MockingBird/ppg_extractor/encoder/vgg.py

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"""VGG2L definition for transformer-transducer."""
import torch
class VGG2L(torch.nn.Module):
"""VGG2L module for transformer-transducer encoder."""
def __init__(self, idim, odim):
"""Construct a VGG2L object.
Args:
idim (int): dimension of inputs
odim (int): dimension of outputs
"""
super(VGG2L, self).__init__()
self.vgg2l = torch.nn.Sequential(
torch.nn.Conv2d(1, 64, 3, stride=1, padding=1),
torch.nn.ReLU(),
torch.nn.Conv2d(64, 64, 3, stride=1, padding=1),
torch.nn.ReLU(),
torch.nn.MaxPool2d((3, 2)),
torch.nn.Conv2d(64, 128, 3, stride=1, padding=1),
torch.nn.ReLU(),
torch.nn.Conv2d(128, 128, 3, stride=1, padding=1),
torch.nn.ReLU(),
torch.nn.MaxPool2d((2, 2)),
)
self.output = torch.nn.Linear(128 * ((idim // 2) // 2), odim)
def forward(self, x, x_mask):
"""VGG2L forward for x.
Args:
x (torch.Tensor): input torch (B, T, idim)
x_mask (torch.Tensor): (B, 1, T)
Returns:
x (torch.Tensor): input torch (B, sub(T), attention_dim)
x_mask (torch.Tensor): (B, 1, sub(T))
"""
x = x.unsqueeze(1)
x = self.vgg2l(x)
b, c, t, f = x.size()
x = self.output(x.transpose(1, 2).contiguous().view(b, t, c * f))
if x_mask is None:
return x, None
else:
x_mask = self.create_new_mask(x_mask, x)
return x, x_mask
def create_new_mask(self, x_mask, x):
"""Create a subsampled version of x_mask.
Args:
x_mask (torch.Tensor): (B, 1, T)
x (torch.Tensor): (B, sub(T), attention_dim)
Returns:
x_mask (torch.Tensor): (B, 1, sub(T))
"""
x_t1 = x_mask.size(2) - (x_mask.size(2) % 3)
x_mask = x_mask[:, :, :x_t1][:, :, ::3]
x_t2 = x_mask.size(2) - (x_mask.size(2) % 2)
x_mask = x_mask[:, :, :x_t2][:, :, ::2]
return x_mask