Open-Sora/opensora/models/vae/model_utils.py
2024-04-26 07:27:26 +00:00

233 lines
9.9 KiB
Python

import numpy as np
import torch
import torch.nn as nn
# from taming.modules.losses.lpips import LPIPS # need to pip install https://github.com/CompVis/taming-transformers
# from taming.modules.discriminator.model import NLayerDiscriminator, weights_init
from einops import rearrange
"""Stripped version of https://github.com/richzhang/PerceptualSimilarity/tree/master/models"""
## NOTE: not used since we only have 'GN'
# def get_norm_layer(norm_type, dtype):
# if norm_type == 'LN':
# # supply a few args with partial function and pass the rest of the args when this norm_fn is called
# norm_fn = functools.partial(nn.LayerNorm, dtype=dtype)
# elif norm_type == 'GN': #
# norm_fn = functools.partial(nn.GroupNorm, dtype=dtype)
# elif norm_type is None:
# norm_fn = lambda: (lambda x: x)
# else:
# raise NotImplementedError(f'norm_type: {norm_type}')
# return norm_fn
class DiagonalGaussianDistribution(object):
def __init__(
self,
parameters,
deterministic=False,
):
self.parameters = parameters
self.mean, self.logvar = torch.chunk(parameters, 2, dim=1) # SCH: channels dim
self.logvar = torch.clamp(self.logvar, -30.0, 20.0)
self.deterministic = deterministic
self.std = torch.exp(0.5 * self.logvar)
self.var = torch.exp(self.logvar)
if self.deterministic:
self.var = self.std = torch.zeros_like(self.mean).to(device=self.parameters.device, dtype=self.mean.dtype)
def sample(self):
# torch.randn: standard normal distribution
x = self.mean + self.std * torch.randn(self.mean.shape).to(device=self.parameters.device, dtype=self.mean.dtype)
return x
def kl(self, other=None):
if self.deterministic:
return torch.Tensor([0.0])
else:
if other is None: # SCH: assumes other is a standard normal distribution
return 0.5 * torch.sum(torch.pow(self.mean, 2) + self.var - 1.0 - self.logvar, dim=[1, 2, 3, 4])
else:
return 0.5 * torch.sum(
torch.pow(self.mean - other.mean, 2) / other.var
+ self.var / other.var
- 1.0
- self.logvar
+ other.logvar,
dim=[1, 2, 3, 4],
)
def nll(self, sample, dims=[1, 2, 3, 4]): # TODO: what does this do?
if self.deterministic:
return torch.Tensor([0.0])
logtwopi = np.log(2.0 * np.pi)
return 0.5 * torch.sum(logtwopi + self.logvar + torch.pow(sample - self.mean, 2) / self.var, dim=dims)
def mode(self): # SCH: used for vae inference?
return self.mean
class VEA3DLoss(nn.Module):
def __init__(
self,
# disc_start,
logvar_init=0.0,
kl_weight=1.0,
pixelloss_weight=1.0,
perceptual_weight=0.1,
disc_loss="hinge",
):
super().__init__()
assert disc_loss in ["hinge", "vanilla"]
self.kl_weight = kl_weight
self.pixel_weight = pixelloss_weight
self.perceptual_loss = LPIPS().eval()
self.perceptual_weight = perceptual_weight
# output log variance
self.logvar = nn.Parameter(torch.ones(size=()) * logvar_init)
def forward(
self,
inputs,
reconstructions,
posteriors,
# optimizer_idx,
# global_step,
weights=None,
):
rec_loss = torch.abs(inputs.contiguous() - reconstructions.contiguous())
if self.perceptual_weight > 0: # NOTE: need in_channels == 3 in order to use!
