Add slice_cond and per-model context window cond resizing (Comfy-Org#12645)

* Add slice_cond and per-model context window cond resizing

* Fix cond_value.size() call in context window cond resizing

* Expose additional advanced inputs for ContextWindowsManualNode

Necessary for WanAnimate context windows workflow, which needs cond_retain_index_list = 0 to work properly with its reference input.

---------

Author: drozbay

comfy/context_windows.py

@@ -93,6 +93,50 @@ def init_callbacks(self):
         return {}
 
 
+def slice_cond(cond_value, window: IndexListContextWindow, x_in: torch.Tensor, device, temporal_dim: int, temporal_scale: int=1, temporal_offset: int=0, retain_index_list: list[int]=[]):
+    if not (hasattr(cond_value, "cond") and isinstance(cond_value.cond, torch.Tensor)):
+        return None
+    cond_tensor = cond_value.cond
+    if temporal_dim >= cond_tensor.ndim:
+        return None
+
+    cond_size = cond_tensor.size(temporal_dim)
+
+    if temporal_scale == 1:
+        expected_size = x_in.size(window.dim) - temporal_offset
+        if cond_size != expected_size:
+            return None
+
+    if temporal_offset == 0 and temporal_scale == 1:
+        sliced = window.get_tensor(cond_tensor, device, dim=temporal_dim, retain_index_list=retain_index_list)
+        return cond_value._copy_with(sliced)
+
+    # skip leading latent positions that have no corresponding conditioning (e.g. reference frames)
+    if temporal_offset > 0:
+        indices = [i - temporal_offset for i in window.index_list[temporal_offset:]]
+        indices = [i for i in indices if 0 <= i]
+    else:
+        indices = list(window.index_list)
+
+    if not indices:
+        return None
+
+    if temporal_scale > 1:
+        scaled = []
+        for i in indices:
+            for k in range(temporal_scale):
+                si = i * temporal_scale + k
+                if si < cond_size:
+                    scaled.append(si)
+        indices = scaled
+        if not indices:
+            return None
+
+    idx = tuple([slice(None)] * temporal_dim + [indices])
+    sliced = cond_tensor[idx].to(device)
+    return cond_value._copy_with(sliced)
+
+
 @dataclass
 class ContextSchedule:
     name: str
@@ -177,10 +221,17 @@ def get_resized_cond(self, cond_in: list[dict], x_in: torch.Tensor, window: Inde
                                     new_cond_item[cond_key] = result
                                     handled = True
                                     break
+                            if not handled and self._model is not None:
+                                result = self._model.resize_cond_for_context_window(
+                                    cond_key, cond_value, window, x_in, device,
+                                    retain_index_list=self.cond_retain_index_list)
+                                if result is not None:
+                                    new_cond_item[cond_key] = result
+                                    handled = True
                             if handled:
                                 continue
                             if isinstance(cond_value, torch.Tensor):
-                                if (self.dim < cond_value.ndim and cond_value(self.dim) == x_in.size(self.dim)) or \
+                                if (self.dim < cond_value.ndim and cond_value.size(self.dim) == x_in.size(self.dim)) or \
                                    (cond_value.ndim < self.dim and cond_value.size(0) == x_in.size(self.dim)):
                                     new_cond_item[cond_key] = window.get_tensor(cond_value, device)
                             # Handle audio_embed (temporal dim is 1)
@@ -224,6 +275,7 @@ def get_context_windows(self, model: BaseModel, x_in: torch.Tensor, model_option
         return context_windows
 
     def execute(self, calc_cond_batch: Callable, model: BaseModel, conds: list[list[dict]], x_in: torch.Tensor, timestep: torch.Tensor, model_options: dict[str]):
+        self._model = model
         self.set_step(timestep, model_options)
         context_windows = self.get_context_windows(model, x_in, model_options)
         enumerated_context_windows = list(enumerate(context_windows))

comfy/model_base.py

@@ -285,6 +285,12 @@ def concat_cond(self, **kwargs):
             return data
         return None
 
+    def resize_cond_for_context_window(self, cond_key, cond_value, window, x_in, device, retain_index_list=[]):
+        """Override in subclasses to handle model-specific cond slicing for context windows.
+        Return a sliced cond object, or None to fall through to default handling.
+        Use comfy.context_windows.slice_cond() for common cases."""
+        return None
+
     def extra_conds(self, **kwargs):
         out = {}
         concat_cond = self.concat_cond(**kwargs)
@@ -1375,6 +1381,12 @@ def extra_conds(self, **kwargs):
         out['vace_strength'] = comfy.conds.CONDConstant(vace_strength)
         return out
 
