Randy Hoffner /
09.17.2003 12:00 AM
Two Decades of TV Technology
FALLS CHURCH, VA.
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. It is probably not necessary to tell anyone who has been in television engineering for the past 20 years that a lot has happened during that time, and that a lot of new technology has come down the pike. In this regard, television is little different from any other technology-based industry, of course. But because television has been a familiar presence in virtually every American's daily life for the past 50 years, the pace and degree of change and advancement over the past 20 years, when compared to the 30 preceding years, has been nothing short of dismaying.
In 1983, we in the industry were using the one-inch videotape format. The one-inch age was really just the second generation of professional video recording technology; the first generation, two-inch quad recording, having lasted nearly 30 years. In fact, in 1983, a substantial amount of material recorded on two-inch quad tape was still being used throughout the industry. One-inch tape had given us the ability to do electronic editing, and also had given us a number of stunt modes such as variable-speed playback, slo-mo playback and freeze-frame capability. Many of these new capabilities, and indeed the very ability to use the one-inch format for professional, color video recording and playback at all, were dependent on the digital time base corrector. Without the digital TBC, the constantly varying time base errors generated by thin one-inch tape's stretchiness precluded precluded its use to successfully record direct-color NTSC (or other format) pictures. Another digital device that had recently burst onto the scene and proved itself useful was the video frame synchronizer, with which the broadcaster could easily re-time incoming video signals to the television plant's clock.
These two devices were bellwethers in the otherwise almost fully analog television technology world of 1983, as they signaled the march to digitization that we have since witnessed.
In 1983, the distribution of network video and audio signals was done on coaxial cable and microwave circuits leased from the still-intact-but soon-to-be-broken apart telephone company. For about the preceding five years, these circuits had carried diplexed video and audio on a single cable or microwave path. Prior to that time, audio and video had traveled via separate paths, with all the quality and reliability problems that implies. Although diplexed circuits constituted a significant improvement over separate paths, anyone who ever saw one of the network "round robin" circuits, in which the signal was looped all around the United States and back to its originating point, knows that satellite distribution was a giant leap forward for quality and reliability. It also changed the face of the television business forever in a fundamental way. With satellite distribution, the staggering cost of a national television network distribution system based on coax and microwave was reduced to a level that spawned the cable network industry and the "500 channel universe" that exists today. Indeed, by the time the major broadcast networks began distributing to their affiliates via satellite, a significant number of cable networks were already operating.
In 1983, television audio was monophonic, and, to put the best face on it, it did not enjoy a reputation for high quality among audiophiles. It was just the next year that the FCC approved the broadcast of mutichannel television sound, and effectively standardized the BTSC system by protecting its pilot. This eventually led to the routine broadcast of stereo and Surround Sound on television, and to the widespread use of a second audio program. The transition to stereo caused stations and networks to augment and replace many components in their in-plant audio distribution systems, and this, combined with the increasing emphasis on audio performance in TV receivers and the resulting upgrades to speaker and amplifier components in receivers, produced a substantial, wide-ranging improvement in television audio for the viewer.
From its beginnings in time base correctors and frame synchronizers, the march toward the digitization of television video and audio accelerated through the 1980's and 90's. The digitization and computerization of television production equipment produced digital recording devices, digital effects generators, digital switchers, CCD cameras, and a vast array of other devices up to and including those that create virtual sets. On the audio side as well, digital recording and mass storage appeared, as well as digital mixing consoles and numerous digital audio effects devices.
TEN YEARS HENCE
By the time TV Technology had turned 10, in 1993, digital video and audio recording and storage had become well established, and the last analog professional video recording format was history. Digital production equipment had also gained a strong foothold, and the trend toward end-to-end digitization of the television broadcast plant was well underway. HDTV, which dawned in the television engineer's consciousness at about the same time that TV Technology appeared on the scene, had metamorphosed with the help of digital compression into digital television broadcasting, with its plethora of choices of scanning formats, audio formats, and data broadcasting alternatives.
Today, we in the television industry are well along in the broadcast of digital HDTV and SDTV, and we are just beginning to see a glimmer of the data services and other enhancements that DTV will facilitate in the future.
TV Technology's first 20 years have chronicled a dizzying array of developments that have truly re-formed television in fundamental ways. A three-network world has become a multi-hundred-network world. Television broadcast plants have made virtually complete transitions from analog to digital platforms, and are increasingly becoming computer-networked platforms. HDTV has become an everyday reality. Television distribution, broadcast and reception are in the middle of a transition from analog to digital technologies. What is all this going to lead to in the future? Prediction is difficult, particularly prediction of the future. We can be sure, though, that whatever the next 20 years brings, we will be reading about it in TV Technology.