Sync Play

• select a main player, mute other players
• use Player.onSync() for other players as an external clock. can be called any time. onSync(null) to disable external clock.
• operations to change playback state: call for all players at the same time
• looping: in main player.onLoop() callback, seek other players to loop begin position set by setRange() or 0 by default
• SetGlobalOption("avsync.audio.adaptive", 1) to keep audio sync with video