forked from NVIDIA/radtts
-
Notifications
You must be signed in to change notification settings - Fork 0
/
transformer.py
199 lines (153 loc) · 6.94 KB
/
transformer.py
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
# adapted from https://github.com/NVIDIA/DeepLearningExamples/blob/master/PyTorch/SpeechSynthesis/FastPitch/fastpitch/transformer.py
# Copyright (c) 2019 NVIDIA CORPORATION. All rights reserved.
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import torch
import torch.nn as nn
import torch.nn.functional as F
from common import get_mask_from_lengths, LinearNorm
class PositionalEmbedding(nn.Module):
def __init__(self, demb):
super(PositionalEmbedding, self).__init__()
self.demb = demb
inv_freq = 1 / (10000 ** (torch.arange(0.0, demb, 2.0) / demb))
self.register_buffer('inv_freq', inv_freq)
def forward(self, pos_seq, bsz=None):
sinusoid_inp = torch.matmul(torch.unsqueeze(pos_seq, -1),
torch.unsqueeze(self.inv_freq, 0))
pos_emb = torch.cat([sinusoid_inp.sin(), sinusoid_inp.cos()], dim=1)
if bsz is not None:
return pos_emb[None, :, :].expand(bsz, -1, -1)
else:
return pos_emb[None, :, :]
class PositionwiseConvFF(nn.Module):
def __init__(self, d_model, d_inner, kernel_size, dropout, pre_lnorm=False):
super(PositionwiseConvFF, self).__init__()
self.d_model = d_model
self.d_inner = d_inner
self.dropout = dropout
self.CoreNet = nn.Sequential(
nn.Conv1d(d_model, d_inner, kernel_size, 1, (kernel_size // 2)),
nn.ReLU(),
# nn.Dropout(dropout), # worse convergence
nn.Conv1d(d_inner, d_model, kernel_size, 1, (kernel_size // 2)),
nn.Dropout(dropout),
)
self.layer_norm = nn.LayerNorm(d_model)
self.pre_lnorm = pre_lnorm
def forward(self, inp):
return self._forward(inp)
def _forward(self, inp):
if self.pre_lnorm:
# layer normalization + positionwise feed-forward
core_out = inp.transpose(1, 2)
core_out = self.CoreNet(self.layer_norm(core_out).to(inp.dtype))
core_out = core_out.transpose(1, 2)
# residual connection
output = core_out + inp
else:
# positionwise feed-forward
core_out = inp.transpose(1, 2)
core_out = self.CoreNet(core_out)
core_out = core_out.transpose(1, 2)
# residual connection + layer normalization
output = self.layer_norm(inp + core_out).to(inp.dtype)
return output
class MultiHeadAttn(nn.Module):
def __init__(self, n_head, d_model, d_head, dropout, dropatt=0.1,
pre_lnorm=False):
super(MultiHeadAttn, self).__init__()
self.n_head = n_head
self.d_model = d_model
self.d_head = d_head
self.scale = 1 / (d_head ** 0.5)
self.pre_lnorm = pre_lnorm
self.qkv_net = nn.Linear(d_model, 3 * n_head * d_head)
self.drop = nn.Dropout(dropout)
self.dropatt = nn.Dropout(dropatt)
self.o_net = nn.Linear(n_head * d_head, d_model, bias=False)
self.layer_norm = nn.LayerNorm(d_model)
def forward(self, inp, attn_mask=None):
return self._forward(inp, attn_mask)
def _forward(self, inp, attn_mask=None):
residual = inp
if self.pre_lnorm:
# layer normalization
inp = self.layer_norm(inp)
n_head, d_head = self.n_head, self.d_head
head_q, head_k, head_v = torch.chunk(self.qkv_net(inp), 3, dim=2)
head_q = head_q.view(inp.size(0), inp.size(1), n_head, d_head)
head_k = head_k.view(inp.size(0), inp.size(1), n_head, d_head)
head_v = head_v.view(inp.size(0), inp.size(1), n_head, d_head)
q = head_q.permute(2, 0, 1, 3).reshape(-1, inp.size(1), d_head)
k = head_k.permute(2, 0, 1, 3).reshape(-1, inp.size(1), d_head)
v = head_v.permute(2, 0, 1, 3).reshape(-1, inp.size(1), d_head)
attn_score = torch.bmm(q, k.transpose(1, 2))
attn_score.mul_(self.scale)
if attn_mask is not None:
attn_mask = attn_mask.unsqueeze(1).to(attn_score.dtype)
attn_mask = attn_mask.repeat(n_head, attn_mask.size(2), 1)
attn_score.masked_fill_(attn_mask.to(torch.bool), -float('inf'))
attn_prob = F.softmax(attn_score, dim=2)
attn_prob = self.dropatt(attn_prob)
attn_vec = torch.bmm(attn_prob, v)
attn_vec = attn_vec.view(n_head, inp.size(0), inp.size(1), d_head)
attn_vec = attn_vec.permute(1, 2, 0, 3).contiguous().view(
inp.size(0), inp.size(1), n_head * d_head)
# linear projection
attn_out = self.o_net(attn_vec)
attn_out = self.drop(attn_out)
# residual connection + layer normalization
output = self.layer_norm(residual + attn_out)
output = output.to(attn_out.dtype)
return output
class TransformerLayer(nn.Module):
def __init__(self, n_head, d_model, d_head, d_inner, kernel_size, dropout,
**kwargs):
super(TransformerLayer, self).__init__()
self.dec_attn = MultiHeadAttn(n_head, d_model, d_head, dropout, **kwargs)
self.pos_ff = PositionwiseConvFF(d_model, d_inner, kernel_size, dropout)
def forward(self, dec_inp, mask=None):
output = self.dec_attn(dec_inp, attn_mask=~mask.squeeze(2))
output *= mask
output = self.pos_ff(output)
output *= mask
return output
class FFTransformer(nn.Module):
def __init__(self, in_dim, out_dim=1, n_layers=6, n_head=1, d_head=64,
d_inner=1024, kernel_size=3, dropout=0.1, dropatt=0.1,
dropemb=0.0):
super(FFTransformer, self).__init__()
self.in_dim = in_dim
self.out_dim = out_dim
self.n_head = n_head
self.d_head = d_head
self.pos_emb = PositionalEmbedding(self.in_dim)
self.drop = nn.Dropout(dropemb)
self.layers = nn.ModuleList()
for _ in range(n_layers):
self.layers.append(
TransformerLayer(
n_head, in_dim, d_head, d_inner, kernel_size, dropout,
dropatt=dropatt)
)
self.dense = LinearNorm(in_dim, out_dim)
def forward(self, dec_inp, in_lens):
# B, C, T --> B, T, C
inp = dec_inp.transpose(1, 2)
mask = get_mask_from_lengths(in_lens)[..., None]
pos_seq = torch.arange(inp.size(1), device=inp.device).to(inp.dtype)
pos_emb = self.pos_emb(pos_seq) * mask
out = self.drop(inp + pos_emb)
for layer in self.layers:
out = layer(out, mask=mask)
out = self.dense(out).transpose(1, 2)
return out