VlcMediaPlayer integrating in QGraphicsView class

Question

I need to use the vlc library with Qt. It's work well, but now i want to use the VlcMediaPlayer in a QGraphicsView and it doesn't work. There are no images displayed. Does anyone have an idea ? This is my code :

 VlcWidgetVideo *widgetVideo = new VlcWidgetVideo;
 _instance = new VlcInstance(VlcCommon::args(), this);
 _player = new VlcMediaPlayer(_instance);     
 _player->setVideoWidget(widgetVideo); 

 m_scene = new QGraphicsScene
        m_scene->addWidget(videoWidget);
 setScene(m_scene);

[EDIT]

I found how to diplay the player by specifying the parent :

VlcWidgetVideo *widgetVideo = new VlcWidgetVideo(this);

But now i can't add other items or widgets above my player. I have this warning :

QGraphicsProxyWidget::setWidget: cannot embed widget 0x1a5005f0 which is not a toplevel widget, and is not a child of an embedded widget

Thanks for paying attention.