Dr. Joseph Flaherty, Senior VP, CBS, Inc.
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oto, I Don't Think We're in Kansas Any More! The digital TV and HDTV cyclone has swept through the industry replacing the Kansas-like tranquillity of NTSC with the turmoil of the digital storm. DTV and HDTV are no longer a 'vision', they are a reality! Invention and standardization are over, and here we are in oz - "O-Z' -for Ones & Zeros. it's a wholly different environment and a wholly now century. it is the dawn of digital TV and the twilight of analog.
Television broadcasting is a 20th century phenomenon with a rich history of technical innovation and improvement that brought the medium from its crude beginnings to the World's most important communications medium. Today, the World over, more people watch television than are literate, and in America there are more homes with television sets than telephones.
Pundits are fond of saying that people watch programs and not technology, but without the technology there would be no programs. Every frame of every picture and every syllable of every word is strained through this technical complex on its way to the viewer, and it has always been such.
American scientists and engineers created this technological miracle, and from the very beginning their constant search for higher quality has been endless. Without their inventive genius in pursuit of excellence there would be no modern television.
In the beginning, on May 7, 1935, in a report on the emergence of television, David Sarnoff, then President of RCA said
"Public interest in television continues unabated since...RCA stated that it was diligently exploring the development of television. Our laboratory efforts have been guided by the principle that the commercial application of such a service could be achieved only through a system of high-definition television."
"Our technical progress may be judged by the fact that we have produced a 343-line picture, as against the crude 30-line television picture of several years ago. The picture frequency of 12 per second has now been raised to 60 per second.'
Even in 1935 the engineers knew that a 60 picture-per-second rate was required to achieve smooth motion portrayal. 30 frames-per-second were, and are, wholly unsatisfactory.
A year later, on June 15, 1936, just two weeks before the first experimental television transmitter went on-the-air atop the Empire State building in New York, Mr. Sarnoff said to the FCC:
"Of the future industries now visible on the horizon television has gripped the public imagination most firmly. To bring television to the perfection needed for public service our work proceeds under high pressure at great cost."
"Such experiments call for ... imagination of the highest order and for the courage to follow where that imagination leads. It is in this spirit that our laboratories and our scientists are diligently and devotedly engaged in a task of the highest service to humanity."
From such work television was born, and today, the same can be said of the genius and dedication in the service of mankind that gave birth to digital HDTV - a technology that is reinventing television broadcasting!
So, what is high definition television? In 1935 it was 343 lines, in prewar England it became 405 lines, by the 1939 New York World's Fair it was 441 lines. 525 line NTSC color was introduced as a "high definition color TV system", and in latter day Europe HDTV became 625 lines.
In short, HDTV has always been, and will always be, the best quality achievable with a given state-of-the-art. HDTV is always the best, not the second best, not the third best, and not the previous best.
"Broadcast Quality' has always been television's "hallmark-of-excellence", pursued by many, equaled by few. Yet through the years, 'Broadcast Quality' has not always meant the same thing. "Broadcast Quality" has seen steady improvements since the 1948 monochrome pictures, through early color and video tape, to improved analog cameras and video tape, to present digital NTSC color.
Today, digital, wide screen, high definition TV will escalate "Broadcast Quality' to a plateau never before imagined.
This HDTV marvel began at NHK in Japan in 1970, and by 1974 the International Telecommunications union, a United Nations treaty organization, adopted a Study Question on high definition television, stating:
...High definition television systems will require a resolution which is approximately equivalent to that of 35mm film and corresponds to at least twice the horizontal and twice the vertical resolution of present television systems'
"The ITU unanimously decided that this question should be studied."
The resulting ITU definition reads:
HDTV is typically portrayed as having roughly twice the vertical and horizontal resolution as is theoretically possible for current TVs; a widescreen picture aspect -ratio of at least 5.,3) displayed on a large screen; better color; and compact disk (CD) quality digital sound".
Three years later, in 1977, the SMPTE formed a Study Group on High Definition Television, and in 1980 the SMPTE published that group's HDTV report. The report stated:
"The appropriate standard of comparison (for HDTV) is the current and prospective optimum performance of a 35mm release print as projected on a wide screen.'
The SMPTE HDTV Study Group concluded:
"The appropriate line rate for HDTV is approximately 1100 lines-per-frame, and the frame rate should be 60 fields per second, interlaced 2-to-1 ... ".
