desktopCapturer

Access information about media sources that can be used to capture audio and video from the desktop using the navigator.mediaDevices.getUserMedia API.

Process: Renderer

The following example shows how to capture video from a desktop window whose title is Electron:

// In the renderer process.
  const {desktopCapturer} = require('electron')
  
  desktopCapturer.getSources({types: ['window', 'screen']}, (error, sources) => {
    if (error) throw error
    for (let i = 0; i < sources.length; ++i) {
      if (sources[i].name === 'Electron') {
        navigator.mediaDevices.getUserMedia({
          audio: false,
          video: {
            mandatory: {
              chromeMediaSource: 'desktop',
              chromeMediaSourceId: sources[i].id,
              minWidth: 1280,
              maxWidth: 1280,
              minHeight: 720,
              maxHeight: 720
            }
          }
        })
        .then((stream) => handleStream(stream))
        .catch((e) => handleError(e))
        return
      }
    }
  })
  
  function handleStream (stream) {
    const video = document.querySelector('video')
    video.srcObject = stream
    video.onloadedmetadata = (e) => video.play()
  }
  
  function handleError (e) {
    console.log(e)
  }

To capture video from a source provided by desktopCapturer the constraints passed to navigator.mediaDevices.getUserMedia must include chromeMediaSource: 'desktop', and audio: false.

To capture both audio and video from the entire desktop the constraints passed to navigator.mediaDevices.getUserMedia must include chromeMediaSource: 'desktop', for both audio and video, but should not include a chromeMediaSourceId constraint.

const constraints = {
    audio: {
      mandatory: {
        chromeMediaSource: 'desktop'
      }
    },
    video: {
      mandatory: {
        chromeMediaSource: 'desktop'
      }
    }
  }

Methods

The desktopCapturer module has the following methods:

desktopCapturer.getSources(options, callback)

• options Object

  • types String[] - An array of Strings that lists the types of desktop sources to be captured, available types are screen and window.
  • thumbnailSize Size (optional) - The size that the media source thumbnail should be scaled to. Default is 150 x 150.

• callback Function

  • error Error
  • sources DesktopCapturerSource[]

Starts gathering information about all available desktop media sources, and calls callback(error, sources) when finished.

sources is an array of DesktopCapturerSource objects, each DesktopCapturerSource represents a screen or an individual window that can be captured.