Date: Sun, 8 Nov 92 16:37 GMT
From: Tansin A. Darcos & Company <0005066432@mcimail.com>
Newsgroups: comp.dcom.telecom
Subject: Re: AT&T's COLOR Videophone WITH MOTION
Organization: TELECOM Digest
X-Submissions-To: telecom@eecs.nwu.edu
X-Administrivia-To: telecom-request@eecs.nwu.edu
X-Telecom-Digest: Volume 12, Issue 833, Message 7 of 9

 = Forwarded Message =
 Date:     Thu Nov 05, 1992  2:11 pm  GMT
 From:     Wayne Geiser
           EMS: INTERNET / MCI ID: 376-5414
           MBX: geiser@roadrunner.pictel.com
 Subject:  Re: AT&T's COLOR Videophone WITH MOTION

> In an ad on page A47 of the Nov. 4 {Washington Post} is an
> advertisement for AT&T's Videophone.

> The ad claims "{available now}.  Just plug it in, turn it on, and
> dial.  Full {color} with motion.  No special wiring or separate
> costs."

> The last I've heard of for video on a phone line was a {still}
> picture in {black and white}.  This one's got me stumped, as I haven't
> the foggiest idea how they can do {color} on a standard POTS line.
> And supposedly with motion too?  I'm just a lowly telephone operations
> supervisor and sometime computer programmer, I can't see how they can
> do this in such a small bandwidth.

> The phone number for information is 1-800-437-9504.

> If their product is even close to what they promise, Picturetel and
> a few others should be scared excrementless.

> Paul Robinson -- TDARCOS@MCIMAIL.COM
> Any opinions are mine alone.

Firstly, let me put my disclaimer right up front.  I'm not a video,
audio, compression, network, or telephone expert (although I've
learned more than I thought I ever wanted to since joining PictureTel
:-)).  My background is mostly in compilers, but am currently working
on UI-type stuff.

It is my understanding, from speaking with the people here who ARE
experts in some of this stuff that color does not add all that much to
the data transmission.  That is, you don't get a whole lot of
bandwidth back if you switch from color to B&W.

The AT&T phone that was announced last year (or was it early this
year?) was B&W with "motion."  The "motion" turned out to be something
on the order of a couple of frames per second.  Definitely not a
threat to PictureTel, CLI, Video Telecom, etc's business!

I suspect that this newest variant is much the same speed.  Try to
find an AT&T store with one of these.  Even under the best of
conditions (little motion, plain background, etc) it will be of
noticably poor quality because of the data limitations of the
transmission line.

To put it into perspective, we think that SEVEN frames per second is
terrible and we are trying to eventually get to THIRTY frames per
second.  Thirty frames per second is the same as the number of
animation stills they use in cartooning.  Supposedly, one cannot tell
the difference between live video and thirty frames per second video.

What about audio?  Full Duplex?  Half Duplex?  I suspect theirs is
HALF.  Ours if FULL (i.e., both sides of a video conference can speak
and be heard at the same time).  It's hard to do, that's why I expect
they didn't.

Bottom Line: We're not concerned about AT&T's product line.  In fact,
getting the public aware of the technology is good.  Having them used
to TWO frames per second simply makes our product look all that much
better when they come to see it. :-)


Wayne Geiser ("Drivel King")   Voice:    (508) 977-8253 
PictureTel Corporation         FAX:      (508) 532-6893 
One Corporation Way            Internet: geiser@pictel.com
Peabody, MA      01960         CIS:      70313,3615