Additional track information

The OTVTrackInfo class contains additional information about the subtitle track, which can be attained through the class’s methods. Typically, that extra information is extracted from the stream’s manifest/playlist, so the availability of the information is dependent on the streams:

isActive() will return true for the selected track, and false for all other subtitle tracks in the list
getName() provides a string describing the track (which may be simply the language)
getLanguage() provides the language code string in either way of ISO-639-1 or ISO-639-2
getEncodeType() returns an integer representing the subtitles’ encoding (see the reference API of OTVTrackInfo for the various values)
getCharacteristics() will return a string of track characteristics as advertised in some HLS streams.
getVideoTrackInfos() will return null for subtitle tracks
getMimeType() will return the MIME type for the track
getAudioChannelCount() will return -1 for subtitle tracks

Click here to view the example code.

JAVA

  OTVTrackInfo[] tracks = mPlayer.getOTVTrackInfo();
  int selectedTrackIndex = -1;
  for (int index = 0; index < tracks.size(); ++index) {
    OTVTrackInfo trackInfo = tracks.valueAt(index);
    if (trackInfo.getType() == OTVTrackInfo.MEDIA_TRACK_TYPE_TIMEDTEXT) {
      // Subtitles track
      if (trackInfo.isActive()) {
        selectedTrackIndex = index;
      }
      StringBuilder trackNameBuilder = track.getName().equals("") ?
          String.format(Locale.ENGLISH,"Track %d",index + 1) :
          track.getName();
      trackNameBuilder.append(" <" + trackInfo.getLanguage() + ">");
      String characteristics = track.getCharacteristics().toLowerCase();
      if (!characteristics.isEmpty()) {
        String[] characteristicsArray = characteristics.split(",");
        for (String chrs : characteristicsArray) {
          if (chrs.equalsIgnoreCase("public.accessibility.transcribes-spoken-dialog") ||
              chrs.equalsIgnoreCase("public.accessibility.describes-music-and-sound") ||
              chrs.equalsIgnoreCase("public.easy-to-read")) {
              trackNameBuilder.append(" (Hard of Hearing)");
              break;
          }
        }
      }
      String encodingType;
      int et = track.getEncodeType();
      switch (et) {
      case OTVTrackInfo.SUBTITLE_TRACK_ENCODING_TYPE_DVB_BITMAP:
        trackNameBuilder.append(" [DVB bitmap]");
        break;
      case OTVTrackInfo.SUBTITLE_TRACK_ENCODING_TYPE_EIA_608:
        trackNameBuilder.append(" [CC608]");
        break;
      case OTVTrackInfo.SUBTITLE_TRACK_ENCODING_TYPE_EIA_708:
        trackNameBuilder.append(" [CC708]");
        break;
      case OTVTrackInfo.SUBTITLE_TRACK_ENCODING_TYPE_ID3:
        trackNameBuilder.append(" [ID3]");
        break;
      case OTVTrackInfo.SUBTITLE_TRACK_ENCODING_TYPE_WEBVTT:
        trackNameBuilder.append(" [WebVTT]");
        break;
      case OTVTrackInfo.SUBTITLE_TRACK_ENCODING_TYPE_SRT:
        trackNameBuilder.append(" [SRT]");
        break;
      case OTVTrackInfo.SUBTITLE_TRACK_ENCODING_TYPE_SMPTE:
        trackNameBuilder.append(" [SMPTE]");
        break;
      default:
        break;
      }
      String trackName = trackNameBuilder.toString();
      ...
    }
  }