# 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. import math from dataclasses import dataclass from typing import Optional, Tuple, Union import numpy as np import torch import torch.nn as nn from ...configuration_utils import ConfigMixin, register_to_config from ...loaders.unet import FromOriginalUNetMixin from ...utils import BaseOutput from ..attention_processor import Attention from ..modeling_utils import ModelMixin # Copied from diffusers.pipelines.wuerstchen.modeling_wuerstchen_common.WuerstchenLayerNorm with WuerstchenLayerNorm -> SDCascadeLayerNorm class SDCascadeLayerNorm(nn.LayerNorm): def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) def forward(self, x): x = x.permute(0, 2, 3, 1) x = super().forward(x) return x.permute(0, 3, 1, 2) class SDCascadeTimestepBlock(nn.Module): def __init__(self, c, c_timestep, conds=[]): super().__init__() self.mapper = nn.Linear(c_timestep, c * 2) self.conds = conds for cname in conds: setattr(self, f"mapper_{cname}", nn.Linear(c_timestep, c * 2)) def forward(self, x, t): t = t.chunk(len(self.conds) + 1, dim=1) a, b = self.mapper(t[0])[:, :, None, None].chunk(2, dim=1) for i, c in enumerate(self.conds): ac, bc = getattr(self, f"mapper_{c}")(t[i + 1])[:, :, None, None].chunk(2, dim=1) a, b = a + ac, b + bc return x * (1 + a) + b class SDCascadeResBlock(nn.Module): def __init__(self, c, c_skip=0, kernel_size=3, dropout=0.0): super().__init__() self.depthwise = nn.Conv2d(c, c, kernel_size=kernel_size, padding=kernel_size // 2, groups=c) self.norm = SDCascadeLayerNorm(c, elementwise_affine=False, eps=1e-6) self.channelwise = nn.Sequential( nn.Linear(c + c_skip, c * 4), nn.GELU(), GlobalResponseNorm(c * 4), nn.Dropout(dropout), nn.Linear(c * 4, c), ) def forward(self, x, x_skip=None): x_res = x x = self.norm(self.depthwise(x)) if x_skip is not None: x = torch.cat([x, x_skip], dim=1) x = self.channelwise(x.permute(0, 2, 3, 1)).permute(0, 3, 1, 2) return x + x_res # from https://github.com/facebookresearch/ConvNeXt-V2/blob/3608f67cc1dae164790c5d0aead7bf2d73d9719b/models/utils.py#L105 class GlobalResponseNorm(nn.Module): def __init__(self, dim): super().__init__() self.gamma = nn.Parameter(torch.zeros(1, 1, 1, dim)) self.beta = nn.Parameter(torch.zeros(1, 1, 1, dim)) def forward(self, x): agg_norm = torch.norm(x, p=2, dim=(1, 2), keepdim=True) stand_div_norm = agg_norm / (agg_norm.mean(dim=-1, keepdim=True) + 1e-6) return self.gamma * (x * stand_div_norm) + self.beta + x class SDCascadeAttnBlock(nn.Module): def __init__(self, c, c_cond, nhead, self_attn=True, dropout=0.0): super().__init__() self.self_attn = self_attn self.norm = SDCascadeLayerNorm(c, elementwise_affine=False, eps=1e-6) self.attention = Attention(query_dim=c, heads=nhead, dim_head=c // nhead, dropout=dropout, bias=True) self.kv_mapper = nn.Sequential(nn.SiLU(), nn.Linear(c_cond, c)) def forward(self, x, kv): kv = self.kv_mapper(kv) norm_x = self.norm(x) if self.self_attn: batch_size, channel, _, _ = x.shape kv = torch.cat([norm_x.view(batch_size, channel, -1).transpose(1, 2), kv], dim=1) x = x + self.attention(norm_x, encoder_hidden_states=kv) return x class UpDownBlock2d(nn.Module): def __init__(self, in_channels, out_channels, mode, enabled=True): super().