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/*
* Copyright 2022 The Android Open Source Project
*
* 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.
*/
#ifndef ULTRAHDR_JPEGENCODERHELPER_H
#define ULTRAHDR_JPEGENCODERHELPER_H
#include <stdio.h> // For jpeglib.h.
// C++ build requires extern C for jpeg internals.
#ifdef __cplusplus
extern "C" {
#endif
#include <jerror.h>
#include <jpeglib.h>
#ifdef __cplusplus
} // extern "C"
#endif
#include <cstdint>
#include <vector>
namespace ultrahdr {
/*
* Encapsulates a converter from raw image (YUV420planer or grey-scale) to JPEG format.
* This class is not thread-safe.
*/
class JpegEncoderHelper {
public:
JpegEncoderHelper();
~JpegEncoderHelper();
/*
* Compresses YUV420Planer image to JPEG format. After calling this method, call
* getCompressedImage() to get the image. |quality| is the jpeg image quality parameter to use.
* It ranges from 1 (poorest quality) to 100 (highest quality). |iccBuffer| is the buffer of
* ICC segment which will be added to the compressed image.
* Returns false if errors occur during compression.
*/
bool compressImage(const uint8_t* yBuffer, const uint8_t* uvBuffer, int width, int height,
int lumaStride, int chromaStride, int quality, const void* iccBuffer,
unsigned int iccSize);
/*
* Returns the compressed JPEG buffer pointer. This method must be called only after calling
* compressImage().
*/
void* getCompressedImagePtr();
/*
* Returns the compressed JPEG buffer size. This method must be called only after calling
* compressImage().
*/
size_t getCompressedImageSize();
/*
* Process 16 lines of Y and 16 lines of U/V each time.
* We must pass at least 16 scanlines according to libjpeg documentation.
*/
static const int kCompressBatchSize = 16;
private:
// initDestination(), emptyOutputBuffer() and emptyOutputBuffer() are callback functions to be
// passed into jpeg library.
static void initDestination(j_compress_ptr cinfo);
static boolean emptyOutputBuffer(j_compress_ptr cinfo);
static void terminateDestination(j_compress_ptr cinfo);
static void outputErrorMessage(j_common_ptr cinfo);
// Returns false if errors occur.
bool encode(const uint8_t* yBuffer, const uint8_t* uvBuffer, int width, int height,
int lumaStride, int chromaStride, int quality, const void* iccBuffer,
unsigned int iccSize);
void setJpegDestination(jpeg_compress_struct* cinfo);
void setJpegCompressStruct(int width, int height, int quality, jpeg_compress_struct* cinfo,
bool isSingleChannel);
// Returns false if errors occur.
bool compressYuv(jpeg_compress_struct* cinfo, const uint8_t* yBuffer, const uint8_t* uvBuffer,
int lumaStride, int chromaStride);
bool compressY(jpeg_compress_struct* cinfo, const uint8_t* yBuffer, int lumaStride);
// The block size for encoded jpeg image buffer.
static const int kBlockSize = 16384;
// The buffer that holds the compressed result.
std::vector<JOCTET> mResultBuffer;
};
} /* namespace ultrahdr */
#endif // ULTRAHDR_JPEGENCODERHELPER_H
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