Add xfyun asr service

engine/config.py

@@ -47,10 +47,17 @@ class LLMConfig:
 @dataclass(frozen=True)
 class STTConfig:
     provider: str = "openai"
+    app_id: str = ""
     api_key: str = ""
+    api_secret: str = ""
     base_url: str | None = None
     model: str = "gpt-4o-mini-transcribe"
     language: str | None = "en"
+    domain: str = "iat"
+    accent: str = "mandarin"
+    encoding: str = "raw"
+    frame_size: int = 1280
+    timeout_sec: float = 10.0
 
 
 @dataclass(frozen=True)

engine/pipeline.py

@@ -30,6 +30,7 @@ from .product_protocol import ProductWebsocketSerializer
 from .services import create_llm_service, create_stt_service, create_tts_service
 from .text_input import ProductTextInputProcessor
 from .text_stream import ProductTextStreamProcessor
+from .transcript_stream import ProductTranscriptStreamProcessor
 
 
 async def run_voice_pipeline(websocket, config: EngineConfig) -> None:
@@ -74,7 +75,7 @@ async def run_pipeline_with_serializer(
         ),
     )
 
-    stt = create_stt_service(config.services.stt)
+    stt = create_stt_service(config.services.stt, config.audio)
     llm = create_llm_service(config.services.llm)
     tts = create_tts_service(config.services.tts, config.audio)
 
@@ -93,6 +94,7 @@ async def run_pipeline_with_serializer(
             transport.input(),
             ProductTextInputProcessor(),
             stt,
+            ProductTranscriptStreamProcessor(),
             user_aggregator,
             llm,
             ProductTextStreamProcessor(),

engine/services.py

@@ -13,10 +13,27 @@ from pipecat.services.openai.tts import VALID_VOICES, OpenAITTSService
 from pipecat.transcriptions.language import Language
 
 from .config import AudioConfig, LLMConfig, STTConfig, TTSConfig
+from .xfyun_asr import DEFAULT_XFYUN_ASR_URL, XfyunASRService
 from .xfyun_tts import DEFAULT_XFYUN_TTS_URL, XfyunTTSService
 
 
-def create_stt_service(config: STTConfig):
+def create_stt_service(config: STTConfig, audio: AudioConfig | None = None):
+    if config.provider == "xfyun":
+        sample_rate = audio.sample_rate_hz if audio else 16000
+        return XfyunASRService(
+            app_id=config.app_id,
+            api_key=config.api_key or "",
+            api_secret=config.api_secret,
+            url=config.base_url or DEFAULT_XFYUN_ASR_URL,
+            language=config.language or "zh_cn",
+            domain=config.domain,
+            accent=config.accent,
+            sample_rate=sample_rate,
+            encoding=config.encoding,
+            frame_size=config.frame_size,
+            open_timeout=config.timeout_sec,
+        )
+
     _require_provider(config.provider, "openai", "stt")
     return OpenAISTTService(
         api_key=config.api_key or None,

engine/transcript_stream.py

@@ -0,0 +1,30 @@
+from __future__ import annotations
+
+from pipecat.frames.frames import (
+    Frame,
+    InterimTranscriptionFrame,
+    OutputTransportMessageUrgentFrame,
+)
+from pipecat.processors.frame_processor import FrameDirection, FrameProcessor
+
+
+class ProductTranscriptStreamProcessor(FrameProcessor):
+    """Mirrors interim STT frames to the product websocket protocol."""
+
+    async def process_frame(self, frame: Frame, direction: FrameDirection) -> None:
+        await super().process_frame(frame, direction)
+
+        if isinstance(frame, InterimTranscriptionFrame):
+            await self.push_frame(
+                OutputTransportMessageUrgentFrame(
+                    message={
+                        "type": "input.transcript.interim",
+                        "text": frame.text,
+                        "user_id": frame.user_id,
+                        "timestamp": frame.timestamp,
+                    }
+                ),
+                FrameDirection.DOWNSTREAM,
+            )
+
+        await self.push_frame(frame, direction)

