ref: 164821c259bd23ef7b93a6541048bc977bf5783f
dir: /js/h264bsd.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.
*/
function H264Decoder(Module, targetCanvas) {
var self = this;
self.Module = Module;
self.released = false;
self.yuvCanvas = null;
self.pStorage = H264Decoder.h264bsdAlloc(self.Module);
H264Decoder.h264bsdInit(self.Module, self.pStorage, 0);
self.targetCanvas = targetCanvas;
self.useWebGL = H264Decoder.detectWebGl();
};
H264Decoder.RDY = 0;
H264Decoder.PIC_RDY = 1;
H264Decoder.HDRS_RDY = 2;
H264Decoder.ERROR = 3;
H264Decoder.PARAM_SET_ERROR = 4;
H264Decoder.MEMALLOC_ERROR = 5;
H264Decoder.prototype.release = function() {
var self = this;
if(self.released) return;
self.released = true;
H264Decoder.h264bsdShutdown(self.Module, self.pStorage);
H264Decoder.h264bsdFree(self.Module, self.pStorage);
};
H264Decoder.prototype.decode = function(data) {
var self = this;
if(typeof data === 'undefined' || !(data instanceof ArrayBuffer)) {
throw new Error("data must be a ArrayBuffer instance")
}
data = new Uint8Array(data);
var pData = 0; //The offset into the heap when decoding
var pAlloced = 0; //The original pointer to the data buffer (for freeing)
var pBytesRead = 0; //Pointer to bytesRead
var length = data.byteLength; //The byte-wise length of the data to decode
var bytesRead = 0; //The number of bytes read from a decode operation
var retCode = 0; //Return code from a decode operation
var lastPicId = 0; //ID of the last picture decoded
//Get a pointer into the heap were our decoded bytes will live
pData = pAlloced = H264Decoder.malloc(self.Module, length);
self.Module.HEAPU8.set(data, pData);
//get a pointer to where bytesRead will be stored: Uint32 = 4 bytes
pBytesRead = H264Decoder.malloc(self.Module, 4);
//Keep decoding frames while there is still something to decode
while(length > 0) {
retCode = H264Decoder.h264bsdDecode(self.Module, self.pStorage, pData, length, lastPicId, pBytesRead);
bytesRead = self.Module.getValue(pBytesRead, 'i32');
console.log('retCode: ', retCode, 'bytesRead: ', bytesRead);
switch(retCode){
case H264Decoder.PIC_RDY:
lastPicId++;
var evt = new CustomEvent("pictureReady", {
detail: self.getNextOutputPicture()
});
if (self.targetCanvas != null){
self.targetCanvas.dispatchEvent(evt);
}
break;
}
length = length - bytesRead;
pData = pData + bytesRead;
}
if(pAlloced != 0) {
H264Decoder.free(self.Module, pAlloced);
}
if(pBytesRead != 0) {
H264Decoder.free(self.Module, pBytesRead);
}
};
H264Decoder.prototype.getNextOutputPicture = function(){
var self = this;
var length = self.getYUVLength();
var pPicId = H264Decoder.malloc(self.Module, 4);
var picId = 0;
var pIsIdrPic = H264Decoder.malloc(self.Module, 4);
var isIdrPic = 0;
var pNumErrMbs = H264Decoder.malloc(self.Module, 4);
var numErrMbs = 0;
var pBytes = H264Decoder.h264bsdNextOutputPicture(self.Module, self.pStorage, pPicId, pIsIdrPic, pNumErrMbs);
var bytes = null;
picId = self.Module.getValue(pPicId, 'i32');
isIdrPic = self.Module.getValue(pIsIdrPic, 'i32');
numErrMbs = self.Module.getValue(pNumErrMbs, 'i32');
bytes = new Uint8Array();
bytes = self.Module.HEAPU8.subarray(pBytes, (pBytes + length));
H264Decoder.free(self.Module, pPicId);
H264Decoder.free(self.Module, pIsIdrPic);
H264Decoder.free(self.Module, pNumErrMbs);
var ret = {};
var croppingInfo = self.getCroppingInfo();
