unsigned char* buffer, size_t size)
+{
+  p->data = buffer;
+  p->allocsize = p->size = size;
+}
+#endif /*LODEPNG_COMPILE_ZLIB*/
+
+#if (defined(LODEPNG_COMPILE_PNG) && defined(LODEPNG_COMPILE_ANCILLARY_CHUNKS)) || defined(LODEPNG_COMPILE_ENCODER)
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned ucvector_push_back(ucvector* p, unsigned char c)
+{
+  if(!ucvector_resize(p, p->size + 1)) return 0;
+  p->data[p->size - 1] = c;
+  return 1;
+}
+#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/
+
+
 /* ////////////////////////////////////////////////////////////////////////// */
 
 #ifdef LODEPNG_COMPILE_PNG
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned string_resize(char** out, size_t size)
+{
+  char* data = (char*)lodepng_realloc(*out, size + 1);
+  if(data)
+  {
+    data[size] = 0; /*null termination char*/
+    *out = data;
+  }
+  return data != 0;
+}
 
-/*free string pointer and set it to NULL*/
-static void string_cleanup(char** out) {
-  lodepng_free(*out);
+/*init a {char*, size_t} pair for use as string*/
+static void string_init(char** out)
+{
   *out = NULL;
+  string_resize(out, 0);
 }
 
-/*also appends null termination character*/
-static char* alloc_string_sized(const char* in, size_t insize) {
-  char* out = (char*)lodepng_malloc(insize + 1);
-  if(out) {
-    lodepng_memcpy(out, in, insize);
-    out[insize] = 0;
-  }
-  return out;
+/*free the above pair again*/
+static void string_cleanup(char** out)
+{
+  lodepng_free(*out);
+  *out = NULL;
 }
 
-/* dynamically allocates a new string with a copy of the null terminated input text */
-static char* alloc_string(const char* in) {
-  return alloc_string_sized(in, lodepng_strlen(in));
+static void string_set(char** out, const char* in)
+{
+  size_t insize = strlen(in), i = 0;
+  if(string_resize(out, insize))
+  {
+    for(i = 0; i < insize; i++)
+    {
+      (*out)[i] = in[i];
+    }
+  }
 }
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
 #endif /*LODEPNG_COMPILE_PNG*/
 
 /* ////////////////////////////////////////////////////////////////////////// */
 
-#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_PNG)
-static unsigned lodepng_read32bitInt(const unsigned char* buffer) {
-  return (((unsigned)buffer[0] << 24u) | ((unsigned)buffer[1] << 16u) |
-         ((unsigned)buffer[2] << 8u) | (unsigned)buffer[3]);
+unsigned lodepng_read32bitInt(const unsigned char* buffer)
+{
+  return (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3];
 }
-#endif /*defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_PNG)*/
 
 #if defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)
 /*buffer must have at least 4 allocated bytes available*/
-static void lodepng_set32bitInt(unsigned char* buffer, unsigned value) {
+static void lodepng_set32bitInt(unsigned char* buffer, unsigned value)
+{
   buffer[0] = (unsigned char)((value >> 24) & 0xff);
   buffer[1] = (unsigned char)((value >> 16) & 0xff);
   buffer[2] = (unsigned char)((value >>  8) & 0xff);
@@ -335,63 +332,54 @@ static void lodepng_set32bitInt(unsigned char* buffer, unsigned value) {
 }
 #endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/
 
+#ifdef LODEPNG_COMPILE_ENCODER
+static void lodepng_add32bitInt(ucvector* buffer, unsigned value)
+{
+  ucvector_resize(buffer, buffer->size + 4); /*todo: give error if resize failed*/
+  lodepng_set32bitInt(&buffer->data[buffer->size - 4], value);
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
 /* ////////////////////////////////////////////////////////////////////////// */
 /* / File IO                                                                / */
 /* ////////////////////////////////////////////////////////////////////////// */
 
 #ifdef LODEPNG_COMPILE_DISK
 
-/* returns negative value on error. This should be pure C compatible, so no fstat. */
-static long lodepng_filesize(const char* filename) {
+unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename)
+{
   FILE* file;
   long size;
-  file = fopen(filename, "rb");
-  if(!file) return -1;
-
-  if(fseek(file, 0, SEEK_END) != 0) {
-    fclose(file);
-    return -1;
-  }
-
-  size = ftell(file);
-  /* It may give LONG_MAX as directory size, this is invalid for us. */
-  if(size == LONG_MAX) size = -1;
 
-  fclose(file);
-  return size;
-}
+  /*provide some proper output values if error will happen*/
+  *out = 0;
+  *outsize = 0;
 
-/* load file into buffer that already has the correct allocated size. Returns error code.*/
-static unsigned lodepng_buffer_file(unsigned char* out, size_t size, const char* filename) {
-  FILE* file;
-  size_t readsize;
   file = fopen(filename, "rb");
   if(!file) return 78;
 
-  readsize = fread(out, 1, size, file);
-  fclose(file);
-
-  if(readsize != size) return 78;
-  return 0;
-}
-
-unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename) {
-  long size = lodepng_filesize(filename);
-  if(size < 0) return 78;
-  *outsize = (size_t)size;
+  /*get filesize:*/
+  fseek(file , 0 , SEEK_END);
+  size = ftell(file);
+  rewind(file);
 
+  /*read contents of the file into the vector*/
+  *outsize = 0;
   *out = (unsigned char*)lodepng_malloc((size_t)size);
-  if(!(*out) && size > 0) return 83; /*the above malloc failed*/
+  if(size && (*out)) (*outsize) = fread(*out, 1, (size_t)size, file);
 
-  return lodepng_buffer_file(*out, (size_t)size, filename);
+  fclose(file);
+  if(!(*out) && size) return 83; /*the above malloc failed*/
+  return 0;
 }
 
 /*write given buffer to the file, overwriting the file, it doesn't append to it.*/
-unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename) {
+unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename)
+{
   FILE* file;
   file = fopen(filename, "wb" );
   if(!file) return 79;
-  fwrite(buffer, 1, buffersize, file);
+  fwrite((char*)buffer , 1 , buffersize, file);
   fclose(file);
   return 0;
 }
@@ -406,210 +394,51 @@ unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const
 
 #ifdef LODEPNG_COMPILE_ZLIB
 #ifdef LODEPNG_COMPILE_ENCODER
-
-typedef struct {
-  ucvector* data;
-  unsigned char bp; /*ok to overflow, indicates bit pos inside byte*/
-} LodePNGBitWriter;
-
-static void LodePNGBitWriter_init(LodePNGBitWriter* writer, ucvector* data) {
-  writer->data = data;
-  writer->bp = 0;
+/*TODO: this ignores potential out of memory errors*/
+#define addBitToStream(/*size_t**/ bitpointer, /*ucvector**/ bitstream, /*unsigned char*/ bit)\
+{\
+  /*add a new byte at the end*/\
+  if(((*bitpointer) & 7) == 0) ucvector_push_back(bitstream, (unsigned char)0);\
+  /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/\
+  (bitstream->data[bitstream->size - 1]) |= (bit << ((*bitpointer) & 0x7));\
+  (*bitpointer)++;\
 }
 
-/*TODO: this ignores potential out of memory errors*/
-#define WRITEBIT(writer, bit){\
-  /* append new byte */\
-  if(((writer->bp) & 7u) == 0) {\
-    if(!ucvector_resize(writer->data, writer->data->size + 1)) return;\
-    writer->data->data[writer->data->size - 1] = 0;\
-  }\
-  (writer->data->data[writer->data->size - 1]) |= (bit << ((writer->bp) & 7u));\
-  ++writer->bp;\
-}
-
-/* LSB of value is written first, and LSB of bytes is used first */
-static void writeBits(LodePNGBitWriter* writer, unsigned value, size_t nbits) {
-  if(nbits == 1) { /* compiler should statically compile this case if nbits == 1 */
-    WRITEBIT(writer, value);
-  } else {
-    /* TODO: increase output size only once here rather than in each WRITEBIT */
-    size_t i;
-    for(i = 0; i != nbits; ++i) {
-      WRITEBIT(writer, (unsigned char)((value >> i) & 1));
-    }
-  }
+static void addBitsToStream(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
+{
+  size_t i;
+  for(i = 0; i < nbits; i++) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> i) & 1));
 }
 
-/* This one is to use for adding huffman symbol, the value bits are written MSB first */
-static void writeBitsReversed(LodePNGBitWriter* writer, unsigned value, size_t nbits) {
+static void addBitsToStreamReversed(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
+{
   size_t i;
-  for(i = 0; i != nbits; ++i) {
-    /* TODO: increase output size only once here rather than in each WRITEBIT */
-    WRITEBIT(writer, (unsigned char)((value >> (nbits - 1u - i)) & 1u));
-  }
+  for(i = 0; i < nbits; i++) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> (nbits - 1 - i)) & 1));
 }
 #endif /*LODEPNG_COMPILE_ENCODER*/
 
 #ifdef LODEPNG_COMPILE_DECODER
 
-typedef struct {
-  const unsigned char* data;
-  size_t size; /*size of data in bytes*/
-  size_t bitsize; /*size of data in bits, end of valid bp values, should be 8*size*/
-  size_t bp;
-  unsigned buffer; /*buffer for reading bits. NOTE: 'unsigned' must support at least 32 bits*/
-} LodePNGBitReader;
-
-/* data size argument is in bytes. Returns error if size too large causing overflow */
-static unsigned LodePNGBitReader_init(LodePNGBitReader* reader, const unsigned char* data, size_t size) {
-  size_t temp;
-  reader->data = data;
-  reader->size = size;
-  /* size in bits, return error if overflow (if size_t is 32 bit this supports up to 500MB)  */
-  if(lodepng_mulofl(size, 8u, &reader->bitsize)) return 105;
-  /*ensure incremented bp can be compared to bitsize without overflow even when it would be incremented 32 too much and
-  trying to ensure 32 more bits*/
-  if(lodepng_addofl(reader->bitsize, 64u, &temp)) return 105;
-  reader->bp = 0;
-  reader->buffer = 0;
-  return 0; /*ok*/
-}
-
-/*
-ensureBits functions:
-Ensures the reader can at least read nbits bits in one or more readBits calls,
-safely even if not enough bits are available.
-Returns 1 if there are enough bits available, 0 if not.
-*/
-
-/*See ensureBits documentation above. This one ensures exactly 1 bit */
-/*static unsigned ensureBits1(LodePNGBitReader* reader) {
-  if(reader->bp >= reader->bitsize) return 0;
-  reader->buffer = (unsigned)reader->data[reader->bp >> 3u] >> (reader->bp & 7u);
-  return 1;
-}*/
-
-/*See ensureBits documentation above. This one ensures up to 9 bits */
-static unsigned ensureBits9(LodePNGBitReader* reader, size_t nbits) {
-  size_t start = reader->bp >> 3u;
-  size_t size = reader->size;
-  if(start + 1u < size) {
-    reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u);
-    reader->buffer >>= (reader->bp & 7u);
-    return 1;
-  } else {
-    reader->buffer = 0;
-    if(start + 0u < size) reader->buffer |= reader->data[start + 0];
-    reader->buffer >>= (reader->bp & 7u);
-    return reader->bp + nbits <= reader->bitsize;
-  }
-}
-
-/*See ensureBits documentation above. This one ensures up to 17 bits */
-static unsigned ensureBits17(LodePNGBitReader* reader, size_t nbits) {
-  size_t start = reader->bp >> 3u;
-  size_t size = reader->size;
-  if(start + 2u < size) {
-    reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u) |
-                     ((unsigned)reader->data[start + 2] << 16u);
-    reader->buffer >>= (reader->bp & 7u);
-    return 1;
-  } else {
-    reader->buffer = 0;
-    if(start + 0u < size) reader->buffer |= reader->data[start + 0];
-    if(start + 1u < size) reader->buffer |= ((unsigned)reader->data[start + 1] << 8u);
-    reader->buffer >>= (reader->bp & 7u);
-    return reader->bp + nbits <= reader->bitsize;
-  }
-}
-
-/*See ensureBits documentation above. This one ensures up to 25 bits */
-static LODEPNG_INLINE unsigned ensureBits25(LodePNGBitReader* reader, size_t nbits) {
-  size_t start = reader->bp >> 3u;
-  size_t size = reader->size;
-  if(start + 3u < size) {
-    reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u) |
-                     ((unsigned)reader->data[start + 2] << 16u) | ((unsigned)reader->data[start + 3] << 24u);
-    reader->buffer >>= (reader->bp & 7u);
-    return 1;
-  } else {
-    reader->buffer = 0;
-    if(start + 0u < size) reader->buffer |= reader->data[start + 0];
-    if(start + 1u < size) reader->buffer |= ((unsigned)reader->data[start + 1] << 8u);
-    if(start + 2u < size) reader->buffer |= ((unsigned)reader->data[start + 2] << 16u);
-    reader->buffer >>= (reader->bp & 7u);
-    return reader->bp + nbits <= reader->bitsize;
-  }
-}
-
-/*See ensureBits documentation above. This one ensures up to 32 bits */
-static LODEPNG_INLINE unsigned ensureBits32(LodePNGBitReader* reader, size_t nbits) {
-  size_t start = reader->bp >> 3u;
-  size_t size = reader->size;
-  if(start + 4u < size) {
-    reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u) |
-                     ((unsigned)reader->data[start + 2] << 16u) | ((unsigned)reader->data[start + 3] << 24u);
-    reader->buffer >>= (reader->bp & 7u);
-    reader->buffer |= (((unsigned)reader->data[start + 4] << 24u) << (8u - (reader->bp & 7u)));
-    return 1;
-  } else {
-    reader->buffer = 0;
-    if(start + 0u < size) reader->buffer |= reader->data[start + 0];
-    if(start + 1u < size) reader->buffer |= ((unsigned)reader->data[start + 1] << 8u);
-    if(start + 2u < size) reader->buffer |= ((unsigned)reader->data[start + 2] << 16u);
-    if(start + 3u < size) reader->buffer |= ((unsigned)reader->data[start + 3] << 24u);
-    reader->buffer >>= (reader->bp & 7u);
-    return reader->bp + nbits <= reader->bitsize;
-  }
-}
-
-/* Get bits without advancing the bit pointer. Must have enough bits available with ensureBits. Max nbits is 31. */
-static unsigned peekBits(LodePNGBitReader* reader, size_t nbits) {
-  /* The shift allows nbits to be only up to 31. */
-  return reader->buffer & ((1u << nbits) - 1u);
-}
-
-/* Must have enough bits available with ensureBits */
-static void advanceBits(LodePNGBitReader* reader, size_t nbits) {
-  reader->buffer >>= nbits;
-  reader->bp += nbits;
-}
+#define READBIT(bitpointer, bitstream) ((bitstream[bitpointer >> 3] >> (bitpointer & 0x7)) & (unsigned char)1)
 
-/* Must have enough bits available with ensureBits */
-static unsigned readBits(LodePNGBitReader* reader, size_t nbits) {
-  unsigned result = peekBits(reader, nbits);
-  advanceBits(reader, nbits);
+static unsigned char readBitFromStream(size_t* bitpointer, const unsigned char* bitstream)
+{
+  unsigned char result = (unsigned char)(READBIT(*bitpointer, bitstream));
+  (*bitpointer)++;
   return result;
 }
 
-/* Public for testing only. steps and result must have numsteps values. */
-unsigned lode_png_test_bitreader(const unsigned char* data, size_t size,
-                                 size_t numsteps, const size_t* steps, unsigned* result) {
-  size_t i;
-  LodePNGBitReader reader;
-  unsigned error = LodePNGBitReader_init(&reader, data, size);
-  if(error) return 0;
-  for(i = 0; i < numsteps; i++) {
-    size_t step = steps[i];
-    unsigned ok;
-    if(step > 25) ok = ensureBits32(&reader, step);
-    else if(step > 17) ok = ensureBits25(&reader, step);
-    else if(step > 9) ok = ensureBits17(&reader, step);
-    else ok = ensureBits9(&reader, step);
-    if(!ok) return 0;
-    result[i] = readBits(&reader, step);
+static unsigned readBitsFromStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
+{
+  unsigned result = 0, i;
+  for(i = 0; i < nbits; i++)
+  {
+    result += ((unsigned)READBIT(*bitpointer, bitstream)) << i;
+    (*bitpointer)++;
   }
-  return 1;
-}
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-static unsigned reverseBits(unsigned bits, unsigned num) {
-  /*TODO: implement faster lookup table based version when needed*/
-  unsigned i, result = 0;
-  for(i = 0; i < num; i++) result |= ((bits >> (num - i - 1u)) & 1u) << i;
   return result;
 }
+#endif /*LODEPNG_COMPILE_DECODER*/
 
 /* ////////////////////////////////////////////////////////////////////////// */
 /* / Deflate - Huffman                                                      / */
@@ -644,8 +473,8 @@ static const unsigned DISTANCEEXTRA[30]
   = {0, 0, 0, 0, 1, 1, 2,  2,  3,  3,  4,  4,  5,  5,   6,   6,   7,   7,   8,
        8,    9,    9,   10,   10,   11,   11,   12,    12,    13,    13};
 
-/*the order in which "code length alphabet code lengths" are stored as specified by deflate, out of this the huffman
-tree of the dynamic huffman tree lengths is generated*/
+/*the order in which "code length alphabet code lengths" are stored, out of this
+the huffman tree of the dynamic huffman tree lengths is generated*/
 static const unsigned CLCL_ORDER[NUM_CODE_LENGTH_CODES]
   = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
 
@@ -654,149 +483,97 @@ static const unsigned CLCL_ORDER[NUM_CODE_LENGTH_CODES]
 /*
 Huffman tree struct, containing multiple representations of the tree
 */
-typedef struct HuffmanTree {
-  unsigned* codes; /*the huffman codes (bit patterns representing the symbols)*/
-  unsigned* lengths; /*the lengths of the huffman codes*/
+typedef struct HuffmanTree
+{
+  unsigned* tree2d;
+  unsigned* tree1d;
+  unsigned* lengths; /*the lengths of the codes of the 1d-tree*/
   unsigned maxbitlen; /*maximum number of bits a single code can get*/
   unsigned numcodes; /*number of symbols in the alphabet = number of codes*/
-  /* for reading only */
-  unsigned char* table_len; /*length of symbol from lookup table, or max length if secondary lookup needed*/
-  unsigned short* table_value; /*value of symbol from lookup table, or pointer to secondary table if needed*/
 } HuffmanTree;
 
-static void HuffmanTree_init(HuffmanTree* tree) {
-  tree->codes = 0;
+/*function used for debug purposes to draw the tree in ascii art with C++*/
+/*
+static void HuffmanTree_draw(HuffmanTree* tree)
+{
+  std::cout << "tree. length: " << tree->numcodes << " maxbitlen: " << tree->maxbitlen << std::endl;
+  for(size_t i = 0; i < tree->tree1d.size; i++)
+  {
+    if(tree->lengths.data[i])
+      std::cout << i << " " << tree->tree1d.data[i] << " " << tree->lengths.data[i] << std::endl;
+  }
+  std::cout << std::endl;
+}*/
+
+static void HuffmanTree_init(HuffmanTree* tree)
+{
+  tree->tree2d = 0;
+  tree->tree1d = 0;
   tree->lengths = 0;
-  tree->table_len = 0;
-  tree->table_value = 0;
 }
 
-static void HuffmanTree_cleanup(HuffmanTree* tree) {
-  lodepng_free(tree->codes);
+static void HuffmanTree_cleanup(HuffmanTree* tree)
+{
+  lodepng_free(tree->tree2d);
+  lodepng_free(tree->tree1d);
   lodepng_free(tree->lengths);
-  lodepng_free(tree->table_len);
-  lodepng_free(tree->table_value);
-}
-
-/* amount of bits for first huffman table lookup (aka root bits), see HuffmanTree_makeTable and huffmanDecodeSymbol.*/
-/* values 8u and 9u work the fastest */
-#define FIRSTBITS 9u
-
-/* a symbol value too big to represent any valid symbol, to indicate reading disallowed huffman bits combination,
-which is possible in case of only 0 or 1 present symbols. */
-#define INVALIDSYMBOL 65535u
-
-/* make table for huffman decoding */
-static unsigned HuffmanTree_makeTable(HuffmanTree* tree) {
-  static const unsigned headsize = 1u << FIRSTBITS; /*size of the first table*/
-  static const unsigned mask = (1u << FIRSTBITS) /*headsize*/ - 1u;
-  size_t i, numpresent, pointer, size; /*total table size*/
-  unsigned* maxlens = (unsigned*)lodepng_malloc(headsize * sizeof(unsigned));
-  if(!maxlens) return 83; /*alloc fail*/
-
-  /* compute maxlens: max total bit length of symbols sharing prefix in the first table*/
-  lodepng_memset(maxlens, 0, headsize * sizeof(*maxlens));
-  for(i = 0; i < tree->numcodes; i++) {
-    unsigned symbol = tree->codes[i];
-    unsigned l = tree->lengths[i];
-    unsigned index;
-    if(l <= FIRSTBITS) continue; /*symbols that fit in first table don't increase secondary table size*/
-    /*get the FIRSTBITS MSBs, the MSBs of the symbol are encoded first. See later comment about the reversing*/
-    index = reverseBits(symbol >> (l - FIRSTBITS), FIRSTBITS);
-    maxlens[index] = LODEPNG_MAX(maxlens[index], l);
-  }
-  /* compute total table size: size of first table plus all secondary tables for symbols longer than FIRSTBITS */
-  size = headsize;
-  for(i = 0; i < headsize; ++i) {
-    unsigned l = maxlens[i];
-    if(l > FIRSTBITS) size += (1u << (l - FIRSTBITS));
-  }
-  tree->table_len = (unsigned char*)lodepng_malloc(size * sizeof(*tree->table_len));
-  tree->table_value = (unsigned short*)lodepng_malloc(size * sizeof(*tree->table_value));
-  if(!tree->table_len || !tree->table_value) {
-    lodepng_free(maxlens);
-    /* freeing tree->table values is done at a higher scope */
-    return 83; /*alloc fail*/
-  }
-  /*initialize with an invalid length to indicate unused entries*/
-  for(i = 0; i < size; ++i) tree->table_len[i] = 16;
-
-  /*fill in the first table for long symbols: max prefix size and pointer to secondary tables*/
-  pointer = headsize;
-  for(i = 0; i < headsize; ++i) {
-    unsigned l = maxlens[i];
-    if(l <= FIRSTBITS) continue;
-    tree->table_len[i] = l;
-    tree->table_value[i] = pointer;
-    pointer += (1u << (l - FIRSTBITS));
-  }
-  lodepng_free(maxlens);
-
-  /*fill in the first table for short symbols, or secondary table for long symbols*/
-  numpresent = 0;
-  for(i = 0; i < tree->numcodes; ++i) {
-    unsigned l = tree->lengths[i];
-    unsigned symbol = tree->codes[i]; /*the huffman bit pattern. i itself is the value.*/
-    /*reverse bits, because the huffman bits are given in MSB first order but the bit reader reads LSB first*/
-    unsigned reverse = reverseBits(symbol, l);
-    if(l == 0) continue;
-    numpresent++;
-
-    if(l <= FIRSTBITS) {
-      /*short symbol, fully in first table, replicated num times if l < FIRSTBITS*/
-      unsigned num = 1u << (FIRSTBITS - l);
-      unsigned j;
-      for(j = 0; j < num; ++j) {
-        /*bit reader will read the l bits of symbol first, the remaining FIRSTBITS - l bits go to the MSB's*/
-        unsigned index = reverse | (j << l);
-        if(tree->table_len[index] != 16) return 55; /*invalid tree: long symbol shares prefix with short symbol*/
-        tree->table_len[index] = l;
-        tree->table_value[index] = i;
-      }
-    } else {
-      /*long symbol, shares prefix with other long symbols in first lookup table, needs second lookup*/
-      /*the FIRSTBITS MSBs of the symbol are the first table index*/
-      unsigned index = reverse & mask;
-      unsigned maxlen = tree->table_len[index];
-      /*log2 of secondary table length, should be >= l - FIRSTBITS*/
-      unsigned tablelen = maxlen - FIRSTBITS;
-      unsigned start = tree->table_value[index]; /*starting index in secondary table*/
-      unsigned num = 1u << (tablelen - (l - FIRSTBITS)); /*amount of entries of this symbol in secondary table*/
-      unsigned j;
-      if(maxlen < l) return 55; /*invalid tree: long symbol shares prefix with short symbol*/
-      for(j = 0; j < num; ++j) {
-        unsigned reverse2 = reverse >> FIRSTBITS; /* l - FIRSTBITS bits */
-        unsigned index2 = start + (reverse2 | (j << (l - FIRSTBITS)));
-        tree->table_len[index2] = l;
-        tree->table_value[index2] = i;
+}
+
+/*the tree representation used by the decoder. return value is error*/
+static unsigned HuffmanTree_make2DTree(HuffmanTree* tree)
+{
+  unsigned nodefilled = 0; /*up to which node it is filled*/
+  unsigned treepos = 0; /*position in the tree (1 of the numcodes columns)*/
+  unsigned n, i;
+
+  tree->tree2d = (unsigned*)lodepng_malloc(tree->numcodes * 2 * sizeof(unsigned));
+  if(!tree->tree2d) return 83; /*alloc fail*/
+
+  /*
+  convert tree1d[] to tree2d[][]. In the 2D array, a value of 32767 means
+  uninited, a value >= numcodes is an address to another bit, a value < numcodes
+  is a code. The 2 rows are the 2 possible bit values (0 or 1), there are as
+  many columns as codes - 1.
+  A good huffmann tree has N * 2 - 1 nodes, of which N - 1 are internal nodes.
+  Here, the internal nodes are stored (what their 0 and 1 option point to).
+  There is only memory for such good tree currently, if there are more nodes
+  (due to too long length codes), error 55 will happen
+  */
+  for(n = 0; n < tree->numcodes * 2; n++)
+  {
+    tree->tree2d[n] = 32767; /*32767 here means the tree2d isn't filled there yet*/
+  }
+
+  for(n = 0; n < tree->numcodes; n++) /*the codes*/
+  {
+    for(i = 0; i < tree->lengths[n]; i++) /*the bits for this code*/
+    {
+      unsigned char bit = (unsigned char)((tree->tree1d[n] >> (tree->lengths[n] - i - 1)) & 1);
+      if(treepos > tree->numcodes - 2) return 55; /*oversubscribed, see comment in lodepng_error_text*/
+      if(tree->tree2d[2 * treepos + bit] == 32767) /*not yet filled in*/
+      {
+        if(i + 1 == tree->lengths[n]) /*last bit*/
+        {
+          tree->tree2d[2 * treepos + bit] = n; /*put the current code in it*/
+          treepos = 0;
+        }
+        else
+        {
+          /*put address of the next step in here, first that address has to be found of course
+          (it's just nodefilled + 1)...*/
+          nodefilled++;
+          /*addresses encoded with numcodes added to it*/
+          tree->tree2d[2 * treepos + bit] = nodefilled + tree->numcodes;
+          treepos = nodefilled;
+        }
       }
+      else treepos = tree->tree2d[2 * treepos + bit] - tree->numcodes;
     }
   }
 
-  if(numpresent < 2) {
-    /* In case of exactly 1 symbol, in theory the huffman symbol needs 0 bits,
-    but deflate uses 1 bit instead. In case of 0 symbols, no symbols can
-    appear at all, but such huffman tree could still exist (e.g. if distance
-    codes are never used). In both cases, not all symbols of the table will be
-    filled in. Fill them in with an invalid symbol value so returning them from
-    huffmanDecodeSymbol will cause error. */
-    for(i = 0; i < size; ++i) {
-      if(tree->table_len[i] == 16) {
-        /* As length, use a value smaller than FIRSTBITS for the head table,
-        and a value larger than FIRSTBITS for the secondary table, to ensure
-        valid behavior for advanceBits when reading this symbol. */
-        tree->table_len[i] = (i < headsize) ? 1 : (FIRSTBITS + 1);
-        tree->table_value[i] = INVALIDSYMBOL;
-      }
-    }
-  } else {
-    /* A good huffman tree has N * 2 - 1 nodes, of which N - 1 are internal nodes.
-    If that is not the case (due to too long length codes), the table will not
-    have been fully used, and this is an error (not all bit combinations can be
-    decoded): an oversubscribed huffman tree, indicated by error 55. */
-    for(i = 0; i < size; ++i) {
-      if(tree->table_len[i] == 16) return 55;
-    }
+  for(n = 0; n < tree->numcodes * 2; n++)
+  {
+    if(tree->tree2d[n] == 32767) tree->tree2d[n] = 0; /*remove possible remaining 32767's*/
   }
 
   return 0;
@@ -807,40 +584,43 @@ Second step for the ...makeFromLengths and ...makeFromFrequencies functions.
 numcodes, lengths and maxbitlen must already be filled in correctly. return
 value is error.
 */
-static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree) {
-  unsigned* blcount;
-  unsigned* nextcode;
-  unsigned error = 0;
-  unsigned bits, n;
+static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree)
+{
+  uivector blcount;
+  uivector nextcode;
+  unsigned bits, n, error = 0;
+
+  uivector_init(&blcount);
+  uivector_init(&nextcode);
+
+  tree->tree1d = (unsigned*)lodepng_malloc(tree->numcodes * sizeof(unsigned));
+  if(!tree->tree1d) error = 83; /*alloc fail*/
 
-  tree->codes = (unsigned*)lodepng_malloc(tree->numcodes * sizeof(unsigned));
-  blcount = (unsigned*)lodepng_malloc((tree->maxbitlen + 1) * sizeof(unsigned));
-  nextcode = (unsigned*)lodepng_malloc((tree->maxbitlen + 1) * sizeof(unsigned));
-  if(!tree->codes || !blcount || !nextcode) error = 83; /*alloc fail*/
+  if(!uivector_resizev(&blcount, tree->maxbitlen + 1, 0)
+  || !uivector_resizev(&nextcode, tree->maxbitlen + 1, 0))
+    error = 83; /*alloc fail*/
 
-  if(!error) {
-    for(n = 0; n != tree->maxbitlen + 1; n++) blcount[n] = nextcode[n] = 0;
+  if(!error)
+  {
     /*step 1: count number of instances of each code length*/
-    for(bits = 0; bits != tree->numcodes; ++bits) ++blcount[tree->lengths[bits]];
+    for(bits = 0; bits < tree->numcodes; bits++) blcount.data[tree->lengths[bits]]++;
     /*step 2: generate the nextcode values*/
-    for(bits = 1; bits <= tree->maxbitlen; ++bits) {
-      nextcode[bits] = (nextcode[bits - 1] + blcount[bits - 1]) << 1u;
+    for(bits = 1; bits <= tree->maxbitlen; bits++)
+    {
+      nextcode.data[bits] = (nextcode.data[bits - 1] + blcount.data[bits - 1]) << 1;
     }
     /*step 3: generate all the codes*/
-    for(n = 0; n != tree->numcodes; ++n) {
-      if(tree->lengths[n] != 0) {
-        tree->codes[n] = nextcode[tree->lengths[n]]++;
-        /*remove superfluous bits from the code*/
-        tree->codes[n] &= ((1u << tree->lengths[n]) - 1u);
-      }
+    for(n = 0; n < tree->numcodes; n++)
+    {
+      if(tree->lengths[n] != 0) tree->tree1d[n] = nextcode.data[tree->lengths[n]]++;
     }
   }
 
-  lodepng_free(blcount);
-  lodepng_free(nextcode);
+  uivector_cleanup(&blcount);
+  uivector_cleanup(&nextcode);
 
-  if(!error) error = HuffmanTree_makeTable(tree);
-  return error;
+  if(!error) return HuffmanTree_make2DTree(tree);
+  else return error;
 }
 
 /*
@@ -849,11 +629,12 @@ by Deflate. maxbitlen is the maximum bits that a code in the tree can have.
 return value is error.
 */
 static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* bitlen,
-                                            size_t numcodes, unsigned maxbitlen) {
+                                            size_t numcodes, unsigned maxbitlen)
+{
   unsigned i;
   tree->lengths = (unsigned*)lodepng_malloc(numcodes * sizeof(unsigned));
   if(!tree->lengths) return 83; /*alloc fail*/
-  for(i = 0; i != numcodes; ++i) tree->lengths[i] = bitlen[i];
+  for(i = 0; i < numcodes; i++) tree->lengths[i] = bitlen[i];
   tree->numcodes = (unsigned)numcodes; /*number of symbols*/
   tree->maxbitlen = maxbitlen;
   return HuffmanTree_makeFromLengths2(tree);
@@ -861,214 +642,235 @@ static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* b
 
 #ifdef LODEPNG_COMPILE_ENCODER
 
-/*BPM: Boundary Package Merge, see "A Fast and Space-Economical Algorithm for Length-Limited Coding",
-Jyrki Katajainen, Alistair Moffat, Andrew Turpin, 1995.*/
-
-/*chain node for boundary package merge*/
-typedef struct BPMNode {
-  int weight; /*the sum of all weights in this chain*/
-  unsigned index; /*index of this leaf node (called "count" in the paper)*/
-  struct BPMNode* tail; /*the next nodes in this chain (null if last)*/
-  int in_use;
-} BPMNode;
-
-/*lists of chains*/
-typedef struct BPMLists {
-  /*memory pool*/
-  unsigned memsize;
-  BPMNode* memory;
-  unsigned numfree;
-  unsigned nextfree;
-  BPMNode** freelist;
-  /*two heads of lookahead chains per list*/
-  unsigned listsize;
-  BPMNode** chains0;
-  BPMNode** chains1;
-} BPMLists;
-
-/*creates a new chain node with the given parameters, from the memory in the lists */
-static BPMNode* bpmnode_create(BPMLists* lists, int weight, unsigned index, BPMNode* tail) {
-  unsigned i;
-  BPMNode* result;
+/*
+A coin, this is the terminology used for the package-merge algorithm and the
+coin collector's problem. This is used to generate the huffman tree.
+A coin can be multiple coins (when they're merged)
+*/
+typedef struct Coin
+{
+  uivector symbols;
+  float weight; /*the sum of all weights in this coin*/
+} Coin;
 
-  /*memory full, so garbage collect*/
-  if(lists->nextfree >= lists->numfree) {
-    /*mark only those that are in use*/
-    for(i = 0; i != lists->memsize; ++i) lists->memory[i].in_use = 0;
-    for(i = 0; i != lists->listsize; ++i) {
-      BPMNode* node;
-      for(node = lists->chains0[i]; node != 0; node = node->tail) node->in_use = 1;
-      for(node = lists->chains1[i]; node != 0; node = node->tail) node->in_use = 1;
-    }
-    /*collect those that are free*/
-    lists->numfree = 0;
-    for(i = 0; i != lists->memsize; ++i) {
-      if(!lists->memory[i].in_use) lists->freelist[lists->numfree++] = &lists->memory[i];
-    }
-    lists->nextfree = 0;
-  }
+static void coin_init(Coin* c)
+{
+  uivector_init(&c->symbols);
+}
 
-  result = lists->freelist[lists->nextfree++];
-  result->weight = weight;
-  result->index = index;
-  result->tail = tail;
-  return result;
+/*argument c is void* so that this dtor can be given as function pointer to the vector resize function*/
+static void coin_cleanup(void* c)
+{
+  uivector_cleanup(&((Coin*)c)->symbols);
 }
 
-/*sort the leaves with stable mergesort*/
-static void bpmnode_sort(BPMNode* leaves, size_t num) {
-  BPMNode* mem = (BPMNode*)lodepng_malloc(sizeof(*leaves) * num);
-  size_t width, counter = 0;
-  for(width = 1; width < num; width *= 2) {
-    BPMNode* a = (counter & 1) ? mem : leaves;
-    BPMNode* b = (counter & 1) ? leaves : mem;
-    size_t p;
-    for(p = 0; p < num; p += 2 * width) {
-      size_t q = (p + width > num) ? num : (p + width);
-      size_t r = (p + 2 * width > num) ? num : (p + 2 * width);
-      size_t i = p, j = q, k;
-      for(k = p; k < r; k++) {
-        if(i < q && (j >= r || a[i].weight <= a[j].weight)) b[k] = a[i++];
-        else b[k] = a[j++];
-      }
-    }
-    counter++;
-  }
-  if(counter & 1) lodepng_memcpy(leaves, mem, sizeof(*leaves) * num);
-  lodepng_free(mem);
+static void coin_copy(Coin* c1, const Coin* c2)
+{
+  c1->weight = c2->weight;
+  uivector_copy(&c1->symbols, &c2->symbols);
 }
 
-/*Boundary Package Merge step, numpresent is the amount of leaves, and c is the current chain.*/
-static void boundaryPM(BPMLists* lists, BPMNode* leaves, size_t numpresent, int c, int num) {
-  unsigned lastindex = lists->chains1[c]->index;
+static void add_coins(Coin* c1, const Coin* c2)
+{
+  size_t i;
+  for(i = 0; i < c2->symbols.size; i++) uivector_push_back(&c1->symbols, c2->symbols.data[i]);
+  c1->weight += c2->weight;
+}
 
-  if(c == 0) {
-    if(lastindex >= numpresent) return;
-    lists->chains0[c] = lists->chains1[c];
-    lists->chains1[c] = bpmnode_create(lists, leaves[lastindex].weight, lastindex + 1, 0);
-  } else {
-    /*sum of the weights of the head nodes of the previous lookahead chains.*/
-    int sum = lists->chains0[c - 1]->weight + lists->chains1[c - 1]->weight;
-    lists->chains0[c] = lists->chains1[c];
-    if(lastindex < numpresent && sum > leaves[lastindex].weight) {
-      lists->chains1[c] = bpmnode_create(lists, leaves[lastindex].weight, lastindex + 1, lists->chains1[c]->tail);
-      return;
-    }
-    lists->chains1[c] = bpmnode_create(lists, sum, lastindex, lists->chains1[c - 1]);
-    /*in the end we are only interested in the chain of the last list, so no
-    need to recurse if we're at the last one (this gives measurable speedup)*/
-    if(num + 1 < (int)(2 * numpresent - 2)) {
-      boundaryPM(lists, leaves, numpresent, c - 1, num);
-      boundaryPM(lists, leaves, numpresent, c - 1, num);
+static void init_coins(Coin* coins, size_t num)
+{
+  size_t i;
+  for(i = 0; i < num; i++) coin_init(&coins[i]);
+}
+
+static void cleanup_coins(Coin* coins, size_t num)
+{
+  size_t i;
+  for(i = 0; i < num; i++) coin_cleanup(&coins[i]);
+}
+
+static int coin_compare(const void* a, const void* b) {
+  float wa = ((const Coin*)a)->weight;
+  float wb = ((const Coin*)b)->weight;
+  return wa > wb ? 1 : wa < wb ? -1 : 0;
+}
+
+static unsigned append_symbol_coins(Coin* coins, const unsigned* frequencies, unsigned numcodes, size_t sum)
+{
+  unsigned i;
+  unsigned j = 0; /*index of present symbols*/
+  for(i = 0; i < numcodes; i++)
+  {
+    if(frequencies[i] != 0) /*only include symbols that are present*/
+    {
+      coins[j].weight = frequencies[i] / (float)sum;
+      uivector_push_back(&coins[j].symbols, i);
+      j++;
     }
   }
+  return 0;
 }
 
 unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies,
-                                      size_t numcodes, unsigned maxbitlen) {
+                                      size_t numcodes, unsigned maxbitlen)
+{
+  unsigned i, j;
+  size_t sum = 0, numpresent = 0;
   unsigned error = 0;
-  unsigned i;
-  size_t numpresent = 0; /*number of symbols with non-zero frequency*/
-  BPMNode* leaves; /*the symbols, only those with > 0 frequency*/
+  Coin* coins; /*the coins of the currently calculated row*/
+  Coin* prev_row; /*the previous row of coins*/
+  unsigned numcoins;
+  unsigned coinmem;
 
   if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/
-  if((1u << maxbitlen) < (unsigned)numcodes) return 80; /*error: represent all symbols*/
 
-  leaves = (BPMNode*)lodepng_malloc(numcodes * sizeof(*leaves));
-  if(!leaves) return 83; /*alloc fail*/
-
-  for(i = 0; i != numcodes; ++i) {
-    if(frequencies[i] > 0) {
-      leaves[numpresent].weight = (int)frequencies[i];
-      leaves[numpresent].index = i;
-      ++numpresent;
+  for(i = 0; i < numcodes; i++)
+  {
+    if(frequencies[i] > 0)
+    {
+      numpresent++;
+      sum += frequencies[i];
     }
   }
 
-  lodepng_memset(lengths, 0, numcodes * sizeof(*lengths));
+  for(i = 0; i < numcodes; i++) lengths[i] = 0;
 
   /*ensure at least two present symbols. There should be at least one symbol
-  according to RFC 1951 section 3.2.7. Some decoders incorrectly require two. To
+  according to RFC 1951 section 3.2.7. To decoders incorrectly require two. To
   make these work as well ensure there are at least two symbols. The
   Package-Merge code below also doesn't work correctly if there's only one
-  symbol, it'd give it the theoretical 0 bits but in practice zlib wants 1 bit*/
-  if(numpresent == 0) {
+  symbol, it'd give it the theoritical 0 bits but in practice zlib wants 1 bit*/
+  if(numpresent == 0)
+  {
     lengths[0] = lengths[1] = 1; /*note that for RFC 1951 section 3.2.7, only lengths[0] = 1 is needed*/
-  } else if(numpresent == 1) {
-    lengths[leaves[0].index] = 1;
-    lengths[leaves[0].index == 0 ? 1 : 0] = 1;
-  } else {
-    BPMLists lists;
-    BPMNode* node;
-
-    bpmnode_sort(leaves, numpresent);
-
-    lists.listsize = maxbitlen;
-    lists.memsize = 2 * maxbitlen * (maxbitlen + 1);
-    lists.nextfree = 0;
-    lists.numfree = lists.memsize;
-    lists.memory = (BPMNode*)lodepng_malloc(lists.memsize * sizeof(*lists.memory));
-    lists.freelist = (BPMNode**)lodepng_malloc(lists.memsize * sizeof(BPMNode*));
-    lists.chains0 = (BPMNode**)lodepng_malloc(lists.listsize * sizeof(BPMNode*));
-    lists.chains1 = (BPMNode**)lodepng_malloc(lists.listsize * sizeof(BPMNode*));
-    if(!lists.memory || !lists.freelist || !lists.chains0 || !lists.chains1) error = 83; /*alloc fail*/
-
-    if(!error) {
-      for(i = 0; i != lists.memsize; ++i) lists.freelist[i] = &lists.memory[i];
-
-      bpmnode_create(&lists, leaves[0].weight, 1, 0);
-      bpmnode_create(&lists, leaves[1].weight, 2, 0);
-
-      for(i = 0; i != lists.listsize; ++i) {
-        lists.chains0[i] = &lists.memory[0];
-        lists.chains1[i] = &lists.memory[1];
+  }
+  else if(numpresent == 1)
+  {
+    for(i = 0; i < numcodes; i++)
+    {
+      if(frequencies[i])
+      {
+        lengths[i] = 1;
+        lengths[i == 0 ? 1 : 0] = 1;
+        break;
       }
+    }
+  }
+  else
+  {
+    /*Package-Merge algorithm represented by coin collector's problem
+    For every symbol, maxbitlen coins will be created*/
+
+    coinmem = numpresent * 2; /*max amount of coins needed with the current algo*/
+    coins = (Coin*)lodepng_malloc(sizeof(Coin) * coinmem);
+    prev_row = (Coin*)lodepng_malloc(sizeof(Coin) * coinmem);
+    if(!coins || !prev_row)
+    {
+      lodepng_free(coins);
+      lodepng_free(prev_row);
+      return 83; /*alloc fail*/
+    }
+    init_coins(coins, coinmem);
+    init_coins(prev_row, coinmem);
+
+    /*first row, lowest denominator*/
+    error = append_symbol_coins(coins, frequencies, numcodes, sum);
+    numcoins = numpresent;
+    qsort(coins, numcoins, sizeof(Coin), coin_compare);
+    if(!error)
+    {
+      unsigned numprev = 0;
+      for(j = 1; j <= maxbitlen && !error; j++) /*each of the remaining rows*/
+      {
+        unsigned tempnum;
+        Coin* tempcoins;
+        /*swap prev_row and coins, and their amounts*/
+        tempcoins = prev_row; prev_row = coins; coins = tempcoins;
+        tempnum = numprev; numprev = numcoins; numcoins = tempnum;
+
+        cleanup_coins(coins, numcoins);
+        init_coins(coins, numcoins);
+
+        numcoins = 0;
+
+        /*fill in the merged coins of the previous row*/
+        for(i = 0; i + 1 < numprev; i += 2)
+        {
+          /*merge prev_row[i] and prev_row[i + 1] into new coin*/
+          Coin* coin = &coins[numcoins++];
+          coin_copy(coin, &prev_row[i]);
+          add_coins(coin, &prev_row[i + 1]);
+        }
+        /*fill in all the original symbols again*/
+        if(j < maxbitlen)
+        {
+          error = append_symbol_coins(coins + numcoins, frequencies, numcodes, sum);
+          numcoins += numpresent;
+        }
+        qsort(coins, numcoins, sizeof(Coin), coin_compare);
+      }
+    }
 
-      /*each boundaryPM call adds one chain to the last list, and we need 2 * numpresent - 2 chains.*/
-      for(i = 2; i != 2 * numpresent - 2; ++i) boundaryPM(&lists, leaves, numpresent, (int)maxbitlen - 1, (int)i);
-
-      for(node = lists.chains1[maxbitlen - 1]; node; node = node->tail) {
-        for(i = 0; i != node->index; ++i) ++lengths[leaves[i].index];
+    if(!error)
+    {
+      /*calculate the lenghts of each symbol, as the amount of times a coin of each symbol is used*/
+      for(i = 0; i < numpresent - 1; i++)
+      {
+        Coin* coin = &coins[i];
+        for(j = 0; j < coin->symbols.size; j++) lengths[coin->symbols.data[j]]++;
       }
     }
 
-    lodepng_free(lists.memory);
-    lodepng_free(lists.freelist);
-    lodepng_free(lists.chains0);
-    lodepng_free(lists.chains1);
+    cleanup_coins(coins, coinmem);
+    lodepng_free(coins);
+    cleanup_coins(prev_row, coinmem);
+    lodepng_free(prev_row);
   }
 
-  lodepng_free(leaves);
   return error;
 }
 
 /*Create the Huffman tree given the symbol frequencies*/
 static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigned* frequencies,
-                                                size_t mincodes, size_t numcodes, unsigned maxbitlen) {
+                                                size_t mincodes, size_t numcodes, unsigned maxbitlen)
+{
   unsigned error = 0;
-  while(!frequencies[numcodes - 1] && numcodes > mincodes) --numcodes; /*trim zeroes*/
-  tree->lengths = (unsigned*)lodepng_malloc(numcodes * sizeof(unsigned));
-  if(!tree->lengths) return 83; /*alloc fail*/
+  while(!frequencies[numcodes - 1] && numcodes > mincodes) numcodes--; /*trim zeroes*/
   tree->maxbitlen = maxbitlen;
   tree->numcodes = (unsigned)numcodes; /*number of symbols*/
+  tree->lengths = (unsigned*)lodepng_realloc(tree->lengths, numcodes * sizeof(unsigned));
+  if(!tree->lengths) return 83; /*alloc fail*/
+  /*initialize all lengths to 0*/
+  memset(tree->lengths, 0, numcodes * sizeof(unsigned));
 
   error = lodepng_huffman_code_lengths(tree->lengths, frequencies, numcodes, maxbitlen);
   if(!error) error = HuffmanTree_makeFromLengths2(tree);
   return error;
 }
+
+static unsigned HuffmanTree_getCode(const HuffmanTree* tree, unsigned index)
+{
+  return tree->tree1d[index];
+}
+
+static unsigned HuffmanTree_getLength(const HuffmanTree* tree, unsigned index)
+{
+  return tree->lengths[index];
+}
 #endif /*LODEPNG_COMPILE_ENCODER*/
 
 /*get the literal and length code tree of a deflated block with fixed tree, as per the deflate specification*/
-static unsigned generateFixedLitLenTree(HuffmanTree* tree) {
+static unsigned generateFixedLitLenTree(HuffmanTree* tree)
+{
   unsigned i, error = 0;
   unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned));
   if(!bitlen) return 83; /*alloc fail*/
 
   /*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/
-  for(i =   0; i <= 143; ++i) bitlen[i] = 8;
-  for(i = 144; i <= 255; ++i) bitlen[i] = 9;
-  for(i = 256; i <= 279; ++i) bitlen[i] = 7;
-  for(i = 280; i <= 287; ++i) bitlen[i] = 8;
+  for(i =   0; i <= 143; i++) bitlen[i] = 8;
+  for(i = 144; i <= 255; i++) bitlen[i] = 9;
+  for(i = 256; i <= 279; i++) bitlen[i] = 7;
+  for(i = 280; i <= 287; i++) bitlen[i] = 8;
 
   error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DEFLATE_CODE_SYMBOLS, 15);
 
@@ -1077,13 +879,14 @@ static unsigned generateFixedLitLenTree(HuffmanTree* tree) {
 }
 
 /*get the distance code tree of a deflated block with fixed tree, as specified in the deflate specification*/
-static unsigned generateFixedDistanceTree(HuffmanTree* tree) {
+static unsigned generateFixedDistanceTree(HuffmanTree* tree)
+{
   unsigned i, error = 0;
   unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned));
   if(!bitlen) return 83; /*alloc fail*/
 
   /*there are 32 distance codes, but 30-31 are unused*/
-  for(i = 0; i != NUM_DISTANCE_SYMBOLS; ++i) bitlen[i] = 5;
+  for(i = 0; i < NUM_DISTANCE_SYMBOLS; i++) bitlen[i] = 5;
   error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DISTANCE_SYMBOLS, 15);
 
   lodepng_free(bitlen);
@@ -1093,21 +896,26 @@ static unsigned generateFixedDistanceTree(HuffmanTree* tree) {
 #ifdef LODEPNG_COMPILE_DECODER
 
 /*
-returns the code. The bit reader must already have been ensured at least 15 bits
+returns the code, or (unsigned)(-1) if error happened
+inbitlength is the length of the complete buffer, in bits (so its byte length times 8)
 */
-static unsigned huffmanDecodeSymbol(LodePNGBitReader* reader, const HuffmanTree* codetree) {
-  unsigned short code = peekBits(reader, FIRSTBITS);
-  unsigned short l = codetree->table_len[code];
-  unsigned short value = codetree->table_value[code];
-  if(l <= FIRSTBITS) {
-    advanceBits(reader, l);
-    return value;
-  } else {
-    unsigned index2;
-    advanceBits(reader, FIRSTBITS);
-    index2 = value + peekBits(reader, l - FIRSTBITS);
-    advanceBits(reader, codetree->table_len[index2] - FIRSTBITS);
-    return codetree->table_value[index2];
+static unsigned huffmanDecodeSymbol(const unsigned char* in, size_t* bp,
+                                    const HuffmanTree* codetree, size_t inbitlength)
+{
+  unsigned treepos = 0, ct;
+  for(;;)
+  {
+    if(*bp >= inbitlength) return (unsigned)(-1); /*error: end of input memory reached without endcode*/
+    /*
+    decode the symbol from the tree. The "readBitFromStream" code is inlined in
+    the expression below because this is the biggest bottleneck while decoding
+    */
+    ct = codetree->tree2d[(treepos << 1) + READBIT(*bp, in)];
+    (*bp)++;
+    if(ct < codetree->numcodes) return ct; /*the symbol is decoded, return it*/
+    else treepos = ct - codetree->numcodes; /*symbol not yet decoded, instead move tree position*/
+
+    if(treepos >= codetree->numcodes) return (unsigned)(-1); /*error: it appeared outside the codetree*/
   }
 }
 #endif /*LODEPNG_COMPILE_DECODER*/
@@ -1118,20 +926,22 @@ static unsigned huffmanDecodeSymbol(LodePNGBitReader* reader, const HuffmanTree*
 /* / Inflator (Decompressor)                                                / */
 /* ////////////////////////////////////////////////////////////////////////// */
 
-/*get the tree of a deflated block with fixed tree, as specified in the deflate specification
-Returns error code.*/
-static unsigned getTreeInflateFixed(HuffmanTree* tree_ll, HuffmanTree* tree_d) {
-  unsigned error = generateFixedLitLenTree(tree_ll);
-  if(error) return error;
-  return generateFixedDistanceTree(tree_d);
+/*get the tree of a deflated block with fixed tree, as specified in the deflate specification*/
+static void getTreeInflateFixed(HuffmanTree* tree_ll, HuffmanTree* tree_d)
+{
+  /*TODO: check for out of memory errors*/
+  generateFixedLitLenTree(tree_ll);
+  generateFixedDistanceTree(tree_d);
 }
 
 /*get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed with a known tree*/
 static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d,
-                                      LodePNGBitReader* reader) {
+                                      const unsigned char* in, size_t* bp, size_t inlength)
+{
   /*make sure that length values that aren't filled in will be 0, or a wrong tree will be generated*/
   unsigned error = 0;
   unsigned n, HLIT, HDIST, HCLEN, i;
+  size_t inbitlength = inlength * 8;
 
   /*see comments in deflateDynamic for explanation of the context and these variables, it is analogous*/
   unsigned* bitlen_ll = 0; /*lit,len code lengths*/
@@ -1140,31 +950,28 @@ static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d,
   unsigned* bitlen_cl = 0;
   HuffmanTree tree_cl; /*the code tree for code length codes (the huffman tree for compressed huffman trees)*/
 
-  if(!ensureBits17(reader, 14)) return 49; /*error: the bit pointer is or will go past the memory*/
+  if((*bp) >> 3 >= inlength - 2) return 49; /*error: the bit pointer is or will go past the memory*/
 
   /*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/
-  HLIT =  readBits(reader, 5) + 257;
+  HLIT =  readBitsFromStream(bp, in, 5) + 257;
   /*number of distance codes. Unlike the spec, the value 1 is added to it here already*/
-  HDIST = readBits(reader, 5) + 1;
+  HDIST = readBitsFromStream(bp, in, 5) + 1;
   /*number of code length codes. Unlike the spec, the value 4 is added to it here already*/
-  HCLEN = readBits(reader, 4) + 4;
-
-  bitlen_cl = (unsigned*)lodepng_malloc(NUM_CODE_LENGTH_CODES * sizeof(unsigned));
-  if(!bitlen_cl) return 83 /*alloc fail*/;
+  HCLEN = readBitsFromStream(bp, in, 4) + 4;
 
   HuffmanTree_init(&tree_cl);
 
-  while(!error) {
+  while(!error)
+  {
     /*read the code length codes out of 3 * (amount of code length codes) bits*/
-    if(lodepng_gtofl(reader->bp, HCLEN * 3, reader->bitsize)) {
-      ERROR_BREAK(50); /*error: the bit pointer is or will go past the memory*/
-    }
-    for(i = 0; i != HCLEN; ++i) {
-      ensureBits9(reader, 3); /*out of bounds already checked above */
-      bitlen_cl[CLCL_ORDER[i]] = readBits(reader, 3);
-    }
-    for(i = HCLEN; i != NUM_CODE_LENGTH_CODES; ++i) {
-      bitlen_cl[CLCL_ORDER[i]] = 0;
+
+    bitlen_cl = (unsigned*)lodepng_malloc(NUM_CODE_LENGTH_CODES * sizeof(unsigned));
+    if(!bitlen_cl) ERROR_BREAK(83 /*alloc fail*/);
+
+    for(i = 0; i < NUM_CODE_LENGTH_CODES; i++)
+    {
+      if(i < HCLEN) bitlen_cl[CLCL_ORDER[i]] = readBitsFromStream(bp, in, 3);
+      else bitlen_cl[CLCL_ORDER[i]] = 0; /*if not, it must stay 0*/
     }
 
     error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl, NUM_CODE_LENGTH_CODES, 7);
@@ -1174,69 +981,85 @@ static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d,
     bitlen_ll = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned));
     bitlen_d = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned));
     if(!bitlen_ll || !bitlen_d) ERROR_BREAK(83 /*alloc fail*/);
-    lodepng_memset(bitlen_ll, 0, NUM_DEFLATE_CODE_SYMBOLS * sizeof(*bitlen_ll));
-    lodepng_memset(bitlen_d, 0, NUM_DISTANCE_SYMBOLS * sizeof(*bitlen_d));
+    for(i = 0; i < NUM_DEFLATE_CODE_SYMBOLS; i++) bitlen_ll[i] = 0;
+    for(i = 0; i < NUM_DISTANCE_SYMBOLS; i++) bitlen_d[i] = 0;
 
     /*i is the current symbol we're reading in the part that contains the code lengths of lit/len and dist codes*/
     i = 0;
-    while(i < HLIT + HDIST) {
-      unsigned code;
-      ensureBits25(reader, 22); /* up to 15 bits for huffman code, up to 7 extra bits below*/
-      code = huffmanDecodeSymbol(reader, &tree_cl);
-      if(code <= 15) /*a length code*/ {
+    while(i < HLIT + HDIST)
+    {
+      unsigned code = huffmanDecodeSymbol(in, bp, &tree_cl, inbitlength);
+      if(code <= 15) /*a length code*/
+      {
         if(i < HLIT) bitlen_ll[i] = code;
         else bitlen_d[i - HLIT] = code;
-        ++i;
-      } else if(code == 16) /*repeat previous*/ {
+        i++;
+      }
+      else if(code == 16) /*repeat previous*/
+      {
         unsigned replength = 3; /*read in the 2 bits that indicate repeat length (3-6)*/
         unsigned value; /*set value to the previous code*/
 
-        if(i == 0) ERROR_BREAK(54); /*can't repeat previous if i is 0*/
+        if(*bp >= inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
+        if (i == 0) ERROR_BREAK(54); /*can't repeat previous if i is 0*/
 
-        replength += readBits(reader, 2);
+        replength += readBitsFromStream(bp, in, 2);
 
         if(i < HLIT + 1) value = bitlen_ll[i - 1];
         else value = bitlen_d[i - HLIT - 1];
         /*repeat this value in the next lengths*/
-        for(n = 0; n < replength; ++n) {
+        for(n = 0; n < replength; n++)
+        {
           if(i >= HLIT + HDIST) ERROR_BREAK(13); /*error: i is larger than the amount of codes*/
           if(i < HLIT) bitlen_ll[i] = value;
           else bitlen_d[i - HLIT] = value;
-          ++i;
+          i++;
         }
-      } else if(code == 17) /*repeat "0" 3-10 times*/ {
+      }
+      else if(code == 17) /*repeat "0" 3-10 times*/
+      {
         unsigned replength = 3; /*read in the bits that indicate repeat length*/
-        replength += readBits(reader, 3);
+        if(*bp >= inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
+
+        replength += readBitsFromStream(bp, in, 3);
 
         /*repeat this value in the next lengths*/
-        for(n = 0; n < replength; ++n) {
+        for(n = 0; n < replength; n++)
+        {
           if(i >= HLIT + HDIST) ERROR_BREAK(14); /*error: i is larger than the amount of codes*/
 
           if(i < HLIT) bitlen_ll[i] = 0;
           else bitlen_d[i - HLIT] = 0;
-          ++i;
+          i++;
         }
-      } else if(code == 18) /*repeat "0" 11-138 times*/ {
+      }
+      else if(code == 18) /*repeat "0" 11-138 times*/
+      {
         unsigned replength = 11; /*read in the bits that indicate repeat length*/
-        replength += readBits(reader, 7);
+        if(*bp >= inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
+
+        replength += readBitsFromStream(bp, in, 7);
 
         /*repeat this value in the next lengths*/
-        for(n = 0; n < replength; ++n) {
+        for(n = 0; n < replength; n++)
+        {
           if(i >= HLIT + HDIST) ERROR_BREAK(15); /*error: i is larger than the amount of codes*/
 
           if(i < HLIT) bitlen_ll[i] = 0;
           else bitlen_d[i - HLIT] = 0;
-          ++i;
+          i++;
         }
-      } else /*if(code == INVALIDSYMBOL)*/ {
-        ERROR_BREAK(16); /*error: tried to read disallowed huffman symbol*/
       }
-      /*check if any of the ensureBits above went out of bounds*/
-      if(reader->bp > reader->bitsize) {
-        /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
-        (10=no endcode, 11=wrong jump outside of tree)*/
-        /* TODO: revise error codes 10,11,50: the above comment is no longer valid */
-        ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
+      else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
+      {
+        if(code == (unsigned)(-1))
+        {
+          /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
+          (10=no endcode, 11=wrong jump outside of tree)*/
+          error = (*bp) > inbitlength ? 10 : 11;
+        }
+        else error = 16; /*unexisting code, this can never happen*/
+        break;
       }
     }
     if(error) break;
@@ -1259,91 +1082,98 @@ static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d,
   return error;
 }
 
-/*inflate a block with dynamic of fixed Huffman tree. btype must be 1 or 2.*/
-static unsigned inflateHuffmanBlock(ucvector* out, LodePNGBitReader* reader,
-                                    unsigned btype, size_t max_output_size) {
+/*inflate a block with dynamic of fixed Huffman tree*/
+static unsigned inflateHuffmanBlock(ucvector* out, const unsigned char* in, size_t* bp,
+                                    size_t* pos, size_t inlength, unsigned btype)
+{
   unsigned error = 0;
   HuffmanTree tree_ll; /*the huffman tree for literal and length codes*/
   HuffmanTree tree_d; /*the huffman tree for distance codes*/
+  size_t inbitlength = inlength * 8;
 
   HuffmanTree_init(&tree_ll);
   HuffmanTree_init(&tree_d);
 
-  if(btype == 1) error = getTreeInflateFixed(&tree_ll, &tree_d);
-  else /*if(btype == 2)*/ error = getTreeInflateDynamic(&tree_ll, &tree_d, reader);
+  if(btype == 1) getTreeInflateFixed(&tree_ll, &tree_d);
+  else if(btype == 2) error = getTreeInflateDynamic(&tree_ll, &tree_d, in, bp, inlength);
 
-  while(!error) /*decode all symbols until end reached, breaks at end code*/ {
+  while(!error) /*decode all symbols until end reached, breaks at end code*/
+  {
     /*code_ll is literal, length or end code*/
-    unsigned code_ll;
-    ensureBits25(reader, 20); /* up to 15 for the huffman symbol, up to 5 for the length extra bits */
-    code_ll = huffmanDecodeSymbol(reader, &tree_ll);
-    if(code_ll <= 255) /*literal symbol*/ {
-      if(!ucvector_resize(out, out->size + 1)) ERROR_BREAK(83 /*alloc fail*/);
-      out->data[out->size - 1] = (unsigned char)code_ll;
-    } else if(code_ll >= FIRST_LENGTH_CODE_INDEX && code_ll <= LAST_LENGTH_CODE_INDEX) /*length code*/ {
+    unsigned code_ll = huffmanDecodeSymbol(in, bp, &tree_ll, inbitlength);
+    if(code_ll <= 255) /*literal symbol*/
+    {
+      if((*pos) >= out->size)
+      {
+        /*reserve more room at once*/
+        if(!ucvector_resize(out, ((*pos) + 1) * 2)) ERROR_BREAK(83 /*alloc fail*/);
+      }
+      out->data[(*pos)] = (unsigned char)(code_ll);
+      (*pos)++;
+    }
+    else if(code_ll >= FIRST_LENGTH_CODE_INDEX && code_ll <= LAST_LENGTH_CODE_INDEX) /*length code*/
+    {
       unsigned code_d, distance;
       unsigned numextrabits_l, numextrabits_d; /*extra bits for length and distance*/
-      size_t start, backward, length;
+      size_t start, forward, backward, length;
 
       /*part 1: get length base*/
       length = LENGTHBASE[code_ll - FIRST_LENGTH_CODE_INDEX];
 
       /*part 2: get extra bits and add the value of that to length*/
       numextrabits_l = LENGTHEXTRA[code_ll - FIRST_LENGTH_CODE_INDEX];
-      if(numextrabits_l != 0) {
-        /* bits already ensured above */
-        length += readBits(reader, numextrabits_l);
-      }
+      if(*bp >= inbitlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/
+      length += readBitsFromStream(bp, in, numextrabits_l);
 
       /*part 3: get distance code*/
-      ensureBits32(reader, 28); /* up to 15 for the huffman symbol, up to 13 for the extra bits */
-      code_d = huffmanDecodeSymbol(reader, &tree_d);
-      if(code_d > 29) {
-        if(code_d <= 31) {
-          ERROR_BREAK(18); /*error: invalid distance code (30-31 are never used)*/
-        } else /* if(code_d == INVALIDSYMBOL) */{
-          ERROR_BREAK(16); /*error: tried to read disallowed huffman symbol*/
+      code_d = huffmanDecodeSymbol(in, bp, &tree_d, inbitlength);
+      if(code_d > 29)
+      {
+        if(code_ll == (unsigned)(-1)) /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
+        {
+          /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
+          (10=no endcode, 11=wrong jump outside of tree)*/
+          error = (*bp) > inlength * 8 ? 10 : 11;
         }
+        else error = 18; /*error: invalid distance code (30-31 are never used)*/
+        break;
       }
       distance = DISTANCEBASE[code_d];
 
       /*part 4: get extra bits from distance*/
       numextrabits_d = DISTANCEEXTRA[code_d];
-      if(numextrabits_d != 0) {
-        /* bits already ensured above */
-        distance += readBits(reader, numextrabits_d);
-      }
+      if(*bp >= inbitlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/
+
+      distance += readBitsFromStream(bp, in, numextrabits_d);
 
       /*part 5: fill in all the out[n] values based on the length and dist*/
-      start = out->size;
+      start = (*pos);
       if(distance > start) ERROR_BREAK(52); /*too long backward distance*/
       backward = start - distance;
+      if((*pos) + length >= out->size)
+      {
+        /*reserve more room at once*/
+        if(!ucvector_resize(out, ((*pos) + length) * 2)) ERROR_BREAK(83 /*alloc fail*/);
+      }
 
-      if(!ucvector_resize(out, out->size + length)) ERROR_BREAK(83 /*alloc fail*/);
-      if(distance < length) {
-        size_t forward;
-        lodepng_memcpy(out->data + start, out->data + backward, distance);
-        start += distance;
-        for(forward = distance; forward < length; ++forward) {
-          out->data[start++] = out->data[backward++];
-        }
-      } else {
-        lodepng_memcpy(out->data + start, out->data + backward, length);
+      for(forward = 0; forward < length; forward++)
+      {
+        out->data[(*pos)] = out->data[backward];
+        (*pos)++;
+        backward++;
+        if(backward >= start) backward = start - distance;
       }
-    } else if(code_ll == 256) {
+    }
+    else if(code_ll == 256)
+    {
       break; /*end code, break the loop*/
-    } else /*if(code_ll == INVALIDSYMBOL)*/ {
-      ERROR_BREAK(16); /*error: tried to read disallowed huffman symbol*/
     }
-    /*check if any of the ensureBits above went out of bounds*/
-    if(reader->bp > reader->bitsize) {
+    else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
+    {
       /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
       (10=no endcode, 11=wrong jump outside of tree)*/
-      /* TODO: revise error codes 10,11,50: the above comment is no longer valid */
-      ERROR_BREAK(51); /*error, bit pointer jumps past memory*/
-    }
-    if(max_output_size && out->size > max_output_size) {
-      ERROR_BREAK(109); /*error, larger than max size*/
+      error = (*bp) > inlength * 8 ? 10 : 11;
+      break;
     }
   }
 
@@ -1353,87 +1183,94 @@ static unsigned inflateHuffmanBlock(ucvector* out, LodePNGBitReader* reader,
   return error;
 }
 
-static unsigned inflateNoCompression(ucvector* out, LodePNGBitReader* reader,
-                                     const LodePNGDecompressSettings* settings) {
-  size_t bytepos;
-  size_t size = reader->size;
-  unsigned LEN, NLEN, error = 0;
-
+static unsigned inflateNoCompression(ucvector* out, const unsigned char* in, size_t* bp, size_t* pos, size_t inlength)
+{
   /*go to first boundary of byte*/
-  bytepos = (reader->bp + 7u) >> 3u;
+  size_t p;
+  unsigned LEN, NLEN, n, error = 0;
+  while(((*bp) & 0x7) != 0) (*bp)++;
+  p = (*bp) / 8; /*byte position*/
 
   /*read LEN (2 bytes) and NLEN (2 bytes)*/
-  if(bytepos + 4 >= size) return 52; /*error, bit pointer will jump past memory*/
-  LEN = (unsigned)reader->data[bytepos] + ((unsigned)reader->data[bytepos + 1] << 8u); bytepos += 2;
-  NLEN = (unsigned)reader->data[bytepos] + ((unsigned)reader->data[bytepos + 1] << 8u); bytepos += 2;
+  if(p >= inlength - 4) return 52; /*error, bit pointer will jump past memory*/
+  LEN = in[p] + 256 * in[p + 1]; p += 2;
+  NLEN = in[p] + 256 * in[p + 1]; p += 2;
 
   /*check if 16-bit NLEN is really the one's complement of LEN*/
-  if(!settings->ignore_nlen && LEN + NLEN != 65535) {
-    return 21; /*error: NLEN is not one's complement of LEN*/
-  }
+  if(LEN + NLEN != 65535) return 21; /*error: NLEN is not one's complement of LEN*/
 
-  if(!ucvector_resize(out, out->size + LEN)) return 83; /*alloc fail*/
+  if((*pos) + LEN >= out->size)
+  {
+    if(!ucvector_resize(out, (*pos) + LEN)) return 83; /*alloc fail*/
+  }
 
   /*read the literal data: LEN bytes are now stored in the out buffer*/
-  if(bytepos + LEN > size) return 23; /*error: reading outside of in buffer*/
-
-  lodepng_memcpy(out->data + out->size - LEN, reader->data + bytepos, LEN);
-  bytepos += LEN;
+  if(p + LEN > inlength) return 23; /*error: reading outside of in buffer*/
+  for(n = 0; n < LEN; n++) out->data[(*pos)++] = in[p++];
 
-  reader->bp = bytepos << 3u;
+  (*bp) = p * 8;
 
   return error;
 }
 
 static unsigned lodepng_inflatev(ucvector* out,
                                  const unsigned char* in, size_t insize,
-                                 const LodePNGDecompressSettings* settings) {
+                                 const LodePNGDecompressSettings* settings)
+{
+  /*bit pointer in the "in" data, current byte is bp >> 3, current bit is bp & 0x7 (from lsb to msb of the byte)*/
+  size_t bp = 0;
   unsigned BFINAL = 0;
-  LodePNGBitReader reader;
-  unsigned error = LodePNGBitReader_init(&reader, in, insize);
+  size_t pos = 0; /*byte position in the out buffer*/
 
-  if(error) return error;
+  unsigned error = 0;
+
+  (void)settings;
 
-  while(!BFINAL) {
+  while(!BFINAL)
+  {
     unsigned BTYPE;
-    if(!ensureBits9(&reader, 3)) return 52; /*error, bit pointer will jump past memory*/
-    BFINAL = readBits(&reader, 1);
-    BTYPE = readBits(&reader, 2);
+    if(bp + 2 >= insize * 8) return 52; /*error, bit pointer will jump past memory*/
+    BFINAL = readBitFromStream(&bp, in);
+    BTYPE = 1 * readBitFromStream(&bp, in);
+    BTYPE += 2 * readBitFromStream(&bp, in);
 
     if(BTYPE == 3) return 20; /*error: invalid BTYPE*/
-    else if(BTYPE == 0) error = inflateNoCompression(out, &reader, settings); /*no compression*/
-    else error = inflateHuffmanBlock(out, &reader, BTYPE, settings->max_output_size); /*compression, BTYPE 01 or 10*/
-    if(!error && settings->max_output_size && out->size > settings->max_output_size) error = 109;
-    if(error) break;
+    else if(BTYPE == 0) error = inflateNoCompression(out, in, &bp, &pos, insize); /*no compression*/
+    else error = inflateHuffmanBlock(out, in, &bp, &pos, insize, BTYPE); /*compression, BTYPE 01 or 10*/
+
+    if(error) return error;
   }
 
