MPlayer HQ Codecs Binaries
Download the tar.bz2 and extract all of the files to a new folder.
Open a konsole/terminal in the new "essential" folder where the binaries were extracted to.
Type su and press enter, then provide your root password.
Now type all of these commands:
cp * /usr/lib/win32
cp * /usr/lib/codecs/
After copying these files, type exit to get back to a normal user, then type this command to test your setup:
You should pass on most tests, with a few warnings, but no errors.