Bug 509769 - Motion Tracker always crashes entire program when applied on a sequence
Summary: Motion Tracker always crashes entire program when applied on a sequence
Status: RESOLVED FIXED
Alias: None
Product: kdenlive
Classification: Applications
Component: Video Effects & Transitions (other bugs)
Version First Reported In: 25.08.0
Platform: Mint (Ubuntu based) Linux
: NOR crash
Target Milestone: ---
Assignee: Jean-Baptiste Mardelle
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-09-22 06:19 UTC by Kris
Modified: 2025-09-27 09:09 UTC (History)
1 user (show)

See Also:
Latest Commit:
Version Fixed In: 25.08.2
Sentry Crash Report:


Attachments
Sequence_motion-tracker_crash-log (8.10 KB, text/plain)
2025-09-24 15:24 UTC, emohr
Details

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Description Kris 2025-09-22 06:19:45 UTC
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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
Comment 1 emohr 2025-09-24 15:24:31 UTC
Created attachment 185216 [details]
Sequence_motion-tracker_crash-log

I can confirm the crash following your steps. Attached the crash log.
Comment 2 Jean-Baptiste Mardelle 2025-09-27 03:27:52 UTC
Git commit abb436f146e1c55f6d3e5a4df8b2b94f925e2572 by Jean-Baptiste Mardelle.
Committed on 27/09/2025 at 03:27.
Pushed by mardelle into branch 'master'.

Fix crash using filter job (tracker, loudness) on sequence clip

M  +1    -0    src/bin/projectclip.h
M  +31   -10   src/jobs/filtertask.cpp
M  +2    -0    src/jobs/filtertask.h

https://invent.kde.org/multimedia/kdenlive/-/commit/abb436f146e1c55f6d3e5a4df8b2b94f925e2572
Comment 3 Jean-Baptiste Mardelle 2025-09-27 03:36:20 UTC
Git commit af78fdd02abe7bca1d6791776387922a9f929e85 by Jean-Baptiste Mardelle.
Committed on 27/09/2025 at 03:36.
Pushed by mardelle into branch 'release/25.08'.

Fix crash using filter job (tracker, loudness) on sequence clip

M  +1    -0    src/bin/projectclip.h
M  +31   -10   src/jobs/filtertask.cpp
M  +2    -0    src/jobs/filtertask.h

https://invent.kde.org/multimedia/kdenlive/-/commit/af78fdd02abe7bca1d6791776387922a9f929e85
Comment 4 Jean-Baptiste Mardelle 2025-09-27 03:39:46 UTC
Ok, so this is now fixed in git, and will be in the 25.08.2 release, to be announced around the 13th of october. The crash is solved in Kdenlive, but to have the Tracker work, you will also need the latest MLT fix: 
https://github.com/mltframework/mlt/commit/d1850cfd6a5f2e3babaf809053102b9d5930ab75
Comment 5 emohr 2025-09-27 09:09:40 UTC
With the latest master of Kdenlive and MLT the crash is fixed.