Adds a third TTS to the irv-ml1 fleet. IndexTTS-2 is Bilibili's
emotion-controllable zero-shot TTS (paper 2506.21619). Distinguishing
capability vs the existing two: timbre and emotion are disentangled —
clone a voice's timbre from one reference and the emotion from a
different reference, OR set emotion via 8-vector, OR derive it from a
text description. Neither CosyVoice 3 nor Qwen3-TTS-1.7B-Base does
this cleanly in English.
Wrapper is owned end-to-end (~150 lines in app.py) — the only existing
FastAPI fork (csllpr/index-tts-fastapi) targets v1 and is a dormant
single-commit repo. Upstream IndexTTS-2 ships only a Gradio webui.
Layout follows the qwen3-tts pattern:
stacks/index-tts/
Dockerfile — CUDA 12.8 base, IndexTTS pinned to a SHA
app.py — FastAPI: POST /v1/audio/speech + /v1/voices
entrypoint.sh — one-time HF snapshot_download of the weights
compose.yaml — env-driven, GPU pinning support, bind mounts
.env.example — port 8192, fp16, paths
README.md — API examples + comparison vs the other TTS
playbooks/deploy-index-tts.yaml — elway playbook for irv-ml1
Voice and emotion libraries are flat host dirs of WAVs, bind-mounted.
Drop a new <name>.wav and /v1/voices picks it up immediately.
License caveat: IndexTTS-2 weights ship under a custom Bilibili
license (free at our scale, not OSI-open). README documents it.
