step(byPresentationTime:wasPinned:)
Moves the cursor by a given delta time on the presentation timeline.
Declaration
func step(byPresentationTime deltaPresentationTime: CMTime, wasPinned outWasPinned: UnsafeMutablePointer<ObjCBool>?) -> CMTimeParameters
- deltaPresentationTime:
The amount of time to move in the presentation timeline.
- outWasPinned:
The system sets the value of this pointer to True if the cursor reaches the beginning or the end of the sample sequence before it reaches the requested time. You may specify
nilif you’re not interested in this information.
Return Value
The amount of time the cursor was moved along the presentation timeline. Because sample cursors snap to sample boundaries when stepped, this value may not be equal to the specified time delta even if the cursor was not pinned.