Presentation time minus decode time, in the track's timescale (0 when the run writes no offsets).
Its bytes, a view into the piece; null when the piece does not hold them (a moof without its mdat).
When it is decoded, in its track's timescale: the fragment's tfdt plus the durations of the samples before it.
Its duration, in the track's timescale.
Whether it is a sync sample (a key frame): its flags do not mark it as a non-sync sample.
Its size, in bytes.
The track the sample belongs to.
One sample of a media fragment.