[mythtv-users] mythfrontend core dumps after upgrade to Ubuntu 24.04

[Peter Bennett]

On 1/2/26 08:41, Alain via mythtv-users wrote:
> Thread 1 "mythfrontend" received signal SIGSEGV, Segmentation fault.
> 0x00007fffee670364 in XDisplayString () from 
> /lib/x86_64-linux-gnu/libX11.so.6
> (gdb) bt
> #0  0x00007fffee670364 in XDisplayString () at 
> /lib/x86_64-linux-gnu/libX11.so.6
> #1  0x00007fff20205f05 in __vaDriverInit_1_0 () at 
> /usr/lib/x86_64-linux-gnu/dri/nvidia_drv_video.so
> #2  0x00007fffee615873 in vaInitialize () at 
> /lib/x86_64-linux-gnu/libva.so.2
> #3  0x00007fffef26de5a in vaapi_device_connect (ctx=0x555556778380, 
> display=0x5555565cfdd0) at libavutil/hwcontext_vaapi.c:1682
> #4  0x00007fffef267bae in av_hwdevice_ctx_create 
> (pdevice_ref=0x7fffffffdf40, type=<optimized out>, device=0x0, 
> opts=0x0, flags=0) at libavutil/hwcontext.c:619
> #5  0x00007ffff77786a7 in MythCodecContext::CreateDevice 
> (Type=AV_HWDEVICE_TYPE_VAAPI, Interop=0x0, Device=...) at 
> decoders/mythcodeccontext.cpp:562
> #6  0x00007ffff78089e3 in MythVAAPIContext::HaveVAAPI (ReCheck=true) 
> at decoders/mythvaapicontext.cpp:427
> #7  0x00007ffff77766d1 in MythCodecContext::GetDecoders (Opts=..., 
> Reinit=true) at decoders/mythcodeccontext.cpp:181
> #8  0x00007ffff77e42eb in MythVideoProfile::InitStatics (Reinit=true) 
> at mythvideoprofile.cpp:1366
> #9  0x00005555555d5916 in operator() (__closure=0x555555e32bb0) at 
> mythfrontend.cpp:2190
> #10 0x00005555555da2d5 in 
> QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, 
> void, main(int, char**)::<lambda()> >::call(struct {...} &, void **) 
> (f=..., arg=0x7fffffffe330)
>     at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:146
> #11 0x00005555555da163 in QtPrivate::Functor<main(int, 
> char**)::<lambda()>, 0>::call<QtPrivate::List<>, void>(struct {...} &, 
> void *, void **) (f=..., arg=0x7fffffffe330)
>     at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:256
> #12 0x00005555555d9df2 in QtPrivate::QFunctorSlotObject<main(int, 
> char**)::<lambda()>, 0, QtPrivate::List<>, void>::impl(int, 
> QtPrivate::QSlotObjectBase *, QObject *, void **, bool *)
>     (which=1, this_=0x555555e32ba0, r=0x555555e23470, 
> a=0x7fffffffe330, ret=0x0) at 
> /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:443
> #13 0x00007ffff237ee16 in ??? () at /lib/x86_64-linux-gnu/libQt5Core.so.5
> #14 0x00007ffff6b20c9f in MythMainWindow::SignalWindowReady 
> (this=0x555555e23470) at moc/moc_mythmainwindow.cpp:250
> #15 0x00007ffff694166d in MythMainWindow::Init (this=0x555555e23470, 
> MayReInit=false) at mythmainwindow.cpp:769
> #16 0x00005555555d6eb4 in main (argc=1, argv=0x7fffffffe7f8) at 
> mythfrontend.cpp:2192
>
> Thanks in advance,
>
> Alain

It is crashing in initialization of VAAPI. Something is going wrong in 
the VAAPI code, in the nvidia driver.

Do other players such as vlc work on this setup?

It looks like a driver problem, as mentioned by another person, check 
the nvidia drivers. You can also try the default ubuntu driver 
(nouveau). That will not support Nvidia decoding, but you could use 
software decoding. It will also give some insight into whether the 
problem is with the driver.

You can also try building the code with VAAPI disabled in configure. 
This is a bit extreme and should not be necessary, and may not solve the 
problem.

Peter