#! /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] $0 input [output]"
   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 [ -n "$1" ]; then
   output="$1"
   shift
else
   output=output.avi
fi

if [ "$vcodec" = mpeg4-hq ]; then
   vcodec=mpeg4
   vopts="-mbd rd -flags +mv4+aic -trellis 2 -cmp 2 -subcmp 2"
fi

if [ "$vcodec" = x264 ]; then
   vcodec=libx264
fi

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

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

if [ "$pass" -eq 1 ]; then
   exec ffmpeg $input_opts -i "$input" -c:v "$vcodec" $vopts $vscale -b:v "$vbitrate" -g 300 -bf 2 -c:a "$acodec" -b:a "$abitrate" $output_opts "$output"

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

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