From: Wolfgang Fritz <wolfgang.fritz@gmx.net>
To: linux-kernel@vger.kernel.org
Subject: Re: [Asterisk] DTMF noise
Date: Wed, 08 Jan 2003 17:30:54 +0100 [thread overview]
Message-ID: <3E1C523E.5050105@gmx.net> (raw)
In-Reply-To: 3E1C4872.7080508@gmx.net
Wolfgang Fritz wrote:
[cut]
>
> There exists a long text about DTMF detection somewhere on the net (I
> may have the link in the office but I'm on vacation now). What I
> remember is that a "correct" DTMF detection requires much more computing
> power as the present i4l implementation needs (much longer audio samples
> for the goertzel filter, a larger number of frequencies to check) and a
> standard test procedure with a lot of test cases which are not available
> to mortal humans (audio tapes from Bellcore IIRC)
>
The link below is not the text I mean above but shows an approach which
is similar to the present i4l implementation but has some improvements
which may be good enough for us.
http://www.mitsubishichips.com/press/dtmf0199e.pdf
> Wolfgang
> >
[cut]
next prev parent reply other threads:[~2003-01-08 16:24 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20030107140012$1b66@gated-at.bofh.it>
[not found] ` <20030107150006$4896@gated-at.bofh.it>
2003-01-07 19:08 ` [Asterisk] DTMF noise Thomas Tonino
2003-01-07 22:46 ` Roy Sigurd Karlsbakk
2003-01-08 7:51 ` Thomas Tonino
2003-01-08 12:43 ` David D. Hagood
2003-01-08 13:04 ` Matti Aarnio
2003-01-08 15:49 ` Wolfgang Fritz
2003-01-08 16:30 ` Wolfgang Fritz [this message]
2003-01-08 19:48 ` Andrew McGregor
2003-01-08 22:19 ` Jamie Lokier
2003-01-09 12:51 ` David D. Hagood
2003-01-09 13:31 ` Wolfgang Fritz
2003-01-09 23:32 ` David D. Hagood
2003-01-10 6:52 ` Matti Aarnio
2003-01-10 12:42 ` David D. Hagood
2003-01-10 12:03 ` Roy Sigurd Karlsbakk
2003-01-08 20:22 ` Thomas Tonino
2003-01-09 12:42 ` David D. Hagood
2003-01-07 13:55 Roy Sigurd Karlsbakk
2003-01-07 14:49 ` [Asterisk] " Mark Spencer
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