[Modular] update the auto pipeline blocks doc (#13148)

* update

* Apply suggestion from @yiyixuxu

* Update docs/source/en/modular_diffusers/auto_pipeline_blocks.md

Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>

* Update docs/source/en/modular_diffusers/auto_pipeline_blocks.md

Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>

* Update docs/source/en/modular_diffusers/auto_pipeline_blocks.md

Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>

* Update docs/source/en/modular_diffusers/auto_pipeline_blocks.md

Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>

* add to api

---------

Co-authored-by: yiyi@huggingface.co <yiyi@ip-26-0-160-103.ec2.internal>
Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>
Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>
Co-authored-by: yiyi@huggingface.co <yiyi@ip-26-0-161-123.ec2.internal>

docs/source/en/api/modular_diffusers/pipeline_blocks.md

@@ -14,4 +14,8 @@
 
 ## AutoPipelineBlocks
 
-[[autodoc]] diffusers.modular_pipelines.modular_pipeline.AutoPipelineBlocks
+[[autodoc]] diffusers.modular_pipelines.modular_pipeline.AutoPipelineBlocks
+
+## ConditionalPipelineBlocks
+
+[[autodoc]] diffusers.modular_pipelines.modular_pipeline.ConditionalPipelineBlocks

docs/source/en/api/pipelines/cosmos.md

@@ -46,6 +46,20 @@ output = pipe(
 output.save("output.png")
 ```
 
+## Cosmos2_5_TransferPipeline
+
+[[autodoc]] Cosmos2_5_TransferPipeline
+  - all
+  - __call__
+
+
+## Cosmos2_5_PredictBasePipeline
+
+[[autodoc]] Cosmos2_5_PredictBasePipeline
+  - all
+  - __call__
+
+
 ## CosmosTextToWorldPipeline
 
 [[autodoc]] CosmosTextToWorldPipeline
@@ -70,12 +84,6 @@ output.save("output.png")
   - all
   - __call__
 
-## Cosmos2_5_PredictBasePipeline
-
-[[autodoc]] Cosmos2_5_PredictBasePipeline
-  - all
-  - __call__
-
 ## CosmosPipelineOutput
 
 [[autodoc]] pipelines.cosmos.pipeline_output.CosmosPipelineOutput

docs/source/en/modular_diffusers/auto_pipeline_blocks.md

@@ -121,7 +121,7 @@ from diffusers.modular_pipelines import AutoPipelineBlocks
 
 class AutoImageBlocks(AutoPipelineBlocks):
     # List of sub-block classes to choose from
-    block_classes = [block_inpaint_cls, block_i2i_cls, block_t2i_cls]
+    block_classes = [InpaintBlock, ImageToImageBlock, TextToImageBlock]
     # Names for each block in the same order
     block_names = ["inpaint", "img2img", "text2img"]
     # Trigger inputs that determine which block to run
@@ -129,8 +129,8 @@ class AutoImageBlocks(AutoPipelineBlocks):
     # - "image" triggers img2img workflow (but only if mask is not provided)
     # - if none of above, runs the text2img workflow (default)
     block_trigger_inputs = ["mask", "image", None]
-    # Description is extremely important for AutoPipelineBlocks
 
+    @property
     def description(self):
         return (
             "Pipeline generates images given different types of conditions!\n"
@@ -141,7 +141,7 @@ class AutoImageBlocks(AutoPipelineBlocks):
         )
 ```
 
-It is **very** important to include a `description` to avoid any confusion over how to run a block and what inputs are required. While [`~modular_pipelines.AutoPipelineBlocks`] are convenient, it's conditional logic may be difficult to figure out if it isn't properly explained.
+It is **very** important to include a `description` to avoid any confusion over how to run a block and what inputs are required. While [`~modular_pipelines.AutoPipelineBlocks`] are convenient, its conditional logic may be difficult to figure out if it isn't properly explained.
 
 Create an instance of `AutoImageBlocks`.
 
@@ -152,5 +152,74 @@ auto_blocks = AutoImageBlocks()
 For more complex compositions, such as nested [`~modular_pipelines.AutoPipelineBlocks`] blocks when they're used as sub-blocks in larger pipelines, use the [`~modular_pipelines.SequentialPipelineBlocks.get_execution_blocks`] method to extract the a block that is actually run based on your input.
 
 ```py
-auto_blocks.get_execution_blocks("mask")
+auto_blocks.get_execution_blocks(mask=True)
+```
+
+## ConditionalPipelineBlocks
+
+[`~modular_pipelines.AutoPipelineBlocks`] is a special case of [`~modular_pipelines.ConditionalPipelineBlocks`]. While [`~modular_pipelines.AutoPipelineBlocks`] selects blocks based on whether a trigger input is provided or not, [`~modular_pipelines.ConditionalPipelineBlocks`] is able to select a block based on custom selection logic provided in the `select_block` method.
+
+Here is the same example written using [`~modular_pipelines.ConditionalPipelineBlocks`] directly:
+
+```py
+from diffusers.modular_pipelines import ConditionalPipelineBlocks
+
+class AutoImageBlocks(ConditionalPipelineBlocks):
+    block_classes = [InpaintBlock, ImageToImageBlock, TextToImageBlock]
+    block_names = ["inpaint", "img2img", "text2img"]
+    block_trigger_inputs = ["mask", "image"]
+    default_block_name = "text2img"
+
+    @property
+    def description(self):
+        return (
+            "Pipeline generates images given different types of conditions!\n"
+            + "This is an auto pipeline block that works for text2img, img2img and inpainting tasks.\n"
+            + " - inpaint workflow is run when `mask` is provided.\n"
+            + " - img2img workflow is run when `image` is provided (but only when `mask` is not provided).\n"
+            + " - text2img workflow is run when neither `image` nor `mask` is provided.\n"
+        )
+
+    def select_block(self, mask=None, image=None) -> str | None:
+        if mask is not None:
+            return "inpaint"
+        if image is not None:
+            return "img2img"
+        return None  # falls back to default_block_name ("text2img")
+```
+
+The inputs listed in `block_trigger_inputs` are passed as keyword arguments to `select_block()`. When `select_block` returns `None`, it falls back to `default_block_name`. If `default_block_name` is also `None`, the entire conditional block is skipped — this is useful for optional processing steps that should only run when specific inputs are provided.
+
+## Workflows
+
+Pipelines that contain conditional blocks ([`~modular_pipelines.AutoPipelineBlocks`] or [`~modular_pipelines.ConditionalPipelineBlocks]`) can support multiple workflows — for example, our SDXL modular pipeline supports a dozen workflows all in one pipeline. But this also means it can be confusing for users to know what workflows are supported and how to run them. For pipeline builders, it's useful to be able to extract only the blocks relevant to a specific workflow.
+
+We recommend defining a `_workflow_map` to give each workflow a name and explicitly list the inputs it requires.
+
+```py
+from diffusers.modular_pipelines import SequentialPipelineBlocks
+
+class MyPipelineBlocks(SequentialPipelineBlocks):
+    block_classes = [TextEncoderBlock, AutoImageBlocks, DecodeBlock]
+    block_names = ["text_encoder", "auto_image", "decode"]
+
+    _workflow_map = {
+        "text2image": {"prompt": True},
+        "image2image": {"image": True, "prompt": True},
+        "inpaint": {"mask": True, "image": True, "prompt": True},
+    }
+```
+
+All of our built-in modular pipelines come with pre-defined workflows. The `available_workflows` property lists all supported workflows:
+
+```py
+pipeline_blocks = MyPipelineBlocks()
+pipeline_blocks.available_workflows
+# ['text2image', 'image2image', 'inpaint']
+```
+
+Retrieve a specific workflow with `get_workflow` to inspect and debug a specific block that executes the workflow.
+
+```py
+pipeline_blocks.get_workflow("inpaint")
 ```

