import torch import os import json from dataclasses import dataclass from einops import rearrange, repeat from typing import Any, Dict, Optional, Tuple from diffusers.models import Transformer2DModel from diffusers.utils import USE_PEFT_BACKEND, BaseOutput, deprecate from diffusers.models.embeddings import get_1d_sincos_pos_embed_from_grid, ImagePositionalEmbeddings, CaptionProjection, PatchEmbed, CombinedTimestepSizeEmbeddings from diffusers.configuration_utils import ConfigMixin, register_to_config from diffusers.models.modeling_utils import ModelMixin from diffusers.models.attention import BasicTransformerBlock from diffusers.models.lora import LoRACompatibleConv, LoRACompatibleLinear from diffusers.utils.torch_utils import maybe_allow_in_graph from diffusers.models.embeddings import SinusoidalPositionalEmbedding from diffusers.models.normalization import AdaLayerNorm, AdaLayerNormZero from diffusers.models.attention_processor import Attention from diffusers.models.activations import GEGLU, GELU, ApproximateGELU from dataclasses import dataclass import torch import torch.nn.functional as F from torch import nn @maybe_allow_in_graph class GatedSelfAttentionDense(nn.Module): r""" A gated self-attention dense layer that combines visual features and object features. Parameters: query_dim (`int`): The number of channels in the query. context_dim (`int`): The number of channels in the context. n_heads (`int`): The number of heads to use for attention. d_head (`int`): The number of channels in each head. """ def __init__(self, query_dim: int, context_dim: int, n_heads: int, d_head: int): super().__init__() # we need a linear projection since we need cat visual feature and obj feature self.linear = nn.Linear(context_dim, query_dim) self.attn = Attention(query_dim=query_dim, heads=n_heads, dim_head=d_head) self.ff = FeedForward(query_dim, activation_fn="geglu") self.norm1 = nn.LayerNorm(query_dim) self.norm2 = nn.LayerNorm(query_dim) self.register_parameter("alpha_attn", nn.Parameter(torch.tensor(0.0))) self.register_parameter("alpha_dense", nn.Parameter(torch.tensor(0.0))) self.enabled = True def forward(self, x: torch.Tensor, objs: torch.Tensor) -> torch.Tensor: if not self.enabled: return x n_visual = x.shape[1] objs = self.linear(objs) x = x + self.alpha_attn.tanh() * self.attn(self.norm1(torch.cat([x, objs], dim=1)))[:, :n_visual, :] x = x + self.alpha_dense.tanh() * self.ff(self.norm2(x)) return x class FeedForward(nn.Module): r""" A feed-forward layer. Parameters: dim (`int`): The number of channels in the input. dim_out (`int`, *optional*): The number of channels in the output. If not given, defaults to `dim`. mult (`int`, *optional*, defaults to 4): The multiplier to use for the hidden dimension. 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. final_dropout (`bool` *optional*, defaults to False): Apply a final dropout. """ def __init__( self, dim: int, dim_out: Optional[int] = None, mult: int = 4, dropout: float = 0.0, activation_fn: str = "geglu", final_dropout: bool = False, ): super().__init__() inner_dim = int(dim * mult) dim_out = dim_out if dim_out is not None else dim linear_cls = LoRACompatibleLinear if not USE_PEFT_BACKEND else nn.Linear if activation_fn == "gelu": act_fn = GELU(dim, inner_dim) if activation_fn == "gelu-approximate": act_fn = GELU(dim, inner_dim, approximate="tanh") elif activation_fn == "geglu": act_fn = GEGLU(dim, inner_dim) elif activation_fn == "geglu-approximate": act_fn = ApproximateGELU(dim, inner_dim) self.net = nn.ModuleList([]) # project in self.net.append(act_fn) # project dropout self.net.append(nn.Dropout(dropout)) # project out self.net.append(linear_cls(inner_dim, dim_out)) # FF as used in Vision Transformer, MLP-Mixer, etc. have a final dropout if final_dropout: self.net.append(nn.Dropout(dropout)) def forward(self, hidden_states: torch.Tensor, scale: float = 1.0) -> torch.Tensor: compatible_cls = (GEGLU,) if USE_PEFT_BACKEND else (GEGLU, LoRACompatibleLinear) for module in self.net: if isinstance(module, compatible_cls): hidden_states = module(hidden_states, scale) else: hidden_states = module(hidden_states) return hidden_states @maybe_allow_in_graph class BasicTransformerBlock_(nn.Module): r""" A basic Transformer block. Parameters: dim (`int`): The number of channels in the input and output. num_attention_heads (`int`): The number of heads to use for multi-head attention. attention_head_dim (`int`): The number of channels in each head. dropout (`float`, *optional*, defaults to 0.0): The dropout probability to use. cross_attention_dim (`int`, *optional*): The