Запись видео с использованием AVAssetWriterInput

Question

Привет Я использую FirebaseMLVission для обнаружения eye blink для моих пользователей.Тем не менее, я мог только заставить его показать вывод, но он не записывает видео.В результате некоторых исследований я пришел к выводу, что единственный способ реализовать это - использовать AVAssetWriterInput.Я пытался реализовать это, но я получаю [AVAssetWriter startWriting] Cannot call method when status is 3 как ошибку.

Я сжал код так, чтобы он не занимал 100 страниц. Если я что-то пропустил, пожалуйста, дайте мне знать.

Я пытался реализовать это Захват видео с помощью AVFoundation

Спасибо

Я пробовал код из: https://geek -is-stupid.github.io / 2017-06-14-как записывать-обнаруживать лица-накладывать-видео-в-реальном времени, используя swift /

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https://github.com/BradLarson/GPUImage/issues/2015

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Руководство по очереди AVAssetWriter Swift 3

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    private let detectors: [Detector] = [.onDeviceFace, .onDeviceText]
    private var currentDetector: Detector = .onDeviceFace
    private var isUsingFrontCamera = true
    private var previewLayer: AVCaptureVideoPreviewLayer!
    private lazy var captureSession = AVCaptureSession()
    private lazy var sessionQueue = DispatchQueue(label: Constant.sessionQueueLabel)
    private lazy var vision = Vision.vision()
    private var lastFrame: CMSampleBuffer?
    fileprivate(set) lazy var isRecording = false
    fileprivate var videoWriter: AVAssetWriter!
    fileprivate var videoWriterInput: AVAssetWriterInput!
    fileprivate var audioWriterInput: AVAssetWriterInput!
    fileprivate var sessionAtSourceTime: CMTime?
    private lazy var previewOverlayView: UIImageView = {

        precondition(isViewLoaded)
        let previewOverlayView = UIImageView(frame: .zero)
        previewOverlayView.translatesAutoresizingMaskIntoConstraints = false
        return previewOverlayView

    }()

    private lazy var annotationOverlayView: UIView = {
        precondition(isViewLoaded)
        let annotationOverlayView = UIView(frame: .zero)
        annotationOverlayView.translatesAutoresizingMaskIntoConstraints = false
        return annotationOverlayView
    }()
    @IBOutlet weak var cameraView: UIView!

    override func viewDidLoad() {
        super.viewDidLoad()
        previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        setupWriter()
        setUpPreviewOverlayView()
        setUpAnnotationOverlayView()
        setUpCaptureSessionOutput()
        setUpCaptureSessionInput()
        // Do any additional setup after loading the view.
    }
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)

        startSession()
    }

    override func viewDidDisappear(_ animated: Bool) {
        super.viewDidDisappear(animated)

        stopSession()
    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()

        previewLayer.frame = cameraView.frame
    }

    // MARK: - IBActions
    @IBAction func RecordButton(_ sender: Any) {
        start()
    }
    @IBAction func StopRecordingButton(_ sender: Any) {
        stop()
    }


fileprivate func setupWriter() {
        do {
            let url = NSURL.fileURL(withPath: NSTemporaryDirectory(), isDirectory: true)

            videoWriter = try AVAssetWriter(url: url, fileType: AVFileType.mp4)

            //Add video input
            videoWriterInput = AVAssetWriterInput(mediaType: AVMediaType.video, outputSettings: [
                AVVideoCodecKey: AVVideoCodecType.h264,
                AVVideoWidthKey: 720,
                AVVideoHeightKey: 1280,
                AVVideoCompressionPropertiesKey: [
                    AVVideoAverageBitRateKey: 2300000,
                ],
                ])
            videoWriterInput.expectsMediaDataInRealTime = true //Make sure we are exporting data at realtime
            if videoWriter.canAdd(videoWriterInput) {
                videoWriter.add(videoWriterInput)
            }

