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PaddleSpeech/paddlespeech/t2s/modules/fftconv1d.py

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# Copyright (c) 2024 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.
import math
import typing
from typing import Optional
from typing import Sequence
import paddle
import paddle.nn as nn
import paddle.nn.functional as F
from ...utils import satisfy_paddle_version
__all__ = [
"fft_conv1d",
"FFTConv1D",
]
def __unfold(x, kernel_size: int, stride: int):
"""1D only unfolding similar to the one from Paddlepaddle.
Notes
------
Given a tensor `x` of size `[*, T]` this will return
a tensor `[*, F, K]` with `K` the kernel size, and `F` the number
of frames. The i-th frame is a view onto `i * stride: i * stride + kernel_size`.
This will automatically pad `x` to cover at least once all entries in `x`.
Args:
x (Tensor):
tensor for which to return the frames.
kernel_size (int):
size of each frame.
stride (int):
stride between each frame.
"""
shape = list(x.shape)
length = shape.pop(-1)
n_frames = math.ceil((max(length, kernel_size) - kernel_size) / stride) + 1
tgt_length = (n_frames - 1) * stride + kernel_size
padded = F.pad(x, (0, tgt_length - length), data_format="NCL")
strides: typing.List[int] = []
for dim in range(padded.dim()):
strides.append(padded.strides[dim])
assert strides.pop(-1) == 1, "data should be contiguous"
strides = strides + [stride, 1]
return padded.as_strided(shape + [n_frames, kernel_size], strides)
def fft_conv1d(
x: paddle.Tensor,
weight: paddle.Tensor,
bias: Optional[paddle.Tensor]=None,
stride: int=1,
padding: int=0,
block_ratio: float=5, ):
"""
Same as `paddle.nn.functional.conv1d` but using FFT for the convolution.
Please check PaddlePaddle documentation for more information.
Notes
------
This function is faster than `paddle.nn.functional.conv1d` only in specific cases.
Typically, the kernel size should be of the order of 256 to see any real gain,
for a stride of 1.
Dilation and groups are not supported at the moment. This function might use
more memory than the default Conv1d implementation.
Args:
x (Tensor):
x signal of shape `[B, C, T]`.
weight (Tensor):
weight of the convolution `[D, C, K]` with `D` the number of output channels.
bias (Tensor or None):
if not None, bias term for the convolution.
stride (int):
stride of convolution.
padding (int):
padding to apply to x.
block_ratio (float):
can be tuned for speed. x is splitted in chunks with a size of `int(block_ratio * kernel_size)`.
Shape:
- Inputs: `x` is `[B, C, T]`, `weight` is `[D, C, K]` and bias is `[D]`.
- Output: `(*, T)`
"""
x = F.pad(x, (padding, padding), data_format="NCL")
batch, _, length = x.shape
out_channels, _, kernel_size = weight.shape
if length < kernel_size:
raise RuntimeError(
f"Input should be at least as large as the kernel size {kernel_size}, "
f"but it is only {length} samples long.")
if block_ratio < 1:
raise RuntimeError("Block ratio must be greater than 1.")
block_size: int = min(int(kernel_size * block_ratio), length)
fold_stride = block_size - kernel_size + 1
# weight = pad_to(weight, block_size)
weight = F.pad(
weight, (0, block_size - weight.shape[-1]),
mode="constant",
value=0.0,
data_format="NCL")
weight_z = paddle.fft.rfft(weight, axis=-1)
# We pad `x` and get the different frames, on which
frames = __unfold(x, block_size, fold_stride)
frames_z = paddle.fft.rfft(frames, axis=-1)
weight_z_coml = paddle.conj(weight_z)
out_z = paddle.einsum("bcft,dct->bdft", frames_z, weight_z_coml)
out = paddle.fft.irfft(out_z, n=block_size, axis=-1)
# The last bit is invalid, because FFT will do a circular convolution.
out = out[..., :-kernel_size + 1]
out = out.reshape([batch, out_channels, -1])
out = out[..., ::stride]
target_length = (length - kernel_size) // stride + 1
out = out[..., :target_length]
if bias is not None:
out += bias[:, None]
return out
class FFTConv1D(paddle.nn.Layer):
"""
Same as `paddle.nn.Conv1D` but based on a custom FFT-based convolution.
Please check PaddlePaddle documentation for more information on `paddle.nn.Conv1D`.
Notes
------
This module is faster than `paddle.nn.Conv1D` only in specific cases.
Typically, `kernel_size` should be of the order of 256 to see any real gain,
for a stride of 1.
Dilation and groups are not supported at the moment. This module might use
more memory than the default Conv1D implementation.
Args:
in_channels (int):
number of `x` channels.
out_channels (int):
number of output channels.
kernel_size (int):
kernel size of convolution.
stride (int):
stride of convolution.
padding (int):
padding to apply to `x`.
bias_attr (bool):
if True, use a bias term.
Examples:
>>> fftconv = FFTConv1D(12, 24, 128, 4)
>>> x = paddle.randn([4, 12, 1024])
>>> print(list(fftconv(x).shape))
[4, 24, 225]
"""
def __init__(
self,
in_channels: int,
out_channels: int,
kernel_size: int,
stride: int=1,
padding: int=0,
bias_attr: bool=True, ):
super(FFTConv1D, self).__init__()
self.in_channels = in_channels
self.out_channels = out_channels
self.kernel_size = kernel_size
self.stride = stride
self.padding = padding
# Create a Conv1D layer to initialize weights and bias
conv = paddle.nn.Conv1D(
in_channels,
out_channels,
kernel_size,
stride=stride,
padding=padding,
bias_attr=bias_attr)
self.weight = conv.weight
if bias_attr:
self.bias = conv.bias
else:
self.bias = None
def forward(self, x: paddle.Tensor):
return fft_conv1d(x, self.weight, self.bias, self.stride, self.padding)
# Currently, the API unfold in Paddle is extremely slow, so __unfold is implemented
# using the `.strides` and `.as_strided` APIs. However, these are only supported in
# Paddle version 2.6 and above, so F.conv1d and Conv1D are used as replacements.
if not satisfy_paddle_version('2.6'):
fft_conv1d = F.conv1d
FFTConv1D = nn.Conv1D