A simple bash script to capture your screen in Linux using ffmpeg and slop

rec_screen.sh

#!/bin/bash

# function that shows you how to use this tool
usage() {
  echo "Usage $0 [-o outfile] [-d outdir] [-f fps]"
  echo "  -o: Specify the output file (default: screen_rec_<current_time_and_date>.mp4)"
  echo "  -d: Specify the output directory (default: ./)"
  echo "  -f: Specify the fps (default: 30)"
  exit 1
}

# defaults
output_file="screen_rec_$(date "+%Y-%m-%d-%H-%M-%S").mp4"
output_dir="./"
fps=30

# command line parsing
while getopts "o:d:f:h" opt; do
  case $opt in
    o) output_file="$OPTARG" ;;
    d) output_dir="$OPTARG" ;;
    f) fps="$OPTARG" ;;
    h) usage ;;
    \?) usage ;;
  esac
done

# check for trailing / at the and of directory path
if [[ $output_dir != */ ]] 
then
  output_dir=${output_dir}"/"
fi
output_path="${output_dir}${output_file}"

# get selected area
selected_area=$(slop -f "%x %y %w %h")

# extract the coordinates and dimensions from teh selected_area
read -r x y w h <<< "$selected_area"

echo "Recording started ..."
ffmpeg -f x11grab -framerate "$fps" -video_size "${w}x${h}" -i :0.0+"$x","$y" -c:v libx264 -preset ultrafast -crf 0 "$output_path"

echo "Recording saved as $output_path"