docs/source/en/training/distributed_inference.md

@@ -111,7 +111,7 @@ if __name__ == "__main__":
 Call `torchrun` to run the inference script and use the `--nproc_per_node` argument to set the number of GPUs to use.
 
 ```bash
-torchrun run_distributed.py --nproc_per_node=2
+torchrun --nproc_per_node=2 run_distributed.py
 ```
 
 ## device_map

scripts/convert_cosmos_to_diffusers.py

@@ -94,9 +94,15 @@ python scripts/convert_cosmos_to_diffusers.py \
     --transformer_type Cosmos-2.5-Transfer-General-2B \
     --transformer_ckpt_path $transformer_ckpt_path \
     --vae_type wan2.1 \
-    --output_path converted/transfer/2b/general/depth \
+    --output_path converted/transfer/2b/general/depth/pipeline \
     --save_pipeline
 
+python scripts/convert_cosmos_to_diffusers.py \
+    --transformer_type Cosmos-2.5-Transfer-General-2B \
+    --transformer_ckpt_path $transformer_ckpt_path \
+    --vae_type wan2.1 \
+    --output_path converted/transfer/2b/general/depth/models
+
 # edge
 transformer_ckpt_path=~/.cache/huggingface/hub/models--nvidia--Cosmos-Transfer2.5-2B/snapshots/eb5325b77d358944da58a690157dd2b8071bbf85/general/edge/61f5694b-0ad5-4ecd-8ad7-c8545627d125_ema_bf16.pt
 
@@ -120,9 +126,15 @@ python scripts/convert_cosmos_to_diffusers.py \
     --transformer_type Cosmos-2.5-Transfer-General-2B \
     --transformer_ckpt_path $transformer_ckpt_path \
     --vae_type wan2.1 \
-    --output_path converted/transfer/2b/general/blur \
+    --output_path converted/transfer/2b/general/blur/pipeline \
     --save_pipeline
 
+python scripts/convert_cosmos_to_diffusers.py \
+    --transformer_type Cosmos-2.5-Transfer-General-2B \
+    --transformer_ckpt_path $transformer_ckpt_path \
+    --vae_type wan2.1 \
+    --output_path converted/transfer/2b/general/blur/models
+
 # seg
 transformer_ckpt_path=~/.cache/huggingface/hub/models--nvidia--Cosmos-Transfer2.5-2B/snapshots/eb5325b77d358944da58a690157dd2b8071bbf85/general/seg/5136ef49-6d8d-42e8-8abf-7dac722a304a_ema_bf16.pt
 
