Almost everywhere one walked on the NAB show floor, there were exhibits showing the new technology. Countless papers on the subject were delivered in the engineering conference. The only question seemed to be which of the two most popular formats to choose.
Sound familiar? It could have been NAB2004, the technology HDTV, and the formats 1080i or 720p. Or it could have been NAB1983, the technology teletext, and the formats NABTS (the North American Broadcast Teletext Standard) or WST (World System Teletext). Being the buzz of the convention doesn’t mean a technology will be commonplace in 20 years.
HDTV seems inevitable because video has always increased in quality, from an eight-scanning-line mechanical (spinning-disk-based) system to 240, from mechanical television to electronic, from black and white to color, from tube-based cameras to solid-state. But the same inexorable progression means that what’s called HDTV today (the 240-line mechanical system was called HDTV in 1935) is likely to be surpassed in the future.
It’s already happening. NTT announced a transmission system for SHDTV (3840 x 2160), and NHK has demonstrated cameras and displays for UHDTV (7680 x 4320). At an NAB digital cinematography camera panel reminiscent of the one at the Hollywood Post Alliance Technology Retreat in February, ARRI described its six-megapixel D20 camera project (1080-line HDTV is two megapixels), Dalsa its eight-megapixel Origin, and Lockheed Martin its 12-megapixel system.
Panasonic’s Varicam has long offered “overcranking” and “undercranking”—the ability to run at faster and slower than normal speeds. At the NAB panel, Kinetta announced a digital cinematography camera with an actual hand crank.
The Varicam can shoot no faster than 60 frames per second. At NAB2004, Grass Valley and Ikegami showed HDTV-resolution cameras that can shoot as fast as 120 pictures per second. They were overshadowed by HDTV-resolution cameras from BandPro, Photron, and Vision Research that were able to capture a thousand frames per second.
If HDTV seemed to have multiple meanings at the convention, so did digital television. FCC chair Michael Powell seemed to waver on his support for the latest plan to speed the transition from analog to digital broadcasting, this time calling for the return of analog channels in 2009 rather than 2007.
The extra two years are to allow the so-called “tuner mandate,” requiring digital reception capability in all TV sets 13 inches and larger with analog tuners by mid-2007, to provide viewers with digital TV receivers. But the Consumer Electronics Association (CEA) Spring HDTV Guide, given out at the show, already listed 220 models of what CEA calls “digital televisions” without any analog tuners and, therefore, not subject to the mandate. Tuner-less monitors work fine with cable and satellite set-top boxes.
An NAB Engineering Conference session on DTV receiver technology described huge improvements over previous models. Zenith’s fifth-generation receiver offers an echo-equalization range of plus or minus 50 microseconds, and it can deal with the infamous “Brazil E” signal with just 24dB of carrier-to-noise ratio. But a paper on receiver performance recommended practices noted that a 58-microsecond echo was found in Philadelphia and that ordinary practices can reduce carrier-to-noise ratios to below even the 15dB needed in a ghost-free environment.
Field testing in Rosslyn, VA in difficult reception sites showed a huge success rate: 65% with no more than four hits in three minutes. But that doesn’t count 14 (out of 78) tests that were below reception threshold.
Just as the inexorable progression to higher quality makes HDTV inevitable, so too does the inexorable move toward digital technology make digital TV broadcasting inevitable. Broadcasters just hope there’ll still be broadcasting by the time it happens.
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