transcribe/serve.py

import queue
import threading
import time
from logging import getLogger
import asyncio
import numpy as np
import config
import collections
from api_model import TransResult, Message

from .utils import log_block, start_thread, get_text_separator, filter_words
from .processing import ProcessingPipes
from .pipelines import MetaItem


logger = getLogger("TranscriptionService")



class WhisperTranscriptionService:
    """
    Whisper语音转录服务类，处理音频流转录和翻译
    """


    def __init__(self, websocket, pipe: ProcessingPipes, language=None, dst_lang=None, client_uid=None):
        print('>>>>>>>>>>>>>>>> init service >>>>>>>>>>>>>>>>>>>>>>')
        print('src_lang:', language)
        self.source_language = language  # 源语言
        self.target_language = dst_lang  # 目标翻译语言
        self.client_uid = client_uid
        # 转录结果稳定性管理
        self.websocket = websocket
        self.translate_pipe = pipe
        # 音频处理相关
        self.sample_rate = config.SAMPLE_RATE

        self.frame_lock = threading.Lock()
        self.segment_lock = threading.Lock()
        # 文本分隔符，根据语言设置
        self.text_separator = get_text_separator(language)
        self.loop = asyncio.get_event_loop()
        #  原始音频队列
        self.frame_queue = queue.Queue()
        #  音频队列缓冲区
        self.frames_np = np.array([], dtype=np.float32)
        #  音频开始的时间点 用于约束最小断句时间
        self.frames_np_start_timestamp = None
        #  完整音频队列
        self.full_segments_queue = collections.deque()
        # 启动处理线程
        self._stop = threading.Event()
        self.translate_thread = start_thread(self._transcription_processing_loop)
        self.frame_processing_thread = start_thread(self._read_frame_processing_loop)
        # 行号
        self.row_number = 0


    def add_frames(self, frame_np: np.ndarray) -> None:
        """添加音频帧到处理队列"""
        self.frame_queue.put(frame_np)

    def _apply_voice_activity_detection(self, frame_np:np.array):
        """应用语音活动检测来优化音频缓冲区"""
        processed_audio = self.translate_pipe.voice_detect(frame_np.tobytes())
        speech_audio =  np.frombuffer(processed_audio.audio, dtype=np.float32)
        speech_status = processed_audio.speech_status
        return speech_audio, speech_status


    def _read_frame_processing_loop(self) -> None:
        """从队列获取音频帧并合并到缓冲区"""
        while not self._stop.is_set():
            frame_np = self.frame_queue.get()
            frame_np, speech_status = self._apply_voice_activity_detection(frame_np)

            if frame_np is None:
                continue

            with self.frame_lock:
                self.frames_np = np.append(self.frames_np, frame_np)

                # 音频开始时间节点 用来统计时间来 达到最小断句时间长度
            if speech_status == "START" and self.frames_np_start_timestamp is None:
                self.frames_np_start_timestamp = time.time()

            # 音频最长时间缓冲区限制，超过了就强制断句
            if len(self.frames_np) >= self.sample_rate * config.MAX_SPEECH_DURATION_S:
                audio_array=self.frames_np.copy()
                with self.segment_lock:
                    self.full_segments_queue.appendleft(audio_array) # 根据时间是否满足三秒长度 来整合音频块
                self.frames_np_start_timestamp = time.time()

                with self.frame_lock:
                    self.frames_np = np.array([], dtype=np.float32)

            # 音频结束信号的时候 整合当前缓冲区
            #   START -- END -- START -- END 通常
            #   START -- END -- END  end块带有音频信息的通常是4096内断的一个短音
            if speech_status == "END" and len(self.frames_np) > 0 and self.frames_np_start_timestamp:
                time_diff = time.time() - self.frames_np_start_timestamp
                if time_diff >= config.FRAME_SCOPE_TIME_THRESHOLD:
                    with self.frame_lock:
                        audio_array=self.frames_np.copy()
                        self.frames_np = np.array([], dtype=np.float32)

                    with self.segment_lock:
                        self.full_segments_queue.appendleft(audio_array) # 根据时间是否满足三秒长度 来整合音频块
                    logger.debug(f"🥳 增加整句到队列")
                    self.frames_np_start_timestamp = None
                   
