Slow performance picking a random image from a directory using Movie File In TOP

Hi!
I was inspired by the functionality described in the help page of the Movie File In TOP where you can have the TOP pick a random image from a folder.

My idea was to have the TOP output a random selection from a library of images (filenames formatted with alphanumeric ID’s). I got the system working but I found that the performance drop was really heavy with each new image.

I was using 4K images but found that even 720p images weren’t performing fast enough for realtime.

Eventually, I settled on exporting my library of images as a video and then pulling a frame at random, instead.

Can someone help me understand why pulling from a folder is slower to perform than a frame from a video?

Thank you!