feat: Integrate IndexTTS2 model and update related schemas and frontend components

This commit is contained in:
2026-03-12 13:30:53 +08:00
parent e5b5a16364
commit 8aec4f6f44
151 changed files with 40077 additions and 85 deletions

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# 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.
import math
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
from einops import rearrange
from torch.nn.utils import weight_norm
from indextts.utils.maskgct.models.codec.amphion_codec.quantize import (
ResidualVQ,
VectorQuantize,
FactorizedVectorQuantize,
LookupFreeQuantize,
)
from indextts.utils.maskgct.models.codec.amphion_codec.vocos import Vocos
def WNConv1d(*args, **kwargs):
return weight_norm(nn.Conv1d(*args, **kwargs))
def WNConvTranspose1d(*args, **kwargs):
return weight_norm(nn.ConvTranspose1d(*args, **kwargs))
# Scripting this brings model speed up 1.4x
@torch.jit.script
def snake(x, alpha):
shape = x.shape
x = x.reshape(shape[0], shape[1], -1)
x = x + (alpha + 1e-9).reciprocal() * torch.sin(alpha * x).pow(2)
x = x.reshape(shape)
return x
class Snake1d(nn.Module):
def __init__(self, channels):
super().__init__()
self.alpha = nn.Parameter(torch.ones(1, channels, 1))
def forward(self, x):
return snake(x, self.alpha)
def init_weights(m):
if isinstance(m, nn.Conv1d):
nn.init.trunc_normal_(m.weight, std=0.02)
nn.init.constant_(m.bias, 0)
if isinstance(m, nn.Linear):
nn.init.trunc_normal_(m.weight, std=0.02)
nn.init.constant_(m.bias, 0)
class ResidualUnit(nn.Module):
def __init__(self, dim: int = 16, dilation: int = 1):
super().__init__()
pad = ((7 - 1) * dilation) // 2
self.block = nn.Sequential(
Snake1d(dim),
WNConv1d(dim, dim, kernel_size=7, dilation=dilation, padding=pad),
Snake1d(dim),
WNConv1d(dim, dim, kernel_size=1),
)
def forward(self, x):
y = self.block(x)
pad = (x.shape[-1] - y.shape[-1]) // 2
if pad > 0:
x = x[..., pad:-pad]
return x + y
class EncoderBlock(nn.Module):
def __init__(self, dim: int = 16, stride: int = 1):
super().__init__()
self.block = nn.Sequential(
ResidualUnit(dim // 2, dilation=1),
ResidualUnit(dim // 2, dilation=3),
ResidualUnit(dim // 2, dilation=9),
Snake1d(dim // 2),
WNConv1d(
dim // 2,
dim,
kernel_size=2 * stride,
stride=stride,
padding=math.ceil(stride / 2),
),
)
def forward(self, x):
return self.block(x)
class CodecEncoder(nn.Module):
def __init__(
self,
d_model: int = 64,
up_ratios: list = [4, 5, 5, 6],
out_channels: int = 256,
use_tanh: bool = False,
cfg=None,
):
super().__init__()
d_model = cfg.d_model if cfg is not None else d_model
up_ratios = cfg.up_ratios if cfg is not None else up_ratios
out_channels = cfg.out_channels if cfg is not None else out_channels
use_tanh = cfg.use_tanh if cfg is not None else use_tanh
# Create first convolution
self.block = [WNConv1d(1, d_model, kernel_size=7, padding=3)]
# Create EncoderBlocks that double channels as they downsample by `stride`
for stride in up_ratios:
d_model *= 2
self.block += [EncoderBlock(d_model, stride=stride)]
# Create last convolution
self.block += [
Snake1d(d_model),
WNConv1d(d_model, out_channels, kernel_size=3, padding=1),
]
if use_tanh:
self.block += [nn.Tanh()]
# Wrap black into nn.Sequential
self.block = nn.Sequential(*self.block)
self.enc_dim = d_model
self.reset_parameters()
def forward(self, x):
return self.block(x)
def reset_parameters(self):
self.apply(init_weights)
class DecoderBlock(nn.Module):
def __init__(self, input_dim: int = 16, output_dim: int = 8, stride: int = 1):
super().__init__()
self.block = nn.Sequential(
Snake1d(input_dim),
