Is the Extigy a true Dolby Digital decoder?

[Ivan Samuelson]

I want to purchase the Creative Extigy external sound card. I see that it
decodes Dolby Digital 5.1 sources.

I currently have my DVD player hooked up to my Logitech 5.1 Z640 speakers.
I want to get the Extigy to listen to TRUE 5.1 surround sound, rather than
the Matrix surround sound that comes with the Logitechs.

I do not plan on hooking up the Extigy to my PC, but I have heard that it
can function without being hooked up to the PC as a true Dolby Digital
converter.

If I hook up my DVD player (which can do Dolby Digital as well as DTS)
directly to the Extigy and then hook up my Z640s to it, will I get true
Dolby Digital 5.1 Surround without hooking the Extigy up to my PC?

Thanks!