==== event_group_descriptor

Defined by ARIB in <<ARIB-B10J>>.

[source,xml]
----
<event_group_descriptor group_type="uint4, required">

  <!-- One per event in actual network -->
  <actual service_id="uint16, required"
          event_id="uint16, required"/>

  <!-- One per event in other networks (group_type == 4 or 5) -->
  <other original_network_id="uint16, required"
         transport_stream_id="uint16, required"
         service_id="uint16, required"
         event_id="uint16, required"/>

  <!-- Optional private data for other group types -->
  <private_data>
    Hexadecimal content
  </private_data>

</event_group_descriptor>
----
