I just wanted to share here how I solved a problem with some old webcams not working under Linux in meet.jit.si web based video conferencing service. I am new here so maybe this post should go into another place. Please tell me if I should move it elsewhere.
The workaround is as easy as launching Chromium, Chrome or Firefox preceeded by LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libv4l/v4l1compat.so as described here: https://bugs.chromium.org/p/webrtc/issues/detail?id=3765
It worked at least for these two webcams that were not detected by webrtc without that:
Logitech Quickcam Express Plus (Device ID 046d:092f ) and Robot-Cam (Device ID 0c45:602c Microdia Clas Ohlson TWC-30XOP Webcam) These are old cameras not supported by uvcvideo drivers and they use old gspca drivers instead.
It worked for me with Linux Mint 19.3 (ubuntu 18.04 based) and another ubuntu 14.04 based distro. In the first one I installed the following packages during testing but I guess they are not needed at all: xawtv xawtv-plugins xawtv-tools v4l-conf v4l-utils v4l2ucp v4l2loopback-utils v4l2loopback-source v4l2loopback-dkms
Hope it will be useful for other people facing the same problem.