Created attachment 142601 [details]
Totem screenshot (of the 20th Century Fox intro)

Totem cannot correctly play MPEG videos with Mesa on a range of AMD GCN cards.
The videos are tainted reddish (see screenshot).

I'm using Mesa 18.2.5 (previously 18.1.9, same problem) from Debian/testing
with Xorg 1.20.3 on a Radeon RX 560 (POLARIS11, DRM 3.26.0, 4.18.0-2-amd64,
LLVM 7.0.1) device, with up-to-date firmware and Linux kernel 4.18.10
(open-source AMDGPU driver).

I've reported this as Totem bug
https://gitlab.gnome.org/GNOME/totem/issues/241#note_370403 and am reporting it
here because the Totem maintainer is convinced that it's a Mesa problem.