dom/webidl/ImageBitmap.webidl
author Gurzau Raul <rgurzau@mozilla.com>
Wed, 13 Dec 2017 23:41:49 +0200
changeset 396289 ccd7b237c4337a00e45bf18ac2d0218c61e1134d
parent 396267 2e263a2519c50359bd6b9663b94d462e5e30249e
child 398218 c0ab6f8f55cd25b9ceb21aa40b64e8057ccf0942
permissions -rw-r--r--
Backed out 22 changesets (bug 1419771) for build bustage build/src/dom/base/FuzzingFunctions.cpp on a CLOSED TREE Backed out changeset b2b7b46c8ad0 (bug 1419771) Backed out changeset 0206657d2ea2 (bug 1419771) Backed out changeset f0f4b98a07b6 (bug 1419771) Backed out changeset 4b52904694f4 (bug 1419771) Backed out changeset 9f40cc12d6c6 (bug 1419771) Backed out changeset f500a61f564c (bug 1419771) Backed out changeset 0bd9d964df8a (bug 1419771) Backed out changeset 1397a6bbb446 (bug 1419771) Backed out changeset 7e77a00fa8b5 (bug 1419771) Backed out changeset 5f6df771459a (bug 1419771) Backed out changeset 7624e70b2965 (bug 1419771) Backed out changeset b9d674bdc723 (bug 1419771) Backed out changeset 5e44aeda4196 (bug 1419771) Backed out changeset 601b49f51b41 (bug 1419771) Backed out changeset d12dc5557982 (bug 1419771) Backed out changeset 6c863ab2e986 (bug 1419771) Backed out changeset 0866d79873ab (bug 1419771) Backed out changeset 8ecc91474621 (bug 1419771) Backed out changeset 19b14deed8fe (bug 1419771) Backed out changeset 000c8d5fbc03 (bug 1419771) Backed out changeset 2e263a2519c5 (bug 1419771) Backed out changeset b628d9298be8 (bug 1419771)

/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * The origin of this IDL file is
 * https://html.spec.whatwg.org/multipage/webappapis.html#images
 *
 * The origin of the extended IDL file is
 * http://w3c.github.io/mediacapture-worker/#imagebitmap-extensions
 */

// Extensions
// Bug 1141979 - [FoxEye] Extend ImageBitmap with interfaces to access its
// underlying image data
//
// Note:
// Our overload resolution implementation doesn't deal with a union as the
// distinguishing argument which means we cannot overload functions via union
// types, a.k.a. we cannot overload createImageBitmap() via ImageBitmapSource
// and BufferSource. Here, we work around this issue by adding the BufferSource
// into ImageBitmapSource.

typedef (HTMLImageElement or
         HTMLVideoElement or
         HTMLCanvasElement or
         Blob or
         ImageData or
         CanvasRenderingContext2D or
         ImageBitmap or
         BufferSource) ImageBitmapSource;

[Exposed=(Window,Worker)]
interface ImageBitmap {
  [Constant]
  readonly attribute unsigned long width;
  [Constant]
  readonly attribute unsigned long height;
};

// It's crucial that there be a way to explicitly dispose of ImageBitmaps
// since they refer to potentially large graphics resources. Some uses
// of this API proposal will result in repeated allocations of ImageBitmaps,
// and garbage collection will not reliably reclaim them quickly enough.
// Here we reuse close(), which also exists on another Transferable type,
// MessagePort. Potentially, all Transferable types should inherit from a
// new interface type "Closeable".
partial interface ImageBitmap {
  // Dispose of all graphical resources associated with this ImageBitmap.
  void close();
};

// ImageBitmap-extensions
// Bug 1141979 - [FoxEye] Extend ImageBitmap with interfaces to access its
// underlying image data

/*
 * An image or a video frame is conceptually a two-dimensional array of data and
 * each element in the array is called a pixel. The pixels are usually stored in
 * a one-dimensional array and could be arranged in a variety of image formats.
 * Developers need to know how the pixels are formatted so that they are able to
 * process them.
 *
 * The image format describes how pixels in an image are arranged. A single
 * pixel has at least one, but usually multiple pixel values. The range of a
 * pixel value varies, which means different image formats use different data
 * types to store a single pixel value.
 *
 * The most frequently used data type is 8-bit unsigned integer whose range is
 * from 0 to 255, others could be 16-bit integer or 32-bit floating points and
 * so forth. The number of pixel values of a single pixel is called the number
 * of channels of the image format. Multiple pixel values of a pixel are used
 * together to describe the captured property which could be color or depth
 * information. For example, if the data is a color image in RGB color space,
 * then it is a three-channel image format and a pixel is described by R, G and
 * B three pixel values with range from 0 to 255. As another example, if the
 * data is a gray image, then it is a single-channel image format with 8-bit
 * unsigned integer data type and the pixel value describes the gray scale. For
 * depth data, it is a single channel image format too, but the data type is
 * 16-bit unsigned integer and the pixel value is the depth level.
 *
 * For those image formats whose pixels contain multiple pixel values, the pixel
 * values might be arranged in one of the following ways:
 * 1) Planar pixel layout:
 *    each channel has its pixel values stored consecutively in separated
 *    buffers (a.k.a. planes) and then all channel buffers are stored
 *    consecutively in memory.
 *    (Ex: RRRRRR......GGGGGG......BBBBBB......)
 * 2) Interleaving pixel layout:
 *    each pixel has its pixel values from all channels stored together and
 *    interleaves all channels.
 *    (Ex: RGBRGBRGBRGBRGB......)
 */


