起因
今天在做项目的时候遇到下载的视频文件格式是m3u8，且播放器不能播放。产品经理提出需要下载可播放的视频格式。便研究起来如何m3u8转mp4并下载。
旧版本
后端所给的是一个对应的加密链接，将加密链接放入 a 标签内即可实现下载功能。但下载的是m3u8文件。
解决方案
在码云上查到一篇关于前端处理m3u8文件格式转化的文章。代码拉取git
我把其中可直接使用的转mp4的部分提取出来。直接调用getMp4(url);即可实现下载与转化！
m3u8Change.js
import { Transmuxer } from '@/utils/mux-mp4.js'
import { message } from 'antd'
const m3u8Change = {
url: '', // 在线链接
tips: 'm3u8 视频', // 顶部提示
title: '', // 视频标题
isPause: false, // 是否暂停下载
isGetMP4: false, // 是否转码为 MP4 下载
durationSecond: 0, // 视频持续时长
isShowRefer: true, // 是否显示推送
downloading: false, // 是否下载中
beginTime: '', // 开始下载的时间
errorNum: 0, // 错误数
finishNum: 0, // 已下载数
downloadIndex: 0, // 当前下载片段
finishList: [], // 下载完成项目
tsUrlList: [], // ts URL数组
mediaFileList: [], // 下载的媒体数组
rangeDownload: { // 特定范围下载
isShowRange: false, // 是否显示范围下载
startSegment: '', // 起始片段
endSegment: '', // 截止片段
targetSegment: 1, // 待下载片段
},
aesConf: { // AES 视频解密配置
method: '', // 加密算法
uri: '', // key 所在文件路径
iv: '', // 偏移值
key: '', // 秘钥
decryptor: null, // 解码器对象
stringToBuffer: function (str) {
return new TextEncoder().encode(str)
},
},
// 获取视频标题
getTitle() {
let { href } = location
const currentUrl = new URL(location.href)
const title = currentUrl.searchParams.get('title')
if (title) {
this.title = title
}
},
// 退出弹窗
onKeyup(event) {
if (event.keyCode === 13) { // 键入ESC
this.getM3U8()
}
},
// ajax 请求
ajax(options) {
options = options || {};
let xhr = new XMLHttpRequest();
if (options.type === 'file') {
xhr.responseType = 'arraybuffer';
}
xhr.onreadystatechange = function () {
if (xhr.readyState === 4) {
let status = xhr.status;
if (status >= 200 && status < 300) {
options.success && options.success(xhr.response);
} else {
options.fail && options.fail(status);
}
}
};
xhr.open("GET", options.url, true);
xhr.send(null);
},
// 合成URL
applyURL(targetURL, baseURL) {
baseURL = baseURL || location.href
if (targetURL.indexOf('http') === 0) {
// 当前页面使用 https 协议时，强制使 ts 资源也使用 https 协议获取
if (location.href.indexOf('https') === 0) {
return targetURL.replace('http://', 'https://')
}
return targetURL
} else if (targetURL[0] === '/') {
let domain = baseURL.split('/')
return domain[0] + '//' + domain[2] + targetURL
} else {
let domain = baseURL.split('/')
domain.pop()
return domain.join('/') + '/' + targetURL
}
},
// 解析为 mp4 下载
getMP4(pullUrl) {
// this.url = 'http://1257120875.vod2.myqcloud.com/0ef121cdvodtransgzp1257120875/3055695e5285890780828799271/v.f230.m3u8';
this.url = pullUrl;
this.isGetMP4 = true
this.getM3U8()
console.log(this.finishNum);
},
// 获取在线文件
getM3U8(onlyGetRange) {
if (!this.url) {
alert('请输入链接')
return
}
if (this.url.toLowerCase().indexOf('.m3u8') === -1) {
alert('链接有误，请重新输入')
return
}
if (this.downloading) {
if (this.finishNum === this.rangeDownload.targetSegment && this.rangeDownload.targetSegment > 0) {
alert("请刷新页面后重试");
} else {
alert('资源下载中，请稍后');
}
return
}
// 在下载页面才触发，代码注入的页面不需要校验
// 当前协议不一致，切换协议
if (location.href.indexOf('blog.luckly-mjw.cn') > -1 && this.url.indexOf(location.protocol) === -1) {
//alert('当前协议不一致，跳转至正确页面重新下载')
location.href = `${this.url.split(':')[0]}://blog.luckly-mjw.cn/tool-show/m3u8-downloader/index.html?source=${this.url}`
return
}
// 在下载页面才触发，修改页面 URL，携带下载路径，避免刷新后丢失
if (location.href.indexOf('blog.luckly-mjw.cn') > -1) {
window.history.replaceState(null, '', `${location.href.split('?')[0]}?source=${this.url}`)
}
this.tips = 'm3u8 文件下载中，请稍后'
this.beginTime = new Date()
this.ajax({
url: this.url,
success: (m3u8Str) => {
this.tsUrlList = []
this.finishList = []
// 提取 ts 视频片段地址
m3u8Str.split('\n').forEach((item) => {
if (item.toLowerCase().indexOf('.ts') > -1 || item.toLowerCase().indexOf('.image') > -1) {
this.tsUrlList.push(this.applyURL(item, this.url))
this.finishList.push({
title: item,
status: ''
})
}
})
console.log('finishList', this.finishList);
// 仅获取视频片段数
if (onlyGetRange) {
this.rangeDownload.isShowRange = true
this.rangeDownload.endSegment = this.tsUrlList.length
this.rangeDownload.targetSegment = this.tsUrlList.length
return
} else {
let startSegment = Math.max('' || 1, 1) // 最小为 1
let endSegment = Math.max('' || this.tsUrlList.length, 1)
startSegment = Math.min(startSegment, this.tsUrlList.length) // 最大为 this.tsUrlList.length
endSegment = Math.min(endSegment, this.tsUrlList.length)
this.rangeDownload.startSegment = Math.min(startSegment, endSegment)
this.rangeDownload.endSegment = Math.max(startSegment, endSegment)
this.rangeDownload.targetSegment = this.rangeDownload.endSegment - this.rangeDownload.startSegment + 1
this.downloadIndex = this.rangeDownload.startSegment - 1
this.downloading = true;
message.info("资源下载中...")
}
// 获取需要下载的 MP4 视频长度
if (this.isGetMP4) {
let infoIndex = 0
m3u8Str.split('\n').forEach(item => {
if (item.toUpperCase().indexOf('#EXTINF:') > -1) { // 计算视频总时长，设置 mp4 信息时使用
infoIndex++
if (this.rangeDownload.startSegment <= infoIndex && infoIndex <= this.rangeDownload.endSegment) {
this.durationSecond += parseFloat(item.split('#EXTINF:')[1])
}
}
})
}
console.log(this.tsUrlList.length);
// 检测视频 AES 加密
if (m3u8Str.indexOf('#EXT-X-KEY') > -1) {
this.aesConf.method = (m3u8Str.match(/(.*METHOD=([^,\s]+))/) || ['', '', ''])[2]
this.aesConf.uri = (m3u8Str.match(/(.*URI="([^"]+))"/) || ['', '', ''])[2]
this.aesConf.iv = (m3u8Str.match(/(.*IV=([^,\s]+))/) || ['', '', ''])[2]
this.aesConf.iv = this.aesConf.iv ? this.aesConf.stringToBuffer(this.aesConf.iv) : ''
this.aesConf.uri = this.applyURL(this.aesConf.uri, this.url)
// let params = m3u8Str.match(/#EXT-X-KEY:([^,]*,?METHOD=([^,]+))?([^,]*,?URI="([^,]+)")?([^,]*,?IV=([^,^\n]+))?/)
// this.aesConf.method = params[2]
// this.aesConf.uri = this.applyURL(params[4], this.url)
// this.aesConf.iv = params[6] ? this.aesConf.stringToBuffer(params[6]) : ''
this.getAES();
} else if (this.tsUrlList.length > 0) { // 如果视频没加密，则直接下载片段，否则先下载秘钥
this.downloadTS()
} else {
alert('资源为空，请查看链接是否有效')
}
},
fail: () => {
alert('链接不正确，请查看链接是否有效')
}
})
},
// 获取AES配置
getAES() {
alert('视频被 AES 加密，点击确认，进行视频解码')
this.ajax({
type: 'file',
url: this.aesConf.uri,
success: (key) => {
// console.log('getAES', key)
// this.aesConf.key = this.aesConf.stringToBuffer(key)
this.aesConf.key = key
this.aesConf.decryptor = new AESDecryptor()
this.aesConf.decryptor.constructor()
this.aesConf.decryptor.expandKey(this.aesConf.key);
this.downloadTS()
},
fail: () => {
alert('视频已进行定制化加密，不提供定制化解密下载')
}
})
},
// ts 片段的 AES 解码
aesDecrypt(data, index) {
let iv = this.aesConf.iv || new Uint8Array([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, index])
return this.aesConf.decryptor.decrypt(data, 0, iv.buffer || iv, true)
},
// 下载分片
downloadTS() {
this.tips = 'ts 视频碎片下载中，请稍后'
console.log(this.tips);
let download = () => {
console.log("index >= this.rangeDownload.endSegment", index >= this.rangeDownload.endSegment);
let isPause = false // 使用另一个变量来保持下载前的暂停状态，避免回调后没修改
let index = this.downloadIndex
if (index >= this.rangeDownload.endSegment) {
return
}
this.downloadIndex++
console.log(this.finishList[index], this.finishList[index].status === '');
if (this.finishList[index] && this.finishList[index].status === '') {
this.ajax({
url: this.tsUrlList[index],
type: 'file',
success: (file) => {
this.dealTS(file, index, () => this.downloadIndex < this.rangeDownload.endSegment && !isPause && download())
console.log(this.dealTS);
},
fail: () => {
console.log('error');
this.errorNum++
this.finishList[index].status = 'error'
if (this.downloadIndex < this.rangeDownload.endSegment) {
!isPause && download()
}
}
})
} else if (this.downloadIndex < this.rangeDownload.endSegment) { // 跳过已经成功的片段
!isPause && download()
}
}
console.log(Math.min(6, this.rangeDownload.targetSegment - this.finishNum));
// 建立多少个 ajax 线程
for (let i = 0; i < Math.min(6, this.rangeDownload.targetSegment - this.finishNum); i++) {
download()
}
},
// 处理 ts 片段，AES 解密、mp4 转码
dealTS(file, index, callback) {
const data = this.aesConf.uri ? this.aesDecrypt(file, index) : file
this.conversionMp4(data, index, (afterData) => { // mp4 转码
this.mediaFileList[index - this.rangeDownload.startSegment + 1] = afterData // 判断文件是否需要解密
this.finishList[index].status = 'finish'
this.finishNum++
if (this.finishNum === this.rangeDownload.targetSegment) {
let fileName = this.title || this.formatTime(this.beginTime, 'YYYY_MM_DD hh_mm_ss')
if (document.title !== 'm3u8 downloader') {
fileName = window.top.document.title
}
this.downloadFile(this.mediaFileList, fileName)
}
callback && callback()
})
},
// 转码为 mp4
conversionMp4(data, index, callback) {
console.log("data", data);
if (this.isGetMP4) {
let transmuxer = new muxjs.Transmuxer({
keepOriginalTimestamps: true,
duration: parseInt(this.durationSecond),
});
transmuxer.on('data', segment => {
if (index === this.rangeDownload.startSegment - 1) {
let data = new Uint8Array(segment.initSegment.byteLength + segment.data.byteLength);
data.set(segment.initSegment, 0);
data.set(segment.data, segment.initSegment.byteLength);
callback(data.buffer)
} else {
callback(segment.data)
}
})
transmuxer.push(new Uint8Array(data));
transmuxer.flush();
} else {
callback(data)
}
},
// 暂停与恢复
togglePause() {
this.isPause = !this.isPause
!this.isPause && this.retryAll()
},
// 重新下载某个片段
retry(index) {
if (this.finishList[index].status === 'error') {
this.finishList[index].status = ''
this.ajax({
url: this.tsUrlList[index],
type: 'file',
success: (file) => {
this.errorNum--
this.dealTS(file, index)
},
fail: () => {
this.finishList[index].status = 'error'
}
})
}
},
// 重新下载所有错误片段
retryAll() {
if (!this.finishList.length || this.isPause) {
return
}
let firstErrorIndex = this.downloadIndex // 没有错误项目，则每次都递增
this.finishList.forEach((item, index) => { // 重置所有片段状态
if (item.status === 'error') {
item.status = ''
firstErrorIndex = Math.min(firstErrorIndex, index)
}
})
this.errorNum = 0
// 已经全部下载进程都跑完了，则重新启动下载进程
if (this.downloadIndex >= this.rangeDownload.endSegment) {
this.downloadIndex = firstErrorIndex
this.downloadTS()
} else { // 否则只是将下载索引，改为最近一个错误的项目，从那里开始遍历
this.downloadIndex = firstErrorIndex
}
},
// 下载整合后的TS文件
downloadFile(fileDataList, fileName) {
this.tips = 'ts 碎片整合中，请留意浏览器下载'
console.log(this.tips);
let fileBlob = null
let a = document.createElement('a')
if (this.isGetMP4) {
fileBlob = new Blob(fileDataList, { type: 'video/mp4' }) // 创建一个Blob对象，并设置文件的 MIME 类型
a.download = fileName + '.mp4'
} else {
fileBlob = new Blob(fileDataList, { type: 'video/MP2T' }) // 创建一个Blob对象，并设置文件的 MIME 类型
a.download = fileName + '.ts'
}
a.href = URL.createObjectURL(fileBlob)
a.style.display = 'none'
document.body.appendChild(a)
a.click()
a.remove()
this.downloading = false
},
// 格式化时间
formatTime(date, formatStr) {
const formatType = {
Y: date.getFullYear(),
M: date.getMonth() + 1,
D: date.getDate(),
h: date.getHours(),
m: date.getMinutes(),
s: date.getSeconds(),
}
return formatStr.replace(
/Y+|M+|D+|h+|m+|s+/g,
target => (new Array(target.length).join('0') + formatType[target[0]]).substr(-target.length)
)
},
// 强制下载现有片段
forceDownload() {
if (this.mediaFileList.length) {
let fileName = this.title || this.formatTime(this.beginTime, 'YYYY_MM_DD hh_mm_ss')
if (document.title !== 'm3u8 downloader') {
fileName = window.top.document.title
}
this.downloadFile(this.mediaFileList, fileName)
} else {
alert('当前无已下载片段')
}
},
// 发生错误，进行提示
alertError(tips) {
alert(tips)
this.downloading = false
this.tips = 'm3u8 视频在线提取工具';
},
// 拷贝本页面本身，解决跨域问题
copyCode() {
if (this.tips !== '代码下载中，请稍后') {
this.tips = '代码下载中，请稍后';
this.ajax({
url: './index.html',
success: (fileStr) => {
let fileList = fileStr.split(`<!--vue 前端框架--\>`);
let dom = fileList[0];
let script = fileList[1] + fileList[2];
script = script.split('// script注入');
script = script[1] + script[2];
if (this.url) {
script = script.replace(`url: '', // 在线链接`, `url: '${this.url}',`);
}
let codeStr = `
// 注入html
let $section = document.createElement('section')
$section.innerHTML = \`${dom}\`
$section.style.width = '100%'
$section.style.height = '800px'
$section.style.top = '0'
$section.style.left = '0'
$section.style.position = 'relative'
$section.style.zIndex = '9999'
$section.style.backgroundColor = 'white'
document.body.appendChild($section);
// 加载 ASE 解密
let $ase = document.createElement('script')
$ase.src = 'https://upyun.luckly-mjw.cn/lib/aes-decryptor.js'
// 加载 mp4 转码
let $mp4 = document.createElement('script')
$mp4.src = 'https://upyun.luckly-mjw.cn/lib/mux-mp4.js'
// 加载 vue
let $vue = document.createElement('script')
$vue.src = 'https://upyun.luckly-mjw.cn/lib/vue.js'
// 监听 vue 加载完成，执行业务代码
$vue.addEventListener('load', () => {${script}})
document.body.appendChild($vue);
document.body.appendChild($mp4);
document.body.appendChild($ase);
alert('注入成功，请滚动到页面底部，若白屏则等待资源加载')
`;
this.copyToClipboard(codeStr);
this.tips = '复制成功，打开视频网页控制台，注入本代码';
},
fail: () => {
alert('链接不正确，请查看链接是否有效');
},
})
}
},
// 拷贝剪切板
copyToClipboard(content) {
clearTimeout(this.timeouter)
if (!document.queryCommandSupported('copy')) {
return false
}
let $input = document.createElement('textarea')
$input.style.opacity = '0'
$input.value = content
document.body.appendChild($input)
$input.select()
const result = document.execCommand('copy')
document.body.removeChild($input)
$input = null
return result
}
}
export default m3u8Change;mux-mp4.js
(function(f){var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.muxjs = f()})(function(){var define,module,exports;return (function(){function r(e,n,t){function o(i,f){if(!n[i]){if(!e[i]){var c="function"==typeof require&&require;if(!f&&c)return c(i,!0);if(u)return u(i,!0);var a=new Error("Cannot find module '"+i+"'");throw a.code="MODULE_NOT_FOUND",a}var p=n[i]={exports:{}};e[i][0].call(p.exports,function(r){var n=e[i][1][r];return o(n||r)},p,p.exports,r,e,n,t)}return n[i].exports}for(var u="function"==typeof require&&require,i=0;i<t.length;i++)o(t[i]);return o}return r})()({1:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*
* A stream-based aac to mp4 converter. This utility can be used to
* deliver mp4s to a SourceBuffer on platforms that support native
* Media Source Extensions.
*/
'use strict';
var Stream = require(31);
var aacUtils = require(2);
// Constants
var AacStream;
/**
* Splits an incoming stream of binary data into ADTS and ID3 Frames.
*/
AacStream = function() {
var
everything = new Uint8Array(),
timeStamp = 0;
AacStream.prototype.init.call(this);
this.setTimestamp = function(timestamp) {
timeStamp = timestamp;
};
this.push = function(bytes) {
var
frameSize = 0,
byteIndex = 0,
bytesLeft,
chunk,
packet,
tempLength;
// If there are bytes remaining from the last segment, prepend them to the
// bytes that were pushed in
if (everything.length) {
tempLength = everything.length;
everything = new Uint8Array(bytes.byteLength + tempLength);
everything.set(everything.subarray(0, tempLength));
everything.set(bytes, tempLength);
} else {
everything = bytes;
}
while (everything.length - byteIndex >= 3) {
if ((everything[byteIndex] === 'I'.charCodeAt(0)) &&
(everything[byteIndex + 1] === 'D'.charCodeAt(0)) &&
(everything[byteIndex + 2] === '3'.charCodeAt(0))) {
// Exit early because we don't have enough to parse
// the ID3 tag header
if (everything.length - byteIndex < 10) {
break;
}
// check framesize
frameSize = aacUtils.parseId3TagSize(everything, byteIndex);
// Exit early if we don't have enough in the buffer
// to emit a full packet
// Add to byteIndex to support multiple ID3 tags in sequence
if (byteIndex + frameSize > everything.length) {
break;
}
chunk = {
type: 'timed-metadata',
data: everything.subarray(byteIndex, byteIndex + frameSize)
};
this.trigger('data', chunk);
byteIndex += frameSize;
continue;
} else if (((everything[byteIndex] & 0xff) === 0xff) &&
((everything[byteIndex + 1] & 0xf0) === 0xf0)) {
// Exit early because we don't have enough to parse
// the ADTS frame header
if (everything.length - byteIndex < 7) {
break;
}
frameSize = aacUtils.parseAdtsSize(everything, byteIndex);
// Exit early if we don't have enough in the buffer
// to emit a full packet
if (byteIndex + frameSize > everything.length) {
break;
}
packet = {
type: 'audio',
data: everything.subarray(byteIndex, byteIndex + frameSize),
pts: timeStamp,
dts: timeStamp
};
this.trigger('data', packet);
byteIndex += frameSize;
continue;
}
byteIndex++;
}
bytesLeft = everything.length - byteIndex;
if (bytesLeft > 0) {
everything = everything.subarray(byteIndex);
} else {
everything = new Uint8Array();
}
};
this.reset = function() {
everything = new Uint8Array();
this.trigger('reset');
};
this.endTimeline = function() {
everything = new Uint8Array();
this.trigger('endedtimeline');
};
};
AacStream.prototype = new Stream();
module.exports = AacStream;
},{"2":2,"31":31}],2:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*
* Utilities to detect basic properties and metadata about Aac data.
*/
'use strict';
var ADTS_SAMPLING_FREQUENCIES = [
96000,
88200,
64000,
48000,
44100,
32000,
24000,
22050,
16000,
12000,
11025,
8000,
7350
];
var parseId3TagSize = function(header, byteIndex) {
var
returnSize = (header[byteIndex + 6] << 21) |
(header[byteIndex + 7] << 14) |
(header[byteIndex + 8] << 7) |
(header[byteIndex + 9]),
flags = header[byteIndex + 5],
footerPresent = (flags & 16) >> 4;
// if we get a negative returnSize clamp it to 0
returnSize = returnSize >= 0 ? returnSize : 0;
if (footerPresent) {
return returnSize + 20;
}
return returnSize + 10;
};
var getId3Offset = function(data, offset) {
if (data.length - offset < 10 ||
data[offset] !== 'I'.charCodeAt(0) ||
data[offset + 1] !== 'D'.charCodeAt(0) ||
data[offset + 2] !== '3'.charCodeAt(0)) {
return offset;
}
offset += parseId3TagSize(data, offset);
return getId3Offset(data, offset);
};
// TODO: use vhs-utils
var isLikelyAacData = function(data) {
var offset = getId3Offset(data, 0);
return data.length >= offset + 2 &&
(data[offset] & 0xFF) === 0xFF &&
(data[offset + 1] & 0xF0) === 0xF0 &&
// verify that the 2 layer bits are 0, aka this
// is not mp3 data but aac data.
(data[offset + 1] & 0x16) === 0x10;
};
var parseSyncSafeInteger = function(data) {
return (data[0] << 21) |
(data[1] << 14) |
(data[2] << 7) |
(data[3]);
};
// return a percent-encoded representation of the specified byte range
// @see http://en.wikipedia.org/wiki/Percent-encoding
var percentEncode = function(bytes, start, end) {
var i, result = '';
for (i = start; i < end; i++) {
result += '%' + ('00' + bytes[i].toString(16)).slice(-2);
}
return result;
};
// return the string representation of the specified byte range,
// interpreted as ISO-8859-1.
var parseIso88591 = function(bytes, start, end) {
return unescape(percentEncode(bytes, start, end)); // jshint ignore:line
};
var parseAdtsSize = function(header, byteIndex) {
var
lowThree = (header[byteIndex + 5] & 0xE0) >> 5,
middle = header[byteIndex + 4] << 3,
highTwo = header[byteIndex + 3] & 0x3 << 11;
return (highTwo | middle) | lowThree;
};
var parseType = function(header, byteIndex) {
if ((header[byteIndex] === 'I'.charCodeAt(0)) &&
(header[byteIndex + 1] === 'D'.charCodeAt(0)) &&
(header[byteIndex + 2] === '3'.charCodeAt(0))) {
return 'timed-metadata';
} else if ((header[byteIndex] & 0xff === 0xff) &&
((header[byteIndex + 1] & 0xf0) === 0xf0)) {
return 'audio';
}
return null;
};
var parseSampleRate = function(packet) {
var i = 0;
while (i + 5 < packet.length) {
if (packet[i] !== 0xFF || (packet[i + 1] & 0xF6) !== 0xF0) {
// If a valid header was not found, jump one forward and attempt to
// find a valid ADTS header starting at the next byte
i++;
continue;
}
return ADTS_SAMPLING_FREQUENCIES[(packet[i + 2] & 0x3c) >>> 2];
}
return null;
};
var parseAacTimestamp = function(packet) {
var frameStart, frameSize, frame, frameHeader;
// find the start of the first frame and the end of the tag
frameStart = 10;
if (packet[5] & 0x40) {
// advance the frame start past the extended header
frameStart += 4; // header size field
frameStart += parseSyncSafeInteger(packet.subarray(10, 14));
}
// parse one or more ID3 frames
// http://id3.org/id3v2.3.0#ID3v2_frame_overview
do {
// determine the number of bytes in this frame
frameSize = parseSyncSafeInteger(packet.subarray(frameStart + 4, frameStart + 8));
if (frameSize < 1) {
return null;
}
frameHeader = String.fromCharCode(packet[frameStart],
packet[frameStart + 1],
packet[frameStart + 2],
packet[frameStart + 3]);
if (frameHeader === 'PRIV') {
frame = packet.subarray(frameStart + 10, frameStart + frameSize + 10);
for (var i = 0; i < frame.byteLength; i++) {
if (frame[i] === 0) {
var owner = parseIso88591(frame, 0, i);
if (owner === 'com.apple.streaming.transportStreamTimestamp') {
var d = frame.subarray(i + 1);
var size = ((d[3] & 0x01) << 30) |
(d[4] << 22) |
(d[5] << 14) |
(d[6] << 6) |
(d[7] >>> 2);
size *= 4;
size += d[7] & 0x03;
return size;
}
break;
}
}
}
frameStart += 10; // advance past the frame header
frameStart += frameSize; // advance past the frame body
} while (frameStart < packet.byteLength);
return null;
};
module.exports = {
isLikelyAacData: isLikelyAacData,
parseId3TagSize: parseId3TagSize,
parseAdtsSize: parseAdtsSize,
parseType: parseType,
parseSampleRate: parseSampleRate,
parseAacTimestamp: parseAacTimestamp
};
},{}],3:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*/
'use strict';
var Stream = require(31);
var ONE_SECOND_IN_TS = require(29).ONE_SECOND_IN_TS;
var AdtsStream;
var
ADTS_SAMPLING_FREQUENCIES = [
96000,
88200,
64000,
48000,
44100,
32000,
24000,
22050,
16000,
12000,
11025,
8000,
7350
];
/*
* Accepts a ElementaryStream and emits data events with parsed
* AAC Audio Frames of the individual packets. Input audio in ADTS
* format is unpacked and re-emitted as AAC frames.
