An object used to modify the presentation state of an asset track being presented by a player.
- iOS 4.0+
- macOS 10.7+
- tvOS 9.0+
This class is intended to represent the presentation state for a track of an asset that's played by an AVPlayer and AVPlayerItem. To ensure safe access to nonatomic properties while dynamic changes in playback state may be reported, clients must serialize their access with the associated
AVPlayer notification queue. Serialization is naturally achieved by invoking the
AVPlayer methods on the main thread or queue.