Bug 480486 - framerate stutters on thumbnail hover
Summary: framerate stutters on thumbnail hover
Status: REPORTED
Alias: None
Product: digikam
Classification: Applications
Component: Thumbs-Album (show other bugs)
Version: 8.2.0
Platform: Microsoft Windows Microsoft Windows
: NOR normal
Target Milestone: ---
Assignee: Digikam Developers
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-01-29 12:17 UTC by digikam
Modified: 2024-01-29 13:08 UTC (History)
1 user (show)

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Description digikam 2024-01-29 12:17:41 UTC
SUMMARY
With a high framerate display (144Hz)  and G-SYNC enabled, mouse pointer movement over thumbnails triggers framerate stuttering for about a second. This only happens when transitioning to a thumbnail. This issue wasn't present in 8.0.0.

STEPS TO REPRODUCE
1. Start digikam and wait for albums to load and any scans to finish
2. In thumbnail or preview windows, hover over the menu or  other sidebars and move the mouse pointer quickly in circles to observe normal mouse smoothness/framerate
3. Move pointer over a thumbnail and move pointer in a circle as before, observe duration of slow framerate
4. Move pointer over another thumbnail moving mouse as before and observe framerate

OBSERVED RESULT
When a thumbnail is first hovered over there is about 1 second of slow framerate before normal framerate returns, this happens for each subsequent thumbnail hover.

EXPECTED RESULT
No framerate loss/shift when hovering between thumbnails

SOFTWARE/OS VERSIONS
Windows:  11 Pro  - Version 10.0.22621 Build 22621
Qt Version:  6.6.0

ADDITIONAL INFORMATION
- Switching to fullscreen vs fullscreen and windowed GSYNC application doesn't make any difference
- Trying to lock the framerate causes brief black frames when hovering between thumbnails
- Albums contain both jpg. and CR3. files
- Does not happen when another window is in the foreground
Comment 1 Maik Qualmann 2024-01-29 12:33:06 UTC
Please test the pre-release digiKam-8.3.0 from here:

https://files.kde.org/digikam/

Also test the new "Force use of software OpenGL rendering" option in the digiKam settings under Miscellaneous-> System.
Please report.

Maik
Comment 2 Maik Qualmann 2024-01-29 12:47:20 UTC
I googled a little, other projects noticed something similar, it is an interaction between G-Sync and the new render engine in Qt6. We will probably not be able to change anything at first, unless you try the software OpenGL option.

Maik
Comment 3 digikam 2024-01-29 13:08:26 UTC
Confirmed that it's still present in 8.3.0.
I tried "Force use of software OpenGL rendering", and also removed the profile in the Nvidia control panel for digikam with no effect.
There doesn't seem to be anything forced in the global Nvidia settings other than having G-sync enabled on fullscreen.

Digikam is still usable, just not as smooth. :)