libavcodec/x86/h264_deblock_sse2.asm
libavcodec/x86/h264_idct_sse2.asm
libavcodec/x86/idct_mmx.c
-- the AC-3 decoder in libavcodec/ac3dec.c
- the X11 grabber in libavdevice/x11grab.c
Some external libraries, e.g. libx264, are under GPL and can be used in