@@ -130,8 +142,14 @@ python scripts/convert_cosmos_to_diffusers.py \
     --transformer_type Cosmos-2.5-Transfer-General-2B \
     --transformer_ckpt_path $transformer_ckpt_path \
     --vae_type wan2.1 \
-    --output_path converted/transfer/2b/general/seg \
+    --output_path converted/transfer/2b/general/seg/pipeline \
     --save_pipeline
+
+python scripts/convert_cosmos_to_diffusers.py \
+    --transformer_type Cosmos-2.5-Transfer-General-2B \
+    --transformer_ckpt_path $transformer_ckpt_path \
+    --vae_type wan2.1 \
+    --output_path converted/transfer/2b/general/seg/models
 ```
 """
 

src/diffusers/loaders/lora_conversion_utils.py

@@ -856,7 +856,7 @@ def _convert_kohya_flux_lora_to_diffusers(state_dict):
                 )
             state_dict = {k: v for k, v in state_dict.items() if not k.startswith("text_encoders.t5xxl.transformer.")}
 
-        has_diffb = any("diff_b" in k and k.startswith(("lora_unet_", "lora_te_")) for k in state_dict)
+        has_diffb = any("diff_b" in k and k.startswith(("lora_unet_", "lora_te_", "lora_te1_")) for k in state_dict)
         if has_diffb:
             zero_status_diff_b = state_dict_all_zero(state_dict, ".diff_b")
             if zero_status_diff_b:
@@ -895,7 +895,7 @@ def _convert_kohya_flux_lora_to_diffusers(state_dict):
         state_dict = {
             _custom_replace(k, limit_substrings): v
             for k, v in state_dict.items()
-            if k.startswith(("lora_unet_", "lora_te_"))
+            if k.startswith(("lora_unet_", "lora_te_", "lora_te1_"))
         }
 
         if any("text_projection" in k for k in state_dict):

src/diffusers/models/attention_dispatch.py

@@ -329,7 +329,11 @@ class _HubKernelConfig:
 _HUB_KERNELS_REGISTRY: dict["AttentionBackendName", _HubKernelConfig] = {
     # TODO: temporary revision for now. Remove when merged upstream into `main`.
     AttentionBackendName._FLASH_3_HUB: _HubKernelConfig(
-        repo_id="kernels-community/flash-attn3", function_attr="flash_attn_func", revision="fake-ops-return-probs"
+        repo_id="kernels-community/flash-attn3",
+        function_attr="flash_attn_func",
+        revision="fake-ops-return-probs",
+        wrapped_forward_attr="flash_attn_interface._flash_attn_forward",
+        wrapped_backward_attr="flash_attn_interface._flash_attn_backward",
     ),
     AttentionBackendName._FLASH_3_VARLEN_HUB: _HubKernelConfig(
         repo_id="kernels-community/flash-attn3",
@@ -729,7 +733,7 @@ def _wrapped_flash_attn_3(
 ) -> tuple[torch.Tensor, torch.Tensor]:
     # Hardcoded for now because pytorch does not support tuple/int type hints
     window_size = (-1, -1)
-    out, lse, *_ = flash_attn_3_func(
+    result = flash_attn_3_func(
         q=q,
         k=k,
         v=v,
@@ -746,7 +750,9 @@ def _wrapped_flash_attn_3(
         pack_gqa=pack_gqa,
         deterministic=deterministic,
         sm_margin=sm_margin,
+        return_attn_probs=True,
     )
+    out, lse, *_ = result
     lse = lse.permute(0, 2, 1)
     return out, lse
 
@@ -1290,36 +1296,62 @@ def _flash_attention_3_hub_forward_op(
     if enable_gqa:
         raise ValueError("`enable_gqa` is not yet supported for flash-attn 3 hub kernels.")
 
-    func = _HUB_KERNELS_REGISTRY[AttentionBackendName._FLASH_3_HUB].kernel_fn
-    out = func(
-        q=query,
-        k=key,
-        v=value,
-        softmax_scale=scale,
+    config = _HUB_KERNELS_REGISTRY[AttentionBackendName._FLASH_3_HUB]
+    wrapped_forward_fn = config.wrapped_forward_fn
+    if wrapped_forward_fn is None:
+        raise RuntimeError(
+            "Flash attention 3 hub kernels must expose `flash_attn_interface._flash_attn_forward` "
+            "for context parallel execution."
+        )
+
+    if scale is None:
+        scale = query.shape[-1] ** (-0.5)
+
+    out, softmax_lse, *_ = wrapped_forward_fn(
+        query,
+        key,
+        value,
+        None,
+        None,  # k_new, v_new
+        None,  # qv
+        None,  # out
+        None,
+        None,
+        None,  # cu_seqlens_q/k/k_new
+        None,
+        None,  # seqused_q/k
+        None,
+        None,  # max_seqlen_q/k
+        None,
+        None,
+        None,  # page_table, kv_batch_idx, leftpad_k
+        None,
+        None,
+        None,  # rotary_cos/sin, seqlens_rotary
+        None,
+        None,
+        None,  # q_descale, k_descale, v_descale
+        scale,
         causal=is_causal,
-        qv=None,
-        q_descale=None,
-        k_descale=None,
-        v_descale=None,
-        window_size=window_size,
+        window_size_left=window_size[0],
+        window_size_right=window_size[1],
+        attention_chunk=0,
         softcap=softcap,
         num_splits=num_splits,
         pack_gqa=pack_gqa,
-        deterministic=deterministic,
         sm_margin=sm_margin,
-        return_attn_probs=return_lse,
     )
 
-    lse = None
-    if return_lse:
-        out, lse = out
-        lse = lse.permute(0, 2, 1).contiguous()
+    lse = softmax_lse.permute(0, 2, 1).contiguous() if return_lse else None
 
     if _save_ctx:
-        ctx.save_for_backward(query, key, value)
+        ctx.save_for_backward(query, key, value, out, softmax_lse)
         ctx.scale = scale
         ctx.is_causal = is_causal
-        ctx._hub_kernel = func
+        ctx.window_size = window_size
+        ctx.softcap = softcap
+        ctx.deterministic = deterministic
+        ctx.sm_margin = sm_margin
 
     return (out, lse) if return_lse else out
 
@@ -1328,54 +1360,49 @@ def _flash_attention_3_hub_backward_op(
     ctx: torch.autograd.function.FunctionCtx,
     grad_out: torch.Tensor,
     *args,
-    window_size: tuple[int, int] = (-1, -1),
-    softcap: float = 0.0,
-    num_splits: int = 1,
-    pack_gqa: bool | None = None,
-    deterministic: bool = False,
-    sm_margin: int = 0,
+    **kwargs,
 ):
-    query, key, value = ctx.saved_tensors
-    kernel_fn = ctx._hub_kernel
-    # NOTE: Unlike the FA2 hub kernel, the FA3 hub kernel does not expose separate wrapped forward/backward
-    # primitives (no `wrapped_forward_attr`/`wrapped_backward_attr` in its `_HubKernelConfig`). We
-    # therefore rerun the forward pass under `torch.enable_grad()` and differentiate through it with
-    # `torch.autograd.grad()`. This is a second forward pass during backward; it can be avoided once
-    # the FA3 hub exposes a dedicated fused backward kernel (analogous to `_wrapped_flash_attn_backward`
-    # in the FA2 hub), at which point this can be refactored to match `_flash_attention_hub_backward_op`.
-    with torch.enable_grad():
-        query_r = query.detach().requires_grad_(True)
-        key_r = key.detach().requires_grad_(True)
-        value_r = value.detach().requires_grad_(True)
-
-        out = kernel_fn(
-            q=query_r,
-            k=key_r,
-            v=value_r,
-            softmax_scale=ctx.scale,
-            causal=ctx.is_causal,
-            qv=None,
-            q_descale=None,
-            k_descale=None,
-            v_descale=None,
-            window_size=window_size,
-            softcap=softcap,
-            num_splits=num_splits,
-            pack_gqa=pack_gqa,
-            deterministic=deterministic,
-            sm_margin=sm_margin,
-            return_attn_probs=False,
+    config = _HUB_KERNELS_REGISTRY[AttentionBackendName._FLASH_3_HUB]
+    wrapped_backward_fn = config.wrapped_backward_fn
+    if wrapped_backward_fn is None:
+        raise RuntimeError(
+            "Flash attention 3 hub kernels must expose `flash_attn_interface._flash_attn_backward` "
+            "for context parallel execution."
         )
-        if isinstance(out, tuple):
-            out = out[0]
 
-        grad_query, grad_key, grad_value = torch.autograd.grad(
-            out,
-            (query_r, key_r, value_r),
-            grad_out,
-            retain_graph=False,
