Save Video Using AVFoundation Swift

you can use this code to save your videos in the photo library , You have to give the follwing parameters in which the most important is OutputURL.path which is filesystem path to the movie file you want to save to the Camera Roll album , For the rest of the parameters you can either pass there respective values or you can also assign nil that depends on your need

func fileOutput(_ output: AVCaptureFileOutput, didFinishRecordingTo outputFileURL: URL, from connections: [AVCaptureConnection], error: Error?) {

if (error != nil) {
        print("Error recording movie: \(error!.localizedDescription)")
    } else {


        UISaveVideoAtPathToSavedPhotosAlbum(outputFileURL.path, nil, #selector(CameraController.video(_:didFinishSavingWithError:contextInfo:)), nil)

    }
    outputURL = nil

}

Thank you for this. It was very helpful to me. Here is a version of Rhythmic Fistman's answer ported to Swift 3 with the required import statements and delegate methods.

import UIKit
import AVFoundation

class ViewController: UIViewController,
AVCaptureFileOutputRecordingDelegate {

var captureSession = AVCaptureSession()
var sessionOutput = AVCaptureStillImageOutput()
var movieOutput = AVCaptureMovieFileOutput()
var previewLayer = AVCaptureVideoPreviewLayer()

@IBOutlet var cameraView: UIView!

override func viewWillAppear(_ animated: Bool) {
    self.cameraView = self.view

    let devices = AVCaptureDevice.devices(withMediaType: AVMediaTypeVideo)
    for device in devices! {
        if (device as AnyObject).position == AVCaptureDevicePosition.front{


            do{

                let input = try AVCaptureDeviceInput(device: device as! AVCaptureDevice)

                if captureSession.canAddInput(input){

                    captureSession.addInput(input)
                    sessionOutput.outputSettings = [AVVideoCodecKey : AVVideoCodecJPEG]

                    if captureSession.canAddOutput(sessionOutput){

                        captureSession.addOutput(sessionOutput)

                        previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
                        previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
                        previewLayer.connection.videoOrientation = AVCaptureVideoOrientation.portrait
                        cameraView.layer.addSublayer(previewLayer)

                        previewLayer.position = CGPoint(x: self.cameraView.frame.width / 2, y: self.cameraView.frame.height / 2)
                        previewLayer.bounds = cameraView.frame


                    }

                    captureSession.addOutput(movieOutput)

                    captureSession.startRunning()

                    let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
                    let fileUrl = paths[0].appendingPathComponent("output.mov")
                    try? FileManager.default.removeItem(at: fileUrl)
                    movieOutput.startRecording(toOutputFileURL: fileUrl, recordingDelegate: self)

                    let delayTime = DispatchTime.now() + 5
                    DispatchQueue.main.asyncAfter(deadline: delayTime) {
                        print("stopping")
                        self.movieOutput.stopRecording()
                    }
                }

            }
            catch{

                print("Error")
            }

        }
    }

}


//MARK: AVCaptureFileOutputRecordingDelegate Methods

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

}

func capture(_ captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAt outputFileURL: URL!, fromConnections connections: [Any]!, error: Error!) {
    print("FINISHED \(error)")
    // save video to camera roll
    if error == nil {
        UISaveVideoAtPathToSavedPhotosAlbum(outputFileURL.path, nil, nil, nil)
    }
}

}

You can save record your video to file by creating and adding an AVCaptureMovieFileOutput to your capture session, and making your ViewController conform to the AVCaptureFileOutputRecordingDelegate.

This example records 5 seconds of video to a file called "output.mov" in the app's Documents directory.

class ViewController: UIViewController, AVCaptureFileOutputRecordingDelegate {

    var captureSession = AVCaptureSession()
    var sessionOutput = AVCaptureStillImageOutput()
    var movieOutput = AVCaptureMovieFileOutput()
    var previewLayer = AVCaptureVideoPreviewLayer()

    @IBOutlet var cameraView: UIView!

    override func viewWillAppear(animated: Bool) {
        self.cameraView = self.view

        let devices = AVCaptureDevice.devicesWithMediaType(AVMediaTypeVideo)
        for device in devices {
            if device.position == AVCaptureDevicePosition.Front{


                do{

                    let input = try AVCaptureDeviceInput(device: device as! AVCaptureDevice)

                    if captureSession.canAddInput(input){

                        captureSession.addInput(input)
                        sessionOutput.outputSettings = [AVVideoCodecKey : AVVideoCodecJPEG]

                        if captureSession.canAddOutput(sessionOutput){

                            captureSession.addOutput(sessionOutput)

                            previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
                            previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
                            previewLayer.connection.videoOrientation = AVCaptureVideoOrientation.Portrait
                            cameraView.layer.addSublayer(previewLayer)

                            previewLayer.position = CGPoint(x: self.cameraView.frame.width / 2, y: self.cameraView.frame.height / 2)
                            previewLayer.bounds = cameraView.frame


                        }

                        captureSession.addOutput(movieOutput)

                        captureSession.startRunning()

                        let paths = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
                        let fileUrl = paths[0].URLByAppendingPathComponent("output.mov")
                        try? NSFileManager.defaultManager().removeItemAtURL(fileUrl)
                        movieOutput.startRecordingToOutputFileURL(fileUrl, recordingDelegate: self)

                        let delayTime = dispatch_time(DISPATCH_TIME_NOW, Int64(5 * Double(NSEC_PER_SEC)))
                        dispatch_after(delayTime, dispatch_get_main_queue()) {
                            print("stopping")
                            self.movieOutput.stopRecording()
                        }
                    }

                }
                catch{

                    print("Error")
                }

            }
        }

    }

    func captureOutput(captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAtURL outputFileURL: NSURL!, fromConnections connections: [AnyObject]!, error: NSError!) {
        print("FINISHED \(error)")
        // save video to camera roll
        if error == nil {
            UISaveVideoAtPathToSavedPhotosAlbum(outputFileURL.path!, nil, nil, nil)
        }
    }

}