Protocol-based easy setup for enabling live preview and capture from camera
Step 1:
Confirm your view / view controller to LivePhotoCapture
class ViewController: UIViewController, LivePhotoCapture {}Step 2: Allow xcode to fill all needed variables and methodes
step 3: add intilizers (if you dont need custom intilizer use the example code)
class ViewController: UIViewController, LivePhotoCapture {
var captureSession: AVCaptureSession?
var photoOutput: AVCapturePhotoOutput?
var cameraPreviewLayer: AVCaptureVideoPreviewLayer?
// This method has to be implemented in the caller class as its @obj func and swift limits usage of this in side protocol extenstions
func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {}
}step 4:
in the view didload or the place were you are plannig to start live preview by calling prepareForPhotoCapture(onView: UIView?, cameraPosition: AVCaptureDevice.Position = .unspecified)
override func viewDidLoad() {
super.viewDidLoad()
prepareForPhotoCapture(onView: cameraPreviewView)
}step 5:
To capture Image call capturePhoto(), once processed you will get call back on,
photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?)
if AVCapturePhoto needs to be converted to UIIMage call processPhoto( photo: AVCapturePhoto) -> UIImage?
class ViewController: UIViewController, LivePhotoCapture {
var captureSession: AVCaptureSession?
var photoOutput: AVCapturePhotoOutput?
var cameraPreviewLayer: AVCaptureVideoPreviewLayer?
// This method has to be implemented in the caller class as its @obj func and swift limits usage of this in side protocol extenstions
func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
// if user is needs a processed UIImage
let image = processPhoto(photo: photo)
}
func capturePhoto(_ sender: UIButton) {
capturePhoto()
}
}step 5:
if View is getting dissapeared or needs to stop live preview,
call stopSession()
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
stopSession()
}step 6:
if live preview needs to be restarted,
call startSession()
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
startSession()
}On your View
For detailed information on how to add prototcol on view follow sample application VideoView.swift
Note
Keep in mind that if we are adding preview to a view's layer all the subviews on it may not be visible, to avoid this please add a seprate view which can be used as a canvas for preview, Refer Demo app for more details