diff --git a/qwenimage/transformer_qwenimage.py b/qwenimage/transformer_qwenimage.py new file mode 100644 index 0000000..af1d6b5 --- /dev/null +++ b/qwenimage/transformer_qwenimage.py @@ -0,0 +1,642 @@ +# Copyright 2025 Qwen-Image Team, 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 functools +import math +from typing import Any, Dict, List, Optional, Tuple, Union + +import torch +import torch.nn as nn +import torch.nn.functional as F + +from diffusers.configuration_utils import ConfigMixin, register_to_config +from diffusers.loaders import FromOriginalModelMixin, PeftAdapterMixin +from diffusers.utils import USE_PEFT_BACKEND, logging, scale_lora_layers, unscale_lora_layers +from diffusers.utils.torch_utils import maybe_allow_in_graph +from diffusers.models.attention import FeedForward, AttentionMixin +from diffusers.models.attention_dispatch import dispatch_attention_fn +from diffusers.models.attention_processor import Attention +from diffusers.models.cache_utils import CacheMixin +from diffusers.models.embeddings import TimestepEmbedding, Timesteps +from diffusers.models.modeling_outputs import Transformer2DModelOutput +from diffusers.models.modeling_utils import ModelMixin +from diffusers.models.normalization import AdaLayerNormContinuous, RMSNorm + + +logger = logging.get_logger(__name__) # pylint: disable=invalid-name + + +def get_timestep_embedding( + timesteps: torch.Tensor, + embedding_dim: int, + flip_sin_to_cos: bool = False, + downscale_freq_shift: float = 1, + scale: float = 1, + max_period: int = 10000, +) -> torch.Tensor: + """ + This matches the implementation in Denoising Diffusion Probabilistic Models: Create sinusoidal timestep embeddings. + + Args + timesteps (torch.Tensor): + a 1-D Tensor of N indices, one per batch element. These may be fractional. + embedding_dim (int): + the dimension of the output. + flip_sin_to_cos (bool): + Whether the embedding order should be `cos, sin` (if True) or `sin, cos` (if False) + downscale_freq_shift (float): + Controls the delta between frequencies between dimensions + scale (float): + Scaling factor applied to the embeddings. + max_period (int): + Controls the maximum frequency of the embeddings + Returns + torch.Tensor: an [N x dim] Tensor of positional embeddings. + """ + assert len(timesteps.shape) == 1, "Timesteps should be a 1d-array" + + half_dim = embedding_dim // 2 + exponent = -math.log(max_period) * torch.arange( + start=0, end=half_dim, dtype=torch.float32, device=timesteps.device + ) + exponent = exponent / (half_dim - downscale_freq_shift) + + emb = torch.exp(exponent).to(timesteps.dtype) + emb = timesteps[:, None].float() * emb[None, :] + + # scale embeddings + emb = scale * emb + + # concat sine and cosine embeddings + emb = torch.cat([torch.sin(emb), torch.cos(emb)], dim=-1) + + # flip sine and cosine embeddings + if flip_sin_to_cos: + emb = torch.cat([emb[:, half_dim:], emb[:, :half_dim]], dim=-1) + + # zero pad + if embedding_dim % 2 == 1: + emb = torch.nn.functional.pad(emb, (0, 1, 0, 0)) + return emb + + +def apply_rotary_emb_qwen( + x: torch.Tensor, + freqs_cis: Union[torch.Tensor, Tuple[torch.Tensor]], + use_real: bool = True, + use_real_unbind_dim: int = -1, +) -> Tuple[torch.Tensor, torch.Tensor]: + """ + Apply rotary embeddings to input tensors using the given frequency tensor. This function applies rotary embeddings + to the given query or key 'x' tensors using the provided frequency tensor 'freqs_cis'. The input tensors are + reshaped as complex numbers, and the frequency tensor is reshaped for broadcasting compatibility. The resulting + tensors contain rotary embeddings and are returned as real tensors. + + Args: + x (`torch.Tensor`): + Query or key tensor to apply rotary embeddings. [B, S, H, D] xk (torch.Tensor): Key tensor to apply + freqs_cis (`Tuple[torch.Tensor]`): Precomputed frequency tensor for complex