ffmpeg -i inputvideo.mp4 -ss 00:00:03 -frames:v 1 foobar.jpeg
https://ottverse.com/thumbnails-screenshots-using-ffmpeg/
https://ottverse.com/thumbnails-screenshots-using-ffmpeg/
no fluff....
[img[]] pasting in the image url%s/>\s*</>\r</g2020-09-12T23:55:00 installed https://packages.debian.org/search?searchon=sourcenames&keywords=dateutils on ChromebookCrostini but invoking the command took searching bin usr bin and such by going to root then find
./usr/bin/dateutils.dadd ./usr/bin/dateutils.dconv ./usr/bin/dateutils.ddiff ./usr/bin/dateutils.dgrep ./usr/bin/dateutils.dround ./usr/bin/dateutils.dseq ./usr/bin/dateutils.dsort ./usr/bin/dateutils.dtest ./usr/bin/dateutils.dzone ./usr/bin/dateutils.strptime$ dateutils.ddiff 2020-05-13 today
info and man works with dateutils