Gstreamer doesn't support VAAPI on amdgpu

[Paul Keith]

The version of gstreamer forked for Ubuntu 20.04 has the commit to remove Mesa from the whitelist but doesn't have the commit merged later to readd it to the whitelist.

Removal: https://github.com/GStreamer/gstreamer-vaapi/commit/a90daabb84f983d2fa05ff3159f7ad59aa648b55

Reintroduction: https://github.com/GStreamer/gstreamer-vaapi/commit/7a186975cc209f1f4d75e902144563e76ce3a14c

I have tested that readding it to the whitelist works:

Before: https://gist.github.com/99daafcff32cf650b5fe11315c01a27d

After: https://gist.github.com/e2a31779f05b706c9347bcf7277def3d

To change the whitelist, I did:
sudo sed -i -e 's/Intel i965 driver/Mesa Gallium driv/g' /usr/lib/x86_64-linux-gnu/gstreamer-1.0/libgstvaapi.so

That changes the whitelist entry for the i965 driver to the Mesa driver for amdgpu. Picking the reintroduction patch linked above and spinning a new version should be enough.

Release:
javelinanddart@jav-bq213cl:~$ lsb_release -rd
Description: Ubuntu 20.04 LTS
Release: 20.04

Version:
javelinanddart@jav-bq213cl:~$ sudo apt-cache policy gstreamer1.0-vaapi
gstreamer1.0-vaapi:
  Installed: 1.16.2-2
  Candidate: 1.16.2-2
  Version table:
 *** 1.16.2-2 500
        500 http://us.archive.ubuntu.com/ubuntu focal/universe amd64 Packages
        100 /var/lib/dpkg/status

What I expected to happen: See After gist

What happened instead: See Before gist