Cannot add Multimedia Widgets to Qt Creator C++ project

[Cazzaniga]

Hi,
I am trying to compile and run the official Media Player Example in Qt:
http://doc.qt.io/qt-5/qtmultimediawidgets-player-example.html
for a Raspberry Pi running Raspbian Jessie. I still have no success: when I build the project, the following error appears:

:-1: error: Unknown module(s) in QT: multimedia multimediawidgets
I installed "sudo apt-get install qtmultimedia5-dev" but without any success. Is it the right module to install?
My Qt should be up to date, and I don't know where the problem can be. Could anyone help please?
Thanks!

[Cazzaniga]

Please, could anyone give some hints? The multimedia package seems to be installed well, but in Qt the folowing error remains:

error: Unknown module(s) in QT: multimedia
Maybe the package has to be manually installed into Qt in some way?
Thanks!

[anda_skoa]

Have you tried on a desktop just to see if it might be Raspberry Pi related?

Cheers,
_

[Cazzaniga]

Thanks anda_skoa,
I think it's not a problem related to the Raspberry Pi, because the build fails in Qt at the desktop side!
EDIT:
perhaps you mean that I should try to not cross-platform for RPi and try to compile for desktop?

[anda_skoa]

Yes, try a desktop build.

Also, if you are cross-compiling, make sure the cross compiled Qt has these modules built.

Cheers,
_

[Cazzaniga]

Also, if you are cross-compiling, make sure the cross compiled Qt has these modules built.
How can I check this? Is it an option in the Qt project Properties?