Bug 474960

Summary:	kdenlive crashes using Rotoscope
Product:	[Applications] kdenlive	Reporter:	Richard <richard.kidd1968>
Component:	Video Effects & Transitions	Assignee:	Jean-Baptiste Mardelle <jb>
Status:	RESOLVED FIXED
Severity:	crash	CC:	fritzibaby
Priority:	NOR
Version First Reported In:	23.08.1
Target Milestone:	---
Platform:	Microsoft Windows
OS:	Microsoft Windows
Latest Commit:		Version Fixed/Implemented In:	23.08.2
Sentry Crash Report:
Attachments:	kdenlivecrashproject

Description Richard 2023-09-28 00:59:33 UTC

SUMMARY
***
NOTE: If you are reporting a crash, please try to attach a backtrace with debug symbols.
See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports
***


STEPS TO REPRODUCE
1.  Load supplied project
2.  Press Play
3.  Watch it crash shortly after

OBSERVED RESULT
Kdenlive crashes. It was crashing in my main project so I extracted the suspect elements to a new project and, bingo! it crashes too.

EXPECTED RESULT
Crash

SOFTWARE/OS VERSIONS
Windows: 

Qt Version: 
Windows 10

ADDITIONAL INFORMATION

Comment 1 emohr 2023-10-01 10:12:12 UTC

The project file is missing. Please use “add an attachment”.

Comment 2 Richard 2023-10-02 23:32:45 UTC

Created attachment 162040 [details]
kdenlivecrashproject

sorry, project attached, had to change to color clips cos videos were too large

Comment 3 Richard 2023-10-02 23:34:33 UTC

I've attached the file, cheers

Comment 4 emohr 2023-10-03 15:13:01 UTC

Thank you for the project file. I can confirm the crash. 
With GDB running no crash happen. It seems to be a race condition.

Comment 5 Jean-Baptiste Mardelle 2023-10-05 07:27:11 UTC

Thanks for your detailled report, this was an interesting bug. MLT's keyframes are currently quite limited and the smooth interpolation uses a Catmull interpolation which sometimes produces some unexpected curve path. Some work is being done on it:
https://github.com/mltframework/mlt/pull/957

So in fact the Transform effect keyframes were requesting a 0x0 rectangle, which crashed the Rotoscoping effect. I now fixed these issues in MLT git and it will be included in our 23.08.2 binaries.