*
* @see http://wiki.multimedia.cx/index.php?title=ADTS
* @see http://wiki.multimedia.cx/?title=Understanding_AAC
*/
AdtsStream = function(handlePartialSegments) {
var
buffer,
frameNum = 0;
AdtsStream.prototype.init.call(this);
this.push = function(packet) {
var
i = 0,
frameLength,
protectionSkipBytes,
frameEnd,
oldBuffer,
sampleCount,
adtsFrameDuration;
if (!handlePartialSegments) {
frameNum = 0;
}
if (packet.type !== 'audio') {
// ignore non-audio data
return;
}
// Prepend any data in the buffer to the input data so that we can parse
// aac frames the cross a PES packet boundary
if (buffer) {
oldBuffer = buffer;
buffer = new Uint8Array(oldBuffer.byteLength + packet.data.byteLength);
buffer.set(oldBuffer);
buffer.set(packet.data, oldBuffer.byteLength);
} else {
buffer = packet.data;
}
// unpack any ADTS frames which have been fully received
// for details on the ADTS header, see http://wiki.multimedia.cx/index.php?title=ADTS
while (i + 5 < buffer.length) {
// Look for the start of an ADTS header..
if ((buffer[i] !== 0xFF) || (buffer[i + 1] & 0xF6) !== 0xF0) {
// If a valid header was not found, jump one forward and attempt to
// find a valid ADTS header starting at the next byte
i++;
continue;
}
// The protection skip bit tells us if we have 2 bytes of CRC data at the
// end of the ADTS header
protectionSkipBytes = (~buffer[i + 1] & 0x01) * 2;
// Frame length is a 13 bit integer starting 16 bits from the
// end of the sync sequence
frameLength = ((buffer[i + 3] & 0x03) << 11) |
(buffer[i + 4] << 3) |
((buffer[i + 5] & 0xe0) >> 5);
sampleCount = ((buffer[i + 6] & 0x03) + 1) * 1024;
adtsFrameDuration = (sampleCount * ONE_SECOND_IN_TS) /
ADTS_SAMPLING_FREQUENCIES[(buffer[i + 2] & 0x3c) >>> 2];
frameEnd = i + frameLength;
// If we don't have enough data to actually finish this ADTS frame, return
// and wait for more data
if (buffer.byteLength < frameEnd) {
return;
}
// Otherwise, deliver the complete AAC frame
this.trigger('data', {
pts: packet.pts + (frameNum * adtsFrameDuration),
dts: packet.dts + (frameNum * adtsFrameDuration),
sampleCount: sampleCount,
audioobjecttype: ((buffer[i + 2] >>> 6) & 0x03) + 1,
channelcount: ((buffer[i + 2] & 1) << 2) |
((buffer[i + 3] & 0xc0) >>> 6),
samplerate: ADTS_SAMPLING_FREQUENCIES[(buffer[i + 2] & 0x3c) >>> 2],
samplingfrequencyindex: (buffer[i + 2] & 0x3c) >>> 2,
// assume ISO/IEC 14496-12 AudioSampleEntry default of 16
samplesize: 16,
data: buffer.subarray(i + 7 + protectionSkipBytes, frameEnd)
});
frameNum++;
// If the buffer is empty, clear it and return
if (buffer.byteLength === frameEnd) {
buffer = undefined;
return;
}
// Remove the finished frame from the buffer and start the process again
buffer = buffer.subarray(frameEnd);
}
};
this.flush = function() {
frameNum = 0;
this.trigger('done');
};
this.reset = function() {
buffer = void 0;
this.trigger('reset');
};
this.endTimeline = function() {
buffer = void 0;
this.trigger('endedtimeline');
};
};
AdtsStream.prototype = new Stream();
module.exports = AdtsStream;
},{"29":29,"31":31}],4:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*/
'use strict';
var Stream = require(31);
var ExpGolomb = require(30);
var H264Stream, NalByteStream;
var PROFILES_WITH_OPTIONAL_SPS_DATA;
/**
* Accepts a NAL unit byte stream and unpacks the embedded NAL units.
*/
NalByteStream = function() {
var
syncPoint = 0,
i,
buffer;
NalByteStream.prototype.init.call(this);
/*
* Scans a byte stream and triggers a data event with the NAL units found.
* @param {Object} data Event received from H264Stream
* @param {Uint8Array} data.data The h264 byte stream to be scanned
*
* @see H264Stream.push
*/
this.push = function(data) {
var swapBuffer;
if (!buffer) {
buffer = data.data;
} else {
swapBuffer = new Uint8Array(buffer.byteLength + data.data.byteLength);
swapBuffer.set(buffer);
swapBuffer.set(data.data, buffer.byteLength);
buffer = swapBuffer;
}
var len = buffer.byteLength;
// Rec. ITU-T H.264, Annex B
// scan for NAL unit boundaries
// a match looks like this:
// 0 0 1 .. NAL .. 0 0 1
// ^ sync point ^ i
// or this:
// 0 0 1 .. NAL .. 0 0 0
// ^ sync point ^ i
// advance the sync point to a NAL start, if necessary
for (; syncPoint < len - 3; syncPoint++) {
if (buffer[syncPoint + 2] === 1) {
// the sync point is properly aligned
i = syncPoint + 5;
break;
}
}
while (i < len) {
// look at the current byte to determine if we've hit the end of
// a NAL unit boundary
switch (buffer[i]) {
case 0:
// skip past non-sync sequences
if (buffer[i - 1] !== 0) {
i += 2;
break;
} else if (buffer[i - 2] !== 0) {
i++;
break;
}
// deliver the NAL unit if it isn't empty
if (syncPoint + 3 !== i - 2) {
this.trigger('data', buffer.subarray(syncPoint + 3, i - 2));
}
// drop trailing zeroes
do {
i++;
} while (buffer[i] !== 1 && i < len);
syncPoint = i - 2;
i += 3;
break;
case 1:
// skip past non-sync sequences
if (buffer[i - 1] !== 0 ||
buffer[i - 2] !== 0) {
i += 3;
break;
}
// deliver the NAL unit
this.trigger('data', buffer.subarray(syncPoint + 3, i - 2));
syncPoint = i - 2;
i += 3;
break;
default:
// the current byte isn't a one or zero, so it cannot be part
// of a sync sequence
i += 3;
break;
}
}
// filter out the NAL units that were delivered
buffer = buffer.subarray(syncPoint);
i -= syncPoint;
syncPoint = 0;
};
this.reset = function() {
buffer = null;
syncPoint = 0;
this.trigger('reset');
};
this.flush = function() {
// deliver the last buffered NAL unit
if (buffer && buffer.byteLength > 3) {
this.trigger('data', buffer.subarray(syncPoint + 3));
}
// reset the stream state
buffer = null;
syncPoint = 0;
this.trigger('done');
};
this.endTimeline = function() {
this.flush();
this.trigger('endedtimeline');
};
};
NalByteStream.prototype = new Stream();
// values of profile_idc that indicate additional fields are included in the SPS
// see Recommendation ITU-T H.264 (4/2013),
// 7.3.2.1.1 Sequence parameter set data syntax
PROFILES_WITH_OPTIONAL_SPS_DATA = {
100: true,
110: true,
122: true,
244: true,
44: true,
83: true,
86: true,
118: true,
128: true,
138: true,
139: true,
134: true
};
/**
* Accepts input from a ElementaryStream and produces H.264 NAL unit data
* events.
*/
H264Stream = function() {
var
nalByteStream = new NalByteStream(),
self,
trackId,
currentPts,
currentDts,
discardEmulationPreventionBytes,
readSequenceParameterSet,
skipScalingList;
H264Stream.prototype.init.call(this);
self = this;
/*
* Pushes a packet from a stream onto the NalByteStream
*
* @param {Object} packet - A packet received from a stream
* @param {Uint8Array} packet.data - The raw bytes of the packet
* @param {Number} packet.dts - Decode timestamp of the packet
* @param {Number} packet.pts - Presentation timestamp of the packet
* @param {Number} packet.trackId - The id of the h264 track this packet came from
* @param {('video'|'audio')} packet.type - The type of packet
*
*/
this.push = function(packet) {
if (packet.type !== 'video') {
return;
}
trackId = packet.trackId;
currentPts = packet.pts;
currentDts = packet.dts;
nalByteStream.push(packet);
};
/*
* Identify NAL unit types and pass on the NALU, trackId, presentation and decode timestamps
* for the NALUs to the next stream component.
* Also, preprocess caption and sequence parameter NALUs.
*
* @param {Uint8Array} data - A NAL unit identified by `NalByteStream.push`
* @see NalByteStream.push
*/
nalByteStream.on('data', function(data) {
var
event = {
trackId: trackId,
pts: currentPts,
dts: currentDts,
data: data
};
switch (data[0] & 0x1f) {
case 0x05:
event.nalUnitType = 'slice_layer_without_partitioning_rbsp_idr';
break;
case 0x06:
event.nalUnitType = 'sei_rbsp';
event.escapedRBSP = discardEmulationPreventionBytes(data.subarray(1));
break;
case 0x07:
event.nalUnitType = 'seq_parameter_set_rbsp';
event.escapedRBSP = discardEmulationPreventionBytes(data.subarray(1));
event.config = readSequenceParameterSet(event.escapedRBSP);
break;
case 0x08:
event.nalUnitType = 'pic_parameter_set_rbsp';
break;
case 0x09:
event.nalUnitType = 'access_unit_delimiter_rbsp';
break;
default:
break;
}
// This triggers data on the H264Stream
self.trigger('data', event);
});
nalByteStream.on('done', function() {
self.trigger('done');
});
nalByteStream.on('partialdone', function() {
self.trigger('partialdone');
});
nalByteStream.on('reset', function() {
self.trigger('reset');
});
nalByteStream.on('endedtimeline', function() {
self.trigger('endedtimeline');
});
this.flush = function() {
nalByteStream.flush();
};
this.partialFlush = function() {
nalByteStream.partialFlush();
};
this.reset = function() {
nalByteStream.reset();
};
this.endTimeline = function() {
nalByteStream.endTimeline();
};
/**
* Advance the ExpGolomb decoder past a scaling list. The scaling
* list is optionally transmitted as part of a sequence parameter
* set and is not relevant to transmuxing.
* @param count {number} the number of entries in this scaling list
* @param expGolombDecoder {object} an ExpGolomb pointed to the
* start of a scaling list
* @see Recommendation ITU-T H.264, Section 7.3.2.1.1.1
*/
skipScalingList = function(count, expGolombDecoder) {
var
lastScale = 8,
nextScale = 8,
j,
deltaScale;
for (j = 0; j < count; j++) {
if (nextScale !== 0) {
deltaScale = expGolombDecoder.readExpGolomb();
nextScale = (lastScale + deltaScale + 256) % 256;
}
lastScale = (nextScale === 0) ? lastScale : nextScale;
}
};
/**
* Expunge any "Emulation Prevention" bytes from a "Raw Byte
* Sequence Payload"
* @param data {Uint8Array} the bytes of a RBSP from a NAL
* unit
* @return {Uint8Array} the RBSP without any Emulation
* Prevention Bytes
*/
discardEmulationPreventionBytes = function(data) {
var
length = data.byteLength,
emulationPreventionBytesPositions = [],
i = 1,
newLength, newData;
// Find all `Emulation Prevention Bytes`
while (i < length - 2) {
if (data[i] === 0 && data[i + 1] === 0 && data[i + 2] === 0x03) {
emulationPreventionBytesPositions.push(i + 2);
i += 2;
} else {
i++;
}
}
// If no Emulation Prevention Bytes were found just return the original
// array
if (emulationPreventionBytesPositions.length === 0) {
return data;
}
// Create a new array to hold the NAL unit data
newLength = length - emulationPreventionBytesPositions.length;
newData = new Uint8Array(newLength);
var sourceIndex = 0;
for (i = 0; i < newLength; sourceIndex++, i++) {
if (sourceIndex === emulationPreventionBytesPositions[0]) {
// Skip this byte
sourceIndex++;
// Remove this position index
emulationPreventionBytesPositions.shift();
}
newData[i] = data[sourceIndex];
}
return newData;
};
/**
* Read a sequence parameter set and return some interesting video
* properties. A sequence parameter set is the H264 metadata that
* describes the properties of upcoming video frames.
* @param data {Uint8Array} the bytes of a sequence parameter set
* @return {object} an object with configuration parsed from the
* sequence parameter set, including the dimensions of the
* associated video frames.
*/
readSequenceParameterSet = function(data) {
var
frameCropLeftOffset = 0,
frameCropRightOffset = 0,
frameCropTopOffset = 0,
frameCropBottomOffset = 0,
sarScale = 1,
expGolombDecoder, profileIdc, levelIdc, profileCompatibility,
chromaFormatIdc, picOrderCntType,
numRefFramesInPicOrderCntCycle, picWidthInMbsMinus1,
picHeightInMapUnitsMinus1,
frameMbsOnlyFlag,
scalingListCount,
sarRatio,
aspectRatioIdc,
i;
expGolombDecoder = new ExpGolomb(data);
profileIdc = expGolombDecoder.readUnsignedByte(); // profile_idc
profileCompatibility = expGolombDecoder.readUnsignedByte(); // constraint_set[0-5]_flag
levelIdc = expGolombDecoder.readUnsignedByte(); // level_idc u(8)
expGolombDecoder.skipUnsignedExpGolomb(); // seq_parameter_set_id
// some profiles have more optional data we don't need
if (PROFILES_WITH_OPTIONAL_SPS_DATA[profileIdc]) {
chromaFormatIdc = expGolombDecoder.readUnsignedExpGolomb();
if (chromaFormatIdc === 3) {
expGolombDecoder.skipBits(1); // separate_colour_plane_flag
}
expGolombDecoder.skipUnsignedExpGolomb(); // bit_depth_luma_minus8
expGolombDecoder.skipUnsignedExpGolomb(); // bit_depth_chroma_minus8
expGolombDecoder.skipBits(1); // qpprime_y_zero_transform_bypass_flag
if (expGolombDecoder.readBoolean()) { // seq_scaling_matrix_present_flag
scalingListCount = (chromaFormatIdc !== 3) ? 8 : 12;
for (i = 0; i < scalingListCount; i++) {
if (expGolombDecoder.readBoolean()) { // seq_scaling_list_present_flag[ i ]
if (i < 6) {
skipScalingList(16, expGolombDecoder);
} else {
skipScalingList(64, expGolombDecoder);
}
}
}
}
}
expGolombDecoder.skipUnsignedExpGolomb(); // log2_max_frame_num_minus4
picOrderCntType = expGolombDecoder.readUnsignedExpGolomb();
if (picOrderCntType === 0) {
expGolombDecoder.readUnsignedExpGolomb(); // log2_max_pic_order_cnt_lsb_minus4
} else if (picOrderCntType === 1) {
expGolombDecoder.skipBits(1); // delta_pic_order_always_zero_flag
expGolombDecoder.skipExpGolomb(); // offset_for_non_ref_pic
expGolombDecoder.skipExpGolomb(); // offset_for_top_to_bottom_field
numRefFramesInPicOrderCntCycle = expGolombDecoder.readUnsignedExpGolomb();
for (i = 0; i < numRefFramesInPicOrderCntCycle; i++) {
expGolombDecoder.skipExpGolomb(); // offset_for_ref_frame[ i ]
}
}
expGolombDecoder.skipUnsignedExpGolomb(); // max_num_ref_frames
expGolombDecoder.skipBits(1); // gaps_in_frame_num_value_allowed_flag
picWidthInMbsMinus1 = expGolombDecoder.readUnsignedExpGolomb();
picHeightInMapUnitsMinus1 = expGolombDecoder.readUnsignedExpGolomb();
frameMbsOnlyFlag = expGolombDecoder.readBits(1);
if (frameMbsOnlyFlag === 0) {
expGolombDecoder.skipBits(1); // mb_adaptive_frame_field_flag
}
expGolombDecoder.skipBits(1); // direct_8x8_inference_flag
if (expGolombDecoder.readBoolean()) { // frame_cropping_flag
frameCropLeftOffset = expGolombDecoder.readUnsignedExpGolomb();
frameCropRightOffset = expGolombDecoder.readUnsignedExpGolomb();
frameCropTopOffset = expGolombDecoder.readUnsignedExpGolomb();
frameCropBottomOffset = expGolombDecoder.readUnsignedExpGolomb();
}
if (expGolombDecoder.readBoolean()) {
// vui_parameters_present_flag
if (expGolombDecoder.readBoolean()) {
// aspect_ratio_info_present_flag
aspectRatioIdc = expGolombDecoder.readUnsignedByte();
switch (aspectRatioIdc) {
case 1: sarRatio = [1, 1]; break;
case 2: sarRatio = [12, 11]; break;
case 3: sarRatio = [10, 11]; break;
case 4: sarRatio = [16, 11]; break;
case 5: sarRatio = [40, 33]; break;
case 6: sarRatio = [24, 11]; break;
case 7: sarRatio = [20, 11]; break;
case 8: sarRatio = [32, 11]; break;
case 9: sarRatio = [80, 33]; break;
case 10: sarRatio = [18, 11]; break;
case 11: sarRatio = [15, 11]; break;
case 12: sarRatio = [64, 33]; break;
case 13: sarRatio = [160, 99]; break;
case 14: sarRatio = [4, 3]; break;
case 15: sarRatio = [3, 2]; break;
case 16: sarRatio = [2, 1]; break;
case 255: {
sarRatio = [expGolombDecoder.readUnsignedByte() << 8 |
expGolombDecoder.readUnsignedByte(),
expGolombDecoder.readUnsignedByte() << 8 |
expGolombDecoder.readUnsignedByte() ];
break;
}
}
if (sarRatio) {
sarScale = sarRatio[0] / sarRatio[1];
}
}
}
return {
profileIdc: profileIdc,
levelIdc: levelIdc,
profileCompatibility: profileCompatibility,
width: Math.ceil((((picWidthInMbsMinus1 + 1) * 16) - frameCropLeftOffset * 2 - frameCropRightOffset * 2) * sarScale),
height: ((2 - frameMbsOnlyFlag) * (picHeightInMapUnitsMinus1 + 1) * 16) - (frameCropTopOffset * 2) - (frameCropBottomOffset * 2),
sarRatio: sarRatio
};
};
};
H264Stream.prototype = new Stream();
module.exports = {
H264Stream: H264Stream,
NalByteStream: NalByteStream
};
},{"30":30,"31":31}],5:[function(require,module,exports){
// constants
var AUDIO_PROPERTIES = [
'audioobjecttype',
'channelcount',
'samplerate',
'samplingfrequencyindex',
'samplesize'
];
module.exports = AUDIO_PROPERTIES;
},{}],6:[function(require,module,exports){
var VIDEO_PROPERTIES = [
'width',
'height',
'profileIdc',
'levelIdc',
'profileCompatibility',
'sarRatio'
];
module.exports = VIDEO_PROPERTIES;
},{}],7:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*/
var highPrefix = [33, 16, 5, 32, 164, 27];
var lowPrefix = [33, 65, 108, 84, 1, 2, 4, 8, 168, 2, 4, 8, 17, 191, 252];
var zeroFill = function(count) {
var a = [];
while (count--) {
a.push(0);
}
return a;
};
var makeTable = function(metaTable) {
return Object.keys(metaTable).reduce(function(obj, key) {
obj[key] = new Uint8Array(metaTable[key].reduce(function(arr, part) {
return arr.concat(part);
}, []));
return obj;
}, {});
};
var silence;
module.exports = function() {
if (!silence) {
// Frames-of-silence to use for filling in missing AAC frames
var coneOfSilence = {
96000: [highPrefix, [227, 64], zeroFill(154), [56]],
88200: [highPrefix, [231], zeroFill(170), [56]],
64000: [highPrefix, [248, 192], zeroFill(240), [56]],
48000: [highPrefix, [255, 192], zeroFill(268), [55, 148, 128], zeroFill(54), [112]],
44100: [highPrefix, [255, 192], zeroFill(268), [55, 163, 128], zeroFill(84), [112]],
32000: [highPrefix, [255, 192], zeroFill(268), [55, 234], zeroFill(226), [112]],
24000: [highPrefix, [255, 192], zeroFill(268), [55, 255, 128], zeroFill(268), [111, 112], zeroFill(126), [224]],
16000: [highPrefix, [255, 192], zeroFill(268), [55, 255, 128], zeroFill(268), [111, 255], zeroFill(269), [223, 108], zeroFill(195), [1, 192]],
12000: [lowPrefix, zeroFill(268), [3, 127, 248], zeroFill(268), [6, 255, 240], zeroFill(268), [13, 255, 224], zeroFill(268), [27, 253, 128], zeroFill(259), [56]],
11025: [lowPrefix, zeroFill(268), [3, 127, 248], zeroFill(268), [6, 255, 240], zeroFill(268), [13, 255, 224], zeroFill(268), [27, 255, 192], zeroFill(268), [55, 175, 128], zeroFill(108), [112]],
8000: [lowPrefix, zeroFill(268), [3, 121, 16], zeroFill(47), [7]]
};
silence = makeTable(coneOfSilence);
}
return silence;
};
},{}],8:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*
* Reads in-band caption information from a video elementary
* stream. Captions must follow the CEA-708 standard for injection
* into an MPEG-2 transport streams.
* @see https://en.wikipedia.org/wiki/CEA-708
* @see https://www.gpo.gov/fdsys/pkg/CFR-2007-title47-vol1/pdf/CFR-2007-title47-vol1-sec15-119.pdf
*/
'use strict';
// -----------------
// Link To Transport
// -----------------
var Stream = require(31);
var cea708Parser = require(23);
var CaptionStream = function() {
CaptionStream.prototype.init.call(this);
this.captionPackets_ = [];
this.ccStreams_ = [
new Cea608Stream(0, 0), // eslint-disable-line no-use-before-define
new Cea608Stream(0, 1), // eslint-disable-line no-use-before-define
new Cea608Stream(1, 0), // eslint-disable-line no-use-before-define
new Cea608Stream(1, 1) // eslint-disable-line no-use-before-define
];
this.reset();
// forward data and done events from CCs to this CaptionStream
this.ccStreams_.forEach(function(cc) {
cc.on('data', this.trigger.bind(this, 'data'));
cc.on('partialdone', this.trigger.bind(this, 'partialdone'));
cc.on('done', this.trigger.bind(this, 'done'));
}, this);
};
CaptionStream.prototype = new Stream();
CaptionStream.prototype.push = function(event) {
var sei, userData, newCaptionPackets;
// only examine SEI NALs
if (event.nalUnitType !== 'sei_rbsp') {
return;
}
// parse the sei
sei = cea708Parser.parseSei(event.escapedRBSP);
// ignore everything but user_data_registered_itu_t_t35
if (sei.payloadType !== cea708Parser.USER_DATA_REGISTERED_ITU_T_T35) {
return;
}
// parse out the user data payload
userData = cea708Parser.parseUserData(sei);
// ignore unrecognized userData
if (!userData) {
return;
}
// Sometimes, the same segment # will be downloaded twice. To stop the
// caption data from being processed twice, we track the latest dts we've
// received and ignore everything with a dts before that. However, since
// data for a specific dts can be split across packets on either side of
// a segment boundary, we need to make sure we *don't* ignore the packets
// from the *next* segment that have dts === this.latestDts_. By constantly
// tracking the number of packets received with dts === this.latestDts_, we
// know how many should be ignored once we start receiving duplicates.
if (event.dts < this.latestDts_) {
// We've started getting older data, so set the flag.
this.ignoreNextEqualDts_ = true;
return;
} else if ((event.dts === this.latestDts_) && (this.ignoreNextEqualDts_)) {
this.numSameDts_--;
if (!this.numSameDts_) {
// We've received the last duplicate packet, time to start processing again
this.ignoreNextEqualDts_ = false;
}
return;
}
// parse out CC data packets and save them for later
newCaptionPackets = cea708Parser.parseCaptionPackets(event.pts, userData);
this.captionPackets_ = this.captionPackets_.concat(newCaptionPackets);
if (this.latestDts_ !== event.dts) {
this.numSameDts_ = 0;
}
this.numSameDts_++;
this.latestDts_ = event.dts;
};
CaptionStream.prototype.flushCCStreams = function(flushType) {
this.ccStreams_.forEach(function(cc) {
return flushType === 'flush' ? cc.flush() : cc.partialFlush();
}, this);
};
CaptionStream.prototype.flushStream = function(flushType) {
// make sure we actually parsed captions before proceeding
if (!this.captionPackets_.length) {
this.flushCCStreams(flushType);
return;
}
// In Chrome, the Array#sort function is not stable so add a
// presortIndex that we can use to ensure we get a stable-sort
this.captionPackets_.forEach(function(elem, idx) {
elem.presortIndex = idx;
});
// sort caption byte-pairs based on their PTS values
this.captionPackets_.sort(function(a, b) {
if (a.pts === b.pts) {
return a.presortIndex - b.presortIndex;
}
return a.pts - b.pts;
});
this.captionPackets_.forEach(function(packet) {
if (packet.type < 2) {
// Dispatch packet to the right Cea608Stream
this.dispatchCea608Packet(packet);
}
// this is where an 'else' would go for a dispatching packets
// to a theoretical Cea708Stream that handles SERVICEn data
}, this);
this.captionPackets_.length = 0;
this.flushCCStreams(flushType);
};
CaptionStream.prototype.flush = function() {
return this.flushStream('flush');
};
// Only called if handling partial data
CaptionStream.prototype.partialFlush = function() {
return this.flushStream('partialFlush');
};
CaptionStream.prototype.reset = function() {
this.latestDts_ = null;
this.ignoreNextEqualDts_ = false;
this.numSameDts_ = 0;
this.activeCea608Channel_ = [null, null];
this.ccStreams_.forEach(function(ccStream) {
ccStream.reset();
});
};
// From the CEA-608 spec:
/*
* When XDS sub-packets are interleaved with other services, the end of each sub-packet shall be followed
* by a control pair to change to a different service. When any of the control codes from 0x10 to 0x1F is
* used to begin a control code pair, it indicates the return to captioning or Text data. The control code pair
* and subsequent data should then be processed according to the FCC rules. It may be necessary for the
* line 21 data encoder to automatically insert a control code pair (i.e. RCL, RU2, RU3, RU4, RDC, or RTD)
* to switch to captioning or Text.
*/
// With that in mind, we ignore any data between an XDS control code and a
// subsequent closed-captioning control code.
