# Copyright (c) 2024 Amphion.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
from typing import Optional, Tuple
import numpy as np
import scipy
import torch
from torch import nn, view_as_real, view_as_complex
from torch import nn
from torch.nn.utils import weight_norm, remove_weight_norm
from torchaudio.functional.functional import _hz_to_mel, _mel_to_hz
import librosa
def safe_log(x: torch.Tensor, clip_val: float = 1e-7) -> torch.Tensor:
"""
Computes the element-wise logarithm of the input tensor with clipping to avoid near-zero values.
Args:
x (Tensor): Input tensor.
clip_val (float, optional): Minimum value to clip the input tensor. Defaults to 1e-7.
Returns:
Tensor: Element-wise logarithm of the input tensor with clipping applied.
"""
return torch.log(torch.clip(x, min=clip_val))
def symlog(x: torch.Tensor) -> torch.Tensor:
return torch.sign(x) * torch.log1p(x.abs())
def symexp(x: torch.Tensor) -> torch.Tensor:
return torch.sign(x) * (torch.exp(x.abs()) - 1)
class STFT(nn.Module):
def __init__(
self,
n_fft: int,
hop_length: int,
win_length: int,
center=True,
):
super().__init__()
self.center = center
self.n_fft = n_fft
self.hop_length = hop_length
self.win_length = win_length
window = torch.hann_window(win_length)
self.register_buffer("window", window)
def forward(self, x: torch.Tensor) -> torch.Tensor:
# x: (B, T * hop_length)
if not self.center:
pad = self.win_length - self.hop_length
x = torch.nn.functional.pad(x, (pad // 2, pad // 2), mode="reflect")
stft_spec = torch.stft(
x,
self.n_fft,
hop_length=self.hop_length,
win_length=self.win_length,
window=self.window,
center=self.center,
return_complex=False,
) # (B, n_fft // 2 + 1, T, 2)
rea = stft_spec[:, :, :, 0] # (B, n_fft // 2 + 1, T, 2)
imag = stft_spec[:, :, :, 1] # (B, n_fft // 2 + 1, T, 2)
log_mag = torch.log(
torch.abs(torch.sqrt(torch.pow(rea, 2) + torch.pow(imag, 2))) + 1e-5
) # (B, n_fft // 2 + 1, T)
phase = torch.atan2(imag, rea) # (B, n_fft // 2 + 1, T)
return log_mag, phase
class ISTFT(nn.Module):
"""
Custom implementation of ISTFT since torch.istft doesn't allow custom padding (other than `center=True`) with
windowing. This is because the NOLA (Nonzero Overlap Add) check fails at the edges.
See issue: https://github.com/pytorch/pytorch/issues/62323
Specifically, in the context of neural vocoding we are interested in "same" padding analogous to CNNs.
The NOLA constraint is met as we trim padded samples anyway.
Args:
n_fft (int): Size of Fourier transform.
hop_length (int): The distance between neighboring sliding window frames.
win_length (int): The size of window frame and STFT filter.
padding (str, optional): Type of padding. Options are "center" or "same". Defaults to "same".
"""
def __init__(
self, n_fft: int, hop_length: int, win_length: int, padding: str = "same"
):
super().__init__()
if padding not in ["center", "same"]:
raise ValueError("Padding must be 'center' or 'same'.")
self.padding = padding
self.n_fft = n_fft
self.hop_length = hop_length
self.win_length = win_length
window = torch.hann_window(win_length)
self.register_buffer("window", window)
def forward(self, spec: torch.Tensor) -> torch.Tensor:
"""
Compute the Inverse Short Time Fourier Transform (ISTFT) of a complex spectrogram.
Args:
spec (Tensor): Input complex spectrogram of shape (B, N, T), where B is the batch size,
N is the number of frequency bins, and T is the number of time frames.
Returns:
Tensor: Reconstructed time-domain signal of shape (B, L), where L is the length of the output signal.
