diff options
Diffstat (limited to 'libpng.3')
| -rw-r--r-- | libpng.3 | 427 |
1 files changed, 110 insertions, 317 deletions
@@ -1,11 +1,11 @@ -.TH LIBPNG 3 "September 29, 2017" +.TH LIBPNG 3 "June 21, 2023" .SH NAME -libpng \- Portable Network Graphics (PNG) Reference Library 1.6.34 +libpng \- Portable Network Graphics (PNG) Reference Library 1.6.40 + .SH SYNOPSIS -\fB -#include <png.h>\fP +\fB#include <png.h>\fP -\fBpng_uint_32 png_access_version_number \fI(void\fP\fB);\fP +\fBpng_uint_32 png_access_version_number (void);\fP \fBvoid png_benign_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP @@ -35,7 +35,7 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.6.34 \fBpng_structp png_create_write_struct_2 (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP -\fBvoid png_data_freer (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIfreer\fP\fB, png_uint_32 \fImask)\fP\fB);\fP +\fBvoid png_data_freer (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIfreer\fP\fB, png_uint_32 \fImask\fP\fB);\fP \fBvoid png_destroy_info_struct (png_structp \fP\fIpng_ptr\fP\fB, png_infopp \fIinfo_ptr_ptr\fP\fB);\fP @@ -225,7 +225,7 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.6.34 \fBint png_image_begin_read_from_stdio (png_imagep \fP\fIimage\fP\fB, FILE* \fIfile\fP\fB);\fP -\fBint, png_image_begin_read_from_memory (png_imagep \fP\fIimage\fP\fB, png_const_voidp \fP\fImemory\fP\fB, png_size_t \fIsize\fP\fB);\fP +\fBint, png_image_begin_read_from_memory (png_imagep \fP\fIimage\fP\fB, png_const_voidp \fP\fImemory\fP\fB, size_t \fIsize\fP\fB);\fP \fBint png_image_finish_read (png_imagep \fP\fIimage\fP\fB, png_colorp \fP\fIbackground\fP\fB, void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, void \fI*colormap\fP\fB);\fP @@ -233,11 +233,11 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.6.34 \fBint png_image_write_to_file (png_imagep \fP\fIimage\fP\fB, const char \fP\fI*file\fP\fB, int \fP\fIconvert_to_8bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, void \fI*colormap\fP\fB);\fP -\fBint png_image_write_to_memory (png_imagep \fP\fIimage\fP\fB, void \fP\fI*memory\fP\fB, png_alloc_size_t * PNG_RESTRICT \fP\fImemory_bytes\fP\fB, int \fP\fIconvert_to_8_bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, const void \fI*colormap)\fP\fB);\fP +\fBint png_image_write_to_memory (png_imagep \fP\fIimage\fP\fB, void \fP\fI*memory\fP\fB, png_alloc_size_t * PNG_RESTRICT \fP\fImemory_bytes\fP\fB, int \fP\fIconvert_to_8_bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, const void \fI*colormap\fP\fB);\fP -\fBint png_image_write_to_stdio (png_imagep \fP\fIimage\fP\fB, FILE \fP\fI*file\fP\fB, int \fP\fIconvert_to_8_bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, void \fI*colormap)\fP\fB);\fP +\fBint png_image_write_to_stdio (png_imagep \fP\fIimage\fP\fB, FILE \fP\fI*file\fP\fB, int \fP\fIconvert_to_8_bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, void \fI*colormap\fP\fB);\fP -\fBvoid png_info_init_3 (png_infopp \fP\fIinfo_ptr\fP\fB, png_size_t \fIpng_info_struct_size\fP\fB);\fP +\fBvoid png_info_init_3 (png_infopp \fP\fIinfo_ptr\fP\fB, size_t \fIpng_info_struct_size\fP\fB);\fP \fBvoid png_init_io (png_structp \fP\fIpng_ptr\fP\fB, FILE \fI*fp\fP\fB);\fP @@ -251,11 +251,11 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.6.34 \fBpng_uint_32 png_permit_mng_features (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fImng_features_permitted\fP\fB);\fP -\fBvoid png_process_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIbuffer_size\fP\fB);\fP +\fBvoid png_process_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, size_t \fIbuffer_size\fP\fB);\fP -\fBpng_size_t png_process_data_pause \fP\fI(png_structp\fP\fB, int \fIsave\fP\fB);\fP +\fBsize_t png_process_data_pause (png_structp \fP\fIpng_ptr\fP\fB, int \fIsave\fP\fB);\fP -\fBpng_uint_32 png_process_data_skip \fI(png_structp\fP\fB);\fP +\fBpng_uint_32 png_process_data_skip (png_structp \fP\fIpng_ptr\fP\fB);\fP \fBvoid png_progressive_combine_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIold_row\fP\fB, png_bytep \fInew_row\fP\fB);\fP @@ -297,7 +297,7 