SoundFontSampleData.fromReader constructor

SoundFontSampleData.fromReader(BinaryReader reader)

Implementation

factory SoundFontSampleData.fromReader(BinaryReader reader) {
  String chunkId = reader.readFourCC();

  if (chunkId != "LIST") {
    throw "The LIST chunk was not found.";
  }

  int end = reader.readInt32();
  end += reader.pos;

  String listType = reader.readFourCC();

  if (listType != "sdta") {
    throw "The type of the LIST chunk must be 'sdta', but was '$listType'.";
  }

  int? bitsPerSample;
  ArrayInt16? samples;

  while (reader.pos < end) {
    String id = reader.readFourCC();
    int size = reader.readInt32();

    switch (id) {
      case "smpl":
        if (samples != null) {
          throw "found more than one smpl chunk";
        }

        bitsPerSample = 16;
        samples = ArrayInt16.fromReader(reader, size ~/ 2);

        break;

      case "sm24":
        // 24 bit audio is not supported.
        reader.skip(size);
        break;

      default:
        throw "The INFO list contains an unknown ID '$id'.";
    }
  }

  if (samples == null || bitsPerSample == null) {
    throw "No valid sample data was found.";
  }

  return SoundFontSampleData(bitsPerSample: bitsPerSample, samples: samples);
}