exponentials. ([S, D], [S, D],) + + Returns: + Tuple[torch.Tensor, torch.Tensor]: Tuple of modified query tensor and key tensor with rotary embeddings. + """ + if use_real: + cos, sin = freqs_cis # [S, D] + cos = cos[None, None] + sin = sin[None, None] + cos, sin = cos.to(x.device), sin.to(x.device) + + if use_real_unbind_dim == -1: + # Used for flux, cogvideox, hunyuan-dit + x_real, x_imag = x.reshape(*x.shape[:-1], -1, 2).unbind(-1) # [B, S, H, D//2] + x_rotated = torch.stack([-x_imag, x_real], dim=-1).flatten(3) + elif use_real_unbind_dim == -2: + # Used for Stable Audio, OmniGen, CogView4 and Cosmos + x_real, x_imag = x.reshape(*x.shape[:-1], 2, -1).unbind(-2) # [B, S, H, D//2] + x_rotated = torch.cat([-x_imag, x_real], dim=-1) + else: + raise ValueError(f"`use_real_unbind_dim={use_real_unbind_dim}` but should be -1 or -2.") + + out = (x.float() * cos + x_rotated.float() * sin).to(x.dtype) + + return out + else: + x_rotated = torch.view_as_complex(x.float().reshape(*x.shape[:-1], -1, 2)) + freqs_cis = freqs_cis.unsqueeze(1) + x_out = torch.view_as_real(x_rotated * freqs_cis).flatten(3) + + return x_out.type_as(x) + + +class QwenTimestepProjEmbeddings(nn.Module): + def __init__(self, embedding_dim): + super().__init__() + + self.time_proj = Timesteps(num_channels=256, flip_sin_to_cos=True, downscale_freq_shift=0, scale=1000) + self.timestep_embedder = TimestepEmbedding(in_channels=256, time_embed_dim=embedding_dim) + + def forward(self, timestep, hidden_states): + timesteps_proj = self.time_proj(timestep) + timesteps_emb = self.timestep_embedder(timesteps_proj.to(dtype=hidden_states.dtype)) # (N, D) + + conditioning = timesteps_emb + + return conditioning + + +class QwenEmbedRope(nn.Module): + def __init__(self, theta: int, axes_dim: List[int], scale_rope=False): + super().__init__() + self.theta = theta + self.axes_dim = axes_dim + pos_index = torch.arange(4096) + neg_index = torch.arange(4096).flip(0) * -1 - 1 + self.pos_freqs = torch.cat( + [ + self.rope_params(pos_index, self.axes_dim[0], self.theta), + self.rope_params(pos_index, self.axes_dim[1], self.theta), + self.rope_params(pos_index, self.axes_dim[2], self.theta), + ], + dim=1, + ) + self.neg_freqs = torch.cat( + [ + self.rope_params(neg_index, self.axes_dim[0], self.theta), + self.rope_params(neg_index, self.axes_dim[1], self.theta), + self.rope_params(neg_index, self.axes_dim[2], self.theta), + ], + dim=1, + ) + self.rope_cache = {} + + # DO NOT USING REGISTER BUFFER HERE, IT WILL CAUSE COMPLEX NUMBERS LOSE ITS IMAGINARY PART + self.scale_rope = scale_rope + + def rope_params(self, index, dim, theta=10000): + """ + Args: + index: [0, 1, 2, 3] 1D Tensor representing the position index of the token + """ + assert dim % 2 == 0 + freqs = torch.outer(index, 1.0 / torch.pow(theta, torch.arange(0, dim, 2).to(torch.float32).div(dim))) + freqs = torch.polar(torch.ones_like(freqs), freqs) + return freqs + + def forward(self, video_fhw, txt_seq_lens, device): + """ + Args: video_fhw: [frame, height, width] a list of 3 integers representing the shape of the video Args: + txt_length: [bs] a list of 1 integers representing the length of the text + """ + if self.pos_freqs.device != device: + self.pos_freqs = self.pos_freqs.to(device) + self.neg_freqs = self.neg_freqs.to(device) + + if isinstance(video_fhw, list): + video_fhw = video_fhw[0] + if not isinstance(video_fhw, list): + video_fhw = [video_fhw] + + vid_freqs = [] + max_vid_index = 0 + for idx, fhw in enumerate(video_fhw): + frame, height, width = fhw + rope_key = f"{idx}_{height}_{width}" + + if not torch.compiler.is_compiling(): + if rope_key not in self.rope_cache: + self.rope_cache[rope_key] = self._compute_video_freqs(frame, height, width, idx) + video_freq = self.rope_cache[rope_key] + else: + video_freq = self._compute_video_freqs(frame, height, width, idx) + video_freq = video_freq.to(device) + vid_freqs.append(video_freq) + + if