Like i said your Personal Computer can decode the ISO as long as you have the tools to mount the image or to stream it to the appropriate PC player, i have successfully done it with an ISO image of a BACKUP of a DVD ISO image to the PC.
@Krenkey, I'm still a little confused about what you have successfully done...
a) mounted a DVD ISO image stored on the DNS-323, via samba, and decoded that DVD ISO with a software DVD player on your PC.
b) streamed a DVD ISO image with the media server on the DNS-323, and decoded that DVD ISO stream with a media client on your PC