06-23-2001, 08:03 AM
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Join Date: Jul 2000
Location: New York, NY
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There's a fascinating Greg Rogers interview of Lee Wood in July's "Widescreen Review." Forum member Wood is director of engineering at CBS affiliate KOIN-TV in Portland, Ore. For his moderated HDTV news
forum, one learns, he daily scourers the Internet starting at 5 a.m.
Among the many tidbits about current HDTV broadcasting that caught my attention:
- KOIN varies the bit rate of HDTV broadcasts depending on the content. (A 6-MHz HDTV signal can carry up to 19.3 million bits per second.) Typical evening broadcasts at KOIN are delivered at 11 Mbps, Wood said, where the MPEG-2 encoding might cause motion artifacting only during action scenes. CBS's Super Bowl got about 15 Mbps to minimize artifacting, and basketball used all 19.3 Mbps.
- KOIN delivers a standard-definition digital channel in a 4:3 format simultaneously with a 16:9 HDTV program (for those with 4:3 screens who don't like letterboxing.) SDTV channels get 4 Mbps.
- Unused bits in a 19.3 Mbps channel are being experimentally used to broadcast data (1-3 Mbps as the bit rate varies with MPEG-2 encoding). Otherwise, unused bits become 'null packets' or blank spaces.
- 1080i vs. 720p is a tradeoff between detail and motion, Wood notes, indicating 1080i can put three times the pixels on screens. Outside of fast-moving sports, the detail is what catches the eye.
- "Satellite delivery of local HDTV stations isn't going to happen anytime soon," he notes, urging cable operators to bundle programming such as HBO with local HD as an advantage.
- The HDTV rollout and the availability of set-top boxes was slowed by the arguments over modulation schemes (8-VSB vs. COFDM), he said. He estimated only about 66,000 in the U.S. can watch HDTV due to limited STB availability.
STOP DVI/HDCP AND
[This message has been edited by John Mason (edited 06-23-2001).]