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.