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avcapturephotooutput-设置不能重复使用

avcapturesession avfoundation camera swift ios

Aakash Dave · 技术社区 · 7 年前

我正在运行iOS 12 Swift 4.2。

我已经实现了一个基本的相机拍摄会话,并点击其中的图像。在我将闪光灯切换到自动/打开/关闭模式之前,一切都很好。单击第一张照片,然后更改闪存模式后,应用程序将崩溃,并出现错误:

[AVCapturePhotoOutput capturePhotoWithSettings:delegate:] Settings may not be re-used'

以下是摄像头的实现:

var captureSession: AVCaptureSession!
var videoPreviewLayer: AVCaptureVideoPreviewLayer!
var capturePhotoOutput: AVCapturePhotoOutput!
let capturePhotoSettings = AVCapturePhotoSettings()


var previewView: UIView!


override func viewDidLoad() {
    startCameraSession()
    setupCaptureOutput()
}

@objc // Tap on a button to capture
func takePhotoOnTap() {
    guard let capturePhotoOutput = self.capturePhotoOutput else { return }

    capturePhotoSettings.isAutoStillImageStabilizationEnabled = true
    capturePhotoSettings.isHighResolutionPhotoEnabled = true
    capturePhotoSettings.flashMode = .auto
    let _ = getSettings(camera: captureDevice!, flashMode: spotmiCameraOptions.flashMode)
    capturePhotoOutput.capturePhoto(with: capturePhotoSettings, delegate: self)
}


    //This is a delegate method from the button
func toggleFlash(mode: FlashMode) {

    switch mode {
    case .auto:
        capturePhotoSettings.flashMode = .auto
    case .enabled:
        capturePhotoSettings.flashMode = .on
    case .disabled:
        capturePhotoSettings.flashMode = .off
    }

}


func setupCaptureOutput() {
    capturePhotoOutput = AVCapturePhotoOutput()
    capturePhotoOutput.isHighResolutionCaptureEnabled = true
    captureSession.addOutput(capturePhotoOutput)
}

func startCameraSession() {

    let captureDevice = AVCaptureDevice.default(.builtInDualCamera, for: AVMediaType.video, position: .back)

    do {
        let input = try AVCaptureDeviceInput(device: captureDevice!)
        captureSession = AVCaptureSession()
        captureSession.addInput(input)
        videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        videoPreviewLayer.videoGravity = .resizeAspectFill
        videoPreviewLayer.frame = self.view.layer.bounds
        camcontainer.layer.addSublayer(videoPreviewLayer)
        captureSession.startRunning()
    } catch {
        print(error.localizedDescription)
    }


}

func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photoSampleBuffer: CMSampleBuffer?, previewPhoto previewPhotoSampleBuffer: CMSampleBuffer?, resolvedSettings: AVCaptureResolvedPhotoSettings, bracketSettings: AVCaptureBracketedStillImageSettings?, error: Error?) {
    guard error == nil, let sampleBuffer = photoSampleBuffer else {
        print("error capturing photo due to \(String(describing: error?.localizedDescription))")
        return
    }
    guard let imageData = AVCapturePhotoOutput.jpegPhotoDataRepresentation(forJPEGSampleBuffer: sampleBuffer, previewPhotoSampleBuffer: previewPhotoSampleBuffer) else  { return }

    let capturedImage = UIImage(data: imageData, scale: 1.0)
    if let image = capturedImage {
        UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
    }
}

    func getSettings(camera: AVCaptureDevice, flashMode: FlashMode) -> AVCapturePhotoSettings {
    let settings = capturePhotoSettings

    if camera.hasFlash {
        switch flashMode {
//            case .auto: settings.flashMode = .auto
        case .enabled: settings.flashMode = .on
        case .disabled: settings.flashMode = .off
        default: settings.flashMode = .auto
        }
    }
    return settings
}

我真的不知道如何准确地重用 captureSettings 每次使用不同的闪光模式时都要更换。我已经回答了几个问题,但主要是关于手电筒的问题。我在找闪光灯。

任何帮助都非常感谢。

2 回复 | 直到 7 年前

Pratap 7 年前

AVCapturePhotoSettings 对象是唯一的,不能重复使用,因此每次使用此方法时都需要获取新设置:

func getSettings(camera: AVCaptureDevice, flashMode: CurrentFlashMode) -> AVCapturePhotoSettings {
    let settings = AVCapturePhotoSettings()

    if camera.hasFlash {
        switch flashMode {
           case .auto: settings.flashMode = .auto
           case .on: settings.flashMode = .on
           default: settings.flashMode = .off
        }
    }
    return settings
}

正如你所看到的, lockConfiguration 不需要。

CurrentFlashMode 是 enum ,这是为了保持清楚:

枚举当前FlashMode{ 断案案案例自动 }

然后在拍摄照片时使用它:

 @IBAction func captureButtonPressed(_ sender: UIButton) {
        let currentSettings = getSettings(camera: currentCamera, flashMode: currentFlashMode)
        photoOutput.capturePhoto(with: currentSettings, delegate: self)
    }

Ethan 7 年前

引用 AVCapturePhotoSettings 医生,见最后一个重要部分:

总结

用于单个照片捕获请求的功能和设置的规范。

宣言

类avCapturePhotosettings:nsObject 讨论

要拍摄照片,请创建并配置一个avCapturePhotosettings对象,然后将其传递给avCapturePhotoOutput CapturePhoto(with:delegate:)方法。 avCapturePhotosettings实例可以包含任何设置组合,而不管该组合是否对给定的捕获会话有效。当您通过将照片设置对象传递给avCapturePhotoOutputCapturePhoto(with:delegate:)方法来启动捕获时,照片捕获输出将验证您的设置以确保确定性行为。例如,flashmode设置必须指定照片输出__的受支持的flashmode s数组中存在的值。有关详细的验证规则,请参阅下面的每个属性说明。

重要的

对多个捕获重复使用avcapturephotosettings实例是非法的。如果设置对象的uniqueid值与以前使用的任何设置对象的uniqueid值匹配,则调用capturephoto(with:delegate:)方法将引发异常(invalidArgumentException)。 To reuse a specific combination of settings, use the init(from:) 初始值设定项从现有照片设置对象创建新的、唯一的avcapturephotosettings实例。

和你一样的问题: this github issue