-            allow_unused=False,
-        )
+    query, key, value, out, softmax_lse = ctx.saved_tensors
+    grad_query = torch.empty_like(query)
+    grad_key = torch.empty_like(key)
+    grad_value = torch.empty_like(value)
+
+    wrapped_backward_fn(
+        grad_out,
+        query,
+        key,
+        value,
+        out,
+        softmax_lse,
+        None,
+        None,  # cu_seqlens_q, cu_seqlens_k
+        None,
+        None,  # seqused_q, seqused_k
+        None,
+        None,  # max_seqlen_q, max_seqlen_k
+        grad_query,
+        grad_key,
+        grad_value,
+        ctx.scale,
+        ctx.is_causal,
+        ctx.window_size[0],
+        ctx.window_size[1],
+        ctx.softcap,
+        ctx.deterministic,
+        ctx.sm_margin,
+    )
+
+    grad_query = grad_query[..., : grad_out.shape[-1]]
+    grad_key = grad_key[..., : grad_out.shape[-1]]
+    grad_value = grad_value[..., : grad_out.shape[-1]]
 
     return grad_query, grad_key, grad_value
 
@@ -1865,12 +1892,9 @@ class TemplatedRingAttention(torch.autograd.Function):
                 out = out.to(torch.float32)
                 lse = lse.to(torch.float32)
 
-            # lse must be 4-D to broadcast with out (B, S, H, D).
-            # Some backends (e.g. cuDNN on torch>=2.9) already return a
-            # trailing-1 dim; others (e.g. flash-hub / native-flash) always
-            # return 3-D lse, so we add the dim here when needed.
-            # See: https://github.com/huggingface/diffusers/pull/12693#issuecomment-3627519544
-            if lse.ndim == 3:
+            # Refer to:
+            # https://github.com/huggingface/diffusers/pull/12693#issuecomment-3627519544
+            if is_torch_version("<", "2.9.0"):
                 lse = lse.unsqueeze(-1)
             if prev_out is not None:
                 out = prev_out - torch.nn.functional.sigmoid(lse - prev_lse) * (prev_out - out)
@@ -2157,11 +2181,10 @@ def _templated_unified_attention(
         scatter_idx,
     )
     if return_lse:
-        # lse from TemplatedRingAttention is 3-D (B, S, H_LOCAL) after its
-        # final squeeze(-1). SeqAllToAllDim requires a 4-D input, so we add
-        # the trailing dim here and remove it after the collective.
-        # See: https://github.com/huggingface/diffusers/pull/12693#issuecomment-3627519544
-        if lse.ndim == 3:
+        # lse is of shape (B, S, H_LOCAL, 1)
+        # Refer to:
+        # https://github.com/huggingface/diffusers/pull/12693#issuecomment-3627519544
+        if is_torch_version("<", "2.9.0"):
             lse = lse.unsqueeze(-1)  # (B, S, H_LOCAL, 1)
         lse = SeqAllToAllDim.apply(ulysses_group, lse, gather_idx, scatter_idx)
         lse = lse.squeeze(-1)
@@ -2680,7 +2703,7 @@ def _flash_varlen_attention_3(
     key_packed = torch.cat(key_valid, dim=0)
     value_packed = torch.cat(value_valid, dim=0)
 
-    out, lse, *_ = flash_attn_3_varlen_func(
+    result = flash_attn_3_varlen_func(
         q=query_packed,
         k=key_packed,
         v=value_packed,
@@ -2690,7 +2713,13 @@ def _flash_varlen_attention_3(
         max_seqlen_k=max_seqlen_k,
         softmax_scale=scale,
         causal=is_causal,
+        return_attn_probs=return_lse,
     )
+    if isinstance(result, tuple):
+        out, lse, *_ = result
+    else:
+        out = result
+        lse = None
     out = out.unflatten(0, (batch_size, -1))
 
     return (out, lse) if return_lse else out

src/diffusers/models/controlnets/controlnet_cosmos.py

@@ -191,7 +191,12 @@ class CosmosControlNetModel(ModelMixin, ConfigMixin, FromOriginalModelMixin):
                 dim=1,
             )
 
-        control_hidden_states = torch.cat([control_hidden_states, torch.zeros_like(controls_latents[:, :1])], dim=1)
+        if condition_mask is not None:
+            control_hidden_states = torch.cat([control_hidden_states, condition_mask], dim=1)
+        else:
+            control_hidden_states = torch.cat(
+                [control_hidden_states, torch.zeros_like(controls_latents[:, :1])], dim=1
+            )
 
         padding_mask_resized = transforms.functional.resize(
             padding_mask, list(control_hidden_states.shape[-2:]), interpolation=transforms.InterpolationMode.NEAREST

src/diffusers/pipelines/cosmos/pipeline_cosmos2_5_transfer.py

@@ -17,9 +17,6 @@ from typing import Callable, Dict, List, Optional, Union
 import numpy as np
 import PIL.Image
 import torch
-import torchvision
-import torchvision.transforms
-import torchvision.transforms.functional
 from transformers import AutoTokenizer, Qwen2_5_VLForConditionalGeneration
 
 from ...callbacks import MultiPipelineCallbacks, PipelineCallback
@@ -54,11 +51,13 @@ else:
 logger = logging.get_logger(__name__)  # pylint: disable=invalid-name
 
 
-def _maybe_pad_video(video: torch.Tensor, num_frames: int):
+def _maybe_pad_or_trim_video(video: torch.Tensor, num_frames: int):
     n_pad_frames = num_frames - video.shape[2]
     if n_pad_frames > 0:
         last_frame = video[:, :, -1:, :, :]
         video = torch.cat((video, last_frame.repeat(1, 1, n_pad_frames, 1, 1)), dim=2)
+    elif num_frames < video.shape[2]:
+        video = video[:, :, :num_frames, :, :]
     return video
 
 
@@ -134,8 +133,8 @@ EXAMPLE_DOC_STRING = """
         >>> controls = [Image.fromarray(x.numpy()) for x in controls.permute(1, 2, 3, 0)]
         >>> export_to_video(controls, "edge_controlled_video_edge.mp4", fps=30)
 
+        >>> # Transfer inference with controls.
         >>> video = pipe(
-        ...     video=input_video[:num_frames],
         ...     controls=controls,
         ...     controls_conditioning_scale=1.0,
         ...     prompt=prompt,
@@ -149,7 +148,7 @@ EXAMPLE_DOC_STRING = """
 
 class Cosmos2_5_TransferPipeline(DiffusionPipeline):
     r"""
-    Pipeline for Cosmos Transfer2.5 base model.
+    Pipeline for Cosmos Transfer2.5, supporting auto-regressive inference.
 
     This model inherits from [`DiffusionPipeline`]. Check the superclass documentation for the generic methods
     implemented for all pipelines (downloading, saving, running on a particular device, etc.).
@@ -166,12 +165,14 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
             A scheduler to be used in combination with `transformer` to denoise the encoded image latents.
         vae ([`AutoencoderKLWan`]):
             Variational Auto-Encoder (VAE) Model to encode and decode videos to and from latent representations.
+        controlnet ([`CosmosControlNetModel`]):
+            ControlNet used to condition generation on control inputs.
     """
 
     model_cpu_offload_seq = "text_encoder->transformer->controlnet->vae"
     _callback_tensor_inputs = ["latents", "prompt_embeds", "negative_prompt_embeds"]
     # We mark safety_checker as optional here to get around some test failures, but it is not really optional
-    _optional_components = ["safety_checker", "controlnet"]
+    _optional_components = ["safety_checker"]
     _exclude_from_cpu_offload = ["safety_checker"]
 
     def __init__(
@@ -181,8 +182,8 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
         transformer: CosmosTransformer3DModel,
         vae: AutoencoderKLWan,
         scheduler: UniPCMultistepScheduler,
-        controlnet: Optional[CosmosControlNetModel],
-        safety_checker: CosmosSafetyChecker = None,
+        controlnet: CosmosControlNetModel,
+        safety_checker: Optional[CosmosSafetyChecker] = None,
     ):
         super().__init__()
 
@@ -384,10 +385,11 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
         num_frames_in: int = 93,
         num_frames_out: int = 93,
         do_classifier_free_guidance: bool = True,
-        dtype: torch.dtype | None = None,
-        device: torch.device | None = None,
-        generator: torch.Generator | list[torch.Generator] | None = None,
-        latents: torch.Tensor | None = None,
