iPhone4可以前后置摄像头同时录像吗

iphone

iphone4是否能够前后置摄像头同时录像？

Swift
import UIKit
import AVFoundation
class CameraViewController: UIViewController {
    var captureSession: AVCaptureSession?
    var frontCamera: AVCaptureDevice?
    var backCamera: AVCaptureDevice?
    var currentCamera: AVCaptureDevice?
    var photoOutput: AVCapturePhotoOutput?
    var cameraPreviewLayer: AVCaptureVIDEOPreviewLayer?
    override func viewDidLoad() {
        super.viewDidLoad()
        setupCaptureSession()
        setupDevice()
        setupInputOutput()
        setupPreviewLayer()
        startRunningCaptureSession()
    }
    func setupCaptureSession() {
        captureSession = AVCaptureSession()
        captureSession?.sessionPreset = AVCaptureSession.Preset.photo
    }
    func setupDevice() {
        let deviceDiscoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaType.vIDEO, position: .unspecified)
        for device in deviceDiscoverySession.devices {
            if device.position == .front {
                frontCamera = device
            } else if device.position == .back {
                backCamera = device
            }
        }
        currentCamera = frontCamera
    }
    func setupInputOutput() {
        do {
            let captureDeviceInput = try AVCaptureDeviceInput(device: currentCamera!)
            captureSession?.addInput(captureDeviceInput)
            photoOutput = AVCapturePhotoOutput()
            if captureSession!.canAddOutput(photoOutput!) {
                captureSession?.addOutput(photoOutput!)
            }
        } catch {
            print(error)
        }
    }
    func setupPreviewLayer() {
        cameraPreviewLayer = AVCaptureVIDEOPreviewLayer(session: captureSession!)
        cameraPreviewLayer?.vIDEOGravity = AVLayerVIDEOGravity.resizeAspectFill
        cameraPreviewLayer?.connection?.vIDEOOrientation = AVCaptureVIDEOOrientation.portrAIt
        cameraPreviewLayer?.frame = view.frame
        view.layer.insertSublayer(cameraPreviewLayer!, at: 0)
    }
    func startRunningCaptureSession() {
        captureSession?.startRunning()
    }
}

iphone 4 不支持前后置摄像头同时录像，该功能在 iphone 5 及更高版本中才被引入。