http://en.wikipedia.org/wiki/DVD_Shrinkaccording to wikipedia, DVD shrink creates iso files of the DVD. compression seems to be done by lowering resolution and quality of the video.
so, if you want to play the video, either u:
1. use dvd shrink to watch
2. use daemon tools/ alcohol and mount the iso then watch like a DVD/VCD
3. use daemon/ alcohol, mount the iso, extract the video stream, recompress with MPEG4 or H264 then mux to avi/mkv/mp4...