How to reproduce memory leak during video playback on Windows:

• extract attached archive with test project;
• copy to 'qml/assets/' two video files: '1.mp4', '2.mp4';
• turn off "Shadow Build" in the project's settings!

Launch project and open Task Manager to inspect running process.
Process will slowly grow in memory, specially look at number of Handles (type of Event, usually created by CreateEvent()).