File size: 5,250 Bytes
0b32ad6
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
"""
Common pooling methods

Authors:
  * Leo 2022
  * Haibin Wu 2022
"""

import torch
import torch.nn as nn
import torch.nn.functional as F

__all__ = [
    "MeanPooling",
    "TemporalAveragePooling",
    "TemporalStatisticsPooling",
    "SelfAttentivePooling",
    "AttentiveStatisticsPooling",
]


class MeanPooling(nn.Module):
    """
    Computes Temporal Average Pooling (MeanPooling over time) Module
    """

    def __init__(self, input_size: int):
        super().__init__()
        self._in_size = input_size

    @property
    def input_size(self) -> int:
        return self._in_size

    @property
    def output_size(self) -> int:
        return self._in_size

    def forward(self, xs: torch.Tensor, xs_len: torch.LongTensor):
        """
        Args:
            xs (torch.Tensor): Input tensor (#batch, frames, input_size).
            xs_len (torch.LongTensor): with the lengths for each sample
        Returns:
            torch.Tensor: Output tensor (#batch, input_size)
        """
        pooled_list = []
        for x, x_len in zip(xs, xs_len):
            pooled = torch.mean(x[:x_len], dim=0)
            pooled_list.append(pooled)
        return torch.stack(pooled_list)


TemporalAveragePooling = MeanPooling


class TemporalStatisticsPooling(nn.Module):
    """
    TemporalStatisticsPooling
    Paper: X-vectors: Robust DNN Embeddings for Speaker Recognition
    Link: http://www.danielpovey.com/files/2018_icassp_xvectors.pdf
    """

    def __init__(self, input_size: int):
        super().__init__()
        self._input_size = input_size

    @property
    def input_size(self) -> int:
        return self._input_size

    @property
    def output_size(self) -> int:
        return self._input_size * 2

    def forward(self, xs, xs_len):
        """
        Computes Temporal Statistics Pooling Module

        Args:
            xs (torch.Tensor): Input tensor (#batch, frames, input_size).
            xs_len (torch.LongTensor): with the lengths for each sample

        Returns:
            torch.Tensor: Output tensor (#batch, output_size)
        """
        pooled_list = []
        for x, x_len in zip(xs, xs_len):
            mean = torch.mean(x[:x_len], dim=0)
            std = torch.std(x[:x_len], dim=0)
            pooled = torch.cat((mean, std), dim=-1)
            pooled_list.append(pooled)
        return torch.stack(pooled_list)


class SelfAttentivePooling(nn.Module):
    """
    SelfAttentivePooling
    Paper: Self-Attentive Speaker Embeddings for Text-Independent Speaker Verification
    Link: https://danielpovey.com/files/2018_interspeech_xvector_attention.pdf
    """

    def __init__(self, input_size: int):
        super().__init__()
        self._indim = input_size
        self.sap_linear = nn.Linear(input_size, input_size)
        self.attention = nn.Parameter(torch.FloatTensor(input_size, 1))

    @property
    def input_size(self) -> int:
        return self._indim

    @property
    def output_size(self) -> int:
        return self._indim

    def forward(self, xs, xs_len):
        """
        Computes Self-Attentive Pooling Module

        Args:
            xs (torch.Tensor): Input tensor (#batch, frames, input_size).
            xs_len (torch.LongTensor): with the lengths for each sample

        Returns:
            torch.Tensor: Output tensor (#batch, input_size)
        """
        pooled_list = []
        for x, x_len in zip(xs, xs_len):
            x = x[:x_len].unsqueeze(0)
            h = torch.tanh(self.sap_linear(x))
            w = torch.matmul(h, self.attention).squeeze(dim=2)
            w = F.softmax(w, dim=1).view(x.size(0), x.size(1), 1)
            x = torch.sum(x * w, dim=1)
            pooled_list.append(x.squeeze(0))
        return torch.stack(pooled_list)


class AttentiveStatisticsPooling(nn.Module):
    """
    AttentiveStatisticsPooling
    Paper: Attentive Statistics Pooling for Deep Speaker Embedding
    Link: https://arxiv.org/pdf/1803.10963.pdf
    """

    def __init__(self, input_size: int):
        super().__init__()
        self._indim = input_size
        self.sap_linear = nn.Linear(input_size, input_size)
        self.attention = nn.Parameter(torch.FloatTensor(input_size, 1))

    @property
    def input_size(self) -> int:
        return self._indim

    @property
    def output_size(self) -> int:
        return self._indim * 2

    def forward(self, xs, xs_len):
        """
        Computes Attentive Statistics Pooling Module

        Args:
            xs (torch.Tensor): Input tensor (#batch, frames, input_size).
            xs_len (torch.LongTensor): with the lengths for each sample

        Returns:
            torch.Tensor: Output tensor (#batch, input_size)
        """
        pooled_list = []
        for x, x_len in zip(xs, xs_len):
            x = x[:x_len].unsqueeze(0)
            h = torch.tanh(self.sap_linear(x))
            w = torch.matmul(h, self.attention).squeeze(dim=2)
            w = F.softmax(w, dim=1).view(x.size(0), x.size(1), 1)
            mu = torch.sum(x * w, dim=1)
            rh = torch.sqrt((torch.sum((x**2) * w, dim=1) - mu**2).clamp(min=1e-5))
            x = torch.cat((mu, rh), 1).squeeze(0)
            pooled_list.append(x)
        return torch.stack(pooled_list)