The correct pattern is to use the platform’s native video player because the user is already familiar with how it operates instead of reinventing the wheel with web jank.
It's actually a C++ app related to music visualization and the video player is one for a preview. I agree in principle though, if there were the equivalent of a <video /> tag in ImGui and OpenFrameworks I'd happily use that :)
They probably have a reason why their product is not just a video. They need integration. Going with what the platform thinks should happen, if it even offers such a control, will probably be a UI disaster in its own right.
