Recording Video with AVFoundation in Swift for iOS

Question

I am having trouble recording video using the code provided. I am using example code created for recording video.

Specifically I am unable to compile this line without this error: "Cannot convert value of type 'ViewController' to specified type 'AVCaptureFileOutputRecordingDelegate'

var recordingDelegate:AVCaptureFileOutputRecordingDelegate? = self

This line is located in a IBAction function:

    @IBAction func RecordButtonPressed(_ sender: Any) {

    var recordingDelegate:AVCaptureFileOutputRecordingDelegate? = self

    var videoFileOutput = AVCaptureMovieFileOutput()
    self.captureSession.addOutput(videoFileOutput)

    let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
    let filePath = documentsURL.appendingPathComponent("temp")

    videoFileOutput.startRecording(toOutputFileURL: filePath, recordingDelegate: recordingDelegate)

    RecordButton.setTitle("Stop", for: .normal);

}

Rest of code is here:

import UIKit
import AVFoundation
import Darwin




class ViewController: UIViewController {



@IBOutlet weak var CameraView: UIImageView!

@IBOutlet weak var RecordButton: UIButton!

@IBOutlet weak var SelectFrButton: UIButton!

@IBOutlet weak var ISOslider: UISlider!

@IBOutlet weak var SSslider: UISlider!

@IBOutlet weak var ISOtextfield: UITextField!

@IBOutlet weak var SStextfield: UITextField!

@IBOutlet weak var TorchSlider: UISlider!

@IBOutlet weak var Torchtextfield: UITextField!

var captureSession = AVCaptureSession();
var DisplaySessionOutput = AVCaptureVideoDataOutput();
var SaveSessionOutput = AVCaptureMovieFileOutput();
var previewLayer = AVCaptureVideoPreviewLayer();
var CaptureDevice:AVCaptureDevice? = nil;
var CurrentTorchLevel:Float = 0.5;


override func viewDidLoad() {
    super.viewDidLoad()

    captureSession.sessionPreset = AVCaptureSessionPresetHigh
    // Loop through all the capture devices on this phone

    let deviceDiscoverySession = AVCaptureDeviceDiscoverySession(deviceTypes: [AVCaptureDeviceType.builtInDuoCamera, AVCaptureDeviceType.builtInTelephotoCamera,AVCaptureDeviceType.builtInWideAngleCamera], mediaType: AVMediaTypeVideo, position: AVCaptureDevicePosition.unspecified)

    for device in (deviceDiscoverySession?.devices)! {
        if(device.position == AVCaptureDevicePosition.back){
            do{

                try device.lockForConfiguration()


                device.setExposureModeCustomWithDuration(CMTimeMake(1, 30), iso: 50, completionHandler: { (time) in

                    // Set text and sliders to correct levels
                    self.ISOslider.maximumValue = (self.CaptureDevice?.activeFormat.maxISO)!;
                    self.ISOslider.minimumValue = (self.CaptureDevice?.activeFormat.minISO)!;

                    self.SSslider.maximumValue = Float((self.CaptureDevice?.activeFormat.maxExposureDuration.seconds)!);
                    self.SSslider.minimumValue = Float((self.CaptureDevice?.activeFormat.minExposureDuration.seconds)!);

                    self.ISOtextfield.text = device.iso.description;
                    self.ISOslider.setValue(device.iso, animated: false)

                    self.SStextfield.text = device.exposureDuration.seconds.description;
                    self.SSslider.setValue(Float(device.exposureDuration.seconds), animated: false);

                    self.TorchSlider.minimumValue = 0.01;
                    self.TorchSlider.maximumValue = 1;
                    self.TorchSlider.value = 0.5;
                    self.Torchtextfield.text = "0.5";
                })




                //Turn torch on

                if (device.torchMode == AVCaptureTorchMode.on) {
                    device.torchMode = AVCaptureTorchMode.off
                } else {
                    try device.setTorchModeOnWithLevel(1.0)

                }

                device.unlockForConfiguration();

