File size: 8,445 Bytes
1da48bb
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
import pdb

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


class ConvNorm(torch.nn.Module):
    def __init__(self, in_channels, out_channels, kernel_size=1, stride=1,
                 padding=None, dilation=1, bias=True, w_init_gain='linear'):
        super(ConvNorm, self).__init__()
        if padding is None:
            assert(kernel_size % 2 == 1)
            padding = int(dilation * (kernel_size - 1) / 2)

        self.conv = torch.nn.Conv1d(in_channels, out_channels,
                                    kernel_size=kernel_size, stride=stride,
                                    padding=padding, dilation=dilation,
                                    bias=bias)

        torch.nn.init.xavier_uniform_(
            self.conv.weight, gain=torch.nn.init.calculate_gain(w_init_gain))

    def forward(self, signal):
        conv_signal = self.conv(signal)
        return conv_signal


class LinearNorm(torch.nn.Module):
    def __init__(self, in_dim, out_dim, bias=True, w_init_gain='linear'):
        super(LinearNorm, self).__init__()
        self.linear_layer = torch.nn.Linear(in_dim, out_dim, bias=bias)

        torch.nn.init.xavier_uniform_(
            self.linear_layer.weight,
            gain=torch.nn.init.calculate_gain(w_init_gain))

    def forward(self, x):
        return self.linear_layer(x)


class Decoder(nn.Module):
    def __init__(self, dim_pre=64, dim_out=45):
        super(Decoder, self).__init__()
        convolutions = []
        for i in range(3):
            conv_layer = nn.Sequential(
                ConvNorm(dim_pre,
                         dim_pre,
                         kernel_size=5, stride=1,
                         padding=2,
                         dilation=1, w_init_gain='relu'),
                nn.BatchNorm1d(dim_pre))
            convolutions.append(conv_layer)
        self.convolutions = nn.ModuleList(convolutions)
        self.linear_projection = LinearNorm(dim_pre, dim_out)

    def forward(self, z, target=None):
        z = F.interpolate(z.transpose(1, 2), scale_factor=2)
        for conv in self.convolutions:
            z = F.relu(conv(z))
        z = z.transpose(1, 2)       # (b, 240, 64)
        decoder_output = self.linear_projection(z)
        if target is None:
            return decoder_output
        else:
            loss = F.l1_loss(decoder_output, target)
            return loss, decoder_output


class Encoder(nn.Module):
    '''
    reference from: https://github.com/bshall/VectorQuantizedCPC/blob/master/model.py
    '''

    def __init__(self, in_channels, channels, n_embeddings, z_dim, c_dim):
        super(Encoder, self).__init__()
        self.conv = nn.Conv1d(in_channels, channels, 4, 2, 1, bias=False)       # T // 2
        # self.conv = nn.Conv1d(in_channels, channels, 3, 1, 1, bias=False)     # T
        self.encoder = nn.Sequential(
            nn.LayerNorm(channels),
            nn.ReLU(True),
            nn.Linear(channels, channels, bias=False),
            nn.LayerNorm(channels),
            nn.ReLU(True),
            nn.Linear(channels, channels, bias=False),
            nn.LayerNorm(channels),
            nn.ReLU(True),
            nn.Linear(channels, channels, bias=False),
            nn.LayerNorm(channels),
            nn.ReLU(True),
            nn.Linear(channels, channels, bias=False),
            nn.LayerNorm(channels),
            nn.ReLU(True),
            nn.Linear(channels, z_dim),
        )
        self.codebook = VQEmbeddingEMA(n_embeddings, z_dim)
        self.rnn = nn.LSTM(z_dim, c_dim, batch_first=True)

    def encode(self, mel):
        z = self.conv(mel)
        z_beforeVQ = self.encoder(z.transpose(1, 2))
        z, r, indices = self.codebook.encode(z_beforeVQ)
        c, _ = self.rnn(z)
        return z, c, z_beforeVQ, indices

    def forward(self, mels):
        z = self.conv(mels.float())  # (bz, 80, 128) -> (bz, 512, 128/2)
        z_beforeVQ = self.encoder(z.transpose(1, 2))  # (bz, 512, 128/2) -> (bz, 128/2, 512) -> (bz, 128/2, 64)
        z, r, loss, perplexity = self.codebook(z_beforeVQ)  # z: (bz, 128/2, 64)
        z, r, indices = self.codebook.encode(z_beforeVQ)
        c, _ = self.rnn(z)  # (64, 128/2, 64) -> (64, 128/2, 256)
        return z, c, z_beforeVQ, loss, perplexity


