==== NPT_reference_descriptor

Defined by MPEG in <<ISO-13818-6>>.

[source,xml]
----
<NPT_reference_descriptor
    post_discontinuity="bool, default=false"
    content_id="uint7, default=0x7F"
    STC_reference="uint33, required"
    NPT_reference="uint33, required"
    scale_numerator="uint16, required"
    scale_denominator="uint16, required"/>
----