+  /*Only now we know the true size of out, resize it to that*/
+  if(!ucvector_resize(out, pos)) error = 83; /*alloc fail*/
+
   return error;
 }
 
 unsigned lodepng_inflate(unsigned char** out, size_t* outsize,
                          const unsigned char* in, size_t insize,
-                         const LodePNGDecompressSettings* settings) {
-  ucvector v = ucvector_init(*out, *outsize);
-  unsigned error = lodepng_inflatev(&v, in, insize, settings);
+                         const LodePNGDecompressSettings* settings)
+{
+  unsigned error;
+  ucvector v;
+  ucvector_init_buffer(&v, *out, *outsize);
+  error = lodepng_inflatev(&v, in, insize, settings);
   *out = v.data;
   *outsize = v.size;
   return error;
 }
 
-static unsigned inflatev(ucvector* out, const unsigned char* in, size_t insize,
-                        const LodePNGDecompressSettings* settings) {
-  if(settings->custom_inflate) {
-    unsigned error = settings->custom_inflate(&out->data, &out->size, in, insize, settings);
-    out->allocsize = out->size;
-    if(error) {
-      /*the custom inflate is allowed to have its own error codes, however, we translate it to code 110*/
-      error = 110;
-      /*if there's a max output size, and the custom zlib returned error, then indicate that error instead*/
-      if(settings->max_output_size && out->size > settings->max_output_size) error = 109;
-    }
-    return error;
-  } else {
-    return lodepng_inflatev(out, in, insize, settings);
+static unsigned inflate(unsigned char** out, size_t* outsize,
+                        const unsigned char* in, size_t insize,
+                        const LodePNGDecompressSettings* settings)
+{
+  if(settings->custom_inflate)
+  {
+    return settings->custom_inflate(out, outsize, in, insize, settings);
+  }
+  else
+  {
+    return lodepng_inflate(out, outsize, in, insize, settings);
   }
 }
 
@@ -1447,23 +1284,35 @@ static unsigned inflatev(ucvector* out, const unsigned char* in, size_t insize,
 
 static const size_t MAX_SUPPORTED_DEFLATE_LENGTH = 258;
 
+/*bitlen is the size in bits of the code*/
+static void addHuffmanSymbol(size_t* bp, ucvector* compressed, unsigned code, unsigned bitlen)
+{
+  addBitsToStreamReversed(bp, compressed, code, bitlen);
+}
+
 /*search the index in the array, that has the largest value smaller than or equal to the given value,
 given array must be sorted (if no value is smaller, it returns the size of the given array)*/
-static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t value) {
-  /*binary search (only small gain over linear). TODO: use CPU log2 instruction for getting symbols instead*/
-  size_t left = 1;
+static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t value)
+{
+  /*linear search implementation*/
+  /*for(size_t i = 1; i < array_size; i++) if(array[i] > value) return i - 1;
+  return array_size - 1;*/
+
+  /*binary search implementation (not that much faster) (precondition: array_size > 0)*/
+  size_t left  = 1;
   size_t right = array_size - 1;
-
-  while(left <= right) {
-    size_t mid = (left + right) >> 1;
-    if(array[mid] >= value) right = mid - 1;
-    else left = mid + 1;
+  while(left <= right)
+  {
+    size_t mid = (left + right) / 2;
+    if(array[mid] <= value) left = mid + 1; /*the value to find is more to the right*/
+    else if(array[mid - 1] > value) right = mid - 1; /*the value to find is more to the left*/
+    else return mid - 1;
   }
-  if(left >= array_size || array[left] > value) left--;
-  return left;
+  return array_size - 1;
 }
 
-static void addLengthDistance(uivector* values, size_t length, size_t distance) {
+static void addLengthDistance(uivector* values, size_t length, size_t distance)
+{
   /*values in encoded vector are those used by deflate:
   0-255: literal bytes
   256: end
@@ -1475,110 +1324,99 @@ static void addLengthDistance(uivector* values, size_t length, size_t distance)
   unsigned dist_code = (unsigned)searchCodeIndex(DISTANCEBASE, 30, distance);
   unsigned extra_distance = (unsigned)(distance - DISTANCEBASE[dist_code]);
 
-  size_t pos = values->size;
-  /*TODO: return error when this fails (out of memory)*/
-  unsigned ok = uivector_resize(values, values->size + 4);
-  if(ok) {
-    values->data[pos + 0] = length_code + FIRST_LENGTH_CODE_INDEX;
-    values->data[pos + 1] = extra_length;
-    values->data[pos + 2] = dist_code;
-    values->data[pos + 3] = extra_distance;
-  }
+  uivector_push_back(values, length_code + FIRST_LENGTH_CODE_INDEX);
+  uivector_push_back(values, extra_length);
+  uivector_push_back(values, dist_code);
+  uivector_push_back(values, extra_distance);
 }
 
-/*3 bytes of data get encoded into two bytes. The hash cannot use more than 3
-bytes as input because 3 is the minimum match length for deflate*/
+static const unsigned HASH_BIT_MASK = 65535;
 static const unsigned HASH_NUM_VALUES = 65536;
-static const unsigned HASH_BIT_MASK = 65535; /*HASH_NUM_VALUES - 1, but C90 does not like that as initializer*/
+static const unsigned HASH_NUM_CHARACTERS = 3;
+static const unsigned HASH_SHIFT = 2;
+/*
+The HASH_NUM_CHARACTERS value is used to make encoding faster by using longer
+sequences to generate a hash value from the stream bytes. Setting it to 3
+gives exactly the same compression as the brute force method, since deflate's
+run length encoding starts with lengths of 3. Setting it to higher values,
+like 6, can make the encoding faster (not always though!), but will cause the
+encoding to miss any length between 3 and this value, so that the compression
+may be worse (but this can vary too depending on the image, sometimes it is
+even a bit better instead).
+The HASH_NUM_VALUES is the amount of unique possible hash values that
+combinations of bytes can give, the higher it is the more memory is needed, but
+if it's too low the advantage of hashing is gone.
+*/
 
-typedef struct Hash {
-  int* head; /*hash value to head circular pos - can be outdated if went around window*/
+typedef struct Hash
+{
+  int* head; /*hash value to head circular pos*/
+  int* val; /*circular pos to hash value*/
   /*circular pos to prev circular pos*/
   unsigned short* chain;
-  int* val; /*circular pos to hash value*/
-
-  /*TODO: do this not only for zeros but for any repeated byte. However for PNG
-  it's always going to be the zeros that dominate, so not important for PNG*/
-  int* headz; /*similar to head, but for chainz*/
-  unsigned short* chainz; /*those with same amount of zeros*/
-  unsigned short* zeros; /*length of zeros streak, used as a second hash chain*/
+  unsigned short* zeros;
 } Hash;
 
-static unsigned hash_init(Hash* hash, unsigned windowsize) {
+static unsigned hash_init(Hash* hash, unsigned windowsize)
+{
   unsigned i;
   hash->head = (int*)lodepng_malloc(sizeof(int) * HASH_NUM_VALUES);
   hash->val = (int*)lodepng_malloc(sizeof(int) * windowsize);
   hash->chain = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize);
-
   hash->zeros = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize);
-  hash->headz = (int*)lodepng_malloc(sizeof(int) * (MAX_SUPPORTED_DEFLATE_LENGTH + 1));
-  hash->chainz = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize);
 
-  if(!hash->head || !hash->chain || !hash->val  || !hash->headz|| !hash->chainz || !hash->zeros) {
-    return 83; /*alloc fail*/
-  }
+  if(!hash->head || !hash->val || !hash->chain || !hash->zeros) return 83; /*alloc fail*/
 
   /*initialize hash table*/
-  for(i = 0; i != HASH_NUM_VALUES; ++i) hash->head[i] = -1;
-  for(i = 0; i != windowsize; ++i) hash->val[i] = -1;
-  for(i = 0; i != windowsize; ++i) hash->chain[i] = i; /*same value as index indicates uninitialized*/
-
-  for(i = 0; i <= MAX_SUPPORTED_DEFLATE_LENGTH; ++i) hash->headz[i] = -1;
-  for(i = 0; i != windowsize; ++i) hash->chainz[i] = i; /*same value as index indicates uninitialized*/
+  for(i = 0; i < HASH_NUM_VALUES; i++) hash->head[i] = -1;
+  for(i = 0; i < windowsize; i++) hash->val[i] = -1;
+  for(i = 0; i < windowsize; i++) hash->chain[i] = i; /*same value as index indicates uninitialized*/
 
   return 0;
 }
 
-static void hash_cleanup(Hash* hash) {
+static void hash_cleanup(Hash* hash)
+{
   lodepng_free(hash->head);
   lodepng_free(hash->val);
   lodepng_free(hash->chain);
-
   lodepng_free(hash->zeros);
-  lodepng_free(hash->headz);
-  lodepng_free(hash->chainz);
 }
 
-
-
-static unsigned getHash(const unsigned char* data, size_t size, size_t pos) {
+static unsigned getHash(const unsigned char* data, size_t size, size_t pos)
+{
   unsigned result = 0;
-  if(pos + 2 < size) {
-    /*A simple shift and xor hash is used. Since the data of PNGs is dominated
-    by zeroes due to the filters, a better hash does not have a significant
-    effect on speed in traversing the chain, and causes more time spend on
-    calculating the hash.*/
-    result ^= ((unsigned)data[pos + 0] << 0u);
-    result ^= ((unsigned)data[pos + 1] << 4u);
-    result ^= ((unsigned)data[pos + 2] << 8u);
+  if (HASH_NUM_CHARACTERS == 3 && pos + 2 < size) {
+    result ^= (data[pos + 0] << (0 * HASH_SHIFT));
+    result ^= (data[pos + 1] << (1 * HASH_SHIFT));
+    result ^= (data[pos + 2] << (2 * HASH_SHIFT));
   } else {
     size_t amount, i;
     if(pos >= size) return 0;
-    amount = size - pos;
-    for(i = 0; i != amount; ++i) result ^= ((unsigned)data[pos + i] << (i * 8u));
+    amount = HASH_NUM_CHARACTERS;
+    if(pos + amount >= size) amount = size - pos;
+    for(i = 0; i < amount; i++) result ^= (data[pos + i] << (i * HASH_SHIFT));
   }
   return result & HASH_BIT_MASK;
 }
 
-static unsigned countZeros(const unsigned char* data, size_t size, size_t pos) {
+static unsigned countZeros(const unsigned char* data, size_t size, size_t pos)
+{
   const unsigned char* start = data + pos;
   const unsigned char* end = start + MAX_SUPPORTED_DEFLATE_LENGTH;
   if(end > data + size) end = data + size;
   data = start;
-  while(data != end && *data == 0) ++data;
+  while (data != end && *data == 0) data++;
   /*subtracting two addresses returned as 32-bit number (max value is MAX_SUPPORTED_DEFLATE_LENGTH)*/
   return (unsigned)(data - start);
 }
 
 /*wpos = pos & (windowsize - 1)*/
-static void updateHashChain(Hash* hash, size_t wpos, unsigned hashval, unsigned short numzeros) {
-  hash->val[wpos] = (int)hashval;
+static void updateHashChain(Hash* hash, size_t wpos, int hashval)
+{
+  hash->val[wpos] = hashval;
   if(hash->head[hashval] != -1) hash->chain[wpos] = hash->head[hashval];
-  hash->head[hashval] = (int)wpos;
-
-  hash->zeros[wpos] = numzeros;
-  if(hash->headz[numzeros] != -1) hash->chainz[wpos] = hash->headz[numzeros];
-  hash->headz[numzeros] = (int)wpos;
+  hash->head[hashval] = wpos;
 }
 
 /*
@@ -1592,11 +1430,11 @@ this hash technique is one out of several ways to speed this up.
 */
 static unsigned encodeLZ77(uivector* out, Hash* hash,
                            const unsigned char* in, size_t inpos, size_t insize, unsigned windowsize,
-                           unsigned minmatch, unsigned nicematch, unsigned lazymatching) {
-  size_t pos;
-  unsigned i, error = 0;
+                           unsigned minmatch, unsigned nicematch, unsigned lazymatching)
+{
+  unsigned pos, i, error = 0;
   /*for large window lengths, assume the user wants no compression loss. Otherwise, max hash chain length speedup.*/
-  unsigned maxchainlength = windowsize >= 8192 ? windowsize : windowsize / 8u;
+  unsigned maxchainlength = windowsize >= 8192 ? windowsize : windowsize / 8;
   unsigned maxlazymatch = windowsize >= 8192 ? MAX_SUPPORTED_DEFLATE_LENGTH : 64;
 
   unsigned usezeros = 1; /*not sure if setting it to false for windowsize < 8192 is better or worse*/
@@ -1608,66 +1446,75 @@ static unsigned encodeLZ77(uivector* out, Hash* hash,
   unsigned lazylength = 0, lazyoffset = 0;
   unsigned hashval;
   unsigned current_offset, current_length;
-  unsigned prev_offset;
   const unsigned char *lastptr, *foreptr, *backptr;
-  unsigned hashpos;
+  unsigned hashpos, prevpos;
 
-  if(windowsize == 0 || windowsize > 32768) return 60; /*error: windowsize smaller/larger than allowed*/
+  if(windowsize <= 0 || windowsize > 32768) return 60; /*error: windowsize smaller/larger than allowed*/
   if((windowsize & (windowsize - 1)) != 0) return 90; /*error: must be power of two*/
 
   if(nicematch > MAX_SUPPORTED_DEFLATE_LENGTH) nicematch = MAX_SUPPORTED_DEFLATE_LENGTH;
 
-  for(pos = inpos; pos < insize; ++pos) {
+  for(pos = inpos; pos < insize; pos++)
+  {
     size_t wpos = pos & (windowsize - 1); /*position for in 'circular' hash buffers*/
     unsigned chainlength = 0;
 
     hashval = getHash(in, insize, pos);
+    updateHashChain(hash, wpos, hashval);
 
-    if(usezeros && hashval == 0) {
-      if(numzeros == 0) numzeros = countZeros(in, insize, pos);
-      else if(pos + numzeros > insize || in[pos + numzeros - 1] != 0) --numzeros;
-    } else {
+    if(usezeros && hashval == 0)
+    {
+      if (numzeros == 0) numzeros = countZeros(in, insize, pos);
+      else if (pos + numzeros >= insize || in[pos + numzeros - 1] != 0) numzeros--;
+      hash->zeros[wpos] = numzeros;
+    }
+    else
+    {
       numzeros = 0;
     }
 
-    updateHashChain(hash, wpos, hashval, numzeros);
-
     /*the length and offset found for the current position*/
     length = 0;
     offset = 0;
 
-    hashpos = hash->chain[wpos];
+    prevpos = hash->head[hashval];
+    hashpos = hash->chain[prevpos];
 
     lastptr = &in[insize < pos + MAX_SUPPORTED_DEFLATE_LENGTH ? insize : pos + MAX_SUPPORTED_DEFLATE_LENGTH];
 
     /*search for the longest string*/
-    prev_offset = 0;
-    for(;;) {
+    for(;;)
+    {
+      /*stop when went completely around the circular buffer*/
+      if(prevpos < wpos && hashpos > prevpos && hashpos <= wpos) break;
+      if(prevpos > wpos && (hashpos <= wpos || hashpos > prevpos)) break;
       if(chainlength++ >= maxchainlength) break;
-      current_offset = (unsigned)(hashpos <= wpos ? wpos - hashpos : wpos - hashpos + windowsize);
 
-      if(current_offset < prev_offset) break; /*stop when went completely around the circular buffer*/
-      prev_offset = current_offset;
-      if(current_offset > 0) {
+      current_offset = hashpos <= wpos ? wpos - hashpos : wpos - hashpos + windowsize;
+      if(current_offset > 0)
+      {
         /*test the next characters*/
         foreptr = &in[pos];
         backptr = &in[pos - current_offset];
 
         /*common case in PNGs is lots of zeros. Quickly skip over them as a speedup*/
-        if(numzeros >= 3) {
+        if(usezeros && hashval == 0 && hash->val[hashpos] == 0 /*hashval[hashpos] may be out of date*/)
+        {
           unsigned skip = hash->zeros[hashpos];
           if(skip > numzeros) skip = numzeros;
           backptr += skip;
           foreptr += skip;
         }
 
-        while(foreptr != lastptr && *backptr == *foreptr) /*maximum supported length by deflate is max length*/ {
+        while(foreptr != lastptr && *backptr == *foreptr) /*maximum supported length by deflate is max length*/
+        {
           ++backptr;
           ++foreptr;
         }
         current_length = (unsigned)(foreptr - &in[pos]);
 
-        if(current_length > length) {
+        if(current_length > length)
+        {
           length = current_length; /*the longest length*/
           offset = current_offset; /*the offset that is related to this longest length*/
           /*jump out once a length of max length is found (speed gain). This also jumps
@@ -1678,60 +1525,69 @@ static unsigned encodeLZ77(uivector* out, Hash* hash,
 
       if(hashpos == hash->chain[hashpos]) break;
 
-      if(numzeros >= 3 && length > numzeros) {
-        hashpos = hash->chainz[hashpos];
-        if(hash->zeros[hashpos] != numzeros) break;
-      } else {
-        hashpos = hash->chain[hashpos];
-        /*outdated hash value, happens if particular value was not encountered in whole last window*/
-        if(hash->val[hashpos] != (int)hashval) break;
-      }
+      prevpos = hashpos;
+      hashpos = hash->chain[hashpos];
     }
 
-    if(lazymatching) {
-      if(!lazy && length >= 3 && length <= maxlazymatch && length < MAX_SUPPORTED_DEFLATE_LENGTH) {
+    if(lazymatching)
+    {
+      if(!lazy && length >= 3 && length <= maxlazymatch && length < MAX_SUPPORTED_DEFLATE_LENGTH)
+      {
         lazy = 1;
         lazylength = length;
         lazyoffset = offset;
         continue; /*try the next byte*/
       }
-      if(lazy) {
+      if(lazy)
+      {
         lazy = 0;
         if(pos == 0) ERROR_BREAK(81);
-        if(length > lazylength + 1) {
+        if(length > lazylength + 1)
+        {
           /*push the previous character as literal*/
           if(!uivector_push_back(out, in[pos - 1])) ERROR_BREAK(83 /*alloc fail*/);
-        } else {
+        }
+        else
+        {
           length = lazylength;
           offset = lazyoffset;
           hash->head[hashval] = -1; /*the same hashchain update will be done, this ensures no wrong alteration*/
-          hash->headz[numzeros] = -1; /*idem*/
-          --pos;
+          pos--;
         }
       }
     }
     if(length >= 3 && offset > windowsize) ERROR_BREAK(86 /*too big (or overflown negative) offset*/);
 
     /*encode it as length/distance pair or literal value*/
-    if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/ {
+    if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/
+    {
       if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/);
-    } else if(length < minmatch || (length == 3 && offset > 4096)) {
+    }
+    else if(length < minmatch || (length == 3 && offset > 4096))
+    {
       /*compensate for the fact that longer offsets have more extra bits, a
       length of only 3 may be not worth it then*/
       if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/);
-    } else {
+    }
+    else
+    {
       addLengthDistance(out, length, offset);
-      for(i = 1; i < length; ++i) {
-        ++pos;
+      for(i = 1; i < length; i++)
+      {
+        pos++;
         wpos = pos & (windowsize - 1);
         hashval = getHash(in, insize, pos);
-        if(usezeros && hashval == 0) {
-          if(numzeros == 0) numzeros = countZeros(in, insize, pos);
-          else if(pos + numzeros > insize || in[pos + numzeros - 1] != 0) --numzeros;
-        } else {
+        updateHashChain(hash, wpos, hashval);
+        if(usezeros && hashval == 0)
+        {
+          if (numzeros == 0) numzeros = countZeros(in, insize, pos);
+          else if (pos + numzeros >= insize || in[pos + numzeros - 1] != 0) numzeros--;
+          hash->zeros[wpos] = numzeros;
+        }
+        else
+        {
           numzeros = 0;
         }
-        updateHashChain(hash, wpos, hashval, numzeros);
       }
     }
   } /*end of the loop through each character of input*/
@@ -1741,34 +1597,38 @@ static unsigned encodeLZ77(uivector* out, Hash* hash,
 
 /* /////////////////////////////////////////////////////////////////////////// */
 
-static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize) {
+static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize)
+{
   /*non compressed deflate block data: 1 bit BFINAL,2 bits BTYPE,(5 bits): it jumps to start of next byte,
   2 bytes LEN, 2 bytes NLEN, LEN bytes literal DATA*/
 
-  size_t i, numdeflateblocks = (datasize + 65534u) / 65535u;
+  size_t i, j, numdeflateblocks = (datasize + 65534) / 65535;
   unsigned datapos = 0;
-  for(i = 0; i != numdeflateblocks; ++i) {
+  for(i = 0; i < numdeflateblocks; i++)
+  {
     unsigned BFINAL, BTYPE, LEN, NLEN;
     unsigned char firstbyte;
-    size_t pos = out->size;
 
     BFINAL = (i == numdeflateblocks - 1);
     BTYPE = 0;
 
+    firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1) << 1) + ((BTYPE & 2) << 1));
+    ucvector_push_back(out, firstbyte);
+
     LEN = 65535;
-    if(datasize - datapos < 65535u) LEN = (unsigned)datasize - datapos;
+    if(datasize - datapos < 65535) LEN = (unsigned)datasize - datapos;
     NLEN = 65535 - LEN;
 
-    if(!ucvector_resize(out, out->size + LEN + 5)) return 83; /*alloc fail*/
+    ucvector_push_back(out, (unsigned char)(LEN % 256));
+    ucvector_push_back(out, (unsigned char)(LEN / 256));
+    ucvector_push_back(out, (unsigned char)(NLEN % 256));
+    ucvector_push_back(out, (unsigned char)(NLEN / 256));
 
-    firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1u) << 1u) + ((BTYPE & 2u) << 1u));
-    out->data[pos + 0] = firstbyte;
-    out->data[pos + 1] = (unsigned char)(LEN & 255);
-    out->data[pos + 2] = (unsigned char)(LEN >> 8u);
-    out->data[pos + 3] = (unsigned char)(NLEN & 255);
-    out->data[pos + 4] = (unsigned char)(NLEN >> 8u);
-    lodepng_memcpy(out->data + pos + 5, data + datapos, LEN);
-    datapos += LEN;
+    /*Decompressed data*/
+    for(j = 0; j < 65535 && datapos < datasize; j++)
+    {
+      ucvector_push_back(out, data[datapos++]);
+    }
   }
 
   return 0;
@@ -1779,13 +1639,16 @@ write the lz77-encoded data, which has lit, len and dist codes, to compressed st
 tree_ll: the tree for lit and len codes.
 tree_d: the tree for distance codes.
 */
-static void writeLZ77data(LodePNGBitWriter* writer, const uivector* lz77_encoded,
-                          const HuffmanTree* tree_ll, const HuffmanTree* tree_d) {
+static void writeLZ77data(size_t* bp, ucvector* out, const uivector* lz77_encoded,
+                          const HuffmanTree* tree_ll, const HuffmanTree* tree_d)
+{
   size_t i = 0;
-  for(i = 0; i != lz77_encoded->size; ++i) {
+  for(i = 0; i < lz77_encoded->size; i++)
+  {
     unsigned val = lz77_encoded->data[i];
-    writeBitsReversed(writer, tree_ll->codes[val], tree_ll->lengths[val]);
-    if(val > 256) /*for a length code, 3 more things have to be added*/ {
+    addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_ll, val), HuffmanTree_getLength(tree_ll, val));
+    if(val > 256) /*for a length code, 3 more things have to be added*/
+    {
       unsigned length_index = val - FIRST_LENGTH_CODE_INDEX;
       unsigned n_length_extra_bits = LENGTHEXTRA[length_index];
       unsigned length_extra_bits = lz77_encoded->data[++i];
@@ -1796,17 +1659,19 @@ static void writeLZ77data(LodePNGBitWriter* writer, const uivector* lz77_encoded
       unsigned n_distance_extra_bits = DISTANCEEXTRA[distance_index];
       unsigned distance_extra_bits = lz77_encoded->data[++i];
 
-      writeBits(writer, length_extra_bits, n_length_extra_bits);
-      writeBitsReversed(writer, tree_d->codes[distance_code], tree_d->lengths[distance_code]);
-      writeBits(writer, distance_extra_bits, n_distance_extra_bits);
+      addBitsToStream(bp, out, length_extra_bits, n_length_extra_bits);
+      addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_d, distance_code),
+                       HuffmanTree_getLength(tree_d, distance_code));
+      addBitsToStream(bp, out, distance_extra_bits, n_distance_extra_bits);
     }
   }
 }
 
 /*Deflate for a block of type "dynamic", that is, with freely, optimally, created huffman trees*/
-static unsigned deflateDynamic(LodePNGBitWriter* writer, Hash* hash,
+static unsigned deflateDynamic(ucvector* out, size_t* bp, Hash* hash,
                                const unsigned char* data, size_t datapos, size_t dataend,
-                               const LodePNGCompressSettings* settings, unsigned final) {
+                               const LodePNGCompressSettings* settings, int final)
+{
   unsigned error = 0;
 
   /*
@@ -1816,7 +1681,7 @@ static unsigned deflateDynamic(LodePNGBitWriter* writer, Hash* hash,
   another huffman tree is used for the dist values ("d"). These two trees are
   stored using their code lengths, and to compress even more these code lengths
   are also run-length encoded and huffman compressed. This gives a huffman tree
-  of code lengths "cl". The code lengths used to describe this third tree are
+  of code lengths "cl". The code lenghts used to describe this third tree are
   the code length code lengths ("clcl").
   */
 
@@ -1825,140 +1690,159 @@ static unsigned deflateDynamic(LodePNGBitWriter* writer, Hash* hash,
   HuffmanTree tree_ll; /*tree for lit,len values*/
   HuffmanTree tree_d; /*tree for distance codes*/
   HuffmanTree tree_cl; /*tree for encoding the code lengths representing tree_ll and tree_d*/
-  unsigned* frequencies_ll = 0; /*frequency of lit,len codes*/
-  unsigned* frequencies_d = 0; /*frequency of dist codes*/
-  unsigned* frequencies_cl = 0; /*frequency of code length codes*/
-  unsigned* bitlen_lld = 0; /*lit,len,dist code lengths (int bits), literally (without repeat codes).*/
-  unsigned* bitlen_lld_e = 0; /*bitlen_lld encoded with repeat codes (this is a rudimentary run length compression)*/
+  uivector frequencies_ll; /*frequency of lit,len codes*/
+  uivector frequencies_d; /*frequency of dist codes*/
+  uivector frequencies_cl; /*frequency of code length codes*/
+  uivector bitlen_lld; /*lit,len,dist code lenghts (int bits), literally (without repeat codes).*/
+  uivector bitlen_lld_e; /*bitlen_lld encoded with repeat codes (this is a rudemtary run length compression)*/
+  /*bitlen_cl is the code length code lengths ("clcl"). The bit lengths of codes to represent tree_cl
+  (these are written as is in the file, it would be crazy to compress these using yet another huffman
+  tree that needs to be represented by yet another set of code lengths)*/
+  uivector bitlen_cl;
   size_t datasize = dataend - datapos;
 
   /*
-  If we could call "bitlen_cl" the the code length code lengths ("clcl"), that is the bit lengths of codes to represent
-  tree_cl in CLCL_ORDER, then due to the huffman compression of huffman tree representations ("two levels"), there are
-  some analogies:
+  Due to the huffman compression of huffman tree representations ("two levels"), there are some anologies:
   bitlen_lld is to tree_cl what data is to tree_ll and tree_d.
   bitlen_lld_e is to bitlen_lld what lz77_encoded is to data.
   bitlen_cl is to bitlen_lld_e what bitlen_lld is to lz77_encoded.
   */
 
   unsigned BFINAL = final;
-  size_t i;
-  size_t numcodes_ll, numcodes_d, numcodes_lld, numcodes_lld_e, numcodes_cl;
+  size_t numcodes_ll, numcodes_d, i;
   unsigned HLIT, HDIST, HCLEN;
 
   uivector_init(&lz77_encoded);
   HuffmanTree_init(&tree_ll);
   HuffmanTree_init(&tree_d);
   HuffmanTree_init(&tree_cl);
-  /* could fit on stack, but >1KB is on the larger side so allocate instead */
-  frequencies_ll = (unsigned*)lodepng_malloc(286 * sizeof(*frequencies_ll));
-  frequencies_d = (unsigned*)lodepng_malloc(30 * sizeof(*frequencies_d));
-  frequencies_cl = (unsigned*)lodepng_malloc(NUM_CODE_LENGTH_CODES * sizeof(*frequencies_cl));
-
-  if(!frequencies_ll || !frequencies_d || !frequencies_cl) error = 83; /*alloc fail*/
+  uivector_init(&frequencies_ll);
+  uivector_init(&frequencies_d);
+  uivector_init(&frequencies_cl);
+  uivector_init(&bitlen_lld);
+  uivector_init(&bitlen_lld_e);
+  uivector_init(&bitlen_cl);
 
   /*This while loop never loops due to a break at the end, it is here to
   allow breaking out of it to the cleanup phase on error conditions.*/
-  while(!error) {
-    lodepng_memset(frequencies_ll, 0, 286 * sizeof(*frequencies_ll));
-    lodepng_memset(frequencies_d, 0, 30 * sizeof(*frequencies_d));
-    lodepng_memset(frequencies_cl, 0, NUM_CODE_LENGTH_CODES * sizeof(*frequencies_cl));
-
-    if(settings->use_lz77) {
+  while(!error)
+  {
+    if(settings->use_lz77)
+    {
       error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize,
                          settings->minmatch, settings->nicematch, settings->lazymatching);
       if(error) break;
-    } else {
+    }
+    else
+    {
       if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83 /*alloc fail*/);
-      for(i = datapos; i < dataend; ++i) lz77_encoded.data[i - datapos] = data[i]; /*no LZ77, but still will be Huffman compressed*/
+      for(i = datapos; i < dataend; i++) lz77_encoded.data[i] = data[i]; /*no LZ77, but still will be Huffman compressed*/
     }
 
+    if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83 /*alloc fail*/);
+    if(!uivector_resizev(&frequencies_d, 30, 0)) ERROR_BREAK(83 /*alloc fail*/);
+
     /*Count the frequencies of lit, len and dist codes*/
-    for(i = 0; i != lz77_encoded.size; ++i) {
+    for(i = 0; i < lz77_encoded.size; i++)
+    {
       unsigned symbol = lz77_encoded.data[i];
-      ++frequencies_ll[symbol];
-      if(symbol > 256) {
+      frequencies_ll.data[symbol]++;
+      if(symbol > 256)
+      {
         unsigned dist = lz77_encoded.data[i + 2];
-        ++frequencies_d[dist];
+        frequencies_d.data[dist]++;
         i += 3;
       }
     }
-    frequencies_ll[256] = 1; /*there will be exactly 1 end code, at the end of the block*/
+    frequencies_ll.data[256] = 1; /*there will be exactly 1 end code, at the end of the block*/
 
     /*Make both huffman trees, one for the lit and len codes, one for the dist codes*/
-    error = HuffmanTree_makeFromFrequencies(&tree_ll, frequencies_ll, 257, 286, 15);
+    error = HuffmanTree_makeFromFrequencies(&tree_ll, frequencies_ll.data, 257, frequencies_ll.size, 15);
     if(error) break;
     /*2, not 1, is chosen for mincodes: some buggy PNG decoders require at least 2 symbols in the dist tree*/
-    error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d, 2, 30, 15);
+    error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d.data, 2, frequencies_d.size, 15);
     if(error) break;
 
-    numcodes_ll = LODEPNG_MIN(tree_ll.numcodes, 286);
-    numcodes_d = LODEPNG_MIN(tree_d.numcodes, 30);
+    numcodes_ll = tree_ll.numcodes; if(numcodes_ll > 286) numcodes_ll = 286;
+    numcodes_d = tree_d.numcodes; if(numcodes_d > 30) numcodes_d = 30;
     /*store the code lengths of both generated trees in bitlen_lld*/
-    numcodes_lld = numcodes_ll + numcodes_d;
-    bitlen_lld = (unsigned*)lodepng_malloc(numcodes_lld * sizeof(*bitlen_lld));
-    /*numcodes_lld_e never needs more size than bitlen_lld*/
-    bitlen_lld_e = (unsigned*)lodepng_malloc(numcodes_lld * sizeof(*bitlen_lld_e));
-    if(!bitlen_lld || !bitlen_lld_e) ERROR_BREAK(83); /*alloc fail*/
-    numcodes_lld_e = 0;
-
-    for(i = 0; i != numcodes_ll; ++i) bitlen_lld[i] = tree_ll.lengths[i];
-    for(i = 0; i != numcodes_d; ++i) bitlen_lld[numcodes_ll + i] = tree_d.lengths[i];
+    for(i = 0; i < numcodes_ll; i++) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_ll, (unsigned)i));
+    for(i = 0; i < numcodes_d; i++) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_d, (unsigned)i));
 
     /*run-length compress bitlen_ldd into bitlen_lld_e by using repeat codes 16 (copy length 3-6 times),
     17 (3-10 zeroes), 18 (11-138 zeroes)*/
-    for(i = 0; i != numcodes_lld; ++i) {
-      unsigned j = 0; /*amount of repetitions*/
-      while(i + j + 1 < numcodes_lld && bitlen_lld[i + j + 1] == bitlen_lld[i]) ++j;
-
-      if(bitlen_lld[i] == 0 && j >= 2) /*repeat code for zeroes*/ {
-        ++j; /*include the first zero*/
-        if(j <= 10) /*repeat code 17 supports max 10 zeroes*/ {
-          bitlen_lld_e[numcodes_lld_e++] = 17;
-          bitlen_lld_e[numcodes_lld_e++] = j - 3;
-        } else /*repeat code 18 supports max 138 zeroes*/ {
+    for(i = 0; i < (unsigned)bitlen_lld.size; i++)
+    {
+      unsigned j = 0; /*amount of repititions*/
+      while(i + j + 1 < (unsigned)bitlen_lld.size && bitlen_lld.data[i + j + 1] == bitlen_lld.data[i]) j++;
+
+      if(bitlen_lld.data[i] == 0 && j >= 2) /*repeat code for zeroes*/
+      {
+        j++; /*include the first zero*/
+        if(j <= 10) /*repeat code 17 supports max 10 zeroes*/
+        {
+          uivector_push_back(&bitlen_lld_e, 17);
+          uivector_push_back(&bitlen_lld_e, j - 3);
+        }
+        else /*repeat code 18 supports max 138 zeroes*/
+        {
           if(j > 138) j = 138;
-          bitlen_lld_e[numcodes_lld_e++] = 18;
-          bitlen_lld_e[numcodes_lld_e++] = j - 11;
+          uivector_push_back(&bitlen_lld_e, 18);
+          uivector_push_back(&bitlen_lld_e, j - 11);
         }
         i += (j - 1);
-      } else if(j >= 3) /*repeat code for value other than zero*/ {
+      }
+      else if(j >= 3) /*repeat code for value other than zero*/
+      {
         size_t k;
-        unsigned num = j / 6u, rest = j % 6u;
-        bitlen_lld_e[numcodes_lld_e++] = bitlen_lld[i];
-        for(k = 0; k < num; ++k) {
-          bitlen_lld_e[numcodes_lld_e++] = 16;
-          bitlen_lld_e[numcodes_lld_e++] = 6 - 3;
+        unsigned num = j / 6, rest = j % 6;
+        uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]);
+        for(k = 0; k < num; k++)
+        {
+          uivector_push_back(&bitlen_lld_e, 16);
+          uivector_push_back(&bitlen_lld_e, 6 - 3);
         }
-        if(rest >= 3) {
-          bitlen_lld_e[numcodes_lld_e++] = 16;
-          bitlen_lld_e[numcodes_lld_e++] = rest - 3;
+        if(rest >= 3)
+        {
+          uivector_push_back(&bitlen_lld_e, 16);
+          uivector_push_back(&bitlen_lld_e, rest - 3);
         }
         else j -= rest;
         i += j;
-      } else /*too short to benefit from repeat code*/ {
-        bitlen_lld_e[numcodes_lld_e++] = bitlen_lld[i];
+      }
+      else /*too short to benefit from repeat code*/
+      {
+        uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]);
       }
     }
 
     /*generate tree_cl, the huffmantree of huffmantrees*/
-    for(i = 0; i != numcodes_lld_e; ++i) {
-      ++frequencies_cl[bitlen_lld_e[i]];
+
+    if(!uivector_resizev(&frequencies_cl, NUM_CODE_LENGTH_CODES, 0)) ERROR_BREAK(83 /*alloc fail*/);
+    for(i = 0; i < bitlen_lld_e.size; i++)
+    {
+      frequencies_cl.data[bitlen_lld_e.data[i]]++;
       /*after a repeat code come the bits that specify the number of repetitions,
       those don't need to be in the frequencies_cl calculation*/
-      if(bitlen_lld_e[i] >= 16) ++i;
+      if(bitlen_lld_e.data[i] >= 16) i++;
     }
 
-    error = HuffmanTree_makeFromFrequencies(&tree_cl, frequencies_cl,
-                                            NUM_CODE_LENGTH_CODES, NUM_CODE_LENGTH_CODES, 7);
+    error = HuffmanTree_makeFromFrequencies(&tree_cl, frequencies_cl.data,
+                                            frequencies_cl.size, frequencies_cl.size, 7);
     if(error) break;
 
-    /*compute amount of code-length-code-lengths to output*/
-    numcodes_cl = NUM_CODE_LENGTH_CODES;
-    /*trim zeros at the end (using CLCL_ORDER), but minimum size must be 4 (see HCLEN below)*/
-    while(numcodes_cl > 4u && tree_cl.lengths[CLCL_ORDER[numcodes_cl - 1u]] == 0) {
-      numcodes_cl--;
+    if(!uivector_resize(&bitlen_cl, tree_cl.numcodes)) ERROR_BREAK(83 /*alloc fail*/);
+    for(i = 0; i < tree_cl.numcodes; i++)
+    {
+      /*lenghts of code length tree is in the order as specified by deflate*/
+      bitlen_cl.data[i] = HuffmanTree_getLength(&tree_cl, CLCL_ORDER[i]);
+    }
+    while(bitlen_cl.data[bitlen_cl.size - 1] == 0 && bitlen_cl.size > 4)
+    {
+      /*remove zeros at the end, but minimum size must be 4*/
+      if(!uivector_resize(&bitlen_cl, bitlen_cl.size - 1)) ERROR_BREAK(83 /*alloc fail*/);
     }
+    if(error) break;
 
     /*
     Write everything into the output
@@ -1966,7 +1850,7 @@ static unsigned deflateDynamic(LodePNGBitWriter* writer, Hash* hash,
     After the BFINAL and BTYPE, the dynamic block consists out of the following:
     - 5 bits HLIT, 5 bits HDIST, 4 bits HCLEN
     - (HCLEN+4)*3 bits code lengths of code length alphabet
-    - HLIT + 257 code lengths of lit/length alphabet (encoded using the code length
+    - HLIT + 257 code lenghts of lit/length alphabet (encoded using the code length
       alphabet, + possible repetition codes 16, 17, 18)
     - HDIST + 1 code lengths of distance alphabet (encoded using the code length
       alphabet, + possible repetition codes 16, 17, 18)
@@ -1975,39 +1859,41 @@ static unsigned deflateDynamic(LodePNGBitWriter* writer, Hash* hash,
     */
 
     /*Write block type*/
-    writeBits(writer, BFINAL, 1);
-    writeBits(writer, 0, 1); /*first bit of BTYPE "dynamic"*/
-    writeBits(writer, 1, 1); /*second bit of BTYPE "dynamic"*/
+    addBitToStream(bp, out, BFINAL);
+    addBitToStream(bp, out, 0); /*first bit of BTYPE "dynamic"*/
+    addBitToStream(bp, out, 1); /*second bit of BTYPE "dynamic"*/
 
     /*write the HLIT, HDIST and HCLEN values*/
-    /*all three sizes take trimmed ending zeroes into account, done either by HuffmanTree_makeFromFrequencies
-    or in the loop for numcodes_cl above, which saves space. */
     HLIT = (unsigned)(numcodes_ll - 257);
     HDIST = (unsigned)(numcodes_d - 1);
-    HCLEN = (unsigned)(numcodes_cl - 4);
-    writeBits(writer, HLIT, 5);
-    writeBits(writer, HDIST, 5);
-    writeBits(writer, HCLEN, 4);
-
-    /*write the code lengths of the code length alphabet ("bitlen_cl")*/
-    for(i = 0; i != numcodes_cl; ++i) writeBits(writer, tree_cl.lengths[CLCL_ORDER[i]], 3);
-
-    /*write the lengths of the lit/len AND the dist alphabet*/
-    for(i = 0; i != numcodes_lld_e; ++i) {
-      writeBitsReversed(writer, tree_cl.codes[bitlen_lld_e[i]], tree_cl.lengths[bitlen_lld_e[i]]);
+    HCLEN = (unsigned)bitlen_cl.size - 4;
+    /*trim zeroes for HCLEN. HLIT and HDIST were already trimmed at tree creation*/
+    while(!bitlen_cl.data[HCLEN + 4 - 1] && HCLEN > 0) HCLEN--;
+    addBitsToStream(bp, out, HLIT, 5);
+    addBitsToStream(bp, out, HDIST, 5);
+    addBitsToStream(bp, out, HCLEN, 4);
+
+    /*write the code lenghts of the code length alphabet*/
+    for(i = 0; i < HCLEN + 4; i++) addBitsToStream(bp, out, bitlen_cl.data[i], 3);
+
+    /*write the lenghts of the lit/len AND the dist alphabet*/
+    for(i = 0; i < bitlen_lld_e.size; i++)
+    {
+      addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_cl, bitlen_lld_e.data[i]),
+                       HuffmanTree_getLength(&tree_cl, bitlen_lld_e.data[i]));
       /*extra bits of repeat codes*/
-      if(bitlen_lld_e[i] == 16) writeBits(writer, bitlen_lld_e[++i], 2);
-      else if(bitlen_lld_e[i] == 17) writeBits(writer, bitlen_lld_e[++i], 3);
-      else if(bitlen_lld_e[i] == 18) writeBits(writer, bitlen_lld_e[++i], 7);
+      if(bitlen_lld_e.data[i] == 16) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 2);
+      else if(bitlen_lld_e.data[i] == 17) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 3);
+      else if(bitlen_lld_e.data[i] == 18) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 7);
     }
 
     /*write the compressed data symbols*/
-    writeLZ77data(writer, &lz77_encoded, &tree_ll, &tree_d);
+    writeLZ77data(bp, out, &lz77_encoded, &tree_ll, &tree_d);
     /*error: the length of the end code 256 must be larger than 0*/
-    if(tree_ll.lengths[256] == 0) ERROR_BREAK(64);
+    if(HuffmanTree_getLength(&tree_ll, 256) == 0) ERROR_BREAK(64);
 
     /*write the end code*/
-    writeBitsReversed(writer, tree_ll.codes[256], tree_ll.lengths[256]);
+    addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256));
 
     break; /*end of error-while*/
   }
@@ -2017,19 +1903,21 @@ static unsigned deflateDynamic(LodePNGBitWriter* writer, Hash* hash,
   HuffmanTree_cleanup(&tree_ll);
   HuffmanTree_cleanup(&tree_d);
   HuffmanTree_cleanup(&tree_cl);
-  lodepng_free(frequencies_ll);
-  lodepng_free(frequencies_d);
-  lodepng_free(frequencies_cl);
-  lodepng_free(bitlen_lld);
-  lodepng_free(bitlen_lld_e);
+  uivector_cleanup(&frequencies_ll);
+  uivector_cleanup(&frequencies_d);
+  uivector_cleanup(&frequencies_cl);
+  uivector_cleanup(&bitlen_lld_e);
+  uivector_cleanup(&bitlen_lld);
+  uivector_cleanup(&bitlen_cl);
 
   return error;
 }
 
-static unsigned deflateFixed(LodePNGBitWriter* writer, Hash* hash,
+static unsigned deflateFixed(ucvector* out, size_t* bp, Hash* hash,
                              const unsigned char* data,
                              size_t datapos, size_t dataend,
-                             const LodePNGCompressSettings* settings, unsigned final) {
+                             const LodePNGCompressSettings* settings, int final)
+{
   HuffmanTree tree_ll; /*tree for literal values and length codes*/
   HuffmanTree tree_d; /*tree for distance codes*/
 
@@ -2040,29 +1928,31 @@ static unsigned deflateFixed(LodePNGBitWriter* writer, Hash* hash,
   HuffmanTree_init(&tree_ll);
   HuffmanTree_init(&tree_d);
 
-  error = generateFixedLitLenTree(&tree_ll);
-  if(!error) error = generateFixedDistanceTree(&tree_d);
+  generateFixedLitLenTree(&tree_ll);
+  generateFixedDistanceTree(&tree_d);
 
-  if(!error) {
-    writeBits(writer, BFINAL, 1);
-    writeBits(writer, 1, 1); /*first bit of BTYPE*/
-    writeBits(writer, 0, 1); /*second bit of BTYPE*/
+  addBitToStream(bp, out, BFINAL);
+  addBitToStream(bp, out, 1); /*first bit of BTYPE*/
+  addBitToStream(bp, out, 0); /*second bit of BTYPE*/
 
-    if(settings->use_lz77) /*LZ77 encoded*/ {
-      uivector lz77_encoded;
-      uivector_init(&lz77_encoded);
-      error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize,
-                         settings->minmatch, settings->nicematch, settings->lazymatching);
-      if(!error) writeLZ77data(writer, &lz77_encoded, &tree_ll, &tree_d);
-      uivector_cleanup(&lz77_encoded);
-    } else /*no LZ77, but still will be Huffman compressed*/ {
-      for(i = datapos; i < dataend; ++i) {
-        writeBitsReversed(writer, tree_ll.codes[data[i]], tree_ll.lengths[data[i]]);
-      }
+  if(settings->use_lz77) /*LZ77 encoded*/
+  {
+    uivector lz77_encoded;
+    uivector_init(&lz77_encoded);
+    error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize,
+                       settings->minmatch, settings->nicematch, settings->lazymatching);
+    if(!error) writeLZ77data(bp, out, &lz77_encoded, &tree_ll, &tree_d);
+    uivector_cleanup(&lz77_encoded);
+  }
+  else /*no LZ77, but still will be Huffman compressed*/
+  {
+    for(i = datapos; i < dataend; i++)
+    {
+      addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, data[i]), HuffmanTree_getLength(&tree_ll, data[i]));
     }
-    /*add END code*/
-    if(!error) writeBitsReversed(writer,tree_ll.codes[256], tree_ll.lengths[256]);
   }
+  /*add END code*/
+  if(!error) addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256));
 
   /*cleanup*/
   HuffmanTree_cleanup(&tree_ll);
@@ -2072,39 +1962,37 @@ static unsigned deflateFixed(LodePNGBitWriter* writer, Hash* hash,
 }
 
 static unsigned lodepng_deflatev(ucvector* out, const unsigned char* in, size_t insize,
-                                 const LodePNGCompressSettings* settings) {
+                                 const LodePNGCompressSettings* settings)
+{
   unsigned error = 0;
   size_t i, blocksize, numdeflateblocks;
+  size_t bp = 0; /*the bit pointer*/
   Hash hash;
-  LodePNGBitWriter writer;
-
-  LodePNGBitWriter_init(&writer, out);
 
   if(settings->btype > 2) return 61;
   else if(settings->btype == 0) return deflateNoCompression(out, in, insize);
   else if(settings->btype == 1) blocksize = insize;
-  else /*if(settings->btype == 2)*/ {
-    /*on PNGs, deflate blocks of 65-262k seem to give most dense encoding*/
-    blocksize = insize / 8u + 8;
-    if(blocksize < 65536) blocksize = 65536;
-    if(blocksize > 262144) blocksize = 262144;
+  else /*if(settings->btype == 2)*/
+  {
+    blocksize = insize / 8 + 8;
+    if(blocksize < 65535) blocksize = 65535;
   }
 
   numdeflateblocks = (insize + blocksize - 1) / blocksize;
   if(numdeflateblocks == 0) numdeflateblocks = 1;
 
   error = hash_init(&hash, settings->windowsize);
+  if(error) return error;
 
-  if(!error) {
-    for(i = 0; i != numdeflateblocks && !error; ++i) {
-      unsigned final = (i == numdeflateblocks - 1);
-      size_t start = i * blocksize;
-      size_t end = start + blocksize;
-      if(end > insize) end = insize;
+  for(i = 0; i < numdeflateblocks && !error; i++)
+  {
+    int final = i == numdeflateblocks - 1;
+    size_t start = i * blocksize;
+    size_t end = start + blocksize;
+    if(end > insize) end = insize;
 
-      if(settings->btype == 1) error = deflateFixed(&writer, &hash, in, start, end, settings, final);
-      else if(settings->btype == 2) error = deflateDynamic(&writer, &hash, in, start, end, settings, final);
-    }
+    if(settings->btype == 1) error = deflateFixed(out, &bp, &hash, in, start, end, settings, final);
+    else if(settings->btype == 2) error = deflateDynamic(out, &bp, &hash, in, start, end, settings, final);
   }
 
   hash_cleanup(&hash);
@@ -2114,9 +2002,12 @@ static unsigned lodepng_deflatev(ucvector* out, const unsigned char* in, size_t
 
 unsigned lodepng_deflate(unsigned char** out, size_t* outsize,
                          const unsigned char* in, size_t insize,
-                         const LodePNGCompressSettings* settings) {
-  ucvector v = ucvector_init(*out, *outsize);
-  unsigned error = lodepng_deflatev(&v, in, insize, settings);
+                         const LodePNGCompressSettings* settings)
+{
+  unsigned error;
+  ucvector v;
+  ucvector_init_buffer(&v, *out, *outsize);
+  error = lodepng_deflatev(&v, in, insize, settings);
   *out = v.data;
   *outsize = v.size;
   return error;
@@ -2124,12 +2015,14 @@ unsigned lodepng_deflate(unsigned char** out, size_t* outsize,
 
 static unsigned deflate(unsigned char** out, size_t* outsize,
                         const unsigned char* in, size_t insize,
-                        const LodePNGCompressSettings* settings) {
-  if(settings->custom_deflate) {
-    unsigned error = settings->custom_deflate(out, outsize, in, insize, settings);
-    /*the custom deflate is allowed to have its own error codes, however, we translate it to code 111*/
-    return error ? 111 : 0;
-  } else {
+                        const LodePNGCompressSettings* settings)
+{
+  if(settings->custom_deflate)
+  {
+    return settings->custom_deflate(out, outsize, in, insize, settings);
+  }
+  else
+  {
     return lodepng_deflate(out, outsize, in, insize, settings);
   }
 }
@@ -2137,32 +2030,36 @@ static unsigned deflate(unsigned char** out, size_t* outsize,
 #endif /*LODEPNG_COMPILE_DECODER*/
 
 /* ////////////////////////////////////////////////////////////////////////// */
-/* / Adler32                                                                / */
+/* / Adler32                                                                  */
 /* ////////////////////////////////////////////////////////////////////////// */
 
-static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len) {
-  unsigned s1 = adler & 0xffffu;
-  unsigned s2 = (adler >> 16u) & 0xffffu;
+static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len)
+{
+   unsigned s1 = adler & 0xffff;
+   unsigned s2 = (adler >> 16) & 0xffff;
 
-  while(len != 0u) {
-    unsigned i;
-    /*at least 5552 sums can be done before the sums overflow, saving a lot of module divisions*/
-    unsigned amount = len > 5552u ? 5552u : len;
+  while(len > 0)
+  {
+    /*at least 5550 sums can be done before the sums overflow, saving a lot of module divisions*/
+    unsigned amount = len > 5550 ? 5550 : len;
     len -= amount;
-    for(i = 0; i != amount; ++i) {
+    while(amount > 0)
+    {
       s1 += (*data++);
       s2 += s1;
+      amount--;
     }
-    s1 %= 65521u;
-    s2 %= 65521u;
+    s1 %= 65521;
+    s2 %= 65521;
   }
 
-  return (s2 << 16u) | s1;
+  return (s2 << 16) | s1;
 }
 
 /*Return the adler32 of the bytes data[0..len-1]*/
-static unsigned adler32(const unsigned char* data, unsigned len) {
-  return update_adler32(1u, data, len);
+static unsigned adler32(const unsigned char* data, unsigned len)
+{
+  return update_adler32(1L, data, len);
 }
 
 /* ////////////////////////////////////////////////////////////////////////// */
@@ -2171,15 +2068,16 @@ static unsigned adler32(const unsigned char* data, unsigned len) {
 
 #ifdef LODEPNG_COMPILE_DECODER
 
-static unsigned lodepng_zlib_decompressv(ucvector* out,
-                                         const unsigned char* in, size_t insize,
-                                         const LodePNGDecompressSettings* settings) {
+unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
+                                 size_t insize, const LodePNGDecompressSettings* settings)
+{
   unsigned error = 0;
   unsigned CM, CINFO, FDICT;
 
   if(insize < 2) return 53; /*error, size of zlib data too small*/
   /*read information from zlib header*/
-  if((in[0] * 256 + in[1]) % 31 != 0) {
+  if((in[0] * 256 + in[1]) % 31 != 0)
+  {
     /*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/
     return 24;
   }
@@ -2190,62 +2088,42 @@ static unsigned lodepng_zlib_decompressv(ucvector* out,
   FDICT = (in[1] >> 5) & 1;
   /*FLEVEL = (in[1] >> 6) & 3;*/ /*FLEVEL is not used here*/
 
-  if(CM != 8 || CINFO > 7) {
+  if(CM != 8 || CINFO > 7)
+  {
     /*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/
     return 25;
   }
-  if(FDICT != 0) {
+  if(FDICT != 0)
+  {
     /*error: the specification of PNG says about the zlib stream:
       "The additional flags shall not specify a preset dictionary."*/
     return 26;
   }
 
-  error = inflatev(out, in + 2, insize - 2, settings);
+  error = inflate(out, outsize, in + 2, insize - 2, settings);
   if(error) return error;
 
-  if(!settings->ignore_adler32) {
+  if(!settings->ignore_adler32)
+  {
     unsigned ADLER32 = lodepng_read32bitInt(&in[insize - 4]);
-    unsigned checksum = adler32(out->data, (unsigned)(out->size));
+    unsigned checksum = adler32(*out, (unsigned)(*outsize));
     if(checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/
   }
 
   return 0; /*no error*/
 }
 
-
-unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
-                                 size_t insize, const LodePNGDecompressSettings* settings) {
-  ucvector v = ucvector_init(*out, *outsize);
-  unsigned error = lodepng_zlib_decompressv(&v, in, insize, settings);
-  *out = v.data;
-  *outsize = v.size;
-  return error;
-}
-
-/*expected_size is expected output size, to avoid intermediate allocations. Set to 0 if not known. */
-static unsigned zlib_decompress(unsigned char** out, size_t* outsize, size_t expected_size,
-                                const unsigned char* in, size_t insize, const LodePNGDecompressSettings* settings) {
-  unsigned error;
-  if(settings->custom_zlib) {
-    error = settings->custom_zlib(out, outsize, in, insize, settings);
-    if(error) {
-      /*the custom zlib is allowed to have its own error codes, however, we translate it to code 110*/
-      error = 110;
-      /*if there's a max output size, and the custom zlib returned error, then indicate that error instead*/
-      if(settings->max_output_size && *outsize > settings->max_output_size) error = 109;
-    }
-  } else {
-    ucvector v = ucvector_init(*out, *outsize);
-    if(expected_size) {
-      /*reserve the memory to avoid intermediate reallocations*/
-      ucvector_resize(&v, *outsize + expected_size);
-      v.size = *outsize;
-    }
-    error = lodepng_zlib_decompressv(&v, in, insize, settings);
-    *out = v.data;
-    *outsize = v.size;
+static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
+                                size_t insize, const LodePNGDecompressSettings* settings)
+{
+  if(settings->custom_zlib)
+  {
+    return settings->custom_zlib(out, outsize, in, insize, settings);
+  }
+  else
+  {
+    return lodepng_zlib_decompress(out, outsize, in, insize, settings);
   }
-  return error;
 }
 
 #endif /*LODEPNG_COMPILE_DECODER*/
@@ -2253,50 +2131,57 @@ static unsigned zlib_decompress(unsigned char** out, size_t* outsize, size_t exp
 #ifdef LODEPNG_COMPILE_ENCODER
 
 unsigned lodepng_zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
-                               size_t insize, const LodePNGCompressSettings* settings) {
+                               size_t insize, const LodePNGCompressSettings* settings)
+{
+  /*initially, *out must be NULL and outsize 0, if you just give some random *out
+  that's pointing to a non allocated buffer, this'll crash*/
+  ucvector outv;
   size_t i;
   unsigned error;
   unsigned char* deflatedata = 0;
   size_t deflatesize = 0;
 
-  error = deflate(&deflatedata, &deflatesize, in, insize, settings);
+  unsigned ADLER32;
+  /*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/
+  unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/
+  unsigned FLEVEL = 0;
+  unsigned FDICT = 0;
+  unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64;
+  unsigned FCHECK = 31 - CMFFLG % 31;
+  CMFFLG += FCHECK;
 
-  *out = NULL;
-  *outsize = 0;
-  if(!error) {
-    *outsize = deflatesize + 6;
-    *out = (unsigned char*)lodepng_malloc(*outsize);
-    if(!*out) error = 83; /*alloc fail*/
-  }
+  /*ucvector-controlled version of the output buffer, for dynamic array*/
+  ucvector_init_buffer(&outv, *out, *outsize);
 
-  if(!error) {
-    unsigned ADLER32 = adler32(in, (unsigned)insize);
-    /*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/
-    unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/
-    unsigned FLEVEL = 0;
-    unsigned FDICT = 0;
-    unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64;
-    unsigned FCHECK = 31 - CMFFLG % 31;
-    CMFFLG += FCHECK;
+  ucvector_push_back(&outv, (unsigned char)(CMFFLG / 256));
+  ucvector_push_back(&outv, (unsigned char)(CMFFLG % 256));
 
-    (*out)[0] = (unsigned char)(CMFFLG >> 8);
-    (*out)[1] = (unsigned char)(CMFFLG & 255);
-    for(i = 0; i != deflatesize; ++i) (*out)[i + 2] = deflatedata[i];
-    lodepng_set32bitInt(&(*out)[*outsize - 4], ADLER32);
+  error = deflate(&deflatedata, &deflatesize, in, insize, settings);
+
+  if(!error)
+  {
+    ADLER32 = adler32(in, (unsigned)insize);
+    for(i = 0; i < deflatesize; i++) ucvector_push_back(&outv, deflatedata[i]);
+    lodepng_free(deflatedata);
+    lodepng_add32bitInt(&outv, ADLER32);
   }
 
-  lodepng_free(deflatedata);
+  *out = outv.data;
+  *outsize = outv.size;
+
   return error;
 }
 
 /* compress using the default or custom zlib function */
 static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
-                              size_t insize, const LodePNGCompressSettings* settings) {
-  if(settings->custom_zlib) {
-    unsigned error = settings->custom_zlib(out, outsize, in, insize, settings);
-    /*the custom zlib is allowed to have its own error codes, however, we translate it to code 111*/
-    return error ? 111 : 0;
-  } else {
+                              size_t insize, const LodePNGCompressSettings* settings)
+{
+  if(settings->custom_zlib)
+  {
+    return settings->custom_zlib(out, outsize, in, insize, settings);
+  }
+  else
+  {
     return lodepng_zlib_compress(out, outsize, in, insize, settings);
   }
 }
@@ -2306,17 +2191,18 @@ static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsign
 #else /*no LODEPNG_COMPILE_ZLIB*/
 
 #ifdef LODEPNG_COMPILE_DECODER
-static unsigned zlib_decompress(unsigned char** out, size_t* outsize, size_t expected_size,
-                                const unsigned char* in, size_t insize, const LodePNGDecompressSettings* settings) {
-  if(!settings->custom_zlib) return 87; /*no custom zlib function provided */
-  (void)expected_size;
+static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
+                                size_t insize, const LodePNGDecompressSettings* settings)
+{
+  if (!settings->custom_zlib) return 87; /*no custom zlib function provided */
   return settings->custom_zlib(out, outsize, in, insize, settings);
 }
 #endif /*LODEPNG_COMPILE_DECODER*/
 #ifdef LODEPNG_COMPILE_ENCODER
 static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
-                              size_t insize, const LodePNGCompressSettings* settings) {
-  if(!settings->custom_zlib) return 87; /*no custom zlib function provided */
+                              size_t insize, const LodePNGCompressSettings* settings)
+{
+  if (!settings->custom_zlib) return 87; /*no custom zlib function provided */
   return settings->custom_zlib(out, outsize, in, insize, settings);
 }
 #endif /*LODEPNG_COMPILE_ENCODER*/
@@ -2330,7 +2216,8 @@ static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsign
 /*this is a good tradeoff between speed and compression ratio*/
 #define DEFAULT_WINDOWSIZE 2048
 
-void lodepng_compress_settings_init(LodePNGCompressSettings* settings) {
+void lodepng_compress_settings_init(LodePNGCompressSettings* settings)
+{
   /*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/
   settings->btype = 2;
   settings->use_lz77 = 1;
@@ -2351,17 +2238,16 @@ const LodePNGCompressSettings lodepng_default_compress_settings = {2, 1, DEFAULT
 
 #ifdef LODEPNG_COMPILE_DECODER
 
-void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings) {
+void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings)
+{
   settings->ignore_adler32 = 0;
-  settings->ignore_nlen = 0;
-  settings->max_output_size = 0;
 
   settings->custom_zlib = 0;
   settings->custom_inflate = 0;
   settings->custom_context = 0;
 }
 
-const LodePNGDecompressSettings lodepng_default_decompress_settings = {0, 0, 0, 0, 0, 0};
+const LodePNGDecompressSettings lodepng_default_decompress_settings = {0, 0, 0, 0};
 
 #endif /*LODEPNG_COMPILE_DECODER*/
 
@@ -2377,8 +2263,6 @@ const LodePNGDecompressSettings lodepng_default_decompress_settings = {0, 0, 0,
 /* / CRC32                                                                  / */
 /* ////////////////////////////////////////////////////////////////////////// */
 
-
-#ifndef LODEPNG_NO_COMPILE_CRC
 /* CRC polynomial: 0xedb88320 */
 static unsigned lodepng_crc32_table[256] = {
            0u, 1996959894u, 3993919788u, 2567524794u,  124634137u, 1886057615u, 3915621685u, 2657392035u,
@@ -2416,89 +2300,110 @@ static unsigned lodepng_crc32_table[256] = {
 };
 
 /*Return the CRC of the bytes buf[0..len-1].*/
-unsigned lodepng_crc32(const unsigned char* data, size_t length) {
-  unsigned r = 0xffffffffu;
-  size_t i;
-  for(i = 0; i < length; ++i) {
-    r = lodepng_crc32_table[(r ^ data[i]) & 0xffu] ^ (r >> 8u);
+unsigned lodepng_crc32(const unsigned char* buf, size_t len)
+{
+  unsigned c = 0xffffffffL;
+  size_t n;
+
+  for(n = 0; n < len; n++)
+  {
+    c = lodepng_crc32_table[(c ^ buf[n]) & 0xff] ^ (c >> 8);
   }
-  return r ^ 0xffffffffu;
+  return c ^ 0xffffffffL;
 }
-#else /* !LODEPNG_NO_COMPILE_CRC */
-unsigned lodepng_crc32(const unsigned char* data, size_t length);
-#endif /* !LODEPNG_NO_COMPILE_CRC */
 
 /* ////////////////////////////////////////////////////////////////////////// */
-/* / Reading and writing PNG color channel bits                             / */
+/* / Reading and writing single bits and bytes from/to stream for LodePNG   / */
 /* ////////////////////////////////////////////////////////////////////////// */
 
-/* The color channel bits of less-than-8-bit pixels are read with the MSB of bytes first,
-so LodePNGBitWriter and LodePNGBitReader can't be used for those. */
-
-static unsigned char readBitFromReversedStream(size_t* bitpointer, const unsigned char* bitstream) {
+static unsigned char readBitFromReversedStream(size_t* bitpointer, const unsigned char* bitstream)
+{
   unsigned char result = (unsigned char)((bitstream[(*bitpointer) >> 3] >> (7 - ((*bitpointer) & 0x7))) & 1);
-  ++(*bitpointer);
+  (*bitpointer)++;
   return result;
 }
 
-/* TODO: make this faster */
-static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits) {
+static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
+{
   unsigned result = 0;
   size_t i;
-  for(i = 0 ; i < nbits; ++i) {
-    result <<= 1u;
-    result |= (unsigned)readBitFromReversedStream(bitpointer, bitstream);
+  for(i = nbits - 1; i < nbits; i--)
+  {
+    result += (unsigned)readBitFromReversedStream(bitpointer, bitstream) << i;
   }
   return result;
 }
 
-static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream, unsigned char bit) {
+#ifdef LODEPNG_COMPILE_DECODER
+static void setBitOfReversedStream0(size_t* bitpointer, unsigned char* bitstream, unsigned char bit)
+{
+  /*the current bit in bitstream must be 0 for this to work*/
+  if(bit)
+  {
+    /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/
+    bitstream[(*bitpointer) >> 3] |= (bit << (7 - ((*bitpointer) & 0x7)));
+  }
+  (*bitpointer)++;
+}
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream, unsigned char bit)
+{
   /*the current bit in bitstream may be 0 or 1 for this to work*/
-  if(bit == 0) bitstream[(*bitpointer) >> 3u] &=  (unsigned char)(~(1u << (7u - ((*bitpointer) & 7u))));
-  else         bitstream[(*bitpointer) >> 3u] |=  (1u << (7u - ((*bitpointer) & 7u)));
-  ++(*bitpointer);
+  if(bit == 0) bitstream[(*bitpointer) >> 3] &=  (unsigned char)(~(1 << (7 - ((*bitpointer) & 0x7))));
+  else         bitstream[(*bitpointer) >> 3] |=  (1 << (7 - ((*bitpointer) & 0x7)));
+  (*bitpointer)++;
 }
 
 /* ////////////////////////////////////////////////////////////////////////// */
 /* / PNG chunks                                                             / */
 /* ////////////////////////////////////////////////////////////////////////// */
 
-unsigned lodepng_chunk_length(const unsigned char* chunk) {
+unsigned lodepng_chunk_length(const unsigned char* chunk)
+{
   return lodepng_read32bitInt(&chunk[0]);
 }
 
-void lodepng_chunk_type(char type[5], const unsigned char* chunk) {
+void lodepng_chunk_type(char type[5], const unsigned char* chunk)
+{
   unsigned i;
-  for(i = 0; i != 4; ++i) type[i] = (char)chunk[4 + i];
+  for(i = 0; i < 4; i++) type[i] = chunk[4 + i];
   type[4] = 0; /*null termination char*/
 }
 
-unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type) {
-  if(lodepng_strlen(type) != 4) return 0;
+unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type)
+{
+  if(strlen(type) != 4) return 0;
   return (chunk[4] == type[0] && chunk[5] == type[1] && chunk[6] == type[2] && chunk[7] == type[3]);
 }
 
-unsigned char lodepng_chunk_ancillary(const unsigned char* chunk) {
+unsigned char lodepng_chunk_ancillary(const unsigned char* chunk)
+{
   return((chunk[4] & 32) != 0);
 }
 
-unsigned char lodepng_chunk_private(const unsigned char* chunk) {
+unsigned char lodepng_chunk_private(const unsigned char* chunk)
+{
   return((chunk[6] & 32) != 0);
 }
 
-unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk) {
+unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk)
+{
   return((chunk[7] & 32) != 0);
 }
 
-unsigned char* lodepng_chunk_data(unsigned char* chunk) {
+unsigned char* lodepng_chunk_data(unsigned char* chunk)
+{
   return &chunk[8];
 }
 
-const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk) {
+const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk)
+{
   return &chunk[8];
 }
 
-unsigned lodepng_chunk_check_crc(const unsigned char* chunk) {
+unsigned lodepng_chunk_check_crc(const unsigned char* chunk)
+{
   unsigned length = lodepng_chunk_length(chunk);
   unsigned CRC = lodepng_read32bitInt(&chunk[length + 8]);
   /*the CRC is taken of the data and the 4 chunk type letters, not the length*/
@@ -2507,109 +2412,68 @@ unsigned lodepng_chunk_check_crc(const unsigned char* chunk) {
   else return 0;
 }
 
-void lodepng_chunk_generate_crc(unsigned char* chunk) {
+void lodepng_chunk_generate_crc(unsigned char* chunk)
+{
   unsigned length = lodepng_chunk_length(chunk);
   unsigned CRC = lodepng_crc32(&chunk[4], length + 4);
   lodepng_set32bitInt(chunk + 8 + length, CRC);
 }
 
-unsigned char* lodepng_chunk_next(unsigned char* chunk, unsigned char* end) {
-  if(chunk >= end || end - chunk < 12) return end; /*too small to contain a chunk*/
-  if(chunk[0] == 0x89 && chunk[1] == 0x50 && chunk[2] == 0x4e && chunk[3] == 0x47
-    && chunk[4] == 0x0d && chunk[5] == 0x0a && chunk[6] == 0x1a && chunk[7] == 0x0a) {
-    /* Is PNG magic header at start of PNG file. Jump to first actual chunk. */
-    return chunk + 8;
-  } else {
-    size_t total_chunk_length;
-    unsigned char* result;
-    if(lodepng_addofl(lodepng_chunk_length(chunk), 12, &total_chunk_length)) return end;
-    result = chunk + total_chunk_length;
-    if(result < chunk) return end; /*pointer overflow*/
-    return result;
-  }
-}
-
-const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk, const unsigned char* end) {
-  if(chunk >= end || end - chunk < 12) return end; /*too small to contain a chunk*/
-  if(chunk[0] == 0x89 && chunk[1] == 0x50 && chunk[2] == 0x4e && chunk[3] == 0x47
-    && chunk[4] == 0x0d && chunk[5] == 0x0a && chunk[6] == 0x1a && chunk[7] == 0x0a) {
-    /* Is PNG magic header at start of PNG file. Jump to first actual chunk. */
-    return chunk + 8;
-  } else {
-    size_t total_chunk_length;
-    const unsigned char* result;
-    if(lodepng_addofl(lodepng_chunk_length(chunk), 12, &total_chunk_length)) return end;
-    result = chunk + total_chunk_length;
-    if(result < chunk) return end; /*pointer overflow*/
-    return result;
-  }
-}
-
-unsigned char* lodepng_chunk_find(unsigned char* chunk, unsigned char* end, const char type[5]) {
-  for(;;) {
-    if(chunk >= end || end - chunk < 12) return 0; /* past file end: chunk + 12 > end */
-    if(lodepng_chunk_type_equals(chunk, type)) return chunk;
-    chunk = lodepng_chunk_next(chunk, end);
-  }
+unsigned char* lodepng_chunk_next(unsigned char* chunk)
+{
+  unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12;
+  return &chunk[total_chunk_length];
 }
 
