[asterisk-users] Echo cancellation and DTMF from the Asterisk console?

[Nikhil Nair]

Hi Alan,

Thanks for these helpful comments.

I had a look at David Rowe's site, and found it very interesting - I'm 
blind myself, and the Louder router project he's working on sounds like a 
wonderful idea.

It looks like I got my wires crossed, to some extent - I hadn't realised 
that all the echo cancellation within Asterisk is line rather than 
acoustic.  While I'm new to all this, I believe it's acoustic echo 
cancellation I need, so it looks like I'll need to take a look at the 
Speex AEC implementation, and maybe get hold of version 1.2beta2 (which 
has significant improvements, apparently).  Maybe Linphone running on the 
same box as Asterisk will be the solution, after all.

That is, if Linphonec will consent to run for me without giving all sorts 
of errors and segfaulting... and I thought this release of Debian was 
supposed to be stable! ;)  Ah well.

Cheers,

Nikhil.



On Tue, 4 Dec 2007, Alan Lord wrote:

> Nikhil Nair wrote:
>> Hi,
>>
>> I'd like to try using a good quality microphone and a set of PC speakers
>> (in the first instance) to create a powerful speakerphone; if I get that
>> working, I'll probably try more elaborate audio equipment.
>>
>
> Interesting... After playing with - and being very impressed by the
> OSLEC Echo canceller - my business partner and I had an idea about using
> it as a module that could be plugged into ALSA (The Linux Sound
> Architecture) so it could be used with various audio devices. It is just
> a pipe dream at this moment however.
>
> The biggest issue I can see is the delays. OSLEC and the other echo
> cancellers in Zaptel are Line Echo Cancellers and as such deal with with
> very short delays. Acoustic echo Cancellation needs to handle far longer
> delays potentially...
>
> I use the Polycom Communicator C100s desktop speaker/mic on Linux, and
> despite the fact that Polycom integrate "most" of their EC software in
> the Windows Driver, it works very well with the OSLEC canceller on the
> line side.
>
> Take a look at the OSLEC package
> (http://www.rowetel.com/ucasterisk/oslec.html) and maybe try and get in
> touch with David Rowe - he is very approachable and very knowledgeable
> on this subject.
>
> HTH
>
> Alan
>
>
> -- 
> The way out is open!
> http://www.theopensourcerer.com
>
>
> _______________________________________________
> --Bandwidth and Colocation Provided by http://www.api-digital.com--
>
> asterisk-users mailing list
> To UNSUBSCRIBE or update options visit:
>   http://lists.digium.com/mailman/listinfo/asterisk-users
>