.cdp extension
 

I've DL Sypho Filter 2 for PSX.
I've unRared without any problem, but the images of the 2 CDs have the extension: .cdp

I've allready burned a lot of CD (.cdi, .nrg, .iso, .bin/.cue, ...) but I've never seen .cdp

What kind of CD-burning utility can I use ?
Thanks.