WNConvTranspose1d(
input_dim,
output_dim,
kernel_size=2 * stride,
stride=stride,
padding=stride // 2 + stride % 2,
output_padding=stride % 2,
),
ResidualUnit(output_dim, dilation=1),
ResidualUnit(output_dim, dilation=3),
ResidualUnit(output_dim, dilation=9),
)
def forward(self, x):
return self.block(x)
class CodecDecoder(nn.Module):
def __init__(
self,
in_channels: int = 256,
upsample_initial_channel: int = 1536,
up_ratios: list = [5, 5, 4, 2],
num_quantizers: int = 8,
codebook_size: int = 1024,
codebook_dim: int = 256,
quantizer_type: str = "vq",
quantizer_dropout: float = 0.5,
commitment: float = 0.25,
codebook_loss_weight: float = 1.0,
use_l2_normlize: bool = False,
codebook_type: str = "euclidean",
kmeans_init: bool = False,
kmeans_iters: int = 10,
decay: float = 0.8,
eps: float = 1e-5,
threshold_ema_dead_code: int = 2,
weight_init: bool = False,
use_vocos: bool = False,
vocos_dim: int = 384,
vocos_intermediate_dim: int = 1152,
vocos_num_layers: int = 8,
n_fft: int = 800,
hop_size: int = 200,
padding: str = "same",
cfg=None,
):
super().__init__()
in_channels = (
cfg.in_channels
if cfg is not None and hasattr(cfg, "in_channels")
else in_channels
)
upsample_initial_channel = (
cfg.upsample_initial_channel
if cfg is not None and hasattr(cfg, "upsample_initial_channel")
else upsample_initial_channel
)
up_ratios = (
cfg.up_ratios
if cfg is not None and hasattr(cfg, "up_ratios")
else up_ratios
)
num_quantizers = (
cfg.num_quantizers
if cfg is not None and hasattr(cfg, "num_quantizers")
else num_quantizers
)
codebook_size = (
cfg.codebook_size
if cfg is not None and hasattr(cfg, "codebook_size")
else codebook_size
)
codebook_dim = (
cfg.codebook_dim
if cfg is not None and hasattr(cfg, "codebook_dim")
else codebook_dim
)
quantizer_type = (
cfg.quantizer_type
if cfg is not None and hasattr(cfg, "quantizer_type")
else quantizer_type
)
quantizer_dropout = (
cfg.quantizer_dropout
if cfg is not None and hasattr(cfg, "quantizer_dropout")
else quantizer_dropout
)
commitment = (
cfg.commitment
if cfg is not None and hasattr(cfg, "commitment")
else commitment
)
codebook_loss_weight = (
cfg.codebook_loss_weight
if cfg is not None and hasattr(cfg, "codebook_loss_weight")
else codebook_loss_weight
)
use_l2_normlize = (
cfg.use_l2_normlize
if cfg is not None and hasattr(cfg, "use_l2_normlize")
else use_l2_normlize
)
codebook_type = (
cfg.codebook_type
if cfg is not None and hasattr(cfg, "codebook_type")
else codebook_type
)
kmeans_init = (
cfg.kmeans_init
if cfg is not None and hasattr(cfg, "kmeans_init")
else kmeans_init
)
kmeans_iters = (
cfg.kmeans_iters
if cfg is not None and hasattr(cfg, "kmeans_iters")
else kmeans_iters
)
decay = cfg.decay if cfg is not None and hasattr(cfg, "decay") else decay
eps = cfg.eps if cfg is not None and hasattr(cfg, "eps") else eps
threshold_ema_dead_code = (
cfg.threshold_ema_dead_code
if cfg is not None and hasattr(cfg, "threshold_ema_dead_code")
else threshold_ema_dead_code
)
weight_init = (
cfg.weight_init
if cfg is not None and hasattr(cfg, "weight_init")
else weight_init
)
use_vocos = (
cfg.use_vocos
if cfg is not None and hasattr(cfg, "use_vocos")
else use_vocos
)
vocos_dim = (
cfg.vocos_dim
if cfg is not None and hasattr(cfg, "vocos_dim")
else vocos_dim
)
vocos_intermediate_dim = (
cfg.vocos_intermediate_dim
if cfg is not None and hasattr(cfg, "vocos_intermediate_dim")
else vocos_intermediate_dim
)
vocos_num_layers = (
cfg.vocos_num_layers
if cfg is not None and hasattr(cfg, "vocos_num_layers")
else vocos_num_layers
)
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
