Chris Nolan wrote: No. 1. It is definitely a violation of the GPL to enable both that and the GPL components at the same time, or to link a version of FFmpeg with FAAC support into a GPLed application and 2. the FFmpeg team also appears to claim it is a violation of the LGPL to have an LGPL build of FFmpeg use non- Free libraries (as opposed to getting used by non-Free applications), a position which may or may not be shared by other parties, but the FFmpeg developers definitely frown upon people redistributing binaries built with --enable-nonfree and will put them into their Hall of Shame. FFmpeg has a native AAC encoder which you can use instead (but which is still considered experimental). Kevin Kofler