How to compile mplayer with support for dvdnav:

since the versions of dvdnav and dvdread generally shipped with most Linux
distributions are generally outdated and unmaintained remove any piece of
dvdnav and dvdread from your computer (something like the command below
should suffice):
$ rm -rf /usr/lib/libdvdnav* /usr/lib/libdvdread* /usr/include/dvdnav* \
         /usr/include/dvdread* /usr/local/lib/libdvdnav* \
         /usr/local/lib/libdvdread* /usr/local/include/dvdnav* \
         /usr/local/include/dvdread* /usr/bin/dvdnav-config \
         /usr/local/bin/dvdnav-config

Now download dvdnav from MPHQ (dvdnav includes its own version of dvdread):
$ svn co svn://svn.mplayerhq.hu/dvdnav/trunk/libdvdnav libdvdnav
$ cd libdvdnav
$ ./autogen.sh && ./configure && make
(or, if you feel brave and want to help us improving the new build system,
$ ./configure2 && make
) 
install it as root with
$ make install

Cd to MPlyer's source tree and run ./configure with your preferred parameters.
After ./configure is run it should say that support for dvdnav and dvdread was enabled,
otherwise investigate in configure.log the sections relative to the two libraries
and try to understand what went wrong; if you can't solve the problem yourself
post to mplayer-users the two sections.

Notice: animated menus are working, but still menus and still scenes are not yet supported.
Also, audio and subtitle languages selection by means of menus don't work yet, but
they can be switched as usual at any time during playback pressing '#' and 'j'
(or with the keys you chose to override those two bindings).