warning message when running a video inside graphics view

int main(int argc, char** argv)
{
	QApplication app(argc, argv);

    QGraphicsScene scene;
    QGraphicsView view(&scene);
    view.setViewport(new QGLWidget);

    QMediaPlayer player;
    player.setMedia(QMediaContent(QUrl("D:/DShowQt/mediasamples/Coral_Reef_Adventure_720.wmv")));
    QGraphicsVideoItem *video = new QGraphicsVideoItem;
    video->setMediaObject(&player);
    video->setSize(QSizeF(640,480));
    player.play();
    scene.addItem(video);
    view.show();
	return app.exec();
}