SIGSEGV on gst_element_set_state when trying to run any of QMediaPlayer examples - Ubuntu 20.10

VictoriaR

Hello Qt forum,
After about a month ago I updated my OS to 20.10, and I believe, after this update I am not able to run any of the Qt examples that rely on QMediaPlayer.
I tried versions of Qt: 5.15.0 and 5.15.2 and it is the same on both.
I ran the videowidget example in the Debug mode, and was able to see the line of code where it fails:
GstStateChangeReturn ret = gst_element_set_state(element, GST_STATE_READY); from the file qgstreamvideooverlay.cpp.
I checked and I believe I have the GStreamer installed, but now started to wonder if I need to update any packages, or what could be the source of this behavior? Any tips?

Here is the screenshot of the debug window, in case if it may be helpful:

Thank you!

SGaist

Hi and welcome to devnet,

Did you try to build your application with the distribution provided Qt ?

VictoriaR

@SGaist said in SIGSEGV on gst_element_set_state when trying to run any of QMediaPlayer examples - Ubuntu 20.10:

y to build your application with the distribution provided Qt

Hello, not sure if I understood correctly, but I didn't build the Qt from source, my Qt is installed using Qt Maintenance Tool for Linux. Would you advise to build the necessary Qt libraries from source to try to solve this problem?

SGaist

Not at all, my suggestion is to use your distribution's package manager to install the development packages for Qt as they provide it.

VictoriaR

Thank you for the suggestion, I had just installed Qt using the apt-get. It installed the latest version 5.14.2. I added the multimedia package. Unfortunately, I'm still experiencing the same issue (SIGSEGV) with this kit as well.

SGaist

Can you test if you can play that media file directly with GStreamer ?

VictoriaR

This post is deleted!

VictoriaR

Yes, I am able to open my mp4 file as well as run the test file.
I use the following command to open up the mp4 video file: gst-launch-1.0 filesrc location=myfile.mp4 ! qtdemux ! avdec_h264 ! queue ! videoconvert ! autovideosink

SGaist

Just to be sure everything is done correctly, does the player get the full path the file ? It should not trigger a segfault though.

VictoriaR

does the player get the full path the file

The SIGSEGV happens on this line: m_mediaPlayer = new QMediaPlayer(this, QMediaPlayer::VideoSurface);. So, I cannot call the constructor of the class.
I feel like it may be a problem with Qt not finding the GStream library path correctly, or something within those lines. Unfortunately, I do not have much understanding beyond that.

SGaist

Which packages of GStreamer did you install ?
Do you also have that in a dummy project with just the video player ?