When trying to play a transition, KDE instantly crashes.

Reproducible: Always

Steps to Reproduce:
1. Adding any transition to a new project with two video files
2. Trying to play it in the video player

Actual Results:  
It instantly crashed.

Expected Results:  
It should play the transition.

-- Backtrace:
Application: Kdenlive (kdenlive), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
[Current thread is 1 (Thread 0x7fe1eb1f98c0 (LWP 5563))]

Thread 22 (Thread 0x7fe1637fd700 (LWP 5777)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fe1da7cf63e in ?? () from /usr/lib/x86_64-linux-gnu/libavcodec-ffmpeg.so.56
#2  0x00007fe1f558a6fa in start_thread (arg=0x7fe1637fd700) at pthread_create.c:333
#3  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 21 (Thread 0x7fe163ffe700 (LWP 5776)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fe1da7cf63e in ?? () from /usr/lib/x86_64-linux-gnu/libavcodec-ffmpeg.so.56
#2  0x00007fe1f558a6fa in start_thread (arg=0x7fe163ffe700) at pthread_create.c:333
#3  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 20 (Thread 0x7fe184ff9700 (LWP 5775)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fe1da7cf63e in ?? () from /usr/lib/x86_64-linux-gnu/libavcodec-ffmpeg.so.56
#2  0x00007fe1f558a6fa in start_thread (arg=0x7fe184ff9700) at pthread_create.c:333
#3  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 19 (Thread 0x7fe199ac3700 (LWP 5774)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fe1da7cf63e in ?? () from /usr/lib/x86_64-linux-gnu/libavcodec-ffmpeg.so.56
#2  0x00007fe1f558a6fa in start_thread (arg=0x7fe199ac3700) at pthread_create.c:333
#3  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 18 (Thread 0x7fe1b2ffe700 (LWP 5773)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fe1da7cf63e in ?? () from /usr/lib/x86_64-linux-gnu/libavcodec-ffmpeg.so.56
#2  0x00007fe1f558a6fa in start_thread (arg=0x7fe1b2ffe700) at pthread_create.c:333
#3  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 17 (Thread 0x7fe1867fc700 (LWP 5772)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fe1c61c995d in video_thread (arg=0x46bce50) at consumer_sdl_audio.c:423
#2  0x00007fe1f558a6fa in start_thread (arg=0x7fe1867fc700) at pthread_create.c:333
#3  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 16 (Thread 0x7fe19547c700 (LWP 5771)):
#0  0x00007fe1f1d34a3c in pa_stream_get_state () from /usr/lib/x86_64-linux-gnu/libpulse.so.0
#1  0x00007fe1cca98fd0 in ?? () from /usr/lib/x86_64-linux-gnu/libSDL-1.2.so.0
#2  0x00007fe1cca6b920 in ?? () from /usr/lib/x86_64-linux-gnu/libSDL-1.2.so.0
#3  0x00007fe1cca750b8 in ?? () from /usr/lib/x86_64-linux-gnu/libSDL-1.2.so.0
#4  0x00007fe1ccab4f59 in ?? () from /usr/lib/x86_64-linux-gnu/libSDL-1.2.so.0
#5  0x00007fe1f558a6fa in start_thread (arg=0x7fe19547c700) at pthread_create.c:333
#6  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 15 (Thread 0x7fe19731d700 (LWP 5770)):
[KCrash Handler]
#6  0x00007fe19f9f025f in addition::update(double, unsigned int*, unsigned int const*, unsigned int const*, unsigned int const*) () from /usr/lib/frei0r-1/addition.so
#7  0x00007fe19f9efa54 in f0r_update2 () from /usr/lib/frei0r-1/addition.so
#8  0x00007fe1ddcfc11a in process_frei0r_item (service=service@entry=0xa7a0f00, position=position@entry=0, time=0, prop=prop@entry=0xa7a0f00, this=this@entry=0x7fe1801c3550, image=image@entry=0x7fe19731caf0, width=width@entry=0x7fe19731ccc4, height=height@entry=0x7fe19731ccc8) at frei0r_helper.c:167
#9  0x00007fe1ddcfbb90 in transition_get_image (a_frame=a_frame@entry=0x7fe1801c3550, image=image@entry=0x7fe19731ccd8, format=format@entry=0x3e1d40c, width=width@entry=0x7fe19731ccc4, height=height@entry=0x7fe19731ccc8, writable=writable@entry=0) at transition_frei0r.c:71
#10 0x00007fe1fc51e757 in mlt_frame_get_image (self=self@entry=0x7fe1801c3550, buffer=buffer@entry=0x7fe19731ccd8, format=format@entry=0x3e1d40c, width=width@entry=0x7fe19731ccc4, height=height@entry=0x7fe19731ccc8, writable=writable@entry=0) at mlt_frame.c:585
#11 0x00007fe1fc5346d9 in producer_get_image (self=self@entry=0x7fe1801ba810, buffer=buffer@entry=0x7fe19731ccd8, format=format@entry=0x3e1d40c, width=width@entry=0x7fe19731ccc4, height=height@entry=0x7fe19731ccc8, writable=writable@entry=0) at mlt_tractor.c:370
#12 0x00007fe1fc51e757 in mlt_frame_get_image (self=self@entry=0x7fe1801ba810, buffer=buffer@entry=0x7fe19731ccd8, format=format@entry=0x3e1d40c, width=width@entry=0x7fe19731ccc4, height=height@entry=0x7fe19731ccc8, writable=writable@entry=0) at mlt_frame.c:585
