WaveGen / src /wavegen_v_spec /model /modules.py
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# Diffusers-derived portions: Attention and AttnProcessor, adapted via F5-TTS from:
# https://github.com/huggingface/diffusers/blob/main/src/diffusers/models/attention_processor.py
# https://github.com/huggingface/diffusers/blob/main/src/diffusers/models/attention.py
# These are modified adaptations for the audio/text model interfaces in this
# file. The following copyright and license notice applies to those portions
# only; other portions retain their respective licenses and attributions.
#
# Copyright 2024 The HuggingFace Team. 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.
#
# A copy is included at docs/licenses/Apache-2.0.txt in the WaveGen package source.
# See docs/THIRD_PARTY_NOTICES.md for the scope and provenance of these portions.
"""
ein notation:
b - batch
n - sequence
nt - text sequence
nw - raw wave length
d - dimension
"""
# ruff: noqa: F722 F821
from __future__ import annotations
import math
from typing import Optional
import torch
import torch.nn.functional as F
import torchaudio
from torch import nn
from x_transformers.x_transformers import apply_rotary_pos_emb
from wavegen_v_spec.model.utils import is_package_available, lens_to_mask
# sinusoidal position embedding
class SinusPositionEmbedding(nn.Module):
def __init__(self, dim):
super().__init__()
self.dim = dim
def forward(self, x, scale=1000):
device = x.device
half_dim = self.dim // 2
emb = math.log(10000) / (half_dim - 1)
emb = torch.exp(torch.arange(half_dim, device=device).float() * -emb)
emb = scale * x.unsqueeze(1) * emb.unsqueeze(0)
emb = torch.cat((emb.sin(), emb.cos()), dim=-1)
return emb
# convolutional position embedding
class ConvPositionEmbedding(nn.Module):
def __init__(self, dim, kernel_size=31, groups=16):
super().__init__()
assert kernel_size % 2 != 0
self.conv1d = nn.Sequential(
nn.Conv1d(dim, dim, kernel_size, groups=groups, padding=kernel_size // 2),
nn.Mish(),
nn.Conv1d(dim, dim, kernel_size, groups=groups, padding=kernel_size // 2),
nn.Mish(),
)
self.layer_need_mask_idx = [i for i, layer in enumerate(self.conv1d) if isinstance(layer, nn.Conv1d)]
def forward(self, x: float["b n d"], mask: bool["b n"] | None = None):
if mask is not None:
mask = mask.unsqueeze(1) # [B 1 N]
x = x.permute(0, 2, 1) # [B D N]
if mask is not None:
x = x.masked_fill(~mask, 0.0)
for i, block in enumerate(self.conv1d):
x = block(x)
if mask is not None and i in self.layer_need_mask_idx:
x = x.masked_fill(~mask, 0.0)
x = x.permute(0, 2, 1) # [B N D]
return x
# rotary positional embedding related
def precompute_freqs_cis(dim: int, end: int, theta: float = 10000.0, theta_rescale_factor=1.0):
# proposed by reddit user bloc97, to rescale rotary embeddings to longer sequence length without fine-tuning
# has some connection to NTK literature
# https://www.reddit.com/r/LocalLLaMA/comments/14lz7j5/ntkaware_scaled_rope_allows_llama_models_to_have/
# https://github.com/lucidrains/rotary-embedding-torch/blob/main/rotary_embedding_torch/rotary_embedding_torch.py
theta *= theta_rescale_factor ** (dim / (dim - 2))
freqs = 1.0 / (theta ** (torch.arange(0, dim, 2)[: (dim // 2)].float() / dim))
t = torch.arange(end, device=freqs.device) # type: ignore
freqs = torch.outer(t, freqs).float() # type: ignore
freqs_cos = torch.cos(freqs) # real part
freqs_sin = torch.sin(freqs) # imaginary part
return torch.cat([freqs_cos, freqs_sin], dim=-1)
def get_pos_embed_indices(start, length, max_pos, scale=1.0):
# length = length if isinstance(length, int) else length.max()
scale = scale * torch.ones_like(start, dtype=torch.float32) # in case scale is a scalar
pos = (
start.unsqueeze(1)
+ (torch.arange(length, device=start.device, dtype=torch.float32).unsqueeze(0) * scale.unsqueeze(1)).long()
)