)
if quantizer_type == "vq":
self.quantizer = ResidualVQ(
input_dim=in_channels,
num_quantizers=num_quantizers,
codebook_size=codebook_size,
codebook_dim=codebook_dim,
quantizer_type=quantizer_type,
quantizer_dropout=quantizer_dropout,
commitment=commitment,
codebook_loss_weight=codebook_loss_weight,
use_l2_normlize=use_l2_normlize,
codebook_type=codebook_type,
kmeans_init=kmeans_init,
kmeans_iters=kmeans_iters,
decay=decay,
eps=eps,
threshold_ema_dead_code=threshold_ema_dead_code,
weight_init=weight_init,
)
elif quantizer_type == "fvq":
self.quantizer = ResidualVQ(
input_dim=in_channels,
num_quantizers=num_quantizers,
codebook_size=codebook_size,
codebook_dim=codebook_dim,
quantizer_type=quantizer_type,
quantizer_dropout=quantizer_dropout,
commitment=commitment,
codebook_loss_weight=codebook_loss_weight,
use_l2_normlize=use_l2_normlize,
)
elif quantizer_type == "lfq":
self.quantizer = ResidualVQ(
input_dim=in_channels,
num_quantizers=num_quantizers,
codebook_size=codebook_size,
codebook_dim=codebook_dim,
quantizer_type=quantizer_type,
)
else:
raise ValueError(f"Unknown quantizer type {quantizer_type}")
if not use_vocos:
# Add first conv layer
channels = upsample_initial_channel
layers = [WNConv1d(in_channels, channels, kernel_size=7, padding=3)]
# Add upsampling + MRF blocks
for i, stride in enumerate(up_ratios):
input_dim = channels // 2**i
output_dim = channels // 2 ** (i + 1)
layers += [DecoderBlock(input_dim, output_dim, stride)]
# Add final conv layer
layers += [
Snake1d(output_dim),
WNConv1d(output_dim, 1, kernel_size=7, padding=3),
nn.Tanh(),
]
self.model = nn.Sequential(*layers)
if use_vocos:
self.model = Vocos(
input_channels=in_channels,
dim=vocos_dim,
intermediate_dim=vocos_intermediate_dim,
num_layers=vocos_num_layers,
adanorm_num_embeddings=None,
n_fft=n_fft,
hop_size=hop_size,
padding=padding,
)
self.reset_parameters()
def forward(self, x=None, vq=False, eval_vq=False, n_quantizers=None):
"""
if vq is True, x = encoder output, then return quantized output;
else, x = quantized output, then return decoder output
"""
if vq is True:
if eval_vq:
self.quantizer.eval()
(
quantized_out,
all_indices,
all_commit_losses,
all_codebook_losses,
all_quantized,
) = self.quantizer(x, n_quantizers=n_quantizers)
return (
quantized_out,
all_indices,
all_commit_losses,
all_codebook_losses,
all_quantized,
)
return self.model(x)
def quantize(self, x, n_quantizers=None):
self.quantizer.eval()
quantized_out, vq, _, _, _ = self.quantizer(x, n_quantizers=n_quantizers)
return quantized_out, vq
# TODO: check consistency of vq2emb and quantize
def vq2emb(self, vq, n_quantizers=None):
return self.quantizer.vq2emb(vq, n_quantizers=n_quantizers)
def decode(self, x):
return self.model(x)
def latent2dist(self, x, n_quantizers=None):
return self.quantizer.latent2dist(x, n_quantizers=n_quantizers)
def reset_parameters(self):
self.apply(init_weights)

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# 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 indextts.utils.maskgct.models.codec.amphion_codec.quantize.factorized_vector_quantize import (
FactorizedVectorQuantize,
)
from indextts.utils.maskgct.models.codec.amphion_codec.quantize.vector_quantize import VectorQuantize
from indextts.utils.maskgct.models.codec.amphion_codec.quantize.lookup_free_quantize import LookupFreeQuantize
from indextts.utils.maskgct.models.codec.amphion_codec.quantize.residual_vq import ResidualVQ

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# 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.
