DTMFDECODE(1) BSD General Commands Manual DTMFDECODE(1)
NAME
dtmfdecode -- decodes DTMF tones from A-law audio data
SYNOPSIS
dtmfdecode
DESCRIPTION
dtmfdecode is part of the isdn4bsd package and is used to detect DTMF tones in the audio stream.
It reads audio G.711 A-law coded data from stdin and outputs the detected numbers values as ASCII characters to stdout.
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.
EXAMPLES
The command:
dtmfdecode < beep.al
will print a "1" to stdout.
STANDARDS
ITU Recommendations G.711
AUTHORS
The dtmfdecode utility was written by Poul-Henning Kamp <phk@freebsd.org>. This man page was written by
Hellmuth Michaelis <hm@freebsd.org>.
BSD
February 15, 1999 BSD
