These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 0.94 s (backtrack: 0/20).


The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)
# required by kde-apps/kamoso-26.08.2::gentoo
# required by =kde-apps/kamoso-26.08.2 (argument)
>=media-plugins/gst-plugins-meta-1.26.11 v4l theora vorbis

!!! The ebuild selected to satisfy "media-plugins/gst-plugins-meta:1.0[alsa,theora,vorbis,v4l]" has unmet requirements.
- media-plugins/gst-plugins-meta-1.26.11::gentoo USE="X a52 aac alsa dts http mp3 x264 -cdda -dv -dvb -dvd -ffmpeg -flac -jack -lame -libass -libvisual -modplug -mpeg -ogg -opus -oss -pulseaudio -taglib -theora -v4l -vaapi -vcd -vorbis -vpx -wavpack"

  The following REQUIRED_USE flag constraints are unsatisfied:
    theora? ( ogg ) vorbis? ( ogg )

  The above constraints are a subset of the following complete expression:
    opus? ( ogg ) theora? ( ogg ) vorbis? ( ogg )

(dependency required by "kde-apps/kamoso-26.08.2::gentoo" [ebuild])
(dependency required by "=kde-apps/kamoso-26.08.2" [argument])