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.6.34 \fBvoid png_set_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fIbackground\fP\fB);\fP -\fBvoid png_set_check_for_invalid_index(png_structrp \fP\fIpng_ptr\fP\fB, int \fIallowed\fP\fB);\fP +\fBvoid png_set_check_for_invalid_index (png_structrp \fP\fIpng_ptr\fP\fB, int \fIallowed\fP\fB);\fP \fBvoid png_set_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIwhite_x\fP\fB, double \fP\fIwhite_y\fP\fB, double \fP\fIred_x\fP\fB, double \fP\fIred_y\fP\fB, double \fP\fIgreen_x\fP\fB, double \fP\fIgreen_y\fP\fB, double \fP\fIblue_x\fP\fB, double \fIblue_y\fP\fB);\fP @@ -353,7 +353,7 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.6.34 \fBvoid png_set_eXIf (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fIexif\fP\fB);\fP -\fBvoid png_set_eXIf_1 (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, const png_uint_32 \fP\fInum_exif\fP\fB, png_bytep \fIexif\fP\fB);\fP +\fBvoid png_set_eXIf_1 (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fInum_exif\fP\fB, png_bytep \fIexif\fP\fB);\fP \fBvoid png_set_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fIhist\fP\fB);\fP @@ -453,7 +453,7 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.6.34 \fBvoid png_set_text_compression_window_bits (png_structp \fP\fIpng_ptr\fP\fB, int \fIwindow_bits\fP\fB);\fP -\fBvoid \fP\fIpng_set_text_compression_method\fP\fB, (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod)\fP\fB);\fP +\fBvoid png_set_text_compression_method (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod\fP\fB);\fP \fBvoid png_set_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fImod_time\fP\fB);\fP @@ -475,15 +475,15 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.6.34 \fBvoid png_set_write_user_transform_fn (png_structp \fP\fIpng_ptr\fP\fB, png_user_transform_ptr \fIwrite_user_transform_fn\fP\fB);\fP -\fBint png_sig_cmp (png_bytep \fP\fIsig\fP\fB, png_size_t \fP\fIstart\fP\fB, png_size_t \fInum_to_check\fP\fB);\fP +\fBint png_sig_cmp (png_bytep \fP\fIsig\fP\fB, size_t \fP\fIstart\fP\fB, size_t \fInum_to_check\fP\fB);\fP \fBvoid png_start_read_image (png_structp \fIpng_ptr\fP\fB);\fP \fBvoid png_warning (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fImessage\fP\fB);\fP -\fBvoid png_write_chunk (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP +\fBvoid png_write_chunk (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_bytep \fP\fIdata\fP\fB, size_t \fIlength\fP\fB);\fP -\fBvoid png_write_chunk_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP +\fBvoid png_write_chunk_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, size_t \fIlength\fP\fB);\fP \fBvoid png_write_chunk_end (png_structp \fIpng_ptr\fP\fB);\fP @@ -515,13 +515,12 @@ the Portable Network Graphics (PNG) format image files. It uses the .IR zlib(3) compression library. Following is a copy of the libpng-manual.txt file that accompanies libpng. + .SH LIBPNG.TXT libpng-manual.txt - A description on how to use and modify libpng - libpng version 1.6.34 - September 29, 2017 - Updated and distributed by Glenn Randers-Pehrson - <glennrp at users.sourceforge.net> - Copyright (c) 1998-2017 Glenn Randers-Pehrson + Copyright (c) 2018-2023 Cosmin Truta + Copyright (c) 1998-2018 Glenn Randers-Pehrson This document is released under the libpng license. For conditions of distribution and use, see the disclaimer @@ -529,9 +528,13 @@ libpng-manual.txt - A description on how to use and modify libpng Based on: - libpng versions 0.97, January 1998, through 1.6.34 - September 29, 2017 + libpng version 1.6.36, December 2018, through 1.6.40 - June 2023 + Updated and distributed by Cosmin Truta + Copyright (c) 2018-2023 Cosmin Truta + + libpng versions 0.97, January 1998, through 1.6.35 - July 2018 Updated and distributed by Glenn Randers-Pehrson - Copyright (c) 1998-2017 Glenn Randers-Pehrson + Copyright (c) 1998-2018 Glenn Randers-Pehrson libpng 1.0 beta 6 - version 0.96 - May 28, 1997 Updated and distributed by Andreas Dilger @@ -563,7 +566,6 @@ libpng-manual.txt - A description on how to use and modify libpng XIII. Detecting libpng