Videoculture 5. Hector and HDTV: tomorrow's television technology
``Hello, Hector, what's been on TV today?'' you say as you walk into the room and flip on the light. ``Good evening, John,'' says Hector. ``I've got several things you might like: a re-run of `M*A*S*H' -- the one where Hawkeye goes crazy -- and a Pink Panther movie. There's also the Philadelphia Orchestra playing Berlioz and the PGA Seniors tournament from Reno -- the one you missed last week. You also asked for everything that's been broadcast today about the Walker spy case, and I have that.''
``Fine, let's see the Walker stuff,'' you say -- and Hector, the Ultimate Channel Selector, turns on the television set.
Hector, of course, is not human. He's a box mounted on top of the TV. He's part of what MIT professor W. Russell Neuman calls ``fifth-generation television,'' which he defines as ``the integration of computers and integrated circuits into media technology.'' Nor is this a blue-sky speculation. Hector's cousins are now at work in MIT laboratory tests.
Combining voice-synthesis and voice-recognition technology with computer-driven videocassette recorders, Hector's job is actually simpler than it might seem. To locate news stories on the Walkers, for example, he simply reads the ``closed captions'' -- the line of text for the hearing-impaired, broadcast along with the picture on many programs and visible on the screen when passed through a special decoder. When he finds the word ``Walker,'' he records the segment.
Hector may be a few years in coming. But within the next decade, experts say, new developments now under way will vastly upgrade the technical quality of television. The more immediate advances will include:
Stereo television. If you've ever gloried in the full-color spectacle of a televised concert -- while suffering through the sound produced by your set's single three-inch speaker -- you may wonder why stereophonic sound has been so long coming. The waiting is nearly over: Last August, a public television station in Chicago, WTTW, became the first to broadcast in stereo, and such cable networks as MTV, the Disney Channel, and the Nashville Network now have stereo sound. Many newer sets, equipped to receive stereo, need only have high-quality speakers plugged in. So far, however, there is little stereo programming available: Much of the sound now broadcast by stereo stations is synthesized electronically from monophonic tracks.
High-definition television. Known as ``HDTV,'' it rejiggers the standard technologies into vastly superior pictures. ``I think it fair to say that HDTV is fully the equivalent of 35-mm film,'' says Renville McMann, vice-president for Advanced Television at the CBS Technology Center in Stamford, Conn.
By more than doubling the number of lines on the screen (from 525 to 1,125), and by elongating the picture's ``aspect ratio'' (width to height proportion) from the present 4 to 3 to 5.3 to 3, engineers can produce richly detailed pictures that promise to revolutionize the televising of sports and the performing arts. That technology can then be given a large display: Forty-inch picture tubes are being developed, and the CBS lab already has a 10-foot TV screen in operation. When coupled with triphonic sound, says Mr. McMann, HDTV will capture ``a whole new audience, because we will be able to give the theater experience in the home.''
When will it happen? If, as many observers hope, an international conference next October can agree on uniform standards, McMann sees HDTV beginning to arrive in homes equipped with direct broadcast satellite dishes in perhaps five years.
Digital technology. Television now operates on an ``analog'' system, in which variations of voltage or frequency correspond to (are ``analogous'' to) variations in the sound and the light of the image. ``Digital'' technology, using computers first to break these variables into millions of tiny chunks of information (represented by either an ``on'' or an ``off'' signal) and then to recombine them, is much more precise and less subject to interference.
Complex and expensive, the technology will first be used only for production, and not in the home. So why will it matter? Richard Green, director of engineering at PBS, says that ``digital will first arrive in the postproduction suite,'' where videotapes are edited into final form. Tape editing is accomplished by making successive copies -- which, using current technology, involves a slight loss of quality each time. Using digital technology, the 200th copy-of-a-copy (or ``generation'') will be as good as the first -- which means that the artistic quality of editing can also improve.
Digital technology also would allow a television transmission, sent from a remote African phone booth to come in to a New York news studio with perfect clarity.