/*
 * The ImageBitmap extensions use this enumeration to negotiate the image format
 * while 1) accessing the underlying data of an ImageBitmap and
 *       2) creating a new ImageBitmap.
 *
 * For each format in this enumeration, we use a 2x2 small image (4 pixels) as
 * example to illustrate the pixel layout.
 *
 * 2x2 image:   +--------+--------+
 *              | pixel1 | pixel2 |
 *              +--------+--------+
 *              | pixel3 | pixel4 |
 *              +--------+--------+
 *
 */
enum ImageBitmapFormat {
  /*
   * Channel order: R, G, B, A
   * Channel size: full rgba-chennels
   * Pixel layout: interleaving rgba-channels
   * Pixel layout illustration:
   *   [Plane1]: R1 G1 B1 A1 R2 G2 B2 A2 R3 G3 B3 A3 R4 G4 B4 A4
   * Data type: 8-bit unsigned integer
   */
  "RGBA32",

  /*
   * Channel order: B, G, R, A
   * Channel size: full bgra-channels
   * Pixel layout: interleaving bgra-channels
   * Pixel layout illustration:
   *   [Plane1]: B1 G1 R1 A1 B2 G2 R2 A2 B3 G3 R3 A3 B4 G4 R4 A4
   * Data type: 8-bit unsigned integer
   */
  "BGRA32",

  /*
   * Channel order: R, G, B
   * Channel size: full rgb-channels
   * Pixel layout: interleaving rgb-channels
   * Pixel layout illustration:
   *   [Plane1]: R1 G1 B1 R2 G2 B2 R3 G3 B3 R4 G4 B4
   * Data type: 8-bit unsigned integer
   */
  "RGB24",

  /*
   * Channel order: B, G, R
   * Channel size: full bgr-channels
   * Pixel layout: interleaving bgr-channels
   * Pixel layout illustration:
   *   [Plane1]: B1 G1 R1 B2 G2 R2 B3 G3 R3 B4 G4 R4
   * Data type: 8-bit unsigned integer
   */
  "BGR24",

  /*
   * Channel order: GRAY
   * Channel size: full gray-channel
   * Pixel layout: planar gray-channel
   * Pixel layout illustration:
   *   [Plane1]: GRAY1 GRAY2 GRAY3 GRAY4
   * Data type: 8-bit unsigned integer
   */
  "GRAY8",

  /*
   * Channel order: Y, U, V
   * Channel size: full yuv-channels
   * Pixel layout: planar yuv-channels
   * Pixel layout illustration:
   *   [Plane1]: Y1 Y2 Y3 Y4
   *   [Plane2]: U1 U2 U3 U4
   *   [Plane3]: V1 V2 V3 V4
   * Data type: 8-bit unsigned integer
   */
  "YUV444P",

  /*
   * Channel order: Y, U, V
   * Channel size: full y-channel, half uv-channels
   * Pixel layout: planar yuv-channels
   * Pixel layout illustration:
   *   [Plane1]: Y1 Y2 Y3 Y4
   *   [Plane2]: U1 U3
   *   [Plane3]: V1 V3
   * Data type: 8-bit unsigned integer
   */
  "YUV422P",

  /*
   * Channel order: Y, U, V
   * Channel size: full y-channel, quarter uv-channels
   * Pixel layout: planar yuv-channels
   * Pixel layout illustration:
   *   [Plane1]: Y1 Y2 Y3 Y4
   *   [Plane2]: U1
   *   [Plane3]: V1
   * Data type: 8-bit unsigned integer
   */
  "YUV420P",

  /*
   * Channel order: Y, U, V
   * Channel size: full y-channel, quarter uv-channels
   * Pixel layout: planar y-channel, interleaving uv-channels
   * Pixel layout illustration:
   *   [Plane1]: Y1 Y2 Y3 Y4
   *   [Plane2]: U1 V1
   * Data type: 8-bit unsigned integer
   */
  "YUV420SP_NV12",

