image/encoders/bmp/nsBMPEncoder.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef mozilla_image_encoders_bmp_nsBMPEncoder_h
   7 #define mozilla_image_encoders_bmp_nsBMPEncoder_h
   8
   9 #include "mozilla/Attributes.h"
  10 #include "mozilla/ReentrantMonitor.h"
  11 #include "mozilla/UniquePtr.h"
  12
  13 #include "imgIEncoder.h"
  14
  15 #include "nsCOMPtr.h"
  16
  17 #define NS_BMPENCODER_CID                            \
  18   { /* 13a5320c-4c91-4FA4-bd16-b081a3ba8c0b */       \
  19     0x13a5320c, 0x4c91, 0x4fa4, {                    \
  20       0xbd, 0x16, 0xb0, 0x81, 0xa3, 0Xba, 0x8c, 0x0b \
  21     }                                                \
  22   }
  23
  24 namespace mozilla {
  25 namespace image {
  26 namespace bmp {
  27
  28 struct FileHeader {
  29   char signature[2];    // String "BM".
  30   uint32_t filesize;    // File size.
  31   int32_t reserved;     // Zero.
  32   uint32_t dataoffset;  // Offset to raster data.
  33 };
  34
  35 struct XYZ {
  36   int32_t x, y, z;
  37 };
  38
  39 struct XYZTriple {
  40   XYZ r, g, b;
  41 };
  42
  43 struct V5InfoHeader {
  44   uint32_t bihsize;           // Header size
  45   int32_t width;              // Uint16 in OS/2 BMPs
  46   int32_t height;             // Uint16 in OS/2 BMPs
  47   uint16_t planes;            // =1
  48   uint16_t bpp;               // Bits per pixel.
  49   uint32_t compression;       // See Compression for valid values
  50   uint32_t image_size;        // (compressed) image size. Can be 0 if
  51                               // compression==0
  52   uint32_t xppm;              // Pixels per meter, horizontal
  53   uint32_t yppm;              // Pixels per meter, vertical
  54   uint32_t colors;            // Used Colors
  55   uint32_t important_colors;  // Number of important colors. 0=all
  56   // The rest of the header is not available in WIN_V3 BMP Files
  57   uint32_t red_mask;     // Bits used for red component
  58   uint32_t green_mask;   // Bits used for green component
  59   uint32_t blue_mask;    // Bits used for blue component
  60   uint32_t alpha_mask;   // Bits used for alpha component
  61   uint32_t color_space;  // 0x73524742=LCS_sRGB ...
  62   // These members are unused unless color_space == LCS_CALIBRATED_RGB
  63   XYZTriple white_point;  // Logical white point
  64   uint32_t gamma_red;     // Red gamma component
  65   uint32_t gamma_green;   // Green gamma component
  66   uint32_t gamma_blue;    // Blue gamma component
  67   uint32_t intent;        // Rendering intent
  68   // These members are unused unless color_space == LCS_PROFILE_*
  69   uint32_t profile_offset;  // Offset to profile data in bytes
  70   uint32_t profile_size;    // Size of profile data in bytes
  71   uint32_t reserved;        // =0
  72
  73   static const uint32_t COLOR_SPACE_LCS_SRGB = 0x73524742;
  74 };
  75
  76 }  // namespace bmp
  77 }  // namespace image
  78 }  // namespace mozilla
  79
  80 // Provides BMP encoding functionality. Use InitFromData() to do the
  81 // encoding. See that function definition for encoding options.
  82
  83 class nsBMPEncoder final : public imgIEncoder {
  84   typedef mozilla::ReentrantMonitor ReentrantMonitor;
  85
  86  public:
  87   NS_DECL_THREADSAFE_ISUPPORTS
  88   NS_DECL_IMGIENCODER
  89   NS_DECL_NSIINPUTSTREAM
  90   NS_DECL_NSIASYNCINPUTSTREAM
  91
  92   nsBMPEncoder();
  93
  94  protected:
  95   ~nsBMPEncoder();
  96
  97   enum Version { VERSION_3 = 3, VERSION_5 = 5 };
  98
  99   // See InitData in the cpp for valid parse options
 100   nsresult ParseOptions(const nsAString& aOptions, Version& aVersionOut,
 101                         uint16_t& aBppOut);
 102   // Obtains data with no alpha in machine-independent byte order
 103   void ConvertHostARGBRow(const uint8_t* aSrc,
 104                           const mozilla::UniquePtr<uint8_t[]>& aDest,
 105                           uint32_t aPixelWidth);
 106   // Thread safe notify listener
 107   void NotifyListener();
 108
 109   // Initializes the bitmap file header member mBMPFileHeader
 110   nsresult InitFileHeader(Version aVersion, uint16_t aBPP, uint32_t aWidth,
 111                           uint32_t aHeight);
 112   // Initializes the bitmap info header member mBMPInfoHeader
 113   nsresult InitInfoHeader(Version aVersion, uint16_t aBPP, uint32_t aWidth,
 114                           uint32_t aHeight);
 115
 116   // Encodes the bitmap file header member mBMPFileHeader
 117   void EncodeFileHeader();
 118   // Encodes the bitmap info header member mBMPInfoHeader
 119   void EncodeInfoHeader();
 120   // Encodes a row of image data which does not have alpha data
 121   void EncodeImageDataRow24(const uint8_t* aData);
 122   // Encodes a row of image data which does have alpha data
 123   void EncodeImageDataRow32(const uint8_t* aData);
 124   // Obtains the current offset filled up to for the image buffer
 125   inline int32_t GetCurrentImageBufferOffset() {
 126     return static_cast<int32_t>(mImageBufferCurr - mImageBufferStart);
 127   }
 128
 129   // These headers will always contain endian independent stuff
 130   // They store the BMP headers which will be encoded
 131   mozilla::image::bmp::FileHeader mBMPFileHeader;
 132   mozilla::image::bmp::V5InfoHeader mBMPInfoHeader;
 133
 134   // Keeps track of the start of the image buffer
 135   uint8_t* mImageBufferStart;
 136   // Keeps track of the current position in the image buffer
 137   uint8_t* mImageBufferCurr;
 138   // Keeps track of the image buffer size
 139   uint32_t mImageBufferSize;
 140   // Keeps track of the number of bytes in the image buffer which are read
 141   uint32_t mImageBufferReadPoint;
 142   // Stores true if the image is done being encoded
 143   bool mFinished;
 144
 145   nsCOMPtr<nsIInputStreamCallback> mCallback;
 146   nsCOMPtr<nsIEventTarget> mCallbackTarget;
 147   uint32_t mNotifyThreshold;
 148 };
 149
 150 #endif  // mozilla_image_encoders_bmp_nsBMPEncoder_h