[Freeswitch-users] Detecting the origin of voice activity using VAD

[Cameron Sorlie]

In a sense, you might say I did futz with mod_vmd ... to create mod_vad.
There appeared to be just no (easy) way to modify the internal VAD code in
the FreeSWITCH core (see switch_rtp.c) to identify the origins of voice
activity. And rather than build into mod_vmd, which is a special purpose
tool, a separate module for VAD seemed like a reasonable idea.

In short, the mod_vad which I've written up independently monitors the read
and the write legs of the session it is run on, and tags each VAD_TALK and
VAD_NOTALK event it fires with a user-supplied identification marker (a
short string) for the leg which the event relates to. At the moment, the VAD
algorithm is dead simple, and is much like the one in the core. I will be
happy to submit this module, in a little while, after I've had a chance to
make it perhaps a bit more useable outside of our own application context.

Cam

On Mon, Mar 2, 2009 at 5:43 PM, <
freeswitch-users-request at lists.freeswitch.org> wrote:

>
> On Mon, Mar 2, 2009 at 11:48 AM, Anthony Minessale
> <anthony.minessale at gmail.com> wrote:
> > i think that's what mod_vmd does
> >
> I think that's right. It just does the opposite - instead of looking
> for differing power levels it looks for the same power level. In other
> words it tries to detect distinctly non-human sound. I'll bet you
> could futz with that code and have it fire off events when it detects
> what it believes is human speech.
>
> -MC
>
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