size of the encoder_hidden_states vector for cross attention. activation_fn (`str`, *optional*, defaults to `"geglu"`): Activation function to be used in feed-forward. num_embeds_ada_norm (: obj: `int`, *optional*): The number of diffusion steps used during training. See `Transformer2DModel`. attention_bias (: obj: `bool`, *optional*, defaults to `False`): Configure if the attentions should contain a bias parameter. only_cross_attention (`bool`, *optional*): Whether to use only cross-attention layers. In this case two cross attention layers are used. double_self_attention (`bool`, *optional*): Whether to use two self-attention layers. In this case no cross attention layers are used. upcast_attention (`bool`, *optional*): Whether to upcast the attention computation to float32. This is useful for mixed precision training. norm_elementwise_affine (`bool`, *optional*, defaults to `True`): Whether to use learnable elementwise affine parameters for normalization. norm_type (`str`, *optional*, defaults to `"layer_norm"`): The normalization layer to use. Can be `"layer_norm"`, `"ada_norm"` or `"ada_norm_zero"`. final_dropout (`bool` *optional*, defaults to False): Whether to apply a final dropout after the last feed-forward layer. attention_type (`str`, *optional*, defaults to `"default"`): The type of attention to use. Can be `"default"` or `"gated"` or `"gated-text-image"`. positional_embeddings (`str`, *optional*, defaults to `None`): The type of positional embeddings to apply to. num_positional_embeddings (`int`, *optional*, defaults to `None`): The maximum number of positional embeddings to apply. """ def __init__( self, dim: int, num_attention_heads: int, attention_head_dim: int, dropout=0.0, cross_attention_dim: Optional[int] = None, activation_fn: str = "geglu", num_embeds_ada_norm: Optional[int] = None, attention_bias: bool = False, only_cross_attention: bool = False, double_self_attention: bool = False, upcast_attention: bool = False, norm_elementwise_affine: bool = True, norm_type: str = "layer_norm", # 'layer_norm', 'ada_norm', 'ada_norm_zero', 'ada_norm_single' norm_eps: float = 1e-5, final_dropout: bool = False, attention_type: str = "default", positional_embeddings: Optional[str] = None, num_positional_embeddings: Optional[int] = None, ): super().__init__() self.only_cross_attention = only_cross_attention self.use_ada_layer_norm_zero = (num_embeds_ada_norm is not None) and norm_type == "ada_norm_zero" self.use_ada_layer_norm = (num_embeds_ada_norm is not None) and norm_type == "ada_norm" self.use_ada_layer_norm_single = norm_type == "ada_norm_single" self.use_layer_norm = norm_type == "layer_norm" if norm_type in ("ada_norm", "ada_norm_zero") and num_embeds_ada_norm is None: raise ValueError( f"`norm_type` is set to {norm_type}, but `num_embeds_ada_norm` is not defined. Please make sure to" f" define `num_embeds_ada_norm` if setting `norm_type` to {norm_type}." ) if positional_embeddings and (num_positional_embeddings is None): raise ValueError( "If `positional_embedding` type is defined, `num_positition_embeddings` must also be defined." ) if positional_embeddings == "sinusoidal": self.pos_embed = SinusoidalPositionalEmbedding(dim, max_seq_length=num_positional_embeddings) else: self.pos_embed = None # Define 3 blocks. Each block has its own normalization layer. # 1. Self-Attn if self.use_ada_layer_norm: self.norm1 = AdaLayerNorm(dim, num_embeds_ada_norm) elif self.use_ada_layer_norm_zero: self.norm1 = AdaLayerNormZero(dim, num_embeds_ada_norm) else: self.norm1 = nn.LayerNorm(dim, elementwise_affine=norm_elementwise_affine, eps=norm_eps) # go here self.attn1 = Attention( query_dim=dim, heads=num_attention_heads, dim_head=attention_head_dim, dropout=dropout, bias=attention_bias, cross_attention_dim=cross_attention_dim if only_cross_attention else None, upcast_attention=upcast_attention, ) # # 2. Cross-Attn # if cross_attention_dim is not None or double_self_attention: # # We currently only use AdaLayerNormZero for self attention where there will only be one attention block. # # I.e. the number of returned modulation chunks from AdaLayerZero would not make sense if returned during # # the second cross attention block. # self.norm2 = ( # AdaLayerNorm(dim, num_embeds_ada_norm) # if self.use_ada_layer_norm # else nn.LayerNorm(dim, elementwise_affine=norm_elementwise_affine, eps=norm_eps) # ) # self.attn2 = Attention( # query_dim=dim, # cross_attention_dim=cross_attention_dim if not double_self_attention else None, # heads=num_attention_heads, # dim_head=attention_head_dim, # dropout=dropout, # bias=attention_bias, # upcast_attention=upcast_attention, # ) # is