The Mysteries of Close Captioning

[Ron]

I know how close captioning is done,
but why does some networks (meaning
CBS)has such bad captioning where
words are dropped and letters are
replaced by funny symbols?

Ron

 

[Mike Berger]

That's usually caused by a weak signal or poor reception.

 

[Sarah]

I know how close captioning is done,
but why does some networks (meaning
CBS)has such bad captioning where
words are dropped and letters are
replaced by funny symbols?

Ron

sometimes cause they put in new equipment or need to change the old
equipment, & don't know that this happens with the captions....so I
email and let them know this & they correct it.

 

[[email protected]]

Ron:
It could be a problem at CBS or more than likely it could be a marginal
signal to your television... or could be a marginal CC decoder in your
tv....
Try a different TV in the same location then at a different location or
a friend's TV at his home to see if you get the same results... post
what you find out.
electricitym
..
..

 

[[email protected]]

CC is encoded in the vertical blanking interval, isn't it?

If you are watching a digital cable channel, or a broadcast of a
digital feed, then is it possible that the errors can result from the
CC information being decoded and encoded over and over?

I am assuming this because digital video does not concern itself with
any part of the signal that is outside the visible screen. So if the
signal is ever digital, the CC data has to be decoded, stored as part
of the digital stream, and then encoded again when it's translated back
to analog. It could happen at your digital cable receiver, and/or at
the cable station, and/or at a broadcast facility that's getting a
digital satellite feed.

 

[Dave Plowman (News)]

I know how close captioning is done, but why does some networks (meaning
CBS)has such bad captioning where words are dropped and letters are
replaced by funny symbols?

Think this is Teletext in UK terms.

Classic symptoms of poor signal level or multipath reception. Look for
ghosting or noise on the main picture.

 

[Andrew Rossmann]

I know how close captioning is done,
but why does some networks (meaning
CBS)has such bad captioning where
words are dropped and letters are
replaced by funny symbols?

CC (and other data like TEXT and XDS) information is encoded just
above the very top of the picture. Sometimes, especially with HD TV's,
you might see it as some thin lines moving around side to side. Any
noise or distortion up there can scramble the CC. If you could get a
very old TV with vertical hold, you might be able to scroll it down to
see.

 

[Alex Bird]

Think this is Teletext in UK terms.

To be pedantic, it's just page 888 of teletext really.

I think it's more robust, e.g. you can record it on VHS, but it has to
break somewhere...

Alex

 

[Ron]

Actually the signal is quite strong, and of the two televisions
that are CC equipped, both of them pick of CBS' signal and
show really bad captioning.

Ron

 

[Dave Plowman (News)]

Actually the signal is quite strong, and of the two televisions
that are CC equipped, both of them pick of CBS' signal and
show really bad captioning.

Look for signs of multipath reception. Ghosting.

 

[clifto]

[email protected] says...

CC (and other data like TEXT and XDS) information is encoded just
above the very top of the picture. Sometimes, especially with HD TV's,
you might see it as some thin lines moving around side to side. Any
noise or distortion up there can scramble the CC.

I have a two-year-old Toshiba 32A62 that gets scrambled data on ONLY
ONE channel, cable channel A&E. A cheap Symphonic next to it, working
from the same RF feed, gets perfect CC data on that same channel. On
all other channels, when there's any garbling both sets will show
identical garbling. So I have my doubts about the implementation of
CC on some sets.

CC can be very amusing! Commercials that say (repeatedly refreshed),
"Sample caption data goes here". Program edits in commercials that
retain parts of the CC from the program, parts that combine in odd
ways. And it's especially fun when one commercial ends with some
blurb that stays through most of the following commercial and seems
to make fun of it (the data will sit there about twenty seconds if
there's no signal to clear it or supersede it).