                else:
                    logger.debug(f"🥳 当前时间与上一句的时间差: {time_diff:.2f}s,继续保留在缓冲区")


    def _transcription_processing_loop(self) -> None:
        """主转录处理循环"""
        frame_epoch = 1

        while not self._stop.is_set():
            time.sleep(0.1)
          
            with self.segment_lock:
                segment_length = len(self.full_segments_queue) 
            if segment_length > 0:
                audio_buffer = self.full_segments_queue.pop()
                partial = False
            else:
                with self.frame_lock:
                    if len(self.frames_np) ==0:
                        continue
                    audio_buffer = self.frames_np[:int(frame_epoch * 1.5 * self.sample_rate)].copy()# 获取 1.5s * epoch 个音频长度
                    partial = True

            logger.debug(f"full_segments_queue size: {segment_length}")
            logger.debug(f"audio buffer size: {len(self.frames_np) / self.sample_rate:.2f}s")
            
            if len(audio_buffer) < int(self.sample_rate):
                # Add a small buffer (e.g., 10ms worth of samples) to be safe
                padding_samples = int(self.sample_rate * 0.01) # e.g., 160 samples for 10ms at 16kHz
                target_length = self.sample_rate + padding_samples
                silence_audio = np.zeros(target_length, dtype=np.float32)
                # Ensure we don't try to copy more data than exists if audio_buffer is very short
                copy_length = min(len(audio_buffer), target_length)
                silence_audio[-copy_length:] = audio_buffer[-copy_length:] # Copy from the end of audio_buffer
                audio_buffer = silence_audio

            
            meta_item = self._transcribe_audio(audio_buffer)
            segments = meta_item.segments
            logger.debug(f"Segments: {segments}")
            segments = filter_words(segments)

            if len(segments):
                seg_text = self.text_separator.join(seg.text for seg in segments)
                if seg_text.strip() in ['', '.', '-']: # 过滤空字符
                    continue
                # 整行
                if not partial:
                    translated_content = self._translate_text_large(seg_text)
                    self.row_number += 1
                    frame_epoch = 1
                else:
                    translated_content = self._translate_text(seg_text)
                    frame_epoch += 1

                result = TransResult(
                    seg_id=self.row_number,
                    context=seg_text,
                    from_=self.source_language,
                    to=self.target_language,
                    tran_content=translated_content,
                    partial=partial
                )
                self._send_result_to_client(result)

    def _transcribe_audio(self, audio_buffer: np.ndarray)->MetaItem:
        """转录音频并返回转录片段"""
        log_block("Audio buffer length", f"{audio_buffer.shape[0]/self.sample_rate:.2f}", "s")
        result = self.translate_pipe.transcribe(audio_buffer.tobytes(), self.source_language)
        log_block("📝 transcribe output", f"{self.text_separator.join(seg.text for seg in result.segments)}", "")

        return result

    def _translate_text(self, text: str) -> str:
        """将文本翻译为目标语言"""
        if not text.strip():
            return ""
        log_block("🐧 Translation input ", f"{text}")

        result = self.translate_pipe.translate(text, self.source_language, self.target_language)
        translated_text = result.translate_content

        log_block("🐧 Translation out ", f"{translated_text}")
        return translated_text

    def _translate_text_large(self, text: str) -> str:
        """将文本翻译为目标语言"""
        if not text.strip():
            return ""
        log_block("Translation input", f"{text}")
        result = self.translate_pipe.translate_large(text, self.source_language, self.target_language)
        translated_text = result.translate_content
        log_block("Translation large model output", f"{translated_text}")
        return translated_text


    def _send_result_to_client(self, result: TransResult) -> None:
        """发送翻译结果到客户端"""
        try:
            message = Message(result=result, request_id=self.client_uid).model_dump_json(by_alias=True)
            coro = self.websocket.send_text(message)
            future = asyncio.run_coroutine_threadsafe(coro, self.loop)
            future.add_done_callback(lambda fut: fut.exception() and self.stop())
        except RuntimeError:
            self.stop()
        except Exception as e:
            logger.error(f"Error sending result to client: {e}")

    def stop(self) -> None:
        """停止所有处理线程并清理资源"""
        self._stop.set()
        logger.info(f"Stopping transcription service for client: {self.client_uid}")