CaptionStream.prototype.dispatchCea608Packet = function(packet) {
// NOTE: packet.type is the CEA608 field
if (this.setsTextOrXDSActive(packet)) {
this.activeCea608Channel_[packet.type] = null;
} else if (this.setsChannel1Active(packet)) {
this.activeCea608Channel_[packet.type] = 0;
} else if (this.setsChannel2Active(packet)) {
this.activeCea608Channel_[packet.type] = 1;
}
if (this.activeCea608Channel_[packet.type] === null) {
// If we haven't received anything to set the active channel, or the
// packets are Text/XDS data, discard the data; we don't want jumbled
// captions
return;
}
this.ccStreams_[(packet.type << 1) + this.activeCea608Channel_[packet.type]].push(packet);
};
CaptionStream.prototype.setsChannel1Active = function(packet) {
return ((packet.ccData & 0x7800) === 0x1000);
};
CaptionStream.prototype.setsChannel2Active = function(packet) {
return ((packet.ccData & 0x7800) === 0x1800);
};
CaptionStream.prototype.setsTextOrXDSActive = function(packet) {
return ((packet.ccData & 0x7100) === 0x0100) ||
((packet.ccData & 0x78fe) === 0x102a) ||
((packet.ccData & 0x78fe) === 0x182a);
};
// ----------------------
// Session to Application
// ----------------------
// This hash maps non-ASCII, special, and extended character codes to their
// proper Unicode equivalent. The first keys that are only a single byte
// are the non-standard ASCII characters, which simply map the CEA608 byte
// to the standard ASCII/Unicode. The two-byte keys that follow are the CEA608
// character codes, but have their MSB bitmasked with 0x03 so that a lookup
// can be performed regardless of the field and data channel on which the
// character code was received.
var CHARACTER_TRANSLATION = {
0x2a: 0xe1, // á
0x5c: 0xe9, // é
0x5e: 0xed, // í
0x5f: 0xf3, // ó
0x60: 0xfa, // ú
0x7b: 0xe7, // ç
0x7c: 0xf7, // ÷
0x7d: 0xd1, // Ñ
0x7e: 0xf1, // ñ
0x7f: 0x2588, // █
0x0130: 0xae, // ®
0x0131: 0xb0, // °
0x0132: 0xbd, // ½
0x0133: 0xbf, // ¿
0x0134: 0x2122, // ™
0x0135: 0xa2, // ¢
0x0136: 0xa3, // £
0x0137: 0x266a, // ♪
0x0138: 0xe0, // à
0x0139: 0xa0, //
0x013a: 0xe8, // è
0x013b: 0xe2, // â
0x013c: 0xea, // ê
0x013d: 0xee, // î
0x013e: 0xf4, // ô
0x013f: 0xfb, // û
0x0220: 0xc1, // Á
0x0221: 0xc9, // É
0x0222: 0xd3, // Ó
0x0223: 0xda, // Ú
0x0224: 0xdc, // Ü
0x0225: 0xfc, // ü
0x0226: 0x2018, // ‘
0x0227: 0xa1, // ¡
0x0228: 0x2a, // *
0x0229: 0x27, // '
0x022a: 0x2014, // —
0x022b: 0xa9, // ©
0x022c: 0x2120, // ℠
0x022d: 0x2022, // •
0x022e: 0x201c, // “
0x022f: 0x201d, // ”
0x0230: 0xc0, // À
0x0231: 0xc2, // Â
0x0232: 0xc7, // Ç
0x0233: 0xc8, // È
0x0234: 0xca, // Ê
0x0235: 0xcb, // Ë
0x0236: 0xeb, // ë
0x0237: 0xce, // Î
0x0238: 0xcf, // Ï
0x0239: 0xef, // ï
0x023a: 0xd4, // Ô
0x023b: 0xd9, // Ù
0x023c: 0xf9, // ù
0x023d: 0xdb, // Û
0x023e: 0xab, // «
0x023f: 0xbb, // »
0x0320: 0xc3, // Ã
0x0321: 0xe3, // ã
0x0322: 0xcd, // Í
0x0323: 0xcc, // Ì
0x0324: 0xec, // ì
0x0325: 0xd2, // Ò
0x0326: 0xf2, // ò
0x0327: 0xd5, // Õ
0x0328: 0xf5, // õ
0x0329: 0x7b, // {
0x032a: 0x7d, // }
0x032b: 0x5c, // \
0x032c: 0x5e, // ^
0x032d: 0x5f, // _
0x032e: 0x7c, // |
0x032f: 0x7e, // ~
0x0330: 0xc4, // Ä
0x0331: 0xe4, // ä
0x0332: 0xd6, // Ö
0x0333: 0xf6, // ö
0x0334: 0xdf, // ß
0x0335: 0xa5, // ¥
0x0336: 0xa4, // ¤
0x0337: 0x2502, // │
0x0338: 0xc5, // Å
0x0339: 0xe5, // å
0x033a: 0xd8, // Ø
0x033b: 0xf8, // ø
0x033c: 0x250c, // ┌
0x033d: 0x2510, // ┐
0x033e: 0x2514, // └
0x033f: 0x2518 // ┘
};
var getCharFromCode = function(code) {
if (code === null) {
return '';
}
code = CHARACTER_TRANSLATION[code] || code;
return String.fromCharCode(code);
};
// the index of the last row in a CEA-608 display buffer
var BOTTOM_ROW = 14;
// This array is used for mapping PACs -> row #, since there's no way of
// getting it through bit logic.
var ROWS = [0x1100, 0x1120, 0x1200, 0x1220, 0x1500, 0x1520, 0x1600, 0x1620,
0x1700, 0x1720, 0x1000, 0x1300, 0x1320, 0x1400, 0x1420];
// CEA-608 captions are rendered onto a 34x15 matrix of character
// cells. The "bottom" row is the last element in the outer array.
var createDisplayBuffer = function() {
var result = [], i = BOTTOM_ROW + 1;
while (i--) {
result.push('');
}
return result;
};
var Cea608Stream = function(field, dataChannel) {
Cea608Stream.prototype.init.call(this);
this.field_ = field || 0;
this.dataChannel_ = dataChannel || 0;
this.name_ = 'CC' + (((this.field_ << 1) | this.dataChannel_) + 1);
this.setConstants();
this.reset();
this.push = function(packet) {
var data, swap, char0, char1, text;
// remove the parity bits
data = packet.ccData & 0x7f7f;
// ignore duplicate control codes; the spec demands they're sent twice
if (data === this.lastControlCode_) {
this.lastControlCode_ = null;
return;
}
// Store control codes
if ((data & 0xf000) === 0x1000) {
this.lastControlCode_ = data;
} else if (data !== this.PADDING_) {
this.lastControlCode_ = null;
}
char0 = data >>> 8;
char1 = data & 0xff;
if (data === this.PADDING_) {
return;
} else if (data === this.RESUME_CAPTION_LOADING_) {
this.mode_ = 'popOn';
} else if (data === this.END_OF_CAPTION_) {
// If an EOC is received while in paint-on mode, the displayed caption
// text should be swapped to non-displayed memory as if it was a pop-on
// caption. Because of that, we should explicitly switch back to pop-on
// mode
this.mode_ = 'popOn';
this.clearFormatting(packet.pts);
// if a caption was being displayed, it's gone now
this.flushDisplayed(packet.pts);
// flip memory
swap = this.displayed_;
this.displayed_ = this.nonDisplayed_;
this.nonDisplayed_ = swap;
// start measuring the time to display the caption
this.startPts_ = packet.pts;
} else if (data === this.ROLL_UP_2_ROWS_) {
this.rollUpRows_ = 2;
this.setRollUp(packet.pts);
} else if (data === this.ROLL_UP_3_ROWS_) {
this.rollUpRows_ = 3;
this.setRollUp(packet.pts);
} else if (data === this.ROLL_UP_4_ROWS_) {
this.rollUpRows_ = 4;
this.setRollUp(packet.pts);
} else if (data === this.CARRIAGE_RETURN_) {
this.clearFormatting(packet.pts);
this.flushDisplayed(packet.pts);
this.shiftRowsUp_();
this.startPts_ = packet.pts;
} else if (data === this.BACKSPACE_) {
if (this.mode_ === 'popOn') {
this.nonDisplayed_[this.row_] = this.nonDisplayed_[this.row_].slice(0, -1);
} else {
this.displayed_[this.row_] = this.displayed_[this.row_].slice(0, -1);
}
} else if (data === this.ERASE_DISPLAYED_MEMORY_) {
this.flushDisplayed(packet.pts);
this.displayed_ = createDisplayBuffer();
} else if (data === this.ERASE_NON_DISPLAYED_MEMORY_) {
this.nonDisplayed_ = createDisplayBuffer();
} else if (data === this.RESUME_DIRECT_CAPTIONING_) {
if (this.mode_ !== 'paintOn') {
// NOTE: This should be removed when proper caption positioning is
// implemented
this.flushDisplayed(packet.pts);
this.displayed_ = createDisplayBuffer();
}
this.mode_ = 'paintOn';
this.startPts_ = packet.pts;
// Append special characters to caption text
} else if (this.isSpecialCharacter(char0, char1)) {
// Bitmask char0 so that we can apply character transformations
// regardless of field and data channel.
// Then byte-shift to the left and OR with char1 so we can pass the
// entire character code to `getCharFromCode`.
char0 = (char0 & 0x03) << 8;
text = getCharFromCode(char0 | char1);
this[this.mode_](packet.pts, text);
this.column_++;
// Append extended characters to caption text
} else if (this.isExtCharacter(char0, char1)) {
// Extended characters always follow their "non-extended" equivalents.
// IE if a "è" is desired, you'll always receive "eè"; non-compliant
// decoders are supposed to drop the "è", while compliant decoders
// backspace the "e" and insert "è".
// Delete the previous character
if (this.mode_ === 'popOn') {
this.nonDisplayed_[this.row_] = this.nonDisplayed_[this.row_].slice(0, -1);
} else {
this.displayed_[this.row_] = this.displayed_[this.row_].slice(0, -1);
}
// Bitmask char0 so that we can apply character transformations
// regardless of field and data channel.
// Then byte-shift to the left and OR with char1 so we can pass the
// entire character code to `getCharFromCode`.
char0 = (char0 & 0x03) << 8;
text = getCharFromCode(char0 | char1);
this[this.mode_](packet.pts, text);
this.column_++;
// Process mid-row codes
} else if (this.isMidRowCode(char0, char1)) {
// Attributes are not additive, so clear all formatting
this.clearFormatting(packet.pts);
// According to the standard, mid-row codes
// should be replaced with spaces, so add one now
this[this.mode_](packet.pts, ' ');
this.column_++;
if ((char1 & 0xe) === 0xe) {
this.addFormatting(packet.pts, ['i']);
}
if ((char1 & 0x1) === 0x1) {
this.addFormatting(packet.pts, ['u']);
}
// Detect offset control codes and adjust cursor
} else if (this.isOffsetControlCode(char0, char1)) {
// Cursor position is set by indent PAC (see below) in 4-column
// increments, with an additional offset code of 1-3 to reach any
// of the 32 columns specified by CEA-608. So all we need to do
// here is increment the column cursor by the given offset.
this.column_ += (char1 & 0x03);
// Detect PACs (Preamble Address Codes)
} else if (this.isPAC(char0, char1)) {
// There's no logic for PAC -> row mapping, so we have to just
// find the row code in an array and use its index :(
var row = ROWS.indexOf(data & 0x1f20);
// Configure the caption window if we're in roll-up mode
if (this.mode_ === 'rollUp') {
// This implies that the base row is incorrectly set.
// As per the recommendation in CEA-608(Base Row Implementation), defer to the number
// of roll-up rows set.
if (row - this.rollUpRows_ + 1 < 0) {
row = this.rollUpRows_ - 1;
}
this.setRollUp(packet.pts, row);
}
if (row !== this.row_) {
// formatting is only persistent for current row
this.clearFormatting(packet.pts);
this.row_ = row;
}
// All PACs can apply underline, so detect and apply
// (All odd-numbered second bytes set underline)
if ((char1 & 0x1) && (this.formatting_.indexOf('u') === -1)) {
this.addFormatting(packet.pts, ['u']);
}
if ((data & 0x10) === 0x10) {
// We've got an indent level code. Each successive even number
// increments the column cursor by 4, so we can get the desired
// column position by bit-shifting to the right (to get n/2)
// and multiplying by 4.
this.column_ = ((data & 0xe) >> 1) * 4;
}
if (this.isColorPAC(char1)) {
// it's a color code, though we only support white, which
// can be either normal or italicized. white italics can be
// either 0x4e or 0x6e depending on the row, so we just
// bitwise-and with 0xe to see if italics should be turned on
if ((char1 & 0xe) === 0xe) {
this.addFormatting(packet.pts, ['i']);
}
}
// We have a normal character in char0, and possibly one in char1
} else if (this.isNormalChar(char0)) {
if (char1 === 0x00) {
char1 = null;
}
text = getCharFromCode(char0);
text += getCharFromCode(char1);
this[this.mode_](packet.pts, text);
this.column_ += text.length;
} // finish data processing
};
};
Cea608Stream.prototype = new Stream();
// Trigger a cue point that captures the current state of the
// display buffer
Cea608Stream.prototype.flushDisplayed = function(pts) {
var content = this.displayed_
// remove spaces from the start and end of the string
.map(function(row) {
try {
return row.trim();
} catch (e) {
// Ordinarily, this shouldn't happen. However, caption
// parsing errors should not throw exceptions and
// break playback.
// eslint-disable-next-line no-console
console.error('Skipping malformed caption.');
return '';
}
})
// combine all text rows to display in one cue
.join('\n')
// and remove blank rows from the start and end, but not the middle
.replace(/^\n+|\n+$/g, '');
if (content.length) {
this.trigger('data', {
startPts: this.startPts_,
endPts: pts,
text: content,
stream: this.name_
});
}
};
/**
* Zero out the data, used for startup and on seek
*/
Cea608Stream.prototype.reset = function() {
this.mode_ = 'popOn';
// When in roll-up mode, the index of the last row that will
// actually display captions. If a caption is shifted to a row
// with a lower index than this, it is cleared from the display
// buffer
this.topRow_ = 0;
this.startPts_ = 0;
this.displayed_ = createDisplayBuffer();
this.nonDisplayed_ = createDisplayBuffer();
this.lastControlCode_ = null;
// Track row and column for proper line-breaking and spacing
this.column_ = 0;
this.row_ = BOTTOM_ROW;
this.rollUpRows_ = 2;
// This variable holds currently-applied formatting
this.formatting_ = [];
};
/**
* Sets up control code and related constants for this instance
*/
Cea608Stream.prototype.setConstants = function() {
// The following attributes have these uses:
// ext_ : char0 for mid-row codes, and the base for extended
// chars (ext_+0, ext_+1, and ext_+2 are char0s for
// extended codes)
// control_: char0 for control codes, except byte-shifted to the
// left so that we can do this.control_ | CONTROL_CODE
// offset_: char0 for tab offset codes
//
// It's also worth noting that control codes, and _only_ control codes,
// differ between field 1 and field2. Field 2 control codes are always
// their field 1 value plus 1. That's why there's the "| field" on the
// control value.
if (this.dataChannel_ === 0) {
this.BASE_ = 0x10;
this.EXT_ = 0x11;
this.CONTROL_ = (0x14 | this.field_) << 8;
this.OFFSET_ = 0x17;
} else if (this.dataChannel_ === 1) {
this.BASE_ = 0x18;
this.EXT_ = 0x19;
this.CONTROL_ = (0x1c | this.field_) << 8;
this.OFFSET_ = 0x1f;
}
// Constants for the LSByte command codes recognized by Cea608Stream. This
// list is not exhaustive. For a more comprehensive listing and semantics see
// http://www.gpo.gov/fdsys/pkg/CFR-2010-title47-vol1/pdf/CFR-2010-title47-vol1-sec15-119.pdf
// Padding
this.PADDING_ = 0x0000;
// Pop-on Mode
this.RESUME_CAPTION_LOADING_ = this.CONTROL_ | 0x20;
this.END_OF_CAPTION_ = this.CONTROL_ | 0x2f;
// Roll-up Mode
this.ROLL_UP_2_ROWS_ = this.CONTROL_ | 0x25;
this.ROLL_UP_3_ROWS_ = this.CONTROL_ | 0x26;
this.ROLL_UP_4_ROWS_ = this.CONTROL_ | 0x27;
this.CARRIAGE_RETURN_ = this.CONTROL_ | 0x2d;
// paint-on mode
this.RESUME_DIRECT_CAPTIONING_ = this.CONTROL_ | 0x29;
// Erasure
this.BACKSPACE_ = this.CONTROL_ | 0x21;
this.ERASE_DISPLAYED_MEMORY_ = this.CONTROL_ | 0x2c;
this.ERASE_NON_DISPLAYED_MEMORY_ = this.CONTROL_ | 0x2e;
};
/**
* Detects if the 2-byte packet data is a special character
*
* Special characters have a second byte in the range 0x30 to 0x3f,
* with the first byte being 0x11 (for data channel 1) or 0x19 (for
* data channel 2).
*
* @param {Integer} char0 The first byte
* @param {Integer} char1 The second byte
* @return {Boolean} Whether the 2 bytes are an special character
*/
Cea608Stream.prototype.isSpecialCharacter = function(char0, char1) {
return (char0 === this.EXT_ && char1 >= 0x30 && char1 <= 0x3f);
};
/**
* Detects if the 2-byte packet data is an extended character
*
* Extended characters have a second byte in the range 0x20 to 0x3f,
* with the first byte being 0x12 or 0x13 (for data channel 1) or
* 0x1a or 0x1b (for data channel 2).
*
* @param {Integer} char0 The first byte
* @param {Integer} char1 The second byte
* @return {Boolean} Whether the 2 bytes are an extended character
*/
Cea608Stream.prototype.isExtCharacter = function(char0, char1) {
return ((char0 === (this.EXT_ + 1) || char0 === (this.EXT_ + 2)) &&
(char1 >= 0x20 && char1 <= 0x3f));
};
/**
* Detects if the 2-byte packet is a mid-row code
*
* Mid-row codes have a second byte in the range 0x20 to 0x2f, with
* the first byte being 0x11 (for data channel 1) or 0x19 (for data
* channel 2).
*
* @param {Integer} char0 The first byte
* @param {Integer} char1 The second byte
* @return {Boolean} Whether the 2 bytes are a mid-row code
*/
Cea608Stream.prototype.isMidRowCode = function(char0, char1) {
return (char0 === this.EXT_ && (char1 >= 0x20 && char1 <= 0x2f));
};
/**
* Detects if the 2-byte packet is an offset control code
*
* Offset control codes have a second byte in the range 0x21 to 0x23,
* with the first byte being 0x17 (for data channel 1) or 0x1f (for
* data channel 2).
*
* @param {Integer} char0 The first byte
* @param {Integer} char1 The second byte
* @return {Boolean} Whether the 2 bytes are an offset control code
*/
Cea608Stream.prototype.isOffsetControlCode = function(char0, char1) {
return (char0 === this.OFFSET_ && (char1 >= 0x21 && char1 <= 0x23));
};
/**
* Detects if the 2-byte packet is a Preamble Address Code
*
* PACs have a first byte in the range 0x10 to 0x17 (for data channel 1)
* or 0x18 to 0x1f (for data channel 2), with the second byte in the
* range 0x40 to 0x7f.
*
* @param {Integer} char0 The first byte
* @param {Integer} char1 The second byte
* @return {Boolean} Whether the 2 bytes are a PAC
*/
Cea608Stream.prototype.isPAC = function(char0, char1) {
return (char0 >= this.BASE_ && char0 < (this.BASE_ + 8) &&
(char1 >= 0x40 && char1 <= 0x7f));
};
/**
* Detects if a packet's second byte is in the range of a PAC color code
*
* PAC color codes have the second byte be in the range 0x40 to 0x4f, or
* 0x60 to 0x6f.
*
* @param {Integer} char1 The second byte
* @return {Boolean} Whether the byte is a color PAC
*/
Cea608Stream.prototype.isColorPAC = function(char1) {
return ((char1 >= 0x40 && char1 <= 0x4f) || (char1 >= 0x60 && char1 <= 0x7f));
};
/**
* Detects if a single byte is in the range of a normal character
*
* Normal text bytes are in the range 0x20 to 0x7f.
*
* @param {Integer} char The byte
* @return {Boolean} Whether the byte is a normal character
*/
Cea608Stream.prototype.isNormalChar = function(char) {
return (char >= 0x20 && char <= 0x7f);
};
/**
* Configures roll-up
*
* @param {Integer} pts Current PTS
* @param {Integer} newBaseRow Used by PACs to slide the current window to
* a new position
*/
Cea608Stream.prototype.setRollUp = function(pts, newBaseRow) {
// Reset the base row to the bottom row when switching modes
if (this.mode_ !== 'rollUp') {
this.row_ = BOTTOM_ROW;
this.mode_ = 'rollUp';
// Spec says to wipe memories when switching to roll-up
this.flushDisplayed(pts);
this.nonDisplayed_ = createDisplayBuffer();
this.displayed_ = createDisplayBuffer();
}
if (newBaseRow !== undefined && newBaseRow !== this.row_) {
// move currently displayed captions (up or down) to the new base row
for (var i = 0; i < this.rollUpRows_; i++) {
this.displayed_[newBaseRow - i] = this.displayed_[this.row_ - i];
this.displayed_[this.row_ - i] = '';
}
}
if (newBaseRow === undefined) {
newBaseRow = this.row_;
}
this.topRow_ = newBaseRow - this.rollUpRows_ + 1;
};
// Adds the opening HTML tag for the passed character to the caption text,
// and keeps track of it for later closing
Cea608Stream.prototype.addFormatting = function(pts, format) {
this.formatting_ = this.formatting_.concat(format);
var text = format.reduce(function(text, format) {
return text + '<' + format + '>';
}, '');
this[this.mode_](pts, text);
};
// Adds HTML closing tags for current formatting to caption text and
// clears remembered formatting
Cea608Stream.prototype.clearFormatting = function(pts) {
if (!this.formatting_.length) {
return;
}
var text = this.formatting_.reverse().reduce(function(text, format) {
return text + '</' + format + '>';
}, '');
this.formatting_ = [];
this[this.mode_](pts, text);
};
// Mode Implementations
Cea608Stream.prototype.popOn = function(pts, text) {
var baseRow = this.nonDisplayed_[this.row_];
// buffer characters
baseRow += text;
this.nonDisplayed_[this.row_] = baseRow;
};
Cea608Stream.prototype.rollUp = function(pts, text) {
var baseRow = this.displayed_[this.row_];
baseRow += text;
this.displayed_[this.row_] = baseRow;
};
Cea608Stream.prototype.shiftRowsUp_ = function() {
var i;
// clear out inactive rows
for (i = 0; i < this.topRow_; i++) {
this.displayed_[i] = '';
}
for (i = this.row_ + 1; i < BOTTOM_ROW + 1; i++) {
this.displayed_[i] = '';
}
// shift displayed rows up
for (i = this.topRow_; i < this.row_; i++) {
this.displayed_[i] = this.displayed_[i + 1];
}
// clear out the bottom row
this.displayed_[this.row_] = '';
};
Cea608Stream.prototype.paintOn = function(pts, text) {
var baseRow = this.displayed_[this.row_];
baseRow += text;
this.displayed_[this.row_] = baseRow;
};
// exports
module.exports = {
CaptionStream: CaptionStream,
Cea608Stream: Cea608Stream
};
},{"23":23,"31":31}],9:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*
* A stream-based mp2t to mp4 converter. This utility can be used to
* deliver mp4s to a SourceBuffer on platforms that support native
* Media Source Extensions.
*/
'use strict';
var Stream = require(31),
CaptionStream = require(8),
StreamTypes = require(11),
TimestampRolloverStream = require(12).TimestampRolloverStream;
// object types
var TransportPacketStream, TransportParseStream, ElementaryStream;
// constants
var
MP2T_PACKET_LENGTH = 188, // bytes
SYNC_BYTE = 0x47;
/**
* Splits an incoming stream of binary data into MPEG-2 Transport
* Stream packets.
*/
TransportPacketStream = function() {
var
buffer = new Uint8Array(MP2T_PACKET_LENGTH),
bytesInBuffer = 0;
TransportPacketStream.prototype.init.call(this);
// Deliver new bytes to the stream.
/**
* Split a stream of data into M2TS packets
**/
this.push = function(bytes) {
var
startIndex = 0,
endIndex = MP2T_PACKET_LENGTH,
everything;
// If there are bytes remaining from the last segment, prepend them to the
// bytes that were pushed in
if (bytesInBuffer) {
everything = new Uint8Array(bytes.byteLength + bytesInBuffer);
everything.set(buffer.subarray(0, bytesInBuffer));
everything.set(bytes, bytesInBuffer);
bytesInBuffer = 0;
} else {
everything = bytes;
}
// While we have enough data for a packet
while (endIndex < everything.byteLength) {
// Look for a pair of start and end sync bytes in the data..
if (everything[startIndex] === SYNC_BYTE && everything[endIndex] === SYNC_BYTE) {
// We found a packet so emit it and jump one whole packet forward in
// the stream
this.trigger('data', everything.subarray(startIndex, endIndex));
startIndex += MP2T_PACKET_LENGTH;
endIndex += MP2T_PACKET_LENGTH;
continue;
}
// If we get here, we have somehow become de-synchronized and we need to step
// forward one byte at a time until we find a pair of sync bytes that denote
// a packet
startIndex++;
endIndex++;
}
// If there was some data left over at the end of the segment that couldn't
// possibly be a whole packet, keep it because it might be the start of a packet
// that continues in the next segment
if (startIndex < everything.byteLength) {
buffer.set(everything.subarray(startIndex), 0);
bytesInBuffer = everything.byteLength - startIndex;
}
};
/**
* Passes identified M2TS packets to the TransportParseStream to be parsed
**/
this.flush = function() {
// If the buffer contains a whole packet when we are being flushed, emit it
// and empty the buffer. Otherwise hold onto the data because it may be
// important for decoding the next segment
if (bytesInBuffer === MP2T_PACKET_LENGTH && buffer[0] === SYNC_BYTE) {
this.trigger('data', buffer);
bytesInBuffer = 0;
}
this.trigger('done');
};
this.endTimeline = function() {
this.flush();
this.trigger('endedtimeline');
};
this.reset = function() {
bytesInBuffer = 0;
this.trigger('reset');
};
};
TransportPacketStream.prototype = new Stream();
/**
* Accepts an MP2T TransportPacketStream and emits data events with parsed
* forms of the individual transport stream packets.
*/
TransportParseStream = function() {
var parsePsi, parsePat, parsePmt, self;
TransportParseStream.prototype.init.call(this);
self = this;
this.packetsWaitingForPmt = [];
this.programMapTable = undefined;
parsePsi = function(payload, psi) {
var offset = 0;
// PSI packets may be split into multiple sections and those
// sections may be split into multiple packets. If a PSI
// section starts in this packet, the payload_unit_start_indicator
// will be true and the first byte of the payload will indicate
// the offset from the current position to the start of the
// section.
if (psi.payloadUnitStartIndicator) {
offset += payload[offset] + 1;
}
if (psi.type === 'pat') {
parsePat(payload.subarray(offset), psi);
} else {
parsePmt(payload.subarray(offset), psi);
}
};
parsePat = function(payload, pat) {
pat.section_number = payload[7]; // eslint-disable-line camelcase
pat.last_section_number = payload[8]; // eslint-disable-line camelcase
// skip the PSI header and parse the first PMT entry
self.pmtPid = (payload[10] & 0x1F) << 8 | payload[11];
pat.pmtPid = self.pmtPid;
};
/**
* Parse out the relevant fields of a Program Map Table (PMT).
* @param payload {Uint8Array} the PMT-specific portion of an MP2T
* packet. The first byte in this array should be the table_id
* field.
* @param pmt {object} the object that should be decorated with
* fields parsed from the PMT.
*/
parsePmt = function(payload, pmt) {
var sectionLength, tableEnd, programInfoLength, offset;
// PMTs can be sent ahead of the time when they should actually
// take effect. We don't believe this should ever be the case
// for HLS but we'll ignore "forward" PMT declarations if we see
// them. Future PMT declarations have the current_next_indicator
// set to zero.
if (!(payload[5] & 0x01)) {
return;
}
// overwrite any existing program map table
self.programMapTable = {
video: null,
audio: null,
'timed-metadata': {}
};
// the mapping table ends at the end of the current section
sectionLength = (payload[1] & 0x0f) << 8 | payload[2];
tableEnd = 3 + sectionLength - 4;
// to determine where the table is, we have to figure out how
// long the program info descriptors are
programInfoLength = (payload[10] & 0x0f) << 8 | payload[11];
// advance the offset to the first entry in the mapping table
offset = 12 + programInfoLength;
while (offset < tableEnd) {
var streamType = payload[offset];
var pid = (payload[offset + 1] & 0x1F) << 8 | payload[offset + 2];
// only map a single elementary_pid for audio and video stream types
// TODO: should this be done for metadata too? for now maintain behavior of
// multiple metadata streams
if (streamType === StreamTypes.H264_STREAM_TYPE &&
self.programMapTable.video === null) {
self.programMapTable.video = pid;
} else if (streamType === StreamTypes.ADTS_STREAM_TYPE &&
self.programMapTable.audio === null) {
self.programMapTable.audio = pid;
} else if (streamType === StreamTypes.METADATA_STREAM_TYPE) {
// map pid to stream type for metadata streams
self.programMapTable['timed-metadata'][pid] = streamType;
}
// move to the next table entry
// skip past the elementary stream descriptors, if present
offset += ((payload[offset + 3] & 0x0F) << 8 | payload[offset + 4]) + 5;
}
// record the map on the packet as well
pmt.programMapTable = self.programMapTable;
};
/**
* Deliver a new MP2T packet to the next stream in the pipeline.
*/
this.push = function(packet) {
var
result = {},
offset = 4;
result.payloadUnitStartIndicator = !!(packet[1] & 0x40);
// pid is a 13-bit field starting at the last bit of packet[1]
result.pid = packet[1] & 0x1f;
result.pid <<= 8;
result.pid |= packet[2];
// if an adaption field is present, its length is specified by the
// fifth byte of the TS packet header. The adaptation field is
// used to add stuffing to PES packets that don't fill a complete
// TS packet, and to specify some forms of timing and control data
// that we do not currently use.
if (((packet[3] & 0x30) >>> 4) > 0x01) {
offset += packet[offset] + 1;
}
// parse the rest of the packet based on the type
if (result.pid === 0) {
result.type = 'pat';
parsePsi(packet.subarray(offset), result);
this.trigger('data', result);
} else if (result.pid === this.pmtPid) {
result.type = 'pmt';
parsePsi(packet.subarray(offset), result);
this.trigger('data', result);
// if there are any packets waiting for a PMT to be found, process them now
while (this.packetsWaitingForPmt.length) {
this.processPes_.apply(this, this.packetsWaitingForPmt.shift());
}
} else if (this.programMapTable === undefined) {
// When we have not seen a PMT yet, defer further processing of
// PES packets until one has been parsed
this.packetsWaitingForPmt.push([packet, offset, result]);
} else {
this.processPes_(packet, offset, result);
}
};
this.processPes_ = function(packet, offset, result) {
// set the appropriate stream type
if (result.pid === this.programMapTable.video) {
result.streamType = StreamTypes.H264_STREAM_TYPE;
} else if (result.pid === this.programMapTable.audio) {
result.streamType = StreamTypes.ADTS_STREAM_TYPE;
} else {
// if not video or audio, it is timed-metadata or unknown
// if unknown, streamType will be undefined
result.streamType = this.programMapTable['timed-metadata'][result.pid];
}
result.type = 'pes';
result.data = packet.subarray(offset);
this.trigger('data', result);
};
};
TransportParseStream.prototype = new Stream();
TransportParseStream.STREAM_TYPES = {
h264: 0x1b,
adts: 0x0f
};
/**
* Reconsistutes program elementary stream (PES) packets from parsed
* transport stream packets. That is, if you pipe an
* mp2t.TransportParseStream into a mp2t.ElementaryStream, the output
* events will be events which capture the bytes for individual PES
* packets plus relevant metadata that has been extracted from the
* container.
