FW: [OpenH323]Acoustic Echo cancellation for simph323

[Ivan R. Judson]

-----Original Message-----
From: openh323-admin at openh323.org [mailto:openh323-admin at openh323.org] On
Behalf Of Andre Adrian
Sent: Friday, June 25, 2004 8:40 AM
To: openh323 at openh323.org
Subject: [OpenH323]Acoustic Echo cancellation for simph323

Hello everybody,

please find as attachment my acoustic echo cancellation (AEC) enhancement
for simph323.
I publish this software with the MPL license.
Please remember: The AEC in your computer helps your telephony partner, not
yourself.
To have a benefit for yourself, your partner needs an AEC, too.
This is a call to all the softphone programmers: Please check this software!
And if you like it put it into your softphone.

This software brings hands-free operation into the VoIP world with no
additional hardware on your computer. Only an AC97 conformal (on-board)
soundcard is necessary.
For details look into the Readme_nlms.txt file in openh323/samples/simple.
With professional equipment (Sennheiser Gooseneck mic, Edirol
loudspeaker) I could get 45dB
of echo attenuation (10dB mic diversity, 29dB acoustic echo cancellation,
6dB acoustic echo
suppression) with white noise. This result is better then the ITU-T
G.168 requirement.

Have fun and tell me your experience with this piece of software!

Andre Adrian <adrianandre at compuserve.de> or <andre.adrian at dfs.de> Selters,
Germany


The acoustic echo cancellation software uses OpenH323 version 1.13.4 as
baseline.

If you have installed openh323 in ~/openh323, go to your home directory,
open the tar-ball and compile the simph323 with the following commands:

cd ~
tar xzf simph323_aec_1.0.tgz
cd openh323/samples/simple
make opt

If you start the program with

./obj_linux_x86_r/simph323 -n -e -l -a

you should get

SimpleH323 Version 1.13.4 by OpenH323 Project on Unix Linux
(2.4.21-99-default-i686)

Local username: anblf
Silence compression is Disabled
Auto answer is 1
FastConnect is Enabled
H245Tunnelling is Enabled
Jitter buffer: 50-250 ms
Sound output device: "/dev/dsp0"
Sound  input device: "/dev/dsp0"
Codecs (in preference order):
 Table:
   iLBC-15k2{sw} <1>
   iLBC-13k3{sw} <2>
   GSM-06.10{sw} <3>
   MS-GSM{sw} <4>
   G.711-uLaw-64k{sw} <5>
   G.711-ALaw-64k{sw} <6>
   SpeexNarrow-18.2k{sw} <7>
   SpeexNarrow-15k{sw} <8>
   SpeexNarrow-11k{sw} <9>
   SpeexNarrow-8k{sw} <10>
   SpeexNarrow-5.95k{sw} <11>
   LPC-10{sw} <12>
   UserInput/hookflash <13>
   UserInput/basicString <14>
   UserInput/dtmf <15>
   UserInput/RFC2833 <16>
 Set:
   0:
     0:
       iLBC-15k2{sw} <1>
       iLBC-13k3{sw} <2>
       GSM-06.10{sw} <3>
       MS-GSM{sw} <4>
       G.711-uLaw-64k{sw} <5>
       G.711-ALaw-64k{sw} <6>
       SpeexNarrow-18.2k{sw} <7>
       SpeexNarrow-15k{sw} <8>
       SpeexNarrow-11k{sw} <9>
       SpeexNarrow-8k{sw} <10>
       SpeexNarrow-5.95k{sw} <11>
       LPC-10{sw} <12>
     1:
       UserInput/hookflash <13>
       UserInput/basicString <14>
       UserInput/dtmf <15>
       UserInput/RFC2833 <16>

Waiting for incoming calls for "anblf"
Press X to exit.
H323>
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