1

I'm using UIImagePickerController to select a video or an image from the user's gallery. With the photos, there's no problem, everything is displayed the way it should be. The problem comes when I'm trying to generate a thumbnail for a video.

Basically, the thumbnail image could end up being displayed upside down or 90 degrees to the left or right. I'm not sure why it happens. Am I missing something or doing something wrong?

extension PostVC : UIImagePickerControllerDelegate, UINavigationControllerDelegate {

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    if let videoUrl = info[UIImagePickerController.InfoKey.mediaURL] as? URL {
        if let thumbnail = self.generateThumbnailForImage(videoUrl) {
            self.videoUrl = videoUrl
            self.photoImageView.image = thumbnail
            self.selectedImage = thumbnail
        }
    }
    if let image = info[UIImagePickerController.InfoKey.originalImage] as? UIImage {
        selectedImage = image
        photoImageView.image = image
        shareButton.isEnabled = true
    }
    dismiss(animated: true, completion: nil)
}

func generateThumbnailForImage(_ fileUrl: URL) -> UIImage? {
    let asset = AVAsset(url: fileUrl)
    let imageGenerator = AVAssetImageGenerator(asset: asset)
    do {
        let thumbnailCGImage = try imageGenerator.copyCGImage(at: CMTimeMake(value: 1, timescale: 10), actualTime: nil) // 1 sec
        return UIImage(cgImage: thumbnailCGImage)

    } catch let err {
        SVProgressHUD.showError(withStatus: err.localizedDescription)
    }
    return nil
  }
}
Dani
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1 Answers1

6

It seems like setting the imageGenerator.appliesPreferredTrackTransform = true solves this issue.

Dani
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