# avoid extra long error.
pos = torch.where(pos < max_pos, pos, max_pos - 1)
return pos
# Global Response Normalization layer (Instance Normalization ?)
class GRN(nn.Module):
def __init__(self, dim):
super().__init__()
self.gamma = nn.Parameter(torch.zeros(1, 1, dim))
self.beta = nn.Parameter(torch.zeros(1, 1, dim))
def forward(self, x):
Gx = torch.norm(x, p=2, dim=1, keepdim=True)
Nx = Gx / (Gx.mean(dim=-1, keepdim=True) + 1e-6)
return self.gamma * (x * Nx) + self.beta + x
# ConvNeXt-V2 Block https://github.com/facebookresearch/ConvNeXt-V2/blob/main/models/convnextv2.py
# ref: https://github.com/bfs18/e2_tts/blob/main/rfwave/modules.py#L108
class ConvNeXtV2Block(nn.Module):
def __init__(
self,
dim: int,
intermediate_dim: int,
dilation: int = 1,
):
super().__init__()
padding = (dilation * (7 - 1)) // 2
self.dwconv = nn.Conv1d(
dim, dim, kernel_size=7, padding=padding, groups=dim, dilation=dilation
) # depthwise conv
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.grn = GRN(intermediate_dim)
self.pwconv2 = nn.Linear(intermediate_dim, dim)
def forward(self, x: torch.Tensor) -> torch.Tensor:
residual = x
x = x.transpose(1, 2) # b n d -> b d n
x = self.dwconv(x)
x = x.transpose(1, 2) # b d n -> b n d
x = self.norm(x)
x = self.pwconv1(x)
x = self.act(x)
x = self.grn(x)
x = self.pwconv2(x)
return residual + x
# RMSNorm
class RMSNorm(nn.Module):
def __init__(self, dim: int, eps: float):
super().__init__()
self.eps = eps
self.weight = nn.Parameter(torch.ones(dim))
# Probe the operator directly. Parsing ``torch.__version__[:3]``
# misclassifies versions such as 2.11 as 2.1 and incorrectly selects
# the manual fallback even though native RMSNorm is available.
self.native_rms_norm = hasattr(F, "rms_norm")
def forward(self, x):
if self.native_rms_norm:
# AMP keeps the master parameter in fp32 while q/k activations
# are bf16. Match their dtypes for native/fused dispatch while
# retaining gradient accumulation into the fp32 master weight.
weight = self.weight
if weight.dtype != x.dtype:
weight = weight.to(dtype=x.dtype)
return F.rms_norm(
x,
normalized_shape=(x.shape[-1],),
weight=weight,
eps=self.eps,
)
input_dtype = x.dtype
variance = x.to(torch.float32).pow(2).mean(-1, keepdim=True)
x = x * torch.rsqrt(variance + self.eps)
return (x * self.weight).to(dtype=input_dtype)
# AdaLayerNorm
# return with modulated x for attn input, and params for later mlp modulation
class AdaLayerNorm(nn.Module):
def __init__(self, dim):
super().__init__()
self.silu = nn.SiLU()
self.linear = nn.Linear(dim, dim * 6)
self.norm = nn.LayerNorm(dim, elementwise_affine=False, eps=1e-6)
def forward(self, x, emb=None):
emb = self.linear(self.silu(emb))
shift_msa, scale_msa, gate_msa, shift_mlp, scale_mlp, gate_mlp = torch.chunk(emb, 6, dim=1)
x = self.norm(x) * (1 + scale_msa[:, None]) + shift_msa[:, None]
return x, gate_msa, shift_mlp, scale_mlp, gate_mlp
# AdaLayerNorm for final layer
# return only with modulated x for attn input, cuz no more mlp modulation
class AdaLayerNorm_Final(nn.Module):
def __init__(self, dim):
super().__init__()
self.silu = nn.SiLU()
self.linear = nn.Linear(dim, dim * 2)
self.norm = nn.LayerNorm(dim, elementwise_affine=False, eps=1e-6)
def forward(self, x, emb):