"""
if self.padding == "center":
# Fallback to pytorch native implementation
return torch.istft(
spec,
self.n_fft,
self.hop_length,
self.win_length,
self.window,
center=True,
)
elif self.padding == "same":
pad = (self.win_length - self.hop_length) // 2
else:
raise ValueError("Padding must be 'center' or 'same'.")
assert spec.dim() == 3, "Expected a 3D tensor as input"
B, N, T = spec.shape
# Inverse FFT
ifft = torch.fft.irfft(spec, self.n_fft, dim=1, norm="backward")
ifft = ifft * self.window[None, :, None]
# Overlap and Add
output_size = (T - 1) * self.hop_length + self.win_length
y = torch.nn.functional.fold(
ifft,
output_size=(1, output_size),
kernel_size=(1, self.win_length),
stride=(1, self.hop_length),
)[:, 0, 0, pad:-pad]
# Window envelope
window_sq = self.window.square().expand(1, T, -1).transpose(1, 2)
window_envelope = torch.nn.functional.fold(
window_sq,
output_size=(1, output_size),
kernel_size=(1, self.win_length),
stride=(1, self.hop_length),
).squeeze()[pad:-pad]
# Normalize
assert (window_envelope > 1e-11).all()
y = y / window_envelope
return y
class MDCT(nn.Module):
"""
Modified Discrete Cosine Transform (MDCT) module.
Args:
frame_len (int): Length of the MDCT frame.
padding (str, optional): Type of padding. Options are "center" or "same". Defaults to "same".
"""
def __init__(self, frame_len: int, padding: str = "same"):
super().__init__()
if padding not in ["center", "same"]:
raise ValueError("Padding must be 'center' or 'same'.")
self.padding = padding
self.frame_len = frame_len
N = frame_len // 2
n0 = (N + 1) / 2
window = torch.from_numpy(scipy.signal.cosine(frame_len)).float()
self.register_buffer("window", window)
pre_twiddle = torch.exp(-1j * torch.pi * torch.arange(frame_len) / frame_len)
post_twiddle = torch.exp(-1j * torch.pi * n0 * (torch.arange(N) + 0.5) / N)
# view_as_real: NCCL Backend does not support ComplexFloat data type
# https://github.com/pytorch/pytorch/issues/71613
self.register_buffer("pre_twiddle", view_as_real(pre_twiddle))
self.register_buffer("post_twiddle", view_as_real(post_twiddle))
def forward(self, audio: torch.Tensor) -> torch.Tensor:
"""
Apply the Modified Discrete Cosine Transform (MDCT) to the input audio.
Args:
audio (Tensor): Input audio waveform of shape (B, T), where B is the batch size
and T is the length of the audio.
Returns:
Tensor: MDCT coefficients of shape (B, L, N), where L is the number of output frames
and N is the number of frequency bins.
"""
if self.padding == "center":
audio = torch.nn.functional.pad(
audio, (self.frame_len // 2, self.frame_len // 2)
)
elif self.padding == "same":
# hop_length is 1/2 frame_len
audio = torch.nn.functional.pad(
audio, (self.frame_len // 4, self.frame_len // 4)
)
else:
raise ValueError("Padding must be 'center' or 'same'.")
x = audio.unfold(-1, self.frame_len, self.frame_len // 2)
N = self.frame_len // 2
x = x * self.window.expand(x.shape)
X = torch.fft.fft(
x * view_as_complex(self.pre_twiddle).expand(x.shape), dim=-1
)[..., :N]
res = X * view_as_complex(self.post_twiddle).expand(X.shape) * np.sqrt(1 / N)
return torch.real(res) * np.sqrt(2)
class IMDCT(nn.Module):
"""
Inverse Modified Discrete Cosine Transform (IMDCT) module.
Args:
frame_len (int): Length of the MDCT frame.
padding (str, optional): Type of padding. Options are "center" or "same". Defaults to "same".