XIV. Source code repository XV. Coding style - XVI. Y2K Compliance in libpng .SH I. Introduction @@ -584,7 +586,7 @@ file format in application programs. The PNG specification (second edition), November 2003, is available as a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2004 (E)) at -<https://www.w3.org/TR/2003/REC-PNG-20031110/ +<https://www.w3.org/TR/2003/REC-PNG-20031110/>. The W3C and ISO documents have identical technical content. The PNG-1.2 specification is available at @@ -592,9 +594,9 @@ The PNG-1.2 specification is available at It is technically equivalent to the PNG specification (second edition) but has some additional material. -The PNG-1.0 specification is available as RFC 2083 +The PNG-1.0 specification is available as RFC 2083 at <https://png-mng.sourceforge.io/pub/png/spec/1.0/> and as a -W3C Recommendation <https://www.w3.org/TR/REC-png-961001>. +W3C Recommendation at <https://www.w3.org/TR/REC-png-961001>. Some additional chunks are described in the special-purpose public chunks documents at <http://www.libpng.org/pub/png/spec/register/> @@ -866,18 +868,18 @@ Customizing libpng. FILE *fp = fopen(file_name, "rb"); if (!fp) { - return (ERROR); + return ERROR; } if (fread(header, 1, number, fp) != number) { - return (ERROR); + return ERROR; } is_png = !png_sig_cmp(header, 0, number); if (!is_png) { - return (NOT_PNG); + return NOT_PNG; } Next, png_struct and png_info need to be allocated and initialized. In @@ -896,7 +898,7 @@ create the structure, so your application should check for that. user_error_fn, user_warning_fn); if (!png_ptr) - return (ERROR); + return ERROR; png_infop info_ptr = png_create_info_struct(png_ptr); @@ -904,7 +906,7 @@ create the structure, so your application should check for that. { png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL); - return (ERROR); + return ERROR; } If you want to use your own memory allocation routines, @@ -939,7 +941,7 @@ free any memory. png_destroy_read_struct(&png_ptr, &info_ptr, &end_info); fclose(fp); - return (ERROR); + return ERROR; } Pass (png_infopp)NULL instead of &end_info if you didn't create @@ -1021,7 +1023,7 @@ input stream. You must supply the function png_byte name[5]; png_byte *data; - png_size_t size; + size_t size; /* Note that libpng has already taken care of the CRC handling */ @@ -1030,9 +1032,9 @@ input stream. You must supply the function unknown chunk structure, process it, and return one of the following: */ - return (\-n); /* chunk had an error */ - return (0); /* did not recognize */ - return (n); /* success */ + return \-n; /* chunk had an error */ + return 0; /* did not recognize */ + return n; /* success */ } (You can give your function another name that you like instead of @@ -1394,7 +1396,7 @@ described below (the latter being the two common names for associated alpha color channels). Note that PNG files always contain non-associated color channels; png_set_alpha_mode() with one of the modes causes the decoder to convert the pixels to an associated form before returning them to your -application. +application. Since it is not necessary to perform arithmetic on opaque color values so long as they are not to be resampled and are in the final color space it is @@ -1521,7 +1523,7 @@ chunks to be assumed to be encoded using sRGB. png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC); In this case the output is assumed to be something like an sRGB conformant -display preceeded by a power-law lookup table of power 1.45. This is how +display preceded by a power-law lookup table of power 1.45. This is how early Mac systems behaved. png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR); @@ -1573,7 +1575,7 @@ faster.) When the default gamma of PNG files doesn't match the output gamma. If you have PNG files with no gamma information png_set_alpha_mode allows -you to provide a default gamma, but it also sets the ouput gamma to the +you to provide a default gamma, but it also sets the output gamma to the matching value. If you know your PNG files have a gamma that doesn't match the output you can take advantage of the fact that png_set_alpha_mode