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

Calculating dependencies ... done!
Dependency resolution took 1.32 s (backtrack: 0/20).

[ebuild  N     ] dev-libs/libunibreak-8.0:0/8::gentoo  USE="-doc -man -static-libs -test" 1063 KiB
[ebuild  N     ] media-libs/alsa-topology-conf-1.2.5.1-r1::gentoo  USE="-verify-sig" 12 KiB
[ebuild  N     ] media-libs/alsa-ucm-conf-1.2.16.1::gentoo  USE="-verify-sig" 83 KiB
[ebuild  N     ] media-libs/alsa-lib-1.2.16.1::gentoo  USE="python -debug -doc -verify-sig" PYTHON_SINGLE_TARGET="python3_14 -python3_12 -python3_13 (-python3_15)" 1104 KiB
[ebuild  N     ] media-libs/dav1d-1.5.4:0/7::gentoo  USE="8bit 10bit asm -test -xxhash" 1015 KiB
[ebuild  N     ] media-libs/x264-0.0.20240513-r1:0/164::gentoo  USE="interlaced -opencl -static-libs" 822 KiB
[ebuild  N     ] media-libs/x265-4.3:0/217::gentoo  USE="10bit 12bit cet -numa -test -vmaf" 2005 KiB
[ebuild  N     ] media-libs/xvid-1.3.7-r2::gentoo  USE="-examples" 683 KiB
[ebuild  N     ] dev-lang/yasm-1.3.0-r2::gentoo  USE="nls" 1458 KiB
[ebuild  N     ] acct-group/jellyfin-0-r1::gentoo  0 KiB
[ebuild  N     ] acct-user/jellyfin-0-r2::gentoo  0 KiB
[ebuild  N     ] x11-libs/libXv-1.0.13::gentoo  USE="-doc" 275 KiB
[ebuild  N     ] media-libs/libass-0.17.5-r1:0/9::gentoo  USE="fontconfig libunibreak -test -verify-sig" 450 KiB
[ebuild  N     ] net-libs/libssh-0.12.2:0/4::gentoo  USE="sftp zlib -debug -examples -fido2 -gssapi -mbedtls -pcap -server -static-libs -test -verify-sig" 742 KiB
[ebuild  N     ] media-libs/libvpx-1.16.0:0/12::gentoo  USE="highbitdepth -doc -postproc -static-libs -test" 5504 KiB
[ebuild  N     ] media-video/ffmpeg-8.1.3:0/60.62.62::gentoo  USE="X alsa bzip2 cairo dav1d drm fontconfig gmp gnutls gpl jpeg2k libass opengl openssl ssh truetype vpx x264 x265 xml xvid zlib -amf -amr -amrenc (-appkit) -bluray -bs2b -cdio -chromaprint -chromium -codec2 -cuda-clang -doc -dvd -fdk -flite -frei0r -fribidi -gcrypt -gme -gsm -iec61883 -ieee1394 -jack -jpegxl -kvazaar -ladspa -lame -lcms -libaom -libaribb24 -libcaca -libilbc -liblc3 -libplacebo -librtmp -libsoxr -lv2 -lzma -modplug -nvenc -ocr -openal -opencl -opencolorio -openh264 -openmpt -opus -pulseaudio -qrcode -qsv -quirc -rabbitmq -rav1e -rist -rubberband -samba -sdl -snappy -sndio -soc -sofa -speex -srt -svg -svt-av1 -theora -twolame -v4l -vaapi -vdpau -verify-sig -vidstab -vmaf -vorbis -vulkan -webp -zeromq -zimg -zvbi" 11458 KiB
[ebuild  N     ] www-apps/jellyfin-bin-12.2::gentoo  86606 KiB

Total: 17 packages (17 new), Size of downloads: 113274 KiB

The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)
# required by www-apps/jellyfin-bin-12.2::gentoo
# required by =www-apps/jellyfin-bin-12.2 (argument)
>=media-video/ffmpeg-8.1.3 vpx