Indeed, rather than being better than necessary, high definition was to finally put television resolution on a par with cinema quality. Today, this has been achieved! Full 1080/1920/60 HDTV equals the end-to-end quality of 35mm cinema film. Thus, America's HDTV is not too good, it's simply catching up with the cinema. Through full HDTV, and only through full HDTV, television will finally achieve its technical maturity.
HDTV made its debut in America in February 1980 when CBS and NHK presented the first HDTV demonstration at the SMPTE Winter TV Conference in San Francisco. This demonstration was quickly followed by demonstrations in Hollywood, New York, and Washington, D.C. Audiences were flabbergasted, and there was no turning back! The HDTV era had begun and television would never again be the same!
What standards might be used for HDTV production in America and throughout the World? Would the NHK standard of 1035 active lines with 1920 samples-per-line and 60 fields interlaced at an aspect ratio of 5:3 become the HDTV standard, or would the World repeat the chaos of its multiple and incompatible SDTV standards
It was the philosopher Santayana who observed that:
At television's birth, it was an era of vacuum tubes and of narrow bandwidth equipment. There were no VTRS, and no all-electronic way to record television signals. There were no geostationery satellites an no way to flash television signals around the World. In short, there was no international television.
Thus, television systems evolved as national or regional services, each with different standards - standards that were frequently incompatible with one another. And so it was when color television emerged. The chaos continued despite the development of video recorders, international satellites, and early digital television equipment.
The World tried to carry this Tower of Babel into the HDTV domain and would have done so was it not for a few visionaries and the International Telecommunications Union. The ITU unanimously approved Recommendation ITU BT-709-3 that created a unique HDTV Common Image Format (CIF) for the production and exchange of HDTV programs worldwide.
This important International Teleconununications Union (ITU) Recommendation states in part:
"Considering:
that parameter values for HDTV production standards should have maximum commonality;
that an active image format of 1920 pixels by 1080 lines provides square pixel sampling, with attendant advantages for interoperability between various applications including digital television and computer imagery;
Recommends:
that for new implementations, particularly where interoperability with other applications is important, systems described in Part II (of document ITU-BT-709-3) are preferred.
Part II describes the CIF system as:
1080/60/2,1; 1080/60/1:1 and 1080/50/1:1; 1080/50/2:1 with 1920 samples per active line at an aspect ratio of 16:9.
Thus, the ITU and its Radiocommunications Study Group 11-R has prepared the World for its first unique worldwide CIF television standard for HDTV program production and program exchange.
The World Broadcasting Unions Technical Committee (WBU-TC) endorsed this ITU Recommendation in 1997. Its statement declared:
"The World Broadcast Unions Technical Committee strongly supports the adoption of a unique standard for program production and exchange of high definition television. This will lead to easier and better exchange of HDTV programs and lower equipment costs. It will accelerate the move to high definition throughout the World."
"The WBU-TC recommends that the unique standard should be the so-called HD-CIF standard which has a 1080 line by 1920 sample by 50HZ/6OHz scanning system. This standard should be used for HDTV production equipment. studio equipment manufacturers are being encouraged to set in motion the means to provide equipment to this standard."
"The WBU-TC warmly recognizes the achievement of the ITU Study Group 11 in including the HD-CIF standard in its Recommendation BT-709-3. This recommendation should form the universally accepted parameter se Color t for high definition television production."
Today, 18 years, 9 months, and 26 days after its U.S. introduction the recommended HDTV standard for production and program exchange is nearly the same as the original NHK HDTV format.
Combined with the ATSC multiple format digital transmission system, DTV and HDTV are reinventing television! DTV and HDTV are a total replacement of America's electronic TV production, carriage, and delivery systems. Every segment of the television business will feel the impact of this digital revolution. Digital technology will radically change television's means of communication, its quality, and its flexibility, the conduct of the business, the scope and effectiveness of the service, and every aspect of the medium.
As of today,189 stations have applied to the FCC for a digital channel.111 stations have their construction permits, and 47 digital stations are on-the-air. DTV and HDTV programs are being produced and broadcast with many more to come. Widescreen DTV and HDTV receivers were introduced last month, and to-date 3000 has been sold with the demand presently outrunning the supply. It is expected that DTV/HDTV receiver sales will continue to escalate.
The Nation's engineers and scientists have devised the World's best digital TV and HDTV system, the government has approved it, mandated it for terrestrial broadcasting, and has assigned broadcasters the last VHF and UHF channels in the radio frequency spectrum to implement the digital TV and HDTV service.