+        dtype: Optional[torch.dtype] = None,
+        device: Optional[torch.device] = None,
+        generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None,
+        latents: Optional[torch.Tensor] = None,
+        num_cond_latent_frames: int = 0,
     ) -> torch.Tensor:
         if isinstance(generator, list) and len(generator) != batch_size:
             raise ValueError(
@@ -402,10 +404,14 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
         W = width // self.vae_scale_factor_spatial
         shape = (B, C, T, H, W)
 
-        if num_frames_in == 0:
-            if latents is None:
-                latents = randn_tensor(shape, generator=generator, device=device, dtype=dtype)
+        if latents is not None:
+            if latents.shape[1:] != shape[1:]:
+                raise ValueError(f"Unexpected `latents` shape, got {latents.shape}, expected {shape}.")
+            latents = latents.to(device=device, dtype=dtype)
+        else:
+            latents = randn_tensor(shape, generator=generator, device=device, dtype=dtype)
 
+        if num_frames_in == 0:
             cond_mask = torch.zeros((B, 1, T, H, W), dtype=latents.dtype, device=latents.device)
             cond_indicator = torch.zeros((B, 1, T, 1, 1), dtype=latents.dtype, device=latents.device)
 
@@ -435,16 +441,12 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
             latents_std = self.latents_std.to(device=device, dtype=dtype)
             cond_latents = (cond_latents - latents_mean) / latents_std
 
-            if latents is None:
-                latents = randn_tensor(shape, generator=generator, device=device, dtype=dtype)
-            else:
-                latents = latents.to(device=device, dtype=dtype)
-
             padding_shape = (B, 1, T, H, W)
             ones_padding = latents.new_ones(padding_shape)
             zeros_padding = latents.new_zeros(padding_shape)
 
-            cond_indicator = latents.new_zeros(1, 1, latents.size(2), 1, 1)
+            cond_indicator = latents.new_zeros(B, 1, latents.size(2), 1, 1)
+            cond_indicator[:, :, 0:num_cond_latent_frames, :, :] = 1.0
             cond_mask = cond_indicator * ones_padding + (1 - cond_indicator) * zeros_padding
 
             return (
@@ -454,34 +456,7 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
                 cond_indicator,
             )
 
-    def _encode_controls(
-        self,
-        controls: Optional[torch.Tensor],
-        height: int,
-        width: int,
-        num_frames: int,
-        dtype: torch.dtype,
-        device: torch.device,
-        generator: torch.Generator | list[torch.Generator] | None,
-    ) -> Optional[torch.Tensor]:
-        if controls is None:
-            return None
-
-        control_video = self.video_processor.preprocess_video(controls, height, width)
-        control_video = _maybe_pad_video(control_video, num_frames)
-
-        control_video = control_video.to(device=device, dtype=self.vae.dtype)
-        control_latents = [
-            retrieve_latents(self.vae.encode(vid.unsqueeze(0)), generator=generator) for vid in control_video
-        ]
-        control_latents = torch.cat(control_latents, dim=0).to(dtype)
-
-        latents_mean = self.latents_mean.to(device=device, dtype=dtype)
-        latents_std = self.latents_std.to(device=device, dtype=dtype)
-        control_latents = (control_latents - latents_mean) / latents_std
-        return control_latents
-
-    # Copied from diffusers.pipelines.cosmos.pipeline_cosmos_text2world.CosmosTextToWorldPipeline.check_inputs
+    # Modified from diffusers.pipelines.cosmos.pipeline_cosmos_text2world.CosmosTextToWorldPipeline.check_inputs
     def check_inputs(
         self,
         prompt,
@@ -489,9 +464,25 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
         width,
         prompt_embeds=None,
         callback_on_step_end_tensor_inputs=None,
+        num_ar_conditional_frames=None,
+        num_ar_latent_conditional_frames=None,
+        num_frames_per_chunk=None,
+        num_frames=None,
+        conditional_frame_timestep=0.1,
     ):
-        if height % 16 != 0 or width % 16 != 0:
-            raise ValueError(f"`height` and `width` have to be divisible by 16 but are {height} and {width}.")
+        if width <= 0 or height <= 0 or height % 16 != 0 or width % 16 != 0:
+            raise ValueError(
+                f"`height` and `width` have to be divisible by 16 (& positive) but are {height} and {width}."
+            )
+
+        if num_frames is not None and num_frames <= 0:
+            raise ValueError(f"`num_frames` has to be a positive integer when provided but is {num_frames}.")
+
+        if conditional_frame_timestep < 0 or conditional_frame_timestep > 1:
+            raise ValueError(
+                "`conditional_frame_timestep` has to be a float in the [0, 1] interval but is "
+                f"{conditional_frame_timestep}."
+            )
 
         if callback_on_step_end_tensor_inputs is not None and not all(
             k in self._callback_tensor_inputs for k in callback_on_step_end_tensor_inputs
@@ -512,6 +503,46 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
         elif prompt is not None and (not isinstance(prompt, str) and not isinstance(prompt, list)):
             raise ValueError(f"`prompt` has to be of type `str` or `list` but is {type(prompt)}")
 
+        if num_ar_latent_conditional_frames is not None and num_ar_conditional_frames is not None:
+            raise ValueError(
+                "Provide only one of `num_ar_conditional_frames` or `num_ar_latent_conditional_frames`, not both."
+            )
+        if num_ar_latent_conditional_frames is None and num_ar_conditional_frames is None:
+            raise ValueError("Provide either `num_ar_conditional_frames` or `num_ar_latent_conditional_frames`.")
+        if num_ar_latent_conditional_frames is not None and num_ar_latent_conditional_frames < 0:
+            raise ValueError("`num_ar_latent_conditional_frames` must be >= 0.")
+        if num_ar_conditional_frames is not None and num_ar_conditional_frames < 0:
+            raise ValueError("`num_ar_conditional_frames` must be >= 0.")
+
+        if num_ar_latent_conditional_frames is not None:
+            num_ar_conditional_frames = max(
+                0, (num_ar_latent_conditional_frames - 1) * self.vae_scale_factor_temporal + 1
+            )
+
+        min_chunk_len = self.vae_scale_factor_temporal + 1
+        if num_frames_per_chunk < min_chunk_len:
+            logger.warning(f"{num_frames_per_chunk=} must be larger than {min_chunk_len=}, setting to min_chunk_len")
+            num_frames_per_chunk = min_chunk_len
+
+        max_frames_by_rope = None
+        if getattr(self.transformer.config, "max_size", None) is not None:
+            max_frames_by_rope = max(
+                size // patch
+                for size, patch in zip(self.transformer.config.max_size, self.transformer.config.patch_size)
+            )
+            if num_frames_per_chunk > max_frames_by_rope:
+                raise ValueError(
+                    f"{num_frames_per_chunk=} is too large for RoPE setting ({max_frames_by_rope=}). "
+                    "Please reduce `num_frames_per_chunk`."
+                )
+
+        if num_ar_conditional_frames >= num_frames_per_chunk:
+            raise ValueError(
+                f"{num_ar_conditional_frames=} must be smaller than {num_frames_per_chunk=} for chunked generation."
+            )
+
+        return num_frames_per_chunk
+
     @property
     def guidance_scale(self):
         return self._guidance_scale
@@ -536,23 +567,22 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
     @replace_example_docstring(EXAMPLE_DOC_STRING)
     def __call__(
         self,
-        image: PipelineImageInput | None = None,
-        video: List[PipelineImageInput] | None = None,
