pcap2audio's Introduction

pcap2audio

what is it

a CLI tool to extract conversation audio from VoIP calls by means of RTP packets residing in pcap files
the retrieved audio is suitable for playing it with your favorite audio editor (e.g. audacity)
the program tries to extract all available audio data based on encountered RTP packets
it will look for associated streams (forward and reversed direction) and mixes them into one single file
generated file names are composed of the starting date of the call for easier identification
works for PCMA only at the time of this writing

software installation

some prerequisites

  sudo apt install gawk tshark sox xxd wget

download the tool

  wget https://raw.githubusercontent.com/sp4rkie/pcap2audio/master/pcap2audio.awklib
  wget https://raw.githubusercontent.com/sp4rkie/pcap2audio/master/pcap2audio
  chmod 755 pcap2audio

how to use it

record some VoIP call with your favorite packet sniffing tool. Example using tcpdump for this:
```
  tcpdump -i eth4 port sip or portrange 14362-14462 -B 4096 -n -c 200000 -w trace.eth4
```
to execute the program simply type (for the example above):
```
  pcap2audio -f trace.eth4
```
this extracts audio in forward and reversed direction (if existent) and mixes both
all results currently end up in /tmp directory.

command line options

  Usage: pcap2audio
    -h                    - print this help and exit
    -f (.+)               - pcap input file
    -v                    - increase logging verbosity