AV-Capture-Photo-Helper

Protocol-based easy setup for enabling live preview and capture from camera

Usage:

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()
    }

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On your View

For detailed information on how to add prototcol on view follow sample application VideoView.swift

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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