PVR support was dropped, so it should be removed from the live ebuild. Reproducible: Always
https://github.com/mpv-player/mpv/commit/475fe453cc8fa828e395da100cf2c07e1e6542ea
Created attachment 419498 [details] mpv-9999.ebuild Addresses https://bugs.gentoo.org/show_bug.cgi?id=568370 as well
I can confirm that I'm having the same issue using the vapoursynth overlay.
Actually, the overlay fixes this issue in the latest update, so you can use that as a temporary fix. I can confirm the issue for the vanilla mpv-9999 tho.
This is a known problem. Fix is on the way, see URL.
commit a31febf615fe165b5cce1532230c9cfb891e5601 Author: Ilya Tumaykin <itumaykin@gmail.com> Date: Tue Dec 22 22:43:57 2015 +0300 media-video/mpv: drop pvr USE as done upstream wrt bug 568018 This was originally submitted by Vindex17 in PR #318. Gentoo-Bug: 568018 Package-Manager: portage-2.2.24