获取AVCaptureSession samplebuffer 一像素的 rgb值

获取AVCaptureSession samplebuffer 一像素的 rgb值

typedef unsigned char byte;
typedef struct RGBPixel{
    byte red, green, blue;
} RGBPixel;

- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
       fromConnection:(AVCaptureConnection *)connection
{ 

    CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
    CVPixelBufferLockBaseAddress(imageBuffer,);

    size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
    size_t width = CVPixelBufferGetWidth(imageBuffer);
    size_t height = CVPixelBufferGetHeight(imageBuffer);
    uint8_t *src_buff = (uint8_t*)CVPixelBufferGetBaseAddress(imageBuffer);

    CVPixelBufferUnlockBaseAddress(imageBuffer, );
    RGBPixel *pixelData = (RGBPixel *)src_buff;

    int len = bytesPerRow * height;
    for(int i=; i<len; i+=){

        RGBPixel pixel = pixelData[i/];

        int a = ;
        int r = pixel.red;
        int g = pixel.green;
        int b = pixel.blue;

        NSLog(@"first values = r:%d g:%d b:%d", r, g, b);

        a = src_buff[i+];
        r = src_buff[i+];
        g = src_buff[i+];
        b = src_buff[i];

        NSLog(@"second values = r:%d g:%d b:%d", r, g, b);

    }

}

如果是BGRA

typedef struct RGBPixel{
    byte blue, green, red;
} RGBPixel;

参考：http://iphonedevsdk.com/forum/iphone-sdk-development/