Swift：以横向比率录制视频

Question

我有一个应用，我需要录制一个小视频。我需要视频的横向宽高比（16（宽）-9（高））。我尝试使用UIImagePickerController强制横向，但似乎Apple不允许它。理想情况下，我希望在横向上始终使用overlayCameraView。

到目前为止我的代码：

extension UIImagePickerController {
    override open func viewDidLoad() {
        super.viewDidLoad()
        NotificationCenter.default.addObserver(self, selector: #selector(self.rotated), name: NSNotification.Name.UIDeviceOrientationDidChange, object: nil)
    }

func rotated() {
    if UIDevice.current.orientation.isLandscape {
        self.pleaseRotateImageView.alpha = 0.0

    } else {
        self.pleaseRotateImageView.alpha = 1.0
    }
}

按下录制视频按钮时

if (UIImagePickerController.isSourceTypeAvailable(.camera)) {
            if UIImagePickerController.availableCaptureModes(for: .front) != nil {
                imagePicker.sourceType = .camera
                imagePicker.mediaTypes = [kUTTypeMovie as String]
                imagePicker.allowsEditing = false
                imagePicker.delegate = self
                imagePicker.videoMaximumDuration = 5
                imagePicker.showsCameraControls = false
                //customView stuff
                let customViewController = CustomOverlayViewController(
                    nibName:"CustomOverlayViewController",
                    bundle: nil
                )
                let customView:CustomOverlayView = customViewController.view as! CustomOverlayView
                customView.frame = self.imagePicker.view.frame
                present(imagePicker, animated: true, completion: {
                    self.imagePicker.cameraOverlayView = customView
                })
            } else {
                let alert = SCLAlertView()
                alert.showWarning("Rear camera doesn't exist", subTitle: "Application cannot access the camera.")
            }
        } else {
            let alert = SCLAlertView()
            alert.showWarning("Camera inaccessable", subTitle: "Application cannot access the camera.")
        }