dschlueter/my_voice_assistant_v2
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feat: Barge-in/Turn-Manager und VAD-Aeusserungserkennung (#4 Ausbau)

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- Barge-in: Antwort-Turn als abbrechbarer asyncio.Task; {"type":"interrupt"} oder
  neue Eingabe bricht laufende Antwort ab -> interrupted-Event (/ws/chat + /ws/voice)
- VAD (app/audio/vad.py): energie-basierte Stille-Erkennung (reines Python, int16-PCM)
- /ws/voice opt-in {"type":"start","vad":true}: automatisches Aeusserungsende ohne end
- Tests: 52 gruen (+5: VAD-Unit, Barge-in, VAD-Auto-Segmentierung)
- Doku aktualisiert (README, BEDIENUNGSANLEITUNG, Architektur)

Offen (schwere Deps/Dienste): echte partielle Live-Transkripte (Streaming-STT),
WebRTC (aiortc). STT laeuft heute pro Aeusserung.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
Dieter Schlüter 2026-06-17 05:06:58 +02:00
commit 093da817d8
6 changed files with 312 additions and 48 deletions
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144
app/api/ws.py
View file

@ -3,14 +3,18 @@
- /ws/chat : Text rein (JSON pro Turn), Antwort als Event-Folge zurueck.
- /ws/voice: Audio rein (binaere Chunks + Control), Transkription -> selbe Pipeline.
Event-Folge der Antwort: ack -> [token*] -> [audio*] -> semantic -> done.
Antwort-Events: ack -> [token*] -> [audio*] -> semantic -> done.
Mit {"stream":true} kommen LLM-Token live, mit {"audio_stream":true} das Audio
satzweise (chunked TTS). /ws/voice sendet zuvor ein transcript-Event.
Spaeter (eigene Increments): partielle Live-Transkripte (Streaming-STT mit VAD),
Barge-in/Turn-Manager und WebRTC.
Barge-in: Ein {"type":"interrupt"}-Frame oder eine neue Eingabe bricht eine laufende
Antwort ab (-> interrupted-Event). Der Antwort-Turn laeuft als abbrechbarer Task.
Spaeter (eigene Increments): echte partielle Live-Transkripte (Streaming-STT-Dienst),
WebRTC.
"""
import asyncio
import json
from fastapi import APIRouter, WebSocket, WebSocketDisconnect
@ -24,6 +28,7 @@ from app.dependencies import (
resolve_output_endpoint,
)
from app.store import SessionOwnershipError
from app.audio.vad import EnergyVAD
router = APIRouter()
@ -126,6 +131,51 @@ async def _run_turn(websocket, store, user, session_id, route, orchestrator, out
await websocket.send_json({"type": "done", "audio_format": "pcm", "sample_rate": 24000})
async def _cancel_active(task, websocket) -> None:
"""Bricht einen laufenden Antwort-Turn ab (Barge-in) und meldet 'interrupted'."""
if task is None or task.done():
return
task.cancel()
try:
await task
except asyncio.CancelledError:
pass
await websocket.send_json({"type": "interrupted"})
async def _chat_turn(websocket, store, user, session_id, text, options):
try:
route, orchestrator, output = await _resolve(user, session_id, options)
except SessionOwnershipError as exc:
await websocket.send_json({"type": "error", "status": 403, "detail": str(exc)})
return
except RoutingError as exc:
await websocket.send_json({"type": "error", "status": 422, "detail": str(exc)})
return
await _run_turn(websocket, store, user, session_id, route, orchestrator, output, text, options)
async def _voice_turn(websocket, store, user, session_id, audio, fmt, options):
try:
route, orchestrator, output = await _resolve(user, session_id, options)
except SessionOwnershipError as exc:
await websocket.send_json({"type": "error", "status": 403, "detail": str(exc)})
return
except RoutingError as exc:
await websocket.send_json({"type": "error", "status": 422, "detail": str(exc)})
return
try:
transcript = await orchestrator.stt.transcribe(audio, fmt=fmt, language=route.language)
except Exception as exc:
await websocket.send_json({"type": "error", "status": 502, "detail": str(exc)})
return
await websocket.send_json({"type": "transcript", "text": transcript})
if not transcript or not transcript.strip():
await websocket.send_json({"type": "error", "detail": "empty transcript"})
return
await _run_turn(websocket, store, user, session_id, route, orchestrator, output, transcript, options)
@router.websocket("/ws/chat")
async def ws_chat(websocket: WebSocket, session_id: str | None = None, token: str | None = None):
user = _authenticate(token)
@ -134,24 +184,26 @@ async def ws_chat(websocket: WebSocket, session_id: str | None = None, token: st
return
await websocket.accept()
store = get_store()
active = None
try:
while True:
msg = await websocket.receive_json()
if msg.get("type") == "interrupt":
await _cancel_active(active, websocket)
active = None
continue
text = (msg.get("text") or "").strip()
if not text:
await websocket.send_json({"type": "error", "detail": "empty text"})
continue
try:
route, orchestrator, output = await _resolve(user, session_id, msg)
except SessionOwnershipError as exc:
await websocket.send_json({"type": "error", "status": 403, "detail": str(exc)})
continue
except RoutingError as exc:
await websocket.send_json({"type": "error", "status": 422, "detail": str(exc)})
continue
await _run_turn(websocket, store, user, session_id, route, orchestrator, output, text, msg)
await _cancel_active(active, websocket) # Barge-in bei neuer Eingabe
active = asyncio.create_task(
_chat_turn(websocket, store, user, session_id, text, msg)
)
except WebSocketDisconnect:
if active and not active.done():
active.cancel()
return
@ -166,15 +218,33 @@ async def ws_voice(websocket: WebSocket, session_id: str | None = None, token: s
audio_buffer = bytearray()
fmt = "wav"
active = None
vad = None
vad_options: dict = {}
async def _start_voice(audio: bytes, options: dict):
nonlocal active
await _cancel_active(active, websocket) # Barge-in bei neuer Aeusserung
active = asyncio.create_task(
_voice_turn(websocket, store, user, session_id, audio, fmt, options)
)
try:
while True:
message = await websocket.receive()
if message["type"] == "websocket.disconnect":
if active and not active.done():
active.cancel()
return
if message.get("bytes") is not None:
audio_buffer.extend(message["bytes"])
# VAD: Aeusserungsende automatisch erkennen (opt-in via start-Frame).
if vad is not None and vad.feed(message["bytes"]):
audio = bytes(audio_buffer)
audio_buffer.clear()
vad.reset()
await _start_voice(audio, vad_options)
continue
raw = message.get("text")
@ -187,9 +257,22 @@ async def ws_voice(websocket: WebSocket, session_id: str | None = None, token: s
continue
ctype = control.get("type")
if ctype == "interrupt":
await _cancel_active(active, websocket)
active = None
continue
if ctype == "start":
audio_buffer.clear()
fmt = control.get("format", "wav")
if control.get("vad"):
vad = EnergyVAD(
sample_rate=control.get("sample_rate", 16000),
threshold=control.get("vad_threshold", 500.0),
silence_ms=control.get("vad_silence_ms", 700.0),
)
vad_options = control
else:
vad = None
continue
if ctype != "end":
continue
@ -198,35 +281,12 @@ async def ws_voice(websocket: WebSocket, session_id: str | None = None, token: s
await websocket.send_json({"type": "error", "detail": "no audio received"})
continue
try:
route, orchestrator, output = await _resolve(user, session_id, control)
except SessionOwnershipError as exc:
await websocket.send_json({"type": "error", "status": 403, "detail": str(exc)})
audio_buffer.clear()
continue
except RoutingError as exc:
await websocket.send_json({"type": "error", "status": 422, "detail": str(exc)})
audio_buffer.clear()
continue
try:
transcript = await orchestrator.stt.transcribe(
bytes(audio_buffer), fmt=fmt, language=route.language
)
except Exception as exc:
await websocket.send_json({"type": "error", "status": 502, "detail": str(exc)})
audio_buffer.clear()
continue
finally:
audio_buffer.clear()
await websocket.send_json({"type": "transcript", "text": transcript})
if not transcript or not transcript.strip():
await websocket.send_json({"type": "error", "detail": "empty transcript"})
continue
await _run_turn(
websocket, store, user, session_id, route, orchestrator, output, transcript, control
)
audio = bytes(audio_buffer)
audio_buffer.clear()
if vad is not None:
vad.reset()
await _start_voice(audio, control)
except WebSocketDisconnect:
if active and not active.done():
active.cancel()
return

