gx10/tts: persist Piper /tts source + manifest (telephony TTS port baseline)

Dockerfile (linux/arm64, en_US-amy-medium baked), tts_service.py (16kHz/16-bit/mono
WAV, numpy resample 22050->16000), gx10-tts.yaml (CPU NodePort 30850, no GPU request),
README (build/import/cutover/verify on the GX10 cluster).

gx10/tts/tts_service.py

@@ -0,0 +1,153 @@
+#!/usr/bin/env python3
+"""GX10 Piper TTS microservice — telephony /tts contract.
+
+POST /tts  {"text": "..."}  -> 16 kHz / 16-bit / mono WAV (canonical 44-byte header)
+GET  /health                -> JSON status
+
+The telephony AsteriskProvider strips the 44-byte WAV header and writes the
+remainder as a `.sln16` (signed-linear 16 kHz) file that Asterisk transcodes to
+any codec. So the response MUST be 16 kHz / 16-bit / mono. The en_US-amy-medium
+voice is 22.05 kHz native, so we resample to 16 kHz (a 22.05 kHz stream treated
+as 16 kHz plays ~1.38x too fast). This is a drop-in upgrade over edge1's
+en_US-amy-low (16 kHz native, lower quality), keeping the exact wire contract.
+"""
+import io
+import logging
+import os
+import sys
+import threading
+import wave
+
+import numpy as np
+from flask import Flask, Response, jsonify, request
+
+API_PORT = int(os.environ.get("TTS_PORT", "8500"))
+PIPER_VOICE = os.environ.get("PIPER_VOICE", "en_US-amy-medium")
+VOICES_DIR = os.environ.get("VOICES_DIR", "/voices")
+TARGET_RATE = int(os.environ.get("TARGET_RATE", "16000"))
+
+logging.basicConfig(
+    level=logging.INFO,
+    format="%(asctime)s [%(levelname)s] %(name)s: %(message)s",
+    stream=sys.stdout,
+)
+log = logging.getLogger("gx10-tts")
+
+piper_voice_obj = None
+piper_loaded = False
+piper_lock = threading.Lock()
+native_rate = None
+
+app = Flask(__name__)
+
+
+def load_piper():
+    """Load the Piper voice model once at startup (shared, lock-guarded)."""
+    global piper_voice_obj, piper_loaded
+    try:
+        from piper import PiperVoice
+        model_path = os.path.join(VOICES_DIR, f"{PIPER_VOICE}.onnx")
+        if not os.path.isfile(model_path):
+            log.error("Piper voice model not found at %s — TTS disabled", model_path)
+            piper_loaded = False
+            return
+        log.info("Loading Piper voice %s from %s", PIPER_VOICE, model_path)
+        piper_voice_obj = PiperVoice.load(model_path)
+        piper_loaded = True
+        log.info("Piper voice loaded")
+    except Exception as exc:  # noqa: BLE001 — fail-soft, /health reports it
+        log.error("Failed to load Piper: %s", exc)
+        piper_loaded = False
+
+
+def synthesize_chunks(text):
+    """Run Piper synthesis under a lock because the loaded voice is shared."""
+    with piper_lock:
+        return list(piper_voice_obj.synthesize(text))
+
+
+def resample_i16(pcm_i16, src_rate, dst_rate):
+    """Linear-interpolation resample of int16 PCM (matches edge1's STT resample)."""
+    if src_rate == dst_rate or len(pcm_i16) == 0:
+        return pcm_i16
+    audio = pcm_i16.astype(np.float32)
+    target_len = int(round(len(audio) * dst_rate / src_rate))
+    if target_len <= 0:
+        return np.zeros(0, dtype=np.int16)
+    idx = np.linspace(0, len(audio) - 1, target_len)
+    res = np.interp(idx, np.arange(len(audio)), audio)
+    return np.clip(np.round(res), -32768, 32767).astype(np.int16)
+
+
+@app.route("/health", methods=["GET"])
+def health():
+    return jsonify({
+        "status": "ok",
+        "voice": PIPER_VOICE,
+        "loaded": piper_loaded,
+        "target_rate": TARGET_RATE,
+        "native_rate": native_rate,
+    })
+
+
+@app.route("/tts", methods=["POST"])
+def tts():
+    """Text -> 16 kHz/16-bit/mono WAV. Mirrors the edge1 speech-pipeline contract."""
+    if not piper_loaded:
+        return jsonify({"error": "Piper TTS model not loaded"}), 503
+
+    data = request.get_json(silent=True)
+    if not data or "text" not in data:
+        return jsonify({"error": "Missing required field: text"}), 400
+
+    text = data["text"].strip()
+    if not text:
+        return jsonify({"error": "Text field is empty"}), 400
+    if len(text) > 10000:
+        return jsonify({"error": "Text too long (max 10000 characters)"}), 400
+
+    try:
+        chunks = synthesize_chunks(text)
+        if not chunks:
+            return jsonify({"error": "No audio produced"}), 500
+
+        global native_rate
+        first = chunks[0]
+        native_rate = first.sample_rate
+
+        if first.sample_width != 2 or first.sample_channels != 1:
+            return jsonify({
+                "error": f"Unexpected PCM format: width={first.sample_width} "
+                         f"channels={first.sample_channels} (need 16-bit mono)"
+            }), 500
+
+        pcm = np.frombuffer(
+            b"".join(c.audio_int16_bytes for c in chunks), dtype=np.int16
+        )
+        out = resample_i16(pcm, native_rate, TARGET_RATE)
+
+        wav_buffer = io.BytesIO()
+        with wave.open(wav_buffer, "wb") as wav_file:
+            wav_file.setnchannels(1)
+            wav_file.setsampwidth(2)
+            wav_file.setframerate(TARGET_RATE)
+            wav_file.writeframes(out.tobytes())
+        wav_buffer.seek(0)
+
+        return Response(
+            wav_buffer.read(),
+            mimetype="audio/wav",
+            headers={"Content-Disposition": 'inline; filename="speech.wav"'},
+        )
+    except Exception as exc:  # noqa: BLE001
+        log.error("TTS synthesis failed: %s", exc)
+        return jsonify({"error": f"Synthesis failed: {exc}"}), 500
+
+
+if __name__ == "__main__":
+    log.info(
+        "GX10 TTS starting on port %d (voice=%s -> %d Hz)",
+        API_PORT, PIPER_VOICE, TARGET_RATE,
+    )
+    load_piper()
+    app.run(host="0.0.0.0", port=API_PORT, threaded=True)