__init__() if mode not in ["up", "down"]: raise ValueError(f"{mode} not supported") interpolation = ( nn.Upsample(scale_factor=2 if mode == "up" else 0.5, mode="bilinear", align_corners=True) if enabled else nn.Identity() ) mapping = nn.Conv2d(in_channels, out_channels, kernel_size=1) self.blocks = nn.ModuleList([interpolation, mapping] if mode == "up" else [mapping, interpolation]) def forward(self, x): for block in self.blocks: x = block(x) return x @dataclass class StableCascadeUNetOutput(BaseOutput): sample: torch.FloatTensor = None class StableCascadeUNet(ModelMixin, ConfigMixin, FromOriginalUNetMixin): _supports_gradient_checkpointing = True @register_to_config def __init__( self, in_channels: int = 16, out_channels: int = 16, timestep_ratio_embedding_dim: int = 64, patch_size: int = 1, conditioning_dim: int = 2048, block_out_channels: Tuple[int] = (2048, 2048), num_attention_heads: Tuple[int] = (32, 32), down_num_layers_per_block: Tuple[int] = (8, 24), up_num_layers_per_block: Tuple[int] = (24, 8), down_blocks_repeat_mappers: Optional[Tuple[int]] = ( 1, 1, ), up_blocks_repeat_mappers: Optional[Tuple[int]] = (1, 1), block_types_per_layer: Tuple[Tuple[str]] = ( ("SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock"), ("SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock"), ), clip_text_in_channels: Optional[int] = None, clip_text_pooled_in_channels=1280, clip_image_in_channels: Optional[int] = None, clip_seq=4, effnet_in_channels: Optional[int] = None, pixel_mapper_in_channels: Optional[int] = None, kernel_size=3, dropout: Union[float, Tuple[float]] = (0.1, 0.1), self_attn: Union[bool, Tuple[bool]] = True, timestep_conditioning_type: Tuple[str] = ("sca", "crp"), switch_level: Optional[Tuple[bool]] = None, ): """ Parameters: in_channels (`int`, defaults to 16): Number of channels in the input sample. out_channels (`int`, defaults to 16): Number of channels in the output sample. timestep_ratio_embedding_dim (`int`, defaults to 64): Dimension of the projected time embedding. patch_size (`int`, defaults to 1): Patch size to use for pixel unshuffling layer conditioning_dim (`int`, defaults to 2048): Dimension of the image and text conditional embedding. block_out_channels (Tuple[int], defaults to (2048, 2048)): Tuple of output channels for each block. num_attention_heads (Tuple[int], defaults to (32, 32)): Number of attention heads in each attention block. Set to -1 to if block types in a layer do not have attention. down_num_layers_per_block (Tuple[int], defaults to [8, 24]): Number of layers in each down block. up_num_layers_per_block (Tuple[int], defaults to [24, 8]): Number of layers in each up block. down_blocks_repeat_mappers (Tuple[int], optional, defaults to [1, 1]): Number of 1x1 Convolutional layers to repeat in each down block. up_blocks_repeat_mappers (Tuple[int], optional, defaults to [1, 1]): Number of 1x1 Convolutional layers to repeat in each up block. block_types_per_layer (Tuple[Tuple[str]], optional, defaults to ( ("SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock"), ("SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock") ): Block types used in each layer of the up/down blocks. clip_text_in_channels (`int`, *optional*, defaults to `None`): Number of input channels for CLIP based text conditioning. clip_text_pooled_in_channels (`int`, *optional*, defaults to 1280): Number of input channels for pooled CLIP text embeddings. clip_image_in_channels (`int`, *optional*): Number of input channels for CLIP based image conditioning. clip_seq (`int`, *optional*, defaults to 4): effnet_in_channels (`int`, *optional*, defaults to `None`): Number of input channels for effnet