File size: 9,887 Bytes
85a7d2c
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
import copy
from typing import Optional, Tuple
import random

from sklearn.cluster import KMeans

import torch
import torch.nn as nn
import torch.nn.functional as F
from torch.nn.modules.utils import consume_prefix_in_state_dict_if_present

URLS = {
    "hubert-discrete": "https://github.com/bshall/hubert/releases/download/v0.1/hubert-discrete-e9416457.pt",
    "hubert-soft": "https://github.com/bshall/hubert/releases/download/v0.1/hubert-soft-0d54a1f4.pt",
    "kmeans100": "https://github.com/bshall/hubert/releases/download/v0.1/kmeans100-50f36a95.pt",
}


class Hubert(nn.Module):
    def __init__(self, num_label_embeddings: int = 100, mask: bool = True):
        super().__init__()
        self._mask = mask
        self.feature_extractor = FeatureExtractor()
        self.feature_projection = FeatureProjection()
        self.positional_embedding = PositionalConvEmbedding()
        self.norm = nn.LayerNorm(768)
        self.dropout = nn.Dropout(0.1)
        self.encoder = TransformerEncoder(
            nn.TransformerEncoderLayer(
                768, 12, 3072, activation="gelu", batch_first=True
            ),
            12,
        )
        self.proj = nn.Linear(768, 256)

        self.masked_spec_embed = nn.Parameter(torch.FloatTensor(768).uniform_())
        self.label_embedding = nn.Embedding(num_label_embeddings, 256)

    def mask(self, x: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor]:
        mask = None
        if self.training and self._mask:
            mask = _compute_mask((x.size(0), x.size(1)), 0.8, 10, x.device, 2)
            x[mask] = self.masked_spec_embed.to(x.dtype)
        return x, mask

    def encode(
        self, x: torch.Tensor, layer: Optional[int] = None
    ) -> Tuple[torch.Tensor, torch.Tensor]:
        x = self.feature_extractor(x)
        x = self.feature_projection(x.transpose(1, 2))
        x, mask = self.mask(x)
        x = x + self.positional_embedding(x)
        x = self.dropout(self.norm(x))
        x = self.encoder(x, output_layer=layer)
        return x, mask

    def logits(self, x: torch.Tensor) -> torch.Tensor:
        logits = torch.cosine_similarity(
            x.unsqueeze(2),
            self.label_embedding.weight.unsqueeze(0).unsqueeze(0),
            dim=-1,
        )
        return logits / 0.1

    def forward(self, x: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor]:
        x, mask = self.encode(x)
        x = self.proj(x)
        logits = self.logits(x)
        return logits, mask


class HubertSoft(Hubert):
    def __init__(self):
        super().__init__()

    @torch.inference_mode()
    def units(self, wav: torch.Tensor) -> torch.Tensor:
        wav = F.pad(wav, ((400 - 320) // 2, (400 - 320) // 2))
        x, _ = self.encode(wav)
        return self.proj(x)


class HubertDiscrete(Hubert):
    def __init__(self, kmeans):
        super().__init__(504)
        self.kmeans = kmeans

    @torch.inference_mode()
    def units(self, wav: torch.Tensor) -> torch.LongTensor:
        wav = F.pad(wav, ((400 - 320) // 2, (400 - 320) // 2))
        x, _ = self.encode(wav, layer=7)
        x = self.kmeans.predict(x.squeeze().cpu().numpy())
        return torch.tensor(x, dtype=torch.long, device=wav.device)


class FeatureExtractor(nn.Module):
    def __init__(self):
        super().__init__()
        self.conv0 = nn.Conv1d(1, 512, 10, 5, bias=False)
        self.norm0 = nn.GroupNorm(512, 512)
        self.conv1 = nn.Conv1d(512, 512, 3, 2, bias=False)
        self.conv2 = nn.Conv1d(512, 512, 3, 2, bias=False)
        self.conv3 = nn.Conv1d(512, 512, 3, 2, bias=False)
        self.conv4 = nn.Conv1d(512, 512, 3, 2, bias=False)
        self.conv5 = nn.Conv1d(512, 512, 2, 2, bias=False)
        self.conv6 = nn.Conv1d(512, 512, 2, 2, bias=False)

    def forward(self, x: torch.Tensor) -> torch.Tensor:
        x = F.gelu(self.norm0(self.conv0(x)))
        x = F.gelu(self.conv1(x))
        x = F.gelu(self.conv2(x))
        x = F.gelu(self.conv3(x))
        x = F.gelu(self.conv4(x))
        x = F.gelu(self.conv5(x))
        x = F.gelu(self.conv6(x))
        return x


class FeatureProjection(nn.Module):
    def __init__(self):
        super().__init__()
        self.norm = nn.LayerNorm(512)
        self.projection = nn.Linear(512, 768)
        self.dropout = nn.Dropout(0.1)

    def forward(self, x: torch.Tensor) -> torch.Tensor:
        x = self.norm(x)
        x = self.projection(x)
        x = self.dropout(x)
        return x


class PositionalConvEmbedding(nn.Module):
    def __init__(self):
        super().__init__()
        self.conv = nn.Conv1d(
            768,
            768,
            kernel_size=128,
            padding=128 // 2,
            groups=16,
        )
        self.conv = nn.utils.weight_norm(self.conv, name="weight", dim=2)

