Bug 483669

Summary: Adding certain effects after Saturation effect, (Color balance, contrast, temperature, etc), alter the colors of footage with red-ish tint.
Product: [Applications] kdenlive Reporter: nuxttux
Component: Video Effects & TransitionsAssignee: Jean-Baptiste Mardelle <jb>
Status: REPORTED ---    
Severity: normal Keywords: qt6
Priority: NOR    
Version First Reported In: 24.02.0   
Target Milestone: ---   
Platform: Flatpak   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description nuxttux 2024-03-15 13:42:05 UTC
SUMMARY
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STEPS TO REPRODUCE
1. Create new project.
2. Import video clip with human characters (for skin tone).
3. Add clip to timeline.
4. Add Saturation effect to clip.
5. Set Saturation to 250 (for more pronounced results).
6. Add following effects after Saturation: Color Balance, Color Contrast, Color Channel Mixer, CMYK adjust, Color Temperature.
7. Toggle effects on and off, except Saturation.


OBSERVED RESULT
Without changing the values of the additional effects (after Saturation), 
the colors in the footage are altered.

EXPECTED RESULT
Without changing the values of the additional effects (after Saturation), 
the colors in the footage should remain unchanged (until users makes changes to values).

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: Linux Mint Cinnamon.
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 6.0.0
Qt Version: 6.6.2

ADDITIONAL INFORMATION
If Saturation is moved to the bottom of the Effect/Composition Stack, the anomaly stops.
The bug is trues in earlier versions of Kdenlive, prior to Qt 6.6.2.
Notice that the anomaly is accumulative with each of the named effects added after Saturation.
Comment 1 nuxttux 2024-03-15 22:49:29 UTC
With closer observation, the anomaly occurs even without Saturation present. It is a lot more subtle, but still present.