-const unsigned char* lodepng_chunk_find_const(const unsigned char* chunk, const unsigned char* end, const char type[5]) {
-  for(;;) {
-    if(chunk >= end || end - chunk < 12) return 0; /* past file end: chunk + 12 > end */
-    if(lodepng_chunk_type_equals(chunk, type)) return chunk;
-    chunk = lodepng_chunk_next_const(chunk, end);
-  }
+const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk)
+{
+  unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12;
+  return &chunk[total_chunk_length];
 }
 
-unsigned lodepng_chunk_append(unsigned char** out, size_t* outsize, const unsigned char* chunk) {
+unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk)
+{
   unsigned i;
-  size_t total_chunk_length, new_length;
+  unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12;
   unsigned char *chunk_start, *new_buffer;
-
-  if(lodepng_addofl(lodepng_chunk_length(chunk), 12, &total_chunk_length)) return 77;
-  if(lodepng_addofl(*outsize, total_chunk_length, &new_length)) return 77;
+  size_t new_length = (*outlength) + total_chunk_length;
+  if(new_length < total_chunk_length || new_length < (*outlength)) return 77; /*integer overflow happened*/
 
   new_buffer = (unsigned char*)lodepng_realloc(*out, new_length);
   if(!new_buffer) return 83; /*alloc fail*/
   (*out) = new_buffer;
-  (*outsize) = new_length;
+  (*outlength) = new_length;
   chunk_start = &(*out)[new_length - total_chunk_length];
 
-  for(i = 0; i != total_chunk_length; ++i) chunk_start[i] = chunk[i];
+  for(i = 0; i < total_chunk_length; i++) chunk_start[i] = chunk[i];
 
   return 0;
 }
 
-/*Sets length and name and allocates the space for data and crc but does not
-set data or crc yet. Returns the start of the chunk in chunk. The start of
-the data is at chunk + 8. To finalize chunk, add the data, then use
-lodepng_chunk_generate_crc */
-static unsigned lodepng_chunk_init(unsigned char** chunk,
-                                   ucvector* out,
-                                   unsigned length, const char* type) {
-  size_t new_length = out->size;
-  if(lodepng_addofl(new_length, length, &new_length)) return 77;
-  if(lodepng_addofl(new_length, 12, &new_length)) return 77;
-  if(!ucvector_resize(out, new_length)) return 83; /*alloc fail*/
-  *chunk = out->data + new_length - length - 12u;
+unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length,
+                              const char* type, const unsigned char* data)
+{
+  unsigned i;
+  unsigned char *chunk, *new_buffer;
+  size_t new_length = (*outlength) + length + 12;
+  if(new_length < length + 12 || new_length < (*outlength)) return 77; /*integer overflow happened*/
+  new_buffer = (unsigned char*)lodepng_realloc(*out, new_length);
+  if(!new_buffer) return 83; /*alloc fail*/
+  (*out) = new_buffer;
+  (*outlength) = new_length;
+  chunk = &(*out)[(*outlength) - length - 12];
 
   /*1: length*/
-  lodepng_set32bitInt(*chunk, length);
+  lodepng_set32bitInt(chunk, (unsigned)length);
 
   /*2: chunk name (4 letters)*/
-  lodepng_memcpy(*chunk + 4, type, 4);
-
-  return 0;
-}
-
-/* like lodepng_chunk_create but with custom allocsize */
-static unsigned lodepng_chunk_createv(ucvector* out,
-                                      unsigned length, const char* type, const unsigned char* data) {
-  unsigned char* chunk;
-  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, length, type));
+  chunk[4] = type[0];
+  chunk[5] = type[1];
+  chunk[6] = type[2];
+  chunk[7] = type[3];
 
   /*3: the data*/
-  lodepng_memcpy(chunk + 8, data, length);
+  for(i = 0; i < length; i++) chunk[8 + i] = data[i];
 
   /*4: CRC (of the chunkname characters and the data)*/
   lodepng_chunk_generate_crc(chunk);
@@ -2617,54 +2481,48 @@ static unsigned lodepng_chunk_createv(ucvector* out,
   return 0;
 }
 
-unsigned lodepng_chunk_create(unsigned char** out, size_t* outsize,
-                              unsigned length, const char* type, const unsigned char* data) {
-  ucvector v = ucvector_init(*out, *outsize);
-  unsigned error = lodepng_chunk_createv(&v, length, type, data);
-  *out = v.data;
-  *outsize = v.size;
-  return error;
-}
-
 /* ////////////////////////////////////////////////////////////////////////// */
-/* / Color types, channels, bits                                            / */
+/* / Color types and such                                                   / */
 /* ////////////////////////////////////////////////////////////////////////// */
 
-/*checks if the colortype is valid and the bitdepth bd is allowed for this colortype.
-Return value is a LodePNG error code.*/
-static unsigned checkColorValidity(LodePNGColorType colortype, unsigned bd) {
-  switch(colortype) {
-    case LCT_GREY:       if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break;
-    case LCT_RGB:        if(!(                                 bd == 8 || bd == 16)) return 37; break;
-    case LCT_PALETTE:    if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8            )) return 37; break;
-    case LCT_GREY_ALPHA: if(!(                                 bd == 8 || bd == 16)) return 37; break;
-    case LCT_RGBA:       if(!(                                 bd == 8 || bd == 16)) return 37; break;
-    case LCT_MAX_OCTET_VALUE: return 31; /* invalid color type */
-    default: return 31; /* invalid color type */
+/*return type is a LodePNG error code*/
+static unsigned checkColorValidity(LodePNGColorType colortype, unsigned bd) /*bd = bitdepth*/
+{
+  switch(colortype)
+  {
+    case 0: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break; /*grey*/
+    case 2: if(!(                                 bd == 8 || bd == 16)) return 37; break; /*RGB*/
+    case 3: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8            )) return 37; break; /*palette*/
+    case 4: if(!(                                 bd == 8 || bd == 16)) return 37; break; /*grey + alpha*/
+    case 6: if(!(                                 bd == 8 || bd == 16)) return 37; break; /*RGBA*/
+    default: return 31;
   }
   return 0; /*allowed color type / bits combination*/
 }
 
-static unsigned getNumColorChannels(LodePNGColorType colortype) {
-  switch(colortype) {
-    case LCT_GREY: return 1;
-    case LCT_RGB: return 3;
-    case LCT_PALETTE: return 1;
-    case LCT_GREY_ALPHA: return 2;
-    case LCT_RGBA: return 4;
-    case LCT_MAX_OCTET_VALUE: return 0; /* invalid color type */
-    default: return 0; /*invalid color type*/
+static unsigned getNumColorChannels(LodePNGColorType colortype)
+{
+  switch(colortype)
+  {
+    case 0: return 1; /*grey*/
+    case 2: return 3; /*RGB*/
+    case 3: return 1; /*palette*/
+    case 4: return 2; /*grey + alpha*/
+    case 6: return 4; /*RGBA*/
   }
+  return 0; /*unexisting color type*/
 }
 
-static unsigned lodepng_get_bpp_lct(LodePNGColorType colortype, unsigned bitdepth) {
+static unsigned lodepng_get_bpp_lct(LodePNGColorType colortype, unsigned bitdepth)
+{
   /*bits per pixel is amount of channels * bits per channel*/
   return getNumColorChannels(colortype) * bitdepth;
 }
 
 /* ////////////////////////////////////////////////////////////////////////// */
 
-void lodepng_color_mode_init(LodePNGColorMode* info) {
+void lodepng_color_mode_init(LodePNGColorMode* info)
+{
   info->key_defined = 0;
   info->key_r = info->key_g = info->key_b = 0;
   info->colortype = LCT_RGBA;
@@ -2673,199 +2531,155 @@ void lodepng_color_mode_init(LodePNGColorMode* info) {
   info->palettesize = 0;
 }
 
-/*allocates palette memory if needed, and initializes all colors to black*/
-static void lodepng_color_mode_alloc_palette(LodePNGColorMode* info) {
-  size_t i;
-  /*if the palette is already allocated, it will have size 1024 so no reallocation needed in that case*/
-  /*the palette must have room for up to 256 colors with 4 bytes each.*/
-  if(!info->palette) info->palette = (unsigned char*)lodepng_malloc(1024);
-  if(!info->palette) return; /*alloc fail*/
-  for(i = 0; i != 256; ++i) {
-    /*Initialize all unused colors with black, the value used for invalid palette indices.
-    This is an error according to the PNG spec, but common PNG decoders make it black instead.
-    That makes color conversion slightly faster due to no error handling needed.*/
-    info->palette[i * 4 + 0] = 0;
-    info->palette[i * 4 + 1] = 0;
-    info->palette[i * 4 + 2] = 0;
-    info->palette[i * 4 + 3] = 255;
-  }
-}
-
-void lodepng_color_mode_cleanup(LodePNGColorMode* info) {
+void lodepng_color_mode_cleanup(LodePNGColorMode* info)
+{
   lodepng_palette_clear(info);
 }
 
-unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source) {
+unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source)
+{
+  size_t i;
   lodepng_color_mode_cleanup(dest);
-  lodepng_memcpy(dest, source, sizeof(LodePNGColorMode));
-  if(source->palette) {
+  *dest = *source;
+  if(source->palette)
+  {
     dest->palette = (unsigned char*)lodepng_malloc(1024);
     if(!dest->palette && source->palettesize) return 83; /*alloc fail*/
-    lodepng_memcpy(dest->palette, source->palette, source->palettesize * 4);
+    for(i = 0; i < source->palettesize * 4; i++) dest->palette[i] = source->palette[i];
   }
   return 0;
 }
 
-LodePNGColorMode lodepng_color_mode_make(LodePNGColorType colortype, unsigned bitdepth) {
-  LodePNGColorMode result;
-  lodepng_color_mode_init(&result);
-  result.colortype = colortype;
-  result.bitdepth = bitdepth;
-  return result;
-}
-
-static int lodepng_color_mode_equal(const LodePNGColorMode* a, const LodePNGColorMode* b) {
+static int lodepng_color_mode_equal(const LodePNGColorMode* a, const LodePNGColorMode* b)
+{
   size_t i;
   if(a->colortype != b->colortype) return 0;
   if(a->bitdepth != b->bitdepth) return 0;
   if(a->key_defined != b->key_defined) return 0;
-  if(a->key_defined) {
+  if(a->key_defined)
+  {
     if(a->key_r != b->key_r) return 0;
     if(a->key_g != b->key_g) return 0;
     if(a->key_b != b->key_b) return 0;
   }
   if(a->palettesize != b->palettesize) return 0;
-  for(i = 0; i != a->palettesize * 4; ++i) {
+  for(i = 0; i < a->palettesize * 4; i++)
+  {
     if(a->palette[i] != b->palette[i]) return 0;
   }
   return 1;
 }
 
-void lodepng_palette_clear(LodePNGColorMode* info) {
+void lodepng_palette_clear(LodePNGColorMode* info)
+{
   if(info->palette) lodepng_free(info->palette);
   info->palette = 0;
   info->palettesize = 0;
 }
 
 unsigned lodepng_palette_add(LodePNGColorMode* info,
-                             unsigned char r, unsigned char g, unsigned char b, unsigned char a) {
-  if(!info->palette) /*allocate palette if empty*/ {
-    lodepng_color_mode_alloc_palette(info);
-    if(!info->palette) return 83; /*alloc fail*/
-  }
-  if(info->palettesize >= 256) {
-    return 108; /*too many palette values*/
+                             unsigned char r, unsigned char g, unsigned char b, unsigned char a)
+{
+  unsigned char* data;
+  /*the same resize technique as C++ std::vectors is used, and here it's made so that for a palette with
+  the max of 256 colors, it'll have the exact alloc size*/
+  if(!info->palette) /*allocate palette if empty*/
+  {
+    /*room for 256 colors with 4 bytes each*/
+    data = (unsigned char*)lodepng_realloc(info->palette, 1024);
+    if(!data) return 83; /*alloc fail*/
+    else info->palette = data;
   }
   info->palette[4 * info->palettesize + 0] = r;
   info->palette[4 * info->palettesize + 1] = g;
   info->palette[4 * info->palettesize + 2] = b;
   info->palette[4 * info->palettesize + 3] = a;
-  ++info->palettesize;
+  info->palettesize++;
   return 0;
 }
 
-/*calculate bits per pixel out of colortype and bitdepth*/
-unsigned lodepng_get_bpp(const LodePNGColorMode* info) {
+unsigned lodepng_get_bpp(const LodePNGColorMode* info)
+{
+  /*calculate bits per pixel out of colortype and bitdepth*/
   return lodepng_get_bpp_lct(info->colortype, info->bitdepth);
 }
 
-unsigned lodepng_get_channels(const LodePNGColorMode* info) {
+unsigned lodepng_get_channels(const LodePNGColorMode* info)
+{
   return getNumColorChannels(info->colortype);
 }
 
-unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info) {
+unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info)
+{
   return info->colortype == LCT_GREY || info->colortype == LCT_GREY_ALPHA;
 }
 
-unsigned lodepng_is_alpha_type(const LodePNGColorMode* info) {
+unsigned lodepng_is_alpha_type(const LodePNGColorMode* info)
+{
   return (info->colortype & 4) != 0; /*4 or 6*/
 }
 
-unsigned lodepng_is_palette_type(const LodePNGColorMode* info) {
+unsigned lodepng_is_palette_type(const LodePNGColorMode* info)
+{
   return info->colortype == LCT_PALETTE;
 }
 
-unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info) {
+unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info)
+{
   size_t i;
-  for(i = 0; i != info->palettesize; ++i) {
+  for(i = 0; i < info->palettesize; i++)
+  {
     if(info->palette[i * 4 + 3] < 255) return 1;
   }
   return 0;
 }
 
-unsigned lodepng_can_have_alpha(const LodePNGColorMode* info) {
+unsigned lodepng_can_have_alpha(const LodePNGColorMode* info)
+{
   return info->key_defined
       || lodepng_is_alpha_type(info)
       || lodepng_has_palette_alpha(info);
 }
 
-static size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) {
-  size_t bpp = lodepng_get_bpp_lct(colortype, bitdepth);
-  size_t n = (size_t)w * (size_t)h;
-  return ((n / 8u) * bpp) + ((n & 7u) * bpp + 7u) / 8u;
+size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color)
+{
+  return (w * h * lodepng_get_bpp(color) + 7) / 8;
 }
 
-size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color) {
-  return lodepng_get_raw_size_lct(w, h, color->colortype, color->bitdepth);
+size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth)
+{
+  return (w * h * lodepng_get_bpp_lct(colortype, bitdepth) + 7) / 8;
 }
 
-
-#ifdef LODEPNG_COMPILE_PNG
-
-/*in an idat chunk, each scanline is a multiple of 8 bits, unlike the lodepng output buffer,
-and in addition has one extra byte per line: the filter byte. So this gives a larger
-result than lodepng_get_raw_size. Set h to 1 to get the size of 1 row including filter byte. */
-static size_t lodepng_get_raw_size_idat(unsigned w, unsigned h, unsigned bpp) {
-  /* + 1 for the filter byte, and possibly plus padding bits per line. */
-  /* Ignoring casts, the expression is equal to (w * bpp + 7) / 8 + 1, but avoids overflow of w * bpp */
-  size_t line = ((size_t)(w / 8u) * bpp) + 1u + ((w & 7u) * bpp + 7u) / 8u;
-  return (size_t)h * line;
-}
-
-#ifdef LODEPNG_COMPILE_DECODER
-/*Safely checks whether size_t overflow can be caused due to amount of pixels.
-This check is overcautious rather than precise. If this check indicates no overflow,
-you can safely compute in a size_t (but not an unsigned):
--(size_t)w * (size_t)h * 8
--amount of bytes in IDAT (including filter, padding and Adam7 bytes)
--amount of bytes in raw color model
-Returns 1 if overflow possible, 0 if not.
-*/
-static int lodepng_pixel_overflow(unsigned w, unsigned h,
-                                  const LodePNGColorMode* pngcolor, const LodePNGColorMode* rawcolor) {
-  size_t bpp = LODEPNG_MAX(lodepng_get_bpp(pngcolor), lodepng_get_bpp(rawcolor));
-  size_t numpixels, total;
-  size_t line; /* bytes per line in worst case */
-
-  if(lodepng_mulofl((size_t)w, (size_t)h, &numpixels)) return 1;
-  if(lodepng_mulofl(numpixels, 8, &total)) return 1; /* bit pointer with 8-bit color, or 8 bytes per channel color */
-
-  /* Bytes per scanline with the expression "(w / 8u) * bpp) + ((w & 7u) * bpp + 7u) / 8u" */
-  if(lodepng_mulofl((size_t)(w / 8u), bpp, &line)) return 1;
-  if(lodepng_addofl(line, ((w & 7u) * bpp + 7u) / 8u, &line)) return 1;
-
-  if(lodepng_addofl(line, 5, &line)) return 1; /* 5 bytes overhead per line: 1 filterbyte, 4 for Adam7 worst case */
-  if(lodepng_mulofl(line, h, &total)) return 1; /* Total bytes in worst case */
-
-  return 0; /* no overflow */
-}
-#endif /*LODEPNG_COMPILE_DECODER*/
-#endif /*LODEPNG_COMPILE_PNG*/
-
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
 
-static void LodePNGUnknownChunks_init(LodePNGInfo* info) {
+static void LodePNGUnknownChunks_init(LodePNGInfo* info)
+{
   unsigned i;
-  for(i = 0; i != 3; ++i) info->unknown_chunks_data[i] = 0;
-  for(i = 0; i != 3; ++i) info->unknown_chunks_size[i] = 0;
+  for(i = 0; i < 3; i++) info->unknown_chunks_data[i] = 0;
+  for(i = 0; i < 3; i++) info->unknown_chunks_size[i] = 0;
 }
 
-static void LodePNGUnknownChunks_cleanup(LodePNGInfo* info) {
+static void LodePNGUnknownChunks_cleanup(LodePNGInfo* info)
+{
   unsigned i;
-  for(i = 0; i != 3; ++i) lodepng_free(info->unknown_chunks_data[i]);
+  for(i = 0; i < 3; i++) lodepng_free(info->unknown_chunks_data[i]);
 }
 
-static unsigned LodePNGUnknownChunks_copy(LodePNGInfo* dest, const LodePNGInfo* src) {
+static unsigned LodePNGUnknownChunks_copy(LodePNGInfo* dest, const LodePNGInfo* src)
+{
   unsigned i;
 
   LodePNGUnknownChunks_cleanup(dest);
 
-  for(i = 0; i != 3; ++i) {
+  for(i = 0; i < 3; i++)
+  {
     size_t j;
     dest->unknown_chunks_size[i] = src->unknown_chunks_size[i];
     dest->unknown_chunks_data[i] = (unsigned char*)lodepng_malloc(src->unknown_chunks_size[i]);
     if(!dest->unknown_chunks_data[i] && dest->unknown_chunks_size[i]) return 83; /*alloc fail*/
-    for(j = 0; j < src->unknown_chunks_size[i]; ++j) {
+    for(j = 0; j < src->unknown_chunks_size[i]; j++)
+    {
       dest->unknown_chunks_data[i][j] = src->unknown_chunks_data[i][j];
     }
   }
@@ -2875,15 +2689,18 @@ static unsigned LodePNGUnknownChunks_copy(LodePNGInfo* dest, const LodePNGInfo*
 
 /******************************************************************************/
 
-static void LodePNGText_init(LodePNGInfo* info) {
+static void LodePNGText_init(LodePNGInfo* info)
+{
   info->text_num = 0;
   info->text_keys = NULL;
   info->text_strings = NULL;
 }
 
-static void LodePNGText_cleanup(LodePNGInfo* info) {
+static void LodePNGText_cleanup(LodePNGInfo* info)
+{
   size_t i;
-  for(i = 0; i != info->text_num; ++i) {
+  for(i = 0; i < info->text_num; i++)
+  {
     string_cleanup(&info->text_keys[i]);
     string_cleanup(&info->text_strings[i]);
   }
@@ -2891,45 +2708,52 @@ static void LodePNGText_cleanup(LodePNGInfo* info) {
   lodepng_free(info->text_strings);
 }
 
-static unsigned LodePNGText_copy(LodePNGInfo* dest, const LodePNGInfo* source) {
+static unsigned LodePNGText_copy(LodePNGInfo* dest, const LodePNGInfo* source)
+{
   size_t i = 0;
-  dest->text_keys = NULL;
-  dest->text_strings = NULL;
+  dest->text_keys = 0;
+  dest->text_strings = 0;
   dest->text_num = 0;
-  for(i = 0; i != source->text_num; ++i) {
+  for(i = 0; i < source->text_num; i++)
+  {
     CERROR_TRY_RETURN(lodepng_add_text(dest, source->text_keys[i], source->text_strings[i]));
   }
   return 0;
 }
 
-static unsigned lodepng_add_text_sized(LodePNGInfo* info, const char* key, const char* str, size_t size) {
+void lodepng_clear_text(LodePNGInfo* info)
+{
+  LodePNGText_cleanup(info);
+}
+
+unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str)
+{
   char** new_keys = (char**)(lodepng_realloc(info->text_keys, sizeof(char*) * (info->text_num + 1)));
   char** new_strings = (char**)(lodepng_realloc(info->text_strings, sizeof(char*) * (info->text_num + 1)));
+  if(!new_keys || !new_strings)
+  {
+    lodepng_free(new_keys);
+    lodepng_free(new_strings);
+    return 83; /*alloc fail*/
+  }
 
-  if(new_keys) info->text_keys = new_keys;
-  if(new_strings) info->text_strings = new_strings;
+  info->text_num++;
+  info->text_keys = new_keys;
+  info->text_strings = new_strings;
 
-  if(!new_keys || !new_strings) return 83; /*alloc fail*/
+  string_init(&info->text_keys[info->text_num - 1]);
+  string_set(&info->text_keys[info->text_num - 1], key);
 
-  ++info->text_num;
-  info->text_keys[info->text_num - 1] = alloc_string(key);
-  info->text_strings[info->text_num - 1] = alloc_string_sized(str, size);
-  if(!info->text_keys[info->text_num - 1] || !info->text_strings[info->text_num - 1]) return 83; /*alloc fail*/
+  string_init(&info->text_strings[info->text_num - 1]);
+  string_set(&info->text_strings[info->text_num - 1], str);
 
   return 0;
 }
 
-unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str) {
-  return lodepng_add_text_sized(info, key, str, lodepng_strlen(str));
-}
-
-void lodepng_clear_text(LodePNGInfo* info) {
-  LodePNGText_cleanup(info);
-}
-
 /******************************************************************************/
 
-static void LodePNGIText_init(LodePNGInfo* info) {
+static void LodePNGIText_init(LodePNGInfo* info)
+{
   info->itext_num = 0;
   info->itext_keys = NULL;
   info->itext_langtags = NULL;
@@ -2937,9 +2761,11 @@ static void LodePNGIText_init(LodePNGInfo* info) {
   info->itext_strings = NULL;
 }
 
-static void LodePNGIText_cleanup(LodePNGInfo* info) {
+static void LodePNGIText_cleanup(LodePNGInfo* info)
+{
   size_t i;
-  for(i = 0; i != info->itext_num; ++i) {
+  for(i = 0; i < info->itext_num; i++)
+  {
     string_cleanup(&info->itext_keys[i]);
     string_cleanup(&info->itext_langtags[i]);
     string_cleanup(&info->itext_transkeys[i]);
@@ -2951,85 +2777,67 @@ static void LodePNGIText_cleanup(LodePNGInfo* info) {
   lodepng_free(info->itext_strings);
 }
 
-static unsigned LodePNGIText_copy(LodePNGInfo* dest, const LodePNGInfo* source) {
+static unsigned LodePNGIText_copy(LodePNGInfo* dest, const LodePNGInfo* source)
+{
   size_t i = 0;
-  dest->itext_keys = NULL;
-  dest->itext_langtags = NULL;
-  dest->itext_transkeys = NULL;
-  dest->itext_strings = NULL;
+  dest->itext_keys = 0;
+  dest->itext_langtags = 0;
+  dest->itext_transkeys = 0;
+  dest->itext_strings = 0;
   dest->itext_num = 0;
-  for(i = 0; i != source->itext_num; ++i) {
+  for(i = 0; i < source->itext_num; i++)
+  {
     CERROR_TRY_RETURN(lodepng_add_itext(dest, source->itext_keys[i], source->itext_langtags[i],
                                         source->itext_transkeys[i], source->itext_strings[i]));
   }
   return 0;
 }
 
-void lodepng_clear_itext(LodePNGInfo* info) {
+void lodepng_clear_itext(LodePNGInfo* info)
+{
   LodePNGIText_cleanup(info);
 }
 
-static unsigned lodepng_add_itext_sized(LodePNGInfo* info, const char* key, const char* langtag,
-                                        const char* transkey, const char* str, size_t size) {
+unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag,
+                           const char* transkey, const char* str)
+{
   char** new_keys = (char**)(lodepng_realloc(info->itext_keys, sizeof(char*) * (info->itext_num + 1)));
   char** new_langtags = (char**)(lodepng_realloc(info->itext_langtags, sizeof(char*) * (info->itext_num + 1)));
   char** new_transkeys = (char**)(lodepng_realloc(info->itext_transkeys, sizeof(char*) * (info->itext_num + 1)));
   char** new_strings = (char**)(lodepng_realloc(info->itext_strings, sizeof(char*) * (info->itext_num + 1)));
+  if(!new_keys || !new_langtags || !new_transkeys || !new_strings)
+  {
+    lodepng_free(new_keys);
+    lodepng_free(new_langtags);
+    lodepng_free(new_transkeys);
+    lodepng_free(new_strings);
+    return 83; /*alloc fail*/
+  }
 
-  if(new_keys) info->itext_keys = new_keys;
-  if(new_langtags) info->itext_langtags = new_langtags;
-  if(new_transkeys) info->itext_transkeys = new_transkeys;
-  if(new_strings) info->itext_strings = new_strings;
-
-  if(!new_keys || !new_langtags || !new_transkeys || !new_strings) return 83; /*alloc fail*/
-
-  ++info->itext_num;
-
-  info->itext_keys[info->itext_num - 1] = alloc_string(key);
-  info->itext_langtags[info->itext_num - 1] = alloc_string(langtag);
-  info->itext_transkeys[info->itext_num - 1] = alloc_string(transkey);
-  info->itext_strings[info->itext_num - 1] = alloc_string_sized(str, size);
-
-  return 0;
-}
-
-unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag,
-                           const char* transkey, const char* str) {
-  return lodepng_add_itext_sized(info, key, langtag, transkey, str, lodepng_strlen(str));
-}
-
-/* same as set but does not delete */
-static unsigned lodepng_assign_icc(LodePNGInfo* info, const char* name, const unsigned char* profile, unsigned profile_size) {
-  if(profile_size == 0) return 100; /*invalid ICC profile size*/
-
-  info->iccp_name = alloc_string(name);
-  info->iccp_profile = (unsigned char*)lodepng_malloc(profile_size);
-
-  if(!info->iccp_name || !info->iccp_profile) return 83; /*alloc fail*/
+  info->itext_num++;
+  info->itext_keys = new_keys;
+  info->itext_langtags = new_langtags;
+  info->itext_transkeys = new_transkeys;
+  info->itext_strings = new_strings;
 
-  lodepng_memcpy(info->iccp_profile, profile, profile_size);
-  info->iccp_profile_size = profile_size;
+  string_init(&info->itext_keys[info->itext_num - 1]);
+  string_set(&info->itext_keys[info->itext_num - 1], key);
 
-  return 0; /*ok*/
-}
+  string_init(&info->itext_langtags[info->itext_num - 1]);
+  string_set(&info->itext_langtags[info->itext_num - 1], langtag);
 
-unsigned lodepng_set_icc(LodePNGInfo* info, const char* name, const unsigned char* profile, unsigned profile_size) {
-  if(info->iccp_name) lodepng_clear_icc(info);
-  info->iccp_defined = 1;
+  string_init(&info->itext_transkeys[info->itext_num - 1]);
+  string_set(&info->itext_transkeys[info->itext_num - 1], transkey);
 
-  return lodepng_assign_icc(info, name, profile, profile_size);
-}
+  string_init(&info->itext_strings[info->itext_num - 1]);
+  string_set(&info->itext_strings[info->itext_num - 1], str);
 
-void lodepng_clear_icc(LodePNGInfo* info) {
-  string_cleanup(&info->iccp_name);
-  lodepng_free(info->iccp_profile);
-  info->iccp_profile = NULL;
-  info->iccp_profile_size = 0;
-  info->iccp_defined = 0;
+  return 0;
 }
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
 
-void lodepng_info_init(LodePNGInfo* info) {
+void lodepng_info_init(LodePNGInfo* info)
+{
   lodepng_color_mode_init(&info->color);
   info->interlace_method = 0;
   info->compression_method = 0;
@@ -3044,41 +2852,31 @@ void lodepng_info_init(LodePNGInfo* info) {
   info->time_defined = 0;
   info->phys_defined = 0;
 
-  info->gama_defined = 0;
-  info->chrm_defined = 0;
-  info->srgb_defined = 0;
-  info->iccp_defined = 0;
-  info->iccp_name = NULL;
-  info->iccp_profile = NULL;
-
   LodePNGUnknownChunks_init(info);
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
 }
 
-void lodepng_info_cleanup(LodePNGInfo* info) {
+void lodepng_info_cleanup(LodePNGInfo* info)
+{
   lodepng_color_mode_cleanup(&info->color);
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
   LodePNGText_cleanup(info);
   LodePNGIText_cleanup(info);
 
-  lodepng_clear_icc(info);
-
   LodePNGUnknownChunks_cleanup(info);
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
 }
 
-unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source) {
+unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source)
+{
   lodepng_info_cleanup(dest);
-  lodepng_memcpy(dest, source, sizeof(LodePNGInfo));
+  *dest = *source;
   lodepng_color_mode_init(&dest->color);
   CERROR_TRY_RETURN(lodepng_color_mode_copy(&dest->color, &source->color));
 
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
   CERROR_TRY_RETURN(LodePNGText_copy(dest, source));
   CERROR_TRY_RETURN(LodePNGIText_copy(dest, source));
-  if(source->iccp_defined) {
-    CERROR_TRY_RETURN(lodepng_assign_icc(dest, source->iccp_name, source->iccp_profile, source->iccp_profile_size));
-  }
 
   LodePNGUnknownChunks_init(dest);
   CERROR_TRY_RETURN(LodePNGUnknownChunks_copy(dest, source));
@@ -3086,17 +2884,25 @@ unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source) {
   return 0;
 }
 
+void lodepng_info_swap(LodePNGInfo* a, LodePNGInfo* b)
+{
+  LodePNGInfo temp = *a;
+  *a = *b;
+  *b = temp;
+}
+
 /* ////////////////////////////////////////////////////////////////////////// */
 
 /*index: bitgroup index, bits: bitgroup size(1, 2 or 4), in: bitgroup value, out: octet array to add bits to*/
-static void addColorBits(unsigned char* out, size_t index, unsigned bits, unsigned in) {
+static void addColorBits(unsigned char* out, size_t index, unsigned bits, unsigned in)
+{
   unsigned m = bits == 1 ? 7 : bits == 2 ? 3 : 1; /*8 / bits - 1*/
   /*p = the partial index in the byte, e.g. with 4 palettebits it is 0 for first half or 1 for second half*/
   unsigned p = index & m;
-  in &= (1u << bits) - 1u; /*filter out any other bits of the input value*/
+  in &= (1 << bits) - 1; /*filter out any other bits of the input value*/
   in = in << (bits * (m - p));
-  if(p == 0) out[index * bits / 8u] = in;
-  else out[index * bits / 8u] |= in;
+  if(p == 0) out[index * bits / 8] = in;
+  else out[index * bits / 8] |= in;
 }
 
 typedef struct ColorTree ColorTree;
@@ -3107,20 +2913,26 @@ This is the data structure used to count the number of unique colors and to get
 index for a color. It's like an octree, but because the alpha channel is used too, each
 node has 16 instead of 8 children.
 */
-struct ColorTree {
+struct ColorTree
+{
   ColorTree* children[16]; /*up to 16 pointers to ColorTree of next level*/
   int index; /*the payload. Only has a meaningful value if this is in the last level*/
 };
 
-static void color_tree_init(ColorTree* tree) {
-  lodepng_memset(tree->children, 0, 16 * sizeof(*tree->children));
+static void color_tree_init(ColorTree* tree)
+{
+  int i;
+  for(i = 0; i < 16; i++) tree->children[i] = 0;
   tree->index = -1;
 }
 
-static void color_tree_cleanup(ColorTree* tree) {
+static void color_tree_cleanup(ColorTree* tree)
+{
   int i;
-  for(i = 0; i != 16; ++i) {
-    if(tree->children[i]) {
+  for(i = 0; i < 16; i++)
+  {
+    if(tree->children[i])
+    {
       color_tree_cleanup(tree->children[i]);
       lodepng_free(tree->children[i]);
     }
@@ -3128,9 +2940,11 @@ static void color_tree_cleanup(ColorTree* tree) {
 }
 
 /*returns -1 if color not present, its index otherwise*/
-static int color_tree_get(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) {
+static int color_tree_get(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a)
+{
   int bit = 0;
-  for(bit = 0; bit < 8; ++bit) {
+  for(bit = 0; bit < 8; bit++)
+  {
     int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1);
     if(!tree->children[i]) return -1;
     else tree = tree->children[i];
@@ -3139,74 +2953,95 @@ static int color_tree_get(ColorTree* tree, unsigned char r, unsigned char g, uns
 }
 
 #ifdef LODEPNG_COMPILE_ENCODER
-static int color_tree_has(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) {
+static int color_tree_has(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a)
+{
   return color_tree_get(tree, r, g, b, a) >= 0;
 }
 #endif /*LODEPNG_COMPILE_ENCODER*/
 
 /*color is not allowed to already exist.
-Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist")
-Returns error code, or 0 if ok*/
-static unsigned color_tree_add(ColorTree* tree,
-                               unsigned char r, unsigned char g, unsigned char b, unsigned char a, unsigned index) {
+Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist")*/
+static void color_tree_add(ColorTree* tree,
+                           unsigned char r, unsigned char g, unsigned char b, unsigned char a, int index)
+{
   int bit;
-  for(bit = 0; bit < 8; ++bit) {
+  for(bit = 0; bit < 8; bit++)
+  {
     int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1);
-    if(!tree->children[i]) {
+    if(!tree->children[i])
+    {
       tree->children[i] = (ColorTree*)lodepng_malloc(sizeof(ColorTree));
-      if(!tree->children[i]) return 83; /*alloc fail*/
       color_tree_init(tree->children[i]);
     }
     tree = tree->children[i];
   }
-  tree->index = (int)index;
-  return 0;
+  tree->index = index;
 }
 
 /*put a pixel, given its RGBA color, into image of any color type*/
 static unsigned rgba8ToPixel(unsigned char* out, size_t i,
                              const LodePNGColorMode* mode, ColorTree* tree /*for palette*/,
-                             unsigned char r, unsigned char g, unsigned char b, unsigned char a) {
-  if(mode->colortype == LCT_GREY) {
-    unsigned char gray = r; /*((unsigned short)r + g + b) / 3u;*/
-    if(mode->bitdepth == 8) out[i] = gray;
-    else if(mode->bitdepth == 16) out[i * 2 + 0] = out[i * 2 + 1] = gray;
-    else {
-      /*take the most significant bits of gray*/
-      gray = ((unsigned)gray >> (8u - mode->bitdepth)) & ((1u << mode->bitdepth) - 1u);
-      addColorBits(out, i, mode->bitdepth, gray);
-    }
-  } else if(mode->colortype == LCT_RGB) {
-    if(mode->bitdepth == 8) {
+                             unsigned char r, unsigned char g, unsigned char b, unsigned char a)
+{
+  if(mode->colortype == LCT_GREY)
+  {
+    unsigned char grey = r; /*((unsigned short)r + g + b) / 3*/;
+    if(mode->bitdepth == 8) out[i] = grey;
+    else if(mode->bitdepth == 16) out[i * 2 + 0] = out[i * 2 + 1] = grey;
+    else
+    {
+      /*take the most significant bits of grey*/
+      grey = (grey >> (8 - mode->bitdepth)) & ((1 << mode->bitdepth) - 1);
+      addColorBits(out, i, mode->bitdepth, grey);
+    }
+  }
+  else if(mode->colortype == LCT_RGB)
+  {
+    if(mode->bitdepth == 8)
+    {
       out[i * 3 + 0] = r;
       out[i * 3 + 1] = g;
       out[i * 3 + 2] = b;
-    } else {
+    }
+    else
+    {
       out[i * 6 + 0] = out[i * 6 + 1] = r;
       out[i * 6 + 2] = out[i * 6 + 3] = g;
       out[i * 6 + 4] = out[i * 6 + 5] = b;
     }
-  } else if(mode->colortype == LCT_PALETTE) {
+  }
+  else if(mode->colortype == LCT_PALETTE)
+  {
     int index = color_tree_get(tree, r, g, b, a);
     if(index < 0) return 82; /*color not in palette*/
     if(mode->bitdepth == 8) out[i] = index;
-    else addColorBits(out, i, mode->bitdepth, (unsigned)index);
-  } else if(mode->colortype == LCT_GREY_ALPHA) {
-    unsigned char gray = r; /*((unsigned short)r + g + b) / 3u;*/
-    if(mode->bitdepth == 8) {
-      out[i * 2 + 0] = gray;
+    else addColorBits(out, i, mode->bitdepth, index);
+  }
+  else if(mode->colortype == LCT_GREY_ALPHA)
+  {
+    unsigned char grey = r; /*((unsigned short)r + g + b) / 3*/;
+    if(mode->bitdepth == 8)
+    {
+      out[i * 2 + 0] = grey;
       out[i * 2 + 1] = a;
-    } else if(mode->bitdepth == 16) {
-      out[i * 4 + 0] = out[i * 4 + 1] = gray;
+    }
+    else if(mode->bitdepth == 16)
+    {
+      out[i * 4 + 0] = out[i * 4 + 1] = grey;
       out[i * 4 + 2] = out[i * 4 + 3] = a;
     }
-  } else if(mode->colortype == LCT_RGBA) {
-    if(mode->bitdepth == 8) {
+  }
+  else if(mode->colortype == LCT_RGBA)
+  {
+    if(mode->bitdepth == 8)
+    {
       out[i * 4 + 0] = r;
       out[i * 4 + 1] = g;
       out[i * 4 + 2] = b;
       out[i * 4 + 3] = a;
-    } else {
+    }
+    else
+    {
       out[i * 8 + 0] = out[i * 8 + 1] = r;
       out[i * 8 + 2] = out[i * 8 + 3] = g;
       out[i * 8 + 4] = out[i * 8 + 5] = b;
@@ -3218,27 +3053,36 @@ static unsigned rgba8ToPixel(unsigned char* out, size_t i,
 }
 
 /*put a pixel, given its RGBA16 color, into image of any color 16-bitdepth type*/
-static void rgba16ToPixel(unsigned char* out, size_t i,
-                         const LodePNGColorMode* mode,
-                         unsigned short r, unsigned short g, unsigned short b, unsigned short a) {
-  if(mode->colortype == LCT_GREY) {
-    unsigned short gray = r; /*((unsigned)r + g + b) / 3u;*/
-    out[i * 2 + 0] = (gray >> 8) & 255;
-    out[i * 2 + 1] = gray & 255;
-  } else if(mode->colortype == LCT_RGB) {
+static unsigned rgba16ToPixel(unsigned char* out, size_t i,
+                              const LodePNGColorMode* mode,
+                              unsigned short r, unsigned short g, unsigned short b, unsigned short a)
+{
+  if(mode->bitdepth != 16) return 85; /*must be 16 for this function*/
+  if(mode->colortype == LCT_GREY)
+  {
+    unsigned short grey = r; /*((unsigned)r + g + b) / 3*/;
+    out[i * 2 + 0] = (grey >> 8) & 255;
+    out[i * 2 + 1] = grey & 255;
+  }
+  else if(mode->colortype == LCT_RGB)
+  {
     out[i * 6 + 0] = (r >> 8) & 255;
     out[i * 6 + 1] = r & 255;
     out[i * 6 + 2] = (g >> 8) & 255;
     out[i * 6 + 3] = g & 255;
     out[i * 6 + 4] = (b >> 8) & 255;
     out[i * 6 + 5] = b & 255;
-  } else if(mode->colortype == LCT_GREY_ALPHA) {
-    unsigned short gray = r; /*((unsigned)r + g + b) / 3u;*/
-    out[i * 4 + 0] = (gray >> 8) & 255;
-    out[i * 4 + 1] = gray & 255;
+  }
+  else if(mode->colortype == LCT_GREY_ALPHA)
+  {
+    unsigned short grey = r; /*((unsigned)r + g + b) / 3*/;
+    out[i * 4 + 0] = (grey >> 8) & 255;
+    out[i * 4 + 1] = grey & 255;
     out[i * 4 + 2] = (a >> 8) & 255;
     out[i * 4 + 3] = a & 255;
-  } else if(mode->colortype == LCT_RGBA) {
+  }
+  else if(mode->colortype == LCT_RGBA)
+  {
     out[i * 8 + 0] = (r >> 8) & 255;
     out[i * 8 + 1] = r & 255;
     out[i * 8 + 2] = (g >> 8) & 255;
@@ -3248,23 +3092,33 @@ static void rgba16ToPixel(unsigned char* out, size_t i,
     out[i * 8 + 6] = (a >> 8) & 255;
     out[i * 8 + 7] = a & 255;
   }
+
+  return 0; /*no error*/
 }
 
 /*Get RGBA8 color of pixel with index i (y * width + x) from the raw image with given color type.*/
-static void getPixelColorRGBA8(unsigned char* r, unsigned char* g,
-                               unsigned char* b, unsigned char* a,
-                               const unsigned char* in, size_t i,
-                               const LodePNGColorMode* mode) {
-  if(mode->colortype == LCT_GREY) {
-    if(mode->bitdepth == 8) {
+static unsigned getPixelColorRGBA8(unsigned char* r, unsigned char* g,
+                                   unsigned char* b, unsigned char* a,
+                                   const unsigned char* in, size_t i,
+                                   const LodePNGColorMode* mode,
+                                   unsigned fix_png)
+{
+  if(mode->colortype == LCT_GREY)
+  {
+    if(mode->bitdepth == 8)
+    {
       *r = *g = *b = in[i];
       if(mode->key_defined && *r == mode->key_r) *a = 0;
       else *a = 255;
-    } else if(mode->bitdepth == 16) {
+    }
+    else if(mode->bitdepth == 16)
+    {
       *r = *g = *b = in[i * 2 + 0];
       if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0;
       else *a = 255;
-    } else {
+    }
+    else
+    {
       unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/
       size_t j = i * mode->bitdepth;
       unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth);
@@ -3272,12 +3126,17 @@ static void getPixelColorRGBA8(unsigned char* r, unsigned char* g,
       if(mode->key_defined && value == mode->key_r) *a = 0;
       else *a = 255;
     }
-  } else if(mode->colortype == LCT_RGB) {
-    if(mode->bitdepth == 8) {
+  }
+  else if(mode->colortype == LCT_RGB)
+  {
+    if(mode->bitdepth == 8)
+    {
       *r = in[i * 3 + 0]; *g = in[i * 3 + 1]; *b = in[i * 3 + 2];
       if(mode->key_defined && *r == mode->key_r && *g == mode->key_g && *b == mode->key_b) *a = 0;
       else *a = 255;
-    } else {
+    }
+    else
+    {
       *r = in[i * 6 + 0];
       *g = in[i * 6 + 2];
       *b = in[i * 6 + 4];
@@ -3286,698 +3145,750 @@ static void getPixelColorRGBA8(unsigned char* r, unsigned char* g,
          && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0;
       else *a = 255;
     }
-  } else if(mode->colortype == LCT_PALETTE) {
+  }
+  else if(mode->colortype == LCT_PALETTE)
+  {
     unsigned index;
     if(mode->bitdepth == 8) index = in[i];
-    else {
+    else
+    {
       size_t j = i * mode->bitdepth;
       index = readBitsFromReversedStream(&j, in, mode->bitdepth);
     }
-    /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/
-    *r = mode->palette[index * 4 + 0];
-    *g = mode->palette[index * 4 + 1];
-    *b = mode->palette[index * 4 + 2];
-    *a = mode->palette[index * 4 + 3];
-  } else if(mode->colortype == LCT_GREY_ALPHA) {
-    if(mode->bitdepth == 8) {
+
+    if(index >= mode->palettesize)
+    {
+      /*This is an error according to the PNG spec, but fix_png can ignore it*/
+      if(!fix_png) return (mode->bitdepth == 8 ? 46 : 47); /*index out of palette*/
+      *r = *g = *b = 0;
+      *a = 255;
+    }
+    else
+    {
+      *r = mode->palette[index * 4 + 0];
+      *g = mode->palette[index * 4 + 1];
+      *b = mode->palette[index * 4 + 2];
+      *a = mode->palette[index * 4 + 3];
+    }
+  }
+  else if(mode->colortype == LCT_GREY_ALPHA)
+  {
+    if(mode->bitdepth == 8)
+    {
       *r = *g = *b = in[i * 2 + 0];
       *a = in[i * 2 + 1];
-    } else {
+    }
+    else
+    {
       *r = *g = *b = in[i * 4 + 0];
       *a = in[i * 4 + 2];
     }
-  } else if(mode->colortype == LCT_RGBA) {
-    if(mode->bitdepth == 8) {
+  }
+  else if(mode->colortype == LCT_RGBA)
+  {
+    if(mode->bitdepth == 8)
+    {
       *r = in[i * 4 + 0];
       *g = in[i * 4 + 1];
       *b = in[i * 4 + 2];
       *a = in[i * 4 + 3];
-    } else {
+    }
+    else
+    {
       *r = in[i * 8 + 0];
       *g = in[i * 8 + 2];
       *b = in[i * 8 + 4];
       *a = in[i * 8 + 6];
     }
   }
+
+  return 0; /*no error*/
 }
 
 /*Similar to getPixelColorRGBA8, but with all the for loops inside of the color
 mode test cases, optimized to convert the colors much faster, when converting
-to the common case of RGBA with 8 bit per channel. buffer must be RGBA with
-enough memory.*/
-static void getPixelColorsRGBA8(unsigned char* LODEPNG_RESTRICT buffer, size_t numpixels,
-                                const unsigned char* LODEPNG_RESTRICT in,
-                                const LodePNGColorMode* mode) {
-  unsigned num_channels = 4;
+to RGBA or RGB with 8 bit per cannel. buffer must be RGBA or RGB output with
+enough memory, if has_alpha is true the output is RGBA. mode has the color mode
+of the input buffer.*/
+static unsigned getPixelColorsRGBA8(unsigned char* buffer, size_t numpixels,
+                                    unsigned has_alpha, const unsigned char* in,
+                                    const LodePNGColorMode* mode,
+                                    unsigned fix_png)
+{
+  unsigned num_channels = has_alpha ? 4 : 3;
   size_t i;
-  if(mode->colortype == LCT_GREY) {
-    if(mode->bitdepth == 8) {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+  if(mode->colortype == LCT_GREY)
+  {
+    if(mode->bitdepth == 8)
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
         buffer[0] = buffer[1] = buffer[2] = in[i];
-        buffer[3] = 255;
-      }
-      if(mode->key_defined) {
-        buffer -= numpixels * num_channels;
-        for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-          if(buffer[0] == mode->key_r) buffer[3] = 0;
-        }
+        if(has_alpha) buffer[3] = mode->key_defined && in[i] == mode->key_r ? 0 : 255;
       }
-    } else if(mode->bitdepth == 16) {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+    }
+    else if(mode->bitdepth == 16)
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
         buffer[0] = buffer[1] = buffer[2] = in[i * 2];
-        buffer[3] = mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r ? 0 : 255;
+        if(has_alpha) buffer[3] = mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r ? 0 : 255;
       }
-    } else {
+    }
+    else
+    {
       unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/
       size_t j = 0;
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
         unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth);
         buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest;
-        buffer[3] = mode->key_defined && value == mode->key_r ? 0 : 255;
+        if(has_alpha) buffer[3] = mode->key_defined && value == mode->key_r ? 0 : 255;
       }
     }
-  } else if(mode->colortype == LCT_RGB) {
-    if(mode->bitdepth == 8) {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-        lodepng_memcpy(buffer, &in[i * 3], 3);
-        buffer[3] = 255;
-      }
-      if(mode->key_defined) {
-        buffer -= numpixels * num_channels;
-        for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-          if(buffer[0] == mode->key_r && buffer[1]== mode->key_g && buffer[2] == mode->key_b) buffer[3] = 0;
-        }
+  }
+  else if(mode->colortype == LCT_RGB)
+  {
+    if(mode->bitdepth == 8)
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
+        buffer[0] = in[i * 3 + 0];
+        buffer[1] = in[i * 3 + 1];
+        buffer[2] = in[i * 3 + 2];
+        if(has_alpha) buffer[3] = mode->key_defined && buffer[0] == mode->key_r
+           && buffer[1]== mode->key_g && buffer[2] == mode->key_b ? 0 : 255;
       }
-    } else {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+    }
+    else
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
         buffer[0] = in[i * 6 + 0];
         buffer[1] = in[i * 6 + 2];
         buffer[2] = in[i * 6 + 4];
-        buffer[3] = mode->key_defined
+        if(has_alpha) buffer[3] = mode->key_defined
            && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
            && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
            && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b ? 0 : 255;
       }
     }
-  } else if(mode->colortype == LCT_PALETTE) {
-    if(mode->bitdepth == 8) {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-        unsigned index = in[i];
-        /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/
-        lodepng_memcpy(buffer, &mode->palette[index * 4], 4);
+  }
+  else if(mode->colortype == LCT_PALETTE)
+  {
+    unsigned index;
+    size_t j = 0;
+    for(i = 0; i < numpixels; i++, buffer += num_channels)
+    {
+      if(mode->bitdepth == 8) index = in[i];
+      else index = readBitsFromReversedStream(&j, in, mode->bitdepth);
+
+      if(index >= mode->palettesize)
+      {
+        /*This is an error according to the PNG spec, but fix_png can ignore it*/
+        if(!fix_png) return (mode->bitdepth == 8 ? 46 : 47); /*index out of palette*/
+        buffer[0] = buffer[1] = buffer[2] = 0;
+        if(has_alpha) buffer[3] = 255;
       }
-    } else {
-      size_t j = 0;
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-        unsigned index = readBitsFromReversedStream(&j, in, mode->bitdepth);
-        /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/
-        lodepng_memcpy(buffer, &mode->palette[index * 4], 4);
+      else
+      {
+        buffer[0] = mode->palette[index * 4 + 0];
+        buffer[1] = mode->palette[index * 4 + 1];
+        buffer[2] = mode->palette[index * 4 + 2];
+        if(has_alpha) buffer[3] = mode->palette[index * 4 + 3];
       }
     }
-  } else if(mode->colortype == LCT_GREY_ALPHA) {
-    if(mode->bitdepth == 8) {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+  }
+  else if(mode->colortype == LCT_GREY_ALPHA)
+  {
+    if(mode->bitdepth == 8)
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
         buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0];
-        buffer[3] = in[i * 2 + 1];
-      }
-    } else {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-        buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0];
-        buffer[3] = in[i * 4 + 2];
+        if(has_alpha) buffer[3] = in[i * 2 + 1];
       }
     }
-  } else if(mode->colortype == LCT_RGBA) {
-    if(mode->bitdepth == 8) {
-      lodepng_memcpy(buffer, in, numpixels * 4);
-    } else {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-        buffer[0] = in[i * 8 + 0];
-        buffer[1] = in[i * 8 + 2];
-        buffer[2] = in[i * 8 + 4];
-        buffer[3] = in[i * 8 + 6];
+    else
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
+        buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0];
+        if(has_alpha) buffer[3] = in[i * 4 + 2];
       }
     }
   }
-}
-
-/*Similar to getPixelColorsRGBA8, but with 3-channel RGB output.*/
-static void getPixelColorsRGB8(unsigned char* LODEPNG_RESTRICT buffer, size_t numpixels,
-                               const unsigned char* LODEPNG_RESTRICT in,
-                               const LodePNGColorMode* mode) {
-  const unsigned num_channels = 3;
-  size_t i;
-  if(mode->colortype == LCT_GREY) {
-    if(mode->bitdepth == 8) {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-        buffer[0] = buffer[1] = buffer[2] = in[i];
-      }
-    } else if(mode->bitdepth == 16) {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-        buffer[0] = buffer[1] = buffer[2] = in[i * 2];
-      }
-    } else {
-      unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/
-      size_t j = 0;
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-        unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth);
-        buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest;
-      }
-    }
-  } else if(mode->colortype == LCT_RGB) {
-    if(mode->bitdepth == 8) {
-      lodepng_memcpy(buffer, in, numpixels * 3);
-    } else {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-        buffer[0] = in[i * 6 + 0];
-        buffer[1] = in[i * 6 + 2];
-        buffer[2] = in[i * 6 + 4];
-      }
-    }
-  } else if(mode->colortype == LCT_PALETTE) {
-    if(mode->bitdepth == 8) {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-        unsigned index = in[i];
-        /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/
-        lodepng_memcpy(buffer, &mode->palette[index * 4], 3);
-      }
-    } else {
-      size_t j = 0;
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-        unsigned index = readBitsFromReversedStream(&j, in, mode->bitdepth);
-        /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/
-        lodepng_memcpy(buffer, &mode->palette[index * 4], 3);
+  else if(mode->colortype == LCT_RGBA)
+  {
+    if(mode->bitdepth == 8)
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
+        buffer[0] = in[i * 4 + 0];
+        buffer[1] = in[i * 4 + 1];
+        buffer[2] = in[i * 4 + 2];
+        if(has_alpha) buffer[3] = in[i * 4 + 3];
       }
     }
-  } else if(mode->colortype == LCT_GREY_ALPHA) {
-    if(mode->bitdepth == 8) {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-        buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0];
-      }
-    } else {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-        buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0];
-      }
-    }
-  } else if(mode->colortype == LCT_RGBA) {
-    if(mode->bitdepth == 8) {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
-        lodepng_memcpy(buffer, &in[i * 4], 3);
-      }
-    } else {
-      for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+    else
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
         buffer[0] = in[i * 8 + 0];
         buffer[1] = in[i * 8 + 2];
         buffer[2] = in[i * 8 + 4];
+        if(has_alpha) buffer[3] = in[i * 8 + 6];
       }
     }
   }
+
+  return 0; /*no error*/
 }
 
 /*Get RGBA16 color of pixel with index i (y * width + x) from the raw image with
 given color type, but the given color type must be 16-bit itself.*/
-static void getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned short* b, unsigned short* a,
-                                const unsigned char* in, size_t i, const LodePNGColorMode* mode) {
-  if(mode->colortype == LCT_GREY) {
+static unsigned getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned short* b, unsigned short* a,
+                                    const unsigned char* in, size_t i, const LodePNGColorMode* mode)
+{
+  if(mode->bitdepth != 16) return 85; /*error: this function only supports 16-bit input*/
+
+  if(mode->colortype == LCT_GREY)
+  {
     *r = *g = *b = 256 * in[i * 2 + 0] + in[i * 2 + 1];
     if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0;
     else *a = 65535;
-  } else if(mode->colortype == LCT_RGB) {
-    *r = 256u * in[i * 6 + 0] + in[i * 6 + 1];
-    *g = 256u * in[i * 6 + 2] + in[i * 6 + 3];
-    *b = 256u * in[i * 6 + 4] + in[i * 6 + 5];
-    if(mode->key_defined
-       && 256u * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
-       && 256u * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
-       && 256u * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0;
+  }
+  else if(mode->colortype == LCT_RGB)
+  {
+    *r = 256 * in[i * 6 + 0] + in[i * 6 + 1];
+    *g = 256 * in[i * 6 + 2] + in[i * 6 + 3];
+    *b = 256 * in[i * 6 + 4] + in[i * 6 + 5];
+    if(mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
+       && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
+       && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0;
     else *a = 65535;
-  } else if(mode->colortype == LCT_GREY_ALPHA) {
-    *r = *g = *b = 256u * in[i * 4 + 0] + in[i * 4 + 1];
-    *a = 256u * in[i * 4 + 2] + in[i * 4 + 3];
-  } else if(mode->colortype == LCT_RGBA) {
-    *r = 256u * in[i * 8 + 0] + in[i * 8 + 1];
-    *g = 256u * in[i * 8 + 2] + in[i * 8 + 3];
-    *b = 256u * in[i * 8 + 4] + in[i * 8 + 5];
-    *a = 256u * in[i * 8 + 6] + in[i * 8 + 7];
   }
+  else if(mode->colortype == LCT_GREY_ALPHA)
+  {
+    *r = *g = *b = 256 * in[i * 4 + 0] + in[i * 4 + 1];
+    *a = 256 * in[i * 4 + 2] + in[i * 4 + 3];
+  }
+  else if(mode->colortype == LCT_RGBA)
+  {
+    *r = 256 * in[i * 8 + 0] + in[i * 8 + 1];
+    *g = 256 * in[i * 8 + 2] + in[i * 8 + 3];
+    *b = 256 * in[i * 8 + 4] + in[i * 8 + 5];
+    *a = 256 * in[i * 8 + 6] + in[i * 8 + 7];
+  }
+  else return 85; /*error: this function only supports 16-bit input, not palettes*/
+
+  return 0; /*no error*/
 }
 
+/*
+converts from any color type to 24-bit or 32-bit (later maybe more supported). return value = LodePNG error code
+the out buffer must have (w * h * bpp + 7) / 8 bytes, where bpp is the bits per pixel of the output color type
+(lodepng_get_bpp) for < 8 bpp images, there may _not_ be padding bits at the end of scanlines.
+*/
 unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
-                         const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
-                         unsigned w, unsigned h) {
+                         LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
+                         unsigned w, unsigned h, unsigned fix_png)
+{
+  unsigned error = 0;
   size_t i;
   ColorTree tree;
-  size_t numpixels = (size_t)w * (size_t)h;
-  unsigned error = 0;
+  size_t numpixels = w * h;
 
-  if(mode_in->colortype == LCT_PALETTE && !mode_in->palette) {
-    return 107; /* error: must provide palette if input mode is palette */
+  if(lodepng_color_mode_equal(mode_out, mode_in))
+  {
+    size_t numbytes = lodepng_get_raw_size(w, h, mode_in);
+    for(i = 0; i < numbytes; i++) out[i] = in[i];
+    return error;
   }
 
-  if(lodepng_color_mode_equal(mode_out, mode_in)) {
-    size_t numbytes = lodepng_get_raw_size(w, h, mode_in);
-    lodepng_memcpy(out, in, numbytes);
-    return 0;
-  }
-
-  if(mode_out->colortype == LCT_PALETTE) {
-    size_t palettesize = mode_out->palettesize;
-    const unsigned char* palette = mode_out->palette;
-    size_t palsize = (size_t)1u << mode_out->bitdepth;
-    /*if the user specified output palette but did not give the values, assume
-    they want the values of the input color type (assuming that one is palette).
-    Note that we never create a new palette ourselves.*/
-    if(palettesize == 0) {
-      palettesize = mode_in->palettesize;
-      palette = mode_in->palette;
-      /*if the input was also palette with same bitdepth, then the color types are also
-      equal, so copy literally. This to preserve the exact indices that were in the PNG
-      even in case there are duplicate colors in the palette.*/
-      if(mode_in->colortype == LCT_PALETTE && mode_in->bitdepth == mode_out->bitdepth) {
-        size_t numbytes = lodepng_get_raw_size(w, h, mode_in);
-        lodepng_memcpy(out, in, numbytes);
-        return 0;
-      }
-    }
-    if(palettesize < palsize) palsize = palettesize;
+  if(mode_out->colortype == LCT_PALETTE)
+  {
+    size_t palsize = 1 << mode_out->bitdepth;
+    if(mode_out->palettesize < palsize) palsize = mode_out->palettesize;
     color_tree_init(&tree);
-    for(i = 0; i != palsize; ++i) {
-      const unsigned char* p = &palette[i * 4];
-      error = color_tree_add(&tree, p[0], p[1], p[2], p[3], (unsigned)i);
-      if(error) break;
+    for(i = 0; i < palsize; i++)
+    {
+      unsigned char* p = &mode_out->palette[i * 4];
+      color_tree_add(&tree, p[0], p[1], p[2], p[3], i);
     }
   }
 
-  if(!error) {
-    if(mode_in->bitdepth == 16 && mode_out->bitdepth == 16) {
-      for(i = 0; i != numpixels; ++i) {
-        unsigned short r = 0, g = 0, b = 0, a = 0;
-        getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
-        rgba16ToPixel(out, i, mode_out, r, g, b, a);
-      }
-    } else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGBA) {
-      getPixelColorsRGBA8(out, numpixels, in, mode_in);
-    } else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB) {
-      getPixelColorsRGB8(out, numpixels, in, mode_in);
-    } else {
-      unsigned char r = 0, g = 0, b = 0, a = 0;
-      for(i = 0; i != numpixels; ++i) {
-        getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in);
-        error = rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a);
-        if(error) break;
-      }
+  if(mode_in->bitdepth == 16 && mode_out->bitdepth == 16)
+  {
+    for(i = 0; i < numpixels; i++)
+    {
+      unsigned short r = 0, g = 0, b = 0, a = 0;
+      error = getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
+      if(error) break;
+      error = rgba16ToPixel(out, i, mode_out, r, g, b, a);
+      if(error) break;
+    }
+  }
+  else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGBA)
+  {
+    error = getPixelColorsRGBA8(out, numpixels, 1, in, mode_in, fix_png);
+  }
+  else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB)
+  {
+    error = getPixelColorsRGBA8(out, numpixels, 0, in, mode_in, fix_png);
+  }
+  else
+  {
+    unsigned char r = 0, g = 0, b = 0, a = 0;
+    for(i = 0; i < numpixels; i++)
+    {
+      error = getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in, fix_png);
+      if(error) break;
+      error = rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a);
+      if(error) break;
     }
   }
 
-  if(mode_out->colortype == LCT_PALETTE) {
+  if(mode_out->colortype == LCT_PALETTE)
+  {
     color_tree_cleanup(&tree);
   }
 
   return error;
 }
 
+#ifdef LODEPNG_COMPILE_ENCODER
 
-/* Converts a single rgb color without alpha from one type to another, color bits truncated to
-their bitdepth. In case of single channel (gray or palette), only the r channel is used. Slow
-function, do not use to process all pixels of an image. Alpha channel not supported on purpose:
-this is for bKGD, supporting alpha may prevent it from finding a color in the palette, from the
-specification it looks like bKGD should ignore the alpha values of the palette since it can use
-any palette index but doesn't have an alpha channel. Idem with ignoring color key. */
-unsigned lodepng_convert_rgb(
-    unsigned* r_out, unsigned* g_out, unsigned* b_out,
-    unsigned r_in, unsigned g_in, unsigned b_in,
-    const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in) {
-  unsigned r = 0, g = 0, b = 0;
-  unsigned mul = 65535 / ((1u << mode_in->bitdepth) - 1u); /*65535, 21845, 4369, 257, 1*/
-  unsigned shift = 16 - mode_out->bitdepth;
-
-  if(mode_in->colortype == LCT_GREY || mode_in->colortype == LCT_GREY_ALPHA) {
-    r = g = b = r_in * mul;
-  } else if(mode_in->colortype == LCT_RGB || mode_in->colortype == LCT_RGBA) {
-    r = r_in * mul;
-    g = g_in * mul;
-    b = b_in * mul;
-  } else if(mode_in->colortype == LCT_PALETTE) {
-    if(r_in >= mode_in->palettesize) return 82;
-    r = mode_in->palette[r_in * 4 + 0] * 257u;
-    g = mode_in->palette[r_in * 4 + 1] * 257u;
-    b = mode_in->palette[r_in * 4 + 2] * 257u;
-  } else {
-    return 31;
-  }
+typedef struct ColorProfile
+{
+  unsigned char sixteenbit; /*needs more than 8 bits per channel*/
+  unsigned char sixteenbit_done;
 
-  /* now convert to output format */
-  if(mode_out->colortype == LCT_GREY || mode_out->colortype == LCT_GREY_ALPHA) {
-    *r_out = r >> shift ;
-  } else if(mode_out->colortype == LCT_RGB || mode_out->colortype == LCT_RGBA) {
-    *r_out = r >> shift ;
-    *g_out = g >> shift ;
-    *b_out = b >> shift ;
-  } else if(mode_out->colortype == LCT_PALETTE) {
-    unsigned i;
-    /* a 16-bit color cannot be in the palette */
-    if((r >> 8) != (r & 255) || (g >> 8) != (g & 255) || (b >> 8) != (b & 255)) return 82;
-    for(i = 0; i < mode_out->palettesize; i++) {
-      unsigned j = i * 4;
-      if((r >> 8) == mode_out->palette[j + 0] && (g >> 8) == mode_out->palette[j + 1] &&
-          (b >> 8) == mode_out->palette[j + 2]) {
-        *r_out = i;
-        return 0;
-      }
-    }
-    return 82;
-  } else {
-    return 31;
+
+  unsigned char colored; /*not greyscale*/
+  unsigned char colored_done;
+
+  unsigned char key; /*a color key is required, or more*/
+  unsigned short key_r; /*these values are always in 16-bit bitdepth in the profile*/
+  unsigned short key_g;
+  unsigned short key_b;
+  unsigned char alpha; /*alpha channel, or alpha palette, required*/
+  unsigned char alpha_done;
+
+  unsigned numcolors;
+  ColorTree tree; /*for listing the counted colors, up to 256*/
+  unsigned char* palette; /*size 1024. Remember up to the first 256 RGBA colors*/
+  unsigned maxnumcolors; /*if more than that amount counted*/
+  unsigned char numcolors_done;
+
+  unsigned greybits; /*amount of bits required for greyscale (1, 2, 4, 8). Does not take 16 bit into account.*/
+  unsigned char greybits_done;
+
+} ColorProfile;
+
+static void color_profile_init(ColorProfile* profile, const LodePNGColorMode* mode)
+{
+  profile->sixteenbit = 0;
+  profile->sixteenbit_done = mode->bitdepth == 16 ? 0 : 1;
+
+  profile->colored = 0;
+  profile->colored_done = lodepng_is_greyscale_type(mode) ? 1 : 0;
+
+  profile->key = 0;
+  profile->alpha = 0;
+  profile->alpha_done = lodepng_can_have_alpha(mode) ? 0 : 1;
+
+  profile->numcolors = 0;
+  color_tree_init(&profile->tree);
+  profile->palette = (unsigned char*)lodepng_malloc(1024);
+  profile->maxnumcolors = 257;
+  if(lodepng_get_bpp(mode) <= 8)
+  {
+    int bpp = lodepng_get_bpp(mode);
+    profile->maxnumcolors = bpp == 1 ? 2 : (bpp == 2 ? 4 : (bpp == 4 ? 16 : 256));
   }
+  profile->numcolors_done = 0;
 
-  return 0;
+  profile->greybits = 1;
+  profile->greybits_done = lodepng_get_bpp(mode) == 1 ? 1 : 0;
 }
 
-#ifdef LODEPNG_COMPILE_ENCODER
-
-void lodepng_color_stats_init(LodePNGColorStats* stats) {
-  /*stats*/
-  stats->colored = 0;
-  stats->key = 0;
-  stats->key_r = stats->key_g = stats->key_b = 0;
-  stats->alpha = 0;
-  stats->numcolors = 0;
-  stats->bits = 1;
-  stats->numpixels = 0;
-  /*settings*/
-  stats->allow_palette = 1;
-  stats->allow_greyscale = 1;
+static void color_profile_cleanup(ColorProfile* profile)
+{
+  color_tree_cleanup(&profile->tree);
+  lodepng_free(profile->palette);
 }
 
 /*function used for debug purposes with C++*/
-/*void printColorStats(LodePNGColorStats* p) {
-  std::cout << "colored: " << (int)p->colored << ", ";
-  std::cout << "key: " << (int)p->key << ", ";
-  std::cout << "key_r: " << (int)p->key_r << ", ";
-  std::cout << "key_g: " << (int)p->key_g << ", ";
-  std::cout << "key_b: " << (int)p->key_b << ", ";
-  std::cout << "alpha: " << (int)p->alpha << ", ";
-  std::cout << "numcolors: " << (int)p->numcolors << ", ";
-  std::cout << "bits: " << (int)p->bits << std::endl;
+/*void printColorProfile(ColorProfile* p)
+{
+  std::cout << "sixteenbit: " << (int)p->sixteenbit << std::endl;
+  std::cout << "sixteenbit_done: " << (int)p->sixteenbit_done << std::endl;
+  std::cout << "colored: " << (int)p->colored << std::endl;
+  std::cout << "colored_done: " << (int)p->colored_done << std::endl;
+  std::cout << "key: " << (int)p->key << std::endl;
+  std::cout << "key_r: " << (int)p->key_r << std::endl;
+  std::cout << "key_g: " << (int)p->key_g << std::endl;
+  std::cout << "key_b: " << (int)p->key_b << std::endl;
+  std::cout << "alpha: " << (int)p->alpha << std::endl;
+  std::cout << "alpha_done: " << (int)p->alpha_done << std::endl;
+  std::cout << "numcolors: " << (int)p->numcolors << std::endl;
+  std::cout << "maxnumcolors: " << (int)p->maxnumcolors << std::endl;
+  std::cout << "numcolors_done: " << (int)p->numcolors_done << std::endl;
+  std::cout << "greybits: " << (int)p->greybits << std::endl;
+  std::cout << "greybits_done: " << (int)p->greybits_done << std::endl;
 }*/
 
 /*Returns how many bits needed to represent given value (max 8 bit)*/
-static unsigned getValueRequiredBits(unsigned char value) {
+unsigned getValueRequiredBits(unsigned short value)
+{
   if(value == 0 || value == 255) return 1;
   /*The scaling of 2-bit and 4-bit values uses multiples of 85 and 17*/
   if(value % 17 == 0) return value % 85 == 0 ? 2 : 4;
   return 8;
 }
 
-/*stats must already have been inited. */
-unsigned lodepng_compute_color_stats(LodePNGColorStats* stats,
-                                     const unsigned char* in, unsigned w, unsigned h,
-                                     const LodePNGColorMode* mode_in) {
-  size_t i;
-  ColorTree tree;
-  size_t numpixels = (size_t)w * (size_t)h;
+/*profile must already have been inited with mode.
+It's ok to set some parameters of profile to done already.*/
+static unsigned get_color_profile(ColorProfile* profile,
+                                  const unsigned char* in,
+                                  size_t numpixels /*must be full image size, for certain filesize based choices*/,
+                                  const LodePNGColorMode* mode,
+                                  unsigned fix_png)
+{
   unsigned error = 0;
+  size_t i;
 
