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PaddleSpeech/paddlespeech/t2s/modules/transformer/encoder.py

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# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# Modified from espnet(https://github.com/espnet/espnet)
from paddle import nn
from paddlespeech.t2s.modules.transformer.attention import MultiHeadedAttention
from paddlespeech.t2s.modules.transformer.embedding import PositionalEncoding
from paddlespeech.t2s.modules.transformer.encoder_layer import EncoderLayer
from paddlespeech.t2s.modules.transformer.multi_layer_conv import Conv1dLinear
from paddlespeech.t2s.modules.transformer.multi_layer_conv import MultiLayeredConv1d
from paddlespeech.t2s.modules.transformer.positionwise_feed_forward import PositionwiseFeedForward
from paddlespeech.t2s.modules.transformer.repeat import repeat
class Encoder(nn.Layer):
"""Transformer encoder module.
Parameters
----------
idim : int
Input dimension.
attention_dim : int
Dimention of attention.
attention_heads : int
The number of heads of multi head attention.
linear_units : int
The number of units of position-wise feed forward.
num_blocks : int
The number of decoder blocks.
dropout_rate : float
Dropout rate.
positional_dropout_rate : float
Dropout rate after adding positional encoding.
attention_dropout_rate : float
Dropout rate in attention.
input_layer : Union[str, paddle.nn.Layer]
Input layer type.
pos_enc_class : paddle.nn.Layer
Positional encoding module class.
`PositionalEncoding `or `ScaledPositionalEncoding`
normalize_before : bool
Whether to use layer_norm before the first block.
concat_after : bool
Whether to concat attention layer's input and output.
if True, additional linear will be applied.
i.e. x -> x + linear(concat(x, att(x)))
if False, no additional linear will be applied. i.e. x -> x + att(x)
positionwise_layer_type : str
"linear", "conv1d", or "conv1d-linear".
positionwise_conv_kernel_size : int
Kernel size of positionwise conv1d layer.
selfattention_layer_type : str
Encoder attention layer type.
padding_idx : int
Padding idx for input_layer=embed.
"""
def __init__(
self,
idim,
attention_dim=256,
attention_heads=4,
linear_units=2048,
num_blocks=6,
dropout_rate=0.1,
positional_dropout_rate=0.1,
attention_dropout_rate=0.0,
input_layer="conv2d",
pos_enc_class=PositionalEncoding,
normalize_before=True,
concat_after=False,
positionwise_layer_type="linear",
positionwise_conv_kernel_size=1,
selfattention_layer_type="selfattn",
padding_idx=-1, ):
"""Construct an Encoder object."""
super(Encoder, self).__init__()
self.conv_subsampling_factor = 1
if input_layer == "linear":
self.embed = nn.Sequential(
nn.Linear(idim, attention_dim, bias_attr=True),
nn.LayerNorm(attention_dim),
nn.Dropout(dropout_rate),
nn.ReLU(),
pos_enc_class(attention_dim, positional_dropout_rate), )
elif input_layer == "embed":
self.embed = nn.Sequential(
nn.Embedding(idim, attention_dim, padding_idx=padding_idx),
pos_enc_class(attention_dim, positional_dropout_rate), )
elif isinstance(input_layer, nn.Layer):
self.embed = nn.Sequential(
input_layer,
pos_enc_class(attention_dim, positional_dropout_rate), )
elif input_layer is None:
self.embed = nn.Sequential(
pos_enc_class(attention_dim, positional_dropout_rate))
else:
raise ValueError("unknown input_layer: " + input_layer)
self.normalize_before = normalize_before
positionwise_layer, positionwise_layer_args = self.get_positionwise_layer(
positionwise_layer_type,
attention_dim,
linear_units,
dropout_rate,
positionwise_conv_kernel_size, )
if selfattention_layer_type in [
"selfattn",
"rel_selfattn",
"legacy_rel_selfattn",
]:
encoder_selfattn_layer = MultiHeadedAttention
encoder_selfattn_layer_args = [
(attention_heads, attention_dim, attention_dropout_rate, )
] * num_blocks
else:
raise NotImplementedError(selfattention_layer_type)
self.encoders = repeat(
num_blocks,
lambda lnum: EncoderLayer(
attention_dim,
encoder_selfattn_layer(*encoder_selfattn_layer_args[lnum]),
positionwise_layer(*positionwise_layer_args),
dropout_rate,
normalize_before,
concat_after, ), )
if self.normalize_before:
self.after_norm = nn.LayerNorm(attention_dim)
def get_positionwise_layer(
self,
positionwise_layer_type="linear",
attention_dim=256,
linear_units=2048,
dropout_rate=0.1,
positionwise_conv_kernel_size=1, ):
"""Define positionwise layer."""
if positionwise_layer_type == "linear":
positionwise_layer = PositionwiseFeedForward
positionwise_layer_args = (attention_dim, linear_units,
dropout_rate)
elif positionwise_layer_type == "conv1d":
positionwise_layer = MultiLayeredConv1d
positionwise_layer_args = (attention_dim, linear_units,
positionwise_conv_kernel_size,
dropout_rate, )
elif positionwise_layer_type == "conv1d-linear":
positionwise_layer = Conv1dLinear
positionwise_layer_args = (attention_dim, linear_units,
positionwise_conv_kernel_size,
dropout_rate, )
else:
raise NotImplementedError("Support only linear or conv1d.")
return positionwise_layer, positionwise_layer_args
def forward(self, xs, masks):
"""Encode input sequence.
Parameters
----------
xs : paddle.Tensor
Input tensor (#batch, time, idim).
masks : paddle.Tensor
Mask tensor (#batch, time).
Returns
----------
paddle.Tensor
Output tensor (#batch, time, attention_dim).
paddle.Tensor
Mask tensor (#batch, time).
"""
xs = self.embed(xs)
xs, masks = self.encoders(xs, masks)
if self.normalize_before:
xs = self.after_norm(xs)
return xs, masks
def forward_one_step(self, xs, masks, cache=None):
"""Encode input frame.
Parameters
----------
xs : paddle.Tensor
Input tensor.
masks : paddle.Tensor
Mask tensor.
cache : List[paddle.Tensor]
List of cache tensors.
Returns
----------
paddle.Tensor
Output tensor.
paddle.Tensor
Mask tensor.
List[paddle.Tensor]
List of new cache tensors.
"""
xs = self.embed(xs)
if cache is None:
cache = [None for _ in range(len(self.encoders))]
new_cache = []
for c, e in zip(cache, self.encoders):
xs, masks = e(xs, masks, cache=c)
new_cache.append(xs)
if self.normalize_before:
xs = self.after_norm(xs)
return xs, masks, new_cache