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><br><span title="neteasefooter"/><hr/>
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