open - ios AVFoundation toca para enfocar

open camera swift 4

Question

Intento crear una aplicación de cámara que, más o menos, actúe como la aplicación de cámara predeterminada. Lo que no funciona para mí en este momento, es tocar para enfocar. Quiero que la cámara enfoque y haga lo que haga en mi punto tocado, tal como lo hace la aplicación real de la cámara.

Aquí está mi viewDidLoad

- (void)viewDidLoad
{
    [super viewDidLoad];

    // Session
    _session = [[AVCaptureSession alloc] init];
    _session.sessionPreset = AVCaptureSessionPresetPhoto;

    // Input
    _videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    _videoInput = [AVCaptureDeviceInput deviceInputWithDevice:_videoDevice error:nil];

    // Output
    _frameOutput = [[AVCaptureVideoDataOutput alloc] init];
    _frameOutput.videoSettings = [NSDictionary dictionaryWithObject:AVVideoCodecJPEG forKey:AVVideoCodecKey];

    [_frameOutput setSampleBufferDelegate:self queue:dispatch_get_main_queue()];
    [_session addInput:_videoInput];
    [_session addOutput:_frameOutput];
    [_session startRunning];
};

Y aquí está el método que debería hacer que mi cámara enfocara todo al hacer clic.

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    [touches enumerateObjectsUsingBlock:^(id obj, BOOL *stop) {
        UITouch *touch = obj;
        CGPoint touchPoint = [touch locationInView:touch.view];
        focusLayer.frame = CGRectMake((touchPoint.x-25), (touchPoint.y-25), 50, 50);

        if ([_videoDevice isFocusPointOfInterestSupported]) {
            NSError *error;
            if ([_videoDevice lockForConfiguration:&error]) {
                [_videoDevice setFocusPointOfInterest:touchPoint];
                [_videoDevice setExposurePointOfInterest:touchPoint];

                [_videoDevice setFocusMode:AVCaptureFocusModeAutoFocus];
                if ([_videoDevice isExposureModeSupported:AVCaptureExposureModeAutoExpose]){
                    [_videoDevice setExposureMode:AVCaptureExposureModeAutoExpose];
                }
                [_videoDevice unlockForConfiguration];
            }
        }


        // NSLog(@"x = %f, y = %f", touchPoint.x, touchPoint.y);
    }];
}

Nada realmente sucede una vez que hago clic en la pantalla.

Answer 1

Tienes que ajustar el touchPoint a un rango de [0,1] usando algo como el siguiente código:

    CGRect screenRect = [[UIScreen mainScreen] bounds];
    screenWidth = screenRect.size.width;
    screenHeight = screenRect.size.height;  
    double focus_x = thisFocusPoint.center.x/screenWidth;
    double focus_y = thisFocusPoint.center.y/screenHeight;

    [[self captureManager].videoDevice lockForConfiguration:&error];
    [[self captureManager].videoDevice setFocusPointOfInterest:CGPointMake(focus_x,focus_y)];
    [[self captureManager].videoDevice unlockForConfiguration];

La documentación sobre esto se puede encontrar en Apple - Pautas de programación AV Foundation - ver la sección Captura de medios, donde encontrará información sobre los modos de enfoque :

Si es compatible, establezca el punto focal utilizando focusPointOfInterest. Usted pasa un CGPoint donde {0,0} representa la parte superior izquierda del área de la imagen, y {1,1} representa la parte inferior derecha en el modo horizontal con el botón de inicio a la derecha, esto se aplica incluso si el dispositivo está en modo vertical .

Answer 2

UITapGestureRecognizer *shortTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapToFocus:)];
shortTap.numberOfTapsRequired=1;
shortTap.numberOfTouchesRequired=1;
[viewCanvasRecording addGestureRecognizer:shortTap];

y luego esto:

- (void)handleTapToFocus:(UITapGestureRecognizer *)tapGesture
{
    AVCaptureDevice *acd=!currentFrontCamera ? captureBackInput.device : captureFrontInput.device;

    if (tapGesture.state == UIGestureRecognizerStateEnded)
    {
        CGPoint thisFocusPoint = [tapGesture locationInView:viewCanvasRecording];

        double focus_x = thisFocusPoint.x/viewCanvasRecording.frame.size.width;
        double focus_y = thisFocusPoint.y/viewCanvasRecording.frame.size.height;

        if ([acd isFocusModeSupported:AVCaptureFocusModeAutoFocus] && [acd isFocusPointOfInterestSupported])
        {
            if ([acd lockForConfiguration:nil])
            {
                [acd setFocusMode:AVCaptureFocusModeAutoFocus];
                [acd setFocusPointOfInterest:CGPointMake(focus_x, focus_y)];

                /*
                if ([acd isExposureModeSupported:AVCaptureExposureModeAutoExpose] && [acd isExposurePointOfInterestSupported])
                {
                    [acd setExposureMode:AVCaptureExposureModeAutoExpose];
                    [acd setExposurePointOfInterest:CGPointMake(focus_x, focus_y)];
                }*/

                [acd unlockForConfiguration];
            }
        }
    }
}

Una versión Swift:

@IBAction func tapToFocus(_ sender: UITapGestureRecognizer) {
    if (sender.state == .ended) {
        let thisFocusPoint = sender.location(in: previewView)

        print("touch to focus ", thisFocusPoint)

        let focus_x = thisFocusPoint.x / previewView.frame.size.width
        let focus_y = thisFocusPoint.y / previewView.frame.size.height

        if (captureDevice!.isFocusModeSupported(.autoFocus) && captureDevice!.isFocusPointOfInterestSupported) {
            do {
                try captureDevice?.lockForConfiguration()
                captureDevice?.focusMode = .autoFocus
                captureDevice?.focusPointOfInterest = CGPoint(x: focus_x, y: focus_y)

                if (captureDevice!.isExposureModeSupported(.autoExpose) && captureDevice!.isExposurePointOfInterestSupported) {
                    captureDevice?.exposureMode = .autoExpose;
                    captureDevice?.exposurePointOfInterest = CGPoint(x: focus_x, y: focus_y);
                 }

                captureDevice?.unlockForConfiguration()
            } catch {
                print(error)
            }
        }
    }
}