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<DIV dir=ltr align=left><SPAN class=877102021-11082009><FONT color=#0000ff
size=2 face=굴림>Well, I am not the person to be asked about how Speex AEC
works :)</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=877102021-11082009><FONT color=#0000ff
size=2 face=굴림></FONT></SPAN><SPAN class=877102021-11082009><FONT color=#0000ff
size=2 face=굴림></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=877102021-11082009><FONT color=#0000ff
size=2 face=굴림>And I was referring speaker input as having direct access
into what has been played thru speaker. (ASIO Soundcard provides interface for
that)</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=877102021-11082009><FONT color=#0000ff
size=2 face=굴림></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=877102021-11082009><FONT color=#0000ff
size=2 face=굴림>So if I am remebering correctly, with data from Mic and
Speaker in sync, speex AEC should do the job. </FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=877102021-11082009><FONT color=#0000ff
size=2 face=굴림></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=877102021-11082009><FONT color=#0000ff
size=2 face=굴림></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=877102021-11082009><FONT color=#0000ff
size=2 face=굴림>Tim</FONT></SPAN></DIV><BR>
<DIV dir=ltr lang=en-us class=OutlookMessageHeader align=left>
<HR tabIndex=-1>
<FONT size=2 face=Tahoma><B>From:</B> Guilherme Balena Versiani
[mailto:guibv@comunip.com.br] <BR><B>Sent:</B> Tuesday, August 11, 2009 1:33
PM<BR><B>To:</B> Tim Na<BR><B>Cc:</B> 'Greger Burman';
speex-dev@xiph.org<BR><B>Subject:</B> Re: [Speex-dev] AEC
troubleshooting<BR></FONT><BR></DIV>
<DIV></DIV>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
href="http://www.comunip.com.br" target=_blank><IMG border=0 hspace=12
align=left src="cid:877102021@11082009-2E58"></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">
<META name=GENERATOR content="MSHTML 8.00.6001.18813">
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=굴림><SPAN
class=951082817-11082009>Ok, let me be more clear on this.</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=굴림><SPAN
class=951082817-11082009></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=굴림><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 size=2 face=굴림><SPAN
class=951082817-11082009></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=굴림><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 size=2 face=굴림><SPAN
class=951082817-11082009></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=굴림><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 size=2 face=굴림><SPAN
class=951082817-11082009></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=굴림><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 size=2 face=굴림><SPAN
class=951082817-11082009></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=굴림><SPAN
class=951082817-11082009>Tim</SPAN></FONT></DIV><BR>
<DIV dir=ltr lang=en-us class=OutlookMessageHeader align=left>
<HR tabIndex=-1>
<FONT size=2 face=Tahoma><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
href="mailto:hna@alu.edu"
moz-do-not-send="true">hna@alu.edu</A>></SPAN><BR>
<BLOCKQUOTE
style="BORDER-LEFT: rgb(204,204,204) 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>
<DIV>
<DIV dir=ltr align=left><SPAN><FONT color=#0000ff size=2 face=굴림>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 size=2 face=굴림>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 size=2 face=굴림>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 size=2
face=굴림>Tim</FONT></SPAN></DIV><BR>
<DIV dir=ltr lang=en-us align=left>
<HR>
<FONT size=2 face=Tahoma><B>From:</B> <A
href="mailto:speex-dev-bounces@xiph.org" target=_blank
moz-do-not-send="true">speex-dev-bounces@xiph.org</A> [mailto:<A
href="mailto:speex-dev-bounces@xiph.org" target=_blank
moz-do-not-send="true">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 href="mailto:speex-dev@xiph.org" target=_blank
moz-do-not-send="true">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></BLOCKQUOTE></DIV><BR><PRE wrap=""><HR SIZE=4 width="90%">
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