emb = self.linear(self.silu(emb))
scale, shift = torch.chunk(emb, 2, dim=1)
x = self.norm(x) * (1 + scale)[:, None, :] + shift[:, None, :]
return x
# FeedForward
class FeedForward(nn.Module):
def __init__(self, dim, dim_out=None, mult=4, dropout=0.0, approximate: str = "none"):
super().__init__()
inner_dim = int(dim * mult)
dim_out = dim_out if dim_out is not None else dim
activation = nn.GELU(approximate=approximate)
project_in = nn.Sequential(nn.Linear(dim, inner_dim), activation)
self.ff = nn.Sequential(project_in, nn.Dropout(dropout), nn.Linear(inner_dim, dim_out))
def forward(self, x):
return self.ff(x)
# Attention with possible joint part
# modified from diffusers/src/diffusers/models/attention_processor.py
class Attention(nn.Module):
def __init__(
self,
processor: AttnProcessor,
dim: int,
heads: int = 8,
dim_head: int = 64,
dropout: float = 0.0,
context_dim: Optional[int] = None, # if not None -> joint attention
context_pre_only: bool = False,
qk_norm: Optional[str] = None,
):
super().__init__()
if not hasattr(F, "scaled_dot_product_attention"):
raise ImportError("Attention equires PyTorch 2.0, to use it, please upgrade PyTorch to 2.0.")
self.processor = processor
self.dim = dim
self.heads = heads
self.inner_dim = dim_head * heads
self.dropout = dropout
self.context_dim = context_dim
self.context_pre_only = context_pre_only
self.to_q = nn.Linear(dim, self.inner_dim)
self.to_k = nn.Linear(dim, self.inner_dim)
self.to_v = nn.Linear(dim, self.inner_dim)
if qk_norm is None:
self.q_norm = None
self.k_norm = None
elif qk_norm == "rms_norm":
self.q_norm = RMSNorm(dim_head, eps=1e-6)
self.k_norm = RMSNorm(dim_head, eps=1e-6)
else:
raise ValueError(f"Unimplemented qk_norm: {qk_norm}")
if self.context_dim is not None:
self.to_q_c = nn.Linear(context_dim, self.inner_dim)
self.to_k_c = nn.Linear(context_dim, self.inner_dim)
self.to_v_c = nn.Linear(context_dim, self.inner_dim)
if qk_norm is None:
self.c_q_norm = None
self.c_k_norm = None
elif qk_norm == "rms_norm":
self.c_q_norm = RMSNorm(dim_head, eps=1e-6)
self.c_k_norm = RMSNorm(dim_head, eps=1e-6)
self.to_out = nn.ModuleList([])
self.to_out.append(nn.Linear(self.inner_dim, dim))
self.to_out.append(nn.Dropout(dropout))
if self.context_dim is not None and not self.context_pre_only:
self.to_out_c = nn.Linear(self.inner_dim, context_dim)
def forward(
self,
x: float["b n d"], # noised input x
c: float["b n d"] = None, # context c
mask: bool["b n"] | None = None,
rope=None, # rotary position embedding for x
c_rope=None, # rotary position embedding for c
) -> torch.Tensor:
if c is not None:
return self.processor(self, x, c=c, mask=mask, rope=rope, c_rope=c_rope)
else:
return self.processor(self, x, mask=mask, rope=rope)
# Attention processor
if is_package_available("flash_attn"):
from flash_attn import flash_attn_func, flash_attn_varlen_func
from flash_attn.bert_padding import pad_input, unpad_input
class AttnProcessor:
def __init__(
self,
pe_attn_head: int | None = None, # number of attention head to apply rope, None for all
attn_backend: str = "torch", # "torch" or "flash_attn"
attn_mask_enabled: bool = True,
):
if attn_backend == "flash_attn":
assert is_package_available("flash_attn"), "Please install flash-attn first."
