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import torch
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import torch.nn as nn
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from diffusers import UNet2DModel, UNet2DConditionModel
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import yaml
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from einops import repeat, rearrange
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from typing import Any
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from torch import Tensor
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def rand_bool(shape: Any, proba: float, device: Any = None) -> Tensor:
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if proba == 1:
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return torch.ones(shape, device=device, dtype=torch.bool)
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elif proba == 0:
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return torch.zeros(shape, device=device, dtype=torch.bool)
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else:
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return torch.bernoulli(torch.full(shape, proba, device=device)).to(torch.bool)
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class FixedEmbedding(nn.Module):
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def __init__(self, features=128):
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super().__init__()
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self.embedding = nn.Embedding(1, features)
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def forward(self, y):
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B, L, C, device = y.shape[0], y.shape[-2], y.shape[-1], y.device
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embed = self.embedding(torch.zeros(B, device=device).long())
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fixed_embedding = repeat(embed, "b c -> b l c", l=L)
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return fixed_embedding
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class P2E_Cross(nn.Module):
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def __init__(self, config):
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super().__init__()
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self.config = config
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self.unet = UNet2DConditionModel(**self.config['unet'])
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self.unet.set_use_memory_efficient_attention_xformers(True)
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self.cfg_embedding = FixedEmbedding(self.config['unet']['cross_attention_dim'])
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self.context_embedding = nn.Sequential(
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nn.Linear(self.config['unet']['cross_attention_dim'], self.config['unet']['cross_attention_dim']),
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nn.SiLU(),
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nn.Linear(self.config['unet']['cross_attention_dim'], self.config['unet']['cross_attention_dim']))
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def forward(self, target, t, prompt, prompt_mask=None,
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train_cfg=False, cfg_prob=0.0):
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B, C = target.shape
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target = target.unsqueeze(-1).unsqueeze(-1)
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if train_cfg:
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if cfg_prob > 0.0:
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batch_mask = rand_bool(shape=(B, 1, 1), proba=cfg_prob, device=target.device)
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fixed_embedding = self.cfg_embedding(prompt).to(target.dtype)
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prompt = torch.where(batch_mask, fixed_embedding, prompt)
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prompt = self.context_embedding(prompt)
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target = target.to(prompt.dtype)
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output = self.unet(sample=target, timestep=t,
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encoder_hidden_states=prompt,
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encoder_attention_mask=prompt_mask)['sample']
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return output.squeeze(-1).squeeze(-1)
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if __name__ == "__main__":
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with open('p2e_cross.yaml', 'r') as fp:
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config = yaml.safe_load(fp)
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device = 'cuda'
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model = P2E_Cross(config['diffwrap']).to(device)
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x = torch.rand((2, 256)).to(device)
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t = torch.randint(0, 1000, (2,)).long().to(device)
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prompt = torch.rand(2, 64, 768).to(device)
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prompt_mask = torch.ones(2, 64).to(device)
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output = model(x, t, prompt, prompt_mask, train_cfg=True, cfg_prob=0.25) |
