import asyncio import numpy as np import ffmpeg from time import time, sleep import math import logging import traceback from datetime import timedelta from whisperlivekit.timed_objects import ASRToken from whisperlivekit.whisper_streaming_custom.whisper_online import online_factory from whisperlivekit.core import TranscriptionEngine # Set up logging once logging.basicConfig(level=logging.INFO, format="%(asctime)s - %(levelname)s - %(message)s") logger = logging.getLogger(__name__) logger.setLevel(logging.DEBUG) SENTINEL = object() # unique sentinel object for end of stream marker def format_time(seconds: float) -> str: """Format seconds as HH:MM:SS.""" return str(timedelta(seconds=int(seconds))) class AudioProcessor: """ Processes audio streams for transcription and diarization. Handles audio processing, state management, and result formatting. """ def __init__(self, **kwargs): """Initialize the audio processor with configuration, models, and state.""" if 'transcription_engine' in kwargs and isinstance(kwargs['transcription_engine'], TranscriptionEngine): models = kwargs['transcription_engine'] else: models = TranscriptionEngine(**kwargs) # Audio processing settings self.args = models.args self.sample_rate = 16000 self.channels = 1 self.samples_per_sec = int(self.sample_rate * self.args.min_chunk_size) self.bytes_per_sample = 2 self.bytes_per_sec = self.samples_per_sec * self.bytes_per_sample self.max_bytes_per_sec = 32000 * 5 # 5 seconds of audio at 32 kHz self.last_ffmpeg_activity = time() self.ffmpeg_health_check_interval = 5 self.ffmpeg_max_idle_time = 10 # State management self.is_stopping = False self.tokens = [] self.buffer_transcription = "" self.buffer_diarization = "" self.full_transcription = "" self.end_buffer = 0 self.end_attributed_speaker = 0 self.lock = asyncio.Lock() self.beg_loop = time() self.sep = " " # Default separator self.last_response_content = "" # Models and processing self.asr = models.asr self.tokenizer = models.tokenizer self.diarization = models.diarization self.ffmpeg_process = self.start_ffmpeg_decoder() self.transcription_queue = asyncio.Queue() if self.args.transcription else None self.diarization_queue = asyncio.Queue() if self.args.diarization else None self.pcm_buffer = bytearray() # Task references self.transcription_task = None self.diarization_task = None self.ffmpeg_reader_task = None self.watchdog_task = None self.all_tasks_for_cleanup = [] # Initialize transcription engine if enabled if self.args.transcription: self.online = online_factory(self.args, models.asr, models.tokenizer) def convert_pcm_to_float(self, pcm_buffer): """Convert PCM buffer in s16le format to normalized NumPy array.""" return np.frombuffer(pcm_buffer, dtype=np.int16).astype(np.float32) / 32768.0 def start_ffmpeg_decoder(self): """Start FFmpeg process for WebM to PCM conversion.""" try: return (ffmpeg.input("pipe:0", format="webm") .output("pipe:1", format="s16le", acodec="pcm_s16le", ac=self.channels, ar=str(self.sample_rate)) .run_async(pipe_stdin=True, pipe_stdout=True, pipe_stderr=True)) except FileNotFoundError: error = """ FFmpeg is not installed or not found in your system's PATH. Please install FFmpeg to enable audio processing. Installation instructions: # Ubuntu/Debian: sudo apt update && sudo apt install ffmpeg # macOS (using Homebrew): brew install ffmpeg # Windows: # 1. Download the latest static build from https://ffmpeg.org/download.html # 2. Extract the archive (e.g., to C:\\FFmpeg). # 3. Add the 'bin' directory (e.g., C:\\FFmpeg\\bin) to your system's PATH environment variable. After installation, please restart the application. """ logger.error(error) raise FileNotFoundError(error) async def restart_ffmpeg(self): """Restart the FFmpeg process after failure.""" logger.warning("Restarting FFmpeg process...") if self.ffmpeg_process: try: # we check if process is still running if self.ffmpeg_process.poll() is None: logger.info("Terminating existing FFmpeg process") self.ffmpeg_process.stdin.close() self.ffmpeg_process.terminate() # wait for termination with timeout try: await asyncio.wait_for( asyncio.get_event_loop().run_in_executor(None, self.ffmpeg_process.wait), timeout=5.0 ) except asyncio.TimeoutError: logger.warning("FFmpeg process did not terminate, killing forcefully") self.ffmpeg_process.kill() await asyncio.get_event_loop().run_in_executor(None, self.ffmpeg_process.wait) except Exception as e: logger.error(f"Error during FFmpeg process termination: {e}") logger.error(traceback.format_exc()) # we start new process