QMediaPlayer doesn't work (no service found for - "org.qt-project.qt.mediaplayer")

Here is the code:

...
QMediaPlayer * media = new QMediaPlayer(this);
media->setMedia(QUrl::fromLocalFile(filename));
...

When i run it, i get following error:

defaultServiceProvider::requestService(): no service found for - "org.qt-project.qt.mediaplayer

What's the problem?

System: Windows 8.1
Qt version: 5.15.1