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
from einops import rearrange
from torch.nn.utils import weight_norm
def WNConv1d(*args, **kwargs):
return weight_norm(nn.Conv1d(*args, **kwargs))
def WNConvTranspose1d(*args, **kwargs):
return weight_norm(nn.ConvTranspose1d(*args, **kwargs))
class FactorizedVectorQuantize(nn.Module):
def __init__(
self,
input_dim,
codebook_size,
codebook_dim,
commitment=0.005,
codebook_loss_weight=1.0,
use_l2_normlize=True,
):
super().__init__()
self.input_dim = input_dim
self.codebook_size = codebook_size
self.codebook_dim = codebook_dim
self.commitment = commitment
self.codebook_loss_weight = codebook_loss_weight
self.use_l2_normlize = use_l2_normlize
if self.input_dim != self.codebook_dim:
self.in_project = WNConv1d(self.input_dim, self.codebook_dim, kernel_size=1)
self.out_project = WNConv1d(
self.codebook_dim, self.input_dim, kernel_size=1
)
else:
self.in_project = nn.Identity()
self.out_project = nn.Identity()
self.codebook = nn.Embedding(self.codebook_size, self.codebook_dim)
def forward(self, z):
"""
Parameters
----------
z: torch.Tensor[B x D x T]
Returns
-------
z_q: torch.Tensor[B x D x T]
Quantized continuous representation of input
commit_loss: Tensor[B]
Commitment loss to train encoder to predict vectors closer to codebook entries
codebook_loss: Tensor[B]
Codebook loss to update the codebook
indices: torch.Tensor[B x T]
Codebook indices (quantized discrete representation of input)
z_e: torch.Tensor[B x D x T]
Projected latents (continuous representation of input before quantization)
"""
# Factorized codes project input into low-dimensional space if self.input_dim != self.codebook_dim
z_e = self.in_project(z)
z_q, indices = self.decode_latents(z_e)
# Compute commitment loss and codebook loss
if self.training:
commit_loss = (
F.mse_loss(z_e, z_q.detach(), reduction="none").mean([1, 2])
* self.commitment
)
codebook_loss = (
F.mse_loss(z_q, z_e.detach(), reduction="none").mean([1, 2])
* self.codebook_loss_weight
)
else:
commit_loss = torch.zeros(z.shape[0], device=z.device)
codebook_loss = torch.zeros(z.shape[0], device=z.device)
z_q = z_e + (z_q - z_e).detach()
z_q = self.out_project(z_q)
return z_q, commit_loss, codebook_loss, indices, z_e
def embed_code(self, embed_id):
return F.embedding(embed_id, self.codebook.weight)
def decode_code(self, embed_id):
return self.embed_code(embed_id).transpose(1, 2)
def decode_latents(self, latents):
encodings = rearrange(latents, "b d t -> (b t) d")
codebook = self.codebook.weight
# L2 normalize encodings and codebook
if self.use_l2_normlize:
encodings = F.normalize(encodings)
codebook = F.normalize(codebook)
# Compute euclidean distance between encodings and codebook,
# if use_l2_normlize is True, the distance is equal to cosine distance
dist = (
encodings.pow(2).sum(1, keepdim=True)
- 2 * encodings @ codebook.t()
+ codebook.pow(2).sum(1, keepdim=True).t()
)
indices = rearrange((-dist).max(1)[1], "(b t) -> b t", b=latents.size(0))
z_q = self.decode_code(indices)
return z_q, indices
def vq2emb(self, vq, out_proj=True):
emb = self.decode_code(vq)
if out_proj:
emb = self.out_project(emb)
return emb
def latent2dist(self, latents):
encodings = rearrange(latents, "b d t -> (b t) d")
codebook = self.codebook.weight
# L2 normalize encodings and codebook
if self.use_l2_normlize:
encodings = F.normalize(encodings)
codebook = F.normalize(codebook)
# Compute euclidean distance between encodings and codebook,
# if use_l2_normlize is True, the distance is equal to cosine distance
dist = (
encodings.pow(2).sum(1, keepdim=True)
- 2 * encodings @ codebook.t()
+ codebook.pow(2).sum(1, keepdim=True).t()
) # (b*t, k)
indices = rearrange((-dist).max(1)[1], "(b t) -> b t", b=latents.size(0))
dist = rearrange(dist, "(b t) k -> b t k", b=latents.size(0))
z_q = self.decode_code(indices)
return -dist, indices, z_q

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# 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.