always sets the output gamma but only sets the PNG @@ -2309,7 +2311,7 @@ the information. If, instead, you want to convert the image to an opaque version with no alpha channel use png_set_background; see below. As of libpng version 1.5.2, almost all useful expansions are supported, the -major ommissions are conversion of grayscale to indexed images (which can be +major omissions are conversion of grayscale to indexed images (which can be done trivially in the application) and conversion of indexed to grayscale (which can be done by a trivial manipulation of the palette.) @@ -2927,7 +2929,7 @@ separate. { png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL); - return (ERROR); + return ERROR; } png_read_end(png_ptr, end_info); @@ -3067,7 +3069,7 @@ png_infop info_ptr; user_error_fn, user_warning_fn); if (!png_ptr) - return (ERROR); + return ERROR; info_ptr = png_create_info_struct(png_ptr); @@ -3075,14 +3077,14 @@ png_infop info_ptr; { png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL); - return (ERROR); + return ERROR; } if (setjmp(png_jmpbuf(png_ptr))) { png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL); - return (ERROR); + return ERROR; } /* This one's new. You can provide functions @@ -3116,7 +3118,7 @@ png_infop info_ptr; { png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL); - return (ERROR); + return ERROR; } /* This one's new also. Simply give it a chunk @@ -3260,7 +3262,7 @@ custom writing functions. See the discussion under Customizing libpng. FILE *fp = fopen(file_name, "wb"); if (!fp) - return (ERROR); + return ERROR; Next, png_struct and png_info need to be allocated and initialized. As these can be both relatively large, you may not want to store these @@ -3275,14 +3277,14 @@ both "png_ptr"; you can call them anything you like, such as user_error_fn, user_warning_fn); if (!png_ptr) - return (ERROR); + return ERROR; png_infop info_ptr = png_create_info_struct(png_ptr); if (!info_ptr) { png_destroy_write_struct(&png_ptr, (png_infopp)NULL); - return (ERROR); + return ERROR; } If you want to use your own memory allocation routines, @@ -3309,7 +3311,7 @@ section below for more information on the libpng error handling. { png_destroy_write_struct(&png_ptr, &info_ptr); fclose(fp); - return (ERROR); + return ERROR; } ... return; @@ -4297,7 +4299,7 @@ in-memory bitmap formats or to be written from the same formats. If these formats do not accommodate your needs then you can, and should, use the more sophisticated APIs above - these support a wide variety of in-memory formats and a wide variety of sophisticated transformations to those formats as well -as a wide variety of APIs to manipulate ancilliary information. +as a wide variety of APIs to manipulate ancillary information. To read a PNG file using the simplified API: @@ -4573,7 +4575,7 @@ Flags containing additional information about the image are held in the 'flags' field of png_image. PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB == 0x01 - This indicates the the RGB values of the in-memory bitmap do not + This indicates that the RGB values of the in-memory bitmap do not correspond to the red, green and blue end-points defined by sRGB. PNG_IMAGE_FLAG_FAST == 0x02 @@ -4620,7 +4622,7 @@ READ APIs The PNG header is read from the stdio FILE object. int png_image_begin_read_from_memory(png_imagep image, - png_const_voidp memory, png_size_t size) + png_const_voidp memory, size_t size) The PNG header is read from the given memory buffer. @@ -4773,10 +4775,10 @@ png_get_io_ptr(). For example: The replacement I/O functions must have prototypes as follows: void user_read_data(png_structp png_ptr, - png_bytep data, png_size_t length); + png_bytep data, size_t length); void user_write_data(png_structp png_ptr, - png_bytep data, png_size_t length); + png_bytep data, size_t length); void user_flush_data(png_structp png_ptr); @@ -5039,7 +5041,7 @@ When PNG_DEBUG = 1, the macros are defined, but only png_debug statements having level = 0 will be printed. There aren't any such statements in this version of libpng, but if you insert some they will be printed. -.SH