Date   : Mon, 03 Aug 2009 17:52:11 +0100
From   : jgh@... (Jonathan Graham Harston)
Subject: Fw: Fwd: ITV Teletext to shut down in January

Philip Pemberton wrote:
> Jonathan Graham Harston wrote:
> > Porbably not. Probably need at least 42 bytes of buffer RAM and
> > read it from there at your leisure.
> 
> And the rest. You're assuming that the TTX signal is a single line per
> frame (or field in the case of interlaced video).
 
No I'm assuming you read the line of data, and once you've read it
you allow the receiver to collect another line. Depending on the
transfer speed you'd probably be able to collect every second data
line per frame and collect the others on the next frame.
 
> IIRC the BBC/IBA/BREMA spec says three lines, and the EBU spec says
> four. Unfortunately I don't have either to hand at the moment, and it's
 
And the stadard doesn't disallow you from using all 625 lines to
carry data. That's how we transmitted stock market data in Hong
Kong, and I believe that a UK bookmakers transmitted full-frame
data over the airwaves with race results and stuff to branch
bookies.
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
A Review of Sheffield City Council's Members' Allowances Scheme
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