remoting/webapp/crd/js/video_frame_recorder.js

   1 // Copyright 2014 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 /**
   6  * @fileoverview
   7  * Class implement the video frame recorder extension client.
   8  */
   9
  10 'use strict';
  11
  12 /** @suppress {duplicate} */
  13 var remoting = remoting || {};
  14
  15 /**
  16  * @constructor
  17  * @param {remoting.ClientPlugin} plugin
  18  */
  19 remoting.VideoFrameRecorder = function(plugin) {
  20   this.fileWriter_ = null;
  21   this.isRecording_ = false;
  22   this.plugin_ = plugin;
  23 };
  24
  25 /**
  26  * Starts or stops video recording.
  27  */
  28 remoting.VideoFrameRecorder.prototype.startStopRecording = function() {
  29   var data = {};
  30   if (this.isRecording_) {
  31     this.isRecording_ = false;
  32     data = { type: 'stop' }
  33
  34     chrome.fileSystem.chooseEntry(
  35         {type: 'saveFile', suggestedName: 'videoRecording.pb'},
  36         this.onFileChosen_.bind(this));
  37   } else {
  38     this.isRecording_ = true;
  39     data = { type: 'start' }
  40   }
  41   this.plugin_.sendClientMessage('video-recorder', JSON.stringify(data));
  42 }
  43
  44 /**
  45  * Returns true if the session is currently being recorded.
  46  * @return {boolean}
  47  */
  48 remoting.VideoFrameRecorder.prototype.isRecording = function() {
  49   return this.isRecording_;
  50 }
  51
  52 /**
  53  * Handles 'video-recorder' extension messages and returns true. Returns
  54  * false for all other message types.
  55  * @param {string} type Type of extension message.
  56  * @param {string} data Content of the extension message.
  57  * @return {boolean}
  58  */
  59 remoting.VideoFrameRecorder.prototype.handleMessage =
  60     function(type, data) {
  61   if (type != 'video-recorder') {
  62     return false;
  63   }
  64
  65   var message = getJsonObjectFromString(data);
  66   var messageType = getStringAttr(message, 'type');
  67   var messageData = getStringAttr(message, 'data');
  68
  69   if (messageType == 'next-frame-reply') {
  70     if (!this.fileWriter_) {
  71       console.log("Received frame but have no writer");
  72       return true;
  73     }
  74     if (!messageData) {
  75       console.log("Finished receiving frames");
  76       this.fileWriter_ = null;
  77       return true;
  78     }
  79
  80     console.log("Received frame");
  81     /* jscompile gets confused if you refer to this as just atob(). */
  82     var videoPacketString = /** @type {string?} */ window.atob(messageData);
  83
  84     console.log("Converted from Base64 - length:" + videoPacketString.length);
  85     var byteArrays = [];
  86
  87     for (var offset = 0; offset < videoPacketString.length; offset += 512) {
  88         var slice = videoPacketString.slice(offset, offset + 512);
  89         var byteNumbers = new Array(slice.length);
  90         for (var i = 0; i < slice.length; i++) {
  91             byteNumbers[i] = slice.charCodeAt(i);
  92         }
  93         var byteArray = new Uint8Array(byteNumbers);
  94         byteArrays.push(byteArray);
  95     }
  96
  97     console.log("Writing frame");
  98     videoPacketString = null;
  99     /**
 100      * Our current compiler toolchain only understands the old (deprecated)
 101      * Blob constructor, which does not accept any parameters.
 102      * TODO(wez): Remove this when compiler is updated (see crbug.com/405298).
 103      * @suppress {checkTypes}
 104      * @param {Array} parts
 105      * @return {Blob}
 106      */
 107     var makeBlob = function(parts) {
 108       return new Blob(parts);
 109     }
 110     var videoPacketBlob = makeBlob(byteArrays);
 111     byteArrays = null;
 112
 113     this.fileWriter_.write(videoPacketBlob);
 114
 115     return true;
 116   }
 117
 118   console.log("Unrecognized message: " + messageType);
 119   return true;
 120 }
 121
 122 /** @param {FileEntry} fileEntry */
 123 remoting.VideoFrameRecorder.prototype.onFileChosen_ = function(fileEntry) {
 124   if (!fileEntry) {
 125     console.log("Cancelled save of video frames.");
 126   } else {
 127     /** @type {function(string):void} */
 128     chrome.fileSystem.getDisplayPath(fileEntry, function(path) {
 129       console.log("Saving video frames to:" + path);
 130     });
 131     fileEntry.createWriter(this.onFileWriter_.bind(this));
 132   }
 133 }
 134
 135 /** @param {FileWriter} fileWriter */
 136 remoting.VideoFrameRecorder.prototype.onFileWriter_ = function(fileWriter) {
 137   console.log("Obtained FileWriter for video frame write");
 138   fileWriter.onwriteend = this.onWriteComplete_.bind(this);
 139   this.fileWriter_ = fileWriter;
 140   this.fetchNextFrame_();
 141 }
 142
 143 remoting.VideoFrameRecorder.prototype.onWriteComplete_ = function(e) {
 144   console.log("Video frame write complete");
 145   this.fetchNextFrame_();
 146 }
 147
 148 remoting.VideoFrameRecorder.prototype.fetchNextFrame_ = function() {
 149   console.log("Request next video frame");
 150   var data = { type: 'next-frame' }
 151   this.plugin_.sendClientMessage('video-recorder', JSON.stringify(data));
 152 }