==== MPEGH_3D_audio_drc_loudness_descriptor

Defined by MPEG in <<ISO-13818-1>>.

[source,xml]
----
<MPEGH_3D_audio_drc_loudness_descriptor>

  <!-- Any number of drcInstructionsUniDrc -->
  <drcInstructionsUniDrc
      drcInstructionsType="uint2, required"
      mae_groupID="uint7, required when drcInstructionsType == 2"
      mae_groupPresetID="uint5, required when drcInstructionsType == 3"
      drcSetId="uint6, required"
      downmixId="uint7, required"
      drcSetEffect="uint16, required"
      bsLimiterPeakTarget="uint8, optional"
      bsDrcSetTargetLoudnessValueUpper="uint6, optional (required when bsDrcSetTargetLoudnessValueLower is set)"
      bsDrcSetTargetLoudnessValueLower="uint6, optional"
      dependsOnDrcSet="uint6, required"
      noIndependentUse="bool, required when dependsOnDrcSet == 0">

    <!-- Any number of additionalDownmixId -->
    <additionalDownmixId value="uint7, required"/>

  </drcInstructionsUniDrc>

  <!-- Any number of loudnessInfo -->
  <loudnessInfo
      loudnessInfoType="uint2, required"
      mae_groupID="uint7, required when loudnessInfoType == 1 || loudnessInfoType == 2"
      mae_groupPresetID="uint5, required when loudnessInfoType == 3">

    <!-- loudnessInfo() structure as defined in ISO/IEC 23003-4 -->
    <loudnessInfo>
      Hexadecimal content
    </loudnessInfo>

  </loudnessInfo>

  <!-- Any number of downmixId -->
  <downmixId
      downmixId="uint7, required"
      downmixType="uint2, required"
      CICPspeakerLayoutIdx="uint6, required"/>

  <!-- At most one -->
  <reserved>
    Hexadecimal content
  </reserved>

</MPEGH_3D_audio_drc_loudness_descriptor>>
----
