Application: kamoso (2.0.2)
KDE Platform Version: 4.14.13
Qt Version: 4.8.7
Operating System: Linux 4.0.0-2-amd64 x86_64
Distribution: Debian GNU/Linux unstable (sid)

-- Information about the crash:
- What I was doing when the application crashed:
every time I start kamoso, it crashes, saying: 

libva info: VA-API version 0.38.0
libva info: va_getDriverName() returns 0
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/nvidia_drv_video.so
libva info: Found init function __vaDriverInit_0_37
libva info: va_openDriver() returns 0
KCrash: Application 'kamoso' crashing...

It starts the camera though (as the LED on the camera turns on), and it happens every time.

The crash can be reproduced every time.

-- Backtrace:
Application: Kamoso (kamoso), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fcf8de7d940 (LWP 13732))]

Thread 5 (Thread 0x7fcf75404700 (LWP 13733)):
#0  __lll_lock_wait () at ../sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:135
#1  0x00007fcf866f2992 in __GI___pthread_mutex_lock (mutex=0x7fcf8df91948 <_rtld_global+2312>) at ../nptl/pthread_mutex_lock.c:115
#2  0x00007fcf8dd80a2d in tls_get_addr_tail (ti=0x7fcf8a4b3f70, dtv=0x24d47d0, the_map=0x7fcf8df46000) at dl-tls.c:765
#3  0x00007fcf8a1cc970 in __cxa_get_globals () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#4  0x00007fcf8a1cc899 in std::uncaught_exception() () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#5  0x00007fcf8b21c329 in qt_message(QtMsgType, const char *, typedef __va_list_tag __va_list_tag *) (msgType=msgType@entry=QtWarningMsg, msg=msg@entry=0x7fcf8b41d850 "QSocketNotifier: Invalid socket %d and type '%s', disabling...", ap=ap@entry=0x7fcf75403970) at global/qglobal.cpp:2476
#6  0x00007fcf8b21c621 in qWarning (msg=msg@entry=0x7fcf8b41d850 "QSocketNotifier: Invalid socket %d and type '%s', disabling...") at global/qglobal.cpp:2575
#7  0x00007fcf8b366c8b in socketNotifierSourceCheck (source=0x7fcf70003000) at kernel/qeventdispatcher_glib.cpp:90
#8  0x00007fcf8576dc11 in g_main_context_check () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#9  0x00007fcf8576e180 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#10 0x00007fcf8576e2ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#11 0x00007fcf8b367406 in QEventDispatcherGlib::processEvents (this=0x7fcf700008e0, flags=...) at kernel/qeventdispatcher_glib.cpp:427
#12 0x00007fcf8b335331 in QEventLoop::processEvents (this=this@entry=0x7fcf75403c40, flags=...) at kernel/qeventloop.cpp:149
#13 0x00007fcf8b3356a5 in QEventLoop::exec (this=this@entry=0x7fcf75403c40, flags=...) at kernel/qeventloop.cpp:204
#14 0x00007fcf8b224579 in QThread::exec (this=this@entry=0x2370800) at thread/qthread.cpp:538
#15 0x00007fcf8b315393 in QInotifyFileSystemWatcherEngine::run (this=0x2370800) at io/qfilesystemwatcher_inotify.cpp:265
#16 0x00007fcf8b226e6c in QThreadPrivate::start (arg=0x2370800) at thread/qthread_unix.cpp:352
#17 0x00007fcf866f0304 in start_thread (arg=0x7fcf75404700) at pthread_create.c:333