"""
def __init__(self, frame_len: int, padding: str = "same"):
super().__init__()
if padding not in ["center", "same"]:
raise ValueError("Padding must be 'center' or 'same'.")
self.padding = padding
self.frame_len = frame_len
N = frame_len // 2
n0 = (N + 1) / 2
window = torch.from_numpy(scipy.signal.cosine(frame_len)).float()
self.register_buffer("window", window)
pre_twiddle = torch.exp(1j * torch.pi * n0 * torch.arange(N * 2) / N)
post_twiddle = torch.exp(1j * torch.pi * (torch.arange(N * 2) + n0) / (N * 2))
self.register_buffer("pre_twiddle", view_as_real(pre_twiddle))
self.register_buffer("post_twiddle", view_as_real(post_twiddle))
def forward(self, X: torch.Tensor) -> torch.Tensor:
"""
Apply the Inverse Modified Discrete Cosine Transform (IMDCT) to the input MDCT coefficients.
Args:
X (Tensor): Input MDCT coefficients of shape (B, L, N), where B is the batch size,
L is the number of frames, and N is the number of frequency bins.
Returns:
Tensor: Reconstructed audio waveform of shape (B, T), where T is the length of the audio.
"""
B, L, N = X.shape
Y = torch.zeros((B, L, N * 2), dtype=X.dtype, device=X.device)
Y[..., :N] = X
Y[..., N:] = -1 * torch.conj(torch.flip(X, dims=(-1,)))
y = torch.fft.ifft(
Y * view_as_complex(self.pre_twiddle).expand(Y.shape), dim=-1
)
y = (
torch.real(y * view_as_complex(self.post_twiddle).expand(y.shape))
* np.sqrt(N)
* np.sqrt(2)
)
result = y * self.window.expand(y.shape)
output_size = (1, (L + 1) * N)
audio = torch.nn.functional.fold(
result.transpose(1, 2),
output_size=output_size,
kernel_size=(1, self.frame_len),
stride=(1, self.frame_len // 2),
)[:, 0, 0, :]
if self.padding == "center":
pad = self.frame_len // 2
elif self.padding == "same":
pad = self.frame_len // 4
else:
raise ValueError("Padding must be 'center' or 'same'.")
audio = audio[:, pad:-pad]
return audio
class FourierHead(nn.Module):
"""Base class for inverse fourier modules."""
def forward(self, x: torch.Tensor) -> torch.Tensor:
"""
Args:
x (Tensor): Input tensor of shape (B, L, H), where B is the batch size,
L is the sequence length, and H denotes the model dimension.
Returns:
Tensor: Reconstructed time-domain audio signal of shape (B, T), where T is the length of the output signal.
"""
raise NotImplementedError("Subclasses must implement the forward method.")
class ISTFTHead(FourierHead):
"""
ISTFT Head module for predicting STFT complex coefficients.
Args:
dim (int): Hidden dimension of the model.
n_fft (int): Size of Fourier transform.
hop_length (int): The distance between neighboring sliding window frames, which should align with
the resolution of the input features.
padding (str, optional): Type of padding. Options are "center" or "same". Defaults to "same".
"""
def __init__(self, dim: int, n_fft: int, hop_length: int, padding: str = "same"):
super().__init__()
out_dim = n_fft + 2
self.out = torch.nn.Linear(dim, out_dim)
self.istft = ISTFT(
n_fft=n_fft, hop_length=hop_length, win_length=n_fft, padding=padding
)
def forward(self, x: torch.Tensor) -> torch.Tensor:
"""
Forward pass of the ISTFTHead module.
Args:
x (Tensor): Input tensor of shape (B, L, H), where B is the batch size,
L is the sequence length, and H denotes the model dimension.
Returns:
Tensor: Reconstructed time-domain audio signal of shape (B, T), where T is the length of the output signal.
