The IUSE variable in ffmpeg-0.4.9_p20050226.ebuild does NOT include the xvid flag (even though the DEPEND variable right below it tests for the flag and requires media-libs/xvid if present). Reproducible: Always Steps to Reproduce: Actual Results: Can't see the flag fore emerge -pv etcetera. Expected Results: I expect all flags used in an ebuild to appear in IUSE. :)
I removed the useflag for now. Later I'll look if is safe to add back xvid support in ffmpeg, actually no functionality is broken since ffmpeg already provides a good mpeg4 codec