#! /bin/sh

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

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

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

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

if [ -z "$acodec" ]; then
   acodec=mp3
else
   acodec="$acodec"
fi

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

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

if [ "$vcodec" = ffmpeg ]; then
   tc_vcodec=ffmpeg
   vopts="-F mpeg4"
elif [ "$vcodec" = h264 ]; then
   tc_vcodec=ffmpeg
   vopts="-F h264"
elif [ "$vcodec" = xvid ]; then
   tc_vcodec=xvid
   vopts=""
elif [ "$vcodec" = copy ]; then
   tc_vcodec=copy
   vopts=""
else
   echo "Unknown video codec $vcodec; known codecs are ffmpeg, h264, xvid, copy" >&2
   exit 1
fi

if [ "$acodec" = mp3 ]; then
   aopts=""
elif [ "$acodec" = copy ]; then
   aopts=""
else
   echo "Unknown audio codec $acodec; known codecs are mp3 and copy" >&2
   exit 1
fi

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

input="$1"
shift

if [ "$pass" -eq 1 ]; then
   exec transcode -i "$input" -y $tc_vcodec      $vopts -u 50 -w "$vbitrate" -b "$abitrate"                  $vscale $ascale -o output.avi "$@"

elif [ "$pass" -eq 2 ]; then

        transcode -i "$input" -y $tc_vcodec,null $vopts -u 50 -w "$vbitrate" -b "$abitrate" -R1 -x auto,null $vscale         -o /dev/null  "$@" &&
   exec transcode -i "$input" -y $tc_vcodec      $vopts -u 50 -w "$vbitrate" -b "$abitrate" -R2              $vscale $ascale -o output.avi "$@"

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