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- # Copyright (c) Alibaba, Inc. and its affiliates.
- import numpy as np
- import torch
- import torch.nn as nn
- import torch.nn.functional as F
- class Conv1d_O(nn.Module):
- def __init__(
- self,
- out_channels,
- kernel_size,
- input_shape=None,
- in_channels=None,
- stride=1,
- dilation=1,
- padding='same',
- groups=1,
- bias=True,
- padding_mode='reflect',
- skip_transpose=False,
- ):
- super().__init__()
- self.kernel_size = kernel_size
- self.stride = stride
- self.dilation = dilation
- self.padding = padding
- self.padding_mode = padding_mode
- self.unsqueeze = False
- self.skip_transpose = skip_transpose
- if input_shape is None and in_channels is None:
- raise ValueError('Must provide one of input_shape or in_channels')
- if in_channels is None:
- in_channels = self._check_input_shape(input_shape)
- self.conv = nn.Conv1d(
- in_channels,
- out_channels,
- self.kernel_size,
- stride=self.stride,
- dilation=self.dilation,
- padding=0,
- groups=groups,
- bias=bias,
- )
- def forward(self, x):
- """Returns the output of the convolution.
- Arguments
- ---------
- x : torch.Tensor (batch, time, channel)
- input to convolve. 2d or 4d tensors are expected.
- """
- if not self.skip_transpose:
- x = x.transpose(1, -1)
- if self.unsqueeze:
- x = x.unsqueeze(1)
- if self.padding == 'same':
- x = self._manage_padding(x, self.kernel_size, self.dilation,
- self.stride)
- elif self.padding == 'causal':
- num_pad = (self.kernel_size - 1) * self.dilation
- x = F.pad(x, (num_pad, 0))
- elif self.padding == 'valid':
- pass
- else:
- raise ValueError(
- "Padding must be 'same', 'valid' or 'causal'. Got "
- + self.padding)
- wx = self.conv(x)
- if self.unsqueeze:
- wx = wx.squeeze(1)
- if not self.skip_transpose:
- wx = wx.transpose(1, -1)
- return wx
- def _manage_padding(
- self,
- x,
- kernel_size: int,
- dilation: int,
- stride: int,
- ):
- # Detecting input shape
- L_in = x.shape[-1]
- # Time padding
- padding = get_padding_elem(L_in, stride, kernel_size, dilation)
- # Applying padding
- x = F.pad(x, padding, mode=self.padding_mode)
- return x
- def _check_input_shape(self, shape):
- """Checks the input shape and returns the number of input channels.
- """
- if len(shape) == 2:
- self.unsqueeze = True
- in_channels = 1
- elif self.skip_transpose:
- in_channels = shape[1]
- elif len(shape) == 3:
- in_channels = shape[2]
- else:
- raise ValueError('conv1d expects 2d, 3d inputs. Got '
- + str(len(shape)))
- # Kernel size must be odd
- if self.kernel_size % 2 == 0:
- raise ValueError(
- 'The field kernel size must be an odd number. Got %s.' %
- (self.kernel_size))
- return in_channels
- # Skip transpose as much as possible for efficiency
- class Conv1d(Conv1d_O):
- def __init__(self, *args, **kwargs):
- super().__init__(skip_transpose=True, *args, **kwargs)
- def get_padding_elem(L_in: int, stride: int, kernel_size: int, dilation: int):
- """This function computes the number of elements to add for zero-padding.