conditioning. pixel_mapper_in_channels (`int`, defaults to `None`): Number of input channels for pixel mapper conditioning. kernel_size (`int`, *optional*, defaults to 3): Kernel size to use in the block convolutional layers. dropout (Tuple[float], *optional*, defaults to (0.1, 0.1)): Dropout to use per block. self_attn (Union[bool, Tuple[bool]]): Tuple of booleans that determine whether to use self attention in a block or not. timestep_conditioning_type (Tuple[str], defaults to ("sca", "crp")): Timestep conditioning type. switch_level (Optional[Tuple[bool]], *optional*, defaults to `None`): Tuple that indicates whether upsampling or downsampling should be applied in a block """ super().__init__() if len(block_out_channels) != len(down_num_layers_per_block): raise ValueError( f"Number of elements in `down_num_layers_per_block` must match the length of `block_out_channels`: {len(block_out_channels)}" ) elif len(block_out_channels) != len(up_num_layers_per_block): raise ValueError( f"Number of elements in `up_num_layers_per_block` must match the length of `block_out_channels`: {len(block_out_channels)}" ) elif len(block_out_channels) != len(down_blocks_repeat_mappers): raise ValueError( f"Number of elements in `down_blocks_repeat_mappers` must match the length of `block_out_channels`: {len(block_out_channels)}" ) elif len(block_out_channels) != len(up_blocks_repeat_mappers): raise ValueError( f"Number of elements in `up_blocks_repeat_mappers` must match the length of `block_out_channels`: {len(block_out_channels)}" ) elif len(block_out_channels) != len(block_types_per_layer): raise ValueError( f"Number of elements in `block_types_per_layer` must match the length of `block_out_channels`: {len(block_out_channels)}" ) if isinstance(dropout, float): dropout = (dropout,) * len(block_out_channels) if isinstance(self_attn, bool): self_attn = (self_attn,) * len(block_out_channels) # CONDITIONING if effnet_in_channels is not None: self.effnet_mapper = nn.Sequential( nn.Conv2d(effnet_in_channels, block_out_channels[0] * 4, kernel_size=1), nn.GELU(), nn.Conv2d(block_out_channels[0] * 4, block_out_channels[0], kernel_size=1), SDCascadeLayerNorm(block_out_channels[0], elementwise_affine=False, eps=1e-6), ) if pixel_mapper_in_channels is not None: self.pixels_mapper = nn.Sequential( nn.Conv2d(pixel_mapper_in_channels, block_out_channels[0] * 4, kernel_size=1), nn.GELU(), nn.Conv2d(block_out_channels[0] * 4, block_out_channels[0], kernel_size=1), SDCascadeLayerNorm(block_out_channels[0], elementwise_affine=False, eps=1e-6), ) self.clip_txt_pooled_mapper = nn.Linear(clip_text_pooled_in_channels, conditioning_dim * clip_seq) if clip_text_in_channels is not None: self.clip_txt_mapper = nn.Linear(clip_text_in_channels, conditioning_dim) if clip_image_in_channels is not None: self.clip_img_mapper = nn.Linear(clip_image_in_channels, conditioning_dim * clip_seq) self.clip_norm = nn.LayerNorm(conditioning_dim, elementwise_affine=False, eps=1e-6) self.embedding = nn.Sequential( nn.PixelUnshuffle(patch_size), nn.Conv2d(in_channels * (patch_size**2), block_out_channels[0], kernel_size=1), SDCascadeLayerNorm(block_out_channels[0], elementwise_affine=False, eps=1e-6), ) def get_block(block_type, in_channels, nhead, c_skip=0, dropout=0, self_attn=True): if block_type == "SDCascadeResBlock": return SDCascadeResBlock(in_channels, c_skip, kernel_size=kernel_size, dropout=dropout) elif block_type == "SDCascadeAttnBlock": return