OpenVoiceChanger

Real-time AI voice changer web application.
Route a microphone through ONNX or RVC models with a low-latency WebSocket audio pipeline.

Quick Start • Model Support • API • Configuration • 한국어 • 日本語

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Features

• Real-time voice conversion with binary WebSocket streaming and AudioWorklet
• ONNX and RVC model support
• Device routing from the browser
• Live pitch and F0 controls while streaming
• Session settings modal for sample rate, chunk size, and runtime visibility
• Runtime visibility for ONNX provider, PyTorch device, GPU, and CUDA status
• One active model at a time, with drag-and-drop upload and activation

Screenshots

Main UI

Settings modal

Quick Start

The commands below assume Windows PowerShell in the repository root.

0. Clone the repository

git clone https://github.com/sioaeko/OpenVoiceChanger.git
cd OpenVoiceChanger

1. Backend setup

python -m venv .venv
.venv\Scripts\Activate.ps1
python -m pip install --upgrade pip
pip install -r backend/requirements.txt
pip install --no-deps git+https://github.com/RVC-Project/Retrieval-based-Voice-Conversion

2. Optional: enable ONNX GPU acceleration

CPU ONNX works with the default requirements. If you want ONNX to use CUDA locally, replace the CPU package with the GPU package:

pip uninstall -y onnxruntime
pip install onnxruntime-gpu==1.23.2

3. Frontend setup

cd frontend
npm install
npm run build
cd ..

4. Prepare model assets

RVC .pth / .pt models need a HuBERT content encoder file.

New-Item -ItemType Directory -Force models\assets | Out-Null

Place the file here:

models/assets/hubert_base.pt

You can override that path with OVC_HUBERT_PATH.

5. Start the app

.venv\Scripts\python.exe -m uvicorn backend.main:app --host 127.0.0.1 --port 8000

Open:

http://127.0.0.1:8000

6. Optional: Vite dev mode

Terminal 1:

.venv\Scripts\python.exe -m uvicorn backend.main:app --reload --host 127.0.0.1 --port 8000

Terminal 2:

cd frontend
npm run dev

Then open http://127.0.0.1:5173.

Model Support

Format	Engine	Notes
.onnx	ONNX Runtime	CPU by default, CUDA if onnxruntime-gpu is installed
.pth / .pt	PyTorch	RVC v1/v2 models, requires hubert_base.pt

Web UI Flow

1. Open the app in your browser.
2. Upload a model file in Model Bay.
3. Click Activate on the model you want to use.
4. Open Settings to review sample rate, chunk size, and runtime status.
5. Pick your input and output devices.
6. Click Start Routing.
7. Adjust pitch and F0 while the stream is running.

API

Method	Endpoint	Description
GET	/health	Health check
GET	/api/config	Sample rate, chunk size, ONNX runtime info, PyTorch runtime info
GET	/api/models/	List uploaded models
POST	/api/models/upload	Upload a model file
DELETE	/api/models/{name}	Delete a model
POST	/api/models/{name}/activate	Activate a model
POST	/api/models/deactivate	Deactivate the current model
GET	/api/models/active	Get the active model
WS	/ws/audio	Real-time audio streaming

Interactive docs are available at /docs while the backend is running.

WebSocket protocol

1. Connect to /ws/audio
2. Send JSON config: {"sample_rate": 40000, "chunk_size": 4096}
3. Send binary audio frames: [uint32 seq_num][uint32 reserved][float32[] PCM samples]
4. Receive processed audio frames in the same format
5. Send settings updates such as {"pitch_shift": 3.0, "f0_method": "harvest"}

Configuration

Environment variables use the OVC_ prefix.

Variable	Default	Description
OVC_MODELS_DIR	models	Model directory
OVC_HOST	0.0.0.0	Backend bind address
OVC_PORT	8000	Backend port
OVC_SAMPLE_RATE	40000	Default sample rate
OVC_CHUNK_SIZE	4096	Default chunk size
OVC_CORS_ORIGINS	["*"]	Allowed CORS origins
OVC_LOG_LEVEL	info	Log level
OVC_HUBERT_PATH	models/assets/hubert_base.pt	HuBERT path for RVC
OVC_RMVPE_ROOT	models/assets/rmvpe	Optional RMVPE assets directory
OVC_RVC_STREAM_CONTEXT_SECONDS	1.0	Per-stream RVC context length
OVC_RVC_INDEX_RATE	0.75	Retrieval mix when a matching .index exists
OVC_RVC_FILTER_RADIUS	3	Harvest median filter radius
OVC_RVC_RMS_MIX_RATE	0.25	RMS envelope blend
OVC_RVC_PROTECT	0.33	Consonant protection

Project Structure

OpenVoiceChanger/
├── backend/
│   ├── main.py
│   ├── config.py
│   ├── routers/
│   └── services/
├── frontend/
│   ├── public/
│   └── src/
├── models/
├── README.md
├── README_KR.md
├── README_JP.md
└── Makefile

Makefile

The included Makefile is a convenience for POSIX shells or WSL.

Command	Description
make install	Install backend and frontend dependencies
make dev	Run backend and frontend dev servers
make dev-backend	Run backend only
make dev-frontend	Run frontend only
make build	Build the frontend
make clean	Remove build artifacts

Requirements

• Python 3.10+
• Node.js 18+
• npm

License

MIT