Hi and welcome to devnet, QtGStreamer is unmaintained. Depending on what you want to do, you can use the custom pipeline option of QMediaPlayer::setMedia.

@jsulm Looks like that is the only way to get the scaled widget correctly. Thanks!

@mrjj I tried the above in main and it worked. #include <QStyleFactory> ... QApplication a(argc, argv); a.setStyle(QStyleFactory::create("Fusion")); ... Thanks and sorry for late reply.

@Christian-Ehrlicher : I created a bug report https://bugreports.qt.io/browse/QTBUG-80916 with a minimal viable example.