media3/docs/hls.md
olly 9e615ce5f3 Update dev guide to use non-deprecated factory
#minor-release

PiperOrigin-RevId: 386966219
2021-07-27 12:27:23 +01:00

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title
HLS

{% include_relative _page_fragments/supported-formats-hls.md %}

Using MediaItem

To play an HLS stream, you need to depend on the HLS module.

implementation 'com.google.android.exoplayer:exoplayer-hls:2.X.X'

{: .language-gradle}

You can then create a MediaItem for an HLS playlist URI and pass it to the player.

// Create a player instance.
SimpleExoPlayer player = new SimpleExoPlayer.Builder(context).build();
// Set the media item to be played.
player.setMediaItem(MediaItem.fromUri(hlsUri));
// Prepare the player.
player.prepare();

{: .language-java}

If your URI doesn't end with .m3u8, you can pass MimeTypes.APPLICATION_M3U8 to setMimeType of MediaItem.Builder to explicitly indicate the type of the content.

The URI of the media item may point to either a media playlist or a master playlist. If the URI points to a master playlist that declares multiple #EXT-X-STREAM-INF tags then ExoPlayer will automatically adapt between variants, taking into account both available bandwidth and device capabilities.

Using HlsMediaSource

For more customization options, you can create a HlsMediaSource and pass it directly to the player instead of a MediaItem.

// Create a data source factory.
DataSource.Factory dataSourceFactory = new DefaultHttpDataSource.Factory();
// Create a HLS media source pointing to a playlist uri.
HlsMediaSource hlsMediaSource =
    new HlsMediaSource.Factory(dataSourceFactory)
        .createMediaSource(MediaItem.fromUri(hlsUri));
// Create a player instance.
SimpleExoPlayer player = new SimpleExoPlayer.Builder(context).build();
// Set the media source to be played.
player.setMediaSource(hlsMediaSource);
// Prepare the player.
player.prepare();

{: .language-java}

Accessing the manifest

You can retrieve the current manifest by calling Player.getCurrentManifest. For HLS you should cast the returned object to HlsManifest. The onTimelineChanged callback of Player.Listener is also called whenever the manifest is loaded. This will happen once for a on-demand content, and possibly many times for live content. The code snippet below shows how an app can do something whenever the manifest is loaded.

player.addListener(
    new Player.Listener() {
      @Override
      public void onTimelineChanged(
          Timeline timeline, @Player.TimelineChangeReason int reason) {
        Object manifest = player.getCurrentManifest();
        if (manifest != null) {
          HlsManifest hlsManifest = (HlsManifest) manifest;
          // Do something with the manifest.
        }
      }
    });

{: .language-java}

Customizing playback

ExoPlayer provides multiple ways for you to tailor playback experience to your app's needs. See the [Customization page][] for examples.

Enabling faster start-up times

You can improve HLS start up times noticeably by enabling chunkless preparation. When you enable chunkless preparation and #EXT-X-STREAM-INF tags contain the CODECS attribute, ExoPlayer will avoid downloading media segments as part of preparation. The following snippet shows how to enable chunkless preparation.

HlsMediaSource hlsMediaSource =
    new HlsMediaSource.Factory(dataSourceFactory)
        .setAllowChunklessPreparation(true)
        .createMediaSource(MediaItem.fromUri(hlsUri));

{: .language-java}

You can find more details in our [Medium post about chunkless preparation][].

Creating high quality HLS content

In order to get the most out of ExoPlayer, there are certain guidelines you can follow to improve your HLS content. Read our [Medium post about HLS playback in ExoPlayer][] for a full explanation. The main points are:

  • Use precise segment durations.
  • Use a continuous media stream; avoid changes in the media structure across segments.
  • Use the #EXT-X-INDEPENDENT-SEGMENTS tag.
  • Prefer demuxed streams, as opposed to files that include both video and audio.
  • Include all information you can in the Master Playlist.

The following guidelines apply specifically for live streams:

  • Use the #EXT-X-PROGRAM-DATE-TIME tag.
  • Use the #EXT-X-DISCONTINUITY-SEQUENCE tag.
  • Provide a long live window. One minute or more is great.

[HlsMediaSource]: {{ site.exo_sdk }}/source/hls/HlsMediaSource.html [HTTP Live Streaming]: https://tools.ietf.org/html/rfc8216 [PlayerView]: {{ site.exo_sdk }}/ui/PlayerView.html [UI components]: {{ site.baseurl }}/ui-components.html [Customization page]: {{ site.baseurl }}/customization.html [Medium post about chunkless preparation]: https://medium.com/google-exoplayer/faster-hls-preparation-f6611aa15ea6 [Medium post about HLS playback in ExoPlayer]: https://medium.com/google-exoplayer/hls-playback-in-exoplayer-a33959a47be7