The roll out and application is now up to broadcasting's creative and
business communities! What are some of the things that they must they consider?
First, In the past all competition in the TV marketplace was based on the same general technical quality. It was 525 line NTSC from the camera on stage to the receiver in the home. senior managers never had to make decisions on program presentation quality. Hereafter, there will be a wide range of technical qualities delivered to viewers from SDTV, through "SDTV multiplex" programming, to full quality HDTV, and technical quality will become an ever increasing factor in the competition for viewers.
There has never been a significant quality improvement in television technology that has not become a part of everyday American life, and DTV and HDTV will be just the latest such "must have" technology in viewers homes.
Second, consider that some broadcasters, cable, and DBS programmers have already declared their intent to provide significant HDTV program services. In the competition for viewers, full, wide screen, high definition programs will be available much of the day, and such high definition programming will be just a 'channel click" away.
Third, it is vital understand that wide screen, high definition is not just pretty pictures for today's small screen TV sets. Rather, it is a wholly new digital platform that will support the larger and vastly improved displays in development for commercialization. HDTV viewed on such large wide screen displays will create an entirely new viewing experience and will finally make the home theater a practical reality.
Fourth, The ATSC standard includes two HDTV transmission systems generally known as 1080I and 720P, but these names are a 'shorthand" for systems with a number of parameters, each of which must be employed as specified in the ATSC standard to achieve HDTV quality. If one or more of these critical parameters are reduced, the overall quality of the picture is reduced and is no longer HDTV. A service cannot properly be called a HDTV service whenever the full ATSC HDTV specifications are not met.
Both the 10801 and 720P systems require a transmission bit rate that is nearly the same and both fill the 6 MHz TV channel. The 720/1280/60P format requires just 8/9 the bit rate of the 1080/1920/60I format. Thus, full quality 720/1280 progressively scanned H]DTV pictures at 60 frames/second do not require a significantly lower transmission bit rate
For film sources operating at their native 24 or 30 frames/second, wherein the motion portrayal is already compromised - the wheels go backwards - both the 1080 and 720 formats areprogressively scanned.in this case, the 720/1280 format will require fewer bits, but it will also have half the resolution of the 1080/1920 format.
The "shorthand" use of the 720P or 1080I HDTV line numbers to describe the entire systems does not mean that the systems will incorporate all the other picture parameters of frame rate and samples/line required to produce full quality HDTV pictures. A 720P system must contain 720 lines x 1280 samples/line x 60 frames/second to qualify as a HDTV system.
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The "shorthand" title of 720P or 10801 can be, and often is, misleading and does not mean that the systems will operate in a HDTV mode!
Fifth, DTV and HDTV are only beginning! NTSC made major duality improvements with time, and rapid DTV and HDTV improvements are to be expected. The American DTV and HDTV system has a great deal of headroom for ongoing improvement.
For example, viewing HDTV today is a bit like Mark Twain's comment that "Wagner's music is better than it sounds". Today HDTV is better than it looks! The display devices are the limiting quality factor. While improvements are being made by the month, as of now, no display has achieved the full quality potential of America's HDTV system.
Yet this development is as it should be! The full potential of any new standard should never be fully encompassed by the existing state-of-the-art, nor should it be so futuristic as to not have its potential achievable in a foreseeable time. America's HDTV standard is beyond the present quality of displays, but not beyond the scope of rapid development. Full HDTV quality displays will rapidly improve and will continue to widen the gap between HDTV and all lesser formats.
Finally, As we evaluate tomorrow's TV and HDTV and plan for its implementation, we must bear in mind that today's standard of service enjoyed by the viewer will not be his level of expectation tomorrow. Good enough is no longer perfect, and may become wholly unsatisfactory. Quality is a moving target, both in programs and in technology. Our judgments as to the future must not be based on today's performance or on minor improvements thereto.
Expanding the artistic horizons of television is a delicate blending of the technical and creative skills, and only through this marriage of talents will we been able to weave the lovely "tapestry of digital television'.
As we take DTV and HDTV into the 21st century we would do well to remember the advice of the Philosopher Santayana when he wrote:
"We must welcome the future, remembering that soon it will be the past, and we must respect the past, remembering that once it was all that was humanly possible."
Let's leave Kansas behind us and move on to this new OZ, the "O-Z" of ones and zeros with the courage, heart, and brains of the original cast!
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