From cf1e9885f4cf0cdb2fe5d499d4c56a2b25499f34 Mon Sep 17 00:00:00 2001
From: kijai <40791699+kijai@users.noreply.github.com>
Date: Wed, 3 Dec 2025 19:16:26 +0200
Subject: [PATCH] Allow freenoise to work on other dims, handle 4D batch
 timestep

Refactor Freenoise function. And fix batch handling as timesteps seem to be expanded to batch size now.
---
 comfy/context_windows.py | 38 ++++++++++++++++++++------------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/comfy/context_windows.py b/comfy/context_windows.py
index cecbe51ad..5c412d1c2 100644
--- a/comfy/context_windows.py
+++ b/comfy/context_windows.py
@@ -192,7 +192,7 @@ class IndexListContextHandler(ContextHandlerABC):
         return resized_cond
 
     def set_step(self, timestep: torch.Tensor, model_options: dict[str]):
-        mask = torch.isclose(model_options["transformer_options"]["sample_sigmas"], timestep, rtol=0.0001)
+        mask = torch.isclose(model_options["transformer_options"]["sample_sigmas"], timestep[0], rtol=0.0001)
         matches = torch.nonzero(mask)
         if torch.numel(matches) == 0:
             raise Exception("No sample_sigmas matched current timestep; something went wrong.")
@@ -324,7 +324,7 @@ def _sampler_sample_wrapper(executor, guider, sigmas, extra_args, callback, nois
         raise Exception("context_handler not found in sampler_sample_wrapper; this should never happen, something went wrong.")
     if not handler.freenoise:
         return executor(guider, sigmas, extra_args, callback, noise, *args, **kwargs)
-    noise = apply_freenoise(noise, handler.context_length, handler.context_overlap, extra_args["seed"])
+    noise = apply_freenoise(noise, handler.dim, handler.context_length, handler.context_overlap, extra_args["seed"])
 
     return executor(guider, sigmas, extra_args, callback, noise, *args, **kwargs)
 
@@ -591,24 +591,26 @@ def shift_window_to_end(window: list[int], num_frames: int):
 
 
 # https://github.com/Kosinkadink/ComfyUI-AnimateDiff-Evolved/blob/90fb1331201a4b29488089e4fbffc0d82cc6d0a9/animatediff/sample_settings.py#L465
-def apply_freenoise(noise: torch.Tensor, context_length: int, context_overlap: int, seed: int):
+def apply_freenoise(noise: torch.Tensor, dim: int, context_length: int, context_overlap: int, seed: int):
     logging.info("Context windows: Applying FreeNoise")
-    generator = torch.manual_seed(seed)
-    latent_video_length = noise.shape[2]
+    generator = torch.Generator(device='cpu').manual_seed(seed)
+    latent_video_length = noise.shape[dim]
     delta = context_length - context_overlap
-    for start_idx in range(0, latent_video_length-context_length, delta):
-        place_idx = start_idx + context_length
-        if place_idx >= latent_video_length:
-            break
-        end_idx = place_idx - 1
 
-        if end_idx + delta >= latent_video_length:
-            final_delta = latent_video_length - place_idx
-            list_idx = torch.tensor(list(range(start_idx,start_idx+final_delta)), device=torch.device("cpu"), dtype=torch.long)
-            list_idx = list_idx[torch.randperm(final_delta, generator=generator)]
-            noise[:, :, place_idx:place_idx + final_delta] = noise[:, :, list_idx]
+    for start_idx in range(0, latent_video_length - context_length, delta):
+        place_idx = start_idx + context_length
+
+        actual_delta = min(delta, latent_video_length - place_idx)
+        if actual_delta <= 0:
             break
-        list_idx = torch.tensor(list(range(start_idx,start_idx+delta)), device=torch.device("cpu"), dtype=torch.long)
-        list_idx = list_idx[torch.randperm(delta, generator=generator)]
-        noise[:, :, place_idx:place_idx + delta] = noise[:, :, list_idx]
+
+        list_idx = torch.randperm(actual_delta, generator=generator, device='cpu') + start_idx
+
+        source_slice = [slice(None)] * noise.ndim
+        source_slice[dim] = list_idx
+        target_slice = [slice(None)] * noise.ndim
+        target_slice[dim] = slice(place_idx, place_idx + actual_delta)
+
+        noise[tuple(target_slice)] = noise[tuple(source_slice)]
+
     return noise