Android playerAdvanced features

Switch subtitle tracks

Learn how to discover, switch, and disable subtitle tracks in the FastPix Android Player.

SubtitleTrack properties

Each SubtitleTrack includes:

  • id — pass to setSubtitleTrack(id) to switch tracks.
  • languageCode / languageName / label — display in your subtitle menu.
  • isSelected, isPlayable, isDefault, isForced — for UI state.
  • Optional: role, codec, groupId.

Listen for subtitle track updates

1import io.fastpix.media3.tracks.SubtitleTrackListener
2
3player.addSubtitleTrackListener(object : SubtitleTrackListener {
4    override fun onSubtitlesLoaded(tracks: List<SubtitleTrack>) {
5        // Populate subtitle selection UI
6    }
7    override fun onSubtitleChange(track: SubtitleTrack?) {
8        // track == null means subtitles are disabled
9    }
10    override fun onSubtitlesLoadedFailed(error: SubtitleTrackError) {
11        // Track not found, not playable, player not ready, etc.
12    }
13    override fun onSubtitleCueChange(info: SubtitleRenderInfo) {
14        // Optional: observe cues (text + timing) if building a custom subtitle renderer
15    }
16})

Switch subtitle track by ID

1val subs = player.getSubtitleTracks()
2val target = subs.firstOrNull()
3if (target != null) {
4    player.setSubtitleTrack(target.id)
5}

Disable subtitles

1player.disableSubtitles()

Set a default subtitle language

Set a preferred subtitle language that applies automatically when tracks become available. This never overrides a manual selection:

1player.setDefaultSubtitleTrack(languageName = "Spanish")

Use BCP-47 / ISO language names like "English", "Spanish", "Hindi". If the preferred language doesn’t exist in the stream, the player keeps its normal selection.