Bug 509769

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SUMMARY
When trying to motion-track a sequence, clicking "analyze to apply effect" freezes the program and it crashes shortly after.

My current work-around is to render the section I need into an mp4 and replace the sequence section with that and then apply tracking.

STEPS TO REPRODUCE
(I tested in brand new project)
1. Add 2 video clips on 2 video tracks
2. Select these 2 clips, right click and click "create sequence"
3. Click the newly created sequence clip and add a motion tracking effect (I tested with algorithm MOSSE and every 1 frame)

OBSERVED RESULT
Kdenlive freezes and crashes in 5-10 seconds.

EXPECTED RESULT
Extracting keyframes with motion tracking should work with sequences as if it was analyzing a normal mp4 clip. 


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: 
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION

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