FAAC is an Advanced Audio Coder (MPEG2-AAC, MPEG4-AAC).
The goal of FAAC is to explore the possibilities of AAC and exceed
the quality of the currently best MP3 encoders.

faac comes with its own version of libmp4v2, but if you use it, you have to
uninstall faac everytime you want to update it, as faac would otherwise 
detect the already installed libmp4v2 and build against it. Then, when you
upgrade to the new package, it doesn't have the included libmp4v2, because
it was part of the old package, so faac is linking to a nonexistent library 
after the upgrade.  Long story short, we strongly recommend using the 
external libmp4v2 (available from SlackBuilds.org); just make sure it is 
installed when you configure faac, and it will be detected automatically.

NOTE: If you have installed faac < 1.26-i486-2_SBo, make sure to remove it 
before either installing libmp4v2 or running the new SlackBuild.