Average color grid pattern

Hi,

I’m setting up a project where I’d like to take a video file and in a grid of 6x21 get an average color within each grid cell.
So like a low-density led display where I take in a video and display an average color within that area on the led.

And so I’m thinking what a fast (least heavy) ways would be to get these colors out of a video file.
Pass the video to a shader each frame to do the math there or something else?

Here’s an example of the grid. Nothing special :slight_smile:

Thanks for tips!