Files
2024-11-01 10:15:27 +08:00

269 lines
11 KiB
Python

# -*- coding: utf-8 -*-
# Copyright (c) Alibaba, Inc. and its affiliates.
import copy
import numbers
import random
import torch
from scepter.modules.model.network.ldm import LatentDiffusion
from scepter.modules.model.registry import (BACKBONES, EMBEDDERS, LOSSES,
MODELS, TOKENIZERS)
from scepter.modules.model.utils.basic_utils import count_params
from scepter.modules.utils.config import dict_to_yaml
from scepter.modules.utils.distribute import we
def disabled_train(self, mode=True):
"""Overwrite model.train with this function to make sure train/eval mode
does not change anymore."""
return self
@MODELS.register_class()
class LatentDiffusionPixart(LatentDiffusion):
para_dict = LatentDiffusion.para_dict
para_dict['DECODER_BIAS'] = {'value': 0, 'description': ''}
def __init__(self, cfg, logger=None):
super().__init__(cfg, logger=logger)
self.decoder_bias = cfg.get('DECODER_BIAS', 0.5)
def construct_network(self):
self.model = BACKBONES.build(self.model_config, logger=self.logger)
self.logger.info('all parameters:{}'.format(count_params(self.model)))
if self.use_ema:
self.model_ema = copy.deepcopy(self.model).eval()
for param in self.model_ema.parameters():
param.requires_grad = False
if self.loss_config:
self.loss = LOSSES.build(self.loss_config, logger=self.logger)
if self.tokenizer_config is not None:
self.tokenizer = TOKENIZERS.build(self.tokenizer_config,
logger=self.logger)
if self.first_stage_config:
self.first_stage_model = MODELS.build(self.first_stage_config,
logger=self.logger)
self.first_stage_model = self.first_stage_model.eval()
self.first_stage_model.train = disabled_train
for param in self.first_stage_model.parameters():
param.requires_grad = False
else:
self.first_stage_model = None
if self.tokenizer_config is not None:
self.cond_stage_config.KWARGS = {
'vocab_size': self.tokenizer.vocab_size
}
if self.cond_stage_config == '__is_unconditional__':
print(
f'Training {self.__class__.__name__} as an unconditional model.'
)
self.cond_stage_model = None
else:
model = EMBEDDERS.build(self.cond_stage_config, logger=self.logger)
self.cond_stage_model = model.eval().requires_grad_(False)
self.cond_stage_model.train = disabled_train
def forward_train(self,
image=None,
noise=None,
prompt=None,
label=None,
**kwargs):
n, c, h, w = image.shape
x_start = self.encode_first_stage(image, **kwargs)
t = torch.randint(0, self.num_timesteps, (n, ),
device=x_start.device).long()
ar = torch.tensor([[h / w]], device=we.device_id).repeat(n, 1)
hw = torch.tensor([[h, w]], dtype=torch.float,
device=we.device_id).repeat(n, 1)
context = {}
cont_mask = None
if prompt and self.cond_stage_model:
with torch.autocast(device_type='cuda',
enabled=True,
dtype=torch.bfloat16):
cont, cont_mask = getattr(self.cond_stage_model,
'encode')(prompt, return_mask=True)
context['crossattn'] = cont.float()
else:
assert label is not None
context['label'] = label
if 'hint' in kwargs and kwargs['hint'] is not None:
hint = kwargs.pop('hint')
if isinstance(context, dict):
context['hint'] = hint
else:
context = {'crossattn': context, 'hint': hint}
else:
hint = None
if self.min_snr_gamma is not None:
alphas = self.diffusion.alphas.to(we.device_id)[t]
sigmas = self.diffusion.sigmas.pow(2).to(we.device_id)[t]
snrs = (alphas / sigmas).clamp(min=1e-20)
min_snrs = snrs.clamp(max=self.min_snr_gamma)
weights = min_snrs / snrs
else:
weights = 1
self.register_probe({'snrs_weights': weights})
loss = self.diffusion.loss(x0=x_start,
t=t,
model=self.model,
model_kwargs={
'cond': context,
'mask': cont_mask,
'data_info': {
'img_hw': hw,
