在上一节,我们实现了桌面捕获功能,并成功把桌面图像和麦克风声音发送给对方。在实际应用中,有时候会需要把桌面与摄像头图像叠加在一起发送,这节课我们就来看下如何实现这一功能。
1.备份与修改
备份demo11并修改demo11为demo12.
2.用新队列存放叠加前的图像数据
修改原函数capCam和capScr,用新的inCamQue和inScrQue存放摄像头和桌面图像Mat:
            
            
              cpp
              
              
            
          
          int fmle::capCam() {
	videoCap.open(0);
	cv::Mat camMat;
	while (true)
	{
		if (!videoCap.isOpened()){
			Sleep(1);
			continue;
		}
		BOOL ifSuccess = videoCap.read(camMat);
		if (camMat.empty())
		{
			Sleep(1);
			continue;
		}
		if (camMat.cols != backWidth || camMat.rows != backHeight){
			resize(camMat, camMat, cv::Size(backWidth, backHeight));
		}
		if (!camMat.empty()){			
			EnterCriticalSection(&videoQueLock);
			tmpVideoQueObj.type = 1;
			tmpVideoQueObj.tmpMat = camMat;
			tmpVideoQueObj.dataLen = camMat.cols*camMat.rows * 3;
			inCamQue.push(tmpVideoQueObj);
			if (inCamQue.size() >videoDataArrNum){
				inCamQue.front().dataLen = 0;
				inCamQue.front().tmpMat.release();
				inCamQue.front().dataLen = NULL;
				inCamQue.pop();
			}
			LeaveCriticalSection(&videoQueLock);
		}
		Sleep(40);
	}
	camMat.release();
	return 0;
}
int fmle::capScr(){
    
    HWND hwnd = GetDesktopWindow();
    cv::Mat scrMat;
    while (true)
    {
        scrMat = hwndToMat(hwnd);        
        if (scrMat.cols != backWidth || scrMat.rows != backHeight){
            resize(scrMat, scrMat, cv::Size(backWidth, backHeight));
        }
        if (scrMat.data&&!scrMat.empty()){        
            cvtColor(scrMat, scrMat, CV_BGRA2BGR);
            //mainDlg->drawMatOfPub(scrMat);
            EnterCriticalSection(&videoQueLock);
            tmpVideoQueObj.type = 1;
            tmpVideoQueObj.tmpMat = scrMat;
            tmpVideoQueObj.dataLen = scrMat.cols*scrMat.rows * 3;
            inScrQue.push(tmpVideoQueObj);
            if (inScrQue.size() >videoDataArrNum){
                inScrQue.front().dataLen = 0;
                inScrQue.front().tmpMat.release();
                inScrQue.front().dataLen = NULL;
                inScrQue.pop();
            }
            LeaveCriticalSection(&videoQueLock);
        }
        Sleep(40);
    }
    scrMat.release();    
    return 0;
}3.分别从桌面和摄像头队列取数据并叠加
新建一线程,调用mixVideo实现桌面和摄像头图像的叠加
            
            
              cpp
              
              
            
          
          int fmle::mixVideo(){
    cv::Mat camMat, scrMat, imageROI;
    while (true){
        if (inScrQue.size() > 0 && inCamQue.size() > 0){
            EnterCriticalSection(&videoQueLock);
            camMat = inCamQue.front().tmpMat.clone();
            resize(camMat, camMat, cv::Size(120, 80));
            scrMat = inScrQue.front().tmpMat.clone();
            if (!camMat.empty() && !scrMat.empty()){
                imageROI = scrMat(cv::Rect(0, 0, camMat.cols, camMat.rows));
                addWeighted(imageROI, 0, camMat, 1, 0.0, imageROI);
                mainDlg->drawMatOfPub(scrMat);
            }
            camMat.release();
            scrMat.release();
            imageROI.release();
            LeaveCriticalSection(&videoQueLock);
        }
        Sleep(40);
    }
    return 0;
}4.调试运行
效果如下:
