#! /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 [-mencoder_options] input.avi..."
   exit 1
fi

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

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

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

if [ -z "$acodec" ]; then
   acodec=mp3lame
else
   acodec="$acodec"
fi

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

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

if [ "$vcodec" = lavc ]; then
   vopts="-lavcopts vcodec=mpeg4:vbitrate=$vbitrate:autoaspect"

elif [ "$vcodec" = lavc-hq ]; then
   vcodec=lavc
   vopts="-lavcopts vcodec=mpeg4:vbitrate=$vbitrate:autoaspect:mbd=2:trell:v4mv:last_pred=2:dia=-1:vmax_b_frames=2:vb_strategy=1:cmp=3:subcmp=3:precmp=0:vqcomp=0.6:turbo"

elif [ "$vcodec" = lavc-vhq ]; then
   vcodec=lavc
   vopts="-lavcopts vcodec=mpeg4:vbitrate=$vbitrate:autoaspect:mbd=2:trell:v4mv:last_pred=3:dia=2:vmax_b_frames=2:vb_strategy=1:cmp=2:subcmp=2:precmp=2:mv0:cbp:predia=2:preme=2:qns=2"

elif [ "$vcodec" = x264 ]; then
   vopts="-x264encopts bitrate=$vbitrate"

elif [ "$vcodec" = x264-hq ]; then
   vcodec=x264
   vopts="-x264encopts bitrate=$vbitrate:subq=5:8x8dct:frameref=2:bframes=3:b_pyramid:weight_b"

elif [ "$vcodec" = x264-vhq ]; then
   vcodec=x264
   vopts="-x264encopts bitrate=$vbitrate:subq=6:8x8dct:frameref=5:bframes=3:b_pyramid:weight_b:partitions=all:me=umh"

elif [ "$vcodec" = xvid ]; then
   vopts="-xvidencopts bitrate=$vbitrate"

elif [ "$vcodec" = xvid-hq ]; then
   vcodec=xvid
   vopts="-xvidencopts bitrate=$vbitrate:chroma_opt:vhq=2:bvhq=1:quant_type=mpeg"

elif [ "$vcodec" = xvid-vhq ]; then
   vcodec=xvid
   vopts="-xvidencopts bitrate=$vbitrate:chroma_opt:vhq=4:bvhq=1:quant_type=mpeg"

elif [ "$vcodec" = copy ]; then
   vopts=""

else
   echo "Unknown video codec $vcodec; known codecs are {lavc,x264,xvid}[-[v]hq], copy" >&2
   exit 1
fi

if [ "$acodec" = mp3lame ]; then
   aopts="-lameopts cbr:br=$abitrate:q=0"
elif [ "$acodec" = copy ]; then
   aopts=""
else
   echo "Unknown audio codec $acodec; known codecs are mp3lame and copy" >&2
   exit 1
fi

if [ "$aid" ]; then
   aopts="$aopts -aid $aid"
fi

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

if [ "$vcodec" = lavc ]; then
   vpass=vpass
elif [ "$vcodec" = x264 ]; then
   vpass=pass
elif [ "$vcodec" = xvid ]; then
   vpass=pass
fi

if [ "$pass" -eq 1 ]; then
   exec mencoder -ovc "$vcodec" $vopts          $vscale -oac "$acodec" $aopts $ascale -o output.avi "$@"

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

        mencoder -ovc "$vcodec" $vopts:$vpass=1 $vscale -nosound                      -o /dev/null "$@" &&
   exec mencoder -ovc "$vcodec" $vopts:$vpass=2 $vscale -oac "$acodec" $aopts $ascale -o output.avi "$@"

elif [ "$pass" -eq 3 ]; then

        mencoder -ovc "$vcodec" $vopts:$vpass=1 $vscale -nosound                      -o /dev/null "$@" &&
        mencoder -ovc "$vcodec" $vopts:$vpass=3 $vscale -nosound                      -o /dev/null "$@" &&
   exec mencoder -ovc "$vcodec" $vopts:$vpass=3 $vscale -oac "$acodec" $aopts $ascale -o output.avi "$@"
                                       # pass=3 is not a typo!

else
   echo "Can only do 1, 2 or 3 passes." >&2
   exit 1
fi