self.scale_rope: + max_vid_index = max(height // 2, width // 2, max_vid_index) + else: + max_vid_index = max(height, width, max_vid_index) + + max_len = max(txt_seq_lens) + txt_freqs = self.pos_freqs[max_vid_index : max_vid_index + max_len, ...] + vid_freqs = torch.cat(vid_freqs, dim=0) + + return vid_freqs, txt_freqs + + @functools.lru_cache(maxsize=None) + def _compute_video_freqs(self, frame, height, width, idx=0): + seq_lens = frame * height * width + freqs_pos = self.pos_freqs.split([x // 2 for x in self.axes_dim], dim=1) + freqs_neg = self.neg_freqs.split([x // 2 for x in self.axes_dim], dim=1) + + freqs_frame = freqs_pos[0][idx : idx + frame].view(frame, 1, 1, -1).expand(frame, height, width, -1) + if self.scale_rope: + freqs_height = torch.cat([freqs_neg[1][-(height - height // 2) :], freqs_pos[1][: height // 2]], dim=0) + freqs_height = freqs_height.view(1, height, 1, -1).expand(frame, height, width, -1) + freqs_width = torch.cat([freqs_neg[2][-(width - width // 2) :], freqs_pos[2][: width // 2]], dim=0) + freqs_width = freqs_width.view(1, 1, width, -1).expand(frame, height, width, -1) + else: + freqs_height = freqs_pos[1][:height].view(1, height, 1, -1).expand(frame, height, width, -1) + freqs_width = freqs_pos[2][:width].view(1, 1, width, -1).expand(frame, height, width, -1) + + freqs = torch.cat([freqs_frame, freqs_height, freqs_width], dim=-1).reshape(seq_lens, -1) + return freqs.clone().contiguous() + + +class QwenDoubleStreamAttnProcessor2_0: + """ + Attention processor for Qwen double-stream architecture, matching DoubleStreamLayerMegatron logic. This processor + implements joint attention computation where text and image streams are processed together. + """ + + _attention_backend = None + + def __init__(self): + if not hasattr(F, "scaled_dot_product_attention"): + raise ImportError( + "QwenDoubleStreamAttnProcessor2_0 requires PyTorch 2.0, to use it, please upgrade PyTorch to 2.0." + ) + + def __call__( + self, + attn: Attention, + hidden_states: torch.FloatTensor, # Image stream + encoder_hidden_states: torch.FloatTensor = None, # Text stream + encoder_hidden_states_mask: torch.FloatTensor = None, + attention_mask: Optional[torch.FloatTensor] = None, + image_rotary_emb: Optional[torch.Tensor] = None, + ) -> torch.FloatTensor: + if encoder_hidden_states is None: + raise ValueError("QwenDoubleStreamAttnProcessor2_0 requires encoder_hidden_states (text stream)") + + seq_txt = encoder_hidden_states.shape[1] + + # Compute QKV for image stream (sample projections) + img_query = attn.to_q(hidden_states) + img_key = attn.to_k(hidden_states) + img_value = attn.to_v(hidden_states) + + # Compute QKV for text stream (context projections) + txt_query = attn.add_q_proj(encoder_hidden_states) + txt_key = attn.add_k_proj(encoder_hidden_states) + txt_value = attn.add_v_proj(encoder_hidden_states) + + # Reshape for multi-head attention + img_query = img_query.unflatten(-1, (attn.heads, -1)) + img_key = img_key.unflatten(-1, (attn.heads, -1)) + img_value = img_value.unflatten(-1, (attn.heads, -1)) + + txt_query = txt_query.unflatten(-1, (attn.heads, -1)) + txt_key = txt_key.unflatten(-1, (attn.heads, -1)) + txt_value = txt_value.unflatten(-1, (attn.heads, -1)) + + # Apply QK normalization + if attn.norm_q is not None: + img_query = attn.norm_q(img_query) + if attn.norm_k is not None: + img_key = attn.norm_k(img_key) + if attn.norm_added_q is not None: + txt_query = attn.norm_added_q(txt_query) + if attn.norm_added_k is not None: + txt_key = attn.norm_added_k(txt_key) + + # Apply RoPE + if image_rotary_emb is not None: + img_freqs, txt_freqs = image_rotary_emb + img_query = apply_rotary_emb_qwen(img_query, img_freqs, use_real=False) + img_key = apply_rotary_emb_qwen(img_key, img_freqs, use_real=False) + txt_query = apply_rotary_emb_qwen(txt_query, txt_freqs, use_real=False) + txt_key = apply_rotary_emb_qwen(txt_key, txt_freqs, use_real=False) + + # Concatenate for joint attention + # Order: [text, image] + joint_query = torch.cat([txt_query, img_query], dim=1) + joint_key = torch.cat([txt_key, img_key], dim=1) + joint_value = torch.cat([txt_value, img_value], dim=1) + + # Compute joint attention + joint_hidden_states = dispatch_attention_fn( + joint_query, + joint_key, + joint_value, + attn_mask=attention_mask, + dropout_p=0.0, + is_causal=False, + backend=self._attention_backend, + ) + + # Reshape back + joint_hidden_states = joint_hidden_states.flatten(2, 3) + joint_hidden_states = joint_hidden_states.to(joint_query.dtype) + + # Split attention outputs back + txt_attn_output = joint_hidden_states[:, :seq_txt, :] # Text part + img_attn_output = joint_hidden_states[:, seq_txt:, :] # Image part + + # Apply output projections + img_attn_output = attn.to_out[0](img_attn_output) + if len(attn.to_out) > 1: + img_attn_output = attn.to_out[1](img_attn_output) # dropout + + txt_attn_output = attn.to_add_out(txt_attn_output) + + return img_attn_output, txt_attn_output + + +@maybe_allow_in_graph +class QwenImageTransformerBlock(nn.Module): + def __init__( + self, dim: int, num_attention_heads: int, attention_head_dim: int, qk_norm: str = "rms_norm", eps: float = 1e-6 + ): + super().__init__() + + self.dim = dim + self.num_attention_heads = num_attention_heads + self.attention_head_dim = attention_head_dim + + # Image processing modules + self.img_mod = nn.Sequential( + nn.SiLU(), + nn.Linear(dim, 6 * dim, bias=True), # For scale, shift, gate for norm1 and norm2 + ) + self.img_norm1 = nn.LayerNorm(dim, elementwise_affine=False, eps=eps) + self.attn = Attention( + query_dim=dim, + cross_attention_dim=None, # Enable cross attention for joint computation + added_kv_proj_dim=dim, # Enable added KV projections for text stream + dim_head=attention_head_dim, + heads=num_attention_heads, + out_dim=dim, + context_pre_only=False, + bias=True, + processor=QwenDoubleStreamAttnProcessor2_0(), + qk_norm=qk_norm, + eps=eps, + ) + self.img_norm2 = nn.LayerNorm(dim, elementwise_affine=False, eps=eps) + self.img_mlp = FeedForward(dim=dim, dim_out=dim, activation_fn="gelu-approximate") + + # Text processing modules + self.txt_mod = nn.Sequential( + nn.SiLU(), + nn.Linear(dim, 6 * dim, bias=True), # For scale, shift, gate for norm1 and norm2 + ) + self.txt_norm1 = nn.LayerNorm(dim, elementwise_affine=False, eps=eps) + # Text doesn't need separate attention - it's handled by img_attn joint computation + self.txt_norm2 = nn.LayerNorm(dim, elementwise_affine=False, eps=eps) + self.txt_mlp = FeedForward(dim=dim, dim_out=dim, activation_fn="gelu-approximate") + + def _modulate(self, x, mod_params): + """Apply modulation to input tensor""" + shift, scale, gate = mod_params.chunk(3, dim=-1) + return x * (1 + scale.unsqueeze(1)) + shift.unsqueeze(1), gate.unsqueeze(1) + + def forward( + self, + hidden_states: torch.Tensor, + encoder_hidden_states: torch.Tensor, + encoder_hidden_states_mask: torch.Tensor, + temb: torch.Tensor, + image_rotary_emb: Optional[Tuple[torch.Tensor, torch.Tensor]] = None, + joint_attention_kwargs: Optional[Dict[str, Any]] = None, + ) -> Tuple[torch.Tensor, torch.Tensor]: + # Get modulation parameters for both streams + img_mod_params = self.img_mod(temb) # [B, 6*dim] + txt_mod_params = self.txt_mod(temb) # [B, 6*dim] + + # Split modulation parameters for norm1 and norm2 + img_mod1, img_mod2 = img_mod_params.chunk(2, dim=-1) # Each [B, 3*dim] + txt_mod1, txt_mod2 = txt_mod_params.chunk(2, dim=-1) # Each [B, 3*dim] + + # Process image stream - norm1 + modulation + img_normed = self.img_norm1(hidden_states) + img_modulated, img_gate1 = self._modulate(img_normed, img_mod1) + + # Process text stream - norm1 + modulation + txt_normed = self.txt_norm1(encoder_hidden_states) + txt_modulated, txt_gate1 = self._modulate(txt_normed, txt_mod1) + + # Use