Strict-causal, zero-shot voice conversion VST — real-time on Apple Silicon (MPS).

• 0 look-ahead — strictly causal. No future frames, KV-cache streaming.
• Content/speaker split — what is said (768d content @25Hz) vs who says it (global embedding).
• Teacher–student — trained by distilling a frozen, bidirectional MioCodec teacher into a causal student.
• Zero-shot VC — GRL disentanglement + Q2D2 bottleneck. No parallel data needed.

# Voicebank
python -m astrape.build_voicebank ref.wav -o speaker.astrape

# Convert
python -m astrape.evaluate --source src.wav --target speaker.astrape --output out.wav

• Q2D2 — Shuster & Nachmani, "Two-Dimensional Quantization for Geometry-Aware Audio Coding", ICML 2026, arXiv:2512.01537
• Mamba — Gu & Dao, "Mamba: Linear-Time Sequence Modeling with Selective State Spaces", 2023, arXiv:2312.00752
• Hyena — Poli et al., "Hyena Hierarchy: Towards Larger Convolutional Language Models", 2023, arXiv:2302.10866
• MioCodec — Aratako/MioCodec-25Hz-44.1kHz-v2 (teacher codec, HuggingFace)
• WavLM — Chen et al., "WavLM: Large-Scale Self-Supervised Pre-Training for Full Stack Speech Processing", 2022
• GRL — Ganin & Lempitsky, "Unsupervised Domain Adaptation by Backpropagation", ICML 2015
• ConvNeXt — Liu et al., "A ConvNet for the 2020s", CVPR 2022
• WavTokenizer — Ji et al., "WavTokenizer: an Efficient Acoustic Discrete Codec Tokenizer", 2024
• Snake / BigVGAN — Lee et al., "BigVGAN: A Universal Neural Vocoder", 2023, arXiv:2206.02944
• iSTFT / Vocos — Siuzdak et al., "Vocos: Closing the Gap Between Time-Domain and Fourier-Based Neural Vocoders", 2024, arXiv:2306.00819
• Predictive Coding — Oord et al., "Representation Learning with Contrastive Predictive Coding (CPC)", 2018
• APCodec — Ai et al., "APCodec: A Neural Audio Codec", IEEE/ACM TASLP 2024, arXiv:2402.10533
• FreeGAN — Is GAN Necessary for Mel Vocoder? (2508.07711)
• DLL-APNet — Distilled Low-Latency causal vocoder (2509.13667)
• APNet2 (2311.11545) · APNet (2305.07952)
• Low-Latency phase prediction, anti-wrapping (2403.17378)
• FreeV — pinv-mel magnitude prior (2406.08196)
• Wavehax — aliasing-free F0 harmonic prior (2411.06807) · MS-Wavehax / streaming analysis (2506.03554)
• Universal Harmonic Discriminator (2512.03486)
• Prosody-Guided Harmonic Attention (2601.14472)