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Hello Tim,<br>
<br>
Please explain exactly what you are meaning by "expose speaker input as
other OS". Did you reference system latency? If you do so, I would like
to understand better how the acoustic echo cancellation works,
regarding the latency between the audio reprodution and the acquired
audio (I had problems with that in the past, so I forgot the use of
Speex mechanism for doing AEC for VoIP systems).<br>
<br>
In short: does Speex AEC have some kind of delay limit between the
voices (the input and the output)?<br>
<br>
Best regards,<br>
<br>
-- <br>
<font face="Arial,Helvetica">
<font size="-1"><b>Guilherme Balena Versiani</b><br>
</font><font size="-2"><i>Software Architect</i><br>
<br>
<a target="_blank" href="http://www.comunip.com.br"><img
src="cid:part1.09020807.01030707@comunip.com.br" align="left"
border="0" hspace="12"></a>
Rua Alvarenga Peixoto, 295 / 5º andar<br>
Lourdes - CEP 30180-120 - Belo Horizonte, MG<br>
(31) 3275-2220 9992-1578
</font></font><br>
<br>
<br>
<br>
Tim Na escreveu:
<blockquote cite="mid:5AF60EA91C7548C0811369A93B5EE6D7@timnanotepc"
type="cite">
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<div dir="ltr" align="left"><font color="#0000ff" face="굴림" size="2"><span
class="951082817-11082009">Ok, let me be more clear on this.</span></font></div>
<div dir="ltr" align="left"><font color="#0000ff" face="굴림" size="2"><span
class="951082817-11082009"></span></font> </div>
<div dir="ltr" align="left"><font color="#0000ff" face="굴림" size="2"><span
class="951082817-11082009">AFAIK, Windows OS doesn't expose speaker
input as other OS ( Linux, Mac OS...). That puts you in bad spot in
using Speex AEC with windows.</span></font></div>
<div dir="ltr" align="left"><font color="#0000ff" face="굴림" size="2"><span
class="951082817-11082009"></span></font> </div>
<div dir="ltr" align="left"><font color="#0000ff" face="굴림" size="2"><span
class="951082817-11082009">Only way to work is to use Soundcard with
ASIO functionality which does give you speaker input. But then you
would have to impose that requirement on all your users.</span></font></div>
<div dir="ltr" align="left"><font color="#0000ff" face="굴림" size="2"><span
class="951082817-11082009"></span></font> </div>
<div dir="ltr" align="left"><font color="#0000ff" face="굴림" size="2"><span
class="951082817-11082009">I heard Speex AEC works great from
developer who used windows with ASIO Soundcard.</span></font></div>
<div dir="ltr" align="left"><font color="#0000ff" face="굴림" size="2"><span
class="951082817-11082009"></span></font> </div>
<div dir="ltr" align="left"><font color="#0000ff" face="굴림" size="2"><span
class="951082817-11082009">Vista AEC DMO or XP DirectSound AEC
function does reasonable job and that's what I am currently using.</span></font></div>
<div dir="ltr" align="left"><font color="#0000ff" face="굴림" size="2"><span
class="951082817-11082009"></span></font> </div>
<div dir="ltr" align="left"><font color="#0000ff" face="굴림" size="2"><span
class="951082817-11082009">Tim</span></font></div>
<br>
<div dir="ltr" class="OutlookMessageHeader" align="left" lang="en-us">
<hr tabindex="-1"><font face="Tahoma" size="2"><b>From:</b>
<a class="moz-txt-link-abbreviated" href="mailto:speex-dev-bounces@xiph.org">speex-dev-bounces@xiph.org</a> [<a class="moz-txt-link-freetext" href="mailto:speex-dev-bounces@xiph.org">mailto:speex-dev-bounces@xiph.org</a>] <b>On
Behalf Of </b>Greger Burman<br>
<b>Sent:</b> Tuesday, August 11, 2009 1:15 AM<br>
<b>To:</b> <a class="moz-txt-link-abbreviated" href="mailto:speex-dev@xiph.org">speex-dev@xiph.org</a><br>
<b>Subject:</b> Re: [Speex-dev] AEC troubleshooting<br>
</font><br>
</div>
<div>I actually forgot to mention that I'm using ultra-wideband mode,
but seems like you understood that anyway. Is this true that Speex echo
cancellation only performs well in narrowband mode !? </div>
<div>I've been using 100 ms as the default tail length. I don't know
what the ideal tail length would be. I have tried shorter and longer
tails but it hasn't made any difference.</div>
<div>Does DirectSound's AEC perform well with high quality recording?
Is it the general opinion that it performs significantly better than
Speex AEC?</div>
<div>cheers</div>
<div>Greger</div>
<div class="gmail_quote">2009/8/10 Tim Na <span dir="ltr"><<a
moz-do-not-send="true" href="mailto:hna@alu.edu">hna@alu.edu</a>></span><br>
<blockquote
style="border-left: 1px solid rgb(204, 204, 204); margin: 0px 0px 0px 0.8ex; padding-left: 1ex;"
class="gmail_quote">
<div>
<div dir="ltr" align="left"><span><font color="#0000ff"
face="굴림" size="2">If you search the mail archive, you will see
that people were only successful using narrowband with long tail length.</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff"
face="굴림" size="2">Unless you have speaker input in perfect sync
with mic input, it is difficult to use Speex AEC.</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff"
face="굴림" size="2">If you don't have restriction on using
Vista's AEC DMO or XP"s DirectSound, I would recommend using those.</font></span></div>
<div dir="ltr" align="left">Â </div>
<div dir="ltr" align="left"><span><font color="#0000ff"
face="굴림" size="2">Tim</font></span></div>
<br>
<div dir="ltr" align="left" lang="en-us">
<hr> <font face="Tahoma" size="2"><b>From:</b> <a
moz-do-not-send="true" href="mailto:speex-dev-bounces@xiph.org"
target="_blank">speex-dev-bounces@xiph.org</a> [mailto:<a
moz-do-not-send="true" href="mailto:speex-dev-bounces@xiph.org"
target="_blank">speex-dev-bounces@xiph.org</a>] <b>On Behalf Of </b>Greger
Burman<br>
<b>Sent:</b> Monday, August 10, 2009 5:40 AM<br>
<b>To:</b> <a moz-do-not-send="true"
href="mailto:speex-dev@xiph.org" target="_blank">speex-dev@xiph.org</a><br>
<b>Subject:</b> [Speex-dev] AEC troubleshooting<br>
</font><br>
</div>
<div>
<div class="h5">
<div>I'm experiencing little to no damping of acoustic echo from
the echo cancellor and I can't figure out why so far. I thought I
should try the echo_diagnostic tool so I built libspeex.dll and
libspeexdsp.dll with the DUMP_ECHO_CANCEL_DATA flag, but I'm not
getting any output files at runtime. Any ideas?<br clear="all">
</div>
<div>Build information:</div>
<div>Speex version: 1.2rc1</div>
<div>Target Win32 x86</div>
<div>MS VC++2008 EE</div>
<div>Configuration: Release, Full optimization, _USE_SSE</div>
<div>DUMP_ECHO_CANCEL_DATA </div>
<br>
-- <br>
Greger Burman<br>
<br>
</div>
</div>
</div>
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</div>
<br>
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<br>
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