Created attachment 142237 [details]
Debugging result for 442880

Having same problem on Manjaro
KDE 5.22.5
Kdenlive latest from git
MLT latest from git
Movit library latest from git
In log, i tried to debug it with GDB. It looks like event_data passed to mlt_events_fire somewhere contains pointer to zero, instead of GLWidget object, it's trying to read some class variable(when "this" is 0x0 pointer), and SEGFAULT happens.

Continue crashing in KDEnlive 21.08.2.
The OS is Ubuntu 20.04 Geforce GT 640 using driver 465 CUDA 11.3.

That bug is recent.
Another detail is in .xsession-errors logs is displayed the lines below when trying start kdenlive with enabled gpu processing movit.

========================
Invalid metadata for "avcolour_space"
Failed to parse "avcolour_space"
Invalid metadata for "avcolor_space"
Failed to parse "avcolor_space"
Invalid metadata for "avdeinterlace"
Failed to parse "avdeinterlace"
Invalid metadata for "swscale"
Failed to parse "swscale"
Invalid metadata for "swresample"
Failed to parse "swresample"
Invalid metadata for "audiochannels"
Failed to parse "audiochannels"
Invalid metadata for "audioconvert"
Failed to parse "audioconvert"
Invalid metadata for "imageconvert"
Failed to parse "imageconvert"
Invalid metadata for "jack"
Failed to parse "jack"
Invalid metadata for "glsl.manager"
Failed to parse "glsl.manager"
Invalid metadata for "movit.convert"
Failed to parse "movit.convert"
Invalid metadata for "movit.crop"
Failed to parse "movit.crop"
Invalid metadata for "movit.resample"
Failed to parse "movit.resample"
Invalid metadata for "movit.resize"
Failed to parse "movit.resize"
Invalid metadata for "telecide"
Failed to parse "telecide"
Invalid metadata for "deinterlace"
Failed to parse "deinterlace"
Unknown asset "avfilter.acompressor"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/acompressor.xml"
Unknown asset "avfilter.aecho"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/aecho.xml"
Unknown asset "avfilter.agate"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/agate.xml"
Unknown asset "avfilter.atadenoise"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_atadenoise.xml"
Unknown asset "avfilter.bwdif"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_bwdif.xml"
Unknown asset "avfilter.deblock"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_deblock.xml"
Unknown asset "avfilter.dedot"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_dedot.xml"
Unknown asset "avfilter.deflate"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_deflate.xml"
Unknown asset "avfilter.derain"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_derain.xml"
Unknown asset "avfilter.doubleweave"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_doubleweave.xml"
Unknown asset "avfilter.field"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_field.xml"
Unknown asset "avfilter.framestep"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_framestep.xml"
Unknown asset "avfilter.fspp"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_fspp.xml"
Unknown asset "avfilter.graphmonitor"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_graphmonitor.xml"
Unknown asset "avfilter.hqdn3d"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_hqdn3d.xml"
Unknown asset "avfilter.inflate"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_inflate.xml"
Unknown asset "avfilter.lagfun"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_lagfun.xml"
Unknown asset "avfilter.random"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_random.xml"
Unknown asset "avfilter.removegrain"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_removegrain.xml"
Unknown asset "avfilter.separatefields"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_separatefields.xml"
Unknown asset "avfilter.shuffleplanes"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_shuffleplanes.xml"
Unknown asset "avfilter.sr"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_sr.xml"
Unknown asset "avfilter.tmix"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_tmix.xml"
Unknown asset "avfilter.w3fdif"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_w3fdif.xml"
Unknown asset "avfilter.weave"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_weave.xml"
Unknown asset "avfilter.yadif"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/avfilter_yadif.xml"
Unknown asset "gpstext"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/gpstext.xml"
Unknown asset "movit.unsharp_mask"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/movit_unsharp_mask.xml"
Unknown asset "region"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/region.xml"
Unknown asset "timewarp"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/speed.xml"
Unknown asset "opencv.tracker"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/tracker.xml"
Unknown asset "opencv.tracker"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/tracker.xml"
Unknown asset "typewriter"
==== PARSING ABORTED FOR: "/usr/share/kdenlive/effects/typewriter.xml"
Unknown asset "region"
defaultServiceProvider::requestService(): no service found for - "org.qt-project.qt.audiosource"
QQmlEngine::setContextForObject(): Object already has a QQmlContext
kdeinit5: Got EXEC_NEW '/usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/kio/file.so' from launcher.
kdeinit5: preparing to launch '/usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/kio/file.so'
kdeinit5: Got EXEC_NEW '/usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/kio/file.so' from launcher.
kdeinit5: preparing to launch '/usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/kio/file.so'
kf5.kservice.services: KServiceTypeTrader: serviceType "ThumbCreator" not found
kf5.kservice.services: KServiceTypeTrader: serviceType "ThumbCreator" not found
QObject::disconnect: Unexpected null parameter
QObject::disconnect: Unexpected null parameter
QObject::disconnect: Unexpected null parameter
QQmlEngine::setContextForObject(): Object already has a QQmlContext
Período: Transição (0.01% day)
kf5.kservice.services: KServiceTypeTrader: serviceType "ThumbCreator" not found
kf5.kservice.services: KServiceTypeTrader: serviceType "ThumbCreator" not found
=== REG FOCUS: false
Período: Transição (0.22% day)
defaultServiceProvider::requestService(): no service found for - "org.qt-project.qt.audiosource"

