#! /bin/sh

if [ -z "$1" ]; then
   echo "Usage: [vcodec=s] [vbitrate=n] [vscale=s] [acodec=s] [abitrate=n] [ascale=s] [pass=n] [input_opts=input_opts] [output_opts=output_opts] [output=output.avi] [crop=w:h:x:y] $0 input1 [input2...]"
   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

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

if [ $# -eq 1 ]; then
   input="$1"
else
   input=concat:"`echo \"$@\" | sed 's/ /|/g'`"
fi

if [ -z "$output" ]; then
   output=output.avi
fi

if [ "$vcodec" = mpeg4 ]; then
   vopts="-g 300 -bf 2"

elif [ "$vcodec" = mpeg4-hq ]; then
   vcodec=mpeg4
   vopts="-g 300 -bf 2 -mbd rd -flags +mv4+aic -trellis 2 -cmp 2 -subcmp 2"

elif [ "$vcodec" = mpeg4-vhq ]; then
   vcodec=mpeg4
   vopts="-g 200 -bf 2 -mbd rd -flags +mv4+aic+qprd+mv0 -flags2 skiprd -trellis 2 -cmp 2 -subcmp 2"

elif [ "$vcodec" = x264 ]; then
   vcodec=libx264

elif [ "$vcodec" = x264-hq ]; then
   vcodec=libx264
   vopts="-preset slow"

elif [ "$vcodec" = x264-vhq ]; then
   vcodec=libx264
   vopts="-preset veryslow"

else
   echo "Unknown video codec $vcodec; known codecs are {mpeg4,x264}[-[v]hq], copy" >&2
   exit 1
fi

if [ "$pass" -eq 1 ]; then
   exec ffmpeg -threads auto $input_opts -i "$input" -c:v "$vcodec" $vopts $vscale -b:v "$vbitrate" -c:a "$acodec" -b:a "$abitrate" $output_opts $crop "$output"

elif [ "$pass" -eq 2 ]; then
   ffmpeg -pass 1 -threads auto $input_opts -i "$input" -c:v "$vcodec" $vopts $vscale -b:v "$vbitrate" -an -f rawvideo -y /dev/null $output_opts $crop &&
   exec ffmpeg -pass 2 -threads auto $input_opts -i "$input" -c:v "$vcodec" $vopts $vscale -b:v "$vbitrate" -c:a "$acodec" -b:a "$abitrate" $output_opts $crop "$output"

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