Captioning Films and TV: A Brief History

Frank B. Withrow - The Dawn Patrol

The U.S. Congress created captioned films in 1958 to make film available to deaf individuals. It was considered comparable to the American Printing House for the Blind, which was established in 1858. The captioning techniques developed for film used a two-stage process. The first set on films developed the captions out of focus as a dark background, then a white caption was developed over the dark background, ensuring a readable caption regardless of the background where it was placed.

In the 1970s, captioning of television became a need for deaf people. Several different systems were examined. The National Institute of Standards and Technology, known between 1901 and 1988 as the National Bureau of Standards, was looking for a way to broadcast correct time signals and developed a coding system using line 21 in the TV signals.

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The NIST did not understand the broadcast industry and that programs were rebroadcast so while line 21 worked, it did not work for correct time so they gave the technology to the Office of Special Education Programs (formerly the Bureau of Education for the Handicapped) in the U. S. Department of Education. The NIST and the Public Broadcasting Service experimented with the line 21 system and developed decoders for its use. Eventually Congress mandated that the decoding system must be built into all television sets.

Broadcasters now encode both EIA-608 (Line21) and EIA-708 (DTV) captions in their programs  – though most broadcasters are up-converting 608 to 708. EIA-708 captions have lots of new features including an impressive amount of font, color, language, and background options.

In the early days of captioning, we dreamed of using different fonts and colors for different speakers. We actually did a few demonstration programs with Michael Jackson and his brothers. Now the new digital technology makes it more reasonable to do so. I am not sure whether that will make a difference. Having watched a number of captioned foreign movies good captions fade into the background, you begin to believe you are hearing the dialogue – not reading it. The most critical issue with caption is readability.

EIA-608 captions are, by nature, analog captions placed in the vertical blanking interval – or line 21 of the video, which is invisible to the end user. Modern DTV transmission of 608 places these captions in the picture user data of the MPEG video stream – then the converter box, tuner, satellite receiver, etc. places them back on line 21.

Both 608 and 708 captions will have to coexist until analog televisions with converters no longer exist – or until the FCC decides that 608 is no longer necessary.

For more information on captioning for the deaf and enhanced audio for the blind contact at the North Carolina Center for Children’s Healthcare Improvement.

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