Files
2026-04-08 04:42:12 -04:00

89 lines
2.9 KiB
Python

import numpy as np
import onnxruntime
class SileroVADOnnx:
"""Silero VAD model loaded via ONNX Runtime (no torchaudio dependency)."""
SAMPLE_RATE = 16000
WINDOW_SIZE = 512 # 32ms at 16kHz
def __init__(self, model_path: str):
opts = onnxruntime.SessionOptions()
opts.inter_op_num_threads = 1
opts.intra_op_num_threads = 1
self.session = onnxruntime.InferenceSession(
model_path, sess_options=opts
)
self._reset_state()
def _reset_state(self):
self._state = np.zeros((2, 1, 128), dtype=np.float32)
def reset_states(self):
self._reset_state()
def __call__(self, chunk: np.ndarray) -> float:
"""Run VAD on a single audio chunk. Returns speech probability."""
input_data = chunk[np.newaxis, :] # add batch dim
sr = np.array(self.SAMPLE_RATE, dtype=np.int64)
ort_inputs = {
"input": input_data,
"sr": sr,
"state": self._state,
}
out, self._state = self.session.run(None, ort_inputs)
return float(out.squeeze())
class StreamingVAD:
"""Wraps Silero VAD (ONNX) for streaming chunk-by-chunk speech detection."""
def __init__(self, model: SileroVADOnnx, threshold: float = 0.5,
min_silence_ms: int = 400):
self.model = model
self.threshold = threshold
self.min_silence_samples = int(
SileroVADOnnx.SAMPLE_RATE * min_silence_ms / 1000
)
self.audio_buffer: list[np.ndarray] = []
self.is_speaking = False
self._silence_samples = 0
def process_chunk(self, chunk_16k: np.ndarray) -> np.ndarray | None:
"""Feed a 512-sample chunk at 16kHz.
Returns the complete utterance as a numpy array when speech ends,
or None if still accumulating.
"""
prob = self.model(chunk_16k.astype(np.float32))
if prob >= self.threshold:
self._silence_samples = 0
if not self.is_speaking:
self.is_speaking = True
self.audio_buffer = []
self.audio_buffer.append(chunk_16k.copy())
elif self.is_speaking:
self._silence_samples += len(chunk_16k)
self.audio_buffer.append(chunk_16k.copy())
if self._silence_samples >= self.min_silence_samples:
self.is_speaking = False
self._silence_samples = 0
if self.audio_buffer:
result = np.concatenate(self.audio_buffer)
self.audio_buffer = []
self.model.reset_states()
return result
self.model.reset_states()
return None
def reset(self):
"""Reset VAD state for a new conversation turn."""
self.audio_buffer = []
self.is_speaking = False
self._silence_samples = 0
self.model.reset_states()