client/src/assets/player/video-renderer.ts

   1 // Thanks: https://github.com/feross/render-media
   2 // TODO: use render-media once https://github.com/feross/render-media/issues/32 is fixed
   3
   4 import { extname } from 'path'
   5 import * as MediaElementWrapper from 'mediasource'
   6 import * as videostream from 'videostream'
   7
   8 const VIDEOSTREAM_EXTS = [
   9   '.m4a',
  10   '.m4v',
  11   '.mp4'
  12 ]
  13
  14 type RenderMediaOptions = {
  15   controls: boolean
  16   autoplay: boolean
  17 }
  18
  19 function renderVideo (
  20   file,
  21   elem: HTMLVideoElement,
  22   opts: RenderMediaOptions,
  23   callback: (err: Error, renderer: any) => void
  24 ) {
  25   validateFile(file)
  26
  27   return renderMedia(file, elem, opts, callback)
  28 }
  29
  30 function renderMedia (file, elem: HTMLVideoElement, opts: RenderMediaOptions, callback: (err: Error, renderer: any) => void) {
  31   const extension = extname(file.name).toLowerCase()
  32   let preparedElem = undefined
  33   let currentTime = 0
  34   let renderer
  35
  36   if (VIDEOSTREAM_EXTS.indexOf(extension) >= 0) {
  37     renderer = useVideostream()
  38   } else {
  39     renderer = useMediaSource()
  40   }
  41
  42   function useVideostream () {
  43     prepareElem()
  44     preparedElem.addEventListener('error', fallbackToMediaSource)
  45     preparedElem.addEventListener('loadstart', onLoadStart)
  46     preparedElem.addEventListener('canplay', onCanPlay)
  47     return videostream(file, preparedElem)
  48   }
  49
  50   function useMediaSource () {
  51     prepareElem()
  52     preparedElem.addEventListener('error', callback)
  53     preparedElem.addEventListener('loadstart', onLoadStart)
  54     preparedElem.addEventListener('canplay', onCanPlay)
  55
  56     const wrapper = new MediaElementWrapper(preparedElem)
  57     const writable = wrapper.createWriteStream(getCodec(file.name))
  58     file.createReadStream().pipe(writable)
  59
  60     if (currentTime) preparedElem.currentTime = currentTime
  61
  62     return wrapper
  63   }
  64
  65   function fallbackToMediaSource () {
  66     preparedElem.removeEventListener('error', fallbackToMediaSource)
  67     preparedElem.removeEventListener('canplay', onCanPlay)
  68
  69     useMediaSource()
  70   }
  71
  72   function prepareElem () {
  73     if (preparedElem === undefined) {
  74       preparedElem = elem
  75
  76       preparedElem.addEventListener('progress', function () {
  77         currentTime = elem.currentTime
  78       })
  79     }
  80   }
  81
  82   function onLoadStart () {
  83     preparedElem.removeEventListener('loadstart', onLoadStart)
  84     if (opts.autoplay) preparedElem.play()
  85   }
  86
  87   function onCanPlay () {
  88     preparedElem.removeEventListener('canplay', onCanPlay)
  89     callback(null, renderer)
  90   }
  91 }
  92
  93 function validateFile (file) {
  94   if (file == null) {
  95     throw new Error('file cannot be null or undefined')
  96   }
  97   if (typeof file.name !== 'string') {
  98     throw new Error('missing or invalid file.name property')
  99   }
 100   if (typeof file.createReadStream !== 'function') {
 101     throw new Error('missing or invalid file.createReadStream property')
 102   }
 103 }
 104
 105 function getCodec (name: string) {
 106   const ext = extname(name).toLowerCase()
 107   return {
 108     '.m4a': 'audio/mp4; codecs="mp4a.40.5"',
 109     '.m4v': 'video/mp4; codecs="avc1.640029, mp4a.40.5"',
 110     '.mkv': 'video/webm; codecs="avc1.640029, mp4a.40.5"',
 111     '.mp3': 'audio/mpeg',
 112     '.mp4': 'video/mp4; codecs="avc1.640029, mp4a.40.5"',
 113     '.webm': 'video/webm; codecs="vorbis, vp8"'
 114   }[ext]
 115 }
 116
 117 export {
 118   renderVideo
 119 }