[qwen-image] edit 2511 support (#12839)

* [qwen-image] edit 2511 support

* Apply style fixes

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

src/diffusers/models/transformers/transformer_qwenimage.py

@@ -14,6 +14,7 @@
 
 import functools
 import math
+from math import prod
 from typing import Any, Dict, List, Optional, Tuple, Union
 
 import numpy as np
@@ -363,7 +364,13 @@ class QwenDoubleStreamAttnProcessor2_0:
 @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
+        self,
+        dim: int,
+        num_attention_heads: int,
+        attention_head_dim: int,
+        qk_norm: str = "rms_norm",
+        eps: float = 1e-6,
+        zero_cond_t: bool = False,
     ):
         super().__init__()
 
@@ -403,10 +410,43 @@ class QwenImageTransformerBlock(nn.Module):
         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):
+        self.zero_cond_t = zero_cond_t
+
+    def _modulate(self, x, mod_params, index=None):
         """Apply modulation to input tensor"""
+        # x: b l d, shift: b d, scale: b d, gate: b d
         shift, scale, gate = mod_params.chunk(3, dim=-1)
-        return x * (1 + scale.unsqueeze(1)) + shift.unsqueeze(1), gate.unsqueeze(1)
+
+        if index is not None:
+            # Assuming mod_params batch dim is 2*actual_batch (chunked into 2 parts)
+            # So shift, scale, gate have shape [2*actual_batch, d]
+            actual_batch = shift.size(0) // 2
+            shift_0, shift_1 = shift[:actual_batch], shift[actual_batch:]  # each: [actual_batch, d]
+            scale_0, scale_1 = scale[:actual_batch], scale[actual_batch:]
+            gate_0, gate_1 = gate[:actual_batch], gate[actual_batch:]
+
+            # index: [b, l] where b is actual batch size
+            # Expand to [b, l, 1] to match feature dimension
+            index_expanded = index.unsqueeze(-1)  # [b, l, 1]
+
+            # Expand chunks to [b, 1, d] then broadcast to [b, l, d]
+            shift_0_exp = shift_0.unsqueeze(1)  # [b, 1, d]
+            shift_1_exp = shift_1.unsqueeze(1)  # [b, 1, d]
+            scale_0_exp = scale_0.unsqueeze(1)
+            scale_1_exp = scale_1.unsqueeze(1)
+            gate_0_exp = gate_0.unsqueeze(1)
+            gate_1_exp = gate_1.unsqueeze(1)
+
+            # Use torch.where to select based on index
+            shift_result = torch.where(index_expanded == 0, shift_0_exp, shift_1_exp)
+            scale_result = torch.where(index_expanded == 0, scale_0_exp, scale_1_exp)
+            gate_result = torch.where(index_expanded == 0, gate_0_exp, gate_1_exp)
+        else:
+            shift_result = shift.unsqueeze(1)
+            scale_result = scale.unsqueeze(1)
+            gate_result = gate.unsqueeze(1)
+
+        return x * (1 + scale_result) + shift_result, gate_result
 
     def forward(
         self,
@@ -416,9 +456,13 @@ class QwenImageTransformerBlock(nn.Module):
         temb: torch.Tensor,
         image_rotary_emb: Optional[Tuple[torch.Tensor, torch.Tensor]] = None,
         joint_attention_kwargs: Optional[Dict[str, Any]] = None,
+        modulate_index: Optional[List[int]] = None,
     ) -> Tuple[torch.Tensor, torch.Tensor]:
         # Get modulation parameters for both streams
         img_mod_params = self.img_mod(temb)  # [B, 6*dim]
+
+        if self.zero_cond_t:
+            temb = torch.chunk(temb, 2, dim=0)[0]
         txt_mod_params = self.txt_mod(temb)  # [B, 6*dim]
 
         # Split modulation parameters for norm1 and norm2
@@ -427,7 +471,7 @@ class QwenImageTransformerBlock(nn.Module):
 
         # Process image stream - norm1 + modulation
         img_normed = self.img_norm1(hidden_states)
-        img_modulated, img_gate1 = self._modulate(img_normed, img_mod1)
+        img_modulated, img_gate1 = self._modulate(img_normed, img_mod1, modulate_index)
 
         # Process text stream - norm1 + modulation
         txt_normed = self.txt_norm1(encoder_hidden_states)
@@ -457,7 +501,7 @@ class QwenImageTransformerBlock(nn.Module):
 
         # Process image stream - norm2 + MLP
         img_normed2 = self.img_norm2(hidden_states)
-        img_modulated2, img_gate2 = self._modulate(img_normed2, img_mod2)
+        img_modulated2, img_gate2 = self._modulate(img_normed2, img_mod2, modulate_index)
         img_mlp_output = self.img_mlp(img_modulated2)
         hidden_states = hidden_states + img_gate2 * img_mlp_output
 
@@ -533,6 +577,7 @@ class QwenImageTransformer2DModel(
         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),
+        zero_cond_t: bool = False,
     ):
         super().__init__()
         self.out_channels = out_channels or in_channels
@@ -553,6 +598,7 @@ class QwenImageTransformer2DModel(
                     dim=self.inner_dim,
                     num_attention_heads=num_attention_heads,
                     attention_head_dim=attention_head_dim,
+                    zero_cond_t=zero_cond_t,
                 )
                 for _ in range(num_layers)
             ]
@@ -562,6 +608,7 @@ class QwenImageTransformer2DModel(
         self.proj_out = nn.Linear(self.inner_dim, patch_size * patch_size * self.out_channels, bias=True)
 
         self.gradient_checkpointing = False
+        self.zero_cond_t = zero_cond_t
 
     def forward(
         self,
@@ -618,6 +665,17 @@ class QwenImageTransformer2DModel(
         hidden_states = self.img_in(hidden_states)
 
         timestep = timestep.to(hidden_states.dtype)
+
+        if self.zero_cond_t:
+            timestep = torch.cat([timestep, timestep * 0], dim=0)
+            modulate_index = torch.tensor(
+                [[0] * prod(sample[0]) + [1] * sum([prod(s) for s in sample[1:]]) for sample in img_shapes],
+                device=timestep.device,
+                dtype=torch.int,
+            )
+        else:
+            modulate_index = None
+
         encoder_hidden_states = self.txt_norm(encoder_hidden_states)
         encoder_hidden_states = self.txt_in(encoder_hidden_states)
 
@@ -641,6 +699,8 @@ class QwenImageTransformer2DModel(
                     encoder_hidden_states_mask,
                     temb,
                     image_rotary_emb,
+                    attention_kwargs,
+                    modulate_index,
                 )
 
             else:
@@ -651,6 +711,7 @@ class QwenImageTransformer2DModel(
                     temb=temb,
                     image_rotary_emb=image_rotary_emb,
                     joint_attention_kwargs=attention_kwargs,
+                    modulate_index=modulate_index,
                 )
 
             # controlnet residual
@@ -659,6 +720,8 @@ class QwenImageTransformer2DModel(
                 interval_control = int(np.ceil(interval_control))
                 hidden_states = hidden_states + controlnet_block_samples[index_block // interval_control]
 
+        if self.zero_cond_t:
+            temb = temb.chunk(2, dim=0)[0]
         # 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)