DrKLO/Telegram · error · IllegalStateException

Unexpected audio encoding: {encoding}

Error message

Unexpected audio encoding: {encoding}

What it means

DefaultAudioSink.getMediaDurationUsForPresenterTimeUs (the per-encoding switch over `encoding`) throws IllegalStateException('Unexpected audio encoding') when the encoding is not one of the handled compressed encodings (e.g. AC3/E-AC3/AC4/DTS/DTS_HD/TrueHD/Opus) nor the explicitly-listed PCM/INVALID/NO_VALUE cases that fall to default. It indicates the sink reached this code path with an encoding the duration calculation does not cover.

Source

Thrown at TMessagesProj/src/main/java/com/google/android/exoplayer2/audio/DefaultAudioSink.java:1797

      case C.ENCODING_DOLBY_TRUEHD:
        int syncframeOffset = Ac3Util.findTrueHdSyncframeOffset(buffer);
        return syncframeOffset == C.INDEX_UNSET
            ? 0
            : (Ac3Util.parseTrueHdSyncframeAudioSampleCount(buffer, syncframeOffset)
                * Ac3Util.TRUEHD_RECHUNK_SAMPLE_COUNT);
      case C.ENCODING_OPUS:
        return OpusUtil.parsePacketAudioSampleCount(buffer);
      case C.ENCODING_PCM_16BIT:
      case C.ENCODING_PCM_16BIT_BIG_ENDIAN:
      case C.ENCODING_PCM_24BIT:
      case C.ENCODING_PCM_32BIT:
      case C.ENCODING_PCM_8BIT:
      case C.ENCODING_PCM_FLOAT:
      case C.ENCODING_AAC_ER_BSAC:
      case C.ENCODING_INVALID:
      case Format.NO_VALUE:
      default:
        throw new IllegalStateException("Unexpected audio encoding: " + encoding);
    }
  }

  @RequiresApi(21)
  private static int writeNonBlockingV21(AudioTrack audioTrack, ByteBuffer buffer, int size) {
    return audioTrack.write(buffer, size, AudioTrack.WRITE_NON_BLOCKING);
  }

  @RequiresApi(21)
  private int writeNonBlockingWithAvSyncV21(
      AudioTrack audioTrack, ByteBuffer buffer, int size, long presentationTimeUs) {
    if (Util.SDK_INT >= 26) {
      // The underlying platform AudioTrack writes AV sync headers directly.
      return audioTrack.write(
          buffer, size, AudioTrack.WRITE_NON_BLOCKING, presentationTimeUs * 1000);
    }
    if (avSyncHeader == null) {
      avSyncHeader = ByteBuffer.allocate(16);

View on GitHub (pinned to 45ab8f4308)

Solutions

  1. Ensure the encoding reaching this path is one enumerated in the switch (extend the switch if you added a new supported encoding).
  2. Avoid requesting presenter-time media duration for unsupported encodings; guard callers before invoking the helper.
  3. Upgrade ExoPlayer — newer versions add cases for encodings missing in older releases.

Example fix

// before
switch (encoding) { /* no case for ENCODING_DOLBY_TRUEHD -> default throws */ }

// after
switch (encoding) {
  case C.ENCODING_DOLBY_TRUEHD:
    return Ac3Util.parseTrueHdSyncframeAudioSampleCount(buffer);
  // ...
}
Defensive patterns

Strategy: validation

Validate before calling

// n/a: internal switch; callers should avoid unsupported encodings reaching this path
// ensure outputEncoding is a value enumerated in getMediaDurationUsForPresenterTimeUs

Try / catch

// not generally catchable — IllegalStateException signals a library bug or unsupported encoding;
// upgrade ExoPlayer or restrict the encodings you feed the sink.

Prevention

When it happens

Trigger: Computing media duration for a presenter time when outputEncoding is a compressed or PCM encoding not enumerated in the switch (or an unrecognized int), so control hits the default branch.

Common situations: Adding support for a new encoding without extending the switch; passing a passthrough encoding the helper never expected; an internal state where outputEncoding was left as an unmapped value.

Related errors

AI-assisted analysis of DrKLO/Telegram@45ab8f4308 (2026-08-14). Data as JSON: /api/errors/c17321edb91dac77. Report an issue: GitHub.