Audio / Media Session Sample

Available in Chrome 57+ | View on GitHub | Browse Samples

Background

The Media Session API lets you customize media notifications by providing metadata information for the media your web app is playing. It also allows you to handle media related events such as seeking or track changing which may come from notifications or media keys.

Credits: Media files are the works of Jan Morgenstern and licensed under CC BY-NC-ND 3.0.

Live Output


JavaScript Snippet

let audio = document.createElement('audio');

let playlist = getAwesomePlaylist();
let index = 0;

function onPlayButtonClick() {
  playAudio();
}

function playAudio() {
  audio.src = playlist[index].src;
  audio.play()
  .then(_ => updateMetadata())
  .catch(error => log(error));
}

function updateMetadata() {
  let track = playlist[index];

  log('Playing ' + track.title + ' track...');
  navigator.mediaSession.metadata = new MediaMetadata({
    title: track.title,
    artist: track.artist,
    album: track.album,
    artwork: track.artwork
  });
}

/* Previous Track & Next Track */

navigator.mediaSession.setActionHandler('previoustrack', function() {
  log('> User clicked "Previous Track" icon.');
  index = (index - 1 + playlist.length) % playlist.length;
  playAudio();
});

navigator.mediaSession.setActionHandler('nexttrack', function() {
  log('> User clicked "Next Track" icon.');
  index = (index + 1) % playlist.length;
  playAudio();
});

audio.addEventListener('ended', function() {
  // Play automatically the next track when audio ends.
  index = (index - 1 + playlist.length) % playlist.length;
  playAudio();
});

/* Seek Backward & Seek Forward */

let defaultSkipTime = 10; /* Time to skip in seconds by default */

navigator.mediaSession.setActionHandler('seekbackward', function(event) {
  log('> User clicked "Seek Backward" icon.');
  const skipTime = event.seekOffset || defaultSkipTime;
  audio.currentTime = Math.max(audio.currentTime - skipTime, 0);
});

navigator.mediaSession.setActionHandler('seekforward', function(event) {
  log('> User clicked "Seek Forward" icon.');
  const skipTime = event.seekOffset || defaultSkipTime;
  audio.currentTime = Math.min(audio.currentTime + skipTime, audio.duration);
});

/* Play & Pause */

navigator.mediaSession.setActionHandler('play', function() {
  log('> User clicked "Play" icon.');
  audio.play();
  // Do something more than just playing audio...
});

navigator.mediaSession.setActionHandler('pause', function() {
  log('> User clicked "Pause" icon.');
  audio.pause();
  // Do something more than just pausing audio...
});

/* Stop (supported since Chrome 77) */

try {
  navigator.mediaSession.setActionHandler('stop', function() {
    log('> User clicked "Stop" icon.');
    // TODO: Clear UI playback...
  });
} catch(error) {
  log('Warning! The "stop" media session action is not supported.');
}

/* Seek To (supported since Chrome 78) */

try {
  navigator.mediaSession.setActionHandler('seekto', function(event) {
    log('> User clicked "Seek To" icon.');
    if (event.fastSeek && ('fastSeek' in audio)) {
      audio.fastSeek(event.seekTime);
      return;
    }
    audio.currentTime = event.seekTime;
  });
} catch(error) {
  log('Warning! The "seekto" media session action is not supported.');
}

/* Utils */

function getAwesomePlaylist() {
  const BASE_URL = 'https://storage.googleapis.com/media-session/';

  return [{
      src: BASE_URL + 'sintel/snow-fight.mp3',
      title: 'Snow Fight',
      artist: 'Jan Morgenstern',
      album: 'Sintel',
      artwork: [
        { src: BASE_URL + 'sintel/artwork-96.png',  sizes: '96x96',   type: 'image/png' },
        { src: BASE_URL + 'sintel/artwork-128.png', sizes: '128x128', type: 'image/png' },
        { src: BASE_URL + 'sintel/artwork-192.png', sizes: '192x192', type: 'image/png' },
        { src: BASE_URL + 'sintel/artwork-256.png', sizes: '256x256', type: 'image/png' },
        { src: BASE_URL + 'sintel/artwork-384.png', sizes: '384x384', type: 'image/png' },
        { src: BASE_URL + 'sintel/artwork-512.png', sizes: '512x512', type: 'image/png' },
      ]
    }, {
      src: BASE_URL + 'big-buck-bunny/prelude.mp3',
      title: 'Prelude',
      artist: 'Jan Morgenstern',
      album: 'Big Buck Bunny',
      artwork: [
        { src: BASE_URL + 'big-buck-bunny/artwork-96.png',  sizes: '96x96',   type: 'image/png' },
        { src: BASE_URL + 'big-buck-bunny/artwork-128.png', sizes: '128x128', type: 'image/png' },
        { src: BASE_URL + 'big-buck-bunny/artwork-192.png', sizes: '192x192', type: 'image/png' },
        { src: BASE_URL + 'big-buck-bunny/artwork-256.png', sizes: '256x256', type: 'image/png' },
        { src: BASE_URL + 'big-buck-bunny/artwork-384.png', sizes: '384x384', type: 'image/png' },
        { src: BASE_URL + 'big-buck-bunny/artwork-512.png', sizes: '512x512', type: 'image/png' },
      ]
    }, {
      src: BASE_URL + 'elephants-dream/the-wires.mp3',
      title: 'The Wires',
      artist: 'Jan Morgenstern',
      album: 'Elephants Dream',
      artwork: [
        { src: BASE_URL + 'elephants-dream/artwork-96.png',  sizes: '96x96',   type: 'image/png' },
        { src: BASE_URL + 'elephants-dream/artwork-128.png', sizes: '128x128', type: 'image/png' },
        { src: BASE_URL + 'elephants-dream/artwork-192.png', sizes: '192x192', type: 'image/png' },
        { src: BASE_URL + 'elephants-dream/artwork-256.png', sizes: '256x256', type: 'image/png' },
        { src: BASE_URL + 'elephants-dream/artwork-384.png', sizes: '384x384', type: 'image/png' },
        { src: BASE_URL + 'elephants-dream/artwork-512.png', sizes: '512x512', type: 'image/png' },
      ]
    }, {
      src: BASE_URL + 'caminandes/original-score.mp3',
      title: 'Original Score',
      artist: 'Jan Morgenstern',
      album: 'Caminandes 2: Gran Dillama',
      artwork: [
        { src: BASE_URL + 'caminandes/artwork-96.png',  sizes: '96x96',   type: 'image/png' },
        { src: BASE_URL + 'caminandes/artwork-128.png', sizes: '128x128', type: 'image/png' },
        { src: BASE_URL + 'caminandes/artwork-192.png', sizes: '192x192', type: 'image/png' },
        { src: BASE_URL + 'caminandes/artwork-256.png', sizes: '256x256', type: 'image/png' },
        { src: BASE_URL + 'caminandes/artwork-384.png', sizes: '384x384', type: 'image/png' },
        { src: BASE_URL + 'caminandes/artwork-512.png', sizes: '512x512', type: 'image/png' },
      ]
    }];
}