ios – 当AVPlayer实际开始播放(从外部来源)时,如何注册

在播放器开始使用AVPlayer播放外部视频(通过互联网)时,我注册了一些麻烦.请在提出解决方案之前阅读该问题.
我像这样初始化玩家:

player = [[AVPlayer alloc] initWithURL:[[NSURL alloc] initWithString:@"http://example.com/video.mp4"]];
playerLayer = [AVPlayerLayer playerLayerWithPlayer:player];
[playerLayer setFrame:[videoView bounds]];
[videoView.layer addSublayer:playerLayer];

这样可以将播放器正确添加到视图中.我添加了以下两行代码来跟踪播放器准备就绪,状态/速率是什么;

[player addObserver:self forKeyPath:@"rate" options:0 context:nil];
[player addObserver:self forKeyPath:@"status" options:0 context:nil];

这两行将调用方法 – (void)observeValueForKeyPath:….当某些内容随AVPlayer的状态或速率而变化时.

到目前为止,它看起来像这样:

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context 
{
    //To print out if it is 'rate' or 'status' that has changed:
    NSLog(@"Changed: %@", keyPath); 

    if ([keyPath isEqualToString:@"rate"]) //If rate has changed:
    { 
        if ([player rate] != 0) //If it started playing
        {
            NSLog(@"Total time: %f", CMTimeGetSeconds([[player currentItem] duration]));
            // This NSLog is supposed to print out the duration of the video.

            [self setControls];
            // This method (setControls) is supposed to set play/pause-buttons 
            // as well as labels for the current and total time of the current video.
        }
    }
    else if ([keyPath isEqualToString:@"status"]) // If the status changed
    {
        if(player.status == AVPlayerStatusReadyToPlay) //If "ReadyToPlay"
        {
            NSLog(@"ReadyToPlay");
            [player play]; //Start the video
        }
    }
}

初始化之后,AVPlayer的状态几乎立即改变为readyToPlay,然后调用[player play].当这种情况发生时,速率变为1.00000,这意味着它实际上以这种速度播放,但是视频现在刚刚开始缓冲,而不是播放.屏幕是黑色的,需要几秒钟的时间,然后开始播放.然而,这个比率表明它开始播放之前.速率保持在1.00000,开始缓冲时不下降到0,这使得我很难知道玩家何时有足够的信息来开始设置控件(I.E时间戳等).

打印出上述视频持续时间的NSLog()打印出南(不是数字),这导致我认为该项目没有准备好播放,但是,速率保持在1.0000,直到它缓存一段时间,那么它实际上会玩,还是以1.0000的速度.

然而,它确实被叫了两次.速率“变化”到1.0000两次,而没有任何其他的.在两个呼叫中,视频的持续时间是可用的变量.

我的目标是尽可能快地获取视频的当前和总时间戳(I.E 0:00/3:52).这也将用于注册滑块的滑动(用于快进等).

当玩家通知我以1.0000的速度播放时,这些值尚未准备好,两次.如果我手动点击“播放”一秒钟之后(并呼叫[播放器播放]),那么它的工作.如何注册以了解视频何时准备就绪,而不只是“准备好准备”?

来自Apple的AVPlayer和this example上的addBoundaryTimeObserverForTimes:queue:usingBlock:.

AVPlayer *player = [AVPlayer playerWithURL:[NSURL URLWithString:@"http://devimages.apple.com/iphone/samples/bipbop/bipbopall.m3u8"]];

[player play];

// Assumes a property: @property (strong) id playerObserver; 
// Cannot use kCMTimeZero so instead use a very small period of time
self.playerObserver = [player addBoundaryTimeObserverForTimes:@[[NSValue valueWithCMTime:CMTimeMake(1, 1000)]] queue:NULL usingBlock:^{

        //Playback started

        [player removeTimeObserver:self.playerObserver];
}];
翻译自:https://stackoverflow.com/questions/20733038/how-can-i-register-for-when-avplayer-actually-starts-playing-from-external-sour

转载注明原文:ios – 当AVPlayer实际开始播放(从外部来源)时,如何注册