QwenAttnProcessor2_0 for joint attention computation + # This directly implements the DoubleStreamLayerMegatron logic: + # 1. Computes QKV for both streams + # 2. Applies QK normalization and RoPE + # 3. Concatenates and runs joint attention + # 4. Splits results back to separate streams + joint_attention_kwargs = joint_attention_kwargs or {} + attn_output = self.attn( + hidden_states=img_modulated, # Image stream (will be processed as "sample") + encoder_hidden_states=txt_modulated, # Text stream (will be processed as "context") + encoder_hidden_states_mask=encoder_hidden_states_mask, + image_rotary_emb=image_rotary_emb, + **joint_attention_kwargs, + ) + + # QwenAttnProcessor2_0 returns (img_output, txt_output) when encoder_hidden_states is provided + img_attn_output, txt_attn_output = attn_output + + # Apply attention gates and add residual (like in Megatron) + hidden_states = hidden_states + img_gate1 * img_attn_output + encoder_hidden_states = encoder_hidden_states + txt_gate1 * txt_attn_output + + # Process image stream - norm2 + MLP + img_normed2 = self.img_norm2(hidden_states) + img_modulated2, img_gate2 = self._modulate(img_normed2, img_mod2) + img_mlp_output = self.img_mlp(img_modulated2) + hidden_states = hidden_states + img_gate2 * img_mlp_output + + # Process text stream - norm2 + MLP + txt_normed2 = self.txt_norm2(encoder_hidden_states) + txt_modulated2, txt_gate2 = self._modulate(txt_normed2, txt_mod2) + txt_mlp_output = self.txt_mlp(txt_modulated2) + encoder_hidden_states = encoder_hidden_states + txt_gate2 * txt_mlp_output + + # Clip to prevent overflow for fp16 + if encoder_hidden_states.dtype == torch.float16: + encoder_hidden_states = encoder_hidden_states.clip(-65504, 65504) + if hidden_states.dtype == torch.float16: + hidden_states = hidden_states.clip(-65504, 65504) + + return encoder_hidden_states, hidden_states + + +class QwenImageTransformer2DModel(ModelMixin, ConfigMixin, PeftAdapterMixin, FromOriginalModelMixin, CacheMixin, AttentionMixin): + """ + The Transformer model introduced in Qwen. + + Args: + patch_size (`int`, defaults to `2`): + Patch size to turn the input data into small patches. + in_channels (`int`, defaults to `64`): + The number of channels in the input. + out_channels (`int`, *optional*, defaults to `None`): + The number of channels in the output. If not specified, it defaults to `in_channels`. + num_layers (`int`, defaults to `60`): + The number of layers of dual stream DiT blocks to use. + attention_head_dim (`int`, defaults to `128`): + The number of dimensions to use for each attention head. + num_attention_heads (`int`, defaults to `24`): + The number of attention heads to use. + joint_attention_dim (`int`, defaults to `3584`): + The number of dimensions to use for the joint attention (embedding/channel dimension of + `encoder_hidden_states`). + guidance_embeds (`bool`, defaults to `False`): + Whether to use guidance embeddings for guidance-distilled variant of the model. + axes_dims_rope (`Tuple[int]`, defaults to `(16, 56, 56)`): + The dimensions to use for the rotary positional embeddings. + """ + + _supports_gradient_checkpointing = True + _no_split_modules = ["QwenImageTransformerBlock"] + _skip_layerwise_casting_patterns = ["pos_embed", "norm"] + _repeated_blocks = ["QwenImageTransformerBlock"] + + @register_to_config + def __init__( + self, + patch_size: int = 2, + in_channels: int = 64, + out_channels: Optional[int] = 16, + num_layers: int = 60, + attention_head_dim: int = 128, + num_attention_heads: int = 24, + joint_attention_dim: int = 3584, + guidance_embeds: bool = False, # TODO: this should probably be removed + axes_dims_rope: Tuple[int, int, int] = (16, 56, 56), + ): + super().