[mythtv-users] VGA to Component adaptors
Tom Lichti
tom at redpepperracing.com
Thu Apr 28 14:00:16 UTC 2005
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
More information about the mythtv-users
mailing list