# Copyright 2024 HunyuanDiT Authors, Qixun Wang and 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.
from typing import Dict, Optional, Union
import torch
from torch import nn
from ...configuration_utils import ConfigMixin, register_to_config
from ...utils import logging
from ...utils.torch_utils import maybe_allow_in_graph
from ..attention import FeedForward
from ..attention_processor import Attention, AttentionProcessor, FusedHunyuanAttnProcessor2_0, HunyuanAttnProcessor2_0
from ..embeddings import (
HunyuanCombinedTimestepTextSizeStyleEmbedding,
PatchEmbed,
PixArtAlphaTextProjection,
)
from ..modeling_outputs import Transformer2DModelOutput
from ..modeling_utils import ModelMixin
from ..normalization import AdaLayerNormContinuous, FP32LayerNorm
logger = logging.get_logger(__name__) # pylint: disable=invalid-name
class AdaLayerNormShift(nn.Module):
r"""
Norm layer modified to incorporate timestep embeddings.
Parameters:
embedding_dim (`int`): The size of each embedding vector.
num_embeddings (`int`): The size of the embeddings dictionary.
"""
def __init__(self, embedding_dim: int, elementwise_affine=True, eps=1e-6):
super().__init__()
self.silu = nn.SiLU()
self.linear = nn.Linear(embedding_dim, embedding_dim)
self.norm = FP32LayerNorm(embedding_dim, elementwise_affine=elementwise_affine, eps=eps)
def forward(self, x: torch.Tensor, emb: torch.Tensor) -> torch.Tensor:
shift = self.linear(self.silu(emb.to(torch.float32)).to(emb.dtype))
x = self.norm(x) + shift.unsqueeze(dim=1)
return x
@maybe_allow_in_graph
class HunyuanDiTBlock(nn.Module):
r"""
Transformer block used in Hunyuan-DiT model (https://github.com/Tencent/HunyuanDiT). Allow skip connection and
QKNorm
Parameters:
dim (`int`):
The number of channels in the input and output.
num_attention_heads (`int`):
The number of headsto use for multi-head attention.
cross_attention_dim (`int`,*optional*):
The size of the encoder_hidden_states vector for cross attention.
dropout(`float`, *optional*, defaults to 0.0):
The dropout probability to use.
activation_fn (`str`,*optional*, defaults to `"geglu"`):
Activation function to be used in feed-forward. .
norm_elementwise_affine (`bool`, *optional*, defaults to `True`):
Whether to use learnable elementwise affine parameters for normalization.
norm_eps (`float`, *optional*, defaults to 1e-6):
A small constant added to the denominator in normalization layers to prevent division by zero.
final_dropout (`bool` *optional*, defaults to False):
Whether to apply a final dropout after the last feed-forward layer.
ff_inner_dim (`int`, *optional*):
The size of the hidden layer in the feed-forward block. Defaults to `None`.
ff_bias (`bool`, *optional*, defaults to `True`):
Whether to use bias in the feed-forward block.
skip (`bool`, *optional*, defaults to `False`):
Whether to use skip connection. Defaults to `False` for down-blocks and mid-blocks.
qk_norm (`bool`, *optional*, defaults to `True`):
Whether to use normalization in QK calculation. Defaults to `True`.
"""
def __init__(
self,
dim: int,
num_attention_heads: int,
cross_attention_dim: int = 1024,
dropout=0.0,
activation_fn: str = "geglu",
norm_elementwise_affine: bool = True,
norm_eps: float = 1e-6,
final_dropout: bool = False,
ff_inner_dim: Optional[int] = None,
ff_bias: bool = True,
skip: bool = False,
qk_norm: bool = True,
):
super().__init__()
