simplest with overlay¶

Watch on youtube.com

doc: https://ffmpeg.org/ffmpeg-filters.html#overlay

In the case of comparison of some processing results and original, this simple overlay may be useful as well.

#! /bin/sh
pref="`basename $0 .sh`"
vtop="Drifting with Cars.mp4"
vbot="Drifting with Cars-ds.mp4"

#
ffmpeg -y -i "${vbot}" -i "${vtop}" -filter_complex "
[1:v]scale=480:270,setsar=1[1v];
[0:v][1v]overlay=x=50:y=H-h-50[v]
" -map '[v]' -an \
  "${pref}.mp4"