VII. MNG support +.SH VII. MNG support The MNG specification (available at http://www.libpng.org/pub/mng) allows certain extensions to PNG for PNG images that are embedded in MNG datastreams. @@ -5066,7 +5068,7 @@ or any other MNG chunks; your application must provide its own support for them. You may wish to consider using libmng (available at https://www.libmng.com/) instead. -.SH VIII. Changes to Libpng from version 0.88 +.SH VIII. Changes to Libpng from version 0.88 It should be noted that versions of libpng later than 0.96 are not distributed by the original libpng author, Guy Schalnat, nor by @@ -5121,7 +5123,7 @@ application: png_uint_32 application_vn = PNG_LIBPNG_VER; -.SH IX. Changes to Libpng from version 1.0.x to 1.2.x +.SH IX. Changes to Libpng from version 1.0.x to 1.2.x Support for user memory management was enabled by default. To accomplish this, the functions png_create_read_struct_2(), @@ -5218,7 +5220,7 @@ which also expands tRNS to alpha was replaced with png_set_expand_gray_1_2_4_to_8() which does not. It has been deprecated since libpng-1.0.18 and 1.2.9. -.SH X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x +.SH X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x Private libpng prototypes and macro definitions were moved from png.h and pngconf.h into a new pngpriv.h header file. @@ -5302,7 +5304,7 @@ behavior in case the application runs out of memory part-way through the process. We changed the prototypes of png_get_compression_buffer_size() and -png_set_compression_buffer_size() to work with png_size_t instead of +png_set_compression_buffer_size() to work with size_t instead of png_uint_32. Support for numbered error messages was removed by default, since we @@ -5328,7 +5330,7 @@ was renamed to PNG_READ_QUANTIZE_SUPPORTED. We removed the trailing '.' from the warning and error messages. -.SH XI. Changes to Libpng from version 1.4.x to 1.5.x +.SH XI. Changes to Libpng from version 1.4.x to 1.5.x From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the function) incorrectly returned a value of type png_uint_32. @@ -5391,7 +5393,7 @@ to png_bytepp, and in png_set_iCCP, from png_charp to png_const_bytep. There are changes of form in png.h, including new and changed macros to declare parts of the API. Some API functions with arguments that are pointers to data not modified within the function have been corrected to -declare these arguments with PNG_CONST. +declare these arguments with const. Much of the internal use of C macros to control the library build has also changed and some of this is visible in the exported header files, in @@ -5586,7 +5588,7 @@ even though the default is to use the macros - this allows applications to choose at app buildtime whether or not to use macros (previously impossible because the functions weren't in the default build.) -.SH XII. Changes to Libpng from version 1.5.x to 1.6.x +.SH XII. Changes to Libpng from version 1.5.x to 1.6.x A "simplified API" has been added (see documentation in png.h and a simple example in contrib/examples/pngtopng.c). The new publicly visible API @@ -5749,7 +5751,7 @@ attempt to decode the Exif profile; it simply returns a byte array containing the profile to the calling application which must do its own decoding. -.SH XIII. Detecting libpng +.SH XIII. Detecting libpng The png_get_io_ptr() function has been present since libpng-0.88, has never changed, and is unaffected by conditional compilation macros. It is the @@ -5773,9 +5775,8 @@ or you can browse it with a web browser at https://github.com/glennrp/libpng or https://sourceforge.net/p/libpng/code/ci/libpng16/tree/ -Patches can be sent to glennrp at users.sourceforge.net or to -png-mng-implement at lists.sourceforge.net or you can upload them to -the libpng bug tracker at +Patches can be sent to png-mng-implement at lists.sourceforge.net or +uploaded to the libpng bug tracker at https://libpng.sourceforge.io/ @@ -5784,9 +5785,9 @@ or as a "pull request" to https://github.com/glennrp/libpng/pulls We also accept patches built from the tar or zip distributions, and -simple verbal discriptions of bug