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IOS: Swift: capture a video screen

What is a screen device called in iOS / Swift?

When I print devices, I get

(
"<AVCaptureFigVideoDevice: 0x134d0f210 [Back Camera][com.apple.avfoundation.avcapturedevice.built-in_video:0]>",
"<AVCaptureFigVideoDevice: 0x134e0af80 [Front Camera][com.apple.avfoundation.avcapturedevice.built-in_video:1]>",
"<AVCaptureFigAudioDevice: 0x174265440 [iPad Microphone][com.apple.avfoundation.avcapturedevice.built-in_audio:0]>"
)

So where is the screen id?

There is too much deprecated object code c, and swift is a moving target. I am looking for a quick solution to capture video from the iPad screen and sound from the built-in microphone. Sound will be a separate issue.

Here is a screenshot for OS X

https://github.com/kennyledet/SwiftCap

    // AVCaptureSession holds inputs and outputs for real-time capture
let mSession = AVCaptureSession()
let mScreenCapOutput = AVCaptureMovieFileOutput()
var mOutputPath = ""
// Just capture main display for now
let mMainDisplayId = CGMainDisplayID()

but I can’t find the display identifier, CGMainDisplayID, for the iPad in the documentation ...

Here is a typical quick camera solution

https://github.com/bradley/iOSSwiftSimpleAVCamera

but it has too many errors and does not compile with iOS 8.1 or 8.2 and captures video from the camera.

func addVideoOutput() {
var rgbOutputSettings: NSDictionary = NSDictionary(object: Int(CInt(kCIFormatRGBA8)), forKey: kCVPixelBufferPixelFormatTypeKey)

    self.videoDeviceOutput = AVCaptureVideoDataOutput()

    self.videoDeviceOutput.alwaysDiscardsLateVideoFrames = true

    self.videoDeviceOutput.setSampleBufferDelegate(self, queue: self.sessionQueue)

    if self.session.canAddOutput(self.videoDeviceOutput) {
        self.session.addOutput(self.videoDeviceOutput)
    }
}

https://developer.apple.com/library/ios/documentation/AudioVideo/Conceptual/AVFoundationPG/Articles/04_MediaCapture.html#//apple_ref/doc/uid/TP40010188-CH5-SW18

Apple objective-c,

/*
 * Create video connection
 */
AVCaptureDeviceInput *videoIn = [[AVCaptureDeviceInput alloc] initWithDevice:[self videoDeviceWithPosition:AVCaptureDevicePositionBack] error:nil];
if ([_captureSession canAddInput:videoIn])
    [_captureSession addInput:videoIn];

AVCaptureVideoDataOutput *videoOut = [[AVCaptureVideoDataOutput alloc] init];
[videoOut setAlwaysDiscardsLateVideoFrames:YES];
[videoOut setVideoSettings:@{(id)kCVPixelBufferPixelFormatTypeKey : [NSNumber numberWithInt:kCVPixelFormatType_32BGRA]}];
dispatch_queue_t videoCaptureQueue = dispatch_queue_create("Video Capture Queue", DISPATCH_QUEUE_SERIAL);
[videoOut setSampleBufferDelegate:self queue:videoCaptureQueue];

if ([_captureSession canAddOutput:videoOut])
    [_captureSession addOutput:videoOut];
_videoConnection = [videoOut connectionWithMediaType:AVMediaTypeVideo];
self.videoOrientation = _videoConnection.videoOrientation;

if([self.session canSetSessionPreset:AVCaptureSessionPreset640x480])
    [self.session setSessionPreset:AVCaptureSessionPreset640x480]; // Lower video resolution to decrease recorded movie size

return YES;
}

.....???

+4
2

iOSSwiftSimpleAVCamera . , , . , , , .

