Build Mencoder from source on Debian Wheezy

su
apt-get install subversion
svn checkout svn://svn.mplayerhq.hu/mplayer/trunk mplayer

apt-get install build-essential
apt-get install git
apt-get build-dep mplayer

[install debian-multimedia]
apt-get install libfaac-dev

cd mplayer
./configure
    [press enter]
make
make install

mencoder -oac help