simple-vcs.sh

#!/bin/bash
PATH=/bin:/usr/bin:/sbin:/usr/sbin

images=20
 
OLDIFS=$IFS
IFS=$(echo -en "\n\b")
 
if [ $1"x" != "x" ]; then
  file=$1;
else
  read -p "Enter file name: " file
fi
 
frames=$(ffmpeg -nostats -i $file -vcodec copy -f rawvideo -y /dev/null 2>&1 | grep frame | awk '{split($0,a,"fps")}END{print a[1]}' | sed 's/.*= *//')
 
offset=$(echo "$frames/$images" | bc)
 
vcs="ffmpeg -loglevel panic -y -i $file -frames 1 -q:v 1 -vf \"select=not(mod(n\,$offset)),scale=-1:200,tile=4x5\" $file.jpg"
 
eval $vcs
IFS=$OLDIFS