CODEWITHSUNDEEP
c++node.jsopencvelectronscreen
Michal
Michal

Reputation: 5220

electron.desktopCapturer to cv.VideoCapture [electron, nodejs, opencv4nodejs]

I spent couple hours browsing the internet and searching for some solution how to capture desktop (or window) and send it to OpenCv VideoCapture so that I can do some computer vision magic on it.

After doing my research the only solution that I was able to think of is starting stream with desktopCapturer and passing the stream to opencv library.

I have this code:

const { desktopCapturer } = require('electron');
var cv = require('electron').remote.require('opencv4nodejs');

...some setup...

navigator.mediaDevices.getUserMedia({
  audio: false,
  video: {
    mandatory: {
      chromeMediaSource: 'desktop',
      chromeMediaSourceId: source.id,
      minWidth: 640,
      maxWidth: 640,
      minHeight: 320,
      maxHeight: 320,
    },
  },
})
.then((stream) => {
  console.log('stream ', stream);
  const videoUrl = URL.createObjectURL(stream);
  console.log('videoUrl', videoUrl);
  const capturedVideo = new cv.VideoCapture(videoUrl);
  console.log('captured video', capturedVideo);
})
.catch((error) => console.error(error));

But I get following error:

image

Upvotes: 1

Views: 676

Answers (1)

Michal
Michal

Reputation: 5220

Following piece of code actually handles the conversion between browser desktop capturer and nodejs for opencv and other libraries:

}).then((stream) => {
  const video = document.createElement('video');
  video.srcObject = stream;
  video.onloadedmetadata = () => {
  video.play();
  setInterval(() => {
    const canvas = document.createElement('canvas');
    canvas.getContext('2d').drawImage(video, 0, 0, 800, 800);
    canvas.toBlob(blob => {
      toBuffer(blob, function (err, buffer) {
        if (err) throw err;
        // do some magic with buffer
      });
    });
  }, 40);
};

Upvotes: 1

Related Questions