Use your phone like a webcam in your linux env

phone-web-cam-on-linux.sh

# STEP 1 
# Install deps
sudo apt install v4l2loopback-dkms
sudo apt install ffmpeg

# STEP 2 
# Create fake webcam dummy device
# It will be used like a stream source in third-party programs like Zoom, Skype, etc
sudo modprobe v4l2loopback card_label="Fake Webcam" exclusive_caps=1

# STEP 3 
# Get rtsp stream and forward it by deviceX into our dummy device which was created later 
# rtsp://ip:port/h264_pcm.sdp - Look in IP Webcam stream's meta data
# /dev/videoX - Look in `ls -1 /dev/video*` list and take the last one
ffmpeg -stream_loop -1 -re -i rtsp://ip:port/h264_pcm.sdp -vcodec rawvideo -vsync 2 -threads 0 -f v4l2 /dev/videoX

After STEP 3 you will have the Fake Webcam device in your devices list of your in third-party program (Zoom, etc)