Something from 24 Things I’ve Learned As A Software Developer Living On Ubuntu For A Weekish:
sudo modprobe v4l2loopback && \ sudo ffmpeg -f x11grab -r 15 -s 1920x1080 -i :0.0+0,623 \ -vcodec rawvideo -threads 0 -pix_fmt yuv420p -f v4l2 /dev/video0
What does this do? It uses ffmpeg to capture a display and output the stream as a v412loopback (easily installed from apt) to a file at /dev/video0, which happens to be the file-system’s representation of the webcam. v412loopback uses the same codec as the webcam, so by running this single line of code, I effectively turn my webcam into a screen-sharing tool, with or without support from WebEx. Couple this with a world-class, open-source broadcasting application like OBS (I still haven’t completely figured this out, but I’m onto something; ), and you have a more powerful screen-sharing tool than anything WebEx could offer anyways.