$NetBSD: dtmfdecode.1,v 1.4 2002/07/29 00:54:45 wiz Exp $
Copyright (c) 1999 Hellmuth Michaelis. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
$Id: dtmfdecode.1,v 1.5 2003/04/16 12:53:08 wiz Exp $
$FreeBSD$
last edit-date: [Mon Dec 13 22:53:13 1999]
.Dd February 15, 1999 .Dt DTMFDECODE 1 .Os .Sh NAME .Nm dtmfdecode .Nd decodes DTMF tones from A-law audio data .Sh SYNOPSIS .Nm .Sh DESCRIPTION .Nm is part of the isdn4bsd package and is used to detect DTMF tones in the audio stream.
Copyright (c) 1999 Hellmuth Michaelis. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
$Id: dtmfdecode.1,v 1.5 2003/04/16 12:53:08 wiz Exp $
$FreeBSD$
last edit-date: [Mon Dec 13 22:53:13 1999]
.Dd February 15, 1999 .Dt DTMFDECODE 1 .Os .Sh NAME .Nm dtmfdecode .Nd decodes DTMF tones from A-law audio data .Sh SYNOPSIS .Nm .Sh DESCRIPTION .Nm is part of the isdn4bsd package and is used to detect DTMF tones in the audio stream.
p It reads audio G.711 A-law coded data from stdin and outputs the detected numbers values as ASCII characters to stdout.
p The detector is implemented as 8 narrow band-pass filters realized with an integer double-cross recursive algorithm. Various ad-hoc methods are employed to provide hysteresis and anti-bounce for the detected signals. .Sh EXAMPLES The command: d -literal -offset indent dtmfdecode \*[Lt] beep.al .Ed
p will print a "1" to stdout. .Sh STANDARDS ITU Recommendations G.711 .Sh AUTHORS The .Nm utility was written by .An Poul-Henning Kamp Aq phk@freebsd.org . This man page was written by .An Hellmuth Michaelis Aq hm@freebsd.org .