Bug 509858

Summary: Motion tracker doesn't work when clip has speed other than 100%
Product: [Applications] kdenlive Reporter: Kris <kris.starr>
Component: Video Effects & TransitionsAssignee: Jean-Baptiste Mardelle <jb>
Status: CONFIRMED ---    
Severity: normal CC: fritzibaby
Priority: NOR    
Version First Reported In: 25.08.0   
Target Milestone: ---   
Platform: Mint (Ubuntu based)   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Kris 2025-09-24 09:16:00 UTC
SUMMARY
When applied on a clip with speed different to 100%, the motion tracker effect will either:
1) Not do anything when clicking "analyze to apply effect"
2) Give a result that makes no sense at all with a simple moving object
3) Perform the tracking seemingly at 100% speed (even if the clip's speed is 50%)
I have never gotten it to work yet. I render the clip at the changed speed and then apply the motion tracking to that as a workaround.

STEPS TO REPRODUCE
1) Add clip with something easy to track to the timeline
2) Significantly change speed (50%, 200%, etc.)
3) Try to apply motion tracking

debug info:

Kdenlive: 25.08.0
Package Type: Flatpak
MLT: 7.33.0
Qt: 6.9.2 (built against 6.9.0 x86_64-little_endian-lp64)
Frameworks: 6.17.0
System: KDE Flatpak runtime
Kernel: linux 6.8.0-71-generic
CPU: x86_64
Windowing System: xcb
GPU: Intel/Mesa Intel(R) UHD Graphics 630 (CFL GT2)
Movit (GPU): disabled
Track Compositing: qtblend
Comment 1 emohr 2025-09-24 15:27:14 UTC
I can confirm the issue. It seems the motion tracker only consider 100% speed when analyzing.