if (self.useWebGL){
ret = {
encoding: 'YUV',
picture: bytes,
height: croppingInfo.height,
width: croppingInfo.width};
}else{
ret = {
encoding: 'RGB',
picture: H264Decoder.convertYUV2RGB(bytes, croppingInfo),
height: croppingInfo.height,
width: croppingInfo.width};
}
return ret;
};
H264Decoder.prototype.getCroppingInfo = function(){
var self = this;
var pCroppingFlag = H264Decoder.malloc(self.Module, 4);
var pLeftOffset = H264Decoder.malloc(self.Module, 4);
var pTopOffset = H264Decoder.malloc(self.Module, 4);
var pWidth = H264Decoder.malloc(self.Module, 4);
var pHeight = H264Decoder.malloc(self.Module, 4);
var result = {
'width': (H264Decoder.h264bsdPicWidth(self.Module, self.pStorage)*16),
'height': (H264Decoder.h264bsdPicHeight(self.Module, self.pStorage)*16),
'top': 0,
'left': 0
};
H264Decoder.free(self.Module, pCroppingFlag);
H264Decoder.free(self.Module, pLeftOffset);
H264Decoder.free(self.Module, pTopOffset);
H264Decoder.free(self.Module, pWidth);
H264Decoder.free(self.Module, pHeight);
return result;
};
H264Decoder.prototype.getYUVLength = function(){
var self = this;
var width = H264Decoder.h264bsdPicWidth(self.Module, self.pStorage);
var height = H264Decoder.h264bsdPicHeight(self.Module, self.pStorage);
return (width * 16 * height * 16) + (2 * width * 16 * height * 8);
};
//http://www.browserleaks.com/webgl#howto-detect-webgl
H264Decoder.detectWebGl = function()
{
if (!!window.WebGLRenderingContext) {
var canvas = document.createElement("canvas"),
names = ["webgl", "experimental-webgl", "moz-webgl", "webkit-3d"],
context = false;
for(var i=0;i<4;i++) {
try {
context = canvas.getContext(names[i]);
if (context && typeof context.getParameter == "function") {
// WebGL is enabled
return true;
}
} catch(e) {}
}
// WebGL is supported, but disabled
return false;
}
// WebGL not supported
return false;
};
//Excessively pink
H264Decoder.convertYUV2RGB = function(yuvBytes, croppingInfo){
var width = croppingInfo.width - croppingInfo.left;
var height = croppingInfo.height - croppingInfo.top;
var rgbBytes = new Uint8Array();
var cb = width * height;
var cr = cb + ((width * height) / 2);
var numPixels = width * height;
var dst = 0;
var dst_width = 0;
var k = 0;
for (var i = 0; i < numPixels; i += 2)
{
k += 1;
var y1 = yuvBytes[i] & 0xff;
var y2 = yuvBytes[i + 1] & 0xff;
var y3 = yuvBytes[width + i] & 0xff;
var y4 = yuvBytes[width + i + 1] & 0xff;
var v = yuvBytes[cr + k] & 0xff;
var u = yuvBytes[cb + k] & 0xff;
v = v - 128;
u = u - 128;
dst = i * 4;
dst_width = width*4 + dst;
// i
rgbBytes[dst] = 0xff;
rgbBytes[dst + 1] = H264Decoder.clamp((298 * (y1 - 16) + 409 * v + 128) >> 8, 255, 0);
rgbBytes[dst + 2] = H264Decoder.clamp((298 * (y1 - 16) - 100 * u - 208 *v + 128) >> 8, 255,0);
rgbBytes[dst + 3] = H264Decoder.clamp((298 * y1 + 516*u + 128) >> 8, 255, 0);
// i + 1
rgbBytes[dst + 4] = 0xff;
rgbBytes[dst + 5] = H264Decoder.clamp((298 * (y2 - 16) + 409 * v + 128) >> 8, 255, 0);
rgbBytes[dst + 6] = H264Decoder.clamp((298 * (y2 - 16) - 100 * u - 208 *v + 128) >> 8, 255,0);
rgbBytes[dst + 7] = H264Decoder.clamp((298 * y2 + 516*u + 128) >> 8, 255, 0);
//width
rgbBytes[dst_width] = 0xff;
rgbBytes[dst_width + 1] = H264Decoder.clamp((298 * (y3 - 16) + 409 * v + 128) >> 8, 255, 0);
rgbBytes[dst_width + 2] = H264Decoder.clamp((298 * (y2 - 16) - 100 * u - 208 *v + 128) >> 8, 255,0);