"""
x = self.out(x).transpose(1, 2)
mag, p = x.chunk(2, dim=1)
mag = torch.exp(mag)
mag = torch.clip(
mag, max=1e2
) # safeguard to prevent excessively large magnitudes
# wrapping happens here. These two lines produce real and imaginary value
x = torch.cos(p)
y = torch.sin(p)
# recalculating phase here does not produce anything new
# only costs time
# phase = torch.atan2(y, x)
# S = mag * torch.exp(phase * 1j)
# better directly produce the complex value
S = mag * (x + 1j * y)
audio = self.istft(S)
return audio
class IMDCTSymExpHead(FourierHead):
"""
IMDCT Head module for predicting MDCT coefficients with symmetric exponential function
Args:
dim (int): Hidden dimension of the model.
mdct_frame_len (int): Length of the MDCT frame.
padding (str, optional): Type of padding. Options are "center" or "same". Defaults to "same".
sample_rate (int, optional): The sample rate of the audio. If provided, the last layer will be initialized
based on perceptual scaling. Defaults to None.
clip_audio (bool, optional): Whether to clip the audio output within the range of [-1.0, 1.0]. Defaults to False.
"""
def __init__(
self,
dim: int,
mdct_frame_len: int,
padding: str = "same",
sample_rate: Optional[int] = None,
clip_audio: bool = False,
):
super().__init__()
out_dim = mdct_frame_len // 2
self.out = nn.Linear(dim, out_dim)
self.imdct = IMDCT(frame_len=mdct_frame_len, padding=padding)
self.clip_audio = clip_audio
if sample_rate is not None:
# optionally init the last layer following mel-scale
m_max = _hz_to_mel(sample_rate // 2)
m_pts = torch.linspace(0, m_max, out_dim)
f_pts = _mel_to_hz(m_pts)
scale = 1 - (f_pts / f_pts.max())
with torch.no_grad():
self.out.weight.mul_(scale.view(-1, 1))
def forward(self, x: torch.Tensor) -> torch.Tensor:
"""
Forward pass of the IMDCTSymExpHead module.
Args:
x (Tensor): Input tensor of shape (B, L, H), where B is the batch size,
L is the sequence length, and H denotes the model dimension.
Returns:
Tensor: Reconstructed time-domain audio signal of shape (B, T), where T is the length of the output signal.
"""
x = self.out(x)
x = symexp(x)
x = torch.clip(
x, min=-1e2, max=1e2
) # safeguard to prevent excessively large magnitudes
audio = self.imdct(x)
if self.clip_audio:
audio = torch.clip(x, min=-1.0, max=1.0)
return audio
class IMDCTCosHead(FourierHead):
"""
IMDCT Head module for predicting MDCT coefficients with parametrizing MDCT = exp(m) ยท cos(p)
Args:
dim (int): Hidden dimension of the model.
mdct_frame_len (int): Length of the MDCT frame.
padding (str, optional): Type of padding. Options are "center" or "same". Defaults to "same".
clip_audio (bool, optional): Whether to clip the audio output within the range of [-1.0, 1.0]. Defaults to False.
"""
def __init__(
self,
dim: int,
mdct_frame_len: int,
padding: str = "same",
clip_audio: bool = False,
):
super().__init__()
self.clip_audio = clip_audio
self.out = nn.Linear(dim, mdct_frame_len)
self.imdct = IMDCT(frame_len=mdct_frame_len, padding=padding)
def forward(self, x: torch.Tensor) -> torch.Tensor:
"""
Forward pass of the IMDCTCosHead module.
Args:
x (Tensor): Input tensor of shape (B, L, H), where B is the batch size,
L is the sequence length, and H denotes the model dimension.
Returns:
Tensor: Reconstructed time-domain audio signal of shape (B, T), where T is the length of the output signal.
"""
x = self.out(x)
m, p = x.chunk(2, dim=2)
m = torch.exp(m).clip(
max=1e2
) # safeguard to prevent excessively large magnitudes
audio = self.imdct(m * torch.cos(p))
if self.clip_audio:
audio = torch.clip(x, min=-1.0, max=1.0)
return audio
class ConvNeXtBlock(nn.Module):
"""ConvNeXt Block adapted from https://github.com/facebookresearch/ConvNeXt to 1D audio signal.
Args:
dim (int): Number of input channels.
intermediate_dim (int): Dimensionality of the intermediate layer.
layer_scale_init_value (float, optional): Initial value for the layer scale. None means no scaling.