#13 0x00007fe1fc531d70 in consumer_read_ahead_thread (arg=0x46bce50) at mlt_consumer.c:897
#14 0x000000000072156d in RenderThread::run (this=0x7fe1900176e0) at /build/kdenlive-orf02E/kdenlive-16.08.0~ubuntu16.04.1/src/monitor/glwidget.cpp:1248
#15 0x00007fe1f765b84e in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#16 0x00007fe1f558a6fa in start_thread (arg=0x7fe19731d700) at pthread_create.c:333
#17 0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 14 (Thread 0x7fe195c7d700 (LWP 5769)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fe1fc53210b in mlt_consumer_rt_frame (self=self@entry=0x46bce50) at mlt_consumer.c:1576
#2  0x00007fe1c61c9d90 in consumer_thread (arg=0x46bce50) at consumer_sdl_audio.c:531
#3  0x00007fe1f558a6fa in start_thread (arg=0x7fe195c7d700) at pthread_create.c:333
#4  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 13 (Thread 0x7fe1b37ff700 (LWP 5767)):
#0  pthread_cond_timedwait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:225
#1  0x00007fe1f765ca26 in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#2  0x00007fe1f76584d3 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007fe1f765b84e in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007fe1f558a6fa in start_thread (arg=0x7fe1b37ff700) at pthread_create.c:333
#5  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 12 (Thread 0x7fe186ffd700 (LWP 5615)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fe1da7cf63e in ?? () from /usr/lib/x86_64-linux-gnu/libavcodec-ffmpeg.so.56
#2  0x00007fe1f558a6fa in start_thread (arg=0x7fe186ffd700) at pthread_create.c:333
#3  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 11 (Thread 0x7fe1877fe700 (LWP 5614)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fe1da7cf63e in ?? () from /usr/lib/x86_64-linux-gnu/libavcodec-ffmpeg.so.56
#2  0x00007fe1f558a6fa in start_thread (arg=0x7fe1877fe700) at pthread_create.c:333
#3  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 10 (Thread 0x7fe187fff700 (LWP 5613)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fe1da7cf63e in ?? () from /usr/lib/x86_64-linux-gnu/libavcodec-ffmpeg.so.56
#2  0x00007fe1f558a6fa in start_thread (arg=0x7fe187fff700) at pthread_create.c:333
#3  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 9 (Thread 0x7fe198c59700 (LWP 5612)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fe1da7cf63e in ?? () from /usr/lib/x86_64-linux-gnu/libavcodec-ffmpeg.so.56
#2  0x00007fe1f558a6fa in start_thread (arg=0x7fe198c59700) at pthread_create.c:333
#3  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 8 (Thread 0x7fe19a2c4700 (LWP 5611)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fe1da7cf63e in ?? () from /usr/lib/x86_64-linux-gnu/libavcodec-ffmpeg.so.56
#2  0x00007fe1f558a6fa in start_thread (arg=0x7fe19a2c4700) at pthread_create.c:333
#3  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 7 (Thread 0x7fe1857fa700 (LWP 5585)):
#0  0x00007fe1f3bc6ac9 in g_mutex_lock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007fe1f3b81939 in g_main_context_prepare () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fe1f3b822cb in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fe1f3b824ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007fe1f7892a9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fe1f7839dea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007fe1f76568a4 in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007fe1f765b84e in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007fe1f558a6fa in start_thread (arg=0x7fe1857fa700) at pthread_create.c:333
#9  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 6 (Thread 0x7fe185ffb700 (LWP 5584)):
#0  0x00007fe1f3b81f3a in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007fe1f3b82400 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fe1f3b824ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fe1f7892a9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007fe1f7839dea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fe1f76568a4 in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007fe1f765b84e in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007fe1f558a6fa in start_thread (arg=0x7fe185ffb700) at pthread_create.c:333
#8  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7fe1c0c7c700 (LWP 5568)):
