The Fedora Project is aware that the Free Software Foundation has stated that the Fraunhofer FDK AAC license is GPL incompatible, specifically, because of Clause 3.

We believe that the fdk-aac software codec implementation that we wish to include in Fedora is no longer encumbered by AAC patents. This fact means that Clause 3 in the FDK AAC license is a "no op", or to put it plainly, if no patents are in play, there are no patent licenses to disclaim. For this (and only this) specific implementation of fdk-aac, we believe that the FDK AAC license is GPL compatible.

Thanks,
Tom