=media-video/libpostproc-10.20140517-r1 has been marked stable, however, the deps on it makes it impossible to use media-video/ffmpeg: RDEPEND=" >=media-video/libav-0.8.2-r2:0= !media-video/ffmpeg:0 abi_x86_32? ( !<=app-emulation/emul-linux-x86-medialibs-20140508-r3 !app-emulation/emul-linux-x86-medialibs[-abi_x86_32(-)] ) " DEPEND="${RDEPEND}" currently, only media-video/ffmpeg-1.2.6-r1 is stable, and it has slot=0, but that's not really the only problem: zero@gato zero-system % grep SLOT /usr/portage/media-video/ffmpeg/*.ebuild /usr/portage/media-video/ffmpeg/ffmpeg-0.10.15.ebuild:SLOT="0.10" /usr/portage/media-video/ffmpeg/ffmpeg-1.0.10.ebuild:SLOT="0" /usr/portage/media-video/ffmpeg/ffmpeg-1.2.12.ebuild:SLOT="0" /usr/portage/media-video/ffmpeg/ffmpeg-1.2.6-r1.ebuild:SLOT="0" /usr/portage/media-video/ffmpeg/ffmpeg-2.2.13.ebuild:FFMPEG_SUBSLOT=52.55.55 /usr/portage/media-video/ffmpeg/ffmpeg-2.2.13.ebuild:SLOT="0/${FFMPEG_SUBSLOT}" /usr/portage/media-video/ffmpeg/ffmpeg-2.5.4.ebuild:FFMPEG_SUBSLOT=54.56.56 /usr/portage/media-video/ffmpeg/ffmpeg-2.5.4.ebuild:SLOT="0/${FFMPEG_SUBSLOT}" /usr/portage/media-video/ffmpeg/ffmpeg-2.6.ebuild:FFMPEG_SUBSLOT=54.56.56 /usr/portage/media-video/ffmpeg/ffmpeg-2.6.ebuild:SLOT="0/${FFMPEG_SUBSLOT}" /usr/portage/media-video/ffmpeg/ffmpeg-9999.ebuild:FFMPEG_SUBSLOT=54.56.56 /usr/portage/media-video/ffmpeg/ffmpeg-9999.ebuild:SLOT="0/${FFMPEG_SUBSLOT}" It looks like all but one version of ffmpeg have slot=0. Essentially it is impossible to use media-video/ffmpeg at this point if anything depends on libpostproc. Unfortunately, on my system a lot seems to pull in libpostproc such as app-emulation/emul-linux-x86-medialibs-20140508-r6
emerge -C postproc and sanely fix use flags. Thanks to iamben for helping debug on irc.