File size: 7,675 Bytes
12bfd03
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the license found in the
# LICENSE file in the root directory of this source tree.
"""MS-STFT discriminator, provided here for reference."""
import typing as tp

import torch
import torchaudio
from einops import rearrange
from torch import nn

from academicodec.modules import NormConv2d

FeatureMapType = tp.List[torch.Tensor]
LogitsType = torch.Tensor
DiscriminatorOutput = tp.Tuple[tp.List[LogitsType], tp.List[FeatureMapType]]


def get_2d_padding(kernel_size: tp.Tuple[int, int],
                   dilation: tp.Tuple[int, int]=(1, 1)):
    return (((kernel_size[0] - 1) * dilation[0]) // 2, (
        (kernel_size[1] - 1) * dilation[1]) // 2)


class DiscriminatorSTFT(nn.Module):
    """STFT sub-discriminator.
    Args:
        filters (int): Number of filters in convolutions
        in_channels (int): Number of input channels. Default: 1
        out_channels (int): Number of output channels. Default: 1
        n_fft (int): Size of FFT for each scale. Default: 1024
        hop_length (int): Length of hop between STFT windows for each scale. Default: 256
        kernel_size (tuple of int): Inner Conv2d kernel sizes. Default: ``(3, 9)``
        stride (tuple of int): Inner Conv2d strides. Default: ``(1, 2)``
        dilations (list of int): Inner Conv2d dilation on the time dimension. Default: ``[1, 2, 4]``
        win_length (int): Window size for each scale. Default: 1024
        normalized (bool): Whether to normalize by magnitude after stft. Default: True
        norm (str): Normalization method. Default: `'weight_norm'`
        activation (str): Activation function. Default: `'LeakyReLU'`
        activation_params (dict): Parameters to provide to the activation function.
        growth (int): Growth factor for the filters. Default: 1
    """

    def __init__(self,
                 filters: int,
                 in_channels: int=1,
                 out_channels: int=1,
                 n_fft: int=1024,
                 hop_length: int=256,
                 win_length: int=1024,
                 max_filters: int=1024,
                 filters_scale: int=1,
                 kernel_size: tp.Tuple[int, int]=(3, 9),
                 dilations: tp.List=[1, 2, 4],
                 stride: tp.Tuple[int, int]=(1, 2),
                 normalized: bool=True,
                 norm: str='weight_norm',
                 activation: str='LeakyReLU',
                 activation_params: dict={'negative_slope': 0.2}):
        super().__init__()
        assert len(kernel_size) == 2
        assert len(stride) == 2
        self.filters = filters
        self.in_channels = in_channels
        self.out_channels = out_channels
        self.n_fft = n_fft
        self.hop_length = hop_length
        self.win_length = win_length
        self.normalized = normalized
        self.activation = getattr(torch.nn, activation)(**activation_params)
        self.spec_transform = torchaudio.transforms.Spectrogram(
            n_fft=self.n_fft,
            hop_length=self.hop_length,
            win_length=self.win_length,
            window_fn=torch.hann_window,
            normalized=self.normalized,
            center=False,
            pad_mode=None,
            power=None)
        spec_channels = 2 * self.in_channels
        self.convs = nn.ModuleList()
        self.convs.append(
            NormConv2d(
                spec_channels,
                self.filters,
                kernel_size=kernel_size,
                padding=get_2d_padding(kernel_size)))
        in_chs = min(filters_scale * self.filters, max_filters)
        for i, dilation in enumerate(dilations):
            out_chs = min((filters_scale**(i + 1)) * self.filters, max_filters)
            self.convs.append(
                NormConv2d(
                    in_chs,
                    out_chs,
                    kernel_size=kernel_size,
                    stride=stride,
                    dilation=(dilation, 1),
                    padding=get_2d_padding(kernel_size, (dilation, 1)),
                    norm=norm))
            in_chs = out_chs
        out_chs = min((filters_scale**(len(dilations) + 1)) * self.filters,
                      max_filters)
        self.convs.append(
            NormConv2d(
                in_chs,
                out_chs,
                kernel_size=(kernel_size[0], kernel_size[0]),
                padding=get_2d_padding((kernel_size[0], kernel_size[0])),
                norm=norm))
        self.conv_post = NormConv2d(
            out_chs,
            self.out_channels,
            kernel_size=(kernel_size[0], kernel_size[0]),
            padding=get_2d_padding((kernel_size[0], kernel_size[0])),
            norm=norm)

    def forward(self, x: torch.Tensor):
        fmap = []
        # print('x ', x.shape)
        z = self.spec_transform(x)  # [B, 2, Freq, Frames, 2]
        # print('z ', z.shape)
        z = torch.cat([z.real, z.imag], dim=1)
        # print('cat_z ', z.shape)
        z = rearrange(z, 'b c w t -> b c t w')
        for i, layer in enumerate(self.convs):
            z = layer(z)
            z = self.activation(z)
            # print('z i', i, z.shape)
            fmap.append(z)
        z = self.conv_post(z)
        # print('logit ', z.shape)
        return z, fmap


class MultiScaleSTFTDiscriminator(nn.Module):
    """Multi-Scale STFT (MS-STFT) discriminator.
    Args:
        filters (int): Number of filters in convolutions
        in_channels (int): Number of input channels. Default: 1
        out_channels (int): Number of output channels. Default: 1
        n_ffts (Sequence[int]): Size of FFT for each scale
        hop_lengths (Sequence[int]): Length of hop between STFT windows for each scale
        win_lengths (Sequence[int]): Window size for each scale
        **kwargs: additional args for STFTDiscriminator
    """

    def __init__(self,
                 filters: int,
                 in_channels: int=1,
                 out_channels: int=1,
                 n_ffts: tp.List[int]=[1024, 2048, 512, 256, 128],
                 hop_lengths: tp.List[int]=[256, 512, 128, 64, 32],
                 win_lengths: tp.List[int]=[1024, 2048, 512, 256, 128],
                 **kwargs):
        super().__init__()
        assert len(n_ffts) == len(hop_lengths) == len(win_lengths)
        self.discriminators = nn.ModuleList([
            DiscriminatorSTFT(
                filters,
                in_channels=in_channels,
                out_channels=out_channels,
                n_fft=n_ffts[i],
                win_length=win_lengths[i],
                hop_length=hop_lengths[i],
                **kwargs) for i in range(len(n_ffts))
        ])
        self.num_discriminators = len(self.discriminators)

    def forward(self, x: torch.Tensor) -> DiscriminatorOutput:
        logits = []
        fmaps = []
        for disc in self.discriminators:
            logit, fmap = disc(x)
            logits.append(logit)
            fmaps.append(fmap)
        return logits, fmaps


def test():
    disc = MultiScaleSTFTDiscriminator(filters=32)
    y = torch.randn(1, 1, 24000)
    y_hat = torch.randn(1, 1, 24000)

    y_disc_r, fmap_r = disc(y)
    y_disc_gen, fmap_gen = disc(y_hat)
    assert len(y_disc_r) == len(y_disc_gen) == len(fmap_r) == len(
        fmap_gen) == disc.num_discriminators

    assert all([len(fm) == 5 for fm in fmap_r + fmap_gen])
    assert all(
        [list(f.shape)[:2] == [1, 32] for fm in fmap_r + fmap_gen for f in fm])
    assert all([len(logits.shape) == 4 for logits in y_disc_r + y_disc_gen])


if __name__ == '__main__':
    test()