# Define 3 blocks. Each block has its own normalization layer.
# NOTE: when new version comes, check norm2 and norm 3
# 1. Self-Attn
self.norm1 = AdaLayerNormShift(dim, elementwise_affine=norm_elementwise_affine, eps=norm_eps)
self.attn1 = Attention(
query_dim=dim,
cross_attention_dim=None,
dim_head=dim // num_attention_heads,
heads=num_attention_heads,
qk_norm="layer_norm" if qk_norm else None,
eps=1e-6,
bias=True,
processor=HunyuanAttnProcessor2_0(),
)
# 2. Cross-Attn
self.norm2 = FP32LayerNorm(dim, norm_eps, norm_elementwise_affine)
self.attn2 = Attention(
query_dim=dim,
cross_attention_dim=cross_attention_dim,
dim_head=dim // num_attention_heads,
heads=num_attention_heads,
qk_norm="layer_norm" if qk_norm else None,
eps=1e-6,
bias=True,
processor=HunyuanAttnProcessor2_0(),
)
# 3. Feed-forward
self.norm3 = FP32LayerNorm(dim, norm_eps, norm_elementwise_affine)
self.ff = FeedForward(
dim,
dropout=dropout, ### 0.0
activation_fn=activation_fn, ### approx GeLU
final_dropout=final_dropout, ### 0.0
inner_dim=ff_inner_dim, ### int(dim * mlp_ratio)
bias=ff_bias,
)
# 4. Skip Connection
if skip:
self.skip_norm = FP32LayerNorm(2 * dim, norm_eps, elementwise_affine=True)
self.skip_linear = nn.Linear(2 * dim, dim)
else:
self.skip_linear = None
# let chunk size default to None
self._chunk_size = None
self._chunk_dim = 0
# Copied from diffusers.models.attention.BasicTransformerBlock.set_chunk_feed_forward
def set_chunk_feed_forward(self, chunk_size: Optional[int], dim: int = 0):
# Sets chunk feed-forward
self._chunk_size = chunk_size
self._chunk_dim = dim
def forward(
self,
hidden_states: torch.Tensor,
encoder_hidden_states: Optional[torch.Tensor] = None,
temb: Optional[torch.Tensor] = None,
image_rotary_emb=None,
skip=None,
) -> torch.Tensor:
# Notice that normalization is always applied before the real computation in the following blocks.
# 0. Long Skip Connection
if self.skip_linear is not None:
cat = torch.cat([hidden_states, skip], dim=-1)
cat = self.skip_norm(cat)
hidden_states = self.skip_linear(cat)
# 1. Self-Attention
norm_hidden_states = self.norm1(hidden_states, temb) ### checked: self.norm1 is correct
attn_output = self.attn1(
norm_hidden_states,
image_rotary_emb=image_rotary_emb,
)
hidden_states = hidden_states + attn_output
# 2. Cross-Attention
hidden_states = hidden_states + self.attn2(
self.norm2(hidden_states),
encoder_hidden_states=encoder_hidden_states,
image_rotary_emb=image_rotary_emb,
)
# FFN Layer ### TODO: switch norm2 and norm3 in the state dict
mlp_inputs = self.norm3(hidden_states)
hidden_states = hidden_states + self.ff(mlp_inputs)
return hidden_states
class HunyuanDiT2DModel(ModelMixin, ConfigMixin):
"""
HunYuanDiT: Diffusion model with a Transformer backbone.
Inherit ModelMixin and ConfigMixin to be compatible with the sampler StableDiffusionPipeline of diffusers.
Parameters:
num_attention_heads (`int`, *optional*, defaults to 16):
The number of heads to use for multi-head attention.
attention_head_dim (`int`, *optional*, defaults to 88):
The number of channels in each head.
in_channels (`int`, *optional*):
The number of channels in the input and output (specify if the input is **continuous**).
patch_size (`int`, *optional*):
The size of the patch to use for the input.
activation_fn (`str`, *optional*, defaults to `"geglu"`):
Activation function to use in feed-forward.
sample_size (`int`, *optional*):
The width of the latent images. This is fixed during training since it is used to learn a number of
position embeddings.
dropout (`float`, *optional*, defaults to 0.0):
The dropout probability to use.
cross_attention_dim (`int`, *optional*):
The number of dimension in the clip text embedding.
hidden_size (`int`, *optional*):
The size of hidden layer in the conditioning embedding layers.
num_layers (`int`, *optional*, defaults to 1):
The number of layers of Transformer blocks to use.
mlp_ratio (`float`, *optional*, defaults to 4.0):
The ratio of the hidden layer size to the input size.
learn_sigma (`bool`, *optional*, defaults to `True`):
Whether to predict variance.
cross_attention_dim_t5 (`int`, *optional*):
The number dimensions in t5 text embedding.
