Unknow files type Shenmue's files

[supterV]

Hi, i'm a fan of open world game's and i've downloaded this game, gonna try with nullDC emulator. But when i finished, there are 3 "unknown extensions" files and i don't know what to do with it. Can anybody help me? https://www.dropbox.com/s/hrryhfty85oah23/Untitled.jpg

Sr for my bad english!

[wude]

try renaming the files to .cdi or use a file type verification soft