[ssamadhi97]

Further lossless compression of DVD video is mostly pointless because mpeg video already employs basic lossless compression schemes to reduce bitrate. The effect of additional lossless compression would be minimal.

AAR.oner: Actually there's a considerable number of lossless video codecs out there, mostly for screen capturing purposes (think recording presentations) or for temporary storage of prefiltered video for multi-pass encoding. However both kinds only offer minimal compression on "natural" video content.