[pulseaudio-discuss] RFC: add multi-channel AEC support

Peter Meerwald pmeerw at pmeerw.net
Tue Dec 4 06:18:22 PST 2012


we'd like to integrate a 4-channel beam-forming/noise suppression/echo 
cancellation module in PulseAudio's AEC framework

the idea is to have a audio source with 4 channels, process that, and pass 
a mono stream to the application (some VoIP, hands-free client); the 
application plays a mono stream

we found some issues in the PA AEC code due to the asymmetric nature of 
the processing (4 channels in, 1 channel out); please consider the patches 

the biggest modification is a proposed change to the modules' pa_xxx_ec_init() 
call: we suggest to replace the parameter blocksize with a parameter 
nframes -- blocksize is ambiguous if source and sink have a different 
number of channels; however, the number of frames is still the same in the 
asymmetric case

we'll follow up with dummy/null implementation of a 4-channel AEC module

BTW, let me introduce Stefan who did most of the work!

thanks, regards, p.


Peter Meerwald
+43-664-2444418 (mobile)

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