+        controls: PipelineImageInput | List[PipelineImageInput],
+        controls_conditioning_scale: Union[float, List[float]] = 1.0,
         prompt: Union[str, List[str]] | None = None,
         negative_prompt: Union[str, List[str]] = DEFAULT_NEGATIVE_PROMPT,
         height: int = 704,
-        width: int | None = None,
-        num_frames: int = 93,
+        width: Optional[int] = None,
+        num_frames: Optional[int] = None,
+        num_frames_per_chunk: int = 93,
         num_inference_steps: int = 36,
         guidance_scale: float = 3.0,
-        num_videos_per_prompt: Optional[int] = 1,
-        generator: torch.Generator | list[torch.Generator] | None = None,
-        latents: torch.Tensor | None = None,
-        controls: Optional[PipelineImageInput | List[PipelineImageInput]] = None,
-        controls_conditioning_scale: float | list[float] = 1.0,
-        prompt_embeds: torch.Tensor | None = None,
-        negative_prompt_embeds: torch.Tensor | None = None,
-        output_type: str = "pil",
+        num_videos_per_prompt: int = 1,
+        generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None,
+        latents: Optional[torch.Tensor] = None,
+        prompt_embeds: Optional[torch.Tensor] = None,
+        negative_prompt_embeds: Optional[torch.Tensor] = None,
+        output_type: Optional[str] = "pil",
         return_dict: bool = True,
         callback_on_step_end: Optional[
             Union[Callable[[int, int, Dict], None], PipelineCallback, MultiPipelineCallbacks]
@@ -560,24 +590,26 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
         callback_on_step_end_tensor_inputs: List[str] = ["latents"],
         max_sequence_length: int = 512,
         conditional_frame_timestep: float = 0.1,
+        num_ar_conditional_frames: Optional[int] = 1,
+        num_ar_latent_conditional_frames: Optional[int] = None,
     ):
         r"""
-        The call function to the pipeline for generation. Supports three modes:
+        `controls` drive the conditioning through ControlNet. Controls are assumed to be pre-processed, e.g. edge maps
+        are pre-computed.
 
-        - **Text2World**: `image=None`, `video=None`, `prompt` provided. Generates a world clip.
-        - **Image2World**: `image` provided, `video=None`, `prompt` provided. Conditions on a single frame.
-        - **Video2World**: `video` provided, `image=None`, `prompt` provided. Conditions on an input clip.
+        Setting `num_frames` will restrict the total number of frames output, if not provided or assigned to None
+        (default) then the number of output frames will match the input `controls`.
 
-        Set `num_frames=93` (default) to produce a world video, or `num_frames=1` to produce a single image frame (the
-        above in "*2Image mode").
-
-        Outputs follow `output_type` (e.g., `"pil"` returns a list of `num_frames` PIL images per prompt).
+        Auto-regressive inference is supported and thus a sliding window of `num_frames_per_chunk` frames are used per
+        denoising loop. In addition, when auto-regressive inference is performed, the previous
+        `num_ar_latent_conditional_frames` or `num_ar_conditional_frames` are used to condition the following denoising
+        inference loops.
 
         Args:
-            image (`PIL.Image.Image`, `np.ndarray`, `torch.Tensor`, *optional*):
-                Optional single image for Image2World conditioning. Must be `None` when `video` is provided.
-            video (`List[PIL.Image.Image]`, `np.ndarray`, `torch.Tensor`, *optional*):
-                Optional input video for Video2World conditioning. Must be `None` when `image` is provided.
+            controls (`PipelineImageInput`, `List[PipelineImageInput]`):
+                Control image or video input used by the ControlNet.
+            controls_conditioning_scale (`float` or `List[float]`, *optional*, defaults to `1.0`):
+                The scale factor(s) for the ControlNet outputs. A single float is broadcast to all control blocks.
             prompt (`str` or `List[str]`, *optional*):
                 The prompt or prompts to guide generation. Required unless `prompt_embeds` is supplied.
             height (`int`, defaults to `704`):
@@ -585,9 +617,10 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
             width (`int`, *optional*):
                 The width in pixels of the generated image. If not provided, this will be determined based on the
                 aspect ratio of the input and the provided height.
-            num_frames (`int`, defaults to `93`):
-                Number of output frames. Use `93` for world (video) generation; set to `1` to return a single frame.
-            num_inference_steps (`int`, defaults to `35`):
+            num_frames (`int`, *optional*):
+                Number of output frames. Defaults to `None` to output the same number of frames as the input
+                `controls`.
+            num_inference_steps (`int`, defaults to `36`):
                 The number of denoising steps. More denoising steps usually lead to a higher quality image at the
                 expense of slower inference.
             guidance_scale (`float`, defaults to `3.0`):
@@ -601,13 +634,9 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
                 A [`torch.Generator`](https://pytorch.org/docs/stable/generated/torch.Generator.html) to make
                 generation deterministic.
             latents (`torch.Tensor`, *optional*):
-                Pre-generated noisy latents sampled from a Gaussian distribution, to be used as inputs for image
-                generation. Can be used to tweak the same generation with different prompts. If not provided, a latents
-                tensor is generated by sampling using the supplied random `generator`.
-            controls (`PipelineImageInput`, `List[PipelineImageInput]`, *optional*):
-                Control image or video input used by the ControlNet. If `None`, ControlNet is skipped.
-            controls_conditioning_scale (`float` or `List[float]`, *optional*, defaults to `1.0`):
-                The scale factor(s) for the ControlNet outputs. A single float is broadcast to all control blocks.
+                Pre-generated noisy latents sampled from a Gaussian distribution, to be used as inputs. Can be used to
+                tweak the same generation with different prompts. If not provided, a latents tensor is generated by
+                sampling using the supplied random `generator`.
             prompt_embeds (`torch.Tensor`, *optional*):
                 Pre-generated text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting. If not
                 provided, text embeddings will be generated from `prompt` input argument.
@@ -630,7 +659,18 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
             max_sequence_length (`int`, defaults to `512`):
                 The maximum number of tokens in the prompt. If the prompt exceeds this length, it will be truncated. If
                 the prompt is shorter than this length, it will be padded.
+            num_ar_conditional_frames (`int`, *optional*, defaults to `1`):
+                Number of frames to condition on subsequent inference loops in auto-regressive inference, i.e. for the
+                second chunk and onwards. Only used if `num_ar_latent_conditional_frames` is `None`.
 
+                This is only used when auto-regressive inference is performed, i.e. when the number of frames in
+                controls is > num_frames_per_chunk
+            num_ar_latent_conditional_frames (`int`, *optional*):
+                Number of latent frames to condition on subsequent inference loops in auto-regressive inference, i.e.
+                for the second chunk and onwards. Only used if `num_ar_conditional_frames` is `None`.