-  /* mark things as done already if it would be impossible to have a more expensive case */
-  unsigned colored_done = lodepng_is_greyscale_type(mode_in) ? 1 : 0;
-  unsigned alpha_done = lodepng_can_have_alpha(mode_in) ? 0 : 1;
-  unsigned numcolors_done = 0;
-  unsigned bpp = lodepng_get_bpp(mode_in);
-  unsigned bits_done = (stats->bits == 1 && bpp == 1) ? 1 : 0;
-  unsigned sixteen = 0; /* whether the input image is 16 bit */
-  unsigned maxnumcolors = 257;
-  if(bpp <= 8) maxnumcolors = LODEPNG_MIN(257, stats->numcolors + (1u << bpp));
-
-  stats->numpixels += numpixels;
-
-  /*if palette not allowed, no need to compute numcolors*/
-  if(!stats->allow_palette) numcolors_done = 1;
-
-  color_tree_init(&tree);
-
-  /*If the stats was already filled in from previous data, fill its palette in tree
-  and mark things as done already if we know they are the most expensive case already*/
-  if(stats->alpha) alpha_done = 1;
-  if(stats->colored) colored_done = 1;
-  if(stats->bits == 16) numcolors_done = 1;
-  if(stats->bits >= bpp) bits_done = 1;
-  if(stats->numcolors >= maxnumcolors) numcolors_done = 1;
-
-  if(!numcolors_done) {
-    for(i = 0; i < stats->numcolors; i++) {
-      const unsigned char* color = &stats->palette[i * 4];
-      error = color_tree_add(&tree, color[0], color[1], color[2], color[3], i);
-      if(error) goto cleanup;
-    }
-  }
-
-  /*Check if the 16-bit input is truly 16-bit*/
-  if(mode_in->bitdepth == 16 && !sixteen) {
-    unsigned short r = 0, g = 0, b = 0, a = 0;
-    for(i = 0; i != numpixels; ++i) {
-      getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
-      if((r & 255) != ((r >> 8) & 255) || (g & 255) != ((g >> 8) & 255) ||
-         (b & 255) != ((b >> 8) & 255) || (a & 255) != ((a >> 8) & 255)) /*first and second byte differ*/ {
-        stats->bits = 16;
-        sixteen = 1;
-        bits_done = 1;
-        numcolors_done = 1; /*counting colors no longer useful, palette doesn't support 16-bit*/
-        break;
-      }
-    }
-  }
-
-  if(sixteen) {
-    unsigned short r = 0, g = 0, b = 0, a = 0;
+  if(mode->bitdepth == 16)
+  {
+    for(i = 0; i < numpixels; i++)
+    {
+      unsigned short r, g, b, a;
+      error = getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode);
+      if(error) break;
 
-    for(i = 0; i != numpixels; ++i) {
-      getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
+      /*a color is considered good for 8-bit if the first byte and the second byte are equal,
+        (so if it's divisible through 257), NOT necessarily if the second byte is 0*/
+      if(!profile->sixteenbit_done
+          && (((r & 255) != ((r >> 8) & 255))
+           || ((g & 255) != ((g >> 8) & 255))
+           || ((b & 255) != ((b >> 8) & 255))))
+      {
+        profile->sixteenbit = 1;
+        profile->sixteenbit_done = 1;
+        profile->greybits_done = 1; /*greybits is not applicable anymore at 16-bit*/
+        profile->numcolors_done = 1; /*counting colors no longer useful, palette doesn't support 16-bit*/
+      }
 
-      if(!colored_done && (r != g || r != b)) {
-        stats->colored = 1;
-        colored_done = 1;
+      if(!profile->colored_done && (r != g || r != b))
+      {
+        profile->colored = 1;
+        profile->colored_done = 1;
+        profile->greybits_done = 1; /*greybits is not applicable anymore*/
       }
 
-      if(!alpha_done) {
-        unsigned matchkey = (r == stats->key_r && g == stats->key_g && b == stats->key_b);
-        if(a != 65535 && (a != 0 || (stats->key && !matchkey))) {
-          stats->alpha = 1;
-          stats->key = 0;
-          alpha_done = 1;
-        } else if(a == 0 && !stats->alpha && !stats->key) {
-          stats->key = 1;
-          stats->key_r = r;
-          stats->key_g = g;
-          stats->key_b = b;
-        } else if(a == 65535 && stats->key && matchkey) {
-          /* Color key cannot be used if an opaque pixel also has that RGB color. */
-          stats->alpha = 1;
-          stats->key = 0;
-          alpha_done = 1;
+      if(!profile->alpha_done && a != 65535)
+      {
+        /*only use color key if numpixels large enough to justify tRNS chunk size*/
+        if(a == 0 && numpixels > 16 && !(profile->key && (r != profile->key_r || g != profile->key_g || b != profile->key_b)))
+        {
+          if(!profile->alpha && !profile->key)
+          {
+            profile->key = 1;
+            profile->key_r = r;
+            profile->key_g = g;
+            profile->key_b = b;
+          }
+        }
+        else
+        {
+          profile->alpha = 1;
+          profile->alpha_done = 1;
+          profile->greybits_done = 1; /*greybits is not applicable anymore*/
         }
       }
-      if(alpha_done && numcolors_done && colored_done && bits_done) break;
-    }
 
-    if(stats->key && !stats->alpha) {
-      for(i = 0; i != numpixels; ++i) {
-        getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
-        if(a != 0 && r == stats->key_r && g == stats->key_g && b == stats->key_b) {
-          /* Color key cannot be used if an opaque pixel also has that RGB color. */
-          stats->alpha = 1;
-          stats->key = 0;
-          alpha_done = 1;
-        }
+      /* Color key cannot be used if an opaque pixel also has that RGB color. */
+      if(!profile->alpha_done && a == 65535 && profile->key
+          && r == profile->key_r && g == profile->key_g && b == profile->key_b)
+      {
+          profile->alpha = 1;
+          profile->alpha_done = 1;
+          profile->greybits_done = 1; /*greybits is not applicable anymore*/
       }
-    }
-  } else /* < 16-bit */ {
-    unsigned char r = 0, g = 0, b = 0, a = 0;
-    for(i = 0; i != numpixels; ++i) {
-      getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in);
 
-      if(!bits_done && stats->bits < 8) {
-        /*only r is checked, < 8 bits is only relevant for grayscale*/
+      if(!profile->greybits_done)
+      {
+        /*assuming 8-bit r, this test does not care about 16-bit*/
         unsigned bits = getValueRequiredBits(r);
-        if(bits > stats->bits) stats->bits = bits;
+        if(bits > profile->greybits) profile->greybits = bits;
+        if(profile->greybits >= 8) profile->greybits_done = 1;
       }
-      bits_done = (stats->bits >= bpp);
 
-      if(!colored_done && (r != g || r != b)) {
-        stats->colored = 1;
-        colored_done = 1;
-        if(stats->bits < 8) stats->bits = 8; /*PNG has no colored modes with less than 8-bit per channel*/
+      if(!profile->numcolors_done)
+      {
+        /*assuming 8-bit rgba, this test does not care about 16-bit*/
+        if(!color_tree_has(&profile->tree, (unsigned char)r, (unsigned char)g, (unsigned char)b, (unsigned char)a))
+        {
+          color_tree_add(&profile->tree, (unsigned char)r, (unsigned char)g, (unsigned char)b, (unsigned char)a,
+            profile->numcolors);
+          if(profile->numcolors < 256)
+          {
+            unsigned char* p = profile->palette;
+            unsigned i = profile->numcolors;
+            p[i * 4 + 0] = (unsigned char)r;
+            p[i * 4 + 1] = (unsigned char)g;
+            p[i * 4 + 2] = (unsigned char)b;
+            p[i * 4 + 3] = (unsigned char)a;
+          }
+          profile->numcolors++;
+          if(profile->numcolors >= profile->maxnumcolors) profile->numcolors_done = 1;
+        }
       }
 
-      if(!alpha_done) {
-        unsigned matchkey = (r == stats->key_r && g == stats->key_g && b == stats->key_b);
-        if(a != 255 && (a != 0 || (stats->key && !matchkey))) {
-          stats->alpha = 1;
-          stats->key = 0;
-          alpha_done = 1;
-          if(stats->bits < 8) stats->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
-        } else if(a == 0 && !stats->alpha && !stats->key) {
-          stats->key = 1;
-          stats->key_r = r;
-          stats->key_g = g;
-          stats->key_b = b;
-        } else if(a == 255 && stats->key && matchkey) {
-          /* Color key cannot be used if an opaque pixel also has that RGB color. */
-          stats->alpha = 1;
-          stats->key = 0;
-          alpha_done = 1;
-          if(stats->bits < 8) stats->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
-        }
+      if(profile->alpha_done && profile->numcolors_done
+      && profile->colored_done && profile->sixteenbit_done && profile->greybits_done)
+      {
+        break;
       }
+    };
+  }
+  else /* < 16-bit */
+  {
+    for(i = 0; i < numpixels; i++)
+    {
+      unsigned char r = 0, g = 0, b = 0, a = 0;
+      error = getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode, fix_png);
+      if(error) break;
 
-      if(!numcolors_done) {
-        if(!color_tree_has(&tree, r, g, b, a)) {
-          error = color_tree_add(&tree, r, g, b, a, stats->numcolors);
-          if(error) goto cleanup;
-          if(stats->numcolors < 256) {
-            unsigned char* p = stats->palette;
-            unsigned n = stats->numcolors;
-            p[n * 4 + 0] = r;
-            p[n * 4 + 1] = g;
-            p[n * 4 + 2] = b;
-            p[n * 4 + 3] = a;
+      if(!profile->colored_done && (r != g || r != b))
+      {
+        profile->colored = 1;
+        profile->colored_done = 1;
+        profile->greybits_done = 1; /*greybits is not applicable anymore*/
+      }
+
+      if(!profile->alpha_done && a != 255)
+      {
+        if(a == 0 && !(profile->key && (r != profile->key_r || g != profile->key_g || b != profile->key_b)))
+        {
+          if(!profile->key)
+          {
+            profile->key = 1;
+            profile->key_r = r;
+            profile->key_g = g;
+            profile->key_b = b;
           }
-          ++stats->numcolors;
-          numcolors_done = stats->numcolors >= maxnumcolors;
+        }
+        else
+        {
+          profile->alpha = 1;
+          profile->alpha_done = 1;
+          profile->greybits_done = 1; /*greybits is not applicable anymore*/
         }
       }
 
-      if(alpha_done && numcolors_done && colored_done && bits_done) break;
-    }
+      /* Color key cannot be used if an opaque pixel also has that RGB color. */
+      if(!profile->alpha_done && a == 255 && profile->key
+          && r == profile->key_r && g == profile->key_g && b == profile->key_b)
+      {
+          profile->alpha = 1;
+          profile->alpha_done = 1;
+          profile->greybits_done = 1; /*greybits is not applicable anymore*/
+      }
 
-    if(stats->key && !stats->alpha) {
-      for(i = 0; i != numpixels; ++i) {
-        getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in);
-        if(a != 0 && r == stats->key_r && g == stats->key_g && b == stats->key_b) {
-          /* Color key cannot be used if an opaque pixel also has that RGB color. */
-          stats->alpha = 1;
-          stats->key = 0;
-          alpha_done = 1;
-          if(stats->bits < 8) stats->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
+      if(!profile->greybits_done)
+      {
+        unsigned bits = getValueRequiredBits(r);
+        if(bits > profile->greybits) profile->greybits = bits;
+        if(profile->greybits >= 8) profile->greybits_done = 1;
+      }
+
+      if(!profile->numcolors_done)
+      {
+        if(!color_tree_has(&profile->tree, r, g, b, a))
+        {
+
+          color_tree_add(&profile->tree, r, g, b, a, profile->numcolors);
+          if(profile->numcolors < 256)
+          {
+            unsigned char* p = profile->palette;
+            unsigned i = profile->numcolors;
+            p[i * 4 + 0] = r;
+            p[i * 4 + 1] = g;
+            p[i * 4 + 2] = b;
+            p[i * 4 + 3] = a;
+          }
+          profile->numcolors++;
+          if(profile->numcolors >= profile->maxnumcolors) profile->numcolors_done = 1;
         }
       }
-    }
 
-    /*make the stats's key always 16-bit for consistency - repeat each byte twice*/
-    stats->key_r += (stats->key_r << 8);
-    stats->key_g += (stats->key_g << 8);
-    stats->key_b += (stats->key_b << 8);
+      if(profile->alpha_done && profile->numcolors_done && profile->colored_done && profile->greybits_done)
+      {
+        break;
+      }
+    };
+  }
+
+  /*make the profile's key always 16-bit for consistency*/
+  if(mode->bitdepth < 16)
+  {
+    /*repeat each byte twice*/
+    profile->key_r *= 257;
+    profile->key_g *= 257;
+    profile->key_b *= 257;
   }
 
-cleanup:
-  color_tree_cleanup(&tree);
   return error;
 }
 
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-/*Adds a single color to the color stats. The stats must already have been inited. The color must be given as 16-bit
-(with 2 bytes repeating for 8-bit and 65535 for opaque alpha channel). This function is expensive, do not call it for
-all pixels of an image but only for a few additional values. */
-static unsigned lodepng_color_stats_add(LodePNGColorStats* stats,
-                                        unsigned r, unsigned g, unsigned b, unsigned a) {
-  unsigned error = 0;
-  unsigned char image[8];
-  LodePNGColorMode mode;
-  lodepng_color_mode_init(&mode);
-  image[0] = r >> 8; image[1] = r; image[2] = g >> 8; image[3] = g;
-  image[4] = b >> 8; image[5] = b; image[6] = a >> 8; image[7] = a;
-  mode.bitdepth = 16;
-  mode.colortype = LCT_RGBA;
-  error = lodepng_compute_color_stats(stats, image, 1, 1, &mode);
-  lodepng_color_mode_cleanup(&mode);
-  return error;
+static void setColorKeyFrom16bit(LodePNGColorMode* mode_out, unsigned r, unsigned g, unsigned b, unsigned bitdepth)
+{
+  unsigned mask = (1 << bitdepth) - 1;
+  mode_out->key_defined = 1;
+  mode_out->key_r = r & mask;
+  mode_out->key_g = g & mask;
+  mode_out->key_b = b & mask;
 }
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
 
-/*Computes a minimal PNG color model that can contain all colors as indicated by the stats.
-The stats should be computed with lodepng_compute_color_stats.
-mode_in is raw color profile of the image the stats were computed on, to copy palette order from when relevant.
-Minimal PNG color model means the color type and bit depth that gives smallest amount of bits in the output image,
-e.g. gray if only grayscale pixels, palette if less than 256 colors, color key if only single transparent color, ...
-This is used if auto_convert is enabled (it is by default).
-*/
-static unsigned auto_choose_color(LodePNGColorMode* mode_out,
-                                  const LodePNGColorMode* mode_in,
-                                  const LodePNGColorStats* stats) {
+/*updates values of mode with a potentially smaller color model. mode_out should
+contain the user chosen color model, but will be overwritten with the new chosen one.*/
+unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out,
+                                   const unsigned char* image, unsigned w, unsigned h,
+                                   const LodePNGColorMode* mode_in,
+                                   LodePNGAutoConvert auto_convert)
+{
+  ColorProfile profile;
   unsigned error = 0;
-  unsigned palettebits;
-  size_t i, n;
-  size_t numpixels = stats->numpixels;
-  unsigned palette_ok, gray_ok;
-
-  unsigned alpha = stats->alpha;
-  unsigned key = stats->key;
-  unsigned bits = stats->bits;
-
-  mode_out->key_defined = 0;
-
-  if(key && numpixels <= 16) {
-    alpha = 1; /*too few pixels to justify tRNS chunk overhead*/
-    key = 0;
-    if(bits < 8) bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
-  }
-
-  gray_ok = !stats->colored;
-  if(!stats->allow_greyscale) gray_ok = 0;
-  if(!gray_ok && bits < 8) bits = 8;
-
-  n = stats->numcolors;
-  palettebits = n <= 2 ? 1 : (n <= 4 ? 2 : (n <= 16 ? 4 : 8));
-  palette_ok = n <= 256 && bits <= 8 && n != 0; /*n==0 means likely numcolors wasn't computed*/
-  if(numpixels < n * 2) palette_ok = 0; /*don't add palette overhead if image has only a few pixels*/
-  if(gray_ok && !alpha && bits <= palettebits) palette_ok = 0; /*gray is less overhead*/
-  if(!stats->allow_palette) palette_ok = 0;
-
-  if(palette_ok) {
-    const unsigned char* p = stats->palette;
-    lodepng_palette_clear(mode_out); /*remove potential earlier palette*/
-    for(i = 0; i != stats->numcolors; ++i) {
-      error = lodepng_palette_add(mode_out, p[i * 4 + 0], p[i * 4 + 1], p[i * 4 + 2], p[i * 4 + 3]);
-      if(error) break;
+  int no_nibbles = auto_convert == LAC_AUTO_NO_NIBBLES || auto_convert == LAC_AUTO_NO_NIBBLES_NO_PALETTE;
+  int no_palette = auto_convert == LAC_AUTO_NO_PALETTE || auto_convert == LAC_AUTO_NO_NIBBLES_NO_PALETTE;
+
+  if(auto_convert == LAC_ALPHA)
+  {
+    if(mode_out->colortype != LCT_RGBA && mode_out->colortype != LCT_GREY_ALPHA) return 0;
+  }
+
+  color_profile_init(&profile, mode_in);
+  if(auto_convert == LAC_ALPHA)
+  {
+    profile.colored_done = 1;
+    profile.greybits_done = 1;
+    profile.numcolors_done = 1;
+    profile.sixteenbit_done = 1;
+  }
+  error = get_color_profile(&profile, image, w * h, mode_in, 0 /*fix_png*/);
+  if(!error && auto_convert == LAC_ALPHA)
+  {
+    if(!profile.alpha)
+    {
+      mode_out->colortype = (mode_out->colortype == LCT_RGBA ? LCT_RGB : LCT_GREY);
+      if(profile.key) setColorKeyFrom16bit(mode_out, profile.key_r, profile.key_g, profile.key_b, mode_out->bitdepth);
+    }
+  }
+  else if(!error && auto_convert != LAC_ALPHA)
+  {
+    mode_out->key_defined = 0;
+
+    if(profile.sixteenbit)
+    {
+      mode_out->bitdepth = 16;
+      if(profile.alpha)
+      {
+        mode_out->colortype = profile.colored ? LCT_RGBA : LCT_GREY_ALPHA;
+      }
+      else
+      {
+        mode_out->colortype = profile.colored ? LCT_RGB : LCT_GREY;
+        if(profile.key) setColorKeyFrom16bit(mode_out, profile.key_r, profile.key_g, profile.key_b, mode_out->bitdepth);
+      }
     }
+    else /*less than 16 bits per channel*/
+    {
+      /*don't add palette overhead if image hasn't got a lot of pixels*/
+      unsigned n = profile.numcolors;
+      int palette_ok = !no_palette && n <= 256 && (n * 2 < w * h);
+      unsigned palettebits = n <= 2 ? 1 : (n <= 4 ? 2 : (n <= 16 ? 4 : 8));
+      int grey_ok = !profile.colored && !profile.alpha; /*grey without alpha, with potentially low bits*/
+      if(palette_ok || grey_ok)
+      {
+        if(!palette_ok || (grey_ok && profile.greybits <= palettebits))
+        {
+          unsigned grey = profile.key_r;
+          mode_out->colortype = LCT_GREY;
+          mode_out->bitdepth = profile.greybits;
+          if(profile.key) setColorKeyFrom16bit(mode_out, grey, grey, grey, mode_out->bitdepth);
+        }
+        else
+        {
+          /*fill in the palette*/
+          unsigned i;
+          unsigned char* p = profile.palette;
+          /*remove potential earlier palette*/
+          lodepng_palette_clear(mode_out);
+          for(i = 0; i < profile.numcolors; i++)
+          {
+            error = lodepng_palette_add(mode_out, p[i * 4 + 0], p[i * 4 + 1], p[i * 4 + 2], p[i * 4 + 3]);
+            if(error) break;
+          }
 
-    mode_out->colortype = LCT_PALETTE;
-    mode_out->bitdepth = palettebits;
-
-    if(mode_in->colortype == LCT_PALETTE && mode_in->palettesize >= mode_out->palettesize
-        && mode_in->bitdepth == mode_out->bitdepth) {
-      /*If input should have same palette colors, keep original to preserve its order and prevent conversion*/
-      lodepng_color_mode_cleanup(mode_out);
-      lodepng_color_mode_copy(mode_out, mode_in);
+          mode_out->colortype = LCT_PALETTE;
+          mode_out->bitdepth = palettebits;
+        }
+      }
+      else /*8-bit per channel*/
+      {
+        mode_out->bitdepth = 8;
+        if(profile.alpha)
+        {
+          mode_out->colortype = profile.colored ? LCT_RGBA : LCT_GREY_ALPHA;
+        }
+        else
+        {
+          mode_out->colortype = profile.colored ? LCT_RGB : LCT_GREY /*LCT_GREY normally won't occur, already done earlier*/;
+          if(profile.key) setColorKeyFrom16bit(mode_out, profile.key_r, profile.key_g, profile.key_b, mode_out->bitdepth);
+        }
+      }
     }
-  } else /*8-bit or 16-bit per channel*/ {
-    mode_out->bitdepth = bits;
-    mode_out->colortype = alpha ? (gray_ok ? LCT_GREY_ALPHA : LCT_RGBA)
-                                : (gray_ok ? LCT_GREY : LCT_RGB);
-    if(key) {
-      unsigned mask = (1u << mode_out->bitdepth) - 1u; /*stats always uses 16-bit, mask converts it*/
-      mode_out->key_r = stats->key_r & mask;
-      mode_out->key_g = stats->key_g & mask;
-      mode_out->key_b = stats->key_b & mask;
-      mode_out->key_defined = 1;
+  }
+
+  color_profile_cleanup(&profile);
+
+  if(mode_out->colortype == LCT_PALETTE && mode_in->palettesize == mode_out->palettesize)
+  {
+    /*In this case keep the palette order of the input, so that the user can choose an optimal one*/
+    size_t i;
+    for(i = 0; i < mode_in->palettesize * 4; i++)
+    {
+      mode_out->palette[i] = mode_in->palette[i];
     }
   }
 
+  if(no_nibbles && mode_out->bitdepth < 8)
+  {
+    /*palette can keep its small amount of colors, as long as no indices use it*/
+    mode_out->bitdepth = 8;
+  }
+
   return error;
 }
 
 #endif /* #ifdef LODEPNG_COMPILE_ENCODER */
 
 /*
-Paeth predictor, used by PNG filter type 4
+Paeth predicter, used by PNG filter type 4
 The parameters are of type short, but should come from unsigned chars, the shorts
 are only needed to make the paeth calculation correct.
 */
-static unsigned char paethPredictor(short a, short b, short c) {
-  short pa = LODEPNG_ABS(b - c);
-  short pb = LODEPNG_ABS(a - c);
-  short pc = LODEPNG_ABS(a + b - c - c);
-  /* return input value associated with smallest of pa, pb, pc (with certain priority if equal) */
-  if(pb < pa) { a = b; pa = pb; }
-  return (pc < pa) ? c : a;
+static unsigned char paethPredictor(short a, short b, short c)
+{
+  short pa = abs(b - c);
+  short pb = abs(a - c);
+  short pc = abs(a + b - c - c);
+
+  if(pc < pa && pc < pb) return (unsigned char)c;
+  else if(pb < pa) return (unsigned char)b;
+  else return (unsigned char)a;
 }
 
 /*shared values used by multiple Adam7 related functions*/
@@ -4003,12 +3914,14 @@ bpp: bits per pixel
  end at a full byte
 */
 static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t filter_passstart[8],
-                                size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp) {
+                                size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp)
+{
   /*the passstart values have 8 values: the 8th one indicates the byte after the end of the 7th (= last) pass*/
   unsigned i;
 
   /*calculate width and height in pixels of each pass*/
-  for(i = 0; i != 7; ++i) {
+  for(i = 0; i < 7; i++)
+  {
     passw[i] = (w + ADAM7_DX[i] - ADAM7_IX[i] - 1) / ADAM7_DX[i];
     passh[i] = (h + ADAM7_DY[i] - ADAM7_IY[i] - 1) / ADAM7_DY[i];
     if(passw[i] == 0) passh[i] = 0;
@@ -4016,14 +3929,15 @@ static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t fil
   }
 
   filter_passstart[0] = padded_passstart[0] = passstart[0] = 0;
-  for(i = 0; i != 7; ++i) {
+  for(i = 0; i < 7; i++)
+  {
     /*if passw[i] is 0, it's 0 bytes, not 1 (no filtertype-byte)*/
     filter_passstart[i + 1] = filter_passstart[i]
-                            + ((passw[i] && passh[i]) ? passh[i] * (1u + (passw[i] * bpp + 7u) / 8u) : 0);
+                            + ((passw[i] && passh[i]) ? passh[i] * (1 + (passw[i] * bpp + 7) / 8) : 0);
     /*bits padded if needed to fill full byte at end of each scanline*/
-    padded_passstart[i + 1] = padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7u) / 8u);
+    padded_passstart[i + 1] = padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7) / 8);
     /*only padded at end of reduced image*/
-    passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7u) / 8u;
+    passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7) / 8;
   }
 }
 
@@ -4035,51 +3949,51 @@ static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t fil
 
 /*read the information from the header and store it in the LodePNGInfo. return value is error*/
 unsigned lodepng_inspect(unsigned* w, unsigned* h, LodePNGState* state,
-                         const unsigned char* in, size_t insize) {
-  unsigned width, height;
+                         const unsigned char* in, size_t insize)
+{
   LodePNGInfo* info = &state->info_png;
-  if(insize == 0 || in == 0) {
+  if(insize == 0 || in == 0)
+  {
     CERROR_RETURN_ERROR(state->error, 48); /*error: the given data is empty*/
   }
-  if(insize < 33) {
+  if(insize < 29)
+  {
     CERROR_RETURN_ERROR(state->error, 27); /*error: the data length is smaller than the length of a PNG header*/
   }
 
   /*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/
-  /* TODO: remove this. One should use a new LodePNGState for new sessions */
   lodepng_info_cleanup(info);
   lodepng_info_init(info);
 
   if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71
-     || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10) {
+     || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10)
+  {
     CERROR_RETURN_ERROR(state->error, 28); /*error: the first 8 bytes are not the correct PNG signature*/
   }
-  if(lodepng_chunk_length(in + 8) != 13) {
-    CERROR_RETURN_ERROR(state->error, 94); /*error: header size must be 13 bytes*/
-  }
-  if(!lodepng_chunk_type_equals(in + 8, "IHDR")) {
+  if(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R')
+  {
     CERROR_RETURN_ERROR(state->error, 29); /*error: it doesn't start with a IHDR chunk!*/
   }
 
   /*read the values given in the header*/
-  width = lodepng_read32bitInt(&in[16]);
-  height = lodepng_read32bitInt(&in[20]);
-  /*TODO: remove the undocumented feature that allows to give null pointers to width or height*/
-  if(w) *w = width;
-  if(h) *h = height;
+  *w = lodepng_read32bitInt(&in[16]);
+  *h = lodepng_read32bitInt(&in[20]);
   info->color.bitdepth = in[24];
   info->color.colortype = (LodePNGColorType)in[25];
   info->compression_method = in[26];
   info->filter_method = in[27];
   info->interlace_method = in[28];
 
-  /*errors returned only after the parsing so other values are still output*/
+  if(!state->decoder.ignore_crc)
+  {
+    unsigned CRC = lodepng_read32bitInt(&in[29]);
+    unsigned checksum = lodepng_crc32(&in[12], 17);
+    if(CRC != checksum)
+    {
+      CERROR_RETURN_ERROR(state->error, 57); /*invalid CRC*/
+    }
+  }
 
-  /*error: invalid image size*/
-  if(width == 0 || height == 0) CERROR_RETURN_ERROR(state->error, 93);
-  /*error: invalid colortype or bitdepth combination*/
-  state->error = checkColorValidity(info->color.colortype, info->color.bitdepth);
-  if(state->error) return state->error;
   /*error: only compression method 0 is allowed in the specification*/
   if(info->compression_method != 0) CERROR_RETURN_ERROR(state->error, 32);
   /*error: only filter method 0 is allowed in the specification*/
@@ -4087,19 +4001,13 @@ unsigned lodepng_inspect(unsigned* w, unsigned* h, LodePNGState* state,
   /*error: only interlace methods 0 and 1 exist in the specification*/
   if(info->interlace_method > 1) CERROR_RETURN_ERROR(state->error, 34);
 
-  if(!state->decoder.ignore_crc) {
-    unsigned CRC = lodepng_read32bitInt(&in[29]);
-    unsigned checksum = lodepng_crc32(&in[12], 17);
-    if(CRC != checksum) {
-      CERROR_RETURN_ERROR(state->error, 57); /*invalid CRC*/
-    }
-  }
-
+  state->error = checkColorValidity(info->color.colortype, info->color.bitdepth);
   return state->error;
 }
 
 static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scanline, const unsigned char* precon,
-                                 size_t bytewidth, unsigned char filterType, size_t length) {
+                                 size_t bytewidth, unsigned char filterType, size_t length)
+{
   /*
   For PNG filter method 0
   unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte,
@@ -4110,92 +4018,69 @@ static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scan
   */
 
   size_t i;
-  switch(filterType) {
+  switch(filterType)
+  {
     case 0:
-      for(i = 0; i != length; ++i) recon[i] = scanline[i];
+      for(i = 0; i < length; i++) recon[i] = scanline[i];
       break;
     case 1:
-      for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i];
-      for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + recon[i - bytewidth];
+      for(i = 0; i < bytewidth; i++) recon[i] = scanline[i];
+      for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth];
       break;
     case 2:
-      if(precon) {
-        for(i = 0; i != length; ++i) recon[i] = scanline[i] + precon[i];
-      } else {
-        for(i = 0; i != length; ++i) recon[i] = scanline[i];
+      if(precon)
+      {
+        for(i = 0; i < length; i++) recon[i] = scanline[i] + precon[i];
+      }
+      else
+      {
+        for(i = 0; i < length; i++) recon[i] = scanline[i];
       }
       break;
     case 3:
-      if(precon) {
-        for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i] + (precon[i] >> 1u);
-        for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) >> 1u);
-      } else {
-        for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i];
-        for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + (recon[i - bytewidth] >> 1u);
+      if(precon)
+      {
+        for(i = 0; i < bytewidth; i++) recon[i] = scanline[i] + precon[i] / 2;
+        for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) / 2);
+      }
+      else
+      {
+        for(i = 0; i < bytewidth; i++) recon[i] = scanline[i];
+        for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth] / 2;
       }
       break;
     case 4:
-      if(precon) {
-        for(i = 0; i != bytewidth; ++i) {
+      if(precon)
+      {
+        for(i = 0; i < bytewidth; i++)
+        {
           recon[i] = (scanline[i] + precon[i]); /*paethPredictor(0, precon[i], 0) is always precon[i]*/
         }
-
-        /* Unroll independent paths of the paeth predictor. A 6x and 8x version would also be possible but that
-        adds too much code. Whether this actually speeds anything up at all depends on compiler and settings. */
-        if(bytewidth >= 4) {
-          for(; i + 3 < length; i += 4) {
-            size_t j = i - bytewidth;
-            unsigned char s0 = scanline[i + 0], s1 = scanline[i + 1], s2 = scanline[i + 2], s3 = scanline[i + 3];
-            unsigned char r0 = recon[j + 0], r1 = recon[j + 1], r2 = recon[j + 2], r3 = recon[j + 3];
-            unsigned char p0 = precon[i + 0], p1 = precon[i + 1], p2 = precon[i + 2], p3 = precon[i + 3];
-            unsigned char q0 = precon[j + 0], q1 = precon[j + 1], q2 = precon[j + 2], q3 = precon[j + 3];
-            recon[i + 0] = s0 + paethPredictor(r0, p0, q0);
-            recon[i + 1] = s1 + paethPredictor(r1, p1, q1);
-            recon[i + 2] = s2 + paethPredictor(r2, p2, q2);
-            recon[i + 3] = s3 + paethPredictor(r3, p3, q3);
-          }
-        } else if(bytewidth >= 3) {
-          for(; i + 2 < length; i += 3) {
-            size_t j = i - bytewidth;
-            unsigned char s0 = scanline[i + 0], s1 = scanline[i + 1], s2 = scanline[i + 2];
-            unsigned char r0 = recon[j + 0], r1 = recon[j + 1], r2 = recon[j + 2];
-            unsigned char p0 = precon[i + 0], p1 = precon[i + 1], p2 = precon[i + 2];
-            unsigned char q0 = precon[j + 0], q1 = precon[j + 1], q2 = precon[j + 2];
-            recon[i + 0] = s0 + paethPredictor(r0, p0, q0);
-            recon[i + 1] = s1 + paethPredictor(r1, p1, q1);
-            recon[i + 2] = s2 + paethPredictor(r2, p2, q2);
-          }
-        } else if(bytewidth >= 2) {
-          for(; i + 1 < length; i += 2) {
-            size_t j = i - bytewidth;
-            unsigned char s0 = scanline[i + 0], s1 = scanline[i + 1];
-            unsigned char r0 = recon[j + 0], r1 = recon[j + 1];
-            unsigned char p0 = precon[i + 0], p1 = precon[i + 1];
-            unsigned char q0 = precon[j + 0], q1 = precon[j + 1];
-            recon[i + 0] = s0 + paethPredictor(r0, p0, q0);
-            recon[i + 1] = s1 + paethPredictor(r1, p1, q1);
-          }
-        }
-
-        for(; i != length; ++i) {
+        for(i = bytewidth; i < length; i++)
+        {
           recon[i] = (scanline[i] + paethPredictor(recon[i - bytewidth], precon[i], precon[i - bytewidth]));
         }
-      } else {
-        for(i = 0; i != bytewidth; ++i) {
+      }
+      else
+      {
+        for(i = 0; i < bytewidth; i++)
+        {
           recon[i] = scanline[i];
         }
-        for(i = bytewidth; i < length; ++i) {
+        for(i = bytewidth; i < length; i++)
+        {
           /*paethPredictor(recon[i - bytewidth], 0, 0) is always recon[i - bytewidth]*/
           recon[i] = (scanline[i] + recon[i - bytewidth]);
         }
       }
       break;
-    default: return 36; /*error: invalid filter type given*/
+    default: return 36; /*error: unexisting filter type given*/
   }
   return 0;
 }
 
-static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) {
+static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
+{
   /*
   For PNG filter method 0
   this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 seven times)
@@ -4208,11 +4093,11 @@ static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w
   unsigned char* prevline = 0;
 
   /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
-  size_t bytewidth = (bpp + 7u) / 8u;
-  /*the width of a scanline in bytes, not including the filter type*/
-  size_t linebytes = lodepng_get_raw_size_idat(w, 1, bpp) - 1u;
+  size_t bytewidth = (bpp + 7) / 8;
+  size_t linebytes = (w * bpp + 7) / 8;
 
-  for(y = 0; y < h; ++y) {
+  for(y = 0; y < h; y++)
+  {
     size_t outindex = linebytes * y;
     size_t inindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
     unsigned char filterType = in[inindex];
@@ -4236,40 +4121,50 @@ out must be big enough AND must be 0 everywhere if bpp < 8 in the current implem
 (because that's likely a little bit faster)
 NOTE: comments about padding bits are only relevant if bpp < 8
 */
-static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) {
+static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
+{
   unsigned passw[7], passh[7];
   size_t filter_passstart[8], padded_passstart[8], passstart[8];
   unsigned i;
 
   Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
 
-  if(bpp >= 8) {
-    for(i = 0; i != 7; ++i) {
+  if(bpp >= 8)
+  {
+    for(i = 0; i < 7; i++)
+    {
       unsigned x, y, b;
-      size_t bytewidth = bpp / 8u;
-      for(y = 0; y < passh[i]; ++y)
-      for(x = 0; x < passw[i]; ++x) {
+      size_t bytewidth = bpp / 8;
+      for(y = 0; y < passh[i]; y++)
+      for(x = 0; x < passw[i]; x++)
+      {
         size_t pixelinstart = passstart[i] + (y * passw[i] + x) * bytewidth;
-        size_t pixeloutstart = ((ADAM7_IY[i] + (size_t)y * ADAM7_DY[i]) * (size_t)w
-                             + ADAM7_IX[i] + (size_t)x * ADAM7_DX[i]) * bytewidth;
-        for(b = 0; b < bytewidth; ++b) {
+        size_t pixeloutstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
+        for(b = 0; b < bytewidth; b++)
+        {
           out[pixeloutstart + b] = in[pixelinstart + b];
         }
       }
     }
-  } else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ {
-    for(i = 0; i != 7; ++i) {
+  }
+  else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/
+  {
+    for(i = 0; i < 7; i++)
+    {
       unsigned x, y, b;
       unsigned ilinebits = bpp * passw[i];
       unsigned olinebits = bpp * w;
       size_t obp, ibp; /*bit pointers (for out and in buffer)*/
-      for(y = 0; y < passh[i]; ++y)
-      for(x = 0; x < passw[i]; ++x) {
+      for(y = 0; y < passh[i]; y++)
+      for(x = 0; x < passw[i]; x++)
+      {
         ibp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
-        obp = (ADAM7_IY[i] + (size_t)y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + (size_t)x * ADAM7_DX[i]) * bpp;
-        for(b = 0; b < bpp; ++b) {
+        obp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
+        for(b = 0; b < bpp; b++)
+        {
           unsigned char bit = readBitFromReversedStream(&ibp, in);
-          setBitOfReversedStream(&obp, out, bit);
+          /*note that this function assumes the out buffer is completely 0, use setBitOfReversedStream otherwise*/
+          setBitOfReversedStream0(&obp, out, bit);
         }
       }
     }
@@ -4277,7 +4172,8 @@ static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsig
 }
 
 static void removePaddingBits(unsigned char* out, const unsigned char* in,
-                              size_t olinebits, size_t ilinebits, unsigned h) {
+                              size_t olinebits, size_t ilinebits, unsigned h)
+{
   /*
   After filtering there are still padding bits if scanlines have non multiple of 8 bit amounts. They need
   to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image buffers
@@ -4290,9 +4186,11 @@ static void removePaddingBits(unsigned char* out, const unsigned char* in,
   unsigned y;
   size_t diff = ilinebits - olinebits;
   size_t ibp = 0, obp = 0; /*input and output bit pointers*/
-  for(y = 0; y < h; ++y) {
+  for(y = 0; y < h; y++)
+  {
     size_t x;
-    for(x = 0; x < olinebits; ++x) {
+    for(x = 0; x < olinebits; x++)
+    {
       unsigned char bit = readBitFromReversedStream(&ibp, in);
       setBitOfReversedStream(&obp, out, bit);
     }
@@ -4304,39 +4202,46 @@ static void removePaddingBits(unsigned char* out, const unsigned char* in,
 the IDAT chunks (with filter index bytes and possible padding bits)
 return value is error*/
 static unsigned postProcessScanlines(unsigned char* out, unsigned char* in,
-                                     unsigned w, unsigned h, const LodePNGInfo* info_png) {
+                                     unsigned w, unsigned h, const LodePNGInfo* info_png)
+{
   /*
   This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype.
   Steps:
-  *) if no Adam7: 1) unfilter 2) remove padding bits (= possible extra bits per scanline if bpp < 8)
+  *) if no Adam7: 1) unfilter 2) remove padding bits (= posible extra bits per scanline if bpp < 8)
   *) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace
   NOTE: the in buffer will be overwritten with intermediate data!
   */
   unsigned bpp = lodepng_get_bpp(&info_png->color);
   if(bpp == 0) return 31; /*error: invalid colortype*/
 
-  if(info_png->interlace_method == 0) {
-    if(bpp < 8 && w * bpp != ((w * bpp + 7u) / 8u) * 8u) {
+  if(info_png->interlace_method == 0)
+  {
+    if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8)
+    {
       CERROR_TRY_RETURN(unfilter(in, in, w, h, bpp));
-      removePaddingBits(out, in, w * bpp, ((w * bpp + 7u) / 8u) * 8u, h);
+      removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h);
     }
-    /*we can immediately filter into the out buffer, no other steps needed*/
+    /*we can immediatly filter into the out buffer, no other steps needed*/
     else CERROR_TRY_RETURN(unfilter(out, in, w, h, bpp));
-  } else /*interlace_method is 1 (Adam7)*/ {
+  }
+  else /*interlace_method is 1 (Adam7)*/
+  {
     unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8];
     unsigned i;
 
     Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
 
-    for(i = 0; i != 7; ++i) {
+    for(i = 0; i < 7; i++)
+    {
       CERROR_TRY_RETURN(unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp));
       /*TODO: possible efficiency improvement: if in this reduced image the bits fit nicely in 1 scanline,
       move bytes instead of bits or move not at all*/
-      if(bpp < 8) {
+      if(bpp < 8)
+      {
         /*remove padding bits in scanlines; after this there still may be padding
         bits between the different reduced images: each reduced image still starts nicely at a byte*/
         removePaddingBits(&in[passstart[i]], &in[padded_passstart[i]], passw[i] * bpp,
-                          ((passw[i] * bpp + 7u) / 8u) * 8u, passh[i]);
+                          ((passw[i] * bpp + 7) / 8) * 8, passh[i]);
       }
     }
 
@@ -4346,17 +4251,21 @@ static unsigned postProcessScanlines(unsigned char* out, unsigned char* in,
   return 0;
 }
 
-static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) {
+static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength)
+{
   unsigned pos = 0, i;
-  color->palettesize = chunkLength / 3u;
-  if(color->palettesize == 0 || color->palettesize > 256) return 38; /*error: palette too small or big*/
-  lodepng_color_mode_alloc_palette(color);
-  if(!color->palette && color->palettesize) {
+  if(color->palette) lodepng_free(color->palette);
+  color->palettesize = chunkLength / 3;
+  color->palette = (unsigned char*)lodepng_malloc(4 * color->palettesize);
+  if(!color->palette && color->palettesize)
+  {
     color->palettesize = 0;
     return 83; /*alloc fail*/
   }
+  if(color->palettesize > 256) return 38; /*error: palette too big*/
 
-  for(i = 0; i != color->palettesize; ++i) {
+  for(i = 0; i < color->palettesize; i++)
+  {
     color->palette[4 * i + 0] = data[pos++]; /*R*/
     color->palette[4 * i + 1] = data[pos++]; /*G*/
     color->palette[4 * i + 2] = data[pos++]; /*B*/
@@ -4366,27 +4275,33 @@ static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* dat
   return 0; /* OK */
 }
 
-static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) {
+static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength)
+{
   unsigned i;
-  if(color->colortype == LCT_PALETTE) {
+  if(color->colortype == LCT_PALETTE)
+  {
     /*error: more alpha values given than there are palette entries*/
-    if(chunkLength > color->palettesize) return 39;
+    if(chunkLength > color->palettesize) return 38;
 
-    for(i = 0; i != chunkLength; ++i) color->palette[4 * i + 3] = data[i];
-  } else if(color->colortype == LCT_GREY) {
-    /*error: this chunk must be 2 bytes for grayscale image*/
+    for(i = 0; i < chunkLength; i++) color->palette[4 * i + 3] = data[i];
+  }
+  else if(color->colortype == LCT_GREY)
+  {
+    /*error: this chunk must be 2 bytes for greyscale image*/
     if(chunkLength != 2) return 30;
 
     color->key_defined = 1;
-    color->key_r = color->key_g = color->key_b = 256u * data[0] + data[1];
-  } else if(color->colortype == LCT_RGB) {
+    color->key_r = color->key_g = color->key_b = 256 * data[0] + data[1];
+  }
+  else if(color->colortype == LCT_RGB)
+  {
     /*error: this chunk must be 6 bytes for RGB image*/
     if(chunkLength != 6) return 41;
 
     color->key_defined = 1;
-    color->key_r = 256u * data[0] + data[1];
-    color->key_g = 256u * data[2] + data[3];
-    color->key_b = 256u * data[4] + data[5];
+    color->key_r = 256 * data[0] + data[1];
+    color->key_g = 256 * data[2] + data[3];
+    color->key_b = 256 * data[4] + data[5];
   }
   else return 42; /*error: tRNS chunk not allowed for other color models*/
 
@@ -4396,47 +4311,52 @@ static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* dat
 
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
 /*background color chunk (bKGD)*/
-static unsigned readChunk_bKGD(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) {
-  if(info->color.colortype == LCT_PALETTE) {
+static unsigned readChunk_bKGD(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
+{
+  if(info->color.colortype == LCT_PALETTE)
+  {
     /*error: this chunk must be 1 byte for indexed color image*/
     if(chunkLength != 1) return 43;
 
-    /*error: invalid palette index, or maybe this chunk appeared before PLTE*/
-    if(data[0] >= info->color.palettesize) return 103;
-
     info->background_defined = 1;
     info->background_r = info->background_g = info->background_b = data[0];
-  } else if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) {
-    /*error: this chunk must be 2 bytes for grayscale image*/
+  }
+  else if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA)
+  {
+    /*error: this chunk must be 2 bytes for greyscale image*/
     if(chunkLength != 2) return 44;
 
-    /*the values are truncated to bitdepth in the PNG file*/
     info->background_defined = 1;
-    info->background_r = info->background_g = info->background_b = 256u * data[0] + data[1];
-  } else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) {
-    /*error: this chunk must be 6 bytes for grayscale image*/
+    info->background_r = info->background_g = info->background_b
+                                 = 256 * data[0] + data[1];
+  }
+  else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA)
+  {
+    /*error: this chunk must be 6 bytes for greyscale image*/
     if(chunkLength != 6) return 45;
 
-    /*the values are truncated to bitdepth in the PNG file*/
     info->background_defined = 1;
-    info->background_r = 256u * data[0] + data[1];
-    info->background_g = 256u * data[2] + data[3];
-    info->background_b = 256u * data[4] + data[5];
+    info->background_r = 256 * data[0] + data[1];
+    info->background_g = 256 * data[2] + data[3];
+    info->background_b = 256 * data[4] + data[5];
   }
 
   return 0; /* OK */
 }
 
 /*text chunk (tEXt)*/
-static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) {
+static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
+{
   unsigned error = 0;
   char *key = 0, *str = 0;
+  unsigned i;
 
-  while(!error) /*not really a while loop, only used to break on error*/ {
+  while(!error) /*not really a while loop, only used to break on error*/
+  {
     unsigned length, string2_begin;
 
     length = 0;
-    while(length < chunkLength && data[length] != 0) ++length;
+    while(length < chunkLength && data[length] != 0) length++;
     /*even though it's not allowed by the standard, no error is thrown if
     there's no null termination char, if the text is empty*/
     if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
@@ -4444,17 +4364,17 @@ static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, siz
     key = (char*)lodepng_malloc(length + 1);
     if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
 
-    lodepng_memcpy(key, data, length);
     key[length] = 0;
+    for(i = 0; i < length; i++) key[i] = data[i];
 
     string2_begin = length + 1; /*skip keyword null terminator*/
 
-    length = (unsigned)(chunkLength < string2_begin ? 0 : chunkLength - string2_begin);
+    length = chunkLength < string2_begin ? 0 : chunkLength - string2_begin;
     str = (char*)lodepng_malloc(length + 1);
     if(!str) CERROR_BREAK(error, 83); /*alloc fail*/
 
-    lodepng_memcpy(str, data + string2_begin, length);
     str[length] = 0;
+    for(i = 0; i < length; i++) str[i] = data[string2_begin + i];
 
     error = lodepng_add_text(info, key, str);
 
@@ -4468,79 +4388,82 @@ static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, siz
 }
 
 /*compressed text chunk (zTXt)*/
-static unsigned readChunk_zTXt(LodePNGInfo* info, const LodePNGDecoderSettings* decoder,
-                               const unsigned char* data, size_t chunkLength) {
+static unsigned readChunk_zTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings,
+                               const unsigned char* data, size_t chunkLength)
+{
   unsigned error = 0;
-
-  /*copy the object to change parameters in it*/
-  LodePNGDecompressSettings zlibsettings = decoder->zlibsettings;
+  unsigned i;
 
   unsigned length, string2_begin;
   char *key = 0;
-  unsigned char* str = 0;
-  size_t size = 0;
+  ucvector decoded;
+
+  ucvector_init(&decoded);
 
-  while(!error) /*not really a while loop, only used to break on error*/ {
-    for(length = 0; length < chunkLength && data[length] != 0; ++length) ;
+  while(!error) /*not really a while loop, only used to break on error*/
+  {
+    for(length = 0; length < chunkLength && data[length] != 0; length++) ;
     if(length + 2 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/
     if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
 
     key = (char*)lodepng_malloc(length + 1);
     if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
 
-    lodepng_memcpy(key, data, length);
     key[length] = 0;
+    for(i = 0; i < length; i++) key[i] = data[i];
 
     if(data[length + 1] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/
 
     string2_begin = length + 2;
     if(string2_begin > chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/
 
-    length = (unsigned)chunkLength - string2_begin;
-    zlibsettings.max_output_size = decoder->max_text_size;
+    length = chunkLength - string2_begin;
     /*will fail if zlib error, e.g. if length is too small*/
-    error = zlib_decompress(&str, &size, 0, &data[string2_begin],
-                            length, &zlibsettings);
-    /*error: compressed text larger than  decoder->max_text_size*/
-    if(error && size > zlibsettings.max_output_size) error = 112;
+    error = zlib_decompress(&decoded.data, &decoded.size,
+                            (unsigned char*)(&data[string2_begin]),
+                            length, zlibsettings);
     if(error) break;
-    error = lodepng_add_text_sized(info, key, (char*)str, size);
+    ucvector_push_back(&decoded, 0);
+
+    error = lodepng_add_text(info, key, (char*)decoded.data);
+
     break;
   }
 
   lodepng_free(key);
-  lodepng_free(str);
+  ucvector_cleanup(&decoded);
 
   return error;
 }
 
 /*international text chunk (iTXt)*/
-static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecoderSettings* decoder,
-                               const unsigned char* data, size_t chunkLength) {
+static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings,
+                               const unsigned char* data, size_t chunkLength)
+{
   unsigned error = 0;
   unsigned i;
 
-  /*copy the object to change parameters in it*/
-  LodePNGDecompressSettings zlibsettings = decoder->zlibsettings;
-
   unsigned length, begin, compressed;
   char *key = 0, *langtag = 0, *transkey = 0;
+  ucvector decoded;
+  ucvector_init(&decoded);
 
-  while(!error) /*not really a while loop, only used to break on error*/ {
+  while(!error) /*not really a while loop, only used to break on error*/
+  {
     /*Quick check if the chunk length isn't too small. Even without check
     it'd still fail with other error checks below if it's too short. This just gives a different error code.*/
     if(chunkLength < 5) CERROR_BREAK(error, 30); /*iTXt chunk too short*/
 
     /*read the key*/
-    for(length = 0; length < chunkLength && data[length] != 0; ++length) ;
+    for(length = 0; length < chunkLength && data[length] != 0; length++) ;
     if(length + 3 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination char, corrupt?*/
     if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
 
     key = (char*)lodepng_malloc(length + 1);
     if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
 
-    lodepng_memcpy(key, data, length);
     key[length] = 0;
+    for(i = 0; i < length; i++) key[i] = data[i];
 
     /*read the compression method*/
     compressed = data[length + 1];
@@ -4552,44 +4475,49 @@ static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecoderSettings*
     /*read the langtag*/
     begin = length + 3;
     length = 0;
-    for(i = begin; i < chunkLength && data[i] != 0; ++i) ++length;
+    for(i = begin; i < chunkLength && data[i] != 0; i++) length++;
 
     langtag = (char*)lodepng_malloc(length + 1);
     if(!langtag) CERROR_BREAK(error, 83); /*alloc fail*/
 
-    lodepng_memcpy(langtag, data + begin, length);
     langtag[length] = 0;
+    for(i = 0; i < length; i++) langtag[i] = data[begin + i];
 
     /*read the transkey*/
     begin += length + 1;
     length = 0;
-    for(i = begin; i < chunkLength && data[i] != 0; ++i) ++length;
+    for(i = begin; i < chunkLength && data[i] != 0; i++) length++;
 
     transkey = (char*)lodepng_malloc(length + 1);
     if(!transkey) CERROR_BREAK(error, 83); /*alloc fail*/
 
-    lodepng_memcpy(transkey, data + begin, length);
     transkey[length] = 0;
+    for(i = 0; i < length; i++) transkey[i] = data[begin + i];
 
     /*read the actual text*/
     begin += length + 1;
 
-    length = (unsigned)chunkLength < begin ? 0 : (unsigned)chunkLength - begin;
+    length = chunkLength < begin ? 0 : chunkLength - begin;
 
-    if(compressed) {
-      unsigned char* str = 0;
-      size_t size = 0;
-      zlibsettings.max_output_size = decoder->max_text_size;
+    if(compressed)
+    {
       /*will fail if zlib error, e.g. if length is too small*/
-      error = zlib_decompress(&str, &size, 0, &data[begin],
-                              length, &zlibsettings);
-      /*error: compressed text larger than  decoder->max_text_size*/
-      if(error && size > zlibsettings.max_output_size) error = 112;
-      if(!error) error = lodepng_add_itext_sized(info, key, langtag, transkey, (char*)str, size);
-      lodepng_free(str);
-    } else {
-      error = lodepng_add_itext_sized(info, key, langtag, transkey, (char*)(data + begin), length);
+      error = zlib_decompress(&decoded.data, &decoded.size,
+                              (unsigned char*)(&data[begin]),
+                              length, zlibsettings);
+      if(error) break;
+      if(decoded.allocsize < decoded.size) decoded.allocsize = decoded.size;
+      ucvector_push_back(&decoded, 0);
     }
+    else
+    {
+      if(!ucvector_resize(&decoded, length + 1)) CERROR_BREAK(error, 83 /*alloc fail*/);
+
+      decoded.data[length] = 0;
+      for(i = 0; i < length; i++) decoded.data[i] = data[begin + i];
+    }
+
+    error = lodepng_add_itext(info, key, langtag, transkey, (char*)decoded.data);
 
     break;
   }
@@ -4597,15 +4525,17 @@ static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecoderSettings*
   lodepng_free(key);
   lodepng_free(langtag);
   lodepng_free(transkey);
+  ucvector_cleanup(&decoded);
 
   return error;
 }
 
-static unsigned readChunk_tIME(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) {
+static unsigned readChunk_tIME(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
+{
   if(chunkLength != 7) return 73; /*invalid tIME chunk size*/
 
   info->time_defined = 1;
-  info->time.year = 256u * data[0] + data[1];
+  info->time.year = 256 * data[0] + data[+ 1];
   info->time.month = data[2];
   info->time.day = data[3];
   info->time.hour = data[4];
@@ -4615,155 +4545,29 @@ static unsigned readChunk_tIME(LodePNGInfo* info, const unsigned char* data, siz
   return 0; /* OK */
 }
 
-static unsigned readChunk_pHYs(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) {
+static unsigned readChunk_pHYs(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
+{
   if(chunkLength != 9) return 74; /*invalid pHYs chunk size*/
 
   info->phys_defined = 1;
-  info->phys_x = 16777216u * data[0] + 65536u * data[1] + 256u * data[2] + data[3];
-  info->phys_y = 16777216u * data[4] + 65536u * data[5] + 256u * data[6] + data[7];
+  info->phys_x = 16777216 * data[0] + 65536 * data[1] + 256 * data[2] + data[3];
+  info->phys_y = 16777216 * data[4] + 65536 * data[5] + 256 * data[6] + data[7];
   info->phys_unit = data[8];
 
   return 0; /* OK */
 }
-
-static unsigned readChunk_gAMA(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) {
-  if(chunkLength != 4) return 96; /*invalid gAMA chunk size*/
-
-  info->gama_defined = 1;
-  info->gama_gamma = 16777216u * data[0] + 65536u * data[1] + 256u * data[2] + data[3];
-
-  return 0; /* OK */
-}
-
-static unsigned readChunk_cHRM(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) {
-  if(chunkLength != 32) return 97; /*invalid cHRM chunk size*/
-
-  info->chrm_defined = 1;
-  info->chrm_white_x = 16777216u * data[ 0] + 65536u * data[ 1] + 256u * data[ 2] + data[ 3];
-  info->chrm_white_y = 16777216u * data[ 4] + 65536u * data[ 5] + 256u * data[ 6] + data[ 7];
-  info->chrm_red_x   = 16777216u * data[ 8] + 65536u * data[ 9] + 256u * data[10] + data[11];
-  info->chrm_red_y   = 16777216u * data[12] + 65536u * data[13] + 256u * data[14] + data[15];
-  info->chrm_green_x = 16777216u * data[16] + 65536u * data[17] + 256u * data[18] + data[19];
-  info->chrm_green_y = 16777216u * data[20] + 65536u * data[21] + 256u * data[22] + data[23];
-  info->chrm_blue_x  = 16777216u * data[24] + 65536u * data[25] + 256u * data[26] + data[27];
-  info->chrm_blue_y  = 16777216u * data[28] + 65536u * data[29] + 256u * data[30] + data[31];
-
-  return 0; /* OK */
-}
-
-static unsigned readChunk_sRGB(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) {
-  if(chunkLength != 1) return 98; /*invalid sRGB chunk size (this one is never ignored)*/
-
-  info->srgb_defined = 1;
-  info->srgb_intent = data[0];
-
-  return 0; /* OK */
-}
-
-static unsigned readChunk_iCCP(LodePNGInfo* info, const LodePNGDecoderSettings* decoder,
-                               const unsigned char* data, size_t chunkLength) {
-  unsigned error = 0;
-  unsigned i;
-  size_t size = 0;
-  /*copy the object to change parameters in it*/
-  LodePNGDecompressSettings zlibsettings = decoder->zlibsettings;
-
-  unsigned length, string2_begin;
-
-  info->iccp_defined = 1;
-  if(info->iccp_name) lodepng_clear_icc(info);
-
-  for(length = 0; length < chunkLength && data[length] != 0; ++length) ;
-  if(length + 2 >= chunkLength) return 75; /*no null termination, corrupt?*/
-  if(length < 1 || length > 79) return 89; /*keyword too short or long*/
-
-  info->iccp_name = (char*)lodepng_malloc(length + 1);
-  if(!info->iccp_name) return 83; /*alloc fail*/
-
-  info->iccp_name[length] = 0;
-  for(i = 0; i != length; ++i) info->iccp_name[i] = (char)data[i];
-
-  if(data[length + 1] != 0) return 72; /*the 0 byte indicating compression must be 0*/
-
-  string2_begin = length + 2;
-  if(string2_begin > chunkLength) return 75; /*no null termination, corrupt?*/
-
-  length = (unsigned)chunkLength - string2_begin;
-  zlibsettings.max_output_size = decoder->max_icc_size;
-  error = zlib_decompress(&info->iccp_profile, &size, 0,
-                          &data[string2_begin],
-                          length, &zlibsettings);
-  /*error: ICC profile larger than  decoder->max_icc_size*/
-  if(error && size > zlibsettings.max_output_size) error = 113;
-  info->iccp_profile_size = size;
-  if(!error && !info->iccp_profile_size) error = 100; /*invalid ICC profile size*/
-  return error;
-}
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-
-unsigned lodepng_inspect_chunk(LodePNGState* state, size_t pos,
-                               const unsigned char* in, size_t insize) {
-  const unsigned char* chunk = in + pos;
-  unsigned chunkLength;
-  const unsigned char* data;
-  unsigned unhandled = 0;
-  unsigned error = 0;
-
-  if(pos + 4 > insize) return 30;
-  chunkLength = lodepng_chunk_length(chunk);
-  if(chunkLength > 2147483647) return 63;
-  data = lodepng_chunk_data_const(chunk);
-  if(data + chunkLength + 4 > in + insize) return 30;
-
-  if(lodepng_chunk_type_equals(chunk, "PLTE")) {
-    error = readChunk_PLTE(&state->info_png.color, data, chunkLength);
-  } else if(lodepng_chunk_type_equals(chunk, "tRNS")) {
-    error = readChunk_tRNS(&state->info_png.color, data, chunkLength);
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-  } else if(lodepng_chunk_type_equals(chunk, "bKGD")) {
-    error = readChunk_bKGD(&state->info_png, data, chunkLength);
-  } else if(lodepng_chunk_type_equals(chunk, "tEXt")) {
-    error = readChunk_tEXt(&state->info_png, data, chunkLength);
-  } else if(lodepng_chunk_type_equals(chunk, "zTXt")) {
-    error = readChunk_zTXt(&state->info_png, &state->decoder, data, chunkLength);
-  } else if(lodepng_chunk_type_equals(chunk, "iTXt")) {
-    error = readChunk_iTXt(&state->info_png, &state->decoder, data, chunkLength);
-  } else if(lodepng_chunk_type_equals(chunk, "tIME")) {
-    error = readChunk_tIME(&state->info_png, data, chunkLength);
-  } else if(lodepng_chunk_type_equals(chunk, "pHYs")) {
-    error = readChunk_pHYs(&state->info_png, data, chunkLength);
-  } else if(lodepng_chunk_type_equals(chunk, "gAMA")) {
-    error = readChunk_gAMA(&state->info_png, data, chunkLength);
-  } else if(lodepng_chunk_type_equals(chunk, "cHRM")) {
-    error = readChunk_cHRM(&state->info_png, data, chunkLength);
-  } else if(lodepng_chunk_type_equals(chunk, "sRGB")) {
-    error = readChunk_sRGB(&state->info_png, data, chunkLength);
-  } else if(lodepng_chunk_type_equals(chunk, "iCCP")) {
-    error = readChunk_iCCP(&state->info_png, &state->decoder, data, chunkLength);
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-  } else {
-    /* unhandled chunk is ok (is not an error) */
-    unhandled = 1;
-  }
-
-  if(!error && !unhandled && !state->decoder.ignore_crc) {
-    if(lodepng_chunk_check_crc(chunk)) return 57; /*invalid CRC*/
-  }
-
-  return error;
-}
 
 /*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/
 static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h,
                           LodePNGState* state,
-                          const unsigned char* in, size_t insize) {
+                          const unsigned char* in, size_t insize)
+{
   unsigned char IEND = 0;
   const unsigned char* chunk;
-  unsigned char* idat; /*the data from idat chunks, zlib compressed*/
-  size_t idatsize = 0;
-  unsigned char* scanlines = 0;
-  size_t scanlines_size = 0, expected_size = 0;
-  size_t outsize = 0;
+  size_t i;
+  ucvector idat; /*the data from idat chunks*/
+  ucvector scanlines;
 
   /*for unknown chunk order*/
   unsigned unknown = 0;
@@ -4771,129 +4575,121 @@ static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h,
   unsigned critical_pos = 1; /*1 = after IHDR, 2 = after PLTE, 3 = after IDAT*/
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
 
-
-  /* safe output values in case error happens */
+  /*provide some proper output values if error will happen*/
   *out = 0;
-  *w = *h = 0;
 
   state->error = lodepng_inspect(w, h, state, in, insize); /*reads header and resets other parameters in state->info_png*/
   if(state->error) return;
 
-  if(lodepng_pixel_overflow(*w, *h, &state->info_png.color, &state->info_raw)) {
-    CERROR_RETURN(state->error, 92); /*overflow possible due to amount of pixels*/
-  }
-
-  /*the input filesize is a safe upper bound for the sum of idat chunks size*/
-  idat = (unsigned char*)lodepng_malloc(insize);
-  if(!idat) CERROR_RETURN(state->error, 83); /*alloc fail*/
-
+  ucvector_init(&idat);
   chunk = &in[33]; /*first byte of the first chunk after the header*/
 
   /*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk.
   IDAT data is put at the start of the in buffer*/
-  while(!IEND && !state->error) {
+  while(!IEND && !state->error)
+  {
     unsigned chunkLength;
     const unsigned char* data; /*the data in the chunk*/
 
     /*error: size of the in buffer too small to contain next chunk*/
-    if((size_t)((chunk - in) + 12) > insize || chunk < in) {
-      if(state->decoder.ignore_end) break; /*other errors may still happen though*/
-      CERROR_BREAK(state->error, 30);
-    }
+    if((size_t)((chunk - in) + 12) > insize || chunk < in) CERROR_BREAK(state->error, 30);
 
     /*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/
     chunkLength = lodepng_chunk_length(chunk);
     /*error: chunk length larger than the max PNG chunk size*/
-    if(chunkLength > 2147483647) {
-      if(state->decoder.ignore_end) break; /*other errors may still happen though*/
-      CERROR_BREAK(state->error, 63);
-    }
+    if(chunkLength > 2147483647) CERROR_BREAK(state->error, 63);
 
-    if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in) {
+    if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in)
+    {
       CERROR_BREAK(state->error, 64); /*error: size of the in buffer too small to contain next chunk*/
     }
 
     data = lodepng_chunk_data_const(chunk);
 
-    unknown = 0;
-
     /*IDAT chunk, containing compressed image data*/
-    if(lodepng_chunk_type_equals(chunk, "IDAT")) {
-      size_t newsize;
-      if(lodepng_addofl(idatsize, chunkLength, &newsize)) CERROR_BREAK(state->error, 95);
-      if(newsize > insize) CERROR_BREAK(state->error, 95);
-      lodepng_memcpy(idat + idatsize, data, chunkLength);
-      idatsize += chunkLength;
+    if(lodepng_chunk_type_equals(chunk, "IDAT"))
+    {
+      size_t oldsize = idat.size;
+      if(!ucvector_resize(&idat, oldsize + chunkLength)) CERROR_BREAK(state->error, 83 /*alloc fail*/);
+      for(i = 0; i < chunkLength; i++) idat.data[oldsize + i] = data[i];
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
       critical_pos = 3;
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-    } else if(lodepng_chunk_type_equals(chunk, "IEND")) {
-      /*IEND chunk*/
+    }
+    /*IEND chunk*/
+    else if(lodepng_chunk_type_equals(chunk, "IEND"))
+    {
       IEND = 1;
-    } else if(lodepng_chunk_type_equals(chunk, "PLTE")) {
-      /*palette chunk (PLTE)*/
+    }
+    /*palette chunk (PLTE)*/
+    else if(lodepng_chunk_type_equals(chunk, "PLTE"))
+    {
       state->error = readChunk_PLTE(&state->info_png.color, data, chunkLength);
       if(state->error) break;
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
       critical_pos = 2;
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-    } else if(lodepng_chunk_type_equals(chunk, "tRNS")) {
-      /*palette transparency chunk (tRNS). Even though this one is an ancillary chunk , it is still compiled
-      in without 'LODEPNG_COMPILE_ANCILLARY_CHUNKS' because it contains essential color information that
-      affects the alpha channel of pixels. */
+    }
+    /*palette transparency chunk (tRNS)*/
+    else if(lodepng_chunk_type_equals(chunk, "tRNS"))
+    {
       state->error = readChunk_tRNS(&state->info_png.color, data, chunkLength);
       if(state->error) break;
+    }
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-      /*background color chunk (bKGD)*/
-    } else if(lodepng_chunk_type_equals(chunk, "bKGD")) {
+    /*background color chunk (bKGD)*/
+    else if(lodepng_chunk_type_equals(chunk, "bKGD"))
+    {
       state->error = readChunk_bKGD(&state->info_png, data, chunkLength);
       if(state->error) break;
-    } else if(lodepng_chunk_type_equals(chunk, "tEXt")) {
-      /*text chunk (tEXt)*/
-      if(state->decoder.read_text_chunks) {
+    }
+    /*text chunk (tEXt)*/
+    else if(lodepng_chunk_type_equals(chunk, "tEXt"))
+    {
+      if(state->decoder.read_text_chunks)
+      {
         state->error = readChunk_tEXt(&state->info_png, data, chunkLength);
         if(state->error) break;
       }
-    } else if(lodepng_chunk_type_equals(chunk, "zTXt")) {
-      /*compressed text chunk (zTXt)*/
-      if(state->decoder.read_text_chunks) {
-        state->error = readChunk_zTXt(&state->info_png, &state->decoder, data, chunkLength);
+    }
+    /*compressed text chunk (zTXt)*/
+    else if(lodepng_chunk_type_equals(chunk, "zTXt"))
+    {
+      if(state->decoder.read_text_chunks)
+      {
+        state->error = readChunk_zTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength);
         if(state->error) break;
       }
-    } else if(lodepng_chunk_type_equals(chunk, "iTXt")) {
-      /*international text chunk (iTXt)*/
-      if(state->decoder.read_text_chunks) {
-        state->error = readChunk_iTXt(&state->info_png, &state->decoder, data, chunkLength);
+    }
+    /*international text chunk (iTXt)*/
+    else if(lodepng_chunk_type_equals(chunk, "iTXt"))
+    {
+      if(state->decoder.read_text_chunks)
+      {
+        state->error = readChunk_iTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength);
         if(state->error) break;
       }
-    } else if(lodepng_chunk_type_equals(chunk, "tIME")) {
+    }
+    else if(lodepng_chunk_type_equals(chunk, "tIME"))
+    {
       state->error = readChunk_tIME(&state->info_png, data, chunkLength);
       if(state->error) break;
-    } else if(lodepng_chunk_type_equals(chunk, "pHYs")) {
+    }
+    else if(lodepng_chunk_type_equals(chunk, "pHYs"))
+    {
       state->error = readChunk_pHYs(&state->info_png, data, chunkLength);
       if(state->error) break;
-    } else if(lodepng_chunk_type_equals(chunk, "gAMA")) {
-      state->error = readChunk_gAMA(&state->info_png, data, chunkLength);
-      if(state->error) break;
-    } else if(lodepng_chunk_type_equals(chunk, "cHRM")) {
-      state->error = readChunk_cHRM(&state->info_png, data, chunkLength);
-      if(state->error) break;
-    } else if(lodepng_chunk_type_equals(chunk, "sRGB")) {
-      state->error = readChunk_sRGB(&state->info_png, data, chunkLength);
-      if(state->error) break;
-    } else if(lodepng_chunk_type_equals(chunk, "iCCP")) {
-      state->error = readChunk_iCCP(&state->info_png, &state->decoder, data, chunkLength);
-      if(state->error) break;
+    }
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-    } else /*it's not an implemented chunk type, so ignore it: skip over the data*/ {
+    else /*it's not an implemented chunk type, so ignore it: skip over the data*/
+    {
       /*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/
-      if(!state->decoder.ignore_critical && !lodepng_chunk_ancillary(chunk)) {
-        CERROR_BREAK(state->error, 69);
-      }
+      if(!lodepng_chunk_ancillary(chunk)) CERROR_BREAK(state->error, 69);
 
       unknown = 1;
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-      if(state->decoder.remember_unknown_chunks) {
+      if(state->decoder.remember_unknown_chunks)
+      {
         state->error = lodepng_chunk_append(&state->info_png.unknown_chunks_data[critical_pos - 1],
                                             &state->info_png.unknown_chunks_size[critical_pos - 1], chunk);
         if(state->error) break;
@@ -4901,150 +4697,143 @@ static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h,
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
     }
 
-    if(!state->decoder.ignore_crc && !unknown) /*check CRC if wanted, only on known chunk types*/ {
+    if(!state->decoder.ignore_crc && !unknown) /*check CRC if wanted, only on known chunk types*/
+    {
       if(lodepng_chunk_check_crc(chunk)) CERROR_BREAK(state->error, 57); /*invalid CRC*/
     }
 
-    if(!IEND) chunk = lodepng_chunk_next_const(chunk, in + insize);
+    if(!IEND) chunk = lodepng_chunk_next_const(chunk);
   }
 