class VQEmbeddingEMA(nn.Module):
    '''
    reference from: https://github.com/bshall/VectorQuantizedCPC/blob/master/model.py
    '''

    def __init__(self, n_embeddings, embedding_dim, commitment_cost=2, decay=0.9999, epsilon=1e-7):
        super(VQEmbeddingEMA, self).__init__()
        self.commitment_cost = commitment_cost
        self.decay = decay
        self.epsilon = epsilon

        init_bound = 1 / 512
        embedding = torch.Tensor(n_embeddings, embedding_dim)
        embedding.uniform_(-init_bound, init_bound)
        self.register_buffer("embedding", embedding)  # only change during forward
        self.register_buffer("ema_count", torch.zeros(n_embeddings))
        self.register_buffer("ema_weight", self.embedding.clone())

    def encode(self, x):
        M, D = self.embedding.size()
        x_flat = x.detach().reshape(-1, D)

        distances = torch.addmm(torch.sum(self.embedding ** 2, dim=1) +
                                torch.sum(x_flat ** 2, dim=1, keepdim=True),
                                x_flat, self.embedding.t(),
                                alpha=-2.0, beta=1.0)

        indices = torch.argmin(distances.float(), dim=-1)
        quantized = F.embedding(indices, self.embedding)
        quantized = quantized.view_as(x)
        residual = x - quantized
        return quantized, residual, indices.view(x.size(0), x.size(1))

    def forward(self, x):
        M, D = self.embedding.size()
        x_flat = x.detach().reshape(-1, D)

        distances = torch.addmm(torch.sum(self.embedding ** 2, dim=1) +
                                torch.sum(x_flat ** 2, dim=1, keepdim=True),
                                x_flat, self.embedding.t(),
                                alpha=-2.0, beta=1.0)  # calculate the distance between each ele in embedding and x

        indices = torch.argmin(distances.float(), dim=-1)
        encodings = F.one_hot(indices, M).float()
        quantized = F.embedding(indices, self.embedding)
        quantized = quantized.view_as(x)

        if self.training:  # EMA based codebook learning
            self.ema_count = self.decay * self.ema_count + (1 - self.decay) * torch.sum(encodings, dim=0)

            n = torch.sum(self.ema_count)
            self.ema_count = (self.ema_count + self.epsilon) / (n + M * self.epsilon) * n

            dw = torch.matmul(encodings.t(), x_flat)
            self.ema_weight = self.decay * self.ema_weight + (1 - self.decay) * dw

            self.embedding = self.ema_weight / self.ema_count.unsqueeze(-1)

        e_latent_loss = F.mse_loss(x, quantized.detach())
        loss = self.commitment_cost * e_latent_loss

        residual = x - quantized

        quantized = x + (quantized - x).detach()

        avg_probs = torch.mean(encodings, dim=0)
        perplexity = torch.exp(-torch.sum(avg_probs * torch.log(avg_probs + 1e-10)))

        return quantized, residual, loss, perplexity


class simpleVQVAE(nn.Module):
    def __init__(self):
        super(simpleVQVAE, self).__init__()
        self.encoder = Encoder(in_channels=15 * 3, channels=512, n_embeddings=512, z_dim=64, c_dim=256)
        self.decoder = Decoder(dim_pre=64, dim_out=45)

    def encode(self,x):
        z, _, _, indices = self.encoder.encode(x.transpose(1, 2))
        return [indices]

    def forward(self, x):
        z, c, z_beforeVQ, loss_vq, perplexity = self.encoder(x.transpose(1, 2))

        loss_recon, output = self.decoder(z, x)
        return output, loss_vq + loss_recon, perplexity


if __name__ == '__main__':
    '''
    cd codebook/
    python -m models.simpleVqvae
    '''
    # model = Encoder(in_channels=80, channels=512, n_embeddings=512, z_dim=64, c_dim=256)
    # x = torch.rand(2, 80, 128)
    # z, c, z_beforeVQ, loss, perplexity = model(x)
    '''
    z: (2, 64, 64)
    c: (2, 64, 256)
    z_beforeVQ: (2, 64, 64)
    loss
    perplexity
    '''

    model = Encoder(in_channels=15 * 3, channels=512, n_embeddings=512, z_dim=64, c_dim=256)
    model2 = Decoder(dim_pre=64, dim_out=45)
    x = torch.rand(2, 240, 15 * 3)
    z, c, z_beforeVQ, loss, perplexity = model(x.transpose(1, 2))
    pdb.set_trace()
    loss, output = model2(z, x)