self-attn if encoder_hidden_states is none # else: # self.norm2 = None # self.attn2 = None # 3. Feed-forward # if not self.use_ada_layer_norm_single: # self.norm3 = nn.LayerNorm(dim, elementwise_affine=norm_elementwise_affine, eps=norm_eps) self.norm3 = nn.LayerNorm(dim, elementwise_affine=norm_elementwise_affine, eps=norm_eps) self.ff = FeedForward(dim, dropout=dropout, activation_fn=activation_fn, final_dropout=final_dropout) # 4. Fuser if attention_type == "gated" or attention_type == "gated-text-image": self.fuser = GatedSelfAttentionDense(dim, cross_attention_dim, num_attention_heads, attention_head_dim) # 5. Scale-shift for PixArt-Alpha. if self.use_ada_layer_norm_single: self.scale_shift_table = nn.Parameter(torch.randn(6, dim) / dim**0.5) # let chunk size default to None self._chunk_size = None self._chunk_dim = 0 def set_chunk_feed_forward(self, chunk_size: Optional[int], dim: int): # Sets chunk feed-forward self._chunk_size = chunk_size self._chunk_dim = dim def forward( self, hidden_states: torch.FloatTensor, attention_mask: Optional[torch.FloatTensor] = None, encoder_hidden_states: Optional[torch.FloatTensor] = None, encoder_attention_mask: Optional[torch.FloatTensor] = None, timestep: Optional[torch.LongTensor] = None, cross_attention_kwargs: Dict[str, Any] = None, class_labels: Optional[torch.LongTensor] = None, ) -> torch.FloatTensor: # Notice that normalization is always applied before the real computation in the following blocks. # 0. Self-Attention batch_size = hidden_states.shape[0] if self.use_ada_layer_norm: norm_hidden_states = self.norm1(hidden_states, timestep) elif self.use_ada_layer_norm_zero: norm_hidden_states, gate_msa, shift_mlp, scale_mlp, gate_mlp = self.norm1( hidden_states, timestep, class_labels, hidden_dtype=hidden_states.dtype ) elif self.use_layer_norm: norm_hidden_states = self.norm1(hidden_states) elif self.use_ada_layer_norm_single: # go here shift_msa, scale_msa, gate_msa, shift_mlp, scale_mlp, gate_mlp = ( self.scale_shift_table[None] + timestep.reshape(batch_size, 6, -1) ).chunk(6, dim=1) norm_hidden_states = self.norm1(hidden_states) norm_hidden_states = norm_hidden_states * (1 + scale_msa) + shift_msa # norm_hidden_states = norm_hidden_states.squeeze(1) else: raise ValueError("Incorrect norm used") if self.pos_embed is not None: norm_hidden_states = self.pos_embed(norm_hidden_states) # 1. Retrieve lora scale. lora_scale = cross_attention_kwargs.get("scale", 1.0) if cross_attention_kwargs is not None else 1.0 # 2. Prepare GLIGEN inputs cross_attention_kwargs = cross_attention_kwargs.copy() if cross_attention_kwargs is not None else {} gligen_kwargs = cross_attention_kwargs.pop("gligen", None) attn_output = self.attn1( norm_hidden_states, encoder_hidden_states=encoder_hidden_states if self.only_cross_attention else None, attention_mask=attention_mask, **cross_attention_kwargs, ) if self.use_ada_layer_norm_zero: attn_output = gate_msa.unsqueeze(1) * attn_output elif self.use_ada_layer_norm_single: attn_output = gate_msa * attn_output hidden_states = attn_output + hidden_states if hidden_states.ndim == 4: hidden_states = hidden_states.squeeze(1) # 2.5 GLIGEN Control if gligen_kwargs is not None: hidden_states = self.fuser(hidden_states, gligen_kwargs["objs"]) # # 3. Cross-Attention # if self.attn2 is not None: # if self.use_ada_layer_norm: # norm_hidden_states = self.norm2(hidden_states, timestep) # elif self.use_ada_layer_norm_zero or self.use_layer_norm: # norm_hidden_states = self.norm2(hidden_states) # elif self.use_ada_layer_norm_single: # # For PixArt norm2 isn't applied here: # # https://github.com/PixArt-alpha/PixArt-alpha/blob/0f55e922376d8b797edd44d25d0e7464b260dcab/diffusion/model/nets/PixArtMS.py#L70C1-L76C103 # norm_hidden_states = hidden_states # else: # raise ValueError("Incorrect norm") # if self.pos_embed is not None and self.use_ada_layer_norm_single is False: # norm_hidden_states = self.pos_embed(norm_hidden_states) # attn_output = self.attn2( # norm_hidden_states, # encoder_hidden_states=encoder_hidden_states, # attention_mask=encoder_attention_mask, # **cross_attention_kwargs, # ) # hidden_states = attn_output + hidden_states # 4. Feed-forward # if not self.use_ada_layer_norm_single: # norm_hidden_states = self.norm3(hidden_states) if self.use_ada_layer_norm_zero: norm_hidden_states = norm_hidden_states * (1 + scale_mlp[:, None]) + shift_mlp[:, None] if self.use_ada_layer_norm_single: # norm_hidden_states = self.norm2(hidden_states) norm_hidden_states = self.norm3(hidden_states) norm_hidden_states = norm_hidden_states * (1 + scale_mlp) + shift_mlp if self._chunk_size is not None: # "feed_forward_chunk_size" can be used to save memory if norm_hidden_states.shape[self._chunk_dim] % self._chunk_size != 0: raise ValueError( f"`hidden_states` dimension to be chunked: {norm_hidden_states.shape[self._chunk_dim]} has to be divisible by chunk size: {self._chunk_size}. Make sure to set an appropriate `chunk_size` when calling `unet.enable_forward_chunking`." ) num_chunks = norm_hidden_states.shape[self._chunk_dim] // self._chunk_size ff_output = torch.cat( [ self.ff(hid_slice, scale=lora_scale) for hid_slice in norm_hidden_states.chunk(num_chunks, dim=self._chunk_dim) ], dim=self._chunk_dim, ) else: ff_output = self.ff(norm_hidden_states, scale=lora_scale) if self.use_ada_layer_norm_zero: ff_output = gate_mlp.unsqueeze(1) * ff_output elif self.use_ada_layer_norm_single: ff_output = gate_mlp * ff_output hidden_states = ff_output + hidden_states if hidden_states.ndim == 4: hidden_states = hidden_states.squeeze(1) return hidden_states class AdaLayerNormSingle(nn.Module): r""" Norm layer adaptive layer norm single (adaLN-single). As proposed in PixArt-Alpha (see: https://arxiv.org/abs/2310.00426; Section 2.3). Parameters: embedding_dim (`int`): The size of each embedding vector. use_additional_conditions (`bool`): To use additional conditions for normalization or not. """ def __init__(self, embedding_dim: int, use_additional_conditions: bool = False): super().__init__() self.emb = CombinedTimestepSizeEmbeddings( embedding_dim, size_emb_dim=embedding_dim // 3, use_additional_conditions=use_additional_conditions ) self.silu = nn.SiLU() self.linear = nn.Linear(embedding_dim, 6 * embedding_dim, bias=True) def forward( self, timestep: torch.Tensor, added_cond_kwargs: Dict[str, torch.Tensor] = None, batch_size: int = None, hidden_dtype: Optional[torch.dtype] = None, ) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor]: # No modulation happening here. embedded_timestep = self.emb(timestep, batch_size=batch_size, hidden_dtype=hidden_dtype, resolution=None, aspect_ratio=None) return self.linear(self.silu(embedded_timestep)), embedded_timestep @dataclass class Transformer3DModelOutput(BaseOutput): """ The output of [`Transformer2DModel`]. Args: sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` or `(batch size, num_vector_embeds - 1, num_latent_pixels)` if [`Transformer2DModel`] is discrete): The hidden states output conditioned on the `encoder_hidden_states` input. If discrete, returns probability distributions for the unnoised latent pixels. """ sample: torch.FloatTensor class LatteT2V(ModelMixin, ConfigMixin): _supports_gradient_checkpointing = True """ A 2D Transformer model for image-like data. 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**). num_layers (`int`, *optional*, defaults to 1): The number of layers of Transformer blocks to use. dropout (`float`, *optional*, defaults to 0.0): The dropout probability to use. cross_attention_dim (`int`, *optional*): The number of `encoder_hidden_states` dimensions to use. sample_size (`int`, *optional*): The width of the latent images (specify if the input is **discrete**). This is fixed during training since it is used to learn a number of position embeddings. num_vector_embeds (`int`, *optional*): The number of classes of the vector embeddings of the latent pixels (specify if the input is **discrete**). Includes the class for the masked latent pixel. activation_fn (`str`, *optional*, defaults to `"geglu"`): Activation function to use in feed-forward. num_embeds_ada_norm ( `int`, *optional*): The number of diffusion steps used during training. Pass if at least one of the norm_layers is `AdaLayerNorm`. This is fixed during training since it is used to learn a number of embeddings that are added to the hidden states. During inference, you can denoise for up to but not more steps than `num_embeds_ada_norm`. attention_bias (`bool`, *optional*): Configure if the `TransformerBlocks` attention should contain a bias parameter. """ @register_to_config def __init__( self, num_attention_heads: int = 16, attention_head_dim: int = 88, in_channels: Optional[int] = None, out_channels: Optional[int] = None, num_layers: int = 1, dropout: float = 0.0, norm_num_groups: int = 32, cross_attention_dim: Optional[int] = None, attention_bias: bool = False, sample_size: Optional[int] = None, num_vector_embeds: Optional[int] = None, patch_size: Optional[int] = None, activation_fn: str = "geglu", num_embeds_ada_norm: Optional[int] = None, use_linear_projection: bool = False, only_cross_attention: bool = False, double_self_attention: bool = False, upcast_attention: bool = False, norm_type: str = "layer_norm", norm_elementwise_affine: bool = True, norm_eps: float = 1e-5, attention_type: str = "default", caption_channels: int = None, video_length: int = 16, ): super().