File size: 6,032 Bytes
d358e26
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import math

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

from models.dit import DiTConVBlock

class DitWrapper(nn.Module):
    """ add FiLM layer to condition time embedding to DiT """
    def __init__(self, hidden_channels, filter_channels, num_heads, kernel_size=3, p_dropout=0.1, gin_channels=0, time_channels=0):
        super().__init__()
        self.time_fusion = FiLMLayer(hidden_channels, time_channels)
        self.conv1 = ConvNeXtBlock(hidden_channels, filter_channels, gin_channels)
        self.conv2 = ConvNeXtBlock(hidden_channels, filter_channels, gin_channels)
        self.conv3 = ConvNeXtBlock(hidden_channels, filter_channels, gin_channels)
        self.block = DiTConVBlock(hidden_channels, hidden_channels, num_heads, kernel_size, p_dropout, gin_channels)
            
    def forward(self, x, c, t, x_mask):
        x = self.time_fusion(x, t) * x_mask
        x = self.conv1(x, c, x_mask)
        x = self.conv2(x, c, x_mask)
        x = self.conv3(x, c, x_mask)
        x = self.block(x, c, x_mask)
        return x

class FiLMLayer(nn.Module):
    """
    Feature-wise Linear Modulation (FiLM) layer
    Reference: https://arxiv.org/abs/1709.07871
    """
    def __init__(self, in_channels, cond_channels):

        super(FiLMLayer, self).__init__()
        self.in_channels = in_channels
        self.film = nn.Conv1d(cond_channels, in_channels * 2, 1)

    def forward(self, x, c):
        gamma, beta = torch.chunk(self.film(c.unsqueeze(2)), chunks=2, dim=1)
        return gamma * x + beta
    
class ConvNeXtBlock(nn.Module):
    def __init__(self, in_channels, filter_channels, gin_channels):
        super().__init__()
        self.dwconv = nn.Conv1d(in_channels, in_channels, kernel_size=7, padding=3, groups=in_channels)
        self.norm = StyleAdaptiveLayerNorm(in_channels, gin_channels)
        self.pwconv = nn.Sequential(nn.Linear(in_channels, filter_channels),
                                    nn.GELU(),
                                    nn.Linear(filter_channels, in_channels))

    def forward(self, x, c, x_mask) -> torch.Tensor:
        residual = x
        x = self.dwconv(x) * x_mask
        x = self.norm(x.transpose(1, 2), c)
        x = self.pwconv(x).transpose(1, 2)
        x = residual + x
        return x * x_mask

class StyleAdaptiveLayerNorm(nn.Module):
    def __init__(self, in_channels, cond_channels):
        """
        Style Adaptive Layer Normalization (SALN) module.

        Parameters:
        in_channels: The number of channels in the input feature maps.
        cond_channels: The number of channels in the conditioning input.
        """
        super(StyleAdaptiveLayerNorm, self).__init__()
        self.in_channels = in_channels

        self.saln = nn.Linear(cond_channels, in_channels * 2, 1)
        self.norm = nn.LayerNorm(in_channels, elementwise_affine=False)
        
        self.reset_parameters()
        
    def reset_parameters(self):
        nn.init.constant_(self.saln.bias.data[:self.in_channels], 1)
        nn.init.constant_(self.saln.bias.data[self.in_channels:], 0)

    def forward(self, x, c):
        gamma, beta = torch.chunk(self.saln(c.unsqueeze(1)), chunks=2, dim=-1)
        return gamma * self.norm(x) + beta
        
    
class SinusoidalPosEmb(nn.Module):
    def __init__(self, dim):
        super().__init__()
        self.dim = dim
        assert self.dim % 2 == 0, "SinusoidalPosEmb requires dim to be even"

    def forward(self, x, scale=1000):
        if x.ndim < 1:
            x = x.unsqueeze(0)
        half_dim = self.dim // 2
        emb = math.log(10000) / (half_dim - 1)
        emb = torch.exp(torch.arange(half_dim, device=x.device).float() * -emb)
        emb = scale * x.unsqueeze(1) * emb.unsqueeze(0)
        emb = torch.cat((emb.sin(), emb.cos()), dim=-1)
        return emb

class TimestepEmbedding(nn.Module):
    def __init__(self, in_channels, out_channels, filter_channels):
        super().__init__()

        self.layer = nn.Sequential(
            nn.Linear(in_channels, filter_channels),
            nn.SiLU(inplace=True),
            nn.Linear(filter_channels, out_channels)
        )

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

# reference: https://github.com/shivammehta25/Matcha-TTS/blob/main/matcha/models/components/decoder.py
class Decoder(nn.Module):
    def __init__(self, hidden_channels, out_channels, filter_channels, dropout=0.05, n_layers=1, n_heads=4, kernel_size=3, gin_channels=0):
        super().__init__()
        self.hidden_channels = hidden_channels
        self.out_channels = out_channels
        self.filter_channels = filter_channels

        self.time_embeddings = SinusoidalPosEmb(hidden_channels)
        self.time_mlp = TimestepEmbedding(hidden_channels, hidden_channels, filter_channels)

        
        self.blocks = nn.ModuleList([DitWrapper(hidden_channels, filter_channels, n_heads, kernel_size, dropout, gin_channels, hidden_channels) for _ in range(n_layers)])
        self.final_proj = nn.Conv1d(hidden_channels, out_channels, 1)

        self.initialize_weights()

    def initialize_weights(self):
        for block in self.blocks:
            nn.init.constant_(block.block.adaLN_modulation[-1].weight, 0)
            nn.init.constant_(block.block.adaLN_modulation[-1].bias, 0)

    def forward(self, x, mask, mu, t, c):
        """Forward pass of the UNet1DConditional model.

        Args:
            x (torch.Tensor): shape (batch_size, in_channels, time)
            mask (_type_): shape (batch_size, 1, time)
            t (_type_): shape (batch_size)
            c (_type_): shape (batch_size, gin_channels)

        Raises:
            ValueError: _description_
            ValueError: _description_

        Returns:
            _type_: _description_
        """

        t = self.time_mlp(self.time_embeddings(t))
        x = torch.cat((x, mu), dim=1)

        for block in self.blocks:
            x = block(x, c, t, mask)

        output = self.final_proj(x * mask)

        return output * mask