Value mismatch between BetterDisplay and MediaMate

[sampotts]

Current Behaviour

The values for brightness shown in MediaMate don't match those in BetterDisplay.

When BetterDisplay shows 69% for both displays, MediaMate shows 68% for the Pro Display XDR and 62% for the Studio Display.

App	Values
BetterDisplay	69% for both displays.
MediaMate	68% for the Pro Display XDR and 62% for the Studio Display.

App	Values
BetterDisplay	75% for both displays.
MediaMate	75% for the Pro Display XDR and 68% for the Studio Display.

App	Values
BetterDisplay	62% for the ProDisplay XDR and 63% for Studio Display.
MediaMate	62% for the Pro Display XDR and 56% for the Studio Display.

BetterDisplay Configuration

MediaMate Configuration

Expected Behaviour

The values match.

Versions

• macOS 14.5
• BetterDisplay Version 2.3.7 Build 30978
• MediaMate 3.5.0 build 278

[waydabber]

Hi there,

please follow this procedure:

1. Exit BetterDisplay
2. Open Terminal
3. Enter the following command (this launches the app with log output enabled):

/Applications/BetterDisplay.app/Contents/MacOS/BetterDisplay -v

4. Make sure Dispatch OSD notifications is enabled under Settings/Application/Integration

5. Adjust the brightness using the keyboard and check the Terminal window's log output.

You should see items like this:

OSD notification sent: {"controlTarget":"combinedBrightness","displayID":4,"maxValue":64,"systemIconID":1,"value":44} 

Check if the value (44 in this example) corresponds properly to the expected OSD value for the brightness. Please note that the OSD uses 64 levels (16 chiclets with 4 substeps each). So 100% is value 64, 50% should be value 32.

If these match up properly, then BetterDisplay is sending the right values, maybe some kind of setting/configuration issue prevents MediaMate from showing the right percentages.

Let me know what are the results are so we can determine the best course of action.

Thanks!

[sampotts]

It looks to me like the numbers are right. The percentages are what MediaMate is displaying and they seem to match the API responses?

100%
[2024-06-24 20:29:33.779] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":4,"maxValue":64,"systemIconID":1,"value":64}
[2024-06-24 20:29:33.780] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":3,"maxValue":64,"systemIconID":1,"value":64}

93% / 87%
[2024-06-24 20:29:51.871] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":4,"maxValue":64,"systemIconID":1,"value":60}
[2024-06-24 20:29:51.872] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":3,"maxValue":64,"systemIconID":1,"value":56}

87% / 81%
[2024-06-24 20:30:05.300] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":4,"maxValue":64,"systemIconID":1,"value":56}
[2024-06-24 20:30:05.300] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":3,"maxValue":64,"systemIconID":1,"value":52}

81% / 75%
[2024-06-24 20:30:16.794] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":4,"maxValue":64,"systemIconID":1,"value":52}
[2024-06-24 20:30:16.795] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":3,"maxValue":64,"systemIconID":1,"value":48}

75% / 68% 
[2024-06-24 20:30:50.087] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":4,"maxValue":64,"systemIconID":1,"value":48}
[2024-06-24 20:30:50.088] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":3,"maxValue":64,"systemIconID":1,"value":44}

68% / 62%
[2024-06-24 20:31:06.825] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":4,"maxValue":64,"systemIconID":1,"value":44}
[2024-06-24 20:31:06.825] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":3,"maxValue":64,"systemIconID":1,"value":40}

62% / 56%
[2024-06-24 20:31:24.200] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":4,"maxValue":64,"systemIconID":1,"value":40}
[2024-06-24 20:31:24.201] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":3,"maxValue":64,"systemIconID":1,"value":36}

[waydabber]

Hi @sampotts - BetterDisplay does not send percentages, only the maxValue (64) and the current value. This works like this (and uses 64 as maxValue) because the feature to send OSD data to MediaMate instead is implemented right where the app would normally use the native macOS OSD framework to produce the OSD. This way mediaMate gets the exact same data macOS would get to show the OSD.