__init__() self.use_linear_projection = use_linear_projection self.num_attention_heads = num_attention_heads self.attention_head_dim = attention_head_dim inner_dim = num_attention_heads * attention_head_dim self.video_length = video_length conv_cls = nn.Conv2d if USE_PEFT_BACKEND else LoRACompatibleConv linear_cls = nn.Linear if USE_PEFT_BACKEND else LoRACompatibleLinear # 1. Transformer2DModel can process both standard continuous images of shape `(batch_size, num_channels, width, height)` as well as quantized image embeddings of shape `(batch_size, num_image_vectors)` # Define whether input is continuous or discrete depending on configuration self.is_input_continuous = (in_channels is not None) and (patch_size is None) self.is_input_vectorized = num_vector_embeds is not None self.is_input_patches = in_channels is not None and patch_size is not None if norm_type == "layer_norm" and num_embeds_ada_norm is not None: deprecation_message = ( f"The configuration file of this model: {self.__class__} is outdated. `norm_type` is either not set or" " incorrectly set to `'layer_norm'`.Make sure to set `norm_type` to `'ada_norm'` in the config." " Please make sure to update the config accordingly as leaving `norm_type` might led to incorrect" " results in future versions. If you have downloaded this checkpoint from the Hugging Face Hub, it" " would be very nice if you could open a Pull request for the `transformer/config.json` file" ) deprecate("norm_type!=num_embeds_ada_norm", "1.0.0", deprecation_message, standard_warn=False) norm_type = "ada_norm" if self.is_input_continuous and self.is_input_vectorized: raise ValueError( f"Cannot define both `in_channels`: {in_channels} and `num_vector_embeds`: {num_vector_embeds}. Make" " sure that either `in_channels` or `num_vector_embeds` is None." ) elif self.is_input_vectorized and self.is_input_patches: raise ValueError( f"Cannot define both `num_vector_embeds`: {num_vector_embeds} and `patch_size`: {patch_size}. Make" " sure that either `num_vector_embeds` or `num_patches` is None." ) elif not self.is_input_continuous and not self.is_input_vectorized and not self.is_input_patches: raise ValueError( f"Has to define `in_channels`: {in_channels}, `num_vector_embeds`: {num_vector_embeds}, or patch_size:" f" {patch_size}. Make sure that `in_channels`, `num_vector_embeds` or `num_patches` is not None." ) # 2. Define input layers if self.is_input_continuous: self.in_channels = in_channels self.norm = torch.nn.GroupNorm(num_groups=norm_num_groups, num_channels=in_channels, eps=1e-6, affine=True) if use_linear_projection: self.proj_in = linear_cls(in_channels, inner_dim) else: self.proj_in = conv_cls(in_channels, inner_dim, kernel_size=1, stride=1, padding=0) elif self.is_input_vectorized: assert sample_size is not None, "Transformer2DModel over discrete input must provide sample_size" assert num_vector_embeds is not None, "Transformer2DModel over discrete input must provide num_embed" self.height = sample_size self.width = sample_size self.num_vector_embeds = num_vector_embeds self.num_latent_pixels = self.height * self.width self.latent_image_embedding = ImagePositionalEmbeddings( num_embed=num_vector_embeds, embed_dim=inner_dim, height=self.height, width=self.width ) elif self.is_input_patches: assert sample_size is not None, "Transformer2DModel over patched input must provide sample_size" self.height = sample_size self.width = sample_size self.patch_size = patch_size interpolation_scale = self.config.sample_size // 64 # => 64 (= 512 pixart) has interpolation scale 1 interpolation_scale = max(interpolation_scale, 1) self.pos_embed = PatchEmbed( height=sample_size, width=sample_size, patch_size=patch_size, in_channels=in_channels, embed_dim=inner_dim, interpolation_scale=interpolation_scale, ) # 3. Define transformers blocks self.transformer_blocks = nn.ModuleList( [ BasicTransformerBlock( inner_dim, num_attention_heads, attention_head_dim, dropout=dropout, cross_attention_dim=cross_attention_dim, activation_fn=activation_fn, num_embeds_ada_norm=num_embeds_ada_norm, attention_bias=attention_bias, only_cross_attention=only_cross_attention, double_self_attention=double_self_attention, upcast_attention=upcast_attention, norm_type=norm_type, norm_elementwise_affine=norm_elementwise_affine, norm_eps=norm_eps, attention_type=attention_type, ) for