'aspect_ratio': ar
}
},
noise=noise,
**kwargs)
loss = loss * weights
loss = loss.mean()
ret = {'loss': loss, 'probe_data': {'prompt': prompt}}
return ret
@torch.no_grad()
def forward_test(self,
image=None,
prompt=None,
label=None,
sampler='ddim',
sample_steps=20,
seed=2023,
guide_scale=4.5,
guide_rescale=0.5,
discretization='trailing',
**kwargs):
g = torch.Generator(device=we.device_id)
seed = seed if seed >= 0 else random.randint(0, 2**32 - 1)
g.manual_seed(seed)
num_samples = label.shape[0] if label is not None else len(prompt)
context = {}
null_context = {}
cont_mask = None
if prompt and self.cond_stage_model:
with torch.autocast(device_type='cuda',
enabled=True,
dtype=torch.bfloat16):
cont, cont_mask = getattr(self.cond_stage_model,
'encode')(prompt, return_mask=True)
context['crossattn'] = cont.float()
null_context['crossattn'] = self.model.y_embedder.y_embedding[
None].repeat(len(prompt), 1, 1)
else:
assert label is not None
context['label'] = label
null_context['label'] = torch.tensor(
[self.model.num_classes]).repeat(num_samples).to(we.device_id)
if 'hint' in kwargs and kwargs['hint'] is not None:
hint = kwargs.pop('hint')
if isinstance(context, dict):
context['hint'] = hint
if isinstance(null_context, dict):
null_context['hint'] = hint
else:
hint = None
if 'index' in kwargs:
kwargs.pop('index')
image_size = None
if 'meta' in kwargs:
meta = kwargs.pop('meta')
if 'image_size' in meta:
h = int(meta['image_size'][0][0])
w = int(meta['image_size'][1][0])
image_size = [h, w]
if 'image_size' in kwargs:
image_size = kwargs.pop('image_size')
if isinstance(image_size, numbers.Number):
image_size = [image_size, image_size]
if image_size is None:
image_size = [1024, 1024]
height, width = image_size
noise = self.noise_sample(num_samples, height // self.size_factor,
width // self.size_factor, g)
# UNet use input n_prompt
samples = self.diffusion.sample(
solver=sampler,
noise=noise,
model=self.model,
model_kwargs=[{
'cond': context,
'mask': cont_mask,
'data_info': {
'img_hw':
torch.tensor([image_size],
dtype=torch.float,
device=we.device_id).repeat(num_samples, 1),
'aspect_ratio':
torch.tensor([[1.]], device=we.device_id).repeat(
num_samples, 1)
}
}, {
'cond': null_context,
'mask': cont_mask,
'data_info': {
'img_hw':
torch.tensor([image_size],
dtype=torch.float,
device=we.device_id).repeat(num_samples, 1),
'aspect_ratio':
torch.tensor([[1.]], device=we.device_id).repeat(
num_samples, 1)
}
}] if guide_scale is not None and guide_scale > 0 else {
'cond': context,
'mask': cont_mask,
'data_info': {
'img_hw':
torch.tensor([image_size],
dtype=torch.float,
device=we.device_id).repeat(num_samples, 1),
'aspect_ratio':
torch.tensor([[1.]], device=we.device_id).repeat(
num_samples, 1)
}
},
cat_uc=False,
steps=sample_steps,
guide_scale=guide_scale,
guide_rescale=guide_rescale,
discretization=discretization,
show_progress=True,
seed=seed,
condition_fn=None,
clamp=None,
percentile=None,
t_max=None,
t_min=None,
discard_penultimate_step=None,
return_intermediate=None,
**kwargs)
x_samples = self.decode_first_stage(samples).float()
x_samples = torch.clamp(
(x_samples + 1.0) / 2.0 + self.decoder_bias / 255,
min=0.0,
max=1.0)
outputs = list()
prompt = label.detach().cpu().numpy().tolist(
) if prompt is None else prompt
for i, (p, img) in enumerate(zip(prompt, x_samples)):
one_tup = {'prompt': str(p), 'n_prompt': '', 'image': img}
if hint is not None:
one_tup.update({'hint': hint[i]})
outputs.append(one_tup)
return outputs
@staticmethod
def get_config_template():
return dict_to_yaml('MODEL',
__class__.__name__,
LatentDiffusionPixart.para_dict,
set_name=True)