serverAppConfigs/serverAppConfigs-docs/Dankclaw/Voice Packs.md

---
type: reference
description: "How a frank-tts voice pack is built on Dankclaw: the three files every pack must carry, the 10-second source-material gate scripts/build-voice-pack.sh enforces, how to add a fourth voice, and what to do when a pinned engine bump changes the extractor's output sizes."
tags:
  - dankclaw
  - frank-tts
  - voices
  - tts
timestamp: 2026-10-18
---

# Voice Packs

A **voice pack** is the unit of identity for **frank-tts**: one directory under
`/home/dank/voices`, named by the voice, carrying the reference audio that makes
the name real plus the pinned engine's own speaker artifacts and a provenance
record. `voice=narrator1` on `POST /v1/audio/speech` resolves to
`/home/dank/voices/narrator1/reference.wav` and to nothing else — a name without
that file is a 400 that lists the names that do exist, because a silent fallback
voice is how a wrong-voice endpoint stays wrong for weeks.

**Host:** Dankclaw (192.168.0.143) — **Pack root:** `/home/dank/voices`, host
state that stays out of the repo, mounted read-only at `/voices` by the façade
unit — **Builder:** `scripts/build-voice-pack.sh` with tunables in
`scripts/voice-packs.env` — **Seam:** `tests/voice_pack_unit.bats` — **Engine:**
arm A `qwentts.cpp`, decided in [[Local TTS and Voice Cloning]].

Packs are **world-readable on purpose** (`drwxr-xr-x`, owner `dank`): the façade
container runs as uid 10000 and reads the mount from outside its own uid map.

## The required files

| File | What it is | Who reads it |
|------|------------|--------------|
| `reference.wav` | the crop: 24 kHz mono `pcm_s16le`, **18–25 s** of clean single-speaker audio | the façade (it is the existence gate for the name) and the engine's boot warmer, which base64s it and registers the voice with no transcript |
| `reference.spk` | the engine's x-vector: **8,192 B** = `enc_dim` 2048 × f32 | the engine, for the ICL/`--ref-spk` path |
| `reference.rvq` | the engine's RVQ code stream: **5,456–6,864 B**, 16 codebooks × T frames packed at 11 bits = 22 B per 12.5 Hz frame | the engine, for the ICL/`--ref-rvq` path |
| `manifest.json` | provenance: source path and sha256, crop start/end offsets, sample rate, duration, the tool and engine commit that made the artifacts, and the `voice` name | humans, and the builder itself on its second gate assertion |

`qwen-codec.log` rides along with the extractor's own record of the run; the
façade ignores anything it does not name and never deletes anything.

Division of enforcement, which is deliberate and not a gap: the **façade** gates
on `reference.wav` because that is the only engine-agnostic term (see the
voice-pack law in `scripts/frank-tts.env`); the **builder** is what refuses to
emit a pack without its engine artifacts; the **engine** registers a voice from
the WAV alone because its own `POST /v1/audio/voices` refuses a lone embedding —
it wants `wav_b64` or **both** `spk_b64` and `rvq_b64`. So the artifacts are in
the pack to make ICL a per-voice opt-in, not to boot it.

## How a pack is built

```bash
# everything except the extractor: gate, crop, probe, plan, the manifest it would write
scripts/build-voice-pack.sh --dry-run narrator1 /home/dank/voices

# the real thing, on the host that holds the engine build
scripts/build-voice-pack.sh narrator1 /home/dank/voices
```

Crops come from `scripts/voice-packs.env` — per voice: source path, offset,
duration, and the source's pinned sha256 — and any of them can be overridden on
the command line (`--source`, `--offset`, `--duration`, `--sha256`, `--tool`).
`--all` walks `VOICE_PACKS`. The builder assumes no GPU, no container, no fleet
endpoint and no network: `ffmpeg` cuts the crop, the pinned extractor makes the
artifacts, and both run `nice -n 19` so a build never competes with the text
endpoints on that box.

The extractor is `qwen-codec` in the `qwentts.cpp` tree at
`VOICE_PACK_ENGINE_COMMIT` (`5916bf7c79dbb4e66fc059cdc507a79a23a28bb4`). Its
usage text, read out of that tree and not guessed:

```
Usage: qwen-codec --model <gguf> [-i <input>] [--talker <gguf>] [--format <fmt>]

Required:
  --model <gguf>          Codec GGUF (qwen-tokenizer-12hz-*.gguf)

Optional:
  --device <name>         Compute device: CUDA0, Vulkan0, MTL0, CPU...
                          (default: best available)
  -i <path>               Input. WAV -> encode, .rvq -> decode
  --talker <gguf>         Talker GGUF (Base only). Encode also extracts the speaker
                          embedding and writes it next to the .rvq as a .spk file
  --format <fmt>          WAV output format: wav16, wav24, wav32 (default: wav16)

Output is auto-named next to input : clip.wav -> clip.rvq, clip.rvq -> clip.wav.
```

Three consequences shape the builder. **There is no `-o`**, so the pack's WAV is
staged under its final stem and the artifacts land beside it with nothing to
rename. **`--talker` must be a _Base_ talker** — the customvoice and voicedesign
GGUFs carry no speaker encoder and the tool says `has no speaker encoder (Base
only)`. **Encode truncates to the hop boundary**, so the `.rvq` size is arithmetic,
not chance: `22 × floor(samples / 1920)` bytes, which is where the recorded
5,456–6,864 B window comes from and why the **effective crop window is
19.84–25 s** even though the WAV law says 18–25 s. A crop shorter than that is
refused before the extractor runs, with the number in the message.

