Added support for Krisp audio filter

src/pipecat/audio/filters/krisp_filter.py

@@ -0,0 +1,78 @@
+#
+# Copyright (c) 2024, Daily
+#
+# SPDX-License-Identifier: BSD 2-Clause License
+#
+
+import numpy as np
+import os
+
+from pipecat.audio.filters.base_audio_filter import BaseAudioFilter
+from loguru import logger
+from pipecat.frames.frames import FilterControlFrame, FilterEnableFrame
+
+try:
+    from pipecat_ai_krisp.audio.krisp_processor import KrispAudioProcessor
+except ModuleNotFoundError as e:
+    logger.error(f"Exception: {e}")
+    logger.error("In order to use the Krisp filter, you need to `pip install pipecat-ai[krisp]`.")
+    raise Exception(f"Missing module: {e}")
+
+
+class KrispFilter(BaseAudioFilter):
+    def __init__(
+        self, sample_type: str = "PCM_16", channels: int = 1, model_path: str = None
+    ) -> None:
+        """
+        Initializes the KrispAudioProcessor with customizable audio processing settings.
+
+        :param sample_type: The type of audio sample, default is 'PCM_16'.
+        :param channels: Number of audio channels, default is 1.
+        :param model_path: Path to the Krisp model; defaults to environment variable KRISP_MODEL_PATH if not provided.
+        """
+        super().__init__()
+
+        # Set model path, checking environment if not specified
+        self._model_path = model_path or os.getenv("KRISP_MODEL_PATH")
+        if not self._model_path:
+            logger.error(
+                "Model path for KrispAudioProcessor is not provided and KRISP_MODEL_PATH is not set."
+            )
+            raise ValueError("Model path for KrispAudioProcessor must be provided.")
+
+        self._sample_type = sample_type
+        self._channels = channels
+        self._sample_rate = 0
+        self._filtering = True
+        self._krisp_processor = None
+
+    async def start(self, sample_rate: int):
+        self._sample_rate = sample_rate
+        self._krisp_processor = KrispAudioProcessor(
+            self._sample_rate, self._sample_type, self._channels, self._model_path
+        )
+
+    async def stop(self):
+        self._krisp_processor = None
+
+    async def process_frame(self, frame: FilterControlFrame):
+        if isinstance(frame, FilterEnableFrame):
+            self._filtering = frame.enable
+
+    async def filter(self, audio: bytes) -> bytes:
+        if not self._filtering:
+            return audio
+
+        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
+
+        # Process the audio chunk to reduce noise
+        reduced_noise = self._krisp_processor.process(data)
+
+        # Clip and set processed audio back to frame
+        audio = np.clip(reduced_noise, -32768, 32767).astype(np.int16).tobytes()
+
+        return audio