audio(filters): add noisereduce filter

src/pipecat/audio/filters/noisereduce_filter.py

@@ -0,0 +1,49 @@
+#
+# Copyright (c) 2024, Daily
+#
+# SPDX-License-Identifier: BSD 2-Clause License
+#
+
+import numpy as np
+
+from pipecat.audio.filters.base_audio_filter import BaseAudioFilter
+
+from loguru import logger
+
+from pipecat.frames.frames import FilterControlFrame
+
+try:
+    import noisereduce as nr
+except ModuleNotFoundError as e:
+    logger.error(f"Exception: {e}")
+    logger.error(
+        "In order to use the noisereduce filter, you need to `pip install pipecat-ai[noisereduce]`."
+    )
+    raise Exception(f"Missing module: {e}")
+
+
+class NoisereduceFilter(BaseAudioFilter):
+    def __init__(self) -> None:
+        self._sample_rate = 0
+
+    async def start(self, sample_rate: int):
+        self._sample_rate = sample_rate
+
+    async def stop(self):
+        pass
+
+    async def process_frame(self, frame: FilterControlFrame):
+        pass
+
+    async def filter(self, audio: bytes) -> bytes:
+        data = np.frombuffer(audio, dtype=np.int16)
+
+        # Add a small epsilon to avoid division by zero.
+        epsilon = 1e-10
+        data = data.astype(np.float32) + epsilon
+
+        # Noise reduction
+        reduced_noise = nr.reduce_noise(y=data, sr=self._sample_rate)
+        audio = np.clip(reduced_noise, -32768, 32767).astype(np.int16).tobytes()
+
+        return audio