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, builtinclass, 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   // png-zlib-level=[0-9]  --  default: "3"
  23   //     Overrides default from compression level for zlib.
  24   // png-filter=[no_filters|none|sub|up|avg|paeth|fast|all]  --  default: "sub"
  25   //     Overrides default filter.
  26   //
  27   //
  28   // APNG:
  29   // -----
  30   // The following options can be used with startImageEncode():
  31   //
  32   // transparency=[yes|no|none]  --  default: "yes"
  33   //     Overrides default from input format. "no" and "none" are equivalent.
  34   // skipfirstframe=[yes|no]  --  default: "no"
  35   //     Controls display of the first frame in animations. PNG-only clients
  36   //     always display the first frame (and only that frame).
  37   // frames=#  --  default: "1"
  38   //     Total number of frames in the image. The first frame, even if skipped,
  39   //     is always included in the count.
  40   // plays=#  --  default: "0"
  41   //     Number of times to play the animation sequence. "0" will repeat
  42   //     forever.
  43   //
  44   // The following options can be used for each frame, with addImageFrame():
  45   //
  46   // transparency=[yes|no|none]  --  default: "yes"
  47   //     Overrides default from input format. "no" and "none" are equivalent.
  48   // delay=#  --  default: "500"
  49   //     Number of milliseconds to display the frame, before moving to the next
  50   //     frame.
  51   // dispose=[none|background|previous]  --  default: "none"
  52   //     What to do with the image's canvas before rendering the next frame.
  53   //     See APNG spec.
  54   // blend=[source|over]  --  default: "source"
  55   //     How to render the new frame on the canvas. See APNG spec.
  56   // xoffset=#  --  default: "0"
  57   // yoffset=#  --  default: "0"
  58   //     Where to draw the frame, relative to the canvas.
  59   //
  60   //
  61   // JPEG:
  62   // -----
  63   //
  64   // quality=#  --  default: "92"
  65   //    Quality of compression, 0-100 (worst-best).
  66   //    Quality >= 90 prevents down-sampling of the color channels.
  67   //
  68   //
  69   // WEBP:
  70   // -----
  71   //
  72   // quality=#  --  default: "92"
  73   //    Quality of compression, 0-100 (worst-best).
  74
  75
  76   // Possible values for input format (note that not all image formats
  77   // support saving alpha channels):
  78
  79     // Input is RGB each pixel is represented by three bytes:
  80     // R, G, and B (in that order, regardless of host endianness)
  81   const uint32_t INPUT_FORMAT_RGB = 0;
  82
  83     // Input is RGB each pixel is represented by four bytes:
  84     // R, G, and B (in that order, regardless of host endianness).
  85     // POST-MULTIPLIED alpha us used (50% transparent red is 0xff000080)
  86   const uint32_t INPUT_FORMAT_RGBA = 1;
  87
  88     // Input is host-endian ARGB: On big-endian machines each pixel is therefore
  89     // ARGB, and for little-endian machiens (Intel) each pixel is BGRA
  90     // (This is used by canvas to match it's internal representation)
  91     //
  92     // PRE-MULTIPLIED alpha is used (That is, 50% transparent red is 0x80800000,
  93     // not 0x80ff0000
  94   const uint32_t INPUT_FORMAT_HOSTARGB = 2;
  95
  96   /* data - list of bytes in the format specified by inputFormat
  97    * width  - width in pixels
  98    * height - height in pixels
  99    * stride - number of bytes per row in the image
 100    *          Normally (width*3) or (width*4), depending on your input format,
 101    *          but some data uses padding at the end of each row, which would
 102    *          be extra.
 103    * inputFormat - one of INPUT_FORMAT_* specifying the format of data
 104    * outputOptions - semicolon-delimited list of name=value pairs that can
 105    *                 give options to the output encoder. Options are encoder-
 106    *                 specific. Just give empty string for default behavior.
 107    */
 108   void initFromData([array, size_is(length), const] in uint8_t data,
 109                     in unsigned long length,
 110                     in uint32_t width,
 111                     in uint32_t height,
 112                     in uint32_t stride,
 113                     in uint32_t inputFormat,
 114                     in AString outputOptions);
 115
 116   /*
 117    * For encoding images which may contain multiple frames, the 1-shot
 118    * initFromData() interface is too simplistic. The alternative is to
 119    * use startImageEncode(), call addImageFrame() one or more times, and
 120    * then finish initialization with endImageEncode().
 121    *
 122    * The arguments are basically the same as in initFromData().
 123    */
 124   void startImageEncode(in uint32_t width,
 125                     in uint32_t height,
 126                     in uint32_t inputFormat,
 127                     in AString outputOptions);
 128
 129   void addImageFrame( [array, size_is(length), const] in uint8_t data,
 130                     in unsigned long length,
 131                     in uint32_t width,
 132                     in uint32_t height,
 133                     in uint32_t stride,
 134                     in uint32_t frameFormat,
 135                     in AString frameOptions);
 136
 137   void endImageEncode();
 138
 139   /*
 140    * Sometimes an encoder can contain another encoder and direct access
 141    * to its buffer is necessary.   It is only safe to assume that the buffer
 142    * returned from getImageBuffer() is of size equal to getImageBufferUsed().
 143    */
 144   [noscript] unsigned long getImageBufferUsed();
 145   [noscript] charPtr getImageBuffer();
 146 };