native_client_sdk/src/examples/api/video_encode/example.js

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 var dataArray;
   6 const MIME_TYPE = "application/octet-stream";
   7
   8 function $(id) {
   9   return document.getElementById(id);
  10 }
  11
  12
  13 function success(stream) {
  14   track = stream.getVideoTracks()[0];
  15   var video = $('video')
  16   video.src = URL.createObjectURL(stream);
  17   video.track = track;
  18   video.play();
  19
  20   var list = $('profileList');
  21   var profile = (list.length < 1) ? 'vp8'
  22     : list.options[list.selectedIndex].value;
  23
  24   common.naclModule.postMessage({
  25     command: 'start',
  26     track: track,
  27     profile: profile,
  28     width: 640,
  29     height: 480
  30   });
  31 }
  32
  33 function failure(e) {
  34   common.logMessage("Error: " + e);
  35 }
  36
  37 function cleanupDownload() {
  38   var download = $('download');
  39   if (!download)
  40     return;
  41   download.parentNode.removeChild(download);
  42 }
  43
  44 function appendDownload(parent, blob, filename) {
  45   var a = document.createElement('a');
  46   a.id = "download";
  47   a.download = filename;
  48   a.href = window.URL.createObjectURL(blob);
  49   a.textContent = 'Download';
  50   a.dataset.downloadurl = [MIME_TYPE, a.download, a.href].join(':');
  51   parent.appendChild(a);
  52 }
  53
  54 function startRecord() {
  55   $('length').innerHTML = ' Size: ' + dataArray.byteLength + ' bytes';
  56   navigator.webkitGetUserMedia({audio: false, video: true},
  57                                success, failure);
  58
  59   $('start').disabled = true;
  60   $('stop').disabled = false;
  61   cleanupDownload();
  62 }
  63
  64 function stopRecord() {
  65   common.naclModule.postMessage({
  66     command: "stop"
  67   });
  68   var video = $('video');
  69   video.pause();
  70   video.track.stop();
  71   video.track = null;
  72
  73   $('start').disabled = false;
  74   $('stop').disabled = true;
  75   appendDownload($('download-box'),
  76                  new Blob([dataArray], { type: MIME_TYPE }),
  77                  'Capture.video');
  78 }
  79
  80 function handleMessage(msg) {
  81   if (msg.data.name == 'data') {
  82     appendData(msg.data.data);
  83   } else if (msg.data.name == 'supportedProfiles') {
  84     common.logMessage('profiles: ' + JSON.stringify(msg.data.profiles));
  85     var profileList = $('profileList');
  86     for (var node in profileList.childNodes)
  87       profileList.remove(node);
  88     for (var i = 0; i < msg.data.profiles.length; i++) {
  89       var item = document.createElement('option');
  90       item.label = item.value = msg.data.profiles[i];
  91       profileList.appendChild(item);
  92     }
  93     $('start').disabled = !(msg.data.profiles.length > 0);
  94   } else if (msg.data.name == 'log') {
  95     common.logMessage(msg.data.message);
  96   }
  97 }
  98
  99 function resetData() {
 100   dataArray = new ArrayBuffer(0);
 101 }
 102
 103 function appendData(data) {
 104   var tmp = new Uint8Array(dataArray.byteLength + data.byteLength);
 105   tmp.set(new Uint8Array(dataArray), 0 );
 106   tmp.set(new Uint8Array(data), dataArray.byteLength);
 107   dataArray = tmp.buffer;
 108   $('length').textContent = ' Size: ' + dataArray.byteLength + ' bytes';
 109 }
 110
 111 function attachListeners() {
 112   $('start').addEventListener('click', function (e) {
 113     resetData();
 114     startRecord();
 115   });
 116   $('stop').addEventListener('click', function (e) {
 117     stopRecord();
 118   });
 119 }
 120
 121 // Called by the common.js module.
 122 function moduleDidLoad() {
 123   // The module is not hidden by default so we can easily see if the plugin
 124   // failed to load.
 125   common.hideModule();
 126 }