The magic about 19.34 was that 540/60i (called 1080i by some) needs every bit and more - I've seen papers that say you need 22Mbps to compensate for the noise caused by interlace. 720/60p provides significantly better pictures at lower bit rates. 720/60p will do well all the way down to 14Mbps (with current generation encoders). I do not recall the details, but there was a robust modulation approach proposed that would deliver 14Mbps and be robust enough for true mobile applications. The folks supporting 8VSB and 540/60i were are cut out of the same cloth - protect their IPR against anything that makes sense for the country. Greed over National interest. At 03:27 PM 12/22/2005 -0500, you wrote: >Bob Miller wrote: > >> There is nothing magical about 19.34 Mbps, 8-VSB and HD. > >Except that 3.3 b/s/Hz seems to be as high as any >practical application of COFDM seems to ever want to go. >And 8-VSB, as standardized in ATSC with the 2/3 >convolutional FEC, is already there. > >So that makes it interesting. It has to be made to work >at high spectral efficiency. It would be infinitely less >interesting (to me, anyway) if practical applications of >COFDM worked well at greater than 3.3 b/s/Hz. > >Not having the crutch of reducing bit rates, at least for >normal operation, makes the exercise interesting. > >Bert > > >---------------------------------------------------------------------- >You can UNSUBSCRIBE from the OpenDTV list in two ways: > >- Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org > >- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line. > > ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.