The Mysteries of Close Captioning

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.

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 . .

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.

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.

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.

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

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

Look for signs of multipath reception. Ghosting.

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).