[mythtv-users] Re: Re: Re: Re: VGA to Component on WEGA

[Cory Papenfuss]

 	I have re-read my post for brain farts but haven't found any.  I 
did *not* say/mean that component is worse than s-vid.  I said that s-vid 
is worse than component, but not necessarily by much.  What I was trying 
to emphasize is that the tvout of most video cards (that I've used, 
anyway) tends to blow chunks.  The quality of the s-vid out of these cards 
is often much worse than broadcast *composite*.  They generally 
suffer from horizontal, vertical, deinterlacing, and other temporal 
scaling artifacts and loss of resolution.

 	If you have *good* quality s-video signal, the luminance bandwidth 
can be arbitrarily good, and the chroma bandwidth can be pretty decent 
(although still modulated on the color subcarrier).  I don't know what the 
bandwidth filtering specs are for "standard" Y/C (s-vid)... maybe there 
aren't any.  All YPbPr does for 480i over Y/C is not modulate the chroma 
on the subcarrier.  The biggest improvement is from composite to Y/C, 
since the luma and chroma don't share the same spectrum and can thus be 
allocated a higher bandwidth and less interference with each other.

-Cory

On Fri, 20 May 2005, Neil wrote:

>> OK. I guess I could clarify that. *GOOD* S-vid isn't that much worse than 
>> component. Unfortunately, many of the cards with tvout have such sucky 
>> quality that it's unusable. The homebrew hardware I built to do s-vid from 
>> VGA gives results essentially the same as the component adapter... just 
>> modulated as NTSC. I have long since given up on TVOUT from video cards for 
>> quality reasons. 
>
> Hi Cory, 
> I totally disagree that component is worse than svideo. Below is the order of 
> quality from good to best: 
> 1. composite(1 video and LR audio channels in RCA interface)
> 2. s-video (looks like a PS2)
> 3. rgbhv
> 4. component(YPbPr in RCA interface)
> 5. dvi 
> I think you really meant composite. It's true that s-vid is better than 
> composite. I really can't see any difference between 3, 4 and 5. Quality of 
> the 3 are awesome most especially in HDTV. 
> Here is a good reference:
> http://www.michaeldvd.com.au/Articles/VideoConnectors/VideoConnectors.asp 
> Thanks, 
> Neil
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*************************************************************************
* Cory Papenfuss                                                        *
* Electrical Engineering candidate Ph.D. graduate student               *
* Virginia Polytechnic Institute and State University                   *
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