SDCascadeAttnBlock(in_channels, conditioning_dim, nhead, self_attn=self_attn, dropout=dropout) elif block_type == "SDCascadeTimestepBlock": return SDCascadeTimestepBlock( in_channels, timestep_ratio_embedding_dim, conds=timestep_conditioning_type ) else: raise ValueError(f"Block type {block_type} not supported") # BLOCKS # -- down blocks self.down_blocks = nn.ModuleList() self.down_downscalers = nn.ModuleList() self.down_repeat_mappers = nn.ModuleList() for i in range(len(block_out_channels)): if i > 0: self.down_downscalers.append( nn.Sequential( SDCascadeLayerNorm(block_out_channels[i - 1], elementwise_affine=False, eps=1e-6), UpDownBlock2d( block_out_channels[i - 1], block_out_channels[i], mode="down", enabled=switch_level[i - 1] ) if switch_level is not None else nn.Conv2d(block_out_channels[i - 1], block_out_channels[i], kernel_size=2, stride=2), ) ) else: self.down_downscalers.append(nn.Identity()) down_block = nn.ModuleList() for _ in range(down_num_layers_per_block[i]): for block_type in block_types_per_layer[i]: block = get_block( block_type, block_out_channels[i], num_attention_heads[i], dropout=dropout[i], self_attn=self_attn[i], ) down_block.append(block) self.down_blocks.append(down_block) if down_blocks_repeat_mappers is not None: block_repeat_mappers = nn.ModuleList() for _ in range(down_blocks_repeat_mappers[i] - 1): block_repeat_mappers.append(nn.Conv2d(block_out_channels[i], block_out_channels[i], kernel_size=1)) self.down_repeat_mappers.append(block_repeat_mappers) # -- up blocks self.up_blocks = nn.ModuleList() self.up_upscalers = nn.ModuleList() self.up_repeat_mappers = nn.ModuleList() for i in reversed(range(len(block_out_channels))): if i > 0: self.up_upscalers.append( nn.Sequential( SDCascadeLayerNorm(block_out_channels[i], elementwise_affine=False, eps=1e-6), UpDownBlock2d( block_out_channels[i], block_out_channels[i - 1], mode="up", enabled=switch_level[i - 1] ) if switch_level is not None else nn.ConvTranspose2d( block_out_channels[i], block_out_channels[i - 1], kernel_size=2, stride=2 ), ) ) else: self.up_upscalers.append(nn.Identity()) up_block = nn.ModuleList() for j in range(up_num_layers_per_block[::-1][i]): for k, block_type in enumerate(block_types_per_layer[i]): c_skip = block_out_channels[i] if i < len(block_out_channels) - 1 and j == k == 0 else 0 block = get_block( block_type, block_out_channels[i], num_attention_heads[i], c_skip=c_skip, dropout=dropout[i], self_attn=self_attn[i], ) up_block.append(block) self.up_blocks.append(up_block) if up_blocks_repeat_mappers is not None: block_repeat_mappers = nn.ModuleList() for _ in range(up_blocks_repeat_mappers[::-1][i] - 1): block_repeat_mappers.append(nn.Conv2d(block_out_channels[i], block_out_channels[i], kernel_size=1)) self.up_repeat_mappers.append(block_repeat_mappers) # OUTPUT self.clf = nn.Sequential( SDCascadeLayerNorm(block_out_channels[0], elementwise_affine=False, eps=1e-6), nn.Conv2d(block_out_channels[0], out_channels * (patch_size**2), kernel_size=1), nn.PixelShuffle(patch_size), ) self.gradient_checkpointing = False def _set_gradient_checkpointing(self, value=False): self.gradient_checkpointing = value def _init_weights(self, m): if isinstance(m, (nn.Conv2d, nn.Linear)): torch.nn.init.xavier_uniform_(m.weight) if m.bias is not None: nn.init.constant_(m.bias, 0) nn.init.normal_(self.clip_txt_pooled_mapper.weight, std=0.02) nn.init.normal_(self.clip_txt_mapper.weight, std=0.02) if