File size: 7,372 Bytes
ee21b96
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
# Copyright (c) Facebook, Inc. and its affiliates.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.


import collections
import contextlib
import wave

try:
    import webrtcvad
except ImportError:
    raise ImportError("Please install py-webrtcvad: pip install webrtcvad")
import argparse
import os
import logging
from tqdm import tqdm

AUDIO_SUFFIX = '.wav'
FS_MS = 30
SCALE = 6e-5
THRESHOLD = 0.3


def read_wave(path):
    """Reads a .wav file.
    Takes the path, and returns (PCM audio data, sample rate).
    """
    with contextlib.closing(wave.open(path, 'rb')) as wf:
        num_channels = wf.getnchannels()
        assert num_channels == 1
        sample_width = wf.getsampwidth()
        assert sample_width == 2
        sample_rate = wf.getframerate()
        assert sample_rate in (8000, 16000, 32000, 48000)
        pcm_data = wf.readframes(wf.getnframes())
        return pcm_data, sample_rate


def write_wave(path, audio, sample_rate):
    """Writes a .wav file.
    Takes path, PCM audio data, and sample rate.
    """
    with contextlib.closing(wave.open(path, 'wb')) as wf:
        wf.setnchannels(1)
        wf.setsampwidth(2)
        wf.setframerate(sample_rate)
        wf.writeframes(audio)


class Frame(object):
    """Represents a "frame" of audio data."""
    def __init__(self, bytes, timestamp, duration):
        self.bytes = bytes
        self.timestamp = timestamp
        self.duration = duration


def frame_generator(frame_duration_ms, audio, sample_rate):
    """Generates audio frames from PCM audio data.
    Takes the desired frame duration in milliseconds, the PCM data, and
    the sample rate.
    Yields Frames of the requested duration.
    """
    n = int(sample_rate * (frame_duration_ms / 1000.0) * 2)
    offset = 0
    timestamp = 0.0
    duration = (float(n) / sample_rate) / 2.0
    while offset + n < len(audio):
        yield Frame(audio[offset:offset + n], timestamp, duration)
        timestamp += duration
        offset += n


def vad_collector(sample_rate, frame_duration_ms,
                  padding_duration_ms, vad, frames):
    """Filters out non-voiced audio frames.
    Given a webrtcvad.Vad and a source of audio frames, yields only
    the voiced audio.
    Uses a padded, sliding window algorithm over the audio frames.
    When more than 90% of the frames in the window are voiced (as
    reported by the VAD), the collector triggers and begins yielding
    audio frames. Then the collector waits until 90% of the frames in
    the window are unvoiced to detrigger.
    The window is padded at the front and back to provide a small
    amount of silence or the beginnings/endings of speech around the
    voiced frames.
    Arguments:
    sample_rate - The audio sample rate, in Hz.
    frame_duration_ms - The frame duration in milliseconds.
    padding_duration_ms - The amount to pad the window, in milliseconds.
    vad - An instance of webrtcvad.Vad.
    frames - a source of audio frames (sequence or generator).
    Returns: A generator that yields PCM audio data.
    """
    num_padding_frames = int(padding_duration_ms / frame_duration_ms)
    # We use a deque for our sliding window/ring buffer.
    ring_buffer = collections.deque(maxlen=num_padding_frames)
    # We have two states: TRIGGERED and NOTTRIGGERED. We start in the
    # NOTTRIGGERED state.
    triggered = False

    voiced_frames = []
    for frame in frames:
        is_speech = vad.is_speech(frame.bytes, sample_rate)

        #  sys.stdout.write('1' if is_speech else '0')
        if not triggered:
            ring_buffer.append((frame, is_speech))
            num_voiced = len([f for f, speech in ring_buffer if speech])
            # If we're NOTTRIGGERED and more than 90% of the frames in
            # the ring buffer are voiced frames, then enter the
            # TRIGGERED state.
            if num_voiced > 0.9 * ring_buffer.maxlen:
                triggered = True
                # We want to yield all the audio we see from now until
                # we are NOTTRIGGERED, but we have to start with the
                # audio that's already in the ring buffer.
                for f, _ in ring_buffer:
                    voiced_frames.append(f)
                ring_buffer.clear()
        else:
            # We're in the TRIGGERED state, so collect the audio data
            # and add it to the ring buffer.
            voiced_frames.append(frame)
            ring_buffer.append((frame, is_speech))
            num_unvoiced = len([f for f, speech in ring_buffer if not speech])
            # If more than 90% of the frames in the ring buffer are
            # unvoiced, then enter NOTTRIGGERED and yield whatever
            # audio we've collected.
            if num_unvoiced > 0.9 * ring_buffer.maxlen:
                triggered = False
                yield [b''.join([f.bytes for f in voiced_frames]),
                       voiced_frames[0].timestamp, voiced_frames[-1].timestamp]
                ring_buffer.clear()
                voiced_frames = []
    # If we have any leftover voiced audio when we run out of input,
    # yield it.
    if voiced_frames:
        yield [b''.join([f.bytes for f in voiced_frames]),
               voiced_frames[0].timestamp, voiced_frames[-1].timestamp]


def main(args):
    # create output folder
    try:
        cmd = f"mkdir -p {args.out_path}"
        os.system(cmd)
    except Exception:
        logging.error("Can not create output folder")
        exit(-1)

    # build vad object
    vad = webrtcvad.Vad(int(args.agg))
    # iterating over wavs in dir
    for file in tqdm(os.listdir(args.in_path)):
        if file.endswith(AUDIO_SUFFIX):
            audio_inpath = os.path.join(args.in_path, file)
            audio_outpath = os.path.join(args.out_path, file)
            audio, sample_rate = read_wave(audio_inpath)
            frames = frame_generator(FS_MS, audio, sample_rate)
            frames = list(frames)
            segments = vad_collector(sample_rate, FS_MS, 300, vad, frames)
            merge_segments = list()
            timestamp_start = 0.0
            timestamp_end = 0.0
            # removing start, end, and long sequences of sils
            for i, segment in enumerate(segments):
                merge_segments.append(segment[0])
                if i and timestamp_start:
                    sil_duration = segment[1] - timestamp_end
                    if sil_duration > THRESHOLD:
                        merge_segments.append(int(THRESHOLD / SCALE)*(b'\x00'))
                    else:
                        merge_segments.append(int((sil_duration / SCALE))*(b'\x00'))
                timestamp_start = segment[1]
                timestamp_end = segment[2]
            segment = b''.join(merge_segments)
            write_wave(audio_outpath, segment, sample_rate)


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Apply vad to a file of fils.')
    parser.add_argument('in_path', type=str, help='Path to the input files')
    parser.add_argument('out_path', type=str,
                        help='Path to save the processed files')
    parser.add_argument('--agg', type=int, default=3,
                        help='The level of aggressiveness of the VAD: [0-3]')
    args = parser.parse_args()

    main(args)