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 *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree.

    <meta charset="utf-8">
    <meta name="description" content="WebRTC code samples">
    <meta name="viewport" content="width=device-width, user-scalable=yes, initial-scale=1, maximum-scale=1">
    <meta itemprop="description" content="Client-side WebRTC code samples">
    <meta itemprop="image" content="../../../images/webrtc-icon-192x192.png">
    <meta itemprop="name" content="WebRTC code samples">
    <meta name="mobile-web-app-capable" content="yes">
    <meta id="theme-color" name="theme-color" content="#ffffff">

    <base target="_blank">

    <title>MediaStream Recording</title>

    <link rel="icon" sizes="192x192" href="../../../images/webrtc-icon-192x192.png">
    <link href="//,400,500,700" rel="stylesheet" type="text/css">
    <link rel="stylesheet" href="../../../css/main.css">
    <link rel="stylesheet" href="css/main.css">



<div id="container">

    <h1><a href="//" title="WebRTC samples homepage">WebRTC samples</a>

    <p>For more information see the MediaStream Recording API <a
            title="W3C MediaStream Recording API Editor's Draft">Editor's&nbsp;Draft</a>.</p>

    <video id="gum" playsinline autoplay muted></video>
    <video id="recorded" playsinline loop></video>

        <button id="start">Start camera</button>
        <button id="record" disabled>Start Recording</button>
        <button id="play" disabled>Play</button>
        <button id="download" disabled>Download</button>

        <h4>Media Stream Constraints options</h4>
        <p>Echo cancellation: <input type="checkbox" id="echoCancellation"></p>

        <span id="errorMsg"></span>

    <a href=""
       title="View source for this page on GitHub" id="viewSource">View source on GitHub</a>


<!-- include adapter for srcObject shim -->
<script src=""></script>
<script src="js/main.js" async></script>
<script src="../../../js/lib/ga.js"></script>



 *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree.
 button {
  margin: 0 3px 10px 0;
  padding-left: 2px;
  padding-right: 2px;
  width: 99px;

button:last-of-type {
  margin: 0;

p.borderBelow {
  margin: 0 0 20px 0;
  padding: 0 0 20px 0;

video {
  vertical-align: top;
  --width: 25vw;
  width: var(--width);
  height: calc(var(--width) * 0.5625);

video:last-of-type {
  margin: 0 0 20px 0;

video#gumVideo {
  margin: 0 20px 20px 0;



*  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
*  Use of this source code is governed by a BSD-style license
*  that can be found in the LICENSE file in the root of the source
*  tree.

// This code is adapted from

'use strict';

/* globals MediaRecorder */

let mediaRecorder;
let recordedBlobs;

const errorMsgElement = document.querySelector('span#errorMsg');
const recordedVideo = document.querySelector('video#recorded');
const recordButton = document.querySelector('button#record');
recordButton.addEventListener('click', () => {
  if (recordButton.textContent === 'Start Recording') {
  } else {
    recordButton.textContent = 'Start Recording';
    playButton.disabled = false;
    downloadButton.disabled = false;

const playButton = document.querySelector('button#play');
playButton.addEventListener('click', () => {
  const superBuffer = new Blob(recordedBlobs, {type: 'video/mp4'});
  recordedVideo.src = null;
  recordedVideo.srcObject = null;
  recordedVideo.src = window.URL.createObjectURL(superBuffer);
  recordedVideo.controls = true;;

const downloadButton = document.querySelector('button#download');
downloadButton.addEventListener('click', () => {
  const blob = new Blob(recordedBlobs, {type: 'video/mp4'});
  const url = window.URL.createObjectURL(blob);
  const a = document.createElement('a'); = 'none';
  a.href = url; = 'test.mp4';
  setTimeout(() => {
  }, 100);

function handleDataAvailable(event) {
  console.log('handleDataAvailable', event);
  if ( && > 0) {

function startRecording() {
  recordedBlobs = [];
  let options = {mimeType: 'video/mp4'};

  try {
    mediaRecorder = new MediaRecorder(, options);
  } catch (e) {
    console.error('Exception while creating MediaRecorder:', e);
    errorMsgElement.innerHTML = `Exception while creating MediaRecorder: ${JSON.stringify(e)}`;

  console.log('Created MediaRecorder', mediaRecorder, 'with options', options);
  recordButton.textContent = 'Stop Recording';
  playButton.disabled = true;
  downloadButton.disabled = true;
  mediaRecorder.onstop = (event) => {
    console.log('Recorder stopped: ', event);
    console.log('Recorded Blobs: ', recordedBlobs);
  mediaRecorder.ondataavailable = handleDataAvailable;
  console.log('MediaRecorder started', mediaRecorder);

function stopRecording() {

function handleSuccess(stream) {
  recordButton.disabled = false;
  console.log('getUserMedia() got stream:', stream); = stream;

  const gumVideo = document.querySelector('video#gum');
  gumVideo.srcObject = stream;

async function init(constraints) {
  try {
    const stream = await navigator.mediaDevices.getUserMedia(constraints);
  } catch (e) {
    console.error('navigator.getUserMedia error:', e);
    errorMsgElement.innerHTML = `navigator.getUserMedia error:${e.toString()}`;

document.querySelector('button#start').addEventListener('click', async () => {
  const hasEchoCancellation = document.querySelector('#echoCancellation').checked;
  const constraints = {
    audio: true,
    video: true
  console.log('Using media constraints:', constraints);
  await init(constraints);