MockingBird/synthesizer/models/global_style_token.py

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import torch
import torch.nn as nn
import torch.nn.init as init
import torch.nn.functional as tFunctional
from synthesizer.gst_hyperparameters import GSTHyperparameters as hp
class GlobalStyleToken(nn.Module):
def __init__(self):
super().__init__()
self.encoder = ReferenceEncoder()
self.stl = STL()
def forward(self, inputs):
enc_out = self.encoder(inputs)
style_embed = self.stl(enc_out)
return style_embed
class ReferenceEncoder(nn.Module):
'''
inputs --- [N, Ty/r, n_mels*r] mels
outputs --- [N, ref_enc_gru_size]
'''
def __init__(self):
super().__init__()
K = len(hp.ref_enc_filters)
filters = [1] + hp.ref_enc_filters
convs = [nn.Conv2d(in_channels=filters[i],
out_channels=filters[i + 1],
kernel_size=(3, 3),
stride=(2, 2),
padding=(1, 1)) for i in range(K)]
self.convs = nn.ModuleList(convs)
self.bns = nn.ModuleList([nn.BatchNorm2d(num_features=hp.ref_enc_filters[i]) for i in range(K)])
out_channels = self.calculate_channels(hp.n_mels, 3, 2, 1, K)
self.gru = nn.GRU(input_size=hp.ref_enc_filters[-1] * out_channels,
hidden_size=hp.E // 2,
batch_first=True)
def forward(self, inputs):
N = inputs.size(0)
out = inputs.view(N, 1, -1, hp.n_mels) # [N, 1, Ty, n_mels]
for conv, bn in zip(self.convs, self.bns):
out = conv(out)
out = bn(out)
out = tFunctional.relu(out) # [N, 128, Ty//2^K, n_mels//2^K]
out = out.transpose(1, 2) # [N, Ty//2^K, 128, n_mels//2^K]
T = out.size(1)
N = out.size(0)
out = out.contiguous().view(N, T, -1) # [N, Ty//2^K, 128*n_mels//2^K]
self.gru.flatten_parameters()
memory, out = self.gru(out) # out --- [1, N, E//2]
return out.squeeze(0)
def calculate_channels(self, L, kernel_size, stride, pad, n_convs):
for i in range(n_convs):
L = (L - kernel_size + 2 * pad) // stride + 1
return L
class STL(nn.Module):
'''
inputs --- [N, E//2]
'''
def __init__(self):
super().__init__()
self.embed = nn.Parameter(torch.FloatTensor(hp.token_num, hp.E // hp.num_heads))
d_q = hp.E // 2
d_k = hp.E // hp.num_heads
# self.attention = MultiHeadAttention(hp.num_heads, d_model, d_q, d_v)
self.attention = MultiHeadAttention(query_dim=d_q, key_dim=d_k, num_units=hp.E, num_heads=hp.num_heads)
init.normal_(self.embed, mean=0, std=0.5)
def forward(self, inputs):
N = inputs.size(0)
query = inputs.unsqueeze(1) # [N, 1, E//2]
keys = tFunctional.tanh(self.embed).unsqueeze(0).expand(N, -1, -1) # [N, token_num, E // num_heads]
style_embed = self.attention(query, keys)
return style_embed
class MultiHeadAttention(nn.Module):
'''
input:
query --- [N, T_q, query_dim]
key --- [N, T_k, key_dim]
output:
out --- [N, T_q, num_units]
'''
def __init__(self, query_dim, key_dim, num_units, num_heads):
super().__init__()
self.num_units = num_units
self.num_heads = num_heads
self.key_dim = key_dim
self.W_query = nn.Linear(in_features=query_dim, out_features=num_units, bias=False)
self.W_key = nn.Linear(in_features=key_dim, out_features=num_units, bias=False)
self.W_value = nn.Linear(in_features=key_dim, out_features=num_units, bias=False)
def forward(self, query, key):
querys = self.W_query(query) # [N, T_q, num_units]
keys = self.W_key(key) # [N, T_k, num_units]
values = self.W_value(key)
split_size = self.num_units // self.num_heads
querys = torch.stack(torch.split(querys, split_size, dim=2), dim=0) # [h, N, T_q, num_units/h]
keys = torch.stack(torch.split(keys, split_size, dim=2), dim=0) # [h, N, T_k, num_units/h]
values = torch.stack(torch.split(values, split_size, dim=2), dim=0) # [h, N, T_k, num_units/h]
# score = softmax(QK^T / (d_k ** 0.5))
scores = torch.matmul(querys, keys.transpose(2, 3)) # [h, N, T_q, T_k]
scores = scores / (self.key_dim ** 0.5)
scores = tFunctional.softmax(scores, dim=3)
# out = score * V
out = torch.matmul(scores, values) # [h, N, T_q, num_units/h]
out = torch.cat(torch.split(out, 1, dim=0), dim=3).squeeze(0) # [N, T_q, num_units]
return out