emerge -pv vlc Calculating dependencies... done! [ebuild R ] media-video/vlc-3.0.8:0/5-9::gentoo USE="X a52 alsa bluray cddb dbus dts dvbpsi dvd encode ffmpeg flac fontconfig gcrypt jpeg libass libnotify libsamplerate mad matroska mp3 mpeg musepack ncurses ogg opus png qt5 ssl svg taglib theora truetype twolame udev vaapi vdpau vorbis xml (-altivec) -aom -archive -aribsub -bidi -chromaprint -chromecast -dav1d -dc1394 -debug (-directx) -faad -fdk -fluidsynth -gme -gnome-keyring -gstreamer -ieee1394 -jack -kate (-libav) -libcaca -libtar -libtiger -linsys -lirc -live -lua -macosx-notifications -modplug -mtp -nfs -omxil -optimisememory -postproc -projectm -pulseaudio -rdp -run-as-root -samba -sdl-image -sftp -shout -sid -skins -soxr -speex -srt -test -tremor -upnp -v4l -vnc -vpx -wayland -x264 -x265 -zeroconf -zvbi" CPU_FLAGS_X86="mmx sse" 0 KiB Total: 1 package (1 reinstall), Size of downloads: 0 KiB I used this stream for reference: https://st01.sslstream.dlf.de/dlf/01/high/opus/stream.opus turns out media-libs/opus is insufficent for *decoding* streams at least, it might be sufficent to *encode* though, but for *decoding* the ebuild should pull in media-libs/opusfile. I'm a bit surprised since there is no need to recompile vlc, so this might be a possible automagic behavior?
turns out this was a poorly configured stream, now it's working without pulling in opusfile.