-  if(!state->error && state->info_png.color.colortype == LCT_PALETTE && !state->info_png.color.palette) {
-    state->error = 106; /* error: PNG file must have PLTE chunk if color type is palette */
-  }
-
-  if(!state->error) {
-    /*predict output size, to allocate exact size for output buffer to avoid more dynamic allocation.
-    If the decompressed size does not match the prediction, the image must be corrupt.*/
-    if(state->info_png.interlace_method == 0) {
-      size_t bpp = lodepng_get_bpp(&state->info_png.color);
-      expected_size = lodepng_get_raw_size_idat(*w, *h, bpp);
-    } else {
-      size_t bpp = lodepng_get_bpp(&state->info_png.color);
-      /*Adam-7 interlaced: expected size is the sum of the 7 sub-images sizes*/
-      expected_size = 0;
-      expected_size += lodepng_get_raw_size_idat((*w + 7) >> 3, (*h + 7) >> 3, bpp);
-      if(*w > 4) expected_size += lodepng_get_raw_size_idat((*w + 3) >> 3, (*h + 7) >> 3, bpp);
-      expected_size += lodepng_get_raw_size_idat((*w + 3) >> 2, (*h + 3) >> 3, bpp);
-      if(*w > 2) expected_size += lodepng_get_raw_size_idat((*w + 1) >> 2, (*h + 3) >> 2, bpp);
-      expected_size += lodepng_get_raw_size_idat((*w + 1) >> 1, (*h + 1) >> 2, bpp);
-      if(*w > 1) expected_size += lodepng_get_raw_size_idat((*w + 0) >> 1, (*h + 1) >> 1, bpp);
-      expected_size += lodepng_get_raw_size_idat((*w + 0), (*h + 0) >> 1, bpp);
+  ucvector_init(&scanlines);
+  if(!state->error)
+  {
+    /*maximum final image length is already reserved in the vector's length - this is not really necessary*/
+    if(!ucvector_resize(&scanlines, lodepng_get_raw_size(*w, *h, &state->info_png.color) + *h))
+    {
+      state->error = 83; /*alloc fail*/
     }
-
-    state->error = zlib_decompress(&scanlines, &scanlines_size, expected_size, idat, idatsize, &state->decoder.zlibsettings);
   }
-  if(!state->error && scanlines_size != expected_size) state->error = 91; /*decompressed size doesn't match prediction*/
-  lodepng_free(idat);
-
-  if(!state->error) {
-    outsize = lodepng_get_raw_size(*w, *h, &state->info_png.color);
-    *out = (unsigned char*)lodepng_malloc(outsize);
-    if(!*out) state->error = 83; /*alloc fail*/
+  if(!state->error)
+  {
+    /*decompress with the Zlib decompressor*/
+    state->error = zlib_decompress(&scanlines.data, &scanlines.size, idat.data,
+                                   idat.size, &state->decoder.zlibsettings);
   }
-  if(!state->error) {
-    lodepng_memset(*out, 0, outsize);
-    state->error = postProcessScanlines(*out, scanlines, *w, *h, &state->info_png);
+  ucvector_cleanup(&idat);
+
+  if(!state->error)
+  {
+    ucvector outv;
+    ucvector_init(&outv);
+    if(!ucvector_resizev(&outv,
+        lodepng_get_raw_size(*w, *h, &state->info_png.color), 0)) state->error = 83; /*alloc fail*/
+    if(!state->error) state->error = postProcessScanlines(outv.data, scanlines.data, *w, *h, &state->info_png);
+    *out = outv.data;
   }
-  lodepng_free(scanlines);
+  ucvector_cleanup(&scanlines);
 }
 
 unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h,
                         LodePNGState* state,
-                        const unsigned char* in, size_t insize) {
+                        const unsigned char* in, size_t insize)
+{
   *out = 0;
   decodeGeneric(out, w, h, state, in, insize);
   if(state->error) return state->error;
-  if(!state->decoder.color_convert || lodepng_color_mode_equal(&state->info_raw, &state->info_png.color)) {
+  if(!state->decoder.color_convert || lodepng_color_mode_equal(&state->info_raw, &state->info_png.color))
+  {
     /*same color type, no copying or converting of data needed*/
     /*store the info_png color settings on the info_raw so that the info_raw still reflects what colortype
     the raw image has to the end user*/
-    if(!state->decoder.color_convert) {
+    if(!state->decoder.color_convert)
+    {
       state->error = lodepng_color_mode_copy(&state->info_raw, &state->info_png.color);
       if(state->error) return state->error;
     }
-  } else { /*color conversion needed*/
+  }
+  else
+  {
+    /*color conversion needed; sort of copy of the data*/
     unsigned char* data = *out;
     size_t outsize;
 
     /*TODO: check if this works according to the statement in the documentation: "The converter can convert
-    from grayscale input color type, to 8-bit grayscale or grayscale with alpha"*/
+    from greyscale input color type, to 8-bit greyscale or greyscale with alpha"*/
     if(!(state->info_raw.colortype == LCT_RGB || state->info_raw.colortype == LCT_RGBA)
-       && !(state->info_raw.bitdepth == 8)) {
+       && !(state->info_raw.bitdepth == 8))
+    {
       return 56; /*unsupported color mode conversion*/
     }
 
     outsize = lodepng_get_raw_size(*w, *h, &state->info_raw);
     *out = (unsigned char*)lodepng_malloc(outsize);
-    if(!(*out)) {
+    if(!(*out))
+    {
       state->error = 83; /*alloc fail*/
     }
-    else state->error = lodepng_convert(*out, data, &state->info_raw,
-                                        &state->info_png.color, *w, *h);
+    else state->error = lodepng_convert(*out, data, &state->info_raw, &state->info_png.color, *w, *h, state->decoder.fix_png);
     lodepng_free(data);
   }
   return state->error;
 }
 
 unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in,
-                               size_t insize, LodePNGColorType colortype, unsigned bitdepth) {
+                               size_t insize, LodePNGColorType colortype, unsigned bitdepth)
+{
   unsigned error;
   LodePNGState state;
   lodepng_state_init(&state);
   state.info_raw.colortype = colortype;
   state.info_raw.bitdepth = bitdepth;
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-  /*disable reading things that this function doesn't output*/
-  state.decoder.read_text_chunks = 0;
-  state.decoder.remember_unknown_chunks = 0;
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
   error = lodepng_decode(out, w, h, &state, in, insize);
   lodepng_state_cleanup(&state);
   return error;
 }
 
-unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) {
+unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
+{
   return lodepng_decode_memory(out, w, h, in, insize, LCT_RGBA, 8);
 }
 
-unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) {
+unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
+{
   return lodepng_decode_memory(out, w, h, in, insize, LCT_RGB, 8);
 }
 
 #ifdef LODEPNG_COMPILE_DISK
 unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename,
-                             LodePNGColorType colortype, unsigned bitdepth) {
-  unsigned char* buffer = 0;
+                             LodePNGColorType colortype, unsigned bitdepth)
+{
+  unsigned char* buffer;
   size_t buffersize;
   unsigned error;
-  /* safe output values in case error happens */
-  *out = 0;
-  *w = *h = 0;
   error = lodepng_load_file(&buffer, &buffersize, filename);
   if(!error) error = lodepng_decode_memory(out, w, h, buffer, buffersize, colortype, bitdepth);
   lodepng_free(buffer);
   return error;
 }
 
-unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) {
+unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename)
+{
   return lodepng_decode_file(out, w, h, filename, LCT_RGBA, 8);
 }
 
-unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) {
+unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename)
+{
   return lodepng_decode_file(out, w, h, filename, LCT_RGB, 8);
 }
 #endif /*LODEPNG_COMPILE_DISK*/
 
-void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings) {
+void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings)
+{
   settings->color_convert = 1;
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
   settings->read_text_chunks = 1;
   settings->remember_unknown_chunks = 0;
-  settings->max_text_size = 16777216;
-  settings->max_icc_size = 16777216; /* 16MB is much more than enough for any reasonable ICC profile */
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
   settings->ignore_crc = 0;
-  settings->ignore_critical = 0;
-  settings->ignore_end = 0;
+  settings->fix_png = 0;
   lodepng_decompress_settings_init(&settings->zlibsettings);
 }
 
@@ -5052,7 +4841,8 @@ void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings) {
 
 #if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER)
 
-void lodepng_state_init(LodePNGState* state) {
+void lodepng_state_init(LodePNGState* state)
+{
 #ifdef LODEPNG_COMPILE_DECODER
   lodepng_decoder_settings_init(&state->decoder);
 #endif /*LODEPNG_COMPILE_DECODER*/
@@ -5064,12 +4854,14 @@ void lodepng_state_init(LodePNGState* state) {
   state->error = 1;
 }
 
-void lodepng_state_cleanup(LodePNGState* state) {
+void lodepng_state_cleanup(LodePNGState* state)
+{
   lodepng_color_mode_cleanup(&state->info_raw);
   lodepng_info_cleanup(&state->info_png);
 }
 
-void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source) {
+void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source)
+{
   lodepng_state_cleanup(dest);
   *dest = *source;
   lodepng_color_mode_init(&dest->info_raw);
@@ -5086,375 +4878,370 @@ void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source) {
 /* / PNG Encoder                                                            / */
 /* ////////////////////////////////////////////////////////////////////////// */
 
+/*chunkName must be string of 4 characters*/
+static unsigned addChunk(ucvector* out, const char* chunkName, const unsigned char* data, size_t length)
+{
+  CERROR_TRY_RETURN(lodepng_chunk_create(&out->data, &out->size, (unsigned)length, chunkName, data));
+  out->allocsize = out->size; /*fix the allocsize again*/
+  return 0;
+}
 
-static unsigned writeSignature(ucvector* out) {
-  size_t pos = out->size;
-  const unsigned char signature[] = {137, 80, 78, 71, 13, 10, 26, 10};
+static void writeSignature(ucvector* out)
+{
   /*8 bytes PNG signature, aka the magic bytes*/
-  if(!ucvector_resize(out, out->size + 8)) return 83; /*alloc fail*/
-  lodepng_memcpy(out->data + pos, signature, 8);
-  return 0;
+  ucvector_push_back(out, 137);
+  ucvector_push_back(out, 80);
+  ucvector_push_back(out, 78);
+  ucvector_push_back(out, 71);
+  ucvector_push_back(out, 13);
+  ucvector_push_back(out, 10);
+  ucvector_push_back(out, 26);
+  ucvector_push_back(out, 10);
 }
 
 static unsigned addChunk_IHDR(ucvector* out, unsigned w, unsigned h,
-                              LodePNGColorType colortype, unsigned bitdepth, unsigned interlace_method) {
-  unsigned char *chunk, *data;
-  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 13, "IHDR"));
-  data = chunk + 8;
-
-  lodepng_set32bitInt(data + 0, w); /*width*/
-  lodepng_set32bitInt(data + 4, h); /*height*/
-  data[8] = (unsigned char)bitdepth; /*bit depth*/
-  data[9] = (unsigned char)colortype; /*color type*/
-  data[10] = 0; /*compression method*/
-  data[11] = 0; /*filter method*/
-  data[12] = interlace_method; /*interlace method*/
+                              LodePNGColorType colortype, unsigned bitdepth, unsigned interlace_method)
+{
+  unsigned error = 0;
+  ucvector header;
+  ucvector_init(&header);
 
-  lodepng_chunk_generate_crc(chunk);
-  return 0;
-}
+  lodepng_add32bitInt(&header, w); /*width*/
+  lodepng_add32bitInt(&header, h); /*height*/
+  ucvector_push_back(&header, (unsigned char)bitdepth); /*bit depth*/
+  ucvector_push_back(&header, (unsigned char)colortype); /*color type*/
+  ucvector_push_back(&header, 0); /*compression method*/
+  ucvector_push_back(&header, 0); /*filter method*/
+  ucvector_push_back(&header, interlace_method); /*interlace method*/
 
-/* only adds the chunk if needed (there is a key or palette with alpha) */
-static unsigned addChunk_PLTE(ucvector* out, const LodePNGColorMode* info) {
-  unsigned char* chunk;
-  size_t i, j = 8;
+  error = addChunk(out, "IHDR", header.data, header.size);
+  ucvector_cleanup(&header);
 
-  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, info->palettesize * 3, "PLTE"));
+  return error;
+}
 
-  for(i = 0; i != info->palettesize; ++i) {
+static unsigned addChunk_PLTE(ucvector* out, const LodePNGColorMode* info)
+{
+  unsigned error = 0;
+  size_t i;
+  ucvector PLTE;
+  ucvector_init(&PLTE);
+  for(i = 0; i < info->palettesize * 4; i++)
+  {
     /*add all channels except alpha channel*/
-    chunk[j++] = info->palette[i * 4 + 0];
-    chunk[j++] = info->palette[i * 4 + 1];
-    chunk[j++] = info->palette[i * 4 + 2];
+    if(i % 4 != 3) ucvector_push_back(&PLTE, info->palette[i]);
   }
+  error = addChunk(out, "PLTE", PLTE.data, PLTE.size);
+  ucvector_cleanup(&PLTE);
 
-  lodepng_chunk_generate_crc(chunk);
-  return 0;
+  return error;
 }
 
-static unsigned addChunk_tRNS(ucvector* out, const LodePNGColorMode* info) {
-  unsigned char* chunk = 0;
-
-  if(info->colortype == LCT_PALETTE) {
-    size_t i, amount = info->palettesize;
+static unsigned addChunk_tRNS(ucvector* out, const LodePNGColorMode* info)
+{
+  unsigned error = 0;
+  size_t i;
+  ucvector tRNS;
+  ucvector_init(&tRNS);
+  if(info->colortype == LCT_PALETTE)
+  {
+    size_t amount = info->palettesize;
     /*the tail of palette values that all have 255 as alpha, does not have to be encoded*/
-    for(i = info->palettesize; i != 0; --i) {
-      if(info->palette[4 * (i - 1) + 3] != 255) break;
-      --amount;
-    }
-    if(amount) {
-      CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, amount, "tRNS"));
-      /*add the alpha channel values from the palette*/
-      for(i = 0; i != amount; ++i) chunk[8 + i] = info->palette[4 * i + 3];
-    }
-  } else if(info->colortype == LCT_GREY) {
-    if(info->key_defined) {
-      CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 2, "tRNS"));
-      chunk[8] = (unsigned char)(info->key_r >> 8);
-      chunk[9] = (unsigned char)(info->key_r & 255);
-    }
-  } else if(info->colortype == LCT_RGB) {
-    if(info->key_defined) {
-      CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 6, "tRNS"));
-      chunk[8] = (unsigned char)(info->key_r >> 8);
-      chunk[9] = (unsigned char)(info->key_r & 255);
-      chunk[10] = (unsigned char)(info->key_g >> 8);
-      chunk[11] = (unsigned char)(info->key_g & 255);
-      chunk[12] = (unsigned char)(info->key_b >> 8);
-      chunk[13] = (unsigned char)(info->key_b & 255);
-    }
-  }
-
-  if(chunk) lodepng_chunk_generate_crc(chunk);
-  return 0;
+    for(i = info->palettesize; i > 0; i--)
+    {
+      if(info->palette[4 * (i - 1) + 3] == 255) amount--;
+      else break;
+    }
+    /*add only alpha channel*/
+    for(i = 0; i < amount; i++) ucvector_push_back(&tRNS, info->palette[4 * i + 3]);
+  }
+  else if(info->colortype == LCT_GREY)
+  {
+    if(info->key_defined)
+    {
+      ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256));
+      ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256));
+    }
+  }
+  else if(info->colortype == LCT_RGB)
+  {
+    if(info->key_defined)
+    {
+      ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256));
+      ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256));
+      ucvector_push_back(&tRNS, (unsigned char)(info->key_g / 256));
+      ucvector_push_back(&tRNS, (unsigned char)(info->key_g % 256));
+      ucvector_push_back(&tRNS, (unsigned char)(info->key_b / 256));
+      ucvector_push_back(&tRNS, (unsigned char)(info->key_b % 256));
+    }
+  }
+
+  error = addChunk(out, "tRNS", tRNS.data, tRNS.size);
+  ucvector_cleanup(&tRNS);
+
+  return error;
 }
 
 static unsigned addChunk_IDAT(ucvector* out, const unsigned char* data, size_t datasize,
-                              LodePNGCompressSettings* zlibsettings) {
+                              LodePNGCompressSettings* zlibsettings)
+{
+  ucvector zlibdata;
   unsigned error = 0;
-  unsigned char* zlib = 0;
-  size_t zlibsize = 0;
 
-  error = zlib_compress(&zlib, &zlibsize, data, datasize, zlibsettings);
-  if(!error) {
-    error = lodepng_chunk_createv(out, zlibsize, "IDAT", zlib);
-  }
-  lodepng_free(zlib);
+  /*compress with the Zlib compressor*/
+  ucvector_init(&zlibdata);
+  error = zlib_compress(&zlibdata.data, &zlibdata.size, data, datasize, zlibsettings);
+  if(!error) error = addChunk(out, "IDAT", zlibdata.data, zlibdata.size);
+  ucvector_cleanup(&zlibdata);
+
   return error;
 }
 
-static unsigned addChunk_IEND(ucvector* out) {
-  return lodepng_chunk_createv(out, 0, "IEND", 0);
+static unsigned addChunk_IEND(ucvector* out)
+{
+  unsigned error = 0;
+  error = addChunk(out, "IEND", 0, 0);
+  return error;
 }
 
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
 
-static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring) {
-  unsigned char* chunk = 0;
-  size_t keysize = lodepng_strlen(keyword), textsize = lodepng_strlen(textstring);
-  size_t size = keysize + 1 + textsize;
-  if(keysize < 1 || keysize > 79) return 89; /*error: invalid keyword size*/
-  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, size, "tEXt"));
-  lodepng_memcpy(chunk + 8, keyword, keysize);
-  chunk[8 + keysize] = 0; /*null termination char*/
-  lodepng_memcpy(chunk + 9 + keysize, textstring, textsize);
-  lodepng_chunk_generate_crc(chunk);
-  return 0;
+static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring)
+{
+  unsigned error = 0;
+  size_t i;
+  ucvector text;
+  ucvector_init(&text);
+  for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&text, (unsigned char)keyword[i]);
+  if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/
+  ucvector_push_back(&text, 0); /*0 termination char*/
+  for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&text, (unsigned char)textstring[i]);
+  error = addChunk(out, "tEXt", text.data, text.size);
+  ucvector_cleanup(&text);
+
+  return error;
 }
 
 static unsigned addChunk_zTXt(ucvector* out, const char* keyword, const char* textstring,
-                              LodePNGCompressSettings* zlibsettings) {
+                              LodePNGCompressSettings* zlibsettings)
+{
   unsigned error = 0;
-  unsigned char* chunk = 0;
-  unsigned char* compressed = 0;
-  size_t compressedsize = 0;
-  size_t textsize = lodepng_strlen(textstring);
-  size_t keysize = lodepng_strlen(keyword);
-  if(keysize < 1 || keysize > 79) return 89; /*error: invalid keyword size*/
-
-  error = zlib_compress(&compressed, &compressedsize,
-                        (const unsigned char*)textstring, textsize, zlibsettings);
-  if(!error) {
-    size_t size = keysize + 2 + compressedsize;
-    error = lodepng_chunk_init(&chunk, out, size, "zTXt");
-  }
-  if(!error) {
-    lodepng_memcpy(chunk + 8, keyword, keysize);
-    chunk[8 + keysize] = 0; /*null termination char*/
-    chunk[9 + keysize] = 0; /*compression method: 0*/
-    lodepng_memcpy(chunk + 10 + keysize, compressed, compressedsize);
-    lodepng_chunk_generate_crc(chunk);
-  }
-
-  lodepng_free(compressed);
+  ucvector data, compressed;
+  size_t i, textsize = strlen(textstring);
+
+  ucvector_init(&data);
+  ucvector_init(&compressed);
+  for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]);
+  if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/
+  ucvector_push_back(&data, 0); /*0 termination char*/
+  ucvector_push_back(&data, 0); /*compression method: 0*/
+
+  error = zlib_compress(&compressed.data, &compressed.size,
+                        (unsigned char*)textstring, textsize, zlibsettings);
+  if(!error)
+  {
+    for(i = 0; i < compressed.size; i++) ucvector_push_back(&data, compressed.data[i]);
+    error = addChunk(out, "zTXt", data.data, data.size);
+  }
+
+  ucvector_cleanup(&compressed);
+  ucvector_cleanup(&data);
   return error;
 }
 
-static unsigned addChunk_iTXt(ucvector* out, unsigned compress, const char* keyword, const char* langtag,
-                              const char* transkey, const char* textstring, LodePNGCompressSettings* zlibsettings) {
+static unsigned addChunk_iTXt(ucvector* out, unsigned compressed, const char* keyword, const char* langtag,
+                              const char* transkey, const char* textstring, LodePNGCompressSettings* zlibsettings)
+{
   unsigned error = 0;
-  unsigned char* chunk = 0;
-  unsigned char* compressed = 0;
-  size_t compressedsize = 0;
-  size_t textsize = lodepng_strlen(textstring);
-  size_t keysize = lodepng_strlen(keyword), langsize = lodepng_strlen(langtag), transsize = lodepng_strlen(transkey);
-
-  if(keysize < 1 || keysize > 79) return 89; /*error: invalid keyword size*/
-
-  if(compress) {
-    error = zlib_compress(&compressed, &compressedsize,
-                          (const unsigned char*)textstring, textsize, zlibsettings);
-  }
-  if(!error) {
-    size_t size = keysize + 3 + langsize + 1 + transsize + 1 + (compress ? compressedsize : textsize);
-    error = lodepng_chunk_init(&chunk, out, size, "iTXt");
-  }
-  if(!error) {
-    size_t pos = 8;
-    lodepng_memcpy(chunk + pos, keyword, keysize);
-    pos += keysize;
-    chunk[pos++] = 0; /*null termination char*/
-    chunk[pos++] = (compress ? 1 : 0); /*compression flag*/
-    chunk[pos++] = 0; /*compression method: 0*/
-    lodepng_memcpy(chunk + pos, langtag, langsize);
-    pos += langsize;
-    chunk[pos++] = 0; /*null termination char*/
-    lodepng_memcpy(chunk + pos, transkey, transsize);
-    pos += transsize;
-    chunk[pos++] = 0; /*null termination char*/
-    if(compress) {
-      lodepng_memcpy(chunk + pos, compressed, compressedsize);
-    } else {
-      lodepng_memcpy(chunk + pos, textstring, textsize);
-    }
-    lodepng_chunk_generate_crc(chunk);
-  }
-
-  lodepng_free(compressed);
+  ucvector data;
+  size_t i, textsize = strlen(textstring);
+
+  ucvector_init(&data);
+
+  for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]);
+  if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/
+  ucvector_push_back(&data, 0); /*null termination char*/
+  ucvector_push_back(&data, compressed ? 1 : 0); /*compression flag*/
+  ucvector_push_back(&data, 0); /*compression method*/
+  for(i = 0; langtag[i] != 0; i++) ucvector_push_back(&data, (unsigned char)langtag[i]);
+  ucvector_push_back(&data, 0); /*null termination char*/
+  for(i = 0; transkey[i] != 0; i++) ucvector_push_back(&data, (unsigned char)transkey[i]);
+  ucvector_push_back(&data, 0); /*null termination char*/
+
+  if(compressed)
+  {
+    ucvector compressed_data;
+    ucvector_init(&compressed_data);
+    error = zlib_compress(&compressed_data.data, &compressed_data.size,
+                          (unsigned char*)textstring, textsize, zlibsettings);
+    if(!error)
+    {
+      for(i = 0; i < compressed_data.size; i++) ucvector_push_back(&data, compressed_data.data[i]);
+    }
+    ucvector_cleanup(&compressed_data);
+  }
+  else /*not compressed*/
+  {
+    for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&data, (unsigned char)textstring[i]);
+  }
+
+  if(!error) error = addChunk(out, "iTXt", data.data, data.size);
+  ucvector_cleanup(&data);
   return error;
 }
 
-static unsigned addChunk_bKGD(ucvector* out, const LodePNGInfo* info) {
-  unsigned char* chunk = 0;
-  if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) {
-    CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 2, "bKGD"));
-    chunk[8] = (unsigned char)(info->background_r >> 8);
-    chunk[9] = (unsigned char)(info->background_r & 255);
-  } else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) {
-    CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 6, "bKGD"));
-    chunk[8] = (unsigned char)(info->background_r >> 8);
-    chunk[9] = (unsigned char)(info->background_r & 255);
-    chunk[10] = (unsigned char)(info->background_g >> 8);
-    chunk[11] = (unsigned char)(info->background_g & 255);
-    chunk[12] = (unsigned char)(info->background_b >> 8);
-    chunk[13] = (unsigned char)(info->background_b & 255);
-  } else if(info->color.colortype == LCT_PALETTE) {
-    CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 1, "bKGD"));
-    chunk[8] = (unsigned char)(info->background_r & 255); /*palette index*/
-  }
-  if(chunk) lodepng_chunk_generate_crc(chunk);
-  return 0;
-}
+static unsigned addChunk_bKGD(ucvector* out, const LodePNGInfo* info)
+{
+  unsigned error = 0;
+  ucvector bKGD;
+  ucvector_init(&bKGD);
+  if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA)
+  {
+    ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256));
+    ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256));
+  }
+  else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA)
+  {
+    ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256));
+    ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256));
+    ucvector_push_back(&bKGD, (unsigned char)(info->background_g / 256));
+    ucvector_push_back(&bKGD, (unsigned char)(info->background_g % 256));
+    ucvector_push_back(&bKGD, (unsigned char)(info->background_b / 256));
+    ucvector_push_back(&bKGD, (unsigned char)(info->background_b % 256));
+  }
+  else if(info->color.colortype == LCT_PALETTE)
+  {
+    ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); /*palette index*/
+  }
+
+  error = addChunk(out, "bKGD", bKGD.data, bKGD.size);
+  ucvector_cleanup(&bKGD);
 
-static unsigned addChunk_tIME(ucvector* out, const LodePNGTime* time) {
-  unsigned char* chunk;
-  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 7, "tIME"));
-  chunk[8] = (unsigned char)(time->year >> 8);
-  chunk[9] = (unsigned char)(time->year & 255);
-  chunk[10] = (unsigned char)time->month;
-  chunk[11] = (unsigned char)time->day;
-  chunk[12] = (unsigned char)time->hour;
-  chunk[13] = (unsigned char)time->minute;
-  chunk[14] = (unsigned char)time->second;
-  lodepng_chunk_generate_crc(chunk);
-  return 0;
+  return error;
 }
 
-static unsigned addChunk_pHYs(ucvector* out, const LodePNGInfo* info) {
-  unsigned char* chunk;
-  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 9, "pHYs"));
-  lodepng_set32bitInt(chunk + 8, info->phys_x);
-  lodepng_set32bitInt(chunk + 12, info->phys_y);
-  chunk[16] = info->phys_unit;
-  lodepng_chunk_generate_crc(chunk);
-  return 0;
+static unsigned addChunk_tIME(ucvector* out, const LodePNGTime* time)
+{
+  unsigned error = 0;
+  unsigned char* data = (unsigned char*)lodepng_malloc(7);
+  if(!data) return 83; /*alloc fail*/
+  data[0] = (unsigned char)(time->year / 256);
+  data[1] = (unsigned char)(time->year % 256);
+  data[2] = time->month;
+  data[3] = time->day;
+  data[4] = time->hour;
+  data[5] = time->minute;
+  data[6] = time->second;
+  error = addChunk(out, "tIME", data, 7);
+  lodepng_free(data);
+  return error;
 }
 
-static unsigned addChunk_gAMA(ucvector* out, const LodePNGInfo* info) {
-  unsigned char* chunk;
-  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 4, "gAMA"));
-  lodepng_set32bitInt(chunk + 8, info->gama_gamma);
-  lodepng_chunk_generate_crc(chunk);
-  return 0;
-}
+static unsigned addChunk_pHYs(ucvector* out, const LodePNGInfo* info)
+{
+  unsigned error = 0;
+  ucvector data;
+  ucvector_init(&data);
 
-static unsigned addChunk_cHRM(ucvector* out, const LodePNGInfo* info) {
-  unsigned char* chunk;
-  CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 32, "cHRM"));
-  lodepng_set32bitInt(chunk + 8, info->chrm_white_x);
-  lodepng_set32bitInt(chunk + 12, info->chrm_white_y);
-  lodepng_set32bitInt(chunk + 16, info->chrm_red_x);
-  lodepng_set32bitInt(chunk + 20, info->chrm_red_y);
-  lodepng_set32bitInt(chunk + 24, info->chrm_green_x);
-  lodepng_set32bitInt(chunk + 28, info->chrm_green_y);
-  lodepng_set32bitInt(chunk + 32, info->chrm_blue_x);
-  lodepng_set32bitInt(chunk + 36, info->chrm_blue_y);
-  lodepng_chunk_generate_crc(chunk);
-  return 0;
-}
+  lodepng_add32bitInt(&data, info->phys_x);
+  lodepng_add32bitInt(&data, info->phys_y);
+  ucvector_push_back(&data, info->phys_unit);
 
-static unsigned addChunk_sRGB(ucvector* out, const LodePNGInfo* info) {
-  unsigned char data = info->srgb_intent;
-  return lodepng_chunk_createv(out, 1, "sRGB", &data);
-}
+  error = addChunk(out, "pHYs", data.data, data.size);
+  ucvector_cleanup(&data);
 
-static unsigned addChunk_iCCP(ucvector* out, const LodePNGInfo* info, LodePNGCompressSettings* zlibsettings) {
-  unsigned error = 0;
-  unsigned char* chunk = 0;
-  unsigned char* compressed = 0;
-  size_t compressedsize = 0;
-  size_t keysize = lodepng_strlen(info->iccp_name);
-
-  if(keysize < 1 || keysize > 79) return 89; /*error: invalid keyword size*/
-  error = zlib_compress(&compressed, &compressedsize,
-                        info->iccp_profile, info->iccp_profile_size, zlibsettings);
-  if(!error) {
-    size_t size = keysize + 2 + compressedsize;
-    error = lodepng_chunk_init(&chunk, out, size, "iCCP");
-  }
-  if(!error) {
-    lodepng_memcpy(chunk + 8, info->iccp_name, keysize);
-    chunk[8 + keysize] = 0; /*null termination char*/
-    chunk[9 + keysize] = 0; /*compression method: 0*/
-    lodepng_memcpy(chunk + 10 + keysize, compressed, compressedsize);
-    lodepng_chunk_generate_crc(chunk);
-  }
-
-  lodepng_free(compressed);
   return error;
 }
 
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
 
 static void filterScanline(unsigned char* out, const unsigned char* scanline, const unsigned char* prevline,
-                           size_t length, size_t bytewidth, unsigned char filterType) {
+                           size_t length, size_t bytewidth, unsigned char filterType)
+{
   size_t i;
-  switch(filterType) {
+  switch(filterType)
+  {
     case 0: /*None*/
-      for(i = 0; i != length; ++i) out[i] = scanline[i];
+      for(i = 0; i < length; i++) out[i] = scanline[i];
       break;
     case 1: /*Sub*/
-      for(i = 0; i != bytewidth; ++i) out[i] = scanline[i];
-      for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - scanline[i - bytewidth];
+      if(prevline)
+      {
+        for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
+        for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth];
+      }
+      else
+      {
+        for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
+        for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth];
+      }
       break;
     case 2: /*Up*/
-      if(prevline) {
-        for(i = 0; i != length; ++i) out[i] = scanline[i] - prevline[i];
-      } else {
-        for(i = 0; i != length; ++i) out[i] = scanline[i];
+      if(prevline)
+      {
+        for(i = 0; i < length; i++) out[i] = scanline[i] - prevline[i];
+      }
+      else
+      {
+        for(i = 0; i < length; i++) out[i] = scanline[i];
       }
       break;
     case 3: /*Average*/
-      if(prevline) {
-        for(i = 0; i != bytewidth; ++i) out[i] = scanline[i] - (prevline[i] >> 1);
-        for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - ((scanline[i - bytewidth] + prevline[i]) >> 1);
-      } else {
-        for(i = 0; i != bytewidth; ++i) out[i] = scanline[i];
-        for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - (scanline[i - bytewidth] >> 1);
+      if(prevline)
+      {
+        for(i = 0; i < bytewidth; i++) out[i] = scanline[i] - prevline[i] / 2;
+        for(i = bytewidth; i < length; i++) out[i] = scanline[i] - ((scanline[i - bytewidth] + prevline[i]) / 2);
+      }
+      else
+      {
+        for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
+        for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth] / 2;
       }
       break;
     case 4: /*Paeth*/
-      if(prevline) {
+      if(prevline)
+      {
         /*paethPredictor(0, prevline[i], 0) is always prevline[i]*/
-        for(i = 0; i != bytewidth; ++i) out[i] = (scanline[i] - prevline[i]);
-        for(i = bytewidth; i < length; ++i) {
+        for(i = 0; i < bytewidth; i++) out[i] = (scanline[i] - prevline[i]);
+        for(i = bytewidth; i < length; i++)
+        {
           out[i] = (scanline[i] - paethPredictor(scanline[i - bytewidth], prevline[i], prevline[i - bytewidth]));
         }
-      } else {
-        for(i = 0; i != bytewidth; ++i) out[i] = scanline[i];
+      }
+      else
+      {
+        for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
         /*paethPredictor(scanline[i - bytewidth], 0, 0) is always scanline[i - bytewidth]*/
-        for(i = bytewidth; i < length; ++i) out[i] = (scanline[i] - scanline[i - bytewidth]);
+        for(i = bytewidth; i < length; i++) out[i] = (scanline[i] - scanline[i - bytewidth]);
       }
       break;
-    default: return; /*invalid filter type given*/
+    default: return; /*unexisting filter type given*/
   }
 }
 
-/* integer binary logarithm, max return value is 31 */
-static size_t ilog2(size_t i) {
-  size_t result = 0;
-  if(i >= 65536) { result += 16; i >>= 16; }
-  if(i >= 256) { result += 8; i >>= 8; }
-  if(i >= 16) { result += 4; i >>= 4; }
-  if(i >= 4) { result += 2; i >>= 2; }
-  if(i >= 2) { result += 1; /*i >>= 1;*/ }
-  return result;
-}
-
-/* integer approximation for i * log2(i), helper function for LFS_ENTROPY */
-static size_t ilog2i(size_t i) {
-  size_t l;
-  if(i == 0) return 0;
-  l = ilog2(i);
-  /* approximate i*log2(i): l is integer logarithm, ((i - (1u << l)) << 1u)
-  linearly approximates the missing fractional part multiplied by i */
-  return i * l + ((i - (1u << l)) << 1u);
+/* log2 approximation. A slight bit faster than std::log. */
+static float flog2(float f)
+{
+  float result = 0;
+  while(f > 32) { result += 4; f /= 16; }
+  while(f > 2) { result++; f /= 2; }
+  return result + 1.442695f * (f * f * f / 3 - 3 * f * f / 2 + 3 * f - 1.83333f);
 }
 
 static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h,
-                       const LodePNGColorMode* color, const LodePNGEncoderSettings* settings) {
+                       const LodePNGColorMode* info, const LodePNGEncoderSettings* settings)
+{
   /*
   For PNG filter method 0
-  out must be a buffer with as size: h + (w * h * bpp + 7u) / 8u, because there are
+  out must be a buffer with as size: h + (w * h * bpp + 7) / 8, because there are
   the scanlines with 1 extra byte per scanline
   */
 
-  unsigned bpp = lodepng_get_bpp(color);
+  unsigned bpp = lodepng_get_bpp(info);
   /*the width of a scanline in bytes, not including the filter type*/
-  size_t linebytes = lodepng_get_raw_size_idat(w, 1, bpp) - 1u;
-
+  size_t linebytes = (w * bpp + 7) / 8;
   /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
-  size_t bytewidth = (bpp + 7u) / 8u;
+  size_t bytewidth = (bpp + 7) / 8;
   const unsigned char* prevline = 0;
   unsigned x, y;
   unsigned error = 0;
@@ -5474,54 +5261,67 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w,
   heuristic is used.
   */
   if(settings->filter_palette_zero &&
-     (color->colortype == LCT_PALETTE || color->bitdepth < 8)) strategy = LFS_ZERO;
+     (info->colortype == LCT_PALETTE || info->bitdepth < 8)) strategy = LFS_ZERO;
 
   if(bpp == 0) return 31; /*error: invalid color type*/
 
-  if(strategy >= LFS_ZERO && strategy <= LFS_FOUR) {
-    unsigned char type = (unsigned char)strategy;
-    for(y = 0; y != h; ++y) {
+  if(strategy == LFS_ZERO)
+  {
+    for(y = 0; y < h; y++)
+    {
       size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
       size_t inindex = linebytes * y;
-      out[outindex] = type; /*filter type byte*/
-      filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, type);
+      out[outindex] = 0; /*filter type byte*/
+      filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, 0);
       prevline = &in[inindex];
     }
-  } else if(strategy == LFS_MINSUM) {
+  }
+  else if(strategy == LFS_MINSUM)
+  {
     /*adaptive filtering*/
-    unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/
+    size_t sum[5];
+    ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
     size_t smallest = 0;
-    unsigned char type, bestType = 0;
+    unsigned type, bestType = 0;
 
-    for(type = 0; type != 5; ++type) {
-      attempt[type] = (unsigned char*)lodepng_malloc(linebytes);
-      if(!attempt[type]) error = 83; /*alloc fail*/
+    for(type = 0; type < 5; type++)
+    {
+      ucvector_init(&attempt[type]);
+      if(!ucvector_resize(&attempt[type], linebytes)) return 83; /*alloc fail*/
     }
 
-    if(!error) {
-      for(y = 0; y != h; ++y) {
+    if(!error)
+    {
+      for(y = 0; y < h; y++)
+      {
         /*try the 5 filter types*/
-        for(type = 0; type != 5; ++type) {
-          size_t sum = 0;
-          filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type);
+        for(type = 0; type < 5; type++)
+        {
+          filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
 
           /*calculate the sum of the result*/
-          if(type == 0) {
-            for(x = 0; x != linebytes; ++x) sum += (unsigned char)(attempt[type][x]);
-          } else {
-            for(x = 0; x != linebytes; ++x) {
+          sum[type] = 0;
+          if(type == 0)
+          {
+            for(x = 0; x < linebytes; x++) sum[type] += (unsigned char)(attempt[type].data[x]);
+          }
+          else
+          {
+            for(x = 0; x < linebytes; x++)
+            {
               /*For differences, each byte should be treated as signed, values above 127 are negative
               (converted to signed char). Filtertype 0 isn't a difference though, so use unsigned there.
               This means filtertype 0 is almost never chosen, but that is justified.*/
-              unsigned char s = attempt[type][x];
-              sum += s < 128 ? s : (255U - s);
+              signed char s = (signed char)(attempt[type].data[x]);
+              sum[type] += s < 0 ? -s : s;
             }
           }
 
           /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
-          if(type == 0 || sum < smallest) {
+          if(type == 0 || sum[type] < smallest)
+          {
             bestType = type;
-            smallest = sum;
+            smallest = sum[type];
           }
         }
 
@@ -5529,70 +5329,81 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w,
 
         /*now fill the out values*/
         out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
-        for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x];
+        for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
       }
     }
 
-    for(type = 0; type != 5; ++type) lodepng_free(attempt[type]);
-  } else if(strategy == LFS_ENTROPY) {
-    unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/
-    size_t bestSum = 0;
+    for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]);
+  }
+  else if(strategy == LFS_ENTROPY)
+  {
+    float sum[5];
+    ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
+    float smallest = 0;
     unsigned type, bestType = 0;
     unsigned count[256];
 
-    for(type = 0; type != 5; ++type) {
-      attempt[type] = (unsigned char*)lodepng_malloc(linebytes);
-      if(!attempt[type]) error = 83; /*alloc fail*/
-    }
-
-    if(!error) {
-      for(y = 0; y != h; ++y) {
-        /*try the 5 filter types*/
-        for(type = 0; type != 5; ++type) {
-          size_t sum = 0;
-          filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type);
-          lodepng_memset(count, 0, 256 * sizeof(*count));
-          for(x = 0; x != linebytes; ++x) ++count[attempt[type][x]];
-          ++count[type]; /*the filter type itself is part of the scanline*/
-          for(x = 0; x != 256; ++x) {
-            sum += ilog2i(count[x]);
-          }
-          /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
-          if(type == 0 || sum > bestSum) {
-            bestType = type;
-            bestSum = sum;
-          }
+    for(type = 0; type < 5; type++)
+    {
+      ucvector_init(&attempt[type]);
+      if(!ucvector_resize(&attempt[type], linebytes)) return 83; /*alloc fail*/
+    }
+
+    for(y = 0; y < h; y++)
+    {
+      /*try the 5 filter types*/
+      for(type = 0; type < 5; type++)
+      {
+        filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
+        for(x = 0; x < 256; x++) count[x] = 0;
+        for(x = 0; x < linebytes; x++) count[attempt[type].data[x]]++;
+        count[type]++; /*the filter type itself is part of the scanline*/
+        sum[type] = 0;
+        for(x = 0; x < 256; x++)
+        {
+          float p = count[x] / (float)(linebytes + 1);
+          sum[type] += count[x] == 0 ? 0 : flog2(1 / p) * p;
+        }
+        /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
+        if(type == 0 || sum[type] < smallest)
+        {
+          bestType = type;
+          smallest = sum[type];
         }
+      }
 
-        prevline = &in[y * linebytes];
+      prevline = &in[y * linebytes];
 
-        /*now fill the out values*/
-        out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
-        for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x];
-      }
+      /*now fill the out values*/
+      out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
+      for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
     }
 
-    for(type = 0; type != 5; ++type) lodepng_free(attempt[type]);
-  } else if(strategy == LFS_PREDEFINED) {
-    for(y = 0; y != h; ++y) {
+    for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]);
+  }
+  else if(strategy == LFS_PREDEFINED)
+  {
+    for(y = 0; y < h; y++)
+    {
       size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
       size_t inindex = linebytes * y;
-      unsigned char type = settings->predefined_filters[y];
+      unsigned type = settings->predefined_filters[y];
       out[outindex] = type; /*filter type byte*/
       filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, type);
       prevline = &in[inindex];
     }
-  } else if(strategy == LFS_BRUTE_FORCE) {
+  }
+  else if(strategy == LFS_BRUTE_FORCE)
+  {
     /*brute force filter chooser.
     deflate the scanline after every filter attempt to see which one deflates best.
     This is very slow and gives only slightly smaller, sometimes even larger, result*/
     size_t size[5];
-    unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/
+    ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
     size_t smallest = 0;
     unsigned type = 0, bestType = 0;
     unsigned char* dummy;
-    LodePNGCompressSettings zlibsettings;
-    lodepng_memcpy(&zlibsettings, &settings->zlibsettings, sizeof(LodePNGCompressSettings));
+    LodePNGCompressSettings zlibsettings = settings->zlibsettings;
     /*use fixed tree on the attempts so that the tree is not adapted to the filtertype on purpose,
     to simulate the true case where the tree is the same for the whole image. Sometimes it gives
     better result with dynamic tree anyway. Using the fixed tree sometimes gives worse, but in rare
@@ -5602,33 +5413,35 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w,
     images only, so disable it*/
     zlibsettings.custom_zlib = 0;
     zlibsettings.custom_deflate = 0;
-    for(type = 0; type != 5; ++type) {
-      attempt[type] = (unsigned char*)lodepng_malloc(linebytes);
-      if(!attempt[type]) error = 83; /*alloc fail*/
-    }
-    if(!error) {
-      for(y = 0; y != h; ++y) /*try the 5 filter types*/ {
-        for(type = 0; type != 5; ++type) {
-          unsigned testsize = (unsigned)linebytes;
-          /*if(testsize > 8) testsize /= 8;*/ /*it already works good enough by testing a part of the row*/
-
-          filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type);
-          size[type] = 0;
-          dummy = 0;
-          zlib_compress(&dummy, &size[type], attempt[type], testsize, &zlibsettings);
-          lodepng_free(dummy);
-          /*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/
-          if(type == 0 || size[type] < smallest) {
-            bestType = type;
-            smallest = size[type];
-          }
+    for(type = 0; type < 5; type++)
+    {
+      ucvector_init(&attempt[type]);
+      ucvector_resize(&attempt[type], linebytes); /*todo: give error if resize failed*/
+    }
+    for(y = 0; y < h; y++) /*try the 5 filter types*/
+    {
+      for(type = 0; type < 5; type++)
+      {
+        unsigned testsize = attempt[type].size;
+        /*if(testsize > 8) testsize /= 8;*/ /*it already works good enough by testing a part of the row*/
+
+        filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
+        size[type] = 0;
+        dummy = 0;
+        zlib_compress(&dummy, &size[type], attempt[type].data, testsize, &zlibsettings);
+        lodepng_free(dummy);
+        /*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/
+        if(type == 0 || size[type] < smallest)
+        {
+          bestType = type;
+          smallest = size[type];
         }
-        prevline = &in[y * linebytes];
-        out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
-        for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x];
       }
+      prevline = &in[y * linebytes];
+      out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
+      for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
     }
-    for(type = 0; type != 5; ++type) lodepng_free(attempt[type]);
+    for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]);
   }
   else return 88; /* unknown filter strategy */
 
@@ -5636,21 +5449,24 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w,
 }
 
 static void addPaddingBits(unsigned char* out, const unsigned char* in,
-                           size_t olinebits, size_t ilinebits, unsigned h) {
+                           size_t olinebits, size_t ilinebits, unsigned h)
+{
   /*The opposite of the removePaddingBits function
   olinebits must be >= ilinebits*/
   unsigned y;
   size_t diff = olinebits - ilinebits;
   size_t obp = 0, ibp = 0; /*bit pointers*/
-  for(y = 0; y != h; ++y) {
+  for(y = 0; y < h; y++)
+  {
     size_t x;
-    for(x = 0; x < ilinebits; ++x) {
+    for(x = 0; x < ilinebits; x++)
+    {
       unsigned char bit = readBitFromReversedStream(&ibp, in);
       setBitOfReversedStream(&obp, out, bit);
     }
     /*obp += diff; --> no, fill in some value in the padding bits too, to avoid
     "Use of uninitialised value of size ###" warning from valgrind*/
-    for(x = 0; x != diff; ++x) setBitOfReversedStream(&obp, out, 0);
+    for(x = 0; x < diff; x++) setBitOfReversedStream(&obp, out, 0);
   }
 }
 
@@ -5665,37 +5481,47 @@ in has the following size in bits: w * h * bpp.
 out is possibly bigger due to padding bits between reduced images
 NOTE: comments about padding bits are only relevant if bpp < 8
 */
-static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) {
+static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
+{
   unsigned passw[7], passh[7];
   size_t filter_passstart[8], padded_passstart[8], passstart[8];
   unsigned i;
 
   Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
 
-  if(bpp >= 8) {
-    for(i = 0; i != 7; ++i) {
+  if(bpp >= 8)
+  {
+    for(i = 0; i < 7; i++)
+    {
       unsigned x, y, b;
-      size_t bytewidth = bpp / 8u;
-      for(y = 0; y < passh[i]; ++y)
-      for(x = 0; x < passw[i]; ++x) {
+      size_t bytewidth = bpp / 8;
+      for(y = 0; y < passh[i]; y++)
+      for(x = 0; x < passw[i]; x++)
+      {
         size_t pixelinstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
         size_t pixeloutstart = passstart[i] + (y * passw[i] + x) * bytewidth;
-        for(b = 0; b < bytewidth; ++b) {
+        for(b = 0; b < bytewidth; b++)
+        {
           out[pixeloutstart + b] = in[pixelinstart + b];
         }
       }
     }
-  } else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ {
-    for(i = 0; i != 7; ++i) {
+  }
+  else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/
+  {
+    for(i = 0; i < 7; i++)
+    {
       unsigned x, y, b;
       unsigned ilinebits = bpp * passw[i];
       unsigned olinebits = bpp * w;
       size_t obp, ibp; /*bit pointers (for out and in buffer)*/
-      for(y = 0; y < passh[i]; ++y)
-      for(x = 0; x < passw[i]; ++x) {
+      for(y = 0; y < passh[i]; y++)
+      for(x = 0; x < passw[i]; x++)
+      {
         ibp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
         obp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
-        for(b = 0; b < bpp; ++b) {
+        for(b = 0; b < bpp; b++)
+        {
           unsigned char bit = readBitFromReversedStream(&ibp, in);
           setBitOfReversedStream(&obp, out, bit);
         }
@@ -5708,36 +5534,45 @@ static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigne
 return value is error**/
 static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const unsigned char* in,
                                     unsigned w, unsigned h,
-                                    const LodePNGInfo* info_png, const LodePNGEncoderSettings* settings) {
+                                    const LodePNGInfo* info_png, const LodePNGEncoderSettings* settings)
+{
   /*
   This function converts the pure 2D image with the PNG's colortype, into filtered-padded-interlaced data. Steps:
-  *) if no Adam7: 1) add padding bits (= possible extra bits per scanline if bpp < 8) 2) filter
+  *) if no Adam7: 1) add padding bits (= posible extra bits per scanline if bpp < 8) 2) filter
   *) if adam7: 1) Adam7_interlace 2) 7x add padding bits 3) 7x filter
   */
   unsigned bpp = lodepng_get_bpp(&info_png->color);
   unsigned error = 0;
 
-  if(info_png->interlace_method == 0) {
-    *outsize = h + (h * ((w * bpp + 7u) / 8u)); /*image size plus an extra byte per scanline + possible padding bits*/
+  if(info_png->interlace_method == 0)
+  {
+    *outsize = h + (h * ((w * bpp + 7) / 8)); /*image size plus an extra byte per scanline + possible padding bits*/
     *out = (unsigned char*)lodepng_malloc(*outsize);
     if(!(*out) && (*outsize)) error = 83; /*alloc fail*/
 
-    if(!error) {
+    if(!error)
+    {
       /*non multiple of 8 bits per scanline, padding bits needed per scanline*/
-      if(bpp < 8 && w * bpp != ((w * bpp + 7u) / 8u) * 8u) {
-        unsigned char* padded = (unsigned char*)lodepng_malloc(h * ((w * bpp + 7u) / 8u));
+      if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8)
+      {
+        unsigned char* padded = (unsigned char*)lodepng_malloc(h * ((w * bpp + 7) / 8));
         if(!padded) error = 83; /*alloc fail*/
-        if(!error) {
-          addPaddingBits(padded, in, ((w * bpp + 7u) / 8u) * 8u, w * bpp, h);
+        if(!error)
+        {
+          addPaddingBits(padded, in, ((w * bpp + 7) / 8) * 8, w * bpp, h);
           error = filter(*out, padded, w, h, &info_png->color, settings);
         }
         lodepng_free(padded);
-      } else {
-        /*we can immediately filter into the out buffer, no other steps needed*/
+      }
+      else
+      {
+        /*we can immediatly filter into the out buffer, no other steps needed*/
         error = filter(*out, in, w, h, &info_png->color, settings);
       }
     }
-  } else /*interlace_method is 1 (Adam7)*/ {
+  }
+  else /*interlace_method is 1 (Adam7)*/
+  {
     unsigned passw[7], passh[7];
     size_t filter_passstart[8], padded_passstart[8], passstart[8];
     unsigned char* adam7;
@@ -5751,20 +5586,25 @@ static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const
     adam7 = (unsigned char*)lodepng_malloc(passstart[7]);
     if(!adam7 && passstart[7]) error = 83; /*alloc fail*/
 
-    if(!error) {
+    if(!error)
+    {
       unsigned i;
 
       Adam7_interlace(adam7, in, w, h, bpp);
-      for(i = 0; i != 7; ++i) {
-        if(bpp < 8) {
+      for(i = 0; i < 7; i++)
+      {
+        if(bpp < 8)
+        {
           unsigned char* padded = (unsigned char*)lodepng_malloc(padded_passstart[i + 1] - padded_passstart[i]);
           if(!padded) ERROR_BREAK(83); /*alloc fail*/
           addPaddingBits(padded, &adam7[passstart[i]],
-                         ((passw[i] * bpp + 7u) / 8u) * 8u, passw[i] * bpp, passh[i]);
+                         ((passw[i] * bpp + 7) / 8) * 8, passw[i] * bpp, passh[i]);
           error = filter(&(*out)[filter_passstart[i]], padded,
                          passw[i], passh[i], &info_png->color, settings);
           lodepng_free(padded);
-        } else {
+        }
+        else
+        {
           error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]],
                          passw[i], passh[i], &info_png->color, settings);
         }
@@ -5779,292 +5619,232 @@ static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const
   return error;
 }
 
+/*
+palette must have 4 * palettesize bytes allocated, and given in format RGBARGBARGBARGBA...
+returns 0 if the palette is opaque,
+returns 1 if the palette has a single color with alpha 0 ==> color key
+returns 2 if the palette is semi-translucent.
+*/
+static unsigned getPaletteTranslucency(const unsigned char* palette, size_t palettesize)
+{
+  size_t i, key = 0;
+  unsigned r = 0, g = 0, b = 0; /*the value of the color with alpha 0, so long as color keying is possible*/
+  for(i = 0; i < palettesize; i++)
+  {
+    if(!key && palette[4 * i + 3] == 0)
+    {
+      r = palette[4 * i + 0]; g = palette[4 * i + 1]; b = palette[4 * i + 2];
+      key = 1;
+      i = (size_t)(-1); /*restart from beginning, to detect earlier opaque colors with key's value*/
+    }
+    else if(palette[4 * i + 3] != 255) return 2;
+    /*when key, no opaque RGB may have key's RGB*/
+    else if(key && r == palette[i * 4 + 0] && g == palette[i * 4 + 1] && b == palette[i * 4 + 2]) return 2;
+  }
+  return key;
+}
+
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize) {
+static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize)
+{
   unsigned char* inchunk = data;
-  while((size_t)(inchunk - data) < datasize) {
+  while((size_t)(inchunk - data) < datasize)
+  {
     CERROR_TRY_RETURN(lodepng_chunk_append(&out->data, &out->size, inchunk));
     out->allocsize = out->size; /*fix the allocsize again*/
-    inchunk = lodepng_chunk_next(inchunk, data + datasize);
+    inchunk = lodepng_chunk_next(inchunk);
   }
   return 0;
 }
-
-static unsigned isGrayICCProfile(const unsigned char* profile, unsigned size) {
-  /*
-  It is a gray profile if bytes 16-19 are "GRAY", rgb profile if bytes 16-19
-  are "RGB ". We do not perform any full parsing of the ICC profile here, other
-  than check those 4 bytes to grayscale profile. Other than that, validity of
-  the profile is not checked. This is needed only because the PNG specification
-  requires using a non-gray color model if there is an ICC profile with "RGB "
-  (sadly limiting compression opportunities if the input data is grayscale RGB
-  data), and requires using a gray color model if it is "GRAY".
-  */
-  if(size < 20) return 0;
-  return profile[16] == 'G' &&  profile[17] == 'R' &&  profile[18] == 'A' &&  profile[19] == 'Y';
-}
-
-static unsigned isRGBICCProfile(const unsigned char* profile, unsigned size) {
-  /* See comment in isGrayICCProfile*/
-  if(size < 20) return 0;
-  return profile[16] == 'R' &&  profile[17] == 'G' &&  profile[18] == 'B' &&  profile[19] == ' ';
-}
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
 
 unsigned lodepng_encode(unsigned char** out, size_t* outsize,
                         const unsigned char* image, unsigned w, unsigned h,
-                        LodePNGState* state) {
+                        LodePNGState* state)
+{
+  LodePNGInfo info;
+  ucvector outv;
   unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/
   size_t datasize = 0;
-  ucvector outv = ucvector_init(NULL, 0);
-  LodePNGInfo info;
-  const LodePNGInfo* info_png = &state->info_png;
-
-  lodepng_info_init(&info);
 
   /*provide some proper output values if error will happen*/
   *out = 0;
   *outsize = 0;
   state->error = 0;
 
-  /*check input values validity*/
-  if((info_png->color.colortype == LCT_PALETTE || state->encoder.force_palette)
-      && (info_png->color.palettesize == 0 || info_png->color.palettesize > 256)) {
+  lodepng_info_init(&info);
+  lodepng_info_copy(&info, &state->info_png);
+
+  if((info.color.colortype == LCT_PALETTE || state->encoder.force_palette)
+      && (info.color.palettesize == 0 || info.color.palettesize > 256))
+  {
     state->error = 68; /*invalid palette size, it is only allowed to be 1-256*/
-    goto cleanup;
+    return state->error;
   }
-  if(state->encoder.zlibsettings.btype > 2) {
-    state->error = 61; /*error: invalid btype*/
-    goto cleanup;
-  }
-  if(info_png->interlace_method > 1) {
-    state->error = 71; /*error: invalid interlace mode*/
-    goto cleanup;
+
+  if(state->encoder.auto_convert != LAC_NO)
+  {
+    state->error = lodepng_auto_choose_color(&info.color, image, w, h, &state->info_raw,
+                                             state->encoder.auto_convert);
   }
-  state->error = checkColorValidity(info_png->color.colortype, info_png->color.bitdepth);
-  if(state->error) goto cleanup; /*error: invalid color type given*/
-  state->error = checkColorValidity(state->info_raw.colortype, state->info_raw.bitdepth);
-  if(state->error) goto cleanup; /*error: invalid color type given*/
+  if(state->error) return state->error;
 
-  /* color convert and compute scanline filter types */
-  lodepng_info_copy(&info, &state->info_png);
-  if(state->encoder.auto_convert) {
-    LodePNGColorStats stats;
-    lodepng_color_stats_init(&stats);
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-    if(info_png->iccp_defined &&
-        isGrayICCProfile(info_png->iccp_profile, info_png->iccp_profile_size)) {
-      /*the PNG specification does not allow to use palette with a GRAY ICC profile, even
-      if the palette has only gray colors, so disallow it.*/
-      stats.allow_palette = 0;
-    }
-    if(info_png->iccp_defined &&
-        isRGBICCProfile(info_png->iccp_profile, info_png->iccp_profile_size)) {
-      /*the PNG specification does not allow to use grayscale color with RGB ICC profile, so disallow gray.*/
-      stats.allow_greyscale = 0;
-    }
-#endif /* LODEPNG_COMPILE_ANCILLARY_CHUNKS */
-    state->error = lodepng_compute_color_stats(&stats, image, w, h, &state->info_raw);
-    if(state->error) goto cleanup;
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-    if(info_png->background_defined) {
-      /*the background chunk's color must be taken into account as well*/
-      unsigned r = 0, g = 0, b = 0;
-      LodePNGColorMode mode16 = lodepng_color_mode_make(LCT_RGB, 16);
-      lodepng_convert_rgb(&r, &g, &b, info_png->background_r, info_png->background_g, info_png->background_b, &mode16, &info_png->color);
-      state->error = lodepng_color_stats_add(&stats, r, g, b, 65535);
-      if(state->error) goto cleanup;
-    }
-#endif /* LODEPNG_COMPILE_ANCILLARY_CHUNKS */
-    state->error = auto_choose_color(&info.color, &state->info_raw, &stats);
-    if(state->error) goto cleanup;
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-    /*also convert the background chunk*/
-    if(info_png->background_defined) {
-      if(lodepng_convert_rgb(&info.background_r, &info.background_g, &info.background_b,
-          info_png->background_r, info_png->background_g, info_png->background_b, &info.color, &info_png->color)) {
-        state->error = 104;
-        goto cleanup;
-      }
-    }
-#endif /* LODEPNG_COMPILE_ANCILLARY_CHUNKS */
+  if(state->encoder.zlibsettings.btype > 2)
+  {
+    CERROR_RETURN_ERROR(state->error, 61); /*error: unexisting btype*/
   }
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-  if(info_png->iccp_defined) {
-    unsigned gray_icc = isGrayICCProfile(info_png->iccp_profile, info_png->iccp_profile_size);
-    unsigned rgb_icc = isRGBICCProfile(info_png->iccp_profile, info_png->iccp_profile_size);
-    unsigned gray_png = info.color.colortype == LCT_GREY || info.color.colortype == LCT_GREY_ALPHA;
-    if(!gray_icc && !rgb_icc) {
-      state->error = 100; /* Disallowed profile color type for PNG */
-      goto cleanup;
-    }
-    if(gray_icc != gray_png) {
-      /*Not allowed to use RGB/RGBA/palette with GRAY ICC profile or vice versa,
-      or in case of auto_convert, it wasn't possible to find appropriate model*/
-      state->error = state->encoder.auto_convert ? 102 : 101;
-      goto cleanup;
-    }
+  if(state->info_png.interlace_method > 1)
+  {
+    CERROR_RETURN_ERROR(state->error, 71); /*error: unexisting interlace mode*/
   }
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-  if(!lodepng_color_mode_equal(&state->info_raw, &info.color)) {
+
+  state->error = checkColorValidity(info.color.colortype, info.color.bitdepth);
+  if(state->error) return state->error; /*error: unexisting color type given*/
+  state->error = checkColorValidity(state->info_raw.colortype, state->info_raw.bitdepth);
+  if(state->error) return state->error; /*error: unexisting color type given*/
+
+  if(!lodepng_color_mode_equal(&state->info_raw, &info.color))
+  {
     unsigned char* converted;
-    size_t size = ((size_t)w * (size_t)h * (size_t)lodepng_get_bpp(&info.color) + 7u) / 8u;
+    size_t size = (w * h * lodepng_get_bpp(&info.color) + 7) / 8;
 
     converted = (unsigned char*)lodepng_malloc(size);
     if(!converted && size) state->error = 83; /*alloc fail*/
-    if(!state->error) {
-      state->error = lodepng_convert(converted, image, &info.color, &state->info_raw, w, h);
-    }
-    if(!state->error) {
-      state->error = preProcessScanlines(&data, &datasize, converted, w, h, &info, &state->encoder);
+    if(!state->error)
+    {
+      state->error = lodepng_convert(converted, image, &info.color, &state->info_raw, w, h, 0 /*fix_png*/);
     }
+    if(!state->error) preProcessScanlines(&data, &datasize, converted, w, h, &info, &state->encoder);
     lodepng_free(converted);
-    if(state->error) goto cleanup;
-  } else {
-    state->error = preProcessScanlines(&data, &datasize, image, w, h, &info, &state->encoder);
-    if(state->error) goto cleanup;
   }
+  else preProcessScanlines(&data, &datasize, image, w, h, &info, &state->encoder);
 
-  /* output all PNG chunks */ {
+  ucvector_init(&outv);
+  while(!state->error) /*while only executed once, to break on error*/
+  {
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
     size_t i;
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
     /*write signature and chunks*/
-    state->error = writeSignature(&outv);
-    if(state->error) goto cleanup;
+    writeSignature(&outv);
     /*IHDR*/
-    state->error = addChunk_IHDR(&outv, w, h, info.color.colortype, info.color.bitdepth, info.interlace_method);
-    if(state->error) goto cleanup;
+    addChunk_IHDR(&outv, w, h, info.color.colortype, info.color.bitdepth, info.interlace_method);
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
     /*unknown chunks between IHDR and PLTE*/
-    if(info.unknown_chunks_data[0]) {
+    if(info.unknown_chunks_data[0])
+    {
       state->error = addUnknownChunks(&outv, info.unknown_chunks_data[0], info.unknown_chunks_size[0]);
-      if(state->error) goto cleanup;
+      if(state->error) break;
     }
-    /*color profile chunks must come before PLTE */
-    if(info.iccp_defined) {
-      state->error = addChunk_iCCP(&outv, &info, &state->encoder.zlibsettings);
-      if(state->error) goto cleanup;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    /*PLTE*/
+    if(info.color.colortype == LCT_PALETTE)
+    {
+      addChunk_PLTE(&outv, &info.color);
     }
-    if(info.srgb_defined) {
-      state->error = addChunk_sRGB(&outv, &info);
-      if(state->error) goto cleanup;
+    if(state->encoder.force_palette && (info.color.colortype == LCT_RGB || info.color.colortype == LCT_RGBA))
+    {
+      addChunk_PLTE(&outv, &info.color);
     }
-    if(info.gama_defined) {
-      state->error = addChunk_gAMA(&outv, &info);
-      if(state->error) goto cleanup;
+    /*tRNS*/
+    if(info.color.colortype == LCT_PALETTE && getPaletteTranslucency(info.color.palette, info.color.palettesize) != 0)
+    {
+      addChunk_tRNS(&outv, &info.color);
     }
-    if(info.chrm_defined) {
-      state->error = addChunk_cHRM(&outv, &info);
-      if(state->error) goto cleanup;
+    if((info.color.colortype == LCT_GREY || info.color.colortype == LCT_RGB) && info.color.key_defined)
+    {
+      addChunk_tRNS(&outv, &info.color);
     }
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-    /*PLTE*/
-    if(info.color.colortype == LCT_PALETTE) {
-      state->error = addChunk_PLTE(&outv, &info.color);
-      if(state->error) goto cleanup;
-    }
-    if(state->encoder.force_palette && (info.color.colortype == LCT_RGB || info.color.colortype == LCT_RGBA)) {
-      /*force_palette means: write suggested palette for truecolor in PLTE chunk*/
-      state->error = addChunk_PLTE(&outv, &info.color);
-      if(state->error) goto cleanup;
-    }
-    /*tRNS (this will only add if when necessary) */
-    state->error = addChunk_tRNS(&outv, &info.color);
-    if(state->error) goto cleanup;
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
     /*bKGD (must come between PLTE and the IDAt chunks*/
-    if(info.background_defined) {
-      state->error = addChunk_bKGD(&outv, &info);
-      if(state->error) goto cleanup;
-    }
+    if(info.background_defined) addChunk_bKGD(&outv, &info);
     /*pHYs (must come before the IDAT chunks)*/
-    if(info.phys_defined) {
-      state->error = addChunk_pHYs(&outv, &info);
-      if(state->error) goto cleanup;
-    }
+    if(info.phys_defined) addChunk_pHYs(&outv, &info);
 
     /*unknown chunks between PLTE and IDAT*/
-    if(info.unknown_chunks_data[1]) {
+    if(info.unknown_chunks_data[1])
+    {
       state->error = addUnknownChunks(&outv, info.unknown_chunks_data[1], info.unknown_chunks_size[1]);
-      if(state->error) goto cleanup;
+      if(state->error) break;
     }
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
     /*IDAT (multiple IDAT chunks must be consecutive)*/
     state->error = addChunk_IDAT(&outv, data, datasize, &state->encoder.zlibsettings);
-    if(state->error) goto cleanup;
+    if(state->error) break;
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
     /*tIME*/
-    if(info.time_defined) {
-      state->error = addChunk_tIME(&outv, &info.time);
-      if(state->error) goto cleanup;
-    }
+    if(info.time_defined) addChunk_tIME(&outv, &info.time);
     /*tEXt and/or zTXt*/
-    for(i = 0; i != info.text_num; ++i) {
-      if(lodepng_strlen(info.text_keys[i]) > 79) {
+    for(i = 0; i < info.text_num; i++)
+    {
+      if(strlen(info.text_keys[i]) > 79)
+      {
         state->error = 66; /*text chunk too large*/
-        goto cleanup;
+        break;
       }
-      if(lodepng_strlen(info.text_keys[i]) < 1) {
+      if(strlen(info.text_keys[i]) < 1)
+      {
         state->error = 67; /*text chunk too small*/
-        goto cleanup;
+        break;
+      }
+      if(state->encoder.text_compression)
+      {
+        addChunk_zTXt(&outv, info.text_keys[i], info.text_strings[i], &state->encoder.zlibsettings);
       }
-      if(state->encoder.text_compression) {
-        state->error = addChunk_zTXt(&outv, info.text_keys[i], info.text_strings[i], &state->encoder.zlibsettings);
-        if(state->error) goto cleanup;
-      } else {
-        state->error = addChunk_tEXt(&outv, info.text_keys[i], info.text_strings[i]);
-        if(state->error) goto cleanup;
+      else
+      {
+        addChunk_tEXt(&outv, info.text_keys[i], info.text_strings[i]);
       }
     }
     /*LodePNG version id in text chunk*/
-    if(state->encoder.add_id) {
-      unsigned already_added_id_text = 0;
-      for(i = 0; i != info.text_num; ++i) {
-        const char* k = info.text_keys[i];
-        /* Could use strcmp, but we're not calling or reimplementing this C library function for this use only */
-        if(k[0] == 'L' && k[1] == 'o' && k[2] == 'd' && k[3] == 'e' &&
-           k[4] == 'P' && k[5] == 'N' && k[6] == 'G' && k[7] == '\0') {
-          already_added_id_text = 1;
+    if(state->encoder.add_id)
+    {
+      unsigned alread_added_id_text = 0;
+      for(i = 0; i < info.text_num; i++)
+      {
+        if(!strcmp(info.text_keys[i], "LodePNG"))
+        {
+          alread_added_id_text = 1;
           break;
         }
       }
-      if(already_added_id_text == 0) {
-        state->error = addChunk_tEXt(&outv, "LodePNG", LODEPNG_VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/
-        if(state->error) goto cleanup;
+      if(alread_added_id_text == 0)
+      {
+        addChunk_tEXt(&outv, "LodePNG", VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/
       }
     }
     /*iTXt*/
-    for(i = 0; i != info.itext_num; ++i) {
-      if(lodepng_strlen(info.itext_keys[i]) > 79) {
+    for(i = 0; i < info.itext_num; i++)
+    {
+      if(strlen(info.itext_keys[i]) > 79)
+      {
         state->error = 66; /*text chunk too large*/
-        goto cleanup;
+        break;
       }
-      if(lodepng_strlen(info.itext_keys[i]) < 1) {
+      if(strlen(info.itext_keys[i]) < 1)
+      {
         state->error = 67; /*text chunk too small*/
-        goto cleanup;
+        break;
       }
-      state->error = addChunk_iTXt(
-          &outv, state->encoder.text_compression,
-          info.itext_keys[i], info.itext_langtags[i], info.itext_transkeys[i], info.itext_strings[i],
-          &state->encoder.zlibsettings);
-      if(state->error) goto cleanup;
+      addChunk_iTXt(&outv, state->encoder.text_compression,
+                    info.itext_keys[i], info.itext_langtags[i], info.itext_transkeys[i], info.itext_strings[i],
+                    &state->encoder.zlibsettings);
     }
 
     /*unknown chunks between IDAT and IEND*/
-    if(info.unknown_chunks_data[2]) {
+    if(info.unknown_chunks_data[2])
+    {
       state->error = addUnknownChunks(&outv, info.unknown_chunks_data[2], info.unknown_chunks_size[2]);
-      if(state->error) goto cleanup;
+      if(state->error) break;
     }
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-    state->error = addChunk_IEND(&outv);
-    if(state->error) goto cleanup;
+    addChunk_IEND(&outv);
+
+    break; /*this isn't really a while loop; no error happened so break out now!*/
   }
 
-cleanup:
   lodepng_info_cleanup(&info);
   lodepng_free(data);
-
   /*instead of cleaning the vector up, give it to the output*/
   *out = outv.data;
   *outsize = outv.size;
@@ -6073,7 +5853,8 @@ cleanup:
 }
 
 unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize, const unsigned char* image,
-                               unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) {
+                               unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth)
+{
   unsigned error;
   LodePNGState state;
   lodepng_state_init(&state);
@@ -6087,17 +5868,20 @@ unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize, const unsig
   return error;
 }
 
-unsigned lodepng_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) {
+unsigned lodepng_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
+{
   return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGBA, 8);
 }
 
-unsigned lodepng_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) {
+unsigned lodepng_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
+{
   return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGB, 8);
 }
 
 #ifdef LODEPNG_COMPILE_DISK
 unsigned lodepng_encode_file(const char* filename, const unsigned char* image, unsigned w, unsigned h,
-                             LodePNGColorType colortype, unsigned bitdepth) {
+                             LodePNGColorType colortype, unsigned bitdepth)
+{
   unsigned char* buffer;
   size_t buffersize;
   unsigned error = lodepng_encode_memory(&buffer, &buffersize, image, w, h, colortype, bitdepth);
@@ -6106,20 +5890,23 @@ unsigned lodepng_encode_file(const char* filename, const unsigned char* image, u
   return error;
 }
 
-unsigned lodepng_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) {
+unsigned lodepng_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h)
+{
   return lodepng_encode_file(filename, image, w, h, LCT_RGBA, 8);
 }
 
-unsigned lodepng_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) {
+unsigned lodepng_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h)
+{
   return lodepng_encode_file(filename, image, w, h, LCT_RGB, 8);
 }
 #endif /*LODEPNG_COMPILE_DISK*/
 
