FFMPEG Extract 100 frames from a file

#!/bin/bash
# 
# Copyright (c) 2017 Kris Occhipinti.
# http://filmsbykris.com 
#
# This program is free software: you can redistribute it and/or modify  
# it under the terms of the GNU General Public License as published by  
# the Free Software Foundation, version 3.
#
# This program is distributed in the hope that it will be useful, but 
# WITHOUT ANY WARRANTY; without even the implied warranty of 
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License 
# along with this program. If not, see .
#

if [ $# -lt 1 ]
then
  echo "Usage: $0