Linux capture device support

[Avasam]

My c920 webcam simply won't work (may or may not be a vmware issue).
I can't get the virtual cam working in OBS.

So I can't test or implement this feature myself 😕 (for all I know it's already working as-is).

[Avasam]

Tagging as "good first issue". It might be as simple as showing it already work as-is.