AVQueuePlayer AVPlayerItemDidPlayToEndTimeNotification 调用失败答案

【问题标题】：AVQueuePlayer AVPlayerItemDidPlayToEndTimeNotification fails to callAVQueuePlayer AVPlayerItemDidPlayToEndTimeNotification 调用失败
【发布时间】：2013-12-16 12:49:50
【问题描述】：

我使用AVQueuePlayer 循环遍历AVPlayerItems 的数组。我循环它的方式，我听AVPlayerItemDidPlayToEndTimeNotification，每次调用它时，我都会将当前对象添加到队列的末尾。代码如下：

    viewWillAppear
{
    ...

    [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(playerItemDidReachEnd:)
                                                     name:AVPlayerItemDidPlayToEndTimeNotification
                                                   object:[_queuePlayer currentItem]];

        [_queuePlayer play];
}
- (void)playerItemDidReachEnd:(NSNotification *)notification {
    AVPlayerItem *p = [notification object];
    AVPlayerItem *fakeNew = [[AVPlayerItem alloc] initWithAsset:p.asset];
    if (_queuePlayer.items.count == 1)
    {
        [p seekToTime:kCMTimeZero];
        [_queuePlayer play];
    }
    else
    {
        [_queuePlayer insertItem:fakeNew afterItem:[_queuePlayer.items lastObject]];
    }
    NSLog(@"array of items to play:%lu", (unsigned long)_queuePlayer.items.count);

}

问题是，该方法只为播放的第一个视频调用，之后，该方法停止被调用，所以如果我在数组中有两部电影，它会同时播放它们+第一个再次，知道为什么会这样吗？

更多信息：还尝试每次都制作一个新播放器并将其设置为分层。同一条消息多次发送失败

- (void)playerItemDidReachEnd:(NSNotification *)notification {
    AVPlayerItem *p = [notification object];
    [self.playList removeObjectAtIndex:0];
    [self.playList addObject:p];
    AVPlayer *newPlayer = [[AVPlayer alloc] initWithPlayerItem:[self.playList objectAtIndex:0]];
    _player = newPlayer;
    self.AVPlayerLayerView.layer.player = self.player;
    [_player play];

}

【问题讨论】：

标签： ios objective-c ios7 avplayer avqueueplayer

【解决方案1】：

经过很多混乱，显然出于某种原因，视图每次都取消注册为观察者，我只是在每次通知后删除并添加观察者：

- (void)playerItemDidReachEnd:(NSNotification *)notification {
    AVPlayerItem *p = [notification object];
    AVPlayerItem *fakeNewItem = [[AVPlayerItem alloc] initWithAsset:p.asset];
    [self.playList removeObjectAtIndex:0];
    [self.playList addObject:fakeNewItem];
    AVPlayer *newPlayer = [[AVPlayer alloc] initWithPlayerItem:[self.playList objectAtIndex:0]];
    _player = newPlayer;
    self.AVPlayerLayerView.layer.player = self.player;
    [[NSNotificationCenter defaultCenter] removeObserver:self];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(playerItemDidReachEnd:)
                                                 name:AVPlayerItemDidPlayToEndTimeNotification
                                               object:[_player currentItem]];
    [_player play];

}

【讨论】：

因为您拒绝通知 AVPlayerItem，并且您正在使用数组初始化 AVQueuePlayer，因此您需要为该数组中的每个 playerItem 注册 AVPlayerItemDidPlayToEndNotification，而不仅仅是 currentItem

【解决方案2】：

寻求解决此问题的干净方法。我改为使用下一段代码

首先，您必须添加必要的代码，以便在再现时间更改时接收来自 AVPlayer 的反馈。

- (void)addPeriodicTimeObserverForReproductionChanges {
    @weakify(self);
    [self.player 
    addPeriodicTimeObserverForInterval:CMTimeMakeWithSeconds(kBQDefaultTimeIntervalReproductionChanges, NSEC_PER_SEC) 
    queue:self.eventsQueue
    usingBlock:^(CMTime time) {
    @strongify(self);
    [self dispatchBlockOnMainQueue:^{
        if ([self.delegate respondsToSelector:@selector(playerItemController:didChangeReproductionTime:)])
             [self.delegate playerItemController:self
                       didChangeReproductionTime:time];

         [self checkForItemPlayToEnd];
     }]; 
 }];

}

- (void)checkForItemPlayToEnd 
{
    CMTime durationScaled = CMTimeConvertScale(self.duration,self.player.currentTime.timescale, kCMTimeRoundingMethod_Default);

    if (CMTIME_COMPARE_INLINE(durationScaled, ==, self.player.currentTime)) {
        [self playerDidFinishReproducingItem];
    }
}

【讨论】：