Reads the samples of a media fragment: every moof in the piece, every track fragment in it, every sample of every
track run, with decode times from tfdt and the init's trex defaults where a fragment names none. null when the
piece holds no moof, a box's size runs past what holds it, a track fragment lacks its tfhd or tfdt, a track run
runs past its box, or a sample has no size anywhere. A track fragment that sets an explicit base data offset (an
offset into a whole file, not a piece) also reads as null.
Reads the samples of a media fragment: every
moofin the piece, every track fragment in it, every sample of every track run, with decode times fromtfdtand the init'strexdefaults where a fragment names none.nullwhen the piece holds nomoof, a box's size runs past what holds it, a track fragment lacks itstfhdortfdt, a track run runs past its box, or a sample has no size anywhere. A track fragment that sets an explicit base data offset (an offset into a whole file, not a piece) also reads asnull.