I watch HDTV over the air for free on my 2005 XP Media Center PC and I often record the goodies to an exteral USB hard drive. -- low cost and fast speed is what customers want in broadband
IIRC, ATSC uses MPEG2 compression, and DirecTV uses MPEG4. Cable can vary with the provider. IME MPEG2 gives a better picture than MPEG4. On paper, MPEG4 seems capable of providing a better overall picture. However in practice it seems to be used mostly to conserve bandwidth.
