hi, my mistake, it can handle 160 as 160 = 2*2*2*2*2*5 and there is the fft-5 there. from what i have seen, it actually uses fft of length double then the frame length so u might want to reduce it to 128, but that might be to low. On Mon, Dec 14, 2009 at 5:16 PM, nir elkayam <nir.elkayam at gmail.com> wrote: > hi, > > try to look into the code and see whether the speex AEC uses FFT 0f 160 or > 256. > I am not sure it will use 160 because it is less effective then 256. > if u could point to the correct place in the code that would be great. > > nir > > > On Mon, Dec 14, 2009 at 5:07 PM, Benny Prijono <bennylp at teluu.com> wrote: > >> On Fri, Dec 11, 2009 at 5:52 PM, fabio cherchi <fabio.cherchi at yahoo.it> >> wrote: >> > Hello, >> > >> > my question is very simple. >> > I realized a hardware version of the kiss fft for the AEC Speex in the >> > pjsip. >> > It can handle 256 samples per frame while the whole application (and >> audio >> > driver) actually is working with 160 samples per frame. >> > >> > I'm evaluating 2 options: >> > >> > 1) to keep the 160 samples per frame and use the zero-padding technique >> to >> > fill the remaining empty frame. >> > Question: does anybody know what's the effect of the zero-padding in the >> > inverse fft? >> > >> >> I'm no FFT master, but I don't think the effect is good! >> >> > 2) to scale up all the system to handle 256 samples per frame. >> > Question: is the pjmedia suitable for 256 samples per frame instead of >> 160? >> > >> >> That should be okay, just open both the sound device and the >> conference bridge to use 256 samples per frame, and let anything else >> unchanged. The conference bridge would automatically do the buffering >> for any ports connected to it, if they use different samples per frame >> setting. >> >> Though the drawback is of course there will be more memmove() >> operations involved. >> >> Cheers >> benny >> >> _______________________________________________ >> Visit our blog: http://blog.pjsip.org >> >> pjsip mailing list >> pjsip at lists.pjsip.org >> http://lists.pjsip.org/mailman/listinfo/pjsip_lists.pjsip.org >> > > > > -- > ??? ?????? > ??: 050-3930056 > nir.elkayam at gmail.com > > -- ??? ?????? ??: 050-3930056 nir.elkayam at gmail.com -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20091214/dce5bb29/attachment.html>
