在 AVFoundation 中镜像视频后,下载的视频未镜像

Downloaded video not mirrored after mirroring video in AVFoundation

一段时间以来,我一直在尝试镜像我的视频,但我似乎无法修复它。我也尝试了以下

 if let connection = movieFileOutput.connection(with: .video) {
        if connection.isVideoMirroringSupported {
          connection.isVideoMirrored = self.videoDeviceInput?.device.position == .front
        }
    }

 if let connection = videoDataOutput.connection(with: .video) {
      if connection.isVideoMirroringSupported {
        connection.isVideoMirrored = self.videoDeviceInput?.device.position == .front
      }
    }

视频在应用程序中得到了镜像,但是当将视频下载到我的照片应用程序时,它又没有镜像了。我该如何解决这个问题?

我的整体代码看起来如何:

  1. automaticallyConfiguresApplicationAudioSession 设置为 false.
  2. 通过获取设备输入并将其添加到 AVCaptureSession
  3. 来配置相机
  4. 设置电影输出,如设置比特率和 iPad 配置方向。这里我还要设置 .isVideoMirrored 属性.
  5. 正在设置会话预设。

添加音频会话设置:

    guard let audioDevice = AVCaptureDevice.default(
      .builtInMicrophone,
      for: .audio,
      position: .unspecified
    ) else { return }

    guard let audioInput = try? AVCaptureDeviceInput(device: audioDevice),
      captureSession.canAddInput(audioInput) else { return }

    guard captureSession.inputs.contains(audioInput) == false else { return }

    captureSession.addInput(audioInput)

我用这个变通方法解决了这个问题,看看它是否有用:

extension CameraViewController: AVCaptureFileOutputRecordingDelegate {
    func fileOutput(_ output: AVCaptureFileOutput, didFinishRecordingTo outputFileURL: URL, from connections: [AVCaptureConnection], error: Error?) {
        if error != nil {
            print("Error recording movie: \(error!.localizedDescription)")
        } else {
            processMovie()
        }
    }

    func processMovie() {
        let asset = AVAsset(url: CameraViewController.movieURL)
        let composition = AVMutableComposition()
        let assetVideoTrack = asset.tracks(withMediaType: .video).last!
        let compositionVideoTrack = composition.addMutableTrack(withMediaType: AVMediaType.video,
                                                                preferredTrackID: CMPersistentTrackID(kCMPersistentTrackID_Invalid))
        try? compositionVideoTrack?.insertTimeRange(CMTimeRangeMake(start: CMTime.zero, duration: asset.duration),
                                                    of: assetVideoTrack,
                                                    at: CMTime.zero)
        if self.currentCameraPosition == .rear {
            compositionVideoTrack?.preferredTransform = assetVideoTrack.preferredTransform
        }
        if self.currentCameraPosition == .front {
            compositionVideoTrack?.preferredTransform = CGAffineTransform(scaleX: -1.0, y: 1.0).rotated(by: CGFloat(Double.pi/2))
        }

        if let exporter = AVAssetExportSession(asset: composition,
                                               presetName: AVAssetExportPresetHighestQuality) {
            exporter.outputURL = CameraViewController.exportMovieURL
            exporter.outputFileType = AVFileType.mov
            exporter.shouldOptimizeForNetworkUse = true
            exporter.exportAsynchronously() {
                DispatchQueue.main.async {
                    self.performSegue(withIdentifier: "ShowVideo", sender: nil)
                }
            }
        }
    }
}