Why is it taking Unity so long to process video's?

So, whenever I switch build platforms or it crashes and I relaunch the project, I get this Hold On dialog, why is it taking so long for it to process the video's I have in the project? What is it doing that in needs to take 2-10 minutes on just one video? Anyway to speed this up? It's getting annoying since I am exporting to 5 platforms.