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
from einops import rearrange
from torch.nn.utils import weight_norm
def WNConv1d(*args, **kwargs):
return weight_norm(nn.Conv1d(*args, **kwargs))
def WNConvTranspose1d(*args, **kwargs):
return weight_norm(nn.ConvTranspose1d(*args, **kwargs))
class LookupFreeQuantize(nn.Module):
def __init__(
self,
input_dim,
codebook_size,
codebook_dim,
):
super().__init__()
self.input_dim = input_dim
self.codebook_size = codebook_size
self.codebook_dim = codebook_dim
assert 2**codebook_dim == codebook_size
if self.input_dim != self.codebook_dim:
self.in_project = WNConv1d(self.input_dim, self.codebook_dim, kernel_size=1)
self.out_project = WNConv1d(
self.codebook_dim, self.input_dim, kernel_size=1
)
else:
self.in_project = nn.Identity()
self.out_project = nn.Identity()
def forward(self, z):
z_e = self.in_project(z)
z_e = F.sigmoid(z_e)
z_q = z_e + (torch.round(z_e) - z_e).detach()
z_q = self.out_project(z_q)
commit_loss = torch.zeros(z.shape[0], device=z.device)
codebook_loss = torch.zeros(z.shape[0], device=z.device)
bits = (
2
** torch.arange(self.codebook_dim, device=z.device)
.unsqueeze(0)
.unsqueeze(-1)
.long()
) # (1, d, 1)
indices = (torch.round(z_e.clone().detach()).long() * bits).sum(1).long()
return z_q, commit_loss, codebook_loss, indices, z_e
def vq2emb(self, vq, out_proj=True):
emb = torch.zeros(
vq.shape[0], self.codebook_dim, vq.shape[-1], device=vq.device
) # (B, d, T)
for i in range(self.codebook_dim):
emb[:, i, :] = (vq % 2).float()
vq = vq // 2
if out_proj:
emb = self.out_project(emb)
return emb

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# 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 Union
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
from einops import rearrange
from torch.nn.utils import weight_norm
from indextts.utils.maskgct.models.codec.amphion_codec.quantize.factorized_vector_quantize import (
FactorizedVectorQuantize,
)
from indextts.utils.maskgct.models.codec.amphion_codec.quantize.vector_quantize import VectorQuantize
from indextts.utils.maskgct.models.codec.amphion_codec.quantize.lookup_free_quantize import LookupFreeQuantize
class ResidualVQ(nn.Module):
"""
Introduced in SoundStream: An end2end neural audio codec
https://arxiv.org/abs/2107.03312
"""
def __init__(
self,
input_dim: int = 256,
num_quantizers: int = 8,
codebook_size: int = 1024,
codebook_dim: int = 256,
quantizer_type: str = "vq", # "vq" or "fvq" or "lfq"
quantizer_dropout: float = 0.5,
**kwargs,
):
super().__init__()
self.input_dim = input_dim
self.num_quantizers = num_quantizers
self.codebook_size = codebook_size
self.codebook_dim = codebook_dim
self.quantizer_type = quantizer_type
self.quantizer_dropout = quantizer_dropout
if quantizer_type == "vq":
VQ = VectorQuantize
elif quantizer_type == "fvq":
VQ = FactorizedVectorQuantize
elif quantizer_type == "lfq":
VQ = LookupFreeQuantize
else:
raise ValueError(f"Unknown quantizer type {quantizer_type}")
self.quantizers = nn.ModuleList(
[
VQ(
input_dim=input_dim,
codebook_size=codebook_size,
codebook_dim=codebook_dim,
**kwargs,
)
for _ in range(num_quantizers)
]
)
def forward(self, z, n_quantizers: int = None):
"""
Parameters
----------
z : Tensor[B x D x T]
n_quantizers : int, optional
No. of quantizers to use
(n_quantizers < self.n_codebooks ex: for quantizer dropout)
Note: if `self.quantizer_dropout` is True, this argument is ignored
when in training mode, and a random number of quantizers is used.
Returns
-------
"quantized_out" : Tensor[B x D x T]
Quantized continuous representation of input
"all_indices" : Tensor[N x B x T]
Codebook indices for each codebook
(quantized discrete representation of input)
"all_commit_losses" : Tensor[N]
"all_codebook_losses" : Tensor[N]
"all_quantized" : Tensor[N x B x D x T]
"""
quantized_out = 0.0
residual = z
all_commit_losses = []
all_codebook_losses = []
all_indices = []
all_quantized = []
if n_quantizers is None:
n_quantizers = self.num_quantizers
if self.training:
n_quantizers = torch.ones((z.shape[0],)) * self.num_quantizers + 1
dropout = torch.randint(1, self.num_quantizers + 1, (z.shape[0],))
n_dropout = int(z.shape[0] * self.quantizer_dropout)
n_quantizers[:n_dropout] = dropout[:n_dropout]
n_quantizers = n_quantizers.to(z.device)
for i, quantizer in enumerate(self.quantizers):
if self.training is False and i >= n_quantizers:
break
z_q_i, commit_loss_i, codebook_loss_i, indices_i, z_e_i = quantizer(
residual
)
# Create mask to apply quantizer dropout
mask = (
torch.full((z.shape[0],), fill_value=i, device=z.device) < n_quantizers
)
quantized_out = quantized_out + z_q_i * mask[:, None, None]
residual = residual - z_q_i
commit_loss_i = (commit_loss_i * mask).mean()
codebook_loss_i = (codebook_loss_i * mask).mean()
all_commit_losses.append(commit_loss_i)
all_codebook_losses.append(codebook_loss_i)
all_indices.append(indices_i)
all_quantized.append(z_q_i)
all_commit_losses, all_codebook_losses, all_indices, all_quantized = map(
torch.stack,
(all_commit_losses, all_codebook_losses, all_indices, all_quantized),
)
return (
quantized_out,
all_indices,
all_commit_losses,
all_codebook_losses,
all_quantized,
)
def vq2emb(self, vq, n_quantizers=None):
quantized_out = 0.0
if n_quantizers is None:
n_quantizers = self.num_quantizers
for idx, quantizer in enumerate(self.quantizers):
if idx >= n_quantizers:
break
quantized_out += quantizer.vq2emb(vq[idx])
return quantized_out
def latent2dist(self, z, n_quantizers=None):
quantized_out = 0.0
residual = z
all_dists = []
all_indices = []
if n_quantizers is None:
n_quantizers = self.num_quantizers
for i, quantizer in enumerate(self.quantizers):
if self.training is False and i >= n_quantizers:
break
dist_i, indices_i, z_q_i = quantizer.latent2dist(residual)
all_dists.append(dist_i)
all_indices.append(indices_i)
quantized_out = quantized_out + z_q_i
residual = residual - z_q_i
all_dists = torch.stack(all_dists)
all_indices = torch.stack(all_indices)
return all_dists, all_indices

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# 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.