Defaults to None.
adanorm_num_embeddings (int, optional): Number of embeddings for AdaLayerNorm.
None means non-conditional LayerNorm. Defaults to None.
"""
def __init__(
self,
dim: int,
intermediate_dim: int,
layer_scale_init_value: float,
adanorm_num_embeddings: Optional[int] = None,
):
super().__init__()
self.dwconv = nn.Conv1d(
dim, dim, kernel_size=7, padding=3, groups=dim
) # depthwise conv
self.adanorm = adanorm_num_embeddings is not None
if adanorm_num_embeddings:
self.norm = AdaLayerNorm(adanorm_num_embeddings, dim, eps=1e-6)
else:
self.norm = nn.LayerNorm(dim, eps=1e-6)
self.pwconv1 = nn.Linear(
dim, intermediate_dim
) # pointwise/1x1 convs, implemented with linear layers
self.act = nn.GELU()
self.pwconv2 = nn.Linear(intermediate_dim, dim)
self.gamma = (
nn.Parameter(layer_scale_init_value * torch.ones(dim), requires_grad=True)
if layer_scale_init_value > 0
else None
)
def forward(
self, x: torch.Tensor, cond_embedding_id: Optional[torch.Tensor] = None
) -> torch.Tensor:
residual = x
x = self.dwconv(x)
x = x.transpose(1, 2) # (B, C, T) -> (B, T, C)
if self.adanorm:
assert cond_embedding_id is not None
x = self.norm(x, cond_embedding_id)
else:
x = self.norm(x)
x = self.pwconv1(x)
x = self.act(x)
x = self.pwconv2(x)
if self.gamma is not None:
x = self.gamma * x
x = x.transpose(1, 2) # (B, T, C) -> (B, C, T)
x = residual + x
return x
class AdaLayerNorm(nn.Module):
"""
Adaptive Layer Normalization module with learnable embeddings per `num_embeddings` classes
Args:
num_embeddings (int): Number of embeddings.
embedding_dim (int): Dimension of the embeddings.
"""
def __init__(self, num_embeddings: int, embedding_dim: int, eps: float = 1e-6):
super().__init__()
self.eps = eps
self.dim = embedding_dim
self.scale = nn.Embedding(
num_embeddings=num_embeddings, embedding_dim=embedding_dim
)
self.shift = nn.Embedding(
num_embeddings=num_embeddings, embedding_dim=embedding_dim
)
torch.nn.init.ones_(self.scale.weight)
torch.nn.init.zeros_(self.shift.weight)
def forward(self, x: torch.Tensor, cond_embedding_id: torch.Tensor) -> torch.Tensor:
scale = self.scale(cond_embedding_id)
shift = self.shift(cond_embedding_id)
x = nn.functional.layer_norm(x, (self.dim,), eps=self.eps)
x = x * scale + shift
return x
class ResBlock1(nn.Module):
"""
ResBlock adapted from HiFi-GAN V1 (https://github.com/jik876/hifi-gan) with dilated 1D convolutions,
but without upsampling layers.
Args:
dim (int): Number of input channels.
kernel_size (int, optional): Size of the convolutional kernel. Defaults to 3.
dilation (tuple[int], optional): Dilation factors for the dilated convolutions.
Defaults to (1, 3, 5).
lrelu_slope (float, optional): Negative slope of the LeakyReLU activation function.
Defaults to 0.1.
layer_scale_init_value (float, optional): Initial value for the layer scale. None means no scaling.
Defaults to None.
