#!/bin/bash

usage="usage: anithumb.sh -i input -o output -s video_size (example: 320x240) [-f start_frame | Default: 0] [-r N between frames| Default:every 15 frames] [-n number_of_frames | Default: 10] [-v video codec | Default: divx5] [-a audio codec | Default: null]";

while getopts ":i:o:s:f:r:n:v:a:h" options; do
  case $options in
    i ) input=$OPTARG;;
    o ) output=$OPTARG;;
    s ) size=$OPTARG;;
    f ) frame=$OPTARG;;
    r ) framerate=$OPTARG;;
    n ) numframes=$OPTARG;;
    v ) video=$OPTARG;;
    a ) audio=$OPTARG;;
    h ) echo $usage;;
    \? ) echo $usage
         exit 1;;
    * ) echo $usage
          exit 1;;
  esac
done

if [ $# == 0 ] ; then
  echo $usage;
  exit 1;
fi

if [ ! $input ] || [ ! $output ] || [ ! $size ] ; then
	echo $usage;
	exit 1;
fi

if [ ! $numframes ]; then
	numframes=10;
fi

if [ ! $framerate ]; then
	framerate=15;
fi

if [ ! $frame ]; then
	frame=0;
	echo "Start frame not defined; Using frame 0";
fi

if [ ! $video ]; then
	video="divx5"
fi

if [ ! $audio ]; then
	audio="null"
fi

COUNTER=1
sframe=$frame
newstring=""
while [  $COUNTER -le $numframes ]; do
	let frame=sframe+framerate*COUNTER
	let nframe=frame+1
	c="$frame-$nframe"
	newstring="$newstring,$c";
        let COUNTER=COUNTER+1 
done

total_frames=`echo $newstring | cut -c 2-`;

cur_dir=$PWD
mkdir /tmp/anithumb

transcode -i $input -x $video,$audio -y jpg -g $size -c $total_frames -o /tmp/anithumb/thumb

cd /tmp/anithumb

for i in thumb* ;
	do j=`echo $i | sed 's/jpg/gif/'`
	echo "Converting $i to $j...";
	convert $i -resize 50% $j
done

echo "Creating animated GIF..."
convert -delay 15 -loop 0 thumb*.gif $cur_dir/$output

rm -rf /tmp/anithumb

echo "Done!";