AVPlayerItemOutputPushDelegate protocol defines common delegate methods for objects participating in
AVPlayerItemOutput push sample output acquisition.
Invoked when the output is commencing a new sequence of media data.
optional func outputSequenceWasFlushed(_
- (void)outputSequenceWasFlushed:(AVPlayerItemOutput * _Nonnull)
This method is invoked after any seeking and change in playback direction. If you are maintaining any queued future media data, you may want to discard those objects after receiving this message.
Available in iOS 7.0 and later.