"""
def __init__(
self,
dim: int,
kernel_size: int = 3,
dilation: Tuple[int, int, int] = (1, 3, 5),
lrelu_slope: float = 0.1,
layer_scale_init_value: Optional[float] = None,
):
super().__init__()
self.lrelu_slope = lrelu_slope
self.convs1 = nn.ModuleList(
[
weight_norm(
nn.Conv1d(
dim,
dim,
kernel_size,
1,
dilation=dilation[0],
padding=self.get_padding(kernel_size, dilation[0]),
)
),
weight_norm(
nn.Conv1d(
dim,
dim,
kernel_size,
1,
dilation=dilation[1],
padding=self.get_padding(kernel_size, dilation[1]),
)
),
weight_norm(
nn.Conv1d(
dim,
dim,
kernel_size,
1,
dilation=dilation[2],
padding=self.get_padding(kernel_size, dilation[2]),
)
),
]
)
self.convs2 = nn.ModuleList(
[
weight_norm(
nn.Conv1d(
dim,
dim,
kernel_size,
1,
dilation=1,
padding=self.get_padding(kernel_size, 1),
)
),
weight_norm(
nn.Conv1d(
dim,
dim,
kernel_size,
1,
dilation=1,
padding=self.get_padding(kernel_size, 1),
)
),
weight_norm(
nn.Conv1d(
dim,
dim,
kernel_size,
1,
dilation=1,
padding=self.get_padding(kernel_size, 1),
)
),
]
)
self.gamma = nn.ParameterList(
[
(
nn.Parameter(
layer_scale_init_value * torch.ones(dim, 1), requires_grad=True
)
if layer_scale_init_value is not None
else None
),
(
nn.Parameter(
layer_scale_init_value * torch.ones(dim, 1), requires_grad=True
)
if layer_scale_init_value is not None
else None
),
(
nn.Parameter(
layer_scale_init_value * torch.ones(dim, 1), requires_grad=True
)
if layer_scale_init_value is not None
else None
),
]
)
def forward(self, x: torch.Tensor) -> torch.Tensor:
for c1, c2, gamma in zip(self.convs1, self.convs2, self.gamma):
xt = torch.nn.functional.leaky_relu(x, negative_slope=self.lrelu_slope)
xt = c1(xt)
xt = torch.nn.functional.leaky_relu(xt, negative_slope=self.lrelu_slope)
xt = c2(xt)
if gamma is not None:
xt = gamma * xt
x = xt + x
return x
def remove_weight_norm(self):
for l in self.convs1:
remove_weight_norm(l)
for l in self.convs2:
remove_weight_norm(l)
@staticmethod
def get_padding(kernel_size: int, dilation: int = 1) -> int:
return int((kernel_size * dilation - dilation) / 2)
class Backbone(nn.Module):
"""Base class for the generator's backbone. It preserves the same temporal resolution across all layers."""
def forward(self, x: torch.Tensor, **kwargs) -> torch.Tensor:
"""
Args:
x (Tensor): Input tensor of shape (B, C, L), where B is the batch size,
C denotes output features, and L is the sequence length.
Returns:
Tensor: Output of shape (B, L, H), where B is the batch size, L is the sequence length,
and H denotes the model dimension.
"""
raise NotImplementedError("Subclasses must implement the forward method.")
class VocosBackbone(Backbone):
"""
Vocos backbone module built with ConvNeXt blocks. Supports additional conditioning with Adaptive Layer Normalization
Args:
input_channels (int): Number of input features channels.
dim (int): Hidden dimension of the model.
intermediate_dim (int): Intermediate dimension used in ConvNeXtBlock.
num_layers (int): Number of ConvNeXtBlock layers.
layer_scale_init_value (float, optional): Initial value for layer scaling. Defaults to `1 / num_layers`.
adanorm_num_embeddings (int, optional): Number of embeddings for AdaLayerNorm.
None means non-conditional model. Defaults to None.
