Add the ability to control microphone volume (#287)

Control microphone volume via UI in device page. Set to the maximum by default and saved in preferences to restore upon restarts.

linux_voice_assistant/__main__.py

@@ -375,6 +375,7 @@ async def main() -> None:
         output_only=args.output_only,
         download_dir=args.download_dir,
         volume=initial_volume,
+        mic_volume=preferences.mic_volume,
         mic_auto_gain=preferences.mic_auto_gain,
         mic_noise_suppression=preferences.mic_noise_suppression,
         timer_max_ring_seconds=args.timer_max_ring_seconds,
@@ -455,7 +456,8 @@ def process_audio(state: ServerState, mic, block_size: int):
             while True:
                 audio_chunk_array = mic_in.record(block_size).reshape(-1)
                 # little-endian 16-bit signed
-                audio_chunk = (np.clip(audio_chunk_array, -1.0, 1.0) * 32767.0).astype("<i2").tobytes()
+                mic_vol_scalar = max(0.1, min(1.0, state.mic_volume / 100.0))
+                audio_chunk = (np.clip(audio_chunk_array * mic_vol_scalar, -1.0, 1.0) * 32767.0).astype("<i2").tobytes()
 
                 if state.satellite is None:
                     continue