Some Thoughts on Digital
Television
I have recently been sharing my house
with six, count 'em, six huge high-definition TV monitors. I'll discuss my insights into
the sets themselves and the technology behind them in a future column, but for now, I
thought it might be interesting to consider how this new form of television came into
being.
In the latter part of 1996, I peered into my crystal ball
and published a remark that nobody was even talking about high-definition television
(HDTV) any more. Even as I was writing that profound judgment, people started talking
about HDTV a lot. On December 26, after years of indecision, the Federal
Communications Commission (FCC) in Washington announced the adoption of a technical
standard for the new kind of television.
It had been a long wait. So long, in fact, that electronics
journalists (myself included) tended routinely to qualify any mention of HDTV with the
phrase "if it ever happens" or some such. Meanwhile, we were stuck with
50-year-old technology.
In reality, broadcasters and set manufacturers managed to
work marvels with the existing system, and the best conventional NTSC signals, as are used
in North America and Japan, can be staggeringly good. But that was only the more
frustrating for those who knew that there was a far better technology around the corner,
someday.
I first saw a demonstration of HDTV almost 25 years ago, in
Japan. The prototype was a visual knockout, looking more like high-quality film than
television. It took a number of years for that prototype to become an actual broadcast
standard in Japan, but it did so and even a decade ago there were many hours of
high-definition broadcasting in that country every week.
It was accepted for a long time that a new form of
television was inevitable, and the FCC -- the US broadcast regulator -- began to look into
it in the mid-1980s. One of the systems that was in the running at first was indeed the
Japanese system. It was dropped early on, however, when the Commission decreed that
whatever standard was chosen, it had to be digital, and the Japanese system was not.
The requirement for digital transmission was natural
enough, given the general trend in consumer electronics. But there was one specific
purpose in abandoning analog: data-reduction techniques would allow a digital
high-definition signal to be squeezed into the six megahertz bandwidth occupied by a
normal NTSC analog signal, so no new spectrum space would be required.
Even with the Japanese system out of the running, there
were still four competing digital standards proposed. Given its past record, the FCC might
well have just picked all four and let them duke it out in the market. That was their
technique when it came to selecting a stereo AM radio standard, and it killed the whole
notion; even now, there are lots of stereo AM stations, but hardly any radios.
To make sure that wouldn't be repeated when it came to
HDTV, some seven companies and institutions, which had backed the various systems, formed
what was universally called the "Grand Alliance," to come up with a single
standard they'd all be happy with. They formed the Advanced Television System Committee
(ATSC) in 1993 to blend the best bits of the four proposed systems into one.
By late 1995 the Committee had finished, and had developed
the system that, with some small modifications, the Commission adopted a year later. That
time was spent in addressing the concerns of several industries that would have to live
with whatever the Commission decided. Computer types didn't like the scanning system
proposed in the original standard, for instance, and movie companies balked at the notion
of a single aspect ratio for all programming.
In the end, rather than delay further, the FCC simply
deleted those sections of the standard and adopted the rest.
The new system means much more than simply a clearer
picture. That's implicit, however, and it's perhaps significant that, except in the
historical part of its announcement, the FCC never used the phrase "high
definition"; throughout the document, the system was called "digital
television" or DTV.
In reality, by the time you figure in the different aspect
ratios, scanning schemes, and so forth, DTV can come in something like 18 different forms,
only a couple of which are true high definition. But, as things are shaking out, HD is in
fact driving the changeover, which is supposed to be complete in the US by the start of
2007, and HDTV sets are one of the hottest items in consumer electronics today.
One irony of this, as pointed out to me by an industry
type, is that people are buying these sets not on the basis of the pictures they can
produce with a true high-definition signal -- which can be spectacular -- but on their
ability to get the most from DVDs. Most HD material is on in prime time, he says, but most
TV sales are made at other times, so most buyers have never seen what their sets are
capable of.
They're in for a very pleasant surprise. Maybe it's been
worth the wait.
...Ian G. Masters
ian@mastersonaudio.com
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