See below for the 2 methods:

• https://stackoverflow.com/questions/42080565/how-to-paint-sequential-image-in-efficient-way-in-qquickpainteditem
• http://blog.qt.io/blog/2015/03/20/introducing-video-filters-in-qt-multimedia/

Which is the more efficient way to display a OpenCV video stream in a QT QuickControls 2 application?