#18 0x00007fcf89c6f14d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7fcf6cb0e700 (LWP 13734)):
#0  syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1  0x00007fcf857b29bf in g_cond_wait () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fcf8549fecd in gst_task_func (task=0x27fb050) at gsttask.c:316
#3  0x00007fcf857952ee in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007fcf85794955 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007fcf866f0304 in start_thread (arg=0x7fcf6cb0e700) at pthread_create.c:333
#6  0x00007fcf89c6f14d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7fcf6430d700 (LWP 13735)):
#0  syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1  0x00007fcf857b29bf in g_cond_wait () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fcf820dc6bd in gst_base_sink_wait_preroll (sink=sink@entry=0x28ebb60) at gstbasesink.c:2204
#3  0x00007fcf820dccc3 in gst_base_sink_do_preroll (sink=sink@entry=0x28ebb60, obj=obj@entry=0x7fcf54028000) at gstbasesink.c:2298
#4  0x00007fcf820dd573 in gst_base_sink_do_sync (basesink=basesink@entry=0x28ebb60, obj=obj@entry=0x7fcf54028000, late=late@entry=0x7fcf6430c860, step_end=step_end@entry=0x7fcf6430c864) at gstbasesink.c:2500
#5  0x00007fcf820de863 in gst_base_sink_chain_unlocked (basesink=basesink@entry=0x28ebb60, obj=obj@entry=0x7fcf54028000, is_list=is_list@entry=0, pad=<optimized out>) at gstbasesink.c:3486
#6  0x00007fcf820dfeb0 in gst_base_sink_chain_main (basesink=0x28ebb60, pad=<optimized out>, obj=0x7fcf54028000, is_list=0) at gstbasesink.c:3647
#7  0x00007fcf8546f998 in gst_pad_chain_data_unchecked (data=0x7fcf54028000, type=4112, pad=0x28ec720) at gstpad.c:4085
#8  gst_pad_push_data (pad=0x28ed020, type=type@entry=4112, data=0x7fcf54028000) at gstpad.c:4337
#9  0x00007fcf85477406 in gst_pad_push (pad=<optimized out>, buffer=<optimized out>) at gstpad.c:4453
#10 0x00007fcf820e9b5d in gst_base_transform_chain (pad=<optimized out>, parent=0x28f6450, buffer=<optimized out>) at gstbasetransform.c:2369
#11 0x00007fcf8546f998 in gst_pad_chain_data_unchecked (data=0x7fcf54028000, type=4112, pad=0x28ecde0) at gstpad.c:4085
#12 gst_pad_push_data (pad=0x28ec4e0, type=type@entry=4112, data=0x7fcf54028000) at gstpad.c:4337
#13 0x00007fcf85477406 in gst_pad_push (pad=<optimized out>, buffer=<optimized out>) at gstpad.c:4453
#14 0x00007fcf820e9b5d in gst_base_transform_chain (pad=<optimized out>, parent=0x28eb0d0, buffer=<optimized out>) at gstbasetransform.c:2369
#15 0x00007fcf8546f998 in gst_pad_chain_data_unchecked (data=0x7fcf54028000, type=4112, pad=0x28ec2a0) at gstpad.c:4085
#16 gst_pad_push_data (pad=0x28ec060, type=type@entry=4112, data=data@entry=0x7fcf54028000) at gstpad.c:4337
#17 0x00007fcf85477406 in gst_pad_push (pad=<optimized out>, buffer=buffer@entry=0x7fcf54028000) at gstpad.c:4453
#18 0x00007fcf6f63f9c9 in gst_queue_push_one (queue=0x28d8470) at gstqueue.c:1336
#19 gst_queue_loop (pad=<optimized out>) at gstqueue.c:1483
#20 0x00007fcf8549fd31 in gst_task_func (task=0x27fb170) at gsttask.c:331