pooled_projection_dim (`int`, *optional*):
The size of the pooled projection.
text_len (`int`, *optional*):
The length of the clip text embedding.
text_len_t5 (`int`, *optional*):
The length of the T5 text embedding.
use_style_cond_and_image_meta_size (`bool`, *optional*):
Whether or not to use style condition and image meta size. True for version <=1.1, False for version >= 1.2
"""
@register_to_config
def __init__(
self,
num_attention_heads: int = 16,
attention_head_dim: int = 88,
in_channels: Optional[int] = None,
patch_size: Optional[int] = None,
activation_fn: str = "gelu-approximate",
sample_size=32,
hidden_size=1152,
num_layers: int = 28,
mlp_ratio: float = 4.0,
learn_sigma: bool = True,
cross_attention_dim: int = 1024,
norm_type: str = "layer_norm",
cross_attention_dim_t5: int = 2048,
pooled_projection_dim: int = 1024,
text_len: int = 77,
text_len_t5: int = 256,
use_style_cond_and_image_meta_size: bool = True,
):
super().__init__()
self.out_channels = in_channels * 2 if learn_sigma else in_channels
self.num_heads = num_attention_heads
self.inner_dim = num_attention_heads * attention_head_dim
self.text_embedder = PixArtAlphaTextProjection(
in_features=cross_attention_dim_t5,
hidden_size=cross_attention_dim_t5 * 4,
out_features=cross_attention_dim,
act_fn="silu_fp32",
)
self.text_embedding_padding = nn.Parameter(
torch.randn(text_len + text_len_t5, cross_attention_dim, dtype=torch.float32)
)
self.pos_embed = PatchEmbed(
height=sample_size,
width=sample_size,
in_channels=in_channels,
embed_dim=hidden_size,
patch_size=patch_size,
pos_embed_type=None,
)
self.time_extra_emb = HunyuanCombinedTimestepTextSizeStyleEmbedding(
hidden_size,
pooled_projection_dim=pooled_projection_dim,
seq_len=text_len_t5,
cross_attention_dim=cross_attention_dim_t5,
use_style_cond_and_image_meta_size=use_style_cond_and_image_meta_size,
)
# HunyuanDiT Blocks
self.blocks = nn.ModuleList(
[
HunyuanDiTBlock(
dim=self.inner_dim,
num_attention_heads=self.config.num_attention_heads,
activation_fn=activation_fn,
ff_inner_dim=int(self.inner_dim * mlp_ratio),
cross_attention_dim=cross_attention_dim,
qk_norm=True, # See http://arxiv.org/abs/2302.05442 for details.
skip=layer > num_layers // 2,
)
for layer in range(num_layers)
]
)
self.norm_out = AdaLayerNormContinuous(self.inner_dim, self.inner_dim, elementwise_affine=False, eps=1e-6)
self.proj_out = nn.Linear(self.inner_dim, patch_size * patch_size * self.out_channels, bias=True)
# Copied from diffusers.models.unets.unet_2d_condition.UNet2DConditionModel.fuse_qkv_projections with FusedAttnProcessor2_0->FusedHunyuanAttnProcessor2_0
def fuse_qkv_projections(self):
"""
Enables fused QKV projections. For self-attention modules, all projection matrices (i.e., query, key, value)
are fused. For cross-attention modules, key and value projection matrices are fused.
<Tip warning={true}>
This API is 🧪 experimental.
</Tip>
"""
self.original_attn_processors = None
for _, attn_processor in self.attn_processors.items():
if "Added" in str(attn_processor.__class__.__name__):
raise ValueError("`fuse_qkv_projections()` is not supported for models having added KV projections.")
self.original_attn_processors = self.attn_processors
for module in self.modules():
if isinstance(module, Attention):
module.fuse_projections(fuse=True)
self.set_attn_processor(FusedHunyuanAttnProcessor2_0())
# Copied from diffusers.models.unets.unet_2d_condition.UNet2DConditionModel.unfuse_qkv_projections
def unfuse_qkv_projections(self):
"""Disables the fused QKV projection if enabled.
<Tip warning={true}>
This API is 🧪 experimental.
