Thread Subject: Proposal for closed captions & timed text

Note

This archival content is maintained by WebAIM and NCDAE on behalf of TEITAC and the U.S. Access Board . Additional details on the updates to section 508 and section 255 can be found at the Access Board web site.

From: Schomburg, Paul
Date: Tue, Aug 28 2007 9:10 AM

Folks: Here is a proposal to provide clarity the requirements for (1)
other digital video source devices, and (2) personal video display
devices. We look forward to discussing this on today's call.



Best regards, Paul



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3. Equipment of this type...

Other digital video source products without broadcast reception
capability, such as playback products for removable media (e.g. optical
disc, tape, flash memory, etc.), IP-enabled playback products for
downloaded or streaming video content, and media player software, that
is procured for the purpose of displaying video on a DTV display or
monitor with a screen size greater than 13 inches.



Uses this standard...

CEA 708 or timed text with functionality equivalent [or comparable] to
CEA-708 (see end-note for definition of functional equivalent)



To provide these functions:

- Pass CEA-708 caption data, when available, to the caption
decoding circuitry of DTV displays

OR

- Decode caption data or timed text, when available, and pass
a decoded ("open-captioned") video signal to the DTV display or monitor.




4. Equipment of this type...

Personal video display products without broadcast reception capability
with an integrated display less than 13 inches. [Examples: Portable
DVD players, Apple iPods, cell phones, etc."]



Uses this standard...

CEA 708 or timed text with functionality equivalent [or comparable] to
CEA 708 (see end-note for definition of functional equivalent)



To provide these functions...

- Decode caption data or timed text, when available, for
viewing on the integrated display unless not readily achievable.

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Rationale: It appropriate to leave the decision to the government
agency as to the type of content and purpose for which the device will
be used.

1. CEA-708 is required for content originally authored for broadcasting
or transmission in an MPEG transport stream. Such content may
thereafter be provided via prerecorded media or downloaded/streamed from
the Internet. Both players of prerecorded media (e.g. DVD, Blu-Ray,
HD-DVD, video tape, etc.) and IP-enabled media players and associated
software will require this capability if they are used to display such
content.

2. Timed text is required for content not authored for broadcasting or
transmission in an MPEG transport stream, but that may be provided via
prerecorded media or downloaded/streamed from the Internet. Such timed
text formats should provide functionality equivalent [or comparable] to
CEA-708 to enable author and/or user control of fonts, background
transparency, and location of text on screen so as to provide the most
accessible viewing experience.



End Note: TEITAC definition of "Functional Equivalent" to CEA 708



Equivalent text display functionalities must:



* support caption placement control by caption authors for any position
within the TV safe area.



* support standard, large, and small caption sizes and must allow the
caption author to choose a size and allow the viewer to choose an
alternative size.



* support eight font variations. Caption authors may specify one of
these eight font styles to be used to write caption text. Equivalents
must include the ability for users to choose among the eight fonts. The
equivalent must display the font chosen by the caption author unless the
user chooses a different font.



* support the eight font styles defined as follows: default
(undefined), monospaced with serifs (similar to Courier), proportionally
spaced with serifs (similar to Times New Roman), monospaced without
serifs (similar to Helvetica Monospaced), proportionally spaced without
serifs (similar to Arial and Swiss), casual font type (similar to Dom
and Impress), cursive font type (similar to Coronet and Marigold), and
small capitals (similar to Engravers Gothic).



* support author and user choice of eight character foreground and eight
character background colors: white, black, red, green, blue, yellow,
magenta and cyan).



* support author and user selection of character and background opacity
options: SOLID, TRANSLUCENT, TRANSPARENT [FLASH option deleted]



* support options for altering the appearance of caption character
edges.



* support the authoring and selection of the six caption services, but
information from only one service need be displayed at a given time.



* include an option that permits a user to choose a setting that will
display captions as intended by the caption provider (a default).
Equivalents must also include an option that allows a viewer's chosen
settings to remain until the viewer chooses to alter these settings,
including during periods when the video source device is powered off.



Multimedia content creation products and/or software must:



* support the creation of equivalent text display functionalities as
listed above



* support interoperability and conversion between other common caption
formats such as CEA 608, CEA 708, and Timed Text (e.g. DFXP).

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