Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!apple!portal!cup.portal.com!PurpleTiger
From: PurpleTiger@cup.portal.com (Grant Christopher Blaha)
Newsgroups: comp.ivideodisc
Subject: Re: Questions
Message-ID: <36211@cup.portal.com>
Date: 25 Nov 90 08:44:05 GMT
References: <9676@jarthur.Claremont.EDU> <39907@ut-emx.uucp>
  <473@tcnz2.tcnz.co.nz>
Organization: The Portal System (TM)
Lines: 65

In <473@tcnz2.tcnz.co.nz> greg@tcnz.co.nz (Greg Calkin) writes:

>Another novice question or two

Everyone's a novice who only knows a slice or two of a big pie.  In other
words, no need to apologize.

>1) How do you handle producing a videodisc to cope with VGA colour and to
>   cope with mono on a MAC, for instance. Are there standard image conversion
>   techniques to allow the production of a IV across a broad range of hardware
.

Your question is refering to two different kinds of media, Videodisc and
hard disk.  A videodisc offers one kind of display standard, analog,
while the hard disk offers another, digital.

Videodisc media is a platform onto itself that has little to do with
computers.  To place this media under computer control one needs special
hardware for whatever computer platform one uses.  So, to answer one part
of your question, videodiscs do not need to be convertered from IBM PC to MAC
to AMIGA to SUN to HP.  They stay the same regardless of computer
platform. Its the responsibility of the special hardware on any given
platform to interface correctly to the videodisc.

Hard disk based media is a different story.  By hard disk, I mean any kind
of image or animation that is stored in a digital form on a general purpose
computer storage device whether it be magnetic or optical.  This where you
start to get concerned about what computer platform you are on and what
file format you are using to store your images.  In addition to worrying
about the computer platform, you also have to worry about the hundreds of
display adapters that can be installed in any given computer.  Sure, its
possible to translate your images from one computer to another and one
format to another, but invariably the differences in resolution and color
depth insures that image data will be lost or the new machine or format
will be under utilized.

Your choice of media is a cost/quality sort of thing.

Videodiscs offer portablity, high quality images, animation and sound,
quick access, and dense information storage.  The drawback to videodisc
media is that its expensive.  Very expensive. Both in terms of hardware
cost and man hours.  Does anyone know how much a videodisc development
station would cost? A playback station?

Hard disks suffer from lack of portability, low image, animation and sound
quality, slow access, and a lack of information space.  The advantage they
have is that they are inexpensive and easy to work with.  On an IBM PC
plaform, for example, you can have animation and sound for a few thousand
or less.  Digital media also offers a level of interactivity that makes
authoring a relatively painless task.  Another advantage of digital media
is that its going somewhere.  Every week something happens to lessen the
short comings of digital media while videodisc media is standing still.

Gee, I could go on and on about this, but rather than ramble further, I
wonder if anyone wants to chime in.  The point I wish to make to Greg is
that there are two kinds of media involved in interactive video and that
its important not to confuse them where implementation issues are involved.
Each has its own set of problems, advantages, and techniques.

Grant Blaha
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