[pulseaudio-discuss] How to implement CS-call module in PA?

[Rémi Denis-Courmont]

Hello,

On Mon, 11 Jan 2010 18:57:56 +0800, tieg <tie.ge at access-company.com> wrote:
> I'd like to implement a CS-Call module in pule audio.
> That is to say voice call data will be handled at user space.
> Such mechanism is different from traditional H/W voice call solution.
> Its pros points is voice data can be rendered specially.
> For example, you can add echo/noise cancellation.
> Is there any examples or guide I can refer to? 

I am not aware of any commonly used standard to get circuit-switched voice
data out of a voice modem. You can typically dial and answer with AT
commands. But as you seem to imply, voice audio is often routed directly in
the hardware to the speakers.

The Nokia N900 does route CS audio through PulseAudio. This is done using a
dedicated kernel driver for Nokia modems talking to a Nokia-specific
PulseAudio plugin. My point is, it's entirely dependent on the specific
hardware whether and if so, how CS audio can be routed from/to user-space
(and PulseAudio in particular). So a generic example wouldn't make much
sense IMHO.

-- 
Rémi Denis-Courmont
http://www.remlab.net
http://fi.linkedin.com/in/remidenis