Latest questions about "overlay"

I'd like to use it with multiple displays. My problem is that I can only apply filter on the main system screen. How can I only apply filters with Ssoverlay on the second screen?

Is there a program that will superimpose a grid onto a photo? Thanks!

When I use MFC to make a tool to capture the screen of a video player, the picture becomes black without the actual image.

My computer shows "video overlay error" whenever I try to open video editing software. The video isn't also displayed in preview mode of this video editing application.