feat(speaker-id): Phase 1 — SpeechBrain ECAPA-TDNN Backend in whisper-bridge

Speaker-ID-Modul (Hermes-Style „echtes Gespraech ohne Wake-Word"-Vision,
Phase 1 von 5). Erkennt Stefans Stimme via 192-dim Embedding + Cosine-
Match gegen einen persistierten Fingerprint.

Module:
- speaker_id.py: lazy-loaded ECAPA-TDNN (HuggingFace), enroll/verify/
  status/delete. Fingerprint = L2-normalisierter Mittelwert aus N
  Enrollment-Samples in /voice-id/fingerprint.json.
  Fail-open: kein Fingerprint → verify() returnt (True, 0.0).
- bridge.py: 3 Message-Handler — voice_id_status_request,
  voice_id_enroll_request (samples[]: base64 16kHz int16 PCM),
  voice_id_delete_request. Enrollment laeuft im Executor (Torch
  blockt sonst die Event-Loop).
- Dockerfile: torch 2.3.1 + torchaudio mit CUDA-12.1-Wheels (sonst
  zieht speechbrain CPU-only Torch rein). Container ~1 GB groesser.
- docker-compose.yml: ./voice-id:/voice-id Bind-Mount fuer Fingerprint-
  Persistenz (ueberlebt Container-Restart).
- rvs/server.js: 6 neue Message-Types in ALLOWED_TYPES.

