[mythtv-users] *huge* difference in picture quality..

papenfuss at juneau.me.vt.edu papenfuss at juneau.me.vt.edu
Wed May 26 15:43:40 EDT 2004


> So, I did a little more research, and it appears S-Video (or "Y/C") is
> somewhere between component (or "Y/Cr/Cb") video and composite video.
> So you should see substantial increase in video quality from composite
> to S-Video.
> 
	Not completely true.  Most of the difference between composite and 
s-video is the better color separation.  In composite signal it is difficult to 
completely separate the C (with its two sub-parts Cr/Cb) from the luminance 
(Y) and you get interference artifacts.  I classical example would be a 
weatherman with a fine mesh checkerboard-patterned black&white tie.  It will 
have funky rainbow banding colors of red/yellow/etc because of cross-talk 
between the Y/C channels on the same wire.  As far as resolution, there is 
very little/no difference, and *no* difference in refresh, etc.  

	With RF-modulated signal (a.k.a "Coax") (by definition composite),
there's typically some more bandwidth reduction that occurs in the cheap
modulators.  Also, some phase distortion resulting in color skewing reduces 
quality.  Not insignificant would be the simple SNR decrease in mixing up and 
mixing back down.

-Cory

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