Unmixed recording calls. different duration problem

[resistor]

Hello everyone!
We have a problem with recording calls. We use Monitor application and have two files for two call legs. After the end of the call we make single file with two stereo channels.
It’s crucial for us get two different unmixed channels.
It works well as usual.
The problem is in situation when one of call participant Muting his softphone and we have two files with different duration. Thats why after mixing we have out of sync resulting record.
We have tried MixMonitor. It works well, but we can’t get unmixed channels.
Is any way to do not stop recording on Mute or other way mixing files with different duration? Or any other suggestions?
Ubuntu 20.04.3 LTS amd64
Asterisk v 16.2.1
Thanks!

[jcolp]

The MixMonitor application has options[1] for separate files for receive and send, and the mixed filename is optional.

[1] Asterisk 16 Application_MixMonitor - Asterisk Project - Asterisk Project Wiki

[resistor]

It works! Thanks!
We installed version 16.27 and used MixMonitor with next parameters:

MixMonitor(,r(r.wav)t(t.wav)Sb)

Unfortunately parameter S isn’t described at asterisk “core show application MixMonitor”. Add it, please if you don’t mind

[jcolp]

It is for me:

    S: When combined with the <r> or <t> option, inserts silence when necessary
    to maintain synchronization between the receive and transmit audio streams.

[rlockard]

I’m on 18.13 and it is NOT there in the description for me either, when I just checked. I’m using it, but it is not there in the description.

[jcolp]

Ah, that’s because of this:

app_mixmonitor
------------------
 * In Asterisk 13.29, a new option flag was added to MixMonitor (the 'S'
   option) that when combined with the r() or t() options would inject
   silence into these files if audio was going to be written to one and
   not that other. This allowed the files specified by r() and t() to
   subsequently be mixed outside of Asterisk and be appropriately
   synchronized. This behavior is now the default, and a new option has
   been added to disable this behavior if desired (the 'n' option).