What does the FCC require of stations with regard to closed captioning?
The core responsibilities of television broadcasters are defined by the FCC. On July 31, 2000, the FCC issued a Report and Order (R&O) in ET Docket No. 99-254 regarding DTV Closed Captions (DTVCC). The R&O amended Part 15 of the FCC Rules, adopting technical standards for the display of closed captions on digital television receivers. It also amended Part 79 to require all captions to be passed through program distribution facilities and reflect the changes in Part 15. The R&O also clarified the compliance date for including closed captions in digital programming.For the deaf and hard-of-hearing (D/HofH), captioning is a lifeline to information and entertainment; it is - in fact - an important part of life for millions of Americans. Captioning gives viewers access to a world of programming that - without this feature - would not be possible. Hearing loss is one of the most common disabilities, with about 28 million D/HofH people in the U.S. - about 10 percent of the total population.
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What specific benefits can digital television bring to closed captioning services?
One of the benefits of DTV captioning is that the display of captioning information can be customized to user needs. Features such as altering the size, color, and type of the font used for display-necessary for certain age groups-are all possible with digital systems.
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What are some of the specific requirements of ET Docket 99-254?
The R&O; adopted Section 9 of CEA-708-B, which specifies the methods for encoding, delivery, and display of DTVCC. Section 9 recommends a minimum set of display and performance standards for DTVCC decoders. However, based on comments filed by numerous consumer advocacy groups, the FCC decided to require DTV receivers to support display features beyond those contained in Section 9. In addition, the FCC incorporated by reference the remaining sections of CEA-708-B into its rules for informational purposes.
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What requirements were placed on consumer electronics manufacturers by the FCC in the DTVCC R&O?
Receiver manufacturers must begin to include DTVCC functionality in DTV devices manufactured as of July 1, 2002. Specifically, 1) all digital television receivers with picture displays in the 4:3 aspect ratio measuring at least 13-in. diagonally, 2) digital television receivers with picture displays in the 16:9 aspect ratio measuring 7.8-in. or larger vertically (this size corresponds to the vertical height of an analog receiver with a 13-in. diagonal display), and 3) all DTV set-top-boxes shipped in interstate commerce or manufactured in the U.S. This rule applies to DTV set-to-boxes whether or not they are marketed with displays.
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What are the DTVCC requirements in the R&O; for program producers and distributors?
The R&O; required programming prepared or formatted for display on digital television receivers before the July 1, 2002, date that digital television decoders are required to be included in digital television devices be considered "pre-rule" programming (as defined in the FCC's existing the closed captioning rules). Therefore, programming prepared or formatted for display on digital television after that date will be considered new programming. The existing rules require an increasing amount of captioned new programming over a multi-year transition period with 100 percent of all new non-exempt programming required to be captioned by January 1, 2006. This means that as of July 1, 2002, DTV services have the same hourly captioning requirement as NTSC services. The average amount required per day in 2002 is nearly 10 hrs (900 hrs/quarter). Those stations operating for part of a quarter are expected to meet the prorated or average daily amount.
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How can television stations originate DTVCC programming?
There are four ways that stations can originate DTV programming with closed captions. First, if programming arrives with DTV captions arrive already formatted and embedded in an MPEG-2 video stream or embedded in, or associated with, a baseband video stream, then the broadcaster is required to insure they are passed through and transmitted to receivers. Second, if the DTV program is being up-converted from an NTSC source, then the caption data in the NTSC program must be translated into CEA-708B format captions using CC types 10 and 11; the NTSC line 21 caption data must also be transcoded and broadcast with the DTV program using CC types 00 or 01 (also known as the 608 compatibility bytes). Third, if the program is locally originated (and not exempt) and captions are being locally created but are not in DTVCC, then again they must be translated into CEA-708B format captions and also carried as 608 compatibility bytes. Fourth, if the program is locally originated (and not exempt) and captions are being locally created as DTVCC, these must comprise the CEA-708B format captions and also 608 compatibility bytes.
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What are "native 608" closed captions?
CEA-608 ("native 608") closed captions are captions formatted and presented in the current analog television system and carried on the two fields of line 21 of the vertical blanking interval. Field one contains CC1, CC2, T1, and T2 (the latter being text services). Field 2 contains CC3, CC4, T3, and T4. CC1 is most often used to carry verbatim English captions and CC3 is increasingly being used for Spanish-language captions and captions edited for young children ("Easy Reader" or "Beginning Reader" captions). The common look and feel of native 608 captions is limited to white block letters within a box-like black background field. Color (non-white) characters, while possible, are only occasionally used due to the 13-year legacy of set-top decoders which cannot display colored captions.
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What are "native 708" closed captions?
CEA-708B is the standard for conveying caption data in a digital television signal. Because the DTV signal does not have a vertical blanking interval, CEA-708B specifies that the captioning data shall be carried in the video user bits of the MPEG-2 bitstream. CEA-708B captions have greatly enhanced formatting and display capabilities compared to NTSC 608 captions. Strictly speaking, native 708 captions are those authored and encoded for CEA-708B use. It is also possible to encode native 708 format captioning from authoring information intended for 608 captioning, although such captions will have the same limitations as translated captions (see below).
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What are "translated" closed captions?
Translated or "upconverted" 708 captions are DTV captions that originated as NTSC 608 format captions. The translation device uses the original NTSC line 21 caption data and generates CEA-708B format captions. These translated 608 captions maintain the look and feel of traditional analog captions although there is no standard specification for the translation method and the look of the resulting captions may be manufacturer-specific. It is also possible for a viewer with a 708 caption decoder to over-ride the transmitted settings such as font size, color and background. The translation occurs at the origination point of video program distribution, not in any form of digital set-top box or receiver.
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Is it possible to upconvert 608 captions to 708 data?
Yes; it is possible to upconvert 608 caption data to true 708 format-in effect using the original 608 data as source material and employing a limited set of CEA-708 features to present the captions to an CEA-708 decoder. These upconverted 608 captions also maintain the look and feel of traditional analog captions, but are presented and decoded using the true digital construct. This up-conversion occurs at the origination point of video program distribution, not in any form of digital set-top box or receiver.
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Is it possible to downconvert 708 captions to the 608 format?
There is no standard way to downconvert 708 captions, and there are many features of 708 captions that are not supported in the 608 format.
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Where can I get additional information on closed captioning?
For additional information on closed captioning, consider the following resources:
Technical Papers and Presentations on DTV Closed Captioning
The following documents provide detailed information on closed captioning for digital television:
 Implementing Closed Captioning for DTV This presentation was given by Graham Jones (NAB) at the 2004 NAB Broadcast Engineering Conference. The paper provides a thorough discussion of DTV CC requirements and practices.
PowerPoint Presentation on CC Implementation This detailed presentation provides supporting graphics to the NAB BEC paper above.
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