-void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings) {
+void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings)
+{
   lodepng_compress_settings_init(&settings->zlibsettings);
   settings->filter_palette_zero = 1;
   settings->filter_strategy = LFS_MINSUM;
-  settings->auto_convert = 1;
+  settings->auto_convert = LAC_AUTO;
   settings->force_palette = 0;
   settings->predefined_filters = 0;
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
@@ -6136,8 +5923,10 @@ void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings) {
 This returns the description of a numerical error code in English. This is also
 the documentation of all the error codes.
 */
-const char* lodepng_error_text(unsigned code) {
-  switch(code) {
+const char* lodepng_error_text(unsigned code)
+{
+  switch(code)
+  {
     case 0: return "no error, everything went ok";
     case 1: return "nothing done yet"; /*the Encoder/Decoder has done nothing yet, error checking makes no sense yet*/
     case 10: return "end of input memory reached without huffman end code"; /*while huffman decoding*/
@@ -6145,18 +5934,16 @@ const char* lodepng_error_text(unsigned code) {
     case 13: return "problem while processing dynamic deflate block";
     case 14: return "problem while processing dynamic deflate block";
     case 15: return "problem while processing dynamic deflate block";
-    /*this error could happen if there are only 0 or 1 symbols present in the huffman code:*/
-    case 16: return "invalid code while processing dynamic deflate block";
+    case 16: return "unexisting code while processing dynamic deflate block";
     case 17: return "end of out buffer memory reached while inflating";
     case 18: return "invalid distance code while inflating";
     case 19: return "end of out buffer memory reached while inflating";
     case 20: return "invalid deflate block BTYPE encountered while decoding";
     case 21: return "NLEN is not ones complement of LEN in a deflate block";
-
-    /*end of out buffer memory reached while inflating:
-    This can happen if the inflated deflate data is longer than the amount of bytes required to fill up
-    all the pixels of the image, given the color depth and image dimensions. Something that doesn't
-    happen in a normal, well encoded, PNG image.*/
+     /*end of out buffer memory reached while inflating:
+     This can happen if the inflated deflate data is longer than the amount of bytes required to fill up
+     all the pixels of the image, given the color depth and image dimensions. Something that doesn't
+     happen in a normal, well encoded, PNG image.*/
     case 22: return "end of out buffer memory reached while inflating";
     case 23: return "end of in buffer memory reached while inflating";
     case 24: return "invalid FCHECK in zlib header";
@@ -6174,15 +5961,20 @@ const char* lodepng_error_text(unsigned code) {
     case 35: return "chunk length of a chunk is too large or the chunk too small";
     case 36: return "illegal PNG filter type encountered";
     case 37: return "illegal bit depth for this color type given";
-    case 38: return "the palette is too small or too big"; /*0, or more than 256 colors*/
-    case 39: return "tRNS chunk before PLTE or has more entries than palette size";
-    case 40: return "tRNS chunk has wrong size for grayscale image";
+    case 38: return "the palette is too big"; /*more than 256 colors*/
+    case 39: return "more palette alpha values given in tRNS chunk than there are colors in the palette";
+    case 40: return "tRNS chunk has wrong size for greyscale image";
     case 41: return "tRNS chunk has wrong size for RGB image";
     case 42: return "tRNS chunk appeared while it was not allowed for this color type";
     case 43: return "bKGD chunk has wrong size for palette image";
-    case 44: return "bKGD chunk has wrong size for grayscale image";
+    case 44: return "bKGD chunk has wrong size for greyscale image";
     case 45: return "bKGD chunk has wrong size for RGB image";
-    case 48: return "empty input buffer given to decoder. Maybe caused by non-existing file?";
+    /*Is the palette too small?*/
+    case 46: return "a value in indexed image is larger than the palette size (bitdepth = 8)";
+    /*Is the palette too small?*/
+    case 47: return "a value in indexed image is larger than the palette size (bitdepth < 8)";
+    /*the input data is empty, maybe a PNG file doesn't exist or is in the wrong path*/
+    case 48: return "empty input or file doesn't exist";
     case 49: return "jumped past memory while generating dynamic huffman tree";
     case 50: return "jumped past memory while generating dynamic huffman tree";
     case 51: return "jumped past memory while inflating huffman block";
@@ -6191,7 +5983,7 @@ const char* lodepng_error_text(unsigned code) {
     case 54: return "repeat symbol in tree while there was no value symbol yet";
     /*jumped past tree while generating huffman tree, this could be when the
     tree will have more leaves than symbols after generating it out of the
-    given lengths. They call this an oversubscribed dynamic bit lengths tree in zlib.*/
+    given lenghts. They call this an oversubscribed dynamic bit lengths tree in zlib.*/
     case 55: return "jumped past tree while generating huffman tree";
     case 56: return "given output image colortype or bitdepth not supported for color conversion";
     case 57: return "invalid CRC encountered (checking CRC can be disabled)";
@@ -6199,18 +5991,17 @@ const char* lodepng_error_text(unsigned code) {
     case 59: return "requested color conversion not supported";
     case 60: return "invalid window size given in the settings of the encoder (must be 0-32768)";
     case 61: return "invalid BTYPE given in the settings of the encoder (only 0, 1 and 2 are allowed)";
-    /*LodePNG leaves the choice of RGB to grayscale conversion formula to the user.*/
-    case 62: return "conversion from color to grayscale not supported";
-    /*(2^31-1)*/
-    case 63: return "length of a chunk too long, max allowed for PNG is 2147483647 bytes per chunk";
+    /*LodePNG leaves the choice of RGB to greyscale conversion formula to the user.*/
+    case 62: return "conversion from color to greyscale not supported";
+    case 63: return "length of a chunk too long, max allowed for PNG is 2147483647 bytes per chunk"; /*(2^31-1)*/
     /*this would result in the inability of a deflated block to ever contain an end code. It must be at least 1.*/
     case 64: return "the length of the END symbol 256 in the Huffman tree is 0";
     case 66: return "the length of a text chunk keyword given to the encoder is longer than the maximum of 79 bytes";
     case 67: return "the length of a text chunk keyword given to the encoder is smaller than the minimum of 1 byte";
     case 68: return "tried to encode a PLTE chunk with a palette that has less than 1 or more than 256 colors";
     case 69: return "unknown chunk type with 'critical' flag encountered by the decoder";
-    case 71: return "invalid interlace mode given to encoder (must be 0 or 1)";
-    case 72: return "while decoding, invalid compression method encountering in zTXt or iTXt chunk (it must be 0)";
+    case 71: return "unexisting interlace mode given to encoder (must be 0 or 1)";
+    case 72: return "while decoding, unexisting compression method encountering in zTXt or iTXt chunk (it must be 0)";
     case 73: return "invalid tIME chunk size";
     case 74: return "invalid pHYs chunk size";
     /*length could be wrong, or data chopped off*/
@@ -6221,43 +6012,16 @@ const char* lodepng_error_text(unsigned code) {
     case 79: return "failed to open file for writing";
     case 80: return "tried creating a tree of 0 symbols";
     case 81: return "lazy matching at pos 0 is impossible";
-    case 82: return "color conversion to palette requested while a color isn't in palette, or index out of bounds";
+    case 82: return "color conversion to palette requested while a color isn't in palette";
     case 83: return "memory allocation failed";
     case 84: return "given image too small to contain all pixels to be encoded";
+    case 85: return "internal color conversion bug";
     case 86: return "impossible offset in lz77 encoding (internal bug)";
     case 87: return "must provide custom zlib function pointer if LODEPNG_COMPILE_ZLIB is not defined";
     case 88: return "invalid filter strategy given for LodePNGEncoderSettings.filter_strategy";
     case 89: return "text chunk keyword too short or long: must have size 1-79";
     /*the windowsize in the LodePNGCompressSettings. Requiring POT(==> & instead of %) makes encoding 12% faster.*/
     case 90: return "windowsize must be a power of two";
-    case 91: return "invalid decompressed idat size";
-    case 92: return "integer overflow due to too many pixels";
-    case 93: return "zero width or height is invalid";
-    case 94: return "header chunk must have a size of 13 bytes";
-    case 95: return "integer overflow with combined idat chunk size";
-    case 96: return "invalid gAMA chunk size";
-    case 97: return "invalid cHRM chunk size";
-    case 98: return "invalid sRGB chunk size";
-    case 99: return "invalid sRGB rendering intent";
-    case 100: return "invalid ICC profile color type, the PNG specification only allows RGB or GRAY";
-    case 101: return "PNG specification does not allow RGB ICC profile on gray color types and vice versa";
-    case 102: return "not allowed to set grayscale ICC profile with colored pixels by PNG specification";
-    case 103: return "invalid palette index in bKGD chunk. Maybe it came before PLTE chunk?";
-    case 104: return "invalid bKGD color while encoding (e.g. palette index out of range)";
-    case 105: return "integer overflow of bitsize";
-    case 106: return "PNG file must have PLTE chunk if color type is palette";
-    case 107: return "color convert from palette mode requested without setting the palette data in it";
-    case 108: return "tried to add more than 256 values to a palette";
-    /*this limit can be configured in LodePNGDecompressSettings*/
-    case 109: return "tried to decompress zlib or deflate data larger than desired max_output_size";
-    case 110: return "custom zlib or inflate decompression failed";
-    case 111: return "custom zlib or deflate compression failed";
-    /*max text size limit can be configured in LodePNGDecoderSettings. This error prevents
-    unreasonable memory consumption when decoding due to impossibly large text sizes.*/
-    case 112: return "compressed text unreasonably large";
-    /*max ICC size limit can be configured in LodePNGDecoderSettings. This error prevents
-    unreasonable memory consumption when decoding due to impossibly large ICC profile*/
-    case 113: return "ICC profile unreasonably large";
   }
   return "unknown error code";
 }
@@ -6270,30 +6034,42 @@ const char* lodepng_error_text(unsigned code) {
 /* ////////////////////////////////////////////////////////////////////////// */
 
 #ifdef LODEPNG_COMPILE_CPP
-namespace lodepng {
+namespace lodepng
+{
 
 #ifdef LODEPNG_COMPILE_DISK
-unsigned load_file(std::vector<unsigned char>& buffer, const std::string& filename) {
-  long size = lodepng_filesize(filename.c_str());
-  if(size < 0) return 78;
-  buffer.resize((size_t)size);
-  return size == 0 ? 0 : lodepng_buffer_file(&buffer[0], (size_t)size, filename.c_str());
+void load_file(std::vector<unsigned char>& buffer, const std::string& filename)
+{
+  std::ifstream file(filename.c_str(), std::ios::in|std::ios::binary|std::ios::ate);
+
+  /*get filesize*/
+  std::streamsize size = 0;
+  if(file.seekg(0, std::ios::end).good()) size = file.tellg();
+  if(file.seekg(0, std::ios::beg).good()) size -= file.tellg();
+
+  /*read contents of the file into the vector*/
+  buffer.resize(size_t(size));
+  if(size > 0) file.read((char*)(&buffer[0]), size);
 }
 
 /*write given buffer to the file, overwriting the file, it doesn't append to it.*/
-unsigned save_file(const std::vector<unsigned char>& buffer, const std::string& filename) {
-  return lodepng_save_file(buffer.empty() ? 0 : &buffer[0], buffer.size(), filename.c_str());
+void save_file(const std::vector<unsigned char>& buffer, const std::string& filename)
+{
+  std::ofstream file(filename.c_str(), std::ios::out|std::ios::binary);
+  file.write(buffer.empty() ? 0 : (char*)&buffer[0], std::streamsize(buffer.size()));
 }
-#endif /* LODEPNG_COMPILE_DISK */
+#endif //LODEPNG_COMPILE_DISK
 
 #ifdef LODEPNG_COMPILE_ZLIB
 #ifdef LODEPNG_COMPILE_DECODER
 unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
-                    const LodePNGDecompressSettings& settings) {
+                    const LodePNGDecompressSettings& settings)
+{
   unsigned char* buffer = 0;
   size_t buffersize = 0;
-  unsigned error = zlib_decompress(&buffer, &buffersize, 0, in, insize, &settings);
-  if(buffer) {
+  unsigned error = zlib_decompress(&buffer, &buffersize, in, insize, &settings);
+  if(buffer)
+  {
     out.insert(out.end(), &buffer[0], &buffer[buffersize]);
     lodepng_free(buffer);
   }
@@ -6301,18 +6077,21 @@ unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, si
 }
 
 unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
-                    const LodePNGDecompressSettings& settings) {
+                    const LodePNGDecompressSettings& settings)
+{
   return decompress(out, in.empty() ? 0 : &in[0], in.size(), settings);
 }
-#endif /* LODEPNG_COMPILE_DECODER */
+#endif //LODEPNG_COMPILE_DECODER
 
 #ifdef LODEPNG_COMPILE_ENCODER
 unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
-                  const LodePNGCompressSettings& settings) {
+                  const LodePNGCompressSettings& settings)
+{
   unsigned char* buffer = 0;
   size_t buffersize = 0;
   unsigned error = zlib_compress(&buffer, &buffersize, in, insize, &settings);
-  if(buffer) {
+  if(buffer)
+  {
     out.insert(out.end(), &buffer[0], &buffer[buffersize]);
     lodepng_free(buffer);
   }
@@ -6320,29 +6099,34 @@ unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size
 }
 
 unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
-                  const LodePNGCompressSettings& settings) {
+                  const LodePNGCompressSettings& settings)
+{
   return compress(out, in.empty() ? 0 : &in[0], in.size(), settings);
 }
-#endif /* LODEPNG_COMPILE_ENCODER */
-#endif /* LODEPNG_COMPILE_ZLIB */
+#endif //LODEPNG_COMPILE_ENCODER
+#endif //LODEPNG_COMPILE_ZLIB
 
 
 #ifdef LODEPNG_COMPILE_PNG
 
-State::State() {
+State::State()
+{
   lodepng_state_init(this);
 }
 
-State::State(const State& other) {
+State::State(const State& other)
+{
   lodepng_state_init(this);
   lodepng_state_copy(this, &other);
 }
 
-State::~State() {
+State::~State()
+{
   lodepng_state_cleanup(this);
 }
 
-State& State::operator=(const State& other) {
+State& State::operator=(const State& other)
+{
   lodepng_state_copy(this, &other);
   return *this;
 }
@@ -6350,31 +6134,36 @@ State& State::operator=(const State& other) {
 #ifdef LODEPNG_COMPILE_DECODER
 
 unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const unsigned char* in,
-                size_t insize, LodePNGColorType colortype, unsigned bitdepth) {
-  unsigned char* buffer = 0;
+                size_t insize, LodePNGColorType colortype, unsigned bitdepth)
+{
+  unsigned char* buffer;
   unsigned error = lodepng_decode_memory(&buffer, &w, &h, in, insize, colortype, bitdepth);
-  if(buffer && !error) {
+  if(buffer && !error)
+  {
     State state;
     state.info_raw.colortype = colortype;
     state.info_raw.bitdepth = bitdepth;
     size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw);
     out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    lodepng_free(buffer);
   }
-  lodepng_free(buffer);
   return error;
 }
 
 unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
-                const std::vector<unsigned char>& in, LodePNGColorType colortype, unsigned bitdepth) {
+                const std::vector<unsigned char>& in, LodePNGColorType colortype, unsigned bitdepth)
+{
   return decode(out, w, h, in.empty() ? 0 : &in[0], (unsigned)in.size(), colortype, bitdepth);
 }
 
 unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
                 State& state,
-                const unsigned char* in, size_t insize) {
+                const unsigned char* in, size_t insize)
+{
   unsigned char* buffer = NULL;
   unsigned error = lodepng_decode(&buffer, &w, &h, &state, in, insize);
-  if(buffer && !error) {
+  if(buffer && !error)
+  {
     size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw);
     out.insert(out.end(), &buffer[0], &buffer[buffersize]);
   }
@@ -6384,30 +6173,31 @@ unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
 
 unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
                 State& state,
-                const std::vector<unsigned char>& in) {
+                const std::vector<unsigned char>& in)
+{
   return decode(out, w, h, state, in.empty() ? 0 : &in[0], in.size());
 }
 
 #ifdef LODEPNG_COMPILE_DISK
 unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const std::string& filename,
-                LodePNGColorType colortype, unsigned bitdepth) {
+                LodePNGColorType colortype, unsigned bitdepth)
+{
   std::vector<unsigned char> buffer;
-  /* safe output values in case error happens */
-  w = h = 0;
-  unsigned error = load_file(buffer, filename);
-  if(error) return error;
+  load_file(buffer, filename);
   return decode(out, w, h, buffer, colortype, bitdepth);
 }
-#endif /* LODEPNG_COMPILE_DECODER */
-#endif /* LODEPNG_COMPILE_DISK */
+#endif //LODEPNG_COMPILE_DECODER
+#endif //LODEPNG_COMPILE_DISK
 
 #ifdef LODEPNG_COMPILE_ENCODER
 unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, unsigned w, unsigned h,
-                LodePNGColorType colortype, unsigned bitdepth) {
+                LodePNGColorType colortype, unsigned bitdepth)
+{
   unsigned char* buffer;
   size_t buffersize;
   unsigned error = lodepng_encode_memory(&buffer, &buffersize, in, w, h, colortype, bitdepth);
-  if(buffer) {
+  if(buffer)
+  {
     out.insert(out.end(), &buffer[0], &buffer[buffersize]);
     lodepng_free(buffer);
   }
@@ -6416,18 +6206,21 @@ unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, unsign
 
 unsigned encode(std::vector<unsigned char>& out,
                 const std::vector<unsigned char>& in, unsigned w, unsigned h,
-                LodePNGColorType colortype, unsigned bitdepth) {
+                LodePNGColorType colortype, unsigned bitdepth)
+{
   if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84;
   return encode(out, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth);
 }
 
 unsigned encode(std::vector<unsigned char>& out,
                 const unsigned char* in, unsigned w, unsigned h,
-                State& state) {
+                State& state)
+{
   unsigned char* buffer;
   size_t buffersize;
   unsigned error = lodepng_encode(&buffer, &buffersize, in, w, h, &state);
-  if(buffer) {
+  if(buffer)
+  {
     out.insert(out.end(), &buffer[0], &buffer[buffersize]);
     lodepng_free(buffer);
   }
@@ -6436,7 +6229,8 @@ unsigned encode(std::vector<unsigned char>& out,
 
 unsigned encode(std::vector<unsigned char>& out,
                 const std::vector<unsigned char>& in, unsigned w, unsigned h,
-                State& state) {
+                State& state)
+{
   if(lodepng_get_raw_size(w, h, &state.info_raw) > in.size()) return 84;
   return encode(out, in.empty() ? 0 : &in[0], w, h, state);
 }
@@ -6444,21 +6238,23 @@ unsigned encode(std::vector<unsigned char>& out,
 #ifdef LODEPNG_COMPILE_DISK
 unsigned encode(const std::string& filename,
                 const unsigned char* in, unsigned w, unsigned h,
-                LodePNGColorType colortype, unsigned bitdepth) {
+                LodePNGColorType colortype, unsigned bitdepth)
+{
   std::vector<unsigned char> buffer;
   unsigned error = encode(buffer, in, w, h, colortype, bitdepth);
-  if(!error) error = save_file(buffer, filename);
+  if(!error) save_file(buffer, filename);
   return error;
 }
 
 unsigned encode(const std::string& filename,
                 const std::vector<unsigned char>& in, unsigned w, unsigned h,
-                LodePNGColorType colortype, unsigned bitdepth) {
+                LodePNGColorType colortype, unsigned bitdepth)
+{
   if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84;
   return encode(filename, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth);
 }
-#endif /* LODEPNG_COMPILE_DISK */
-#endif /* LODEPNG_COMPILE_ENCODER */
-#endif /* LODEPNG_COMPILE_PNG */
-} /* namespace lodepng */
+#endif //LODEPNG_COMPILE_DISK
+#endif //LODEPNG_COMPILE_ENCODER
+#endif //LODEPNG_COMPILE_PNG
+} //namespace lodepng
 #endif /*LODEPNG_COMPILE_CPP*/
diff --git a/src/zopflipng/lodepng/lodepng.h b/src/zopflipng/lodepng/lodepng.h
index 6801cb7..c497a5c 100644
--- a/src/zopflipng/lodepng/lodepng.h
+++ b/src/zopflipng/lodepng/lodepng.h
@@ -1,7 +1,7 @@
 /*
-LodePNG version 20201017
+LodePNG version 20131222
 
-Copyright (c) 2005-2020 Lode Vandevenne
+Copyright (c) 2005-2013 Lode Vandevenne
 
 This software is provided 'as-is', without any express or implied
 warranty. In no event will the authors be held liable for any damages
@@ -28,7 +28,10 @@ freely, subject to the following restrictions:
 
 #include <string.h> /*for size_t*/
 
-extern const char* LODEPNG_VERSION_STRING;
+#ifdef __cplusplus
+#include <vector>
+#include <string>
+#endif /*__cplusplus*/
 
 /*
 The following #defines are used to create code sections. They can be disabled
@@ -36,52 +39,42 @@ to disable code sections, which can give faster compile time and smaller binary.
 The "NO_COMPILE" defines are designed to be used to pass as defines to the
 compiler command to disable them without modifying this header, e.g.
 -DLODEPNG_NO_COMPILE_ZLIB for gcc.
-In addition to those below, you can also define LODEPNG_NO_COMPILE_CRC to
-allow implementing a custom lodepng_crc32.
 */
 /*deflate & zlib. If disabled, you must specify alternative zlib functions in
 the custom_zlib field of the compress and decompress settings*/
 #ifndef LODEPNG_NO_COMPILE_ZLIB
 #define LODEPNG_COMPILE_ZLIB
 #endif
-
 /*png encoder and png decoder*/
 #ifndef LODEPNG_NO_COMPILE_PNG
 #define LODEPNG_COMPILE_PNG
 #endif
-
 /*deflate&zlib decoder and png decoder*/
 #ifndef LODEPNG_NO_COMPILE_DECODER
 #define LODEPNG_COMPILE_DECODER
 #endif
-
 /*deflate&zlib encoder and png encoder*/
 #ifndef LODEPNG_NO_COMPILE_ENCODER
 #define LODEPNG_COMPILE_ENCODER
 #endif
-
 /*the optional built in harddisk file loading and saving functions*/
 #ifndef LODEPNG_NO_COMPILE_DISK
 #define LODEPNG_COMPILE_DISK
 #endif
-
 /*support for chunks other than IHDR, IDAT, PLTE, tRNS, IEND: ancillary and unknown chunks*/
 #ifndef LODEPNG_NO_COMPILE_ANCILLARY_CHUNKS
 #define LODEPNG_COMPILE_ANCILLARY_CHUNKS
 #endif
-
 /*ability to convert error numerical codes to English text string*/
 #ifndef LODEPNG_NO_COMPILE_ERROR_TEXT
 #define LODEPNG_COMPILE_ERROR_TEXT
 #endif
-
 /*Compile the default allocators (C's free, malloc and realloc). If you disable this,
 you can define the functions lodepng_free, lodepng_malloc and lodepng_realloc in your
 source files with custom allocators.*/
 #ifndef LODEPNG_NO_COMPILE_ALLOCATORS
 #define LODEPNG_COMPILE_ALLOCATORS
 #endif
-
 /*compile the C++ version (you can disable the C++ wrapper here even when compiling for C++)*/
 #ifdef __cplusplus
 #ifndef LODEPNG_NO_COMPILE_CPP
@@ -89,25 +82,15 @@ source files with custom allocators.*/
 #endif
 #endif
 
-#ifdef LODEPNG_COMPILE_CPP
-#include <vector>
-#include <string>
-#endif /*LODEPNG_COMPILE_CPP*/
-
 #ifdef LODEPNG_COMPILE_PNG
-/*The PNG color types (also used for raw image).*/
-typedef enum LodePNGColorType {
-  LCT_GREY = 0, /*grayscale: 1,2,4,8,16 bit*/
+/*The PNG color types (also used for raw).*/
+typedef enum LodePNGColorType
+{
+  LCT_GREY = 0, /*greyscale: 1,2,4,8,16 bit*/
   LCT_RGB = 2, /*RGB: 8,16 bit*/
   LCT_PALETTE = 3, /*palette: 1,2,4,8 bit*/
-  LCT_GREY_ALPHA = 4, /*grayscale with alpha: 8,16 bit*/
-  LCT_RGBA = 6, /*RGB with alpha: 8,16 bit*/
-  /*LCT_MAX_OCTET_VALUE lets the compiler allow this enum to represent any invalid
-  byte value from 0 to 255 that could be present in an invalid PNG file header. Do
-  not use, compare with or set the name LCT_MAX_OCTET_VALUE, instead either use
-  the valid color type names above, or numeric values like 1 or 7 when checking for
-  particular disallowed color type byte values, or cast to integer to print it.*/
-  LCT_MAX_OCTET_VALUE = 255
+  LCT_GREY_ALPHA = 4, /*greyscale with alpha: 8,16 bit*/
+  LCT_RGBA = 6 /*RGB with alpha: 8,16 bit*/
 } LodePNGColorType;
 
 #ifdef LODEPNG_COMPILE_DECODER
@@ -209,10 +192,10 @@ unsigned lodepng_encode24_file(const char* filename,
 
 
 #ifdef LODEPNG_COMPILE_CPP
-namespace lodepng {
+namespace lodepng
+{
 #ifdef LODEPNG_COMPILE_DECODER
-/*Same as lodepng_decode_memory, but decodes to an std::vector. The colortype
-is the format to output the pixels to. Default is RGBA 8-bit per channel.*/
+/*Same as lodepng_decode_memory, but decodes to an std::vector.*/
 unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
                 const unsigned char* in, size_t insize,
                 LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
@@ -227,12 +210,11 @@ Same as the other decode functions, but instead takes a filename as input.
 unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
                 const std::string& filename,
                 LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
-#endif /* LODEPNG_COMPILE_DISK */
-#endif /* LODEPNG_COMPILE_DECODER */
+#endif //LODEPNG_COMPILE_DISK
+#endif //LODEPNG_COMPILE_DECODER
 
 #ifdef LODEPNG_COMPILE_ENCODER
-/*Same as lodepng_encode_memory, but encodes to an std::vector. colortype
-is that of the raw input data. The output PNG color type will be auto chosen.*/
+/*Same as lodepng_encode_memory, but encodes to an std::vector.*/
 unsigned encode(std::vector<unsigned char>& out,
                 const unsigned char* in, unsigned w, unsigned h,
                 LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
@@ -251,9 +233,9 @@ unsigned encode(const std::string& filename,
 unsigned encode(const std::string& filename,
                 const std::vector<unsigned char>& in, unsigned w, unsigned h,
                 LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
-#endif /* LODEPNG_COMPILE_DISK */
-#endif /* LODEPNG_COMPILE_ENCODER */
-} /* namespace lodepng */
+#endif //LODEPNG_COMPILE_DISK
+#endif //LODEPNG_COMPILE_ENCODER
+} //namespace lodepng
 #endif /*LODEPNG_COMPILE_CPP*/
 #endif /*LODEPNG_COMPILE_PNG*/
 
@@ -265,26 +247,17 @@ const char* lodepng_error_text(unsigned code);
 #ifdef LODEPNG_COMPILE_DECODER
 /*Settings for zlib decompression*/
 typedef struct LodePNGDecompressSettings LodePNGDecompressSettings;
-struct LodePNGDecompressSettings {
-  /* Check LodePNGDecoderSettings for more ignorable errors such as ignore_crc */
+struct LodePNGDecompressSettings
+{
   unsigned ignore_adler32; /*if 1, continue and don't give an error message if the Adler32 checksum is corrupted*/
-  unsigned ignore_nlen; /*ignore complement of len checksum in uncompressed blocks*/
 
-  /*Maximum decompressed size, beyond this the decoder may (and is encouraged to) stop decoding,
-  return an error, output a data size > max_output_size and all the data up to that point. This is
-  not hard limit nor a guarantee, but can prevent excessive memory usage. This setting is
-  ignored by the PNG decoder, but is used by the deflate/zlib decoder and can be used by custom ones.
-  Set to 0 to impose no limit (the default).*/
-  size_t max_output_size;
-
-  /*use custom zlib decoder instead of built in one (default: null).
-  Should return 0 if success, any non-0 if error (numeric value not exposed).*/
+  /*use custom zlib decoder instead of built in one (default: null)*/
   unsigned (*custom_zlib)(unsigned char**, size_t*,
                           const unsigned char*, size_t,
                           const LodePNGDecompressSettings*);
   /*use custom deflate decoder instead of built in one (default: null)
-  if custom_zlib is not null, custom_inflate is ignored (the zlib format uses deflate).
-  Should return 0 if success, any non-0 if error (numeric value not exposed).*/
+  if custom_zlib is used, custom_deflate is ignored since only the built in
+  zlib function will call custom_deflate*/
   unsigned (*custom_inflate)(unsigned char**, size_t*,
                              const unsigned char*, size_t,
                              const LodePNGDecompressSettings*);
@@ -302,12 +275,13 @@ Settings for zlib compression. Tweaking these settings tweaks the balance
 between speed and compression ratio.
 */
 typedef struct LodePNGCompressSettings LodePNGCompressSettings;
-struct LodePNGCompressSettings /*deflate = compress*/ {
+struct LodePNGCompressSettings /*deflate = compress*/
+{
   /*LZ77 related settings*/
   unsigned btype; /*the block type for LZ (0, 1, 2 or 3, see zlib standard). Should be 2 for proper compression.*/
   unsigned use_lz77; /*whether or not to use LZ77. Should be 1 for proper compression.*/
-  unsigned windowsize; /*must be a power of two <= 32768. higher compresses more but is slower. Default value: 2048.*/
-  unsigned minmatch; /*minimum lz77 length. 3 is normally best, 6 can be better for some PNGs. Default: 0*/
+  unsigned windowsize; /*must be a power of two <= 32768. higher compresses more but is slower. Typical value: 2048.*/
+  unsigned minmatch; /*mininum lz77 length. 3 is normally best, 6 can be better for some PNGs. Default: 0*/
   unsigned nicematch; /*stop searching if >= this length found. Set to 258 for best compression. Default: 128*/
   unsigned lazymatching; /*use lazy matching: better compression but a bit slower. Default: true*/
 
@@ -335,7 +309,8 @@ Color mode of an image. Contains all information required to decode the pixel
 bits to RGBA colors. This information is the same as used in the PNG file
 format, and is used both for PNG and raw image data in LodePNG.
 */
-typedef struct LodePNGColorMode {
+typedef struct LodePNGColorMode
+{
   /*header (IHDR)*/
   LodePNGColorType colortype; /*color type, see PNG standard or documentation further in this header file*/
   unsigned bitdepth;  /*bits per sample, see PNG standard or documentation further in this header file*/
@@ -344,25 +319,23 @@ typedef struct LodePNGColorMode {
   palette (PLTE and tRNS)
 
   Dynamically allocated with the colors of the palette, including alpha.
-  This field may not be allocated directly, use lodepng_color_mode_init first,
-  then lodepng_palette_add per color to correctly initialize it (to ensure size
-  of exactly 1024 bytes).
-
-  The alpha channels must be set as well, set them to 255 for opaque images.
+  When encoding a PNG, to store your colors in the palette of the LodePNGColorMode, first use
+  lodepng_palette_clear, then for each color use lodepng_palette_add.
+  If you encode an image without alpha with palette, don't forget to put value 255 in each A byte of the palette.
 
   When decoding, by default you can ignore this palette, since LodePNG already
   fills the palette colors in the pixels of the raw RGBA output.
 
   The palette is only supported for color type 3.
   */
-  unsigned char* palette; /*palette in RGBARGBA... order. Must be either 0, or when allocated must have 1024 bytes*/
-  size_t palettesize; /*palette size in number of colors (amount of used bytes is 4 * palettesize)*/
+  unsigned char* palette; /*palette in RGBARGBA... order. When allocated, must be either 0, or have size 1024*/
+  size_t palettesize; /*palette size in number of colors (amount of bytes is 4 * palettesize)*/
 
   /*
   transparent color key (tRNS)
 
   This color uses the same bit depth as the bitdepth value in this struct, which can be 1-bit to 16-bit.
-  For grayscale PNGs, r, g and b will all 3 be set to the same.
+  For greyscale PNGs, r, g and b will all 3 be set to the same.
 
   When decoding, by default you can ignore this information, since LodePNG sets
   pixels with this key to transparent already in the raw RGBA output.
@@ -370,7 +343,7 @@ typedef struct LodePNGColorMode {
   The color key is only supported for color types 0 and 2.
   */
   unsigned key_defined; /*is a transparent color key given? 0 = false, 1 = true*/
-  unsigned key_r;       /*red/grayscale component of color key*/
+  unsigned key_r;       /*red/greyscale component of color key*/
   unsigned key_g;       /*green component of color key*/
   unsigned key_b;       /*blue component of color key*/
 } LodePNGColorMode;
@@ -380,8 +353,6 @@ void lodepng_color_mode_init(LodePNGColorMode* info);
 void lodepng_color_mode_cleanup(LodePNGColorMode* info);
 /*return value is error code (0 means no error)*/
 unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source);
-/* Makes a temporary LodePNGColorMode that does not need cleanup (no palette) */
-LodePNGColorMode lodepng_color_mode_make(LodePNGColorType colortype, unsigned bitdepth);
 
 void lodepng_palette_clear(LodePNGColorMode* info);
 /*add 1 color to the palette*/
@@ -393,7 +364,7 @@ unsigned lodepng_get_bpp(const LodePNGColorMode* info);
 /*get the amount of color channels used, based on colortype in the struct.
 If a palette is used, it counts as 1 channel.*/
 unsigned lodepng_get_channels(const LodePNGColorMode* info);
-/*is it a grayscale type? (only colortype 0 or 4)*/
+/*is it a greyscale type? (only colortype 0 or 4)*/
 unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info);
 /*has it got an alpha channel? (only colortype 2 or 6)*/
 unsigned lodepng_is_alpha_type(const LodePNGColorMode* info);
@@ -415,7 +386,8 @@ size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* colo
 
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
 /*The information of a Time chunk in PNG.*/
-typedef struct LodePNGTime {
+typedef struct LodePNGTime
+{
   unsigned year;    /*2 bytes used (0-65535)*/
   unsigned month;   /*1-12*/
   unsigned day;     /*1-31*/
@@ -426,73 +398,52 @@ typedef struct LodePNGTime {
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
 
 /*Information about the PNG image, except pixels, width and height.*/
-typedef struct LodePNGInfo {
+typedef struct LodePNGInfo
+{
   /*header (IHDR), palette (PLTE) and transparency (tRNS) chunks*/
   unsigned compression_method;/*compression method of the original file. Always 0.*/
   unsigned filter_method;     /*filter method of the original file*/
-  unsigned interlace_method;  /*interlace method of the original file: 0=none, 1=Adam7*/
+  unsigned interlace_method;  /*interlace method of the original file*/
   LodePNGColorMode color;     /*color type and bits, palette and transparency of the PNG file*/
 
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
   /*
-  Suggested background color chunk (bKGD)
-
-  This uses the same color mode and bit depth as the PNG (except no alpha channel),
-  with values truncated to the bit depth in the unsigned integer.
-
-  For grayscale and palette PNGs, the value is stored in background_r. The values
-  in background_g and background_b are then unused.
+  suggested background color chunk (bKGD)
+  This color uses the same color mode as the PNG (except alpha channel), which can be 1-bit to 16-bit.
 
-  So when decoding, you may get these in a different color mode than the one you requested
-  for the raw pixels.
+  For greyscale PNGs, r, g and b will all 3 be set to the same. When encoding
+  the encoder writes the red one. For palette PNGs: When decoding, the RGB value
+  will be stored, not a palette index. But when encoding, specify the index of
+  the palette in background_r, the other two are then ignored.
 
-  When encoding with auto_convert, you must use the color model defined in info_png.color for
-  these values. The encoder normally ignores info_png.color when auto_convert is on, but will
-  use it to interpret these values (and convert copies of them to its chosen color model).
-
-  When encoding, avoid setting this to an expensive color, such as a non-gray value
-  when the image is gray, or the compression will be worse since it will be forced to
-  write the PNG with a more expensive color mode (when auto_convert is on).
-
-  The decoder does not use this background color to edit the color of pixels. This is a
-  completely optional metadata feature.
+  The decoder does not use this background color to edit the color of pixels.
   */
   unsigned background_defined; /*is a suggested background color given?*/
-  unsigned background_r;       /*red/gray/palette component of suggested background color*/
+  unsigned background_r;       /*red component of suggested background color*/
   unsigned background_g;       /*green component of suggested background color*/
   unsigned background_b;       /*blue component of suggested background color*/
 
   /*
-  Non-international text chunks (tEXt and zTXt)
+  non-international text chunks (tEXt and zTXt)
 
   The char** arrays each contain num strings. The actual messages are in
   text_strings, while text_keys are keywords that give a short description what
   the actual text represents, e.g. Title, Author, Description, or anything else.
 
-  All the string fields below including strings, keys, names and language tags are null terminated.
-  The PNG specification uses null characters for the keys, names and tags, and forbids null
-  characters to appear in the main text which is why we can use null termination everywhere here.
-
-  A keyword is minimum 1 character and maximum 79 characters long (plus the
-  additional null terminator). It's discouraged to use a single line length
-  longer than 79 characters for texts.
+  A keyword is minimum 1 character and maximum 79 characters long. It's
+  discouraged to use a single line length longer than 79 characters for texts.
 
   Don't allocate these text buffers yourself. Use the init/cleanup functions
   correctly and use lodepng_add_text and lodepng_clear_text.
-
-  Standard text chunk keywords and strings are encoded using Latin-1.
   */
   size_t text_num; /*the amount of texts in these char** buffers (there may be more texts in itext)*/
   char** text_keys; /*the keyword of a text chunk (e.g. "Comment")*/
   char** text_strings; /*the actual text*/
 
   /*
-  International text chunks (iTXt)
+  international text chunks (iTXt)
   Similar to the non-international text chunks, but with additional strings
-  "langtags" and "transkeys", and the following text encodings are used:
-  keys: Latin-1, langtags: ASCII, transkeys and strings: UTF-8.
-  keys must be 1-79 characters (plus the additional null terminator), the other
-  strings are any length.
+  "langtags" and "transkeys".
   */
   size_t itext_num; /*the amount of international texts in this PNG*/
   char** itext_keys; /*the English keyword of the text chunk (e.g. "Comment")*/
@@ -511,86 +462,11 @@ typedef struct LodePNGInfo {
   unsigned phys_unit; /*may be 0 (unknown unit) or 1 (metre)*/
 
   /*
-  Color profile related chunks: gAMA, cHRM, sRGB, iCPP
-
-  LodePNG does not apply any color conversions on pixels in the encoder or decoder and does not interpret these color
-  profile values. It merely passes on the information. If you wish to use color profiles and convert colors, please
-  use these values with a color management library.
-
-  See the PNG, ICC and sRGB specifications for more information about the meaning of these values.
-  */
-
-  /* gAMA chunk: optional, overridden by sRGB or iCCP if those are present. */
-  unsigned gama_defined; /* Whether a gAMA chunk is present (0 = not present, 1 = present). */
-  unsigned gama_gamma;   /* Gamma exponent times 100000 */
-
-  /* cHRM chunk: optional, overridden by sRGB or iCCP if those are present. */
-  unsigned chrm_defined; /* Whether a cHRM chunk is present (0 = not present, 1 = present). */
-  unsigned chrm_white_x; /* White Point x times 100000 */
-  unsigned chrm_white_y; /* White Point y times 100000 */
-  unsigned chrm_red_x;   /* Red x times 100000 */
-  unsigned chrm_red_y;   /* Red y times 100000 */
-  unsigned chrm_green_x; /* Green x times 100000 */
-  unsigned chrm_green_y; /* Green y times 100000 */
-  unsigned chrm_blue_x;  /* Blue x times 100000 */
-  unsigned chrm_blue_y;  /* Blue y times 100000 */
-
-  /*
-  sRGB chunk: optional. May not appear at the same time as iCCP.
-  If gAMA is also present gAMA must contain value 45455.
-  If cHRM is also present cHRM must contain respectively 31270,32900,64000,33000,30000,60000,15000,6000.
-  */
-  unsigned srgb_defined; /* Whether an sRGB chunk is present (0 = not present, 1 = present). */
-  unsigned srgb_intent;  /* Rendering intent: 0=perceptual, 1=rel. colorimetric, 2=saturation, 3=abs. colorimetric */
-
-  /*
-  iCCP chunk: optional. May not appear at the same time as sRGB.
-
-  LodePNG does not parse or use the ICC profile (except its color space header field for an edge case), a
-  separate library to handle the ICC data (not included in LodePNG) format is needed to use it for color
-  management and conversions.
-
-  For encoding, if iCCP is present, gAMA and cHRM are recommended to be added as well with values that match the ICC
-  profile as closely as possible, if you wish to do this you should provide the correct values for gAMA and cHRM and
-  enable their '_defined' flags since LodePNG will not automatically compute them from the ICC profile.
-
-  For encoding, the ICC profile is required by the PNG specification to be an "RGB" profile for non-gray
-  PNG color types and a "GRAY" profile for gray PNG color types. If you disable auto_convert, you must ensure
-  the ICC profile type matches your requested color type, else the encoder gives an error. If auto_convert is
-  enabled (the default), and the ICC profile is not a good match for the pixel data, this will result in an encoder
-  error if the pixel data has non-gray pixels for a GRAY profile, or a silent less-optimal compression of the pixel
-  data if the pixels could be encoded as grayscale but the ICC profile is RGB.
-
-  To avoid this do not set an ICC profile in the image unless there is a good reason for it, and when doing so
-  make sure you compute it carefully to avoid the above problems.
-  */
-  unsigned iccp_defined;      /* Whether an iCCP chunk is present (0 = not present, 1 = present). */
-  char* iccp_name;            /* Null terminated string with profile name, 1-79 bytes */
-  /*
-  The ICC profile in iccp_profile_size bytes.
-  Don't allocate this buffer yourself. Use the init/cleanup functions
-  correctly and use lodepng_set_icc and lodepng_clear_icc.
-  */
-  unsigned char* iccp_profile;
-  unsigned iccp_profile_size; /* The size of iccp_profile in bytes */
-
-  /* End of color profile related chunks */
-
-
-  /*
-  unknown chunks: chunks not known by LodePNG, passed on byte for byte.
-
-  There are 3 buffers, one for each position in the PNG where unknown chunks can appear.
-  Each buffer contains all unknown chunks for that position consecutively.
-  The 3 positions are:
-  0: between IHDR and PLTE, 1: between PLTE and IDAT, 2: between IDAT and IEND.
-
-  For encoding, do not store critical chunks or known chunks that are enabled with a "_defined" flag
-  above in here, since the encoder will blindly follow this and could then encode an invalid PNG file
-  (such as one with two IHDR chunks or the disallowed combination of sRGB with iCCP). But do use
-  this if you wish to store an ancillary chunk that is not supported by LodePNG (such as sPLT or hIST),
-  or any non-standard PNG chunk.
-
+  unknown chunks
+  There are 3 buffers, one for each position in the PNG where unknown chunks can appear
+  each buffer contains all unknown chunks for that position consecutively
+  The 3 buffers are the unknown chunks between certain critical chunks:
+  0: IHDR-PLTE, 1: PLTE-IDAT, 2: IDAT-IEND
   Do not allocate or traverse this data yourself. Use the chunk traversing functions declared
   later, such as lodepng_chunk_next and lodepng_chunk_append, to read/write this struct.
   */
@@ -606,16 +482,12 @@ void lodepng_info_cleanup(LodePNGInfo* info);
 unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source);
 
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str); /*push back both texts at once*/
 void lodepng_clear_text(LodePNGInfo* info); /*use this to clear the texts again after you filled them in*/
+unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str); /*push back both texts at once*/
 
+void lodepng_clear_itext(LodePNGInfo* info); /*use this to clear the itexts again after you filled them in*/
 unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag,
                            const char* transkey, const char* str); /*push back the 4 texts of 1 chunk at once*/
-void lodepng_clear_itext(LodePNGInfo* info); /*use this to clear the itexts again after you filled them in*/
-
-/*replaces if exists*/
-unsigned lodepng_set_icc(LodePNGInfo* info, const char* name, const unsigned char* profile, unsigned profile_size);
-void lodepng_clear_icc(LodePNGInfo* info); /*use this to clear the texts again after you filled them in*/
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
 
 /*
@@ -624,49 +496,40 @@ LodePNGColorMode structs to describe the input and output color type.
 See the reference manual at the end of this header file to see which color conversions are supported.
 return value = LodePNG error code (0 if all went ok, an error if the conversion isn't supported)
 The out buffer must have size (w * h * bpp + 7) / 8, where bpp is the bits per pixel
-of the output color type (lodepng_get_bpp).
-For < 8 bpp images, there should not be padding bits at the end of scanlines.
-For 16-bit per channel colors, uses big endian format like PNG does.
-Return value is LodePNG error code
+of the output color type (lodepng_get_bpp)
+The fix_png value works as described in struct LodePNGDecoderSettings.
+Note: for 16-bit per channel colors, uses big endian format like PNG does.
 */
 unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
-                         const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
-                         unsigned w, unsigned h);
+                         LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
+                         unsigned w, unsigned h, unsigned fix_png);
 
 #ifdef LODEPNG_COMPILE_DECODER
 /*
 Settings for the decoder. This contains settings for the PNG and the Zlib
 decoder, but not the Info settings from the Info structs.
 */
-typedef struct LodePNGDecoderSettings {
+typedef struct LodePNGDecoderSettings
+{
   LodePNGDecompressSettings zlibsettings; /*in here is the setting to ignore Adler32 checksums*/
 
-  /* Check LodePNGDecompressSettings for more ignorable errors such as ignore_adler32 */
   unsigned ignore_crc; /*ignore CRC checksums*/
-  unsigned ignore_critical; /*ignore unknown critical chunks*/
-  unsigned ignore_end; /*ignore issues at end of file if possible (missing IEND chunk, too large chunk, ...)*/
-  /* TODO: make a system involving warnings with levels and a strict mode instead. Other potentially recoverable
-     errors: srgb rendering intent value, size of content of ancillary chunks, more than 79 characters for some
-     strings, placement/combination rules for ancillary chunks, crc of unknown chunks, allowed characters
-     in string keys, etc... */
-
+  /*
+  The fix_png setting, if 1, makes the decoder tolerant towards some PNG images
+  that do not correctly follow the PNG specification. This only supports errors
+  that are fixable, were found in images that are actually used on the web, and
+  are silently tolerated by other decoders as well. Currently only one such fix
+  is implemented: if a palette index is out of bounds given the palette size,
+  interpret it as opaque black.
+  By default this value is 0, which makes it stop with an error on such images.
+  */
+  unsigned fix_png;
   unsigned color_convert; /*whether to convert the PNG to the color type you want. Default: yes*/
 
 #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
   unsigned read_text_chunks; /*if false but remember_unknown_chunks is true, they're stored in the unknown chunks*/
-
   /*store all bytes from unknown chunks in the LodePNGInfo (off by default, useful for a png editor)*/
   unsigned remember_unknown_chunks;
-
-  /* maximum size for decompressed text chunks. If a text chunk's text is larger than this, an error is returned,
-  unless reading text chunks is disabled or this limit is set higher or disabled. Set to 0 to allow any size.
-  By default it is a value that prevents unreasonably large strings from hogging memory. */
-  size_t max_text_size;
-
-  /* maximum size for compressed ICC chunks. If the ICC profile is larger than this, an error will be returned. Set to
-  0 to allow any size. By default this is a value that prevents ICC profiles that would be much larger than any
-  legitimate profile could be to hog memory. */
-  size_t max_icc_size;
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
 } LodePNGDecoderSettings;
 
@@ -675,15 +538,11 @@ void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings);
 
 #ifdef LODEPNG_COMPILE_ENCODER
 /*automatically use color type with less bits per pixel if losslessly possible. Default: AUTO*/
-typedef enum LodePNGFilterStrategy {
+typedef enum LodePNGFilterStrategy
+{
   /*every filter at zero*/
-  LFS_ZERO = 0,
-  /*every filter at 1, 2, 3 or 4 (paeth), unlike LFS_ZERO not a good choice, but for testing*/
-  LFS_ONE = 1,
-  LFS_TWO = 2,
-  LFS_THREE = 3,
-  LFS_FOUR = 4,
-  /*Use filter that gives minimum sum, as described in the official PNG filter heuristic.*/
+  LFS_ZERO,
+  /*Use filter that gives minumum sum, as described in the official PNG filter heuristic.*/
   LFS_MINSUM,
   /*Use the filter type that gives smallest Shannon entropy for this scanline. Depending
   on the image, this is better or worse than minsum.*/
@@ -697,39 +556,46 @@ typedef enum LodePNGFilterStrategy {
   LFS_PREDEFINED
 } LodePNGFilterStrategy;
 
-/*Gives characteristics about the integer RGBA colors of the image (count, alpha channel usage, bit depth, ...),
-which helps decide which color model to use for encoding.
-Used internally by default if "auto_convert" is enabled. Public because it's useful for custom algorithms.*/
-typedef struct LodePNGColorStats {
-  unsigned colored; /*not grayscale*/
-  unsigned key; /*image is not opaque and color key is possible instead of full alpha*/
-  unsigned short key_r; /*key values, always as 16-bit, in 8-bit case the byte is duplicated, e.g. 65535 means 255*/
-  unsigned short key_g;
-  unsigned short key_b;
-  unsigned alpha; /*image is not opaque and alpha channel or alpha palette required*/
-  unsigned numcolors; /*amount of colors, up to 257. Not valid if bits == 16 or allow_palette is disabled.*/
-  unsigned char palette[1024]; /*Remembers up to the first 256 RGBA colors, in no particular order, only valid when numcolors is valid*/
-  unsigned bits; /*bits per channel (not for palette). 1,2 or 4 for grayscale only. 16 if 16-bit per channel required.*/
-  size_t numpixels;
-
-  /*user settings for computing/using the stats*/
-  unsigned allow_palette; /*default 1. if 0, disallow choosing palette colortype in auto_choose_color, and don't count numcolors*/
-  unsigned allow_greyscale; /*default 1. if 0, choose RGB or RGBA even if the image only has gray colors*/
-} LodePNGColorStats;
-
-void lodepng_color_stats_init(LodePNGColorStats* stats);
-
-/*Get a LodePNGColorStats of the image. The stats must already have been inited.
-Returns error code (e.g. alloc fail) or 0 if ok.*/
-unsigned lodepng_compute_color_stats(LodePNGColorStats* stats,
-                                     const unsigned char* image, unsigned w, unsigned h,
-                                     const LodePNGColorMode* mode_in);
+/*automatically use color type with less bits per pixel if losslessly possible. Default: LAC_AUTO*/
+typedef enum LodePNGAutoConvert
+{
+  LAC_NO, /*use color type user requested*/
+  LAC_ALPHA, /*use color type user requested, but if only opaque pixels and RGBA or grey+alpha, use RGB or grey*/
+  LAC_AUTO, /*use PNG color type that can losslessly represent the uncompressed image the smallest possible*/
+  /*
+  like AUTO, but do not choose 1, 2 or 4 bit per pixel types.
+  sometimes a PNG image compresses worse if less than 8 bits per pixels.
+  */
+  LAC_AUTO_NO_NIBBLES,
+  /*
+  like AUTO, but never choose palette color type. For small images, encoding
+  the palette may take more bytes than what is gained. Note that AUTO also
+  already prevents encoding the palette for extremely small images, but that may
+  not be sufficient because due to the compression it cannot predict when to
+  switch.
+  */
+  LAC_AUTO_NO_PALETTE,
+  LAC_AUTO_NO_NIBBLES_NO_PALETTE
+} LodePNGAutoConvert;
+
+
+/*
+Automatically chooses color type that gives smallest amount of bits in the
+output image, e.g. grey if there are only greyscale pixels, palette if there
+are less than 256 colors, ...
+The auto_convert parameter allows limiting it to not use palette, ...
+*/
+unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out,
+                                   const unsigned char* image, unsigned w, unsigned h,
+                                   const LodePNGColorMode* mode_in,
+                                   LodePNGAutoConvert auto_convert);
 
 /*Settings for the encoder.*/
-typedef struct LodePNGEncoderSettings {
+typedef struct LodePNGEncoderSettings
+{
   LodePNGCompressSettings zlibsettings; /*settings for the zlib encoder, such as window size, ...*/
 
-  unsigned auto_convert; /*automatically choose output PNG color type. Default: true*/
+  LodePNGAutoConvert auto_convert; /*how to automatically choose output PNG color type, if at all*/
 
   /*If true, follows the official PNG heuristic: if the PNG uses a palette or lower than
   8 bit depth, set all filters to zero. Otherwise use the filter_strategy. Note that to
@@ -762,7 +628,8 @@ void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings);
 
 #if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER)
 /*The settings, state and information for extended encoding and decoding.*/
-typedef struct LodePNGState {
+typedef struct LodePNGState
+{
 #ifdef LODEPNG_COMPILE_DECODER
   LodePNGDecoderSettings decoder; /*the decoding settings*/
 #endif /*LODEPNG_COMPILE_DECODER*/
@@ -772,6 +639,10 @@ typedef struct LodePNGState {
   LodePNGColorMode info_raw; /*specifies the format in which you would like to get the raw pixel buffer*/
   LodePNGInfo info_png; /*info of the PNG image obtained after decoding*/
   unsigned error;
+#ifdef LODEPNG_COMPILE_CPP
+  //For the lodepng::State subclass.
+  virtual ~LodePNGState(){}
+#endif
 } LodePNGState;
 
 /*init, cleanup and copy functions to use with this struct*/
@@ -791,7 +662,7 @@ unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h,
 
 /*
 Read the PNG header, but not the actual data. This returns only the information
-that is in the IHDR chunk of the PNG, such as width, height and color type. The
+that is in the header chunk of the PNG, such as width, height and color type. The
 information is placed in the info_png field of the LodePNGState.
 */
 unsigned lodepng_inspect(unsigned* w, unsigned* h,
@@ -799,20 +670,6 @@ unsigned lodepng_inspect(unsigned* w, unsigned* h,
                          const unsigned char* in, size_t insize);
 #endif /*LODEPNG_COMPILE_DECODER*/
 
-/*
-Reads one metadata chunk (other than IHDR) of the PNG file and outputs what it
-read in the state. Returns error code on failure.
-Use lodepng_inspect first with a new state, then e.g. lodepng_chunk_find_const
-to find the desired chunk type, and if non null use lodepng_inspect_chunk (with
-chunk_pointer - start_of_file as pos).
-Supports most metadata chunks from the PNG standard (gAMA, bKGD, tEXt, ...).
-Ignores unsupported, unknown, non-metadata or IHDR chunks (without error).
-Requirements: &in[pos] must point to start of a chunk, must use regular
-lodepng_inspect first since format of most other chunks depends on IHDR, and if
-there is a PLTE chunk, that one must be inspected before tRNS or bKGD.
-*/
-unsigned lodepng_inspect_chunk(LodePNGState* state, size_t pos,
-                               const unsigned char* in, size_t insize);
 
 #ifdef LODEPNG_COMPILE_ENCODER
 /*This function allocates the out buffer with standard malloc and stores the size in *outsize.*/
@@ -826,30 +683,14 @@ The lodepng_chunk functions are normally not needed, except to traverse the
 unknown chunks stored in the LodePNGInfo struct, or add new ones to it.
 It also allows traversing the chunks of an encoded PNG file yourself.
 
-The chunk pointer always points to the beginning of the chunk itself, that is
-the first byte of the 4 length bytes.
-
-In the PNG file format, chunks have the following format:
--4 bytes length: length of the data of the chunk in bytes (chunk itself is 12 bytes longer)
--4 bytes chunk type (ASCII a-z,A-Z only, see below)
--length bytes of data (may be 0 bytes if length was 0)
--4 bytes of CRC, computed on chunk name + data
-
-The first chunk starts at the 8th byte of the PNG file, the entire rest of the file
-exists out of concatenated chunks with the above format.
-
-PNG standard chunk ASCII naming conventions:
--First byte: uppercase = critical, lowercase = ancillary
--Second byte: uppercase = public, lowercase = private
--Third byte: must be uppercase
--Fourth byte: uppercase = unsafe to copy, lowercase = safe to copy
+PNG standard chunk naming conventions:
+First byte: uppercase = critical, lowercase = ancillary
+Second byte: uppercase = public, lowercase = private
+Third byte: must be uppercase
+Fourth byte: uppercase = unsafe to copy, lowercase = safe to copy
 */
 
-/*
-Gets the length of the data of the chunk. Total chunk length has 12 bytes more.
-There must be at least 4 bytes to read from. If the result value is too large,
-it may be corrupt data.
-*/
+/*get the length of the data of the chunk. Total chunk length has 12 bytes more.*/
 unsigned lodepng_chunk_length(const unsigned char* chunk);
 
 /*puts the 4-byte type in null terminated string*/
@@ -877,38 +718,24 @@ unsigned lodepng_chunk_check_crc(const unsigned char* chunk);
 /*generates the correct CRC from the data and puts it in the last 4 bytes of the chunk*/
 void lodepng_chunk_generate_crc(unsigned char* chunk);
 
-/*
-Iterate to next chunks, allows iterating through all chunks of the PNG file.
-Input must be at the beginning of a chunk (result of a previous lodepng_chunk_next call,
-or the 8th byte of a PNG file which always has the first chunk), or alternatively may
-point to the first byte of the PNG file (which is not a chunk but the magic header, the
-function will then skip over it and return the first real chunk).
-Will output pointer to the start of the next chunk, or at or beyond end of the file if there
-is no more chunk after this or possibly if the chunk is corrupt.
-Start this process at the 8th byte of the PNG file.
-In a non-corrupt PNG file, the last chunk should have name "IEND".
-*/
-unsigned char* lodepng_chunk_next(unsigned char* chunk, unsigned char* end);
-const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk, const unsigned char* end);
-
-/*Finds the first chunk with the given type in the range [chunk, end), or returns NULL if not found.*/
-unsigned char* lodepng_chunk_find(unsigned char* chunk, unsigned char* end, const char type[5]);
-const unsigned char* lodepng_chunk_find_const(const unsigned char* chunk, const unsigned char* end, const char type[5]);
+/*iterate to next chunks. don't use on IEND chunk, as there is no next chunk then*/
+unsigned char* lodepng_chunk_next(unsigned char* chunk);
+const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk);
 
 /*
 Appends chunk to the data in out. The given chunk should already have its chunk header.
-The out variable and outsize are updated to reflect the new reallocated buffer.
+The out variable and outlength are updated to reflect the new reallocated buffer.
 Returns error code (0 if it went ok)
 */
-unsigned lodepng_chunk_append(unsigned char** out, size_t* outsize, const unsigned char* chunk);
+unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk);
 
 /*
 Appends new chunk to out. The chunk to append is given by giving its length, type
 and data separately. The type is a 4-letter string.
-The out variable and outsize are updated to reflect the new reallocated buffer.
+The out variable and outlength are updated to reflect the new reallocated buffer.
 Returne error code (0 if it went ok)
 */
-unsigned lodepng_chunk_create(unsigned char** out, size_t* outsize, unsigned length,
+unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length,
                               const char* type, const unsigned char* data);
 
 
@@ -991,19 +818,21 @@ unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const
 #endif /*LODEPNG_COMPILE_DISK*/
 
 #ifdef LODEPNG_COMPILE_CPP
-/* The LodePNG C++ wrapper uses std::vectors instead of manually allocated memory buffers. */
-namespace lodepng {
+//The LodePNG C++ wrapper uses std::vectors instead of manually allocated memory buffers.
+namespace lodepng
+{
 #ifdef LODEPNG_COMPILE_PNG
-class State : public LodePNGState {
+class State : public LodePNGState
+{
   public:
     State();
     State(const State& other);
-    ~State();
+    virtual ~State();
     State& operator=(const State& other);
 };
 
 #ifdef LODEPNG_COMPILE_DECODER
-/* Same as other lodepng::decode, but using a State for more settings and information. */
+//Same as other lodepng::decode, but using a State for more settings and information.
 unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
                 State& state,
                 const unsigned char* in, size_t insize);
@@ -1013,7 +842,7 @@ unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
 #endif /*LODEPNG_COMPILE_DECODER*/
 
 #ifdef LODEPNG_COMPILE_ENCODER
-/* Same as other lodepng::encode, but using a State for more settings and information. */
+//Same as other lodepng::encode, but using a State for more settings and information.
 unsigned encode(std::vector<unsigned char>& out,
                 const unsigned char* in, unsigned w, unsigned h,
                 State& state);
@@ -1024,63 +853,56 @@ unsigned encode(std::vector<unsigned char>& out,
 
 #ifdef LODEPNG_COMPILE_DISK
 /*
-Load a file from disk into an std::vector.
-return value: error code (0 means ok)
+Load a file from disk into an std::vector. If the vector is empty, then either
+the file doesn't exist or is an empty file.
 */
-unsigned load_file(std::vector<unsigned char>& buffer, const std::string& filename);
+void load_file(std::vector<unsigned char>& buffer, const std::string& filename);
 
 /*
 Save the binary data in an std::vector to a file on disk. The file is overwritten
 without warning.
 */
-unsigned save_file(const std::vector<unsigned char>& buffer, const std::string& filename);
-#endif /* LODEPNG_COMPILE_DISK */
-#endif /* LODEPNG_COMPILE_PNG */
+void save_file(const std::vector<unsigned char>& buffer, const std::string& filename);
+#endif //LODEPNG_COMPILE_DISK
+#endif //LODEPNG_COMPILE_PNG
 
 #ifdef LODEPNG_COMPILE_ZLIB
 #ifdef LODEPNG_COMPILE_DECODER
-/* Zlib-decompress an unsigned char buffer */
+//Zlib-decompress an unsigned char buffer
 unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
                     const LodePNGDecompressSettings& settings = lodepng_default_decompress_settings);
 
-/* Zlib-decompress an std::vector */
+//Zlib-decompress an std::vector
 unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
                     const LodePNGDecompressSettings& settings = lodepng_default_decompress_settings);
-#endif /* LODEPNG_COMPILE_DECODER */
+#endif //LODEPNG_COMPILE_DECODER
 
 #ifdef LODEPNG_COMPILE_ENCODER
-/* Zlib-compress an unsigned char buffer */
+//Zlib-compress an unsigned char buffer
 unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
                   const LodePNGCompressSettings& settings = lodepng_default_compress_settings);
 
-/* Zlib-compress an std::vector */
+//Zlib-compress an std::vector
 unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
                   const LodePNGCompressSettings& settings = lodepng_default_compress_settings);
-#endif /* LODEPNG_COMPILE_ENCODER */
-#endif /* LODEPNG_COMPILE_ZLIB */
-} /* namespace lodepng */
+#endif //LODEPNG_COMPILE_ENCODER
+#endif //LODEPNG_COMPILE_ZLIB
+} //namespace lodepng
 #endif /*LODEPNG_COMPILE_CPP*/
 
 /*
 TODO:
 [.] test if there are no memory leaks or security exploits - done a lot but needs to be checked often
-[.] check compatibility with various compilers  - done but needs to be redone for every newer version
+[.] check compatibility with vareous compilers  - done but needs to be redone for every newer version
 [X] converting color to 16-bit per channel types
-[X] support color profile chunk types (but never let them touch RGB values by default)
-[ ] support all public PNG chunk types (almost done except sBIT, sPLT and hIST)
+[ ] read all public PNG chunk types (but never let the color profile and gamma ones touch RGB values)
 [ ] make sure encoder generates no chunks with size > (2^31)-1
 [ ] partial decoding (stream processing)
 [X] let the "isFullyOpaque" function check color keys and transparent palettes too
 [X] better name for the variables "codes", "codesD", "codelengthcodes", "clcl" and "lldl"
-[ ] allow treating some errors like warnings, when image is recoverable (e.g. 69, 57, 58)
-[ ] make warnings like: oob palette, checksum fail, data after iend, wrong/unknown crit chunk, no null terminator in text, ...
-[ ] error messages with line numbers (and version)
-[ ] errors in state instead of as return code?
-[ ] new errors/warnings like suspiciously big decompressed ztxt or iccp chunk
+[ ] don't stop decoding on errors like 69, 57, 58 (make warnings)
+[ ] make option to choose if the raw image with non multiple of 8 bits per scanline should have padding bits or not
 [ ] let the C++ wrapper catch exceptions coming from the standard library and return LodePNG error codes
-[ ] allow user to provide custom color conversion functions, e.g. for premultiplied alpha, padding bits or not, ...
-[ ] allow user to give data (void*) to custom allocator
-[X] provide alternatives for C library functions not present on some platforms (memcpy, ...)
 */
 
 #endif /*LODEPNG_H inclusion guard*/
@@ -1110,9 +932,8 @@ LodePNG Documentation
   10. examples
    10.1. decoder C++ example
    10.2. decoder C example
-  11. state settings reference
-  12. changes
-  13. contact information
+  11. changes
+  12. contact information
 
 
 1. about
@@ -1175,10 +996,8 @@ The following features are supported by the decoder:
 *) zlib decompression (inflate)
 *) zlib compression (deflate)
 *) CRC32 and ADLER32 checksums
-*) colorimetric color profile conversions: currently experimentally available in lodepng_util.cpp only,
-   plus alternatively ability to pass on chroma/gamma/ICC profile information to other color management system.
 *) handling of unknown chunks, allowing making a PNG editor that stores custom and unknown chunks.
-*) the following chunks are supported by both encoder and decoder:
+*) the following chunks are supported (generated/interpreted) by both encoder and decoder:
     IHDR: header information
     PLTE: color palette
     IDAT: pixel data
@@ -1190,10 +1009,6 @@ The following features are supported by the decoder:
     bKGD: suggested background color
     pHYs: physical dimensions
     tIME: modification time
-    cHRM: RGB chromaticities
-    gAMA: RGB gamma correction
-    iCCP: ICC color profile
-    sRGB: rendering intent
 
 1.2. features not supported
 ---------------------------
@@ -1202,10 +1017,10 @@ The following features are _not_ supported:
 
 *) some features needed to make a conformant PNG-Editor might be still missing.
 *) partial loading/stream processing. All data must be available and is processed in one call.
-*) The following public chunks are not (yet) supported but treated as unknown chunks by LodePNG:
-    sBIT
-    hIST
-    sPLT
+*) The following public chunks are not supported but treated as unknown chunks by LodePNG
+    cHRM, gAMA, iCCP, sRGB, sBIT, hIST, sPLT
+   Some of these are not supported on purpose: LodePNG wants to provide the RGB values
+   stored in the pixels, not values modified by system dependent gamma or color models.
 
 
 2. C and C++ version
@@ -1279,7 +1094,7 @@ LodePNGColorMode info_raw
 When decoding, here you can specify which color type you want
 the resulting raw image to be. If this is different from the colortype of the
 PNG, then the decoder will automatically convert the result. This conversion
-always works, except if you want it to convert a color PNG to grayscale or to
+always works, except if you want it to convert a color PNG to greyscale or to
 a palette with missing colors.
 
 By default, 32-bit color is used for the result.
@@ -1375,7 +1190,7 @@ can encode the colors of all pixels without information loss.
 An important thing to note about LodePNG, is that the color type of the PNG, and
 the color type of the raw image, are completely independent. By default, when
 you decode a PNG, you get the result as a raw image in the color type you want,
-no matter whether the PNG was encoded with a palette, grayscale or RGBA color.
+no matter whether the PNG was encoded with a palette, greyscale or RGBA color.
 And if you encode an image, by default LodePNG will automatically choose the PNG
 color type that gives good compression based on the values of colors and amount
 of colors in the image. It can be configured to let you control it instead as
@@ -1383,10 +1198,10 @@ well, though.
 
 To be able to do this, LodePNG does conversions from one color mode to another.
 It can convert from almost any color type to any other color type, except the
-following conversions: RGB to grayscale is not supported, and converting to a
+following conversions: RGB to greyscale is not supported, and converting to a
 palette when the palette doesn't have a required color is not supported. This is
 not supported on purpose: this is information loss which requires a color
-reduction algorithm that is beyond the scope of a PNG encoder (yes, RGB to gray
+reduction algorithm that is beyong the scope of a PNG encoder (yes, RGB to grey
 is easy, but there are multiple ways if you want to give some channels more
 weight).
 
@@ -1407,10 +1222,10 @@ decoding to have another color type, a conversion is done by LodePNG.
 
 The PNG specification gives the following color types:
 
-0: grayscale, bit depths 1, 2, 4, 8, 16
+0: greyscale, bit depths 1, 2, 4, 8, 16
 2: RGB, bit depths 8 and 16
 3: palette, bit depths 1, 2, 4 and 8
-4: grayscale with alpha, bit depths 8 and 16
+4: greyscale with alpha, bit depths 8 and 16
 6: RGBA, bit depths 8 and 16
 
 Bit depth is the amount of bits per pixel per color channel. So the total amount
@@ -1425,22 +1240,20 @@ behaviour.
 
 If, when decoding, you want the raw image to be something else than the default,
 you need to set the color type and bit depth you want in the LodePNGColorMode,
-or the parameters colortype and bitdepth of the simple decoding function.
+or the parameters of the simple function of LodePNG you're using.
 
-If, when encoding, you use another color type than the default in the raw input
+If, when encoding, you use another color type than the default in the input
 image, you need to specify its color type and bit depth in the LodePNGColorMode
-of the raw image, or use the parameters colortype and bitdepth of the simple
-encoding function.
+of the raw image, or use the parameters of the simplefunction of LodePNG you're
+using.
 
 If, when encoding, you don't want LodePNG to choose the output PNG color type
 but control it yourself, you need to set auto_convert in the encoder settings
-to false, and specify the color type you want in the LodePNGInfo of the
-encoder (including palette: it can generate a palette if auto_convert is true,
-otherwise not).
+to LAC_NONE, and specify the color type you want in the LodePNGInfo of the
+encoder.
 
-If the input and output color type differ (whether user chosen or auto chosen),
-LodePNG will do a color conversion, which follows the rules below, and may
-sometimes result in an error.
+If you do any of the above, LodePNG may need to do a color conversion, which
+follows the rules below, and may sometimes not be allowed.
 
 To avoid some confusion:
 -the decoder converts from PNG to raw image
@@ -1459,34 +1272,31 @@ To avoid some confusion:
  the raw image correctly before encoding.
 -both encoder and decoder use the same color converter.
 
-The function lodepng_convert does the color conversion. It is available in the
-interface but normally isn't needed since the encoder and decoder already call
-it.
-
 Non supported color conversions:
--color to grayscale when non-gray pixels are present: no error is thrown, but
-the result will look ugly because only the red channel is taken (it assumes all
-three channels are the same in this case so ignores green and blue). The reason
-no error is given is to allow converting from three-channel grayscale images to
-one-channel even if there are numerical imprecisions.
--anything to palette when the palette does not have an exact match for a from-color
-in it: in this case an error is thrown
+-color to greyscale: no error is thrown, but the result will look ugly because
+only the red channel is taken
+-anything, to palette when that palette does not have that color in it: in this
+case an error is thrown
 
 Supported color conversions:
 -anything to 8-bit RGB, 8-bit RGBA, 16-bit RGB, 16-bit RGBA
--any gray or gray+alpha, to gray or gray+alpha
+-any grey or grey+alpha, to grey or grey+alpha
 -anything to a palette, as long as the palette has the requested colors in it
 -removing alpha channel
 -higher to smaller bitdepth, and vice versa
 
-If you want no color conversion to be done (e.g. for speed or control):
+If you want no color conversion to be done:
 -In the encoder, you can make it save a PNG with any color type by giving the
 raw color mode and LodePNGInfo the same color mode, and setting auto_convert to
-false.
+LAC_NO.
 -In the decoder, you can make it store the pixel data in the same color type
 as the PNG has, by setting the color_convert setting to false. Settings in
 info_raw are then ignored.
 