  /*
   * Channel order: Y, V, U
   * Channel size: full y-channel, quarter vu-channels
   * Pixel layout: planar y-channel, interleaving vu-channels
   * Pixel layout illustration:
   *   [Plane1]: Y1 Y2 Y3 Y4
   *   [Plane2]: V1 U1
   * Data type: 8-bit unsigned integer
   */
  "YUV420SP_NV21",

  /*
   * Channel order: H, S, V
   * Channel size: full hsv-channels
   * Pixel layout: interleaving hsv-channels
   * Pixel layout illustration:
   *   [Plane1]: H1 S1 V1 H2 S2 V2 H3 S3 V3
   * Data type: 32-bit floating point value
   */
  "HSV",

  /*
   * Channel order: l, a, b
   * Channel size: full lab-channels
   * Pixel layout: interleaving lab-channels
   * Pixel layout illustration:
   *   [Plane1]: l1 a1 b1 l2 a2 b2 l3 a3 b3
   * Data type: 32-bit floating point value
   */
  "Lab",

  /*
   * Channel order: DEPTH
   * Channel size: full depth-channel
   * Pixel layout: planar depth-channel
   * Pixel layout illustration:
   *   [Plane1]: DEPTH1 DEPTH2 DEPTH3 DEPTH4
   * Data type: 16-bit unsigned integer
   */
  "DEPTH",
};

enum ChannelPixelLayoutDataType {
  "uint8",
  "int8",
  "uint16",
  "int16",
  "uint32",
  "int32",
  "float32",
  "float64"
};

/*
 * Two concepts, ImagePixelLayout and ChannelPixelLayout, together generalize
 * the variety of pixel layouts among image formats.
 *
 * The ChannelPixelLayout represents the pixel layout of a single channel in a
 * certain image format and the ImagePixelLayout is just the collection of
 * ChannelPixelLayouts. So, the ChannelPixelLayout is defined as a dictionary
 * type with properties to describe the layout and the ImagePixelLayout is just
 * an alias name to a sequence of ChannelPixelLayout objects.
 *
 * Since an image format is composed of at least one channel, an
 * ImagePixelLayout object contains at least one ChannelPixelLayout object.
 *
 * Although an image or a video frame is a two-dimensional structure, its data
 * is usually stored in a one-dimensional array in the row-major way and the
 * ChannelPixelLayout objects use the following properties to describe the
 * layout of pixel values in the buffer.
 *
 * 1) offset:
 *    denotes the beginning position of the channel's data relative to the
 *    beginning position of the one-dimensional array.
 * 2) width & height:
 *    denote the width and height of the channel respectively. Each channel in
 *    an image format may have different height and width.
 * 3) data type:
 *    denotes the format used to store one single pixel value.
 * 4) stride:
 *    the number of bytes between the beginning two consecutive rows in memory.
 *    (The total bytes of each row plus the padding bytes of each raw.)
 * 5) skip value:
 *    the value is zero for the planar pixel layout, and a positive integer for
 *    the interleaving pixel layout. (Describes how many bytes there are between
 *    two adjacent pixel values in this channel.)
 */

/*
 * Example1: RGBA image, width = 620, height = 480, stride = 2560
 *
 * chanel_r: offset = 0, width = 620, height = 480, data type = uint8, stride = 2560, skip = 3
 * chanel_g: offset = 1, width = 620, height = 480, data type = uint8, stride = 2560, skip = 3
 * chanel_b: offset = 2, width = 620, height = 480, data type = uint8, stride = 2560, skip = 3
 * chanel_a: offset = 3, width = 620, height = 480, data type = uint8, stride = 2560, skip = 3
 *
 *         <---------------------------- stride ---------------------------->
 *         <---------------------- width x 4 ---------------------->
 * [index] 01234   8   12  16  20  24  28                           2479    2559
 *         |||||---|---|---|---|---|---|----------------------------|-------|
 * [data]  RGBARGBARGBARGBARGBAR___R___R...                         A%%%%%%%%
 * [data]  RGBARGBARGBARGBARGBAR___R___R...                         A%%%%%%%%
 * [data]  RGBARGBARGBARGBARGBAR___R___R...                         A%%%%%%%%
 *              ^^^
 *              r-skip
 */