self.pe_attn_head = pe_attn_head
self.attn_backend = attn_backend
self.attn_mask_enabled = attn_mask_enabled
def __call__(
self,
attn: Attention,
x: float["b n d"], # noised input x
mask: bool["b n"] | None = None,
rope=None, # rotary position embedding
) -> torch.FloatTensor:
batch_size = x.shape[0]
# `sample` projections
query = attn.to_q(x)
key = attn.to_k(x)
value = attn.to_v(x)
# attention
inner_dim = key.shape[-1]
head_dim = inner_dim // attn.heads
query = query.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
key = key.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
value = value.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
# qk norm
if attn.q_norm is not None:
query = attn.q_norm(query)
if attn.k_norm is not None:
key = attn.k_norm(key)
# apply rotary position embedding
if rope is not None:
freqs, xpos_scale = rope
q_xpos_scale, k_xpos_scale = (xpos_scale, xpos_scale**-1.0) if xpos_scale is not None else (1.0, 1.0)
if self.pe_attn_head is not None:
pn = self.pe_attn_head
query[:, :pn, :, :] = apply_rotary_pos_emb(query[:, :pn, :, :], freqs, q_xpos_scale)
key[:, :pn, :, :] = apply_rotary_pos_emb(key[:, :pn, :, :], freqs, k_xpos_scale)
else:
query = apply_rotary_pos_emb(query, freqs, q_xpos_scale)
key = apply_rotary_pos_emb(key, freqs, k_xpos_scale)
if self.attn_backend == "torch":
# mask. e.g. inference got a batch with different target durations, mask out the padding
if self.attn_mask_enabled and mask is not None:
attn_mask = mask
attn_mask = attn_mask.unsqueeze(1).unsqueeze(1) # 'b n -> b 1 1 n'
attn_mask = attn_mask.expand(batch_size, attn.heads, query.shape[-2], key.shape[-2])
else:
attn_mask = None
x = F.scaled_dot_product_attention(query, key, value, attn_mask=attn_mask, dropout_p=0.0, is_causal=False)
x = x.transpose(1, 2).reshape(batch_size, -1, attn.heads * head_dim)
elif self.attn_backend == "flash_attn":
query = query.transpose(1, 2) # [b, h, n, d] -> [b, n, h, d]
key = key.transpose(1, 2)
value = value.transpose(1, 2)
if self.attn_mask_enabled and mask is not None:
query, indices, q_cu_seqlens, q_max_seqlen_in_batch, _ = unpad_input(query, mask)
key, _, k_cu_seqlens, k_max_seqlen_in_batch, _ = unpad_input(key, mask)
value, _, _, _, _ = unpad_input(value, mask)
x = flash_attn_varlen_func(
query,
key,
value,
q_cu_seqlens,
k_cu_seqlens,
q_max_seqlen_in_batch,
k_max_seqlen_in_batch,
)
x = pad_input(x, indices, batch_size, q_max_seqlen_in_batch)
x = x.reshape(batch_size, -1, attn.heads * head_dim)
else:
x = flash_attn_func(query, key, value, dropout_p=0.0, causal=False)
x = x.reshape(batch_size, -1, attn.heads * head_dim)
x = x.to(query.dtype)
# linear proj
x = attn.to_out[0](x)
# dropout
x = attn.to_out[1](x)
if mask is not None:
mask = mask.unsqueeze(-1)
x = x.masked_fill(~mask, 0.0)
return x
# Joint Attention processor for MM-DiT
# modified from diffusers/src/diffusers/models/attention_processor.py
# DiT Block
class DiTBlock(nn.Module):
def __init__(
self,
dim,
heads,
dim_head,
ff_mult=4,
dropout=0.1,
qk_norm=None,
pe_attn_head=None,
attn_backend="torch", # "torch" or "flash_attn"
attn_mask_enabled=True,
):
super().__init__()
self.attn_norm = AdaLayerNorm(dim)
self.attn = Attention(
processor=AttnProcessor(
pe_attn_head=pe_attn_head,
attn_backend=attn_backend,
attn_mask_enabled=attn_mask_enabled,
),
dim=dim,
heads=heads,
dim_head=dim_head,
dropout=dropout,
qk_norm=qk_norm,
