[PD] phase-canceling

[joel silvestre]

Le lundi 23 février 2009 à 23:02 +0100, yohannes a écrit :
> hello everybody,
> 
> maybe sounds absurd:
> 
> is it possible to cancel an whole signal of an mic input through 
> phase-canceling?
> 
> if yes, how can i do dat in pd?
> 

Hi yohannes,

maybe you are looking for something like an acoustic echo canceller.
Speex has one:

http://www.speex.org/docs/manual/speex-manual/node4.html#SECTION00450000000000000000

maec~.c is a more than ugly very first attempt for an external quickly
written to give speex a try. 
I had quite good results, close to 20dB rejection, with only one micro
and only one speaker. Rejection is close to nothing with 2 speakers. As
I need a good rejection with 5 speakers I gave up. 

All the best,
Joël

-------------- next part --------------
A non-text attachment was scrubbed...
Name: maec~.c
Type: text/x-csrc
Size: 4834 bytes
Desc: not available
URL: <http://lists.puredata.info/pipermail/pd-list/attachments/20090224/63835a94/attachment.c>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Makefile
Type: text/x-makefile
Size: 1974 bytes
Desc: not available
URL: <http://lists.puredata.info/pipermail/pd-list/attachments/20090224/63835a94/attachment.bin>