View source for Create audio from packet dumps located in a spooldir

If you need to get audio from a SIP and RTP packets dump stored in spooldir by voipmonitor sniffer,
continue reading.

= Requires =
to have full RTP+SIP captures in a spooldir you get this with following options voipmonitor.conf
 savesip=yes
 savertp=yes
''You can also use capture rules in a GUI to get full RTP captures only for some IPs/Telnums''

= Example =
== Get (SIP+RTP) pcaps and merge them to single file ==
you need to locate SIP+RTP packet dumps in a spooldir using DATE and HH:MM and call-id header of the call's SIP session

=== Locate and untar SIP and RTP ===
Example is for the call with '''call-id: ad856a3587b477e2f8edc21856c6f2e1''' (done  at '''2021-03-30 14:44''') from spooldir with default compression settings
 tar --wildcards -xOf '/var/spool/voipmonitor/2021-03-30/14/44/RTP/rtp_2021-03-30-14-44.tar' 'ad856a3587b477e2f8edc21856c6f2e1.pcap*' > tmp/aa/ad856a3587b477e2f8edc21856c6f2e1_RTP_lzo.pcap
 tar --wildcards -C /tmp/aa -xzf '/var/spool/voipmonitor/2021-03-30/14/44/SIP/sip_2021-03-30-14-44.tar.gz' 'ad856a3587b477e2f8edc21856c6f2e1.pcap*'

=== Decompress LZO === 
you need to decompress RTP packet dump using sniffer binary (by default the RTP packet dumps are additionally compressed with internal fast LZO compression tool)
 voipmonitor -kc --unlzo-gui='/tmp/aa/ad856a3587b477e2f8edc21856c6f2e1_RTP_lzo.pcap /tmp/aa/ad856a3587b477e2f8edc21856c6f2e1_RTP.pcap'

=== Merge SIP and RTP packets together ===
 mergecap /tmp/aa/ad856a3587b477e2f8edc21856c6f2e1_RTP.pcap /tmp/aa/ad856a3587b477e2f8edc21856c6f2e1.pcap -w /tmp/aa/merged.pcap

== Use sniffer binary and GUI's codecs binary to generate the audio file ==
you need to put link of vmcodecs binary into PATH and prepare config file for audio create

=== create link to vmcodecs binary ===
to create the link to vmcodecs binary located in ./bin subfolder of voipmonitor's GUI - this is necessary to allow to create audio also from other then g711 codecs (requires working GUI license and GUI installation)
 ln -s /var/www/html/bin/vmcodecs /sbin/vmcodecs

=== create the new config file for audio create ===
Example content of a file  '''/etc/voipmonitorcliwav.conf''' file:
 [general]
 saveaudio=ogg
 ogg_quality = 0.1
 #saveaudio=wav
 saveaudio_stereo=no
 saveaudio_afterconnect = yes
 
 nocdr=yes
 keycheck=/var/www/html/php/lib/keycheck.php
 spooldir=/tmp

=== the CLI command for generate the audio ===
 voipmonitor --config-file /etc/voipmonitorcliwav.conf -k -v0 -r /tmp/aa/merged.pcap  --json_config='[{"saveaudio":"wav"},{"spooldir":"/tmp/testAu"}]'
Note: the settings done in /etc/voipmonitorcliwav.conf is overriden with the '''--json-config''' option, above command will results in '''wav''' file in '''/tmp/testAu''' folder.