<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:p="urn:schemas-microsoft-com:office:powerpoint" xmlns:a="urn:schemas-microsoft-com:office:access" xmlns:dt="uuid:C2F41010-65B3-11d1-A29F-00AA00C14882" xmlns:s="uuid:BDC6E3F0-6DA3-11d1-A2A3-00AA00C14882" xmlns:rs="urn:schemas-microsoft-com:rowset" xmlns:z="#RowsetSchema" xmlns:b="urn:schemas-microsoft-com:office:publisher" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns:c="urn:schemas-microsoft-com:office:component:spreadsheet" xmlns:oa="urn:schemas-microsoft-com:office:activation" xmlns:html="http://www.w3.org/TR/REC-html40" xmlns:q="http://schemas.xmlsoap.org/soap/envelope/" xmlns:D="DAV:" xmlns:x2="http://schemas.microsoft.com/office/excel/2003/xml" xmlns:ois="http://schemas.microsoft.com/sharepoint/soap/ois/" xmlns:dir="http://schemas.microsoft.com/sharepoint/soap/directory/" xmlns:ds="http://www.w3.org/2000/09/xmldsig#" xmlns:dsp="http://schemas.microsoft.com/sharepoint/dsp" xmlns:udc="http://schemas.microsoft.com/data/udc" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:sps="http://schemas.microsoft.com/sharepoint/soap/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:udcxf="http://schemas.microsoft.com/data/udc/xmlfile" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv=Content-Type content="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 12 (filtered medium)">
<style>
<!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p
{mso-style-priority:99;
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;}
@page Section1
{size:612.0pt 792.0pt;
margin:2.0cm 42.5pt 2.0cm 3.0cm;}
div.Section1
{page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=RU link=blue vlink=purple>
<div class=Section1>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Well, to me it sounds like business of DSP code itself to do
such a filtering. <o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>It sounds like bad idea if DSP will be detecting “raw”
DTMF while some upper-level code (like channel driver or even application code)
is post-processing it eliminating false alerts.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>So it is not question of generating BEGIN frames, it is more
like a question of improving DTMF detection in DSP.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'>
<p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:
"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'> asterisk-dev-bounces@lists.digium.com
[mailto:asterisk-dev-bounces@lists.digium.com] <b>On Behalf Of </b>John Aughey<br>
<b>Sent:</b> Monday, December 03, 2007 4:35 AM<br>
<b>To:</b> Asterisk Developers Mailing List<br>
<b>Subject:</b> Re: [asterisk-dev] DTMF end accepted without begin<o:p></o:p></span></p>
</div>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal style='margin-bottom:12.0pt'>The begin frames (and
associated end frames) are helpful to filter out short dtmf reads.
There's even a #define which specifies the minimum length of a dtmf tone.
One problem we're having is multiple dtmf detections on a noisy cell phone
connection, which should be mostly filtered by knowing the begin and end time
so that the length can be properly measured and filtered if needed. <br>
<br>
John<o:p></o:p></p>
<div>
<p class=MsoNormal>On Dec 2, 2007 6:58 PM, Dmitry Andrianov <<a
href="mailto:dimas@dataart.com">dimas@dataart.com</a>> wrote:<o:p></o:p></p>
<div>
<div>
<p><span lang=EN-US style='font-size:11.0pt;color:#1F497D'>As far as I
understand, Asterisk DSP code does not generate DTMF_BEGIN frames (at least
unless DSP_DIGITMODE_MUTECONF+DSP_DIGITMODE_MUTEMAX flags are passed to DSP
– I do not completely understand that branch of code). This means it is
not problem with your configuration, it is the way how DSP code works now.</span><o:p></o:p></p>
<p><span lang=EN-US style='font-size:11.0pt;color:#1F497D'> </span><o:p></o:p></p>
<p><span lang=EN-US style='font-size:11.0pt;color:#1F497D'>I believe this can
be easily fixed if anyone needs these BEGIN frames.</span><o:p></o:p></p>
<p><span lang=EN-US style='font-size:11.0pt;color:#1F497D'> </span><o:p></o:p></p>
<div style='border:none;border-top:solid windowtext 1.0pt;padding:3.0pt 0cm 0cm 0cm;
border-color:-moz-use-text-color -moz-use-text-color'>
<p><b><span lang=EN-US style='font-size:10.0pt'>From:</span></b><span
lang=EN-US style='font-size:10.0pt'> <a
href="mailto:asterisk-dev-bounces@lists.digium.com" target="_blank">asterisk-dev-bounces@lists.digium.com</a>
[mailto:<a href="mailto:asterisk-dev-bounces@lists.digium.com" target="_blank">asterisk-dev-bounces@lists.digium.com</a>]
<b>On Behalf Of </b>John Aughey<br>
<b>Sent:</b> Sunday, December 02, 2007 3:20 PM<br>
<b>To:</b> <a href="mailto:asterisk-dev@lists.digium.com" target="_blank">asterisk-dev@lists.digium.com</a><br>
<b>Subject:</b> [asterisk-dev] DTMF end accepted without begin</span><o:p></o:p></p>
</div>
<div>
<div>
<p> <o:p></o:p></p>
<p>I was having problems with consistent DTMF detection on a FXO Zap device, so
I turned on DTMF logging. I noticed that it always reports "DTMF end
accepted without begin" for every digit pressed. I've verified this
on 1.4.15 and the latest svn release. It indicates a duration of 0ms
which is consistent with not receiving a begin event. The tones get
"detected", but it can't do any filtering based on duration this way.<br>
<br>
This seems to be a core problem that the Zap layer isn't passing on DTMF_BEGIN
events. Is this a known issue or is anyone working on this problem?
Or could I have something messed up in my own configuration?<br>
<br>
Thanks<br>
<br>
John Aughey<o:p></o:p></p>
</div>
</div>
</div>
</div>
<p class=MsoNormal><br>
_______________________________________________<br>
--Bandwidth and Colocation Provided by <a href="http://www.api-digital.com--"
target="_blank">http://www.api-digital.com--</a><br>
<br>
asterisk-dev mailing list<br>
To UNSUBSCRIBE or update options visit: <br>
<a href="http://lists.digium.com/mailman/listinfo/asterisk-dev"
target="_blank">http://lists.digium.com/mailman/listinfo/asterisk-dev</a><o:p></o:p></p>
</div>
<p class=MsoNormal><o:p> </o:p></p>
</div>
</body>
</html>