The time range of the track within the overall timeline of the asset.
- iOS 4.0+
- macOS 10.7+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 6.0+
If the time range’s start is greater than
zero, the track does not initially have media data to present when its asset is presented. One case in which this may occur is when an audio track is delayed in order to align the start of audio with a specific video frame. You can test for this as follows: