I left a similar comment on the video when it came out but this audience will be a little more savvy to this.

So he makes the high quality scan of the Sonic Adventure box and then does a 90 degree rotation, this take the system 9 1/2 hours to complete!

Yes it is a 16Mhz(?) 386 but for the life of me, I cannot comprehend how it could take that long unless they are using some very poorly optimized system.

You basically just need to take data and read it in a different order from one buffer to another, you could even segment it into much smaller blocks and just batch it up like that to avoid RAM limits. But that is not what we see, it is wild!