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From: Roy Sigurd Karlsbakk <roy@karlsbakk.net>
Organization: ProntoTV AS
To: Matti Aarnio <matti.aarnio@zmailer.org>,
       Kernel mailing list <linux-kernel@vger.kernel.org>
Subject: Re: i4l dtmf errors
Date: Sat, 14 Dec 2002 15:54:29 +0100
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>   Quick reading of  drivers/isdn/isdn_audio.c(*)  shows that it does use
>   fixed-point G?rtzel (Goertzel in english) algorithm for detecting
>   tones, but it does _not_ do comparison of received overall signal
>   power vs. detected DTMF tone powers.
>
>   When there is signal power outside the DTMF channels, signal should
>   not be detected.  Also, DTMF tone powers should be roughly equal,
>   and exactly two tones should be present for valid detection.
>
>       http://www.numerix-dsp.com/goertzel.html
>
>   Adding those power tests should be fairly trivial, but I leave it
>   to Somebody Else...

Is there a 'somebody else' (perhaps the isdn maintainer?) that have time to 
look at this?

thanks

roy
-- 
Roy Sigurd Karlsbakk, Datavaktmester
ProntoTV AS - http://www.pronto.tv/
Tel: +47 9801 3356

Computers are like air conditioners.
They stop working when you open Windows.

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