[mythtv-users] VGA to Component adaptors

[Tom Lichti]

Cory Papenfuss wrote:
>> I just found this cable: 
>> http://www.tigerdirect.ca/applications/SearchTools/item-details.asp?EdpNo=173735&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."

I saw that, but chose to ignore it... :)

> 
>     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.

I'm glad there are smart guys out there, cause this chair is holding up 
a dummy... :)

Thanks for the info, much appreciated. I think I'm just going to get the 
Crescendo unit, it seems to be the one to get. Now, do I get internal or 
external...I have one free PCI slot...but then I couldn't add another 
tuner...grrr... :)

Tom