if the DVD will play in a typical DVD settop player (the kind that hook up to a TV), then yes, it was most likely encoded to an MPEG-2 video file. as per DVD spec, the resolution is going to be 720x480 (NTSC format) or 720x576 (PAL format)... unless it's on a CDR as a "VCD" (VideoCD), in which case the resolution would be approximately half the DVD resolution.