Playing videos in AVPlayer - ios

Question

My app currently plays 2 videos at the same time, functionally, but I all the SO answers i've seen utilizes lots of Key-Value code. Is it bad/wrong if I just do the bare minimum listed below?
viewdidload
AVURLAsset *asset = [AVURLAsset assetWithURL:[NSURL URLWithString:firstVideo.videoURL]];
AVPlayerItem *item = [AVPlayerItem playerItemWithAsset:asset];
self.player1 = [AVPlayer playerWithPlayerItem:item];
[topPlayer setMovieToPlayer:self.player1];
AVURLAsset *asset2 = [AVURLAsset assetWithURL:[NSURL URLWithString:secondVideo.videoURL]];
AVPlayerItem *item2 = [AVPlayerItem playerItemWithAsset:asset2];
self.player2 = [AVPlayer playerWithPlayerItem:item2];
[bottomPlayer setMovieToPlayer:self.player2];
((AVPlayerLayer *)[self.topPlayer layer]).videoGravity = AVLayerVideoGravityResizeAspectFill;
((AVPlayerLayer *)[self.bottomPlayer layer]).videoGravity = AVLayerVideoGravityResizeAspectFill;
[self.player1 play];
[self.player2 play];
The above code is all I use to play a video, and it works fine. Occasionally there is a ~1s delay, how can I wait until both the videos are ready to play, then play them both?

Answer 1

use KVO to observer the player's status, and play videos when both's status is ready.
[yourPlayerItem addObserver:self forKeyPath:#"status" options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew context:nil];
and in kvo:
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
if ([keyPath isEqualToString:#"status"]) {
AVPlayerStatus status = [change[NSKeyValueChangeNewKey] integerValue];
switch (status) {
case AVPlayerStatusUnknown:
//do something
break;
case AVPlayerStatusReadyToPlay:
{
//check which avplayer is ready, by check the parametric object isEqual:yourPlayerItem
//use a bool value to record the ready status. after two bools are YES, then play the video
}
break;
case AVPlayerStatusFailed:
{
AVPlayerItem *playerItem = (AVPlayerItem *)object;
[self assetFailedToPrepareForPlayback:playerItem.error];
}
break;
}
}
}