Bug 454445

Summary: It would be nice if RGB range: Automatic would also display the currently chosen value
Product: [Applications] systemsettings Reporter: John <ilikefoss>
Component: kcm_kscreenAssignee: kscreen-bugs-null <kscreen-bugs-null>
Status: CONFIRMED ---    
Severity: wishlist CC: kde, nate, plasma-bugs-null, xaver.hugl
Priority: NOR Keywords: usability
Version First Reported In: 6.3.0   
Target Milestone: ---   
Platform: Debian unstable   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description John 2022-05-26 15:48:35 UTC 
SUMMARY
***
It would be nice if RGB range: Automatic would also display the currently chosen value
***


STEPS TO REPRODUCE
1. Open systems Settings
2. Go to Display and Monitor
3. Look at RGB range value (I'm not sure if this is available for all GPU vendors), it might be an Intel only thing.

OBSERVED RESULT
The RGB range value by default is Automatic.
But it's not clear which one of the two values (Full, Limited) has been automatically choosen for the current GPU / computer

EXPECTED RESULT
To display if possible which option has been choosen automatically so we know if the best  value for our GPU / monitor is being used or we need to check the cables, upgrade the Linux kernel, Mesa drivers, etc.
Something like:
Automatic (current: Full)
Or 
Automatic (current: Limited)

Right now since it's not clear which one has been selected automatically I always go there change it manually to Full just to be sure, but I would like to avoid doing that if I see that the Automatic chooses the right thing for my computer.

If this depends on the driver and the drivers doesn't report back what it has chosen, then tthat's it, it's ok leaving as it is.
Maybe explain why this is not possible in that tooltip next to it and hopefully one day the driver developers seeing it, will add that information too to their drivers in a way that KDE can read it and display it.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma:
KDE Plasma Version: 5.24.90
KDE Frameworks Version: 5.95
Qt Version: 5.15.4

ADDITIONAL INFORMATION
From: neon-testing-20220524-1822.iso + updates from Discover
Tested on Wayland
Comment 1 Zamundaaa 2022-05-26 23:31:36 UTC 
It would indeed be nice, sadly the driver doesn't currently expose that sort of information to us. It's a known problem and will hopefully be tackled soon™ with all the other color management stuff being worked on. However, I fully expect it to still take a long while to be done.
Other than just waiting for that kernel fix, we could also
1. roll our own automatic detection. Something basic should be pretty quick to set up, although it may depend on us parsing more edid info (which I'd like to avoid diving into until we can use libedid to take care of that for us). Or
2. remove the automatic option completely and always default to full rgb range. Something like 98% of monitors and TVs out there have that and new ones should all be full rgb range, so it likely wouldn't be that bad.

Both have the problem that they can cause unexpected regressions for some users with limited rgb TVs though...
Comment 2 John 2022-05-28 05:19:03 UTC 
(In reply to Zamundaaa from comment #1)
> It would indeed be nice, sadly the driver doesn't currently expose that sort
> of information to us. It's a known problem and will hopefully be tackled
> soon™ with all the other color management stuff being worked on. However, I
> fully expect it to still take a long while to be done.
> Other than just waiting for that kernel fix, we could also
> 1. roll our own automatic detection. Something basic should be pretty quick
> to set up, although it may depend on us parsing more edid info (which I'd
> like to avoid diving into until we can use libedid to take care of that for
> us). Or
> 2. remove the automatic option completely and always default to full rgb
> range. Something like 98% of monitors and TVs out there have that and new
> ones should all be full rgb range, so it likely wouldn't be that bad.
> 
> Both have the problem that they can cause unexpected regressions for some
> users with limited rgb TVs though...

I would go with option number 2 as long as the users that have monitors and TVs that do not support the full range can still navigate to that control panel page and change it to limited.
From what I understand they should still be able to do that.
As for the other option I understand and I would wait for the libedid too.

If nothing could be done now, I completely understand.

Thank you!
Comment 3 Nate Graham 2025-02-27 23:12:21 UTC 
*** Bug 500701 has been marked as a duplicate of this bug. ***