code: public void setAudioDecoderConfiguration(IRTMPEvent decoderConfig) {
          if (decoderConfig instanceof IStreamData) {
              IoBuffer data = ((IStreamData<?>) decoderConfig).getData().asReadOnlyBuffer();
              audioConfigurationTag = ImmutableTag.build(decoderConfig.getDataType(), 0, data, 0);
          }
      }
docs: Sets a audio decoder configuration; some codecs require this, such as AAC.
  
  @param decoderConfig
  audio codec configuration