What was the error in TMPGEnc?
Oh, the best kind! It's the type of error you get before posting a question on the topic, but when someone asks for it, it goes away and everything works
TMPGEnc seems to have successfully converted the file to MPG2, but I don't know how good the file is, since WMP claims to not be able to download the right decompressor, and PowerDVD shuts down with errors. DVDlab is muxing the file at the moment, so we'll see what it produces.
Thanks again, guys. If this doesn't work out I'll try the Doom9 guide. I keep forgetting about that great site.
ps-to tell the truth, TMPGEnc was giving me a variety of errors, depending on what I attempted to do with the AVI (VCD/SVCD/DVD/my own settings). Half of them stopped the conversion, the other half halted the process entirely.
*edit*
Looks like it wasn't successful. The file has no audible audio track. I'll try the Doom9 guide.