The data reference object contains a table of data references (normally URLs)
that declare the location(s) of the media data used within the presentation.
The data reference index in the sample description ties entries in this table
to the samples in the track. A track may be split over several sources in
The data entry is either a DataEntryUrnBox or a DataEntryUrlBox.
Fields inherited from class net.sourceforge.jaad.mp4.boxes.FullBox