#0  0x00007fe1f3bc6ae4 in g_mutex_unlock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007fe1f3b822be in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fe1f3b824ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fe1f7892a9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007fe1f7839dea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fe1f76568a4 in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007fe1f84073c5 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007fe1f765b84e in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007fe1f558a6fa in start_thread (arg=0x7fe1c0c7c700) at pthread_create.c:333
#9  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7fe1c24be700 (LWP 5566)):
#0  0x00007fe1f6c5ce8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fe1f3b8239c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fe1f3b824ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fe1f7892a9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007fe1f7839dea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fe1f76568a4 in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007fe1f84073c5 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007fe1f765b84e in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007fe1f558a6fa in start_thread (arg=0x7fe1c24be700) at pthread_create.c:333
#9  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7fe1cf613700 (LWP 5565)):
#0  0x00007fe1f6c5ce8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fe1d75b264c in ?? () from /lib/x86_64-linux-gnu/libusb-1.0.so.0
#2  0x00007fe1f558a6fa in start_thread (arg=0x7fe1cf613700) at pthread_create.c:333
#3  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7fe1e8aa6700 (LWP 5564)):
#0  0x00007fe1f6c5ce8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fe1f18ecc62 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007fe1f18ee8d7 in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007fe1eadf8629 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#4  0x00007fe1f765b84e in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fe1f558a6fa in start_thread (arg=0x7fe1e8aa6700) at pthread_create.c:333
#6  0x00007fe1f6c68b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7fe1eb1f98c0 (LWP 5563)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fe1f18eceb9 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007fe1f18ee617 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007fe1f18ee721 in xcb_wait_for_reply () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#4  0x00007fe1eadf72fa in QXcbConnection::sync() () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#5  0x00007fe1eae16efe in ?? () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#6  0x00007fe1eae17096 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#7  0x00007fe1f8dfe663 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#8  0x00007fe1f8dfea8c in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#9  0x00007fe1f8e1cc1f in QWidgetPrivate::syncBackingStore() () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#10 0x00007fe1f8e33d88 in QWidget::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#11 0x00007fe1f8f49d8b in QMainWindow::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#12 0x00007fe1faaf7147 in KMainWindow::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libKF5XmlGui.so.5
#13 0x00007fe1fab2f4e5 in KXmlGuiWindow::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libKF5XmlGui.so.5
#14 0x00007fe1f8df105c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#15 0x00007fe1f8df6516 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#16 0x00007fe1f783c62b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#17 0x00007fe1f783ea26 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#18 0x00007fe1f7892673 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#19 0x00007fe1f3b821a7 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007fe1f3b82400 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#21 0x00007fe1f3b824ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#22 0x00007fe1f7892a7f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#23 0x00007fe1f7839dea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#24 0x00007fe1f7841e8c in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#25 0x0000000000489f62 in main (argc=1, argv=<optimized out>) at /build/kdenlive-orf02E/kdenlive-16.08.0~ubuntu16.04.1/src/main.cpp:158