+
+                This is only used when auto-regressive inference is performed, i.e. when the number of frames in
+                controls is > num_frames_per_chunk
         Examples:
 
         Returns:
@@ -650,21 +690,40 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
             callback_on_step_end_tensor_inputs = callback_on_step_end.tensor_inputs
 
         if width is None:
-            frame = image or video[0] if image or video else None
-            if frame is None and controls is not None:
-                frame = controls[0] if isinstance(controls, list) else controls
-                if isinstance(frame, (torch.Tensor, np.ndarray)) and len(frame.shape) == 4:
-                    frame = controls[0]
+            frame = controls[0] if isinstance(controls, list) else controls
+            if isinstance(frame, list):
+                frame = frame[0]
+            if isinstance(frame, (torch.Tensor, np.ndarray)):
+                if frame.ndim == 5:
+                    frame = frame[0, 0]
+                elif frame.ndim == 4:
+                    frame = frame[0]
 
-            if frame is None:
-                width = int((height + 16) * (1280 / 720))
-            elif isinstance(frame, PIL.Image.Image):
+            if isinstance(frame, PIL.Image.Image):
                 width = int((height + 16) * (frame.width / frame.height))
             else:
+                if frame.ndim != 3:
+                    raise ValueError("`controls` must contain 3D frames in CHW format.")
                 width = int((height + 16) * (frame.shape[2] / frame.shape[1]))  # NOTE: assuming C H W
 
-        # Check inputs. Raise error if not correct
-        self.check_inputs(prompt, height, width, prompt_embeds, callback_on_step_end_tensor_inputs)
+        num_frames_per_chunk = self.check_inputs(
+            prompt,
+            height,
+            width,
+            prompt_embeds,
+            callback_on_step_end_tensor_inputs,
+            num_ar_conditional_frames,
+            num_ar_latent_conditional_frames,
+            num_frames_per_chunk,
+            num_frames,
+            conditional_frame_timestep,
+        )
+
+        if num_ar_latent_conditional_frames is not None:
+            num_cond_latent_frames = num_ar_latent_conditional_frames
+            num_ar_conditional_frames = max(0, (num_cond_latent_frames - 1) * self.vae_scale_factor_temporal + 1)
+        else:
+            num_cond_latent_frames = max(0, (num_ar_conditional_frames - 1) // self.vae_scale_factor_temporal + 1)
 
         self._guidance_scale = guidance_scale
         self._current_timestep = None
@@ -709,102 +768,137 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
         vae_dtype = self.vae.dtype
         transformer_dtype = self.transformer.dtype
 
-        img_context = torch.zeros(
-            batch_size,
-            self.transformer.config.img_context_num_tokens,
-            self.transformer.config.img_context_dim_in,
-            device=prompt_embeds.device,
-            dtype=transformer_dtype,
-        )
-        encoder_hidden_states = (prompt_embeds, img_context)
-        neg_encoder_hidden_states = (negative_prompt_embeds, img_context)
-
-        num_frames_in = None
-        if image is not None:
-            if batch_size != 1:
-                raise ValueError(f"batch_size must be 1 for image input (given {batch_size})")
-
-            image = torchvision.transforms.functional.to_tensor(image).unsqueeze(0)
-            video = torch.cat([image, torch.zeros_like(image).repeat(num_frames - 1, 1, 1, 1)], dim=0)
-            video = video.unsqueeze(0)
-            num_frames_in = 1
-        elif video is None:
-            video = torch.zeros(batch_size, num_frames, 3, height, width, dtype=torch.uint8)
-            num_frames_in = 0
-        else:
-            num_frames_in = len(video)
-
-            if batch_size != 1:
-                raise ValueError(f"batch_size must be 1 for video input (given {batch_size})")
-
-        assert video is not None
-        video = self.video_processor.preprocess_video(video, height, width)
-
-        # pad with last frame (for video2world)
-        num_frames_out = num_frames
-        video = _maybe_pad_video(video, num_frames_out)
-        assert num_frames_in <= num_frames_out, f"expected ({num_frames_in=}) <= ({num_frames_out=})"
-
-        video = video.to(device=device, dtype=vae_dtype)
-
-        num_channels_latents = self.transformer.config.in_channels - 1
-        latents, cond_latent, cond_mask, cond_indicator = self.prepare_latents(
-            video=video,
-            batch_size=batch_size * num_videos_per_prompt,
-            num_channels_latents=num_channels_latents,
-            height=height,
-            width=width,
-            num_frames_in=num_frames_in,
-            num_frames_out=num_frames,
-            do_classifier_free_guidance=self.do_classifier_free_guidance,
-            dtype=torch.float32,
-            device=device,
-            generator=generator,
-            latents=latents,
-        )
-        cond_timestep = torch.ones_like(cond_indicator) * conditional_frame_timestep
-        cond_mask = cond_mask.to(transformer_dtype)
-
-        controls_latents = None
-        if controls is not None:
-            controls_latents = self._encode_controls(
-                controls,
-                height=height,
-                width=width,
-                num_frames=num_frames,
+        if getattr(self.transformer.config, "img_context_dim_in", None):
+            img_context = torch.zeros(
+                batch_size,
+                self.transformer.config.img_context_num_tokens,
+                self.transformer.config.img_context_dim_in,
+                device=prompt_embeds.device,
                 dtype=transformer_dtype,
-                device=device,
-                generator=generator,
             )
 
-        padding_mask = latents.new_zeros(1, 1, height, width, dtype=transformer_dtype)
+            if num_videos_per_prompt > 1:
+                img_context = img_context.repeat_interleave(num_videos_per_prompt, dim=0)
 
-        # Denoising loop
-        self.scheduler.set_timesteps(num_inference_steps, device=device)
-        timesteps = self.scheduler.timesteps
-        self._num_timesteps = len(timesteps)
-        num_warmup_steps = len(timesteps) - num_inference_steps * self.scheduler.order
+            encoder_hidden_states = (prompt_embeds, img_context)
+            neg_encoder_hidden_states = (negative_prompt_embeds, img_context)
+        else:
+            encoder_hidden_states = prompt_embeds
+            neg_encoder_hidden_states = negative_prompt_embeds
 
-        gt_velocity = (latents - cond_latent) * cond_mask
-        with self.progress_bar(total=num_inference_steps) as progress_bar:
-            for i, t in enumerate(timesteps):
-                if self.interrupt:
-                    continue
-
-                self._current_timestep = t.cpu().item()
-
-                # NOTE: assumes sigma(t) \in [0, 1]
-                sigma_t = (
-                    torch.tensor(self.scheduler.sigmas[i].item())
-                    .unsqueeze(0)
-                    .to(device=device, dtype=transformer_dtype)
+        control_video = self.video_processor.preprocess_video(controls, height, width)
+        if control_video.shape[0] != batch_size:
+            if control_video.shape[0] == 1:
+                control_video = control_video.repeat(batch_size, 1, 1, 1, 1)
+            else:
+                raise ValueError(
+                    f"Expected controls batch size {batch_size} to match prompt batch size, but got {control_video.shape[0]}."
                 )
 
-                in_latents = cond_mask * cond_latent + (1 - cond_mask) * latents
-                in_latents = in_latents.to(transformer_dtype)
