image/decoders/nsPNGDecoder.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 nsPNGDecoder_h
   8 #define nsPNGDecoder_h
   9
  10 #include "Decoder.h"
  11
  12 #include "gfxTypes.h"
  13
  14 #include "nsCOMPtr.h"
  15
  16 #include "png.h"
  17
  18 #include "qcms.h"
  19
  20 namespace mozilla {
  21 namespace image {
  22 class RasterImage;
  23
  24 class nsPNGDecoder : public Decoder
  25 {
  26 public:
  27   explicit nsPNGDecoder(RasterImage* aImage);
  28   virtual ~nsPNGDecoder();
  29
  30   virtual void InitInternal() MOZ_OVERRIDE;
  31   virtual void WriteInternal(const char* aBuffer, uint32_t aCount) MOZ_OVERRIDE;
  32   virtual Telemetry::ID SpeedHistogram() MOZ_OVERRIDE;
  33
  34   void CreateFrame(png_uint_32 x_offset, png_uint_32 y_offset,
  35                    int32_t width, int32_t height,
  36                    gfx::SurfaceFormat format);
  37   void EndImageFrame();
  38
  39   // Check if PNG is valid ICO (32bpp RGBA)
  40   // http://blogs.msdn.com/b/oldnewthing/archive/2010/10/22/10079192.aspx
  41   bool IsValidICO() const
  42   {
  43     // If there are errors in the call to png_get_IHDR, the error_callback in
  44     // nsPNGDecoder.cpp is called.  In this error callback we do a longjmp, so
  45     // we need to save the jump buffer here. Oterwise we'll end up without a
  46     // proper callstack.
  47     if (setjmp(png_jmpbuf(mPNG))) {
  48       // We got here from a longjmp call indirectly from png_get_IHDR
  49       return false;
  50     }
  51
  52     png_uint_32
  53         png_width,  // Unused
  54         png_height; // Unused
  55
  56     int png_bit_depth,
  57         png_color_type;
  58
  59     if (png_get_IHDR(mPNG, mInfo, &png_width, &png_height, &png_bit_depth,
  60                      &png_color_type, nullptr, nullptr, nullptr)) {
  61
  62       return ((png_color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
  63                png_color_type == PNG_COLOR_TYPE_RGB) &&
  64               png_bit_depth == 8);
  65     } else {
  66       return false;
  67     }
  68   }
  69
  70 public:
  71   png_structp mPNG;
  72   png_infop mInfo;
  73   nsIntRect mFrameRect;
  74   uint8_t* mCMSLine;
  75   uint8_t* interlacebuf;
  76   qcms_profile* mInProfile;
  77   qcms_transform* mTransform;
  78
  79   gfx::SurfaceFormat format;
  80
  81   // For size decodes
  82   uint8_t mSizeBytes[8]; // Space for width and height, both 4 bytes
  83   uint32_t mHeaderBytesRead;
  84
  85   // whether CMS or premultiplied alpha are forced off
  86   uint32_t mCMSMode;
  87
  88   uint8_t mChannels;
  89   bool mFrameHasNoAlpha;
  90   bool mFrameIsHidden;
  91   bool mDisablePremultipliedAlpha;
  92
  93   struct AnimFrameInfo
  94   {
  95     AnimFrameInfo();
  96 #ifdef PNG_APNG_SUPPORTED
  97     AnimFrameInfo(png_structp aPNG, png_infop aInfo);
  98 #endif
  99
 100     DisposalMethod mDispose;
 101     BlendMethod mBlend;
 102     int32_t mTimeout;
 103   };
 104
 105   AnimFrameInfo mAnimInfo;
 106
 107   // The number of frames we've finished.
 108   uint32_t mNumFrames;
 109
 110   // libpng callbacks
 111   // We put these in the class so that they can access protected members.
 112   static void PNGAPI info_callback(png_structp png_ptr, png_infop info_ptr);
 113   static void PNGAPI row_callback(png_structp png_ptr, png_bytep new_row,
 114                                   png_uint_32 row_num, int pass);
 115 #ifdef PNG_APNG_SUPPORTED
 116   static void PNGAPI frame_info_callback(png_structp png_ptr,
 117                                          png_uint_32 frame_num);
 118 #endif
 119   static void PNGAPI end_callback(png_structp png_ptr, png_infop info_ptr);
 120   static void PNGAPI error_callback(png_structp png_ptr,
 121                                     png_const_charp error_msg);
 122   static void PNGAPI warning_callback(png_structp png_ptr,
 123                                       png_const_charp warning_msg);
 124
 125   // This is defined in the PNG spec as an invariant. We use it to
 126   // do manual validation without libpng.
 127   static const uint8_t pngSignatureBytes[];
 128 };
 129
 130 } // namespace image
 131 } // namespace mozilla
 132
 133 #endif // nsPNGDecoder_h