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PaddleSpeech/paddlespeech/server/utils/vad.py

79 lines
3.3 KiB

# Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import collections
import webrtcvad
class VADAudio():
def __init__(self,
aggressiveness=2,
rate=16000,
frame_duration_ms=20,
sample_width=2,
padding_ms=200,
padding_ratio=0.9):
"""Initializes VAD with given aggressivenes and sets up internal queues"""
self.vad = webrtcvad.Vad(aggressiveness)
self.rate = rate
self.sample_width = sample_width
self.frame_duration_ms = frame_duration_ms
self._frame_length = int(rate * (frame_duration_ms / 1000.0) *
self.sample_width)
self._buffer_queue = collections.deque()
self.ring_buffer = collections.deque(maxlen=padding_ms //
frame_duration_ms)
self._ratio = padding_ratio
self.triggered = False
def add_audio(self, audio):
"""Adds new audio to internal queue"""
for x in audio:
self._buffer_queue.append(x)
def frame_generator(self):
"""Generator that yields audio frames of frame_duration_ms"""
while len(self._buffer_queue) > self._frame_length:
frame = bytearray()
for _ in range(self._frame_length):
frame.append(self._buffer_queue.popleft())
yield bytes(frame)
def vad_collector(self):
"""Generator that yields series of consecutive audio frames comprising each utterence, separated by yielding a single None.
Determines voice activity by ratio of frames in padding_ms. Uses a buffer to include padding_ms prior to being triggered.
Example: (frame, ..., frame, None, frame, ..., frame, None, ...)
|---utterence---| |---utterence---|
"""
for frame in self.frame_generator():
is_speech = self.vad.is_speech(frame, self.rate)
if not self.triggered:
self.ring_buffer.append((frame, is_speech))
num_voiced = len(
[f for f, speech in self.ring_buffer if speech])
if num_voiced > self._ratio * self.ring_buffer.maxlen:
self.triggered = True
for f, s in self.ring_buffer:
yield f
self.ring_buffer.clear()
else:
yield frame
self.ring_buffer.append((frame, is_speech))
num_unvoiced = len(
[f for f, speech in self.ring_buffer if not speech])
if num_unvoiced > self._ratio * self.ring_buffer.maxlen:
self.triggered = False
yield None
self.ring_buffer.clear()