Well, there is a list of files in libav, which are also under GPL-license [1]. I do not know, whether those files are used for building.
Anton [1] http://packages.debian.org/changelogs/pool/main/liba/libav/current/copyright 2012/11/27 trophime <christophe.troph...@lncmi.cnrs.fr>: > libav -- To UNSUBSCRIBE, email to debian-bugs-rc-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
