Enjoy ... Everything from the cli.

#!/bin/bash

Trap Ctrl+C to stop both recordings

trap 'kill 0' SIGINT

RECORD SCREEN + MIC TO ONE FILE

ffmpeg
-f x11grab -video_size 1920x1080 -framerate 30 -i "$DISPLAY"
-f pulse -i default
-c:v libx264 -preset ultrafast
-c:a aac
~/Videos/capscreen.mkv &

RECORD WEBCAM TO SEPARATE FILE

ffmpeg
-f v4l2 -input_format mjpeg -video_size 1280x720 -i /dev/video0
-c:v libx264 -preset ultrafast
~/Videos/webcam.mkv &

Wait for background jobs

wait