Bug 474602

Summary: Slow rendering with mere defish inserted
Product: [Applications] kdenlive Reporter: fehler-im-programm
Component: Rendering & ExportAssignee: Jean-Baptiste Mardelle <jb>
Status: CONFIRMED ---    
Severity: normal CC: fritzibaby
Priority: NOR    
Version First Reported In: 23.08.0   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: Projectfile "Bug Slow rendering with mere defish inserted.kdenlive"
testimage3.png

Description fehler-im-programm 2023-09-17 00:12:54 UTC
Created attachment 161663 [details]
Projectfile "Bug Slow rendering with mere defish inserted.kdenlive"

STEPS TO REPRODUCE
1. Insert any Clip twice
2. Insert defish in 1 clip
3. Render and watch frame per second

OBSERVED RESULT
Clip with only defish inserted renders at about 1/3 speed

EXPECTED RESULT
Render speed remains the same

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
Comment 1 fehler-im-programm 2023-09-17 00:13:41 UTC
Created attachment 161664 [details]
testimage3.png
Comment 2 emohr 2024-09-22 09:31:25 UTC
I can confirm the issue. If you set in Defish the Interpolator to “Lanczos” rendering goes down to zero frame and uses 50% CPU. I think this cannot be solved until we implement GPU rendering.
Comment 3 fehler-im-programm 2024-09-22 10:00:28 UTC
(In reply to emohr from comment #2)
> I can confirm the issue. If you set in Defish the Interpolator to “Lanczos”
> rendering goes down to zero frame and uses 50% CPU. I think this cannot be
> solved until we implement GPU rendering.

Ok. Thanks for the hint.