Newsgroups: comp.speech
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From: clanton@ukraine.corp.mot.com (Chris Clanton)
Subject: ADPCM algorithms
Reply-To: clanton@ukraine.corp.mot.com
Organization: Motorola, Inc.
Date: Wed, 1 Jun 1994 14:41:27 GMT
Message-ID: <1994Jun1.144127.10250@lmpsbbs.comm.mot.com>
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Hi Readers,
 
I was trying to find information on 32 kbps ADPCM algorithms other than G.721 32kbps
ADPCM.  Specifically, I have heard about two other algorithms:

1.)  Something called COM101.  It seems to be recognized but not adopted by
     the CCITT/ITU.  It is a 32 kbps algorithm developed by OKI which is
     supposed to offer speech quality comparable to G.721 but also offers
     the added feature of supporting high speed (9600-14400 bps) voiceband
     modem signals.  I have some IEEE articles on this algorithm.  Has  
     anyone worked with it?  Does it really sound as good as G.721 ADPCM?
 
2.)  Something called COM102.  It is also recognized by the ITU.  It is
     supposed to be a data optimized 32kbps ADPCM algorithm that samples
     analog signals at 6400 Hz (5 bits per sample) instead of 8 kHz (4 bits).
     It is used a lot for coding information put on international links
     (I think when you make an international call, it gets coded using this
     algorithm).  Can I buy a part that does COM102 (preferably an IC) or
     is there software (preferably DSP560001 or 56116) available that does it?
     ANY information on this algorithm would be VERY useful!


I'm not even sure if this is the right place to post this.  I posted a similar
note in comp.dsp.  Can anyone help?

Thanks      


