以正确的方向合并多个视频资源 swift

Question

我只是想拼接（合并）一组视频（具有正确的原始方向），而且 但是有些视频的方向不正确视频。例如，使用当前的 preferredTransform，前置视频是倒置的（即，如果您用手在左侧拍摄视频，它现在将在右侧..）而后置摄像头视频则保持原样。

我已经尝试查看很多关于此的问题，但 none 似乎解决了这个问题。我只需要视频保持原来的方向！

func merge(arrayVideos:[AVAsset], completion:@escaping (URL?, Error?) -> ()) {


          let mainComposition = AVMutableComposition()
          let compositionVideoTrack = mainComposition.addMutableTrack(withMediaType: .video, preferredTrackID: kCMPersistentTrackID_Invalid)
  compositionVideoTrack?.preferredTransform = CGAffineTransform(rotationAngle: (.pi)/2) 

          let soundtrackTrack = mainComposition.addMutableTrack(withMediaType: .audio, preferredTrackID: kCMPersistentTrackID_Invalid)

            var insertTime = CMTime.zero

          for videoAsset in arrayVideos {
            try! compositionVideoTrack?.insertTimeRange(CMTimeRangeMake(start: .zero, duration: videoAsset.duration), of: videoAsset.tracks(withMediaType: .video)[0], at: insertTime)
            try! soundtrackTrack?.insertTimeRange(CMTimeRangeMake(start: .zero, duration: videoAsset.duration), of: videoAsset.tracks(withMediaType: .audio)[0], at: insertTime)

            insertTime = CMTimeAdd(insertTime, videoAsset.duration)
          }

          let outputFileURL = URL(fileURLWithPath: NSTemporaryDirectory() + "merge.mp4")

          let fileManager = FileManager()
          try? fileManager.removeItem(at: outputFileURL)

          let exporter = AVAssetExportSession(asset: mainComposition, presetName: AVAssetExportPresetHighestQuality)

          exporter?.outputURL = outputFileURL
          exporter?.outputFileType = AVFileType.mp4
          exporter?.shouldOptimizeForNetworkUse = true

          exporter?.exportAsynchronously {
            if let url = exporter?.outputURL{
                completion(url, nil)
            }
            if let error = exporter?.error {
                completion(nil, error)
            }
          }
        }

Answer 1

我解决了问题！！

参考我的回答：

How to correctly orient multiple video tracks (taken on front facing cam and back facing), before merging or during?

以正确的方向合并多个视频资源 swift

Merge multiple video assets with correct orientation swift

avfoundation

ios

avmutablecomposition

avasset

swift