MULTIMON(1) General Commands Manual MULTIMON(1)NAME
multimon - program to decode radio transmissions
SYNOPSIS
multimon [options] [input_file]
DESCRIPTION
This manual page documents briefly the multimon command. This manual page was written for the Debian GNU/Linux distribution because the
original program does not have a manual page.
The multimon software can decode a variety of digital transmission modes commonly found on UHF radio. A standard PC soundcard is used to
acquire the signal from a transceiver. The decoding is done completely in software. Currently, the following modes are supported:
* AX.25
o 1200 Baud AFSK
o 2400 Baud AFSK (2 variants)
o 4800 Baud HAPN
o 9600 Baud FSK (G3RUH)
* POCSAG
o 512 Baud
o 1200 Baud
o 2400 Baud
* Miscellaneous
o DTMF
o ZVEI
o SCOPE
An arbitrary set of the above modes may run concurrently on the same input signal (provided the CPU power is sufficient), so you do not
have to know in advance which mode is used. Note however that some modes might require modifications to the radio (especially the 9600 baud
FSK and the POCSAG modes) to work properly.
AX.25 - Amateur Packet Radio protocol datagram format
POCSAG (Post Office Code Standards Advisory Group) is a common paging transmission format.
DTMF - Dual Tone Multi Frequency. Commonly used in in-band telephone dialing.
ZVEI- The German Electrical and Electronic Manufacturers' Association - paging tone format.
SCOPE - show samples in a rudimentary oscilloscope display on an X server.
Multimon does not decode Morse code signals.
OPTIONS -t <type>
input file type (any other type than raw requires sox)
allowed types: raw aiff au hcom sf voc cdr dat smp wav maud vwe
-a <demod>
add demodulator
-s <demod>
subtract demodulator
Where <demod> is one of: POCSAG512 POCSAG1200 POCSAG2400 EAS AFSK1200 AFSK2400 AFSK2400_2 HAPN4800 FSK9600 DTMF ZVEI SCOPE
The -a and -s options may be given multiple times to specify the desired list of demodulators.
EXAMPLE
Decode signal modulations from a sound file /tmp/message.wav without using a SCOPE display:
multimon -s SCOPE -t wav /tmp/message.wav
With no input file specified, the program listens directly to the sound card using the /dev/dsp interface. So to decode (only) DTMF tones
on the sound card input:
multimon -a DTMF
NOTICE
Please note that monitoring commercial services may be prohibited in some countries, this software should therefore only be used to monitor
the amateur radio service.
SEE ALSO gen(1) http://www.qsl.net/kb9mwr/projects/pager/Two-Tone%20Pager%20Decoding%20Using%20Multimon.pdf
BUGS
The DTMF and ZVEI decoders have more frequent spurious detection reports.
AUTHOR
This manual page was written by A. Maitland Bottoms <bottoms@debian.org>, for the Debian GNU/Linux system (but may be used by others).
June 19, 2000 MULTIMON(1)
Check Out this Related Man Page
Net::SIP::DTMF(3pm) User Contributed Perl Documentation Net::SIP::DTMF(3pm)NAME
Net::SIP::DTMF - DTMF RTP packet generating and extracting
SYNOPSIS
use Net::SIP::DTMF;
my $sub = dtmf_generator(
11, # event '#'
100, # duration 100ms
rfc2833_type => 101, # RTP type 101 for telephone-event/8000
# audio_type => 0, # RTP type 0 for PCMU/8000
);
while (...) {
my @pkt = $sub->($sequence,$timestamp,$srcid);
last if ! @pkt; # dtmf done
next if $buf[0] eq ''; # more coming, but no data this time (pause)
.. send @pkts ...
}
use Net::SIP::DTMF;
my $sub = dtmf_extractor(
rfc2833_type => 101, # RTP type 101 for telephone-event/8000
audio_type => 0, # RTP type 0 for PCMU/8000
);
while (...) {
if ( my ($event,$duration,$type) = $sub->($packet)) {
# event received
...
}
}
DESCRIPTION
This package provides functions for generating RTP packets containing DTMF events or extracting DTMF events from RTP packets.
FUNCTIONS
dtmf_generator ( EVENT, DURATION, %ARGS )
Generates a function which is used to generate packets for the given EVENT.
EVENT is the event numer (0..15) or undef if it should just generate silence or pause. DURATION is the time for the event in ms. ARGS
contain information how the event should be packed: either as RFC2833 RTP event or as RTP audio PCMU/8000. %ARGS can be
rfc2833_type => rtp_type
Gives the RTP payload type number for rfc2833 RTP events (telephone-event/8000). If not given will try audio_type instead.
audio_type => rtp_type
Gives the RTP payload type number for PCMU/8000. If not given and no rfc2833_type given it will croak.
volume => volume
Sets the volume for RTP event according to rfc2833.
The generated function should then be called with SEQUENCE,TIMESTAMP,SRCID to generate the RTP packets and will return @RTP_PACKETS,
with
() - DTMF event is finished
$RTP_PACKETS[0] eq '' - no RTP packet for this call (pause)
@RTP_PACKETS - RTP packets which can be send to the peer
dtmf_extractor ( %ARGS )
Generates a function which is used to extract DTMF events. Keys rfc2833_type and audio_type have the same meaning as in generate_dtmf.
It will only attempt to extract DTMF events from rfc2833 RTP events or audio if the relevant rtp_type is given.
The function will be called with the RTP packet as the only argument and will return () if no new events where found or
(EVENT,DURATION,TYPE) if an event finished, where DURATION is the duration in ms and TYPE is audio|rfc2833.
For performance reasons it is best to use only rfc2833 if the peer supports it.
perl v5.14.2 2012-06-12 Net::SIP::DTMF(3pm)