fixes, reported either to the +simple verbal descriptions of bug fixes, reported either to the SourceForge bug tracker, to the png-mng-implement at lists.sf.net -mailing list, as github issues, or directly to glennrp. +mailing list, as github issues. .SH XV. Coding style @@ -5807,7 +5808,7 @@ braces on separate lines: The braces can be omitted from simple one-line actions: if (condition) - return (0); + return 0; We use 3-space indentation, except for continued statements which are usually indented the same as the first line of the statement @@ -5926,61 +5927,6 @@ Lines do not exceed 80 characters. Other rules can be inferred by inspecting the libpng source. -.SH XVI. Y2K Compliance in libpng - -Since the PNG Development group is an ad-hoc body, we can't make -an official declaration. - -This is your unofficial assurance that libpng from version 0.71 and -upward through 1.6.34 are Y2K compliant. It is my belief that earlier -versions were also Y2K compliant. - -Libpng only has two year fields. One is a 2-byte unsigned integer -that will hold years up to 65535. The other, which is deprecated, -holds the date in text format, and will hold years up to 9999. - -The integer is - "png_uint_16 year" in png_time_struct. - -The string is - "char time_buffer[29]" in png_struct. This is no longer used -in libpng-1.6.x and will be removed from libpng-1.7.0. - -There are seven time-related functions: - - png_convert_to_rfc_1123_buffer() in png.c - (formerly png_convert_to_rfc_1152() in error, and - also formerly png_convert_to_rfc_1123()) - png_convert_from_struct_tm() in pngwrite.c, called - in pngwrite.c - png_convert_from_time_t() in pngwrite.c - png_get_tIME() in pngget.c - png_handle_tIME() in pngrutil.c, called in pngread.c - png_set_tIME() in pngset.c - png_write_tIME() in pngwutil.c, called in pngwrite.c - -All appear to handle dates properly in a Y2K environment. The -png_convert_from_time_t() function calls gmtime() to convert from system -clock time, which returns (year - 1900), which we properly convert to -the full 4-digit year. There is a possibility that applications using -libpng are not passing 4-digit years into the png_convert_to_rfc_1123() -function, or that they are incorrectly passing only a 2-digit year -instead of "year - 1900" into the png_convert_from_struct_tm() function, -but this is not under our control. The libpng documentation has always -stated that it works with 4-digit years, and the APIs have been -documented as such. - -The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned -integer to hold the year, and can hold years as large as 65535. - -zlib, upon which libpng depends, is also Y2K compliant. It contains -no date-related code. - - - Glenn Randers-Pehrson - libpng maintainer - PNG Development Group - .SH NOTE Note about libpng version numbers: @@ -5991,9 +5937,9 @@ on the library has not always been consistent and straightforward. The following table summarizes matters since version 0.89c, which was the first widely used release: - source png.h png.h shared-lib - version string int version - ------- ------ ----- ---------- + source png.h png.h shared-lib + version string int version + ------- ------ ----- ---------- 0.89c "1.0 beta 3" 0.89 89 1.0.89 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] @@ -6028,61 +5974,54 @@ the first widely used release: 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) 1.0.7 1 10007 (still compatible) ... - 1.0.19 10 10019 10.so.0.19[.0] + 1.0.69 10 10069 10.so.0.69[.0] ... 1.2.59 13 10259 12.so.0.59[.0] ... + 1.4.20 14 10420 14.so.0.20[.0] + ... 