//
//  AppDelegate.swift
//  iOSSwiftSimpleAVCamera
//
//  Created by Bradley Griffith on 7/1/14.
//  Copyright (c) 2014 Bradley Griffith. All rights reserved.
//

import UIKit
import CoreData

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?


    func applicationDidFinishLaunching(application: UIApplication) {

    }

    func applicationWillResignActive(application: UIApplication) {
        // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
        // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
    }

    func applicationDidEnterBackground(application: UIApplication) {
        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
        // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
    }

    func applicationWillEnterForeground(application: UIApplication) {
        // Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
    }

    func applicationDidBecomeActive(application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    }

    func applicationWillTerminate(application: UIApplication) {
        // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
        // Saves changes in the application managed object context before the application terminates.
        self.saveContext()
    }

    func saveContext () {
        var error: NSError? = nil
        let managedObjectContext = self.managedObjectContext
        //if managedObjectContext != nil {
            if managedObjectContext.hasChanges && !managedObjectContext.save(&error) {
                // Replace this implementation with code to handle the error appropriately.
                // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
                //println("Unresolved error \(error), \(error.userInfo)")
                abort()
           // &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&}
        }
    }

    // #pragma mark - Core Data stack

    // Returns the managed object context for the application.
    // If the context doesn't already exist, it is created and bound to the persistent store coordinator for the application.
    var managedObjectContext: NSManagedObjectContext {
        if !(_managedObjectContext != nil) {
            let coordinator = self.persistentStoreCoordinator
            //if coordinator != nil {
                _managedObjectContext = NSManagedObjectContext()
                _managedObjectContext!.persistentStoreCoordinator = coordinator
            //&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&}
        }
        return _managedObjectContext!
    }
    var _managedObjectContext: NSManagedObjectContext? = nil

    // Returns the managed object model for the application.
    // If the model doesn't already exist, it is created from the application model.
    var managedObjectModel: NSManagedObjectModel {
        if !(_managedObjectModel != nil) {
            let modelURL = NSBundle.mainBundle().URLForResource("iOSSwiftSimpleAVCamera", withExtension: "momd")
            _managedObjectModel = NSManagedObjectModel(contentsOfURL: modelURL!)
        }
        return _managedObjectModel!
    }
    var _managedObjectModel: NSManagedObjectModel? = nil

    // Returns the persistent store coordinator for the application.
    // If the coordinator doesn't already exist, it is created and the application store added to it.
    var persistentStoreCoordinator: NSPersistentStoreCoordinator {
        if !(_persistentStoreCoordinator != nil) {
            let storeURL = self.applicationDocumentsDirectory.URLByAppendingPathComponent("iOSSwiftSimpleAVCamera.sqlite")
            var error: NSError? = nil
            _persistentStoreCoordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
            if _persistentStoreCoordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: storeURL, options: nil, error: &error) == nil {
                /*
                Replace this implementation with code to handle the error appropriately.

                abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.

                Typical reasons for an error here include:
                * The persistent store is not accessible;
                * The schema for the persistent store is incompatible with current managed object model.
                Check the error message to determine what the actual problem was.


                If the persistent store is not accessible, there is typically something wrong with the file path. Often, a file URL is pointing into the application resources directory instead of a writeable directory.

                If you encounter schema incompatibility errors during development, you can reduce their frequency by:
                * Simply deleting the existing store:
                NSFileManager.defaultManager().removeItemAtURL(storeURL, error: nil)

                * Performing automatic lightweight migration by passing the following dictionary as the options parameter:
                [NSMigratePersistentStoresAutomaticallyOption: true, NSInferMappingModelAutomaticallyOption: true}

                Lightweight migration will only work for a limited set of schema changes; consult "Core Data Model Versioning and Data Migration Programming Guide" for details.

                */
                //println("Unresolved error \(error), \(error.userInfo)")
                abort()
            }
        }
        return _persistentStoreCoordinator!
    }
    var _persistentStoreCoordinator: NSPersistentStoreCoordinator? = nil

    // #pragma mark - Application Documents directory

    // Returns the URL to the application Documents directory.
    var applicationDocumentsDirectory: NSURL {
        let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
        return urls[urls.endIndex-1] as! NSURL
    }

}

CameraSessionController

//
//  CameraSessionController.swift
//  iOSSwiftSimpleAVCamera
//
//  Created by Bradley Griffith on 7/1/14.
//  Copyright (c) 2014 Bradley Griffith. All rights reserved.
//


import UIKit
import AVFoundation
import CoreMedia
import CoreImage

@objc protocol CameraSessionControllerDelegate {
    optional func cameraSessionDidOutputSampleBuffer(sampleBuffer: CMSampleBuffer!)
}

class CameraSessionController: NSObject, AVCaptureVideoDataOutputSampleBufferDelegate {

    var session: AVCaptureSession!
    var sessionQueue: dispatch_queue_t!
    var videoDeviceInput: AVCaptureDeviceInput!
    var videoDeviceOutput: AVCaptureVideoDataOutput!
    var stillImageOutput: AVCaptureStillImageOutput!
    var runtimeErrorHandlingObserver: AnyObject?
    var sessionDelegate: CameraSessionControllerDelegate?


