==== HEVC_subregion_descriptor

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

[source,xml]
----
<HEVC_subregion_descriptor
    SubstreamIDsPerLine="uint7, required"
    TotalSubstreamIDs="uint8, required"
    LevelFullPanorama="uint8, required">

  <SubregionLayout
      PreambleSubstreamID="uint7, optional"
      Level="uint8, required"
      PictureSizeHor="uint16, required"
      PictureSizeVer="uint16, required">

    <Pattern>
      <Substream offset="int8, required"/>
    </Pattern>

  </SubregionLayout>

</HEVC_subregion_descriptor>
----