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
from einops import rearrange, repeat
from torch.nn.utils import weight_norm
def WNConv1d(*args, **kwargs):
return weight_norm(nn.Conv1d(*args, **kwargs))
def WNConvTranspose1d(*args, **kwargs):
return weight_norm(nn.ConvTranspose1d(*args, **kwargs))
def l2norm(t):
return F.normalize(t, p=2, dim=-1)
def ema_inplace(moving_avg, new, decay):
moving_avg.data.mul_(decay).add_(new, alpha=(1 - decay))
def laplace_smoothing(x, n_categories, eps=1e-5):
return (x + eps) / (x.sum() + n_categories * eps)
def sample_vectors(samples, num):
num_samples, device = samples.shape[0], samples.device
if num_samples >= num:
indices = torch.randperm(num_samples, device=device)[:num]
else:
indices = torch.randint(0, num_samples, (num,), device=device)
return samples[indices]
def kmeans(samples, num_clusters, num_iters=10, use_cosine_sim=False):
dim, dtype, device = samples.shape[-1], samples.dtype, samples.device
means = sample_vectors(samples, num_clusters)
for _ in range(num_iters):
if use_cosine_sim:
dists = samples @ means.t()
else:
diffs = rearrange(samples, "n d -> n () d") - rearrange(
means, "c d -> () c d"
)
dists = -(diffs**2).sum(dim=-1)
buckets = dists.max(dim=-1).indices
bins = torch.bincount(buckets, minlength=num_clusters)
zero_mask = bins == 0
bins_min_clamped = bins.masked_fill(zero_mask, 1)
new_means = buckets.new_zeros(num_clusters, dim, dtype=dtype)
new_means.scatter_add_(0, repeat(buckets, "n -> n d", d=dim), samples)
new_means = new_means / bins_min_clamped[..., None]
if use_cosine_sim:
new_means = l2norm(new_means)
means = torch.where(zero_mask[..., None], means, new_means)
return means, bins
class EuclideanCodebook(nn.Module):
def __init__(
self,
dim,
codebook_size,
kmeans_init=False,
kmeans_iters=10,
decay=0.8,
eps=1e-5,
threshold_ema_dead_code=2,
weight_init=False,
):
super().__init__()
self.decay = decay
init_fn = torch.randn if not weight_init else torch.zeros
embed = init_fn(codebook_size, dim)
if weight_init:
nn.init.uniform_(embed, -1 / codebook_size, 1 / codebook_size)
self.codebook_size = codebook_size
self.kmeans_iters = kmeans_iters
self.eps = eps
self.threshold_ema_dead_code = threshold_ema_dead_code
self.register_buffer(
"initted", torch.Tensor([not kmeans_init])
) # if kmeans_init is True, then initted is False; otherwise, initted is True
self.register_buffer("cluster_size", torch.zeros(codebook_size))
self.register_buffer("embed", embed)
self.register_buffer("embed_avg", embed.clone())
def init_embed_(self, data):
embed, cluster_size = kmeans(data, self.codebook_size, self.kmeans_iters)
self.embed.data.copy_(embed)
self.embed_avg.data.copy_(embed)
self.cluster_size.data.copy_(cluster_size)
self.initted.data.copy_(torch.Tensor([True]))
def replace(self, samples, mask):
modified_codebook = torch.where(
mask[..., None], sample_vectors(samples, self.codebook_size), self.embed
)
self.embed.data.copy_(modified_codebook)
def expire_codes_(self, batch_samples):
if self.threshold_ema_dead_code == 0:
return
expired_codes = self.cluster_size < self.threshold_ema_dead_code
if not torch.any(expired_codes):
return
batch_samples = rearrange(batch_samples, "... d -> (...) d")
self.replace(batch_samples, mask=expired_codes)
def forward(self, x):
shape, dtype = x.shape, x.dtype
flatten = rearrange(x, "... d -> (...) d")
