I need a repository (for apt-get) to install mplayer and their dependences.
Who can help me?

If mplayer is not in the apt-tree (it wasn't when I last used Debian) you can just download the source and compile it.

Or add this to your /etc/apt/sources.list
deb ftp://ftp.nerim.net/debian-marillat/ testing main

There are also packages for unstable,stable and source. Beside of mplayer packages they also have xmms-wma so xmms can play wma files.

In the bottom of this site you find the addresses to put into sources.list
http://opensource.nchc.org.tw/apt/marillat/

My advice is to download the MPlayer source and build a .deb file yourself. It's really easy to build a MPlayer.deb file yourself (the MPlayer source has build in support for making debian pakages). The advantage of doing it this way is that you can configure MPlayer exactly the way you want to (with or without GUI, the location of different codecs, etc.).

On this site you can find a HowTo for building a MPlayer.deb file.

This the command I use to build a MPlayer.deb file (just as an example, you might want different options, or you might have your codecs in a different location):

DEB_BUILD_OPTIONS="--disable-runtime-cpudetection --enable-gui --with-win32libdir=/usr/local/lib/codecs --with-reallibdir=/usr/local/lib/codecs --with-extralibdir=/usr/local/lib/codecs" fakeroot debian/rules binary

When you've build a .deb file you can install it with dpkg.

Good luck.

I highly recommend the nerim packages. Mplayer worked beautifully out of the box for me from them.

You will have to edit /etc/mplayer/mplayer.conf and change the vo line to vo=xv. I believe the default is vo=x11 and with that setting, you won't get proper fullscreening. Other than that, perfection.