AVassetImageGenerator에서 얻은 이미지가 화면에 표시되는 방향과 일치하지 않을 때의 대응

발생한 문제

참조(최종 방향)

재현 코드

var asset: AVURLAsset

〜〜〜

let generator = AVAssetImageGenerator(asset: asset)
let captureImage: CGImageRef = generator.copyCGImageAtTime(asset.duration, actualTime: nil, error: nil)
var image = UIImage(CGImage: captureImage)

대응 코드

var track = asset.tracksWithMediaType(AVMediaTypeVideo)
if let media = track[0] as? AVAssetTrack {
  var naturalSize: CGSize = media.naturalSize
  var transform: CGAffineTransform = media.preferredTransform

  if transform.tx == naturalSize.width && transform.ty == naturalSize.height {
     UIImage(CGImage: captureImage scale: 1.0 orientation: UIImageOrientation.Down)
  } else if transform.tx == 0 && transform.ty == 0 {
     UIImage(CGImage: captureImage scale: 1.0 orientation: UIImageOrientation.Up)
  } else if transform.tx == 0 && transform.ty == naturalSize.width {
     UIImage(CGImage: captureImage scale: 1.0 orientation: UIImageOrientation.Left)
  } else {
     UIImage(CGImage: captureImage scale: 1.0 orientation: UIImageOrientation.Right)
  }
}