Arch Linux

Description:
Videos fail to play in epiphany, which gives this warning:

(WebKitWebProcess:2): GStreamer-WARNING **: [timestamp]: Failed to load plugin '/usr/lib/gstreamer-1.0/libgstlibav.so': libmfx.so.1: cannot open shared object file: No such file or directory

The warning goes away, and videos work, after installing libmfx.

I already had intel-media-sdk installed as a dependency of ffmpeg which should be providing libmfx, but gst-libav can't seem to find it.

ldconfig shows both versions available:
899: libmfx.so.1 (libc6,x86-64) => /opt/intel/mediasdk/lib/libmfx.so.1
900: libmfx.so.1 (libc6,x86-64) => /usr/lib/libmfx.so.1
901: libmfx.so (libc6,x86-64) => /opt/intel/mediasdk/lib/libmfx.so
902: libmfx.so (libc6,x86-64) => /usr/lib/libmfx.so

Lone_Wolf suggests rebuilding gst-libav:
https://bbs.archlinux.org/viewtopic.php?pid=1884436#p1884436

Package versions:
extra/epiphany 3.34.3.1-1
extra/gst-libav 1.16.2-1
extra/ffmpeg 1:4.2.2-1
community/intel-media-sdk 19.4.0-1
community/libmfx 1.25-3

Steps to reproduce:
1. Install epiphany and gst-libav.
2. Run epiphany in a terminal.
3. Observe warning message when attempting to load a video, and that video does not play.
4. Install libmfx
5. Run epiphany in a terminal.
6. Notice the lack of warning message and that videos play.