gecko-dev/image/public/imgIEncoder.idl

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/* -*- Mode: C++; 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/. */
#include "nsISupports.idl"
#include "nsIAsyncInputStream.idl"
#include "nsIEventTarget.idl"
/**
* imgIEncoder interface
*/
[scriptable, uuid(4baa2d6e-fee7-42df-ae3f-5fbebc0c267c)]
interface imgIEncoder : nsIAsyncInputStream
{
// Possible values for outputOptions. Multiple values are semicolon-separated.
//
// PNG:
// ----
// transparency=[yes|no|none] -- default: "yes"
// Overrides default from input format. "no" and "none" are equivalent.
//
//
// APNG:
// -----
// The following options can be used with startImageEncode():
//
// transparency=[yes|no|none] -- default: "yes"
// Overrides default from input format. "no" and "none" are equivalent.
// skipfirstframe=[yes|no] -- default: "no"
// Controls display of the first frame in animations. PNG-only clients
// always display the first frame (and only that frame).
// frames=# -- default: "1"
// Total number of frames in the image. The first frame, even if skipped,
// is always included in the count.
// plays=# -- default: "0"
// Number of times to play the animation sequence. "0" will repeat
// forever.
//
// The following options can be used for each frame, with addImageFrame():
//
// transparency=[yes|no|none] -- default: "yes"
// Overrides default from input format. "no" and "none" are equivalent.
// delay=# -- default: "500"
// Number of milliseconds to display the frame, before moving to the next
// frame.
// dispose=[none|background|previous] -- default: "none"
// What to do with the image's canvas before rendering the next frame.
// See APNG spec.
// blend=[source|over] -- default: "source"
// How to render the new frame on the canvas. See APNG spec.
// xoffset=# -- default: "0"
// yoffset=# -- default: "0"
// Where to draw the frame, relative to the canvas.
//
//
// JPEG:
// -----
//
// quality=# -- default: "92"
// Quality of compression, 0-100 (worst-best).
// Quality >= 90 prevents down-sampling of the color channels.
// Possible values for input format (note that not all image formats
// support saving alpha channels):
// Input is RGB each pixel is represented by three bytes:
// R, G, and B (in that order, regardless of host endianness)
const uint32_t INPUT_FORMAT_RGB = 0;
// Input is RGB each pixel is represented by four bytes:
// R, G, and B (in that order, regardless of host endianness).
// POST-MULTIPLIED alpha us used (50% transparent red is 0xff000080)
const uint32_t INPUT_FORMAT_RGBA = 1;
// Input is host-endian ARGB: On big-endian machines each pixel is therefore
// ARGB, and for little-endian machiens (Intel) each pixel is BGRA
// (This is used by canvas to match it's internal representation)
//
// PRE-MULTIPLIED alpha is used (That is, 50% transparent red is 0x80800000,
// not 0x80ff0000
const uint32_t INPUT_FORMAT_HOSTARGB = 2;
/* data - list of bytes in the format specified by inputFormat
* width - width in pixels
* height - height in pixels
* stride - number of bytes per row in the image
* Normally (width*3) or (width*4), depending on your input format,
* but some data uses padding at the end of each row, which would
* be extra.
* inputFormat - one of INPUT_FORMAT_* specifying the format of data
* outputOptions - semicolon-delimited list of name=value pairs that can
* give options to the output encoder. Options are encoder-
* specific. Just give empty string for default behavior.
*/
void initFromData([array, size_is(length), const] in uint8_t data,
in unsigned long length,
in uint32_t width,
in uint32_t height,
in uint32_t stride,
in uint32_t inputFormat,
in AString outputOptions);
/*
* For encoding images which may contain multiple frames, the 1-shot
* initFromData() interface is too simplistic. The alternative is to
* use startImageEncode(), call addImageFrame() one or more times, and
* then finish initialization with endImageEncode().
*
* The arguments are basically the same as in initFromData().
*/
void startImageEncode(in uint32_t width,
in uint32_t height,
in uint32_t inputFormat,
in AString outputOptions);
void addImageFrame( [array, size_is(length), const] in uint8_t data,
in unsigned long length,
in uint32_t width,
in uint32_t height,
in uint32_t stride,
in uint32_t frameFormat,
in AString frameOptions);
void endImageEncode();
/*
* Sometimes an encoder can contain another encoder and direct access
* to its buffer is necessary. It is only safe to assume that the buffer
* returned from getImageBuffer() is of size equal to getImageBufferUsed().
*/
[noscript] unsigned long getImageBufferUsed();
[noscript] charPtr getImageBuffer();
};