*/
ElementaryStream = function() {
var
self = this,
// PES packet fragments
video = {
data: [],
size: 0
},
audio = {
data: [],
size: 0
},
timedMetadata = {
data: [],
size: 0
},
programMapTable,
parsePes = function(payload, pes) {
var ptsDtsFlags;
// get the packet length, this will be 0 for video
pes.packetLength = 6 + ((payload[4] << 8) | payload[5]);
// find out if this packets starts a new keyframe
pes.dataAlignmentIndicator = (payload[6] & 0x04) !== 0;
// PES packets may be annotated with a PTS value, or a PTS value
// and a DTS value. Determine what combination of values is
// available to work with.
ptsDtsFlags = payload[7];
// PTS and DTS are normally stored as a 33-bit number. Javascript
// performs all bitwise operations on 32-bit integers but javascript
// supports a much greater range (52-bits) of integer using standard
// mathematical operations.
// We construct a 31-bit value using bitwise operators over the 31
// most significant bits and then multiply by 4 (equal to a left-shift
// of 2) before we add the final 2 least significant bits of the
// timestamp (equal to an OR.)
if (ptsDtsFlags & 0xC0) {
// the PTS and DTS are not written out directly. For information
// on how they are encoded, see
// http://dvd.sourceforge.net/dvdinfo/pes-hdr.html
pes.pts = (payload[9] & 0x0E) << 27 |
(payload[10] & 0xFF) << 20 |
(payload[11] & 0xFE) << 12 |
(payload[12] & 0xFF) << 5 |
(payload[13] & 0xFE) >>> 3;
pes.pts *= 4; // Left shift by 2
pes.pts += (payload[13] & 0x06) >>> 1; // OR by the two LSBs
pes.dts = pes.pts;
if (ptsDtsFlags & 0x40) {
pes.dts = (payload[14] & 0x0E) << 27 |
(payload[15] & 0xFF) << 20 |
(payload[16] & 0xFE) << 12 |
(payload[17] & 0xFF) << 5 |
(payload[18] & 0xFE) >>> 3;
pes.dts *= 4; // Left shift by 2
pes.dts += (payload[18] & 0x06) >>> 1; // OR by the two LSBs
}
}
// the data section starts immediately after the PES header.
// pes_header_data_length specifies the number of header bytes
// that follow the last byte of the field.
pes.data = payload.subarray(9 + payload[8]);
},
/**
* Pass completely parsed PES packets to the next stream in the pipeline
**/
flushStream = function(stream, type, forceFlush) {
var
packetData = new Uint8Array(stream.size),
event = {
type: type
},
i = 0,
offset = 0,
packetFlushable = false,
fragment;
// do nothing if there is not enough buffered data for a complete
// PES header
if (!stream.data.length || stream.size < 9) {
return;
}
event.trackId = stream.data[0].pid;
// reassemble the packet
for (i = 0; i < stream.data.length; i++) {
fragment = stream.data[i];
packetData.set(fragment.data, offset);
offset += fragment.data.byteLength;
}
// parse assembled packet's PES header
parsePes(packetData, event);
// non-video PES packets MUST have a non-zero PES_packet_length
// check that there is enough stream data to fill the packet
packetFlushable = type === 'video' || event.packetLength <= stream.size;
// flush pending packets if the conditions are right
if (forceFlush || packetFlushable) {
stream.size = 0;
stream.data.length = 0;
}
// only emit packets that are complete. this is to avoid assembling
// incomplete PES packets due to poor segmentation
if (packetFlushable) {
self.trigger('data', event);
}
};
ElementaryStream.prototype.init.call(this);
/**
* Identifies M2TS packet types and parses PES packets using metadata
* parsed from the PMT
**/
this.push = function(data) {
({
pat: function() {
// we have to wait for the PMT to arrive as well before we
// have any meaningful metadata
},
pes: function() {
var stream, streamType;
switch (data.streamType) {
case StreamTypes.H264_STREAM_TYPE:
stream = video;
streamType = 'video';
break;
case StreamTypes.ADTS_STREAM_TYPE:
stream = audio;
streamType = 'audio';
break;
case StreamTypes.METADATA_STREAM_TYPE:
stream = timedMetadata;
streamType = 'timed-metadata';
break;
default:
// ignore unknown stream types
return;
}
// if a new packet is starting, we can flush the completed
// packet
if (data.payloadUnitStartIndicator) {
flushStream(stream, streamType, true);
}
// buffer this fragment until we are sure we've received the
// complete payload
stream.data.push(data);
stream.size += data.data.byteLength;
},
pmt: function() {
var
event = {
type: 'metadata',
tracks: []
};
programMapTable = data.programMapTable;
// translate audio and video streams to tracks
if (programMapTable.video !== null) {
event.tracks.push({
timelineStartInfo: {
baseMediaDecodeTime: 0
},
id: +programMapTable.video,
codec: 'avc',
type: 'video'
});
}
if (programMapTable.audio !== null) {
event.tracks.push({
timelineStartInfo: {
baseMediaDecodeTime: 0
},
id: +programMapTable.audio,
codec: 'adts',
type: 'audio'
});
}
self.trigger('data', event);
}
})[data.type]();
};
this.reset = function() {
video.size = 0;
video.data.length = 0;
audio.size = 0;
audio.data.length = 0;
this.trigger('reset');
};
/**
* Flush any remaining input. Video PES packets may be of variable
* length. Normally, the start of a new video packet can trigger the
* finalization of the previous packet. That is not possible if no
* more video is forthcoming, however. In that case, some other
* mechanism (like the end of the file) has to be employed. When it is
* clear that no additional data is forthcoming, calling this method
* will flush the buffered packets.
*/
this.flushStreams_ = function() {
// !!THIS ORDER IS IMPORTANT!!
// video first then audio
flushStream(video, 'video');
flushStream(audio, 'audio');
flushStream(timedMetadata, 'timed-metadata');
};
this.flush = function() {
this.flushStreams_();
this.trigger('done');
};
};
ElementaryStream.prototype = new Stream();
var m2ts = {
PAT_PID: 0x0000,
MP2T_PACKET_LENGTH: MP2T_PACKET_LENGTH,
TransportPacketStream: TransportPacketStream,
TransportParseStream: TransportParseStream,
ElementaryStream: ElementaryStream,
TimestampRolloverStream: TimestampRolloverStream,
CaptionStream: CaptionStream.CaptionStream,
Cea608Stream: CaptionStream.Cea608Stream,
MetadataStream: require(10)
};
for (var type in StreamTypes) {
if (StreamTypes.hasOwnProperty(type)) {
m2ts[type] = StreamTypes[type];
}
}
module.exports = m2ts;
},{"10":10,"11":11,"12":12,"31":31,"8":8}],10:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*
* Accepts program elementary stream (PES) data events and parses out
* ID3 metadata from them, if present.
* @see http://id3.org/id3v2.3.0
*/
'use strict';
var
Stream = require(31),
StreamTypes = require(11),
// return a percent-encoded representation of the specified byte range
// @see http://en.wikipedia.org/wiki/Percent-encoding
percentEncode = function(bytes, start, end) {
var i, result = '';
for (i = start; i < end; i++) {
result += '%' + ('00' + bytes[i].toString(16)).slice(-2);
}
return result;
},
// return the string representation of the specified byte range,
// interpreted as UTf-8.
parseUtf8 = function(bytes, start, end) {
return decodeURIComponent(percentEncode(bytes, start, end));
},
// return the string representation of the specified byte range,
// interpreted as ISO-8859-1.
parseIso88591 = function(bytes, start, end) {
return unescape(percentEncode(bytes, start, end)); // jshint ignore:line
},
parseSyncSafeInteger = function(data) {
return (data[0] << 21) |
(data[1] << 14) |
(data[2] << 7) |
(data[3]);
},
tagParsers = {
TXXX: function(tag) {
var i;
if (tag.data[0] !== 3) {
// ignore frames with unrecognized character encodings
return;
}
for (i = 1; i < tag.data.length; i++) {
if (tag.data[i] === 0) {
// parse the text fields
tag.description = parseUtf8(tag.data, 1, i);
// do not include the null terminator in the tag value
tag.value = parseUtf8(tag.data, i + 1, tag.data.length).replace(/\0*$/, '');
break;
}
}
tag.data = tag.value;
},
WXXX: function(tag) {
var i;
if (tag.data[0] !== 3) {
// ignore frames with unrecognized character encodings
return;
}
for (i = 1; i < tag.data.length; i++) {
if (tag.data[i] === 0) {
// parse the description and URL fields
tag.description = parseUtf8(tag.data, 1, i);
tag.url = parseUtf8(tag.data, i + 1, tag.data.length);
break;
}
}
},
PRIV: function(tag) {
var i;
for (i = 0; i < tag.data.length; i++) {
if (tag.data[i] === 0) {
// parse the description and URL fields
tag.owner = parseIso88591(tag.data, 0, i);
break;
}
}
tag.privateData = tag.data.subarray(i + 1);
tag.data = tag.privateData;
}
},
MetadataStream;
MetadataStream = function(options) {
var
settings = {
debug: !!(options && options.debug),
// the bytes of the program-level descriptor field in MP2T
// see ISO/IEC 13818-1:2013 (E), section 2.6 "Program and
// program element descriptors"
descriptor: options && options.descriptor
},
// the total size in bytes of the ID3 tag being parsed
tagSize = 0,
// tag data that is not complete enough to be parsed
buffer = [],
// the total number of bytes currently in the buffer
bufferSize = 0,
i;
MetadataStream.prototype.init.call(this);
// calculate the text track in-band metadata track dispatch type
// https://html.spec.whatwg.org/multipage/embedded-content.html#steps-to-expose-a-media-resource-specific-text-track
this.dispatchType = StreamTypes.METADATA_STREAM_TYPE.toString(16);
if (settings.descriptor) {
for (i = 0; i < settings.descriptor.length; i++) {
this.dispatchType += ('00' + settings.descriptor[i].toString(16)).slice(-2);
}
}
this.push = function(chunk) {
var tag, frameStart, frameSize, frame, i, frameHeader;
if (chunk.type !== 'timed-metadata') {
return;
}
// if data_alignment_indicator is set in the PES header,
// we must have the start of a new ID3 tag. Assume anything
// remaining in the buffer was malformed and throw it out
if (chunk.dataAlignmentIndicator) {
bufferSize = 0;
buffer.length = 0;
}
// ignore events that don't look like ID3 data
if (buffer.length === 0 &&
(chunk.data.length < 10 ||
chunk.data[0] !== 'I'.charCodeAt(0) ||
chunk.data[1] !== 'D'.charCodeAt(0) ||
chunk.data[2] !== '3'.charCodeAt(0))) {
if (settings.debug) {
// eslint-disable-next-line no-console
console.log('Skipping unrecognized metadata packet');
}
return;
}
// add this chunk to the data we've collected so far
buffer.push(chunk);
bufferSize += chunk.data.byteLength;
// grab the size of the entire frame from the ID3 header
if (buffer.length === 1) {
// the frame size is transmitted as a 28-bit integer in the
// last four bytes of the ID3 header.
// The most significant bit of each byte is dropped and the
// results concatenated to recover the actual value.
tagSize = parseSyncSafeInteger(chunk.data.subarray(6, 10));
// ID3 reports the tag size excluding the header but it's more
// convenient for our comparisons to include it
tagSize += 10;
}
// if the entire frame has not arrived, wait for more data
if (bufferSize < tagSize) {
return;
}
// collect the entire frame so it can be parsed
tag = {
data: new Uint8Array(tagSize),
frames: [],
pts: buffer[0].pts,
dts: buffer[0].dts
};
for (i = 0; i < tagSize;) {
tag.data.set(buffer[0].data.subarray(0, tagSize - i), i);
i += buffer[0].data.byteLength;
bufferSize -= buffer[0].data.byteLength;
buffer.shift();
}
// find the start of the first frame and the end of the tag
frameStart = 10;
if (tag.data[5] & 0x40) {
// advance the frame start past the extended header
frameStart += 4; // header size field
frameStart += parseSyncSafeInteger(tag.data.subarray(10, 14));
// clip any padding off the end
tagSize -= parseSyncSafeInteger(tag.data.subarray(16, 20));
}
// parse one or more ID3 frames
// http://id3.org/id3v2.3.0#ID3v2_frame_overview
do {
// determine the number of bytes in this frame
frameSize = parseSyncSafeInteger(tag.data.subarray(frameStart + 4, frameStart + 8));
if (frameSize < 1) {
// eslint-disable-next-line no-console
return console.log('Malformed ID3 frame encountered. Skipping metadata parsing.');
}
frameHeader = String.fromCharCode(tag.data[frameStart],
tag.data[frameStart + 1],
tag.data[frameStart + 2],
tag.data[frameStart + 3]);
frame = {
id: frameHeader,
data: tag.data.subarray(frameStart + 10, frameStart + frameSize + 10)
};
frame.key = frame.id;
if (tagParsers[frame.id]) {
tagParsers[frame.id](frame);
// handle the special PRIV frame used to indicate the start
// time for raw AAC data
if (frame.owner === 'com.apple.streaming.transportStreamTimestamp') {
var
d = frame.data,
size = ((d[3] & 0x01) << 30) |
(d[4] << 22) |
(d[5] << 14) |
(d[6] << 6) |
(d[7] >>> 2);
size *= 4;
size += d[7] & 0x03;
frame.timeStamp = size;
// in raw AAC, all subsequent data will be timestamped based
// on the value of this frame
// we couldn't have known the appropriate pts and dts before
// parsing this ID3 tag so set those values now
if (tag.pts === undefined && tag.dts === undefined) {
tag.pts = frame.timeStamp;
tag.dts = frame.timeStamp;
}
this.trigger('timestamp', frame);
}
}
tag.frames.push(frame);
frameStart += 10; // advance past the frame header
frameStart += frameSize; // advance past the frame body
} while (frameStart < tagSize);
this.trigger('data', tag);
};
};
MetadataStream.prototype = new Stream();
module.exports = MetadataStream;
},{"11":11,"31":31}],11:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*/
'use strict';
module.exports = {
H264_STREAM_TYPE: 0x1B,
ADTS_STREAM_TYPE: 0x0F,
METADATA_STREAM_TYPE: 0x15
};
},{}],12:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*
* Accepts program elementary stream (PES) data events and corrects
* decode and presentation time stamps to account for a rollover
* of the 33 bit value.
*/
'use strict';
var Stream = require(31);
var MAX_TS = 8589934592;
var RO_THRESH = 4294967296;
var TYPE_SHARED = 'shared';
var handleRollover = function(value, reference) {
var direction = 1;
if (value > reference) {
// If the current timestamp value is greater than our reference timestamp and we detect a
// timestamp rollover, this means the roll over is happening in the opposite direction.
// Example scenario: Enter a long stream/video just after a rollover occurred. The reference
// point will be set to a small number, e.g. 1. The user then seeks backwards over the
// rollover point. In loading this segment, the timestamp values will be very large,
// e.g. 2^33 - 1. Since this comes before the data we loaded previously, we want to adjust
// the time stamp to be `value - 2^33`.
direction = -1;
}
// Note: A seek forwards or back that is greater than the RO_THRESH (2^32, ~13 hours) will
// cause an incorrect adjustment.
while (Math.abs(reference - value) > RO_THRESH) {
value += (direction * MAX_TS);
}
return value;
};
var TimestampRolloverStream = function(type) {
var lastDTS, referenceDTS;
TimestampRolloverStream.prototype.init.call(this);
// The "shared" type is used in cases where a stream will contain muxed
// video and audio. We could use `undefined` here, but having a string
// makes debugging a little clearer.
this.type_ = type || TYPE_SHARED;
this.push = function(data) {
// Any "shared" rollover streams will accept _all_ data. Otherwise,
// streams will only accept data that matches their type.
if (this.type_ !== TYPE_SHARED && data.type !== this.type_) {
return;
}
if (referenceDTS === undefined) {
referenceDTS = data.dts;
}
data.dts = handleRollover(data.dts, referenceDTS);
data.pts = handleRollover(data.pts, referenceDTS);
lastDTS = data.dts;
this.trigger('data', data);
};
this.flush = function() {
referenceDTS = lastDTS;
this.trigger('done');
};
this.endTimeline = function() {
this.flush();
this.trigger('endedtimeline');
};
this.discontinuity = function() {
referenceDTS = void 0;
lastDTS = void 0;
};
this.reset = function() {
this.discontinuity();
this.trigger('reset');
};
};
TimestampRolloverStream.prototype = new Stream();
module.exports = {
TimestampRolloverStream: TimestampRolloverStream,
handleRollover: handleRollover
};
},{"31":31}],13:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*/
var coneOfSilence = require(7);
var clock = require(29);
/**
* Sum the `byteLength` properties of the data in each AAC frame
*/
var sumFrameByteLengths = function(array) {
var
i,
currentObj,
sum = 0;
// sum the byteLength's all each nal unit in the frame
for (i = 0; i < array.length; i++) {
currentObj = array[i];
sum += currentObj.data.byteLength;
}
return sum;
};
// Possibly pad (prefix) the audio track with silence if appending this track
// would lead to the introduction of a gap in the audio buffer
var prefixWithSilence = function(
track,
frames,
audioAppendStartTs,
videoBaseMediaDecodeTime
) {
var
baseMediaDecodeTimeTs,
frameDuration = 0,
audioGapDuration = 0,
audioFillFrameCount = 0,
audioFillDuration = 0,
silentFrame,
i,
firstFrame;
if (!frames.length) {
return;
}
baseMediaDecodeTimeTs =
clock.audioTsToVideoTs(track.baseMediaDecodeTime, track.samplerate);
// determine frame clock duration based on sample rate, round up to avoid overfills
frameDuration = Math.ceil(clock.ONE_SECOND_IN_TS / (track.samplerate / 1024));
if (audioAppendStartTs && videoBaseMediaDecodeTime) {
// insert the shortest possible amount (audio gap or audio to video gap)
audioGapDuration =
baseMediaDecodeTimeTs - Math.max(audioAppendStartTs, videoBaseMediaDecodeTime);
// number of full frames in the audio gap
audioFillFrameCount = Math.floor(audioGapDuration / frameDuration);
audioFillDuration = audioFillFrameCount * frameDuration;
}
// don't attempt to fill gaps smaller than a single frame or larger
// than a half second
if (audioFillFrameCount < 1 || audioFillDuration > clock.ONE_SECOND_IN_TS / 2) {
return;
}
silentFrame = coneOfSilence()[track.samplerate];
if (!silentFrame) {
// we don't have a silent frame pregenerated for the sample rate, so use a frame
// from the content instead
silentFrame = frames[0].data;
}
for (i = 0; i < audioFillFrameCount; i++) {
firstFrame = frames[0];
frames.splice(0, 0, {
data: silentFrame,
dts: firstFrame.dts - frameDuration,
pts: firstFrame.pts - frameDuration
});
}
track.baseMediaDecodeTime -=
Math.floor(clock.videoTsToAudioTs(audioFillDuration, track.samplerate));
};
// If the audio segment extends before the earliest allowed dts
// value, remove AAC frames until starts at or after the earliest
// allowed DTS so that we don't end up with a negative baseMedia-
// DecodeTime for the audio track
var trimAdtsFramesByEarliestDts = function(adtsFrames, track, earliestAllowedDts) {
if (track.minSegmentDts >= earliestAllowedDts) {
return adtsFrames;
}
// We will need to recalculate the earliest segment Dts
track.minSegmentDts = Infinity;
return adtsFrames.filter(function(currentFrame) {
// If this is an allowed frame, keep it and record it's Dts
if (currentFrame.dts >= earliestAllowedDts) {
track.minSegmentDts = Math.min(track.minSegmentDts, currentFrame.dts);
track.minSegmentPts = track.minSegmentDts;
return true;
}
// Otherwise, discard it
return false;
});
};
// generate the track's raw mdat data from an array of frames
var generateSampleTable = function(frames) {
var
i,
currentFrame,
samples = [];
for (i = 0; i < frames.length; i++) {
currentFrame = frames[i];
samples.push({
size: currentFrame.data.byteLength,
duration: 1024 // For AAC audio, all samples contain 1024 samples
});
}
return samples;
};
// generate the track's sample table from an array of frames
var concatenateFrameData = function(frames) {
var
i,
currentFrame,
dataOffset = 0,
data = new Uint8Array(sumFrameByteLengths(frames));
for (i = 0; i < frames.length; i++) {
currentFrame = frames[i];
data.set(currentFrame.data, dataOffset);
dataOffset += currentFrame.data.byteLength;
}
return data;
};
module.exports = {
prefixWithSilence: prefixWithSilence,
trimAdtsFramesByEarliestDts: trimAdtsFramesByEarliestDts,
generateSampleTable: generateSampleTable,
concatenateFrameData: concatenateFrameData
};
},{"29":29,"7":7}],14:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*
* Reads in-band CEA-708 captions out of FMP4 segments.
* @see https://en.wikipedia.org/wiki/CEA-708
*/
'use strict';
var discardEmulationPreventionBytes = require(23).discardEmulationPreventionBytes;
var CaptionStream = require(8).CaptionStream;
var findBox = require(15);
var parseTfdt = require(25);
var parseTrun = require(27);
var parseTfhd = require(26);
/**
* Maps an offset in the mdat to a sample based on the the size of the samples.
* Assumes that `parseSamples` has been called first.
*
* @param {Number} offset - The offset into the mdat
* @param {Object[]} samples - An array of samples, parsed using `parseSamples`
* @return {?Object} The matching sample, or null if no match was found.
*
* @see ISO-BMFF-12/2015, Section 8.8.8
**/
var mapToSample = function(offset, samples) {
var approximateOffset = offset;
for (var i = 0; i < samples.length; i++) {
var sample = samples[i];
if (approximateOffset < sample.size) {
return sample;
}
approximateOffset -= sample.size;
}
return null;
};
/**
* Finds SEI nal units contained in a Media Data Box.
* Assumes that `parseSamples` has been called first.
*
* @param {Uint8Array} avcStream - The bytes of the mdat
* @param {Object[]} samples - The samples parsed out by `parseSamples`
* @param {Number} trackId - The trackId of this video track
* @return {Object[]} seiNals - the parsed SEI NALUs found.
* The contents of the seiNal should match what is expected by
* CaptionStream.push (nalUnitType, size, data, escapedRBSP, pts, dts)
*
* @see ISO-BMFF-12/2015, Section 8.1.1
* @see Rec. ITU-T H.264, 7.3.2.3.1
**/
var findSeiNals = function(avcStream, samples, trackId) {
var
avcView = new DataView(avcStream.buffer, avcStream.byteOffset, avcStream.byteLength),
result = [],
seiNal,
i,
length,
lastMatchedSample;
for (i = 0; i + 4 < avcStream.length; i += length) {
length = avcView.getUint32(i);
i += 4;
// Bail if this doesn't appear to be an H264 stream
if (length <= 0) {
continue;
}
switch (avcStream[i] & 0x1F) {
case 0x06:
var data = avcStream.subarray(i + 1, i + 1 + length);
var matchingSample = mapToSample(i, samples);
seiNal = {
nalUnitType: 'sei_rbsp',
size: length,
data: data,
escapedRBSP: discardEmulationPreventionBytes(data),
trackId: trackId
};
if (matchingSample) {
seiNal.pts = matchingSample.pts;
seiNal.dts = matchingSample.dts;
lastMatchedSample = matchingSample;
} else if (lastMatchedSample) {
// If a matching sample cannot be found, use the last
// sample's values as they should be as close as possible
seiNal.pts = lastMatchedSample.pts;
seiNal.dts = lastMatchedSample.dts;
} else {
// eslint-disable-next-line no-console
console.log("We've encountered a nal unit without data. See mux.js#233.");
break;
}
result.push(seiNal);
break;
default:
break;
}
}
return result;
};
/**
* Parses sample information out of Track Run Boxes and calculates
* the absolute presentation and decode timestamps of each sample.
*
* @param {Array<Uint8Array>} truns - The Trun Run boxes to be parsed
* @param {Number} baseMediaDecodeTime - base media decode time from tfdt
@see ISO-BMFF-12/2015, Section 8.8.12
* @param {Object} tfhd - The parsed Track Fragment Header
* @see inspect.parseTfhd
* @return {Object[]} the parsed samples
*
* @see ISO-BMFF-12/2015, Section 8.8.8
**/
var parseSamples = function(truns, baseMediaDecodeTime, tfhd) {
var currentDts = baseMediaDecodeTime;
var defaultSampleDuration = tfhd.defaultSampleDuration || 0;
var defaultSampleSize = tfhd.defaultSampleSize || 0;
var trackId = tfhd.trackId;
var allSamples = [];
truns.forEach(function(trun) {
// Note: We currently do not parse the sample table as well
// as the trun. It's possible some sources will require this.
// moov > trak > mdia > minf > stbl
var trackRun = parseTrun(trun);
var samples = trackRun.samples;
samples.forEach(function(sample) {
if (sample.duration === undefined) {
sample.duration = defaultSampleDuration;
}
if (sample.size === undefined) {
sample.size = defaultSampleSize;
}
sample.trackId = trackId;
sample.dts = currentDts;
if (sample.compositionTimeOffset === undefined) {
sample.compositionTimeOffset = 0;
}
sample.pts = currentDts + sample.compositionTimeOffset;
currentDts += sample.duration;
});
allSamples = allSamples.concat(samples);
});
return allSamples;
};
/**
* Parses out caption nals from an FMP4 segment's video tracks.
*
* @param {Uint8Array} segment - The bytes of a single segment
* @param {Number} videoTrackId - The trackId of a video track in the segment
* @return {Object.<Number, Object[]>} A mapping of video trackId to
* a list of seiNals found in that track
**/
var parseCaptionNals = function(segment, videoTrackId) {
// To get the samples
var trafs = findBox(segment, ['moof', 'traf']);
// To get SEI NAL units
var mdats = findBox(segment, ['mdat']);
var captionNals = {};
var mdatTrafPairs = [];
// Pair up each traf with a mdat as moofs and mdats are in pairs
mdats.forEach(function(mdat, index) {
var matchingTraf = trafs[index];
mdatTrafPairs.push({
mdat: mdat,
traf: matchingTraf
});
});
mdatTrafPairs.forEach(function(pair) {
var mdat = pair.mdat;
var traf = pair.traf;
var tfhd = findBox(traf, ['tfhd']);
// Exactly 1 tfhd per traf
var headerInfo = parseTfhd(tfhd[0]);
var trackId = headerInfo.trackId;
var tfdt = findBox(traf, ['tfdt']);
// Either 0 or 1 tfdt per traf
var baseMediaDecodeTime = (tfdt.length > 0) ? parseTfdt(tfdt[0]).baseMediaDecodeTime : 0;
var truns = findBox(traf, ['trun']);
var samples;
var seiNals;
// Only parse video data for the chosen video track
if (videoTrackId === trackId && truns.length > 0) {
samples = parseSamples(truns, baseMediaDecodeTime, headerInfo);
seiNals = findSeiNals(mdat, samples, trackId);
if (!captionNals[trackId]) {
captionNals[trackId] = [];
}
captionNals[trackId] = captionNals[trackId].concat(seiNals);
}
});
return captionNals;
};
/**
* Parses out inband captions from an MP4 container and returns
* caption objects that can be used by WebVTT and the TextTrack API.