59
app/audio/vad.py Normal file
View file

@ -0,0 +1,59 @@
"""Einfache energie-basierte Sprachaktivitaetserkennung (VAD).
Reines Python (stdlib `array`), arbeitet auf s16le-PCM (mono). Erkennt das Ende
einer Aeusserung anhand andauernder Stille nach erkannter Sprache. Damit kann der
Server in /ws/voice Aeusserungen automatisch segmentieren, ohne dass der Client
ein explizites Ende-Signal schickt.
Hinweis: Das ersetzt keinen echten Streaming-STT-Dienst (keine wortweisen
Teil-Transkripte) - es bestimmt nur die Aeusserungsgrenzen.
"""
import array
import math
def rms(pcm: bytes) -> float:
"""Lautstaerke (RMS) eines s16le-PCM-Puffers; 0.0 bei leerem Puffer."""
usable = len(pcm) - (len(pcm) % 2)
if usable <= 0:
return 0.0
samples = array.array("h")
samples.frombytes(pcm[:usable])
if not samples:
return 0.0
return math.sqrt(sum(s * s for s in samples) / len(samples))
class EnergyVAD:
def __init__(self, sample_rate: int = 16000, threshold: float = 500.0, silence_ms: float = 700.0):
self.sample_rate = sample_rate
self.threshold = threshold
self.silence_ms = silence_ms
self._speech_started = False
self._silence_ms = 0.0
def feed(self, pcm: bytes) -> bool:
"""Verarbeitet einen Audio-Chunk.
Liefert True, sobald nach erkannter Sprache genug Stille (silence_ms)
vergangen ist - die Aeusserung gilt dann als beendet.
"""
level = rms(pcm)
n_samples = len(pcm) // 2
chunk_ms = (n_samples / self.sample_rate) * 1000.0 if self.sample_rate else 0.0
if level >= self.threshold:
self._speech_started = True
self._silence_ms = 0.0
return False
if self._speech_started:
self._silence_ms += chunk_ms
if self._silence_ms >= self.silence_ms:
return True
return False
def reset(self) -> None:
self._speech_started = False
self._silence_ms = 0.0