So I got the .ONE unpacker and the .PRS unpacker, and here is what happened.
I unpacked the one to a bunch of .PRS files. Then I used prsdec auto.exe, and instead of .DFF files, I got some .BIN files. Help!
Do the files work when you rename them to .DFF?
BIN just stands for "binary", as in, any kind of data. It's like using DAT. File extension do not specify the file type. If you are unsure what kind of diles you have, open them in a HEX editor and take a look at the first few bytes of data (check the ASCII interpretation, too, most files have a few characters up front which specify their type). For Example, GIF files begin with "GIF" (followed by "89a" or "87a"). So, I'd suggest comparing your BIN file's first few bytes with those of a working DFF file you already have.
The bin files are renamed Renderware *.DFF files. There is a script for them modified for Sonic Heroes which doesn't fucking work... at all. Or atleast I can't get it to work, and I tried, 3 times.