On 09/21/2009 12:46 PM, Tilghman Lesher wrote:
> On Sunday 20 September 2009 22:32:41 Tzafrir Cohen wrote:
>    
>> Isn't 40ms the minimal time for a valid dtmf digit?
>>      
> $ grep -C1 'define AST_MIN_DTMF_DURATION' main/channel.c
> /*! Minimum allowed digit length - 80ms */
> #define AST_MIN_DTMF_DURATION 80
>
> This post, from the archives, is instructive and germane to the code in
> question:
> http://lists.digium.com/pipermail/asterisk-dev/2007-April/027271.html
>
>    
If a DTMF decoder doesn't register a digit in under 40ms its broken. 
80ms is the minimum total digit cycle time many people specify, 
including the silence between digits. This time varies between specs, 
though. Some things specify the minimum cycle as 100ms.

Steve


_______________________________________________
-- Bandwidth and Colocation Provided by http://www.api-digital.com --

AstriCon 2009 - October 13 - 15 Phoenix, Arizona
Register Now: http://www.astricon.net

asterisk-users mailing list
To UNSUBSCRIBE or update options visit:
   http://lists.digium.com/mailman/listinfo/asterisk-users

Reply via email to