I would suggest trying zamzar.com, which is an online video converter. Mplayer and vlc can also play it IF they have the codecs.
What you convert it to exactly depends on what your DVD player knows how to read.
I'd start by trying to convert it to popular formats. MP4, avi, flv or the DVD vob type of file are examples. 3GP might work too, but the quality is inferior IMO.