Plasma TV and closed caption

[Jim]

I bought a plasma TV (Panasonic) but since it does not have a tuner,
it seems there is no requirement to support closed caption input.
Therefore, I know I can get an external decoder... But was wondering
if anyone has any experience (comments good/bad) with external
decoders and a plasma TV...? I also assume that getting a tuner card
may also include the decoder, but I have read some negative comments
about the Panasonic tuner card.

Also, would be interested in hearing any other ways to get this on my
plasma TV... Like getting software for my computer and feeding the TV
signal through the computer first...

Also, if anyone knows a better newsgroup for this discussion, please
let me know.

While I'm at it, we noticed on our regular TV which has a built-in
encoder, when hitting pause on a videotape, etc., the text goes away.
Sort of defeats the purpose when trying to read closed caption. Are
there some decoders which leave the text on the screen when
pausing...?

Thanks.
Jim

[Michael Liebman]

jm-...@xemaps.com (Jim) wrote in
news:8c655ed5.03022...@posting.google.com:

> But was wondering
> if anyone has any experience (comments good/bad) with external
> decoders and a plasma TV...?

There should be nothing wrong with using an external caption decoder with
any form of monitor. This is a common configuration in a professional
setting. If you purchase a consumer receiver/tuner, from any manufacturer,
it will most likely have a closed caption/XDS decoder. I believe that it is
the receiver component that has the requirement for the line 21 decoder.

> Also, would be interested in hearing any other ways to get this on my
> plasma TV... Like getting software for my computer and feeding the TV
> signal through the computer first...

You should be able to use a TV tuner card that has an NTSC output. However,
the quality may not be what you expect and it may be just as cost effective
to purchase a standalone external receiver.

> While I'm at it, we noticed on our regular TV which has a built-in
> encoder, when hitting pause on a videotape, etc., the text goes away.
> Sort of defeats the purpose when trying to read closed caption.

I wouldn't say it defeats the purpose, since the primary caption
information is intended to improve accessibility to a level equal to that
of baseline accessibility. When you pause a tape, you can hear the last
thing said over and over again.

That said, there are two technical reasons why the caption is not displayed
indefinitely. First, most displays are suseptible to burn in, where an
image displayed for an extended period of time destroys the display so that
you see the image after it is gone. If captions were displayed for an
indefinite period of time, it _might_ damage your display device.

Secondly, a caption decoder has no way of telling if a video tape has been
paused or if the caption information has just gone away. Caption
information is sent as a pattern of alternating white and black stripes,
transmitted in a portion of the picture that is normally not seen by the
viewer. Caption decoders look for a specific preface pattern to flash on
each frame. If the proper pattern is not found in the proper way, the
caption data is invalid and not displayed. When you pause a tape, the
caption information is not being passed to the decoder in a valid way so
the decoder assumes that it should not display anything.

I'm having trouble finding good technical and non-technical information
captioning, but you might want to start with the FCC information at
http://www.fcc.gov/cgb/consumerfacts/closedcaption.html.

HTH,
Michael

--
Michael Liebman
"I sig, therefore I am."

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