Phonon::VideoPlayer doesn't display video on Windows 7

#include <QApplication>
#include <QWidget>
#include <Phonon>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QWidget *myWidget = new QWidget;
    myWidget->show();
    Phonon::VideoPlayer *player = new Phonon::VideoPlayer(Phonon::VideoCategory, myWidget);
    QObject::connect(player, SIGNAL(finished()), player, SLOT(deleteLater()));
    player->play(QString::fromLatin1("winsat.wmv"));
    return a.exec();
}

#include "mediaplayerwidget.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MediaPlayerWidget w;
    w.show();
    
    return a.exec();
}

#include "mediaplayerwidget.h"

#include <QVBoxLayout>

MediaPlayerWidget::MediaPlayerWidget(QWidget *parent) :
    QWidget(parent),
    audioOutput(Phonon::VideoCategory),
    videoWidget(new Phonon::VideoWidget(this))
{
    QVBoxLayout *vLayout = new QVBoxLayout(this);
    vLayout->setContentsMargins(8, 8, 8, 8);
    QVBoxLayout *videoLayout = new QVBoxLayout();
    videoLayout->addWidget(videoWidget);
    videoLayout->setContentsMargins(0, 0, 0, 0);
    videoWindow.setLayout(videoLayout);
    videoWindow.setMinimumSize(100, 100);
    vLayout->addWidget(&videoWindow);

    Phonon::createPath(&mediaObject, &audioOutput);
    Phonon::createPath(&mediaObject, videoWidget);

    resize(500, 500);
    videoWindow.show();

    QString fileName(QString::fromLatin1("winsat.wmv"));
    mediaObject.setCurrentSource(Phonon::MediaSource(fileName));
    mediaObject.play();
}

MediaPlayerWidget::~MediaPlayerWidget()
{
}