/*
 * Example2: YUV420P image, width = 620, height = 480, stride = 640
 *
 * chanel_y: offset = 0, width = 620, height = 480, stride = 640, skip = 0
 * chanel_u: offset = 307200, width = 310, height = 240, data type = uint8, stride = 320, skip = 0
 * chanel_v: offset = 384000, width = 310, height = 240, data type = uint8, stride = 320, skip = 0
 *
 *         <--------------------------- y-stride --------------------------->
 *         <----------------------- y-width ----------------------->
 * [index] 012345                                                  619      639
 *         ||||||--------------------------------------------------|--------|
 * [data]  YYYYYYYYYYYYYYYYYYYYYYYYYYYYY...                        Y%%%%%%%%%
 * [data]  YYYYYYYYYYYYYYYYYYYYYYYYYYYYY...                        Y%%%%%%%%%
 * [data]  YYYYYYYYYYYYYYYYYYYYYYYYYYYYY...                        Y%%%%%%%%%
 * [data]  ......
 *         <-------- u-stride ---------->
 *         <----- u-width ----->
 * [index] 307200              307509   307519
 *         |-------------------|--------|
 * [data]  UUUUUUUUUU...       U%%%%%%%%%
 * [data]  UUUUUUUUUU...       U%%%%%%%%%
 * [data]  UUUUUUUUUU...       U%%%%%%%%%
 * [data]  ......
 *         <-------- v-stride ---------->
 *         <- --- v-width ----->
 * [index] 384000              384309   384319
 *         |-------------------|--------|
 * [data]  VVVVVVVVVV...       V%%%%%%%%%
 * [data]  VVVVVVVVVV...       V%%%%%%%%%
 * [data]  VVVVVVVVVV...       V%%%%%%%%%
 * [data]  ......
 */

/*
 * Example3: YUV420SP_NV12 image, width = 620, height = 480, stride = 640
 *
 * chanel_y: offset = 0, width = 620, height = 480, stride = 640, skip = 0
 * chanel_u: offset = 307200, width = 310, height = 240, data type = uint8, stride = 640, skip = 1
 * chanel_v: offset = 307201, width = 310, height = 240, data type = uint8, stride = 640, skip = 1
 *
 *         <--------------------------- y-stride -------------------------->
 *         <----------------------- y-width ---------------------->
 * [index] 012345                                                 619      639
 *         ||||||-------------------------------------------------|--------|
 * [data]  YYYYYYYYYYYYYYYYYYYYYYYYYYYYY...                       Y%%%%%%%%%
 * [data]  YYYYYYYYYYYYYYYYYYYYYYYYYYYYY...                       Y%%%%%%%%%
 * [data]  YYYYYYYYYYYYYYYYYYYYYYYYYYYYY...                       Y%%%%%%%%%
 * [data]  ......
 *         <--------------------- u-stride / v-stride -------------------->
 *         <------------------ u-width + v-width ----------------->
 * [index] 307200(u-offset)                                       307819  307839
 *         |------------------------------------------------------|-------|
 * [index] |307201(v-offset)                                      |307820 |
 *         ||-----------------------------------------------------||------|
 * [data]  UVUVUVUVUVUVUVUVUVUVUVUVUVUVUV...                      UV%%%%%%%
 * [data]  UVUVUVUVUVUVUVUVUVUVUVUVUVUVUV...                      UV%%%%%%%
 * [data]  UVUVUVUVUVUVUVUVUVUVUVUVUVUVUV...                      UV%%%%%%%
 *          ^            ^
 *         u-skip        v-skip
 */

/*
 * Example4: DEPTH image, width = 640, height = 480, stride = 1280
 *
 * chanel_d: offset = 0, width = 640, height = 480, data type = uint16, stride = 1280, skip = 0
 *
 * note: each DEPTH value uses two bytes
 *
 *         <----------------------- d-stride ---------------------->
 *         <----------------------- d-width ----------------------->
 * [index] 02468                                                   1278
 *         |||||---------------------------------------------------|
 * [data]  DDDDDDDDDDDDDDDDDDDDDDDDDDDDD...                        D
 * [data]  DDDDDDDDDDDDDDDDDDDDDDDDDDDDD...                        D
 * [data]  DDDDDDDDDDDDDDDDDDDDDDDDDDDDD...                        D
 * [data]  ......
 */

dictionary ChannelPixelLayout {
    required unsigned long              offset;
    required unsigned long              width;
    required unsigned long              height;
    required ChannelPixelLayoutDataType dataType;
    required unsigned long              stride;
    required unsigned long              skip;
};

typedef sequence<ChannelPixelLayout> ImagePixelLayout;

partial interface ImageBitmap {
    [Throws, Func="mozilla::dom::ImageBitmap::ExtensionsEnabled"]
    ImageBitmapFormat               findOptimalFormat (optional sequence<ImageBitmapFormat> aPossibleFormats);
    [Throws, Func="mozilla::dom::ImageBitmap::ExtensionsEnabled"]
    long                            mappedDataLength (ImageBitmapFormat aFormat);
    [Throws, Func="mozilla::dom::ImageBitmap::ExtensionsEnabled"]
    Promise<ImagePixelLayout> mapDataInto (ImageBitmapFormat aFormat, BufferSource aBuffer, long aOffset);
};