This package is needed for media-libs/libav[x265]. Please keyword =media-libs/x265-1.4 and then remove the keyword mask from your architecture's package.use.mask.
Marked ~ppc64.
Maybe remaining arches could simply keep the use.mask (to not make their trees grow more if not really needed)
Alpha is opting out of x265 until we have a user request.
Sparc is out. We will keep x265 for now.
https://bugs.gentoo.org/show_bug.cgi?id=548964#c4
~ia64 keyworded Last arch. Closing.