Animated screen on a still image

Hi everyone,

I think this would be the right place for this question since I’d imagine it involves some compositing work.

I am rendering an image for work of a big space that has a large LED wall in the back. I want to animate to screen with motion graphics and export as a gif to share with the client, but I want to avoid having to render the entire image multiple frames.
The screen is partially blocked by human figures, and although I’m new to compositing in blender, I assume there is an efficient way to compose the animated layer with some alpha masking from the foreground models (without having to use other software photoshop/aftereffects etc.)

Maybe it’s actually easier to to it with external software but I want to believe there’s a better way to export the final gif with only the blender compositor. (Also because I want to try and improve my production pipeline in what I can do with just blender).

Thanks a lot

Maybe you can do something like have two scenes, the foreground scene that you render once with transparency (Cycles Render Properties -> Film -> Transparent) enabled and you only render that once, and a second scene with just the screen using an image sequence or movie as an image texture which should render relatively quickly and then it ought to be a simple matter to composite them together in Blender’s compositor.