frei0r-plugins : A minimalistic plugin API for video effects ( https://www.dyne.org/software/frei0r/ )
vocoder-ladspa : A vocoder is a sound effect that can make a human voice soun ( http://www.sirlab.de/linux/descr_vocoder.html )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a seden
For Paludis use this rsync : rsync://gentoo.zugaina.org/seden-portage
If you have a problem : ycarus(-at-)zugaina.org