__init__() + self.out_channels = out_channels or in_channels + self.inner_dim = num_attention_heads * attention_head_dim + + self.pos_embed = QwenEmbedRope(theta=10000, axes_dim=list(axes_dims_rope), scale_rope=True) + + self.time_text_embed = QwenTimestepProjEmbeddings(embedding_dim=self.inner_dim) + + self.txt_norm = RMSNorm(joint_attention_dim, eps=1e-6) + + self.img_in = nn.Linear(in_channels, self.inner_dim) + self.txt_in = nn.Linear(joint_attention_dim, self.inner_dim) + + self.transformer_blocks = nn.ModuleList( + [ + QwenImageTransformerBlock( + dim=self.inner_dim, + num_attention_heads=num_attention_heads, + attention_head_dim=attention_head_dim, + ) + for _ 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) + + self.gradient_checkpointing = False + + def forward( + self, + hidden_states: torch.Tensor, + encoder_hidden_states: torch.Tensor = None, + encoder_hidden_states_mask: torch.Tensor = None, + timestep: torch.LongTensor = None, + image_rotary_emb: Optional[Tuple[torch.Tensor, torch.Tensor]] = None, + guidance: torch.Tensor = None, # TODO: this should probably be removed + attention_kwargs: Optional[Dict[str, Any]] = None, + return_dict: bool = True, + ) -> Union[torch.Tensor, Transformer2DModelOutput]: + """ + The [`QwenTransformer2DModel`] forward method. + + Args: + hidden_states (`torch.Tensor` of shape `(batch_size, image_sequence_length, in_channels)`): + Input `hidden_states`. + encoder_hidden_states (`torch.Tensor` of shape `(batch_size, text_sequence_length, joint_attention_dim)`): + Conditional embeddings (embeddings computed from the input conditions such as prompts) to use. + encoder_hidden_states_mask (`torch.Tensor` of shape `(batch_size, text_sequence_length)`): + Mask of the input conditions. + timestep ( `torch.LongTensor`): + Used to indicate denoising step. + attention_kwargs (`dict`, *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). + return_dict (`bool`, *optional*, defaults to `True`): + Whether or not to return a [`~models.transformer_2d.Transformer2DModelOutput`] 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. + """ + if attention_kwargs is not None: + attention_kwargs = attention_kwargs.copy() + lora_scale = attention_kwargs.pop("scale", 1.0) + else: + lora_scale = 1.0 + + if USE_PEFT_BACKEND: + # weight the lora layers by setting `lora_scale` for each PEFT layer + scale_lora_layers(self, lora_scale) + else: + if attention_kwargs is not None and attention_kwargs.get("scale", None) is not None: + logger.warning( + "Passing `scale` via `joint_attention_kwargs` when not using the PEFT backend is ineffective." + ) + + hidden_states = self.img_in(hidden_states) + + timestep = timestep.to(hidden_states.dtype) + encoder_hidden_states = self.txt_norm(encoder_hidden_states) + encoder_hidden_states = self.txt_in(encoder_hidden_states) + + if guidance is not None: + guidance = guidance.to(hidden_states.dtype) * 1000 + + temb = ( + self.time_text_embed(timestep, hidden_states) + if guidance is None + else self.time_text_embed(timestep, guidance, hidden_states) + ) + + for index_block, block in enumerate(self.transformer_blocks): + if torch.is_grad_enabled() and self.gradient_checkpointing: + encoder_hidden_states, hidden_states = self._gradient_checkpointing_func( + block, + hidden_states, + encoder_hidden_states, + encoder_hidden_states_mask, + temb, + image_rotary_emb, + ) + + else: + encoder_hidden_states, hidden_states = block( + hidden_states=hidden_states, + encoder_hidden_states=encoder_hidden_states, + encoder_hidden_states_mask=encoder_hidden_states_mask, + temb=temb, + image_rotary_emb=image_rotary_emb, + joint_attention_kwargs=attention_kwargs, + ) + + # Use only the image part (hidden_states) from the dual-stream blocks + hidden_states = self.norm_out(hidden_states, temb) + output = self.proj_out(hidden_states) + + if USE_PEFT_BACKEND: + # remove `lora_scale` from each PEFT layer + unscale_lora_layers(self, lora_scale) + + if not return_dict: + return (output,) + + return Transformer2DModelOutput(sample=output) \ No newline at end of file