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# Copyright 2019 Tomoki Hayashi | |
# MIT License (https://opensource.org/licenses/MIT) | |
# Adapted by Florian Lux 2021 | |
import torch | |
from Layers.LayerNorm import LayerNorm | |
class DurationPredictor(torch.nn.Module): | |
""" | |
Duration predictor module. | |
This is a module of duration predictor described | |
in `FastSpeech: Fast, Robust and Controllable Text to Speech`_. | |
The duration predictor predicts a duration of each frame in log domain | |
from the hidden embeddings of encoder. | |
.. _`FastSpeech: Fast, Robust and Controllable Text to Speech`: | |
https://arxiv.org/pdf/1905.09263.pdf | |
Note: | |
The calculation domain of outputs is different | |
between in `forward` and in `inference`. In `forward`, | |
the outputs are calculated in log domain but in `inference`, | |
those are calculated in linear domain. | |
""" | |
def __init__(self, idim, n_layers=2, n_chans=384, kernel_size=3, dropout_rate=0.1, offset=1.0): | |
""" | |
Initialize duration predictor module. | |
Args: | |
idim (int): Input dimension. | |
n_layers (int, optional): Number of convolutional layers. | |
n_chans (int, optional): Number of channels of convolutional layers. | |
kernel_size (int, optional): Kernel size of convolutional layers. | |
dropout_rate (float, optional): Dropout rate. | |
offset (float, optional): Offset value to avoid nan in log domain. | |
""" | |
super(DurationPredictor, self).__init__() | |
self.offset = offset | |
self.conv = torch.nn.ModuleList() | |
for idx in range(n_layers): | |
in_chans = idim if idx == 0 else n_chans | |
self.conv += [torch.nn.Sequential(torch.nn.Conv1d(in_chans, n_chans, kernel_size, stride=1, padding=(kernel_size - 1) // 2, ), torch.nn.ReLU(), | |
LayerNorm(n_chans, dim=1), torch.nn.Dropout(dropout_rate), )] | |
self.linear = torch.nn.Linear(n_chans, 1) | |
def _forward(self, xs, x_masks=None, is_inference=False): | |
xs = xs.transpose(1, -1) # (B, idim, Tmax) | |
for f in self.conv: | |
xs = f(xs) # (B, C, Tmax) | |
# NOTE: calculate in log domain | |
xs = self.linear(xs.transpose(1, -1)).squeeze(-1) # (B, Tmax) | |
if is_inference: | |
# NOTE: calculate in linear domain | |
xs = torch.clamp(torch.round(xs.exp() - self.offset), min=0).long() # avoid negative value | |
if x_masks is not None: | |
xs = xs.masked_fill(x_masks, 0.0) | |
return xs | |
def forward(self, xs, x_masks=None): | |
""" | |
Calculate forward propagation. | |
Args: | |
xs (Tensor): Batch of input sequences (B, Tmax, idim). | |
x_masks (ByteTensor, optional): | |
Batch of masks indicating padded part (B, Tmax). | |
Returns: | |
Tensor: Batch of predicted durations in log domain (B, Tmax). | |
""" | |
return self._forward(xs, x_masks, False) | |
def inference(self, xs, x_masks=None): | |
""" | |
Inference duration. | |
Args: | |
xs (Tensor): Batch of input sequences (B, Tmax, idim). | |
x_masks (ByteTensor, optional): | |
Batch of masks indicating padded part (B, Tmax). | |
Returns: | |
LongTensor: Batch of predicted durations in linear domain (B, Tmax). | |
""" | |
return self._forward(xs, x_masks, True) | |
class DurationPredictorLoss(torch.nn.Module): | |
""" | |
Loss function module for duration predictor. | |
The loss value is Calculated in log domain to make it Gaussian. | |
""" | |
def __init__(self, offset=1.0, reduction="mean"): | |
""" | |
Args: | |
offset (float, optional): Offset value to avoid nan in log domain. | |
reduction (str): Reduction type in loss calculation. | |
""" | |
super(DurationPredictorLoss, self).__init__() | |
self.criterion = torch.nn.MSELoss(reduction=reduction) | |
self.offset = offset | |
def forward(self, outputs, targets): | |
""" | |
Calculate forward propagation. | |
Args: | |
outputs (Tensor): Batch of prediction durations in log domain (B, T) | |
targets (LongTensor): Batch of groundtruth durations in linear domain (B, T) | |
Returns: | |
Tensor: Mean squared error loss value. | |
Note: | |
`outputs` is in log domain but `targets` is in linear domain. | |
""" | |
# NOTE: outputs is in log domain while targets in linear | |
targets = torch.log(targets.float() + self.offset) | |
loss = self.criterion(outputs, targets) | |
return loss | |