I have a simple question about tag.

I want to build a simple full screen video chat that runs on phonegap (mobile) and desktop browsers (Chrome)

What i need is the video to stay full screen both if it comes from a mobile camera or desktop browser camera, i guess they will have different aspect ratio and i don't understand how to merge the problem.

What i am afraid of is, when video comes from a mobile camera then how could it fit the entire browser screen (full screen) which is bigger?

I am sorry if i didn't tried anything yet, but i just would like to understand how to start with, the logic behind.

Any tip appreciated!