Using OpenCV Output as Webcam

Question

So, I want to write a program to make the processed output from OpenCV be seen as a WebCam. I want to use it to create effects for a program like Skype. I am stuck and Googl

Answer 1

One way is to doing this is send Mat object directly to socket and at the received side convert byte array to Mat but the problem is you need to install OpenCV on both both PC. In another way you can use Mjpeg streamer to stream video to ibternet and process the video at receiving side, here you need to install OpenCV on receiving side only.

Using Socket

Get Mat.data and directly send to the socket, the data format is like BGR BGR BGR.... On the receiving side you should know the size of image you are going to receive. After receiving just assign the received buffer(BGR BGR... array) to a Mat of size you already know.

Client:-

Mat frame;
frame = (frame.reshape(0,1)); // to make it continuous

int  imgSize = frame.total()*frame.elemSize();

// Send data here
bytes = send(clientSock, frame.data, imgSize, 0))

Server:-

Mat  img = Mat::zeros( height,width, CV_8UC3);
   int  imgSize = img.total()*img.elemSize();
   uchar sockData[imgSize];

 //Receive data here

   for (int i = 0; i < imgSize; i += bytes) {
   if ((bytes = recv(connectSock, sockData +i, imgSize  - i, 0)) == -1) {
     quit("recv failed", 1);
    }
   }

 // Assign pixel value to img

 int ptr=0;
 for (int i = 0;  i < img.rows; i++) {
  for (int j = 0; j < img.cols; j++) {                                     
   img.at(i,j) = cv::Vec3b(sockData[ptr+ 0],sockData[ptr+1],sockData[ptr+2]);
   ptr=ptr+3;
   }
  }

For socket programming you can refer this link

Using Mjpeg Streamer

Here you need to install Mjpeg streamer software in PC where web cam attached and on all receiving PC you need to install OpenCV and process from there. You can directly open web stream using OpenCV VideoCapture class like

Cap.open("http://192.168.1.30:8080/?dummy=param.mjpg");