* @see https://developer.mozilla.org/en-US/docs/Web/API/VTTCue
* @see https://developer.mozilla.org/en-US/docs/Web/API/TextTrack
* Assumes that `probe.getVideoTrackIds` and `probe.timescale` have been called first
*
* @param {Uint8Array} segment - The fmp4 segment containing embedded captions
* @param {Number} trackId - The id of the video track to parse
* @param {Number} timescale - The timescale for the video track from the init segment
*
* @return {?Object[]} parsedCaptions - A list of captions or null if no video tracks
* @return {Number} parsedCaptions[].startTime - The time to show the caption in seconds
* @return {Number} parsedCaptions[].endTime - The time to stop showing the caption in seconds
* @return {String} parsedCaptions[].text - The visible content of the caption
**/
var parseEmbeddedCaptions = function(segment, trackId, timescale) {
var seiNals;
// the ISO-BMFF spec says that trackId can't be zero, but there's some broken content out there
if (trackId === null) {
return null;
}
seiNals = parseCaptionNals(segment, trackId);
return {
seiNals: seiNals[trackId],
timescale: timescale
};
};
/**
* Converts SEI NALUs into captions that can be used by video.js
**/
var CaptionParser = function() {
var isInitialized = false;
var captionStream;
// Stores segments seen before trackId and timescale are set
var segmentCache;
// Stores video track ID of the track being parsed
var trackId;
// Stores the timescale of the track being parsed
var timescale;
// Stores captions parsed so far
var parsedCaptions;
// Stores whether we are receiving partial data or not
var parsingPartial;
/**
* A method to indicate whether a CaptionParser has been initalized
* @returns {Boolean}
**/
this.isInitialized = function() {
return isInitialized;
};
/**
* Initializes the underlying CaptionStream, SEI NAL parsing
* and management, and caption collection
**/
this.init = function(options) {
captionStream = new CaptionStream();
isInitialized = true;
parsingPartial = options ? options.isPartial : false;
// Collect dispatched captions
captionStream.on('data', function(event) {
// Convert to seconds in the source's timescale
event.startTime = event.startPts / timescale;
event.endTime = event.endPts / timescale;
parsedCaptions.captions.push(event);
parsedCaptions.captionStreams[event.stream] = true;
});
};
/**
* Determines if a new video track will be selected
* or if the timescale changed
* @return {Boolean}
**/
this.isNewInit = function(videoTrackIds, timescales) {
if ((videoTrackIds && videoTrackIds.length === 0) ||
(timescales && typeof timescales === 'object' &&
Object.keys(timescales).length === 0)) {
return false;
}
return trackId !== videoTrackIds[0] ||
timescale !== timescales[trackId];
};
/**
* Parses out SEI captions and interacts with underlying
* CaptionStream to return dispatched captions
*
* @param {Uint8Array} segment - The fmp4 segment containing embedded captions
* @param {Number[]} videoTrackIds - A list of video tracks found in the init segment
* @param {Object.<Number, Number>} timescales - The timescales found in the init segment
* @see parseEmbeddedCaptions
* @see m2ts/caption-stream.js
**/
this.parse = function(segment, videoTrackIds, timescales) {
var parsedData;
if (!this.isInitialized()) {
return null;
// This is not likely to be a video segment
} else if (!videoTrackIds || !timescales) {
return null;
} else if (this.isNewInit(videoTrackIds, timescales)) {
// Use the first video track only as there is no
// mechanism to switch to other video tracks
trackId = videoTrackIds[0];
timescale = timescales[trackId];
// If an init segment has not been seen yet, hold onto segment
// data until we have one.
// the ISO-BMFF spec says that trackId can't be zero, but there's some broken content out there
} else if (trackId === null || !timescale) {
segmentCache.push(segment);
return null;
}
// Now that a timescale and trackId is set, parse cached segments
while (segmentCache.length > 0) {
var cachedSegment = segmentCache.shift();
this.parse(cachedSegment, videoTrackIds, timescales);
}
parsedData = parseEmbeddedCaptions(segment, trackId, timescale);
if (parsedData === null || !parsedData.seiNals) {
return null;
}
this.pushNals(parsedData.seiNals);
// Force the parsed captions to be dispatched
this.flushStream();
return parsedCaptions;
};
/**
* Pushes SEI NALUs onto CaptionStream
* @param {Object[]} nals - A list of SEI nals parsed using `parseCaptionNals`
* Assumes that `parseCaptionNals` has been called first
* @see m2ts/caption-stream.js
**/
this.pushNals = function(nals) {
if (!this.isInitialized() || !nals || nals.length === 0) {
return null;
}
nals.forEach(function(nal) {
captionStream.push(nal);
});
};
/**
* Flushes underlying CaptionStream to dispatch processed, displayable captions
* @see m2ts/caption-stream.js
**/
this.flushStream = function() {
if (!this.isInitialized()) {
return null;
}
if (!parsingPartial) {
captionStream.flush();
} else {
captionStream.partialFlush();
}
};
/**
* Reset caption buckets for new data
**/
this.clearParsedCaptions = function() {
parsedCaptions.captions = [];
parsedCaptions.captionStreams = {};
};
/**
* Resets underlying CaptionStream
* @see m2ts/caption-stream.js
**/
this.resetCaptionStream = function() {
if (!this.isInitialized()) {
return null;
}
captionStream.reset();
};
/**
* Convenience method to clear all captions flushed from the
* CaptionStream and still being parsed
* @see m2ts/caption-stream.js
**/
this.clearAllCaptions = function() {
this.clearParsedCaptions();
this.resetCaptionStream();
};
/**
* Reset caption parser
**/
this.reset = function() {
segmentCache = [];
trackId = null;
timescale = null;
if (!parsedCaptions) {
parsedCaptions = {
captions: [],
// CC1, CC2, CC3, CC4
captionStreams: {}
};
} else {
this.clearParsedCaptions();
}
this.resetCaptionStream();
};
this.reset();
};
module.exports = CaptionParser;
},{"15":15,"23":23,"25":25,"26":26,"27":27,"8":8}],15:[function(require,module,exports){
var toUnsigned = require(28).toUnsigned;
var parseType = require(19);
var findBox = function(data, path) {
var results = [],
i, size, type, end, subresults;
if (!path.length) {
// short-circuit the search for empty paths
return null;
}
for (i = 0; i < data.byteLength;) {
size = toUnsigned(data[i] << 24 |
data[i + 1] << 16 |
data[i + 2] << 8 |
data[i + 3]);
type = parseType(data.subarray(i + 4, i + 8));
end = size > 1 ? i + size : data.byteLength;
if (type === path[0]) {
if (path.length === 1) {
// this is the end of the path and we've found the box we were
// looking for
results.push(data.subarray(i + 8, end));
} else {
// recursively search for the next box along the path
subresults = findBox(data.subarray(i + 8, end), path.slice(1));
if (subresults.length) {
results = results.concat(subresults);
}
}
}
i = end;
}
// we've finished searching all of data
return results;
};
module.exports = findBox;
},{"19":19,"28":28}],16:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*/
// Convert an array of nal units into an array of frames with each frame being
// composed of the nal units that make up that frame
// Also keep track of cummulative data about the frame from the nal units such
// as the frame duration, starting pts, etc.
var groupNalsIntoFrames = function(nalUnits) {
var
i,
currentNal,
currentFrame = [],
frames = [];
// TODO added for LHLS, make sure this is OK
frames.byteLength = 0;
frames.nalCount = 0;
frames.duration = 0;
currentFrame.byteLength = 0;
for (i = 0; i < nalUnits.length; i++) {
currentNal = nalUnits[i];
// Split on 'aud'-type nal units
if (currentNal.nalUnitType === 'access_unit_delimiter_rbsp') {
// Since the very first nal unit is expected to be an AUD
// only push to the frames array when currentFrame is not empty
if (currentFrame.length) {
currentFrame.duration = currentNal.dts - currentFrame.dts;
// TODO added for LHLS, make sure this is OK
frames.byteLength += currentFrame.byteLength;
frames.nalCount += currentFrame.length;
frames.duration += currentFrame.duration;
frames.push(currentFrame);
}
currentFrame = [currentNal];
currentFrame.byteLength = currentNal.data.byteLength;
currentFrame.pts = currentNal.pts;
currentFrame.dts = currentNal.dts;
} else {
// Specifically flag key frames for ease of use later
if (currentNal.nalUnitType === 'slice_layer_without_partitioning_rbsp_idr') {
currentFrame.keyFrame = true;
}
currentFrame.duration = currentNal.dts - currentFrame.dts;
currentFrame.byteLength += currentNal.data.byteLength;
currentFrame.push(currentNal);
}
}
// For the last frame, use the duration of the previous frame if we
// have nothing better to go on
if (frames.length &&
(!currentFrame.duration ||
currentFrame.duration <= 0)) {
currentFrame.duration = frames[frames.length - 1].duration;
}
// Push the final frame
// TODO added for LHLS, make sure this is OK
frames.byteLength += currentFrame.byteLength;
frames.nalCount += currentFrame.length;
frames.duration += currentFrame.duration;
frames.push(currentFrame);
return frames;
};
// Convert an array of frames into an array of Gop with each Gop being composed
// of the frames that make up that Gop
// Also keep track of cummulative data about the Gop from the frames such as the
// Gop duration, starting pts, etc.
var groupFramesIntoGops = function(frames) {
var
i,
currentFrame,
currentGop = [],
gops = [];
// We must pre-set some of the values on the Gop since we
// keep running totals of these values
currentGop.byteLength = 0;
currentGop.nalCount = 0;
currentGop.duration = 0;
currentGop.pts = frames[0].pts;
currentGop.dts = frames[0].dts;
// store some metadata about all the Gops
gops.byteLength = 0;
gops.nalCount = 0;
gops.duration = 0;
gops.pts = frames[0].pts;
gops.dts = frames[0].dts;
for (i = 0; i < frames.length; i++) {
currentFrame = frames[i];
if (currentFrame.keyFrame) {
// Since the very first frame is expected to be an keyframe
// only push to the gops array when currentGop is not empty
if (currentGop.length) {
gops.push(currentGop);
gops.byteLength += currentGop.byteLength;
gops.nalCount += currentGop.nalCount;
gops.duration += currentGop.duration;
}
currentGop = [currentFrame];
currentGop.nalCount = currentFrame.length;
currentGop.byteLength = currentFrame.byteLength;
currentGop.pts = currentFrame.pts;
currentGop.dts = currentFrame.dts;
currentGop.duration = currentFrame.duration;
} else {
currentGop.duration += currentFrame.duration;
currentGop.nalCount += currentFrame.length;
currentGop.byteLength += currentFrame.byteLength;
currentGop.push(currentFrame);
}
}
if (gops.length && currentGop.duration <= 0) {
currentGop.duration = gops[gops.length - 1].duration;
}
gops.byteLength += currentGop.byteLength;
gops.nalCount += currentGop.nalCount;
gops.duration += currentGop.duration;
// push the final Gop
gops.push(currentGop);
return gops;
};
/*
* Search for the first keyframe in the GOPs and throw away all frames
* until that keyframe. Then extend the duration of the pulled keyframe
* and pull the PTS and DTS of the keyframe so that it covers the time
* range of the frames that were disposed.
*
* @param {Array} gops video GOPs
* @returns {Array} modified video GOPs
*/
var extendFirstKeyFrame = function(gops) {
var currentGop;
if (!gops[0][0].keyFrame && gops.length > 1) {
// Remove the first GOP
currentGop = gops.shift();
gops.byteLength -= currentGop.byteLength;
gops.nalCount -= currentGop.nalCount;
// Extend the first frame of what is now the
// first gop to cover the time period of the
// frames we just removed
gops[0][0].dts = currentGop.dts;
gops[0][0].pts = currentGop.pts;
gops[0][0].duration += currentGop.duration;
}
return gops;
};
/**
* Default sample object
* see ISO/IEC 14496-12:2012, section 8.6.4.3
*/
var createDefaultSample = function() {
return {
size: 0,
flags: {
isLeading: 0,
dependsOn: 1,
isDependedOn: 0,
hasRedundancy: 0,
degradationPriority: 0,
isNonSyncSample: 1
}
};
};
/*
* Collates information from a video frame into an object for eventual
* entry into an MP4 sample table.
*
* @param {Object} frame the video frame
* @param {Number} dataOffset the byte offset to position the sample
* @return {Object} object containing sample table info for a frame
*/
var sampleForFrame = function(frame, dataOffset) {
var sample = createDefaultSample();
sample.dataOffset = dataOffset;
sample.compositionTimeOffset = frame.pts - frame.dts;
sample.duration = frame.duration;
sample.size = 4 * frame.length; // Space for nal unit size
sample.size += frame.byteLength;
if (frame.keyFrame) {
sample.flags.dependsOn = 2;
sample.flags.isNonSyncSample = 0;
}
return sample;
};
// generate the track's sample table from an array of gops
var generateSampleTable = function(gops, baseDataOffset) {
var
h, i,
sample,
currentGop,
currentFrame,
dataOffset = baseDataOffset || 0,
samples = [];
for (h = 0; h < gops.length; h++) {
currentGop = gops[h];
for (i = 0; i < currentGop.length; i++) {
currentFrame = currentGop[i];
sample = sampleForFrame(currentFrame, dataOffset);
dataOffset += sample.size;
samples.push(sample);
}
}
return samples;
};
// generate the track's raw mdat data from an array of gops
var concatenateNalData = function(gops) {
var
h, i, j,
currentGop,
currentFrame,
currentNal,
dataOffset = 0,
nalsByteLength = gops.byteLength,
numberOfNals = gops.nalCount,
totalByteLength = nalsByteLength + 4 * numberOfNals,
data = new Uint8Array(totalByteLength),
view = new DataView(data.buffer);
// For each Gop..
for (h = 0; h < gops.length; h++) {
currentGop = gops[h];
// For each Frame..
for (i = 0; i < currentGop.length; i++) {
currentFrame = currentGop[i];
// For each NAL..
for (j = 0; j < currentFrame.length; j++) {
currentNal = currentFrame[j];
view.setUint32(dataOffset, currentNal.data.byteLength);
dataOffset += 4;
data.set(currentNal.data, dataOffset);
dataOffset += currentNal.data.byteLength;
}
}
}
return data;
};
// generate the track's sample table from a frame
var generateSampleTableForFrame = function(frame, baseDataOffset) {
var
sample,
dataOffset = baseDataOffset || 0,
samples = [];
sample = sampleForFrame(frame, dataOffset);
samples.push(sample);
return samples;
};
// generate the track's raw mdat data from a frame
var concatenateNalDataForFrame = function(frame) {
var
i,
currentNal,
dataOffset = 0,
nalsByteLength = frame.byteLength,
numberOfNals = frame.length,
totalByteLength = nalsByteLength + 4 * numberOfNals,
data = new Uint8Array(totalByteLength),
view = new DataView(data.buffer);
// For each NAL..
for (i = 0; i < frame.length; i++) {
currentNal = frame[i];
view.setUint32(dataOffset, currentNal.data.byteLength);
dataOffset += 4;
data.set(currentNal.data, dataOffset);
dataOffset += currentNal.data.byteLength;
}
return data;
};
module.exports = {
groupNalsIntoFrames: groupNalsIntoFrames,
groupFramesIntoGops: groupFramesIntoGops,
extendFirstKeyFrame: extendFirstKeyFrame,
generateSampleTable: generateSampleTable,
concatenateNalData: concatenateNalData,
generateSampleTableForFrame: generateSampleTableForFrame,
concatenateNalDataForFrame: concatenateNalDataForFrame
};
},{}],17:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*/
module.exports = {
generator: require(18),
probe: require(20),
Transmuxer: require(22).Transmuxer,
AudioSegmentStream: require(22).AudioSegmentStream,
VideoSegmentStream: require(22).VideoSegmentStream,
CaptionParser: require(14)
};
},{"14":14,"18":18,"20":20,"22":22}],18:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*
* Functions that generate fragmented MP4s suitable for use with Media
* Source Extensions.
*/
'use strict';
var UINT32_MAX = Math.pow(2, 32) - 1;
var box, dinf, esds, ftyp, mdat, mfhd, minf, moof, moov, mvex, mvhd,
trak, tkhd, mdia, mdhd, hdlr, sdtp, stbl, stsd, traf, trex,
trun, types, MAJOR_BRAND, MINOR_VERSION, AVC1_BRAND, VIDEO_HDLR,
AUDIO_HDLR, HDLR_TYPES, VMHD, SMHD, DREF, STCO, STSC, STSZ, STTS;
var customDuration = 0xffffffff;
// pre-calculate constants
(function() {
var i;
types = {
avc1: [], // codingname
avcC: [],
btrt: [],
dinf: [],
dref: [],
esds: [],
ftyp: [],
hdlr: [],
mdat: [],
mdhd: [],
mdia: [],
mfhd: [],
minf: [],
moof: [],
moov: [],
mp4a: [], // codingname
mvex: [],
mvhd: [],
pasp: [],
sdtp: [],
smhd: [],
stbl: [],
stco: [],
stsc: [],
stsd: [],
stsz: [],
stts: [],
styp: [],
tfdt: [],
tfhd: [],
traf: [],
trak: [],
trun: [],
trex: [],
tkhd: [],
vmhd: []
};
// In environments where Uint8Array is undefined (e.g., IE8), skip set up so that we
// don't throw an error
if (typeof Uint8Array === 'undefined') {
return;
}
for (i in types) {
if (types.hasOwnProperty(i)) {
types[i] = [
i.charCodeAt(0),
i.charCodeAt(1),
i.charCodeAt(2),
i.charCodeAt(3)
];
}
}
MAJOR_BRAND = new Uint8Array([
'i'.charCodeAt(0),
's'.charCodeAt(0),
'o'.charCodeAt(0),
'm'.charCodeAt(0)
]);
AVC1_BRAND = new Uint8Array([
'a'.charCodeAt(0),
'v'.charCodeAt(0),
'c'.charCodeAt(0),
'1'.charCodeAt(0)
]);
MINOR_VERSION = new Uint8Array([0, 0, 0, 1]);
VIDEO_HDLR = new Uint8Array([
0x00, // version 0
0x00, 0x00, 0x00, // flags
0x00, 0x00, 0x00, 0x00, // pre_defined
0x76, 0x69, 0x64, 0x65, // handler_type: 'vide'
0x00, 0x00, 0x00, 0x00, // reserved
0x00, 0x00, 0x00, 0x00, // reserved
0x00, 0x00, 0x00, 0x00, // reserved
0x56, 0x69, 0x64, 0x65,
0x6f, 0x48, 0x61, 0x6e,
0x64, 0x6c, 0x65, 0x72, 0x00 // name: 'VideoHandler'
]);
AUDIO_HDLR = new Uint8Array([
0x00, // version 0
0x00, 0x00, 0x00, // flags
0x00, 0x00, 0x00, 0x00, // pre_defined
0x73, 0x6f, 0x75, 0x6e, // handler_type: 'soun'
0x00, 0x00, 0x00, 0x00, // reserved
0x00, 0x00, 0x00, 0x00, // reserved
0x00, 0x00, 0x00, 0x00, // reserved
0x53, 0x6f, 0x75, 0x6e,
0x64, 0x48, 0x61, 0x6e,
0x64, 0x6c, 0x65, 0x72, 0x00 // name: 'SoundHandler'
]);
HDLR_TYPES = {
video: VIDEO_HDLR,
audio: AUDIO_HDLR
};
DREF = new Uint8Array([
0x00, // version 0
0x00, 0x00, 0x00, // flags
0x00, 0x00, 0x00, 0x01, // entry_count
0x00, 0x00, 0x00, 0x0c, // entry_size
0x75, 0x72, 0x6c, 0x20, // 'url' type
0x00, // version 0
0x00, 0x00, 0x01 // entry_flags
]);
SMHD = new Uint8Array([
0x00, // version
0x00, 0x00, 0x00, // flags
0x00, 0x00, // balance, 0 means centered
0x00, 0x00 // reserved
]);
STCO = new Uint8Array([
0x00, // version
0x00, 0x00, 0x00, // flags
0x00, 0x00, 0x00, 0x00 // entry_count
]);
STSC = STCO;
STSZ = new Uint8Array([
0x00, // version
0x00, 0x00, 0x00, // flags
0x00, 0x00, 0x00, 0x00, // sample_size
0x00, 0x00, 0x00, 0x00 // sample_count
]);
STTS = STCO;
VMHD = new Uint8Array([
0x00, // version
0x00, 0x00, 0x01, // flags
0x00, 0x00, // graphicsmode
0x00, 0x00,
0x00, 0x00,
0x00, 0x00 // opcolor
]);
}());
box = function(type) {
var
payload = [],
size = 0,
i,
result,
view;
for (i = 1; i < arguments.length; i++) {
payload.push(arguments[i]);
}
i = payload.length;
// calculate the total size we need to allocate
while (i--) {
size += payload[i].byteLength;
}
result = new Uint8Array(size + 8);
view = new DataView(result.buffer, result.byteOffset, result.byteLength);
view.setUint32(0, result.byteLength);
result.set(type, 4);
// copy the payload into the result
for (i = 0, size = 8; i < payload.length; i++) {
result.set(payload[i], size);
size += payload[i].byteLength;
}
return result;
};
dinf = function() {
return box(types.dinf, box(types.dref, DREF));
};
esds = function(track) {
return box(types.esds, new Uint8Array([
0x00, // version
0x00, 0x00, 0x00, // flags
// ES_Descriptor
0x03, // tag, ES_DescrTag
0x19, // length
0x00, 0x00, // ES_ID
0x00, // streamDependenceFlag, URL_flag, reserved, streamPriority
// DecoderConfigDescriptor
0x04, // tag, DecoderConfigDescrTag
0x11, // length
0x40, // object type
0x15, // streamType
0x00, 0x06, 0x00, // bufferSizeDB
0x00, 0x00, 0xda, 0xc0, // maxBitrate
0x00, 0x00, 0xda, 0xc0, // avgBitrate
// DecoderSpecificInfo
0x05, // tag, DecoderSpecificInfoTag
0x02, // length
// ISO/IEC 14496-3, AudioSpecificConfig
// for samplingFrequencyIndex see ISO/IEC 13818-7:2006, 8.1.3.2.2, Table 35
(track.audioobjecttype << 3) | (track.samplingfrequencyindex >>> 1),
(track.samplingfrequencyindex << 7) | (track.channelcount << 3),
0x06, 0x01, 0x02 // GASpecificConfig
]));
};
ftyp = function() {
return box(types.ftyp, MAJOR_BRAND, MINOR_VERSION, MAJOR_BRAND, AVC1_BRAND);
};
hdlr = function(type) {
return box(types.hdlr, HDLR_TYPES[type]);
};
mdat = function(data) {
return box(types.mdat, data);
};
mdhd = function(track) {
var result = new Uint8Array([
0x00, // version 0
0x00, 0x00, 0x00, // flags
0x00, 0x00, 0x00, 0x02, // creation_time
0x00, 0x00, 0x00, 0x03, // modification_time
0x00, 0x01, 0x5f, 0x90, // timescale, 90,000 "ticks" per second
(track.duration >>> 24) & 0xFF,
(track.duration >>> 16) & 0xFF,
(track.duration >>> 8) & 0xFF,
track.duration & 0xFF, // duration
0x55, 0xc4, // 'und' language (undetermined)
0x00, 0x00
]);
// Use the sample rate from the track metadata, when it is
// defined. The sample rate can be parsed out of an ADTS header, for
// instance.
if (track.samplerate) {
result[12] = (track.samplerate >>> 24) & 0xFF;
result[13] = (track.samplerate >>> 16) & 0xFF;
result[14] = (track.samplerate >>> 8) & 0xFF;
result[15] = (track.samplerate) & 0xFF;
// 重置该轨道长度
track.duration = track.duration / 90000 * track.samplerate;
result[16] = (track.duration >>> 24) & 0xFF;
result[17] = (track.duration >>> 16) & 0xFF;
result[18] = (track.duration >>> 8) & 0xFF;
result[19] = (track.duration) & 0xFF;
}
return box(types.mdhd, result);
};
mdia = function(track) {
return box(types.mdia, mdhd(track), hdlr(track.type), minf(track));
};
mfhd = function(sequenceNumber) {
return box(types.mfhd, new Uint8Array([
0x00,
0x00, 0x00, 0x00, // flags
(sequenceNumber & 0xFF000000) >> 24,
(sequenceNumber & 0xFF0000) >> 16,
(sequenceNumber & 0xFF00) >> 8,
sequenceNumber & 0xFF // sequence_number
]));
};
minf = function(track) {
return box(types.minf,
track.type === 'video' ? box(types.vmhd, VMHD) : box(types.smhd, SMHD),
dinf(),
stbl(track));
};
moof = function(sequenceNumber, tracks) {
var
trackFragments = [],
i = tracks.length;
// build traf boxes for each track fragment
while (i--) {
trackFragments[i] = traf(tracks[i]);
}
return box.apply(null, [
types.moof,
mfhd(sequenceNumber)
].concat(trackFragments));
};
/**
* Returns a movie box.
* @param tracks {array} the tracks associated with this movie
* @see ISO/IEC 14496-12:2012(E), section 8.2.1
*/
moov = function(tracks) {
var
i = tracks.length,
boxes = [];
while (i--) {
boxes[i] = trak(tracks[i]);
}
return box.apply(null, [types.moov, mvhd(customDuration)].concat(boxes).concat(mvex(tracks)));
};
mvex = function(tracks) {
var
i = tracks.length,
boxes = [];
while (i--) {
boxes[i] = trex(tracks[i]);
}
return box.apply(null, [types.mvex].concat(boxes));
};
mvhd = function(duration) {
var
bytes = new Uint8Array([
0x00, // version 0
0x00, 0x00, 0x00, // flags
0x00, 0x00, 0x00, 0x01, // creation_time
0x00, 0x00, 0x00, 0x02, // modification_time
0x00, 0x01, 0x5f, 0x90, // timescale, 90,000 "ticks" per second
(duration & 0xFF000000) >> 24,
(duration & 0xFF0000) >> 16,
(duration & 0xFF00) >> 8,
duration & 0xFF, // duration
0x00, 0x01, 0x00, 0x00, // 1.0 rate
0x01, 0x00, // 1.0 volume
0x00, 0x00, // reserved
0x00, 0x00, 0x00, 0x00, // reserved
0x00, 0x00, 0x00, 0x00, // reserved
0x00, 0x01, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x01, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x40, 0x00, 0x00, 0x00, // transformation: unity matrix
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, // pre_defined
0xff, 0xff, 0xff, 0xff // next_track_ID
]);
return box(types.mvhd, bytes);
};
sdtp = function(track) {
var
samples = track.samples || [],
bytes = new Uint8Array(4 + samples.length),
flags,
i;
// leave the full box header (4 bytes) all zero
// write the sample table
for (i = 0; i < samples.length; i++) {
flags = samples[i].flags;
bytes[i + 4] = (flags.dependsOn << 4) |
(flags.isDependedOn << 2) |
(flags.hasRedundancy);
}
return box(types.sdtp,
bytes);
};
stbl = function(track) {
return box(types.stbl,
stsd(track),
box(types.stts, STTS),
box(types.stsc, STSC),
box(types.stsz, STSZ),
box(types.stco, STCO));
};
(function() {
var videoSample, audioSample;
stsd = function(track) {
return box(types.stsd, new Uint8Array([
0x00, // version 0
0x00, 0x00, 0x00, // flags
0x00, 0x00, 0x00, 0x01
]), track.type === 'video' ? videoSample(track) : audioSample(track));
};
videoSample = function(track) {
var
sps = track.sps || [],
pps = track.pps || [],
sequenceParameterSets = [],
pictureParameterSets = [],
i,
avc1Box;
// assemble the SPSs
for (i = 0; i < sps.length; i++) {
sequenceParameterSets.push((sps[i].byteLength & 0xFF00) >>> 8);
sequenceParameterSets.push((sps[i].byteLength & 0xFF)); // sequenceParameterSetLength
sequenceParameterSets = sequenceParameterSets.concat(Array.prototype.slice.call(sps[i])); // SPS
}
// assemble the PPSs
for (i = 0; i < pps.length; i++) {
pictureParameterSets.push((pps[i].byteLength & 0xFF00) >>> 8);
pictureParameterSets.push((pps[i].byteLength & 0xFF));
pictureParameterSets = pictureParameterSets.concat(Array.prototype.slice.call(pps[i]));
}
avc1Box = [
types.avc1, new Uint8Array([
0x00, 0x00, 0x00,
0x00, 0x00, 0x00, // reserved
0x00, 0x01, // data_reference_index
0x00, 0x00, // pre_defined
0x00, 0x00, // reserved
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, // pre_defined
(track.width & 0xff00) >> 8,
track.width & 0xff, // width
(track.height & 0xff00) >> 8,
track.height & 0xff, // height
0x00, 0x48, 0x00, 0x00, // horizresolution
0x00, 0x48, 0x00, 0x00, // vertresolution
0x00, 0x00, 0x00, 0x00, // reserved
0x00, 0x01, // frame_count
0x13,
0x76, 0x69, 0x64, 0x65,
0x6f, 0x6a, 0x73, 0x2d,
0x63, 0x6f, 0x6e, 0x74,
0x72, 0x69, 0x62, 0x2d,
0x68, 0x6c, 0x73, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, // compressorname
0x00, 0x18, // depth = 24
0x11, 0x11 // pre_defined = -1
]),
box(types.avcC, new Uint8Array([
0x01, // configurationVersion
track.profileIdc, // AVCProfileIndication
track.profileCompatibility, // profile_compatibility
track.levelIdc, // AVCLevelIndication
0xff // lengthSizeMinusOne, hard-coded to 4 bytes
].concat(
[sps.length], // numOfSequenceParameterSets
sequenceParameterSets, // "SPS"
[pps.length], // numOfPictureParameterSets
pictureParameterSets // "PPS"
))),
box(types.btrt, new Uint8Array([
0x00, 0x1c, 0x9c, 0x80, // bufferSizeDB
0x00, 0x2d, 0xc6, 0xc0, // maxBitrate
0x00, 0x2d, 0xc6, 0xc0 // avgBitrate
]))
];
if (track.sarRatio) {
var
hSpacing = track.sarRatio[0],
vSpacing = track.sarRatio[1];
avc1Box.push(
box(types.pasp, new Uint8Array([
(hSpacing & 0xFF000000) >> 24,
(hSpacing & 0xFF0000) >> 16,
(hSpacing & 0xFF00) >> 8,
hSpacing & 0xFF,
(vSpacing & 0xFF000000) >> 24,
(vSpacing & 0xFF0000) >> 16,
(vSpacing & 0xFF00) >> 8,
vSpacing & 0xFF
]))
);
}
return box.apply(null, avc1Box);
};
audioSample = function(track) {
return box(types.mp4a, new Uint8Array([
// SampleEntry, ISO/IEC 14496-12
0x00, 0x00, 0x00,
0x00, 0x00, 0x00, // reserved
0x00, 0x01, // data_reference_index
// AudioSampleEntry, ISO/IEC 14496-12
0x00, 0x00, 0x00, 0x00, // reserved
0x00, 0x00, 0x00, 0x00, // reserved
(track.channelcount & 0xff00) >> 8,
(track.channelcount & 0xff), // channelcount
(track.samplesize & 0xff00) >> 8,
(track.samplesize & 0xff), // samplesize
0x00, 0x00, // pre_defined
0x00, 0x00, // reserved
(track.samplerate & 0xff00) >> 8,
(track.samplerate & 0xff),
0x00, 0x00 // samplerate, 16.16
// MP4AudioSampleEntry, ISO/IEC 14496-14
]), esds(track));
};
}());
tkhd = function(track) {
var result = new Uint8Array([
0x00, // version 0
0x00, 0x00, 0x07, // flags
0x00, 0x00, 0x00, 0x00, // creation_time
0x00, 0x00, 0x00, 0x00, // modification_time
(track.id & 0xFF000000) >> 24,
(track.id & 0xFF0000) >> 16,
(track.id & 0xFF00) >> 8,
track.id & 0xFF, // track_ID
0x00, 0x00, 0x00, 0x00, // reserved
(track.duration & 0xFF000000) >> 24,
(track.duration & 0xFF0000) >> 16,
(track.duration & 0xFF00) >> 8,
track.duration & 0xFF, // duration
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, // reserved
0x00, 0x00, // layer
0x00, 0x00, // alternate_group
0x01, 0x00, // non-audio track volume
0x00, 0x00, // reserved
0x00, 0x01, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x01, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x40, 0x00, 0x00, 0x00, // transformation: unity matrix
(track.width & 0xFF00) >> 8,
track.width & 0xFF,
0x00, 0x00, // width
(track.height & 0xFF00) >> 8,
track.height & 0xFF,
0x00, 0x00 // height
]);
return box(types.tkhd, result);
};
/**
* Generate a track fragment (traf) box. A traf box collects metadata
* about tracks in a movie fragment (moof) box.
*/
traf = function(track) {
var trackFragmentHeader, trackFragmentDecodeTime, trackFragmentRun,
sampleDependencyTable, dataOffset,
upperWordBaseMediaDecodeTime, lowerWordBaseMediaDecodeTime;
trackFragmentHeader = box(types.tfhd, new Uint8Array([
0x00, // version 0
0x00, 0x00, 0x3a, // flags
(track.id & 0xFF000000) >> 24,
(track.id & 0xFF0000) >> 16,
(track.id & 0xFF00) >> 8,
(track.id & 0xFF), // track_ID
0x00, 0x00, 0x00, 0x01, // sample_description_index
0x00, 0x00, 0x00, 0x00, // default_sample_duration
0x00, 0x00, 0x00, 0x00, // default_sample_size
0x00, 0x00, 0x00, 0x00 // default_sample_flags
]));
upperWordBaseMediaDecodeTime = Math.floor(track.baseMediaDecodeTime / (UINT32_MAX + 1));
lowerWordBaseMediaDecodeTime = Math.floor(track.baseMediaDecodeTime % (UINT32_MAX + 1));
trackFragmentDecodeTime = box(types.tfdt, new Uint8Array([
0x01, // version 1
0x00, 0x00, 0x00, // flags
// baseMediaDecodeTime
(upperWordBaseMediaDecodeTime >>> 24) & 0xFF,
(upperWordBaseMediaDecodeTime >>> 16) & 0xFF,
(upperWordBaseMediaDecodeTime >>> 8) & 0xFF,
upperWordBaseMediaDecodeTime & 0xFF,
(lowerWordBaseMediaDecodeTime >>> 24) & 0xFF,
(lowerWordBaseMediaDecodeTime >>> 16) & 0xFF,
(lowerWordBaseMediaDecodeTime >>> 8) & 0xFF,
lowerWordBaseMediaDecodeTime & 0xFF
]));
// the data offset specifies the number of bytes from the start of
// the containing moof to the first payload byte of the associated
// mdat
dataOffset = (32 + // tfhd
20 + // tfdt
8 + // traf header
16 + // mfhd
8 + // moof header
8); // mdat header
// audio tracks require less metadata
if (track.type === 'audio') {
trackFragmentRun = trun(track, dataOffset);
return box(types.traf,
trackFragmentHeader,
trackFragmentDecodeTime,
trackFragmentRun);
}
// video tracks should contain an independent and disposable samples
// box (sdtp)
// generate one and adjust offsets to match
sampleDependencyTable = sdtp(track);
trackFragmentRun = trun(track,
sampleDependencyTable.length + dataOffset);
return box(types.traf,
trackFragmentHeader,
trackFragmentDecodeTime,
trackFragmentRun,
sampleDependencyTable);
};
/**
* Generate a track box.
* @param track {object} a track definition
* @return {Uint8Array} the track box
*/
trak = function(track) {
track.duration = track.duration || customDuration;
return box(types.trak,
tkhd(track),
mdia(track));
};
trex = function(track) {
var result = new Uint8Array([
0x00, // version 0
0x00, 0x00, 0x00, // flags
(track.id & 0xFF000000) >> 24,
(track.id & 0xFF0000) >> 16,
(track.id & 0xFF00) >> 8,
(track.id & 0xFF), // track_ID
0x00, 0x00, 0x00, 0x01, // default_sample_description_index
0x00, 0x00, 0x00, 0x00, // default_sample_duration
0x00, 0x00, 0x00, 0x00, // default_sample_size
0x00, 0x01, 0x00, 0x01 // default_sample_flags
]);
// the last two bytes of default_sample_flags is the sample
// degradation priority, a hint about the importance of this sample
// relative to others. Lower the degradation priority for all sample
// types other than video.
if (track.type !== 'video') {
result[result.length - 1] = 0x00;
}
return box(types.trex, result);
};
(function() {
var audioTrun, videoTrun, trunHeader;
// This method assumes all samples are uniform. That is, if a
// duration is present for the first sample, it will be present for
// all subsequent samples.
// see ISO/IEC 14496-12:2012, Section 8.8.8.1
trunHeader = function(samples, offset) {
var durationPresent = 0, sizePresent = 0,
flagsPresent = 0, compositionTimeOffset = 0;
// trun flag constants
if (samples.length) {
if (samples[0].duration !== undefined) {
durationPresent = 0x1;
}
if (samples[0].size !== undefined) {
sizePresent = 0x2;
}
if (samples[0].flags !== undefined) {
flagsPresent = 0x4;
}
if (samples[0].compositionTimeOffset !== undefined) {
compositionTimeOffset = 0x8;
}
}
return [
0x00, // version 0
0x00,
durationPresent | sizePresent | flagsPresent | compositionTimeOffset,
0x01, // flags
(samples.length & 0xFF000000) >>> 24,
(samples.length & 0xFF0000) >>> 16,
(samples.length & 0xFF00) >>> 8,
samples.length & 0xFF, // sample_count
(offset & 0xFF000000) >>> 24,
(offset & 0xFF0000) >>> 16,
(offset & 0xFF00) >>> 8,
offset & 0xFF // data_offset
];
};
videoTrun = function(track, offset) {
var bytesOffest, bytes, header, samples, sample, i;
samples = track.samples || [];
offset += 8 + 12 + (16 * samples.length);
header = trunHeader(samples, offset);
bytes = new Uint8Array(header.length + samples.length * 16);
bytes.set(header);
bytesOffest = header.length;
for (i = 0; i < samples.length; i++) {
sample = samples[i];
bytes[bytesOffest++] = (sample.duration & 0xFF000000) >>> 24;
bytes[bytesOffest++] = (sample.duration & 0xFF0000) >>> 16;
bytes[bytesOffest++] = (sample.duration & 0xFF00) >>> 8;
bytes[bytesOffest++] = sample.duration & 0xFF; // sample_duration
bytes[bytesOffest++] = (sample.size & 0xFF000000) >>> 24;
bytes[bytesOffest++] = (sample.size & 0xFF0000) >>> 16;
bytes[bytesOffest++] = (sample.size & 0xFF00) >>> 8;
bytes[bytesOffest++] = sample.size & 0xFF; // sample_size
bytes[bytesOffest++] = (sample.flags.isLeading << 2) | sample.flags.dependsOn;
bytes[bytesOffest++] = (sample.flags.isDependedOn << 6) |
(sample.flags.hasRedundancy << 4) |
(sample.flags.paddingValue << 1) |
sample.flags.isNonSyncSample;
bytes[bytesOffest++] = sample.flags.degradationPriority & 0xF0 << 8;
bytes[bytesOffest++] = sample.flags.degradationPriority & 0x0F; // sample_flags
bytes[bytesOffest++] = (sample.compositionTimeOffset & 0xFF000000) >>> 24;
bytes[bytesOffest++] = (sample.compositionTimeOffset & 0xFF0000) >>> 16;
bytes[bytesOffest++] = (sample.compositionTimeOffset & 0xFF00) >>> 8;
bytes[bytesOffest++] = sample.compositionTimeOffset & 0xFF; // sample_composition_time_offset
}
return box(types.trun, bytes);
};
audioTrun = function(track, offset) {
var bytes, bytesOffest, header, samples, sample, i;
samples = track.samples || [];
offset += 8 + 12 + (8 * samples.length);
header = trunHeader(samples, offset);
bytes = new Uint8Array(header.length + samples.length * 8);
bytes.set(header);
bytesOffest = header.length;
for (i = 0; i < samples.length; i++) {
sample = samples[i];
bytes[bytesOffest++] = (sample.duration & 0xFF000000) >>> 24;
bytes[bytesOffest++] = (sample.duration & 0xFF0000) >>> 16;
bytes[bytesOffest++] = (sample.duration & 0xFF00) >>> 8;
bytes[bytesOffest++] = sample.duration & 0xFF; // sample_duration
bytes[bytesOffest++] = (sample.size & 0xFF000000) >>> 24;
bytes[bytesOffest++] = (sample.size & 0xFF0000) >>> 16;
bytes[bytesOffest++] = (sample.size & 0xFF00) >>> 8;
bytes[bytesOffest++] = sample.size & 0xFF; // sample_size
}
return box(types.trun, bytes);
};
trun = function(track, offset) {
if (track.type === 'audio') {
return audioTrun(track, offset);
}
return videoTrun(track, offset);
};
}());
module.exports = {
ftyp: ftyp,
mdat: mdat,
moof: moof,
moov: moov,
setDuration: function(duration) {
if (duration) {
customDuration = duration * 90000; // 乘以 timescale
}
},
initSegment: function(tracks) {
var
fileType = ftyp(),
movie = moov(tracks),
result;
result = new Uint8Array(fileType.byteLength + movie.byteLength);
result.set(fileType);
result.set(movie, fileType.byteLength);
return result;
}
};
},{}],19:[function(require,module,exports){
var parseType = function(buffer) {
var result = '';
result += String.fromCharCode(buffer[0]);
result += String.fromCharCode(buffer[1]);
result += String.fromCharCode(buffer[2]);
result += String.fromCharCode(buffer[3]);
return result;
};
module.exports = parseType;
},{}],20:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*
* Utilities to detect basic properties and metadata about MP4s.
*/
'use strict';
var toUnsigned = require(28).toUnsigned;
var toHexString = require(28).toHexString;
var findBox = require(15);
var parseType = require(19);
var parseTfhd = require(26);
var parseTrun = require(27);
var parseTfdt = require(25);
var timescale, startTime, compositionStartTime, getVideoTrackIds, getTracks,
getTimescaleFromMediaHeader;
/**
* Parses an MP4 initialization segment and extracts the timescale
* values for any declared tracks. Timescale values indicate the
* number of clock ticks per second to assume for time-based values
* elsewhere in the MP4.
*
* To determine the start time of an MP4, you need two pieces of
* information: the timescale unit and the earliest base media decode
* time. Multiple timescales can be specified within an MP4 but the
* base media decode time is always expressed in the timescale from
* the media header box for the track:
* ```
* moov > trak > mdia > mdhd.timescale
* ```
* @param init {Uint8Array} the bytes of the init segment
* @return {object} a hash of track ids to timescale values or null if
* the init segment is malformed.
*/
timescale = function(init) {
var
result = {},
traks = findBox(init, ['moov', 'trak']);
// mdhd timescale
return traks.reduce(function(result, trak) {
var tkhd, version, index, id, mdhd;
tkhd = findBox(trak, ['tkhd'])[0];
if (!tkhd) {
return null;
}
version = tkhd[0];
index = version === 0 ? 12 : 20;
id = toUnsigned(tkhd[index] << 24 |
tkhd[index + 1] << 16 |
tkhd[index + 2] << 8 |
tkhd[index + 3]);
mdhd = findBox(trak, ['mdia', 'mdhd'])[0];
if (!mdhd) {
return null;
}
version = mdhd[0];
index = version === 0 ? 12 : 20;
result[id] = toUnsigned(mdhd[index] << 24 |
mdhd[index + 1] << 16 |
mdhd[index + 2] << 8 |
mdhd[index + 3]);
return result;
}, result);
};
/**
* Determine the base media decode start time, in seconds, for an MP4
* fragment. If multiple fragments are specified, the earliest time is
* returned.
*
* The base media decode time can be parsed from track fragment
* metadata:
* ```
* moof > traf > tfdt.baseMediaDecodeTime
* ```
* It requires the timescale value from the mdhd to interpret.
*
* @param timescale {object} a hash of track ids to timescale values.
* @return {number} the earliest base media decode start time for the
* fragment, in seconds
*/
startTime = function(timescale, fragment) {
var trafs, baseTimes, result;
// we need info from two childrend of each track fragment box
trafs = findBox(fragment, ['moof', 'traf']);
// determine the start times for each track
baseTimes = [].concat.apply([], trafs.map(function(traf) {
return findBox(traf, ['tfhd']).map(function(tfhd) {
var id, scale, baseTime;
// get the track id from the tfhd
id = toUnsigned(tfhd[4] << 24 |
tfhd[5] << 16 |
tfhd[6] << 8 |
tfhd[7]);
// assume a 90kHz clock if no timescale was specified
scale = timescale[id] || 90e3;
// get the base media decode time from the tfdt
baseTime = findBox(traf, ['tfdt']).map(function(tfdt) {
var version, result;
version = tfdt[0];
result = toUnsigned(tfdt[4] << 24 |
tfdt[5] << 16 |
tfdt[6] << 8 |
tfdt[7]);
if (version === 1) {
result *= Math.pow(2, 32);
result += toUnsigned(tfdt[8] << 24 |
tfdt[9] << 16 |
tfdt[10] << 8 |
tfdt[11]);
}
return result;
})[0];
baseTime = baseTime || Infinity;
// convert base time to seconds
return baseTime / scale;
});
}));
// return the minimum
result = Math.min.apply(null, baseTimes);
return isFinite(result) ? result : 0;
};
/**
* Determine the composition start, in seconds, for an MP4
* fragment.
*
* The composition start time of a fragment can be calculated using the base
* media decode time, composition time offset, and timescale, as follows:
*
* compositionStartTime = (baseMediaDecodeTime + compositionTimeOffset) / timescale
*
* All of the aforementioned information is contained within a media fragment's
* `traf` box, except for timescale info, which comes from the initialization
* segment, so a track id (also contained within a `traf`) is also necessary to
* associate it with a timescale
*
*
* @param timescales {object} - a hash of track ids to timescale values.
* @param fragment {Unit8Array} - the bytes of a media segment
* @return {number} the composition start time for the fragment, in seconds
**/
compositionStartTime = function(timescales, fragment) {
var trafBoxes = findBox(fragment, ['moof', 'traf']);
var baseMediaDecodeTime = 0;
var compositionTimeOffset = 0;
var trackId;
if (trafBoxes && trafBoxes.length) {
// The spec states that track run samples contained within a `traf` box are contiguous, but
// it does not explicitly state whether the `traf` boxes themselves are contiguous.
// We will assume that they are, so we only need the first to calculate start time.
var tfhd = findBox(trafBoxes[0], ['tfhd'])[0];
var trun = findBox(trafBoxes[0], ['trun'])[0];
var tfdt = findBox(trafBoxes[0], ['tfdt'])[0];
if (tfhd) {
var parsedTfhd = parseTfhd(tfhd);
trackId = parsedTfhd.trackId;
}
if (tfdt) {
var parsedTfdt = parseTfdt(tfdt);
baseMediaDecodeTime = parsedTfdt.baseMediaDecodeTime;
}
if (trun) {
var parsedTrun = parseTrun(trun);
if (parsedTrun.samples && parsedTrun.samples.length) {
compositionTimeOffset = parsedTrun.samples[0].compositionTimeOffset || 0;
}
}
}
// Get timescale for this specific track. Assume a 90kHz clock if no timescale was
// specified.
var timescale = timescales[trackId] || 90e3;
// return the composition start time, in seconds
return (baseMediaDecodeTime + compositionTimeOffset) / timescale;
};
/**
* Find the trackIds of the video tracks in this source.
* Found by parsing the Handler Reference and Track Header Boxes:
* moov > trak > mdia > hdlr
* moov > trak > tkhd
*
* @param {Uint8Array} init - The bytes of the init segment for this source
* @return {Number[]} A list of trackIds
*
* @see ISO-BMFF-12/2015, Section 8.4.3
**/
getVideoTrackIds = function(init) {
var traks = findBox(init, ['moov', 'trak']);
var videoTrackIds = [];
traks.forEach(function(trak) {
var hdlrs = findBox(trak, ['mdia', 'hdlr']);
var tkhds = findBox(trak, ['tkhd']);
hdlrs.forEach(function(hdlr, index) {
var handlerType = parseType(hdlr.subarray(8, 12));
var tkhd = tkhds[index];
var view;
var version;
var trackId;
if (handlerType === 'vide') {
view = new DataView(tkhd.buffer, tkhd.byteOffset, tkhd.byteLength);
version = view.getUint8(0);
trackId = (version === 0) ? view.getUint32(12) : view.getUint32(20);
videoTrackIds.push(trackId);
}
});
});
return videoTrackIds;
};
getTimescaleFromMediaHeader = function(mdhd) {
// mdhd is a FullBox, meaning it will have its own version as the first byte
var version = mdhd[0];
var index = version === 0 ? 12 : 20;
return toUnsigned(
mdhd[index] << 24 |
mdhd[index + 1] << 16 |
mdhd[index + 2] << 8 |
mdhd[index + 3]
);
};
/**
* Get all the video, audio, and hint tracks from a non fragmented
* mp4 segment
*/
getTracks = function(init) {
var traks = findBox(init, ['moov', 'trak']);
var tracks = [];
traks.forEach(function(trak) {
var track = {};
var tkhd = findBox(trak, ['tkhd'])[0];
var view, tkhdVersion;
// id
if (tkhd) {
view = new DataView(tkhd.buffer, tkhd.byteOffset, tkhd.byteLength);
tkhdVersion = view.getUint8(0);
track.id = (tkhdVersion === 0) ? view.getUint32(12) : view.getUint32(20);
}
var hdlr = findBox(trak, ['mdia', 'hdlr'])[0];
// type
if (hdlr) {
var type = parseType(hdlr.subarray(8, 12));
if (type === 'vide') {
track.type = 'video';
} else if (type === 'soun') {
track.type = 'audio';
} else {
track.type = type;
}
}
// codec
var stsd = findBox(trak, ['mdia', 'minf', 'stbl', 'stsd'])[0];
if (stsd) {
var sampleDescriptions = stsd.subarray(8);
// gives the codec type string
track.codec = parseType(sampleDescriptions.subarray(4, 8));
var codecBox = findBox(sampleDescriptions, [track.codec])[0];
var codecConfig, codecConfigType;
if (codecBox) {
// https://tools.ietf.org/html/rfc6381#section-3.3
if ((/^[a-z]vc[1-9]$/i).test(track.codec)) {
// we don't need anything but the "config" parameter of the
// avc1 codecBox
codecConfig = codecBox.subarray(78);
codecConfigType = parseType(codecConfig.subarray(4, 8));
if (codecConfigType === 'avcC' && codecConfig.length > 11) {
track.codec += '.';
// left padded with zeroes for single digit hex
// profile idc
track.codec += toHexString(codecConfig[9]);
// the byte containing the constraint_set flags
track.codec += toHexString(codecConfig[10]);
// level idc
track.codec += toHexString(codecConfig[11]);
} else {
// TODO: show a warning that we couldn't parse the codec
// and are using the default
track.codec = 'avc1.4d400d';
}
} else if ((/^mp4[a,v]$/i).test(track.codec)) {
// we do not need anything but the streamDescriptor of the mp4a codecBox
codecConfig = codecBox.subarray(28);
codecConfigType = parseType(codecConfig.subarray(4, 8));
if (codecConfigType === 'esds' && codecConfig.length > 20 && codecConfig[19] !== 0) {
track.codec += '.' + toHexString(codecConfig[19]);
// this value is only a single digit
track.codec += '.' + toHexString((codecConfig[20] >>> 2) & 0x3f).replace(/^0/, '');
} else {
// TODO: show a warning that we couldn't parse the codec
// and are using the default
track.codec = 'mp4a.40.2';
}
} else {
// TODO: show a warning? for unknown codec type
}
}
}
var mdhd = findBox(trak, ['mdia', 'mdhd'])[0];
if (mdhd) {
track.timescale = getTimescaleFromMediaHeader(mdhd);
}
tracks.push(track);
});
return tracks;
};
module.exports = {
// export mp4 inspector's findBox and parseType for backwards compatibility
findBox: findBox,
parseType: parseType,
timescale: timescale,
startTime: startTime,
compositionStartTime: compositionStartTime,
videoTrackIds: getVideoTrackIds,
tracks: getTracks,
getTimescaleFromMediaHeader: getTimescaleFromMediaHeader
};
},{"15":15,"19":19,"25":25,"26":26,"27":27,"28":28}],21:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*/
var ONE_SECOND_IN_TS = require(29).ONE_SECOND_IN_TS;
/**
* Store information about the start and end of the track and the
* duration for each frame/sample we process in order to calculate
* the baseMediaDecodeTime
*/
var collectDtsInfo = function(track, data) {
if (typeof data.pts === 'number') {
if (track.timelineStartInfo.pts === undefined) {
track.timelineStartInfo.pts = data.pts;
}
if (track.minSegmentPts === undefined) {
track.minSegmentPts = data.pts;
} else {
track.minSegmentPts = Math.min(track.minSegmentPts, data.pts);
}
if (track.maxSegmentPts === undefined) {
track.maxSegmentPts = data.pts;
} else {
track.maxSegmentPts = Math.max(track.maxSegmentPts, data.pts);
}
}
if (typeof data.dts === 'number') {
if (track.timelineStartInfo.dts === undefined) {
track.timelineStartInfo.dts = data.dts;
}
if (track.minSegmentDts === undefined) {
track.minSegmentDts = data.dts;
} else {
track.minSegmentDts = Math.min(track.minSegmentDts, data.dts);
}
if (track.maxSegmentDts === undefined) {
track.maxSegmentDts = data.dts;
} else {
track.maxSegmentDts = Math.max(track.maxSegmentDts, data.dts);
}
}
};
/**
* Clear values used to calculate the baseMediaDecodeTime between
* tracks
*/
var clearDtsInfo = function(track) {
delete track.minSegmentDts;
delete track.maxSegmentDts;
delete track.minSegmentPts;
delete track.maxSegmentPts;
};
/**
* Calculate the track's baseMediaDecodeTime based on the earliest
* DTS the transmuxer has ever seen and the minimum DTS for the
* current track
* @param track {object} track metadata configuration
* @param keepOriginalTimestamps {boolean} If true, keep the timestamps
* in the source; false to adjust the first segment to start at 0.
*/
var calculateTrackBaseMediaDecodeTime = function(track, keepOriginalTimestamps) {
var
baseMediaDecodeTime,
scale,
minSegmentDts = track.minSegmentDts;
// Optionally adjust the time so the first segment starts at zero.
if (!keepOriginalTimestamps) {
minSegmentDts -= track.timelineStartInfo.dts;
}
// track.timelineStartInfo.baseMediaDecodeTime is the location, in time, where
// we want the start of the first segment to be placed
baseMediaDecodeTime = track.timelineStartInfo.baseMediaDecodeTime;
// Add to that the distance this segment is from the very first
baseMediaDecodeTime += minSegmentDts;
// baseMediaDecodeTime must not become negative
baseMediaDecodeTime = Math.max(0, baseMediaDecodeTime);
if (track.type === 'audio') {
// Audio has a different clock equal to the sampling_rate so we need to
// scale the PTS values into the clock rate of the track
scale = track.samplerate / ONE_SECOND_IN_TS;
baseMediaDecodeTime *= scale;
baseMediaDecodeTime = Math.floor(baseMediaDecodeTime);
}
return baseMediaDecodeTime;
};
module.exports = {
clearDtsInfo: clearDtsInfo,
calculateTrackBaseMediaDecodeTime: calculateTrackBaseMediaDecodeTime,
collectDtsInfo: collectDtsInfo
};
},{"29":29}],22:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*
* A stream-based mp2t to mp4 converter. This utility can be used to
* deliver mp4s to a SourceBuffer on platforms that support native
* Media Source Extensions.
