image/decoders/nsJPEGDecoder.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  *
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_image_decoders_nsJPEGDecoder_h
   8 #define mozilla_image_decoders_nsJPEGDecoder_h
   9
  10 #include "RasterImage.h"
  11 #include "SurfacePipe.h"
  12 #include "EXIF.h"
  13
  14 // On Windows systems, RasterImage.h brings in 'windows.h', which defines INT32.
  15 // But the jpeg decoder has its own definition of INT32. To avoid build issues,
  16 // we need to undefine the version from 'windows.h'.
  17 #undef INT32
  18
  19 #include "Decoder.h"
  20
  21 extern "C" {
  22 #include "jpeglib.h"
  23 }
  24
  25 #include <setjmp.h>
  26
  27 namespace mozilla::image {
  28
  29 typedef struct {
  30   struct jpeg_error_mgr pub;  // "public" fields for IJG library
  31   jmp_buf setjmp_buffer;      // For handling catastropic errors
  32 } decoder_error_mgr;
  33
  34 typedef enum {
  35   JPEG_HEADER,  // Reading JFIF headers
  36   JPEG_START_DECOMPRESS,
  37   JPEG_DECOMPRESS_PROGRESSIVE,  // Output progressive pixels
  38   JPEG_DECOMPRESS_SEQUENTIAL,   // Output sequential pixels
  39   JPEG_DONE,
  40   JPEG_SINK_NON_JPEG_TRAILER,  // Some image files have a
  41                                // non-JPEG trailer
  42   JPEG_ERROR
  43 } jstate;
  44
  45 class RasterImage;
  46 struct Orientation;
  47
  48 class nsJPEGDecoder : public Decoder {
  49  public:
  50   virtual ~nsJPEGDecoder();
  51
  52   DecoderType GetType() const override { return DecoderType::JPEG; }
  53
  54   void NotifyDone();
  55
  56  protected:
  57   nsresult InitInternal() override;
  58   LexerResult DoDecode(SourceBufferIterator& aIterator,
  59                        IResumable* aOnResume) override;
  60   nsresult FinishInternal() override;
  61
  62   Maybe<Telemetry::HistogramID> SpeedHistogram() const override;
  63
  64  protected:
  65   EXIFData ReadExifData() const;
  66   WriteState OutputScanlines();
  67
  68  private:
  69   friend class DecoderFactory;
  70
  71   // Decoders should only be instantiated via DecoderFactory.
  72   nsJPEGDecoder(RasterImage* aImage, Decoder::DecodeStyle aDecodeStyle);
  73
  74   enum class State { JPEG_DATA, FINISHED_JPEG_DATA };
  75
  76   void FinishRow(uint32_t aLastSourceRow);
  77   LexerTransition<State> ReadJPEGData(const char* aData, size_t aLength);
  78   LexerTransition<State> FinishedJPEGData();
  79
  80   StreamingLexer<State> mLexer;
  81
  82  public:
  83   struct jpeg_decompress_struct mInfo;
  84   struct jpeg_source_mgr mSourceMgr;
  85   decoder_error_mgr mErr;
  86   jstate mState;
  87
  88   uint32_t mBytesToSkip;
  89
  90   const JOCTET* mSegment;  // The current segment we are decoding from
  91   uint32_t mSegmentLen;    // amount of data in mSegment
  92
  93   JOCTET* mBackBuffer;
  94   uint32_t mBackBufferLen;   // Offset of end of active backtrack data
  95   uint32_t mBackBufferSize;  // size in bytes what mBackBuffer was created with
  96   uint32_t mBackBufferUnreadLen;  // amount of data currently in mBackBuffer
  97
  98   JOCTET* mProfile;
  99   uint32_t mProfileLength;
 100
 101   uint32_t* mCMSLine;
 102
 103   bool mReading;
 104
 105   const Decoder::DecodeStyle mDecodeStyle;
 106
 107   SurfacePipe mPipe;
 108 };
 109
 110 }  // namespace mozilla::image
 111
 112 #endif  // mozilla_image_decoders_nsJPEGDecoder_h