A simple way to create videos of your screen on linux!

screv.sh

# Screen Video Capture
#! /usr/bin/env sh

length=${1-3}
delay=${2-0}

geometry=($(xrectsel "%wx%h %x,%y"))
output_dir="$(xdg-user-dir VIDEOS)/captures"

mkdir -p "$output_dir"

sleep $delay

ffmpeg -t "$length" -video_size "${geometry[0]}" \
    -f x11grab -i ":0.0+${geometry[1]}" \
    -c:v libx264 -preset ultrafast \
    -pix_fmt yuv420p \
    -vf "scale=448:-2:flags=lanczos+full_chroma_inp+full_chroma_int+accurate_rnd" \
    -flags +global_header -movflags faststart \
    "$output_dir/$(date +"%y_%d_%m_%H_%M_%S").mp4"