    /* Class Methods
    ------------------------------------------*/

    class func deviceWithMediaType(mediaType: NSString, position: AVCaptureDevicePosition) -> AVCaptureDevice {
        var devices: NSArray = AVCaptureDevice.devicesWithMediaType(mediaType as String)
        var captureDevice: AVCaptureDevice = devices.firstObject as! AVCaptureDevice

        for object:AnyObject in devices {
            let device = object as! AVCaptureDevice
            if (device.position == position) {
                captureDevice = device
                break
            }
        }

        return captureDevice
    }


    /* Lifecycle
    ------------------------------------------*/

    override init() {
        super.init();

        self.session = AVCaptureSession()

        self.authorizeCamera();

        self.sessionQueue = dispatch_queue_create("CameraSessionController Session", DISPATCH_QUEUE_SERIAL)

        dispatch_async(self.sessionQueue, {
            self.session.beginConfiguration()
            self.addVideoInput()
            self.addVideoOutput()
            self.addStillImageOutput()
            self.session.commitConfiguration()
            })
    }


    /* Instance Methods
    ------------------------------------------*/

    func authorizeCamera() {
        AVCaptureDevice.requestAccessForMediaType(AVMediaTypeVideo, completionHandler: {
            (granted: Bool) -> Void in
            // If permission hasn't been granted, notify the user.
            if !granted {
                dispatch_async(dispatch_get_main_queue(), {
                    UIAlertView(
                        title: "Could not use camera!",
                        message: "This application does not have permission to use camera. Please update your privacy settings.",
                        delegate: self,
                        cancelButtonTitle: "OK").show()
                    })
            }
            });
    }

    func addVideoInput() -> Bool {
        var success: Bool = false
        var error: NSError?

        var videoDevice: AVCaptureDevice = CameraSessionController.deviceWithMediaType(AVMediaTypeVideo, position: AVCaptureDevicePosition.Back)
        self.videoDeviceInput = AVCaptureDeviceInput.deviceInputWithDevice(videoDevice, error: &error) as! AVCaptureDeviceInput;
        if !(error != nil) {
            if self.session.canAddInput(self.videoDeviceInput) {
                self.session.addInput(self.videoDeviceInput)
                success = true
            }
        }

        return success
    }

    func addVideoOutput() {
        //&&&&&&&&&&&&&&&&&&&&&var rgbOutputSettings: NSDictionary = NSDictionary(object: Int(CInt(kCIFormatRGBA8)), forKey: kCVPixelBufferPixelFormatTypeKey)

        self.videoDeviceOutput = AVCaptureVideoDataOutput()

        self.videoDeviceOutput.alwaysDiscardsLateVideoFrames = true

        self.videoDeviceOutput.setSampleBufferDelegate(self, queue: self.sessionQueue)

        if self.session.canAddOutput(self.videoDeviceOutput) {
            self.session.addOutput(self.videoDeviceOutput)
        }
    }

    func addStillImageOutput() {
        self.stillImageOutput = AVCaptureStillImageOutput()
        self.stillImageOutput.outputSettings = [AVVideoCodecKey: AVVideoCodecJPEG]

        if self.session.canAddOutput(self.stillImageOutput) {
            self.session.addOutput(self.stillImageOutput)
        }
    }

    func startCamera() {
        dispatch_async(self.sessionQueue, {
            var weakSelf: CameraSessionController? = self
            self.runtimeErrorHandlingObserver = NSNotificationCenter.defaultCenter().addObserverForName(AVCaptureSessionRuntimeErrorNotification, object: self.sessionQueue, queue: nil, usingBlock: {
                (note: NSNotification!) -> Void in

                let strongSelf: CameraSessionController = weakSelf!