d in range(num_layers) ] ) # Define temporal transformers blocks self.temporal_transformer_blocks = nn.ModuleList( [ BasicTransformerBlock_( # one attention inner_dim, num_attention_heads, # num_attention_heads attention_head_dim, # attention_head_dim 72 dropout=dropout, cross_attention_dim=None, activation_fn=activation_fn, num_embeds_ada_norm=num_embeds_ada_norm, attention_bias=attention_bias, only_cross_attention=only_cross_attention, double_self_attention=False, upcast_attention=upcast_attention, norm_type=norm_type, norm_elementwise_affine=norm_elementwise_affine, norm_eps=norm_eps, attention_type=attention_type, ) for d in range(num_layers) ] ) # 4. Define output layers self.out_channels = in_channels if out_channels is None else out_channels if self.is_input_continuous: # TODO: should use out_channels for continuous projections if use_linear_projection: self.proj_out = linear_cls(inner_dim, in_channels) else: self.proj_out = conv_cls(inner_dim, in_channels, kernel_size=1, stride=1, padding=0) elif self.is_input_vectorized: self.norm_out = nn.LayerNorm(inner_dim) self.out = nn.Linear(inner_dim, self.num_vector_embeds - 1) elif self.is_input_patches and norm_type != "ada_norm_single": self.norm_out = nn.LayerNorm(inner_dim, elementwise_affine=False, eps=1e-6) self.proj_out_1 = nn.Linear(inner_dim, 2 * inner_dim) self.proj_out_2 = nn.Linear(inner_dim, patch_size * patch_size * self.out_channels) elif self.is_input_patches and norm_type == "ada_norm_single": self.norm_out = nn.LayerNorm(inner_dim, elementwise_affine=False, eps=1e-6) self.scale_shift_table = nn.Parameter(torch.randn(2, inner_dim) / inner_dim**0.5) self.proj_out = nn.Linear(inner_dim, patch_size * patch_size * self.out_channels) # 5. PixArt-Alpha blocks. self.adaln_single = None self.use_additional_conditions = False if norm_type == "ada_norm_single": self.use_additional_conditions = self.config.sample_size == 128 # False, 128 -> 1024 # TODO(Sayak, PVP) clean this, for now we use sample size to determine whether to use # additional conditions until we find better name self.adaln_single = AdaLayerNormSingle(inner_dim, use_additional_conditions=self.use_additional_conditions) self.caption_projection = None if caption_channels is not None: self.caption_projection = CaptionProjection(in_features=caption_channels, hidden_size=inner_dim) self.gradient_checkpointing = False # define temporal positional embedding temp_pos_embed = self.get_1d_sincos_temp_embed(inner_dim, video_length) # 1152 hidden size self.register_buffer("temp_pos_embed", torch.from_numpy(temp_pos_embed).float().unsqueeze(0), persistent=False) def _set_gradient_checkpointing(self, module, value=False): self.gradient_checkpointing = value def forward( self, hidden_states: torch.Tensor, timestep: Optional[torch.LongTensor] = None, encoder_hidden_states: Optional[torch.Tensor] = None, added_cond_kwargs: Dict[str, torch.Tensor] = None, class_labels: Optional[torch.LongTensor] = None, cross_attention_kwargs: Dict[str, Any] = None, attention_mask: Optional[torch.Tensor] = None, encoder_attention_mask: Optional[torch.Tensor] = None, use_image_num: int = 0, enable_temporal_attentions: bool = True, return_dict: bool = True, ): """ The [`Transformer2DModel`] forward method. Args: hidden_states (`torch.LongTensor` of shape `(batch size, num latent pixels)` if discrete, `torch.FloatTensor` of shape `(batch size, frame, channel, height, width)` if continuous): Input `hidden_states`. encoder_hidden_states ( `torch.FloatTensor` of shape `(batch size, sequence len, embed dims)`, *optional*): Conditional embeddings for cross attention layer. If not given, cross-attention defaults to self-attention. timestep ( `torch.LongTensor`, *optional*): Used to indicate denoising step. Optional timestep to be applied as an embedding in `AdaLayerNorm`. class_labels ( `torch.LongTensor` of shape `(batch size, num classes)`, *optional*): Used to indicate class labels conditioning. Optional class labels to be applied as an embedding in `AdaLayerZeroNorm`. cross_attention_kwargs ( `Dict[str, Any]`, *optional*): A kwargs dictionary that if specified is passed along to the `AttentionProcessor` as defined under `self.processor` in [diffusers.models.attention_processor](https://github.com/huggingface/diffusers/blob/main/src/diffusers/models/attention_processor.py). attention_mask ( `torch.Tensor`, *optional*): An attention mask of shape `(batch, key_tokens)` is applied to `encoder_hidden_states`. If `1` the mask is kept, otherwise if `0` it is