virtual-webcam chrome extension

This is a proof of concept of adding a virtual MediaDevice in a browser extension.

NOTE: You can use it as a regular library, check out cam.html.

To use (Chromium):

• download or clone the repo
• go to chrome://extensions
• enable Developer Mode
• Load unpacked
• Browse to the folder with the extension (where the manifest.json is)
• Note:Pages will need to be reloaded after an extension is installed to be able to use it

To use (Firefox):

• download or clone the repo
• go to about:debugging#/runtime/this-firefox
• Click "Load Temporary Add-on..."
• Browse to the folder with the extension and select the manifest.json
• Note:Pages will need to be reloaded after an extension is installed to be able to use it

Now any (most) pages using getUserMedia should be able to see a "Chrome Virtual Webcam" device

Should work on Chromium based browsers that support extensions.

Caveats:

• Some pages use shims or do some checks that might break with the extension
  • WebRTC samples: https://webrtc.github.io/samples/src/content/devices/input-output/
• For now, the Virtual Webcam takes the default webcam and applies a WebGL filter to it
  • That means that the default webcam can be the last used webcam in the system, if there are several
• Change filters in js/media-devices.js

Tested with

• Hangouts
• Meet
• Zoom
• Doesn't seem to work on Duo

Security concerns, what if a bad actor wants to capture and broadcast the stream:

• The browser will tell the user that they're using a developer extension (a bit weak as security measures go)
• The webcam light will still turn on. Doesn't solve if the actor is active during a valid video call, though.
• I guess it's possible -and probably easy- to stream from an extension to another server. Nothing is preventing any extension creator from doing it right now, without a virtual webcam. Just MitM and record.

Ideas:

• Shader editor
• Youtube video to replace feed
• Add ML like FaceMesh or other feature detection systems:
  • add privacy bar over eyes
• Try to stream from a canvas in a page (shader editor, drawing, etc.) as a MediaSource.

License

This project is licensed under the CC-BY-4.0 License