try: logger.info("Starting new FFmpeg process") self.ffmpeg_process = self.start_ffmpeg_decoder() self.pcm_buffer = bytearray() self.last_ffmpeg_activity = time() logger.info("FFmpeg process restarted successfully") except Exception as e: logger.error(f"Failed to restart FFmpeg process: {e}") logger.error(traceback.format_exc()) # try again after 5s await asyncio.sleep(5) try: self.ffmpeg_process = self.start_ffmpeg_decoder() self.pcm_buffer = bytearray() self.last_ffmpeg_activity = time() logger.info("FFmpeg process restarted successfully on second attempt") except Exception as e2: logger.critical(f"Failed to restart FFmpeg process on second attempt: {e2}") logger.critical(traceback.format_exc()) async def update_transcription(self, new_tokens, buffer, end_buffer, full_transcription, sep): """Thread-safe update of transcription with new data.""" async with self.lock: self.tokens.extend(new_tokens) self.buffer_transcription = buffer self.end_buffer = end_buffer self.full_transcription = full_transcription self.sep = sep async def update_diarization(self, end_attributed_speaker, buffer_diarization=""): """Thread-safe update of diarization with new data.""" async with self.lock: self.end_attributed_speaker = end_attributed_speaker if buffer_diarization: self.buffer_diarization = buffer_diarization async def add_dummy_token(self): """Placeholder token when no transcription is available.""" async with self.lock: current_time = time() - self.beg_loop self.tokens.append(ASRToken( start=current_time, end=current_time + 1, text=".", speaker=-1, is_dummy=True )) async def get_current_state(self): """Get current state.""" async with self.lock: current_time = time() # Calculate remaining times remaining_transcription = 0 if self.end_buffer > 0: remaining_transcription = max(0, round(current_time - self.beg_loop - self.end_buffer, 2)) remaining_diarization = 0 if self.tokens: latest_end = max(self.end_buffer, self.tokens[-1].end if self.tokens else 0) remaining_diarization = max(0, round(latest_end - self.end_attributed_speaker, 2)) return { "tokens": self.tokens.copy(), "buffer_transcription": self.buffer_transcription, "buffer_diarization": self.buffer_diarization, "end_buffer": self.end_buffer, "end_attributed_speaker": self.end_attributed_speaker, "sep": self.sep, "remaining_time_transcription": remaining_transcription, "remaining_time_diarization": remaining_diarization } async def reset(self): """Reset all state variables to initial values.""" async with self.lock: self.tokens = [] self.buffer_transcription = self.buffer_diarization = "" self.end_buffer = self.end_attributed_speaker = 0 self.full_transcription = self.last_response_content = "" self.beg_loop = time() async def ffmpeg_stdout_reader(self): """Read audio data from FFmpeg stdout and process it.""" loop = asyncio.get_event_loop() beg = time() while True: try: current_time = time() elapsed_time = math.floor((current_time - beg) * 10) / 10 buffer_size = max(int(32000 * elapsed_time), 4096) beg = current_time # Detect idle state much more quickly if current_time - self.last_ffmpeg_activity > self.ffmpeg_max_idle_time: logger.warning(f"FFmpeg process idle for {current_time - self.last_ffmpeg_activity:.2f}s. Restarting...") await self.restart_ffmpeg() beg = time() self.last_ffmpeg_activity = time() continue chunk = await loop.run_in_executor(None, self.ffmpeg_process.stdout.read, buffer_size) if chunk: self.last_ffmpeg_activity = time() if not chunk: logger.info("FFmpeg stdout closed, no more data to read.") break self.pcm_buffer.extend(chunk) # Send to diarization if enabled if self.args.diarization and self.diarization_queue: await self.diarization_queue.put( self.convert_pcm_to_float(self.pcm_buffer).copy() ) # Process when enough data if len(self.pcm_buffer) >= self.bytes_per_sec: if len(self.pcm_buffer) > self.max_bytes_per_sec: logger.warning( f"Audio buffer too large: {len(self.pcm_buffer) / self.bytes_per_sec:.2f}s. " f"Consider using a smaller model." ) # Process audio chunk pcm_array = self.convert_pcm_to_float(self.pcm_buffer[:self.max_bytes_per_sec]) self.pcm_buffer = self.pcm_buffer[self.max_bytes_per_sec:] # Send to transcription if enabled if self.args.transcription and self.transcription_queue: await self.transcription_queue.put(pcm_array.copy()) # Sleep if no processing is happening if not self.args.transcription and not self.args.diarization: await asyncio.sleep(0.1) except Exception as e: logger.warning(f"Exception in ffmpeg_stdout_reader: {e}") logger.warning(f"Traceback: {traceback.format_exc()}") break logger.info("FFmpeg stdout processing finished. Signaling downstream processors.") if self.args.transcription and self.transcription_queue: await self.transcription_queue.put(SENTINEL) logger.debug("Sentinel put into transcription_queue.") if self.args.diarization and self.diarization_queue: await self.diarization_queue.put(SENTINEL) logger.debug("Sentinel put into diarization_queue.") async def transcription_processor(self): """Process audio chunks for transcription.""" self.full_transcription = "" self.sep = self.online.asr.sep cumulative_pcm_duration_stream_time = 0.0 while True: try: pcm_array = await self.transcription_queue.get() if pcm_array is SENTINEL: logger.debug("Transcription processor received sentinel. Finishing.") self.transcription_queue.task_done() break if not self.online: # Should not happen if queue is used logger.warning("Transcription processor: self.online not initialized.") self.transcription_queue.task_done() continue asr_internal_buffer_duration_s = len(self.online.audio_buffer) / self.online.SAMPLING_RATE transcription_lag_s = max(0.0, time() - self.beg_loop - self.end_buffer) logger.info( f"ASR processing: internal_buffer={asr_internal_buffer_duration_s:.2f}s, " f"lag={transcription_lag_s:.2f}s." ) # Process transcription duration_this_chunk = len(pcm_array) / self.sample_rate if isinstance(pcm_array, np.ndarray) else 0 cumulative_pcm_duration_stream_time += duration_this_chunk stream_time_end_of_current_pcm = cumulative_pcm_duration_stream_time self.online.insert_audio_chunk(pcm_array, stream_time_end_of_current_pcm) new_tokens, current_audio_processed_upto = self.online.process_iter() if new_tokens: self.full_transcription += self.sep.join([t.text for t in new_tokens]) # Get buffer information _buffer_transcript_obj = self.online.get_buffer() buffer_text = _buffer_transcript_obj.text candidate_end_times = [self.end_buffer] if new_tokens: candidate_end_times.append(new_tokens[-1].end) if _buffer_transcript_obj.end is not None: candidate_end_times.append(_buffer_transcript_obj.end) candidate_end_times.append(current_audio_processed_upto) new_end_buffer = max(candidate_end_times) # Avoid duplicating content if buffer_text in self.full_transcription: buffer_text = "" await self.update_transcription( new_tokens, buffer_text, new_end_buffer, self.full_transcription, self.sep ) self.transcription_queue.task_done() except Exception as e: logger.warning(f"Exception in transcription_processor: {e}") logger.warning(f"Traceback: {traceback.format_exc()}") if 'pcm_array' in locals() and pcm_array is not SENTINEL : # Check if pcm_array was assigned from queue self.transcription_queue.task_done() logger.info("Transcription processor task finished.") async def diarization_processor(self, diarization_obj): """Process audio chunks for speaker diarization.""" buffer_diarization = "" while True: try: pcm_array = await self.diarization_queue.get() if pcm_array is SENTINEL: logger.debug("Diarization processor received sentinel. Finishing.") self.diarization_queue.task_done() break # Process diarization await diarization_obj.diarize(pcm_array) # Get current state and update speakers state = await self.get_current_state() new_end = diarization_obj.assign_speakers_to_tokens( state["end_attributed_speaker"], state["tokens"] ) await self.update_diarization(new_end, buffer_diarization) self.diarization_queue.task_done() except Exception as e: logger.warning(f"Exception in diarization_processor: {e}") logger.warning(f"Traceback: {traceback.format_exc()}") if 'pcm_array' in locals() and pcm_array is not SENTINEL: self.diarization_queue.task_done() logger.info("Diarization processor task finished.") async def results_formatter(self): """Format processing results for output.""" while True: try: # Get current state state = await self.get_current_state() tokens = state["tokens"] buffer_transcription = state["buffer_transcription"] buffer_diarization = state["buffer_diarization"] end_attributed_speaker = state["end_attributed_speaker"] sep = state["sep"] # Add dummy tokens if needed if (not tokens or tokens[-1].is_dummy) and not self.args.transcription and self.args.diarization: await self.add_dummy_token() sleep(0.5) state = await self.get_current_state() tokens = state["tokens"] # Format output previous_speaker = -1 lines = [] last_end_diarized = 0 undiarized_text = [] # Process each token for token in tokens: speaker = token.speaker # Handle diarization if self.args.diarization: if (speaker in [-1, 0]) and token.end >= end_attributed_speaker: undiarized_text.append(token.text) continue elif (speaker in [-1, 0]) and token.end < end_attributed_speaker: speaker = previous_speaker if speaker not in [-1, 0]: last_end_diarized = max(token.end, last_end_diarized) # Group by speaker if speaker != previous_speaker or not lines: lines.append({ "speaker": speaker, "text": token.text, "beg": format_time(token.start), "end": format_time(token.end), "diff": round(token.end - last_end_diarized, 2) }) previous_speaker = speaker elif token.text: # Only append if text isn't empty lines[-1]["text"] += sep + token.text lines[-1]["end"] = format_time(token.end) lines[-1]["diff"] = round(token.end - last_end_diarized, 2) # Handle undiarized text if undiarized_text: combined = sep.join(undiarized_text) if buffer_transcription: combined += sep await self.update_diarization(end_attributed_speaker, combined) buffer_diarization = combined response_status = "active_transcription" final_lines_for_response = lines.copy() if not tokens and not buffer_transcription and not buffer_diarization: response_status = "no_audio_detected" final_lines_for_response = [] elif response_status == "active_transcription" and not final_lines_for_response: final_lines_for_response = [{ "speaker": 1, "text": "", "beg": format_time(state.get("end_buffer", 0)), "end": format_time(state.get("end_buffer", 0)), "diff": 0 }] response = { "status": response_status, "lines": final_lines_for_response, "buffer_transcription": buffer_transcription, "buffer_diarization": buffer_diarization, "remaining_time_transcription": state["remaining_time_transcription"], "remaining_time_diarization": state["remaining_time_diarization"] } current_response_signature = f"{response_status} | " + \ ' '.join([f"{line['speaker']} {line['text']}" for line in final_lines_for_response]) + \ f" | {buffer_transcription} | {buffer_diarization}" if current_response_signature != self.last_response_content and \ (final_lines_for_response or buffer_transcription or buffer_diarization or response_status == "no_audio_detected"): yield response self.last_response_content = current_response_signature # Check for termination condition if self.is_stopping: all_processors_done = True if self.args.transcription and self.transcription_task and not self.transcription_task.done(): all_processors_done = False if self.args.diarization and self.diarization_task and not self.diarization_task.done(): all_processors_done = False if all_processors_done: logger.info("Results formatter: All upstream processors are done and in stopping state. Terminating.") final_state = await self.get_current_state() return await asyncio.sleep(0.1) # Avoid overwhelming the client except Exception as e: logger.warning(f"Exception in results_formatter: {e}") logger.warning(f"Traceback: {traceback.format_exc()}") await asyncio.sleep(0.5) # Back off on error async def create_tasks(self): """Create and start processing tasks.""" self.all_tasks_for_cleanup = [] processing_tasks_for_watchdog = [] if self.args.transcription and self.online: self.transcription_task = asyncio.create_task(self.transcription_processor()) self.all_tasks_for_cleanup.append(self.transcription_task) processing_tasks_for_watchdog.append(self.transcription_task) if self.args.diarization and self.diarization: self.diarization_task = asyncio.create_task(self.diarization_processor(self.diarization)) self.all_tasks_for_cleanup.append(self.diarization_task) processing_tasks_for_watchdog.append(self.diarization_task) self.ffmpeg_reader_task = asyncio.create_task(self.ffmpeg_stdout_reader()) self.all_tasks_for_cleanup.append(self.ffmpeg_reader_task) processing_tasks_for_watchdog.append(self.ffmpeg_reader_task) # Monitor overall system health self.watchdog_task = asyncio.create_task(self.watchdog(processing_tasks_for_watchdog)) self.all_tasks_for_cleanup.append(self.watchdog_task) return self.results_formatter() async def watchdog(self, tasks_to_monitor): """Monitors the health of critical processing tasks.""" while True: try: await asyncio.sleep(10) current_time = time() for i, task in enumerate(tasks_to_monitor): if task.done(): exc = task.exception() task_name = task.get_name() if hasattr(task, 'get_name') else f"Monitored Task {i}" if exc: logger.error(f"{task_name} unexpectedly completed with exception: {exc}") else: logger.info(f"{task_name} completed normally.") ffmpeg_idle_time = current_time - self.last_ffmpeg_activity if ffmpeg_idle_time > 15: logger.warning(f"FFmpeg idle for {ffmpeg_idle_time:.2f}s - may need attention.") if ffmpeg_idle_time > 30 and not self.is_stopping: logger.error("FFmpeg idle for too long and not in stopping phase, forcing restart.") await self.restart_ffmpeg() except asyncio.CancelledError: logger.info("Watchdog task cancelled.") break except Exception as e: logger.error(f"Error in watchdog task: {e}", exc_info=True) async def cleanup(self): """Clean up resources when processing is complete.""" logger.info("Starting cleanup of AudioProcessor resources.") for task in self.all_tasks_for_cleanup: if task and not task.done(): task.cancel() created_tasks = [t for t in self.all_tasks_for_cleanup if t] if created_tasks: await asyncio.gather(*created_tasks, return_exceptions=True) logger.info("All processing tasks cancelled or finished.") if self.ffmpeg_process: if self.ffmpeg_process.stdin and not self.ffmpeg_process.stdin.closed: try: self.ffmpeg_process.stdin.close() except Exception as e: logger.warning(f"Error closing ffmpeg stdin during cleanup: {e}") # Wait for ffmpeg process to terminate if self.ffmpeg_process.poll() is None: # Check if process is still running logger.info("Waiting for FFmpeg process to terminate...") try: # Run wait in executor to avoid blocking async loop await asyncio.get_event_loop().run_in_executor(None, self.ffmpeg_process.wait, 5.0) # 5s timeout except Exception as e: # subprocess.TimeoutExpired is not directly caught by asyncio.wait_for with run_in_executor logger.warning(f"FFmpeg did not terminate gracefully, killing. Error: {e}") self.ffmpeg_process.kill() await asyncio.get_event_loop().run_in_executor(None, self.ffmpeg_process.wait) # Wait for kill logger.info("FFmpeg process terminated.") if self.args.diarization and hasattr(self, 'diarization') and hasattr(self.diarization, 'close'): self.diarization.close() logger.info("AudioProcessor cleanup complete.") async def process_audio(self, message): """Process incoming audio data.""" # If already stopping or stdin is closed, ignore further audio, especially residual chunks. if self.is_stopping or (self.ffmpeg_process and self.ffmpeg_process.stdin and self.ffmpeg_process.stdin.closed): logger.warning(f"AudioProcessor is stopping or stdin is closed. Ignoring incoming audio message (length: {len(message)}).") if not message and self.ffmpeg_process and self.ffmpeg_process.stdin and not self.ffmpeg_process.stdin.closed: logger.info("Received empty message while already in stopping state; ensuring stdin is closed.") try: self.ffmpeg_process.stdin.close() except Exception as e: logger.warning(f"Error closing ffmpeg stdin on redundant stop signal during stopping state: {e}") return if not message: # primary signal to start stopping logger.info("Empty audio message received, initiating stop sequence.") self.is_stopping = True if self.ffmpeg_process and self.ffmpeg_process.stdin and not self.ffmpeg_process.stdin.closed: try: self.ffmpeg_process.stdin.close() logger.info("FFmpeg stdin closed due to primary stop signal.") except Exception as e: logger.warning(f"Error closing ffmpeg stdin on stop: {e}") return retry_count = 0 max_retries = 3 # Log periodic heartbeats showing ongoing audio proc current_time = time() if not hasattr(self, '_last_heartbeat') or current_time - self._last_heartbeat >= 10: logger.debug(f"Processing audio chunk, last FFmpeg activity: {current_time - self.last_ffmpeg_activity:.2f}s ago") self._last_heartbeat = current_time while retry_count < max_retries: try: if not self.ffmpeg_process or not hasattr(self.ffmpeg_process, 'stdin') or self.ffmpeg_process.poll() is not None: logger.warning("FFmpeg process not available, restarting...") await self.restart_ffmpeg() loop = asyncio.get_running_loop() try: await asyncio.wait_for( loop.run_in_executor(None, lambda: self.ffmpeg_process.stdin.write(message)), timeout=2.0 ) except asyncio.TimeoutError: logger.warning("FFmpeg write operation timed out, restarting...") await self.restart_ffmpeg() retry_count += 1 continue try: await asyncio.wait_for( loop.run_in_executor(None, self.ffmpeg_process.stdin.flush), timeout=2.0 ) except asyncio.TimeoutError: logger.warning("FFmpeg flush operation timed out, restarting...") await self.restart_ffmpeg() retry_count += 1 continue self.last_ffmpeg_activity = time() return except (BrokenPipeError, AttributeError, OSError) as e: retry_count += 1 logger.warning(f"Error writing to FFmpeg: {e}. Retry {retry_count}/{max_retries}...") if retry_count < max_retries: await self.restart_ffmpeg() await asyncio.sleep(0.5) else: logger.error("Maximum retries reached for FFmpeg process") await self.restart_ffmpeg() return