+The function lodepng_convert does the color conversion. It is available in the
+interface but normally isn't needed since the encoder and decoder already call
+it.
+
 6.3. padding bits
 -----------------
 
@@ -1495,7 +1305,7 @@ have a bit amount that isn't a multiple of 8, then padding bits are used so that
 scanline starts at a fresh byte. But that is NOT true for the LodePNG raw input and output.
 The raw input image you give to the encoder, and the raw output image you get from the decoder
 will NOT have these padding bits, e.g. in the case of a 1-bit image with a width
-of 7 pixels, the first pixel of the second scanline will the 8th bit of the first byte,
+of 7 pixels, the first pixel of the second scanline will the the 8th bit of the first byte,
 not the first bit of a new byte.
 
 6.4. A note about 16-bits per channel and endianness
@@ -1531,11 +1341,6 @@ of the error in English as a string.
 
 Check the implementation of lodepng_error_text to see the meaning of each code.
 
-It is not recommended to use the numerical values to programmatically make
-different decisions based on error types as the numbers are not guaranteed to
-stay backwards compatible. They are for human consumption only. Programmatically
-only 0 or non-0 matter.
-
 
 8. chunks and PNG editing
 -------------------------
@@ -1601,12 +1406,12 @@ Iterate to the next chunk. This works if you have a buffer with consecutive chun
 functions do no boundary checking of the allocated data whatsoever, so make sure there is enough
 data available in the buffer to be able to go to the next chunk.
 
-unsigned lodepng_chunk_append(unsigned char** out, size_t* outsize, const unsigned char* chunk):
-unsigned lodepng_chunk_create(unsigned char** out, size_t* outsize, unsigned length,
+unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk):
+unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length,
                               const char* type, const unsigned char* data):
 
 These functions are used to create new chunks that are appended to the data in *out that has
-length *outsize. The append function appends an existing chunk to the new data. The create
+length *outlength. The append function appends an existing chunk to the new data. The create
 function creates a new chunk with the given parameters and appends it. Type is the 4-letter
 name of the chunk.
 
@@ -1617,7 +1422,7 @@ The LodePNGInfo struct contains fields with the unknown chunk in it. It has 3
 buffers (each with size) to contain 3 types of unknown chunks:
 the ones that come before the PLTE chunk, the ones that come between the PLTE
 and the IDAT chunks, and the ones that come after the IDAT chunks.
-It's necessary to make the distinction between these 3 cases because the PNG
+It's necessary to make the distionction between these 3 cases because the PNG
 standard forces to keep the ordering of unknown chunks compared to the critical
 chunks, but does not force any other ordering rules.
 
@@ -1650,8 +1455,6 @@ LodePNG. For the C++ version, only the standard C++ library is needed on top.
 Add the files lodepng.c(pp) and lodepng.h to your project, include
 lodepng.h where needed, and your program can read/write PNG files.
 
-It is compatible with C90 and up, and C++03 and up.
-
 If performance is important, use optimization when compiling! For both the
 encoder and decoder, this makes a large difference.
 
@@ -1667,40 +1470,49 @@ LodePNG is developed in gcc so this compiler is natively supported. It gives no
 warnings with compiler options "-Wall -Wextra -pedantic -ansi", with gcc and g++
 version 4.7.1 on Linux, 32-bit and 64-bit.
 
-*) Clang
-
-Fully supported and warning-free.
-
 *) Mingw
 
-The Mingw compiler (a port of gcc for Windows) should be fully supported by
-LodePNG.
+The Mingw compiler (a port of gcc) for Windows is fully supported by LodePNG.
+
+*) Visual Studio 2005 and up, Visual C++ Express Edition 2005 and up
 
-*) Visual Studio and Visual C++ Express Edition
+Visual Studio may give warnings about 'fopen' being deprecated. A multiplatform library
+can't support the proposed Visual Studio alternative however, so LodePNG keeps using
+fopen. If you don't want to see the deprecated warnings, put this on top of lodepng.h
+before the inclusions:
+#define _CRT_SECURE_NO_DEPRECATE
 
-LodePNG should be warning-free with warning level W4. Two warnings were disabled
-with pragmas though: warning 4244 about implicit conversions, and warning 4996
-where it wants to use a non-standard function fopen_s instead of the standard C
-fopen.
+Other than the above warnings, LodePNG should be warning-free with warning
+level 3 (W3). Warning level 4 (W4) will give warnings about integer conversions.
+I'm not planning to resolve these warnings. To get rid of them, let Visual
+Studio use warning level W3 for lodepng.cpp only: right click lodepng.cpp,
+Properties, C/C++, General, Warning Level: Level 3 (/W3).
 
 Visual Studio may want "stdafx.h" files to be included in each source file and
 give an error "unexpected end of file while looking for precompiled header".
-This is not standard C++ and will not be added to the stock LodePNG. You can
+That is not standard C++ and will not be added to the stock LodePNG. You can
 disable it for lodepng.cpp only by right clicking it, Properties, C/C++,
 Precompiled Headers, and set it to Not Using Precompiled Headers there.
 
-NOTE: Modern versions of VS should be fully supported, but old versions, e.g.
-VS6, are not guaranteed to work.
+*) Visual Studio 6.0
+
+LodePNG support for Visual Studio 6.0 is not guaranteed because VS6 doesn't
+follow the C++ standard correctly.
+
+*) Comeau C/C++
+
+Vesion 20070107 compiles without problems on the Comeau C/C++ Online Test Drive
+at http://www.comeaucomputing.com/tryitout in both C90 and C++ mode.
 
 *) Compilers on Macintosh
 
-LodePNG has been reported to work both with gcc and LLVM for Macintosh, both for
-C and C++.
+LodePNG has been reported to work both with the gcc and LLVM for Macintosh, both
+for C and C++.
 
 *) Other Compilers
 
-If you encounter problems on any compilers, feel free to let me know and I may
-try to fix it if the compiler is modern and standards compliant.
+If you encounter problems on other compilers, feel free to let me know and I may
+try to fix it if the compiler is modern standards complient.
 
 
 10. examples
@@ -1715,7 +1527,8 @@ examples can be found on the LodePNG website.
 #include "lodepng.h"
 #include <iostream>
 
-int main(int argc, char *argv[]) {
+int main(int argc, char *argv[])
+{
   const char* filename = argc > 1 ? argv[1] : "test.png";
 
   //load and decode
@@ -1734,7 +1547,8 @@ int main(int argc, char *argv[]) {
 
 #include "lodepng.h"
 
-int main(int argc, char *argv[]) {
+int main(int argc, char *argv[])
+{
   unsigned error;
   unsigned char* image;
   size_t width, height;
@@ -1750,51 +1564,8 @@ int main(int argc, char *argv[]) {
   return 0;
 }
 
-11. state settings reference
-----------------------------
-
-A quick reference of some settings to set on the LodePNGState
-
-For decoding:
-
-state.decoder.zlibsettings.ignore_adler32: ignore ADLER32 checksums
-state.decoder.zlibsettings.custom_...: use custom inflate function
-state.decoder.ignore_crc: ignore CRC checksums
-state.decoder.ignore_critical: ignore unknown critical chunks
-state.decoder.ignore_end: ignore missing IEND chunk. May fail if this corruption causes other errors
-state.decoder.color_convert: convert internal PNG color to chosen one
-state.decoder.read_text_chunks: whether to read in text metadata chunks
-state.decoder.remember_unknown_chunks: whether to read in unknown chunks
-state.info_raw.colortype: desired color type for decoded image
-state.info_raw.bitdepth: desired bit depth for decoded image
-state.info_raw....: more color settings, see struct LodePNGColorMode
-state.info_png....: no settings for decoder but ouput, see struct LodePNGInfo
-
-For encoding:
-
-state.encoder.zlibsettings.btype: disable compression by setting it to 0
-state.encoder.zlibsettings.use_lz77: use LZ77 in compression
-state.encoder.zlibsettings.windowsize: tweak LZ77 windowsize
-state.encoder.zlibsettings.minmatch: tweak min LZ77 length to match
-state.encoder.zlibsettings.nicematch: tweak LZ77 match where to stop searching
-state.encoder.zlibsettings.lazymatching: try one more LZ77 matching
-state.encoder.zlibsettings.custom_...: use custom deflate function
-state.encoder.auto_convert: choose optimal PNG color type, if 0 uses info_png
-state.encoder.filter_palette_zero: PNG filter strategy for palette
-state.encoder.filter_strategy: PNG filter strategy to encode with
-state.encoder.force_palette: add palette even if not encoding to one
-state.encoder.add_id: add LodePNG identifier and version as a text chunk
-state.encoder.text_compression: use compressed text chunks for metadata
-state.info_raw.colortype: color type of raw input image you provide
-state.info_raw.bitdepth: bit depth of raw input image you provide
-state.info_raw: more color settings, see struct LodePNGColorMode
-state.info_png.color.colortype: desired color type if auto_convert is false
-state.info_png.color.bitdepth: desired bit depth if auto_convert is false
-state.info_png.color....: more color settings, see struct LodePNGColorMode
-state.info_png....: more PNG related settings, see struct LodePNGInfo
-
-
-12. changes
+
+11. changes
 -----------
 
 The version number of LodePNG is the date of the change given in the format
@@ -1803,60 +1574,28 @@ yyyymmdd.
 Some changes aren't backwards compatible. Those are indicated with a (!)
 symbol.
 
-Not all changes are listed here, the commit history in github lists more:
-https://github.com/lvandeve/lodepng
-
-*) 17 okt 2020: prevent decoding too large text/icc chunks by default.
-*) 06 mar 2020: simplified some of the dynamic memory allocations.
-*) 12 jan 2020: (!) added 'end' argument to lodepng_chunk_next to allow correct
-   overflow checks.
-*) 14 aug 2019: around 25% faster decoding thanks to huffman lookup tables.
-*) 15 jun 2019: (!) auto_choose_color API changed (for bugfix: don't use palette
-   if gray ICC profile) and non-ICC LodePNGColorProfile renamed to
-   LodePNGColorStats.
-*) 30 dec 2018: code style changes only: removed newlines before opening braces.
-*) 10 sep 2018: added way to inspect metadata chunks without full decoding.
-*) 19 aug 2018: (!) fixed color mode bKGD is encoded with and made it use
-   palette index in case of palette.
-*) 10 aug 2018: (!) added support for gAMA, cHRM, sRGB and iCCP chunks. This
-   change is backwards compatible unless you relied on unknown_chunks for those.
-*) 11 jun 2018: less restrictive check for pixel size integer overflow
-*) 14 jan 2018: allow optionally ignoring a few more recoverable errors
-*) 17 sep 2017: fix memory leak for some encoder input error cases
-*) 27 nov 2016: grey+alpha auto color model detection bugfix
-*) 18 apr 2016: Changed qsort to custom stable sort (for platforms w/o qsort).
-*) 09 apr 2016: Fixed colorkey usage detection, and better file loading (within
-   the limits of pure C90).
-*) 08 dec 2015: Made load_file function return error if file can't be opened.
-*) 24 okt 2015: Bugfix with decoding to palette output.
-*) 18 apr 2015: Boundary PM instead of just package-merge for faster encoding.
-*) 24 aug 2014: Moved to github
-*) 23 aug 2014: Reduced needless memory usage of decoder.
-*) 28 jun 2014: Removed fix_png setting, always support palette OOB for
-    simplicity. Made ColorProfile public.
-*) 09 jun 2014: Faster encoder by fixing hash bug and more zeros optimization.
 *) 22 dec 2013: Power of two windowsize required for optimization.
 *) 15 apr 2013: Fixed bug with LAC_ALPHA and color key.
 *) 25 mar 2013: Added an optional feature to ignore some PNG errors (fix_png).
-*) 11 mar 2013: (!) Bugfix with custom free. Changed from "my" to "lodepng_"
+*) 11 mar 2013 (!): Bugfix with custom free. Changed from "my" to "lodepng_"
     prefix for the custom allocators and made it possible with a new #define to
     use custom ones in your project without needing to change lodepng's code.
 *) 28 jan 2013: Bugfix with color key.
 *) 27 okt 2012: Tweaks in text chunk keyword length error handling.
-*) 8 okt 2012: (!) Added new filter strategy (entropy) and new auto color mode.
+*) 8 okt 2012 (!): Added new filter strategy (entropy) and new auto color mode.
     (no palette). Better deflate tree encoding. New compression tweak settings.
     Faster color conversions while decoding. Some internal cleanups.
 *) 23 sep 2012: Reduced warnings in Visual Studio a little bit.
-*) 1 sep 2012: (!) Removed #define's for giving custom (de)compression functions
+*) 1 sep 2012 (!): Removed #define's for giving custom (de)compression functions
     and made it work with function pointers instead.
 *) 23 jun 2012: Added more filter strategies. Made it easier to use custom alloc
     and free functions and toggle #defines from compiler flags. Small fixes.
-*) 6 may 2012: (!) Made plugging in custom zlib/deflate functions more flexible.
-*) 22 apr 2012: (!) Made interface more consistent, renaming a lot. Removed
+*) 6 may 2012 (!): Made plugging in custom zlib/deflate functions more flexible.
+*) 22 apr 2012 (!): Made interface more consistent, renaming a lot. Removed
     redundant C++ codec classes. Reduced amount of structs. Everything changed,
     but it is cleaner now imho and functionality remains the same. Also fixed
-    several bugs and shrunk the implementation code. Made new samples.
-*) 6 nov 2011: (!) By default, the encoder now automatically chooses the best
+    several bugs and shrinked the implementation code. Made new samples.
+*) 6 nov 2011 (!): By default, the encoder now automatically chooses the best
     PNG color model and bit depth, based on the amount and type of colors of the
     raw image. For this, autoLeaveOutAlphaChannel replaced by auto_choose_color.
 *) 9 okt 2011: simpler hash chain implementation for the encoder.
@@ -1865,7 +1604,7 @@ https://github.com/lvandeve/lodepng
     A bug with the PNG filtertype heuristic was fixed, so that it chooses much
     better ones (it's quite significant). A setting to do an experimental, slow,
     brute force search for PNG filter types is added.
-*) 17 aug 2011: (!) changed some C zlib related function names.
+*) 17 aug 2011 (!): changed some C zlib related function names.
 *) 16 aug 2011: made the code less wide (max 120 characters per line).
 *) 17 apr 2011: code cleanup. Bugfixes. Convert low to 16-bit per sample colors.
 *) 21 feb 2011: fixed compiling for C90. Fixed compiling with sections disabled.
@@ -1890,7 +1629,7 @@ https://github.com/lvandeve/lodepng
 *) 20 jan 2008: support for unknown chunks allowing using LodePNG for an editor.
 *) 18 jan 2008: support for tIME and pHYs chunks added to encoder and decoder.
 *) 17 jan 2008: ability to encode and decode compressed zTXt chunks added
-    Also various fixes, such as in the deflate and the padding bits code.
+    Also vareous fixes, such as in the deflate and the padding bits code.
 *) 13 jan 2008: Added ability to encode Adam7-interlaced images. Improved
     filtering code of encoder.
 *) 07 jan 2008: (!) changed LodePNG to use ISO C90 instead of C++. A
@@ -1961,7 +1700,7 @@ https://github.com/lvandeve/lodepng
 *) 12 aug 2005: Initial release (C++, decoder only)
 
 
-13. contact information
+12. contact information
 -----------------------
 
 Feel free to contact me with suggestions, problems, comments, ... concerning
@@ -1973,5 +1712,5 @@ Domain: gmail dot com.
 Account: lode dot vandevenne.
 
 
-Copyright (c) 2005-2020 Lode Vandevenne
+Copyright (c) 2005-2013 Lode Vandevenne
 */
diff --git a/src/zopflipng/lodepng/lodepng_util.cpp b/src/zopflipng/lodepng/lodepng_util.cpp
index 574138a..a429b69 100644
--- a/src/zopflipng/lodepng/lodepng_util.cpp
+++ b/src/zopflipng/lodepng/lodepng_util.cpp
@@ -1,7 +1,7 @@
 /*
 LodePNG Utils
 
-Copyright (c) 2005-2020 Lode Vandevenne
+Copyright (c) 2005-2012 Lode Vandevenne
 
 This software is provided 'as-is', without any express or implied
 warranty. In no event will the authors be held liable for any damages
@@ -24,12 +24,13 @@ freely, subject to the following restrictions:
 */
 
 #include "lodepng_util.h"
-#include <iostream>  // TODO: remove, don't print stuff from here, return errors instead
-#include <stdlib.h> /* allocations */
+#include <iostream>
 
-namespace lodepng {
+namespace lodepng
+{
 
-LodePNGInfo getPNGHeaderInfo(const std::vector<unsigned char>& png) {
+LodePNGInfo getPNGHeaderInfo(const std::vector<unsigned char>& png)
+{
   unsigned w, h;
   lodepng::State state;
   lodepng_inspect(&w, &h, &state, &png[0], png.size());
@@ -37,52 +38,60 @@ LodePNGInfo getPNGHeaderInfo(const std::vector<unsigned char>& png) {
 }
 
 unsigned getChunkInfo(std::vector<std::string>& names, std::vector<size_t>& sizes,
-                      const std::vector<unsigned char>& png) {
+                      const std::vector<unsigned char>& png)
+{
   // Listing chunks is based on the original file, not the decoded png info.
-  const unsigned char *chunk, *end;
+  const unsigned char *chunk, *begin, *end;
   end = &png.back() + 1;
-  chunk = &png.front() + 8;
+  begin = chunk = &png.front() + 8;
 
-  while(chunk < end && end - chunk >= 8) {
+  while(chunk + 8 < end && chunk >= begin)
+  {
     char type[5];
     lodepng_chunk_type(type, chunk);
     if(std::string(type).size() != 4) return 1;
 
-    unsigned length = lodepng_chunk_length(chunk);
     names.push_back(type);
-    sizes.push_back(length);
-    chunk = lodepng_chunk_next_const(chunk, end);
+    sizes.push_back(lodepng_chunk_length(chunk));
+
+    chunk = lodepng_chunk_next_const(chunk);
   }
   return 0;
 }
 
 unsigned getChunks(std::vector<std::string> names[3],
                    std::vector<std::vector<unsigned char> > chunks[3],
-                   const std::vector<unsigned char>& png) {
-  const unsigned char *chunk, *next, *end;
+                   const std::vector<unsigned char>& png)
+{
+  const unsigned char *chunk, *next, *begin, *end;
   end = &png.back() + 1;
-  chunk = &png.front() + 8;
+  begin = chunk = &png.front() + 8;
 
   int location = 0;
 
-  while(chunk < end && end - chunk >= 8) {
+  while(chunk + 8 < end && chunk >= begin)
+  {
     char type[5];
     lodepng_chunk_type(type, chunk);
     std::string name(type);
     if(name.size() != 4) return 1;
 
-    next = lodepng_chunk_next_const(chunk, end);
+    next = lodepng_chunk_next_const(chunk);
 
-    if(name == "IHDR") {
+    if(name == "IHDR")
+    {
       location = 0;
-    } else if(name == "PLTE") {
+    }
+    else if(name == "PLTE")
+    {
       location = 1;
-    } else if(name == "IDAT") {
+    }
+    else if(name == "IDAT")
+    {
       location = 2;
-    } else if(name == "IEND") {
-      break; // anything after IEND is not part of the PNG or the 3 groups here.
-    } else {
-      if(next >= end) return 1; // invalid chunk, content too far
+    }
+    else if(name != "IEND")
+    {
       names[location].push_back(name);
       chunks[location].push_back(std::vector<unsigned char>(chunk, next));
     }
@@ -94,31 +103,40 @@ unsigned getChunks(std::vector<std::string> names[3],
 
 
 unsigned insertChunks(std::vector<unsigned char>& png,
-                      const std::vector<std::vector<unsigned char> > chunks[3]) {
-  const unsigned char *chunk, *begin, *end;
+                      const std::vector<std::vector<unsigned char> > chunks[3])
+{
+  const unsigned char *chunk, *next, *begin, *end;
   end = &png.back() + 1;
   begin = chunk = &png.front() + 8;
 
-  long l0 = 0; //location 0: IHDR-l0-PLTE (or IHDR-l0-l1-IDAT)
-  long l1 = 0; //location 1: PLTE-l1-IDAT (or IHDR-l0-l1-IDAT)
-  long l2 = 0; //location 2: IDAT-l2-IEND
+  size_t l0 = 0; //location 0: IHDR-l0-PLTE (or IHDR-l0-l1-IDAT)
+  size_t l1 = 0; //location 1: PLTE-l1-IDAT (or IHDR-l0-l1-IDAT)
+  size_t l2 = 0; //location 2: IDAT-l2-IEND
 
-  while(chunk < end && end - chunk >= 8) {
+  while(chunk + 8 < end && chunk >= begin)
+  {
     char type[5];
     lodepng_chunk_type(type, chunk);
     std::string name(type);
     if(name.size() != 4) return 1;
 
-    if(name == "PLTE") {
+    next = lodepng_chunk_next_const(chunk);
+
+    if(name == "PLTE")
+    {
       if(l0 == 0) l0 = chunk - begin + 8;
-    } else if(name == "IDAT") {
+    }
+    else if(name == "IDAT")
+    {
       if(l0 == 0) l0 = chunk - begin + 8;
       if(l1 == 0) l1 = chunk - begin + 8;
-    } else if(name == "IEND") {
+    }
+    else if(name == "IEND")
+    {
       if(l2 == 0) l2 = chunk - begin + 8;
     }
 
-    chunk = lodepng_chunk_next_const(chunk, end);
+    chunk = next;
   }
 
   std::vector<unsigned char> result;
@@ -135,7 +153,8 @@ unsigned insertChunks(std::vector<unsigned char>& png,
 }
 
 unsigned getFilterTypesInterlaced(std::vector<std::vector<unsigned char> >& filterTypes,
-                                  const std::vector<unsigned char>& png) {
+                                  const std::vector<unsigned char>& png)
+{
   //Get color type and interlace type
   lodepng::State state;
   unsigned w, h;
@@ -151,43 +170,46 @@ unsigned getFilterTypesInterlaced(std::vector<std::vector<unsigned char> >& filt
 
   std::vector<unsigned char> zdata;
 
-  while(chunk < end && end - chunk >= 8) {
+  while(chunk + 8 < end && chunk >= begin)
+  {
     char type[5];
     lodepng_chunk_type(type, chunk);
-    if(std::string(type).size() != 4) break; //Probably not a PNG file
+    if(std::string(type).size() != 4) return 1; //Probably not a PNG file
 
-    if(std::string(type) == "IDAT") {
+    if(std::string(type) == "IDAT")
+    {
       const unsigned char* cdata = lodepng_chunk_data_const(chunk);
       unsigned clength = lodepng_chunk_length(chunk);
-      if(chunk + clength + 12 > end || clength > png.size() || chunk + clength + 12 < begin) {
-        // corrupt chunk length
-        return 1;
-      }
 
-      for(unsigned i = 0; i < clength; i++) {
+      for(unsigned i = 0; i < clength; i++)
+      {
         zdata.push_back(cdata[i]);
       }
     }
 
-    chunk = lodepng_chunk_next_const(chunk, end);
+    chunk = lodepng_chunk_next_const(chunk);
   }
 
-  //Decompress all IDAT data (if the while loop ended early, this might fail)
+  //Decompress all IDAT data
   std::vector<unsigned char> data;
   error = lodepng::decompress(data, &zdata[0], zdata.size());
 
   if(error) return 1;
 
-  if(state.info_png.interlace_method == 0) {
+  if(state.info_png.interlace_method == 0)
+  {
     filterTypes.resize(1);
 
     //A line is 1 filter byte + all pixels
     size_t linebytes = 1 + lodepng_get_raw_size(w, 1, &state.info_png.color);
 
-    for(size_t i = 0; i < data.size(); i += linebytes) {
+    for(size_t i = 0; i < data.size(); i += linebytes)
+    {
       filterTypes[0].push_back(data[i]);
     }
-  } else {
+  }
+  else
+  {
     //Interlaced
     filterTypes.resize(7);
     static const unsigned ADAM7_IX[7] = { 0, 4, 0, 2, 0, 1, 0 }; /*x start values*/
@@ -195,12 +217,14 @@ unsigned getFilterTypesInterlaced(std::vector<std::vector<unsigned char> >& filt
     static const unsigned ADAM7_DX[7] = { 8, 8, 4, 4, 2, 2, 1 }; /*x delta values*/
     static const unsigned ADAM7_DY[7] = { 8, 8, 8, 4, 4, 2, 2 }; /*y delta values*/
     size_t pos = 0;
-    for(size_t j = 0; j < 7; j++) {
+    for(int j = 0; j < 7; j++)
+    {
       unsigned w2 = (w - ADAM7_IX[j] + ADAM7_DX[j] - 1) / ADAM7_DX[j];
       unsigned h2 = (h - ADAM7_IY[j] + ADAM7_DY[j] - 1) / ADAM7_DY[j];
-      if(ADAM7_IX[j] >= w || ADAM7_IY[j] >= h) continue;
+      if(ADAM7_IX[j] >= w || ADAM7_IY[j] >= h) w2 = h2 = 0;
       size_t linebytes = 1 + lodepng_get_raw_size(w2, 1, &state.info_png.color);
-      for(size_t i = 0; i < h2; i++) {
+      for(size_t i = 0; i < h2; i++)
+      {
         filterTypes[j].push_back(data[pos]);
         pos += linebytes;
       }
@@ -210,38 +234,37 @@ unsigned getFilterTypesInterlaced(std::vector<std::vector<unsigned char> >& filt
 }
 
 
-unsigned getFilterTypes(std::vector<unsigned char>& filterTypes, const std::vector<unsigned char>& png) {
+unsigned getFilterTypes(std::vector<unsigned char>& filterTypes, const std::vector<unsigned char>& png)
+{
   std::vector<std::vector<unsigned char> > passes;
   unsigned error = getFilterTypesInterlaced(passes, png);
   if(error) return error;
 
-  if(passes.size() == 1) {
+  if(passes.size() == 1)
+  {
     filterTypes.swap(passes[0]);
-  } else {
-    // Simplify interlaced filter types to get a single filter value per scanline:
-    // put pass 6 and 7 alternating in the one vector, these filters
-    // correspond to the closest to what it would be for non-interlaced
-    // image. If the image is only 1 pixel wide, pass 6 doesn't exist so the
-    // alternative values column0 are used. The shift values are to match
-    // the y position in the interlaced sub-images.
-    // NOTE: the values 0-6 match Adam7's passes 1-7.
-    const unsigned column0[8] = {0, 6, 4, 6, 2, 6, 4, 6};
-    const unsigned column1[8] = {5, 6, 5, 6, 5, 6, 5, 6};
-    const unsigned shift0[8] = {3, 1, 2, 1, 3, 1, 2, 1};
-    const unsigned shift1[8] = {1, 1, 1, 1, 1, 1, 1, 1};
+  }
+  else
+  {
     lodepng::State state;
     unsigned w, h;
     lodepng_inspect(&w, &h, &state, &png[0], png.size());
-    const unsigned* column = w > 1 ? column1 : column0;
-    const unsigned* shift = w > 1 ? shift1 : shift0;
-    for(size_t i = 0; i < h; i++) {
-      filterTypes.push_back(passes[column[i & 7u]][i >> shift[i & 7u]]);
+    /*
+    Interlaced. Simplify it: put pass 6 and 7 alternating in the one vector so
+    that one filter per scanline of the uninterlaced image is given, with that
+    filter corresponding the closest to what it would be for non-interlaced
+    image.
+    */
+    for(size_t i = 0; i < h; i++)
+    {
+      filterTypes.push_back(i % 2 == 0 ? passes[5][i / 2] : passes[6][i / 2]);
     }
   }
   return 0; /* OK */
 }
 
-int getPaletteValue(const unsigned char* data, size_t i, int bits) {
+int getPaletteValue(const unsigned char* data, size_t i, int bits)
+{
   if(bits == 8) return data[i];
   else if(bits == 4) return (data[i / 2] >> ((i % 2) * 4)) & 15;
   else if(bits == 2) return (data[i / 4] >> ((i % 4) * 2)) & 3;
@@ -249,1245 +272,69 @@ int getPaletteValue(const unsigned char* data, size_t i, int bits) {
   else return 0;
 }
 
-
-////////////////////////////////////////////////////////////////////////////////
-
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-
-
-
-// Only temporarily here until this is integrated into lodepng.c(pp)
-#define LODEPNG_MAX(a, b) (((a) > (b)) ? (a) : (b))
-#define LODEPNG_MIN(a, b) (((a) < (b)) ? (a) : (b))
-
-// Only temporarily here until this is integrated into lodepng.c(pp)
-#ifdef LODEPNG_COMPILE_ALLOCATORS
-static void* lodepng_malloc(size_t size) {
-  return malloc(size);
-}
-static void lodepng_free(void* ptr) {
-  free(ptr);
-}
-#else /*LODEPNG_COMPILE_ALLOCATORS*/
-void* lodepng_malloc(size_t size);
-void lodepng_free(void* ptr);
-#endif /*LODEPNG_COMPILE_ALLOCATORS*/
-
-/* avoid needing <float.h> for FLT_MAX. This assumes IEEE 32-bit float. */
-static const float lodepng_flt_max = 3.40282346638528859811704183484516925e38f;
-
-/* define infinity and NaN in a way compatible with ANSI C90 (no INFINITY or NAN macros) yet also with visual studio */
-/* visual studio doesn't allow division through a zero literal, but allows it through non-const variable set to zero */
-float lodepng_flt_zero_ = 0.0f;
-static const float lodepng_flt_inf = 1.0f / lodepng_flt_zero_; /* infinity */
-static const float lodepng_flt_nan = 0.0f / lodepng_flt_zero_; /* not a number */
-
-
-/* powf polyfill, 5-6 digits accurate, 33-80% slower than powf, assumes IEEE
-32-bit float, but other than that multiplatform and no math lib needed
-(note: powf also isn't in ISO C90, and pow is slower). */
-static float lodepng_powf(float x, float y) {
-  float j, t0, t1, l;
-  int i = 0;
-  /* handle all the special floating point rules */
-  if(x == 1 || y == 0) return 1; /*these cases return 1 even if the other value is NaN, as specified*/
-  if(y == 1) return x;
-  if(!(x > 0 && x <= lodepng_flt_max && y == y && y <= lodepng_flt_max && y >= -lodepng_flt_max)) {
-    if(y == 1) return x; /* preserves negative-0 */
-    if(x != x || y != y) return x + y; /* nan */
-    if(x > 0) {
-      if(x > lodepng_flt_max) return y <= 0 ? (y == 0 ? 1 : 0) : x; /* x = +infinity */
-    } else {
-      if(!(y < -1073741824.0f || y > 1073741824.0f)) { /* large y always even integer, but cast would overflow */
-        i = (int)y;
-        if(i != y) {
-          return (x < -lodepng_flt_max) ? (y < 0 ? 0 : lodepng_flt_inf) :
-              (x == 0 ? (y < 0 ? lodepng_flt_inf : 0) : lodepng_flt_nan);
-        }
-        if(i & 1) return x == 0 ? (y < 0 ? (1 / x) : x) : -lodepng_powf(-x, y);
-      }
-      if(x == 0) return y <= 0 ? lodepng_flt_inf : 0;
-      if(x < -lodepng_flt_max) { /* x == -infinity */
-        return y <= 0 ? (y == 0 ? 1 : 0) : ((i & 1) ?
-            -lodepng_flt_inf : lodepng_flt_inf);
-      }
-      x = -x;
-      if(x == 1) return 1;
-    }
-    if(y < -lodepng_flt_max || y > lodepng_flt_max) return ((x < 1) != (y > 0)) ? (y < 0 ? -y : y) : 0;
-  }
-
-  l = x;
-  j = 0;
-  while(l < (1.0f / 65536)) { j -= 16; l *= 65536.0f; }
-  while(l > 65536) { j += 16; l *= (1.0f / 65536); }
-  while(l < 1) { j--; l *= 2.0f; }
-  while(l > 2) { j++; l *= 0.5f; }
-  /* polynomial to approximate log2(x) with x in range 1..2 */
-  t0 = -0.393118410458557f + l * (-0.0883639468229365f + l * (0.466142650227994f + l * 0.0153397331014276f));
-  t1 = 0.0907447971403586f + l * (0.388892024755479f + l * 0.137228280305862f);
-  l = t0 / t1 + j;
-
-  l *= y; /* using the formula exp2(y * log2(x)) */
-
-  /* prevent int shift overflow, 0 or inf result are ok to return since exp will be taken, 127 is max float exponent */
-  if(l <= -128.0f || l >= 128.0f) return ((x > 1) == (y > 0)) ? lodepng_flt_inf : 0;
-  i = (int)l;
-  l -= i;
-  /* polynomial to approximate exp2(x) with x in range -1..1 */
-  t0 = 1.0f + l * (0.41777833582744256f + l * (0.0728482595347711f + l * 0.005635023478609625f));
-  t1 = 1.0f + l * (-0.27537016151408167f + l * 0.023501446055084033f);
-  while(i <= -31) { t0 *= (1.0f / 2147483648.0f); i += 31; }
-  while(i >= 31) { t0 *= 2147483648.0f; i -= 31; }
-  return (i < 0) ? (t0 / (t1 * (1 << -i))) : ((t0 * (1 << i)) / t1);
-}
-
-/* Parameters of a tone reproduction curve, either with a power law formula or with a lookup table. */
-typedef struct {
-  unsigned type; /* 0=linear, 1=lut, 2 = simple gamma, 3-6 = parametric (matches ICC parametric types 1-4) */
-  float* lut; /* for type 1 */
-  size_t lut_size;
-  float gamma; /* for type 2 and more */
-  float a, b, c, d, e, f; /* parameters for type 3-7 */
-} LodePNGICCCurve;
-
-void lodepng_icc_curve_init(LodePNGICCCurve* curve) {
-  curve->lut = 0;
-  curve->lut_size = 0;
-}
-
-void lodepng_icc_curve_cleanup(LodePNGICCCurve* curve) {
-  lodepng_free(curve->lut);
-}
-
-/* Values parsed from ICC profile, see parseICC for more information about this subset.*/
-typedef struct {
-  /* 0 = color model not supported by PNG (CMYK, Lab, ...), 1 = gray, 2 = RGB */
-  int inputspace;
-  int version_major;
-  int version_minor;
-  int version_bugfix;
-
-  /* The whitepoint of the profile connection space (PCS). Should always be D50, but parsed and used anyway.
-  (to be clear, whitepoint and illuminant are synonyms in practice, but here field "illuminant" is ICC's
-  "global" whitepoint that is always D50, and the field "white" below allows deriving the whitepoint of
-  the particular RGB space represented here) */
-  float illuminant[3];
-
-  /* if true, has chromatic adaptation matrix that must be used. If false, you must compute a chromatic adaptation
-  matrix yourself from "illuminant" and "white". */
-  unsigned has_chad;
-  float chad[9]; /* chromatic adaptation matrix, if given */
-
-  /* The whitepoint of the RGB color space as stored in the ICC file. If has_chad, must be adapted with the
-  chad matrix to become the one we need to go to absolute XYZ (in fact ICC implies it should then be
-  exactly D50 in the file, redundantly, before this transformation with chad), else use as-is (then its
-  values can actually be something else than D50, and are the ones we need). */
-  unsigned has_whitepoint;
-  float white[3];
-  /* Chromaticities of the RGB space in XYZ color space, but given such that you must still
-  whitepoint adapt them from D50 to the RGB space whitepoint to go to absolute XYZ (if has_chad,
-  with chad, else with bradford adaptation matrix from illuminant to white). */
-  unsigned has_chromaticity;
-  float red[3];
-  float green[3];
-  float blue[3];
-
-  unsigned has_trc; /* TRC = tone reproduction curve (aka "gamma correction") */
-
-  /* TRC's for the three channels (only first one used if grayscale) */
-  LodePNGICCCurve trc[3];
-} LodePNGICC;
-
-void lodepng_icc_init(LodePNGICC* icc) {
-  lodepng_icc_curve_init(&icc->trc[0]);
-  lodepng_icc_curve_init(&icc->trc[1]);
-  lodepng_icc_curve_init(&icc->trc[2]);
-}
-
-void lodepng_icc_cleanup(LodePNGICC* icc) {
-  lodepng_icc_curve_cleanup(&icc->trc[0]);
-  lodepng_icc_curve_cleanup(&icc->trc[1]);
-  lodepng_icc_curve_cleanup(&icc->trc[2]);
-}
-
-/* ICC tone response curve, nonlinear (encoded) to linear.
-Input and output in range 0-1. If color was integer 0-255, multiply with (1.0f/255)
-to get the correct floating point behavior.
-Outside of range 0-1, will not clip but either return x itself, or in cases
-where it makes sense, a value defined by the same function.
-NOTE: ICC requires clipping, but we do that only later when converting float to integer.*/
-static float iccForwardTRC(const LodePNGICCCurve* curve, float x) {
-  if(curve->type == 0) {
-    return x;
-  }
-  if(curve->type == 1) { /* Lookup table */
-    float v0, v1, fraction;
-    size_t index;
-    if(!curve->lut) return 0; /* error */
-    if(x < 0) return x;
-    index = (size_t)(x * (curve->lut_size - 1));
-    if(index >= curve->lut_size) return x;
-
-    /* LERP */
-    v0 = curve->lut[index];
-    v1 = (index + 1 < curve->lut_size) ? curve->lut[index + 1] : 1.0f;
-    fraction = (x * (curve->lut_size - 1)) - index;
-    return v0 * (1 - fraction) + v1 * fraction;
-  }
-  if(curve->type == 2) {
-    /* Gamma expansion */
-    return (x > 0) ? lodepng_powf(x, curve->gamma) : x;
-  }
-  /* TODO: all the ones below are untested */
-  if(curve->type == 3) {
-    if(x < 0) return x;
-    return x >= (-curve->b / curve->a) ? (lodepng_powf(curve->a * x + curve->b, curve->gamma) + curve->c) : 0;
-  }
-  if(curve->type == 4) {
-    if(x < 0) return x;
-    return x >= (-curve->b / curve->a) ? (lodepng_powf(curve->a * x + curve->b, curve->gamma) + curve->c) : curve->c;
-  }
-  if(curve->type == 5) {
-    return x >= curve->d ? (lodepng_powf(curve->a * x + curve->b, curve->gamma)) : (curve->c * x);
-  }
-  if(curve->type == 6) {
-    return x >= curve->d ? (lodepng_powf(curve->a * x + curve->b, curve->gamma) + curve->c) : (curve->c * x + curve->f);
-  }
-  return 0;
-}
-
-/* ICC tone response curve, linear to nonlinear (encoded).
-Input and output in range 0-1. Outside of that range, will not clip but either
-return x itself, or in cases where it makes sense, a value defined by the same function.
-NOTE: ICC requires clipping, but we do that only later when converting float to integer.*/
-static float iccBackwardTRC(const LodePNGICCCurve* curve, float x) {
-  if(curve->type == 0) {
-    return x;
-  }
-  if(curve->type == 1) {
-    size_t a, b, m;
-    float v;
-    if(x <= 0) return x;
-    if(x >= 1) return x;
-    /* binary search in the table */
-    /* TODO: use faster way of inverting the lookup table */
-    a = 0;
-    b = curve->lut_size;
-    for(;;) {
-      if(a == b) return curve->lut[a];
-      if(a + 1 == b) {
-        /* LERP */
-        float v0 = curve->lut[a];
-        float v1 = curve->lut[b];
-        float fraction;
-        if(v0 == v1) return v0;
-        fraction = (x - v0) / (v1 - v0);
-        return v0 * (1 - fraction) + v1 * fraction;
-      }
-      m = (a + b) / 2u;
-      v = curve->lut[m];
-      if(v > x) {
-        b = m;
-      } else {
-        a = m;
-      }
-    }
-    return 0;
-  }
-  if(curve->type == 2) {
-    /* Gamma compression */
-    return (x > 0) ? lodepng_powf(x, 1.0f / curve->gamma) : x;
-  }
-  /* TODO: all the ones below are untested  */
-  if(curve->type == 3) {
-    if(x < 0) return x;
-    return x > 0 ? ((lodepng_powf(x, 1.0f / curve->gamma) - curve->b) / curve->a) : (-curve->b / curve->a);
-  }
-  if(curve->type == 4) {
-    if(x < 0) return x;
-    return x > curve->c ?
-        ((lodepng_powf(x - curve->c, 1.0f / curve->gamma) - curve->b) / curve->a) :
-        (-curve->b / curve->a);
-  }
-  if(curve->type == 5) {
-    return x > (curve->c * curve->d) ?
-        ((lodepng_powf(x, 1.0f / curve->gamma) - curve->b) / curve->a) :
-        (x / curve->c);
-  }
-  if(curve->type == 6) {
-    return x > (curve->c * curve->d + curve->f) ?
-        ((lodepng_powf(x - curve->c, 1.0f / curve->gamma) - curve->b) / curve->a) :
-        ((x - curve->f) / curve->c);
-  }
-  return 0;
-}
-
-static unsigned decodeICCUint16(const unsigned char* data, size_t size, size_t* pos) {
-  *pos += 2;
-  if (*pos > size) return 0;
-  return (unsigned)((data[*pos - 2] << 8) | (data[*pos - 1]));
-}
-
-static unsigned decodeICCUint32(const unsigned char* data, size_t size, size_t* pos) {
-  *pos += 4;
-  if (*pos > size) return 0;
-  return (unsigned)((data[*pos - 4] << 24) | (data[*pos - 3] << 16) | (data[*pos - 2] << 8) | (data[*pos - 1] << 0));
-}
-
-static int decodeICCInt32(const unsigned char* data, size_t size, size_t* pos) {
-  *pos += 4;
-  if (*pos > size) return 0;
-  /*TODO: this is incorrect if sizeof(int) != 4*/
-  return (data[*pos - 4] << 24) | (data[*pos - 3] << 16) | (data[*pos - 2] << 8) | (data[*pos - 1] << 0);
-}
-
-static float decodeICC15Fixed16(const unsigned char* data, size_t size, size_t* pos) {
-  return decodeICCInt32(data, size, pos) / 65536.0;
-}
-
-static unsigned isICCword(const unsigned char* data, size_t size, size_t pos, const char* word) {
-  if(pos + 4 > size) return 0;
-  return data[pos + 0] == (unsigned char)word[0] &&
-         data[pos + 1] == (unsigned char)word[1] &&
-         data[pos + 2] == (unsigned char)word[2] &&
-         data[pos + 3] == (unsigned char)word[3];
-}
-
-/* Parses a subset of the ICC profile, supporting the necessary mix of ICC v2
-and ICC v4 required to correctly convert the RGB color space to XYZ.
-Does not parse values not related to this specific PNG-related purpose, and
-does not support non-RGB profiles or lookup-table based chroma (but it
-supports lookup tables for TRC aka "gamma"). */
-static unsigned parseICC(LodePNGICC* icc, const unsigned char* data, size_t size) {
-  size_t i, j;
-  size_t pos = 0;
-  unsigned version;
-  unsigned inputspace;
-  size_t numtags;
-
-  if(size < 132) return 1; /* Too small to be a valid icc profile. */
-
-  icc->has_chromaticity = 0;
-  icc->has_whitepoint = 0;
-  icc->has_trc = 0;
-  icc->has_chad = 0;
-
-  icc->trc[0].type = icc->trc[1].type = icc->trc[2].type = 0;
-  icc->white[0] = icc->white[1] = icc->white[2] = 0;
-  icc->red[0] = icc->red[1] = icc->red[2] = 0;
-  icc->green[0] = icc->green[1] = icc->green[2] = 0;
-  icc->blue[0] = icc->blue[1] = icc->blue[2] = 0;
-
-  pos = 8;
-  version = decodeICCUint32(data, size, &pos);
-  if(pos >= size) return 1;
-  icc->version_major = (int)((version >> 24) & 255);
-  icc->version_minor = (int)((version >> 20) & 15);
-  icc->version_bugfix = (int)((version >> 16) & 15);
-
-  pos = 16;
-  inputspace = decodeICCUint32(data, size, &pos);
-  if(pos >= size) return 1;
-  if(inputspace == 0x47524159) {
-    /* The string  "GRAY" as unsigned 32-bit int. */
-    icc->inputspace = 1;
-  } else if(inputspace == 0x52474220) {
-    /* The string  "RGB " as unsigned 32-bit int. */
-    icc->inputspace = 2;
-  } else {
-    /* unsupported by PNG (CMYK, YCbCr, Lab, HSV, ...) */
-    icc->inputspace = 0;
-  }
-
-  /* Should always be 0.9642, 1.0, 0.8249 */
-  pos = 68;
-  icc->illuminant[0] = decodeICC15Fixed16(data, size, &pos);
-  icc->illuminant[1] = decodeICC15Fixed16(data, size, &pos);
-  icc->illuminant[2] = decodeICC15Fixed16(data, size, &pos);
-
-  pos = 128;
-  numtags = decodeICCUint32(data, size, &pos);
-  if(pos >= size) return 1;
-  /* scan for tags we want to handle */
-  for(i = 0; i < numtags; i++) {
-    size_t offset;
-    unsigned tagsize;
-    size_t namepos = pos;
-    pos += 4;
-    offset = decodeICCUint32(data, size, &pos);
-    tagsize = decodeICCUint32(data, size, &pos);
-    if(pos >= size || offset >= size) return 1;
-    if(offset + tagsize > size) return 1;
-    if(tagsize < 8) return 1;
-
-    if(isICCword(data, size, namepos, "wtpt")) {
-      offset += 8; /* skip tag and reserved */
-      icc->white[0] = decodeICC15Fixed16(data, size, &offset);
-      icc->white[1] = decodeICC15Fixed16(data, size, &offset);
-      icc->white[2] = decodeICC15Fixed16(data, size, &offset);
-      icc->has_whitepoint = 1;
-    } else if(isICCword(data, size, namepos, "rXYZ")) {
-      offset += 8; /* skip tag and reserved */
-      icc->red[0] = decodeICC15Fixed16(data, size, &offset);
-      icc->red[1] = decodeICC15Fixed16(data, size, &offset);
-      icc->red[2] = decodeICC15Fixed16(data, size, &offset);
-      icc->has_chromaticity = 1;
-    } else if(isICCword(data, size, namepos, "gXYZ")) {
-      offset += 8; /* skip tag and reserved */
-      icc->green[0] = decodeICC15Fixed16(data, size, &offset);
-      icc->green[1] = decodeICC15Fixed16(data, size, &offset);
-      icc->green[2] = decodeICC15Fixed16(data, size, &offset);
-      icc->has_chromaticity = 1;
-    } else if(isICCword(data, size, namepos, "bXYZ")) {
-      offset += 8; /* skip tag and reserved */
-      icc->blue[0] = decodeICC15Fixed16(data, size, &offset);
-      icc->blue[1] = decodeICC15Fixed16(data, size, &offset);
-      icc->blue[2] = decodeICC15Fixed16(data, size, &offset);
-      icc->has_chromaticity = 1;
-    } else if(isICCword(data, size, namepos, "chad")) {
-      offset += 8; /* skip datatype keyword "sf32" and reserved */
-      for(j = 0; j < 9; j++) {
-        icc->chad[j] = decodeICC15Fixed16(data, size, &offset);
-      }
-      icc->has_chad = 1;
-    } else if(isICCword(data, size, namepos, "rTRC") ||
-              isICCword(data, size, namepos, "gTRC") ||
-              isICCword(data, size, namepos, "bTRC") ||
-              isICCword(data, size, namepos, "kTRC")) {
-      char c = (char)data[namepos];
-      /* both 'k' and 'r' are stored in channel 0 */
-      int channel = (c == 'b') ? 2 : (c == 'g' ? 1 : 0);
-      /* "curv": linear, gamma power or LUT */
-      if(isICCword(data, size, offset, "curv")) {
-        size_t count;
-        LodePNGICCCurve* trc = &icc->trc[channel];
-        icc->has_trc = 1;
-        offset += 8; /* skip tag "curv" and reserved */
-        count = decodeICCUint32(data, size, &offset);
-        if(count == 0) {
-          trc->type = 0; /* linear */
-        } else if(count == 1) {
-          trc->type = 2; /* gamma */
-          trc->gamma = decodeICCUint16(data, size, &offset) / 256.0f;
-        } else {
-          trc->type = 1; /* LUT */
-          if(offset + count * 2 > size || count > 16777216) return 1; /* also avoid crazy count */
-          trc->lut_size = count;
-          trc->lut = (float*)lodepng_malloc(count * sizeof(float));
-          for(j = 0; j < count; j++) {
-            trc->lut[j] = decodeICCUint16(data, size, &offset) * (1.0f / 65535.0f);
-          }
-        }
-      }
-      /* "para": parametric formula with gamma power, multipliers, biases and comparison point */
-      /* TODO: test this on a realistic sample */
-      if(isICCword(data, size, offset, "para")) {
-        unsigned type;
-        LodePNGICCCurve* trc = &icc->trc[channel];
-        icc->has_trc = 1;
-        offset += 8; /* skip tag "para" and reserved */
-        type = decodeICCUint16(data, size, &offset);
-        offset += 2;
-        if(type > 4) return 1; /* unknown parametric curve type */
-        trc->type = type + 2;
-        trc->gamma = decodeICC15Fixed16(data, size, &offset);
-        if(type >= 1) {
-          trc->a = decodeICC15Fixed16(data, size, &offset);
-          trc->b = decodeICC15Fixed16(data, size, &offset);
-        }
-        if(type >= 2) {
-          trc->c = decodeICC15Fixed16(data, size, &offset);
-        }
-        if(type >= 3) {
-          trc->d = decodeICC15Fixed16(data, size, &offset);
-        }
-        if(type == 4) {
-          trc->e = decodeICC15Fixed16(data, size, &offset);
-          trc->f = decodeICC15Fixed16(data, size, &offset);
-        }
-      }
-      /* TODO: verify: does the "chrm" tag participate in computation so should be parsed? */
-    }
-    /* Return error if any parse went beyond the filesize. Note that the
-    parsing itself was always safe since it bound-checks inside. */
-    if(offset > size) return 1;
-  }
-
-  return 0;
-}
-
-/* Multiplies 3 vector values with 3x3 matrix */
-static void mulMatrix(float* x2, float* y2, float* z2, const float* m, double x, double y, double z) {
-  /* double used as inputs even though in general the images are float, so the sums happen in
-  double precision, because float can give numerical problems for nearby values */
-  *x2 = x * m[0] + y * m[1] + z * m[2];
-  *y2 = x * m[3] + y * m[4] + z * m[5];
-  *z2 = x * m[6] + y * m[7] + z * m[8];
-}
-
-static void mulMatrixMatrix(float* result, const float* a, const float* b) {
-  int i;
-  float temp[9]; /* temp is to allow result and a or b to be the same */
-  mulMatrix(&temp[0], &temp[3], &temp[6], a, b[0], b[3], b[6]);
-  mulMatrix(&temp[1], &temp[4], &temp[7], a, b[1], b[4], b[7]);
-  mulMatrix(&temp[2], &temp[5], &temp[8], a, b[2], b[5], b[8]);
-  for(i = 0; i < 9; i++) result[i] = temp[i];
-}
-
-/* Inverts 3x3 matrix in place */
-static unsigned invMatrix(float* m) {
-  int i;
-  /* double used instead of float for intermediate computations to avoid
-  intermediate numerical precision issues */
-  double e0 = (double)m[4] * m[8] - (double)m[5] * m[7];
-  double e3 = (double)m[5] * m[6] - (double)m[3] * m[8];
-  double e6 = (double)m[3] * m[7] - (double)m[4] * m[6];
-  /* inverse determinant */
-  double d = 1.0 / (m[0] * e0 + m[1] * e3 + m[2] * e6);
-  float result[9];
-  if((d > 0 ? d : -d) > 1e15) return 1; /* error, likely not invertible */
-  result[0] = e0 * d;
-  result[1] = ((double)m[2] * m[7] - (double)m[1] * m[8]) * d;
-  result[2] = ((double)m[1] * m[5] - (double)m[2] * m[4]) * d;
-  result[3] = e3 * d;
-  result[4] = ((double)m[0] * m[8] - (double)m[2] * m[6]) * d;
-  result[5] = ((double)m[3] * m[2] - (double)m[0] * m[5]) * d;
-  result[6] = e6 * d;
-  result[7] = ((double)m[6] * m[1] - (double)m[0] * m[7]) * d;
-  result[8] = ((double)m[0] * m[4] - (double)m[3] * m[1]) * d;
-  for(i = 0; i < 9; i++) m[i] = result[i];
-  return 0; /* ok */
-}
-
-/* Get the matrix to go from linear RGB to XYZ given the RGB whitepoint and chromaticities in XYZ colorspace */
-static unsigned getChrmMatrixXYZ(float* m,
-                                 float wX, float wY, float wZ,
-                                 float rX, float rY, float rZ,
-                                 float gX, float gY, float gZ,
-                                 float bX, float bY, float bZ) {
-  float t[9];
-  float rs, gs, bs;
-  t[0] = rX; t[1] = gX; t[2] = bX;
-  t[3] = rY; t[4] = gY; t[5] = bY;
-  t[6] = rZ; t[7] = gZ; t[8] = bZ;
-  if(invMatrix(t)) return 1; /* error, not invertible */
-  mulMatrix(&rs, &gs, &bs, t, wX, wY, wZ);
-  m[0] = rs * rX; m[1] = gs * gX; m[2] = bs * bX;
-  m[3] = rs * rY; m[4] = gs * gY; m[5] = bs * bY;
-  m[6] = rs * rZ; m[7] = gs * gZ; m[8] = bs * bZ;
-  return 0;
-}
-
-/* Get the matrix to go from linear RGB to XYZ given the RGB whitepoint and chromaticities in xy colorspace */
-static unsigned getChrmMatrixXY(float* m,
-                                float wx, float wy,
-                                float rx, float ry,
-                                float gx, float gy,
-                                float bx, float by) {
-  if(wy == 0 || ry == 0 || gy == 0 || by == 0) {
-    return 1; /* error, division through zero */
-  } else {
-    float wX = wx / wy, wY = 1, wZ = (1 - wx - wy) / wy;
-    float rX = rx / ry, rY = 1, rZ = (1 - rx - ry) / ry;
-    float gX = gx / gy, gY = 1, gZ = (1 - gx - gy) / gy;
-    float bX = bx / by, bY = 1, bZ = (1 - bx - by) / by;
-    return getChrmMatrixXYZ(m, wX, wY, wZ, rX, rY, rZ, gX, gY, gZ, bX, bY, bZ);
-  }
-}
-
-/* Returns matrix that adapts from source whitepoint 0 to destination whitepoint 1.
-Types: 0=XYZ scaling, 1=Bradford, 2=Vonkries */
-static unsigned getAdaptationMatrix(float* m, int type,
-                                    float wx0, float wy0, float wz0,
-                                    float wx1, float wy1, float wz1) {
-  int i;
-  static const float bradford[9] = {
-    0.8951f, 0.2664f, -0.1614f,
-    -0.7502f, 1.7135f, 0.0367f,
-    0.0389f, -0.0685f, 1.0296f
-  };
-  static const float bradfordinv[9] = {
-    0.9869929f, -0.1470543f, 0.1599627f,
-    0.4323053f, 0.5183603f, 0.0492912f,
-   -0.0085287f, 0.0400428f, 0.9684867f
-  };
-  static const float vonkries[9] = {
-    0.40024f, 0.70760f, -0.08081f,
-    -0.22630f, 1.16532f, 0.04570f,
-    0.00000f, 0.00000f, 0.91822f,
-  };
-  static const float vonkriesinv[9] = {
-    1.8599364f, -1.1293816f, 0.2198974f,
-    0.3611914f, 0.6388125f, -0.0000064f,
-   0.0000000f, 0.0000000f, 1.0890636f
-  };
-  if(type == 0) {
-    for(i = 0; i < 9; i++) m[i] = 0;
-    m[0] = wx1 / wx0;
-    m[4] = wy1 / wy0;
-    m[8] = wz1 / wz0;
-  } else {
-    const float* cat = (type == 1) ? bradford : vonkries;
-    const float* inv = (type == 1) ? bradfordinv : vonkriesinv;
-    float rho0, gam0, bet0, rho1, gam1, bet1, rho2, gam2, bet2;
-    mulMatrix(&rho0, &gam0, &bet0, cat, wx0, wy0, wz0);
-    mulMatrix(&rho1, &gam1, &bet1, cat, wx1, wy1, wz1);
-    rho2 = rho1 / rho0;
-    gam2 = gam1 / gam0;
-    bet2 = bet1 / bet0;
-    /* Multiply diagonal matrix with cat */
-    for(i = 0; i < 3; i++) {
-      m[i + 0] = rho2 * cat[i + 0];
-      m[i + 3] = gam2 * cat[i + 3];
-      m[i + 6] = bet2 * cat[i + 6];
-    }
-    mulMatrixMatrix(m, inv, m);
-  }
-  return 0; /* ok */
-}
-
-/* validate whether the ICC profile is supported here for PNG */
-static unsigned validateICC(const LodePNGICC* icc) {
-  /* disable for unsupported things in the icc profile */
-  if(icc->inputspace == 0) return 0;
-  /* if we didn't recognize both chrm and trc, then maybe the ICC uses data
-  types not supported here yet, so fall back to not using it. */
-  if(icc->inputspace == 2) {
-    /* RGB profile should have chromaticities */
-    if(!icc->has_chromaticity) return 0;
-  }
-  /* An ICC profile without whitepoint is invalid for the kind of profiles used here. */
-  if(!icc->has_whitepoint) return 0;
-  if(!icc->has_trc) return 0;
-  return 1; /* ok */
-}
-
-/* Returns chromaticity matrix for given ICC profile, adapted from ICC's
-global illuminant as necessary.
-Also returns the profile's whitepoint.
-In case of a gray profile (icc->inputspace == 1), the identity matrix will be returned
-so in that case you could skip the transform. */
-static unsigned getICCChrm(float m[9], float whitepoint[3], const LodePNGICC* icc) {
-  size_t i;
-  if(icc->inputspace == 2) { /* RGB profile */
-    float red[3], green[3], blue[3];
-    float white[3]; /* the whitepoint of the RGB color space (absolute) */
-    /* Adaptation matrix a.
-    This is an adaptation needed for ICC's file format (due to it using
-    an internal global illuminant unrelated to the actual images) */
-    float a[9] = {1,0,0, 0,1,0, 0,0,1};
-    /* If the profile has chromatic adaptation matrix "chad", use that one,
-    else compute it from the illuminant and whitepoint. */
-    if(icc->has_chad) {
-      for(i = 0; i < 9; i++) a[i] = icc->chad[i];
-      invMatrix(a);
-    } else {
-      if(getAdaptationMatrix(a, 1, icc->illuminant[0], icc->illuminant[1], icc->illuminant[2],
-                             icc->white[0], icc->white[1], icc->white[2])) {
-        return 1; /* error computing matrix */
-      }
-    }
-    /* If the profile has a chad, then also the RGB's whitepoint must also be adapted from it (and the one
-    given is normally D50). If it did not have a chad, then the whitepoint given is already the adapted one. */
-    if(icc->has_chad) {
-      mulMatrix(&white[0], &white[1], &white[2], a, icc->white[0], icc->white[1], icc->white[2]);
-    } else {
-      for(i = 0; i < 3; i++) white[i] = icc->white[i];
-    }
-
-    mulMatrix(&red[0], &red[1], &red[2], a, icc->red[0], icc->red[1], icc->red[2]);
-    mulMatrix(&green[0], &green[1], &green[2], a, icc->green[0], icc->green[1], icc->green[2]);
-    mulMatrix(&blue[0], &blue[1], &blue[2], a, icc->blue[0], icc->blue[1], icc->blue[2]);
-
-    if(getChrmMatrixXYZ(m, white[0], white[1], white[2], red[0], red[1], red[2],
-                        green[0], green[1], green[2], blue[0], blue[1], blue[2])) {
-      return 1; /* error computing matrix */
-    }
-    /* output absolute whitepoint of the original RGB model */
-    whitepoint[0] = white[0];
-    whitepoint[1] = white[1];
-    whitepoint[2] = white[2];
-  } else {
-    /* output the unity matrix, for doing no transform */
-    m[0] = m[4] = m[8] = 1;
-    m[1] = m[2] = m[3] = m[5] = m[6] = m[7] = 0;
-    /* grayscale, don't do anything. That means we are implicitely using equal energy whitepoint "E", indicate
-    this to the output. */
-    whitepoint[0] = whitepoint[1] = whitepoint[2] = 1;
-  }
-  return 0; /* success */
-}
-
-/* Outputs whitepoint and matrix to go from the icc or info profile (depending on what was in the PNG) to XYZ,
-without applying any (rendering intent related) whitepoint adaptation */
-static unsigned getChrm(float m[9], float whitepoint[3], unsigned use_icc,
-                        const LodePNGICC* icc, const LodePNGInfo* info) {
-  size_t i;
-  if(use_icc) {
-    if(getICCChrm(m, whitepoint, icc)) return 1;  /* error in the matrix computations */
-  } else if(info->chrm_defined && !info->srgb_defined) {
-    float wx = info->chrm_white_x / 100000.0f, wy = info->chrm_white_y / 100000.0f;
-    float rx = info->chrm_red_x / 100000.0f, ry = info->chrm_red_y / 100000.0f;
-    float gx = info->chrm_green_x / 100000.0f, gy = info->chrm_green_y / 100000.0f;
-    float bx = info->chrm_blue_x / 100000.0f, by = info->chrm_blue_y / 100000.0f;
-    if(getChrmMatrixXY(m, wx, wy, rx, ry, gx, gy, bx, by)) return 1; /* returns if error */
-    /* Output whitepoint, xyY to XYZ: */
-    whitepoint[0] = wx / wy;
-    whitepoint[1] = 1;
-    whitepoint[2] = (1 - wx - wy) / wy;
-  } else {
-    /* the standard linear sRGB to XYZ matrix */
-    static const float srgb[9] = {
-        0.4124564f, 0.3575761f, 0.1804375f,
-        0.2126729f, 0.7151522f, 0.0721750f,
-        0.0193339f, 0.1191920f, 0.9503041f
-    };
-    for(i = 0; i < 9; i++) m[i] = srgb[i];
-    /* sRGB's whitepoint xyY "0.3127,0.3290,1" in XYZ: */
-    whitepoint[0] = 0.9504559270516716f;
-    whitepoint[1] = 1;
-    whitepoint[2] = 1.0890577507598784f;
-  }
-  return 0;
-}
-
-/* Returns whether the color chunks in info represent the default PNG sRGB,
-which is when either no colorometry fields are present at all, or an srgb
-field or chrm/gama field with default values are present.
-ICC chunks representing sRGB are currently considered not the same. */
-static unsigned isSRGB(const LodePNGInfo* info) {
-  if(!info) return 1; /* the default is considered sRGB. */
-
-  /* TODO: support some ICC profiles that represent sRGB too. Tricky due to
-  possible slight deviations and many ways of representing its gamma function. */
-  if(info->iccp_defined) return 0;
-
-  if(info->srgb_defined) return 1;
-
-  /* The gamma chunk is unable to represent sRGB's two-part gamma, so cannot
-  be sRGB, even if it's the default 45455. */
-  if(info->gama_defined) return 0;
-
-  if(info->chrm_defined) {
-    if(info->chrm_white_x != 31270 || info->chrm_white_y != 32900) return 0;
-    if(info->chrm_red_x != 64000 || info->chrm_red_y != 33000) return 0;
-    if(info->chrm_green_x != 30000 || info->chrm_green_y != 60000) return 0;
-    if(info->chrm_blue_x != 15000 || info->chrm_blue_y != 6000) return 0;
-  }
-
-  return 1;
-}
-
-/* Checks whether the RGB models are equal (chromaticities, ...). The raw byte
-format is allowed to be different. Input pointers are allowed to be null,
-they then represent the default PNG sRGB (same as having no color model
-chunks at all or an srgb chunk in the PNG) */
-static unsigned modelsEqual(const LodePNGState* state_a,
-                            const LodePNGState* state_b) {
-  size_t i;
-  const LodePNGInfo* a = state_a ? &state_a->info_png : 0;
-  const LodePNGInfo* b = state_b ? &state_b->info_png : 0;
-  if(isSRGB(a) != isSRGB(b)) return 0;
-  /* now a and b are guaranteed to be non-NULL */
-  if(a->iccp_defined != b->iccp_defined) return 0;
-  if(a->iccp_defined) {
-    if(a->iccp_profile_size != b->iccp_profile_size) return 0;
-    /* TODO: return equal in more cases, such as when two ICC profiles that are
-    not byte-for-byte equal, but represent the same color model. */
-    for(i = 0; i < a->iccp_profile_size; i++) {
-      if(a->iccp_profile[i] != b->iccp_profile[i]) return 0;
-    }
-    /* since the ICC model overrides gamma and chrm, those can be ignored. */
-    /* TODO: this doesn't cover the case where the ICC profile is invalid */
-    return 1;
-  }
-
-  if(a->srgb_defined != b->srgb_defined) return 0;
-  if(a->srgb_defined) {
-    /* since the sRGB model overrides gamma and chrm, those can be ignored.
-    srgb_intent not checked since the conversion ignores it */
-    return 1;
-  }
-
-  if(a->gama_defined != b->gama_defined) return 0;
-  if(a->gama_defined) {
-    if(a->gama_gamma != b->gama_gamma) return 0;
-  }
-
-  if(a->chrm_defined != b->chrm_defined) return 0;
-  if(a->chrm_defined) {
-    if(a->chrm_white_x != b->chrm_white_x) return 0;
-    if(a->chrm_white_y != b->chrm_white_y) return 0;
-    if(a->chrm_red_x != b->chrm_red_x) return 0;
-    if(a->chrm_red_y != b->chrm_red_y) return 0;
-    if(a->chrm_green_x != b->chrm_green_x) return 0;
-    if(a->chrm_green_y != b->chrm_green_y) return 0;
-    if(a->chrm_blue_x != b->chrm_blue_x) return 0;
-    if(a->chrm_blue_y != b->chrm_blue_y) return 0;
-  }
-
-  return 1;
-}
-
-/* Converts in-place. Does not clamp. Do not use for integer input, make table instead there. */
-static void convertToXYZ_gamma(float* out, const float* in, unsigned w, unsigned h,
-                               const LodePNGInfo* info, unsigned use_icc, const LodePNGICC* icc) {
-  size_t i, c;
-  size_t n = w * h;
-  for(i = 0; i < n * 4; i++) {
-    out[i] = in[i];
-  }
-  if(use_icc) {
-    for(i = 0; i < n; i++) {
-      for(c = 0; c < 3; c++) {
-        /* TODO: this is likely very slow */
-        out[i * 4 + c] = iccForwardTRC(&icc->trc[c], in[i * 4 + c]);
-      }
-    }
-  } else if(info->gama_defined && !info->srgb_defined) {
-    /* nothing to do if gamma is 1 */
-    if(info->gama_gamma != 100000) {
-      float gamma = 100000.0f / info->gama_gamma;
-      for(i = 0; i < n; i++) {
-        for(c = 0; c < 3; c++) {
-          float v = in[i * 4 + c];
-          out[i * 4 + c] = (v <= 0) ? v : lodepng_powf(v, gamma);
-        }
-      }
-    }
-  } else {
-    for(i = 0; i < n; i++) {
-      for(c = 0; c < 3; c++) {
-        /* sRGB gamma expand */
-        float v = in[i * 4 + c];
-        out[i * 4 + c] = (v < 0.04045f) ? (v / 12.92f) : lodepng_powf((v + 0.055f) / 1.055f, 2.4f);
-      }
-    }
-  }
-}
-
-/* Same as convertToXYZ_gamma, but creates a lookup table rather than operating on an image */
-static void convertToXYZ_gamma_table(float* out, size_t n, size_t c,
-                                     const LodePNGInfo* info, unsigned use_icc, const LodePNGICC* icc) {
-  size_t i;
-  float mul = 1.0f / (n - 1);
-  if(use_icc) {
-    for(i = 0; i < n; i++) {
-      float v = i * mul;
-      out[i] = iccForwardTRC(&icc->trc[c], v);
-    }
-  } else if(info->gama_defined && !info->srgb_defined) {
-    /* no power needed if gamma is 1 */
-    if(info->gama_gamma == 100000) {
-      for(i = 0; i < n; i++) {
-        out[i] = i * mul;
-      }
-    } else {
-      float gamma = 100000.0f / info->gama_gamma;
-      for(i = 0; i < n; i++) {
-        float v = i * mul;
-        out[i] = lodepng_powf(v, gamma);
-      }
-    }
-  } else {
-    for(i = 0; i < n; i++) {
-      /* sRGB gamma expand */
-      float v = i * mul;
-      out[i] = (v < 0.04045f) ? (v / 12.92f) : lodepng_powf((v + 0.055f) / 1.055f, 2.4f);
-    }
-  }
-}
-
-/* In-place */
-static unsigned convertToXYZ_chrm(float* im, unsigned w, unsigned h,
-                                  const LodePNGInfo* info, unsigned use_icc, const LodePNGICC* icc,
-                                  float whitepoint[3]) {
-  unsigned error = 0;
-  size_t i;
-  size_t n = w * h;
-  float m[9]; /* XYZ to linear RGB matrix */
-
-  /* Must be called even for grayscale, to get the correct whitepoint to output */
-  error = getChrm(m, whitepoint, use_icc, icc, info);
-  if(error) return error;
-
-  /* Note: no whitepoint adaptation done to m here, because we only do the
-  adaptation in convertFromXYZ (we only whitepoint adapt when going to the
-  target RGB space, but here we're going from the source RGB space to XYZ) */
-
-  /* Apply the above computed linear-RGB-to-XYZ matrix to the pixels.
-  Skip the transform if it's the unit matrix (which is the case if grayscale profile) */
-  if(!use_icc || icc->inputspace == 2) {
-    for(i = 0; i < n; i++) {
-      size_t j = i * 4;
-      mulMatrix(&im[j + 0], &im[j + 1], &im[j + 2], m, im[j + 0], im[j + 1], im[j + 2]);
-    }
-  }
-
-  return 0;
-}
-
-unsigned convertToXYZ(float* out, float whitepoint[3], const unsigned char* in,
-                      unsigned w, unsigned h, const LodePNGState* state) {
-  unsigned error = 0;
-  size_t i;
-  size_t n = w * h;
-  const LodePNGColorMode* mode_in = &state->info_raw;
-  const LodePNGInfo* info = &state->info_png;
-  unsigned char* data = 0;
-  float* gammatable = 0;
-  int bit16 = mode_in->bitdepth > 8;
-  size_t num = bit16 ? 65536 : 256;
-  LodePNGColorMode tempmode = lodepng_color_mode_make(LCT_RGBA, bit16 ? 16 : 8);
-
-
-  unsigned use_icc = 0;
-  LodePNGICC icc;
-  lodepng_icc_init(&icc);
-  if(info->iccp_defined) {
-    error = parseICC(&icc, info->iccp_profile, info->iccp_profile_size);
-    if(error) goto cleanup; /* corrupted ICC profile */
-    use_icc = validateICC(&icc);
-  }
-
-  data = (unsigned char*)lodepng_malloc(w * h * (bit16 ? 8 : 4));
-  error = lodepng_convert(data, in, &tempmode, mode_in, w, h);
-  if(error) goto cleanup;
-
-  /* Handle transfer function */
-  {
-    float* gammatable_r;
-    float* gammatable_g;
-    float* gammatable_b;
-
-    /* RGB ICC, can have three different transfer functions */
-    if(use_icc && icc.inputspace == 2) {
-      gammatable = (float*)lodepng_malloc(num * 3 * sizeof(float));
-      gammatable_r = &gammatable[num * 0];
-      gammatable_g = &gammatable[num * 1];
-      gammatable_b = &gammatable[num * 2];
-      convertToXYZ_gamma_table(gammatable_r, num, 0, info, use_icc, &icc);
-      convertToXYZ_gamma_table(gammatable_g, num, 1, info, use_icc, &icc);
-      convertToXYZ_gamma_table(gammatable_b, num, 2, info, use_icc, &icc);
-    } else {
-      gammatable = (float*)lodepng_malloc(num * sizeof(float));
-      gammatable_r = gammatable_g = gammatable_b = gammatable;
-      convertToXYZ_gamma_table(gammatable, num, 0, info, use_icc, &icc);
-    }
-
-    if(bit16) {
-      for(i = 0; i < n; i++) {
-        out[i * 4 + 0] = gammatable_r[data[i * 8 + 0] * 256u + data[i * 8 + 1]];
-        out[i * 4 + 1] = gammatable_g[data[i * 8 + 2] * 256u + data[i * 8 + 3]];
-        out[i * 4 + 2] = gammatable_b[data[i * 8 + 4] * 256u + data[i * 8 + 5]];
-        out[i * 4 + 3] = (data[i * 8 + 6] * 256 + data[i * 8 + 7]) * (1 / 65535.0f);
-      }
-    } else {
-      for(i = 0; i < n; i++) {
-        out[i * 4 + 0] = gammatable_r[data[i * 4 + 0]];
-        out[i * 4 + 1] = gammatable_g[data[i * 4 + 1]];
-        out[i * 4 + 2] = gammatable_b[data[i * 4 + 2]];
-        out[i * 4 + 3] = data[i * 4 + 3] * (1 / 255.0f);
-      }
-    }
-  }
-
-  convertToXYZ_chrm(out, w, h, info, use_icc, &icc, whitepoint);
-
-cleanup:
-  lodepng_icc_cleanup(&icc);
-  lodepng_free(data);
-  lodepng_free(gammatable);
-  return error;
-}
-
-unsigned convertToXYZFloat(float* out, float whitepoint[3], const float* in,
-                           unsigned w, unsigned h, const LodePNGState* state) {
-  unsigned error = 0;
-  const LodePNGInfo* info = &state->info_png;
-
-  unsigned use_icc = 0;
-  LodePNGICC icc;
-  lodepng_icc_init(&icc);
-  if(info->iccp_defined) {
-    error = parseICC(&icc, info->iccp_profile, info->iccp_profile_size);
-    if(error) goto cleanup; /* corrupted ICC profile */
-    use_icc = validateICC(&icc);
-  }
-  /* Input is floating point, so lookup table cannot be used, but it's ensured to
-  use float pow, not the slower double pow. */
-  convertToXYZ_gamma(out, in, w, h, info, use_icc, &icc);
-  convertToXYZ_chrm(out, w, h, info, use_icc, &icc, whitepoint);
-
-cleanup:
-  lodepng_icc_cleanup(&icc);
-  return error;
-}
-
-static unsigned convertFromXYZ_chrm(float* out, const float* in, unsigned w, unsigned h,
-                                    const LodePNGInfo* info, unsigned use_icc, const LodePNGICC* icc,
-                                    const float whitepoint[3], unsigned rendering_intent) {
-  size_t i;
-  size_t n = w * h;
-
-  float m[9]; /* XYZ to linear RGB matrix */
-  float white[3]; /* The whitepoint (absolute) of the target RGB space */
-
-  if(getChrm(m, white, use_icc, icc, info)) return 1;
-  if(invMatrix(m)) return 1; /* error, not invertible */
-
-  /* for relative rendering intent (any except absolute "3"), must whitepoint adapt to the original whitepoint.
-  this also ensures grayscale stays grayscale (with absolute, grayscale could become e.g. blue or sepia) */
-  if(rendering_intent != 3) {
-    float a[9] = {1,0,0, 0,1,0, 0,0,1};
-    /* "white" = absolute whitepoint of the new target RGB space, read from the target color profile.
-    "whitepoint" is original absolute whitepoint (input as parameter of this function) of an
-    RGB space the XYZ data once had before it was converted to XYZ, in other words the whitepoint that
-    we want to adapt our current data to to make sure values that had equal R==G==B in the old space have
-    the same property now (white stays white and gray stays gray).
-    Note: "absolute" whitepoint above means, can be used as-is, not needing further adaptation itself like icc.white does.*/
-    if(getAdaptationMatrix(a, 1, whitepoint[0], whitepoint[1], whitepoint[2], white[0], white[1], white[2])) {
-      return 1;
-    }
-    /* multiply the from xyz matrix with the adaptation matrix: in total,
-    the resulting matrix first adapts in XYZ space, then converts to RGB*/
-    mulMatrixMatrix(m, m, a);
-  }
-
-  /* Apply the above computed XYZ-to-linear-RGB matrix to the pixels.
-  This transformation also includes the whitepoint adaptation. The transform
-  can be skipped only if it's the unit matrix (only if grayscale profile and no
-  whitepoint adaptation, such as with rendering intent 3)*/
-  if(!use_icc || icc->inputspace == 2 || rendering_intent != 3) {
-    for(i = 0; i < n; i++) {
-      size_t j = i * 4;
-      mulMatrix(&out[j + 0], &out[j + 1], &out[j + 2], m, in[j + 0], in[j + 1], in[j + 2]);
-      out[j + 3] = in[j + 3];
-    }
-  } else {
-    for(i = 0; i < n * 4; i++) {
-      out[i] = in[i];
-    }
-  }
-
-  return 0;
-}
-
-/* Converts in-place. Does not clamp. */
-static void convertFromXYZ_gamma(float* im, unsigned w, unsigned h,
-                                 const LodePNGInfo* info, unsigned use_icc, const LodePNGICC* icc) {
-  size_t i, c;
-  size_t n = w * h;
-  if(use_icc) {
-    for(i = 0; i < n; i++) {
-      for(c = 0; c < 3; c++) {
-        /* TODO: this is likely very slow */
-        im[i * 4 + c] = iccBackwardTRC(&icc->trc[c], im[i * 4 + c]);
-      }
-    }
-  } else if(info->gama_defined && !info->srgb_defined) {
-    /* nothing to do if gamma is 1 */
-    if(info->gama_gamma != 100000) {
-      float gamma = info->gama_gamma / 100000.0f;
-      for(i = 0; i < n; i++) {
-        for(c = 0; c < 3; c++) {
-          if(im[i * 4 + c] > 0) im[i * 4 + c] = lodepng_powf(im[i * 4 + c], gamma);
-        }
-      }
-    }
-  } else {
-    for(i = 0; i < n; i++) {
-      for(c = 0; c < 3; c++) {
-        /* sRGB gamma compress */
-        float* v = &im[i * 4 + c];
-        *v = (*v < 0.0031308f) ? (*v * 12.92f) : (1.055f * lodepng_powf(*v, 1 / 2.4f) - 0.055f);
-      }
-    }
-  }
-}
-
-unsigned convertFromXYZ(unsigned char* out, const float* in, unsigned w, unsigned h,
-                        const LodePNGState* state,
-                        const float whitepoint[3], unsigned rendering_intent) {
-  unsigned error = 0;
-  size_t i, c;
-  size_t n = w * h;
-  const LodePNGColorMode* mode_out = &state->info_raw;
-  const LodePNGInfo* info = &state->info_png;
-  int bit16 = mode_out->bitdepth > 8;
-  float* im = 0;
-  unsigned char* data = 0;
-
-  /* parse ICC if present */
-  unsigned use_icc = 0;
-  LodePNGICC icc;
-  lodepng_icc_init(&icc);
-  if(info->iccp_defined) {
-    error = parseICC(&icc, info->iccp_profile, info->iccp_profile_size);
-    if(error) goto cleanup; /* corrupted ICC profile */
-    use_icc = validateICC(&icc);
-  }
-
-  /* Handle gamut */
-  im = (float*)lodepng_malloc(w * h * 4 * sizeof(float));
-  error = convertFromXYZ_chrm(im, in, w, h, info, use_icc, &icc, whitepoint, rendering_intent);
-  if(error) goto cleanup;
-
-  /* Handle transfer function */
-  /* Input is floating point, so lookup table cannot be used, but it's ensured to use float pow, not the slower double pow. */
-  convertFromXYZ_gamma(im, w, h, info, use_icc, &icc);
-
-  /* Convert to integer output */
-  data = (unsigned char*)lodepng_malloc(w * h * 8);
-  /* TODO: check if also 1/2/4 bit case needed: rounding is at different fine-grainedness for 8 and 16 bits below. */
-  if(bit16) {
-    LodePNGColorMode mode16 = lodepng_color_mode_make(LCT_RGBA, 16);
-    for(i = 0; i < n; i++) {
-      for(c = 0; c < 4; c++) {
-        size_t j = i * 8 + c * 2;
-        int i16 = (int)(0.5f + 65535.0f * LODEPNG_MIN(LODEPNG_MAX(0.0f, im[i * 4 + c]), 1.0f));
-        data[j + 0] = i16 >> 8;
-        data[j + 1] = i16 & 255;
-      }
-    }
-    error = lodepng_convert(out, data, mode_out, &mode16, w, h);
-    if(error) goto cleanup;
-  } else {
-    LodePNGColorMode mode8 = lodepng_color_mode_make(LCT_RGBA, 8);
-    for(i = 0; i < n; i++) {
-      for(c = 0; c < 4; c++) {
-        int i8 = (int)(0.5f + 255.0f * LODEPNG_MIN(LODEPNG_MAX(0.0f, im[i * 4 + c]), 1.0f));
-        data[i * 4 + c] = i8;
-      }
-    }
-    error = lodepng_convert(out, data, mode_out, &mode8, w, h);
-    if(error) goto cleanup;
-  }
-
-cleanup:
-  lodepng_icc_cleanup(&icc);
-  lodepng_free(im);
-  lodepng_free(data);
-  return error;
-}
-
-unsigned convertFromXYZFloat(float* out, const float* in, unsigned w, unsigned h,
-                             const LodePNGState* state,
-                             const float whitepoint[3], unsigned rendering_intent) {
-  unsigned error = 0;
-  const LodePNGInfo* info = &state->info_png;
-
-  /* parse ICC if present */
-  unsigned use_icc = 0;
-  LodePNGICC icc;
-  lodepng_icc_init(&icc);
-  if(info->iccp_defined) {
-    error = parseICC(&icc, info->iccp_profile, info->iccp_profile_size);
-    if(error) goto cleanup; /* corrupted ICC profile */
-    use_icc = validateICC(&icc);
-  }
-
-  /* Handle gamut */
-  error = convertFromXYZ_chrm(out, in, w, h, info, use_icc, &icc, whitepoint, rendering_intent);
-  if(error) goto cleanup;
-
-  /* Handle transfer function */
-  convertFromXYZ_gamma(out, w, h, info, use_icc, &icc);
-
-cleanup:
-  lodepng_icc_cleanup(&icc);
-  return error;
-}
-
-unsigned convertRGBModel(unsigned char* out, const unsigned char* in,
-                         unsigned w, unsigned h,
-                         const LodePNGState* state_out,
-                         const LodePNGState* state_in,
-                         unsigned rendering_intent) {
-  if(modelsEqual(state_in, state_out)) {
-    return lodepng_convert(out, in, &state_out->info_raw, &state_in->info_raw, w, h);
-  } else {
-    unsigned error = 0;
-    float* xyz = (float*)lodepng_malloc(w * h * 4 * sizeof(float));
-    float whitepoint[3];
-    error = convertToXYZ(&xyz[0], whitepoint, in, w, h, state_in);
-    if (!error) error = convertFromXYZ(out, &xyz[0], w, h, state_out, whitepoint, rendering_intent);
-    lodepng_free(xyz);
-    return error;
-  }
-}
-
-unsigned convertToSrgb(unsigned char* out, const unsigned char* in,
-                       unsigned w, unsigned h,
-                       const LodePNGState* state_in) {
-  LodePNGState srgb;
-  lodepng_state_init(&srgb);
-  lodepng_color_mode_copy(&srgb.info_raw, &state_in->info_raw);
-  return convertRGBModel(out, in, w, h, &srgb, state_in, 1);
-}
-
-unsigned convertFromSrgb(unsigned char* out, const unsigned char* in,
-                         unsigned w, unsigned h,
-                         const LodePNGState* state_out) {
-  LodePNGState srgb;
-  lodepng_state_init(&srgb);
-  lodepng_color_mode_copy(&srgb.info_raw, &state_out->info_raw);
-  return convertRGBModel(out, in, w, h, state_out, &srgb, 1);
-}
-
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-
-////////////////////////////////////////////////////////////////////////////////
-
-
-
 //This uses a stripped down version of picoPNG to extract detailed zlib information while decompressing.
-static const unsigned long LENBASE[29] = {3,4,5,6,7,8,9,10,11,13,15,17,19,23,27,31,35,43,51,59,67,83,99,115,131,163,195,227,258};
-static const unsigned long LENEXTRA[29] = {0,0,0,0,0,0,0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4,  4,  5,  5,  5,  5,  0};
-static const unsigned long DISTBASE[30] = {1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193,257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577};
-static const unsigned long DISTEXTRA[30] = {0,0,0,0,1,1,2, 2, 3, 3, 4, 4, 5, 5,  6,  6,  7,  7,  8,  8,   9,   9,  10,  10,  11,  11,  12,   12,   13,   13};
-static const unsigned long CLCL[19] = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; //code length code lengths
-
-struct ExtractZlib { // Zlib decompression and information extraction
+static const unsigned long LENBASE[29] =
+    {3,4,5,6,7,8,9,10,11,13,15,17,19,23,27,31,35,43,51,59,67,83,99,115,131,163,195,227,258};
+static const unsigned long LENEXTRA[29] =
+    {0,0,0,0,0,0,0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4,  4,  5,  5,  5,  5,  0};
+static const unsigned long DISTBASE[30] =
+    {1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193,257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577};
+static const unsigned long DISTEXTRA[30] =
+    {0,0,0,0,1,1,2, 2, 3, 3, 4, 4, 5, 5,  6,  6,  7,  7,  8,  8,   9,   9,  10,  10,  11,  11,  12,   12,   13,   13};
+static const unsigned long CLCL[19] =
+    {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; //code length code lengths
+
+struct ExtractZlib // Zlib decompression and information extraction
+{
   std::vector<ZlibBlockInfo>* zlibinfo;
-  ExtractZlib(std::vector<ZlibBlockInfo>* info) : zlibinfo(info) {};
   int error;
 
