Within the Track Fragment Box, there are zero or more Track Run Boxes. If the
duration-is-empty flag is set in the track fragment box, there are no track
runs. A track run documents a contiguous set of samples for a track.
If the data-offset is not present, then the data for this run starts
immediately after the data of the previous run, or at the base-data-offset
defined by the track fragment header if this is the first run in a track
If the data-offset is present, it is relative to the base-data-offset
established in the track fragment header.
Fields inherited from class net.sourceforge.jaad.mp4.boxes.FullBox