I'm having trouble getting sound to work when playing .mkv files with mplayer

Typing in:
# mplayer movie.mkv

I get:
Trying to force audio codec driver family libmad...
Opening audio decoder: [faad] AAC (MPEG2/4 Advanced Audio Coding)
mplayer: relocation error: mplayer: undefined symbol: faacDecOpen

So I try using another audio codec

Typing in:
# mplayer -ac mad movie.mkv

I get:
Forced audio codec: mad
Cannot find codec for audio format 0x4134504D.
Read DOCS/HTML/en/codecs.html!

The video plays, but there is no sound. I was wondering if there was a specific audio codec I should have used.

Oh, and I tried downloading libfaad2_0 through urpmi. It says everything has already been installed.

You will need to download and compile the following libraries from Matroska official site.

libeblml
libmatroska

Once compiled you can copy the libs to the default codecs directory e.g. /usr/lib/codecs or /usr/local/lib/codecs