Hello. I have the following situation. AEC is used in network chat software over DirectSound API. Echo and reference signals are almost aligned (delay is no more than 30ms). When echo is emulated in notebook (built-in speakers + mic) everything goes fine and echo is cancelled. But when configuration includes stand-alone speakers and mic no echo is removed. Audio is in 22050 hz at 16 bit mono format, number of samples to process were 441 and tail was used 4096. Dumps are here: http://rapidshare.com/files/317389207/speex_AEC_test.rar.html nb_*** - working configuration (notebook) sa_*** - standalone speakers with no echo removed Can it be because of differences in fixed and arbitrary acoustic systems? I will appreciate any of your advises or thoughts. Thanks! Anton A. Shpakovsky Multimedia Software Developer -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/speex-dev/attachments/20100315/e9ffff48/attachment.htm
One thing I can think of is if you are using two or more speakers. If the speakers are not at the exact same distance from the mic, you will get more than one echo. AEC can not handle that. Try disconnecting all but one speaker and see if it makes any difference. cheers Greger 2010/3/15 Anton A. Shpakovsky <saa at tomsksoft.com>> Hello. > > I have the following situation. AEC is used in network chat software > > over DirectSound API. Echo and reference signals are almost aligned > > (delay is no more than 30ms). When echo is emulated in notebook > > (built-in speakers + mic) everything goes fine and echo is cancelled. > > But when configuration includes stand-alone speakers and mic no echo is > > removed. Audio is in 22050 hz at 16 bit mono format, number of samples > > to process were 441 and tail was used 4096. > > > > Dumps are here: > http://rapidshare.com/files/317389207/speex_AEC_test.rar.html > > nb_*** - working configuration (notebook) > > sa_*** - standalone speakers with no echo removed > > > > Can it be because of differences in fixed and arbitrary acoustic systems? > > I will appreciate any of your advises or thoughts. > > > > Thanks! > > > > Anton A. Shpakovsky > > Multimedia Software Developer > > > > _______________________________________________ > Speex-dev mailing list > Speex-dev at xiph.org > http://lists.xiph.org/mailman/listinfo/speex-dev >-------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/speex-dev/attachments/20100315/564be9c0/attachment.htm
If more than one speaker receives the *same* signal, it doesn't matter the number of speakers. It only gets tricky when the speakers are playing slightly different signals (e.g. from a stereo song). Jean-Marc Quoting Greger Burman <greger at mobile-robotics.com>:> One thing I can think of is if you are using two or more speakers. If the > speakers are not at the exact same distance from the mic, you will get more > than one echo. AEC can not handle that. Try disconnecting all but one > speaker and see if it makes any difference. > > cheers > Greger > > 2010/3/15 Anton A. Shpakovsky <saa at tomsksoft.com> > > > Hello. > > > > I have the following situation. AEC is used in network chat software > > > > over DirectSound API. Echo and reference signals are almost aligned > > > > (delay is no more than 30ms). When echo is emulated in notebook > > > > (built-in speakers + mic) everything goes fine and echo is cancelled. > > > > But when configuration includes stand-alone speakers and mic no echo is > > > > removed. Audio is in 22050 hz at 16 bit mono format, number of samples > > > > to process were 441 and tail was used 4096. > > > > > > > > Dumps are here: > > http://rapidshare.com/files/317389207/speex_AEC_test.rar.html > > > > nb_*** - working configuration (notebook) > > > > sa_*** - standalone speakers with no echo removed > > > > > > > > Can it be because of differences in fixed and arbitrary acoustic systems? > > > > I will appreciate any of your advises or thoughts. > > > > > > > > Thanks! > > > > > > > > Anton A. Shpakovsky > > > > Multimedia Software Developer > > > > > > > > _______________________________________________ > > Speex-dev mailing list > > Speex-dev at xiph.org > > http://lists.xiph.org/mailman/listinfo/speex-dev > > >
Hi again. I've tried turning off one of the speakers, played with polarity of the speakers - no effect. I cannot say that echo is not removed at all - I definitely hear the distortion of the echo but it still remains as an unpleasant "robo-voice" in the background. Is the speakers' volume level crucial for speex AEC, or it can successfully adapt? I just can't understand why does it happening? Attempts to use testecho.exe on not-working dumps were unsuccessful even when I played with the signal delay values (it's not more than 10-20 ms, sometimes even less), volume levels... I will appreciate if somebody tries to check my dumps, that are still here: http://rapidshare.com/files/317389207/speex_AEC_test.rar.html Thanks, Anton. From: speex-dev-bounces at xiph.org [mailto:speex-dev-bounces at xiph.org] On Behalf Of Greger Burman Sent: Monday, March 15, 2010 6:16 PM To: speex-dev at xiph.org Subject: Re: [Speex-dev] AEC strangest behavior One thing I can think of is if you are using two or more speakers. If the speakers are not at the exact same distance from the mic, you will get more than one echo. AEC can not handle that. Try disconnecting all but one speaker and see if it makes any difference. cheers Greger 2010/3/15 Anton A. Shpakovsky <saa at tomsksoft.com <mailto:saa at tomsksoft.com> > Hello. I have the following situation. AEC is used in network chat software over DirectSound API. Echo and reference signals are almost aligned (delay is no more than 30ms). When echo is emulated in notebook (built-in speakers + mic) everything goes fine and echo is cancelled. But when configuration includes stand-alone speakers and mic no echo is removed. Audio is in 22050 hz at 16 bit mono format, number of samples to process were 441 and tail was used 4096. Dumps are here: http://rapidshare.com/files/317389207/speex_AEC_test.rar.html nb_*** - working configuration (notebook) sa_*** - standalone speakers with no echo removed Can it be because of differences in fixed and arbitrary acoustic systems? I will appreciate any of your advises or thoughts. Thanks! Anton A. Shpakovsky Multimedia Software Developer _______________________________________________ Speex-dev mailing list Speex-dev at xiph.org <mailto:Speex-dev at xiph.org> http://lists.xiph.org/mailman/listinfo/speex-dev <http://lists.xiph.org/mailman/listinfo/speex-dev> -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/speex-dev/attachments/20100317/637df845/attachment.htm