Swift: CameraClass Explained

class CameraClass: NSObject, AVCaptureFileOutputRecordingDelegate {
    var session = AVCaptureSession()
    var videoDeviceInput: AVCaptureDeviceInput?
    var movieOutput = AVCaptureMovieFileOutput()

This class inherits from NSObject and conforms to AVCaptureFileOutputRecordingDelegate, enabling it to respond to recording events. The session and outputs are declared here.

override init() {
    super.init()
    prepare()
}

The initializer calls prepare() to request camera access and configure the session once permission is granted.

func prepare() {
    AVCaptureDevice.requestAccess(for: .video) { granted in
        if granted {
            print("Camera access granted")
            DispatchQueue.main.async {
                self.setupSession()
            }
        } else {
            print("Camera access denied")
        }
    }
}

Requests video permission. If granted, proceeds to setup the capture session on the main thread.

private func setupSession() {
    session.beginConfiguration()

    guard let camera = AVCaptureDevice.default(for: .video) else {
        print("No camera found")
        session.commitConfiguration()
        return
    }

Starts configuration. Attempts to access the default video camera. If unavailable, ends configuration early.

    do {
        let input = try AVCaptureDeviceInput(device: camera)
        if session.canAddInput(input) {
            session.addInput(input)
            videoDeviceInput = input
        }

Creates an input from the camera device and adds it to the session if allowed.

        if session.canAddOutput(movieOutput) {
            session.addOutput(movieOutput)
        }

Adds a video file output to the session.

        session.commitConfiguration()
        session.startRunning()
    } catch {
        print("Error setting up camera: \(error)")
        session.commitConfiguration()
    }
}

Commits the session configuration and starts the session. Catches and prints any setup errors.

func startRecording(to fileURL: URL) {
    if !movieOutput.isRecording {
        movieOutput.startRecording(to: fileURL, recordingDelegate: self)
    }
}

Begins recording to a specified URL if the output is not already recording.

func stopRecording() {
    if movieOutput.isRecording {
        movieOutput.stopRecording()
    }
}

Stops the recording session if it is active.

func fileOutput(_ output: AVCaptureFileOutput,
                didFinishRecordingTo outputFileURL: URL,
                from connections: [AVCaptureConnection],
                error: Error?) {
    if let error = error {
        print("Recording error: \(error)")
    } else {
        print("Video saved to: \(outputFileURL)")
    }
}

This delegate method is triggered when recording finishes. It checks for errors and prints the location of the saved video.