#21 0x00007fcf857952ee in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#22 0x00007fcf85794955 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#23 0x00007fcf866f0304 in start_thread (arg=0x7fcf6430d700) at pthread_create.c:333
#24 0x00007fcf89c6f14d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7fcf67fff700 (LWP 13736)):
#0  syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1  0x00007fcf857b29bf in g_cond_wait () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fcf8549fecd in gst_task_func (task=0x27fb290) at gsttask.c:316
#3  0x00007fcf857952ee in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007fcf85794955 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007fcf866f0304 in start_thread (arg=0x7fcf67fff700) at pthread_create.c:333
#6  0x00007fcf89c6f14d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7fcf8de7d940 (LWP 13732)):
[KCrash Handler]
#6  QBasicAtomicOps<4>::deref<int> (_q_value=@0x7fcf8ad32bc0: 1684625233) at ../../include/QtCore/../../src/corelib/arch/qatomic_x86.h:219
#7  QBasicAtomicInteger<int>::deref (this=0x7fcf8ad32bc0 <qt_meta_stringdata_QWidget>) at ../../include/QtCore/../../src/corelib/thread/qbasicatomic.h:128
#8  QtPrivate::RefCount::deref (this=0x7fcf8ad32bc0 <qt_meta_stringdata_QWidget>) at ../../include/QtCore/../../src/corelib/tools/qrefcount.h:67
#9  QByteArray::~QByteArray (this=<optimized out>, __in_chrg=<optimized out>) at ../../include/QtCore/../../src/corelib/tools/qbytearray.h:459
#10 rawStringData (index=<optimized out>, mo=mo@entry=0x64ab00 <QWidget::staticMetaObject>) at kernel/qmetaobject.cpp:156
#11 objectClassName (m=m@entry=0x64ab00 <QWidget::staticMetaObject>) at kernel/qmetaobject.cpp:301
#12 QMetaObject::className (this=this@entry=0x64ab00 <QWidget::staticMetaObject>) at kernel/qmetaobject.cpp:311
#13 0x00007fcf64f3473f in QMetaTypeIdQObject<QWidget*, 8>::qt_metatype_id () at ../../include/QtCore/../../src/corelib/kernel/qmetatype.h:1760
#14 0x00007fcf64ecee77 in QMetaTypeId2<QWidget*>::qt_metatype_id () at ../../include/QtCore/../../src/corelib/kernel/qmetatype.h:1584
#15 qMetaTypeId<QWidget*> () at ../../include/QtCore/../../src/corelib/kernel/qmetatype.h:1726
#16 qRegisterMetaType<QWidget*> () at ../../include/QtCore/../../src/corelib/kernel/qmetatype.h:1732
#17 qRegisterWidgetsVariant () at kernel/qwidgetsvariant.cpp:150
#18 (anonymous namespace)::qRegisterWidgetsVariant_ctor_class_::qRegisterWidgetsVariant_ctor_class_ (this=<optimized out>) at kernel/qwidgetsvariant.cpp:154
#19 __static_initialization_and_destruction_0 (__priority=65535, __initialize_p=1) at kernel/qwidgetsvariant.cpp:154
#20 _GLOBAL__sub_I_qwidgetsvariant.cpp(void) () at kernel/qwidgetsvariant.cpp:154
#21 0x00007fcf8dd7e26a in call_init (l=<optimized out>, argc=argc@entry=1, argv=argv@entry=0x7ffdbf618988, env=env@entry=0x7ffdbf618998) at dl-init.c:72
#22 0x00007fcf8dd7e37b in call_init (env=0x7ffdbf618998, argv=0x7ffdbf618988, argc=1, l=<optimized out>) at dl-init.c:30
