Source can be found here, and from this FreeSWITCH-users thread:

Majdi Bsoul majdi at ieee.org
Mon Nov 1 13:14:10 PDT 2010



Hello guys,

I am trying to minimize the footprint of FreeSWITCH runtime and remove un-needed modules and their libs. 
This modules is not mentioned any where and not much on the web.
Could u please provide more info on what functionalities it provides?

I'm planning to use FreeSWITCH for only SIP/sofia and Jingle/gtalk.

Thanks,


Mario G mario_fs at mgtech.com
Mon Nov 1 16:54:50 PDT 2010



It is used to handle file formats to generate email of voicemail. I am
using it and it works fine. I handles different file formats. I am using
aaif to send voicemails to an iPhone. Here they are:
http://wiki.freeswitch.org/wiki/Mod_playback#mod_sndfile


Anthony Minessale anthony.minessale at gmail.com
Mon Nov 1 16:55:10 PDT 2010



its used to support multiple sound file formats.


Steven Ayre steveayre at gmail.com
Tue Nov 2 02:52:19 PDT 2010



It provides support for reading most of the sound file formats that FS
supports. Almost anything that involves a sound file (e.g. voicemail,
playback, IVR, record etc) requires it. It isn't necessary if you're
just routing calls between endpoints, but anything more complex
probably requires it.

-Steve

February 2020 : added config file for mod_sndfile (sndfile.conf.xml) which currently has only one param called  "allowed-extensions" which allows to configure only certain file extensions to be loaded. Eg: <param name="allowed-extensions" value="wav,raw,r8,r16,ogg"/>