image/imgIEncoder.idl

   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 #include "nsISupports.idl"
   7 #include "nsIAsyncInputStream.idl"
   8 #include "nsIEventTarget.idl"
   9
  10 /**
  11  * imgIEncoder interface
  12  */
  13 [scriptable, uuid(4baa2d6e-fee7-42df-ae3f-5fbebc0c267c)]
  14 interface imgIEncoder : nsIAsyncInputStream
  15 {
  16   // Possible values for outputOptions. Multiple values are semicolon-separated.
  17   //
  18   // PNG:
  19   // ----
  20   // transparency=[yes|no|none]  --  default: "yes"
  21   //     Overrides default from input format. "no" and "none" are equivalent.
  22   //
  23   //
  24   // APNG:
  25   // -----
  26   // The following options can be used with startImageEncode():
  27   //
  28   // transparency=[yes|no|none]  --  default: "yes"
  29   //     Overrides default from input format. "no" and "none" are equivalent.
  30   // skipfirstframe=[yes|no]  --  default: "no"
  31   //     Controls display of the first frame in animations. PNG-only clients
  32   //     always display the first frame (and only that frame).
  33   // frames=#  --  default: "1"
  34   //     Total number of frames in the image. The first frame, even if skipped,
  35   //     is always included in the count.
  36   // plays=#  --  default: "0"
  37   //     Number of times to play the animation sequence. "0" will repeat
  38   //     forever.
  39   //
  40   // The following options can be used for each frame, with addImageFrame():
  41   //
  42   // transparency=[yes|no|none]  --  default: "yes"
  43   //     Overrides default from input format. "no" and "none" are equivalent.
  44   // delay=#  --  default: "500"
  45   //     Number of milliseconds to display the frame, before moving to the next
  46   //     frame.
  47   // dispose=[none|background|previous]  --  default: "none"
  48   //     What to do with the image's canvas before rendering the next frame.
  49   //     See APNG spec.
  50   // blend=[source|over]  --  default: "source"
  51   //     How to render the new frame on the canvas. See APNG spec.
  52   // xoffset=#  --  default: "0"
  53   // yoffset=#  --  default: "0"
  54   //     Where to draw the frame, relative to the canvas.
  55   //
  56   //
  57   // JPEG:
  58   // -----
  59   //
  60   // quality=#  --  default: "92"
  61   //    Quality of compression, 0-100 (worst-best).
  62   //    Quality >= 90 prevents down-sampling of the color channels.
  63
  64
  65   // Possible values for input format (note that not all image formats
  66   // support saving alpha channels):
  67
  68     // Input is RGB each pixel is represented by three bytes:
  69     // R, G, and B (in that order, regardless of host endianness)
  70   const uint32_t INPUT_FORMAT_RGB = 0;
  71
  72     // Input is RGB each pixel is represented by four bytes:
  73     // R, G, and B (in that order, regardless of host endianness).
  74     // POST-MULTIPLIED alpha us used (50% transparent red is 0xff000080)
  75   const uint32_t INPUT_FORMAT_RGBA = 1;
  76
  77     // Input is host-endian ARGB: On big-endian machines each pixel is therefore
  78     // ARGB, and for little-endian machiens (Intel) each pixel is BGRA
  79     // (This is used by canvas to match it's internal representation)
  80     //
  81     // PRE-MULTIPLIED alpha is used (That is, 50% transparent red is 0x80800000,
  82     // not 0x80ff0000
  83   const uint32_t INPUT_FORMAT_HOSTARGB = 2;
  84
  85   /* data - list of bytes in the format specified by inputFormat
  86    * width  - width in pixels
  87    * height - height in pixels
  88    * stride - number of bytes per row in the image
  89    *          Normally (width*3) or (width*4), depending on your input format,
  90    *          but some data uses padding at the end of each row, which would
  91    *          be extra.
  92    * inputFormat - one of INPUT_FORMAT_* specifying the format of data
  93    * outputOptions - semicolon-delimited list of name=value pairs that can
  94    *                 give options to the output encoder. Options are encoder-
  95    *                 specific. Just give empty string for default behavior.
  96    */
  97   void initFromData([array, size_is(length), const] in uint8_t data,
  98                     in unsigned long length,
  99                     in uint32_t width,
 100                     in uint32_t height,
 101                     in uint32_t stride,
 102                     in uint32_t inputFormat,
 103                     in AString outputOptions);
 104
 105   /*
 106    * For encoding images which may contain multiple frames, the 1-shot
 107    * initFromData() interface is too simplistic. The alternative is to
 108    * use startImageEncode(), call addImageFrame() one or more times, and
 109    * then finish initialization with endImageEncode().
 110    *
 111    * The arguments are basically the same as in initFromData().
 112    */
 113   void startImageEncode(in uint32_t width,
 114                     in uint32_t height,
 115                     in uint32_t inputFormat,
 116                     in AString outputOptions);
 117
 118   void addImageFrame( [array, size_is(length), const] in uint8_t data,
 119                     in unsigned long length,
 120                     in uint32_t width,
 121                     in uint32_t height,
 122                     in uint32_t stride,
 123                     in uint32_t frameFormat,
 124                     in AString frameOptions);
 125
 126   void endImageEncode();
 127
 128   /*
 129    * Sometimes an encoder can contain another encoder and direct access
 130    * to its buffer is necessary.   It is only safe to assume that the buffer
 131    * returned from getImageBuffer() is of size equal to getImageBufferUsed().
 132    */
 133   [noscript] unsigned long getImageBufferUsed();
 134   [noscript] charPtr getImageBuffer();
 135 };