chatterbox-fast v0.1.0

Sub-second streaming TTS on Chatterbox-Turbo via adaptive buffer-ratchet
chunking. First audio in ~0.5s (vs ~5s one-shot) with no quality compromise —
chunk joins land on natural sentence pauses and the stream converges to one
large near-full-context chunk within 2-3 joins. Works because the engine runs
faster than realtime; the no-starvation guarantee is proven in a GPU-free
simulation (tests/test_scheduler.py).

- chatterbox_fast/scheduler.py: the adaptive-chunk scheduler (pure logic, no GPU)
- chatterbox_fast/app.py: FastAPI server (POST /tts streaming, /voices, /health)
- bench.py: streaming client (ground-truth TTFB + starvation check)
- Self-contained Dockerfile (slim base + chatterbox-tts from PyPI)
- Three public-domain LibriVox starter voices baked in (see voices/ATTRIBUTION.md)

MIT licensed.

Dockerfile

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+# chatterbox-fast — self-contained image. No external/private base: a slim Python
+# base + the public chatterbox-tts package on PyPI, which pulls a single
+# consistent torch+torchaudio (CUDA wheels) — no torchvision, so none of the
+# torch/torchvision version-pinning conflicts a PyTorch base image causes.
+#
+# The ~6 GB Chatterbox-Turbo weights are NOT baked — they download from
+# HuggingFace into HF_HOME on first run. The starter VOICES are baked (see
+# voices/) so a fresh container can synthesize out of the box.
+FROM python:3.11-slim
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+        ffmpeg libsndfile1 \
+    && rm -rf /var/lib/apt/lists/*
+
+ENV HF_HOME=/app/hf_cache \
+    CBF_VOICES_DIR=/app/voices \
+    CBF_DEFAULT_VOICE=catharine \
+    CBF_MODEL_DEVICE=cuda \
+    CBF_BIND=0.0.0.0 \
+    CBF_PORT=8197 \
+    PYTHONUNBUFFERED=1
+
+WORKDIR /app
+COPY pyproject.toml README.md ./
+COPY chatterbox_fast ./chatterbox_fast
+COPY voices ./voices
+
+# torch is already provided by the base image; pip resolves chatterbox-tts +
+# the server deps against it.
+RUN pip install --no-cache-dir .
+
+EXPOSE 8197
+HEALTHCHECK --interval=30s --timeout=10s --start-period=180s --retries=3 \
+    CMD python -c "import urllib.request,sys; b=urllib.request.urlopen('http://127.0.0.1:8197/health',timeout=5).read(); sys.exit(0 if b'\"status\":\"ok\"' in b.replace(b' ',b'') else 1)"
+
+CMD ["chatterbox-fast"]