</Tip>
"""
if self.original_attn_processors is not None:
self.set_attn_processor(self.original_attn_processors)
@property
# Copied from diffusers.models.unets.unet_2d_condition.UNet2DConditionModel.attn_processors
def attn_processors(self) -> Dict[str, AttentionProcessor]:
r"""
Returns:
`dict` of attention processors: A dictionary containing all attention processors used in the model with
indexed by its weight name.
"""
# set recursively
processors = {}
def fn_recursive_add_processors(name: str, module: torch.nn.Module, processors: Dict[str, AttentionProcessor]):
if hasattr(module, "get_processor"):
processors[f"{name}.processor"] = module.get_processor()
for sub_name, child in module.named_children():
fn_recursive_add_processors(f"{name}.{sub_name}", child, processors)
return processors
for name, module in self.named_children():
fn_recursive_add_processors(name, module, processors)
return processors
# Copied from diffusers.models.unets.unet_2d_condition.UNet2DConditionModel.set_attn_processor
def set_attn_processor(self, processor: Union[AttentionProcessor, Dict[str, AttentionProcessor]]):
r"""
Sets the attention processor to use to compute attention.
Parameters:
processor (`dict` of `AttentionProcessor` or only `AttentionProcessor`):
The instantiated processor class or a dictionary of processor classes that will be set as the processor
for **all** `Attention` layers.
If `processor` is a dict, the key needs to define the path to the corresponding cross attention
processor. This is strongly recommended when setting trainable attention processors.
"""
count = len(self.attn_processors.keys())
if isinstance(processor, dict) and len(processor) != count:
raise ValueError(
f"A dict of processors was passed, but the number of processors {len(processor)} does not match the"
f" number of attention layers: {count}. Please make sure to pass {count} processor classes."
)
def fn_recursive_attn_processor(name: str, module: torch.nn.Module, processor):
if hasattr(module, "set_processor"):
if not isinstance(processor, dict):
module.set_processor(processor)
else:
module.set_processor(processor.pop(f"{name}.processor"))
for sub_name, child in module.named_children():
fn_recursive_attn_processor(f"{name}.{sub_name}", child, processor)
for name, module in self.named_children():
fn_recursive_attn_processor(name, module, processor)
def set_default_attn_processor(self):
"""
Disables custom attention processors and sets the default attention implementation.
"""
self.set_attn_processor(HunyuanAttnProcessor2_0())
def forward(
self,
hidden_states,
timestep,
encoder_hidden_states=None,
text_embedding_mask=None,
encoder_hidden_states_t5=None,
text_embedding_mask_t5=None,
image_meta_size=None,
style=None,
image_rotary_emb=None,
controlnet_block_samples=None,
return_dict=True,
):
"""
The [`HunyuanDiT2DModel`] forward method.
Args:
hidden_states (`torch.Tensor` of shape `(batch size, dim, height, width)`):
The input tensor.
timestep ( `torch.LongTensor`, *optional*):
Used to indicate denoising step.
encoder_hidden_states ( `torch.Tensor` of shape `(batch size, sequence len, embed dims)`, *optional*):
Conditional embeddings for cross attention layer. This is the output of `BertModel`.
text_embedding_mask: torch.Tensor
An attention mask of shape `(batch, key_tokens)` is applied to `encoder_hidden_states`. This is the output
of `BertModel`.
encoder_hidden_states_t5 ( `torch.Tensor` of shape `(batch size, sequence len, embed dims)`, *optional*):
Conditional embeddings for cross attention layer. This is the output of T5 Text Encoder.
text_embedding_mask_t5: torch.Tensor
An attention mask of shape `(batch, key_tokens)` is applied to `encoder_hidden_states`. This is the output
of T5 Text Encoder.
image_meta_size (torch.Tensor):
Conditional embedding indicate the image sizes
style: torch.Tensor:
Conditional embedding indicate the style
image_rotary_emb (`torch.Tensor`):
The image rotary embeddings to apply on query and key tensors during attention calculation.
return_dict: bool
Whether to return a dictionary.
