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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_image_decoders_nsJPEGDecoder_h
#define mozilla_image_decoders_nsJPEGDecoder_h
#include "RasterImage.h"
#include "SurfacePipe.h"
#include "EXIF.h"
// On Windows systems, RasterImage.h brings in 'windows.h', which defines INT32.
// But the jpeg decoder has its own definition of INT32. To avoid build issues,
// we need to undefine the version from 'windows.h'.
#undef INT32
#include "Decoder.h"
extern "C" {
#include "jpeglib.h"
}
#include <setjmp.h>
namespace mozilla::image {
typedef struct {
struct jpeg_error_mgr pub; // "public" fields for IJG library
jmp_buf setjmp_buffer; // For handling catastropic errors
} decoder_error_mgr;
typedef enum {
JPEG_HEADER, // Reading JFIF headers
JPEG_START_DECOMPRESS,
JPEG_DECOMPRESS_PROGRESSIVE, // Output progressive pixels
JPEG_DECOMPRESS_SEQUENTIAL, // Output sequential pixels
JPEG_DONE,
JPEG_SINK_NON_JPEG_TRAILER, // Some image files have a
// non-JPEG trailer
JPEG_ERROR
} jstate;
class RasterImage;
struct Orientation;
class nsJPEGDecoder : public Decoder {
public:
virtual ~nsJPEGDecoder();
DecoderType GetType() const override { return DecoderType::JPEG; }
void NotifyDone();
protected:
nsresult InitInternal() override;
LexerResult DoDecode(SourceBufferIterator& aIterator,
IResumable* aOnResume) override;
nsresult FinishInternal() override;
Maybe<Telemetry::HistogramID> SpeedHistogram() const override;
protected:
EXIFData ReadExifData() const;
WriteState OutputScanlines();
private:
friend class DecoderFactory;
// Decoders should only be instantiated via DecoderFactory.
nsJPEGDecoder(RasterImage* aImage, Decoder::DecodeStyle aDecodeStyle);
enum class State { JPEG_DATA, FINISHED_JPEG_DATA };
void FinishRow(uint32_t aLastSourceRow);
LexerTransition<State> ReadJPEGData(const char* aData, size_t aLength);
LexerTransition<State> FinishedJPEGData();
StreamingLexer<State> mLexer;
public:
struct jpeg_decompress_struct mInfo;
struct jpeg_source_mgr mSourceMgr;
decoder_error_mgr mErr;
jstate mState;
uint32_t mBytesToSkip;
const JOCTET* mSegment; // The current segment we are decoding from
uint32_t mSegmentLen; // amount of data in mSegment
JOCTET* mBackBuffer;
uint32_t mBackBufferLen; // Offset of end of active backtrack data
uint32_t mBackBufferSize; // size in bytes what mBackBuffer was created with
uint32_t mBackBufferUnreadLen; // amount of data currently in mBackBuffer
JOCTET* mProfile;
uint32_t mProfileLength;
uint32_t* mCMSLine;
bool mReading;
const Decoder::DecodeStyle mDecodeStyle;
SurfacePipe mPipe;
};
} // namespace mozilla::image
#endif // mozilla_image_decoders_nsJPEGDecoder_h
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