Swift3 Swift 3 AVCaptureSession图像输出为纵向而非横向

我制作了一个简单的iOS应用程序，可以拍照并将其保存到设备库中。我希望输出一个横向图像，但相机产生的是横向图像的纵向方向，比如说50x100，图像旋转90度。我希望图像是横向的，但我不确定我的代码出了什么问题

我需要将预览层设置为横向，因此我将AVCaptureVideoOrientation设置为所需的方向

previewLayer.connection.videoOrientation = AVCaptureVideoOrientation.landscapeRight

以下是配置：

override func viewWillAppear(_ animated: Bool) {

    let devices = AVCaptureDevice.devices(withMediaType: AVMediaTypeVideo)
    for device in devices! {
        if (device as AnyObject).position == AVCaptureDevicePosition.back {

            do {

                let input = try AVCaptureDeviceInput(device: device as! AVCaptureDevice)

                if (captureSession.canAddInput(input)) {

                    captureSession.sessionPreset = AVCaptureSessionPresetPhoto
                    captureSession.addInput(input)
                    sessionOutput.outputSettings = [AVVideoCodecKey : AVVideoCodecJPEG]


                    if (captureSession.canAddOutput(sessionOutput)) {

                        captureSession.addOutput(sessionOutput)
                        captureSession.startRunning()

                        previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
                        previewLayer.videoGravity = AVLayerVideoGravityResize
                        previewLayer.connection.videoOrientation = AVCaptureVideoOrientation.landscapeRight
                        previewLayer.frame = self.cameraView.bounds
                        cameraView.layer.addSublayer(previewLayer)

                        previewLayer.position = CGPoint(x: self.cameraView.frame.width / 2, y: self.cameraView.frame.height / 2)
                        previewLayer.bounds = cameraView.frame

                        cameraView.addSubview(captureBtn)
                        cameraView.addSubview(shutterTimer)

                    }

                }

            } catch let err {

                print(err)
                return

            }

        }
    }

}

图像输出

if let videoConnection = sessionOutput.connection(withMediaType: AVMediaTypeVideo) {

        sessionOutput.captureStillImageAsynchronously(from: videoConnection, completionHandler: { (buffer, error) in

            let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(buffer)
            let image = UIImage(data: imageData!)!
            UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
            print(UIImage(data: imageData!)!)

        })

    }

---

我明白了！，因此，在将图像保存到库中之前，必须根据预览层上的内容设置输出方向，只需添加以下行：

videoConnection.videoOrientation = .landscapeRight

if let videoConnection = sessionOutput.connection(withMediaType: AVMediaTypeVideo) {
        // set output orientation before saving
        videoConnection.videoOrientation = .landscapeRight
        sessionOutput.captureStillImageAsynchronously(from: videoConnection, completionHandler: { (buffer, error) in

            let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(buffer)
            let image = UIImage(data: imageData!)!
            UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)                
        })

    }