hasattr(self, "clip_txt_mapper") else None nn.init.normal_(self.clip_img_mapper.weight, std=0.02) if hasattr(self, "clip_img_mapper") else None if hasattr(self, "effnet_mapper"): nn.init.normal_(self.effnet_mapper[0].weight, std=0.02) # conditionings nn.init.normal_(self.effnet_mapper[2].weight, std=0.02) # conditionings if hasattr(self, "pixels_mapper"): nn.init.normal_(self.pixels_mapper[0].weight, std=0.02) # conditionings nn.init.normal_(self.pixels_mapper[2].weight, std=0.02) # conditionings torch.nn.init.xavier_uniform_(self.embedding[1].weight, 0.02) # inputs nn.init.constant_(self.clf[1].weight, 0) # outputs # blocks for level_block in self.down_blocks + self.up_blocks: for block in level_block: if isinstance(block, SDCascadeResBlock): block.channelwise[-1].weight.data *= np.sqrt(1 / sum(self.config.blocks[0])) elif isinstance(block, SDCascadeTimestepBlock): nn.init.constant_(block.mapper.weight, 0) def get_timestep_ratio_embedding(self, timestep_ratio, max_positions=10000): r = timestep_ratio * max_positions half_dim = self.config.timestep_ratio_embedding_dim // 2 emb = math.log(max_positions) / (half_dim - 1) emb = torch.arange(half_dim, device=r.device).float().mul(-emb).exp() emb = r[:, None] * emb[None, :] emb = torch.cat([emb.sin(), emb.cos()], dim=1) if self.config.timestep_ratio_embedding_dim % 2 == 1: # zero pad emb = nn.functional.pad(emb, (0, 1), mode="constant") return emb.to(dtype=r.dtype) def get_clip_embeddings(self, clip_txt_pooled, clip_txt=None, clip_img=None): if len(clip_txt_pooled.shape) == 2: clip_txt_pool = clip_txt_pooled.unsqueeze(1) clip_txt_pool = self.clip_txt_pooled_mapper(clip_txt_pooled).view( clip_txt_pooled.size(0), clip_txt_pooled.size(1) * self.config.clip_seq, -1 ) if clip_txt is not None and clip_img is not None: clip_txt = self.clip_txt_mapper(clip_txt) if len(clip_img.shape) == 2: clip_img = clip_img.unsqueeze(1) clip_img = self.clip_img_mapper(clip_img).view( clip_img.size(0), clip_img.size(1) * self.config.clip_seq, -1 ) clip = torch.cat([clip_txt, clip_txt_pool, clip_img], dim=1) else: clip = clip_txt_pool return self.clip_norm(clip) def _down_encode(self, x, r_embed, clip): level_outputs = [] block_group = zip(self.down_blocks, self.down_downscalers, self.down_repeat_mappers) if self.training and self.gradient_checkpointing: def create_custom_forward(module): def custom_forward(*inputs): return module(*inputs) return custom_forward for down_block, downscaler, repmap in block_group: x = downscaler(x) for i in range(len(repmap) + 1): for block in down_block: if isinstance(block, SDCascadeResBlock): x = torch.utils.checkpoint.checkpoint(create_custom_forward(block), x, use_reentrant=False) elif isinstance(block, SDCascadeAttnBlock): x = torch.utils.checkpoint.checkpoint( create_custom_forward(block), x, clip, use_reentrant=False ) elif isinstance(block, SDCascadeTimestepBlock): x = torch.utils.checkpoint.checkpoint( create_custom_forward(block), x, r_embed, use_reentrant=False ) else: x = x = torch.utils.checkpoint.checkpoint( create_custom_forward(block), use_reentrant=False ) if i < len(repmap): x = repmap[i](x) level_outputs.insert(0, x) else: for down_block, downscaler, repmap in block_group: x = downscaler(x) for i in range(len(repmap) + 1): for block in down_block: if isinstance(block, SDCascadeResBlock): x = block(x) elif isinstance(block, SDCascadeAttnBlock): x = block(x, clip) elif isinstance(block, SDCascadeTimestepBlock): x = block(x, r_embed) else: x = block(x) if i < len(repmap): x = repmap[i](x) level_outputs.insert(0, x) return level_outputs def _up_decode(self, level_outputs, r_embed, clip): x = level_outputs[0] block_group = zip(self.up_blocks, self.up_upscalers, self.up_repeat_mappers) if self.training and self.gradient_checkpointing: def create_custom_forward(module): def custom_forward(*inputs): return module(*inputs) return custom_forward for i, (up_block, upscaler, repmap) in enumerate(block_group): for j in range(len(repmap) + 1): for k, block in enumerate(up_block): if isinstance(block, SDCascadeResBlock): skip = level_outputs[i] if k == 0 and i > 0 else None if skip is not None and (x.size(-1) != skip.size(-1) or x.size(-2) != skip.size(-2)): orig_type = x.dtype x = torch.nn.functional.interpolate( x.float(), skip.shape[-2:], mode="bilinear", align_corners=True ) x = x.to(orig_type) x = torch.utils.checkpoint.checkpoint( create_custom_forward(block), x, skip, use_reentrant=False ) elif isinstance(block, SDCascadeAttnBlock): x = torch.utils.checkpoint.checkpoint( create_custom_forward(block), x, clip, use_reentrant=False ) elif isinstance(block, SDCascadeTimestepBlock): x = torch.utils.checkpoint.checkpoint( create_custom_forward(block), x, r_embed, use_reentrant=False ) else: x = torch.utils.checkpoint.checkpoint(create_custom_forward(block), x, use_reentrant=False) if j < len(repmap): x = repmap[j](x) x = upscaler(x) else: for i, (up_block, upscaler, repmap) in enumerate(block_group): for j in range(len(repmap) + 1): for k, block in enumerate(up_block): if isinstance(block, SDCascadeResBlock): skip = level_outputs[i] if k == 0 and i > 0 else None if skip is not None and (x.size(-1) != skip.size(-1) or x.size(-2) != skip.size(-2)): orig_type = x.dtype x = torch.nn.functional.interpolate( x.float(), skip.shape[-2:], mode="bilinear", align_corners=True ) x = x.to(orig_type) x = block(x, skip) elif isinstance(block, SDCascadeAttnBlock): x = block(x, clip) elif isinstance(block, SDCascadeTimestepBlock): x = block(x, r_embed) else: x = block(x) if j < len(repmap): x = repmap[j](x) x = upscaler(x) return x def forward( self, sample, timestep_ratio, clip_text_pooled, clip_text=None, clip_img=None, effnet=None, pixels=None, sca=None, crp=None, return_dict=True, ): if pixels is None: pixels = sample.new_zeros(sample.size(0), 3, 8, 8) # Process the conditioning embeddings timestep_ratio_embed = self.get_timestep_ratio_embedding(timestep_ratio) for c in self.config.timestep_conditioning_type: if c == "sca": cond = sca elif c == "crp": cond = crp else: cond = None t_cond = cond or torch.zeros_like(timestep_ratio) timestep_ratio_embed = torch.cat([timestep_ratio_embed, self.get_timestep_ratio_embedding(t_cond)], dim=1) clip = self.get_clip_embeddings(clip_txt_pooled=clip_text_pooled, clip_txt=clip_text, clip_img=clip_img) # Model Blocks x = self.embedding(sample) if hasattr(self, "effnet_mapper") and effnet is not None: x = x + self.effnet_mapper( nn.functional.interpolate(effnet, size=x.shape[-2:], mode="bilinear", align_corners=True) ) if hasattr(self, "pixels_mapper"): x = x + nn.functional.interpolate( self.pixels_mapper(pixels), size=x.shape[-2:], mode="bilinear", align_corners=True ) level_outputs = self._down_encode(x, timestep_ratio_embed, clip) x = self._up_decode(level_outputs, timestep_ratio_embed, clip) sample = self.clf(x) if not return_dict: return (sample,) return StableCascadeUNetOutput(sample=sample)