QML application performance is crippled after Video playback

After playing video the performance of entire application decreases significantly. I have no FPS measurements, but the difference is easily noticeable with a naked eye.

Steps to reproduce:
1. Start the attached application
2. Scroll the list at the bottom of the screen to see how smooth the scrolling should be
3. Click "Load video" at the top of the screen
4. Wait for Video element to load and start playing
5. Click "Unload video" at the top of the screen
6. Scroll the list at the bottom of the screen

Actual results:
6. Scrolling looks much worse than in step 2.

Expected results:
6. Scrolling is as smooth as in step 2.