您实际上如何播放AVAssetTrack，而不是AVURLAsset？

Question

假设您的视频文件很小

let p = Bundle.main.path(forResource: "small", ofType: "mp4")
let url = NSURL.fileURL(withPath: p!)

您可以轻松地将其设为播放器项目并播放..

let pi = AVPlayerItem(url: url)
av.player = AVPlayer(playerItem: pi)

或者，您可以将其设置为AVURLAsset，然后获取其中一个曲目

AVAssetTrack

 asset = AVURLAsset(url: url)
 let tracks:[AVAssetTrack] = asset!.tracks
 print(tracks.count)
 let track:AVAssetTrack = tracks[2]

那....您怎么播放其中一首曲目？

您如何播放AVAssetTrack？

Answer 1

以下代码显示了如何创建仅包含所需曲目的AVMutableComposition，然后像播放任何AVAsset一样播放构图，因为也许是令人惊讶的考虑了名称，它是一个：

let asset = AVURLAsset(url: url)
let track = asset.tracks[1]  // or whatever

let composition = AVMutableComposition()
let compositionTrack = composition.addMutableTrack(withMediaType: track.mediaType, preferredTrackID: kCMPersistentTrackID_Invalid)

try! compositionTrack?.insertTimeRange(CMTimeRange(start: .zero, duration: asset.duration), of: track, at: .zero)

let playerItem = AVPlayerItem(asset: composition)  // play me in your AVPlayer

现实生活中的

N.B。应该tracks和duration异步加载。