[Freeswitch-users] Remove inband DTMF on record_session

Matt Broad matt at inveroak.com
Fri Jan 25 23:14:57 MSK 2013

Thanks for the response Steve, is there a way of checking the dtmf type? I
have tried looking at the Sofia profile but cannot see any details
regarding dtmf.

 I assume that this is determined by my sip provider?


On Friday, 25 January 2013, Steven Ayre wrote:

> If you're using RFC2833 then that's not in the audio itself so won't be
> recorded. It is possible though that the caller is ending DTMF both in and
> out of band (which is fine as long as you only try to detect one or the
> other but not both).
> -Steve
> On 25 January 2013 14:27, Matt Broad <matt at inveroak.com> wrote:
> Hi,
> sorry to interject into your message, but I was looking to do something
> similar to Tamas.
> I have the need to prevent the DTMF from being recorded when using
> record_session. I am using RFC2833 (i think :) ), is this at all possible
> in the current Freeswitch build?
> Matt
> On 21 January 2013 07:25, Tamas Jalsovszky <jalsot at gmail.com> wrote:
> Hello Moy,
> Inserting silence instead of the tone would be fine for me. I think the >=
> 50ms delay in recording is not an issue. I guess, removing from "live"
> streams would be harder and would introduce the delay you mentioned.
> So you have a plan to add such a functionality in the near future? That
> would be amazing :)
> Regards,
>   Jalsot
> On Mon, Jan 21, 2013 at 2:48 AM, Moises Silva <moises.silva at gmail.com>wrote:
> On Sun, Jan 20, 2013 at 4:12 PM, Tamas Jalsovszky <jalsot at gmail.com>wrote:
> Hello,
> Is there a way to to remove inbad DTMF from the recorded wav file
> (conditionaly)?
> If not, how could be that done the easyiest way and a way it could get
> into FS git?
> As FS has a great DTMF detector and it has probably all the stuff doing
> such a feature, I think it would be much better than using an external tool
> for removing DTMF from finished wav file - and it would consume more I/O
> probably.
> Removing it would not be that hard (ie, inserting silence instead).
> Removing it without leaving a trace any DTMF was ever there sounds a tad
> more difficult. If you're ok with inserting a silence instead of the tone,
> extending the record_session app to detect and remove DTMF is probably what
> I'd do.
> It is also possible to create a new app that monitors the audio stream and
> silence the stream when DTMF is detected, but since the detection takes a
> few milliseconds (~50ms), there would be a bit of "bleeding" of DTMF in the
> signal, unless the new app also delays the signal by 50ms and then has a
> way to strip the DTMF completely.
> *Moises Silva
> **Manager, Software Engineering***
> msilva at sangoma.com
> Sangoma Technologies
> 100 Renfrew Drive, Suite 100, Markham, ON L3R 9R6 Canada


This email and any attachments to it are confidential and are intended
solely for the use of the individual to whom it is addressed. Any views or
opinions expressed are solely those of the author and do not necessarily
represent those of InverOak Limited.

If you are not the intended recipient of this email, you must neither take
any action based upon its contents, nor copy or show it to anyone. Please
contact the sender if you believe you have received this email in error.

This email including any attachments cannot be guaranteed to be 100% secure
or error-free as information could be intercepted, corrupted, lost,
destroyed, out-dated, or containing viruses. The sender therefore does not
accept liability for any errors or omissions in the contents of this
message which arise as a result of email transmission.

InverOak Limited is a company registered in England & Wales under company
number 04529594, whose registered address is Old Barn house, 2 Wannions
Close, Botley, Chesham, Buckinghamshire, HP5 1YA, United Kingdom.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.freeswitch.org/pipermail/freeswitch-users/attachments/20130125/3945b13c/attachment-0001.html 

Join us at ClueCon 2011 Aug 9-11, 2011
More information about the FreeSWITCH-users mailing list