File size: 6,174 Bytes
2d47d90
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import torch
import torch.nn as nn
import torch.nn.functional as F
import numpy as np
import copy
import math
from transformers import Wav2Vec2Model,Wav2Vec2Config
from transformers.modeling_outputs import BaseModelOutput
from typing import Optional, Tuple
_CONFIG_FOR_DOC = "Wav2Vec2Config"

# the implementation of Wav2Vec2Model is borrowed from https://huggingface.co/transformers/_modules/transformers/models/wav2vec2/modeling_wav2vec2.html#Wav2Vec2Model
# initialize our encoder with the pre-trained wav2vec 2.0 weights.
def _compute_mask_indices(
    shape: Tuple[int, int],
    mask_prob: float,
    mask_length: int,
    attention_mask: Optional[torch.Tensor] = None,
    min_masks: int = 0,
) -> np.ndarray:
    bsz, all_sz = shape
    mask = np.full((bsz, all_sz), False)

    all_num_mask = int(
        mask_prob * all_sz / float(mask_length)
        + np.random.rand()
    )
    all_num_mask = max(min_masks, all_num_mask)
    mask_idcs = []
    padding_mask = attention_mask.ne(1) if attention_mask is not None else None
    for i in range(bsz):
        if padding_mask is not None:
            sz = all_sz - padding_mask[i].long().sum().item()
            num_mask = int(
                mask_prob * sz / float(mask_length)
                + np.random.rand()
            )
            num_mask = max(min_masks, num_mask)
        else:
            sz = all_sz
            num_mask = all_num_mask

        lengths = np.full(num_mask, mask_length)

        if sum(lengths) == 0:
            lengths[0] = min(mask_length, sz - 1)

        min_len = min(lengths)
        if sz - min_len <= num_mask:
            min_len = sz - num_mask - 1

        mask_idc = np.random.choice(sz - min_len, num_mask, replace=False)
        mask_idc = np.asarray([mask_idc[j] + offset for j in range(len(mask_idc)) for offset in range(lengths[j])])
        mask_idcs.append(np.unique(mask_idc[mask_idc < sz]))

    min_len = min([len(m) for m in mask_idcs])
    for i, mask_idc in enumerate(mask_idcs):
        if len(mask_idc) > min_len:
            mask_idc = np.random.choice(mask_idc, min_len, replace=False)
        mask[i, mask_idc] = True
    return mask

# linear interpolation layer
def linear_interpolation(features, input_fps, output_fps, output_len=None):
    features = features.transpose(1, 2)
    seq_len = features.shape[2] / float(input_fps)
    if output_len is None:
        output_len = int(seq_len * output_fps)
    output_features = F.interpolate(features,size=output_len,align_corners=True,mode='linear')
    return output_features.transpose(1, 2)

class Wav2Vec2Model(Wav2Vec2Model):
    def __init__(self, config):
        super().__init__(config)
        self.args = config
        self.args.audio_fps = 15 #args.audio_fps
        #input_values 16K hz, 49fps, 20ms overlap, 25ms recepion field 
    def forward(
        self,
        input_values,
        dataset="beat",
        attention_mask=None,
        output_attentions=None,
        output_hidden_states=None,
        return_dict=None,
        frame_num=None
    ):  
        #print(input_values.shape)
        self.config.output_attentions = True
        output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
        output_hidden_states = (
            output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
        )
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict

        hidden_states = self.feature_extractor(input_values)
        hidden_states = hidden_states.transpose(1, 2)
        #print(hidden_states.shape)
        if dataset == "beat":
            hidden_states = linear_interpolation(hidden_states, 49, self.args.audio_fps, output_len=frame_num)
        #print(hidden_states.shape)
        if attention_mask is not None:
            output_lengths = self._get_feat_extract_output_lengths(attention_mask.sum(-1))
            attention_mask = torch.zeros(
                hidden_states.shape[:2], dtype=hidden_states.dtype, device=hidden_states.device
            )
            attention_mask[
                (torch.arange(attention_mask.shape[0], device=hidden_states.device), output_lengths - 1)
            ] = 1
            attention_mask = attention_mask.flip([-1]).cumsum(-1).flip([-1]).bool()

        hidden_states = self.feature_projection(hidden_states)[0]
        #print(hidden_states.shape)
        if self.config.apply_spec_augment and self.training:
            batch_size, sequence_length, hidden_size = hidden_states.size()
            if self.config.mask_time_prob > 0:
                mask_time_indices = _compute_mask_indices(
                    (batch_size, sequence_length),
                    self.config.mask_time_prob,
                    self.config.mask_time_length,
                    attention_mask=attention_mask,
                    min_masks=2,
                )
                hidden_states[torch.from_numpy(mask_time_indices)] = self.masked_spec_embed.to(hidden_states.dtype)
            if self.config.mask_feature_prob > 0:
                mask_feature_indices = _compute_mask_indices(
                    (batch_size, hidden_size),
                    self.config.mask_feature_prob,
                    self.config.mask_feature_length,
                )
                mask_feature_indices = torch.from_numpy(mask_feature_indices).to(hidden_states.device)
                hidden_states[mask_feature_indices[:, None].expand(-1, sequence_length, -1)] = 0
        encoder_outputs = self.encoder(
            hidden_states,
            attention_mask=attention_mask,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            return_dict=return_dict,
        )
        hidden_states = encoder_outputs[0]
        #print(encoder_outputs.shape)
        if not return_dict:
            return (hidden_states,) + encoder_outputs[1:]

        return hidden_states
#     BaseModelOutput(
#             last_hidden_state=hidden_states,
#             hidden_states=encoder_outputs.hidden_states,
#             attentions=encoder_outputs.attentions,
#         )