xcode - 如何检查 AVPlayer 是否有视频或只有音频？

Question

我尝试播放一些“媒体”，但在 AVPlayer 启动时我不知道它是音频还是视频。

我连接了播放器层，它工作正常。

self.avPlayerLayer = [AVPlayerLayer playerLayerWithPlayer:[[PCPlayerManager sharedManager] audioPlayer]];
avPlayerLayer.videoGravity = AVLayerVideoGravityResizeAspect;
avPlayerLayer.frame = CGRectMake(0, 0, videoView.frame.size.width, videoView.frame.size.height);
[videoView.layer addSublayer:avPlayerLayer];

但是如何检查是否有视频，以便添加/删除一些选项？

Answer 1

来自 Apple 的示例代码项目 AVSimplePlayer：

// Set up an AVPlayerLayer according to whether the asset contains video.
if ([[(AVAsset *)asset tracksWithMediaType:AVMediaTypeVideo] count] != 0)

Answer 2

对于 Swift 4.2，您可以执行以下操作：

func isAudioAvailable() -> Bool? {
   return self.player?._asset?.tracks.filter({$0.mediaType == AVMediaType.audio}).count != 0   
}

func isVideoAvailable() -> Bool? {
   return self.player?._asset?.tracks.filter({$0.mediaType == AVMediaType.video}).count != 0   
}

或作为扩展

extension AVPlayer {
    var isAudioAvailable: Bool? {
        return self._asset?.tracks.filter({$0.mediaType == AVMediaType.audio}).count != 0
    }

    var isVideoAvailable: Bool? {
        return self._asset?.tracks.filter({$0.mediaType == AVMediaType.video}).count != 0
    }
}

Answer 3

我不确定但AVPlayerItem有以下数组[mPlayerItem.asset.tracks]它包含两个对象，一个用于视频，另一个用于音频。按如下方式访问它以[mPlayerItem.asset.tracks objectAtIndex:0]获取视频和[mPlayerItem.asset.tracks objectAtIndex:1]音频。

Answer 4

更新： sean-stayns 在 Swift 5.5 中的回答

extension AVPlayer {
    var isAudioAvailable: Bool? {
        return self.currentItem?.asset.tracks.filter({$0.mediaType == .audio}).count != 0
    }

    var isVideoAvailable: Bool? {
        return self.currentItem?.asset.tracks.filter({$0.mediaType == .video}).count != 0
    }
}

Answer 5

我发现了这个更好的解决方案

func isVideoAvailable(item: AVPlayerItem) -> Bool {
        for video in item.tracks {
            if video.assetTrack?.mediaType == .video {
                return true
            }
        }
        return false
}

和这个

  if currentItem.tracks.contains(where: { track in
     track.assetTrack?.mediaType == .video
  }) {

     // This Code goes Here!
  }

Answer 6

这帮助了我：

    // source from https://stackoverflow.com/a/55581216 Changed for last release AVFoundation
    func isAudioAvailable() -> Bool? {
        return self.player.currentItem?.tracks.filter({$0.assetTrack!.mediaType == AVMediaType.audio}).count != 0
    }
    
    func isVideoAvailable() -> Bool? {
        return self.player.currentItem?.tracks.filter({$0.assetTrack!.mediaType == AVMediaType.video}).count != 0
    }