search for: qcurv

...wever it has shown to be very hard to make the speech switching reliable under situations where the far-end signal is very strong compared to the near-end signal in the mic signal (rec). We have converted the AEC and preprocessor code to matlab and are able to look at all signals. We can modify the Qcurve-function to bring more attention to the near-end signal or we can modify the echo_noise estimation (add gain and accumulation) to bring more attention to the residual echo suppression. However it is hard to optimize for both. My question is if anyone have any tips of how to make speex preprocesso...

...sed when near-end talks. > Can you explain what ... problem you've encountered? Our main problem is that it is hard to have good reliance on a high "gain2" when near-end is talking, resulting in missing conversation in one direction. Some improvement can be made by modifying the Qcurve function but it is very sensitive. A secondary problem we also have is that the residual echo during decay of far-end talk is not suppressed very well. This is probably caused by the strong echo coupling plus a fairly reverberant room. We have been able to solve this by adding a weighting factor...

...art -------------- Index: preprocess.c =================================================================== --- preprocess.c (revision 10007) +++ preprocess.c (working copy) @@ -761,7 +761,8 @@ } Zframe /= (freq_end-freq_start); } - + st->Zlast = Zframe; + Pframe = qcurve(Zframe); /*fprintf (stderr, "%f\n", Pframe);*/

...ong > compared to the near-end signal in the mic signal (rec). Can you explain what you mean here by "speech switching" and problem you've encountered? > We have > converted the AEC and preprocessor code to matlab and are able to look > at all signals. We can modify the Qcurve-function to bring more > attention to the near-end signal or we can modify the echo_noise > estimation (add gain and accumulation) to bring more attention to the > residual echo suppression. However it is hard to optimize for both. There's also a parameter to control the maximum amou...

.... I suspect that the residual echo estimation also doesn't help. > Our main problem is that it is hard to have good reliance on a high > "gain2" when near-end is talking, resulting in missing conversation > in one direction. Some improvement can be made by modifying the > Qcurve function but it is very sensitive. > > A secondary problem we also have is that the residual echo during > decay of far-end talk is not suppressed very well. This is probably > caused by the strong echo coupling plus a fairly reverberant room. We > have been able to solve this by a...

...ur main problem with the gain during near end talk. >> Our main problem is that it is hard to have good reliance on a high >> "gain2" when near-end is talking, resulting in missing conversation >> in one direction. Some improvement can be made by modifying the >> Qcurve function but it is very sensitive. >> >> A secondary problem we also have is that the residual echo during >> decay of far-end talk is not suppressed very well. This is probably >> caused by the strong echo coupling plus a fairly reverberant room. We >> have been abl...