*/
'use strict';
var Stream = require(31);
var mp4 = require(18);
var frameUtils = require(16);
var audioFrameUtils = require(13);
var trackDecodeInfo = require(21);
var m2ts = require(9);
var clock = require(29);
var AdtsStream = require(3);
var H264Stream = require(4).H264Stream;
var AacStream = require(1);
var isLikelyAacData = require(2).isLikelyAacData;
var ONE_SECOND_IN_TS = require(29).ONE_SECOND_IN_TS;
var AUDIO_PROPERTIES = require(5);
var VIDEO_PROPERTIES = require(6);
// object types
var VideoSegmentStream, AudioSegmentStream, Transmuxer, CoalesceStream;
/**
* Compare two arrays (even typed) for same-ness
*/
var arrayEquals = function(a, b) {
var
i;
if (a.length !== b.length) {
return false;
}
// compare the value of each element in the array
for (i = 0; i < a.length; i++) {
if (a[i] !== b[i]) {
return false;
}
}
return true;
};
var generateVideoSegmentTimingInfo = function(
baseMediaDecodeTime,
startDts,
startPts,
endDts,
endPts,
prependedContentDuration
) {
var
ptsOffsetFromDts = startPts - startDts,
decodeDuration = endDts - startDts,
presentationDuration = endPts - startPts;
// The PTS and DTS values are based on the actual stream times from the segment,
// however, the player time values will reflect a start from the baseMediaDecodeTime.
// In order to provide relevant values for the player times, base timing info on the
// baseMediaDecodeTime and the DTS and PTS durations of the segment.
return {
start: {
dts: baseMediaDecodeTime,
pts: baseMediaDecodeTime + ptsOffsetFromDts
},
end: {
dts: baseMediaDecodeTime + decodeDuration,
pts: baseMediaDecodeTime + presentationDuration
},
prependedContentDuration: prependedContentDuration,
baseMediaDecodeTime: baseMediaDecodeTime
};
};
/**
* Constructs a single-track, ISO BMFF media segment from AAC data
* events. The output of this stream can be fed to a SourceBuffer
* configured with a suitable initialization segment.
* @param track {object} track metadata configuration
* @param options {object} transmuxer options object
* @param options.keepOriginalTimestamps {boolean} If true, keep the timestamps
* in the source; false to adjust the first segment to start at 0.
*/
AudioSegmentStream = function(track, options) {
var
adtsFrames = [],
sequenceNumber = 0,
earliestAllowedDts = 0,
audioAppendStartTs = 0,
videoBaseMediaDecodeTime = Infinity;
options = options || {};
AudioSegmentStream.prototype.init.call(this);
this.push = function(data) {
trackDecodeInfo.collectDtsInfo(track, data);
if (track) {
AUDIO_PROPERTIES.forEach(function(prop) {
track[prop] = data[prop];
});
}
// buffer audio data until end() is called
adtsFrames.push(data);
};
this.setEarliestDts = function(earliestDts) {
earliestAllowedDts = earliestDts;
};
this.setVideoBaseMediaDecodeTime = function(baseMediaDecodeTime) {
videoBaseMediaDecodeTime = baseMediaDecodeTime;
};
this.setAudioAppendStart = function(timestamp) {
audioAppendStartTs = timestamp;
};
this.flush = function() {
var
frames,
moof,
mdat,
boxes,
frameDuration;
// return early if no audio data has been observed
if (adtsFrames.length === 0) {
this.trigger('done', 'AudioSegmentStream');
return;
}
frames = audioFrameUtils.trimAdtsFramesByEarliestDts(
adtsFrames, track, earliestAllowedDts);
track.baseMediaDecodeTime = trackDecodeInfo.calculateTrackBaseMediaDecodeTime(
track, options.keepOriginalTimestamps);
audioFrameUtils.prefixWithSilence(
track, frames, audioAppendStartTs, videoBaseMediaDecodeTime);
// we have to build the index from byte locations to
// samples (that is, adts frames) in the audio data
track.samples = audioFrameUtils.generateSampleTable(frames);
// concatenate the audio data to constuct the mdat
mdat = mp4.mdat(audioFrameUtils.concatenateFrameData(frames));
adtsFrames = [];
moof = mp4.moof(sequenceNumber, [track]);
boxes = new Uint8Array(moof.byteLength + mdat.byteLength);
// bump the sequence number for next time
sequenceNumber++;
boxes.set(moof);
boxes.set(mdat, moof.byteLength);
trackDecodeInfo.clearDtsInfo(track);
frameDuration = Math.ceil(ONE_SECOND_IN_TS * 1024 / track.samplerate);
// TODO this check was added to maintain backwards compatibility (particularly with
// tests) on adding the timingInfo event. However, it seems unlikely that there's a
// valid use-case where an init segment/data should be triggered without associated
// frames. Leaving for now, but should be looked into.
if (frames.length) {
this.trigger('timingInfo', {
start: frames[0].pts,
end: frames[0].pts + (frames.length * frameDuration)
});
}
this.trigger('data', {track: track, boxes: boxes});
this.trigger('done', 'AudioSegmentStream');
};
this.reset = function() {
trackDecodeInfo.clearDtsInfo(track);
adtsFrames = [];
this.trigger('reset');
};
};
AudioSegmentStream.prototype = new Stream();
/**
* Constructs a single-track, ISO BMFF media segment from H264 data
* events. The output of this stream can be fed to a SourceBuffer
* configured with a suitable initialization segment.
* @param track {object} track metadata configuration
* @param options {object} transmuxer options object
* @param options.alignGopsAtEnd {boolean} If true, start from the end of the
* gopsToAlignWith list when attempting to align gop pts
* @param options.keepOriginalTimestamps {boolean} If true, keep the timestamps
* in the source; false to adjust the first segment to start at 0.
*/
VideoSegmentStream = function(track, options) {
var
sequenceNumber = 0,
nalUnits = [],
gopsToAlignWith = [],
config,
pps;
options = options || {};
VideoSegmentStream.prototype.init.call(this);
delete track.minPTS;
this.gopCache_ = [];
/**
* Constructs a ISO BMFF segment given H264 nalUnits
* @param {Object} nalUnit A data event representing a nalUnit
* @param {String} nalUnit.nalUnitType
* @param {Object} nalUnit.config Properties for a mp4 track
* @param {Uint8Array} nalUnit.data The nalUnit bytes
* @see lib/codecs/h264.js
**/
this.push = function(nalUnit) {
trackDecodeInfo.collectDtsInfo(track, nalUnit);
// record the track config
if (nalUnit.nalUnitType === 'seq_parameter_set_rbsp' && !config) {
config = nalUnit.config;
track.sps = [nalUnit.data];
VIDEO_PROPERTIES.forEach(function(prop) {
track[prop] = config[prop];
}, this);
}
if (nalUnit.nalUnitType === 'pic_parameter_set_rbsp' &&
!pps) {
pps = nalUnit.data;
track.pps = [nalUnit.data];
}
// buffer video until flush() is called
nalUnits.push(nalUnit);
};
/**
* Pass constructed ISO BMFF track and boxes on to the
* next stream in the pipeline
**/
this.flush = function() {
var
frames,
gopForFusion,
gops,
moof,
mdat,
boxes,
prependedContentDuration = 0,
firstGop,
lastGop;
// Throw away nalUnits at the start of the byte stream until
// we find the first AUD
while (nalUnits.length) {
if (nalUnits[0].nalUnitType === 'access_unit_delimiter_rbsp') {
break;
}
nalUnits.shift();
}
// Return early if no video data has been observed
if (nalUnits.length === 0) {
this.resetStream_();
this.trigger('done', 'VideoSegmentStream');
return;
}
// Organize the raw nal-units into arrays that represent
// higher-level constructs such as frames and gops
// (group-of-pictures)
frames = frameUtils.groupNalsIntoFrames(nalUnits);
gops = frameUtils.groupFramesIntoGops(frames);
// If the first frame of this fragment is not a keyframe we have
// a problem since MSE (on Chrome) requires a leading keyframe.
//
// We have two approaches to repairing this situation:
// 1) GOP-FUSION:
// This is where we keep track of the GOPS (group-of-pictures)
// from previous fragments and attempt to find one that we can
// prepend to the current fragment in order to create a valid
// fragment.
// 2) KEYFRAME-PULLING:
// Here we search for the first keyframe in the fragment and
// throw away all the frames between the start of the fragment
// and that keyframe. We then extend the duration and pull the
// PTS of the keyframe forward so that it covers the time range
// of the frames that were disposed of.
//
// #1 is far prefereable over #2 which can cause "stuttering" but
// requires more things to be just right.
if (!gops[0][0].keyFrame) {
// Search for a gop for fusion from our gopCache
gopForFusion = this.getGopForFusion_(nalUnits[0], track);
if (gopForFusion) {
// in order to provide more accurate timing information about the segment, save
// the number of seconds prepended to the original segment due to GOP fusion
prependedContentDuration = gopForFusion.duration;
gops.unshift(gopForFusion);
// Adjust Gops' metadata to account for the inclusion of the
// new gop at the beginning
gops.byteLength += gopForFusion.byteLength;
gops.nalCount += gopForFusion.nalCount;
gops.pts = gopForFusion.pts;
gops.dts = gopForFusion.dts;
gops.duration += gopForFusion.duration;
} else {
// If we didn't find a candidate gop fall back to keyframe-pulling
gops = frameUtils.extendFirstKeyFrame(gops);
}
}
// Trim gops to align with gopsToAlignWith
if (gopsToAlignWith.length) {
var alignedGops;
if (options.alignGopsAtEnd) {
alignedGops = this.alignGopsAtEnd_(gops);
} else {
alignedGops = this.alignGopsAtStart_(gops);
}
if (!alignedGops) {
// save all the nals in the last GOP into the gop cache
this.gopCache_.unshift({
gop: gops.pop(),
pps: track.pps,
sps: track.sps
});
// Keep a maximum of 6 GOPs in the cache
this.gopCache_.length = Math.min(6, this.gopCache_.length);
// Clear nalUnits
nalUnits = [];
// return early no gops can be aligned with desired gopsToAlignWith
this.resetStream_();
this.trigger('done', 'VideoSegmentStream');
return;
}
// Some gops were trimmed. clear dts info so minSegmentDts and pts are correct
// when recalculated before sending off to CoalesceStream
trackDecodeInfo.clearDtsInfo(track);
gops = alignedGops;
}
trackDecodeInfo.collectDtsInfo(track, gops);
// First, we have to build the index from byte locations to
// samples (that is, frames) in the video data
track.samples = frameUtils.generateSampleTable(gops);
// Concatenate the video data and construct the mdat
mdat = mp4.mdat(frameUtils.concatenateNalData(gops));
track.baseMediaDecodeTime = trackDecodeInfo.calculateTrackBaseMediaDecodeTime(
track, options.keepOriginalTimestamps);
this.trigger('processedGopsInfo', gops.map(function(gop) {
return {
pts: gop.pts,
dts: gop.dts,
byteLength: gop.byteLength
};
}));
firstGop = gops[0];
lastGop = gops[gops.length - 1];
this.trigger(
'segmentTimingInfo',
generateVideoSegmentTimingInfo(
track.baseMediaDecodeTime,
firstGop.dts,
firstGop.pts,
lastGop.dts + lastGop.duration,
lastGop.pts + lastGop.duration,
prependedContentDuration));
this.trigger('timingInfo', {
start: gops[0].pts,
end: gops[gops.length - 1].pts + gops[gops.length - 1].duration
});
// save all the nals in the last GOP into the gop cache
this.gopCache_.unshift({
gop: gops.pop(),
pps: track.pps,
sps: track.sps
});
// Keep a maximum of 6 GOPs in the cache
this.gopCache_.length = Math.min(6, this.gopCache_.length);
// Clear nalUnits
nalUnits = [];
this.trigger('baseMediaDecodeTime', track.baseMediaDecodeTime);
this.trigger('timelineStartInfo', track.timelineStartInfo);
moof = mp4.moof(sequenceNumber, [track]);
// it would be great to allocate this array up front instead of
// throwing away hundreds of media segment fragments
boxes = new Uint8Array(moof.byteLength + mdat.byteLength);
// Bump the sequence number for next time
sequenceNumber++;
boxes.set(moof);
boxes.set(mdat, moof.byteLength);
this.trigger('data', {track: track, boxes: boxes});
this.resetStream_();
// Continue with the flush process now
this.trigger('done', 'VideoSegmentStream');
};
this.reset = function() {
this.resetStream_();
nalUnits = [];
this.gopCache_.length = 0;
gopsToAlignWith.length = 0;
this.trigger('reset');
};
this.resetStream_ = function() {
trackDecodeInfo.clearDtsInfo(track);
// reset config and pps because they may differ across segments
// for instance, when we are rendition switching
config = undefined;
pps = undefined;
};
// Search for a candidate Gop for gop-fusion from the gop cache and
// return it or return null if no good candidate was found
this.getGopForFusion_ = function(nalUnit) {
var
halfSecond = 45000, // Half-a-second in a 90khz clock
allowableOverlap = 10000, // About 3 frames @ 30fps
nearestDistance = Infinity,
dtsDistance,
nearestGopObj,
currentGop,
currentGopObj,
i;
// Search for the GOP nearest to the beginning of this nal unit
for (i = 0; i < this.gopCache_.length; i++) {
currentGopObj = this.gopCache_[i];
currentGop = currentGopObj.gop;
// Reject Gops with different SPS or PPS
if (!(track.pps && arrayEquals(track.pps[0], currentGopObj.pps[0])) ||
!(track.sps && arrayEquals(track.sps[0], currentGopObj.sps[0]))) {
continue;
}
// Reject Gops that would require a negative baseMediaDecodeTime
if (currentGop.dts < track.timelineStartInfo.dts) {
continue;
}
// The distance between the end of the gop and the start of the nalUnit
dtsDistance = (nalUnit.dts - currentGop.dts) - currentGop.duration;
// Only consider GOPS that start before the nal unit and end within
// a half-second of the nal unit
if (dtsDistance >= -allowableOverlap &&
dtsDistance <= halfSecond) {
// Always use the closest GOP we found if there is more than
// one candidate
if (!nearestGopObj ||
nearestDistance > dtsDistance) {
nearestGopObj = currentGopObj;
nearestDistance = dtsDistance;
}
}
}
if (nearestGopObj) {
return nearestGopObj.gop;
}
return null;
};
// trim gop list to the first gop found that has a matching pts with a gop in the list
// of gopsToAlignWith starting from the START of the list
this.alignGopsAtStart_ = function(gops) {
var alignIndex, gopIndex, align, gop, byteLength, nalCount, duration, alignedGops;
byteLength = gops.byteLength;
nalCount = gops.nalCount;
duration = gops.duration;
alignIndex = gopIndex = 0;
while (alignIndex < gopsToAlignWith.length && gopIndex < gops.length) {
align = gopsToAlignWith[alignIndex];
gop = gops[gopIndex];
if (align.pts === gop.pts) {
break;
}
if (gop.pts > align.pts) {
// this current gop starts after the current gop we want to align on, so increment
// align index
alignIndex++;
continue;
}
// current gop starts before the current gop we want to align on. so increment gop
// index
gopIndex++;
byteLength -= gop.byteLength;
nalCount -= gop.nalCount;
duration -= gop.duration;
}
if (gopIndex === 0) {
// no gops to trim
return gops;
}
if (gopIndex === gops.length) {
// all gops trimmed, skip appending all gops
return null;
}
alignedGops = gops.slice(gopIndex);
alignedGops.byteLength = byteLength;
alignedGops.duration = duration;
alignedGops.nalCount = nalCount;
alignedGops.pts = alignedGops[0].pts;
alignedGops.dts = alignedGops[0].dts;
return alignedGops;
};
// trim gop list to the first gop found that has a matching pts with a gop in the list
// of gopsToAlignWith starting from the END of the list
this.alignGopsAtEnd_ = function(gops) {
var alignIndex, gopIndex, align, gop, alignEndIndex, matchFound;
alignIndex = gopsToAlignWith.length - 1;
gopIndex = gops.length - 1;
alignEndIndex = null;
matchFound = false;
while (alignIndex >= 0 && gopIndex >= 0) {
align = gopsToAlignWith[alignIndex];
gop = gops[gopIndex];
if (align.pts === gop.pts) {
matchFound = true;
break;
}
if (align.pts > gop.pts) {
alignIndex--;
continue;
}
if (alignIndex === gopsToAlignWith.length - 1) {
// gop.pts is greater than the last alignment candidate. If no match is found
// by the end of this loop, we still want to append gops that come after this
// point
alignEndIndex = gopIndex;
}
gopIndex--;
}
if (!matchFound && alignEndIndex === null) {
return null;
}
var trimIndex;
if (matchFound) {
trimIndex = gopIndex;
} else {
trimIndex = alignEndIndex;
}
if (trimIndex === 0) {
return gops;
}
var alignedGops = gops.slice(trimIndex);
var metadata = alignedGops.reduce(function(total, gop) {
total.byteLength += gop.byteLength;
total.duration += gop.duration;
total.nalCount += gop.nalCount;
return total;
}, { byteLength: 0, duration: 0, nalCount: 0 });
alignedGops.byteLength = metadata.byteLength;
alignedGops.duration = metadata.duration;
alignedGops.nalCount = metadata.nalCount;
alignedGops.pts = alignedGops[0].pts;
alignedGops.dts = alignedGops[0].dts;
return alignedGops;
};
this.alignGopsWith = function(newGopsToAlignWith) {
gopsToAlignWith = newGopsToAlignWith;
};
};
VideoSegmentStream.prototype = new Stream();
/**
* A Stream that can combine multiple streams (ie. audio & video)
* into a single output segment for MSE. Also supports audio-only
* and video-only streams.
* @param options {object} transmuxer options object
* @param options.keepOriginalTimestamps {boolean} If true, keep the timestamps
* in the source; false to adjust the first segment to start at media timeline start.
*/
CoalesceStream = function(options, metadataStream) {
// Number of Tracks per output segment
// If greater than 1, we combine multiple
// tracks into a single segment
this.numberOfTracks = 0;
this.metadataStream = metadataStream;
options = options || {};
if (typeof options.remux !== 'undefined') {
this.remuxTracks = !!options.remux;
} else {
this.remuxTracks = true;
}
if (typeof options.keepOriginalTimestamps === 'boolean') {
this.keepOriginalTimestamps = options.keepOriginalTimestamps;
} else {
this.keepOriginalTimestamps = false;
}
this.pendingTracks = [];
this.videoTrack = null;
this.pendingBoxes = [];
this.pendingCaptions = [];
this.pendingMetadata = [];
this.pendingBytes = 0;
this.emittedTracks = 0;
CoalesceStream.prototype.init.call(this);
// Take output from multiple
this.push = function(output) {
// buffer incoming captions until the associated video segment
// finishes
if (output.text) {
return this.pendingCaptions.push(output);
}
// buffer incoming id3 tags until the final flush
if (output.frames) {
return this.pendingMetadata.push(output);
}
// Add this track to the list of pending tracks and store
// important information required for the construction of
// the final segment
this.pendingTracks.push(output.track);
this.pendingBytes += output.boxes.byteLength;
// TODO: is there an issue for this against chrome?
// We unshift audio and push video because
// as of Chrome 75 when switching from
// one init segment to another if the video
// mdat does not appear after the audio mdat
// only audio will play for the duration of our transmux.
if (output.track.type === 'video') {
this.videoTrack = output.track;
this.pendingBoxes.push(output.boxes);
}
if (output.track.type === 'audio') {
this.audioTrack = output.track;
this.pendingBoxes.unshift(output.boxes);
}
};
};
CoalesceStream.prototype = new Stream();
CoalesceStream.prototype.flush = function(flushSource) {
var
offset = 0,
event = {
captions: [],
captionStreams: {},
metadata: [],
info: {}
},
caption,
id3,
initSegment,
timelineStartPts = 0,
i;
if (this.pendingTracks.length < this.numberOfTracks) {
if (flushSource !== 'VideoSegmentStream' &&
flushSource !== 'AudioSegmentStream') {
// Return because we haven't received a flush from a data-generating
// portion of the segment (meaning that we have only recieved meta-data
// or captions.)
return;
} else if (this.remuxTracks) {
// Return until we have enough tracks from the pipeline to remux (if we
// are remuxing audio and video into a single MP4)
return;
} else if (this.pendingTracks.length === 0) {
// In the case where we receive a flush without any data having been
// received we consider it an emitted track for the purposes of coalescing
// `done` events.
// We do this for the case where there is an audio and video track in the
// segment but no audio data. (seen in several playlists with alternate
// audio tracks and no audio present in the main TS segments.)
this.emittedTracks++;
if (this.emittedTracks >= this.numberOfTracks) {
this.trigger('done');
this.emittedTracks = 0;
}
return;
}
}
if (this.videoTrack) {
timelineStartPts = this.videoTrack.timelineStartInfo.pts;
VIDEO_PROPERTIES.forEach(function(prop) {
event.info[prop] = this.videoTrack[prop];
}, this);
} else if (this.audioTrack) {
timelineStartPts = this.audioTrack.timelineStartInfo.pts;
AUDIO_PROPERTIES.forEach(function(prop) {
event.info[prop] = this.audioTrack[prop];
}, this);
}
if (this.videoTrack || this.audioTrack) {
if (this.pendingTracks.length === 1) {
event.type = this.pendingTracks[0].type;
} else {
event.type = 'combined';
}
this.emittedTracks += this.pendingTracks.length;
initSegment = mp4.initSegment(this.pendingTracks);
// Create a new typed array to hold the init segment
event.initSegment = new Uint8Array(initSegment.byteLength);
// Create an init segment containing a moov
// and track definitions
event.initSegment.set(initSegment);
// Create a new typed array to hold the moof+mdats
event.data = new Uint8Array(this.pendingBytes);
// Append each moof+mdat (one per track) together
for (i = 0; i < this.pendingBoxes.length; i++) {
event.data.set(this.pendingBoxes[i], offset);
offset += this.pendingBoxes[i].byteLength;
}
// Translate caption PTS times into second offsets to match the
// video timeline for the segment, and add track info
for (i = 0; i < this.pendingCaptions.length; i++) {
caption = this.pendingCaptions[i];
caption.startTime = clock.metadataTsToSeconds(
caption.startPts, timelineStartPts, this.keepOriginalTimestamps);
caption.endTime = clock.metadataTsToSeconds(
caption.endPts, timelineStartPts, this.keepOriginalTimestamps);
event.captionStreams[caption.stream] = true;
event.captions.push(caption);
}
// Translate ID3 frame PTS times into second offsets to match the
// video timeline for the segment
for (i = 0; i < this.pendingMetadata.length; i++) {
id3 = this.pendingMetadata[i];
id3.cueTime = clock.metadataTsToSeconds(
id3.pts, timelineStartPts, this.keepOriginalTimestamps);
event.metadata.push(id3);
}
// We add this to every single emitted segment even though we only need
// it for the first
event.metadata.dispatchType = this.metadataStream.dispatchType;
// Reset stream state
this.pendingTracks.length = 0;
this.videoTrack = null;
this.pendingBoxes.length = 0;
this.pendingCaptions.length = 0;
this.pendingBytes = 0;
this.pendingMetadata.length = 0;
// Emit the built segment
// We include captions and ID3 tags for backwards compatibility,
// ideally we should send only video and audio in the data event
this.trigger('data', event);
// Emit each caption to the outside world
// Ideally, this would happen immediately on parsing captions,
// but we need to ensure that video data is sent back first
// so that caption timing can be adjusted to match video timing
for (i = 0; i < event.captions.length; i++) {
caption = event.captions[i];
this.trigger('caption', caption);
}
// Emit each id3 tag to the outside world
// Ideally, this would happen immediately on parsing the tag,
// but we need to ensure that video data is sent back first
// so that ID3 frame timing can be adjusted to match video timing
for (i = 0; i < event.metadata.length; i++) {
id3 = event.metadata[i];
this.trigger('id3Frame', id3);
}
}
// Only emit `done` if all tracks have been flushed and emitted
if (this.emittedTracks >= this.numberOfTracks) {
this.trigger('done');
this.emittedTracks = 0;
}
};
CoalesceStream.prototype.setRemux = function(val) {
this.remuxTracks = val;
};
/**
* A Stream that expects MP2T binary data as input and produces
* corresponding media segments, suitable for use with Media Source
* Extension (MSE) implementations that support the ISO BMFF byte
* stream format, like Chrome.
*/
Transmuxer = function(options) {
var
self = this,
hasFlushed = true,
videoTrack,
audioTrack;
Transmuxer.prototype.init.call(this);
options = options || {};
this.baseMediaDecodeTime = options.baseMediaDecodeTime || 0;
this.transmuxPipeline_ = {};
mp4.setDuration(options.duration)
this.setupAacPipeline = function() {
var pipeline = {};
this.transmuxPipeline_ = pipeline;
pipeline.type = 'aac';
pipeline.metadataStream = new m2ts.MetadataStream();
// set up the parsing pipeline
pipeline.aacStream = new AacStream();
pipeline.audioTimestampRolloverStream = new m2ts.TimestampRolloverStream('audio');
pipeline.timedMetadataTimestampRolloverStream = new m2ts.TimestampRolloverStream('timed-metadata');
pipeline.adtsStream = new AdtsStream();
pipeline.coalesceStream = new CoalesceStream(options, pipeline.metadataStream);
pipeline.headOfPipeline = pipeline.aacStream;
pipeline.aacStream
.pipe(pipeline.audioTimestampRolloverStream)
.pipe(pipeline.adtsStream);
pipeline.aacStream
.pipe(pipeline.timedMetadataTimestampRolloverStream)
.pipe(pipeline.metadataStream)
.pipe(pipeline.coalesceStream);
pipeline.metadataStream.on('timestamp', function(frame) {
pipeline.aacStream.setTimestamp(frame.timeStamp);
});
pipeline.aacStream.on('data', function(data) {
if ((data.type !== 'timed-metadata' && data.type !== 'audio') || pipeline.audioSegmentStream) {
return;
}
audioTrack = audioTrack || {
timelineStartInfo: {
baseMediaDecodeTime: self.baseMediaDecodeTime
},
codec: 'adts',
type: 'audio'
};
// hook up the audio segment stream to the first track with aac data
pipeline.coalesceStream.numberOfTracks++;
pipeline.audioSegmentStream = new AudioSegmentStream(audioTrack, options);
pipeline.audioSegmentStream.on('timingInfo',
self.trigger.bind(self, 'audioTimingInfo'));
// Set up the final part of the audio pipeline
pipeline.adtsStream
.pipe(pipeline.audioSegmentStream)
.pipe(pipeline.coalesceStream);
// emit pmt info
self.trigger('trackinfo', {
hasAudio: !!audioTrack,
hasVideo: !!videoTrack
});
});
// Re-emit any data coming from the coalesce stream to the outside world
pipeline.coalesceStream.on('data', this.trigger.bind(this, 'data'));
// Let the consumer know we have finished flushing the entire pipeline
pipeline.coalesceStream.on('done', this.trigger.bind(this, 'done'));
};
this.setupTsPipeline = function() {
var pipeline = {};
this.transmuxPipeline_ = pipeline;
pipeline.type = 'ts';
pipeline.metadataStream = new m2ts.MetadataStream();
// set up the parsing pipeline
pipeline.packetStream = new m2ts.TransportPacketStream();
pipeline.parseStream = new m2ts.TransportParseStream();
pipeline.elementaryStream = new m2ts.ElementaryStream();
pipeline.timestampRolloverStream = new m2ts.TimestampRolloverStream();
pipeline.adtsStream = new AdtsStream();
pipeline.h264Stream = new H264Stream();
pipeline.captionStream = new m2ts.CaptionStream();
pipeline.coalesceStream = new CoalesceStream(options, pipeline.metadataStream);
pipeline.headOfPipeline = pipeline.packetStream;
// disassemble MPEG2-TS packets into elementary streams
pipeline.packetStream
.pipe(pipeline.parseStream)
.pipe(pipeline.elementaryStream)
.pipe(pipeline.timestampRolloverStream);
// !!THIS ORDER IS IMPORTANT!!
