S-VIDEO TO COMPOSITE CABLE

Archived from groups: alt.video.laserdisc (More info?)

On 13 Jul 2004 12:57:26 -0700, shower_urinator@lycos.com (shower
urinator) wrote:

>Could one benifit from connecting an s-video to composite cable from
>the s-video output on a laserdisc player to the composite input on a
>television? This would cause the signal to pass through the laserdisc
>player comb filter as well as the television comb filter.


Hehe, no,because mixing the chroma and luminace back together gets you
back where you started, and with poorer results since the original
broadcast-standard coherent composite signal has been screwed up by
the comb filter. And you can't "daisy-chain" comb filters, it has to
work with the original coherent signal, one pass only.


"Coherent" means the colour burst and colour phase are locked at a
specific timing and phase in relation to the horizontal sync. All
laserdisc players put out a coherent signal. A VHS machine without TBC
puts out non-coherent video, the colour burst is completely random and
changing in phase to the horizontal. Comb filters CAN separate the
chroma and luminance to some degree from such a signal, but the
results are still unstable.

.. Steve ..