Newsgroups: sci.electronics.misc
Subject: Re: Convert DVI-I analog signals to Component Video?
References: 
Leland Hosford  writes:

> Hi,
> 
> I've recently installed an ATI video card on my computer that outputs
> video with a DVI-I connector. It came with a DVI-I to VGA adapter. Since
> a pricy DVI-I capable flat panel TV is not anywhere near being in my
> budget,  lately I've been wondering if I have any other options. I
> notice from looking at the pinout of the DVI-I connector ( see the DVI
> connector pinout at http://www.nti1.com/technote.html#dvi ) that, in
> addition to the digital signals, it also includes analog video signals
> (C1=analog red, C2=analog green, C3=analog blue, C4=analog horiz sync,
> C5=analog ground). 

Those are those signals that this DVI-I to VGA adapter most
propably just wires to the VGA connector output.

> My current television accepts Component Video (red,
> green, blue) signals (output by most DVD players) which is a higher
> quality input than S-video. I would really like to be able to take the
> analog video signals output on my video card's DVI-I connector and have
> them converted such that they could be fed into the Component Video of
> my television. But I have no idea how difficult that would be. I've
> looked for adapters that do this but haven't yet found any.
> 
> So, is there anyone who knows enough to answer any of the following
> questions:
> 
> 1) What are the differences between Component Video (red, green, blue)
> and the analog video signals in a DVI-I connector (analog red, analog
> green, analog blue, analog horiz sync, analog ground)? Or, where I would
> find specifications for those two signal types.

Check the following web pages:
http://www.hut.fi/Misc/Electronics/circuits/vga2tv/
http://www.epanorama.net/documents/vga2rgb/index.html

> 2) Is it possible to convert the analog video signals in a DVI-I
> connector (analog red, analog green, analog blue, analog horiz sync,
> analog ground) to Component Video (red, green, blue)?

It is technically possible. Not particularly easy though.

> 3) Does anyone currently market such a converter?

There are external VGA to TV converters on the market.
Some have RGB output suitable for TV also. Quality
and prices vary greatly. I have no special recommendation
for a device to buy.
 
> Thanks,
> Leland Hosford
> 
> To send me e-mail remove "NOT!" both times it occurs. Sorry for the
> inconvenience; I'm trying to avoid letting the spammers know my address.

-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/