AVPlayer播放

AVPlayer音频播放器基本实现

#import <AVFoundation/AVFoundation.h>
@property (nonatomic, strong) AVPlayer *player;

• 播放

- (void)playWithURL:(NSURL *)url {    
    // 1. 资源的请求
    AVURLAsset *asset = [AVURLAsset assetWithURL:url];
    
    // 2. 资源的组织
    AVPlayerItem *item = [AVPlayerItem playerItemWithAsset:asset];
    // 当资源的组织者, 告诉我们资源准备好了之后, 我们再播放
    // AVPlayerItemStatus status
    [item addObserver:self forKeyPath:@"status" options:NSKeyValueObservingOptionNew context:nil];
    
    // 3. 资源的播放
    self.player = [AVPlayer playerWithPlayerItem:item];
    
}

• 暂停

- (void)pause {
    [self.player pause];
}

• 继续

- (void)resume {
    [self.player play];
}

• 停止

- (void)stop {
    [self.player pause];
    self.player = nil;
}

• 进度条拉动

- (void)seekWithProgress:(float)progress {

    if (progress < 0 || progress > 1) {
        return;
    }

    // 可以指定时间节点去播放
    // 时间: CMTime : 影片时间
    // 影片时间 -> 秒
    // 秒 -> 影片时间
    
    // 1. 当前音频资源的总时长
    CMTime totalTime = self.player.currentItem.duration;
    // 2. 当前音频, 已经播放的时长
//    self.player.currentItem.currentTime
    
    NSTimeInterval totalSec = CMTimeGetSeconds(totalTime);
    NSTimeInterval playTimeSec = totalSec * progress;
    CMTime currentTime = CMTimeMake(playTimeSec, 1);
    
    [self.player seekToTime:currentTime completionHandler:^(BOOL finished) {
        if (finished) {
            NSLog(@"确定加载这个时间点的音频资源");
        }else {
            NSLog(@"取消加载这个时间点的音频资源");
        }
    }];
    
    
}

• 快进一段时间

- (void)seekWithTimeDiffer:(NSTimeInterval)timeDiffer {
    
    // 1. 当前音频资源的总时长
    CMTime totalTime = self.player.currentItem.duration;
    NSTimeInterval totalTimeSec = CMTimeGetSeconds(totalTime);
    // 2. 当前音频, 已经播放的时长
    CMTime playTime = self.player.currentItem.currentTime;
    NSTimeInterval playTimeSec = CMTimeGetSeconds(playTime);
    playTimeSec += timeDiffer;
    
    
    
    [self seekWithProgress:playTimeSec / totalTimeSec];
    
}

• 倍数播放

- (void)setRate:(float)rate {
    
    [self.player setRate:rate];
    
}

• 静音

- (void)setMuted:(BOOL)muted {
    self.player.muted = muted;
}

• 调节音量

- (void)setVolume:(float)volume {
    
    if (volume < 0 || volume > 1) {
        return;
    }
    if (volume > 0) {
        [self setMuted:NO];
    }
    
    self.player.volume = volume;
}

#pragma mark - KVO
-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSKeyValueChangeKey,id> *)change context:(void *)context {
    
    if ([keyPath isEqualToString:@"status"]) {
        AVPlayerItemStatus status = [change[NSKeyValueChangeNewKey] integerValue];
        if (status == AVPlayerItemStatusReadyToPlay) {
            NSLog(@"资源准备好了, 这时候播放就没有问题");
            [self.player play];
        }else {
            NSLog(@"状态未知");
        }
    }
}