What the topic says, for some reason there is a really old version of avidemux in the tree, which depends on a 4 years old x264 and blocks it from being updated. This is really unfortunate, especially since ebuilds for current avidemux seem to exist, see https://bugs.gentoo.org/830464 - whoever is responsible for this please consider updating those ebuilds. thanks!
Thanks, I'll call this a duplicate, but I'll look into the original bug now. *** This bug has been marked as a duplicate of bug 830464 ***