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From: brett@cayman.amd.com (Brett Stewart)
Newsgroups: comp.multimedia
Subject: Re: DVI questions
Summary: Did I miss something?
Message-ID: <1991Feb20.203009.27357@mozart.amd.com>
Date: 20 Feb 91 20:30:09 GMT
References: <4999@mcrware.UUCP> <1991Feb13.090453.16347@abblund.se> <1252@prlhp1.prl.philips.co.uk>
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Organization: Advanced Micro Devices, Inc., Austin, Texas
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I have heard it touted here that self-digitization is an advantage
of DVI over CDI.  Did I miss something, or is it no longer true for
DVI that you either send your tapes to Princeton and pay $250 a
minute for Intel to compress your FMV into DVI format, or you use
the self-digitization which is low res, introduces visual artifacts,
and consumes space faster, and therefore quite inferior to the
quality that would be desired in a production multimedia product?

(This information comes from Intel Publication 240694-001 which is a
collection of article reprints)

Also, I have looked carefully at the i750 specs.  Again, am I
missing something, or does the i750 set NOT have the ability to do
MAC's, and therefore not have the ability to do at least fast JPEG
compression/decompression, which has at its heart the Discrete Cosine
Transform, which is best performed with a MAC capability?  I believe the
MPEG algorithms also use DCT-like MAC computations, with additional
requirements also beyond the i750.  The literature implies that the
compression/decompression capabilities are one-sided, ie many
seconds per frame to compress, but realtime playback.  Therefore, the
i750 would be inappropriate for certain kinds of groupware
multimedia, that might feature realtime video captured, compressed
and transmitted over a network.  (Admittedly, this last is not a
stated goal of DVI. However, the 'I' IS supposed to mean Interactive.)

The i750 set looks like a very good product - I am not intending to
disparage it but rather to understand its capabilities.

If somebody from Intel is listening, can you say what sort of
compression you do up there at Princeton?  Is it something like a
Fractal transform?  Will it ever be published, so that the types of
applications I just described might be made compatible with DVI by
enterprising third parties?

Any replies are welcome.  If I receive mail that contains points of
view which are not posted, I will summarize them for the benefit of
the net unless requested otherwise.
Brett Stewart
Advanced Micro Devices, Inc.           +1 512 462 5051 FAX
5900 E. Ben White Blvd MS561           +1 512 462 4336 Telephone
Austin, Texas 78741      USA           Brett.Stewart@AMD.com