                CaptureDevice = device;

                let input = try AVCaptureDeviceInput(device: CaptureDevice)
                if(captureSession.canAddInput(input)){
                    captureSession.addInput(input);

                    if(captureSession.canAddOutput(DisplaySessionOutput)){
                        captureSession.addOutput(DisplaySessionOutput);
                        previewLayer = AVCaptureVideoPreviewLayer(session: captureSession);
                        previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
                        previewLayer.connection.videoOrientation = AVCaptureVideoOrientation.portrait;
                        CameraView.layer.addSublayer(previewLayer);
                    }
                }
            }
            catch{
                print("exception!");
            }
        }
    }

    CameraView.transform = CGAffineTransform.init(scaleX: -1, y: -1);

    captureSession.startRunning()


}

    // Do any additional setup after loading the view, typically from a nib.


override func viewDidLayoutSubviews() {

    previewLayer.frame = CameraView.bounds

}


override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


@IBAction func RecordButtonPressed(_ sender: Any) {

    var recordingDelegate:AVCaptureFileOutputRecordingDelegate? = self

    var videoFileOutput = AVCaptureMovieFileOutput()
    self.captureSession.addOutput(videoFileOutput)

    let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
    let filePath = documentsURL.appendingPathComponent("temp")

    videoFileOutput.startRecording(toOutputFileURL: filePath, recordingDelegate: recordingDelegate)

    RecordButton.setTitle("Stop", for: .normal);

}

@IBAction func ISOvaluechanged(_ sender: Any) {

    SetVideoSettings(isolevel: ISOslider.value, exposurelevel: AVCaptureExposureDurationCurrent, TorchLevel: CurrentTorchLevel)
}

@IBAction func SSvaluechanged(_ sender: Any) {

    let time = CMTimeMake(Int64(self.SSslider.value * 1000000),1000000);
    SetVideoSettings(isolevel: AVCaptureISOCurrent, exposurelevel: time, TorchLevel: CurrentTorchLevel)
}

@IBAction func ISOtextchanged(_ sender: Any) {

}

@IBAction func SStextchanged(_ sender: Any) {

    //let time = CMTimeMake(Int64(exposurelevel * 100000),100000);

}


@IBAction func ChooseButtonPressed(_ sender: Any) {
}

func ShowAlert(AlertMessage: String) {

    let alertController = UIAlertController(title: "Alert", message: AlertMessage, preferredStyle: .alert)

    self.present(alertController, animated: true, completion:nil)

    let OKAction = UIAlertAction(title: "OK", style: .default) { (action:UIAlertAction) in
    }

    alertController.addAction(OKAction)

}

@IBAction func TorchSliderChanged(_ sender: Any) {

    CurrentTorchLevel = self.TorchSlider.value;
    SetVideoSettings(isolevel: AVCaptureISOCurrent, exposurelevel: AVCaptureExposureDurationCurrent, TorchLevel: CurrentTorchLevel);
}

func SetVideoSettings(isolevel: Float, exposurelevel: CMTime, TorchLevel: Float) {

    var newISOval = isolevel;
    var newSSval  = exposurelevel;
    let newTorchVal = TorchLevel;

    if(newISOval == FLT_MAX){
        // Pass through 0,0 for maintaining current SS.
    }

    else if(newISOval > (self.CaptureDevice?.activeFormat.maxISO)!) {

        newISOval = (self.CaptureDevice?.activeFormat.maxISO)!;
    }

    else if(newISOval < (self.CaptureDevice?.activeFormat.minISO)!) {

        newISOval = (self.CaptureDevice?.activeFormat.minISO)!;
    }

    if(newSSval.timescale == 0){
        // Pass through 0,0 for maintaining current SS.
    }

    else if(CMTimeCompare(newSSval, (self.CaptureDevice?.activeFormat.maxExposureDuration)!)  > 0) {

        newSSval = (self.CaptureDevice?.activeFormat.maxExposureDuration)!;
    }

    else if(CMTimeCompare(newSSval,(self.CaptureDevice?.activeFormat.minExposureDuration)!) < 0) {

        newSSval = (self.CaptureDevice?.activeFormat.minExposureDuration)!;
    }



      do {

        try self.CaptureDevice?.lockForConfiguration();

        try CaptureDevice?.setTorchModeOnWithLevel(newTorchVal);

