Binary/Raw data from QR Code scanning with swift 4.0 by AVFoundation.

QRScanVC.swift

//
//  QRScanVC.swift
//
//  Created by Farshchi, Navid on 1/2/18.
//

import UIKit
import AVFoundation

class QRScanVC: UIViewController, AVCaptureMetadataOutputObjectsDelegate {

    //The camera preview frame
    @IBOutlet weak var previewFrame: UIView!
    
    var videoCaptureDevice = AVCaptureDevice.default(for: .video)
    var device = AVCaptureDevice.default(for: .video)
    var output = AVCaptureMetadataOutput()
    var previewLayer: AVCaptureVideoPreviewLayer?
    
    var captureSession = AVCaptureSession()
    var code: String?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        self.setupCamera()
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
    }
    
    private func setupCamera() {
        do {
            let input = try AVCaptureDeviceInput(device: videoCaptureDevice!)
            
            if self.captureSession.canAddInput(input) {
                self.captureSession.addInput(input)
            }
            
            self.previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
            
            if let videoPreviewLayer = self.previewLayer {
                videoPreviewLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
                videoPreviewLayer.frame = self.previewFrame.bounds
                self.previewFrame.layer.addSublayer(videoPreviewLayer)
            }
            
            let metadataOutput = AVCaptureMetadataOutput()
            if self.captureSession.canAddOutput(metadataOutput) {
                self.captureSession.addOutput(metadataOutput)
                
                metadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
                metadataOutput.metadataObjectTypes = [AVMetadataObject.ObjectType.upce, AVMetadataObject.ObjectType.code39, AVMetadataObject.ObjectType.code39Mod43, AVMetadataObject.ObjectType.ean13, AVMetadataObject.ObjectType.ean8, AVMetadataObject.ObjectType.code93, AVMetadataObject.ObjectType.code128, AVMetadataObject.ObjectType.pdf417, AVMetadataObject.ObjectType.qr, AVMetadataObject.ObjectType.aztec]
                
            } else {
                print("Could not add metadata output")
            }
        } catch {
            print("Error while setting camera")
        }
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        // This if for start capture session again while the VC become visible
        if (captureSession.isRunning == false) {
            captureSession.startRunning();
        }
    }
    
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        // This if for stopping capture session while the VC is not visible
        if (captureSession.isRunning == true) {
            captureSession.stopRunning();
        }
    }
    
    func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
        
        print(metadataObjects)
        
        for metadataObject in metadataObjects {
            print("type: " + metadataObject.type.rawValue)
            
            let readableObject = metadataObject as! AVMetadataMachineReadableCodeObject;
            let rawReadableObjectTemp = readableObject.value(forKeyPath: "_internal.basicDescriptor")! as! [String:Any]
            let rawReadableObject = rawReadableObjectTemp["BarcodeRawData"] as? Data
            
            if let rawBytes = rawReadableObject {
                print(rawBytes)
                let dataString = rawBytes.hexEncodedString()
                print("dataString: \(dataString)")
                
            }
        }
    }
}