Closed Captioning

Types of Captioning

Subtitling

Most Captioning Is Closed

Closed captioning is most common because it's required by law in the United States.  It is also the most inflexible form of captioning.

The features of traditional closed captioning are:

• Monospaced characters
• Limited set of characters
• Viewer's TV decoder draws characters on the screen
• Viewer can turn captions on and off
• Black background
• 32 characters per line
• 15 lines in image area (safe title)

Viewers can select from four channels of closed captioning.  English captions on one channel and Spanish captions on the other, for example.

However, traditional closed captioning has very limited foreign language support.  Some accented characters used in French or Spanish are not available except on high definition video.

Closed captions are quite readable, however.  Which explains why they're so popular even among fully hearing people in gyms, waiting rooms, and in taverns.

AutoCaption II has a full range of tools for closed captioning.  What's even more important is that AutoCaption lets you can switch easily from closed captioning to subtitling projects and back again.

Yes, AutoCaption II will make closed caption files for many DVD authoring packages.

Captions are said to be closed when special electronics are necessary to make the captions visible.  This distinction is becoming blurred because DVD players let the user select from 32 channels of otherwise invisible subtitling.  Ironically, most DVD players will not decode traditional closed captions.

More about closed captioning guidelines in a PDF file from The Captioned Media Program of the National Association of the Deaf.  We think these are the most objective and non-commercial guidelines.

The popularity of and demand for closed captioning probably stems from a government requirement that practically all television sets offered for sale in the United States after July 1, 1993 have built-in closed caption decoders (see 47 USC 330) and that programming contain an increasingly higher percentage of captioning (see 47 CFR 79.1).

If you want the real nitty-gritty on the analog protocol and the traditional closed caption character set endorsed by the United States Government, take a look at 47 CFR 15.119 published in 2001 for analog signal information (Text version, PDF version has tables) or 47 CFR 15.122 for digital signal information (Text version, PDF version has tables).

Other sources of information about deaf issues, captioning history, and opinion are available from countless commercial, educational, and advocacy enterprises such as: the National Captioning Institute, WGBH affiliated organizations, Gary Robson, Rochester Institute of Technology and Gallaudet University.