MarsSeed [1] filed a deletion request for libvpx-1.6 [2]: Nothing requires this legacy version from 2018, and it conflicts with repo's libvpx and therefore with gstreamer, ffmpeg, vlc, mpv, firefox.
So this cannot be used in a typical desktop system. Better to delete. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/libvpx-1.6/
