At 11:51 AM -0500 2/21/07, Manfredi, Albert E wrote:
Craig, being obnoxious does not make you, or anyone else, right. And throwing a lot of words at something so basically simple does not either. If a 576i SD program takes, on average, roughly 5 Mb/s, that's average and not peak, then 3 of these take an average (not peak) 15 Mb/s, and four take an average (not peak) 20 Mb/s. Reduce the quality of the 576i SD to an average (not peak) of 4 Mb/s, which is what decent SD programs here use for 480i, and you're still requiring an average (not peak) of 12 to 16 Mb/s for 3 or 4 SD programs. The BBC claimed, from their real-world testing, that this many SD programs would have to be removed to make room for one H.264 HDTV program. That looks to me very much like a low estimate of 12 Mb/s, and a high estimate of 20 Mb/s. Throw whatever prefiltering words you like at this, the results are not a dramatic improvement compared with H.262. As I already said, I do not doubt that H.264 will give better results as the bit rate is reduced. But there's no reason for over-hyping it, either. I'm not a salesman for H.264. I'm just after some unvarnished truth, rather than press releases.
Your hopeless Bert.Maybe the problem is that the BBC, and European broadcasters in general care a great deal more about delivered video quality than the broadcast and multi-channel distribution industries in the U.S. You probably do not even notice when most of the resolution has been sucked out of a program to make it fit into a DTV sub-channel. Nor do you notice when an HD feed is lower quality than a good SD feed.
Your rant above proves how shallow your knowledge is in this area. The BBC clearly stated that they are using h.264 for HD because of its advantage in quality versus bandwidth. Yes, you can use both MPEG-2 and h.264 to "overstuff" a DTV channel, but NOT without significant pre-processing that limits delivered resolution. All things being equal the delivered image quality using h.264 will be significantly better than for MPEG-2 given the same number of programs in the same amount of bandwidth.
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