- Arguments
- ---------
- L_in : int
- stride: int
- kernel_size : int
- dilation : int
- """
- if stride > 1:
- n_steps = math.ceil(((L_in - kernel_size * dilation) / stride) + 1)
- L_out = stride * (n_steps - 1) + kernel_size * dilation
- padding = [kernel_size // 2, kernel_size // 2]
- else:
- L_out = (L_in - dilation * (kernel_size - 1) - 1) // stride + 1
- padding = [(L_in - L_out) // 2, (L_in - L_out) // 2]
- return padding
- class BatchNorm1d_O(nn.Module):
- def __init__(
- self,
- input_shape=None,
- input_size=None,
- eps=1e-05,
- momentum=0.1,
- affine=True,
- track_running_stats=True,
- combine_batch_time=False,
- skip_transpose=False,
- ):
- super().__init__()
- self.combine_batch_time = combine_batch_time
- self.skip_transpose = skip_transpose
- if input_size is None and skip_transpose:
- input_size = input_shape[1]
- elif input_size is None:
- input_size = input_shape[-1]
- self.norm = nn.BatchNorm1d(
- input_size,
- eps=eps,
- momentum=momentum,
- affine=affine,
- track_running_stats=track_running_stats,
- )
- def forward(self, x):
- """Returns the normalized input tensor.
- Arguments
- ---------
- x : torch.Tensor (batch, time, [channels])
- input to normalize. 2d or 3d tensors are expected in input
- 4d tensors can be used when combine_dims=True.
- """
- shape_or = x.shape
- if self.combine_batch_time:
- if x.ndim == 3:
- x = x.reshape(shape_or[0] * shape_or[1], shape_or[2])
- else:
- x = x.reshape(shape_or[0] * shape_or[1], shape_or[3],
- shape_or[2])
- elif not self.skip_transpose:
- x = x.transpose(-1, 1)
- x_n = self.norm(x)
- if self.combine_batch_time:
- x_n = x_n.reshape(shape_or)
- elif not self.skip_transpose:
- x_n = x_n.transpose(1, -1)
- return x_n
- class BatchNorm1d(BatchNorm1d_O):
- def __init__(self, *args, **kwargs):
- super().__init__(skip_transpose=True, *args, **kwargs)
- class Xvector(torch.nn.Module):
- """This model extracts X-vectors for speaker recognition and diarization.
- Arguments
- ---------
- device : str
- Device used e.g. "cpu" or "cuda".
- activation : torch class
- A class for constructing the activation layers.
- tdnn_blocks : int
- Number of time-delay neural (TDNN) layers.
- tdnn_channels : list of ints
- Output channels for TDNN layer.
- tdnn_kernel_sizes : list of ints
- List of kernel sizes for each TDNN layer.
- tdnn_dilations : list of ints
- List of dilations for kernels in each TDNN layer.
- lin_neurons : int
- Number of neurons in linear layers.
- Example
- -------
- >>> compute_xvect = Xvector('cpu')
- >>> input_feats = torch.rand([5, 10, 40])
- >>> outputs = compute_xvect(input_feats)
- >>> outputs.shape
- torch.Size([5, 1, 512])
- """
- def __init__(
- self,
- device='cpu',
- activation=torch.nn.LeakyReLU,
- tdnn_blocks=5,
- tdnn_channels=[512, 512, 512, 512, 1500],
- tdnn_kernel_sizes=[5, 3, 3, 1, 1],
- tdnn_dilations=[1, 2, 3, 1, 1],
- lin_neurons=512,
- in_channels=80,
- ):
- super().__init__()
- self.blocks = nn.ModuleList()
- # TDNN layers
- for block_index in range(tdnn_blocks):
- out_channels = tdnn_channels[block_index]
- self.blocks.extend([
- Conv1d(
- in_channels=in_channels,
- out_channels=out_channels,
- kernel_size=tdnn_kernel_sizes[block_index],
- dilation=tdnn_dilations[block_index],
- ),
- activation(),
- BatchNorm1d(input_size=out_channels),
- ])
- in_channels = tdnn_channels[block_index]
- def forward(self, x, lens=None):
- """Returns the x-vectors.
- Arguments
- ---------
- x : torch.Tensor
- """
- x = x.transpose(1, 2)
- for layer in self.blocks:
- try:
- x = layer(x, lengths=lens)
- except TypeError:
- x = layer(x)
- x = x.transpose(1, 2)
- return x
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