#!/bin/sh
help(){
    echo "Usage: $0 <filename.[ppm|pnm|png]>"
    exit 0
}
if test "$#" = "1"
then
    case $1 in
*.pnm)
        ifilter=cat
        input="$1"
        base=`echo $input | sed "s/\.pnm$//"` ;;
*.ppm)
        ifilter=cat
        input="$1"
        base=`echo $input | sed "s/\.ppm$//"` ;;
*.png)
        ifilter=pngtopnm
        input="$1"
        base=`echo $input | sed "s/\.png$//"` ;;
*)
        help ;;
    esac
    echo Transcoding $input to $base.mpg....
    sleep 1
    $ifilter $input |
	ppmtoy4m -A10:11 | mpeg2enc -f7 -T60 -o $base.m2v
	mplex -f7 "$base".m2v -o "$base".mpg
else
	help
fi