I'm trying to understand the chips used in progressive DVD players and the effect when watching DVDs. I understand how the Sage/Faroudja and Genisis chips are different from one another in their performance. Each chip is a de-interlacer. So what is the purpose of them. I understand 3:2 pulldown telecine that takes 24 fps movies and makes video from it. What makes a DVD player progressive compared to an interlaced player? So here is my question: What format do DVD's consist of? Are they all video? Are they all progressive? Are they a mixture of both? If I have an HDTV display, why would I care about a de-interlacer? I'm just a little confused about the technology. For instance, if movies have always been converted from 24 fps to 30 for video tapes, why have I never seen combing on video tapes?