electron/docs/api/desktop-capturer.md

desktopCapturer

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

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.webkitGetUserMedia({
        audio: false,
        video: {
          mandatory: {
            chromeMediaSource: 'desktop',
            chromeMediaSourceId: sources[i].id,
            minWidth: 1280,
            maxWidth: 1280,
            minHeight: 720,
            maxHeight: 720
          }
        }
      }, handleStream, handleError)
      return
    }
  }
})

function handleStream (stream) {
  document.querySelector('video').src = URL.createObjectURL(stream)
}

function handleError (e) {
  console.log(e)
}

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

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

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 Object (optional) - The suggested size that the media source thumbnail should be scaled to, defaults to {width: 150, height: 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.