            //Add audio input
            audioWriterInput = AVAssetWriterInput(mediaType: AVMediaType.audio, outputSettings: [
                AVFormatIDKey: kAudioFormatMPEG4AAC,
                AVNumberOfChannelsKey: 1,
                AVSampleRateKey: 44100,
                AVEncoderBitRateKey: 64000,
                ])
            audioWriterInput.expectsMediaDataInRealTime = true
            if videoWriter.canAdd(audioWriterInput) {
                videoWriter.add(audioWriterInput)
            }

            videoWriter.startWriting() //Means ready to write down the file
        }
        catch let error {
            debugPrint(error.localizedDescription)
        }
    }

private func setUpCaptureSessionOutput() {
        sessionQueue.async {
            self.captureSession.beginConfiguration()
            // When performing latency tests to determine ideal capture settings,
            // run the app in 'release' mode to get accurate performance metrics
            self.captureSession.sessionPreset = AVCaptureSession.Preset.medium
            //let output = AVCaptureMovieFileOutput()
            let output = AVCaptureVideoDataOutput()
            var audioDataOutput = AVCaptureAudioDataOutput()
            output.videoSettings =
                [(kCVPixelBufferPixelFormatTypeKey as String): kCVPixelFormatType_32BGRA]
            let outputQueue = DispatchQueue(label: Constant.videoDataOutputQueueLabel)
            output.setSampleBufferDelegate(self, queue: outputQueue)
            guard self.captureSession.canAddOutput(output) else {
                print("Failed to add capture session output.")
                return
            }
            self.captureSession.addOutput(output)
            //self.captureSession.addOutput(self.movieOutput)
            self.captureSession.commitConfiguration()
            self.captureSession.startRunning()
        }
    }
private func setUpCaptureSessionInput() {
        sessionQueue.async {
            let cameraPosition: AVCaptureDevice.Position = self.isUsingFrontCamera ? .front : .back
            guard let device = self.captureDevice(forPosition: cameraPosition) else {
                print("Failed to get capture device for camera position: \(cameraPosition)")
                return
            }
            do {
                self.captureSession.beginConfiguration()
                let currentInputs = self.captureSession.inputs
                for input in currentInputs {
                    self.captureSession.removeInput(input)
                }
                let audioInput = AVCaptureDevice.default(for: AVMediaType.audio)
                let input = try AVCaptureDeviceInput(device: device)
                guard self.captureSession.canAddInput(input) else {
                    print("Failed to add capture session input.")
                    return
                }
                self.captureSession.addInput(input)
                try self.captureSession.addInput(AVCaptureDeviceInput(device: audioInput!))
                self.captureSession.commitConfiguration()
            } catch {
                print("Failed to create capture device input: \(error.localizedDescription)")
            }



        }
    }

    private func startSession() {
        sessionQueue.async {
            self.captureSession.startRunning()
        }
    }

    private func stopSession() {
        sessionQueue.async {
            self.captureSession.stopRunning()
        }
    }

extension CameraTestViewController: AVCaptureVideoDataOutputSampleBufferDelegate {

    func captureOutput(
        _ output: AVCaptureOutput,
        didOutput sampleBuffer: CMSampleBuffer,
        from connection: AVCaptureConnection
        ) {
        guard let imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) else {
            print("Failed to get image buffer from sample buffer.")
            return
        }
        let writable = canWrite()

        if writable,
            sessionAtSourceTime == nil {
            //Start writing
            sessionAtSourceTime = CMSampleBufferGetPresentationTimeStamp(sampleBuffer)
            videoWriter.startSession(atSourceTime: sessionAtSourceTime!)
        }
        if videoWriterInput.isReadyForMoreMediaData {
            //Write video buffer
            videoWriterInput.append(sampleBuffer)
        }
        else if writable,
        //captureOutput == audioDataOutput,
        audioWriterInput.isReadyForMoreMediaData {
        //Write audio buffer
        audioWriterInput.append(sampleBuffer)
        }

        lastFrame = sampleBuffer
        let visionImage = VisionImage(buffer: sampleBuffer)
        let metadata = VisionImageMetadata()
        let orientation = UIUtilities.imageOrientation(
            fromDevicePosition: isUsingFrontCamera ? .front : .back
        )
        let visionOrientation = UIUtilities.visionImageOrientation(from: orientation)
        metadata.orientation = visionOrientation
        visionImage.metadata = metadata
        let imageWidth = CGFloat(CVPixelBufferGetWidth(imageBuffer))
        let imageHeight = CGFloat(CVPixelBufferGetHeight(imageBuffer))
        switch currentDetector {
        case .onDeviceFace:
            detectFacesOnDevice(in: visionImage, width: imageWidth, height: imageHeight)
        case .onDeviceText:
            recognizeTextOnDevice(in: visionImage, width: imageWidth, height: imageHeight)
        }


    }
}