rgbBytes[dst_width + 3] = H264Decoder.clamp((298 * y3 + 516*u + 128) >> 8, 255, 0);
//width + 1
rgbBytes[dst_width + 4] = 0xff;
rgbBytes[dst_width + 5] = H264Decoder.clamp((298 * (y4 - 16) + 409 * v + 128) >> 8, 255, 0);
rgbBytes[dst_width + 6] = H264Decoder.clamp((298 * (y4 - 16) - 100 * u - 208 *v + 128) >> 8, 255,0);
rgbBytes[dst_width + 7] = H264Decoder.clamp((298 * y4 + 516*u + 128) >> 8, 255, 0);
if (i != 0 && (i+2)%width ==0) {
i += width;
}
}
return rgbBytes;
};
H264Decoder.clamp = function(num, max, min) {
return Math.min(Math.max(num, min), max);
};
// u32 h264bsdDecode(storage_t *pStorage, u8 *byteStrm, u32 len, u32 picId, u32 *readBytes);
H264Decoder.h264bsdDecode = function(Module, pStorage, pBytes, len, picId, pBytesRead) {
return Module.ccall('h264bsdDecode', Number,
[Number, Number, Number, Number, Number],
[pStorage, pBytes, len, picId, pBytesRead]);
};
// storage_t* h264bsdAlloc();
H264Decoder.h264bsdAlloc = function(Module) {
return Module.ccall('h264bsdAlloc', Number);
};
// void h264bsdFree(storage_t *pStorage);
H264Decoder.h264bsdFree = function(Module, pStorage) {
Module.ccall('h264bsdFree', null, [Number], [pStorage]);
};
// u32 h264bsdInit(storage_t *pStorage, u32 noOutputReordering);
H264Decoder.h264bsdInit = function(Module, pStorage, noOutputReordering) {
return Module.ccall('h264bsdInit', Number, [Number, Number], [pStorage, noOutputReordering]);
};
//void h264bsdShutdown(storage_t *pStorage);
H264Decoder.h264bsdShutdown = function(Module, pStorage) {
Module.ccall('h264bsdShutdown', null, [Number], [pStorage]);
};
// u8* h264bsdNextOutputPicture(storage_t *pStorage, u32 *picId, u32 *isIdrPic, u32 *numErrMbs);
H264Decoder.h264bsdNextOutputPicture = function(Module, pStorage, pPicId, pIsIdrPic, pNumErrMbs) {
return Module.ccall('h264bsdNextOutputPicture',
Number,
[Number, Number, Number, Number],
[pStorage, pPicId, pIsIdrPic, pNumErrMbs]);
};
// u32 h264bsdPicWidth(storage_t *pStorage);
H264Decoder.h264bsdPicWidth = function(Module, pStorage) {
return Module.ccall('h264bsdPicWidth', Number, [Number], [pStorage]);
};
// u32 h264bsdPicHeight(storage_t *pStorage);
H264Decoder.h264bsdPicHeight = function(Module, pStorage) {
return Module.ccall('h264bsdPicHeight', Number, [Number], [pStorage]);
};
// void h264bsdCroppingParams(storage_t *pStorage, u32 *croppingFlag, u32 *left, u32 *width, u32 *top, u32 *height);
H264Decoder.h264bsdCroppingParams = function(Module, pStorage, pCroppingFlag, pLeft, pWidth, pTop, pHeight) {
return Module.ccall('h264bsdCroppingParams',
Number,
[Number, Number, Number, Number, Number, Number, Number],
[pStorage, pCroppingFlag, pLeft, pWidth, pTop, pHeight]);
};
// u32 h264bsdCheckValidParamSets(storage_t *pStorage);
H264Decoder.h264bsdCheckValidParamSets = function(Module, pStorage){
return Module.ccall('h264bsdCheckValidParamSets', Number, [Number], [pStorage]);
};
// void* malloc(size_t size);
H264Decoder.malloc = function(Module, size){
return Module.ccall('malloc', Number, [Number], [size]);
};
// void free(void* ptr);
H264Decoder.free = function(Module, ptr){
return Module.ccall('free', null, [Number], [ptr]);
};
// void* memcpy(void* dest, void* src, size_t size);
H264Decoder.memcpy = function(Module, length){
return Module.ccall('malloc', Number, [Number, Number, Number], [dest, src, size]);
};