Is it possible to record a video in chunks using the snap camera kit?

On iOS you can totally implement this yourself using the SCCameraKitOutputRequiringPixelBufferDelegate to grab the camera frame and pipe them into an AVAssetWriter

class CameraKitOutputToImage: NSObject, Output, OutputRequiringPixelBuffer, SCCameraKitOutputRequiringPixelBufferDelegate  {

    var view: UIViewController;

    var currentlyRequiresPixelBuffer: Bool

    var delegate: SCCameraKitOutputRequiringPixelBufferDelegate?

    func outputChangedRequirements(_ output: OutputRequiringPixelBuffer) {

    }

    func cameraKit(_ cameraKit: CameraKitProtocol, didOutputTexture texture: Texture) {

    }

    func cameraKit(_ cameraKit: CameraKitProtocol, didOutputVideoSampleBuffer sampleBuffer: CMSampleBuffer) {

        // you get your frames here! pipe them into your video creator

    }

    func cameraKit(_ cameraKit: CameraKitProtocol, didOutputAudioSampleBuffer sampleBuffer: CMSampleBuffer) {

    }

    init (view: UIViewController) {
        self.currentlyRequiresPixelBuffer = true;
        self.view = view;
        super.init();
    }

    func togglePixelBuffer () {
        self.currentlyRequiresPixelBuffer = !self.currentlyRequiresPixelBuffer;
    }
}

...

class CustomizedCameraViewController: CameraViewController {

    @State private var cameraFrame: CameraKitOutputToImage?

    override func viewDidLoad() {
            super.viewDidLoad()
            self.cameraController.cameraKit.add(output: cameraFrame(view: self));
     }

...

Warning: this next part is unverified GPT output

import AVFoundation

class VideoCreator {
    private var assetWriter: AVAssetWriter!
    private var videoInput: AVAssetWriterInput!
    private var pixelBufferAdaptor: AVAssetWriterInputPixelBufferAdaptor!

    init(outputURL: URL, size: CGSize) {
        do {
            assetWriter = try AVAssetWriter(outputURL: outputURL, fileType: .mp4)

            let videoOutputSettings: [String: Any] = [
                AVVideoCodecKey: AVVideoCodecType.h264,
                AVVideoWidthKey: size.width,
                AVVideoHeightKey: size.height
            ]

            videoInput = AVAssetWriterInput(mediaType: .video, outputSettings: videoOutputSettings)
            pixelBufferAdaptor = AVAssetWriterInputPixelBufferAdaptor(assetWriterInput: videoInput, sourcePixelBufferAttributes: nil)

            if assetWriter.canAdd(videoInput) {
                assetWriter.add(videoInput)
            }

        } catch {
            print("Error initializing AVAssetWriter: \(error.localizedDescription)")
        }
    }

    func start() {
        if assetWriter.startWriting() {
            assetWriter.startSession(atSourceTime: .zero)
        }
    }

    func append(sampleBuffer: CMSampleBuffer) {
        if let pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) {
            while !videoInput.isReadyForMoreMediaData {
                usleep(10)
            }
            pixelBufferAdaptor.append(pixelBuffer, withPresentationTime: CMSampleBufferGetPresentationTimeStamp(sampleBuffer))
        }
    }

    func finish(completion: @escaping () -> Void) {
        videoInput.markAsFinished()
        assetWriter.finishWriting {
            completion()
        }
    }
}

Then you would add code like this into the delegate wherever it makes sense

let outputURL = ... // URL to save the mp4 file
let videoSize = CGSize(width: 1280, height: 720)
let videoCreator = VideoCreator(outputURL: outputURL, size: videoSize)

videoCreator.start()

func cameraKit(_ cameraKit: CameraKitProtocol, didOutputVideoSampleBuffer sampleBuffer: CMSampleBuffer) {
      //if is user holding down record then {
      videoCreator.append(sampleBuffer: yourSampleBuffer)
     //}
}

// if user is done recording then {
videoCreator.finish {
    print("Video saved!")
}
// }