Xref: utzoo comp.sys.amiga:36548 comp.sys.amiga.tech:6109
Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!oliveb!amiga!cbmvax!higgin
From: higgin@cbmvax.UUCP (Paul Higginbottom)
Newsgroups: comp.sys.amiga,comp.sys.amiga.tech
Subject: Re: Chaining Genlocks
Message-ID: <7245@cbmvax.UUCP>
Date: 10 Jul 89 12:50:08 GMT
References: <367@cbnewsd.ATT.COM>
Reply-To: higgin@cbmvax.UUCP (Paul Higginbottom)
Organization: Commodore Technology, West Chester, PA
Lines: 38

In article <367@cbnewsd.ATT.COM> jmdavis@cbnewsd.ATT.COM (j.michael.davis) writes:
$Is it possible to chain two genlocks together, RGB out to RGB in?

No Genlock that I am aware of for the Amiga has RGB in.

They are either composite or Y/C input, and composite, Y/C or
RGB (A2300 only) output.

If you can live without RGB, read on...

$The end result is to get live video in between two computer animated
$planes, and to do it cheaply.

Amiga Genlocks overlay computer graphics ON TOP of video.  The only
way I am aware of to get video on top of computer graphics, is with
a chroma key.

$Quite frankly I don't think this is possible, as the genlock attempts
$to synch one of the system clocks to the video frequency and the chained
$to genlock would be trying to synch up the clock of the other genlock.

Chaining Genlocks has been done, since the timing is passed along, but
given the usual functionality of Genlocks on the Amiga, chaining is used
to overlay computer graphics over computer graphics over video.  A company
I work with to produce training videotapes uses this technique.  It allows
titles to overlay animations, over video, for example.  By chaining
Genlocks, one avoids a generation loss to tape.

$Also, i believe the output of the genlock is analog, even though the input
$has digital information associated with it. (Color 0 is determined through
$digital means, not by color comparison.)

If by input you mean the Amiga video, that is correct.  I usually associate
input with the incoming video.

	I hope this clarifies things a little.

	Paul.