Adjusting Gamma levels does nothing

[TheGift73]

I'm using version 3.0.3 Vetinari on my Windows x64 machine, and when I try to adjust the gamma levels for a film/video that I am watching, it will have no effect at all. All previous versions of VLC have been fine in this regard.

I have the Image Adjust box ticked, but adjusting the slider (it moves, but has no effect) does nothing? All the other sliders for colour corrections work fine.

Reverting back to version 2.2.6 is fine.

[Jean-Baptiste Kempf]

Disable hardware decoding in preferences.

[TheGift73]

I disabled Hardware-accelerated decoding under Preferences>Input/Codecs, but it had no effect.

[Jean-Baptiste Kempf]

I disabled Hardware-accelerated decoding under Preferences>Input/Codecs, but it had no effect.

Please share your logs, then, please.

[TheGift73]

[Update] Came back from work today (rebooted machine) and it now works fine with Hardware-accelerated decoding disabled as suggested.

Many thanks.

[Jean-Baptiste Kempf]

[Update] Came back from work today (rebooted machine) and it now works fine with Hardware-accelerated decoding disabled as suggested.

Many thanks.

Please share logs.

[adrian]

Hi Jean-Baptiste Kempf,

I had the same issue and disabling the hardware acceleration under the Preferences > Input/Codecs worked. Though it took me a few hours to find this thread using different keywords on Google.

So, my question now is, why? What is causing this issue? Is this a known issue? Is it caused by only certain types of hardware? Is there a list of known offenders? Does it matter what OS is being used? Maybe a verification step could be done in the code to check that the gamma has actually changed so that automatic detection can actually work? Or is that code already there but is failing?

Sorry for all the Qs. but I like VLC and it is a shame that this failure happens and wonder if anything can be done to stop this from happening or at the very least, warn the user that a problem could occur and proposing a possible solution, saving the user hours of frustration. Short term solution could be that a help balloon pop up saying this could be an issue the first time a user slides the gamma control after VLC startup, and proposing turning off hardware acceleration (specifying where that is since the preferences is a large beast of options). The balloon could have a "Don't show me again" checkbox as well.

Thoughts?


A

[AudioDude]

I noticed that when typing in a value in the "Gamma" input field, saving preferences, and restarting VLC, the value was back to 1.00.

[BobJewett]

I had the same problem of the gamma slider not working. I discovered by accident that turning on some Geometry function, such as rotate (of 0) would enable the gamma slider. (Windows 7. Yes, I know.)

[jbperez808]

This seems to be a UX issue.

None of the other solutions mentioned worked for me, but I discoverd I had to click on the "Sharpen" checkbox. Then the gamma slider works!

[jondissed]

Bug still present, v.3.0.26, Windows 11. Gamma slider does nothing unless "Sharpen" or "Banding removal" or "Film grain" is checked.

[Lotesdelere]

Bug still present, v.3.0.26, Windows 11. Gamma slider does nothing unless "Sharpen" or "Banding removal" or "Film grain" is checked.

Yes, I can reproduce the issue.
You should create a new feature request ticket on the VLC Trac with your above report and the link to this thread:
https://code.videolan.org/videolan/vlc/-/issues