[mythtv-users] VGA to Component adaptors

[Joshua Ebel]

Don't want to get lost on a tangent here of asking if every cable on the
Internet works but... it was only $4.86 on: 

http://www.nugadgets.com/products/ProductDetails/4.1294.1.html

The product description on Steren's site 'says' it will do SVGA RGB to (Y,
Pr, Pb), (Y, Cr, Cb) standards and RGB high resolution standards. I opted
for the RCA 5 connector model to connect to my Mitsubishi HD that has the
RGBHV ports on it's DTV input.

Avsforums said some people are using this cable but some users mentioned
that the color is a little better with a different more expensive brand.

http://200.78.227.133/
Steren 253-606IV 6´ Python HDTV SVGA to 5 RCA

Python™ HDTV SVGA Component Video Cables
Unparalleled Quality and Performance for
High-Definition Video and Audio Equipment
Fully support (Y, Pr, Pb), (Y, Cr, Cb) and
RGB high resolution standards
Precision 75½ Impedance for Max. Signal Transfer
EMI-RFI Protected Double High-Density Aluminum Shield
100% 0.12mm Aluminum-Polyester Foil Shield
3 Mini-Coax 95% Copper-Braid Shielded Conductors
95% Spiral-Wound-Shield H/V Sync Conductors
99.99% Pure Oxygen-Free Copper Wire
Bundled Cable Configuration
Ultra-Flex Satin-Ivory Rubber 13mm OD PVC Jacket
Low-Attenuation Foamed Cellular Dielectric
24K Gold-Plated Heavy Duty Connectors
Color-Coded – Fully Molded Construction

Here is a link to a homebrew from a previous post on mythtv-users. He has
the same TV as I:
http://restricted.dyndns.org/hookingpc2hdtv.html
[Pic of what my ports look like]
http://restricted.dyndns.org/rgbhvport.jpgw

Hope this works for me. If you know any reasons it shouldn't work please let
me know.

Thanks,

-Joshua Ebel
joshebel at gmail.com


-----Original Message-----
From: mythtv-users-bounces at mythtv.org
[mailto:mythtv-users-bounces at mythtv.org] On Behalf Of Cory Papenfuss
Sent: Thursday, April 28, 2005 6:57 AM
To: Tom Lichti
Cc: Discussion about mythtv
Subject: Re: [mythtv-users] VGA to Component adaptors

> I just found this cable: 
>
http://www.tigerdirect.ca/applications/SearchTools/item-details.asp?EdpNo=17
3735&CatId=0
>
> Do you think there is any chance it would work out of the box? I'm
thinking 
> no, but it's almost worth trying. Could I hurt anything by using it?
>
> Thanks
> Tom

 	Look at the fine print on the bottom:
"Note: Your video source must provide a YPbPr component video signal from 
the HD15 port to use this cable."

 	That cable is no different from BNC breakout cables that provide 
RGBHV... just that it has RCA ends on it and relies on the Green signal to 
be the Y (and have composite sync on it).  I did a little 'net research 
this morning and concluded the following:

- EIA 770.1 and 770.2 define 480i and 480p analog component signals.  I'm 
pretty sure that they allow unipolar sync signals like standard video.
- EIA 770.3 (and SMPTE-274M) define HDTV analog component.  Colorspace is 
*slightly* different, and the sync is definately defined to be bipolar.

 	Basically, you could use one of those cables to get component out 
of RGB if it'll do sync on green.  Most vid cards that do sync on green 
are unipolar, I think, so it'd be abusing the spec.  It might work on some 
TV's and not others.

 	What you really want is a vid card that is smart enough to tell 
the computer it's doing Xv colorspace transformation, to get the YUV 
data... then not actually do it and barf out the YPbPr the three DACs. 
The sync should also be correct.

 	In other words... not likely.

*************************************************************************
* Cory Papenfuss                                                        *
* Electrical Engineering candidate Ph.D. graduate student               *
* Virginia Polytechnic Institute and State University                   *
*************************************************************************