Please stable media-video/obs-studio-31.1.0, this works fine on the amd64 system and only open bug seems to effect x86 only.
I suppose you mean 30.1.0? :] In any case, that was added only a week ago, and there is a 30.1.1 out already. I might also like to sort out the USE-flags (pipewire for example), and other things before this...
I'll put this on hold, but keep around as a reminder or sorts, in preparation.