iOS Video recording with AVFoundation - ios

Question

I need to open the camera and record the process. Also I have a timer, so according to the timer interval I should save multiple videos without stopping the record process.
So I use AVFoundation and in timer action I call 2 functions (stopRecording, startRecording).
TimerInterval is 4 seconds.
When I call stopRecording method "didFinishRecordingToOutputFileAtURL" delegate method does not return the record source immediately, it returns after 3 seconds, so I lose every second record.
Is there any other way to organize this kind of process or how can I fix this issue?
Thanks
func start(complition: (Error?, Bool)->()) {
setupSession { success in
if !success {
print("Error!")
return
}
setupPreview()
startSession()
let timeInterval = 4
timer = Timer.scheduledTimer(timeInterval: timeInterval, target: self, selector: #selector(timerAction), userInfo: nil, repeats: true)
}
}
func setupSession(complition: (Bool)->()) {
captureSession.beginConfiguration()
guard let camera = AVCaptureDevice.default(for: .video) else {
complition(false)
return
}
guard let mic = AVCaptureDevice.default(for: .audio) else {
complition(false)
return
}
do {
let videoInput = try AVCaptureDeviceInput(device: camera)
let audioInput = try AVCaptureDeviceInput(device: mic)
for input in [videoInput, audioInput] {
if captureSession.canAddInput(input) {
captureSession.addInput(input)
}
}
activeInput = videoInput
} catch {
print("Error setting device input: \(error)")
complition(false)
return
}
captureSession.addOutput(movieOutput)
captureSession.commitConfiguration()
}
func setupPreview() {
previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
previewLayer.frame = containerView.bounds
previewLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
containerView.layer.addSublayer(previewLayer)
}
func startSession() {
if !captureSession.isRunning {
DispatchQueue.global(qos: .default).async { [weak self] in
self?.captureSession.startRunning()
}
}
}
func stopSession() {
if captureSession.isRunning {
DispatchQueue.global(qos: .default).async() { [weak self] in
self?.captureSession.stopRunning()
}
}
}
public func captureMovie() {
guard let connection = movieOutput.connection(with: .video) else {
return
}
if connection.isVideoStabilizationSupported {
connection.preferredVideoStabilizationMode = .auto
}
let device = activeInput.device
if device.isSmoothAutoFocusEnabled {
do {
try device.lockForConfiguration()
device.isSmoothAutoFocusEnabled = true
device.unlockForConfiguration()
} catch {
print("error: \(error)")
}
}
guard let outUrl = tempURL else { return }
movieOutput.startRecording(to: outUrl, recordingDelegate: self)
}
public func stopRecording() {
if movieOutput.isRecording {
movieOutput.stopRecording()
}
}
func fileOutput(_ output: AVCaptureFileOutput, didFinishRecordingTo outputFileURL: URL, from connections: [AVCaptureConnection], error: Error?) {
print(Date.now, " ", "file")
if let error = error {
print("error: \(error.localizedDescription)")
} else {
// Save the source
}
}
#objc private func timerAction() {
print(Date.now, " timerAction")
stopRecording()
captureMovie()
}