AVPlayer: iOS的高级播放器

AVPlayer 是 iOS 中比较常用的播放器，灵活性高，功能强大。

创建 player

AVAsset *asset = [AVAsset assetWithURL:[NSURL fileURLWithPath:outputString]];
AVPlayerItem *item = [AVPlayerItem playerItemWithAsset:asset];
_player = [AVPlayer playerWithPlayerItem:item];

设置预览图层

_playerLayer = [AVPlayerLayer playerLayerWithPlayer:_player];
[self.view.layer addSublayer:_playerLayer];
_playerLayer.frame = self.view.bounds;

播放

[_player play];

循环播放

这里用Observer去监听播放器的时间，如果快播完了，就seek到0秒。

float duration = CMTimeGetSeconds(asset.duration);
__strong typeof(self) weakSelf = self;
[self.player addPeriodicTimeObserverForInterval:CMTimeMake(1.0, 30.0)
                                          queue:dispatch_get_main_queue()
                                      usingBlock:^(CMTime time) {
    __strong typeof(weakSelf) strongSelf = weakSelf;
    NSLog(@"%@__%@", @(duration), @(CMTimeGetSeconds(time)));
    if (duration - CMTimeGetSeconds(time) <= 0.01) {
        [strongSelf.player seekToTime:kCMTimeZero];
        [strongSelf.player play];
    }
}];

暂停

[_player pause];

seek

[_player seekToTime:kCMTimeZero];
[_player play];

倍速

可以在播放的时候改变。

_player.rate = 2;

这里介绍了一些常用的播放器操作，还有一些细节需要注意，比如前后台切换，音频路由等。