Someone

burn_dvd () 
{ 
    if [ -n "$1" ]; then
        if [ -d $1 ]; then
            growisofs -dvd-compat -speed=2 -Z /dev/dvd -f -r -J -v -joliet-long $@;
        else
            if [ -f $1 ]; then
                growisofs -dvd-compat -speed=2 -Z /dev/dvd=$1;
            else
                echo "Target neither file nor dir - dunno what to do.";
            fi;
        fi;
        eject /dev/dvd;
    else
        echo "Usage: ${FUNCNAME[0]} <file|dir>";
    fi
}