`avectorscope=mode=polar’¶

Watch on youtube.com

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

#! /bin/sh
ifn="Air on the G String (from Orchestral Suite no. 3, BWV 1068).mp3"
ifnb="`basename \"${ifn}\" .mp3`"
pref="`basename $0 .sh`"

#
ffmpeg -y -i "${ifn}" -filter_complex "
[0:a]avectorscope=mode=polar:s=1920x1080[v]
" -map '[v]' -map '0:a' -c:a copy \
  "${pref}_${ifnb}.mp4"