audioStsd_(streamInfo) {
    const channelsCount = streamInfo.stream.channelsCount || 2;
    const audioSamplingRate = streamInfo.stream.audioSamplingRate || 44100;
    const bytes = new Uint8Array([
      0x00, 0x00, 0x00, // reserved
      0x00, 0x00, 0x00, // reserved
      0x00, 0x01, // data_reference_index
      0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, // reserved
      0x00,
      channelsCount, // channel count
      0x00, 0x10, // sampleSize:16bits
      0x00, 0x00, 0x00, 0x00, // reserved2
      ...this.breakNumberIntoBytes_(audioSamplingRate, 2), // Sample Rate
      0x00, 0x00,
    ]);
    return bytes;
  }
Generate STSD bytes

@param {shaka.util.Mp4Generator.StreamInfo} streamInfo
@return {!Uint8Array}
@private