File size: 6,999 Bytes
ce3fda6
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
# --------------------------------------------------------
# BEATs: Audio Pre-Training with Acoustic Tokenizers (https://arxiv.org/abs/2212.09058)
# Github source: https://github.com/microsoft/unilm/tree/master/beats
# Copyright (c) 2022 Microsoft
# Licensed under The MIT License [see LICENSE for details]
# Based on fairseq code bases
# https://github.com/pytorch/fairseq
# --------------------------------------------------------


import torch
import torch.nn as nn
from torch.nn import LayerNorm
import torchaudio.compliance.kaldi as ta_kaldi

from .backbone import (
    TransformerEncoder,
)

import logging
from typing import Optional

logger = logging.getLogger(__name__)


class BEATsConfig:
    def __init__(self, cfg=None):
        self.input_patch_size: int = 16  # path size of patch embedding
        self.embed_dim: int = 512  # patch embedding dimension
        self.conv_bias: bool = False  # include bias in conv encoder

        self.encoder_layers: int = 12  # num encoder layers in the transformer
        self.hidden_size: int = 4096  # 3584 for Qwen2
        self.encoder_embed_dim: int = 768  # encoder embedding dimension
        self.encoder_ffn_embed_dim: int = 3072  # encoder embedding dimension for FFN
        self.encoder_attention_heads: int = 12  # num encoder attention heads
        self.activation_fn: str = "gelu"  # activation function to use

        self.layer_wise_gradient_decay_ratio: float = 0.6  # ratio for layer-wise gradient decay
        self.layer_norm_first: bool = False  # apply layernorm first in the transformer
        self.deep_norm: bool = True  # apply deep_norm first in the transformer

        # dropouts
        self.dropout: float = 0.0  # dropout probability for the transformer
        self.attention_dropout: float = 0.0  # dropout probability for attention weights
        self.activation_dropout: float = 0.0  # dropout probability after activation in FFN
        self.encoder_layerdrop: float = 0.05  # probability of dropping a tarnsformer layer
        self.dropout_input: float = 0.0  # dropout to apply to the input (after feat extr)

        # positional embeddings
        self.conv_pos: int = 128  # number of filters for convolutional positional embeddings
        self.conv_pos_groups: int = 16  # number of groups for convolutional positional embedding

        # relative position embedding
        self.relative_position_embedding: bool = True  # apply relative position embedding
        self.num_buckets: int = 320  # number of buckets for relative position embedding
        self.max_distance: int = 800  # maximum distance for relative position embedding
        self.gru_rel_pos: bool = True  # apply gated relative position embedding

        # label predictor
        self.finetuned_model: bool = True  # whether the model is a fine-tuned model.
        self.predictor_dropout: float = 0.0  # dropout probability for the predictor
        self.predictor_class: int = 527  # target class number for the predictor

        if cfg is not None:
            self.update(cfg)

    def update(self, cfg: dict):
        self.__dict__.update(cfg)


class BEATs(nn.Module):
    def __init__(
            self,
            cfg: BEATsConfig,
    ) -> None:
        super().__init__()
        logger.info(f"BEATs Config: {cfg.__dict__}")

        self.cfg = cfg

        self.embed = cfg.embed_dim
        self.post_extract_proj = (
            nn.Linear(self.embed, cfg.encoder_embed_dim)
            if self.embed != cfg.encoder_embed_dim
            else None
        )

        self.input_patch_size = cfg.input_patch_size
        self.patch_embedding = nn.Conv2d(1, self.embed, kernel_size=self.input_patch_size, stride=self.input_patch_size,
                                         bias=cfg.conv_bias)

        self.dropout_input = nn.Dropout(cfg.dropout_input)

        assert not cfg.deep_norm or not cfg.layer_norm_first
        self.encoder = TransformerEncoder(cfg)
        self.layer_norm = LayerNorm(self.embed)

        if cfg.finetuned_model:
            self.predictor_dropout = nn.Dropout(cfg.predictor_dropout)
            self.predictor = nn.Linear(cfg.encoder_embed_dim, cfg.predictor_class)
        else:
            self.predictor = None

    def forward_padding_mask(
            self,
            features: torch.Tensor,
            padding_mask: torch.Tensor,
    ) -> torch.Tensor:
        extra = padding_mask.size(1) % features.size(1)
        if extra > 0:
            padding_mask = padding_mask[:, :-extra]
        padding_mask = padding_mask.view(
            padding_mask.size(0), features.size(1), -1
        )
        padding_mask = padding_mask.all(-1)
        return padding_mask

    def preprocess(
            self,
            source: torch.Tensor,
            fbank_mean: float = 15.41663,
            fbank_std: float = 6.55582,
    ) -> torch.Tensor:
        '''
        fbanks = []
        for waveform in source:
            waveform = waveform.unsqueeze(0) * 2 ** 15
            fbank = ta_kaldi.fbank(waveform, num_mel_bins=128, sample_frequency=16000, frame_length=25, frame_shift=10)
            fbanks.append(fbank)
        fbank = torch.stack(fbanks, dim=0)
        '''
        fbank = source
        fbank = (fbank - fbank_mean) / (2 * fbank_std)
        return fbank

    def extract_features(
            self,
            source: torch.Tensor,
            padding_mask: Optional[torch.Tensor] = None,
            fbank_mean: float = 15.41663,
            fbank_std: float = 6.55582,
            feature_only=True,
    ):
        fbank = self.preprocess(source, fbank_mean=fbank_mean, fbank_std=fbank_std)

        if padding_mask is not None:
            padding_mask = self.forward_padding_mask(fbank, padding_mask)

        fbank = fbank.unsqueeze(1)
        features = self.patch_embedding(fbank)
        T = features.shape[2]
        F = features.shape[3]
        features = features.reshape(features.shape[0], features.shape[1], -1)
        features = features.transpose(1, 2)
        features = self.layer_norm(features)

        if padding_mask is not None:
            padding_mask = self.forward_padding_mask(features, padding_mask)

        if self.post_extract_proj is not None:
            features = self.post_extract_proj(features)

        x = self.dropout_input(features)

        x, layer_results = self.encoder(
            x,
            padding_mask=padding_mask,
        )
        if not feature_only and self.predictor is not None:
            x = self.predictor_dropout(x)
            logits = self.predictor(x)

            if padding_mask is not None and padding_mask.any():
                logits[padding_mask] = 0
                logits = logits.sum(dim=1)
                logits = logits / (~padding_mask).sum(dim=1).unsqueeze(-1).expand_as(logits)
            else:
                logits = logits.mean(dim=1)

            lprobs = torch.sigmoid(logits)

            return lprobs, padding_mask
        else:
            return x, T, F