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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20091214/5c2405d9/attachment.html>
