🎙️ mod_voicechanger — FreeSWITCH Module

A custom FreeSWITCH module for real-time voice morphing during active SIP calls.

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🛠️ Installation Guide

1. Clone the Repository

Option A — via Git:

git clone https://github.com/humayun2000444/mod_voicechanger.git
cd mod_voicechanger

Option B — unzip the attached module if you're using a packaged release:

cd ~/humayun/freeswitch_mods/mod_voicechanger

Then, clone the required dependency:

git clone https://github.com/Signalsmith-Audio/linear.git
cd linear
mkdir -p signalsmith-linear

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2. Build the Module

cd ~/humayun/freeswitch_mods/mod_voicechanger
mkdir build
cd build
cmake ../src
make
sudo make install

This will compile and install mod_voicechanger.so.

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3. Install the Module Binary

sudo groupadd freeswitch
sudo useradd -g freeswitch freeswitch

sudo cp mod_voicechanger.so /usr/local/freeswitch/mod/
sudo chown freeswitch:freeswitch /usr/local/freeswitch/mod/mod_voicechanger.so

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4. Auto-load the Module on Startup

Edit the module autoload config:

sudo nano /etc/freeswitch/autoload_configs/modules.conf.xml

Add the following line inside the <modules> section:

<load module="mod_voicechanger"/>

Then restart FreeSWITCH:

sudo systemctl restart freeswitch

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📞 Usage Instructions

1. Create Two SIP Extensions

Ensure two SIP users are configured and registered:

• User 1:

  • Username: 1000
  • Password: 1000

• User 2:

  • Username: 1001
  • Password: 1001

📌 Domain and server address: Use your FreeSWITCH server IP and SIP port.
Find it using:

fs_cli -x "sofia status"

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2. Make a Call Between the Two Extensions

Place a call from 1000 to 1001 using a SIP client or FreeSWITCH CLI:

fs_cli -x "originate user/1000 user/1001"

Check active calls:

fs_cli -x "show calls"

Identify the UUID for the call leg you want to morph (typically the second one).

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3. Use the Voice Changer Module

Start morphing:

voicechanger start <UUID> <factor>

Adjust morphing factor:

voicechanger set <UUID> <new_factor>

Stop morphing:

voicechanger stop <UUID>

Example:

voicechanger start 68ad2658-0b35-44a0-ba7b-a408b7344063 1.2
voicechanger set   68ad2658-0b35-44a0-ba7b-a408b7344063 1.5
voicechanger stop  68ad2658-0b35-44a0-ba7b-a408b7344063

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📝 Notes

• Morphing factors:

  • >1.0: increases pitch (e.g., 1.2, 1.5)
  • <1.0: lowers pitch (e.g., 0.8)

• Make sure:

  • The module is placed in /usr/local/freeswitch/mod/
  • The module has proper ownership (freeswitch:freeswitch)
  • FreeSWITCH was restarted after placing the module

• Verify module loaded:

fs_cli -x "show modules" | grep voicechanger