The build is staged and published, never assembled in place: `reference.wav` is
the file the façade reads, so it moves into position **last**, after the
artifacts and the manifest. A failed extractor therefore leaves a pack directory
that is not a voice. Nothing is ever deleted — an existing pack is refused unless
`--force`, and `--force` moves the whole old directory to
`/home/dank/voices/.AGENTTRASH/<voice>-<UTC>/` and builds fresh beside it.

Measured on the shipped `narrator1` crop (2026-10-18, `--dry-run` against the
real source): 98.739–118.636 s → `955,378 B` of 24 kHz mono `pcm_s16le`, 19.897
s, planned `.rvq` 5,456 B — the same byte counts the trial produced by hand, and
the extractor itself costs 1.8–2.1 s and 1.3–1.5 GiB peak per voice.

## The 10-second gate

Project-wide source-material invariant: **the first 10 seconds of any sample
file used to generate voices is forbidden material.** An offset that starts
inside it is refused with exit 1 and a message that names the invariant, before
a directory is created:

```
ERROR: source-material invariant violated: the crop must start past the first
10 s of the source file, and 'narrator1' asks for 4.5 s into … — nothing was
written.
```

The same gate is then asserted **from the manifest** that was just written —
`.crop.offset_seconds >= .invariant.forbidden_source_seconds`, plus the recorded
sha256 against the source it claims — so a pack cannot reach disk carrying a
forbidden crop even if the offsets in the env file are edited into nonsense.
`10` is not a knob: `scripts/voice-packs.env` carries the offsets, the sample
rate, the windows and the engine facts, but the forbidden region is a constant in
the builder. `tests/voice_pack_unit.bats` pins both halves (a refusal that
creates nothing, and one legal crop that builds the whole pack) and applies the
invariant to every crop in the tracked pack list.

## Adding a fourth voice

1. Pick the source file and hash it: `sha256sum /path/to/sample.wav`. A crop
   offset is a claim about one exact file, so the digest goes in the env with it.
2. Find a speech-dense stretch **past 10 s**. The trial's recipe, applied once:
   `ffmpeg -ss 60 -t 600 -i SRC -af silencedetect=noise=-35dB:d=0.6 -f null -`,
   build the runs of non-silence, keep runs ≥ 18 s, take the longest (earliest
   on ties), and cap at 25 s. Aim for 20–25 s: shorter than 19.84 s and the
   `.rvq` falls under the floor.
3. Add the four lines to `scripts/voice-packs.env` and the name to
   `VOICE_PACKS`:

   ```
   VOICE_PACKS="narrator1 narrator2 narrator3 narrator4"

   VOICE_PACK_NARRATOR4_SOURCE=/home/dank/voice-sources/audiosample4.m4b
   VOICE_PACK_NARRATOR4_OFFSET=142.31
   VOICE_PACK_NARRATOR4_DURATION=24
   VOICE_PACK_NARRATOR4_SHA256=<64 hex>
   ```

   The name must be lowercase `[a-z0-9._-]`: the façade matches the directory
   name verbatim while `tts-server` lowercases names internally, so an uppercase
   name would be reported one way by the façade and another by the engine. The
   builder refuses one anyway.
4. `scripts/build-voice-pack.sh --dry-run narrator4 /home/dank/voices`, read the
   plan, then drop `--dry-run`.
5. `./tests/run.sh` (the pack-list invariant test covers the new row for free).
6. Register it with the running engine. The engine's voice registry is
   memory-only and warm-on-boot, but a restart re-decodes **every** voice (6–8 s
   each), so adding one pack uses the hook instead:

   ```bash
   podman exec frank-tts-engine /app/warm-voices.sh
   curl -s localhost:7772/v1/audio/voices      # the façade's list, not the engine's
   ```

   The hook walks `/voices` and registers **every** pack that has a
   `reference.wav`, on every run — the engine replaces a name it already holds
   (`tools/tts-server.cpp:148` at the pinned commit: *"Re-registering a name
   replaces the previous entry."*) — then synthesizes twice per voice and logs
   `voice <name> cold=…ms warm=…ms` to the unit's journal. The two numbers should
   be close; see law 1 of [[Frank TTS Engine]] for what they measure. The rootless
   unit restart — `systemctl --user restart frank-tts-engine.service` — is for when
   the unit or its env changed, not for a new pack.

