ref: e9abdf4e1f0586d3b50cc19c34098c1be13b9d68
dir: h264bsd/js/h264bsd_decoder.js
//
// Copyright (c) 2013 Sam Leitch. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
/**
* This class wraps the details of the h264bsd library.
* Module object is an Emscripten module provided globally by h264bsd_asm.js
*
* In order to use this class, you first queue encoded data using queueData.
* Each call to decode() will decode a single encoded element.
* When decode() return H264bsdDecoder.PIC_RDY, a picture is ready in the output buffer.
* The output buffer can be accessed by calling getNextOutputPicture()
* An output picture may also be decoded using an H264bsdCanvas.
* When you're done decoding, make sure to call release() to clean up internal buffers.
*/
function H264bsdDecoder(module) {
this.module = module;
this.released = false;
this.pInput = 0;
this.inputLength = 0;
this.inputOffset = 0;
this.pStorage = module._h264bsdAlloc();
module._h264bsdInit(this.pStorage, 0);
};
H264bsdDecoder.RDY = 0;
H264bsdDecoder.PIC_RDY = 1;
H264bsdDecoder.HDRS_RDY = 2;
H264bsdDecoder.ERROR = 3;
H264bsdDecoder.PARAM_SET_ERROR = 4;
H264bsdDecoder.MEMALLOC_ERROR = 5;
/**
* Clean up memory used by the decoder
*/
H264bsdDecoder.prototype.release = function() {
var module = this.module;
var pStorage = this.pStorage;
var pInput = this.pInput;
if(pStorage != 0) {
module._h264bsdShutdown(pStorage);
module._h264bsdFree(pStorage);
}
if(pInput != 0) {
module._free(pInput);
}
this.pStorage = 0;
this.pInput = 0;
this.inputLength = 0;
this.inputOffset = 0;
};
/**
* Queue ArrayBuffer data to be decoded
*/
H264bsdDecoder.prototype.queueData(data) {
var module = this.module
var pInput = this.pInput;
var inputLength = this.inputLength;
var inputOffset = this.inputOffset;
if(typeof data === 'undefined' || !(data instanceof ArrayBuffer)) {
throw new Error("data must be a ArrayBuffer instance")
}
data = new Uint8Array(data);
if(pInput === 0) {
inputLength = data.byteLength;
pInput = module._malloc(inputLength);
inputOffset = 0;
module.HEAPU8.set(data, pInput);
} else {
var remainingInputLength = inputLength - inputOffset;
var newInputLength = remainingInputLength + data.byteLength;
var pNewInput = module._malloc(newInputLength);
module._memcpy(pNewInput, pInput + inputOffset, remainingInputLength);
module.HEAPU8.set(data, pNewInput + remainingInputLength);
module._free(pInput);
pInput = pNewInput;
inputLength = newInputLength;
inputOffset = 0;
}
this.pInput = input;
this.inputLength = inputLength;
this.inputOffset = inputOffset;
}
/**
* Decodes the next NAL unit from the queued data.
* Returns H264bsdDecoder.PIC_RDY when a new picture is ready.
* Pictures can be accessed using nextOutputPicture() or nextOutputPictureARGB()
*/
H264bsdDecoder.prototype.decode = function(picId) {
var module = this.module;
var pStorage = this.pStorage;
var pInput = this.pInput;
var inputLength = this.inputLength;
var inputOffset = this.inputOffset;
if(pInput == 0) return H264bsdDecoder.ERROR;
var pBytesRead = module._malloc(4);
var retCode = module._h264bsdDecode(pStorage, pInput + inputOffset, inputLength - inputOffset, 0, pBytesRead);
var bytesRead = module.getValue(pBytesRead, 'i32');
module._free(pBytesRead);
inputOffset += bytesRead;
if(inputOffset >= inputLength) {
module._free(pInput);
pInput = 0;
inputOffset = 0;
inputLength = 0;
}
this.pInput = pInput;
this.inputLength = inputLength;
this.inputOffset = inputOffset;
return retCode;
};
/**
* Returns the next output picture as an I420 encoded image.
*/
H264bsdDecoder.prototype.nextOutputPicture = function() {
var module = this.module;
var pStorage = this.pStorage;
var pPicId = module._malloc(4);
var pIsIdrPic = module._malloc(4);
var pNumErrMbs = module._malloc(4);
var pBytes = module._h264bsdNextOutputPicture(pStorage, pPicId, pIsIdrPic, pNumErrMbs);
// None of these values are currently used.
module._free(pPicId);
module._free(pIsIdrPic);
module._free(pNumErrMbs);
var outputSizeMB = this.getOutputSizeMB();
var outputLength = (outputSizeMB.width * outputSizeMB.height) * 3 / 2;
var outputBytes = new UInt8Array(self.Module.HEAPU8, pBytes, outputLength);
return outputBytes
};
/**
* Returns the next output picture as an ARGB encoded image.
* Note: There is extra overhead required to convert the image to ARGB.
* This method should be avoided if possible.
*/
H264bsdDecoder.prototype.nextOutputPictureARGB = function() {
var module = this.module;
var pStorage = this.pStorage;
var pPicId = module._malloc(4);
var pIsIdrPic = module._malloc(4);
var pNumErrMbs = module._malloc(4);
var pBytes = module._h264bsdNextOutputPictureARGB(pStorage, pPicId, pIsIdrPic, pNumErrMbs);
// None of these values are currently used.
module._free(pPicId);
module._free(pIsIdrPic);
module._free(pNumErrMbs);
var outputSizeMB = this.getOutputSizeMB();
var outputLength = (outputSizeMB.width * outputSizeMB.height) * 4;
var outputBytes = new UInt8Array(self.Module.HEAPU8, pBytes, outputLength);
return outputBytes
};
/**
* Returns an object containing the width and height of output pictures in MB.
* This value is only valid after at least one call to decode() has returned H264bsdDecoder.HDRS_RDY
*/
H264bsdDecoder.prototype.outputSizeMB = function() {
var module = this.module;
var pStorage = this.pStorage;
var width = module._h264bsdPicWidth(pStorage);
var height = module._h264bsdPicHeight(pStorage);
return {'width': width, 'height': height};
};
/**
* Returns the info used to crop output images to there final viewing dimensions.
* If this method returns null no cropping info is provided and the full image should be presented.
*/
H264bsdDecoder.prototype.croppingInfo = function(){
var module = this.module;
var pStorage = this.pStorage;
var pCroppingFlag = self.malloc_(4);
var pLeftOffset = self.malloc_(4);
var pWidth = self.malloc_(4);
var pTopOffset = self.malloc_(4);
var pHeight = self.malloc_(4);
module._h264bsdCroppingParams(pStorage, pCroppingFlag, pLeftOffset, pWidth, pTopOffset, pHeight);
var croppingFlag = self.Module.getValue(pCroppingFlag, 'i32');
var leftOffset = self.Module.getValue(pLeftOffset, 'i32');
var width = self.Module.getValue(pWidth, 'i32');
var topOffset = self.Module.getValue(pTopOffset, 'i32');
var height = self.Module.getValue(pHeight, 'i32');
module._free(pCroppingFlag);
module._free(pLeftOffset);
module._free(pWidth);
module._free(pTopOffset);
module._free(pHeight);
if(croppingFlag === 0) return null;
return {
'width': width,
'height': height,
'top': topOffset,
'left': leftOffset
};
};