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

newzera dev

Recording video in chunks means: record something for a while, then pause for sometime, again record something and so on..

stevenxu

@newzera dev Looks like you also raised a support ticket on this topic and is now resolved.

Sharing here for future devs that might have the same question:

There is no direct API to do that however app dev can use the current APIs to start-stop recording themselves.

stevenxu

@newzera dev Hmm good question.. You should be able to, but let me double check with our team. Hang tightt thanks!

kaileygu

thanks for sharing this information
its nice for me

aidan

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!")
}
// }

stevenxu

@aidan MVP. Ty!