"""
def __init__(
self,
input_channels: int,
dim: int,
intermediate_dim: int,
num_layers: int,
layer_scale_init_value: Optional[float] = None,
adanorm_num_embeddings: Optional[int] = None,
):
super().__init__()
self.input_channels = input_channels
self.embed = nn.Conv1d(input_channels, dim, kernel_size=7, padding=3)
self.adanorm = adanorm_num_embeddings is not None
if adanorm_num_embeddings:
self.norm = AdaLayerNorm(adanorm_num_embeddings, dim, eps=1e-6)
else:
self.norm = nn.LayerNorm(dim, eps=1e-6)
layer_scale_init_value = layer_scale_init_value or 1 / num_layers
self.convnext = nn.ModuleList(
[
ConvNeXtBlock(
dim=dim,
intermediate_dim=intermediate_dim,
layer_scale_init_value=layer_scale_init_value,
adanorm_num_embeddings=adanorm_num_embeddings,
)
for _ in range(num_layers)
]
)
self.final_layer_norm = nn.LayerNorm(dim, eps=1e-6)
self.apply(self._init_weights)
def _init_weights(self, m):
if isinstance(m, (nn.Conv1d, nn.Linear)):
nn.init.trunc_normal_(m.weight, std=0.02)
nn.init.constant_(m.bias, 0)
def forward(self, x: torch.Tensor, **kwargs) -> torch.Tensor:
bandwidth_id = kwargs.get("bandwidth_id", None)
x = self.embed(x)
if self.adanorm:
assert bandwidth_id is not None
x = self.norm(x.transpose(1, 2), cond_embedding_id=bandwidth_id)
else:
x = self.norm(x.transpose(1, 2))
x = x.transpose(1, 2)
for conv_block in self.convnext:
x = conv_block(x, cond_embedding_id=bandwidth_id)
x = self.final_layer_norm(x.transpose(1, 2))
return x
class VocosResNetBackbone(Backbone):
"""
Vocos backbone module built with ResBlocks.
Args:
input_channels (int): Number of input features channels.
dim (int): Hidden dimension of the model.
num_blocks (int): Number of ResBlock1 blocks.
layer_scale_init_value (float, optional): Initial value for layer scaling. Defaults to None.
"""
def __init__(
self,
input_channels,
dim,
num_blocks,
layer_scale_init_value=None,
):
super().__init__()
self.input_channels = input_channels
self.embed = weight_norm(
nn.Conv1d(input_channels, dim, kernel_size=3, padding=1)
)
layer_scale_init_value = layer_scale_init_value or 1 / num_blocks / 3
self.resnet = nn.Sequential(
*[
ResBlock1(dim=dim, layer_scale_init_value=layer_scale_init_value)
for _ in range(num_blocks)
]
)
def forward(self, x: torch.Tensor, **kwargs) -> torch.Tensor:
x = self.embed(x)
x = self.resnet(x)
x = x.transpose(1, 2)
return x
class Vocos(nn.Module):
def __init__(
self,
input_channels: int = 256,
dim: int = 384,
intermediate_dim: int = 1152,
num_layers: int = 8,
n_fft: int = 800,
hop_size: int = 200,
padding: str = "same",
adanorm_num_embeddings=None,
cfg=None,
):
super().__init__()
input_channels = (
cfg.input_channels
if cfg is not None and hasattr(cfg, "input_channels")
else input_channels
)
dim = cfg.dim if cfg is not None and hasattr(cfg, "dim") else dim
intermediate_dim = (
cfg.intermediate_dim
if cfg is not None and hasattr(cfg, "intermediate_dim")
else intermediate_dim
)
num_layers = (
cfg.num_layers
if cfg is not None and hasattr(cfg, "num_layers")
else num_layers
)
adanorm_num_embeddings = (
cfg.adanorm_num_embeddings
if cfg is not None and hasattr(cfg, "adanorm_num_embeddings")
else adanorm_num_embeddings
)
n_fft = cfg.n_fft if cfg is not None and hasattr(cfg, "n_fft") else n_fft
hop_size = (
cfg.hop_size if cfg is not None and hasattr(cfg, "hop_size") else hop_size
)
padding = (
cfg.padding if cfg is not None and hasattr(cfg, "padding") else padding
)
self.backbone = VocosBackbone(
input_channels=input_channels,
dim=dim,
intermediate_dim=intermediate_dim,
num_layers=num_layers,
adanorm_num_embeddings=adanorm_num_embeddings,
)
self.head = ISTFTHead(dim, n_fft, hop_size, padding)
def forward(self, x):
x = self.backbone(x)
x = self.head(x)
return x[:, None, :]