Specifically, the GPL parts of Libav are
-- optional x86 optimizations in the files
- libavcodec/x86/idct_mmx.c
- the X11 grabber in libavdevice/x11grab.c
+- the texi2pod.pl tool
+- the following filters in libavfilter:
+ - vf_blackframe.c
+ - vf_boxblur.c
+ - vf_cropdetect.c
+ - vf_delogo.c
+ - vf_hqdn3d.c
+ - vf_yadif.c
There are a handful of files under other licensing terms, namely: