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Discussion Starter · #1 ·
Does anyone have information if ATSC HDTV signals have Closed Captioning (CC) info?


Shows that have CC in standard definition do not have them on 1080i HD channels on my TV - is that because CC does not exist in HDTV or because my STB ot TV cannot process CC in HD?
 

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Good question!

Hopefully some good answers will come forth here.


In the analog world, closed-captioning is sent as data, on video line 21 of each field. In digital, there is no line 21. The first 22 or so lines of the 262.5 that make up a field are in the "blanking" or non-picture area of the video. That's why 525-line NTSC video equates to 480-line digital....about 480 lines carry the picture.


The digital TV standards have a place to carry CC, as packets of data....not riding within the video signal. I'm not sure if the STBs can all decode this into actual "on screen" text. Maybe someone from a manufacturer is reading this and can answer.


We are also looking for a means to convert the CC packets into an actual line-21 data that can be read on a regular TV or SDTV monitor, since our SDTV channel is being rebroadcast on translator and cable TV.
 

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You may want to do a search on the forum rather than rely on my short memory. This topic has come up some, but has never received much attention. As I recall, there have been reports of some STBs having the capability to decode ATSC text captioning (the Dish 6000 is NOT one of them, BTW) from a few sources that are including the data stream in broadcast.


Gerald C
 

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Quote:
Originally posted by kenglish
Hopefully some good answers will come forth here.
Ken, see this quote from a fellow broadcaster on the forum:

Quote:
Originally posted by bdfox18doe on 04-19-02


The RCA DTC100 and the Samsung SIRt150 (with V1.8) work with DTv captioning, IF the local stations are translating it into their dtv signal.

Call your local stations, and ask the engineers if they are translating the

analog captions via 608. It's fairly easy to do, and not that expensive.

We support it here on both HD and SD channels. The legal requirement

for DTV CC compliance is July 2002.


__________________

Regards,

Bob Davis, DOE

WCCB-Fox18/WCCB-DT27
Gerald C
 

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The RCA DTC-100 and most of the new 'APG enabled' DirecTV tuners will decode HD or SD digital captions if the station is sending them out. For HD services it usually takes a separate piece of equipment to capture them from the station's analog signal and translate them into the DTV caption standard then feed them to the HDTV encoder. Many SD encoders can pluck them out of the analog video and properly encode them for digital transmission.


Note that as of July 1, 2002 DTV stations are supposed to be able to pass through captions if they are contained in the program. However, many stations do not have the transcoder for HD captions and many other don't know how to enable them for SD services. DTV encoder manufacturers are terrible when it comes to documentation and recommended practices.
 

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Lee-


It's interesting that there's an FCC deadline for broadcast of CC, but there doesn't seem to be a mandate to include CC capability in ATSC STBs (as there currently is for analog sets > x in. Anyone know more details? In particular, why the Dish 6000 is non-compliant?


Gerald C
 

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Thanks Guys....


Going in to the TheSys PSIP generator and creating multiple program titles (just called them "SDTV Simulcast") then tagging them with Closed-Caption descriptors, has now turned on CC to the many thousands of homes in Southern Utah which receive our SDTV signal via analog translator, as well as all the digital viewers.


Good thread going here.
 

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Discussion Starter · #8 ·
On top of CC, there are other data signals I am not sure HDTV will take care of.


For example, my TV set can adjust time based on local PBS broadcast - is it going to be there in ATSC HDTV as well?


Is teletext (dominant in Europe) going to be supported?


Are interactive services like news going to be there one day (Scientific Atlanta Exporer users, hit blue Select button while on cnn and you'll get interactive news ticker on screen).
 

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The STT (System Time Table) in the PSIP of each DTV station contains current time info. But, the scary part is...."each". Every station's clock here in SLC is different! So, the STB is using the clock from whatever DTV station it last looked at, either programming or just to momentarily update the EPG (Electronic Program Guides).


Don't know about Teletext...it's comparable to data services, which are allowed. Probably would use a different box, though. WOW-TV is one type of service.


Lee....

Have you tried putting the analog station's program guide into the DTV PSIP? I just did, and it seems to work! (May be another good excuse for us to get Trib Media data inputted each week.)
 

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Ken, we declare the analog channel in the VCT using PSIP as well, that

way we have EPG for the analog , using the RCA DTC100. Works Well.That is now recommended practice for broadcasters.


With the RCA DTC100, if a timer is set for record on one channel, but the STB is on another with the incorrect STT, then the recording is wrong.

We use the Adrienne Electronics Time code card in the PSIP PC to slave

the STT to house timecode. Works very well, and auto corrects for DST.

Less than $500...
 

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Ken, Bob,


Yes. We have 'declared' the analog service in our PSIP stream since day-one and it properly shows up (call sign, etc) in the guide info on those units able to process it. We also include PSIP program info for the analog channel (6-0) in the stream and any unit able to use it (primarily the DTC-100) properly displays the program information (EIT and ETT data).


To keep the (STT) time correct I am running 'Dimension 4' (a freeware program) to sync the Triveni PSIP computer system to NBS Internet time hourly. The correction is usually much less than 1 second. You can probably run it on any PSIP source computer system with Internet access.


Gerald,


The FCC DTV Caption mandate DOES include a requirement for receiver, tuners (STBs) and PC cards to be able to decode DTV captions sold after July 1, 2002. I suspect this has been overlooked in the consumer electronics side as much as the requirement for broadcasters to pass them has been on the broadcaster side.
 

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Quote:
Originally posted by Lee Wood
The FCC DTV Caption mandate DOES include a requirement for receiver, tuners (STBs) and PC cards to be able to decode DTV captions sold after July 1, 2002...
So does this mean that the Dish 6000 is going to be discontinued on July 1? :)


Is there a grandfathering clause for units/models already on the market? Or maybe we're due a software update. Here's to hoping!


Gerald C
 

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Discussion Starter · #13 ·
I talked to tech support at my cable provider (Rogers) and they said CC is not currently possible on their HD channels...
 

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HBO-HD does provide close captioning if you receive it

directly from C-Band via 4DTV and the HDD-200.
 

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Now if HBO could only get CC working on DirecTV..


Lee, thanks for the Dimension 4 tip..will go a looking..Using Thales' Pearl

PSIP here..:)
 
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