                dispatch_async(strongSelf.sessionQueue, {
                    strongSelf.session.startRunning()
                })
            })
            self.session.startRunning()
        })
    }

    func teardownCamera() {
        dispatch_async(self.sessionQueue, {
            self.session.stopRunning()
            NSNotificationCenter.defaultCenter().removeObserver(self.runtimeErrorHandlingObserver!)
        })
    }

    func focusAndExposeAtPoint(point: CGPoint) {
        dispatch_async(self.sessionQueue, {
            var device: AVCaptureDevice = self.videoDeviceInput.device
            var error: NSErrorPointer!

            if device.lockForConfiguration(error) {
                if device.focusPointOfInterestSupported && device.isFocusModeSupported(AVCaptureFocusMode.AutoFocus) {
                    device.focusPointOfInterest = point
                    device.focusMode = AVCaptureFocusMode.AutoFocus
                }

                if device.exposurePointOfInterestSupported && device.isExposureModeSupported(AVCaptureExposureMode.AutoExpose) {
                    device.exposurePointOfInterest = point
                    device.exposureMode = AVCaptureExposureMode.AutoExpose
                }

                device.unlockForConfiguration()
            }
            else {
                // TODO: Log error.
            }
        })
    }

    func captureImage(completion:((image: UIImage?, error: NSError?) -> Void)?) {




        if (completion != nil){
        if(self.stillImageOutput != nil) {
            return
            }}

        dispatch_async(self.sessionQueue, {

            self.stillImageOutput.captureStillImageAsynchronouslyFromConnection(self.stillImageOutput.connectionWithMediaType(AVMediaTypeVideo), completionHandler: {
                (imageDataSampleBuffer: CMSampleBuffer?, error: NSError?) -> Void in


                if (imageDataSampleBuffer != nil)
                {
                    if(error != nil)
                    {
                        completion!(image:nil, error:nil)

                    }
                }

                else if (imageDataSampleBuffer != nil) {
                    var imageData: NSData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(imageDataSampleBuffer)
                    var image: UIImage = UIImage(data: imageData)!
                    completion!(image:image, error:nil)
                }
                })
            })
    }


    /* AVCaptureVideoDataOutput Delegate
    ------------------------------------------*/

    func captureOutput(captureOutput: AVCaptureOutput!, didOutputSampleBuffer sampleBuffer: CMSampleBuffer!, fromConnection connection: AVCaptureConnection!) {
        self.sessionDelegate?.cameraSessionDidOutputSampleBuffer?(sampleBuffer)
    }

}


//
//  CameraViewController.swift
//  iOSSwiftSimpleAVCamera
//
//  Created by Bradley Griffith on 7/1/14.
//  Copyright (c) 2014 Bradley Griffith. All rights reserved.
//


import UIKit
import CoreMedia
import AVFoundation

class CameraViewController: UIViewController, CameraSessionControllerDelegate {

    var cameraSessionController: CameraSessionController!
    var previewLayer: AVCaptureVideoPreviewLayer!


    /* Lifecycle
    ------------------------------------------*/

    override func viewDidLoad() {
        super.viewDidLoad()

        self.cameraSessionController = CameraSessionController()
        self.cameraSessionController.sessionDelegate = self
        self.setupPreviewLayer()
    }

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)

        self.cameraSessionController.startCamera()
    }

    override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)

        self.cameraSessionController.teardownCamera()
    }


    /* Instance Methods
    ------------------------------------------*/

    func setupPreviewLayer() {
        var minSize = min(self.view.bounds.size.width, self.view.bounds.size.height)
        var bounds: CGRect = CGRectMake(0.0, 0.0, minSize, minSize)
        self.previewLayer = AVCaptureVideoPreviewLayer(session: self.cameraSessionController.session)
        self.previewLayer.bounds = bounds
        self.previewLayer.position = CGPointMake(CGRectGetMidX(self.view.bounds), CGRectGetMidY(self.view.bounds))
        self.previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill

        self.view.layer.addSublayer(self.previewLayer)
    }

    func cameraSessionDidOutputSampleBuffer(sampleBuffer: CMSampleBuffer!) {
        // Any frame processing could be done here.
    }

}
+1

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