Phase 2 (next): App-Enrollment-Flow + Diagnostic-Voice-ID-Section.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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"""
Speaker-ID Backend fuer ARIAs Stimmen-Erkennung.
Nutzt SpeechBrain ECAPA-TDNN (192-dim Embeddings, auf VoxCeleb-1+2 trainiert).
Fingerprint = gemittelter, L2-normalisierter Embedding-Vektor aus N
Enrollment-Samples. Verify: cosine_similarity(neue_aufnahme, fingerprint).
Persistenz: /voice-id/fingerprint.json (Float-Liste + Metadaten).
Modell-Cache: /root/.cache/huggingface/ (Bind-Mount mit f5tts geteilt).
Verhalten OHNE Enrollment (kein Fingerprint vorhanden):
verify() → (True, 0.0) — Fail-open, damit Speaker-ID-Gating den
ungeenrollten Brain-Pfad nicht versehentlich blockiert.
"""
from __future__ import annotations
import base64
import json
import logging
import os
import time
from pathlib import Path
from typing import Optional
import numpy as np
logger = logging.getLogger(__name__)
VOICE_ID_DIR = Path(os.environ.get("VOICE_ID_DIR", "/voice-id"))
FINGERPRINT_FILE = VOICE_ID_DIR / "fingerprint.json"
# Cosine-Threshold: 0.5 ist konservativ (wenig false-positives), 0.3 ist
# locker (mehr Treffer auch bei Nebengeraeuschen). Stefan kann's per
# Diagnostic-Setting feintunen.
DEFAULT_THRESHOLD = 0.5
# Minimal-Sample-Laenge fuer ein verlaessliches Embedding (~1s @ 16kHz int16 = 32000 bytes)
MIN_SAMPLE_BYTES = 32000
_model = None
def _ensure_loaded():
"""Lazy-Load des ECAPA-TDNN. Holt das Modell beim ersten Aufruf von HF;
danach cached im HF-Cache-Volume. Erste Init: ~30s download + load,
danach <1s warm. Wirft bei Fehler — Caller muss catchen + fail-open."""
global _model
if _model is not None:
return _model
import torch
from speechbrain.inference.speaker import EncoderClassifier
device = "cuda" if torch.cuda.is_available() else "cpu"
logger.info("[speaker-id] loading ECAPA-TDNN on %s ...", device)
_model = EncoderClassifier.from_hparams(
source="speechbrain/spkrec-ecapa-voxceleb",
savedir="/root/.cache/huggingface/speechbrain-ecapa",
run_opts={"device": device},
)
logger.info("[speaker-id] model ready (device=%s)", device)
return _model
def _audio_bytes_to_tensor(audio_bytes: bytes):
"""int16 LE PCM (16kHz mono) → Torch-Tensor (1, N), normalisiert auf [-1, 1]."""
import torch
arr = np.frombuffer(audio_bytes, dtype=np.int16).astype(np.float32) / 32768.0
return torch.from_numpy(arr).unsqueeze(0)
def embed(audio_bytes: bytes) -> np.ndarray:
"""Berechnet das Speaker-Embedding fuer einen Audio-Chunk.
Erwartet 16kHz int16 LE PCM Mono. Returns 192-dim numpy float32."""
import torch
model = _ensure_loaded()
wav = _audio_bytes_to_tensor(audio_bytes)
with torch.no_grad():
emb = model.encode_batch(wav)
return emb.squeeze().cpu().numpy().astype(np.float32)
def cosine_similarity(a: np.ndarray, b: np.ndarray) -> float:
"""Kosinus-Aehnlichkeit zwischen zwei 1D-Vektoren, Range [-1, 1].
Hoeher = aehnlicher. Bei normalisierten Vektoren ist das gleich dem Skalarprodukt."""
na = np.linalg.norm(a)
nb = np.linalg.norm(b)
if na < 1e-9 or nb < 1e-9:
return 0.0
return float(np.dot(a, b) / (na * nb))
def save_fingerprint(embeddings: list[np.ndarray], sample_durations_s: list[float]) -> dict:
"""Mittelt + L2-normalisiert die Embeddings und schreibt sie nach
FINGERPRINT_FILE. Returns das gespeicherte Dict."""
if not embeddings:
raise ValueError("Keine Embeddings zum Speichern")
VOICE_ID_DIR.mkdir(parents=True, exist_ok=True)
stacked = np.stack(embeddings)
mean = stacked.mean(axis=0)
mean = mean / max(np.linalg.norm(mean), 1e-9)
data = {
"version": 1,
"embedding": mean.tolist(),
"embedding_dim": int(mean.shape[0]),
"sample_count": len(embeddings),
"sample_durations_s": [float(s) for s in sample_durations_s],
"updated_at": int(time.time()),
}
FINGERPRINT_FILE.write_text(json.dumps(data, indent=2), encoding="utf-8")
logger.info("[speaker-id] fingerprint gespeichert: %d Samples, dim=%d, total_s=%.1f",
len(embeddings), mean.shape[0], sum(sample_durations_s))
return data
def load_fingerprint() -> Optional[dict]:
"""Returns das Fingerprint-Dict oder None wenn noch nicht enrolled."""
if not FINGERPRINT_FILE.exists():
return None
try:
return json.loads(FINGERPRINT_FILE.read_text(encoding="utf-8"))
except Exception as exc:
logger.warning("[speaker-id] fingerprint laden fehlgeschlagen: %s", exc)
return None
def delete_fingerprint() -> bool:
"""Loescht den Fingerprint (z.B. fuer Re-Enrollment). True wenn was weg ist."""
if FINGERPRINT_FILE.exists():
FINGERPRINT_FILE.unlink()
logger.info("[speaker-id] fingerprint geloescht")
return True
return False
def verify(audio_bytes: bytes, threshold: float = DEFAULT_THRESHOLD) -> tuple[bool, float]:
"""Returns (is_match, similarity).
Fail-open: wenn kein Fingerprint vorhanden ist oder das Embedding-Modell
crasht, returnt (True, 0.0) — kein Filtering. Sonst wuerde ein kaputter
Speaker-ID-Service die ganze Aufnahme blockieren."""
fp = load_fingerprint()
if fp is None:
return True, 0.0
if len(audio_bytes) < MIN_SAMPLE_BYTES:
# Zu wenig Audio fuer ein verlaessliches Embedding → durchlassen
return True, 0.0
try:
saved_emb = np.array(fp["embedding"], dtype=np.float32)
new_emb = embed(audio_bytes)
except Exception as exc:
logger.warning("[speaker-id] verify embed failed: %s — fail-open", exc)
return True, 0.0
sim = cosine_similarity(new_emb, saved_emb)
return sim >= threshold, sim
def status() -> dict:
"""Status-Snapshot fuer die App / Diagnostic."""
fp = load_fingerprint()
return {
"enrolled": fp is not None,
"sample_count": fp.get("sample_count", 0) if fp else 0,
"sample_durations_s": fp.get("sample_durations_s", []) if fp else [],
"updated_at": fp.get("updated_at") if fp else None,
"embedding_dim": fp.get("embedding_dim") if fp else None,
"default_threshold": DEFAULT_THRESHOLD,
}
def enroll_from_samples(samples_b64: list[str]) -> dict:
"""Verarbeitet base64-Samples (16kHz int16 LE PCM Mono) zu einem neuen
Fingerprint. Returns Status-Dict. Wirft ValueError wenn nichts brauchbar ist."""
if not samples_b64:
raise ValueError("Keine Samples uebergeben")
embeddings: list[np.ndarray] = []
durations: list[float] = []
rejected: list[dict] = []
for idx, s in enumerate(samples_b64):
try:
raw = base64.b64decode(s)
except Exception as exc:
rejected.append({"index": idx, "reason": f"base64: {exc}"})
continue
if len(raw) < MIN_SAMPLE_BYTES:
rejected.append({"index": idx, "reason": f"zu kurz ({len(raw)} bytes)"})
continue
try:
emb = embed(raw)
embeddings.append(emb)
durations.append(len(raw) / 2 / 16000.0)
except Exception as exc:
rejected.append({"index": idx, "reason": f"embed: {exc}"})
if not embeddings:
raise ValueError(
f"Keine Samples konnten verarbeitet werden ({len(rejected)} rejected). "
f"Details: {rejected[:3]}"
)
fingerprint = save_fingerprint(embeddings, durations)
fingerprint["rejected"] = rejected
return fingerprint