From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 8 Jan 2003 07:56:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 8 Jan 2003 07:56:03 -0500 Received: from mail.zmailer.org ([62.240.94.4]:13719 "EHLO mail.zmailer.org") by vger.kernel.org with ESMTP id ; Wed, 8 Jan 2003 07:56:02 -0500 Date: Wed, 8 Jan 2003 15:04:40 +0200 From: Matti Aarnio To: "David D. Hagood" Cc: linux-kernel Subject: Re: [Asterisk] DTMF noise Message-ID: <20030108130440.GC5948@mea-ext.zmailer.org> References: <3E1BD88A.4080808@users.sf.net> <3E1C1CDE.8090600@sktc.net> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <3E1C1CDE.8090600@sktc.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 08, 2003 at 06:43:10AM -0600, David D. Hagood wrote: > Thomas Tonino wrote: > >Roy Sigurd Karlsbakk wrote: > >>so - we DO NOT need a 'simplistic' DTMF decoder. > > > >You need a good one. But good can be simplistic, is what I'm saying. > > > >DTMF was designed to be easy to decode reliably. Complex doesn't > >automatically mean better. > > I haven't looked at the code, but I'd recommend using a bank of Goertzel > filters - Do look into drivers/isdn/isdn_audio.c That does use Görtzel filter, but does not do complete energy comparisons -> false detections. /Matti Aarnio