## When the extractor's output size changes on an engine bump

The builder treats the two artifact sizes as properties of the pinned engine, so
an engine bump that changes them **fails the build**: `reference.spk is N B,
expected 8192 B` or `reference.rvq is N B, expected …`. That is the failure being
loud, not a bug. Work through it in order:

1. Re-read the tool's own numbers rather than trusting this page: `qwen-codec`
   prints `SpeakerEncoder] Loaded: enc_dim=…` and `Pipeline] Ready: hop … , …
   codebooks @ … Hz` on every run, and the pinned tree's
   `tools/qwen-codec.cpp` documents the packing. `enc_dim × 4` is the `.spk`;
   `codebooks × code_bits / 8` bytes per frame × frames is the `.rvq`.
2. Decide whether the new number is intended. A changed `enc_dim` means the old
   `.spk` files are unreadable by the new engine, so **every** pack must be
   rebuilt, not just the failing one.
3. Update the four arithmetic lines in `scripts/voice-packs.env`
   (`VOICE_PACK_SPK_BYTES`, `VOICE_PACK_RVQ_MIN_BYTES`, `VOICE_PACK_RVQ_MAX_BYTES`,
   and `VOICE_PACK_RVQ_BYTES_PER_FRAME` if the codebook packing changed) **and**
   `VOICE_PACK_ENGINE_COMMIT`, `VOICE_PACK_TOOL`, `VOICE_PACK_CODEC_MODEL`,
   `VOICE_PACK_TALKER_MODEL` to the new build. An env diff that moves the sizes
   without moving the commit is the mistake to avoid.
4. Rebuild all three packs with `--force` (the retired directories keep the old
   bytes readable beside their replacements until a human clears them), then
   re-run the warm hook: `podman exec frank-tts-engine /app/warm-voices.sh`. That
   hook registers **every** pack it finds on every run, and the engine replaces a
   name it already holds — `tools/tts-server.cpp:148` at the pinned commit says so
   in its own words: *"Re-registering a name replaces the previous entry."* So the
   rebuilt `reference.wav` is what the running engine speaks afterwards, and the
   hook's cold/warm pass is what re-snapshots it. A restart
   (`systemctl --user restart frank-tts-engine.service`) is what an ENGINE bump
   needs — the registry is memory-only and lives in that process — and the unit
   runs the same hook on every start anyway, so a restart is never worse, only
   slower.
5. `./tests/voice_pack_unit.bats` — the stub in that seam reproduces the packing
   law, so it needs the same arithmetic update as the env file. The seam's
   engine-bump test is exactly this scenario with a wrong `.spk` size, and its
   assertion — no `reference.wav`, no manifest — is the property that matters.

## Host state (census 2026-10-18, read-only)

- `/home/dank/voices/` holds `narrator1`, `narrator2`, `narrator3`, each with
  `reference.wav`, a `reference16k.wav`, and a `manifest.json` **in the trial's
  own schema** (`kind: voice-reference-pack`, a silence-scan record). They carry
  **no** `reference.spk` / `reference.rvq`: the trial's artifacts live in its own
  work directory (`/home/dank/voice-audition/qwentts/voices/`, and only for
  narrator1 and narrator2). The builder's first real run is therefore a
  migration, and it should be a `--force` run per voice so the old directories
  are retired rather than left half-updated.
- The three source files (`/home/blank/audiosample.mp3`,
  `audiosample2.m4b`, `audiosample3.m4b`, digests pinned in
  `scripts/voice-packs.env`) live on the workstation, not on Dankclaw; the
  builder reads them from `$VOICE_PACK_SOURCE_DIR=/home/dank/voice-sources`, so
  they have to be copied there once before a build.
- `VOICE_PACK_TOOL` points at the trial's build tree
  (`/home/dank/voice-audition/qwentts/qwentts.cpp/build/qwen-codec`, checked out
  at exactly `5916bf7c`), and the two GGUFs live at
  `/home/dank/models/Qwen3-TTS-GGUF/`, the engine slice's fetch target — that
  path and its fetch state belong to [[Frank TTS Engine]].
- Whether the façade (7772) and the engine (8880) are up and serving is deploy
  state on [[Frank TTS]] / [[Frank TTS Engine]] — read it there, not from this
  census.

## Known gaps, on purpose

- **No transcript in the manifest.** ICL wants a `ref_text` that matches the
  crop, and the trial's machine transcripts came back wrong ("Demon Souls" for
  *Dark Souls*). Transcribing on the host is not a fix, so the pack carries none
  and the engine registers the WAV-only voice, which is what its boot warmer
  does anyway. When ICL becomes a per-voice opt-in, the curated transcript
  belongs in this manifest — a human-supplied field, not something the builder
  can derive.
- **No 16 kHz variant.** The packs the trial left behind carry
  `reference16k.wav` for the `llama-tts-cli` rollback engine; arm A is native
  24 kHz, so the builder emits one reference. `--force` retires the whole
  directory including that variant, so if the rollback engine is ever revived:
  `ffmpeg -i reference.wav -ar 16000 -c:a pcm_s16le reference16k.wav`.
- **No loudness pass.** The trial's pipeline also measured and normalised
  (two-pass `loudnorm`, `astats`, `ebur128`, spectrograms) to a `-16 LUFS` spec.
  None of that is in the pack law, which asks for 24 kHz mono inside the
  duration window, so the builder does only that; a future engine that is
  loudness-sensitive should get the pass as an explicit, documented step.