embed = self.embed.t() # (codebook_size, dim) -> (dim, codebook_size)
if not self.initted:
self.init_embed_(flatten)
dist = -(
flatten.pow(2).sum(1, keepdim=True)
- 2 * flatten @ embed
+ embed.pow(2).sum(0, keepdim=True)
)
embed_ind = dist.max(dim=-1).indices
embed_onehot = F.one_hot(embed_ind, self.codebook_size).type(dtype)
embed_ind = embed_ind.view(*shape[:-1])
quantize = F.embedding(embed_ind, self.embed)
if self.training:
ema_inplace(self.cluster_size, embed_onehot.sum(0), self.decay)
embed_sum = (
flatten.t() @ embed_onehot
) # (dim, ...) @ (..., codebook_size) -> (dim, codebook_size)
ema_inplace(self.embed_avg, embed_sum.t(), self.decay)
cluster_size = (
laplace_smoothing(self.cluster_size, self.codebook_size, self.eps)
* self.cluster_size.sum()
)
embed_normalized = self.embed_avg / cluster_size.unsqueeze(1)
self.embed.data.copy_(embed_normalized)
self.expire_codes_(x)
return quantize, embed_ind
def vq2emb(self, vq):
quantize = F.embedding(vq, self.embed)
return quantize
def latent2dist(self, x):
shape, dtype = x.shape, x.dtype
flatten = rearrange(x, "... d -> (...) d")
embed = self.embed.t() # (codebook_size, dim) -> (dim, codebook_size)
if not self.initted:
self.init_embed_(flatten)
dist = -(
flatten.pow(2).sum(1, keepdim=True)
- 2 * flatten @ embed
+ embed.pow(2).sum(0, keepdim=True)
)
embed_ind = dist.max(dim=-1).indices
embed_ind = embed_ind.view(*shape[:-1])
quantize = F.embedding(embed_ind, self.embed)
dist = dist.view(*shape[:-1], -1)
return dist, embed_ind, quantize
class SimpleCodebook(nn.Module):
def __init__(
self,
dim,
codebook_size,
use_l2_normlize=False,
):
super().__init__()
self.dim = dim
self.codebook_size = codebook_size
self.use_l2_normlize = use_l2_normlize
self.embed = nn.Embedding(self.codebook_size, self.dim)
def forward(self, x):
shape, dtype = x.shape, x.dtype
flatten = rearrange(x, "... d -> (...) d")
embed = self.embed.weight.t() # (codebook_size, dim) -> (dim, codebook_size)
if self.use_l2_normlize:
flatten = F.normalize(flatten)
embed = F.normalize(embed)
dist = -(
flatten.pow(2).sum(1, keepdim=True)
- 2 * flatten @ embed
+ embed.pow(2).sum(0, keepdim=True)
)
embed_ind = dist.max(dim=-1).indices
embed_ind = embed_ind.view(*shape[:-1])
quantize = F.embedding(embed_ind, self.embed)
return quantize, embed_ind
def vq2emb(self, vq):
quantize = F.embedding(vq, self.embed.weight)
return quantize
def latent2dist(self, x):
shape, dtype = x.shape, x.dtype
flatten = rearrange(x, "... d -> (...) d")
embed = self.embed.weight.t() # (codebook_size, dim) -> (dim, codebook_size)
if self.use_l2_normlize:
flatten = F.normalize(flatten)
embed = F.normalize(embed)
dist = -(
flatten.pow(2).sum(1, keepdim=True)
- 2 * flatten @ embed
+ embed.pow(2).sum(0, keepdim=True)
)
embed_ind = dist.max(dim=-1).indices
embed_ind = embed_ind.view(*shape[:-1])
quantize = F.embedding(embed_ind, self.embed)
dist = dist.view(*shape[:-1], -1)
return dist, embed_ind, quantize
class VectorQuantize(nn.Module):
"""Vector quantization and factorized vecotor quantization implementation
Args:
input_dim (int): Dimension of input.
codebook_size (int): Codebook size.
codebook_dim (int): Codebook dimension. We suggest use codebook_dim = input_dim
if use codebook_type == "euclidean", otherwise, if you want to use
factorized vector quantization, use codebook_dim as small number (e.g. 8 or 32).
