THIRD_PARTY_NOTICES.md

Third-party notices

ApexSVC's own code is licensed under AGPL-3.0-or-later (see LICENSE). The components listed below are vendored, wrapped, or pulled at runtime. Each keeps its original license and authorship; the SPDX identifier next to each entry is the upstream license, not ApexSVC's. Visit the linked upstreams for full license texts.

NeuCoSVC / NeuCoSVC2

• Upstream: https://github.com/thuhcsi/NeuCoSVC (branch NeuCoSVC2)
• Paper: Sha et al., "Neural Concatenative Singing Voice Conversion", arXiv:2312.04919
• License: MIT
• Files vendored: the NSF HiFi-GAN generator (GeneratorNSF, source-filter excited HiFi-GAN), kNN matcher, and small audio utility helpers, under svc/synth/, svc/match/, and svc/utils/. The training code, dataset scaffolding, REAPER pitch wrapper, and Phoneme Hallucinator are NOT vendored.

WavLM (Microsoft)

• Upstream: https://github.com/microsoft/unilm/tree/master/wavlm
• License: MIT
• Used as the content encoder (layer 6). Weights pulled at first run from the microsoft/wavlm-large Hugging Face repository.

TorchFCPE

• Upstream: https://github.com/CNChTu/FCPE (PyPI: torchfcpe)
• License: MIT
• Default F0 extractor. Installed as a regular pip dependency, weights are bundled in the wheel.

praat-parselmouth (optional F0 backend)

• Upstream: https://github.com/YannickJadoul/Parselmouth
• License: GPL-3.0-or-later (Praat itself), Parselmouth bindings under MIT.
• Wraps Praat's autocorrelation pitch tracker. Used when --f0-method praat is selected.

librosa (optional F0 backend)

• Upstream: https://github.com/librosa/librosa
• License: ISC
• Provides PYIN, used when --f0-method pyin is selected.

kNN-VC

• Upstream: https://github.com/bshall/knn-vc
• License: MIT
• Method inspiration for the retrieval-style matcher (Baas et al., "Voice Conversion With Just Nearest Neighbors", InterSpeech 2023). No code vendored, just the technique.

Silero VAD

• Upstream: https://github.com/snakers4/silero-vad
• License: MIT
• Used for reference-audio voice activity detection. Pulled as a pip dependency, weights downloaded on first run.

PyTorch / torchaudio

• Upstream: https://pytorch.org
• License: BSD-3-Clause
• Pinned to the cu121 wheel index in pyproject.toml for Windows CUDA support.

Gradio

• Upstream: https://github.com/gradio-app/gradio
• License: Apache-2.0
• Powers the local web UI in app.py.

Other runtime dependencies

Standard scientific Python stack (NumPy, SciPy, soundfile, resampy, tqdm, click, Hugging Face huggingface_hub / transformers / safetensors / omegaconf, gdown). All used as regular pip packages under their respective permissive licenses (BSD, MIT, Apache-2.0). See pyproject.toml for the full pinned list.