#!/bin/bash

###########################
#
# Export a video to an image sequence at a 
# particular framerate.
#
###########################

MULTIPLE=2
RATE=`echo "scale=0;24/${MULTIPLE}" | bc`

INPUT="${1}"
OUTPUT="${2}"
INVERT="${3}"

WIDTH=323
HEIGHT=242

if [[ "${INVERT}" != "" ]]; then
	INVERT="negate,"
fi

mkdir -p "${OUTPUT}"

ffmpeg -y -re -i "${INPUT}" \
	-f image2 \
	-r ${RATE} \
	-vf ${INVERT}crop=in_h/3*4:in_h,scale=$WIDTH:$HEIGHT,setsar=1:1 \
	"${OUTPUT}/image_%06d.png"