#! /bin/sh

if [ -z "$1" ]; then
   echo "Usage: [vcodec=s] [vbitrate=n] [vscale=s] [aid=n] [acodec=s] [abitrate=n] [ascale=s] [pass=n] $0 input.avi [-ffmpeg_options]"
   exit 1
fi

if [ -z "$vcodec" ]; then
   vcodec=mpeg4
fi

if [ -z "$vbitrate" ]; then
   vbitrate=1600k
fi

if [ -n "$vscale" ]; then
   vscale="-s $vscale"
fi

if [ -z "$acodec" ]; then
   acodec=libmp3lame
fi

if [ -z "$abitrate" ]; then
   abitrate=256k
fi

if [ -z "$pass" ]; then
   pass=1
fi

input="$1"
shift

if [ "$pass" -eq 1 ]; then
   exec ffmpeg -i "$input" -f avi -c:v "$vcodec" -b:v "$vbitrate" -g 300 -bf 2 -c:a "$acodec" -b:a "$abitrate" "$@" output.avi

elif [ "$pass" -eq 2 ]; then
   ffmpeg -pass 1 -i "$input" -f avi -c:v "$vcodec" -b:v "$vbitrate" -g 300 -bf 2 -an -f rawvideo -y /dev/null "$@" &&
   exec ffmpeg -pass 2 -i "$input" -f avi -c:v "$vcodec" -b:v "$vbitrate" -g 300 -bf 2 -c:a "$acodec" -b:a "$abitrate" "$@" output.avi

else
   echo "Can only do 1 or 2 passes." >&2
   exit 1
fi