        CaptureDevice?.setExposureModeCustomWithDuration(newSSval, iso: newISOval, completionHandler: { (time) in

            // Set text and sliders to correct levels
            self.ISOtextfield.text = self.CaptureDevice?.iso.description;
            self.ISOslider.setValue((self.CaptureDevice?.iso)!, animated: false)

            self.SStextfield.text = self.CaptureDevice?.exposureDuration.seconds.description;
            self.SSslider.setValue(Float((self.CaptureDevice?.exposureDuration.seconds)!), animated: false);

            self.TorchSlider.setValue(self.CurrentTorchLevel, animated: false);
            self.Torchtextfield.text = self.CurrentTorchLevel.description;

        })

        self.CaptureDevice?.unlockForConfiguration();

    }

    catch {
        ShowAlert(AlertMessage: "Unable to set camera settings");
        self.CaptureDevice?.unlockForConfiguration();


    }

}

func captureOutput(captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAtURL outputFileURL: NSURL!, fromConnections connections: [AnyObject]!, error: NSError!) {
    return
}

func captureOutput(captureOutput: AVCaptureFileOutput!, didStartRecordingToOutputFileAtURL fileURL: NSURL!, fromConnections connections: [AnyObject]!) {
    return
}

}

Thank you for any help you can provide!

gwinyai · Accepted Answer · 2016-11-28T19:40:12.163

1

Make an extension for your UIViewController that makes it conform to AVCaptureFileOutputRecordingDelegate. Remove and add the final two methods in your ViewController class into it.

   class ViewController:UIViewController {
      //your methods as usual but remove the final two methods and add them to the extension that follows. Those methods are what will make you conform to AVCaptureFileOutputRecordingDelegate
   }

  extension ViewController: AVCaptureFileOutputRecordingDelegate {
    func capture(_ captureOutput: AVCaptureFileOutput!, didStartRecordingToOutputFileAt fileURL: URL!, fromConnections connections: [Any]!) {

}

func capture(_ captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAt outputFileURL: URL!, fromConnections connections: [Any]!, error: Error!) {

}
  }

You can do the same thing by extending your UIViewController as below but I thought I'd give you a clean solution as above. You can choose.

    class ViewController:UIViewController, AVCaptureFileOutputRecordingDelegate {
  //your methods as usual but you keep your final two methods this time 

    func capture(_ captureOutput: AVCaptureFileOutput!, didStartRecordingToOutputFileAt fileURL: URL!, fromConnections connections: [Any]!) {

}

func capture(_ captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAt outputFileURL: URL!, fromConnections connections: [Any]!, error: Error!) {

}
    }

edited Nov 28 '16 at 19:40

answered Nov 28 '16 at 18:54

gwinyai

2,560
2
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17

Hi, thanks for the help. I tried the second solution but received the error: "Type 'ViewController' does not confirm to protocol 'AVCaptureFileOutputRecordingDelegate'" – aforward Nov 28 '16 at 19:14
To conform to AVCaptureFileOutputRecordingDelegate you need the two captureOutput methods in ViewController. I have updated my solution to include these more clearly. Do you still have them in there? The first error you got was because View Controller did not extend AVCaptureFileOutputRecordingDelegate so when you used 'self' in your @IBAction, Xcode was trying to convert a UIViewController to a AVCaptureFileOutputRecordingDelegate. – gwinyai Nov 28 '16 at 19:32
Figured it out. The methods have changed in Swift 3.0: https://developer.apple.com/reference/avfoundation/avcapturefileoutputrecordingdelegate (I'd suggest changing your answer for future troubleshooting. Thanks again for your help! – aforward Nov 28 '16 at 19:36
Yes. I wanted to give you the Swift 3 conventions but I thought you were using Swift 2 or something and I did not check if the methods were spelt correctly. I'll edit my answer with the correct Swift 3 and it should work. – gwinyai Nov 28 '16 at 19:38
I didn't know there was such a difference or I would have included it in the question. Definitely will from now on. – aforward Nov 28 '16 at 19:39
Cool. Yes in future you must be specific about Swift version. Method names have changed greatly. Hope all is well now. – gwinyai Nov 28 '16 at 19:41

Recording Video with AVFoundation in Swift for iOS

1 Answers1