assert inputs.size(1) == 3, f"using vgg16 that requires 3 input channels but got {inputs.size(1)}"
# SCH: transform to [(B,T), C, H, W] shape for percetual loss over each frame
B = inputs.shape[0]
inputs = rearrange(inputs, "B C T H W -> (B T) C H W")
reconstructions = rearrange(reconstructions, "B C T H W -> (B T) C H W")
# permutated_input = torch.permute(inputs, (0, 2, 1, 3, 4)) # [B, C, T, H, W] --> [B, T, C, H, W]
# permutated_rec = torch.permute(reconstructions, (0, 2, 1, 3, 4))
# data_shape = permutated_input.size()
# p_loss = self.perceptual_loss(
# permutated_input.reshape(-1, data_shape[-3], data_shape[-2],data_shape[-1]).contiguous(),
# permutated_rec.reshape(-1, data_shape[-3], data_shape[-2],data_shape[-1]).contiguous()
# )
p_loss = self.perceptual_loss(inputs.contiguous(), reconstructions.contiguous())
# SCH: shape back p_loss
# permuted_p_loss = torch.permute(p_loss.reshape(data_shape[0], data_shape[1], 1, 1, 1), (0,2,1,3,4))
# rec_loss = rec_loss + self.perceptual_weight * permuted_p_loss
p_loss = rearrange(p_loss, "(B T) C H W -> B C T H W", B=B)
rec_loss = rec_loss + self.perceptual_weight * p_loss
nll_loss = rec_loss / torch.exp(self.logvar) + self.logvar
weighted_nll_loss = nll_loss
if weights is not None:
weighted_nll_loss = weights * nll_loss
weighted_nll_loss = torch.sum(weighted_nll_loss) / weighted_nll_loss.shape[0]
nll_loss = torch.sum(nll_loss) / nll_loss.shape[0]
kl_loss = posteriors.kl()
kl_loss = torch.sum(kl_loss) / kl_loss.shape[0]
loss = weighted_nll_loss + self.kl_weight * kl_loss # TODO: add discriminator loss later
return loss
class VEA3DLossWithDiscriminator(nn.Module):
def __init__(
self,
# disc_start,
logvar_init=0.0,
kl_weight=1.0,
pixelloss_weight=1.0,
disc_num_layers=3,
disc_in_channels=3,
disc_factor=1.0,
disc_weight=1.0,
perceptual_weight=1.0,
use_actnorm=False,
disc_conditional=False,
disc_loss="hinge",
):
super().__init__()
assert disc_loss in ["hinge", "vanilla"]
self.kl_weight = kl_weight
self.pixel_weight = pixelloss_weight
self.perceptual_loss = LPIPS().eval()
self.perceptual_weight = perceptual_weight
# output log variance
self.logvar = nn.Parameter(torch.ones(size=()) * logvar_init)
# self.discriminator = NLayerDiscriminator(input_nc=disc_in_channels,
# n_layers=disc_num_layers,
# use_actnorm=use_actnorm
# ).apply(weights_init)
# self.discriminator_iter_start = disc_start
# self.disc_loss = hinge_d_loss if disc_loss == "hinge" else vanilla_d_loss
# self.disc_factor = disc_factor
# self.discriminator_weight = disc_weight
# self.disc_conditional = disc_conditional
# TODO: for discriminator
# def calculate_adaptive_weight(self, nll_loss, g_loss, last_layer=None):
# if last_layer is not None:
# nll_grads = torch.autograd.grad(nll_loss, last_layer, retain_graph=True)[0]
# g_grads = torch.autograd.grad(g_loss, last_layer, retain_graph=True)[0]
# else:
# nll_grads = torch.autograd.grad(nll_loss, self.last_layer[0], retain_graph=True)[0]
# g_grads = torch.autograd.grad(g_loss, self.last_layer[0], retain_graph=True)[0]
# d_weight = torch.norm(nll_grads) / (torch.norm(g_grads) + 1e-4)
# d_weight = torch.clamp(d_weight, 0.0, 1e4).detach()
# d_weight = d_weight * self.discriminator_weight
# return d_weight
def forward(
self,
inputs,
reconstructions,
posteriors,
# optimizer_idx,
# global_step,
last_layer=None,
cond=None,
split="train",
weights=None,
):
rec_loss = torch.abs(inputs.contiguous() - reconstructions.contiguous())
if self.perceptual_weight > 0: # NOTE: need in_channels == 3 in order to use!
assert inputs.size(1) == 3, f"using vgg16 that requires 3 input channels but got {inputs.size(1)} "
# SCH: transform to [(B,T), C, H, W] shape for percetual loss over each frame
permutated_input = torch.permute(inputs, (0, 2, 1, 3, 4)) # [B, C, T, H, W] --> [B, T, C, H, W]
permutated_rec = torch.permute(reconstructions, (0, 2, 1, 3, 4))
data_shape = permutated_input.size()
p_loss = self.perceptual_loss(
permutated_input.reshape(-1, data_shape[-3], data_shape[-2], data_shape[-1]).contiguous(),
permutated_rec.reshape(-1, data_shape[-3], data_shape[-2], data_shape[-1]).contiguous(),
)
# SCH: shape back p_loss
permuted_p_loss = torch.permute(p_loss.reshape(data_shape[0], data_shape[1], 1, 1, 1), (0, 2, 1, 3, 4))
rec_loss = rec_loss + self.perceptual_weight * permuted_p_loss
nll_loss = rec_loss / torch.exp(self.logvar) + self.logvar
weighted_nll_loss = nll_loss
if weights is not None:
weighted_nll_loss = weights * nll_loss
weighted_nll_loss = torch.sum(weighted_nll_loss) / weighted_nll_loss.shape[0]
nll_loss = torch.sum(nll_loss) / nll_loss.shape[0]
kl_loss = posteriors.kl()
kl_loss = torch.sum(kl_loss) / kl_loss.shape[0]
loss = weighted_nll_loss + self.kl_weight * kl_loss # TODO: add discriminator loss later
# log = {"{}/total_loss".format(split): loss.clone().detach().mean(),
# "{}/logvar".format(split): self.logvar.detach(),
# "{}/kl_loss".format(split): kl_loss.detach().mean(),
# "{}/nll_loss".format(split): nll_loss.detach().mean(),
# "{}/rec_loss".format(split): rec_loss.detach().mean(),
# # "{}/d_weight".format(split): d_weight.detach(),
# # "{}/disc_factor".format(split): torch.tensor(disc_factor),
# # "{}/g_loss".format(split): g_loss.detach().mean(),
# }
return loss