HDR Mode Switching

Have a MythTV related problem? Ask for help from other MythTV users here.

Moderator: Forum Moderators

Post Reply
felixfurtak
Newcomer
Posts: 1
Joined: Thu Mar 24, 2022 9:21 am
New Zealand

HDR Mode Switching

Post by felixfurtak »

My first post on the forum, but a long time user.

I was really excited to read in the release notes for v32 the following commit
[24f018d6ec] HDR: Enable HDR mode switching,

- this is only currently supported when using a DRM authenticated connection - which for clarity generally means using eglfs when neither
X11 or wayland are running
- there is no setting for this yet - as any failure probably just means displaying washed out HDR - just like the existing code:)
- tested with amdgpu but should work with Intel (untested) and various SoCs
- will definitely NOT work with *anything* nvidia
- limited display testing (one LG with HDR10 and one Samsung with HDR10 and HLG)
- NOTE: For the time being at least, the OSD will look a little gaudy/ over saturated when HDR is enabled (as they are non-HDR images).

To try out, switch to an unused VT (e.g. CTRL-ALT F3) and start mythfrontend with something like 'mythfrontend -platform eglfs' (you may need to check the permissions of your mouse/keyboard devices to ensure these still work).

Check the logs for relevant details and the 'System Status' frontend screen will show any HDR support in the 'Display' section.
It's great to see this feature arriving, and I would love to know if anyone else has managed to get it working.

My hardware seems to meet the requirements (running amdgpu on a Ryzen with integrated graphics), together with a LG TV which supports HDR10 and HLG and I'm pretty sure my HDR10 source material is suitable since it causes the TV to correctly switch to HDR mode when played on the TV's internal media player or through an NVIDIA shield.

The commit notes seem to work in as much that EGLFS platform starts up fine, and the logs report the TV as supported, but unfortunately no switching. I added my user to the input group in /etc/group in order to get the keyboard/mouse to work.

Are there any more secrets to getting mode switching to work that anyone could share?

Thanks,
Felix
Post Reply