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<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Hi.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Just want to share some experience. <o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I’ve tried several commercial AEC solutions – negotiations,
signing NDA – but still no better results than speex get.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Now I’m working with GIPS SDK – I heard that Skype do not use
GIPS VoiceEngine anymore, but yes – WLM, Yahoo and AOL messengers are using
GIPS VE.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>And it is not only echo suppression. Their SDK is very powerful
and I hope soon I will get some positive results.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>As for now – SPEEX is the best.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Regards,<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Anton A. Shpakovsky<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
speex-dev-bounces@xiph.org [mailto:speex-dev-bounces@xiph.org] <b>On Behalf Of </b>limaoquan2000<br>
<b>Sent:</b> Thursday, June 10, 2010 2:14 AM<br>
<b>To:</b> speex-dev@xiph.org<br>
<b>Subject:</b> Re: [Speex-dev] Sound card problem in acoustic echo
cancellation<o:p></o:p></span></p>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal style='margin-bottom:12.0pt'>Then why ONE sound card have
different capture and playback rate?<br>
It must be ONE single physical clock generator which is used by both ADC and
DAC<br>
in the sound card, isn't it?<br>
If you are a hardware engineer. Will you design two different physical clock
for<br>
ADC and DAC seperately?<br>
What on earth causes this problem? Who knows its intrinsic real reason?<br>
<br>
Isn't there any other solutions?<br>
For example, I have also tested Microsoft MSN and Skype. It seems that AEC<br>
function of those softwares are all no problem. Their AEC are designed by GIPS.<br>
I guess that must be some solutions.<br>
The solution of GIPS is only echo suppression?<br>
<br>
Em 02-06-2010 04:41, ce09@polyu.edu.hk escreveu:<br>
> Hi All,<br>
><br>
> I am a research associate in the Hong Kong Polytechnic University. One of<br>
> my research interests is acoustic echo cancellation. Now I meet a big
problem.<br>
> When I was testing my own AEC module, I found that it was almost perfect
in<br>
> few computers but much worse in other computers. Then I tried AEC module
in<br>
> speex, it was almost the same result.<br>
><br>
> Then I found the reason is that sound cards of most computers have
different<br>
> sampling and playing rate, so it is almost impossible for the adaptive
filter<br>
> to converge and reach best result. For example, long time average sampling
and<br>
> playing rate of a sound card is 7999.864Hz and 7980.129Hz respectively.
Sound<br>
> cards of the computers which shown perfect AEC result are the only sound
cards<br>
> which keep the same sampling and playing rate.<br>
><br>
> Then, what can I do to solve the problem? Could you please give me any
advice?<br>
> BTW: I am working on Windows XP platform and I have tried DirectSound.<br>
><br>
> Your Sincerely<br>
> Li Maoquan<br>
<br>
<br>
<o:p></o:p></p>
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<p class=MsoNormal><a href="http://ym.163.com/?from=od3" target="_blank"><span
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