1.5.30 15 10530 15.so.15.30[.0] ... - 1.6.34 16 10634 16.so.16.34[.0] - -Henceforth the source version will match the shared-library minor -and patch numbers; the shared-library major version number will be -used for changes in backward compatibility, as it is intended. The -PNG_PNGLIB_VER macro, which is not used within libpng but is available -for applications, is an unsigned integer of the form xyyzz corresponding -to the source version x.y.z (leading zeros in y and z). Beta versions -were given the previous public release number plus a letter, until -version 1.0.6j; from then on they were given the upcoming public -release number plus "betaNN" or "rcNN". + 1.6.35 16 10635 16.so.16.35[.0] + +Henceforth the source version will match the shared-library minor and +patch numbers; the shared-library major version number will be used for +changes in backward compatibility, as it is intended. +The PNG_PNGLIB_VER macro, which is not used within libpng but is +available for applications, is an unsigned integer of the form XYYZZ +corresponding to the source version X.Y.Z (leading zeros in Y and Z). +Beta versions were given the previous public release number plus a +letter, until version 1.0.6j; from then on they were given the upcoming +public release number plus "betaNN" or "rcNN". .SH "SEE ALSO" -.IR libpngpf(3) ", " png(5) -.LP -.IR libpng : +.BR "png"(5) .IP -https://libpng.sourceforge.io/ (follow the [DOWNLOAD] link) -http://www.libpng.org/pub/png - +The PNG (Portable Network Graphics) format specification. .LP -.IR zlib : +.B libpng .IP -(generally) at the same location as -.I libpng -or at +http://www.libpng.org/pub/png/libpng.html (canonical home page) .br -https://zlib.net/ - +https://github.com/pnggroup/libpng (canonical Git repository) +.br +https://libpng.sourceforge.io (downloadable archives) .LP -.IR PNG specification: RFC 2083 +.B zlib .IP -(generally) at the same location as -.I libpng -or at +https://zlib.net (canonical home page) .br -https://www.ietf.org/rfc/rfc2083.txt +https://github.com/madler/zlib (canonical Git repository) .br -or (as a W3C Recommendation) at -.br -https://www.w3.org/TR/REC-png.html - +A copy of zlib may also be found at the same location as libpng. .LP In the case of any inconsistency between the PNG specification and this library, the specification takes precedence. .SH AUTHORS -This man page: Glenn Randers-Pehrson -<glennrp at users.sourceforge.net> +This man page: +Initially created by Glenn Randers-Pehrson. +Maintained by Cosmin Truta. The contributing authors would like to thank all those who helped with testing, bug fixes, and patience. This wouldn't have been @@ -6090,160 +6029,14 @@ possible without all of you. Thanks to Frank J. T. Wojcik for helping with the documentation. -Libpng version 1.6.34 - September 29, 2017: +Libpng: Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc. -Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net). +Maintained by Cosmin Truta. -Supported by the PNG development group +Supported by the PNG development group. .br -png-mng-implement at lists.sf.net -(subscription required; visit -png-mng-implement at lists.sourceforge.net (subscription required; visit -https://lists.sourceforge.net/lists/listinfo/png-mng-implement -to subscribe). - -.SH NOTICES: - -This copy of the libpng notices is provided for your convenience. In case of -any discrepancy between this copy and the notices in the file png.h that is -included in the libpng distribution, the latter shall prevail. - -COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: - -If you modify libpng you may insert additional notices immediately following -this sentence. - -This code is released under the libpng license. - -libpng versions 1.0.7, July 1, 2000 through 1.6.34, September 29, 2017 are -Copyright (c) 2000-2002, 2004, 2006-2017 Glenn Randers-Pehrson, are -derived from libpng-1.0.6, and are distributed according to the same -disclaimer and license as libpng-1.0.6 with the following individuals -added to the list of Contributing Authors: - - Simon-Pierre Cadieux - Eric S. Raymond - Mans Rullgard - Cosmin Truta - Gilles Vollant - James Yu - Mandar Sahastrabuddhe - Google Inc. - Vadim Barkov - -and with the following additions to the disclaimer: - - There is no warranty against interference with your enjoyment of the - library or against infringement. There is no warranty that our - efforts or the library will fulfill any of your particular purposes - or needs. This library is provided with all faults, and the entire - risk of satisfactory quality, performance, accuracy, and effort is with - the user. - -Some files in the "contrib" directory