Capture Photo from Camera Preview Layer Swift 3

BodyguardViewController.swift

//
//  BodyguardViewController.swift
//  My Mobile Bodyguard
//
//  Created by Koray Zorluoglu on 06.07.17.
//  Copyright © 2017 Koray Zorluoglu. All rights reserved.
//

import UIKit
import AVFoundation
import Darwin


class BodyguardViewController: UIViewController, AVCaptureVideoDataOutputSampleBufferDelegate   {

    @IBOutlet weak var captureImageView: UIImageView!
    
    var captureSession = AVCaptureSession()
    var previewLayer : CALayer!
    
    var captureDevice : AVCaptureDevice!
    var startPhotoCapture = false
    
    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        prepareCamera()

      }

    
    func prepareCamera() {
     captureSession.sessionPreset = AVCaptureSessionPresetPhoto
        if let availableDevices = AVCaptureDeviceDiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaTypeVideo, position: .front).devices {
            captureDevice = availableDevices.first
            beginSession()
        }
    }
    
 
    func beginSession(){
        
        do {
            let captureDeviceInput = try AVCaptureDeviceInput(device: captureDevice) as AVCaptureDeviceInput
        
            if captureSession.inputs.isEmpty {
                self.captureSession.addInput(captureDeviceInput)
            }
        } catch{
            print(error.localizedDescription)
        }
        

        
        if let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession){
            self.previewLayer = previewLayer
            //self.view.layer.addSublayer(self.previewLayer)
            //self.previewLayer.frame = self.view.layer.frame
            captureSession.startRunning()
            
            let dataOutput = AVCaptureVideoDataOutput()
            dataOutput.videoSettings = [(kCVPixelBufferPixelFormatTypeKey as NSString):NSNumber(value:kCVPixelFormatType_32BGRA)]
            dataOutput.alwaysDiscardsLateVideoFrames = true
            
            if captureSession.canAddOutput(dataOutput){
                captureSession.addOutput(dataOutput)
            }
            
            captureSession.commitConfiguration()
            
            
            let queue = DispatchQueue(label: "mymobilebodyguard")
            dataOutput.setSampleBufferDelegate(self, queue: queue)
        }
    }
    
    func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputSampleBuffer sampleBuffer: CMSampleBuffer!, from connection: AVCaptureConnection!) {
        
        if startPhotoCapture {
 
            
            var evenCount = 0
             
            // Break loop when the third even number is encountered.
            myCondition : while true {
                if let image = getImageFormSampleBuffer(buffer: sampleBuffer){
                    DispatchQueue.main.sync {
                        self.captureImageView.image = image
                         print(image.description)
                    }
                     // Print the value.
                    print(evenCount)
                    sleep(1)
                
                    
                    if evenCount == 4 {
                        break myCondition
                    }

                    evenCount += 1

 
                }
            }

 
            
        
        }
    }
 
    
    
    func getImageFormSampleBuffer(buffer:CMSampleBuffer) -> UIImage? {
        if let pixelBuffer = CMSampleBufferGetImageBuffer(buffer){
            let ciImage = CIImage(cvPixelBuffer: pixelBuffer)
            let context = CIContext()
            let imageRect = CGRect(x: 0, y: 0, width: CVPixelBufferGetWidth(pixelBuffer), height: CVPixelBufferGetHeight(pixelBuffer))
            
            if let image = context.createCGImage(ciImage, from: imageRect){
                return UIImage(cgImage: image, scale: UIScreen.main.scale, orientation: .right)
            }
            
        }
        return nil
    }
    
    func stopCaptureSession(){
        self.captureSession.stopRunning()
        
        if let inputs = captureSession.inputs as? [AVCaptureDeviceInput]{
            for input in inputs{
                self.captureSession.removeInput(input)
            }
        }
    }
 
    
    override func viewDidAppear(_ animated: Bool) {
        playVideo()
     }
 
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        prepareCamera()
    }
    
    private func playVideo() {
        guard let path = Bundle.main.path(forResource: "polizei", ofType:"mp4") else {
            debugPrint("polizei.mp4 not found")
            return
        }
        let player = AVPlayer(url: URL(fileURLWithPath: path))
        let playerLayer = AVPlayerLayer(player: player)
        playerLayer.frame = self.view.bounds
        self.view.layer.addSublayer(playerLayer)
        player.play()
        
        startPhotoCapture = true

        
    }
    

}