Originally Posted by sneals2000
I think that it is the TV station that decides whether the captions are 608, 708 or both, rather than the source of the show. In other words the delivered video tape of the show (or the file if it has been syndicated by a non-tape method?) contains the captions in a format that can be coded as 608 or 708 - or both?
The broadcaster remains responsible for the captioning, but both types of captions are required. I'd think that syndicated shows would come with at least the native captions that had been generated for the program, and possibly both might be present.
Page 4 of "Implementing Closed Captions"
(mentioned earlier) discusses recording DTVCC data. It sounds that it's possible to record and playback DTVCCs by using video servers and separate files for the captions. (However, since I don't have sufficient background in this area, I don't understand the terminology and thus the document fully.)
Here's a question for the engineers on this thread:
The "Law and Order" series were created for one network, NBC, but are frequently syndicated to other networks. "Stargate Atlantis" was produced for the Sci-Fi HD channel but is being shown now on Fox channels. Both seem to have a problem with standard digital captions on my local channels since my Sharp HDTV can't display captions for those reruns on the digital channel, although the CECBs *are* able to display captions. Why would the Sharp HDTV have problems displaying any captions for such programs on the digital channels, while the CECB can display digital captions?
(If I were to complain to the stations involved that my HDTV can't see captions from their digital broadcasts even though a CECB can, they're likely just to tell me I have a problem with my HDTV, even though it can decode digital captions for prime-time programming from most channels. It's curious that the inexpensive but newer CECB can do a better job deciphering some digital captions than my 2006 HDTV can---but it seems the TV stations ought to be broadcasting digital captions in a way that's compatible with all HDTVs manufactured after July 1, 2002.)
So your 708 captions are open-captioned and burned into the recordings, but ATSC 608 captions are not burned in and carried in blanking, recorded, and decoded by your TV and not your CECB?
I don't have to turn on the 708 captions from the CECB, but if I want open-captioned recordings, I'll activate the 708 captions so the video images of them will be recorded. (There's a completely separate process to burn in open captions for films used in movie theaters that really does burn in the captions, creating openings for white light from the projector to shine through, so I think it's best to avoid using the term "burning" for 708 captions created by CECBs.)
I could choose to burn in the ATSC 608 captions if I wanted to, because the CECBs I've tested so far can decode ATSC 608 data as well as 708 data. (I don't like the look of the 608 captions decoded by the CECBs I've tested, however, so I'd choose better 708 captions instead.)
Now here's a kicker....
I can see two kinds of 608 captions at once via the CECB (the ones decoded by the CECB and the ones decoded by the TV.) The decoding of the ATSC 608 data by the CECB clearly doesn't prevent the same data from being converted into Line 21 captions and getting decoded by the analog TV.
Likewise, decoding the 708 captions on the CECB doesn't prevent my analog TV from decoding the line 21 captions that are still being transmitted by the CECB. At times, this phenomenon allows me to see that the 708 captions are significantly out of sync with the 608 captions; I've seen this with reruns of "The Simpsons" and the syndicated "Law and Order" reruns. (The digital captions can be so delayed as to make the program too confusing to watch.)
It's very useful to have a TV that has a CC button on the remote so that it's easier to turn the TV's CCs on or off. Unfortunately, the older TVs don't tend to have that feature.
Is that NTSC analogue channel 20 tuned using an analogue source - or digital channel 20 tuned using a CECB?
In the USA at this time, before the digital transition has taken place, all the analog channels are using the integers, and all the digital channels are represented with decimal points or sometimes dashes. If you see someone talking about 4.1, for example, that's a digital channel. On some remote controls, a button is marked with a dash instead of a period, and to go to a channel directly, one pushes 20 dash 1 to go to channel 20.1.
So at this time in the USA, channel 20 is automatically an analog channel, and 20.1 is automatically a digital channel. After the transition on February 17, 2009, I'd guess that the basic channel number will presumably be used for either the HD digital channel or an SD channel (but I don't know much about that process).
The CECBs are designed to tune only the digital channels (except for the few that can pass through analog channels).
That is a recording made from a CECB tuned to 20.1 connected to the Tivo?
Yep - could be that a local station timeshifting isn't timeshifting the caption data and just the video?
I have no idea! Seems to me there could be problems occuring at a variety of points along the way.