AVPlayer不播放

在我的項目中，我使用Kolada視圖(here)來呈現一堆卡片，每張卡片上都有一個視頻。有時當我加載下一個視頻時，我的AVPlayer無法播放視頻，它只會顯示第一幀並被凍結。我使用幾個觀察者來追蹤視頻實際播放的時間，如果它可能跟上播放。如果觀察員沒有正確解除分配，觀衆是否會導致播放凍結？如果不是，還有什麼會導致AVPlayer播放停止播放？AVPlayer不播放

更新：我注意到playbackLikelyToKeepUp有時不會被調用，而當發生這種情況時，即使我更改了播放器項目，AVPlayer也不會再次調用它。因此，視頻播放從不恢復。

init(frame: CGRect, mediaURL: NSURL, thumbURL: NSURL?, isLoop: Bool) { 
    self.mediaURL = mediaURL 
    self.isLoop = isLoop 

    let asset = AVAsset(URL: mediaURL) 
    let item = AVPlayerItem(asset: asset) 
    player = AVPlayer(playerItem: item) 
    player!.actionAtItemEnd = .None 

    super.init(frame: frame) 

    asset.loadValuesAsynchronouslyForKeys(["duration"], completionHandler: {() -> Void in 
     var error: NSError? 
     let keyStatus: AVKeyValueStatus = asset.statusOfValueForKey("duration", error: &error) 
     switch (keyStatus) { 

     case .Loaded: 
      let duration: CMTime = asset.duration 
      self.currentDuration = duration 
      self.delegate?.updateDuration() 
     default: 
      break 
     } 

    }) 

    NSNotificationCenter.defaultCenter().addObserver(
     self, 
     selector: #selector(MediaPlayerView.playerItemDidReachEnd(_:)), 
     name: AVPlayerItemDidPlayToEndTimeNotification, 
     object: player!.currentItem) 

    self.timeObserver = self.player!.addPeriodicTimeObserverForInterval(CMTimeMakeWithSeconds(1.0/30.0, Int32(NSEC_PER_SEC)), queue: nil, usingBlock: { 
     [weak self] (time) -> Void in 

     if time.value > 0 { 
      self?.spinnerView?.stopAnimating() 
      if(self?.player != nil){ 
       if(self?.player!.rate > 0){ 
        self?.placeholderImageView?.hidden = true 
       } 
      } 

      let timeInSeconds = CMTimeGetSeconds(time) 
      self?.delegate?.playbackReachedTime(timeInSeconds) 

     } 
    }) 

    player!.currentItem?.addObserver(self, forKeyPath: playbackLikelyToKeepUp, options: .New, context: &observationContext) 
    player!.addObserver(self, forKeyPath: "rate", options: .New, context: &observationContext) 

    let tapGesture = UITapGestureRecognizer(target: self, action: #selector(MediaPlayerView.playerIsTapped(_:))) 
    addGestureRecognizer(tapGesture) 
}

來源

2016-07-19 Josh O' Connor

是一個ViewController的初始化器？ –

該avplayer作爲唯一的一個實例和一個觀察者在所有卡片視圖中跟蹤視頻結尾 –

加載下一個視頻時是否刪除了上一個視頻？ – Godinall