Just use this:
ffmpeg -f v4l2 -i /dev/video0 -q:v 5 -f mjpeg -listen 1 http://0.0.0.0:8090
then access your cam using any software like obs, any virtual cam.
http://<ip>:8090
Notes: ffmpeg
- Long audio & shortvideo:
ffmpeg -i Downloads/pooja_updated.mp4 -i aum.opus -map 0:v:0 -map 1:a:0 -c:v copy -shortest -y output3.mp4
ffmpeg -i <input file> -vcodec libx265 -crf 28 <output file>