How Do you Capture Close Caption Line 21 From A HVR 2250 in Real Time

[rshapiro]

Does anybody know how to capture Close Caption Line 21 from a Hauppauge HVR 2250 in real time without using ccextractor?
I would need graphedit thumbnail pictures plus any programming suggestions and codecs to help me accomplish what I need
to do.

Thanks,

Bob

[usually_quiet]

Closed caption rendering and file writing
http://msdn.microsoft.com/en-us/library/windows/desktop/dd407354(v=vs.85).aspx

This would only allow capturing EIA-608 closed captions as video, not as text. CCExtractor's source code (available at SourceForge) might give you some clues for saving closed captions as text, even if you don't want to use CCExtractor itself.

[rshapiro]

thanks - if you come up with more let me know.
It seems that locating how to accomplish this with the HVR 2250 is somewhat harder then the PVR 500
We are trying to capture this in real time which ccextractor does not allow you to do, but you are correct
there might be some clues as to how to accomplish this.

[usually_quiet]

thanks - if you come up with more let me know.
It seems that locating how to accomplish this with the HVR 2250 is somewhat harder then the PVR 500
We are trying to capture this in real time which ccextractor does not allow you to do, but you are correct
there might be some clues as to how to accomplish this.

If you have not already done so, you might contact CCExtractor's developer, Carlos, to see if there is a way to use CCExtractor to capture in real time.

[rshapiro]

I have contacted with Carlos yesterday he is not aware about capturing close caption in real time.

[Bjs]

Might be worth a look

DVBTextSub ... modified aussie version, write to srt

DV Scheduler

Alsp post 164860 has graphedit info worth reading

[rshapiro]

Thanks we will look into it, hopefully that might be a solution. I was able to capture the close caption from ccextractor, but you have go take each chunk of video data and process it instead of being able to from the live video stream extract the data as it is happening.
If you have any other idea let me know. Bob

[usually_quiet]

Although some people here think teletext and N. American closed captions are highly similar, they are not in fact closely related technologies and it is very doubtful that you will learn much that you can use for N. American closed caption decoding by exploring teletext decoding. The DirectShow filters used and coding will be different for the most part.

[jagabo]

Step 1) Hire programmer with experience in DirectShow and video...

[rshapiro]

usually_quiet - The project we do need both close caption and teletext - I realize there is a difference.
I am working with a programmer who is familiar with DirectShow I am just trying to help him point him down the right direction.
This is a rather complicated project and there is just not a lot of information out there.

[jagabo]

http://nootropicdesign.com/projectlab/2011/03/20/decoding-closed-captioning/
http://www.compendiumarcana.com/vbi/

[rshapiro]

jagobo - Thanks for the help. I have a couple boards here from www.postech.com that also captures just that close text into a .txt file.
What we are doing is attempting to life the close caption text directly from the Hauppauge HVR 2250 board in a live stream. The
data would be chunked in 2 minute chunks. If you have any more ideas let me know.

[cfsmp3]

I have contacted with Carlos yesterday he is not aware about capturing close caption in real time.

Actually I'm not aware of capturing with that card (in real time or not).

Real time closed captioning extraction works fine in CCExtractor using HDHomeRun, for example.

[usually_quiet]

If that is true, then latest US model Silicondust HDHomeRun Dual would be a good test subject for the initial US phase of this project. I know its ATSC/QAM tuners are as good or better than those used in the HVR 2250, and the price is often a little lower. The HDHomeRun Dual has no analog capability but that shouldn't be a problem. There is no point in including analog TV in the initial phase of this project because any remaining low-power analog TV stations that were exempt from the US 2009 analog shutoff are required to either convert or shut down by Sept. 1, 2015. Plus, as low power stations, someone would have to be close to them to receive a usable signal.

[cfsmp3]

If that is true, then latest US model Silicondust HDHomeRun Dual would be a good test subject for the initial US phase of this project.

I use a HDHomeRun personally for CCExtractor development. It works so great I'm not going to consider supporting any other hardware unless someone pays for the effort - it's as simple as that So unless the hardware is already there and there's an excellent reason not to replace it with the very affordable HDHomeRun it's a no-brainer.

http://www.ccextractor.org/using-ccextractor/hdhomerun.html

[usually_quiet]

If that is true, then latest US model Silicondust HDHomeRun Dual would be a good test subject for the initial US phase of this project.

