交互式流行手势时AVPlayer视频冻结

Question

我写了AVPlayer的示例代码用于视频播放。根据Apple docs最初的视频播放器：

- (AVPlayer *)player {
    if (!_player) {
        AVURLAsset *asset = [AVURLAsset URLAssetWithURL:[NSURL URLWithString:kVideoURL] options:nil];
        AVPlayerItem *playerItem = [[AVPlayerItem alloc] initWithAsset:asset];
        [playerItem addObserver:self forKeyPath:@"status" options:NSKeyValueObservingOptionNew context:nil];
        [playerItem addObserver:self forKeyPath:@"loadedTimeRanges" options:NSKeyValueObservingOptionNew context:nil];
        _player = [[AVPlayer alloc] initWithPlayerItem:playerItem];
    }
    return _player;
}

问题： 当我试图通过交互式手势弹出viewController时，视频帧甚至在某个时候停滞不前。 Here is the snapshot

有人可以帮助我吗？非常感谢!!!