Deck Waveform: Green background and flickering

[uklotzde]

Bug Description

The deck waveform changes from a black to a green background after hitting play:

Eventually it switches back to black or even starts to flicker. The flickering occurs when moving the mouse over skin controls.

Mesa Intel® HD Graphics 530 (SKL GT2) on Fedora 37 / Mesa 22.3

Version

2.4.0

OS

Fedora 37

[uklotzde]

All decks are affected. Seems to be an OpenGL issue with the legacy widgets.

[scratchmonkeystudio]

Weirdly I get this behavior (2.3.3 on Fedora 37 X11) but the background is cyan rather than green. Also it goes away if I kill the compositor.

[uklotzde]

The coloring issues might be caused by this bug: ValveSoftware/gamescope#356 The wrong waveform colors are generated by the analyzer and not related to the graphics drivers. See also: #11483

[daschuer]

Which waveforms are exactly effected? Is Mixxx 2.3.4 also affected?

[Swiftb0y]

Confirmed. Using Fedora 37, OpenGL 4.3 Mesa Intel (UHD) Graphics (CML GT2). Mesa 23.0. The flickering color changes based on skin, its green on Deere, cyan on Latenight, red/orange (not sure) on Tango and green on Shade. Mixxx 2.3.4 is also affected. Waveform in question are GL and GLSL variants. CPU rendered variants are not affected. waveform introduced in #10989 are also not affected.

[daschuer]

We had a similar issue with the recently introduced VU meters an the Tango Skin.

#11430
#11422

The issue there is that the transparent GL widget fails to adopt the non GL background piamp and draws green instead. I wonder if this is a regression in our 2.3 branch.
But anyway. I see a good chance to fix this with the same solution in our stable 2.3. branch.

[daschuer]

@Swiftb0y, can you confirm that the waveform itself behaves normal and only the background is affected?

[Swiftb0y]

How would I go about that? Comment out the background renderer in the render stack?

[m0dB]

Potential fix in #11523
(I can't reproduce the issue, so someone who can, please try)