#!/bin/sh

if [ $# != 4 ]
then
   echo "usage: $0 source_file start_frame last_frame output_file_base"
   exit 1
fi

if [ -f "$4.vob" ] 
then 
	echo "$4.vob already exists!"
else
	lastf=$(echo "scale=0; $3-$2+1" | bc -l)

	echo "starting frame =" $2
	echo "number frames =" $lastf

	lav2yuv +n -o $2 -f $lastf $1 | yuvscaler -M RATIO_8_9_1_1 -O DVD | mpeg2enc -4 1 -2 1 -n n -N -P -I 0 -f 8 -q 6 -a 2 -o ./$4.m2v

	echo "Testing audio stats..."
	vol=`(lav2wav +n -o $2 -f $3 $1 | sox -t wav - -t wav /dev/null stat) 2>&1 | grep adjustment | sed 's/Volume\ adjustment:\ \ \ \ \ \ \ \ //'`
	vol2=$(echo "scale=3; $vol*2/3" | bc -l)
	echo "Vol adj. = " $vol2
	lav2wav +n -o $2 -f $3 $1 | sox -v $vol2 -t wav - -t wav -  | ffmpeg -i /dev/stdin -y -vn -ab 192 -ac 6 -ar 48000 -acodec ac3 ./$4.ac3

	mplex -f 8 -o $4.vob $4.m2v $4.ac3
fi