Sonic Unleashed (Wii) - "Temple Entrance" Cutscene (Game Rip) 4K60 Upscale
This is the 4K60 (not AI) upscale of the raw 640x360 .sfd file of the cutscene "Temple Entrance" from Sonic Unleashed for Wii, straight from the disc of the game.
Using the .sfd file, I first had to extract the audio as a .wav file using the SFD Video Converter:
https://gamebanana.com/tools/7715 (click "Manual Download")
After downloading the converter, you just click on the SFD Video Converter icon, then click the first option "SFD to MPG", then in the folder that opens up, move the .sfd file you want to use, then click the "SFD to MPG Converter" item, and then you'll see the black cmd window pop up and the conversions will be done automatically. Once that's done (it only takes a few seconds depending on the file's size), the folder will now have an .mpg version of the video (don't use this as it's desynced), an .mp3 (sometimes .mp2) audio file, and finally a .wav audio file which is the highest quality.
The two audio files will be named "tmp" so rename them to the .sfd file's name. VERY IMPORTANT: Move all files you want to keep (including the .sfd file if it's your only copy) out of the folder as once you close the folder proper (you have to close it via the bottom right of your desktop where the hidden icons are kept), everything in it is deleted. You can keep using the same folder for other .sfd files, just rename the tmp audio files as they pop up, as any still called "tmp" will be overwritten when a new conversion happens. Also the converter only works with one .sfd file at a time so moving a bunch of them into the folder at once is pointless.
Then I had to do a lossless .mp4 conversion of the SFD file via Handbrake (opening it in Avidemux first causes it to get horrifically low-res for some reason), and making sure to remove any audio from the SFD file (as even Handbrake can't open that properly either) as audio you see will be nearly blank data but might have audio artifacts in it. And only then FINALLY open the resulting .mp4 file in Avidemux, add in the aforementioned .wav audio file, and then upscale the merged file. This isn't as complex as it sounds honestly.