// demux the streams
pipeline.timestampRolloverStream
.pipe(pipeline.h264Stream);
pipeline.timestampRolloverStream
.pipe(pipeline.adtsStream);
pipeline.timestampRolloverStream
.pipe(pipeline.metadataStream)
.pipe(pipeline.coalesceStream);
// Hook up CEA-608/708 caption stream
pipeline.h264Stream.pipe(pipeline.captionStream)
.pipe(pipeline.coalesceStream);
pipeline.elementaryStream.on('data', function(data) {
var i;
if (data.type === 'metadata') {
i = data.tracks.length;
// scan the tracks listed in the metadata
while (i--) {
if (!videoTrack && data.tracks[i].type === 'video') {
videoTrack = data.tracks[i];
videoTrack.timelineStartInfo.baseMediaDecodeTime = self.baseMediaDecodeTime;
} else if (!audioTrack && data.tracks[i].type === 'audio') {
audioTrack = data.tracks[i];
audioTrack.timelineStartInfo.baseMediaDecodeTime = self.baseMediaDecodeTime;
}
}
// hook up the video segment stream to the first track with h264 data
if (videoTrack && !pipeline.videoSegmentStream) {
pipeline.coalesceStream.numberOfTracks++;
pipeline.videoSegmentStream = new VideoSegmentStream(videoTrack, options);
pipeline.videoSegmentStream.on('timelineStartInfo', function(timelineStartInfo) {
// When video emits timelineStartInfo data after a flush, we forward that
// info to the AudioSegmentStream, if it exists, because video timeline
// data takes precedence. Do not do this if keepOriginalTimestamps is set,
// because this is a particularly subtle form of timestamp alteration.
if (audioTrack && !options.keepOriginalTimestamps) {
audioTrack.timelineStartInfo = timelineStartInfo;
// On the first segment we trim AAC frames that exist before the
// very earliest DTS we have seen in video because Chrome will
// interpret any video track with a baseMediaDecodeTime that is
// non-zero as a gap.
pipeline.audioSegmentStream.setEarliestDts(timelineStartInfo.dts - self.baseMediaDecodeTime);
}
});
pipeline.videoSegmentStream.on('processedGopsInfo',
self.trigger.bind(self, 'gopInfo'));
pipeline.videoSegmentStream.on('segmentTimingInfo',
self.trigger.bind(self, 'videoSegmentTimingInfo'));
pipeline.videoSegmentStream.on('baseMediaDecodeTime', function(baseMediaDecodeTime) {
if (audioTrack) {
pipeline.audioSegmentStream.setVideoBaseMediaDecodeTime(baseMediaDecodeTime);
}
});
pipeline.videoSegmentStream.on('timingInfo',
self.trigger.bind(self, 'videoTimingInfo'));
// Set up the final part of the video pipeline
pipeline.h264Stream
.pipe(pipeline.videoSegmentStream)
.pipe(pipeline.coalesceStream);
}
if (audioTrack && !pipeline.audioSegmentStream) {
// hook up the audio segment stream to the first track with aac data
pipeline.coalesceStream.numberOfTracks++;
pipeline.audioSegmentStream = new AudioSegmentStream(audioTrack, options);
pipeline.audioSegmentStream.on('timingInfo',
self.trigger.bind(self, 'audioTimingInfo'));
// Set up the final part of the audio pipeline
pipeline.adtsStream
.pipe(pipeline.audioSegmentStream)
.pipe(pipeline.coalesceStream);
}
// emit pmt info
self.trigger('trackinfo', {
hasAudio: !!audioTrack,
hasVideo: !!videoTrack
});
}
});
// Re-emit any data coming from the coalesce stream to the outside world
pipeline.coalesceStream.on('data', this.trigger.bind(this, 'data'));
pipeline.coalesceStream.on('id3Frame', function(id3Frame) {
id3Frame.dispatchType = pipeline.metadataStream.dispatchType;
self.trigger('id3Frame', id3Frame);
});
pipeline.coalesceStream.on('caption', this.trigger.bind(this, 'caption'));
// Let the consumer know we have finished flushing the entire pipeline
pipeline.coalesceStream.on('done', this.trigger.bind(this, 'done'));
};
// hook up the segment streams once track metadata is delivered
this.setBaseMediaDecodeTime = function(baseMediaDecodeTime) {
var pipeline = this.transmuxPipeline_;
if (!options.keepOriginalTimestamps) {
this.baseMediaDecodeTime = baseMediaDecodeTime;
}
if (audioTrack) {
audioTrack.timelineStartInfo.dts = undefined;
audioTrack.timelineStartInfo.pts = undefined;
trackDecodeInfo.clearDtsInfo(audioTrack);
if (pipeline.audioTimestampRolloverStream) {
pipeline.audioTimestampRolloverStream.discontinuity();
}
}
if (videoTrack) {
if (pipeline.videoSegmentStream) {
pipeline.videoSegmentStream.gopCache_ = [];
}
videoTrack.timelineStartInfo.dts = undefined;
videoTrack.timelineStartInfo.pts = undefined;
trackDecodeInfo.clearDtsInfo(videoTrack);
pipeline.captionStream.reset();
}
if (pipeline.timestampRolloverStream) {
pipeline.timestampRolloverStream.discontinuity();
}
};
this.setAudioAppendStart = function(timestamp) {
if (audioTrack) {
this.transmuxPipeline_.audioSegmentStream.setAudioAppendStart(timestamp);
}
};
this.setRemux = function(val) {
var pipeline = this.transmuxPipeline_;
options.remux = val;
if (pipeline && pipeline.coalesceStream) {
pipeline.coalesceStream.setRemux(val);
}
};
this.alignGopsWith = function(gopsToAlignWith) {
if (videoTrack && this.transmuxPipeline_.videoSegmentStream) {
this.transmuxPipeline_.videoSegmentStream.alignGopsWith(gopsToAlignWith);
}
};
// feed incoming data to the front of the parsing pipeline
this.push = function(data) {
if (hasFlushed) {
var isAac = isLikelyAacData(data);
if (isAac && this.transmuxPipeline_.type !== 'aac') {
this.setupAacPipeline();
} else if (!isAac && this.transmuxPipeline_.type !== 'ts') {
this.setupTsPipeline();
}
hasFlushed = false;
}
this.transmuxPipeline_.headOfPipeline.push(data);
};
// flush any buffered data
this.flush = function() {
hasFlushed = true;
// Start at the top of the pipeline and flush all pending work
this.transmuxPipeline_.headOfPipeline.flush();
};
this.endTimeline = function() {
this.transmuxPipeline_.headOfPipeline.endTimeline();
};
this.reset = function() {
if (this.transmuxPipeline_.headOfPipeline) {
this.transmuxPipeline_.headOfPipeline.reset();
}
};
// Caption data has to be reset when seeking outside buffered range
this.resetCaptions = function() {
if (this.transmuxPipeline_.captionStream) {
this.transmuxPipeline_.captionStream.reset();
}
};
};
Transmuxer.prototype = new Stream();
module.exports = {
Transmuxer: Transmuxer,
VideoSegmentStream: VideoSegmentStream,
AudioSegmentStream: AudioSegmentStream,
AUDIO_PROPERTIES: AUDIO_PROPERTIES,
VIDEO_PROPERTIES: VIDEO_PROPERTIES,
// exported for testing
generateVideoSegmentTimingInfo: generateVideoSegmentTimingInfo
};
},{"1":1,"13":13,"16":16,"18":18,"2":2,"21":21,"29":29,"3":3,"31":31,"4":4,"5":5,"6":6,"9":9}],23:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*
* Reads in-band caption information from a video elementary
* stream. Captions must follow the CEA-708 standard for injection
* into an MPEG-2 transport streams.
* @see https://en.wikipedia.org/wiki/CEA-708
* @see https://www.gpo.gov/fdsys/pkg/CFR-2007-title47-vol1/pdf/CFR-2007-title47-vol1-sec15-119.pdf
*/
'use strict';
// Supplemental enhancement information (SEI) NAL units have a
// payload type field to indicate how they are to be
// interpreted. CEAS-708 caption content is always transmitted with
// payload type 0x04.
var USER_DATA_REGISTERED_ITU_T_T35 = 4,
RBSP_TRAILING_BITS = 128;
/**
* Parse a supplemental enhancement information (SEI) NAL unit.
* Stops parsing once a message of type ITU T T35 has been found.
*
* @param bytes {Uint8Array} the bytes of a SEI NAL unit
* @return {object} the parsed SEI payload
* @see Rec. ITU-T H.264, 7.3.2.3.1
*/
var parseSei = function(bytes) {
var
i = 0,
result = {
payloadType: -1,
payloadSize: 0
},
payloadType = 0,
payloadSize = 0;
// go through the sei_rbsp parsing each each individual sei_message
while (i < bytes.byteLength) {
// stop once we have hit the end of the sei_rbsp
if (bytes[i] === RBSP_TRAILING_BITS) {
break;
}
// Parse payload type
while (bytes[i] === 0xFF) {
payloadType += 255;
i++;
}
payloadType += bytes[i++];
// Parse payload size
while (bytes[i] === 0xFF) {
payloadSize += 255;
i++;
}
payloadSize += bytes[i++];
// this sei_message is a 608/708 caption so save it and break
// there can only ever be one caption message in a frame's sei
if (!result.payload && payloadType === USER_DATA_REGISTERED_ITU_T_T35) {
var userIdentifier = String.fromCharCode(
bytes[i + 3],
bytes[i + 4],
bytes[i + 5],
bytes[i + 6]);
if (userIdentifier === 'GA94') {
result.payloadType = payloadType;
result.payloadSize = payloadSize;
result.payload = bytes.subarray(i, i + payloadSize);
break;
} else {
result.payload = void 0;
}
}
// skip the payload and parse the next message
i += payloadSize;
payloadType = 0;
payloadSize = 0;
}
return result;
};
// see ANSI/SCTE 128-1 (2013), section 8.1
var parseUserData = function(sei) {
// itu_t_t35_contry_code must be 181 (United States) for
// captions
if (sei.payload[0] !== 181) {
return null;
}
// itu_t_t35_provider_code should be 49 (ATSC) for captions
if (((sei.payload[1] << 8) | sei.payload[2]) !== 49) {
return null;
}
// the user_identifier should be "GA94" to indicate ATSC1 data
if (String.fromCharCode(sei.payload[3],
sei.payload[4],
sei.payload[5],
sei.payload[6]) !== 'GA94') {
return null;
}
// finally, user_data_type_code should be 0x03 for caption data
if (sei.payload[7] !== 0x03) {
return null;
}
// return the user_data_type_structure and strip the trailing
// marker bits
return sei.payload.subarray(8, sei.payload.length - 1);
};
// see CEA-708-D, section 4.4
var parseCaptionPackets = function(pts, userData) {
var results = [], i, count, offset, data;
// if this is just filler, return immediately
if (!(userData[0] & 0x40)) {
return results;
}
// parse out the cc_data_1 and cc_data_2 fields
count = userData[0] & 0x1f;
for (i = 0; i < count; i++) {
offset = i * 3;
data = {
type: userData[offset + 2] & 0x03,
pts: pts
};
// capture cc data when cc_valid is 1
if (userData[offset + 2] & 0x04) {
data.ccData = (userData[offset + 3] << 8) | userData[offset + 4];
results.push(data);
}
}
return results;
};
var discardEmulationPreventionBytes = function(data) {
var
length = data.byteLength,
emulationPreventionBytesPositions = [],
i = 1,
newLength, newData;
// Find all `Emulation Prevention Bytes`
while (i < length - 2) {
if (data[i] === 0 && data[i + 1] === 0 && data[i + 2] === 0x03) {
emulationPreventionBytesPositions.push(i + 2);
i += 2;
} else {
i++;
}
}
// If no Emulation Prevention Bytes were found just return the original
// array
if (emulationPreventionBytesPositions.length === 0) {
return data;
}
// Create a new array to hold the NAL unit data
newLength = length - emulationPreventionBytesPositions.length;
newData = new Uint8Array(newLength);
var sourceIndex = 0;
for (i = 0; i < newLength; sourceIndex++, i++) {
if (sourceIndex === emulationPreventionBytesPositions[0]) {
// Skip this byte
sourceIndex++;
// Remove this position index
emulationPreventionBytesPositions.shift();
}
newData[i] = data[sourceIndex];
}
return newData;
};
// exports
module.exports = {
parseSei: parseSei,
parseUserData: parseUserData,
parseCaptionPackets: parseCaptionPackets,
discardEmulationPreventionBytes: discardEmulationPreventionBytes,
USER_DATA_REGISTERED_ITU_T_T35: USER_DATA_REGISTERED_ITU_T_T35
};
},{}],24:[function(require,module,exports){
var parseSampleFlags = function(flags) {
return {
isLeading: (flags[0] & 0x0c) >>> 2,
dependsOn: flags[0] & 0x03,
isDependedOn: (flags[1] & 0xc0) >>> 6,
hasRedundancy: (flags[1] & 0x30) >>> 4,
paddingValue: (flags[1] & 0x0e) >>> 1,
isNonSyncSample: flags[1] & 0x01,
degradationPriority: (flags[2] << 8) | flags[3]
};
};
module.exports = parseSampleFlags;
},{}],25:[function(require,module,exports){
var toUnsigned = require(28).toUnsigned;
var tfdt = function(data) {
var result = {
version: data[0],
flags: new Uint8Array(data.subarray(1, 4)),
baseMediaDecodeTime: toUnsigned(data[4] << 24 | data[5] << 16 | data[6] << 8 | data[7])
};
if (result.version === 1) {
result.baseMediaDecodeTime *= Math.pow(2, 32);
result.baseMediaDecodeTime += toUnsigned(data[8] << 24 | data[9] << 16 | data[10] << 8 | data[11]);
}
return result;
};
module.exports = tfdt;
},{"28":28}],26:[function(require,module,exports){
var tfhd = function(data) {
var
view = new DataView(data.buffer, data.byteOffset, data.byteLength),
result = {
version: data[0],
flags: new Uint8Array(data.subarray(1, 4)),
trackId: view.getUint32(4)
},
baseDataOffsetPresent = result.flags[2] & 0x01,
sampleDescriptionIndexPresent = result.flags[2] & 0x02,
defaultSampleDurationPresent = result.flags[2] & 0x08,
defaultSampleSizePresent = result.flags[2] & 0x10,
defaultSampleFlagsPresent = result.flags[2] & 0x20,
durationIsEmpty = result.flags[0] & 0x010000,
defaultBaseIsMoof = result.flags[0] & 0x020000,
i;
i = 8;
if (baseDataOffsetPresent) {
i += 4; // truncate top 4 bytes
// FIXME: should we read the full 64 bits?
result.baseDataOffset = view.getUint32(12);
i += 4;
}
if (sampleDescriptionIndexPresent) {
result.sampleDescriptionIndex = view.getUint32(i);
i += 4;
}
if (defaultSampleDurationPresent) {
result.defaultSampleDuration = view.getUint32(i);
i += 4;
}
if (defaultSampleSizePresent) {
result.defaultSampleSize = view.getUint32(i);
i += 4;
}
if (defaultSampleFlagsPresent) {
result.defaultSampleFlags = view.getUint32(i);
}
if (durationIsEmpty) {
result.durationIsEmpty = true;
}
if (!baseDataOffsetPresent && defaultBaseIsMoof) {
result.baseDataOffsetIsMoof = true;
}
return result;
};
module.exports = tfhd;
},{}],27:[function(require,module,exports){
var parseSampleFlags = require(24);
var trun = function(data) {
var
result = {
version: data[0],
flags: new Uint8Array(data.subarray(1, 4)),
samples: []
},
view = new DataView(data.buffer, data.byteOffset, data.byteLength),
// Flag interpretation
dataOffsetPresent = result.flags[2] & 0x01, // compare with 2nd byte of 0x1
firstSampleFlagsPresent = result.flags[2] & 0x04, // compare with 2nd byte of 0x4
sampleDurationPresent = result.flags[1] & 0x01, // compare with 2nd byte of 0x100
sampleSizePresent = result.flags[1] & 0x02, // compare with 2nd byte of 0x200
sampleFlagsPresent = result.flags[1] & 0x04, // compare with 2nd byte of 0x400
sampleCompositionTimeOffsetPresent = result.flags[1] & 0x08, // compare with 2nd byte of 0x800
sampleCount = view.getUint32(4),
offset = 8,
sample;
if (dataOffsetPresent) {
// 32 bit signed integer
result.dataOffset = view.getInt32(offset);
offset += 4;
}
// Overrides the flags for the first sample only. The order of
// optional values will be: duration, size, compositionTimeOffset
if (firstSampleFlagsPresent && sampleCount) {
sample = {
flags: parseSampleFlags(data.subarray(offset, offset + 4))
};
offset += 4;
if (sampleDurationPresent) {
sample.duration = view.getUint32(offset);
offset += 4;
}
if (sampleSizePresent) {
sample.size = view.getUint32(offset);
offset += 4;
}
if (sampleCompositionTimeOffsetPresent) {
if (result.version === 1) {
sample.compositionTimeOffset = view.getInt32(offset);
} else {
sample.compositionTimeOffset = view.getUint32(offset);
}
offset += 4;
}
result.samples.push(sample);
sampleCount--;
}
while (sampleCount--) {
sample = {};
if (sampleDurationPresent) {
sample.duration = view.getUint32(offset);
offset += 4;
}
if (sampleSizePresent) {
sample.size = view.getUint32(offset);
offset += 4;
}
if (sampleFlagsPresent) {
sample.flags = parseSampleFlags(data.subarray(offset, offset + 4));
offset += 4;
}
if (sampleCompositionTimeOffsetPresent) {
if (result.version === 1) {
sample.compositionTimeOffset = view.getInt32(offset);
} else {
sample.compositionTimeOffset = view.getUint32(offset);
}
offset += 4;
}
result.samples.push(sample);
}
return result;
};
module.exports = trun;
},{"24":24}],28:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*/
var toUnsigned = function(value) {
return value >>> 0;
};
var toHexString = function(value) {
return ('00' + value.toString(16)).slice(-2);
};
module.exports = {
toUnsigned: toUnsigned,
toHexString: toHexString
};
},{}],29:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*/
var
ONE_SECOND_IN_TS = 90000, // 90kHz clock
secondsToVideoTs,
secondsToAudioTs,
videoTsToSeconds,
audioTsToSeconds,
audioTsToVideoTs,
videoTsToAudioTs,
metadataTsToSeconds;
secondsToVideoTs = function(seconds) {
return seconds * ONE_SECOND_IN_TS;
};
secondsToAudioTs = function(seconds, sampleRate) {
return seconds * sampleRate;
};
videoTsToSeconds = function(timestamp) {
return timestamp / ONE_SECOND_IN_TS;
};
audioTsToSeconds = function(timestamp, sampleRate) {
return timestamp / sampleRate;
};
audioTsToVideoTs = function(timestamp, sampleRate) {
return secondsToVideoTs(audioTsToSeconds(timestamp, sampleRate));
};
videoTsToAudioTs = function(timestamp, sampleRate) {
return secondsToAudioTs(videoTsToSeconds(timestamp), sampleRate);
};
/**
* Adjust ID3 tag or caption timing information by the timeline pts values
* (if keepOriginalTimestamps is false) and convert to seconds
*/
metadataTsToSeconds = function(timestamp, timelineStartPts, keepOriginalTimestamps) {
return videoTsToSeconds(keepOriginalTimestamps ? timestamp : timestamp - timelineStartPts);
};
module.exports = {
ONE_SECOND_IN_TS: ONE_SECOND_IN_TS,
secondsToVideoTs: secondsToVideoTs,
secondsToAudioTs: secondsToAudioTs,
videoTsToSeconds: videoTsToSeconds,
audioTsToSeconds: audioTsToSeconds,
audioTsToVideoTs: audioTsToVideoTs,
videoTsToAudioTs: videoTsToAudioTs,
metadataTsToSeconds: metadataTsToSeconds
};
},{}],30:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*/
'use strict';
var ExpGolomb;
/**
* Parser for exponential Golomb codes, a variable-bitwidth number encoding
* scheme used by h264.
*/
ExpGolomb = function(workingData) {
var
// the number of bytes left to examine in workingData
workingBytesAvailable = workingData.byteLength,
// the current word being examined
workingWord = 0, // :uint
// the number of bits left to examine in the current word
workingBitsAvailable = 0; // :uint;
// ():uint
this.length = function() {
return (8 * workingBytesAvailable);
};
// ():uint
this.bitsAvailable = function() {
return (8 * workingBytesAvailable) + workingBitsAvailable;
};
// ():void
this.loadWord = function() {
var
position = workingData.byteLength - workingBytesAvailable,
workingBytes = new Uint8Array(4),
availableBytes = Math.min(4, workingBytesAvailable);
if (availableBytes === 0) {
throw new Error('no bytes available');
}
workingBytes.set(workingData.subarray(position,
position + availableBytes));
workingWord = new DataView(workingBytes.buffer).getUint32(0);
// track the amount of workingData that has been processed
workingBitsAvailable = availableBytes * 8;
workingBytesAvailable -= availableBytes;
};
// (count:int):void
this.skipBits = function(count) {
var skipBytes; // :int
if (workingBitsAvailable > count) {
workingWord <<= count;
workingBitsAvailable -= count;
} else {
count -= workingBitsAvailable;
skipBytes = Math.floor(count / 8);
count -= (skipBytes * 8);
workingBytesAvailable -= skipBytes;
this.loadWord();
workingWord <<= count;
workingBitsAvailable -= count;
}
};
// (size:int):uint
this.readBits = function(size) {
var
bits = Math.min(workingBitsAvailable, size), // :uint
valu = workingWord >>> (32 - bits); // :uint
// if size > 31, handle error
workingBitsAvailable -= bits;
if (workingBitsAvailable > 0) {
workingWord <<= bits;
} else if (workingBytesAvailable > 0) {
this.loadWord();
}
bits = size - bits;
if (bits > 0) {
return valu << bits | this.readBits(bits);
}
return valu;
};
// ():uint
this.skipLeadingZeros = function() {
var leadingZeroCount; // :uint
for (leadingZeroCount = 0; leadingZeroCount < workingBitsAvailable; ++leadingZeroCount) {
if ((workingWord & (0x80000000 >>> leadingZeroCount)) !== 0) {
// the first bit of working word is 1
workingWord <<= leadingZeroCount;
workingBitsAvailable -= leadingZeroCount;
return leadingZeroCount;
}
}
// we exhausted workingWord and still have not found a 1
this.loadWord();
return leadingZeroCount + this.skipLeadingZeros();
};
// ():void
this.skipUnsignedExpGolomb = function() {
this.skipBits(1 + this.skipLeadingZeros());
};
// ():void
this.skipExpGolomb = function() {
this.skipBits(1 + this.skipLeadingZeros());
};
// ():uint
this.readUnsignedExpGolomb = function() {
var clz = this.skipLeadingZeros(); // :uint
return this.readBits(clz + 1) - 1;
};
// ():int
this.readExpGolomb = function() {
var valu = this.readUnsignedExpGolomb(); // :int
if (0x01 & valu) {
// the number is odd if the low order bit is set
return (1 + valu) >>> 1; // add 1 to make it even, and divide by 2
}
return -1 * (valu >>> 1); // divide by two then make it negative
};
// Some convenience functions
// :Boolean
this.readBoolean = function() {
return this.readBits(1) === 1;
};
// ():int
this.readUnsignedByte = function() {
return this.readBits(8);
};
this.loadWord();
};
module.exports = ExpGolomb;
},{}],31:[function(require,module,exports){
/**
* mux.js
*
* Copyright (c) Brightcove
* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
*
* A lightweight readable stream implemention that handles event dispatching.
* Objects that inherit from streams should call init in their constructors.
*/
'use strict';
var Stream = function() {
this.init = function() {
var listeners = {};
/**
* Add a listener for a specified event type.
* @param type {string} the event name
* @param listener {function} the callback to be invoked when an event of
* the specified type occurs
*/
this.on = function(type, listener) {
if (!listeners[type]) {
listeners[type] = [];
}
listeners[type] = listeners[type].concat(listener);
};
/**
* Remove a listener for a specified event type.
* @param type {string} the event name
* @param listener {function} a function previously registered for this
* type of event through `on`
*/
this.off = function(type, listener) {
var index;
if (!listeners[type]) {
return false;
}
index = listeners[type].indexOf(listener);
listeners[type] = listeners[type].slice();
listeners[type].splice(index, 1);
return index > -1;
};
/**
* Trigger an event of the specified type on this stream. Any additional
* arguments to this function are passed as parameters to event listeners.
* @param type {string} the event name
*/
this.trigger = function(type) {
var callbacks, i, length, args;
callbacks = listeners[type];
if (!callbacks) {
return;
}
// Slicing the arguments on every invocation of this method
// can add a significant amount of overhead. Avoid the
// intermediate object creation for the common case of a
// single callback argument
if (arguments.length === 2) {
length = callbacks.length;
for (i = 0; i < length; ++i) {
callbacks[i].call(this, arguments[1]);
}
} else {
args = [];
i = arguments.length;
for (i = 1; i < arguments.length; ++i) {
args.push(arguments[i]);
}
length = callbacks.length;
for (i = 0; i < length; ++i) {
callbacks[i].apply(this, args);
}
}
};
/**
* Destroys the stream and cleans up.
*/
this.dispose = function() {
listeners = {};
};
};
};
/**
* Forwards all `data` events on this stream to the destination stream. The
* destination stream should provide a method `push` to receive the data
* events as they arrive.
* @param destination {stream} the stream that will receive all `data` events
* @param autoFlush {boolean} if false, we will not call `flush` on the destination
* when the current stream emits a 'done' event
* @see http://nodejs.org/api/stream.html#stream_readable_pipe_destination_options
*/
Stream.prototype.pipe = function(destination) {
this.on('data', function(data) {
destination.push(data);
});
this.on('done', function(flushSource) {
destination.flush(flushSource);
});
this.on('partialdone', function(flushSource) {
destination.partialFlush(flushSource);
});
this.on('endedtimeline', function(flushSource) {
destination.endTimeline(flushSource);
});
this.on('reset', function(flushSource) {
destination.reset(flushSource);
});
return destination;
};
// Default stream functions that are expected to be overridden to perform
// actual work. These are provided by the prototype as a sort of no-op
// implementation so that we don't have to check for their existence in the
// `pipe` function above.
Stream.prototype.push = function(data) {
this.trigger('data', data);
};
Stream.prototype.flush = function(flushSource) {
this.trigger('done', flushSource);
};
Stream.prototype.partialFlush = function(flushSource) {
this.trigger('partialdone', flushSource);
};
Stream.prototype.endTimeline = function(flushSource) {
this.trigger('endedtimeline', flushSource);
};
Stream.prototype.reset = function(flushSource) {
this.trigger('reset', flushSource);
};
module.exports = Stream;
},{}]},{},[17])(17)
});
使用页面引入
import m3u8Change from '@/utils/m3u8Change';
使用
m3u8Change.getMP4(pullUrl);