"""
height, width = hidden_states.shape[-2:]
hidden_states = self.pos_embed(hidden_states)
temb = self.time_extra_emb(
timestep, encoder_hidden_states_t5, image_meta_size, style, hidden_dtype=timestep.dtype
) # [B, D]
# text projection
batch_size, sequence_length, _ = encoder_hidden_states_t5.shape
encoder_hidden_states_t5 = self.text_embedder(
encoder_hidden_states_t5.view(-1, encoder_hidden_states_t5.shape[-1])
)
encoder_hidden_states_t5 = encoder_hidden_states_t5.view(batch_size, sequence_length, -1)
encoder_hidden_states = torch.cat([encoder_hidden_states, encoder_hidden_states_t5], dim=1)
text_embedding_mask = torch.cat([text_embedding_mask, text_embedding_mask_t5], dim=-1)
text_embedding_mask = text_embedding_mask.unsqueeze(2).bool()
encoder_hidden_states = torch.where(text_embedding_mask, encoder_hidden_states, self.text_embedding_padding)
skips = []
for layer, block in enumerate(self.blocks):
if layer > self.config.num_layers // 2:
if controlnet_block_samples is not None:
skip = skips.pop() + controlnet_block_samples.pop()
else:
skip = skips.pop()
hidden_states = block(
hidden_states,
temb=temb,
encoder_hidden_states=encoder_hidden_states,
image_rotary_emb=image_rotary_emb,
skip=skip,
) # (N, L, D)
else:
hidden_states = block(
hidden_states,
temb=temb,
encoder_hidden_states=encoder_hidden_states,
image_rotary_emb=image_rotary_emb,
) # (N, L, D)
if layer < (self.config.num_layers // 2 - 1):
skips.append(hidden_states)
if controlnet_block_samples is not None and len(controlnet_block_samples) != 0:
raise ValueError("The number of controls is not equal to the number of skip connections.")
# final layer
hidden_states = self.norm_out(hidden_states, temb.to(torch.float32))
hidden_states = self.proj_out(hidden_states)
# (N, L, patch_size ** 2 * out_channels)
# unpatchify: (N, out_channels, H, W)
patch_size = self.pos_embed.patch_size
height = height // patch_size
width = width // patch_size
hidden_states = hidden_states.reshape(
shape=(hidden_states.shape[0], height, width, patch_size, patch_size, self.out_channels)
)
hidden_states = torch.einsum("nhwpqc->nchpwq", hidden_states)
output = hidden_states.reshape(
shape=(hidden_states.shape[0], self.out_channels, height * patch_size, width * patch_size)
)
if not return_dict:
return (output,)
return Transformer2DModelOutput(sample=output)
# Copied from diffusers.models.unets.unet_3d_condition.UNet3DConditionModel.enable_forward_chunking
def enable_forward_chunking(self, chunk_size: Optional[int] = None, dim: int = 0) -> None:
"""
Sets the attention processor to use [feed forward
chunking](https://huggingface.co/blog/reformer#2-chunked-feed-forward-layers).
Parameters:
chunk_size (`int`, *optional*):
The chunk size of the feed-forward layers. If not specified, will run feed-forward layer individually
over each tensor of dim=`dim`.
dim (`int`, *optional*, defaults to `0`):
The dimension over which the feed-forward computation should be chunked. Choose between dim=0 (batch)
or dim=1 (sequence length).
"""
if dim not in [0, 1]:
raise ValueError(f"Make sure to set `dim` to either 0 or 1, not {dim}")
# By default chunk size is 1
chunk_size = chunk_size or 1
def fn_recursive_feed_forward(module: torch.nn.Module, chunk_size: int, dim: int):
if hasattr(module, "set_chunk_feed_forward"):
module.set_chunk_feed_forward(chunk_size=chunk_size, dim=dim)
for child in module.children():
fn_recursive_feed_forward(child, chunk_size, dim)
for module in self.children():
fn_recursive_feed_forward(module, chunk_size, dim)
# Copied from diffusers.models.unets.unet_3d_condition.UNet3DConditionModel.disable_forward_chunking
def disable_forward_chunking(self):
def fn_recursive_feed_forward(module: torch.nn.Module, chunk_size: int, dim: int):
if hasattr(module, "set_chunk_feed_forward"):
module.set_chunk_feed_forward(chunk_size=chunk_size, dim=dim)
for child in module.children():
fn_recursive_feed_forward(child, chunk_size, dim)
for module in self.children():
fn_recursive_feed_forward(module, None, 0)