[Asterisk-Users] Echo

[Klaus-Peter Junghanns]

Morning,

so, now we got it again. We have a reached a point where a GPLed
capi driver is needed. Without it will be impossible, because the
smallest packets we can get from capi is 128 bytes (=16ms).
But i am not sure if we can make you C2/C4 guys happy since the
design is not open (like the hfc-pci is).
I've been thinking about this for a long time, and we had discussions
about it in #asterisk very often. Raise your hand if you need it ;-)


regards
kapejod

-- 
Klaus-Peter Junghanns

CEO,CTO
Junghanns.NET GmbH
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fon:    +49 30 79705390
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email:  kpj at junghanns.net



Am Mon, 2003-02-24 um 10.43 schrieb Roy Sigurd Karlsbakk:
> > > i4l uses the modem.conf file, not the zapata.conf file.
> > > and no, it does not echo cancelation, i'm waiting for Mark
> > > to seperate it out from the zap driver, like he did for the
> > > dsp functions.
> >
> > Unfortunately, echo cancellation is not as easy to pull out as the dsp
> > routines.  The problem is that in order to use an echo canceller like
> > "mec" and "sec" varieties, you must have very good correlation between
> > signal transmitted and signal received.  In other words, you need to know
> > that "this byte/short in this receive buffer was the one that we received
> > exactly when the physical device was transmitting that byte/short in that
> > transmit buffer".  That's why echo cancellation is done in-kernel, and in
> > zaptel, because we have that very correlation.
> 
> ...so for this to be moved to CAPI, it needs to be done in kernel space as 
> well?
> 
> -- 
> Roy Sigurd Karlsbakk, Datavaktmester
> ProntoTV AS - http://www.pronto.tv/
> Tel: +47 9801 3356
> 
> Computers are like air conditioners.
> They stop working when you open Windows.
> 
> 
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