Note: originally when the interface was developed I think MediaMate did not show percentages so the fact that it calculates percentage value is probably a new development. Since in some instances BetterDisplay does not use a 0-100% scale (for example when software HDR/XDR upscaling is used), this for sure causes discrepancies, but in your case as only hardware brightness is used, this should not be the case.

[waydabber]

Let's add @wouter01 to this issue, maybe he has some insights.

[sampotts]

BetterDisplay does not send percentages, only the maxValue (64) and the current value.

Oh yeah, I get that. When I say "It looks to me like the numbers are right." I mean I calculated what I'd expect to see from the API output based on the values displayed by MediaMate and they seemed right (rounded).

For example. MediaMate displays 62% and 56% when the API output was:

[2024-06-24 20:31:24.200] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":4,"maxValue":64,"systemIconID":1,"value":40}
[2024-06-24 20:31:24.201] OSD notification sent: {"controlTarget":"hardwareBrightness","displayID":3,"maxValue":64,"systemIconID":1,"value":36}

62% of 64 is 39.68 and the API output was 40 56% of 64 is 35.84 and the API output was 36.

Meanwhile with the above values, BetterDisplay shows 63% for both displays. So is there an issue with how I've configured BetterDisplay, or a bug in it's UI?

[waydabber]

Hmm. I am not sure. If the brightness percentage does not match the OSD, then something must be affecting it. If you change the brightness using the keyboard, do you see the slider value changing to the desired level? If so, what are the values as you progress from 0% to 100% with each keyboard press and do they remain at the set value or change slightly afterwards?

BetterDisplay continuously reads the brightness level of Apple displays and adjusts its sliders accordingly so it might be that even though after a keypress the brightness is set to a certain level but then the display or macOS compensates for whatever reasons (ambient light sensor, other processes interfering etc) and thus the slider value slightly changes - this won't be reflected in MediaMate's OSD as that reflects the OSD event only. You should have the app's menu open (and maybe System Setting's brightness slider) and see if the slider and brightness value in it changes in any direction by itself after the keypress.

[Wouter01]

Hi, sorry for only having a look at this now. Is there something I can do about this?

[sampotts]

In macOS Settings, both displays have Automatically adjust brightness enabled and from what I can see, when I adjust the brightness, both values are in identical positions on the sliders. I

In BetterDisplay, when I adjust the brightness with the keyboard, both values are identical but I did notice the value flickering around at some levels:

https://github.com/waydabber/BetterDisplay/assets/719092/33e7dedd-59f8-42da-8918-a2e5197bbf06

[waydabber]

@Wouter01 - I don't think so - if I understand right the values are sent correctly and MediaMate calculates the percentages based on that right.

@sampotts - and are the levels correct then (I guess they show the same level because they are synced as a group or the keyboard is set to affect them all, right?) Does the flickering happen as well when the auto brightness is disabled?

[waydabber]

(note: I could add some logic to prevent the percentage value from flickering annoyingly when the brightness hovers around the threshold between two percentage numbers due to system brightness changing like that).

[sampotts]

There's something odd going on for sure, I can't seem to disable auto brightness adjustment. I can disable it but when I flick back and forth between the two displays, it will toggle itself back on. I guess this could be related. I also noticed that the brightness sliders are in sligthly different positions now.

https://github.com/waydabber/BetterDisplay/assets/719092/f6782634-bab9-4abc-b66f-eb9bae009b1f

[waydabber]

I am not sure what's wrong with auto brightness for the display - this might be some kind of macOS issue. The sliders being at different locations might be normal if one or both displays have auto brightness enabled, as the displays each have their sensors and they might drift.

You should be able to fully synchronize them by enabling auto brightness for one or the other display only and use BetterDisplay's Groups/Synchronization feature for brightness syncing make one display (the one with ambient sensor enabled) as sync source and the other a target + enable syncing external events for the sync config (so ambient light sensor induced changes are synced also).