Wie capture frame-by-frame-Bilder aus iPhone-video-Aufzeichnung in Echtzeit

Ich versuche zur Messung der Sättigung der ausgewählten Farbe in real-Zeit, wie diese:

Ich bin nach diese Anleitung von Apple. Ich aktualisierte den code für die Arbeit mit BOGEN, und natürlich aus meiner Sicht-controller ein AVCaptureVideoDataOutputSampleBufferDelegate, aber ich weiß nicht, wie Sie tatsächlich beginnen, erfassen Sie die Daten, wie in der Inbetriebnahme der Kamera, um einige konkrete Eingabe.

Hier ist mein code:

#import "ViewController.h"

@interface ViewController ()

@property (nonatomic, strong) AVCaptureSession *session;
@property (nonatomic, strong) AVCaptureVideoPreviewLayer *previewLayer;

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    //Do any additional setup after loading the view, typically from a nib

    [self setupCaptureSession];

}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    //Dispose of any resources that can be recreated.
}

//Create and configure a capture session and start it running
- (void)setupCaptureSession
{
    NSError *error = nil;

    //Create the session
    AVCaptureSession *session = [[AVCaptureSession alloc] init];

    //Configure the session to produce lower resolution video frames, if your
    //processing algorithm can cope. We'll specify medium quality for the
    //chosen device.
    session.sessionPreset = AVCaptureSessionPresetMedium;

    //Find a suitable AVCaptureDevice
    AVCaptureDevice *device = [AVCaptureDevice
                               defaultDeviceWithMediaType:AVMediaTypeVideo];

    //Create a device input with the device and add it to the session.
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device
                                                                        error:&error];
    if (!input) {
        //Handling the error appropriately.
    }
    [session addInput:input];

    //Create a VideoDataOutput and add it to the session
    AVCaptureVideoDataOutput *output = [[AVCaptureVideoDataOutput alloc] init];
    [session addOutput:output];

    //Configure your output.
    dispatch_queue_t queue = dispatch_queue_create("myQueue", NULL);
    [output setSampleBufferDelegate:self queue:queue];

    //Specify the pixel format
    output.videoSettings =
    [NSDictionary dictionaryWithObject:
     [NSNumber numberWithInt:kCVPixelFormatType_32BGRA]
                                forKey:(id)kCVPixelBufferPixelFormatTypeKey];


    //Start the session running to start the flow of data
    [self startCapturingWithSession:session];

    //Assign session to an ivar.
    [self setSession:session];
}

- (void)startCapturingWithSession: (AVCaptureSession *) captureSession
{
    //----- DISPLAY THE PREVIEW LAYER -----
    //Display it full screen under out view controller existing controls
    NSLog(@"Display the preview layer");
    CGRect layerRect = [[[self view] layer] bounds];
    [self.previewLayer setBounds:layerRect];
    [self.previewLayer setPosition:CGPointMake(CGRectGetMidX(layerRect),
                                          CGRectGetMidY(layerRect))];
    //[[[self view] layer] addSublayer:[[self CaptureManager] self.previewLayer]];
    //We use this instead so it goes on a layer behind our UI controls (avoids us having to manually bring each control to the front):
    UIView *CameraView = [[UIView alloc] init];
    [[self view] addSubview:CameraView];
    [self.view sendSubviewToBack:CameraView];

    [[CameraView layer] addSublayer:self.previewLayer];


    //----- START THE CAPTURE SESSION RUNNING -----
    [captureSession startRunning];
}

//Delegate routine that is called when a sample buffer was written
- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
       fromConnection:(AVCaptureConnection *)connection
{
    //Create a UIImage from the sample buffer data
    UIImage *image = [self imageFromSampleBuffer:sampleBuffer];
}

//Create a UIImage from sample buffer data
- (UIImage *) imageFromSampleBuffer:(CMSampleBufferRef) sampleBuffer
{
    //Get a CMSampleBuffer's Core Video image buffer for the media data
    CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
    //Lock the base address of the pixel buffer
    CVPixelBufferLockBaseAddress(imageBuffer, 0);

    //Get the number of bytes per row for the pixel buffer
    void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);

    //Get the number of bytes per row for the pixel buffer
    size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
    //Get the pixel buffer width and height
    size_t width = CVPixelBufferGetWidth(imageBuffer);
    size_t height = CVPixelBufferGetHeight(imageBuffer);

    //Create a device-dependent RGB color space
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

    //Create a bitmap graphics context with the sample buffer data
    CGContextRef context = CGBitmapContextCreate(baseAddress, width, height, 8,
                                                 bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
    //Create a Quartz image from the pixel data in the bitmap graphics context
    CGImageRef quartzImage = CGBitmapContextCreateImage(context);
    //Unlock the pixel buffer
    CVPixelBufferUnlockBaseAddress(imageBuffer,0);

    //Free up the context and color space
    CGContextRelease(context);
    CGColorSpaceRelease(colorSpace);

    //Create an image object from the Quartz image
    UIImage *image = [UIImage imageWithCGImage:quartzImage];

    //Release the Quartz image
    CGImageRelease(quartzImage);

    return (image);
}

@end