Play a video on qt 5.12 c++

SGaist

Hi,

You did not answer @jsulm's question: how exactly did you install Qt ? Using the Qt Online Installer ? Using your distribution package manager ?

Also how did you install Qt Creator ?

If you installed Qt using the package manager, you have to install the corresponding development packages.

jsulm

@AliM93 said in Play a video on qt 5.12 c++:

QtCreator/latest/lib/Qt

This looks like the installation directory of QtCreator which doesn't matter.
Again: how exactly did you install Qt? Did you install Qt packages provided by your distribution (via apt)?
Please answer the questions else nobody will be able to help you.

Pablo J. Rogina

@AliM93 said in Play a video on qt 5.12 c++:

:-1: error: cannot find -lQt5::Multimedia

I guess you may need to try a different name for the library...

target_link_libraries(agree_gui ${QT_LIBRARIES} ${catkin_LIBRARIES}
(
Qt5Multimedia
)

AliM93

@Pablo-J-Rogina i've tried but same error.

AliM93

@jsulm https://ros-qtc-plugin.readthedocs.io/en/latest/_source/How-to-Install-Users.html
i used this link because i need also to install the ros plugin. i followed the bionic online installer

jsulm

@AliM93 That link describes how to install QtCreator (not Qt) and a QtCreator plug-in. So, my question is still not answered...

AliM93

@jsulm i used this and only this one so maybe i did not install Qt

SGaist

Then it's not a maybe, you just have installed Qt Creator.

In any case, are you trying to build a Qt application for ROS or just a Qt application ?

AliM93

@SGaist i''m trying to build a qt application for ROS

SGaist

Then install Qt.

Where did you get Qt Creator from ?

AliM93

@SGaist I got it from the link that i posted. I follow that link and then i installed qt creator with the ROS plugin.
How can i install qt?

I noticed that in my Qt creator folder i have also this path:
QtCreator -> latest -> lib -> Qt --> (...)
may this mean i have also installed Qt? The code i wrote since now works well. is it possible that i installed only Qt Creator without Qt?

Sorry for my bad installation skills.
thank you all.

jsulm

@AliM93 said in Play a video on qt 5.12 c++:

QtCreator -> latest -> lib -> Qt --> (...)
may this mean i have also installed Qt?

No, these are Qt libraries used by QtCreator (QtCreator is a Qt application).
"is it possible that i installed only Qt Creator without Qt?" - I think so, as the link you posted only talks about QtCreator installation.

"How can i install qt?" - you can use Qt Online Installer (from official Qt web site). On Linux you can install Qt packages provided by the Linux distribution.

AliM93

Thanks.

And may the qt installation change something in my Qt creator application?
Sorry buy i'm terrified by the fact that i cannot use anymore the ROS plugin and so the application i implemented since now.

thanks.

jsulm

@AliM93 said in Play a video on qt 5.12 c++:

And may the qt installation change something in my Qt creator application?

No

Pablo J. Rogina

@AliM93 said in Play a video on qt 5.12 c++:

i used this link because i need also to install the ros plugin.

It looks like you need to understand what the ROS QtC plugin is, and its purpose. From the plugin website:

The ROS Qt Creator Plug-in is developed specifically for ROS to increase a developers' efficiency by simplifying tasks and creating a centralized location for ROS tools

So the idea is that you can use Qt Creator (which is no less and no more than an IDE) to deal with most of the tasks/features of developing some component for the ROS world.

Those components you'll develop with the help of the ROS QtC plugin and using Qt Creator may have nothing to do with Qt framework, I mean, they could be just plain C++ applications usable within a ROS environment but using none of the Qt framework capabilities (i.e. GUI widgets, networking, multimedia, etc.)

Given that said, I think is also possible to develop some ROS application that include some Qt framework feature. At this point, you need to decide what to do then:

if you're going to use the Qt library files installed as part of the ROS QtC plugin deployment you did (because Qt Creator is a Qt application after all, and it needs some Qt libraries to run)
Install Qt framework along your Qt Creator + ROS plugin installation

#1 is what it seems you have done so far (...the application i implemented since now...), but be aware that you'll be limited by the Qt version and Qt modules that such Qt Creator installation is based on.