+    def resize_cond_for_context_window(self, cond_key, cond_value, window, x_in, device, retain_index_list=[]):
+        if cond_key == "vace_context":
+            import comfy.context_windows
+            return comfy.context_windows.slice_cond(cond_value, window, x_in, device, temporal_dim=3, retain_index_list=retain_index_list)
+        return super().resize_cond_for_context_window(cond_key, cond_value, window, x_in, device, retain_index_list=retain_index_list)
+
 class WAN21_Camera(WAN21):
     def __init__(self, model_config, model_type=ModelType.FLOW, image_to_video=False, device=None):
         super(WAN21, self).__init__(model_config, model_type, device=device, unet_model=comfy.ldm.wan.model.CameraWanModel)
@@ -1427,6 +1439,12 @@ def extra_conds(self, **kwargs):
 
         return out
 
+    def resize_cond_for_context_window(self, cond_key, cond_value, window, x_in, device, retain_index_list=[]):
+        if cond_key == "audio_embed":
+            import comfy.context_windows
+            return comfy.context_windows.slice_cond(cond_value, window, x_in, device, temporal_dim=1)
+        return super().resize_cond_for_context_window(cond_key, cond_value, window, x_in, device, retain_index_list=retain_index_list)
+
 class WAN22_Animate(WAN21):
     def __init__(self, model_config, model_type=ModelType.FLOW, image_to_video=False, device=None):
         super(WAN21, self).__init__(model_config, model_type, device=device, unet_model=comfy.ldm.wan.model_animate.AnimateWanModel)
@@ -1444,6 +1462,14 @@ def extra_conds(self, **kwargs):
             out['pose_latents'] = comfy.conds.CONDRegular(self.process_latent_in(pose_latents))
         return out
 
+    def resize_cond_for_context_window(self, cond_key, cond_value, window, x_in, device, retain_index_list=[]):
+        import comfy.context_windows
+        if cond_key == "face_pixel_values":
+            return comfy.context_windows.slice_cond(cond_value, window, x_in, device, temporal_dim=2, temporal_scale=4, temporal_offset=1)
+        if cond_key == "pose_latents":
+            return comfy.context_windows.slice_cond(cond_value, window, x_in, device, temporal_dim=2, temporal_offset=1)
+        return super().resize_cond_for_context_window(cond_key, cond_value, window, x_in, device, retain_index_list=retain_index_list)
+
 class WAN22_S2V(WAN21):
     def __init__(self, model_config, model_type=ModelType.FLOW, device=None):
         super(WAN21, self).__init__(model_config, model_type, device=device, unet_model=comfy.ldm.wan.model.WanModel_S2V)
@@ -1480,6 +1506,12 @@ def extra_conds_shapes(self, **kwargs):
             out['reference_motion'] = reference_motion.shape
         return out
 
+    def resize_cond_for_context_window(self, cond_key, cond_value, window, x_in, device, retain_index_list=[]):
+        if cond_key == "audio_embed":
+            import comfy.context_windows
+            return comfy.context_windows.slice_cond(cond_value, window, x_in, device, temporal_dim=1)
+        return super().resize_cond_for_context_window(cond_key, cond_value, window, x_in, device, retain_index_list=retain_index_list)
+
 class WAN22(WAN21):
     def __init__(self, model_config, model_type=ModelType.FLOW, image_to_video=False, device=None):
         super(WAN21, self).__init__(model_config, model_type, device=device, unet_model=comfy.ldm.wan.model.WanModel)

comfy_extras/nodes_context_windows.py

@@ -27,8 +27,8 @@ def define_schema(cls) -> io.Schema:
                 io.Combo.Input("fuse_method", options=comfy.context_windows.ContextFuseMethods.LIST_STATIC, default=comfy.context_windows.ContextFuseMethods.PYRAMID, tooltip="The method to use to fuse the context windows."),
                 io.Int.Input("dim", min=0, max=5, default=0, tooltip="The dimension to apply the context windows to."),
                 io.Boolean.Input("freenoise", default=False, tooltip="Whether to apply FreeNoise noise shuffling, improves window blending."),
-                #io.String.Input("cond_retain_index_list", default="", tooltip="List of latent indices to retain in the conditioning tensors for each window, for example setting this to '0' will use the initial start image for each window."),
-                #io.Boolean.Input("split_conds_to_windows", default=False, tooltip="Whether to split multiple conditionings (created by ConditionCombine) to each window based on region index."),
+                io.String.Input("cond_retain_index_list", default="", tooltip="List of latent indices to retain in the conditioning tensors for each window, for example setting this to '0' will use the initial start image for each window."),
+                io.Boolean.Input("split_conds_to_windows", default=False, tooltip="Whether to split multiple conditionings (created by ConditionCombine) to each window based on region index."),
             ],
             outputs=[
                 io.Model.Output(tooltip="The model with context windows applied during sampling."),