AVPlayer的使用+简单的播放器Demo

学习内容

先上项目地址，一个简单的AVPlayerDemo: https://github.com/practiceqian/QCAVPlayerDemo

AVPlayer学习

几个播放器相关的类

AVPlayer、AVURLAsset、AVPlayerItem、AVPlayerLayer

//控制播放器的播放、暂停、播放速度
@property (nonatomic,strong) AVPlayer * player;
//管理资源对象，提供播放数据源
@property (nonatomic,strong) AVPlayerItem* playItem;
//负责显示视频，如果没有添加该类，只有声音没有画面
@property (nonatomic,strong) AVPlayerLayer* playerLayer;

构建一个简单的播放器

//一个UIImageView，构建播放器的显示区域
self.playerView = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height/3)];
[self.view addSubview:self.playerView];

//播放资源
NSURL* playUrl = [NSURL URLWithString:@"http://clips.vorwaerts-gmbh.de/big_buck_bunny.mp4"];
self.playItem = [AVPlayerItem playerItemWithURL:playUrl];
//播放器实例
self.player = [AVPlayer playerWithPlayerItem:self.playItem];
//显示区域
self.playerLayer = [AVPlayerLayer playerLayerWithPlayer:self.player];
self.playerLayer.frame = self.playerView.bounds;
//将显示区域添加到UIImageView上
[self.playerView.layer addSublayer:self.playerLayer];
//开始播放
[self.player play];

效果如图
- 可以在UIImageView的容器中看到画面，但是此时依然不能控制播放的进度等

使用AVPlayer控制播放行为

//播放
[self.player play];
//暂停
[self.player pause];
//控制播放速度
self.player.rate = 2.0

使用AVPlayerItem控制播放状态

//三种播放状态
typedef NS_ENUM(NSInteger, AVPlayerItemStatus) {
	AVPlayerItemStatusUnknown = 0,	//未知
	AVPlayerItemStatusReadyToPlay = 1,	//准备播放
	AVPlayerItemStatusFailed = 2	//播放失败
};

使用KVO进行监听播放状态

//对status进行监听
[self.playItem addObserver:self forKeyPath:@"status" options:NSKeyValueObservingOptionNew context:nil];
//监听的回调
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSKeyValueChangeKey,id> *)change context:(void *)context{
    if ([object isKindOfClass:[AVPlayerItem class]]) {
        if ([keyPath isEqualToString:@"status"]) {
          //根据播放的三种状态进行处理
            switch (self.playItem.status) {
                case AVPlayerItemStatusUnknown:
                    NSLog(@"播放状态未知");
                    break;
                case AVPlayerItemStatusReadyToPlay:
                    NSLog(@"准备播放");
                    break;
                case AVPlayerItemStatusFailed:
                    NSLog(@"播放失败");
                    break;;
                default:
                    break;
            }
        }
    }
}

获取播放时间

//CMTime是以分数的形式表示时间，value表示分子，timescale表示分母，flags是位掩码，表示时间的指定状态。
typedef struct{
    CMTimeValue    value;     // 帧数
    CMTimeScale    timescale;  // 帧率（影片每秒有几帧）
    CMTimeFlags    flags;        
    CMTimeEpoch    epoch;    
} CMTime;

//获取当前的播放时间
float currentTime = self.playItem.currentTime.value/self.playItem.currentTime.timescale;
//获取视频的总时间(一般在准备播放状态时获取)
float totalTime = CMTimeGetSeconds(self.playItem.duration);

监听播放的进度

__weak typeof(self) weakSelf = self;
//CMTimeMake(1,1),一秒钟监听一次
[self.player addPeriodicTimeObserverForInterval:CMTimeMake(1, 1) queue:nil usingBlock:^(CMTime time) {
  AVPlayerItem* item = weakSelf.playItem;
  float curTime = item.currentTime.value/item.currentTime.timescale;
  NSLog(@"当前时间:%.0f",curTime);
}];

监听缓冲的进度

[self.playItem addObserver:self forKeyPath:@"loadedTimeRanges" options:NSKeyValueObservingOptionNew context:nil];
---------------------------------------------------------------
  if ([keyPath isEqualToString:@"loadedTimeRanges"]){
  NSArray *array = self.playItem.loadedTimeRanges;
  CMTimeRange timeRange = [array.firstObject CMTimeRangeValue];//本次缓冲时间范围
  float startSeconds = CMTimeGetSeconds(timeRange.start);
  float durationSeconds = CMTimeGetSeconds(timeRange.duration); NSTimeInterval totalBuffer = startSeconds + durationSeconds;//缓冲总长度
  NSLog(@"当前已缓冲时间：%f",totalBuffer);
}

监听已缓存时间充足/不足

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

最后的demo

最后欢迎关注我的iOS学习总结——每天学一点iOS：https://github.com/practiceqian/one-day-one-iOS-summary

AVPlayer的使用+简单的播放器Demo

学习内容

AVPlayer学习

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