Technology Corner: Randy Hoffner

Randy Hoffner is manager of technology and strategic planning at ABC, New York, N.Y. The views expressed in his column are his own, and not necessarily those of ABC. Write to him c/o TV Technology.

The Next Step in HDTV: Super Hi-Vision
Those who have been involved in the television industry for a while might remember that the first HDTV system to be commercialized was the Hi-Vision system.

Hi-Def DVDs Are Finally Here
We are all aware that high-definition DVDs have been a long time coming, and as ever with A/V recording technology, two incompatible formats are vying for the hearts of consumers.

What Time is It?
Television engineers are quite aware of the importance of the accurate measurement of time. Precise frequency references as well as an accurate knowledge of the time of day have always been critical in television.

Maybe the CRT Isn't Quite Dead Yet
You may be hearing about the demise of the venerable CRT, which has been the display device used in most of the TV sets we have watched since television became a commercial reality.

1080p Displays: In Search of Applications
If you have attended any recent tradeshow featuring displays or paid attention to the display press, you will have seen and heard about 1080p displays.

EBU Likes Progressive Scan HDTV
Although the HD-MAC experience caused European broadcasters to question whether HDTV would ever be viable in Europe, the situation is rather different now from 12 years ago. There are three reasons to indicate the time for HDTV has come in Europe.

A Primer on Advanced 24p
The 24 fps film format has been used on television since television began.

Is Film Becoming an Endangered Species?
Video successfully supplanted film in newsgathering long ago, but in spite of the video recording industry's best efforts, film prevailed as the capture method for theatrical movies and primetime television. That tide appears to be turning.

CRTs Give Way to New Era of Display Technology
Today, it is apparent that the venerable CRT television set that we have been watching since the 1950s is living on borrowed time.

One-Chip Sensors -- The Bayer Pattern
Single-chip video cameras have traditionally been largely lower-cost consumer devices, but some professional video cameras, notably some video cameras designed to replace motion-film cameras, now use single-chip sensors.

MPEG-4 Advanced Video Coding Emerges
As might be expected, there are some differences between U.S. HDTV and European HDTV.

Twenty Years in TV Technology
A lot of television technology has come and gone since 1985, and we will take a quick look at some of the high points in those two decades.

HDTV and the Resolving Power of the Eye
What is the relationship between resolving power, screen resolution and viewing distance from the screen?

Achieving Full-Res HD with the 2K Projector
The 2K chip, as its name implies, has 2,048 horizontal mirrors and 1,080 vertical rows or lines, which permits mapping 1920 x 1080 HD images directly onto the pixel array.

LCD Displays: Fixing the Problems
Principal shortcomings, we will recall, include narrow viewing angles and slow response times. Let's look at how one shortcoming is being addressed.

Added Video Effects Aggravate Lip-Sync
Going digital has solved a number of the technical problems we had in the analog television era, but it has generated a few of its own.

Audio On Videotape
Back in 1987, TV Technology published an article that briefly traced the historical evolution of audio recording on videotape formats, and held that audio was clearly subordinate to video in early VTR designs.

HDTV: From 1925 to 1994
Inevitably, shortly after it became feasible to transmit intelligence through the air using electromagnetic waves, people began thinking about and experimenting with using the wireless to transmit visual images.

Lamps for Microdisplay Projection
We have recently taken a look at some of the older and the newer ways television pictures are shown, considering both direct-view displays and projection displays. It is fair to say that one of the strong trends in the television display business is the increasing proportion of projection displays being purchased.

Display Resolution
We have recently examined television display technologies old and new; now we'll look at the spatial resolution capabilities of the display technologies that are commonly used in television and video today.

Advanced Displays, Pt. II
Last month, we looked at television and video displays, old and new, examining the venerable cathode ray tube in both its direct view and its projector roles, and the newest projection technology commonly found, micromirror semiconductors. Two other display technologies are finding increasingly frequent use today: liquid crystal and plasma.

Displays, Old and New
The emergence of HDTV and the consequent demand for larger screens, along with the rapid development of alternative technologies, has resulted in the venerable CRT television display being strongly challenged by other types of display devices. What are the most prevalent TV display devices available, and how do they work?

ATSC Recommends AV Sync Rules
Audio-video synchronization has been one of the major casualties of the DTV era. The industry has become well-aware of this problem

Aspect Ratio: It Used to Be Easy
Although aspect ratio has always been a factor in television, for many decades only one aspect ratio was available: 4:3. With apologies to accomplished punsters, that picture has changed.

Two Decades of TV Technology
As we celebrate TV Technology's 20th anniversary, it seems the perfect time to take a look back over our collective shoulders and see just how far television technology has come in the past 20 years.

Audio for HDTV: Then and Now
Way back in 1990, the International Telecommu-nications Union's CCIR, or International Radio Consultative Committee, got a jump on audio for HDTV.

Digital Audio Sample Rates: The 48 kHz Question
"How did 48 kHz emerge as the professional digital audio sample rate?" As we will see, television had a great influence on this number.

What Is Modulation Transfer Function?
In an earlier column, we spoke of the maximum resolution capability of a film stock, expressed in line pairs per millimeter. Although this is a valuable parameter with which to establish a frame of reference, we said at the time that things are really more complex than a single number, and we mentioned the concept of modulation transfer function (MTF). What is MTF, and what may we determine from it?

24P Video: Is Film Dead Again?
It must have been soon after the invention of the videotape recorder that the first predictions of the demise of film arose. The latest perceived threat to celluloid (well, not really celluloid) is 1080P/24 fps video.

What is 4:2:2?
4:4:4, 4:2:2, 4:2:0 -- what do these numbers mean, and where did they come from?

(11.28.01)

DTV Latency
Throughput delay, commonly referred to as latency, is an inescapable consequence of using digital audio and video technologies.

PSIP Data Often Incorrect, Missing
On the long list of all that is wrong with DTV implementation are the problems involving the broadcasting of incorrect – or simply missing – system information and other data that is necessary to facilitate the correct operation of the DTV receiver.

ITV Catches Fire
Interactive TV is happening. Many of us remember companies (although we can’t quite remember their names) trying mightily to convince us that interactive TV was the wave of the future at NAB conventions of around a decade ago.

The Last Word on Time
Previously, we have taken a look at how cesium clocks, the most-accurate time and frequency references available to us, work.

NTSC Signals Have a TSID, Too
MPEG-2 transport streams, of which ATSC transport streams are a subset, can be uniquely identified with a Transport Stream Identifier, also known as a TSID. NTSC signals are not transport streams, but they have TSIDs too, which in their case stands for Transmission Signal Identifier.

Video Description Is On the Way
The FCC has recently issued another Report and Order that will affect your life as a television engineer. In FCC 00-258, adopted July 21, 2000, video description is made a requirement for broadcasters and many cablecasters.

1932 Technology Update
In these days when we are concerning ourselves with such technological topics as digital compression, this writer recently came across a document written in 1932 entitled "Report on the Investigation of the Light-Beam Type of Volume Indicator."

The Artifacts of Motion
One thing that television and the movies have in common is that both portray motion by capturing and displaying a series of still pictures, albeit in very different ways.

What About Metadata?
One of the opportunities created by the digitalization of television is the ability of digital media and transports to carry metadata in addition to video and audio.

Interest in Progressive Scanning in Japan Increases
HDTV originated in Japan, where the original HDTV scanning format, 1035i, was developed. A pioneer of HDTV, Japanese public broadcaster NHK has been an aggressive and vocal promoter of interlaced HDTV, to the point that Japanese broadcast equipment manufacturers have until recently demonstrated reluctance to publicly embrace progressively scanned DTV formats.