<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
  </head>
  <body text="#000000" bgcolor="#FFFFFF">
    <p>The false positive rate for the DTMF decoder in spandsp is
      extremely low. Tests show it has one of the lowest false positive
      rates in the industry. If you are seeing significant false
      positives you might actually have some DTMF in the audio. Can you
      capture some troublesome audio to a file for analysis?</p>
    <p>Regards,</p>
    <p>Steve<br>
    </p>
    <div class="moz-cite-prefix">On 01/29/2018 02:35 PM, Roman Dissauer
      wrote:<br>
    </div>
    <blockquote type="cite"
      cite="mid:57951C1A-1F3E-487E-8CFA-EBF633CCF1FC@dissauer.net">
      <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
      Hi Guys,
      <div class=""><br class="">
      </div>
      <div class="">we have troubles reliably recognizing DTMF tones by
        using dialplan application start_dtmf.</div>
      <div class="">From our carriers we get some calls with inband DTMF
        and some with RFC2833. To our customers we need to always do
        RFC2833. Therefore we check SDP information and enable
        start_dtmf when RFC2833 is not available on the incoming call.
        When start_dtmf is executed we have a lot of false positives
        mostly at the start of audio but also during the call.</div>
      <div class=""><br class="">
      </div>
      <div class="">Is there a way to prevent false DTMF detection? Does
        anyone have same issues and a solution for it?</div>
      <div class=""><br class="">
      </div>
      <div class="">Kind regards<br class="">
        <div class="">
          <div>Roman Dissauer</div>
          <div><br class="">
          </div>
          <div>
            <div class=""><font class="" color="#53655a"
                face="GillSans-SemiBold"><b class="">RDI SOLUTIONS e.U.</b></font></div>
            <div class=""><font class="" color="#4d4e4c"
                face="GillSans-Light">Rosasgasse 13/24</font></div>
            <div class=""><font class="" color="#4d4e4c"
                face="GillSans-Light">1120 Wien, Österreich</font></div>
            <div class=""><font class="" color="#4d4e4c"
                face="GillSans-Light">T: +43 1 3530349 - 10</font></div>
            <div class=""><font class="" color="#4d4e4c"
                face="GillSans-Light">F: +43 1 3530349 - 99</font></div>
            <div class=""><font class="" color="#4d4e4c"
                face="GillSans-Light"><a
                  href="mailto:roman.dissauer@rdi.at" class=""
                  moz-do-not-send="true">roman.dissauer@rdi.at</a></font></div>
            <div class=""><font class="" color="#4d4e4c"
                face="GillSans-SemiBold"><b class=""><a
                    href="http://www.rdi.at" class=""
                    moz-do-not-send="true">www.rdi.at</a></b></font></div>
            <div class=""><font class="" color="#4d4e4c"
                face="GillSans-SemiBold"><b class=""><br class="">
                </b></font></div>
          </div>
        </div>
      </div>
      <br>
      <fieldset class="mimeAttachmentHeader"></fieldset>
      <br>
      <pre wrap="">_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
<a class="moz-txt-link-abbreviated" href="mailto:consulting@freeswitch.org">consulting@freeswitch.org</a>
<a class="moz-txt-link-freetext" href="http://www.freeswitchsolutions.com">http://www.freeswitchsolutions.com</a>

Official FreeSWITCH Sites
<a class="moz-txt-link-freetext" href="http://www.freeswitch.org">http://www.freeswitch.org</a>
<a class="moz-txt-link-freetext" href="http://confluence.freeswitch.org">http://confluence.freeswitch.org</a>
<a class="moz-txt-link-freetext" href="http://www.cluecon.com">http://www.cluecon.com</a>

FreeSWITCH-users mailing list
<a class="moz-txt-link-abbreviated" href="mailto:FreeSWITCH-users@lists.freeswitch.org">FreeSWITCH-users@lists.freeswitch.org</a>
<a class="moz-txt-link-freetext" href="http://lists.freeswitch.org/mailman/listinfo/freeswitch-users">http://lists.freeswitch.org/mailman/listinfo/freeswitch-users</a>
UNSUBSCRIBE:<a class="moz-txt-link-freetext" href="http://lists.freeswitch.org/mailman/options/freeswitch-users">http://lists.freeswitch.org/mailman/options/freeswitch-users</a>
<a class="moz-txt-link-freetext" href="http://www.freeswitch.org">http://www.freeswitch.org</a></pre>
    </blockquote>
    <br>
  </body>
</html>