Qt5 Separating a video widget

I am trying to find a way to create and separate a video widget into two parts, in order to process stereo videos:

• The first one would play a part of the video;
• The second one would play the other part of the video.

I currently do not know where to start. I am searching around qt multimedia module, but I do not know how to achieve this behavior.

Does anyone have an idea?

I was also thinking to build two video widgets and run them into two threads but they have to be perfectly synchronized. The idea was to cut the video into two ones with ffmpeg and affecting each one to a video widget. However I do not think it would be easy to achieve this (each frame would have to be sync).

Thanks for your answers.