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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I’ve worked on implementing Speex
AEC to smartphone on the exactly same platform as you have. The result is
pretty good. I can remove most of the acoustic echo. I’m still tuning the
performance to minimize the remaining echo. Here are the key points: <o:p></o:p></span></font></p>
<ol style='margin-top:0in' start=1 type=1>
<li class=MsoNormal style='color:navy;mso-list:l0 level1 lfo1'><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial'>You
have to sync microphone and speaker properly; otherwise it wouldn’t
give you a good result.<o:p></o:p></span></font></li>
<li class=MsoNormal style='color:navy;mso-list:l0 level1 lfo1'><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial'>You
have to optimize Speex AEC in order to run on mobile device in real time.<o:p></o:p></span></font></li>
</ol>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Regards,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Dennis<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabindex=-1>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
speex-dev-bounces@xiph.org [mailto:speex-dev-bounces@xiph.org] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Mohammed Sulaiman<br>
<b><span style='font-weight:bold'>Sent:</span></b> Friday, February 08, 2008
7:55 AM<br>
<b><span style='font-weight:bold'>To:</span></b> Speex-dev@xiph.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> [Speex-dev] Echo
Canceller on Windows Mobile</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Hi Jean Marc,<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>We are running the speex echo canceller code on a Windows Mobile
smartphone using a TI OMAP 201MHz 850. We are making voip calls and audio
is working without echo canceller code. Simply adding the following 2 functions
whether the echo cancellation is wired in (ie we use the output
frame ) or not performance becomes terrible. Note 2 separate
threads are used to handle audio.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Playing Audio thread:<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Write to codec<o:p></o:p></span></font></p>
</div>
<p class=MsoNormal><font size=2 face=Courier><span style='font-size:10.0pt;
font-family:Courier'>speex_echo_playback(echo_state, echo_frame);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span style='font-size:
10.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span style='font-size:
10.0pt'>Capturing audio thread:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span style='font-size:
10.0pt'>Receive buffer<o:p></o:p></span></font></p>
<div>
<p class=MsoNormal><font size=2 face=Courier><span style='font-size:10.0pt;
font-family:Courier'>speex_echo_capture(echo_state, input_frame, output_frame);<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>We have compiled for fixed point.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>We are using codec buffer size of 256 bytes ie 128, 16bit samples.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>SpeexEchoState* iEchoState = speex_echo_state_init(ECHO_FRAME_SIZE,
ECHO_FILTER_SIZE);<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>ECHO_FRAME_SIZE = 128<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>ECHO_FILTER_SIZE = 1024<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Any ideas?<o:p></o:p></span></font></p>
</div>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Do you know whether any one has this running on Windows Mobile
platforms successfully.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Regards<o:p></o:p></span></font></p>
</div>
<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'> <o:p></o:p></span></font></p>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=1 width="100%" align=center>
</span></font></div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Sent from <a
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- a smarter inbox.<o:p></o:p></span></font></p>
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