[mythtv-users] Hard frontend crash with vaapi on Ubuntu 20.04 and Mythtv 31

[OpenMedia Support]

I'm running an Intel N3150 based NUC as a dedicated frontend for MythTV
and it keep getting hard crashes during video playback with VAAPI. Id
appreciate some guidance on how to best debug the problem.

Hardware - Gigabyte Brix Intel N3150 / 4GB Ram / 120GB SSD

OS - Ubuntu 20.04 LTS - regularly patched

MythTV Backend - on different hardware with DVB-T and DVB-S cards

MythTV Frontend - Lastest version from the PPA -
http://ppa.launchpad.net/mythbuntu/31/ubuntu

Video playback currently uses a custom VAAPI profile, but the out of the
box VAAPI profile also has issues. It appears to occur when playing H.264
based content. Our DVB-T FTA service is H.264 for both HD and SD material.
It can occur when we're simply watching a show, and the video / audio
freezes and I need to hard-reset the Brix hardware.

I've configured for
 - max_cpus = 3
 - deinterlacer - low:shader:driver
 - decoder - vaapi
 - videorender - opengl-hw
 - skiploop - 0

I'll try and reproduce with "-v playback" enabled but at present there is
nothing obvious in the frontend or system logs when the crash occurs.

I'd really appreciate it if anyone else seen similar issues and could
provide guidance.