ios - 使用 AVPlayer 处理流事件

Question

我正在构建一个播放音频流（来自网络广播）的应用程序。

我正在使用AVPlayer它。

1. 我想知道AVPlayer's当连接速度很慢或用户刚刚单击“播放”时，您将如何处理“缓冲”。我想检测到AVPlayer“缓冲”以显示UIActivityIndicatorView.

2. 在后台运行时出现同样的问题。这种情况下缓冲怎么办？

Answer 1

对于第一个问题

你可以参考我对这个话题的回答ios avplayer trigger streaming is out of buffer

对于第二个

以下是我如何解决同样的问题：

在处理缓冲区空事件的地方添加以下代码：

    if (object == playerItem && [keyPath isEqualToString:@"playbackBufferEmpty"])
    {
        if (playerItem.playbackBufferEmpty) {
            [[NSNotificationCenter defaultCenter] postNotificationName:@"message" object:@"Buffering..."];
            
            if([[UIApplication sharedApplication] applicationState] == UIApplicationStateBackground)
            {
                task = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^(void) {
                }];
            }
        }
    }

现在，在缓冲区准备好再次运行后，您将不得不停止此后台任务：

if (object == playerItem && [keyPath isEqualToString:@"playbackLikelyToKeepUp"])
{
    if (playerItem.playbackLikelyToKeepUp)
    {
        [player play];
        
        if([[UIApplication sharedApplication] applicationState] == UIApplicationStateBackground)
        {
            [[UIApplication sharedApplication] endBackgroundTask:task];
            task = 0;
        }
    }
}

ps：任务在我的 .h 文件中声明为UIBackgroundTaskIdentifier task;

Answer 2

我已经找到了解决这个问题的方法。

if (self.avPlayer.currentItem.playbackLikelyToKeepUp == NO) 
{
    // Show activity indicator
}

Answer 3

对于斯威夫特 3

这对我来说很好，也许它可以帮助，self?.bufferState()在里面打电话addPeriodicTimeObserver

    private func bufferState() {
    if let currentItem = self.avPlayer.currentItem {
        if currentItem.status == AVPlayerItemStatus.readyToPlay {
            if currentItem.isPlaybackLikelyToKeepUp {
                print("Playing ")
            } else if currentItem.isPlaybackBufferEmpty {
                print("Buffer empty - show loader")
            }  else if currentItem.isPlaybackBufferFull {
                print("Buffer full - hide loader")
            } else {
                print("Buffering ")
            }
        } else if currentItem.status == AVPlayerItemStatus.failed {
            print("Failed ")
        } else if currentItem.status == AVPlayerItemStatus.unknown {
            print("Unknown ")
        }
    } else {
        print("avPlayer.currentItem is nil")
    }
}

Answer 4

试试这个：

AVPlayerItem* mPlayerItem;

---

if(context == AVPlayerDemoPlaybackViewControllerCurrentItemBufferEmptyContext) 
{
    if (object == self.mPlayerItem && [path isEqualToString:@"playbackBufferEmpty"]) 
    {
        if (self.mPlayerItem.playbackBufferEmpty)
        {
            playBufferEmpty = TRUE;
            [indicator startAnimating];
            [vidStreaminglabel setText:@"Buffering..."];
            [vidStreaminglabel setHidden:NO];
        }
    }
}

else if(context == AVPlayerDemoPlaybackViewControllerCurrentItemPlayBackBufferFullContext)
{
    if (object == mPlayerItem && [path isEqualToString:@"playbackBufferFull"]){
        if (self.mPlayerItem.playbackBufferFull) {
            [mPlayer play];
        }
    }
}

else if (context == AVPlayerDemoPlaybackViewControllerCurrentItemPlayBackLikelyToKeepUpContext)
{
    if (object == mPlayerItem && [path isEqualToString:@"playbackLikelyToKeepUp"])
    {
         if(self.mPlayerItem.playbackLikelyToKeepUp)
         {
             // Autoplay after buffer 
             if(!(mRestoreAfterScrubbingRate != 0.f || [self.mPlayer rate] != 0.f))
             {
                 if (self.presentingViewController) {
                     [mPlayer play];
                 }

                 playBufferEmpty = FALSE;
                 [indicator stopAnimating];
                 [vidStreaminglabel setHidden:YES];
             }
        }
    }
}