sourceTrackIDForFrameTiming
An identifier of the source track from which the video composition derives frame timing.
Declaration
var sourceTrackIDForFrameTiming: CMPersistentTrackID { get set }Discussion
If an empty edit is encountered in the source asset’s track, the compositor composes frames as needed up to the frequency specified in frameDuration property. Otherwise the frame timing for the video composition is derived from the source asset’s track with the corresponding ID.