DrKLO/Telegram · warning · UnhandledAudioFormatException

Unhandled format: {inputAudioFormat}

Error message

Unhandled format: {inputAudioFormat}

What it means

FloatResamplingAudioProcessor.onConfigure throws UnhandledAudioFormatException when the input encoding is not 'high resolution PCM' (Util.isEncodingHighResolutionPcm returns false). This processor specifically converts higher-than-16-bit integer PCM (24-bit, 32-bit int) to 32-bit float; it does not handle 8-bit, 16-bit, float, or compressed encodings. 16-bit and float inputs are not 'high resolution' and are rejected so the pipeline can route them elsewhere (16-bit needs no resampling; float is already float).

Source

Thrown at TMessagesProj/src/main/java/com/google/android/exoplayer2/audio/FloatResamplingAudioProcessor.java:45

 *
 * <ul>
 *   <li>{@link C#ENCODING_PCM_24BIT}
 *   <li>{@link C#ENCODING_PCM_32BIT}
 *   <li>{@link C#ENCODING_PCM_FLOAT} ({@link #isActive()} will return {@code false})
 * </ul>
 */
/* package */ final class FloatResamplingAudioProcessor extends BaseAudioProcessor {

  private static final int FLOAT_NAN_AS_INT = Float.floatToIntBits(Float.NaN);
  private static final double PCM_32_BIT_INT_TO_PCM_32_BIT_FLOAT_FACTOR = 1.0 / 0x7FFFFFFF;

  @Override
  @CanIgnoreReturnValue
  public AudioFormat onConfigure(AudioFormat inputAudioFormat)
      throws UnhandledAudioFormatException {
    @C.PcmEncoding int encoding = inputAudioFormat.encoding;
    if (!Util.isEncodingHighResolutionPcm(encoding)) {
      throw new UnhandledAudioFormatException(inputAudioFormat);
    }
    return encoding != C.ENCODING_PCM_FLOAT
        ? new AudioFormat(
            inputAudioFormat.sampleRate, inputAudioFormat.channelCount, C.ENCODING_PCM_FLOAT)
        : AudioFormat.NOT_SET;
  }

  @Override
  public void queueInput(ByteBuffer inputBuffer) {
    int position = inputBuffer.position();
    int limit = inputBuffer.limit();
    int size = limit - position;

    ByteBuffer buffer;
    switch (inputAudioFormat.encoding) {
      case C.ENCODING_PCM_24BIT:
        buffer = replaceOutputBuffer((size / 3) * 4);
        for (int i = position; i < limit; i += 3) {

View on GitHub (pinned to 45ab8f4308)

Solutions

1. Only insert FloatResamplingAudioProcessor in the chain when the source encoding is ENCODING_PCM_24BIT or ENCODING_PCM_32BIT (high-resolution integer PCM).
2. For sources that may be mixed, guard insertion: if inputAudioFormat is hi-res PCM include it, otherwise omit it.
3. Configure the audio sink (DefaultAudioSink) to negotiate the right chain; the sink will skip processors whose onConfigure throws UnhandledAudioFormatException if they report NOT_SET appropriately — ensure the processor is only active for hi-res.

Example fix

// before: always added
List<AudioProcessor> chain = List.of(floatResamplingProcessor); // throws on 16-bit input
// after: conditionally include
List<AudioProcessor> chain = new ArrayList<>();
if (Util.isEncodingHighResolutionPcm(inputAudioFormat.encoding)
    && inputAudioFormat.encoding != C.ENCODING_PCM_FLOAT) {
  chain.add(floatResamplingProcessor);
}

@C.Encoding int enc = inputAudioFormat.encoding;
boolean needsFloatResample = Util.isEncodingHighResolutionPcm(enc)
    && enc != C.ENCODING_PCM_FLOAT;
// only add FloatResamplingAudioProcessor when needsFloatResample is true

When it happens

Trigger: Feeding 16-bit PCM, 8-bit PCM, or already-float PCM into FloatResamplingAudioProcessor; a pipeline that always inserts this processor regardless of source encoding; a format change mid-playback dropping below the hi-res threshold.

Common situations: Default audio chain that includes float resampling but plays a standard 16-bit track; toggling output to float on a stereo 16-bit source; source switch from 24-bit FLAC to 16-bit MP3 without disabling the resampler.

Related errors

• Unhandled format: {inputAudioFormat}
• Unhandled format: {inputAudioFormat}
• Unhandled format: {inputAudioFormat}
• Unhandled format: {inputAudioFormat}
• Invalid output encoding (mode={outputMode}) for: {inputForma

AI-assisted analysis of DrKLO/Telegram@45ab8f4308 (2026-08-14). Data as JSON: /api/errors/b618431737e180ba. Report an issue: GitHub.