A half-open range of media time, [start, endExclusive).
[start, endExclusive)
Half-open so ranges concatenate without sharing a frame: the clip ending at ten seconds and the clip starting at ten seconds overlap on no sample.
How long the range covers, or null while the end is open and the source has not been probed.
Where the range ends, or null to run to the end of the source.
Where the range starts.
Tests a media time against the range.