Santo Google!

Foi só fazer uma pesquisa no Google por "install-css.sh" (o nome do script que acompanhava as versões anteriores do KnoppMyth) e, num dos primeiros links, surgiu um post com este script:

#!/bin/sh
# Shell script to install libdvdcss under Debian GNU Linux
# Many DVDs use css for encryption. To play these discs, a special library
# is needed to decode them, libdvdcss. Due to legal problems, Debian and most
# Linux distibutions cannot distribute libdvdcss
# Use this shell script to install the libdvdcss under DEBIN GNU/Linux
# --------------------------------------------------------------------------
# Refer url for more info:
# Copyright info - http://www.dtek.chalmers.se/~dvd/
# -------------------------------------------------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# -------------------------------------------------------------------------

set -e

site=http://www.dtek.chalmers.se/groups/dvd/deb/
arch=$(dpkg --print-installation-architecture)

soname=2
uversion=1.2.5
#available="alpha hppa i386 ia64 powerpc s390 sparc"
available="i386"
version=${uversion}-1

if ! type wget > /dev/null ; then
echo "Install wget and run this script again"
exit 1
fi

for a in $available; do
if [ "$a" = "$arch" ]; then
wget ${site}libdvdcss${soname}_${version}_${arch}.deb -O /tmp/libdvdcss.deb
dpkg -i /tmp/libdvdcss.deb
exit $?
fi
done

echo "No binary deb available. Will try to build and install it."
echo "You need to have debhelper, dpkg-dev and fakeroot installed."
echo "If not, interrupt now, install them and rerun this script."
echo ""
echo "This is higly experimental, look out for what happens below."
echo "If you want to stop, interrupt now (control-c), else press"
echo "return to proceed"
read dum

mkdir -p /tmp/dvd
cd /tmp/dvd
wget ${site}libdvdcss_${uversion}.orig.tar.gz
wget ${site}libdvdcss_${version}.diff.gz
wget ${site}libdvdcss_${version}.dsc
dpkg-source -x libdvdcss_${version}.dsc
cd libdvdcss-${uversion}
fakeroot ./debian/rules binary
echo "Any problems? Interrupt now (control-c) and try to fix"
echo "manually, else go on and install (return)."
dpkg -i ../libdvdcss${soname}_${version}_${arch}.deb

Foi só rodar e pronto! DVD ok!