discarded. Mask will be converted into a bias, which adds large negative values to the attention scores corresponding to "discard" tokens. encoder_attention_mask ( `torch.Tensor`, *optional*): Cross-attention mask applied to `encoder_hidden_states`. Two formats supported: * Mask `(batch, sequence_length)` True = keep, False = discard. * Bias `(batch, 1, sequence_length)` 0 = keep, -10000 = discard. If `ndim == 2`: will be interpreted as a mask, then converted into a bias consistent with the format above. This bias will be added to the cross-attention scores. return_dict (`bool`, *optional*, defaults to `True`): Whether or not to return a [`~models.unet_2d_condition.UNet2DConditionOutput`] instead of a plain tuple. Returns: If `return_dict` is True, an [`~models.transformer_2d.Transformer2DModelOutput`] is returned, otherwise a `tuple` where the first element is the sample tensor. """ input_batch_size, c, frame, h, w = hidden_states.shape frame = frame - use_image_num hidden_states = rearrange(hidden_states, 'b c f h w -> (b f) c h w').contiguous() # ensure attention_mask is a bias, and give it a singleton query_tokens dimension. # we may have done this conversion already, e.g. if we came here via UNet2DConditionModel#forward. # we can tell by counting dims; if ndim == 2: it's a mask rather than a bias. # expects mask of shape: # [batch, key_tokens] # adds singleton query_tokens dimension: # [batch, 1, key_tokens] # this helps to broadcast it as a bias over attention scores, which will be in one of the following shapes: # [batch, heads, query_tokens, key_tokens] (e.g. torch sdp attn) # [batch * heads, query_tokens, key_tokens] (e.g. xformers or classic attn) if attention_mask is not None and attention_mask.ndim == 2: # assume that mask is expressed as: # (1 = keep, 0 = discard) # convert mask into a bias that can be added to attention scores: # (keep = +0, discard = -10000.0) attention_mask = (1 - attention_mask.to(hidden_states.dtype)) * -10000.0 attention_mask = attention_mask.unsqueeze(1) # convert encoder_attention_mask to a bias the same way we do for attention_mask if encoder_attention_mask is not None and encoder_attention_mask.ndim == 2: # ndim == 2 means no image joint encoder_attention_mask = (1 - encoder_attention_mask.to(hidden_states.dtype)) * -10000.0 encoder_attention_mask = encoder_attention_mask.unsqueeze(1) encoder_attention_mask = repeat(encoder_attention_mask, 'b 1 l -> (b f) 1 l', f=frame).contiguous() elif encoder_attention_mask is not None and encoder_attention_mask.ndim == 3: # ndim == 3 means image joint encoder_attention_mask = (1 - encoder_attention_mask.to(hidden_states.dtype)) * -10000.0 encoder_attention_mask_video = encoder_attention_mask[:, :1, ...] encoder_attention_mask_video = repeat(encoder_attention_mask_video, 'b 1 l -> b (1 f) l', f=frame).contiguous() encoder_attention_mask_image = encoder_attention_mask[:, 1:, ...] encoder_attention_mask = torch.cat([encoder_attention_mask_video, encoder_attention_mask_image], dim=1) encoder_attention_mask = rearrange(encoder_attention_mask, 'b n l -> (b n) l').contiguous().unsqueeze(1) # Retrieve lora scale. lora_scale = cross_attention_kwargs.get("scale", 1.0) if cross_attention_kwargs is not None else 1.0 # 1. Input if self.is_input_patches: # here height, width = hidden_states.shape[-2] // self.patch_size, hidden_states.shape[-1] // self.patch_size num_patches = height * width hidden_states = self.pos_embed(hidden_states) # alrady add positional embeddings if self.adaln_single is not None: if self.use_additional_conditions and added_cond_kwargs is None: raise ValueError( "`added_cond_kwargs` cannot be None when using additional conditions for `adaln_single`." ) # batch_size = hidden_states.shape[0] batch_size = input_batch_size timestep, embedded_timestep = self.adaln_single( timestep, added_cond_kwargs, batch_size=batch_size, hidden_dtype=hidden_states.dtype ) # 2. Blocks if self.caption_projection is not None: batch_size = hidden_states.shape[0] encoder_hidden_states = self.caption_projection(encoder_hidden_states) # 3 120 1152 if use_image_num != 0 and self.training: encoder_hidden_states_video = encoder_hidden_states[:, :1, ...] encoder_hidden_states_video = repeat(encoder_hidden_states_video, 'b 1 t d -> b (1 f) t d', f=frame).contiguous() encoder_hidden_states_image = encoder_hidden_states[:, 1:, ...] encoder_hidden_states = torch.cat([encoder_hidden_states_video, encoder_hidden_states_image], dim=1) encoder_hidden_states_spatial = rearrange(encoder_hidden_states, 'b f t d -> (b f) t d').contiguous() else: encoder_hidden_states_spatial = repeat(encoder_hidden_states, 'b t d -> (b f) t d', f=frame).contiguous() # prepare timesteps for spatial and temporal block timestep_spatial = repeat(timestep, 'b d -> (b f) d', f=frame + use_image_num).contiguous() timestep_temp = repeat(timestep, 'b d -> (b p) d', p=num_patches).contiguous() for i, (spatial_block, temp_block) in enumerate(zip(self.transformer_blocks, self.temporal_transformer_blocks)): if self.training and self.gradient_checkpointing: hidden_states = torch.utils.checkpoint.checkpoint( spatial_block, hidden_states, attention_mask, encoder_hidden_states_spatial, encoder_attention_mask, timestep_spatial, cross_attention_kwargs, class_labels, use_reentrant=False, ) if enable_temporal_attentions: hidden_states = rearrange(hidden_states, '(b f) t d -> (b t) f d', b=input_batch_size).contiguous() if use_image_num != 0: # image-video joitn training hidden_states_video = hidden_states[:, :frame, ...] hidden_states_image = hidden_states[:, frame:, ...] if i == 0: hidden_states_video = hidden_states_video + self.temp_pos_embed hidden_states_video = torch.utils.checkpoint.checkpoint( temp_block, hidden_states_video, None, # attention_mask None, # encoder_hidden_states None, # encoder_attention_mask timestep_temp, cross_attention_kwargs, class_labels, use_reentrant=False, ) hidden_states = torch.cat([hidden_states_video, hidden_states_image], dim=1) hidden_states = rearrange(hidden_states, '(b t) f d -> (b f) t d', b=input_batch_size).contiguous() else: if i == 0: hidden_states = hidden_states + self.temp_pos_embed hidden_states = torch.utils.checkpoint.checkpoint( temp_block, hidden_states, None, # attention_mask None, # encoder_hidden_states None, # encoder_attention_mask timestep_temp, cross_attention_kwargs, class_labels, use_reentrant=False, ) hidden_states = rearrange(hidden_states, '(b t) f d -> (b f) t d', b=input_batch_size).contiguous() else: hidden_states = spatial_block( hidden_states, attention_mask, encoder_hidden_states_spatial, encoder_attention_mask, timestep_spatial, cross_attention_kwargs, class_labels, ) if enable_temporal_attentions: hidden_states = rearrange(hidden_states, '(b f) t d -> (b t) f d', b=input_batch_size).contiguous() if use_image_num != 0 and self.training: hidden_states_video = hidden_states[:, :frame, ...] hidden_states_image = hidden_states[:, frame:, ...] hidden_states_video = temp_block( hidden_states_video, None, # attention_mask None, # encoder_hidden_states None, # encoder_attention_mask timestep_temp, cross_attention_kwargs, class_labels, ) hidden_states = torch.cat([hidden_states_video, hidden_states_image], dim=1) hidden_states = rearrange(hidden_states, '(b t) f d -> (b f) t d', b=input_batch_size).contiguous() else: if i == 0 and frame > 1: hidden_states = hidden_states + self.temp_pos_embed hidden_states = temp_block( hidden_states, None, # attention_mask None, # encoder_hidden_states None, # encoder_attention_mask timestep_temp, cross_attention_kwargs, class_labels, ) hidden_states = rearrange(hidden_states, '(b t) f d -> (b f) t d', b=input_batch_size).contiguous() if self.is_input_patches: if self.config.norm_type != "ada_norm_single": conditioning = self.transformer_blocks[0].norm1.emb( timestep, class_labels, hidden_dtype=hidden_states.dtype ) shift, scale = self.proj_out_1(F.silu(conditioning)).chunk(2, dim=1) hidden_states = self.norm_out(hidden_states) * (1 + scale[:, None]) + shift[:, None] hidden_states = self.proj_out_2(hidden_states) elif self.config.norm_type == "ada_norm_single": embedded_timestep = repeat(embedded_timestep, 'b d -> (b f) d', f=frame + use_image_num).contiguous() shift, scale = (self.scale_shift_table[None] + embedded_timestep[:, None]).chunk(2, dim=1) hidden_states = self.norm_out(hidden_states) # Modulation hidden_states = hidden_states * (1 + scale) + shift hidden_states = self.proj_out(hidden_states) # unpatchify if self.adaln_single is None: height = width = int(hidden_states.shape[1] ** 0.5) hidden_states = hidden_states.reshape( shape=(-1, height, width, self.patch_size, self.patch_size, self.out_channels) ) hidden_states = torch.einsum("nhwpqc->nchpwq", hidden_states) output = hidden_states.reshape( shape=(-1, self.out_channels, height * self.patch_size, width * self.patch_size) ) output = rearrange(output, '(b f) c h w -> b c f h w', b=input_batch_size).contiguous() if not return_dict: return (output,) return Transformer3DModelOutput(sample=output) def get_1d_sincos_temp_embed(self, embed_dim, length): pos = torch.arange(0, length).unsqueeze(1) return get_1d_sincos_pos_embed_from_grid(embed_dim, pos)