External DSP(Digital Signal Processor) interface for FreeSwitch(TM) voice communications platform

This module allow you to use any external application to proceed media trafic inside of FreeSwich(TM) channel. Your application should be able to receive voice stream from STDIN and send voice stream to STDOUT. This modeule was tested with GStreamer v1.0.

Building as a part of FreeSwitch(TM) source tree

To build module as a part of FreeSwitch source tree perform following steps:

• Add it as a git submodule add --name kvishnivetsky-mod_external_dsp https://github.com/kvishnivetsky/mod_external_dsp src/mod/applications/mod_external_dsp
• Add src/mod/applications/mod_external_dsp/Makefile to AC_CONFIG_FILES of configure.ac
• Add applications/mod_external_dsp to modules.conf
• Build entire FreeSwitch project or module only

Configuration

No any static configuration is needed.

Usage

To start DSP:

• establish a channel, bridged or not does not matter
• run API command process_audio <UUID> start <your external aplication with arguments>

To stop DSP:

• run API command process_audio <UUID> stop

Example

PCMU channel and GStreamer as a processor:

process_audio 48692d63-b8de-41ca-b21d-f27db8484346 start gst-launch-1.0 -q fdsrc ! rawaudioparse use-sink-caps=false format=mulaw sample-rate=8000 num-channels=1 ! mulawdec ! audioconvert ! audioconvert ! mulawenc ! fdsink