I use a HDHomeRun personally for CCExtractor development. It works so great I'm not going to consider supporting any other hardware unless someone pays for the effort - it's as simple as that So unless the hardware is already there and there's an excellent reason not to replace it with the very affordable HDHomeRun it's a no-brainer.

http://www.ccextractor.org/using-ccextractor/hdhomerun.html

From the linked webpage above:

Starting in version 0.65, CCExtractor can process a stream being delivered via UDP, so there's no need to capture video to a file in order to get the subtitles.

So, you are saying it would be possible to use CCExtractor even with an HVR-2250 (the OP does already have one) if its demodulated MPEG-2 video stream was sent over a network via UDP?

[cfsmp3]

From the linked webpage above:

Starting in version 0.65, CCExtractor can process a stream being delivered via UDP, so there's no need to capture video to a file in order to get the subtitles.

So, you are saying it would be possible to use CCExtractor even with an HVR-2250 (the OP does already have one) if its demodulated MPEG-2 video stream was sent over a network via UDP?

I don't make any claim about any device except the HDHomeRun. It's the only one I've tested.

Others may or may not work. If you try let me know either way

[cfsmp3]

To add to this topic, here's a demo of real time capture:

http://gsocdev.ccextractor.org/~ruslan/view_cc.php?id=1

(note: it will only work for a bit, so if you are interested check it out quickly)

[usually_quiet]

To add to this topic, here's a demo of real time capture:

http://gsocdev.ccextractor.org/~ruslan/view_cc.php?id=1

(note: it will only work for a bit, so if you are interested check it out quickly)

Thanks. That was interesting. I hope the OP and the programmer that he hired for the project will have a chance to view it too.

[jagabo]

I don't get it. You claim to have a programmer that knows DirectShow but he can't figure out how to capture video and store it in 2 minute segments? And further, he can't figure out how to decode the trivial line 21 closed captions? Or in the case of a capture device with a driver that does that for you, he can't figure out how to connect to the caption pin of the driver and spit out text? You obviously need a new programmer.

[usually_quiet]

I don't get it. You claim to have a programmer that knows DirectShow but he can't figure out how to capture video and store it in 2 minute segments? And further, he can't figure out how to decode the trivial line 21 closed captions? Or in the case of a capture device with a driver that does that for you, he can't figure out how to connect to the caption pin of the driver and spit out text? You obviously need a new programmer.

He's processing a digital signal, so they aren't really Line 21 CCs. I tried using the filters in links I posted and they weren't useful. They are for processing analog captures.

I don't think it is likely that even a good programmer will be able to get the closed captions as text using only the DirectShow filters included with the HVR-2250's device drivers.

Windows Media Center can display digital closed captions, but I don't know how they process them. I couldn't get the filters supplied by Microsoft that are available in GraphEdit to do anything with digital closed captions. For what it is worth, VLC uses code borrowed from CCExtractor for closed caption decoding.

[jagabo]

I don't get it. You claim to have a programmer that knows DirectShow but he can't figure out how to capture video and store it in 2 minute segments? And further, he can't figure out how to decode the trivial line 21 closed captions? Or in the case of a capture device with a driver that does that for you, he can't figure out how to connect to the caption pin of the driver and spit out text? You obviously need a new programmer.

He's processing a digital signal, so they aren't really Line 21 CCs.

I don't think the OP has specified what he's capturing. But he has specifically asked for line 21 closed caption decoding. If he's dealing with EIA-708 closed captions from ATSC caps he just has to parse the transport stream. That's what the programmer is for.

[usually_quiet]

I don't think the OP has specified what he's capturing. But he has specifically asked for line 21 closed caption decoding. If he's dealing with EIA-708 closed captions from ATSC caps he just has to parse the transport stream. That's what the programmer is for.

They probably will want to use EIA 608 for ATSC instead, at least to start with, since there is code for it available that the programmer can borrow from. EIA-708 is apparently not trivial to deal with. Carlos, CCExtractor's developer, has been working on that for a while now.

[jagabo]

Sorry, that was a typo. I meant EIA-608.

[cfsmp3]

EIA-708 is apparently not trivial to deal with. Carlos, CCExtractor's developer, has been working on that for a while now.

Nah, I started it a long time ago but I've never bother to finish it. Reasons

1) The extra stuff in EIA-708 (such as font size, windows, etc) cannot be exported to plain text.
2) If you strip all that stuff then you get the same output as when processing EIA-608
3) All broadcasts (that I know of) come with EIA-608
4) Most broadcasts just export the EIA-608 data to EIA-708 anyway

So as you can see the motivation to finish EIA-708 support is not there. It doesn't buy me (personally) anything. Why bother?

If any company needs it I'm available for hire. But I'm not going to do it on my own time, at least until I have a reason to do it.

Or of course, if someone feels like sending me a patch I'll be happy to integrate it