    def forward(self, x: torch.Tensor) -> torch.Tensor:
        x = self.conv(x.transpose(1, 2))
        x = F.gelu(x[:, :, :-1])
        return x.transpose(1, 2)


class TransformerEncoder(nn.Module):
    def __init__(
        self, encoder_layer: nn.TransformerEncoderLayer, num_layers: int
    ) -> None:
        super(TransformerEncoder, self).__init__()
        self.layers = nn.ModuleList(
            [copy.deepcopy(encoder_layer) for _ in range(num_layers)]
        )
        self.num_layers = num_layers

    def forward(
        self,
        src: torch.Tensor,
        mask: torch.Tensor = None,
        src_key_padding_mask: torch.Tensor = None,
        output_layer: Optional[int] = None,
    ) -> torch.Tensor:
        output = src
        for layer in self.layers[:output_layer]:
            output = layer(
                output, src_mask=mask, src_key_padding_mask=src_key_padding_mask
            )
        return output


def _compute_mask(
    shape: Tuple[int, int],
    mask_prob: float,
    mask_length: int,
    device: torch.device,
    min_masks: int = 0,
) -> torch.Tensor:
    batch_size, sequence_length = shape

    if mask_length < 1:
        raise ValueError("`mask_length` has to be bigger than 0.")

    if mask_length > sequence_length:
        raise ValueError(
            f"`mask_length` has to be smaller than `sequence_length`, but got `mask_length`: {mask_length} and `sequence_length`: {sequence_length}`"
        )

    # compute number of masked spans in batch
    num_masked_spans = int(mask_prob * sequence_length / mask_length + random.random())
    num_masked_spans = max(num_masked_spans, min_masks)

    # make sure num masked indices <= sequence_length
    if num_masked_spans * mask_length > sequence_length:
        num_masked_spans = sequence_length // mask_length

    # SpecAugment mask to fill
    mask = torch.zeros((batch_size, sequence_length), device=device, dtype=torch.bool)

    # uniform distribution to sample from, make sure that offset samples are < sequence_length
    uniform_dist = torch.ones(
        (batch_size, sequence_length - (mask_length - 1)), device=device
    )

    # get random indices to mask
    mask_indices = torch.multinomial(uniform_dist, num_masked_spans)

    # expand masked indices to masked spans
    mask_indices = (
        mask_indices.unsqueeze(dim=-1)
        .expand((batch_size, num_masked_spans, mask_length))
        .reshape(batch_size, num_masked_spans * mask_length)
    )
    offsets = (
        torch.arange(mask_length, device=device)[None, None, :]
        .expand((batch_size, num_masked_spans, mask_length))
        .reshape(batch_size, num_masked_spans * mask_length)
    )
    mask_idxs = mask_indices + offsets

    # scatter indices to mask
    mask = mask.scatter(1, mask_idxs, True)

    return mask


def hubert_discrete(
    pretrained: bool = True,
    progress: bool = True,
) -> HubertDiscrete:
    r"""HuBERT-Discrete from `"A Comparison of Discrete and Soft Speech Units for Improved Voice Conversion"`.
    Args:
        pretrained (bool): load pretrained weights into the model
        progress (bool): show progress bar when downloading model
    """
    kmeans = kmeans100(pretrained=pretrained, progress=progress)
    hubert = HubertDiscrete(kmeans)
    if pretrained:
        checkpoint = torch.hub.load_state_dict_from_url(
            URLS["hubert-discrete"], progress=progress
        )
        consume_prefix_in_state_dict_if_present(checkpoint, "module.")
        hubert.load_state_dict(checkpoint)
        hubert.eval()
    return hubert


def hubert_soft(
    pretrained: bool = True,
    progress: bool = True,
) -> HubertSoft:
    r"""HuBERT-Soft from `"A Comparison of Discrete and Soft Speech Units for Improved Voice Conversion"`.
    Args:
        pretrained (bool): load pretrained weights into the model
        progress (bool): show progress bar when downloading model
    """
    hubert = HubertSoft()
    if pretrained:
        checkpoint = torch.hub.load_state_dict_from_url(
            URLS["hubert-soft"], progress=progress
        )
        consume_prefix_in_state_dict_if_present(checkpoint, "module.")
        hubert.load_state_dict(checkpoint)
        hubert.eval()
    return hubert


def _kmeans(
    num_clusters: int, pretrained: bool = True, progress: bool = True
) -> KMeans:
    kmeans = KMeans(num_clusters)
    if pretrained:
        checkpoint = torch.hub.load_state_dict_from_url(
            URLS[f"kmeans{num_clusters}"], progress=progress
        )
        kmeans.__dict__["n_features_in_"] = checkpoint["n_features_in_"]
        kmeans.__dict__["_n_threads"] = checkpoint["_n_threads"]
        kmeans.__dict__["cluster_centers_"] = checkpoint["cluster_centers_"].numpy()
    return kmeans


def kmeans100(pretrained: bool = True, progress: bool = True) -> KMeans:
    r"""
    k-means checkpoint for HuBERT-Discrete with 100 clusters.
    Args:
        pretrained (bool): load pretrained weights into the model
        progress (bool): show progress bar when downloading model
    """
    return _kmeans(100, pretrained, progress)