glintEncodeOpus function

Uint8List glintEncodeOpus(Float32List pcm, int channels, { int bitrate = 96000, bool vbr = false, })

Encode interleaved 48 kHz float PCM (±1.0, channels = 1 or 2) to a complete Ogg-Opus file (CELT-only, 20 ms frames). vbr selects unconstrained VBR. Input MUST be 48 kHz — resample first with glintResample. Returns the .opus file bytes.

Implementation

Uint8List glintEncodeOpus(Float32List pcm, int channels,
    {int bitrate = 96000, bool vbr = false}) {
  if (channels < 1 || channels > 2 || pcm.isEmpty) {
    throw StateError('opus encode: bad channels/empty input');
  }
  final lib = _loadLibrary();
  final fn = lib.lookupFunction<_OpusEncFileNative, _OpusEncFile>(
      'glint_opus_encode_file');
  final free = lib.lookupFunction<_FreeNative, _Free>('glint_free');
  final inPtr = calloc<Float>(pcm.length);
  inPtr.asTypedList(pcm.length).setAll(0, pcm);
  final outSize = calloc<Int32>();
  try {
    final frames = pcm.length ~/ channels;
    final ptr = fn(inPtr, frames, channels, bitrate, vbr ? 1 : 0, outSize);
    if (ptr == nullptr || outSize.value <= 0) {
      throw StateError('opus encode failed');
    }
    final out = Uint8List.fromList(ptr.asTypedList(outSize.value));
    free(ptr.cast<Void>());
    return out;
  } finally {
    calloc.free(inPtr);
    calloc.free(outSize);
  }
}