CLOSED CAPTIONING WITH THE LINE 21 SYSTEM Sharon Earley NATIONAL CAPTIONING INSTITUTE, INC. ABSTRACT nationally. At present, 300,000 viewers across ~he country who use Line 21 Tele­ Closed captioning has enabled the hear­ Captio~decoding devices enjoy over 40 ing impaired to enjoy television more fully hours per week of predominantly prime-time over the past three years. Although over­ network programming. More than 200 major the-air broadcasters have provided the bulk advertisers caption their commercials and of closed-captioned programs, the partici­ support the costs of captioning television pation of the cable industry is both grow­ specials and series. ing and promising. The Line 21 system, with its proven transmission and reception Although the closed-caption service strengths, is an ideally suited caption began three years ago primarily as a delivery system for cablecasters. The Line broadcast network service, it has expanded 21 signal passes intact over satellite and into many other delivery systems -­ cable. It can be recorded in three-quarter satellite syndication, videocassette, and half-inch formats, and no special ac­ videodisk, local broadcast and cable. commodations are required to retransmit it. Decoding devices, specifically designed for DEVELOPMENTS IN CABLE cable, are currently available, as is a system which enables a local operator to The cable industry's first involve­ caption its own prograrrming in a cost­ ment in closed captioning was the delivery effective manner. The National Captioning of closed-captioned network programs to Institute sees the full participation of subscribers. Since 1982, however, cable cablecasters in the provision of closed support and involvement in the closed­ captions as an important step in increas­ caption service has been active and ing the access of the hearing impaired to growing rapidly. television programming. In early 1982 Showtime became the CLOSED-CAPTION SERVICE first subscription service to offer its own closed-captioned programming -- the For the past three decades, television BIZARRE series. Shortly thereafter Show­ has been a primary medium of communica­ time added selected movies to its closed­ tion for most Americans. It has become our captioned fare. In mid 1982 Colormax Elec­ major source of information about the world tronic Corporation began production of two and our principal source of entertainment. closed-caption decoding devices designed But for many years, television's voice specifically for the cable audience -- a remained distorted, muted or totally combination converter/Line 21 decoder, and silent for some 16 million Americans with a Line 21 decoder module that attaches to impaired hearing. The situation changed a cable converter. Such units and the in March, 1980, when the Public Broad­ standard Sears (Sanyo) TeleCaption decoder casting Service and the ABC and NBC are being acquired by operators such as television networks began broadcasting 16 Tampa Cable Television and American Cable hours of predominantly prime-time program­ Systems, whose specific commitments to ming with closed captions produced by the provide closed-caption decoders were made National Captioning Institute, Inc. (NCI). in their franchise bids. Closed captioning involves represent­ Cable subscribers can now obtaln news ing the sound track of television programs and features of special interest to the in subtitles which are telecast as data in hearing impaired via the KEYFAX National the vertical blanking interval and are Teletext Magazine, a service provided co­ visible only to those viewers whose sets operatively by NCI and KEYCOM Electronics are equipped with special decoding devices. Publishing. Most recently, Tribune Cable While in theory closed captions can be Communications, lnc., has agreed to pro­ provided by any teletext system, only one, vide funds to closed caption one movie currently known as the Line 21 system, is every month for hearing-impaired sub­ actually in use and delivering captions scribers. The first movie captioned under 180 this arrangement is POLTERGEIST, to appear During this same period and on into on Showtime in June, 1983. Other MSO's are 1975. PBS was studyinq the various techni- currently considering similar underwriting cal hurdles it faced in developing an arrangements to provide closed-caption approach to closed-captioned television. services for the benefit of their hearing­ By November, 1975, sufficient work had impaired subscribers. been completed for PBS to file a petition with the Federal Communications Commission While such activities generate (FCC) requesting the allocation of Line 21 enormous good will and demonstrate the for the introduction of a closed-captioned cable industry's commitment to serve all service. In December, 1976, the FCC ap­ facets of its market, they also make good proved such an allocation. With the FCC business sense. NCI research indicates approval obtained, PBS began fabrication that while currently only 38% of all of the caption editing console which en­ decoder households subscribe to cable ables caption preparation to be completed television, 82% would subscribe to basic efficiently, secured agreements from manu­ cable services if closed-captioned cable facturers to produce the encoder which services were available. Under those lays the Line 21 data stream into the circumstances, 68% would subscribe to vertical interval and the first consumer pay cable compared to the 28% who currently decoders -- a integrated 19" color do so. Further, of those who do not own a television set and the add-on decoder -­ closed-caption decoder, approximately 78% which Sears Roebuck agreed to retail. would rent one from a cable company. Finally, the question of who would perform the actual captioning service was answered CLOSED-CAPTION SYSTEM DEVELOPMENT when the non-profit and private National Captioning Institute was incorporated The Line 21 system was designed in early 1979. specifically to provide closed captions to the hearing impaired. For this reason, CAPTION CREATION AND ENCODING fundamental to its specifications was that it require little investment in NCI creates captions in three differ­ effort and hardware by the telecaster, ent ways, depending upon the nature of that it be sufficiently rugged to pass un­ the program to be captioned. A recent ad­ modified through all television media, and vance in caption creation technology that it be inexpensive for the consumer to known as real-time captioning enables vir­ access. tually every program type to be closed captioned. The three methods employed by Development of the Line 21 closed­ NCI to caption, and a method available to captioning system was conducted by the PES local program suppliers, are described Engineering Department with funds provided below. by the U.S. Department of Health, Educa­ tion and Welfare (HEW) . This work com­ Prerecorded Programming. NCI receives menced in 1973 and was largely completed in a time-coded videocassette dub of the pro­ 1979. The PES task had three major compo­ gram master and, if available, a script of nents, each of which had to be completed ~he program. A caption editor works with successfully before a closed-captioning the program in short sections, and corn­ service could be implemented. poses each caption. The editor determines the caption content, its location on the The first task was to evaluate the screen, and the times at which it will technique of closed captioning as a mean­ appear and disappear. All of this data is ingful service for the hearing impaired. To entered onto an 8" floppy disk via the measure this, PBS established an experi­ caption editing console, which has word mental closed-captioning capability and processing capability to facilitate the conducted controlled testing with the process. Once all captions for a program hearing-impaired community during 1974. have been prepared and entered, they are PBS obtained the cooperation of 12 member played back over video and checked for stations across the country who demon­ accuracy and quality. strated closed-captioned television pro­ grams to the hearing-impaired viewers and The captions on disk are transferred had them complete over 1,400 opinion forms. to Line 21, Field 1 of the standard NTSC Gallaudet College, the world's foremost video signal in the encoding process. To educational institution for the hearing encode captions a Simple Encoder, com­ impaired, analyzed the completed question­ prised basically of a microprocessor, a naires. The major findings were that 90% time code reader and a floppy disk reader, of the audience said they could not have is utilized. Required inputs are SMPTE understood the TV programs shown to them time code and program video from the had they not been captioned and 95% master videotape. The microprocessor syn­ said they would purchase special equipment chronizes the serial caption data with the to receive closed captions. time code and requests additional captions 181 from the disk reader when the encoder LIVE ENCODING memory buffer is near depletion. The cap­ tion data is inserted into Line 21 of the video. Advance Script TAPE ENCODING -----, Caption I Live Editing NCI r----------, Console I I I Pro- I 3/4-inch Caption 1 r--------,--~~ Editing I TV Live Producer I Display I I .J . NCI I I DLsk j L,. __ ------- r I r- I ' ENCODING J J Video I FACILITY I I I I L_TB_A!;i.Sl'--l!S.§.I.Ql-JJ:A.£IIJU - J 1 I Master I I Video- Master 1 I tape Audio Tape L..: ____________ _J Live News and Events. For news and other programs, scripts are not available to NCI in advance of broadcast. Until last year, such programs were uncaptionable. In October, 1982, however, NCI began to ern­ Prescripted Live Programs. Presiden­ ploy its real-time captioning system on a tial addresses and other programs which daily basis to caption ABC-TV's WORLD NEWS are broadcast live are often accurately TONIGHT. The system has been employed to prescripted. With the cooperation of the caption space shuttle launches and the White House or producer, NCI obtains Academy Awards.