MP4GetSampleSync - Get the state of the sample sync flag
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 state of the sync flag, either true (1) or false (0).
Upon an error, -1.
MP4GetSampleSync returns the state of the sync/random access flag of
the specified sample from the specified track.