# webui

A pipeline studio: strip a voice with **demucs**, edit it with **AuK** (emotion, pitch, speed,
free-form instructions — with preview and undo/reset), then generate new speech in that voice
with **MOSS-TTS**.

## Why this exists

Manually chaining demucs → AuK → MOSS-TTS across three separate venvs (via SSH one-off scripts)
worked but made it slow to experiment — especially with AuK's pitch/emotion controls, where you
really want to preview a result and back out if it's wrong (see the pitch-overshoot findings in
`auk/README.md`) rather than committing to a specific edit blind.

## Architecture

A single lightweight Gradio app (`app.py`) that **shells out** to each tool's own isolated venv
via subprocess, rather than merging their dependencies into one environment — MOSS-TTS pins
`transformers==5.0.0`, AuK needs `4.57.6`; they can't coexist in one venv. This app's own venv
only needs `gradio` itself.

Each stage's output becomes the next stage's input by filesystem path; a `history` list backs
the undo/reset buttons in the voice editor.

## Setup

```bash
python3 -m venv .venv && . .venv/bin/activate
pip install gradio
```

Assumes `demucs/`, `auk/`, and `tts/` (siblings in this repo) already have their own working
venvs and, for `auk/`, downloaded model weights — see their READMEs.

## Running

```bash
python3 app.py
```

Serves on `0.0.0.0:7860`. The app automatically calls ComfyUI's `/free` endpoint (if its queue
is empty) before each heavy step, to reduce GPU contention on a shared box — see the DNS/routing
and GPU-contention notes earlier in this project's history for why that matters here.

## Known limitations (inherited from the underlying tools)

- **AuK's real usable clip length is ~25-30s**, not several minutes — feeding it a long recording
  will OOM even with `--cpu_offload` (see `auk/README.md`). This app doesn't chunk long inputs
  automatically; keep reference clips short.
- **AuK's pitch-editing instruction-following is unreliable** — even "1 semitone" has measured
  out at ~4+ semitones of actual shift in testing. The UI surfaces a warning; preview before
  trusting a pitch edit.
- Each stage is a blocking subprocess call (model load + inference each time) — the UI will
  appear to hang for anywhere from ~10s to a couple of minutes per click, with no progress bar
  yet.
- No queueing/locking across browser tabs or concurrent users — this is a single-GPU box, so two
  simultaneous generations will contend for VRAM.