In my experience, the Speex AEC is one of the less-mature parts of the Speex eco-system. In my Silverlight/C# port of Speex 1.2RC1, after automated tuning of every parameter I could think of, I could at best get something like 65% of the echo removed. However, if I combined it with the Speex pre-processor with echo suppression enabled, it was much more usable: I could achieve something like 90-95% of the echo removed. There was certainly some attenuation of the original signal, but the result was of usable quality (if not really in the neighborhood of, say, what Skype is able to achieve).<div>
<br></div><div>My recommendation would be to spend the time to create a test harness that tries echo cancellation/echo suppression with every possible set of parameters, and measure the actual results achieved.<br clear="all">
<br>Ken Smith<br>Cell: 425-443-2359<br>Email: <a href="mailto:ken@alanta.com" target="_blank">ken@alanta.com</a><br>Blog: <a href="http://blog.wouldbetheologian.com/" target="_blank">http://blog.wouldbetheologian.com/</a><br>
<br><br><div class="gmail_quote">On Mon, Mar 7, 2011 at 9:09 AM, KS <span dir="ltr"><<a href="mailto:wakeup1504@gmail.com">wakeup1504@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div>Hi,</div>
<div> </div>
<div>From the Speex Manual, section 6.2.1 (Echo Cancellation - Troubleshooting), it was mentioned that echo cancellation will not work if the playback and capture is done on 2 different soundcard. I would like to know whether this is true. I trying to use Speex Echo Cancellation on capture audio from a webcam mic with the playback through my onboard audio. </div>
<div> </div>
<div>Based on what is mentioned in the troubleshooting guide, does this mean that I would never be able to get the Echo Cancellation to work in my scenario?</div>
<div> </div>
<div>For my testing, I was using an echo tail length of 100ms and frame size of 20ms. Using this setting, I found that the echo cancellation does work, but it is too aggressive and cause the actual voice to get attentuation as well, resulting in audio distortion that sounds like audio drop. Increase the echo tail length to 120ms made the voice attentuation issue less severe, but resulted in much of the echo remaining in the audio.</div>
<div> </div>
<div>Does anyone have any advise on what I can look at and what parameters I can tweak to try to improve the Speex Echo Cancellation performance? I already using 1.2rc1. Thanks.</div>
<div> </div>
<div>regards,</div>
<div> </div><font color="#888888">
<div> </div>
<div>KS</div>
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