)
self.ff_norm = nn.LayerNorm(dim, elementwise_affine=False, eps=1e-6)
self.ff = FeedForward(dim=dim, mult=ff_mult, dropout=dropout, approximate="tanh")
def forward(self, x, t, mask=None, rope=None): # x: noised input, t: time embedding
# pre-norm & modulation for attention input
norm, gate_msa, shift_mlp, scale_mlp, gate_mlp = self.attn_norm(x, emb=t)
# attention
attn_output = self.attn(x=norm, mask=mask, rope=rope)
# process attention output for input x
x = x + gate_msa.unsqueeze(1) * attn_output
norm = self.ff_norm(x) * (1 + scale_mlp[:, None]) + shift_mlp[:, None]
ff_output = self.ff(norm)
x = x + gate_mlp.unsqueeze(1) * ff_output
return x
# time step conditioning embedding
class TimestepEmbedding(nn.Module):
def __init__(self, dim, freq_embed_dim=256):
super().__init__()
self.time_embed = SinusPositionEmbedding(freq_embed_dim)
self.time_mlp = nn.Sequential(nn.Linear(freq_embed_dim, dim), nn.SiLU(), nn.Linear(dim, dim))
def forward(self, timestep: float["b"]):
time_hidden = self.time_embed(timestep)
time_hidden = time_hidden.to(timestep.dtype)
time = self.time_mlp(time_hidden) # b d
return time
# auxiliary loss for mel spectrogram
class MelSpectrogramLoss(nn.Module):
"""
General PyTorch implementation of the Multi-Scale Mel Spectrogram Loss from DAC.
Reference: https://github.com/descriptinc/lyrebird-audiotools
"""
def __init__(
self,
sample_rate: int = 24000,
n_mels: List[int] = [5, 10, 20, 40, 80, 160, 320],
window_lengths: List[int] = [32, 64, 128, 256, 512, 1024, 2048],
mel_fmin: List[float] = [0, 0, 0, 0, 0, 0, 0],
mel_fmax: List[Optional[float]] = [None, None, None, None, None, None, None],
pow: float = 1.0,
clamp_eps: float = 1e-5,
weight: float = 1.0,
):
super().__init__()
self.sample_rate = sample_rate
self.weight = weight
self.pow = pow
self.clamp_eps = clamp_eps
assert len(n_mels) == len(window_lengths), "n_mels and window_lengths must have the same length"
self.mel_transforms = nn.ModuleList()
for i, (nm, wl) in enumerate(zip(n_mels, window_lengths)):
fmin = mel_fmin[i] if i < len(mel_fmin) else 0.0
fmax = mel_fmax[i] if i < len(mel_fmax) else None
# DAC default logic: hop_length = window_length // 4
hop_length = wl // 4
transform = torchaudio.transforms.MelSpectrogram(
sample_rate=sample_rate,
n_fft=wl, # using window_length as n_fft usually
win_length=wl,
hop_length=hop_length,
n_mels=nm,
f_min=fmin,
f_max=fmax,
power=1.0, # computing Magnitude Mel (power=1.0) initially
normalized=False,
center=True,
pad_mode="reflect"
)
self.mel_transforms.append(transform)
def forward(
self,
x_pred: torch.Tensor,
x_true: torch.Tensor,
frame_mask: torch.Tensor | None = None,
frame_lengths: torch.Tensor | None = None,
):
"""
Args:
x_pred: [B, T] or [B, 1, T] Estimated Waveform
x_true: [B, T] or [B, 1, T] Ground Truth Waveform
Returns:
Weighted scalar loss
"""
# Ensure correct shape [B, T] for torchaudio, or [B, 1, T] is also fine but usually squeeze
if x_pred.ndim == 3 and x_pred.shape[1] == 1:
x_pred = x_pred.squeeze(1)
if x_true.ndim == 3 and x_true.shape[1] == 1:
x_true = x_true.squeeze(1)
total_loss = x_pred.new_tensor(0.0)
use_mask = frame_mask is not None
if use_mask:
span_starts, span_ends = self._get_span_bounds_from_mask(frame_mask, frame_lengths)
span_starts = span_starts.to(device=x_pred.device)
span_ends = span_ends.to(device=x_pred.device)
for mel_transform in self.mel_transforms:
