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Running
on
Zero
from abc import ABC | |
import torch | |
import torch.nn.functional as F | |
from modules.diffusion_transformer import DiT | |
from modules.commons import sequence_mask | |
from tqdm import tqdm | |
class BASECFM(torch.nn.Module, ABC): | |
def __init__( | |
self, | |
args, | |
): | |
super().__init__() | |
self.sigma_min = 1e-6 | |
self.estimator = None | |
self.in_channels = args.DiT.in_channels | |
self.criterion = torch.nn.MSELoss() if args.reg_loss_type == "l2" else torch.nn.L1Loss() | |
if hasattr(args.DiT, 'zero_prompt_speech_token'): | |
self.zero_prompt_speech_token = args.DiT.zero_prompt_speech_token | |
else: | |
self.zero_prompt_speech_token = False | |
def inference(self, mu, x_lens, prompt, style, f0, n_timesteps, temperature=1.0, inference_cfg_rate=0.5): | |
"""Forward diffusion | |
Args: | |
mu (torch.Tensor): output of encoder | |
shape: (batch_size, n_feats, mel_timesteps) | |
mask (torch.Tensor): output_mask | |
shape: (batch_size, 1, mel_timesteps) | |
n_timesteps (int): number of diffusion steps | |
temperature (float, optional): temperature for scaling noise. Defaults to 1.0. | |
spks (torch.Tensor, optional): speaker ids. Defaults to None. | |
shape: (batch_size, spk_emb_dim) | |
cond: Not used but kept for future purposes | |
Returns: | |
sample: generated mel-spectrogram | |
shape: (batch_size, n_feats, mel_timesteps) | |
""" | |
B, T = mu.size(0), mu.size(1) | |
z = torch.randn([B, self.in_channels, T], device=mu.device) * temperature | |
t_span = torch.linspace(0, 1, n_timesteps + 1, device=mu.device) | |
return self.solve_euler(z, x_lens, prompt, mu, style, f0, t_span, inference_cfg_rate) | |
def solve_euler(self, x, x_lens, prompt, mu, style, f0, t_span, inference_cfg_rate=0.5): | |
""" | |
Fixed euler solver for ODEs. | |
Args: | |
x (torch.Tensor): random noise | |
t_span (torch.Tensor): n_timesteps interpolated | |
shape: (n_timesteps + 1,) | |
mu (torch.Tensor): output of encoder | |
shape: (batch_size, n_feats, mel_timesteps) | |
mask (torch.Tensor): output_mask | |
shape: (batch_size, 1, mel_timesteps) | |
spks (torch.Tensor, optional): speaker ids. Defaults to None. | |
shape: (batch_size, spk_emb_dim) | |
cond: Not used but kept for future purposes | |
""" | |
t, _, dt = t_span[0], t_span[-1], t_span[1] - t_span[0] | |
# I am storing this because I can later plot it by putting a debugger here and saving it to a file | |
# Or in future might add like a return_all_steps flag | |
sol = [] | |
# apply prompt | |
prompt_len = prompt.size(-1) | |
prompt_x = torch.zeros_like(x) | |
prompt_x[..., :prompt_len] = prompt[..., :prompt_len] | |
x[..., :prompt_len] = 0 | |
if self.zero_prompt_speech_token: | |
mu[..., :prompt_len] = 0 | |
for step in tqdm(range(1, len(t_span))): | |
dphi_dt = self.estimator(x, prompt_x, x_lens, t.unsqueeze(0), style, mu, f0) | |
# Classifier-Free Guidance inference introduced in VoiceBox | |
if inference_cfg_rate > 0: | |
cfg_dphi_dt = self.estimator( | |
x, torch.zeros_like(prompt_x), x_lens, t.unsqueeze(0), | |
torch.zeros_like(style), | |
torch.zeros_like(mu), None | |
) | |
dphi_dt = ((1.0 + inference_cfg_rate) * dphi_dt - | |
inference_cfg_rate * cfg_dphi_dt) | |
x = x + dt * dphi_dt | |
t = t + dt | |
sol.append(x) | |
if step < len(t_span) - 1: | |
dt = t_span[step + 1] - t | |
x[:, :, :prompt_len] = 0 | |
return sol[-1] | |
def forward(self, x1, x_lens, prompt_lens, mu, style, f0=None): | |
"""Computes diffusion loss | |
Args: | |
x1 (torch.Tensor): Target | |
shape: (batch_size, n_feats, mel_timesteps) | |
mask (torch.Tensor): target mask | |
shape: (batch_size, 1, mel_timesteps) | |
mu (torch.Tensor): output of encoder | |
shape: (batch_size, n_feats, mel_timesteps) | |
spks (torch.Tensor, optional): speaker embedding. Defaults to None. | |
shape: (batch_size, spk_emb_dim) | |
Returns: | |
loss: conditional flow matching loss | |
y: conditional flow | |
shape: (batch_size, n_feats, mel_timesteps) | |
""" | |
b, _, t = x1.shape | |
# random timestep | |
t = torch.rand([b, 1, 1], device=mu.device, dtype=x1.dtype) | |
# sample noise p(x_0) | |
z = torch.randn_like(x1) | |
y = (1 - (1 - self.sigma_min) * t) * z + t * x1 | |
u = x1 - (1 - self.sigma_min) * z | |
prompt = torch.zeros_like(x1) | |
for bib in range(b): | |
prompt[bib, :, :prompt_lens[bib]] = x1[bib, :, :prompt_lens[bib]] | |
# range covered by prompt are set to 0 | |
y[bib, :, :prompt_lens[bib]] = 0 | |
if self.zero_prompt_speech_token: | |
mu[bib, :, :prompt_lens[bib]] = 0 | |
estimator_out = self.estimator(y, prompt, x_lens, t.squeeze(), style, mu, f0) | |
loss = 0 | |
for bib in range(b): | |
loss += self.criterion(estimator_out[bib, :, prompt_lens[bib]:x_lens[bib]], u[bib, :, prompt_lens[bib]:x_lens[bib]]) | |
loss /= b | |
return loss, y | |
class CFM(BASECFM): | |
def __init__(self, args): | |
super().__init__( | |
args | |
) | |
if args.dit_type == "DiT": | |
self.estimator = DiT(args) | |
else: | |
raise NotImplementedError(f"Unknown diffusion type {args.dit_type}") | |