C++ VideoBuffer::data方法代码示例

void CaptureCallback::ContextData::readImage()
{
    int width = _graphicsContext->getTraits()->width;
    int height = _graphicsContext->getTraits()->height;

    if (width!=_width || _height!=height)
    {
        _width = width; 
        _height = height;
    }
    

    if (_delegate)
    {
 
        VideoBuffer *buffer = _delegate->getVideoBuffer();

        GLint internalFormat = GL_BGRA;     // This is fine for iOS

#ifdef ANDROID                              // Depending in the platform / android version, the pixel format will change
        glGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_FORMAT, &internalFormat);
        if (internalFormat == GL_RGB)
            internalFormat = GL_RGBA;
#endif
        
        buffer->pixelFormat = internalFormat;


        size_t bpp = buffer->bpp();
        size_t bpr = buffer->bpr();

        GLubyte *pixelBufferData = (GLubyte *)buffer->data();

        glReadPixels(0, 0, width, height, internalFormat, GL_UNSIGNED_BYTE, pixelBufferData);

        
        if (bpr != width*bpp){

            // There is some padding expected in the buffer, let's move stuff around
            for (int y = height-1; y > 0; --y){

                memmove(pixelBufferData + y * bpr, pixelBufferData + y * width * bpp, width * bpp);

            }
            
        } 
        
        _delegate->didCaptureImage();
        
    }
}

//.........这里部分代码省略.........
    namedWindow("Vision",1);
    //createTrackbar("Thresh Type", "Vision", &type, 4, NULL); // callback not needed
	  //createTrackbar("Min Value", "Vision", &defMin, 255, NULL); // callback not needed
	  //createTrackbar("Max Value", "Vision", &defMax, 255, NULL); // callback not needed
	  createTrackbar("Percent Tall", "Vision", &defTall, 20, NULL); // callback not needed
	  createTrackbar("Percent Narr", "Vision", &defNarr, 20, NULL); // callback not needed
	} else {
	  table->PutNumber("Horizontal Percent Error", defTall);
	  table->PutNumber("Vertical Percent Error", defNarr);
	}
	
	for (int i = 0; i<10; i++)
		start[i] = getmsofday(); // pre-load with 'now'
	for (int i = 0; 1; i++) {
		// Receive key-press updates, it is required if you want to output images,
		// so the task takes a moment to update the display.
		if (waitKey(1) > 0)
			break;
		
    string fileStream = "Mask"; // Default if no table present
		if (table->IsConnected()) {
	    NetworkTable *StreamsTable = table->GetSubTable("File Streams");
	    if (StreamsTable && StreamsTable->ContainsKey("selected")) {
        fileStream = StreamsTable->GetString("selected");
      }
		}
		
		ShowMask = (fileStream == "Mask");
		
		// Grab a frame from the vision API
		VideoBuffer buffer = v.grabFrame();
		
		// Put the frame into an OpenCV image matrix with a single color (gray scale)
		Mat image(height, width, CV_8UC1, buffer.data(), false); // AKA 'Y'

    Mat dst; // this will be a RGB version of the source image
    
#if defined(YOU_WANT_RGB_COLOR_INSTEAD_OF_GREYSCALE)    
		// There is more data after the gray scale (Y) that contains U&V
		Mat cb(height/2, width/2, CV_8UC1, buffer.data()+(height*width), false); // 'U'
		Mat cr(height/2, width/2, CV_8UC1, buffer.data()+(height*width)*5/4, false); // 'V'

    // size up cb and cr to be same as y
    Mat CB;
    resize(cb,CB,cvSize(width,height));
    Mat CR;
    resize(cr,CR,cvSize(width,height));
    
    // empty image same as full (gray scale) image, but 3 channels:
    Mat ycbcr(height,width, CV_8UC3);

    Mat in[] = {image, CB, CR};
    int fromto[] = {0,0, 1,1, 2,2}; // YUV
    
    // mash 3 channels from 2 matrix into a single 3 channel matrix:
    mixChannels(in,3, &ycbcr,1, fromto,3);
    
    // convert that 3 channel YUV matrix into 3 channel RGB (displayable)
    cvtColor(ycbcr,image,CV_YCrCb2RGB);
		if (ShowMask) {
      dst = image.clone(); // make a copy, as we want dst to have the same RGB version
    }
#else
    // After calculates, we want to draw 'on' the image, showing our results
    // graphically in some fashion -- that has to happen on a RGB
		if (ShowMask) {