MP4GetSampleDuration - Get the duration of a track sample
hFile Specifies the mp4 file to which the operation applies.
Specifies the track to which the operation applies.
Specifies the sample to which the operation applies. Caveat: the
first sample has id 1 not 0.
Upon success, the sample duration in track time scale units. Upon an
MP4GetSampleDuration returns the duration of the specified sample from
the specified track in the track time scale units. See
MP4ConvertFromTrackDuration() for how to map this value to another time