espnet2.gan_codec.shared.encoder.seanet.get_extra_padding_for_conv1d

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espnet2.gan_codec.shared.encoder.seanet.get_extra_padding_for_conv1d(x: Tensor, kernel_size: int, stride: int, padding_total: int = 0) → int

Calculate the extra padding required for a 1D convolution operation to ensure

that the last window is fully utilized. This is important for reconstructing an output of the same length, as some time steps may be removed even with padding.

The function computes how much additional padding is needed at the end of the input tensor to ensure that the output tensor retains the correct size.

For instance, with total padding = 4, kernel size = 4, stride = 2: : 0 0 1 2 3 4 5 0 0 # (0s are padding) 1 2 3 # (out-frames of a convolution, last 0 is never used) 0 0 1 2 3 4 5 0 # (out-tr.conv., but pos.5 will get removed as padding) <br/>

1 2 3 4 # once you removed padding, we are missing one time step !

• Parameters:
  • x (torch.Tensor) – The input tensor of shape (batch_size, channels, length).
  • kernel_size (int) – The size of the convolutional kernel.
  • stride (int) – The stride of the convolution.
  • padding_total (int , optional) – The total padding applied to the input. Defaults to 0.
• Returns: The amount of extra padding needed at the end of the input tensor.
• Return type: int

Examples

>>> import torch
>>> x = torch.randn(1, 1, 6)  # (batch_size=1, channels=1, length=6)
>>> kernel_size = 4
>>> stride = 2
>>> padding_total = 4
>>> extra_padding = get_extra_padding_for_conv1d(x, kernel_size, stride, padding_total)
>>> print(extra_padding)  # Outputs the extra padding required

NOTE

This function is crucial for ensuring that all time steps are processed during convolution, especially in scenarios where the input length is not perfectly divisible by the stride.