and some configure-generated -files that are distributed with libpng have other copyright owners and -are released under other open source licenses. - -libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are -Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from -libpng-0.96, and are distributed according to the same disclaimer and -license as libpng-0.96, with the following individuals added to the list -of Contributing Authors: - - Tom Lane - Glenn Randers-Pehrson - Willem van Schaik - -libpng versions 0.89, June 1996, through 0.96, May 1997, are -Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, -and are distributed according to the same disclaimer and license as -libpng-0.88, with the following individuals added to the list of -Contributing Authors: - - John Bowler - Kevin Bracey - Sam Bushell - Magnus Holmgren - Greg Roelofs - Tom Tanner - -Some files in the "scripts" directory have other copyright owners -but are released under this license. - -libpng versions 0.5, May 1995, through 0.88, January 1996, are -Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. - -For the purposes of this copyright and license, "Contributing Authors" -is defined as the following set of individuals: - - Andreas Dilger - Dave Martindale - Guy Eric Schalnat - Paul Schmidt - Tim Wegner - -The PNG Reference Library is supplied "AS IS". The Contributing Authors -and Group 42, Inc. disclaim all warranties, expressed or implied, -including, without limitation, the warranties of merchantability and of -fitness for any purpose. The Contributing Authors and Group 42, Inc. -assume no liability for direct, indirect, incidental, special, exemplary, -or consequential damages, which may result from the use of the PNG -Reference Library, even if advised of the possibility of such damage. - -Permission is hereby granted to use, copy, modify, and distribute this -source code, or portions hereof, for any purpose, without fee, subject -to the following restrictions: - - 1. The origin of this source code must not be misrepresented. - - 2. Altered versions must be plainly marked as such and must not - be misrepresented as being the original source. - - 3. This Copyright notice may not be removed or altered from any - source or altered source distribution. - -The Contributing Authors and Group 42, Inc. specifically permit, without -fee, and encourage the use of this source code as a component to -supporting the PNG file format in commercial products. If you use this -source code in a product, acknowledgment is not required but would be -appreciated. - -END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE. - -TRADEMARK: - -The name "libpng" has not been registered by the Copyright owner -as a trademark in any jurisdiction. However, because libpng has -been distributed and maintained world-wide, continually since 1995, -the Copyright owner claims "common-law trademark protection" in any -jurisdiction where common-law trademark is recognized. - -OSI CERTIFICATION: - -Libpng is OSI Certified Open Source Software. OSI Certified Open Source is -a certification mark of the Open Source Initiative. OSI has not addressed -the additional disclaimers inserted at version 1.0.7. - -EXPORT CONTROL: - -The Copyright owner believes that the Export Control Classification -Number (ECCN) for libpng is EAR99, which means not subject to export -controls or International Traffic in Arms Regulations (ITAR) because -it is open source, publicly available software, that does not contain -any encryption software. See the EAR, paragraphs 734.3(b)(3) and -734.7(b). - -A "png_get_copyright" function is available, for convenient use in "about" -boxes and the like: - - printf("%s", png_get_copyright(NULL)); - -Also, the PNG logo (in PNG format, of course) is supplied in the -files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). - -Glenn Randers-Pehrson -glennrp at users.sourceforge.net -September 29, 2017 +png-mng-implement at lists.sourceforge.net. (Subscription is required; +visit https://lists.sourceforge.net/lists/listinfo/png-mng-implement +to subscribe.) .\" end of man page - |