⚡ FocalCodec

A low-bitrate single-codebook 16 kHz speech codec based on focal modulation.

• 📜 Preprint: https://arxiv.org/abs/2502.04465

• 🌐 Project Page: https://lucadellalib.github.io/focalcodec-web/

• 🔊 Downstream Tasks: https://github.com/lucadellalib/audiocodecs

---

📌 Available Checkpoints

Checkpoint	Token Rate (Hz)	Bitrate (kbps)	Dataset
lucadellalib/focalcodec_50hz	50.0	0.65	LibriTTS960
lucadellalib/focalcodec_25hz	25.0	0.33	LibriTTS960
lucadellalib/focalcodec_12_5hz	12.5	0.16	LibriTTS960

---

🛠️️ Installation

First of all, install Python 3.8 or later. Then, open a terminal and run:

pip install huggingface-hub safetensors soundfile torch torchaudio

---

▶️ Quickstart

NOTE: the audio-samples directory contains audio samples that you can download and use to test the codec.

You can easily load the model using torch.hub without cloning the repository:

import torch
import torchaudio

# Load FocalCodec model
config = "lucadellalib/focalcodec_50hz"
codec = torch.hub.load(
    "lucadellalib/focalcodec", "focalcodec", config=config, force_reload=True
)
codec.eval().requires_grad_(False)

# Load and preprocess the input audio
audio_file = "audio-samples/librispeech-dev-clean/251-118436-0003.wav"
sig, sample_rate = torchaudio.load(audio_file)
sig = torchaudio.functional.resample(sig, sample_rate, codec.sample_rate)

# Encode audio into tokens
toks = codec.sig_to_toks(sig)  # Shape: (batch, time)
print(toks.shape)
print(toks)

# Convert tokens to their corresponding binary spherical codes
codes = codec.toks_to_codes(toks)  # Shape: (batch, time, log2 codebook_size)
print(codes.shape)
print(codes)

# Decode tokens back into a waveform
rec_sig = codec.toks_to_sig(toks)

# Save the reconstructed audio
rec_sig = torchaudio.functional.resample(rec_sig, codec.sample_rate, sample_rate)
torchaudio.save("reconstruction.wav", rec_sig, sample_rate)

Alternatively, you can install FocalCodec as a standard Python package using pip:

pip install focalcodec@git+https://github.com/lucadellalib/focalcodec.git@main#egg=focalcodec

Once installed, you can import it in your scripts:

import focalcodec

config = "lucadellalib/focalcodec_50hz"
codec = focalcodec.FocalCodec.from_pretrained(config)

Check the code documentation for more details on model usage and available configurations.

---

🎤 Running the Demo Script

Clone or download and extract the repository, navigate to <path-to-repository>, open a terminal and run:

Speech Resynthesis

python demo.py \
--input_file audio-samples/librispeech-dev-clean/251-118436-0003.wav \
--output_file reconstruction.wav

Voice Conversion

python demo.py \
--input_file audio-samples/librispeech-dev-clean/251-118436-0003.wav \
--output_file reconstruction.wav \
--reference_files audio-samples/librispeech-dev-clean/84

---

@ Citing

@article{dellalibera2025focalcodec,
    title   = {{FocalCodec}: Low-Bitrate Speech Coding via Focal Modulation Networks},
    author  = {Luca {Della Libera} and Francesco Paissan and Cem Subakan and Mirco Ravanelli},
    journal = {arXiv preprint arXiv:2502.04465},
    year    = {2025},
}

---

📧 Contact

[email protected]

---