[pulseaudio-discuss] Best place/way to incorporate a convolver into the audio stream

[Neil Wilson]

Hi,

I've been spending a bit of time playing with Digital Room Correction
and I'm trying to work out the best place/way of including the
convolver filter into the audio stream.

Obviously I can hack this in and make it work in one situation, but I
want a more elegant design that will work in a number of scenarios:

- locally with one sound card.
- locally with multiple sound outputs (with a different filter
configuration for each output).
- filter running locally talking to a dumb device output over the
network (Apple Airport for example).
- talking to another pulseaudio soundserver on the network.

with a view to making this relatively easy to use for the average
'consumer'. That suggests Pulseaudio rather than a Jack setup.

I'm not sure front end solutions (in the media player or Gstreamer)
are appropriate since it would stop, say, applications like Spotify
under Wine working properly (incidentally I've packaged Wine with
PulseAudio drivers for Ubuntu -
http://www.3spoken.co.uk/2009/08/making-wine-sound-work-with-pulseaudio.html).

Is there a way with PulseAudio to include the convolver in the audio
stream or should I be looking at patching the filter in at the ALSA
layer? Am I looking at this the right way? What would you suggest as
the best design approach here?

All suggestions appreciated.

TIA

-- 
Neil Wilson