iphone – AVPlayerItem replaceCurrentItemWithPlayerItem Blocking

关于应用程序的第@L_944_0@上下文…
  – 有很多UI操作涉及视频播放器(主要是滚动)
  – 视频是动态的，根据我们当前的页面进行更改。
  – 所以视频必须是动态的，不断变化，UI也需要响应

我最初使用的是MPMoviePlayerController，但是由于某些要求我不得不回到AVPlayer上
我为AVPlayer制作了自己的包装。
要更改videoPlayer中的内容，这是AVPlayer-wrapper类中的方法

/**We need to change the whole playerItem each time we wish to change a video url */
-(void)initializePlayerWithUrl:(NSURL *)url
{
    AVPlayerItem *tempItem = [AVPlayerItem playerItemWithURL:url];

    [tempItem addObserver:self forKeyPath:@"status"
                  options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew
                  context:nil];
    [tempItem addObserver:self forKeyPath:@"playBACkBufferEmpty"
                  options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew
                  context:nil];

    //Not sure if this should be stopped or paused under the ideal circumstances
    //these will be changed to custom enums later
    [self setPlayBACkState:MPMoviePlayBACkStateStopped];
    [self setLoadState:MPMovieLoadStateUnkNown];
    [self.videoPlayer replaceCurrentItemWithPlayerItem:tempItem];

    //This is required only if we wish to pause the video immediately as we change the url
    //[self.videoPlayer pause];
}

现在的一切都很正常……除了..

[self.videoPlayer replaceCurrentItemWithPlayerItem:tempItem];

似乎阻止UI几分之一秒，在滚动这些使UI真的没有反应和丑陋的这个操作不能在后台执行

这有什么修复或解决方法吗？

AVAsset *asset = [AVAsset assetWithURL:self.mediaURL];
[asset loadValuesAsynchronouslyForKeys:@[@"duration"] completionHandler:^{
    AVPlayerItem *newItem = [[AVPlayerItem alloc] initWithAsset:asset];
    [self.avPlayer replaceCurrentItemWithPlayerItem:newItem];
}];