MixMonitor

Da Voismart Knowledge Base.
[Synopsis]
Record a call and mix the audio during the recording

[Description]
  MixMonitor(<file>.<ext>[|<options>[|<command>]])

Records the audio on the current channel to the specified file.
If the filename is an absolute path, uses that path, otherwise
creates the file in the configured monitoring directory from
asterisk.conf.

Valid options:
 a      - Append to the file instead of overwriting it.
 b      - Only save audio to the file while the channel is bridged.
          Note: Does not include conferences or sounds played to each bridged
                party.
 v(<x>) - Adjust the heard volume by a factor of <x> (range -4 to 4)
 V(<x>) - Adjust the spoken volume by a factor of <x> (range -4 to 4)
 W(<x>) - Adjust the both heard and spoken volumes by a factor of <x>
         (range -4 to 4)

<command> will be executed when the recording is over
Any strings matching ^{X} will be unescaped to ${X}.
All variables will be evaluated at the time MixMonitor is called.
The variable MIXMONITOR_FILENAME will contain the filename used to record.