[Freeswitch-users] mod_stress

[Steven Ayre]

Media bugs are used to hook into the call and provide decoded audio to the
module. That requires transcoding, naturally. See stress_callback which is
called for each audio frame plus some init/cleanup hooks, and read up on
the API at http://docs.freeswitch.org/group__mb1.html.

I suspect read vs write would correspond to the speaking/listening
directions of the channel. Read from caller, write to caller? The names
come from the media bug API. The read/write options will add the
corresponding media bug, stop will remove them.

SWITCH_ADD_APP tells you it's a dialplan application - it's started from
dialplan, although you can also trigger dialplan apps on a channel via ESL
using uuid_broadcast.

The FFT algorithm is used to extract the frequencies present in the sample
(the power spectrum). The algorithm then tries to detect stressed based on
that. Looks like the algorithm at least in part attempts to look for tremor
in the voice. More tremor indicates more stress. Over a threshold it raises
an event.

Bear in mind that as it's pattern recognition (and little tested at that)
you'll get a lot of false positives and false negatives. It's also looking
for something in the voice that may or may not be there - some people might
be able to speak with an unstressed voice when they're actually quite
stressed.

-Steve




On 22 January 2013 11:19, Peter Steinbach <lists at telefaks.de> wrote:

>  Hello Anthony,
>
> although it may be incomplete, it may be useful for us. Can you give us
> some basic explanation, how this works?
> I can see in the code that there is a stress command with read|write|stop
> parameter.
> Is this to be issued via event socket or is it a dialplan application? I
> suspect that "read" somehow starts the detection and "stop" somehow stops
> the detection. For "write"  I currently have no idea.
>
> I would be happy to test this and report my configuration, explanations
> and examples in the wiki.
>
> Best regards
> Peter
>
>
>
> On 01/22/13 00:30, Anthony Minessale wrote:
>
> That module is incomplete we made it several years ago to test some code
> that was supposed to pick up on stress in your voice in a media bug so we
> could fire events and whisper "lie" to the caller as he talked to the guy.
>
>
>
> On Mon, Jan 21, 2013 at 4:56 PM, Peter Steinbach <lists at telefaks.de>wrote:
>
>> I am also wondering, what this module does in detail.
>>
>> Regarding the source code, I can see that FFT's are made in order to to
>> get some sort of frequency profile.
>> But the code and remarks do not give me a clue how this module actually
>> works.
>>
>> Best regards Peter
>>
>>
>>
>> On 05/26/12 15:05, BF wrote:
>> > Hello,
>> >
>> > I'd like to know what the "stress write" from mod_stress module does. I
>> have hard time finding documentation or an example about mod_stress module.
>> >
>> > Anyone?
>> >
>> > Thank you.
>> >
>> > Eric
>> >
>> _________________________________________________________________________
>> > Professional FreeSWITCH Consulting Services:
>> > consulting at freeswitch.org
>> > http://www.freeswitchsolutions.com
>> >
>> > 
>> > 
>> >
>> > Official FreeSWITCH Sites
>> > http://www.freeswitch.org
>> > http://wiki.freeswitch.org
>> > http://www.cluecon.com
>> >
>> > Join Us At ClueCon - Aug 7-9, 2012
>> >
>> > FreeSWITCH-users mailing list
>> > FreeSWITCH-users at lists.freeswitch.org
>> > http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>> > UNSUBSCRIBE:
>> http://lists.freeswitch.org/mailman/options/freeswitch-users
>> > http://www.freeswitch.org
>> >
>>
>>
>> --
>> With kind regards
>> Peter Steinbach
>>
>> Telefaks Services GmbH
>> mailto:lists (att) telefaks.de
>> Internet: www.telefaks.de
>>
>>
>> _________________________________________________________________________
>> Professional FreeSWITCH Consulting Services:
>> consulting at freeswitch.org
>> http://www.freeswitchsolutions.com
>>
>> 
>> 
>>
>> Official FreeSWITCH Sites
>> http://www.freeswitch.org
>> http://wiki.freeswitch.org
>> http://www.cluecon.com
>>
>> FreeSWITCH-users mailing list
>> FreeSWITCH-users at lists.freeswitch.org
>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
>> http://www.freeswitch.org
>>
>
>
>
>  --
> Anthony Minessale II
>
> FreeSWITCH http://www.freeswitch.org/
> ClueCon http://www.cluecon.com/
> Twitter: http://twitter.com/FreeSWITCH_wire
>
> AIM: anthm
> MSN:anthony_minessale at hotmail.com
> GTALK/JABBER/PAYPAL:anthony.minessale at gmail.com
> IRC: irc.freenode.net #freeswitch
>
> FreeSWITCH Developer Conference
> sip:888 at conference.freeswitch.org
> googletalk:conf+888 at conference.freeswitch.org
> pstn:+19193869900
>
>
> _________________________________________________________________________
> Professional FreeSWITCH Consulting Services:consulting at freeswitch.orghttp://www.freeswitchsolutions.com
>
> FreeSWITCH-powered IP PBX: The CudaTel Communication Server
>
> Official FreeSWITCH Siteshttp://www.freeswitch.orghttp://wiki.freeswitch.orghttp://www.cluecon.com
>
> FreeSWITCH-users mailing listFreeSWITCH-users at lists.freeswitch.orghttp://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-usershttp://www.freeswitch.org
>
>
>
> --
> With kind regards
> Peter Steinbach
>
> Telefaks Services GmbHmailto:lists <lists> (att) telefaks.de
> Internet: www.telefaks.de
>
>
> _________________________________________________________________________
> Professional FreeSWITCH Consulting Services:
> consulting at freeswitch.org
> http://www.freeswitchsolutions.com
>
> 
> 
>
> Official FreeSWITCH Sites
> http://www.freeswitch.org
> http://wiki.freeswitch.org
> http://www.cluecon.com
>
> FreeSWITCH-users mailing list
> FreeSWITCH-users at lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> http://www.freeswitch.org
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.freeswitch.org/pipermail/freeswitch-users/attachments/20130122/1d652c7d/attachment-0001.html