AVPlayer項緩衝區爲空

我使用播放流內容的AVPlayer。我想知道緩衝區爲空的時間以及準備播放的時間。但觀察者「playbackBufferEmpty」和「playbackLikelyToKeepUp」不會每次都按需要工作。他們有時工作，但往往不工作。我只在OSX 10.7.5下使用iPad模擬器iOS 6.1。這是我如何設置，並聽取了觀察員：AVPlayer項緩衝區爲空

- (void)playAudioStream:(NSURL *)audioStreamURL 
{ 
if(_audioPlayer && _audioPlayer.currentItem) 
{ 
    [_audioPlayer removeObserver:self forKeyPath:StatusKey]; 
    [_audioPlayer.currentItem removeObserver:self forKeyPath:@"playbackBufferEmpty"]; 
    [_audioPlayer.currentItem removeObserver:self forKeyPath:@"playbackLikelyToKeepUp"]; 
} 

AVPlayerItem *playerItem = [AVPlayerItem playerItemWithURL:audioStreamURL]; 

[playerItem addObserver:self forKeyPath:@"playbackBufferEmpty" options:NSKeyValueObservingOptionNew context:nil]; 
[playerItem addObserver:self forKeyPath:@"playbackLikelyToKeepUp" options:NSKeyValueObservingOptionNew context:nil]; 

_audioPlayer = [AVPlayer playerWithPlayerItem:playerItem]; 

[_audioPlayer addObserver:self forKeyPath:StatusKey options:NSKeyValueObservingOptionNew context:nil]; 

//[_audioPlayer replaceCurrentItemWithPlayerItem:playerItem]; 
//_audioPlayer.actionAtItemEnd = AVPlayerActionAtItemEndNone; 
[_audioPlayer play]; 
} 
... 

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context 
{ 
if ([keyPath isEqualToString:@"playbackBufferEmpty"]) 
{ 
    if (_audioPlayer.currentItem.playbackBufferEmpty) 
    { 
     ... 
    } 

} 

if ([keyPath isEqualToString:@"playbackLikelyToKeepUp"]) 
{ 
    if (_audioPlayer.currentItem.playbackLikelyToKeepUp) 
    { 
     ... 
    } 
} 
}

請幫我用正確的方式來獲得「緩衝空」和「緩衝區準備就緒」事件（例如，當網絡連接斷開）。謝謝！

來源

2013-07-30 Dmitry Vasiljev

添加觀察者時需要使用上下文。這裏是你的示例代碼。

初始化上下文

static void *playbackLikelyToKeepUpKVOToken = &playbackLikelyToKeepUpKVOToken; 
static void *playbackBufferEmpty = &playbackBufferEmpty; 
static void *playbackBufferFull = &playbackBufferFull;

添加觀察

[self.playerItem removeObserver:self forKeyPath:@"playbackBufferEmpty" context:playbackBufferEmpty]; 
[self.playerItem removeObserver:self forKeyPath:@"playbackLikelyToKeepUp" context:playbackLikelyToKeepUpKVOToken]; 
[self.playerItem removeObserver:self forKeyPath:@"playbackBufferFull" context:playbackBufferFull];

手柄

if (context == playbackLikelyToKeepUpKVOToken) 
{ 
    if (self.playerItem.playbackLikelyToKeepUp) 
    { 
     NSLog(@"recieve playbackLikelyToKeepUp"); 
    } 

} 
else if (context == playbackBufferEmpty) 
{ 
    if (self.playerItem.playbackBufferEmpty) 
    { 
     NSLog(@"recieve playbackBufferEmpty"); 
    } 
} 
else if(context == playbackBufferFull) 
{ 
    NSLog(@"recieve playbackBufferFull"); 
} 
else 
{ 
    [super observeValueForKeyPath:path ofObject:object change:change context:context]; 
}

來源

2014-12-04 10:49:52

@Nghia陳的回答幫助了我。他只是混淆添加觀察家/刪除觀察員（我們既需要）

添加觀察員：

[self.playerItem addObserver:self forKeyPath:@"playbackBufferEmpty" options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew context:playbackBufferEmpty]; 
[self.playerItem addObserver:self forKeyPath:@"playbackLikelyToKeepUp" options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew context:playbackLikelyToKeepUpKVOToken]; 
[self.playerItem addObserver:self forKeyPath:@"playbackBufferFull" options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew context:playbackBufferFull];

刪除觀察員：

[self.playerItem removeObserver:self forKeyPath:@"playbackBufferEmpty" context:playbackBufferEmpty]; 
[self.playerItem removeObserver:self forKeyPath:@"playbackLikelyToKeepUp" context:playbackLikelyToKeepUpKVOToken]; 
[self.playerItem removeObserver:self forKeyPath:@"playbackBufferFull" context:playbackBufferFull];

來源

2016-10-21 08:29:11 user1105951

AVPlayer項緩衝區爲空

回答

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