Playground to capture ios video input stream into a window

AVCaptureDevice-playground.swift

import Cocoa
import AVFoundation
import CoreMediaIO
import XCPlayground

var currentDevice: AVCaptureDevice!
var currentName: String!
var currentUUID: String!

var window = NSWindow(contentRect: NSRect(x: 30, y: 30, width: 375, height: 667),
                      styleMask: NSTitledWindowMask, backing: .buffered, defer: false)

let frame = NSRect(x: 0, y: 0, width: 375, height: 667)
let preview = NSView(frame: frame)


class IOSDeviceHelper: NSObject {

  override init () {
    super.init()
    visible()
  }

  
  func visible () {
    var prop = CMIOObjectPropertyAddress(
      mSelector: CMIOObjectPropertySelector(kCMIOHardwarePropertyAllowScreenCaptureDevices),
      mScope: CMIOObjectPropertyScope(kCMIOObjectPropertyScopeGlobal),
      mElement: CMIOObjectPropertyElement(kCMIOObjectPropertyElementMaster))
    
    var allow : UInt32 = 1
    let dataSize : UInt32 = 4
    let zero : UInt32 = 0
    CMIOObjectSetPropertyData(CMIOObjectID(kCMIOObjectSystemObject), &prop, zero, nil, dataSize, &allow)
  }

  func start () {
    print("\(AVCaptureDevice.devices().count)")
    NotificationCenter.default
        .addObserver(forName: NSNotification.Name.AVCaptureDeviceWasDisconnected, object: nil, queue: nil)
    { (notif) -> Void in
      self.iosDeviceDetached(device: notif.object! as! AVCaptureDevice)
    }
    
    NotificationCenter.default
      .addObserver(forName: NSNotification.Name.AVCaptureDeviceWasConnected, object: nil, queue: nil)
    { (notif) -> Void in
      self.iosDeviceAttached(device: notif.object! as! AVCaptureDevice)
    }
  }

  func iosDeviceAttached(device:AVCaptureDevice) {
    print("ios device attached \(device)")
    print("Found device \(device.localizedName)")
    
    if device.modelID! == "iOS Device" {
      currentDevice = device
      currentName = currentDevice.localizedName
      currentUUID = currentDevice.uniqueID
      print("hello \(currentName) aka \(currentUUID)")

      let session = AVCaptureSession()
      let input = (try! AVCaptureDeviceInput(device: currentDevice))
      let output = AVCaptureVideoDataOutput()
      
      session.addOutput(output)
      session.addInput(input)
      
      let layerPreview = AVCaptureVideoPreviewLayer(session: session)
      layerPreview?.videoGravity = AVLayerVideoGravityResizeAspectFill
      layerPreview?.frame = preview.bounds
    
      preview.layer = layerPreview
      preview.wantsLayer = true
      
      window.contentView!.addSubview(preview)
      window.makeKeyAndOrderFront(nil)
      
      session.startRunning()
    }
  }
  func iosDeviceDetached(device:AVCaptureDevice) {
    print("ios device detached")
    
    print("stop running")
    // session.stopRunning()
  }
}

let iosHelper = IOSDeviceHelper();
iosHelper.start();

// NSRunLoop.mainRunLoop().run()
XCPSetExecutionShouldContinueIndefinitely(continueIndefinitely: true)