I have found where issue was. One commit in mlt library 8 months ago changed API, but kdenlive not.
Fix:
Replace
"
  static void onThreadCreate(mlt_properties owner, GLWidget *self, RenderThread **thread, int *priority, thread_function_t function, void *data)
{
    Q_UNUSED(owner)
    Q_UNUSED(priority)
    // self->clearFrameRenderer();
    self->createThread(thread, function, data);
    self->lockMonitor();
}
" 
in file src/monitor/glwidget.cpp
to
"
static void onThreadCreate(mlt_properties owner, void* listener_data, mlt_event_data event_data)
{
    Q_UNUSED(owner)
    mlt_event_data_thread thread_data = *((mlt_event_data_thread*)mlt_event_data_to_object(event_data));
    // self->clearFrameRenderer();
    GLWidget* self = ((GLWidget*)(listener_data));
    self->createThread((RenderThread**)thread_data.thread, thread_data.function, thread_data.data);
    self->lockMonitor();
}
".
Now i'm experiencing another bug, i can't import any clip, segfault happening in movit library, because gl context not initialized somewhere.

Thanks a lot for investigating this issue. There was indeed a change that I didn't spot. I will push a change to update our usage of MLT. With my change, Kdenlive now starts with movit and can open a clip but crashes when switching from one bin clip to another...

Git commit b24148d53ec26651f48f4bf6fe368d9861eea155 by Jean-Baptiste Mardelle.
Committed on 16/11/2021 at 14:29.
Pushed by mardelle into branch 'release/21.12'.

Fix MLT api change causing startup crash on movit (Movit still not usable)

M  +24   -16   src/monitor/glwidget.cpp
M  +1    -1    src/monitor/glwidget.h

https://invent.kde.org/multimedia/kdenlive/commit/b24148d53ec26651f48f4bf6fe368d9861eea155

(In reply to Jean-Baptiste Mardelle from comment #6)
> Thanks a lot for investigating this issue. There was indeed a change that I
> didn't spot. I will push a change to update our usage of MLT. With my
> change, Kdenlive now starts with movit and can open a clip but crashes when
> switching from one bin clip to another...

Thanks for fixing this! Bug with clip import/switch i have fixed by providing openGL context to every task, you can look at merge request !261

The fixes was added in Kdenlive 21.12 beta or will be in next release ?

Kdenlive 21.12 enabling movit not crash when starting Kdenlive.

Kdenlive crashes when I try to open a video with movit enabled.
If I open a video with movit disabled and save the project, then turn on movit and load the saved project, everything works.

I opened a bug report, but I think it's the same problem.
https://bugs.kde.org/show_bug.cgi?id=449692

That bug have returned in some previous versions.
22.08.2 appimage if enabling movit crash kdenlive startup .. not is possible start kdenlive

*** Bug 449692 has been marked as a duplicate of this bug. ***

Hi!

Please note that MOVIT has been experimental so far and was not well maintained. Due to lots of issue we recently disabled it. See https://invent.kde.org/multimedia/kdenlive/-/commit/41b74bd282e8a96be3b75f423f8101fa506d858d

In the long run there are plans to add a GPU again either with enhanced MOVIT or a new system, there is no eta yet.

Thanks again for your report!