[Ubuntu] Audio and video not working properly

[AlessandroNegri]

Hi all,
sorry but I need a strong help. I have been running qlc+ on windows and (quite) all was fine. Now, due to unstability problem on windows (audio/video glitching), I want to try with Ubuntu 16.04 LTS. Here comes the problem
I've istalled firstly GStreamer0.10, then QT5 multimedia library, then QT5.

Code: Select all

sudo add-apt-repository ppa:mc3man/trusty-media
sudo apt-get update
sudo apt-get install gstreamer0.10-ffmpeg
sudo apt-get install libqt5multimedia5 qtmultimedia5-dev
sudo sh -c "echo 'deb http://download.opensuse.org/repositories/home:/mcallegari79/xUbuntu_16.04/ /' > /etc/apt/sources.list.d/qlcplus-qt5.list"
sudo apt-get update
sudo apt-get install qlcplus-qt5
wget http://download.opensuse.org/repositories/home:mcallegari79/xUbuntu_16.04/Release.key
sudo apt-key add - < Release.key
sudo apt-get update

All compile and work fine since I load the first video/audio in QLC+.... And surprisingly, not working! Also with example!
The audio is simply not working: I push example/preview and the sound is not reproduced.
The video example/preview still open a black window, but neither audio nor images are shown and, when closing the window, QLC and the window stuck.
I think it's a problem with QT, but not shure... I've read the discussion between sbenejam and mcallegari (viewtopic.php?f=12&t=9988&hilit=video+ubuntu+16), but I'm not able to do that things, since I'm quite new with linux.
Both video and audio works fine with Ubuntu/GNOME players and vlc.

I'm working on Ubuntu 16.04 64bit, QLC+ 4.10.5, both GStreamer 0.10 and 1.x (the latest) installed.

[Edit]
If I remove QT5 and recompile/reinstall QLC+, video function disappears, but audio works properly.
New improvement... Just add some additional required packages....

Code: Select all

sudo apt-get update
sudo apt-get install g++ make git build-essential qt5-default qtbase5-dev qtscript5-dev qtmultimedia5-dev libqt5multimedia5-plugins qttools5-dev-tools fakeroot debhelper devscripts pkg-config
sudo apt-get install libasound2-dev libusb-dev libftdi-dev libudev-dev libmad0-dev libsndfile1-dev libfftw3-dev

And reinstalled both QT5 and QLC+. Now audio works, but not video: when I press preview on video function, a black window open with sound, but no images. After a while all gets stuck (audio and also QLC program )

Thanks,
Alessandro Negri

[sbenejam]

Hi Allessandro,
For now the only way to get video playing correctly on Ubuntu 16.04 is the solution that mcallegari explains in this discussion. viewtopic.php?f=12&t=9988&hilit=video+u ... 6&start=10.
- Since ubuntu 16.04 the default gstreamer version is 1.0, the Qt5 version in Ubuntu is linked to gstreamer 0.10. Some gstreamer-0.10 packages are missiing.
- The Qt5 binaries that you can download from Qt website are linked to gstreamer 0.10 too.
- The only way to make Qt5 work with gstreamer 1.0 is build yourself from sources with gstreamer-1.0 support. And then build QLC+ with this Qt5 version.
- Audio plays fine with QLC+ built with Ubuntu default Qt5. And Qt5 versions linked to gstreamer-0.10.

Regards

Santiago Benejam

[mcallegari]

I just checked, and apparently the situation is changing with Qt 5.8.0.
The QtMultimedia libraries are now linking against gstreamer 1.0. Finally !

Checked on: https://download.qt.io/snapshots/qt/5.8/5.8.0-rc/585/

[sbenejam]

Hi Massimo,
Good news. I will try and test soon. Also I can test if this modification is still needed to get video playback as expected. viewtopic.php?f=12&t=9988&hilit=video+u ... =10#p43980

I just checked, and apparently the situation is changing with Qt 5.8.0.
The QtMultimedia libraries are now linking against gstreamer 1.0. Finally !

Checked on: https://download.qt.io/snapshots/qt/5.8/5.8.0-rc/585/

[AlessandroNegri]

I just checked, and apparently the situation is changing with Qt 5.8.0.
The QtMultimedia libraries are now linking against gstreamer 1.0. Finally !

Checked on: https://download.qt.io/snapshots/qt/5.8/5.8.0-rc/585/

In the end they seems to care about us ahahah

Santiago, I've already seen that discussion, but I think I'm not able to do so. However I will try the modification you and Callegari suggested.
@Callegari: Are you gonna plan to make a new version of qlsplus-qt5 with QT 5.8.0??? if I was able I would have try to do it and help you, but sorry I do not have the right knowledge to do it

Thanks both

P.S. I'm studying automation and control engeneering and I'm using this program for free theater show (we are a group of friends doing it amateurly), because of its completeness and simplicity. If there's something I could do in oreder to help you, just ask and I will try to do my best.
Check also this fixture viewtopic.php?f=3&t=9999 it's a moving head we are using and it works fine.

[sbenejam]

Hi Massimo,
I tested Qt5.8-rc version seems that is linked to gst-1.0 but video playback only works well with the modified videoprovider.cpp. Without the modified videoprovider.cpp video window shows a black screen.

[mcallegari]

@Alessandro

@Callegari: Are you gonna plan to make a new version of qlsplus-qt5 with QT 5.8.0???

Definitely not, for 2 reasons:
1- Qt 5.8.0 has not even been released (the link I posted is a release candidate)
2- QLC+ on Linux relies on shared libraries, so I don't really know which Qt version is installed in the distro

This video playback thing is a whole mess of the Qt company and unfortunately I can't help it, despite my many ticket reports and emails to the development mailing list. They just don't seem to care about bugs on QtMultimedia.

@Santiago

I tested Qt5.8-rc version seems that is linked to gst-1.0 but video playback only works well with the modified videoprovider.cpp. Without the modified videoprovider.cpp video window shows a black screen.

Alright, thanks for the feedback. I need to test the change also on Windows and macOS, but in any case it's a disgusting change caused by the poor QtMultimedia reliability