From 6eb3f46cbe7cabb1b5e2bbe7c9643b3e2795daaa Mon Sep 17 00:00:00 2001
From: imonlinux <39863321+imonlinux@users.noreply.github.com>
Date: Wed, 19 Nov 2025 18:48:44 -0800
Subject: [PATCH] Create audio_engine.py

Brand new file. Encapsulates audio logic, suppresses warnings, fixes busy wait.
---
 linux_voice_assistant/audio_engine.py | 163 ++++++++++++++++++++++++++
 1 file changed, 163 insertions(+)
 create mode 100644 linux_voice_assistant/audio_engine.py

diff --git a/linux_voice_assistant/audio_engine.py b/linux_voice_assistant/audio_engine.py
new file mode 100644
index 0000000..546b91e
--- /dev/null
+++ b/linux_voice_assistant/audio_engine.py
@@ -0,0 +1,163 @@
+"""Audio processing engine."""
+
+import asyncio
+import logging
+import threading
+import time
+import warnings
+from typing import List, Optional, Union
+
+import numpy as np
+import soundcard as sc
+
+from pymicro_wakeword import MicroWakeWord, MicroWakeWordFeatures
+from pyopen_wakeword import OpenWakeWord, OpenWakeWordFeatures
+
+from .models import ServerState
+
+_LOGGER = logging.getLogger(__name__)
+
+# Suppress the "log(0)" warning from pymicro_wakeword
+warnings.filterwarnings("ignore", category=RuntimeWarning, module="pymicro_wakeword")
+
+
+class AudioEngine:
+    def __init__(self, state: ServerState, mic, block_size: int):
+        self.state = state
+        self.mic = mic
+        self.block_size = block_size
+        self._thread: Optional[threading.Thread] = None
+
+    def start(self):
+        """Starts the audio processing thread."""
+        self._thread = threading.Thread(
+            target=self._process_audio,
+            daemon=True,
+            name="AudioEngineThread"
+        )
+        self._thread.start()
+
+    def stop(self):
+        """Stops the audio processing thread."""
+        self.state.shutdown = True
+        # Ensure thread wakes up if waiting
+        self.state.mic_muted_event.set()
+        if self._thread:
+            self._thread.join()
+
+    def _process_audio(self):
+        """Main audio processing loop."""
+        _LOGGER.debug("Audio engine started.")
+        
+        micro_features = MicroWakeWordFeatures()
+        oww_features: Optional[OpenWakeWordFeatures] = None
+        
+        wake_words: List[Union[MicroWakeWord, OpenWakeWord]] = []
+        micro_inputs: List[np.ndarray] = []
+        oww_inputs: List[np.ndarray] = []
+        has_oww = False
+        last_active: Optional[float] = None
+        
+        try:
+            while True:
+                # --- Handle Mute State ---
+                if not self.state.mic_muted_event.is_set():
+                    _LOGGER.debug("Audio thread muted. Waiting...")
+                    self.state.mic_muted_event.wait()
+                    
+                    if self.state.shutdown:
+                        return
+
+                    # Unmuted: Clear buffers and prepare
+                    _LOGGER.debug("Audio thread unmuted. Flushing...")
+                    micro_features.reset()
+                    if oww_features is not None:
+                        oww_features.reset()
+                    
+                    # FIX: Allow immediate activation (don't set to 'now')
+                    last_active = None 
+                    
+                    # Flush hardware buffer
+                    try:
+                        with self.mic.recorder(samplerate=16000, channels=1, blocksize=self.block_size) as mic_in:
+                            mic_in.flush()
+                    except Exception as e:
+                        _LOGGER.warning("Error flushing mic: %s", e)
+                
+                if self.state.shutdown:
+                    return
+                
+                # --- Main Recording Loop ---
+                _LOGGER.debug("Opening audio input device: %s", self.mic.name)
+                with self.mic.recorder(samplerate=16000, channels=1, blocksize=self.block_size) as mic_in:
+                    while self.state.mic_muted_event.is_set():
+                        if self.state.shutdown:
+                            return 
+                        
+                        audio_chunk_array = mic_in.record(self.block_size).reshape(-1)
+                        audio_chunk = (
+                            (np.clip(audio_chunk_array, -1.0, 1.0) * 32767.0)
+                            .astype("<i2")
+                            .tobytes()
+                        )
+
+                        if self.state.satellite is None:
+                            time.sleep(0.01)
+                            continue
+                        
+                        # Update active wake words if changed
+                        if (not wake_words) or (self.state.wake_words_changed):
+                            self.state.wake_words_changed = False
+                            wake_words = [
+                                ww for ww in self.state.wake_words.values() 
+                                if ww.id in self.state.active_wake_words
+                            ]
+                            has_oww = any(isinstance(ww, OpenWakeWord) for ww in wake_words)
+                            
+                            if has_oww and (oww_features is None):
+                                _LOGGER.debug("Initializing OpenWakeWord features...")
+                                oww_features = OpenWakeWordFeatures.from_builtin()
+                        
+                        try:
+                            # Feature extraction
+                            micro_inputs.clear()
+                            micro_inputs.extend(micro_features.process_streaming(audio_chunk))
+                            
+                            if has_oww and oww_features:
+                                oww_inputs.clear()
+                                oww_inputs.extend(oww_features.process_streaming(audio_chunk))
+                            
+                            # Detection
+                            for wake_word in wake_words:
+                                activated = False
+                                if isinstance(wake_word, MicroWakeWord):
+                                    if any(wake_word.process_streaming(mi) for mi in micro_inputs): 
+                                        activated = True
+                                elif isinstance(wake_word, OpenWakeWord):
+                                    if any(p > 0.5 for oi in oww_inputs for p in wake_word.process_streaming(oi)): 
+                                        activated = True
+                                
+                                if activated:
+                                    now = time.monotonic()
+                                    if (last_active is None) or ((now - last_active) > self.state.refractory_seconds):
+                                        self.state.loop.call_soon_threadsafe(self.state.satellite.wakeup, wake_word)
+                                        last_active = now
+                            
+                            # Stop word detection
+                            stopped = False
+                            for micro_input in micro_inputs:
+                                if self.state.stop_word.process_streaming(micro_input):
+                                    stopped = True
+
+                            if stopped and (self.state.stop_word.id in self.state.active_wake_words):
+                                self.state.loop.call_soon_threadsafe(self.state.satellite.stop)
+                                
+                            # Pass audio to satellite (for voice streaming)
+                            self.state.loop.call_soon_threadsafe(self.state.satellite.handle_audio, audio_chunk)
+
+                        except Exception: 
+                            _LOGGER.exception("Unexpected error handling audio")
+        
+        except Exception as e:
+            _LOGGER.critical("A soundcard error occurred: %s", e)
+            self.state.loop.call_soon_threadsafe(self.state.loop.stop)