MarsSeed [1] filed a deletion request for gst-plugin-viperfx-git [2]: This upstream fork has been discontinued since 2017. [a] AUR has the latest fork which had its last commit in 2020. [b] [a] https://github.com/vipersaudio/gst-plugin-viperfx [b] https://aur.archlinux.org/packages/gst-plugin-viper4linux-git [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/gst-plugin-viperfx-git/