Note: This does NOT WORK ON FORKPHORUS. This project is a full-motion video player, with pause, tracking, and volume controls! Click the volume icon to open the slider, and click it again to hide it! Uploading your own is trickier than the audio player. Here's how: Go to ezgif.com and convert your desired video to a GIF. (For longer videos, I would use CloudConvert, though it leaves behind an annoying dithering effect.) Lots of costumes can crash Scratch, so be wary of that. Uploading a 500-megabyte gif into this project probably isn't a good idea. The framerate is your biggest enemy. Depending on the video, finding the proper level of compression can require a lot of trial and error. Upload it here, and change the variable fps to your desired fps. The audio scanning works the same way as with the audio scanner, except you need to delete the old variables in the lists for this video.
Illumination Credit to @qucchia for inspiration.