Begins loading media data to prime the media pipelines for playback.
- iOS 6.0+
- macOS 10.8+
- tvOS 9.0+
The playback rate to use when determining how much data to load.
A block to execute when the player finishes the load attempt. This block takes a single Boolean parameter that contains
trueif the data was loaded or
falseif there was a problem. For example, the value might be
falseif the preroll was interrupted by a time change or incompatible rate change.
This method loads data starting at the item’s current playback time. The current rate for the playback item should always be 0 prior to calling this method. After the method calls the completion handler, you can change the item’s playback rate to begin playback.