commitment (float): Weight for commitment loss.
use_l2_normlize (bool): Whether to use l2 normlized codes for factorized vecotor quantization,
we suggest use it as True if you want to use factorized vector quantization
kmeans_init (bool): Whether to use kmeans to initialize the codebooks.
kmeans_iters (int): Number of iterations used for kmeans initialization.
decay (float): Decay for exponential moving average over the codebooks.
epsilon (float): Epsilon value for numerical stability.
threshold_ema_dead_code (int): Threshold for dead code expiration. Replace any codes
that have an exponential moving average cluster size less than the specified threshold with
randomly selected vector from the current batch.
"""
def __init__(
self,
input_dim,
codebook_size,
codebook_dim,
commitment=0.005,
codebook_loss_weight=1.0,
use_l2_normlize=False,
codebook_type="euclidean", # "euclidean" or "simple"
kmeans_init=False,
kmeans_iters=10,
decay=0.8,
eps=1e-5,
threshold_ema_dead_code=2,
weight_init=False,
):
super().__init__()
self.input_dim = input_dim
self.codebook_size = codebook_size
self.codebook_dim = codebook_dim
self.commitment = commitment
self.codebook_loss_weight = codebook_loss_weight
self.use_l2_normlize = use_l2_normlize
self.codebook_type = codebook_type
self.kmeans_init = kmeans_init
self.kmeans_iters = kmeans_iters
self.decay = decay
self.eps = eps
self.threshold_ema_dead_code = threshold_ema_dead_code
self.weight_init = weight_init
if self.input_dim != self.codebook_dim:
self.in_project = WNConv1d(self.input_dim, self.codebook_dim, kernel_size=1)
self.out_project = WNConv1d(
self.codebook_dim, self.input_dim, kernel_size=1
)
else:
self.in_project = nn.Identity()
self.out_project = nn.Identity()
if self.codebook_type == "euclidean":
self.codebook = EuclideanCodebook(
self.codebook_dim,
codebook_size=self.codebook_size,
kmeans_init=self.kmeans_init,
kmeans_iters=self.kmeans_iters,
decay=self.decay,
eps=self.eps,
threshold_ema_dead_code=self.threshold_ema_dead_code,
weight_init=self.weight_init,
)
elif self.codebook_type == "simple":
self.codebook = SimpleCodebook(
self.codebook_dim,
codebook_size=self.codebook_size,
use_l2_normlize=self.use_l2_normlize,
)
else:
raise NotImplementedError(
f"codebook_type {self.codebook_type} is not implemented!"
)
def forward(self, z):
"""
Parameters
----------
z: torch.Tensor[B x D x T]
Returns
-------
z_q: torch.Tensor[B x D x T]
Quantized continuous representation of input
commit_loss: Tensor[B]
Commitment loss to train encoder to predict vectors closer to codebook entries
codebook_loss: Tensor[B]
Codebook loss to update the codebook
indices: torch.Tensor[B x T]
Codebook indices (quantized discrete representation of input)
z_e: torch.Tensor[B x D x T]
Projected latents (continuous representation of input before quantization)
"""
# Factorized codes project input into low-dimensional space if self.input_dim != self.codebook_dim
z_e = self.in_project(z)
z_q, indices = self.decode_latents(z_e)
# Compute commitment loss and codebook loss
if self.training:
commit_loss = (
F.mse_loss(z_e, z_q.detach(), reduction="none").mean([1, 2])
* self.commitment
)
codebook_loss = (
F.mse_loss(z_q, z_e.detach(), reduction="none").mean([1, 2])
* self.codebook_loss_weight
)
else:
commit_loss = torch.zeros(z.shape[0], device=z.device)
codebook_loss = torch.zeros(z.shape[0], device=z.device)
z_q = z_e + (z_q - z_e).detach()
z_q = self.out_project(z_q)
return z_q, commit_loss, codebook_loss, indices, z_e
def decode_latents(self, latents):
encodings = rearrange(latents, "b d t -> b t d")
z_q, indices = self.codebook(encodings)
z_q = z_q.transpose(1, 2)
return z_q, indices
def vq2emb(self, vq, out_proj=True):
emb = self.codebook.vq2emb(vq)
emb = emb.transpose(1, 2)
if out_proj:
emb = self.out_project(emb)
return emb
def latent2dist(self, latents):
latents = rearrange(latents, "b d t -> b t d")
dist, embed_ind, quantize = self.codebook.latent2dist(latents)
return dist, embed_ind, quantize.transpose(1, 2)

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# 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) · 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, :]