Video Background on any HTML page

To underlay webcam video onto any web page…

1. Include the viddybg script file.
2. Use ctrl alt k (or cmd alt k on Mac) to switch underlay on or off (try it now).
3. Use ctrl alt x (or cmd alt x on Mac) to flip the image horizontally (mirrored by default).

The image fills the screen but stays horizontally centred if the screen is narrowed, so the presenter remains central to the page.