kokoro/server.py

#!/usr/bin/env python3
"""Kokoro TTS Wyoming protocol server for Home Assistant integration."""

import argparse
import asyncio
import logging
import sys
from concurrent.futures import ThreadPoolExecutor
from functools import partial
from pathlib import Path

import numpy as np
import yaml

from wyoming.audio import AudioChunk, AudioStart, AudioStop
from wyoming.event import Event
from wyoming.handler import AsyncEventHandler
from wyoming.info import Attribution, Describe, Info, TtsProgram, TtsVoice
from wyoming.server import AsyncServer
from wyoming.tts import Synthesize

_LOGGER = logging.getLogger(__name__)

KOKORO_SAMPLE_RATE = 24000
SAMPLE_WIDTH = 2   # 16-bit PCM
CHANNELS = 1


def load_config(path: str) -> dict:
    with open(path) as f:
        return yaml.safe_load(f)


def build_wyoming_info(config: dict) -> Info:
    voices = [
        TtsVoice(
            name=v["name"],
            description=v.get("description", v["name"]),
            attribution=Attribution(
                name="Kokoro-82M",
                url="https://huggingface.co/hexgrad/Kokoro-82M",
            ),
            installed=True,
            version="1.0",
            languages=[v.get("language", "en-us")],
        )
        for v in config["tts"]["voices"]
    ]

    return Info(
        tts=[
            TtsProgram(
                name="kokoro",
                description="Kokoro 82M TTS via ROCm",
                attribution=Attribution(
                    name="hexgrad/Kokoro-82M",
                    url="https://huggingface.co/hexgrad/Kokoro-82M",
                ),
                installed=True,
                version="0.9.4",
                voices=voices,
            )
        ]
    )


class KokoroEventHandler(AsyncEventHandler):
    def __init__(
        self,
        wyoming_info: Info,
        pipeline,
        config: dict,
        executor: ThreadPoolExecutor,
        *args,
        **kwargs,
    ):
        super().__init__(*args, **kwargs)
        self.wyoming_info = wyoming_info
        self.pipeline = pipeline
        self.config = config
        self.executor = executor

    async def handle_event(self, event: Event) -> bool:
        if Describe.is_type(event.type):
            await self.write_event(self.wyoming_info.event())
            return True

        if Synthesize.is_type(event.type):
            await self._handle_synthesize(Synthesize.from_event(event))
            return True

        return True

    async def _handle_synthesize(self, synth: Synthesize) -> None:
        text = synth.text.strip()
        if not text:
            await self.write_event(AudioStart(
                rate=KOKORO_SAMPLE_RATE, width=SAMPLE_WIDTH, channels=CHANNELS
            ).event())
            await self.write_event(AudioStop().event())
            return

        # Resolve voice: prefer client request, fall back to config default
        default_voice = self.config["tts"].get("default_voice", "af_heart")
        voice_name = (
            synth.voice.name
            if (synth.voice and synth.voice.name)
            else default_voice
        )
        speed = self.config["tts"].get("default_speed", 1.0)

        _LOGGER.info("Synthesize: voice=%s text=%r", voice_name, text[:80])

        await self.write_event(
            AudioStart(
                rate=KOKORO_SAMPLE_RATE, width=SAMPLE_WIDTH, channels=CHANNELS
            ).event()
        )

        try:
            chunk_queue: asyncio.Queue = asyncio.Queue()
            loop = asyncio.get_event_loop()

            def _generate():
                try:
                    for _, _, audio in self.pipeline(text, voice=voice_name, speed=speed):
                        if audio is None:
                            continue
                        # float32 [-1, 1] → int16
                        pcm = (np.clip(audio, -1.0, 1.0) * 32767).astype(np.int16)
                        asyncio.run_coroutine_threadsafe(
                            chunk_queue.put(pcm.tobytes()), loop
                        )
                except Exception as exc:
                    asyncio.run_coroutine_threadsafe(chunk_queue.put(exc), loop)
                finally:
                    asyncio.run_coroutine_threadsafe(chunk_queue.put(None), loop)

            self.executor.submit(_generate)

            while True:
                item = await chunk_queue.get()
                if item is None:
                    break
                if isinstance(item, Exception):
                    raise item
                await self.write_event(
                    AudioChunk(
                        rate=KOKORO_SAMPLE_RATE,
                        width=SAMPLE_WIDTH,
                        channels=CHANNELS,
                        audio=item,
                    ).event()
                )
        except Exception:
            _LOGGER.exception("Error during synthesis")
        finally:
            await self.write_event(AudioStop().event())


async def main() -> None:
    parser = argparse.ArgumentParser(description="Kokoro TTS Wyoming server")
    parser.add_argument(
        "--config", default="/app/config.yaml", help="Path to config.yaml"
    )
    parser.add_argument("--debug", action="store_true", help="Enable debug logging")
    args = parser.parse_args()

    logging.basicConfig(
        level=logging.DEBUG if args.debug else logging.INFO,
        format="%(asctime)s %(levelname)s %(name)s: %(message)s",
    )

    config = load_config(args.config)
    uri = config["server"]["uri"]
    device = config["tts"].get("device", "cuda")
    lang = config["tts"].get("language", "a")

    _LOGGER.info("Loading Kokoro pipeline (device=%s, lang=%s)...", device, lang)

    # Import here so startup logging appears first
    import torch
    from kokoro import KPipeline

    if device == "cuda" and not torch.cuda.is_available():
        _LOGGER.warning("CUDA/ROCm not available, falling back to CPU")
        device = "cpu"

    _LOGGER.info("GPU available: %s", torch.cuda.is_available())
    if torch.cuda.is_available():
        _LOGGER.info("Device name: %s", torch.cuda.get_device_name(0))

    pipeline = KPipeline(lang_code=lang, device=device)
    wyoming_info = build_wyoming_info(config)
    executor = ThreadPoolExecutor(max_workers=1, thread_name_prefix="kokoro")

    _LOGGER.info("Starting Wyoming server at %s", uri)

    server = AsyncServer.from_uri(uri)
    await server.run(
        partial(
            KokoroEventHandler,
            wyoming_info,
            pipeline,
            config,
            executor,
        )
    )


if __name__ == "__main__":
    try:
        asyncio.run(main())
    except KeyboardInterrupt:
        pass