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From: eah1@gauguin.wustl.edu (Edward Anthony Hutchins)
Subject: Re: Let's build software cryptophones for over the internet...
Message-ID: <1993Apr27.075011.12624@wuecl.wustl.edu>
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Organization: Washington University, School of Engineering, St. Louis MO
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Date: Tue, 27 Apr 1993 07:50:11 GMT
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Hmmm.... CELP takes up about 12.6 MIPS for full duplex, and has been
implemented on about a million DSP chips... the 56001 card in my PC only cost
about $700, and I'm sure once demand goes up the prices would drop. The Analog
Devices 21020 board that we're looking at now cost about $500 (academic price).
I don't think hardware is something to worry about... if you get it working,
people will snap up internet phone cards like there was no tomorrow.
What we need here is a good implementation of CELP (the government code is
absolute crap, I got a 30% speedup after looking at it for a couple of hours),
and modifications to pgp to allow it to compress/decompress 144 bit frames
every 30msec... I think the AD21020 should have enough juice for this (50MIPS).
As part of the project I'm working on now, we're trying to get CELP up and
running in realtime full duplex mode... I gotta find the source to pgp and
see how tough it would be to integrate the en/decryption parts into the code.
I'll play with it. Anyone else out there got an AD21020 setup?
	- Ed
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