#23 _dl_init (main_map=main_map@entry=0x29dcc90, argc=1, argv=0x7ffdbf618988, env=0x7ffdbf618998) at dl-init.c:120
#24 0x00007fcf8dd828a8 in dl_open_worker (a=a@entry=0x7ffdbf6176d8) at dl-open.c:569
#25 0x00007fcf8dd7e114 in _dl_catch_error (objname=objname@entry=0x7ffdbf6176c8, errstring=errstring@entry=0x7ffdbf6176d0, mallocedp=mallocedp@entry=0x7ffdbf6176c7, operate=operate@entry=0x7fcf8dd824e0 <dl_open_worker>, args=args@entry=0x7ffdbf6176d8) at dl-error.c:187
#26 0x00007fcf8dd81f63 in _dl_open (file=0x2b3d080 "/usr/lib/vlc/plugins/gui/libqt4_plugin.so", mode=-2147483647, caller_dlopen=0x7fcf66e277af, nsid=-2, argc=<optimized out>, argv=<optimized out>, env=0x7ffdbf618998) at dl-open.c:653
#27 0x00007fcf84b01f09 in dlopen_doit (a=a@entry=0x7ffdbf6178f0) at dlopen.c:66
#28 0x00007fcf8dd7e114 in _dl_catch_error (objname=0x2280b90, errstring=0x2280b98, mallocedp=0x2280b88, operate=0x7fcf84b01eb0 <dlopen_doit>, args=0x7ffdbf6178f0) at dl-error.c:187
#29 0x00007fcf84b024d9 in _dlerror_run (operate=operate@entry=0x7fcf84b01eb0 <dlopen_doit>, args=args@entry=0x7ffdbf6178f0) at dlerror.c:163
#30 0x00007fcf84b01fa1 in __dlopen (file=<optimized out>, mode=<optimized out>) at dlopen.c:87
#31 0x00007fcf66e277af in ?? () from /usr/lib/libvlccore.so.8
#32 0x00007fcf66e0b8ab in ?? () from /usr/lib/libvlccore.so.8
#33 0x00007fcf66e0bbd8 in ?? () from /usr/lib/libvlccore.so.8
#34 0x00007fcf66e0bb34 in ?? () from /usr/lib/libvlccore.so.8
#35 0x00007fcf66e0c0b4 in ?? () from /usr/lib/libvlccore.so.8
#36 0x00007fcf66e0c6aa in ?? () from /usr/lib/libvlccore.so.8
#37 0x00007fcf66d9271d in libvlc_InternalInit () from /usr/lib/libvlccore.so.8
#38 0x00007fcf66b63a8b in libvlc_new () from /usr/lib/libvlc.so.5
#39 0x00007fcf670b5f6b in LibVLC::init () at ../../src/utils/libvlc.cpp:117
#40 0x00007fcf670974d3 in Phonon::VLC::Backend::Backend (this=0x2699610, parent=<optimized out>) at ../../src/backend.cpp:90
#41 0x00007fcf67098193 in qt_plugin_instance () at ../../src/backend.cpp:56
#42 0x00007fcf8b319b8b in QPluginLoader::instance (this=this@entry=0x7ffdbf618330) at plugin/qpluginloader.cpp:204
#43 0x00007fcf6c104941 in Phonon::KdePlatformPlugin::createBackend (this=this@entry=0x2753e60, newService=...) at ../../../phonon/platform_kde/kdeplatformplugin.cpp:130
#44 0x00007fcf6c1050df in Phonon::KdePlatformPlugin::createBackend (this=0x2753e60) at ../../../phonon/platform_kde/kdeplatformplugin.cpp:183
#45 0x00007fcf8d872e06 in ?? () from /usr/lib/x86_64-linux-gnu/libphonon.so.4
#46 0x00007fcf8d874258 in Phonon::Factory::backend(bool) () from /usr/lib/x86_64-linux-gnu/libphonon.so.4
#47 0x00007fcf8d8749a2 in ?? () from /usr/lib/x86_64-linux-gnu/libphonon.so.4
#48 0x00007fcf8d86803f in ?? () from /usr/lib/x86_64-linux-gnu/libphonon.so.4
#49 0x00007fcf8d86552f in ?? () from /usr/lib/x86_64-linux-gnu/libphonon.so.4
#50 0x00007fcf8d881452 in Phonon::createPlayer(Phonon::Category, Phonon::MediaSource const&) () from /usr/lib/x86_64-linux-gnu/libphonon.so.4
#51 0x000000000041e817 in _start ()

Reported using DrKonqi