x_mels = mel_transform(x_pred)
y_mels = mel_transform(x_true)
mel_mask = None
if use_mask:
hop = int(mel_transform.hop_length)
mel_t = x_mels.shape[-1]
mel_mask = torch.zeros(
(x_mels.shape[0], mel_t),
device=x_mels.device,
dtype=torch.bool,
)
for i in range(x_mels.shape[0]):
s = int(span_starts[i].item())
e = int(span_ends[i].item())
if e <= s:
continue
ms = s // hop
me = (e + hop - 1) // hop
ms = max(0, min(ms, mel_t))
me = max(0, min(me, mel_t))
if me > ms:
mel_mask[i, ms:me] = True
if not mel_mask.any():
continue
mel_mask = mel_mask.unsqueeze(1)
# Log Magnitude Loss
# Formula: L1( log10(x^pow + eps), log10(y^pow + eps) )
x_log = x_mels.clamp(min=self.clamp_eps).pow(self.pow).log10()
y_log = y_mels.clamp(min=self.clamp_eps).pow(self.pow).log10()
diff_full = (x_log - y_log).abs()
if mel_mask is None:
diff = diff_full.mean(dim=(1, 2))
else:
diff = []
for i in range(diff_full.shape[0]):
m = mel_mask[i]
if m.any():
diff.append(diff_full[i].masked_select(m).mean())
else:
diff.append(diff_full.new_tensor(0.0))
diff = torch.stack(diff, dim=0)
total_loss += diff.mean()
return total_loss * self.weight
@staticmethod
def _get_span_bounds_from_mask(mask: torch.Tensor, lengths: torch.Tensor | None = None) -> tuple[torch.Tensor, torch.Tensor]:
"""Convert boolean frame mask [B, T] into per-sample [start, end) bounds.
This helper assumes one contiguous masked span per sample (matching current
random-span masking strategy). If a sample has no masked frame, start=end=0.
"""
if mask.dtype != torch.bool:
mask = mask.bool()
bsz, t = mask.shape
device = mask.device
if lengths is None:
lengths = torch.full((bsz,), t, device=device, dtype=torch.long)
else:
lengths = lengths.to(device=device, dtype=torch.long)
starts = torch.zeros((bsz,), device=device, dtype=torch.long)
ends = torch.zeros((bsz,), device=device, dtype=torch.long)
for i in range(bsz):
li = int(lengths[i].item())
row = mask[i, :li]
idx = row.nonzero(as_tuple=False).squeeze(-1)
if idx.numel() == 0:
continue
starts[i] = idx[0]
ends[i] = idx[-1] + 1
return starts, ends
@staticmethod
def _aligned_random_span_mask(
lengths: torch.Tensor,
frac_lengths: torch.Tensor,
align_to: int,
max_length: int | None = None,
) -> torch.Tensor:
"""Sample one contiguous mask span per sample with boundary alignment.
Args:
lengths: [B] valid sequence lengths in model frames.
frac_lengths: [B] desired masked length fraction.
align_to: span start/end alignment in model frames.
max_length: optional mask width. If None, use lengths.max().
Returns:
bool mask with shape [B, max_length].
"""
assert align_to >= 1
device = lengths.device
lengths = lengths.to(dtype=torch.long)
frac_lengths = frac_lengths.to(device=device, dtype=torch.float32)
max_len = int(lengths.max().item()) if max_length is None else int(max_length)
mask = torch.zeros((lengths.shape[0], max_len), device=device, dtype=torch.bool)
for i in range(lengths.shape[0]):
li = int(lengths[i].item())
if li <= 0:
continue
target = int((frac_lengths[i].item() * li))
target = max(1, min(target, li))
span_len = ((target + align_to - 1) // align_to) * align_to
span_len = min(span_len, li)
max_start = li - span_len
if max_start <= 0:
start = 0
else:
candidate = torch.randint(0, max_start + 1, (1,), device=device).item()
start = (candidate // align_to) * align_to
start = min(start, max_start)
end = start + span_len
mask[i, start:end] = True
return mask