engine/xfyun_asr.py

@@ -0,0 +1,335 @@
+from __future__ import annotations
+
+import asyncio
+import base64
+import hashlib
+import hmac
+import json
+import os
+from collections.abc import AsyncGenerator
+from datetime import datetime, timezone
+from email.utils import format_datetime
+from typing import Any
+from urllib.parse import urlencode, urlparse
+
+from loguru import logger
+
+from pipecat.frames.frames import (
+    CancelFrame,
+    EndFrame,
+    ErrorFrame,
+    Frame,
+    InterimTranscriptionFrame,
+    TranscriptionFrame,
+    VADUserStartedSpeakingFrame,
+    VADUserStoppedSpeakingFrame,
+)
+from pipecat.processors.frame_processor import FrameDirection
+from pipecat.services.stt_service import STTService
+from pipecat.transcriptions.language import Language
+from pipecat.utils.time import time_now_iso8601
+from websockets.asyncio.client import connect as websocket_connect
+from websockets.protocol import State
+
+
+DEFAULT_XFYUN_ASR_URL = "wss://iat-api.xfyun.cn/v2/iat"
+
+
+class XfyunASRService(STTService):
+    """iFlytek/Xfyun streaming voice dictation service for Pipecat."""
+
+    def __init__(
+        self,
+        *,
+        app_id: str,
+        api_key: str,
+        api_secret: str,
+        url: str | None = None,
+        language: str = "zh_cn",
+        domain: str = "iat",
+        accent: str = "mandarin",
+        sample_rate: int = 16000,
+        encoding: str = "raw",
+        frame_size: int = 1280,
+        open_timeout: float = 10.0,
+        **kwargs,
+    ) -> None:
+        super().__init__(sample_rate=sample_rate, **kwargs)
+        self._app_id = app_id or os.environ.get("XFYUN_APP_ID", "")
+        self._api_key = api_key or os.environ.get("XFYUN_API_KEY", "")
+        self._api_secret = api_secret or os.environ.get("XFYUN_API_SECRET", "")
+        self._url = url or DEFAULT_XFYUN_ASR_URL
+        self._language = language
+        self._domain = domain
+        self._accent = accent
+        self._encoding = encoding
+        self._frame_size = frame_size
+        self._open_timeout = open_timeout
+
+        self._websocket = None
+        self._receive_task = None
+        self._audio_buffer = bytearray()
+        self._sent_first_frame = False
+        self._sent_final_frame = False
+        self._partials: list[str] = []
+        self._last_text = ""
+
+    async def cleanup(self) -> None:
+        await self._close_utterance()
+        await super().cleanup()
+
+    async def stop(self, frame: EndFrame) -> None:
+        await self._close_utterance()
+        await super().stop(frame)
+
+    async def cancel(self, frame: CancelFrame) -> None:
+        await self._close_utterance()
+        await super().cancel(frame)
+
+    async def process_frame(self, frame: Frame, direction: FrameDirection) -> None:
+        await super().process_frame(frame, direction)
+
+        if isinstance(frame, VADUserStartedSpeakingFrame):
+            await self._start_utterance()
+        elif isinstance(frame, VADUserStoppedSpeakingFrame):
+            await self._finish_utterance()
+
+    async def run_stt(self, audio: bytes) -> AsyncGenerator[Frame | None, None]:
+        if not audio:
+            yield None
+            return
+
+        if not self._websocket or self._websocket.state is not State.OPEN:
+            await self._start_utterance()
+
+        self._audio_buffer.extend(audio)
+        await self._flush_audio_buffer(final=False)
+        yield None
+
+    async def _start_utterance(self) -> None:
+        if self._websocket and self._websocket.state is State.OPEN:
+            return
+
+        if not self._app_id or not self._api_key or not self._api_secret:
+            await self.push_error("Xfyun ASR requires app_id, api_key, and api_secret")
+            return
+
+        if self.sample_rate not in (8000, 16000):
+            await self.push_error("Xfyun ASR sample rate must be 8000 or 16000")
+            return
+
+        self._audio_buffer.clear()
+        self._partials = []
+        self._last_text = ""
+        self._sent_first_frame = False
+        self._sent_final_frame = False
+
+        auth_url = _build_auth_url(self._url, self._api_key, self._api_secret)
+        try:
+            self._websocket = await websocket_connect(
+                auth_url,
+                max_size=None,
+                open_timeout=self._open_timeout,
+            )
+        except Exception as exc:
+            await self.push_error(f"Xfyun ASR connection failed: {exc}", exception=exc)
+            self._websocket = None
+            return
+
+        self._receive_task = self.create_task(
+            self._receive_messages(),
+            name="xfyun_asr_receive",
+        )
+
+    async def _finish_utterance(self) -> None:
+        if not self._websocket or self._websocket.state is not State.OPEN:
+            return
+
+        await self._flush_audio_buffer(final=True)
+        if not self._sent_first_frame:
+            await self._close_utterance()
+            return
+
+        if not self._sent_final_frame:
+            await self._send_payload({"data": {"status": 2}})
+            self.request_finalize()
+            self._sent_final_frame = True
+
+    async def _close_utterance(self) -> None:
+        current_task = asyncio.current_task()
+        if self._receive_task and self._receive_task is not current_task:
+            await self.cancel_task(self._receive_task)
+            self._receive_task = None
+
+        websocket = self._websocket
+        self._websocket = None
+        if websocket and websocket.state is State.OPEN:
+            try:
+                await websocket.close()
+            except Exception:
+                pass
+
+        self._audio_buffer.clear()
+        self._sent_first_frame = False
+        self._sent_final_frame = False
+
+    async def _flush_audio_buffer(self, *, final: bool) -> None:
+        while len(self._audio_buffer) >= self._frame_size:
+            chunk = bytes(self._audio_buffer[: self._frame_size])
+            del self._audio_buffer[: self._frame_size]
+            await self._send_audio_chunk(chunk, status=1)
+
+        if final and self._audio_buffer:
+            chunk = bytes(self._audio_buffer)
+            self._audio_buffer.clear()
+            await self._send_audio_chunk(chunk, status=1)
+
+    async def _send_audio_chunk(self, audio: bytes, *, status: int) -> None:
+        if not audio:
+            return
+
+        if not self._sent_first_frame:
+            payload = {
+                "common": {"app_id": self._app_id},
+                "business": {
+                    "language": self._language,
+                    "domain": self._domain,
+                    "accent": self._accent,
+                },
+                "data": {
+                    "status": 0,
+                    "format": f"audio/L16;rate={self.sample_rate}",
+                    "encoding": self._encoding,
+                    "audio": base64.b64encode(audio).decode("utf-8"),
+                },
+            }
+            self._sent_first_frame = True
+        else:
+            payload = {
+                "data": {
+                    "status": status,
+                    "format": f"audio/L16;rate={self.sample_rate}",
+                    "encoding": self._encoding,
+                    "audio": base64.b64encode(audio).decode("utf-8"),
+                }
+            }
+
+        await self._send_payload(payload)
+
+    async def _send_payload(self, payload: dict[str, Any]) -> None:
+        if not self._websocket or self._websocket.state is not State.OPEN:
+            return
+        await self._websocket.send(json.dumps(payload, ensure_ascii=False))
+
+    async def _receive_messages(self) -> None:
+        websocket = self._websocket
+        if not websocket:
+            return
+
+        try:
+            async for message in websocket:
+                await self._process_response(json.loads(message))
+        except Exception as exc:
+            if self._websocket is websocket:
+                await self.push_error(f"Xfyun ASR receive failed: {exc}", exception=exc)
+        finally:
+            if self._websocket is websocket:
+                self._websocket = None
+            self._receive_task = None
+
+    async def _process_response(self, payload: dict[str, Any]) -> None:
+        code = payload.get("code", -1)
+        if code != 0:
+            message = payload.get("message", "unknown error")
+            sid = payload.get("sid")
+            await self.push_error(f"Xfyun ASR error code={code}, sid={sid}, message={message}")
+            return
+
+        data = payload.get("data")
+        if not isinstance(data, dict):
+            return
+
+        recognition = data.get("result")
+        if isinstance(recognition, dict):
+            text = self._apply_recognition_result(recognition)
+            if text and text != self._last_text:
+                self._last_text = text
+                await self.push_frame(
+                    InterimTranscriptionFrame(
+                        text,
+                        self._user_id,
+                        time_now_iso8601(),
+                        _language_or_none(self._language),
+                        result=payload,
+                    )
+                )
+
+        if data.get("status") == 2:
+            final_text = self._last_text
+            if final_text:
+                self.confirm_finalize()
+                await self.push_frame(
+                    TranscriptionFrame(
+                        final_text,
+                        self._user_id,
+                        time_now_iso8601(),
+                        _language_or_none(self._language),
+                        result=payload,
+                    )
+                )
+            await self._close_utterance()
+
+    def _apply_recognition_result(self, recognition: dict[str, Any]) -> str:
+        partial = _extract_text_from_result(recognition)
+        if not partial:
+            return self._last_text
+
+        if recognition.get("pgs") == "rpl" and recognition.get("rg"):
+            start, end = recognition["rg"]
+            if 1 <= start <= len(self._partials):
+                self._partials[start - 1 : end] = [partial]
+            else:
+                logger.debug(f"Ignoring out-of-range Xfyun replacement rg={recognition['rg']}")
+        else:
+            self._partials.append(partial)
+
+        return "".join(self._partials)
+
+
+def _extract_text_from_result(result: dict[str, Any]) -> str:
+    words: list[str] = []
+    for item in result.get("ws", []):
+        for candidate in item.get("cw", []):
+            word = candidate.get("w")
+            if word:
+                words.append(word)
+    return "".join(words)
+
+
+def _build_auth_url(url: str, api_key: str, api_secret: str) -> str:
+    parsed = urlparse(url)
+    host = parsed.netloc
+    path = parsed.path or "/v2/iat"
+    date = format_datetime(datetime.now(timezone.utc), usegmt=True)
+    request_line = f"GET {path} HTTP/1.1"
+    signature_origin = f"host: {host}\ndate: {date}\n{request_line}"
+    signature_sha = hmac.new(
+        api_secret.encode("utf-8"),
+        signature_origin.encode("utf-8"),
+        digestmod=hashlib.sha256,
+    ).digest()
+    signature = base64.b64encode(signature_sha).decode("utf-8")
+    authorization_origin = (
+        f'api_key="{api_key}", algorithm="hmac-sha256", '
+        f'headers="host date request-line", signature="{signature}"'
+    )
+    authorization = base64.b64encode(authorization_origin.encode("utf-8")).decode("utf-8")
+    query = urlencode({"authorization": authorization, "date": date, "host": host})
+    return f"{url}?{query}"
+
+
+def _language_or_none(value: str) -> Language | None:
+    try:
+        return Language(value)
+    except ValueError:
+        return None