Path: utzoo!utgpu!watserv1!maytag!xenitec!lemsys!clemon
From: clemon@lemsys.UUCP (Craig Lemon)
Newsgroups: comp.sys.amiga
Subject: Re: Commodore De-interlacer
Message-ID: <3766.658255715@lemsys.UUCP>
Date: Sat Nov 10 10:48:35 1990
Followup-To: comp.sys.amiga
In-Reply-To: hood@cbmvax.commodore.com (Scott Hood)

In a message posted on 7 Nov 90 22:03:45 GMT,
hood@cbmvax.commodore.com (Scott Hood) wrote:
SH>In article <1990Nov7.181228.3182@uokmax.ecn.uoknor.edu> drtiller@uokmax.ecn.uoknor.edu (Donald Richard Tillery Jr) writes:
SH>>>> (about the flickering first half line)
SH>>>>       Every time this subject comes up, I ask why the C-A deinterlacer can't
SH>>>>handle the first scan line in whatever way the flickerFixer does.  I've never
SH>>>>seen any answer to this.  I'd just like to know whether the problem is due to
SH>>>>a design or manufacturing error, or is the deliberate result of some cost
SH>>>>reduction measure.

SH>>>So the question arises: What does flickerFixer put in there?

SH>>Yes, but what does the electron beam scan have to do with the problem?
SH>>Whatever happens to the signal at the monitor isn't causing the 1/3
SH>>line flicker, the de-interlacer is.  That means that the timing in
SH>>the A2320 doesn't sync every frame until about 1/3 of the way into the
SH>>first scan line.  The lack of sync causes a variation from frame to
SH>>frame that results in oposing information appearing as flicker.
SH>>Obviously the FF overcomes this by syncing earlier or (more likely
SH>>since I talked to the FF guy and this seems to be his technique for
SH>>eliminating problems - i.e. garbage on the right edge) just covering
SH>>the offending video with blanking.  A similar solution for the A2320
SH>>would be reasonable (BTW, the FF displays "about 719 by 479 hi-res
SH>>pixels", I wonder why :-).
SH>>
SH>>Rick Tillery
SH>>(drtiller@uokmax.ecn.uoknor.edu)

SH>I guess that I should put this one to rest once and for all.  The
SH>problem is with the way that the Amber chip did the de-interlacing.  It
SH>has nothing to do with beam position or sync or any other such
SH>infromation, but these are not unreasonable guesses!  When the Amber
SH>chip was in development I did not think that this was such a bad
SH>artifact (I know, I know, how could one be so foolish!) and only a few
SH>people said anything about this flickering 1/2 line.
SH>
SH>Scott Hood 

	This is necessarily a reply directly to Scott.  When I first heard
of the release of the A2230, I thought, "Great!, and look at the price!" 
Now I'm wondering if it is so great.  Is the general conensus that the FF
is much better than the A2230?  Is this flickering problem ONLY on the
first scan line or does the whole screen flicker a bit?  Are there any
other known problems with the A2230?  What about colour etc...How does the
actual picture quality compare with the FF (should be exactly the same, I
know.  I'm just making sure.)?

--
 Craig Lemon - Kitchener, Ontario. Amiga B2000/10--2400 bps--AmigaUUCP 1.03D
 clemon@lemsys.UUCP   or   lemsys!clemon@xenitec.on.ca
 ....!{uunet}!watmath!xenitec!lemsys!clemon