[Speex-dev] echo cancellation test problem on Windows OS.

Duane Storey duane at counterpath.com
Tue Oct 11 18:54:42 PDT 2005

Clocks are rarely synchronized on audio devices.. on Windows it's completely
likely to have the microphone give you 8100 samples a second, and have the
speaker accept 8000 samples a second.. You generally have to do some sort of
clock synchronization manually.  It works with files because you are
essentially forcing the near end and far end signals to have the same clock.


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-----Original Message-----
From: speex-dev-bounces at xiph.org [mailto:speex-dev-bounces at xiph.org] On
Behalf Of lee kyung moon
Sent: Tuesday, October 11, 2005 6:47 PM
To: speex-dev at xiph.org
Subject: [Speex-dev] echo cancellation test problem on Windows OS.

Hi, all.
I'm a programmer lived in Korea.
This time, I was investingating echo cancellation and found speex echo 
cancellation related API.
But echo stilll remains.

1. echo cancellation using only files works propertly.
2. echo cancellation using sound device works not propertly.

You can download test files as followed.

http://www.vdream.co.kr/temp/ec/echocancel.wmv ( testing screen capture 
file )

http://www.vdream.co.kr/temp/ec/echocancel.zip ( test files )

The reason why echo still remains is that speaking signal from sound device 
differs from speaking signal from file, I guess.

It's my pleasure to see my testring files.
Thanks in advanced.

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