Hold Button to record a video with AVFoundation, Swift 3 - ios

Question

I am trying to figure out how to record a video using AVFoundation in Swift. I have got as far as creating a custom camera but I only figured out how to take still pictures with it and I can't figure out how to record video. Hope you can help me figure this one out.
I want to hold the takePhotoButton to record the video and then it will be previewed where I preview my current still photos. Your help will really help me continuing my project. Thanks a lot!
import UIKit
import AVFoundation
#available(iOS 10.0, *)
class CameraViewController: UIViewController,AVCaptureVideoDataOutputSampleBufferDelegate {
let photoSettings = AVCapturePhotoSettings()
var audioPlayer = AVAudioPlayer()
var captureSession = AVCaptureSession()
var videoDeviceInput: AVCaptureDeviceInput!
var previewLayer = AVCaptureVideoPreviewLayer()
var frontCamera: Bool = false
var captureDevice:AVCaptureDevice!
var takePhoto = false
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
prepareCamera()
}
func prepareCamera() {
captureSession.sessionPreset = AVCaptureSessionPresetPhoto
if let availableDevices = AVCaptureDeviceDiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaTypeVideo, position: .back).devices {
captureDevice = availableDevices.first
beginSession()
}
}
func frontCamera(_ front: Bool){
let devices = AVCaptureDevice.devices()
do{
try captureSession.removeInput(AVCaptureDeviceInput(device:captureDevice!))
}catch{
print("Error")
}
for device in devices!{
if((device as AnyObject).hasMediaType(AVMediaTypeVideo)){
if front{
if (device as AnyObject).position == AVCaptureDevicePosition.front {
captureDevice = device as? AVCaptureDevice
do{
try captureSession.addInput(AVCaptureDeviceInput(device: captureDevice!))
}catch{}
break
}
}else{
if (device as AnyObject).position == AVCaptureDevicePosition.back {
captureDevice = device as? AVCaptureDevice
do{
try captureSession.addInput(AVCaptureDeviceInput(device: captureDevice!))
}catch{}
break
}
}
}
}
}
func beginSession () {
do {
let captureDeviceInput = try AVCaptureDeviceInput(device: captureDevice)
if let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession) {
self.previewLayer = previewLayer
containerView.layer.addSublayer(previewLayer as? CALayer ?? CALayer())
self.previewLayer.frame = self.view.layer.frame
self.previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
previewLayer.connection.videoOrientation = AVCaptureVideoOrientation.portrait
captureSession.startRunning()
let dataOutput = AVCaptureVideoDataOutput()
dataOutput.videoSettings = [(kCVPixelBufferPixelFormatTypeKey as NSString):NSNumber(value:kCVPixelFormatType_32BGRA)]
dataOutput.alwaysDiscardsLateVideoFrames = true
if captureSession.canAddOutput(dataOutput) {
captureSession.addOutput(dataOutput)
photoSettings.isHighResolutionPhotoEnabled = true
photoSettings.isAutoStillImageStabilizationEnabled = true
}
captureSession.commitConfiguration()
let queue = DispatchQueue(label: "com.NightOut.captureQueue")
dataOutput.setSampleBufferDelegate(self, queue: queue)
}
}
#IBAction func takePhoto(_ sender: Any) {
takePhoto = true
photoSettings.isHighResolutionPhotoEnabled = true
photoSettings.isAutoStillImageStabilizationEnabled = true
}
func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputSampleBuffer sampleBuffer: CMSampleBuffer!, from connection: AVCaptureConnection!) {
if takePhoto {
takePhoto = false
if let image = self.getImageFromSampleBuffer(buffer: sampleBuffer) {
let photoVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "PhotoVC") as! PhotoPreviewViewController
photoVC.takenPhoto = image
DispatchQueue.main.async {
self.present(photoVC, animated: true, completion: {
self.stopCaptureSession()
})
}
}
}
}
func getImageFromSampleBuffer (buffer:CMSampleBuffer) -> UIImage? {
if let pixelBuffer = CMSampleBufferGetImageBuffer(buffer) {
let ciImage = CIImage(cvPixelBuffer: pixelBuffer)
let context = CIContext()
let imageRect = CGRect(x: 0, y: 0, width: CVPixelBufferGetWidth(pixelBuffer), height: CVPixelBufferGetHeight(pixelBuffer))
if let image = context.createCGImage(ciImage, from: imageRect) {
return UIImage(cgImage: image, scale: UIScreen.main.scale, orientation: .leftMirrored)
}
}
return nil
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
self.captureSession.stopRunning()
}
func stopCaptureSession () {
self.captureSession.stopRunning()
if let inputs = captureSession.inputs as? [AVCaptureDeviceInput] {
for input in inputs {
self.captureSession.removeInput(input)
}
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
#IBAction func DismissButtonAction(_ sender: UIButton) {
UIView.animate(withDuration: 0.1, animations: {
self.DismissButton.transform = CGAffineTransform.identity.scaledBy(x: 0.8, y: 0.8)
}, completion: { (finish) in
UIView.animate(withDuration: 0.1, animations: {
self.DismissButton.transform = CGAffineTransform.identity
})
})
performSegue(withIdentifier: "Segue", sender: nil)
}
}

Answer 1

To identify the holding down the button and releasing it, can be done in different ways. The easiest way would be adding a target for UIControlEvents.TouchUpInside and UIControlEvents.TouchDown for capture button like below.
aButton.addTarget(self, action: Selector("holdRelease:"), forControlEvents: UIControlEvents.TouchUpInside);
aButton.addTarget(self, action: Selector("HoldDown:"), forControlEvents: UIControlEvents.TouchDown)
//target functions
func HoldDown(sender:UIButton)
{
// Start recording the video
}
func holdRelease(sender:UIButton)
{
// Stop recording the video
}
There are other ways as well, like adding a long tap gesture recognizer to button or view and start/stop based on recognizer state. More info can be found here in another SO answer UIButton with hold down action and release action
Video Recording
You need to add AVCaptureMovieFileOutput to your capture session and use the method startRecordingToOutputFileURL to start the video recording.
Things to notice
Implement AVCaptureFileOutputRecordingDelegate method to identify the start and didFinish recording
File path should be meaningful, Which means you should give the correct file path which your app has access.
Have this code inside HoldDown() method to start recording
let videoFileOutput = AVCaptureMovieFileOutput()
self.captureSession?.addOutput(videoFileOutput)
let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0] as URL
let filePath = documentsURL.appendingPathComponent("tempMovie")
videoFileOutput.startRecording(toOutputFileURL: filePath, recordingDelegate: self)
to stop recording use vidoeFileOutput.stopRecording()

Answer 2

You need to use AVCaptureMovieFileOutput. Add AVCaptureMovieFileOutput to a capture session using addOutput(_:)
Starting a Recording
You start recording a QuickTime movie using
startRecording(to:recordingDelegate:). You need to supply a
file-based URL and a delegate. The URL must not identify an existing
file, because the movie file output does not overwrite existing
resources. You must also have permission to write to the specified
location. The delegate must conform to the
AVCaptureFileOutputRecordingDelegate protocol, and must implement the
fileOutput(_:didFinishRecordingTo:from:error:)
method.
See docs for more info.