Capture 504 lines

[jmac698]

Hi,
Wondering if anyone knows a way to capture all lines of video, including VBI area.
I see someone who's done it, but hasn't released the code:
http://aarongiles.com/?p=238
Also someone who made an oscilloscope but I can't record it:
http://www.nomadelectronics.com/Vidcap/DirectShow/VBIScope/VBIScope.aspx

I guess I can connect the dump filter to the vbi output pin, but I'm not sure which lines it records?

There's a few uses for this. There's a filter to parse a video clip with CC data and save to a text file. Laser discs put their frame number in line 17. Intercast uses 10 lines of VBI to send web pages at 10kb/s. I have some old VHS tapes with intercast data on them. I'd also want to record some of the real 486 line video I have.
It would be a great archive format, that is 504 line video. Game emulators really need this for some laserdisc games.

[Ghitulescu]

I think 8x8 can be reprogrammed to output the whole 625 lines.

[pandy]

I think 8x8 can be reprogrammed to output the whole 625 lines.

And i think that DSCaler offer some limited code support for this non-standard capture (however DScaler is very old and i think no longer maintained project - what a pity)

[Ghitulescu]

From a linux project
Gunther Mayer's bttv card gallery (graphical version of this text file :-) is available at: http://mayerg.gmxhome.de/bttv/bttv-gallery.html


Suppported cards:
Bt848/Bt848a/Bt849/Bt878/Bt879 cards
------------------------------------

All cards with Bt848/Bt848a/Bt849/Bt878/Bt879 and normal Composite/S-VHS inputs are supported. Teletext and Intercast support (PAL only) for ALL cards via VBI sample decoding in software.

Some cards with additional multiplexing of inputs or other additional fancy chips are only partially supported (unless specifications by the card manufacturer are given). When a card is listed here it isn't necessarily fully supported.

All other cards only differ by additional components as tuners, sound decoders, EEPROMs, teletext decoders ...


Unsupported Cards:
------------------

Cards with Zoran (ZR) or Philips (SAA) or ISA are not supported by this driver.
........

[kieranrk]

You can probably do it with the Blackmagic tools since the API allows extraction of VBI lines from SDI. Presumably that will work for analogue as well.

[jmac698]

From what I read, cards had to support reading whole VBI area because of the Intel Intercast initiative, it was required for logo certification. So there should be a lot of cards which do this through Directshow, no special driver or hacks needed. It should be fairly simple to code and I might have to try it if there's no alternative. I'll take a look at these Blackmagic tools.
Things like bttool might let me tweak the registers directly, I'd love to play with that.
Oops, I searched the entire SDK documentation and no mentioned of VBI or Closed Caption :(

[jmac698]

Yay! I managed to do it. You can make a filter graph and dump from the VBI output pin. You get 11 lines of video, luma only. In my case there were 1700 samples per line with a sample rate of 28.6363MHz. You get the bottom then the top field (I assume). It's easy to read with rawreader. I can read 59.365uS of the line, starting soon after hsync. Haven't quite worked out where I am in each line. I can see a line21 signal with 7 pulses at the start.

[jmac698]

You can sort of view it like this, I found rawreader and rawsource unstable. Maybe it's 2.6mt?

rawsource(dir+"vbi.y8",1700,12,"Y8")
bilinearresize(1700/2,10)
pointresize(1700/2,100)

[GrofLuigi]

Coming late to the party, but maybe VBI View (http://pctuner.ru/page-al-vbi_view.html) can be of some use? The page is in Russian, but it has source code and few English comments inside it...

Also, something similar (http://sourceforge.net/projects/vbi-tools) that I don't know what it is... :eek:

:helpful:

GL