==== AC3_audio_stream_descriptor

Defined by ATSC in <<ATSC-A52>>.

This is the ATSC version of the AC-3 descriptor.
DVB uses a distinct descriptor.
In <<ATSC-A52>>, the so-called "System A" designates ATSC while "System B" designates DVB.

[source,xml]
----
<ATSC_AC3_audio_stream_descriptor
    sample_rate_code="uint3, required"
    bsid="uint5, required"
    bit_rate_code="uint6, required"
    surround_mode="uint2, required"
    bsmod="uint3, required"
    num_channels="uint4, required"
    full_svc="bool, required"
    mainid="uint3, optional"
    priority="uint2, optional"
    asvcflags="uint8, optional"
    text="string, optional"
    language="char3, optional"
    language_2="char3, optional">

  <additional_info>
    Hexadecimal content
  </additional_info>

</ATSC_AC3_audio_stream_descriptor>
----
