support qwen-image-edit lowres fix

diffsynth/models/qwen_image_dit.py

@@ -166,6 +166,66 @@ class QwenEmbedRope(nn.Module):
         return vid_freqs, txt_freqs
 
 
+    def forward_sampling(self, video_fhw, txt_seq_lens, device):
+        self._expand_pos_freqs_if_needed(video_fhw, txt_seq_lens)
+        if self.pos_freqs.device != device:
+            self.pos_freqs = self.pos_freqs.to(device)
+            self.neg_freqs = self.neg_freqs.to(device)
+
+        vid_freqs = []
+        max_vid_index = 0
+        for idx, fhw in enumerate(video_fhw):
+            frame, height, width = fhw
+            rope_key = f"{idx}_{height}_{width}"
+            if idx > 0 and f"{0}_{height}_{width}" not in self.rope_cache:
+                frame_0, height_0, width_0 = video_fhw[0]
+
+                rope_key_0 = f"0_{height_0}_{width_0}"
+                spatial_freqs_0 = self.rope_cache[rope_key_0].reshape(frame_0, height_0, width_0, -1)
+                h_indices = torch.linspace(0, height_0 - 1, height).long()
+                w_indices = torch.linspace(0, width_0 - 1, width).long()
+                h_grid, w_grid = torch.meshgrid(h_indices, w_indices, indexing='ij')
+                sampled_rope = spatial_freqs_0[:, h_grid, w_grid, :]
+
+                freqs_pos = self.pos_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)
+                sampled_rope[:, :, :, :freqs_frame.shape[-1]] = freqs_frame
+
+                seq_lens = frame * height * width
+                self.rope_cache[rope_key] = sampled_rope.reshape(seq_lens, -1).clone()
+            if rope_key not in self.rope_cache:
+                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)
+                self.rope_cache[rope_key] = freqs.clone()
+            vid_freqs.append(self.rope_cache[rope_key].contiguous())
+
+            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
+
+
 class QwenFeedForward(nn.Module):
     def __init__(
         self,