在AVPlayer中播放与坏互联网的流

Question

当AVPlayer播放来自网络流的资源时,它会在到达下载内容的末尾时暂停.

所以,我的问题是,如何知道它因网络不良而停止了？如何在下载之后播放它,比方说,下一个10秒的资产？

Answer 1

您可以在AVPlayer获取空缓冲区时添加观察者:

[[self.tracksPlayer currentItem] addObserver:self 
                                  forKeyPath:@"playbackBufferEmpty" 
                                     options:NSKeyValueObservingOptionNew
                                     context:nil];

还有一个观察者,这样你就可以知道AVPlayer何时缓冲到足以跟上:

[[self.tracksPlayer currentItem] addObserver:self 
                                  forKeyPath:@"playbackLikelyToKeepUp" 
                                     options:NSKeyValueObservingOptionNew 
                                     context:nil];

然后在KVO回调中检查一下:

- (void)observeValueForKeyPath:(NSString *)keyPath 
                      ofObject:(id)object 
                        change:(NSDictionary *)change 
                       context:(void *)context {

   if (object == [self.tracksPlayer currentItem] && 
      [keyPath isEqualToString:@"playbackBufferEmpty"]) {

      if ([self.tracksPlayer currentItem].playbackBufferEmpty) {
          NSLog(@"Buffer Empty"); 
      }
   } else if (object == [self.tracksPlayer currentItem] && 
             [keyPath isEqualToString:@"playbackLikelyToKeepUp"]) {

      if ([self.tracksPlayer currentItem].playbackLikelyToKeepUp) {
          NSLog(@"LikelyToKeepUp");
      }
   }
}