-  unsigned long readBitFromStream(size_t& bitp, const unsigned char* bits) {
+  ExtractZlib(std::vector<ZlibBlockInfo>* output) : zlibinfo(output) {};
+
+  unsigned long readBitFromStream(size_t& bitp, const unsigned char* bits)
+  {
     unsigned long result = (bits[bitp >> 3] >> (bitp & 0x7)) & 1;
     bitp++;
     return result;
   }
 
-  unsigned long readBitsFromStream(size_t& bitp, const unsigned char* bits, size_t nbits) {
+  unsigned long readBitsFromStream(size_t& bitp, const unsigned char* bits, size_t nbits)
+  {
     unsigned long result = 0;
     for(size_t i = 0; i < nbits; i++) result += (readBitFromStream(bitp, bits)) << i;
     return result;
   }
 
-  struct HuffmanTree {
-    int makeFromLengths(const std::vector<unsigned long>& bitlen, unsigned long maxbitlen) { //make tree given the lengths
+  struct HuffmanTree
+  {
+    int makeFromLengths(const std::vector<unsigned long>& bitlen, unsigned long maxbitlen)
+    { //make tree given the lengths
       unsigned long numcodes = (unsigned long)(bitlen.size()), treepos = 0, nodefilled = 0;
       std::vector<unsigned long> tree1d(numcodes), blcount(maxbitlen + 1, 0), nextcode(maxbitlen + 1, 0);
       //count number of instances of each code length
       for(unsigned long bits = 0; bits < numcodes; bits++) blcount[bitlen[bits]]++;
-      for(unsigned long bits = 1; bits <= maxbitlen; bits++) {
+      for(unsigned long bits = 1; bits <= maxbitlen; bits++)
+      {
         nextcode[bits] = (nextcode[bits - 1] + blcount[bits - 1]) << 1;
       }
       //generate all the codes
       for(unsigned long n = 0; n < numcodes; n++) if(bitlen[n] != 0) tree1d[n] = nextcode[bitlen[n]]++;
       tree2d.clear(); tree2d.resize(numcodes * 2, 32767); //32767 here means the tree2d isn't filled there yet
       for(unsigned long n = 0; n < numcodes; n++) //the codes
-      for(unsigned long i = 0; i < bitlen[n]; i++) { //the bits for this code
+      for(unsigned long i = 0; i < bitlen[n]; i++) //the bits for this code
+      {
         unsigned long bit = (tree1d[n] >> (bitlen[n] - i - 1)) & 1;
         if(treepos > numcodes - 2) return 55;
-        if(tree2d[2 * treepos + bit] == 32767) { //not yet filled in
-          if(i + 1 == bitlen[n]) {
+        if(tree2d[2 * treepos + bit] == 32767) //not yet filled in
+        {
+          if(i + 1 == bitlen[n])
+          {
             //last bit
             tree2d[2 * treepos + bit] = n;
             treepos = 0;
-          } else {
+          }
+          else
+          {
             //addresses are encoded as values > numcodes
             tree2d[2 * treepos + bit] = ++nodefilled + numcodes;
             treepos = nodefilled;
@@ -1497,7 +344,8 @@ struct ExtractZlib { // Zlib decompression and information extraction
       }
       return 0;
     }
-    int decode(bool& decoded, unsigned long& result, size_t& treepos, unsigned long bit) const { //Decodes a symbol from the tree
+    int decode(bool& decoded, unsigned long& result, size_t& treepos, unsigned long bit) const
+    { //Decodes a symbol from the tree
       unsigned long numcodes = (unsigned long)tree2d.size() / 2;
       if(treepos >= numcodes) return 11; //error: you appeared outside the codetree
       result = tree2d[2 * treepos + bit];
@@ -1509,11 +357,13 @@ struct ExtractZlib { // Zlib decompression and information extraction
     std::vector<unsigned long> tree2d;
   };
 
-  void inflate(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, size_t inpos = 0) {
+  void inflate(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, size_t inpos = 0)
+  {
     size_t bp = 0, pos = 0; //bit pointer and byte pointer
     error = 0;
     unsigned long BFINAL = 0;
-    while(!BFINAL && !error) {
+    while(!BFINAL && !error)
+    {
       size_t uncomprblockstart = pos;
       size_t bpstart = bp;
       if(bp >> 3 >= in.size()) { error = 52; return; } //error, bit pointer will jump past memory
@@ -1530,7 +380,8 @@ struct ExtractZlib { // Zlib decompression and information extraction
     }
   }
 
-  void generateFixedTrees(HuffmanTree& tree, HuffmanTree& treeD) { //get the tree of a deflated block with fixed tree
+  void generateFixedTrees(HuffmanTree& tree, HuffmanTree& treeD) //get the tree of a deflated block with fixed tree
+  {
     std::vector<unsigned long> bitlen(288, 8), bitlenD(32, 5);;
     for(size_t i = 144; i <= 255; i++) bitlen[i] = 9;
     for(size_t i = 256; i <= 279; i++) bitlen[i] = 7;
@@ -1540,19 +391,22 @@ struct ExtractZlib { // Zlib decompression and information extraction
 
   //the code tree for Huffman codes, dist codes, and code length codes
   HuffmanTree codetree, codetreeD, codelengthcodetree;
-  unsigned long huffmanDecodeSymbol(const unsigned char* in, size_t& bp, const HuffmanTree& tree, size_t inlength) {
+  unsigned long huffmanDecodeSymbol(const unsigned char* in, size_t& bp, const HuffmanTree& codetree, size_t inlength)
+  {
     //decode a single symbol from given list of bits with given code tree. return value is the symbol
     bool decoded; unsigned long ct;
-    for(size_t treepos = 0;;) {
+    for(size_t treepos = 0;;)
+    {
       if((bp & 0x07) == 0 && (bp >> 3) > inlength) { error = 10; return 0; } //error: end reached without endcode
-      error = tree.decode(decoded, ct, treepos, readBitFromStream(bp, in));
+      error = codetree.decode(decoded, ct, treepos, readBitFromStream(bp, in));
       if(error) return 0; //stop, an error happened
       if(decoded) return ct;
     }
   }
 
   void getTreeInflateDynamic(HuffmanTree& tree, HuffmanTree& treeD,
-                             const unsigned char* in, size_t& bp, size_t inlength) {
+                             const unsigned char* in, size_t& bp, size_t inlength)
+  {
     size_t bpstart = bp;
     //get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed with a known tree
     std::vector<unsigned long> bitlen(288, 0), bitlenD(32, 0);
@@ -1569,33 +423,42 @@ struct ExtractZlib { // Zlib decompression and information extraction
     for(size_t i = 0; i < codelengthcode.size(); i++) zlibinfo->back().clcl.push_back(codelengthcode[i]);
     error = codelengthcodetree.makeFromLengths(codelengthcode, 7); if(error) return;
     size_t i = 0, replength;
-    while(i < HLIT + HDIST) {
+    while(i < HLIT + HDIST)
+    {
       unsigned long code = huffmanDecodeSymbol(in, bp, codelengthcodetree, inlength); if(error) return;
       zlibinfo->back().treecodes.push_back(code); //tree symbol code
       if(code <= 15)  { if(i < HLIT) bitlen[i++] = code; else bitlenD[i++ - HLIT] = code; } //a length code
-      else if(code == 16) { //repeat previous
+      else if(code == 16) //repeat previous
+      {
         if(bp >> 3 >= inlength) { error = 50; return; } //error, bit pointer jumps past memory
         replength = 3 + readBitsFromStream(bp, in, 2);
         unsigned long value; //set value to the previous code
         if((i - 1) < HLIT) value = bitlen[i - 1];
         else value = bitlenD[i - HLIT - 1];
-        for(size_t n = 0; n < replength; n++) { //repeat this value in the next lengths
+        for(size_t n = 0; n < replength; n++) //repeat this value in the next lengths
+        {
           if(i >= HLIT + HDIST) { error = 13; return; } //error: i is larger than the amount of codes
           if(i < HLIT) bitlen[i++] = value; else bitlenD[i++ - HLIT] = value;
         }
-      } else if(code == 17) { //repeat "0" 3-10 times
+      }
+      else if(code == 17) //repeat "0" 3-10 times
+      {
         if(bp >> 3 >= inlength) { error = 50; return; } //error, bit pointer jumps past memory
         replength = 3 + readBitsFromStream(bp, in, 3);
         zlibinfo->back().treecodes.push_back(replength); //tree symbol code repetitions
-        for(size_t n = 0; n < replength; n++) { //repeat this value in the next lengths
+        for(size_t n = 0; n < replength; n++) //repeat this value in the next lengths
+        {
           if(i >= HLIT + HDIST) { error = 14; return; } //error: i is larger than the amount of codes
           if(i < HLIT) bitlen[i++] = 0; else bitlenD[i++ - HLIT] = 0;
         }
-      } else if(code == 18) { //repeat "0" 11-138 times
+      }
+      else if(code == 18) //repeat "0" 11-138 times
+      {
         if(bp >> 3 >= inlength) { error = 50; return; } //error, bit pointer jumps past memory
         replength = 11 + readBitsFromStream(bp, in, 7);
         zlibinfo->back().treecodes.push_back(replength); //tree symbol code repetitions
-        for(size_t n = 0; n < replength; n++) { //repeat this value in the next lengths
+        for(size_t n = 0; n < replength; n++) //repeat this value in the next lengths
+        {
           if(i >= HLIT + HDIST) { error = 15; return; } //error: i is larger than the amount of codes
           if(i < HLIT) bitlen[i++] = 0; else bitlenD[i++ - HLIT] = 0;
         }
@@ -1609,17 +472,19 @@ struct ExtractZlib { // Zlib decompression and information extraction
     if(error) return;
     zlibinfo->back().treebits = bp - bpstart;
     //lit/len/end symbol lengths
-    for(size_t j = 0; j < bitlen.size(); j++) zlibinfo->back().litlenlengths.push_back(bitlen[j]);
+    for(size_t i = 0; i < bitlen.size(); i++) zlibinfo->back().litlenlengths.push_back(bitlen[i]);
     //dist lengths
-    for(size_t j = 0; j < bitlenD.size(); j++) zlibinfo->back().distlengths.push_back(bitlenD[j]);
+    for(size_t i = 0; i < bitlenD.size(); i++) zlibinfo->back().distlengths.push_back(bitlenD[i]);
   }
 
   void inflateHuffmanBlock(std::vector<unsigned char>& out,
-                           const unsigned char* in, size_t& bp, size_t& pos, size_t inlength, unsigned long btype) {
+                           const unsigned char* in, size_t& bp, size_t& pos, size_t inlength, unsigned long btype)
+  {
     size_t numcodes = 0, numlit = 0, numlen = 0; //for logging
     if(btype == 1) { generateFixedTrees(codetree, codetreeD); }
     else if(btype == 2) { getTreeInflateDynamic(codetree, codetreeD, in, bp, inlength); if(error) return; }
-    for(;;) {
+    for(;;)
+    {
       unsigned long code = huffmanDecodeSymbol(in, bp, codetree, inlength); if(error) return;
       numcodes++;
       zlibinfo->back().lz77_lcode.push_back(code); //output code
@@ -1629,13 +494,15 @@ struct ExtractZlib { // Zlib decompression and information extraction
       zlibinfo->back().lz77_lvalue.push_back(0);
       zlibinfo->back().lz77_dvalue.push_back(0);
 
-      if(code == 256) {
-        break; //end code
-      } else if(code <= 255) { //literal symbol
+      if(code == 256) break; //end code
+      else if(code <= 255) //literal symbol
+      {
         out.push_back((unsigned char)(code));
         pos++;
         numlit++;
-      } else if(code >= 257 && code <= 285) { //length code
+      }
+      else if(code >= 257 && code <= 285) //length code
+      {
         size_t length = LENBASE[code - 257], numextrabits = LENEXTRA[code - 257];
         if((bp >> 3) >= inlength) { error = 51; return; } //error, bit pointer will jump past memory
         length += readBitsFromStream(bp, in, numextrabits);
@@ -1645,7 +512,8 @@ struct ExtractZlib { // Zlib decompression and information extraction
         if((bp >> 3) >= inlength) { error = 51; return; } //error, bit pointer will jump past memory
         dist += readBitsFromStream(bp, in, numextrabitsD);
         size_t start = pos, back = start - dist; //backwards
-        for(size_t i = 0; i < length; i++) {
+        for(size_t i = 0; i < length; i++)
+        {
           out.push_back(out[back++]);
           pos++;
           if(back >= start) back = start - dist;
@@ -1663,21 +531,24 @@ struct ExtractZlib { // Zlib decompression and information extraction
   }
 
   void inflateNoCompression(std::vector<unsigned char>& out,
-                            const unsigned char* in, size_t& bp, size_t& pos, size_t inlength) {
+                            const unsigned char* in, size_t& bp, size_t& pos, size_t inlength)
+  {
     while((bp & 0x7) != 0) bp++; //go to first boundary of byte
     size_t p = bp / 8;
     if(p >= inlength - 4) { error = 52; return; } //error, bit pointer will jump past memory
-    unsigned long LEN = in[p] + 256u * in[p + 1], NLEN = in[p + 2] + 256u * in[p + 3]; p += 4;
+    unsigned long LEN = in[p] + 256 * in[p + 1], NLEN = in[p + 2] + 256 * in[p + 3]; p += 4;
     if(LEN + NLEN != 65535) { error = 21; return; } //error: NLEN is not one's complement of LEN
     if(p + LEN > inlength) { error = 23; return; } //error: reading outside of in buffer
-    for(unsigned long n = 0; n < LEN; n++) {
+    for(unsigned long n = 0; n < LEN; n++)
+    {
       out.push_back(in[p++]); //read LEN bytes of literal data
       pos++;
     }
     bp = p * 8;
   }
 
-  int decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in) { //returns error value
+  int decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in) //returns error value
+  {
     if(in.size() < 2) { return 53; } //error, size of zlib data too small
     //error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way
     if((in[0] * 256 + in[1]) % 31 != 0) { return 24; }
@@ -1691,11 +562,15 @@ struct ExtractZlib { // Zlib decompression and information extraction
   }
 };
 
-struct ExtractPNG { //PNG decoding and information extraction
+struct ExtractPNG //PNG decoding and information extraction
+{
   std::vector<ZlibBlockInfo>* zlibinfo;
-  ExtractPNG(std::vector<ZlibBlockInfo>* info) : zlibinfo(info) {};
   int error;
-  void decode(const unsigned char* in, size_t size) {
+
+  ExtractPNG(std::vector<ZlibBlockInfo>* output) : zlibinfo(output) {};
+
+  void decode(const unsigned char* in, size_t size)
+  {
     error = 0;
     if(size == 0 || in == 0) { error = 48; return; } //the given data is empty
     readPngHeader(&in[0], size); if(error) return;
@@ -1704,7 +579,8 @@ struct ExtractPNG { //PNG decoding and information extraction
     bool IEND = false;
     //loop through the chunks, ignoring unknown chunks and stopping at IEND chunk.
     //IDAT data is put at the start of the in buffer
-    while(!IEND) {
+    while(!IEND)
+    {
       //error: size of the in buffer too small to contain next chunk
       if(pos + 8 >= size) { error = 30; return; }
       size_t chunkLength = read32bitInt(&in[pos]); pos += 4;
@@ -1712,13 +588,18 @@ struct ExtractPNG { //PNG decoding and information extraction
       //error: size of the in buffer too small to contain next chunk
       if(pos + chunkLength >= size) { error = 35; return; }
       //IDAT chunk, containing compressed image data
-      if(in[pos + 0] == 'I' && in[pos + 1] == 'D' && in[pos + 2] == 'A' && in[pos + 3] == 'T') {
+      if(in[pos + 0] == 'I' && in[pos + 1] == 'D' && in[pos + 2] == 'A' && in[pos + 3] == 'T')
+      {
         idat.insert(idat.end(), &in[pos + 4], &in[pos + 4 + chunkLength]);
         pos += (4 + chunkLength);
-      } else if(in[pos + 0] == 'I' && in[pos + 1] == 'E' && in[pos + 2] == 'N' && in[pos + 3] == 'D') {
+      }
+      else if(in[pos + 0] == 'I' && in[pos + 1] == 'E' && in[pos + 2] == 'N' && in[pos + 3] == 'D')
+      {
           pos += 4;
           IEND = true;
-      } else { //it's not an implemented chunk type, so ignore it: skip over the data
+      }
+      else //it's not an implemented chunk type, so ignore it: skip over the data
+      {
         pos += (chunkLength + 4); //skip 4 letters and uninterpreted data of unimplemented chunk
       }
       pos += 4; //step over CRC (which is ignored)
@@ -1730,7 +611,8 @@ struct ExtractPNG { //PNG decoding and information extraction
   }
 
   //read the information from the header and store it in the Info
-  void readPngHeader(const unsigned char* in, size_t inlength) {
+  void readPngHeader(const unsigned char* in, size_t inlength)
+  {
     if(inlength < 29) { error = 27; return; } //error: the data length is smaller than the length of the header
     if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71
     || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10) { error = 28; return; } //no PNG signature
@@ -1738,28 +620,33 @@ struct ExtractPNG { //PNG decoding and information extraction
     if(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R') { error = 29; return; }
   }
 
-  unsigned long readBitFromReversedStream(size_t& bitp, const unsigned char* bits) {
+  unsigned long readBitFromReversedStream(size_t& bitp, const unsigned char* bits)
+  {
     unsigned long result = (bits[bitp >> 3] >> (7 - (bitp & 0x7))) & 1;
     bitp++;
     return result;
   }
 
-  unsigned long readBitsFromReversedStream(size_t& bitp, const unsigned char* bits, unsigned long nbits) {
+  unsigned long readBitsFromReversedStream(size_t& bitp, const unsigned char* bits, unsigned long nbits)
+  {
     unsigned long result = 0;
     for(size_t i = nbits - 1; i < nbits; i--) result += ((readBitFromReversedStream(bitp, bits)) << i);
     return result;
   }
 
-  void setBitOfReversedStream(size_t& bitp, unsigned char* bits, unsigned long bit) {
+  void setBitOfReversedStream(size_t& bitp, unsigned char* bits, unsigned long bit)
+  {
     bits[bitp >> 3] |=  (bit << (7 - (bitp & 0x7))); bitp++;
   }
 
-  unsigned long read32bitInt(const unsigned char* buffer) {
-    return (unsigned int)((buffer[0] << 24u) | (buffer[1] << 16u) | (buffer[2] << 8u) | buffer[3]);
+  unsigned long read32bitInt(const unsigned char* buffer)
+  {
+    return (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3];
   }
 };
 
-void extractZlibInfo(std::vector<ZlibBlockInfo>& zlibinfo, const std::vector<unsigned char>& in) {
+void extractZlibInfo(std::vector<ZlibBlockInfo>& zlibinfo, const std::vector<unsigned char>& in)
+{
   ExtractPNG decoder(&zlibinfo);
   decoder.decode(&in[0], in.size());
 
diff --git a/src/zopflipng/lodepng/lodepng_util.h b/src/zopflipng/lodepng/lodepng_util.h
index 97fd804..b18ac71 100644
--- a/src/zopflipng/lodepng/lodepng_util.h
+++ b/src/zopflipng/lodepng/lodepng_util.h
@@ -1,7 +1,7 @@
 /*
 LodePNG Utils
 
-Copyright (c) 2005-2020 Lode Vandevenne
+Copyright (c) 2005-2012 Lode Vandevenne
 
 This software is provided 'as-is', without any express or implied
 warranty. In no event will the authors be held liable for any damages
@@ -25,17 +25,16 @@ freely, subject to the following restrictions:
 
 /*
 Extra C++ utilities for LodePNG, for convenience.
-Not part of the stable API of lodepng, more loose separate utils.
 */
 
-#ifndef LODEPNG_UTIL_H
-#define LODEPNG_UTIL_H
-
 #include <string>
 #include <vector>
 #include "lodepng.h"
 
-namespace lodepng {
+#pragma once
+
+namespace lodepng
+{
 
 /*
 Returns info from the header of the PNG by value, purely for convenience.
@@ -115,147 +114,11 @@ is the second half of the 3th byte, in big endian (PNG's endian order).
 */
 int getPaletteValue(const unsigned char* data, size_t i, int bits);
 
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-
-/* Similar to convertRGBModel, but the 'to' model is sRGB. The pixel format
-of in and out must be the same and is given by state_in->info_raw. An
-error may occur if the pixel format cannot contain the new colors (e.g. palette) */
-unsigned convertToSrgb(unsigned char* out, const unsigned char* in,
-                       unsigned w, unsigned h,
-                       const LodePNGState* state_in);
-
-/* Similar to convertRGBModel, but the 'from' model is sRGB. The pixel format
-of in and out must be the same and is given by state_out->info_raw. An
-error may occur if the pixel format cannot contain the new colors (e.g. palette) */
-unsigned convertFromSrgb(unsigned char* out, const unsigned char* in,
-                         unsigned w, unsigned h,
-                         const LodePNGState* state_out);
-
-/*
-Converts from one RGB model to another RGB model.
-Similar to calling convertToXYZ followed by convertFromXYZ, but may be
-more efficient and more precise (e.g. no computation needed when both models
-are the same). See their documentation for more info.
-
-Parameters:
-
-*) out: output pixel data
-*) in: input pixel data
-*) w, h: image size
-*) state_out: output RGB color model in state_out->info_png and byte format in state_out->info_raw.
-*) state_in: output RGB color model in state_in->info_png and byte format in state_in->info_raw
-*) return value: 0 if ok, positive value if error
-*) rendering_intent: 1 for relative, 3 for absolute, should be relative for standard behavior.
-   See description at convertFromXYZ.
-*/
-unsigned convertRGBModel(unsigned char* out, const unsigned char* in,
-                         unsigned w, unsigned h,
-                         const LodePNGState* state_out,
-                         const LodePNGState* state_in,
-                         unsigned rendering_intent);
-
-/*
-Converts the RGB color to the absolute XYZ color space given the RGB color profile
-chunks in the PNG info.
-
-Color space here refers to the different possible RGB spaces with different
-possible chromaticities or whitepoint and XYZ color from colorimetry, not the
-LodePNGColorType that describes the byte based encoding.
-
-You need this function only if the PNG could contain data in an arbitrary RGB
-color space and you wish to output to a display or format that does not provide
-color management for you (so you need to convert rather than pass on the profile
-to it) but expects a certain RGB format (e.g. sRGB). See the background info below.
-
-Supports the gAMA, cHRM, sRGB and iCCP colorimetry chunks. If no colometry chunks are present
-(that is, in state->info_png, the fields gama_defined, chrm_defined, srgb_defined and
-iccp_defined are all 0), it assumes the format is sRGB.
-For more information, see the chunk specifications in the PNG specification.
-
-Some background:
-
-A PNG image contains RGB data inside, but this data may use a specific RGB model (by default sRGB but
-different if colorimetry chunks are given).
-The computer display and/or operating system can have another RGB model (typically sRGB, or wider gamut
-or HDR formats).
-
-The PNG chunks describe what format the data inside has, not the format of the display. To correctly
-display a PNG image on a display, a conversion is needed from the PNG model to the display model if their
-models differ. Some options to achieve that are:
-*) If your use case already supports color management on its own, you can give it the RGB values straight from
-   the PNG image and give it the information from the cHRM, gAMA, sRGB and iCCP chunks (which you can find
-   in the LodePNGInfo), and the color management should then handle it correctly for you. You don't need
-   this function here in that case.
-*) If your use case does not support color management, you may instead want to give it the RGB values in a
-   consistent color model, such as sRGB, but the PNG does not necessarily have it in this desired model.
-   In that case, use the function below (or a similar one from a CMS library if you prefer) to convert it to
-   the absolute color space XYZ, and then you can convert it to the target RGB with the counterpart convertFromXYZ
-   further below.
-
-Parameters:
-
-*) out: 4 floats per pixel, X,Y,Z,alpha color format, in range 0-1 (normally, not clipped if beyond), must
-   be allocated to have 4 * w * h floats available.
-*) whitepoint: output argument, the whitepoint the original RGB data used, given in absolute XYZ. Needed for
-   relative rendering intents: give these values to counterpart function convertFromXYZ.
-*) in: input RGB color, in byte format given by state->info_raw and RGB color profile given by info->info_png
-*) w, h: image size
-*) state (when using a LodePNG decode function that takes a LodePNGState parameter, can directly use that one):
-   state->info_png: PNG info with possibly an RGB color model in cHRM,gAMA and/or sRGB chunks
-   state->info_raw: byte format of in (amount of channels, bit depth)
-*) return value: 0 if ok, positive value if error
-*/
-unsigned convertToXYZ(float* out, float whitepoint[3],
-                      const unsigned char* in, unsigned w, unsigned h,
-                      const LodePNGState* state);
-
-/*
-Same as convertToXYZ but takes floating point input. Slower.
-The main black..white range in 0..1. Does not clip values that are outside that range.
-*/
-unsigned convertToXYZFloat(float* out, float whitepoint[3], const float* in,
-                           unsigned w, unsigned h, const LodePNGState* state);
-
-/*
-Converts XYZ to RGB in the RGB color model given by info and byte format by mode_out.
-If info has no coloremtry chunks, converts to sRGB.
-Parameters:
-*) out: output color in byte format given by state->info_raw and RGB color profile given
-   by info->info_png. Must have enough bytes allocated to contain pixels in the given byte format.
-*) in: 4 floats per pixel, X,Y,Z,alpha color format, in range 0-1 (normally).
-*) whitepoint: input argument, the original whitepoint in absolute XYZ that the pixel data
-   in "in" had back when it was in a previous RGB space. Needed to preserve the whitepoint
-   in the new target RGB space for relative rendering intent.
-*) rendering_intent: the desired rendering intent, with numeric meaning matching the
-   values used by ICC: 0=perceptual, 1=relative, 2=saturation, 3=absolute.
-   Should be 1 for normal use cases, it adapts white to match that of different RGB
-   models which is the best practice. Using 3 may change the color of white and may
-   turn grayscale into colors of a certain tone. Using 0 and 2 will have the same
-   effect as 1 because using those requires more data than the matrix-based RGB profiles
-   supporetd here have.
-*) w, h: image size
-*) state:
-   state->info_png: PNG info with possibly an RGB color profile in cHRM,gAMA and/or sRGB chunks
-   state->info_raw: byte format of out (amount of channels, bit depth)
-*) return value: 0 if ok, positive value if error
-*/
-unsigned convertFromXYZ(unsigned char* out, const float* in, unsigned w, unsigned h,
-                        const LodePNGState* state,
-                        const float whitepoint[3], unsigned rendering_intent);
-
-/*
-Same as convertFromXYZ but outputs the RGB colors in floating point.
-The main black..white range in 0..1. Does not clip values that are outside that range.
-*/
-unsigned convertFromXYZFloat(float* out, const float* in, unsigned w, unsigned h,
-                             const LodePNGState* state,
-                             const float whitepoint[3], unsigned rendering_intent);
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-
 /*
 The information for extractZlibInfo.
 */
-struct ZlibBlockInfo {
+struct ZlibBlockInfo
+{
   int btype; //block type (0-2)
   size_t compressedbits; //size of compressed block in bits
   size_t uncompressedbytes; //size of uncompressed block in bytes
@@ -286,5 +149,3 @@ struct ZlibBlockInfo {
 void extractZlibInfo(std::vector<ZlibBlockInfo>& zlibinfo, const std::vector<unsigned char>& in);
 
 } // namespace lodepng
-
-#endif /*LODEPNG_UTIL_H inclusion guard*/
diff --git a/src/zopflipng/zopflipng_bin.cc b/src/zopflipng/zopflipng_bin.cc
index ea764b9..3faea06 100644
--- a/src/zopflipng/zopflipng_bin.cc
+++ b/src/zopflipng/zopflipng_bin.cc
@@ -21,7 +21,6 @@
 #include <stdio.h>
 
 #include "lodepng/lodepng.h"
-#include "lodepng/lodepng_util.h"
 #include "zopflipng_lib.h"
 
 // Returns directory path (including last slash) in dir, filename without
@@ -48,17 +47,7 @@ void GetFileNameParts(const std::string& filename,
   }
 }
 
-// Returns whether the file exists and we have read permissions.
-bool FileExists(const std::string& filename) {
-  FILE* file = fopen(filename.c_str(), "rb");
-  if (file) {
-    fclose(file);
-    return true;
-  }
-  return false;
-}
-
-// Returns the size of the file, if it exists and we have read permissions.
+// Returns the size of the file
 size_t GetFileSize(const std::string& filename) {
   size_t size;
   FILE* file = fopen(filename.c_str(), "rb");
@@ -79,7 +68,8 @@ void ShowHelp() {
          " previous run and not overwritten if its filesize is smaller.\n"
          "\n"
          "Options:\n"
-         "-m: compress more: use more iterations (depending on file size)\n"
+         "-m: compress more: use more iterations (depending on file size) and"
+         " use block split strategy 3\n"
          "--prefix=[fileprefix]: Adds a prefix to output filenames. May also"
          " contain a directory path. When using a prefix, multiple input files"
          " can be given and the output filenames are generated with the"
@@ -103,7 +93,8 @@ void ShowHelp() {
          "--iterations=[number]: number of iterations, more iterations makes it"
          " slower but provides slightly better compression. Default: 15 for"
          " small files, 5 for large files.\n"
-         "--splitting=[0-3]: ignored, left for backwards compatibility\n"
+         "--splitting=[0-3]: block split strategy:"
+         " 0=none, 1=first, 2=last, 3=try both and take the best\n"
          "--filters=[types]: filter strategies to try:\n"
          " 0-4: give all scanlines PNG filter type 0-4\n"
          " m: minimum sum\n"
@@ -119,19 +110,9 @@ void ShowHelp() {
          " set of filters to try is --filters=0me.\n"
          "--keepchunks=nAME,nAME,...: keep metadata chunks with these names"
          " that would normally be removed, e.g. tEXt,zTXt,iTXt,gAMA, ... \n"
-         " Due to adding extra data, this increases the result size. Keeping"
-         " bKGD or sBIT chunks may cause additional worse compression due to"
-         " forcing a certain color type, it is advised to not keep these for"
-         " web images because web browsers do not use these chunks. By default"
-         " ZopfliPNG only keeps (and losslessly modifies) the following chunks"
-         " because they are essential: IHDR, PLTE, tRNS, IDAT and IEND.\n"
-         "--keepcolortype: Keep original color type (RGB, RGBA, gray,"
-         " gray+alpha or palette) and bit depth of the PNG.\n"
-         " This results in a loss of compression opportunities, e.g. it will no"
-         " longer convert a 4-channel RGBA image to 2-channel gray+alpha if the"
-         " image only had translucent gray pixels.\n"
-         " May be useful if a device does not support decoding PNGs of a"
-         " particular color type.\n"
+         " Due to adding extra data, this increases the result size. By default"
+         " ZopfliPNG only keeps the following chunks because they are"
+         " essential: IHDR, PLTE, tRNS, IDAT and IEND.\n"
          "\n"
          "Usage examples:\n"
          "Optimize a file and overwrite if smaller: zopflipng infile.png"
@@ -139,8 +120,8 @@ void ShowHelp() {
          "Compress more: zopflipng -m infile.png outfile.png\n"
          "Optimize multiple files: zopflipng --prefix a.png b.png c.png\n"
          "Compress really good and trying all filter strategies: zopflipng"
-         " --iterations=500 --filters=01234mepb --lossy_8bit"
-         " --lossy_transparent infile.png outfile.png\n");
+         " --iterations=500 --splitting=3 --filters=01234mepb"
+         " --lossy_8bit --lossy_transparent infile.png outfile.png\n");
 }
 
 void PrintSize(const char* label, size_t size) {
@@ -170,6 +151,7 @@ int main(int argc, char *argv[]) {
   std::string prefix = "zopfli_";  // prefix for output filenames
 
   std::vector<std::string> files;
+  std::vector<char> options;
   for (int i = 1; i < argc; i++) {
     std::string arg = argv[i];
     if (arg[0] == '-' && arg.size() > 1 && arg[1] != '-') {
@@ -182,6 +164,7 @@ int main(int argc, char *argv[]) {
         } else if (c == 'm') {
           png_options.num_iterations *= 4;
           png_options.num_iterations_large *= 4;
+          png_options.block_split_strategy = 3;
         } else if (c == 'q') {
           png_options.use_zopfli = false;
         } else if (c == 'h') {
@@ -199,8 +182,6 @@ int main(int argc, char *argv[]) {
       int num = atoi(value.c_str());
       if (name == "--always_zopflify") {
         always_zopflify = true;
-      } else if (name == "--verbose") {
-        png_options.verbose = true;
       } else if (name == "--lossy_transparent") {
         png_options.lossy_transparent = true;
       } else if (name == "--lossy_8bit") {
@@ -210,7 +191,8 @@ int main(int argc, char *argv[]) {
         png_options.num_iterations = num;
         png_options.num_iterations_large = num;
       } else if (name == "--splitting") {
-        // ignored
+        if (num < 0 || num > 3) num = 1;
+        png_options.block_split_strategy = num;
       } else if (name == "--filters") {
         for (size_t j = 0; j < value.size(); j++) {
           ZopfliPNGFilterStrategy strategy = kStrategyZero;
@@ -246,8 +228,6 @@ int main(int argc, char *argv[]) {
                  " --keepchunks=gAMA,cHRM,sRGB,iCCP\n");
           return 0;
         }
-      } else if (name == "--keepcolortype") {
-        png_options.keep_colortype = true;
       } else if (name == "--prefix") {
         use_prefix = true;
         if (!value.empty()) prefix = value;
@@ -307,77 +287,26 @@ int main(int argc, char *argv[]) {
     lodepng::State inputstate;
     std::vector<unsigned char> resultpng;
 
-    error = lodepng::load_file(origpng, files[i]);
-    if (!error) {
-      error = ZopfliPNGOptimize(origpng, png_options,
-                                png_options.verbose, &resultpng);
-    }
+    lodepng::load_file(origpng, files[i]);
+    error = ZopfliPNGOptimize(origpng, png_options, true, &resultpng);
 
     if (error) {
-      if (error == 1) {
-        printf("Decoding error\n");
-      } else {
-        printf("Decoding error %u: %s\n", error, lodepng_error_text(error));
-      }
+      printf("Decoding error %i: %s\n", error, lodepng_error_text(error));
     }
 
     // Verify result, check that the result causes no decoding errors
     if (!error) {
-      error = lodepng::decode(image, w, h, resultpng);
-      if (!error) {
-        std::vector<unsigned char> origimage;
-        unsigned origw, origh;
-        lodepng::decode(origimage, origw, origh, origpng);
-        if (origw != w || origh != h || origimage.size() != image.size()) {
-          error = 1;
-        } else {
-          for (size_t i = 0; i < image.size(); i += 4) {
-            bool same_alpha = image[i + 3] == origimage[i + 3];
-            bool same_rgb =
-                (png_options.lossy_transparent && image[i + 3] == 0) ||
-                (image[i + 0] == origimage[i + 0] &&
-                 image[i + 1] == origimage[i + 1] &&
-                 image[i + 2] == origimage[i + 2]);
-            if (!same_alpha || !same_rgb) {
-              error = 1;
-              break;
-            }
-          }
-        }
-      }
-      if (error) {
-        printf("Error: verification of result failed, keeping original."
-               " Error: %u.\n", error);
-        // Reset the error to 0, instead set output back to the original. The
-        // input PNG is valid, zopfli failed on it so treat as if it could not
-        // make it smaller.
-        error = 0;
-        resultpng = origpng;
-      }
+      error = lodepng::decode(image, w, h, inputstate, resultpng);
+      if (error) printf("Error: verification of result failed.\n");
     }
 
     if (error) {
+      printf("There was an error\n");
       total_errors++;
     } else {
-      size_t origsize = origpng.size();
+      size_t origsize = GetFileSize(files[i]);
       size_t resultsize = resultpng.size();
 
-      if (!png_options.keepchunks.empty()) {
-        std::vector<std::string> names;
-        std::vector<size_t> sizes;
-        lodepng::getChunkInfo(names, sizes, resultpng);
-        for (size_t i = 0; i < names.size(); i++) {
-          if (names[i] == "bKGD" || names[i] == "sBIT") {
-            printf("Forced to keep original color type due to keeping bKGD or"
-                   " sBIT chunk. Try without --keepchunks for better"
-                   " compression.\n");
-            break;
-          }
-        }
-      }
-
-      PrintSize("Input size", origsize);
-      PrintResultSize("Result size", origsize, resultsize);
       if (resultsize < origsize) {
         printf("Result is smaller\n");
       } else if (resultsize == origsize) {
@@ -387,6 +316,8 @@ int main(int argc, char *argv[]) {
             ? "Original was smaller\n"
             : "Preserving original PNG since it was smaller\n");
       }
+      PrintSize("Input size", origsize);
+      PrintResultSize("Result size", origsize, resultsize);
 
       std::string out_filename = user_out_filename;
       if (use_prefix) {
@@ -401,29 +332,28 @@ int main(int argc, char *argv[]) {
       if (resultpng.size() < origsize) total_files_smaller++;
       else if (resultpng.size() == origsize) total_files_equal++;
 
-      if (!always_zopflify && resultpng.size() >= origsize) {
-        // Set output file to input since zopfli didn't improve it.
+      if (!always_zopflify && resultpng.size() > origsize) {
+        // Set output file to input since input was smaller.
         resultpng = origpng;
       }
 
-      bool already_exists = FileExists(out_filename);
       size_t origoutfilesize = GetFileSize(out_filename);
+      bool already_exists = true;
+      if (origoutfilesize == 0) already_exists = false;
 
       // When using a prefix, and the output file already exist, assume it's
       // from a previous run. If that file is smaller, it may represent a
       // previous run with different parameters that gave a smaller PNG image.
-      // This also applies when not using prefix but same input as output file.
       // In that case, do not overwrite it. This behaviour can be removed by
       // adding the always_zopflify flag.
       bool keep_earlier_output_file = already_exists &&
-          resultpng.size() >= origoutfilesize && !always_zopflify &&
-          (use_prefix || !different_output_name);
+          resultpng.size() >= origoutfilesize && !always_zopflify && use_prefix;
 
       if (keep_earlier_output_file) {
         // An output file from a previous run is kept, add that files' size
         // to the output size statistics.
         total_out_size += origoutfilesize;
-        if (use_prefix) {
+        if (different_output_name) {
           printf(resultpng.size() == origoutfilesize
               ? "File not written because a previous run was as good.\n"
               : "File not written because a previous run was better.\n");
@@ -442,11 +372,8 @@ int main(int argc, char *argv[]) {
         }
         if (confirmed) {
           if (!dryrun) {
-            if (lodepng::save_file(resultpng, out_filename) != 0) {
-              printf("Failed to write to file %s\n", out_filename.c_str());
-            } else {
-              total_files_saved++;
-            }
+            lodepng::save_file(resultpng, out_filename);
+            total_files_saved++;
           }
           total_out_size += resultpng.size();
         } else {
diff --git a/src/zopflipng/zopflipng_lib.cc b/src/zopflipng/zopflipng_lib.cc
index 15188db..c310790 100644..100755
--- a/src/zopflipng/zopflipng_lib.cc
+++ b/src/zopflipng/zopflipng_lib.cc
@@ -19,10 +19,7 @@
 
 #include "zopflipng_lib.h"
 
-#include <errno.h>
 #include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 #include <set>
 #include <vector>
 
@@ -31,11 +28,9 @@
 #include "../zopfli/deflate.h"
 
 ZopfliPNGOptions::ZopfliPNGOptions()
-  : verbose(false)
-  , lossy_transparent(false)
+  : lossy_transparent(false)
   , lossy_8bit(false)
   , auto_filter_strategy(true)
-  , keep_colortype(false)
   , use_zopfli(true)
   , num_iterations(15)
   , num_iterations_large(5)
@@ -53,18 +48,40 @@ unsigned CustomPNGDeflate(unsigned char** out, size_t* outsize,
   ZopfliOptions options;
   ZopfliInitOptions(&options);
 
-  options.verbose = png_options->verbose;
   options.numiterations = insize < 200000
       ? png_options->num_iterations : png_options->num_iterations_large;
 
-  ZopfliDeflate(&options, 2 /* Dynamic */, 1, in, insize, &bp, out, outsize);
+  if (png_options->block_split_strategy == 3) {
+    // Try both block splitting first and last.
+    unsigned char* out2 = 0;
+    size_t outsize2 = 0;
+    options.blocksplittinglast = 0;
+    ZopfliDeflate(&options, 2 /* Dynamic */, 1, in, insize, &bp, out, outsize);
+    bp = 0;
+    options.blocksplittinglast = 1;
+    ZopfliDeflate(&options, 2 /* Dynamic */, 1,
+                  in, insize, &bp, &out2, &outsize2);
+
+    if (outsize2 < *outsize) {
+      free(*out);
+      *out = out2;
+      *outsize = outsize2;
+      printf("Block splitting last was better\n");
+    } else {
+      free(out2);
+    }
+  } else {
+    if (png_options->block_split_strategy == 0) options.blocksplitting = 0;
+    options.blocksplittinglast = png_options->block_split_strategy == 2;
+    ZopfliDeflate(&options, 2 /* Dynamic */, 1, in, insize, &bp, out, outsize);
+  }
 
   return 0;  // OK
 }
 
 // Returns 32-bit integer value for RGBA color.
 static unsigned ColorIndex(const unsigned char* color) {
-  return color[0] + 256u * color[1] + 65536u * color[2] + 16777216u * color[3];
+  return color[0] + 256u * color[1] + 65536u * color[1] + 16777216u * color[3];
 }
 
 // Counts amount of colors in the image, up to 257. If transparent_counts_as_one
@@ -111,7 +128,6 @@ void LossyOptimizeTransparent(lodepng::State* inputstate, unsigned char* image,
         r = image[i * 4 + 0];
         g = image[i * 4 + 1];
         b = image[i * 4 + 2];
-        break;
       }
     }
   }
@@ -159,7 +175,7 @@ void LossyOptimizeTransparent(lodepng::State* inputstate, unsigned char* image,
 // Returns 0 if ok, other value for error
 unsigned TryOptimize(
     const std::vector<unsigned char>& image, unsigned w, unsigned h,
-    const lodepng::State& inputstate, bool bit16, bool keep_colortype,
+    const lodepng::State& inputstate, bool bit16,
     const std::vector<unsigned char>& origfile,
     ZopfliPNGFilterStrategy filterstrategy,
     bool use_zopfli, int windowsize, const ZopfliPNGOptions* png_options,
@@ -173,10 +189,6 @@ unsigned TryOptimize(
     state.encoder.zlibsettings.custom_context = png_options;
   }
 
-  if (keep_colortype) {
-    state.encoder.auto_convert = 0;
-    lodepng_color_mode_copy(&state.info_png.color, &inputstate.info_png.color);
-  }
   if (inputstate.info_png.color.colortype == LCT_PALETTE) {
     // Make it preserve the original palette order
     lodepng_color_mode_copy(&state.info_raw, &inputstate.info_png.color);
@@ -204,20 +216,16 @@ unsigned TryOptimize(
       state.encoder.filter_strategy = LFS_BRUTE_FORCE;
       break;
     case kStrategyOne:
-      state.encoder.filter_strategy = LFS_ONE;
-      break;
     case kStrategyTwo:
-      state.encoder.filter_strategy = LFS_TWO;
-      break;
     case kStrategyThree:
-      state.encoder.filter_strategy = LFS_THREE;
-      break;
     case kStrategyFour:
-      state.encoder.filter_strategy = LFS_FOUR;
+      // Set the filters of all scanlines to that number.
+      filters.resize(h, filterstrategy);
+      state.encoder.filter_strategy = LFS_PREDEFINED;
+      state.encoder.predefined_filters = &filters[0];
       break;
     case kStrategyPredefined:
       lodepng::getFilterTypes(filters, origfile);
-      if (filters.size() != h) return 1;  // Error getting filters
       state.encoder.filter_strategy = LFS_PREDEFINED;
       state.encoder.predefined_filters = &filters[0];
       break;
@@ -232,25 +240,24 @@ unsigned TryOptimize(
 
   // For very small output, also try without palette, it may be smaller thanks
   // to no palette storage overhead.
-  if (!error && out->size() < 4096 && !keep_colortype) {
-    if (lodepng::getPNGHeaderInfo(*out).color.colortype == LCT_PALETTE) {
-      LodePNGColorStats stats;
-      lodepng_color_stats_init(&stats);
-      lodepng_compute_color_stats(&stats, &image[0], w, h, &state.info_raw);
-      // Too small for tRNS chunk overhead.
-      if (w * h <= 16 && stats.key) stats.alpha = 1;
-      state.encoder.auto_convert = 0;
-      state.info_png.color.colortype = (stats.alpha ? LCT_RGBA : LCT_RGB);
-      state.info_png.color.bitdepth = 8;
-      state.info_png.color.key_defined = (stats.key && !stats.alpha);
-      if (state.info_png.color.key_defined) {
-        state.info_png.color.key_defined = 1;
-        state.info_png.color.key_r = (stats.key_r & 255u);
-        state.info_png.color.key_g = (stats.key_g & 255u);
-        state.info_png.color.key_b = (stats.key_b & 255u);
+  if (!error && out->size() < 4096) {
+    lodepng::State teststate;
+    std::vector<unsigned char> temp;
+    lodepng::decode(temp, w, h, teststate, *out);
+    LodePNGColorMode& color = teststate.info_png.color;
+    if (color.colortype == LCT_PALETTE) {
+      std::vector<unsigned char> out2;
+      state.encoder.auto_convert = LAC_ALPHA;
+      bool grey = true;
+      for (size_t i = 0; i < color.palettesize; i++) {
+        if (color.palette[i * 4 + 0] != color.palette[i * 4 + 2]
+            || color.palette[i * 4 + 1] != color.palette[i * 4 + 2]) {
+          grey = false;
+          break;
+        }
       }
+      if (grey) state.info_png.color.colortype = LCT_GREY_ALPHA;
 
-      std::vector<unsigned char> out2;
       error = lodepng::encode(out2, image, w, h, state);
       if (out2.size() < out->size()) out->swap(out2);
     }
@@ -269,8 +276,7 @@ unsigned TryOptimize(
 // filter type.
 unsigned AutoChooseFilterStrategy(const std::vector<unsigned char>& image,
                                   unsigned w, unsigned h,
-                                  const lodepng::State& inputstate,
-                                  bool bit16, bool keep_colortype,
+                                  const lodepng::State& inputstate, bool bit16,
                                   const std::vector<unsigned char>& origfile,
                                   int numstrategies,
                                   ZopfliPNGFilterStrategy* strategies,
@@ -287,9 +293,8 @@ unsigned AutoChooseFilterStrategy(const std::vector<unsigned char>& image,
 
   for (int i = 0; i < numstrategies; i++) {
     out.clear();
-    unsigned error = TryOptimize(image, w, h, inputstate, bit16, keep_colortype,
-                                 origfile, strategies[i], false, windowsize, 0,
-                                 &out);
+    unsigned error = TryOptimize(image, w, h, inputstate, bit16, origfile,
+                                 strategies[i], false, windowsize, 0, &out);
     if (error) return error;
     if (bestsize == 0 || out.size() < bestsize) {
       bestsize = out.size();
@@ -304,27 +309,6 @@ unsigned AutoChooseFilterStrategy(const std::vector<unsigned char>& image,
   return 0;  /* OK */
 }
 
-// Outputs the intersection of keepnames and non-essential chunks which are in
-// the PNG image.
-void ChunksToKeep(const std::vector<unsigned char>& origpng,
-                  const std::vector<std::string>& keepnames,
-                  std::set<std::string>* result) {
-  std::vector<std::string> names[3];
-  std::vector<std::vector<unsigned char> > chunks[3];
-
-  lodepng::getChunks(names, chunks, origpng);
-
-  for (size_t i = 0; i < 3; i++) {
-    for (size_t j = 0; j < names[i].size(); j++) {
-      for (size_t k = 0; k < keepnames.size(); k++) {
-        if (keepnames[k] == names[i][j]) {
-          result->insert(names[i][j]);
-        }
-      }
-    }
-  }
-}
-
 // Keeps chunks with given names from the original png by literally copying them
 // into the new png
 void KeepChunks(const std::vector<unsigned char>& origpng,
@@ -380,41 +364,15 @@ int ZopfliPNGOptimize(const std::vector<unsigned char>& origpng,
   lodepng::State inputstate;
   error = lodepng::decode(image, w, h, inputstate, origpng);
 
-  bool keep_colortype = png_options.keep_colortype;
-
-  if (!png_options.keepchunks.empty()) {
-    // If the user wants to keep the non-essential chunks bKGD or sBIT, the
-    // input color type has to be kept since the chunks format depend on it.
-    // This may severely hurt compression if it is not an ideal color type.
-    // Ideally these chunks should not be kept for web images. Handling of bKGD
-    // chunks could be improved by changing its color type but not done yet due
-    // to its additional complexity, for sBIT such improvement is usually not
-    // possible.
-    std::set<std::string> keepchunks;
-    ChunksToKeep(origpng, png_options.keepchunks, &keepchunks);
-    if (keepchunks.count("bKGD") || keepchunks.count("sBIT")) {
-      if (!keep_colortype && verbose) {
-        printf("Forced to keep original color type due to keeping bKGD or sBIT"
-               " chunk.\n");
-      }
-      keep_colortype = true;
-    }
-  }
-
   if (error) {
     if (verbose) {
-      if (error == 1) {
-        printf("Decoding error\n");
-      } else {
-        printf("Decoding error %u: %s\n", error, lodepng_error_text(error));
-      }
+      printf("Decoding error %i: %s\n", error, lodepng_error_text(error));
     }
     return error;
   }
 
   bool bit16 = false;  // Using 16-bit per channel raw image
-  if (inputstate.info_png.color.bitdepth == 16 &&
-      (keep_colortype || !png_options.lossy_8bit)) {
+  if (inputstate.info_png.color.bitdepth == 16 && !png_options.lossy_8bit) {
     // Decode as 16-bit
     image.clear();
     error = lodepng::decode(image, w, h, origpng, LCT_RGBA, 16);
@@ -429,7 +387,7 @@ int ZopfliPNGOptimize(const std::vector<unsigned char>& origpng,
 
     if (png_options.auto_filter_strategy) {
       error = AutoChooseFilterStrategy(image, w, h, inputstate, bit16,
-                                       keep_colortype, origpng,
+                                       origpng,
                                        /* Don't try brute force */
                                        kNumFilterStrategies - 1,
                                        filterstrategies, strategy_enable);
@@ -443,8 +401,8 @@ int ZopfliPNGOptimize(const std::vector<unsigned char>& origpng,
       if (!strategy_enable[i]) continue;
 
       std::vector<unsigned char> temp;
-      error = TryOptimize(image, w, h, inputstate, bit16, keep_colortype,
-                          origpng, filterstrategies[i], true /* use_zopfli */,
+      error = TryOptimize(image, w, h, inputstate, bit16, origpng,
+                          filterstrategies[i], true /* use_zopfli */,
                           windowsize, &png_options, &temp);
       if (!error) {
         if (verbose) {
@@ -465,64 +423,3 @@ int ZopfliPNGOptimize(const std::vector<unsigned char>& origpng,
 
   return error;
 }
-
-extern "C" void CZopfliPNGSetDefaults(CZopfliPNGOptions* png_options) {
-
-  memset(png_options, 0, sizeof(*png_options));
-  // Constructor sets the defaults
-  ZopfliPNGOptions opts;
-
-  png_options->lossy_transparent    = opts.lossy_transparent;
-  png_options->lossy_8bit           = opts.lossy_8bit;
-  png_options->auto_filter_strategy = opts.auto_filter_strategy;
-  png_options->use_zopfli           = opts.use_zopfli;
-  png_options->num_iterations       = opts.num_iterations;
-  png_options->num_iterations_large = opts.num_iterations_large;
-  png_options->block_split_strategy = opts.block_split_strategy;
-}
-
-extern "C" int CZopfliPNGOptimize(const unsigned char* origpng,
-                                  const size_t origpng_size,
-                                  const CZopfliPNGOptions* png_options,
-                                  int verbose,
-                                  unsigned char** resultpng,
-                                  size_t* resultpng_size) {
-  ZopfliPNGOptions opts;
-
-  // Copy over to the C++-style struct
-  opts.lossy_transparent    = !!png_options->lossy_transparent;
-  opts.lossy_8bit           = !!png_options->lossy_8bit;
-  opts.auto_filter_strategy = !!png_options->auto_filter_strategy;
-  opts.use_zopfli           = !!png_options->use_zopfli;
-  opts.num_iterations       = png_options->num_iterations;
-  opts.num_iterations_large = png_options->num_iterations_large;
-  opts.block_split_strategy = png_options->block_split_strategy;
-
-  for (int i = 0; i < png_options->num_filter_strategies; i++) {
-    opts.filter_strategies.push_back(png_options->filter_strategies[i]);
-  }
-
-  for (int i = 0; i < png_options->num_keepchunks; i++) {
-    opts.keepchunks.push_back(png_options->keepchunks[i]);
-  }
-
-  const std::vector<unsigned char> origpng_cc(origpng, origpng + origpng_size);
-  std::vector<unsigned char> resultpng_cc;
-
-  int ret = ZopfliPNGOptimize(origpng_cc, opts, !!verbose, &resultpng_cc);
-  if (ret) {
-    return ret;
-  }
-
-  *resultpng_size = resultpng_cc.size();
-  *resultpng      = (unsigned char*) malloc(resultpng_cc.size());
-  if (!(*resultpng)) {
-    return ENOMEM;
-  }
-
-  memcpy(*resultpng,
-         reinterpret_cast<unsigned char*>(&resultpng_cc[0]),
-         resultpng_cc.size());
-
-  return 0;
-}
diff --git a/src/zopflipng/zopflipng_lib.h b/src/zopflipng/zopflipng_lib.h
index b2bcd12..cb749fc 100644
--- a/src/zopflipng/zopflipng_lib.h
+++ b/src/zopflipng/zopflipng_lib.h
@@ -22,17 +22,9 @@
 #ifndef ZOPFLIPNG_LIB_H_
 #define ZOPFLIPNG_LIB_H_
 
-#ifdef __cplusplus
-
 #include <string>
 #include <vector>
 
-extern "C" {
-
-#endif
-
-#include <stdlib.h>
-
 enum ZopfliPNGFilterStrategy {
   kStrategyZero = 0,
   kStrategyOne = 1,
@@ -46,54 +38,9 @@ enum ZopfliPNGFilterStrategy {
   kNumFilterStrategies /* Not a strategy but used for the size of this enum */
 };
 
-typedef struct CZopfliPNGOptions {
-  int lossy_transparent;
-  int lossy_8bit;
-
-  enum ZopfliPNGFilterStrategy* filter_strategies;
-  // How many strategies to try.
-  int num_filter_strategies;
-
-  int auto_filter_strategy;
-
-  char** keepchunks;
-  // How many entries in keepchunks.
-  int num_keepchunks;
-
-  int use_zopfli;
-
-  int num_iterations;
-
-  int num_iterations_large;
-
-  int block_split_strategy;
-} CZopfliPNGOptions;
-
-// Sets the default options
-// Does not allocate or set keepchunks or filter_strategies
-void CZopfliPNGSetDefaults(CZopfliPNGOptions *png_options);
-
-// Returns 0 on success, error code otherwise
-// The caller must free resultpng after use
-int CZopfliPNGOptimize(const unsigned char* origpng,
-    const size_t origpng_size,
-    const CZopfliPNGOptions* png_options,
-    int verbose,
-    unsigned char** resultpng,
-    size_t* resultpng_size);
-
-#ifdef __cplusplus
-}  // extern "C"
-#endif
-
-// C++ API
-#ifdef __cplusplus
-
 struct ZopfliPNGOptions {
   ZopfliPNGOptions();
 
-  bool verbose;
-
   // Allow altering hidden colors of fully transparent pixels
   bool lossy_transparent;
   // Convert 16-bit per channel images to 8-bit per channel
@@ -105,16 +52,6 @@ struct ZopfliPNGOptions {
   // Automatically choose filter strategy using less good compression
   bool auto_filter_strategy;
 
-  // Keep original color type (RGB, RGBA, gray, gray+alpha or palette) and bit
-  // depth of the PNG.
-  // This results in a loss of compression opportunities, e.g. it will no
-  // longer convert a 4-channel RGBA image to 2-channel gray+alpha if the image
-  // only had translucent gray pixels.
-  // May be useful if a device does not support decoding PNGs of a particular
-  // color type.
-  // Default value: false.
-  bool keep_colortype;
-
   // PNG chunks to keep
   // chunks to literally copy over from the original PNG to the resulting one
   std::vector<std::string> keepchunks;
@@ -128,7 +65,7 @@ struct ZopfliPNGOptions {
   // Zopfli number of iterations on large images
   int num_iterations_large;
 
-  // Unused, left for backwards compatiblity.
+  // 0=none, 1=first, 2=last, 3=both
   int block_split_strategy;
 };
 
@@ -139,6 +76,4 @@ int ZopfliPNGOptimize(const std::vector<unsigned char>& origpng,
     bool verbose,
     std::vector<unsigned char>* resultpng);
 
-#endif  // __cplusplus
-
 #endif  // ZOPFLIPNG_LIB_H_