-                in_timestep = cond_indicator * cond_timestep + (1 - cond_indicator) * sigma_t
-                control_blocks = None
-                if controls_latents is not None and self.controlnet is not None:
+        num_frames_out = control_video.shape[2]
+        if num_frames is not None:
+            num_frames_out = min(num_frames_out, num_frames)
+
+        control_video = _maybe_pad_or_trim_video(control_video, num_frames_out)
+
+        # chunk information
+        num_latent_frames_per_chunk = (num_frames_per_chunk - 1) // self.vae_scale_factor_temporal + 1
+        chunk_stride = num_frames_per_chunk - num_ar_conditional_frames
+        chunk_idxs = [
+            (start_idx, min(start_idx + num_frames_per_chunk, num_frames_out))
+            for start_idx in range(0, num_frames_out - num_ar_conditional_frames, chunk_stride)
+        ]
+
+        video_chunks = []
+        latents_mean = self.latents_mean.to(dtype=vae_dtype, device=device)
+        latents_std = self.latents_std.to(dtype=vae_dtype, device=device)
+
+        def decode_latents(latents):
+            latents = latents * latents_std + latents_mean
+            video = self.vae.decode(latents.to(dtype=self.vae.dtype, device=device), return_dict=False)[0]
+            return video
+
+        latents_arg = latents
+        initial_num_cond_latent_frames = 0
+        latent_chunks = []
+        num_chunks = len(chunk_idxs)
+        total_steps = num_inference_steps * num_chunks
+        with self.progress_bar(total=total_steps) as progress_bar:
+            for chunk_idx, (start_idx, end_idx) in enumerate(chunk_idxs):
+                if chunk_idx == 0:
+                    prev_output = torch.zeros((batch_size, num_frames_per_chunk, 3, height, width), dtype=vae_dtype)
+                    prev_output = self.video_processor.preprocess_video(prev_output, height, width)
+                else:
+                    prev_output = video_chunks[-1].clone()
+                    if num_ar_conditional_frames > 0:
+                        prev_output[:, :, :num_ar_conditional_frames] = prev_output[:, :, -num_ar_conditional_frames:]
+                        prev_output[:, :, num_ar_conditional_frames:] = -1  # -1 == 0 in processed video space
+                    else:
+                        prev_output.fill_(-1)
+
+                chunk_video = prev_output.to(device=device, dtype=vae_dtype)
+                chunk_video = _maybe_pad_or_trim_video(chunk_video, num_frames_per_chunk)
+                latents, cond_latent, cond_mask, cond_indicator = self.prepare_latents(
+                    video=chunk_video,
+                    batch_size=batch_size * num_videos_per_prompt,
+                    num_channels_latents=self.transformer.config.in_channels - 1,
+                    height=height,
+                    width=width,
+                    num_frames_in=chunk_video.shape[2],
+                    num_frames_out=num_frames_per_chunk,
+                    do_classifier_free_guidance=self.do_classifier_free_guidance,
+                    dtype=torch.float32,
+                    device=device,
+                    generator=generator,
+                    num_cond_latent_frames=initial_num_cond_latent_frames
+                    if chunk_idx == 0
+                    else num_cond_latent_frames,
+                    latents=latents_arg,
+                )
+                cond_mask = cond_mask.to(transformer_dtype)
+                cond_timestep = torch.ones_like(cond_indicator) * conditional_frame_timestep
+                padding_mask = latents.new_zeros(1, 1, height, width, dtype=transformer_dtype)
+
+                chunk_control_video = control_video[:, :, start_idx:end_idx, ...].to(
+                    device=device, dtype=self.vae.dtype
+                )
+                chunk_control_video = _maybe_pad_or_trim_video(chunk_control_video, num_frames_per_chunk)
+                if isinstance(generator, list):
+                    controls_latents = [
+                        retrieve_latents(self.vae.encode(chunk_control_video[i].unsqueeze(0)), generator=generator[i])
+                        for i in range(chunk_control_video.shape[0])
+                    ]
+                else:
+                    controls_latents = [
+                        retrieve_latents(self.vae.encode(vid.unsqueeze(0)), generator=generator)
+                        for vid in chunk_control_video
+                    ]
+                controls_latents = torch.cat(controls_latents, dim=0).to(transformer_dtype)
+
+                controls_latents = (controls_latents - latents_mean) / latents_std
+
+                # Denoising loop
+                self.scheduler.set_timesteps(num_inference_steps, device=device)
+                timesteps = self.scheduler.timesteps
+                self._num_timesteps = len(timesteps)
+
+                gt_velocity = (latents - cond_latent) * cond_mask
+                for i, t in enumerate(timesteps):
+                    if self.interrupt:
+                        continue
+
+                    self._current_timestep = t.cpu().item()
+
+                    # NOTE: assumes sigma(t) \in [0, 1]
+                    sigma_t = (
+                        torch.tensor(self.scheduler.sigmas[i].item())
+                        .unsqueeze(0)
+                        .to(device=device, dtype=transformer_dtype)
+                    )
+
+                    in_latents = cond_mask * cond_latent + (1 - cond_mask) * latents
+                    in_latents = in_latents.to(transformer_dtype)
+                    in_timestep = cond_indicator * cond_timestep + (1 - cond_indicator) * sigma_t
                     control_output = self.controlnet(
                         controls_latents=controls_latents,
                         latents=in_latents,
@@ -817,20 +911,18 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
                     )
                     control_blocks = control_output[0]
 
-                noise_pred = self.transformer(
-                    hidden_states=in_latents,
-                    timestep=in_timestep,
-                    encoder_hidden_states=encoder_hidden_states,
-                    block_controlnet_hidden_states=control_blocks,
-                    condition_mask=cond_mask,
-                    padding_mask=padding_mask,
-                    return_dict=False,
-                )[0]
-                noise_pred = gt_velocity + noise_pred * (1 - cond_mask)
+                    noise_pred = self.transformer(
+                        hidden_states=in_latents,
+                        timestep=in_timestep,
+                        encoder_hidden_states=encoder_hidden_states,
+                        block_controlnet_hidden_states=control_blocks,
+                        condition_mask=cond_mask,
+                        padding_mask=padding_mask,
+                        return_dict=False,
+                    )[0]
+                    noise_pred = gt_velocity + noise_pred * (1 - cond_mask)
 
-                if self.do_classifier_free_guidance:
-                    control_blocks = None
-                    if controls_latents is not None and self.controlnet is not None:
+                    if self.do_classifier_free_guidance:
                         control_output = self.controlnet(
                             controls_latents=controls_latents,
                             latents=in_latents,
@@ -843,46 +935,50 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
                         )
                         control_blocks = control_output[0]
 
-                    noise_pred_neg = self.transformer(
-                        hidden_states=in_latents,
-                        timestep=in_timestep,
-                        encoder_hidden_states=neg_encoder_hidden_states,  # NOTE: negative prompt
-                        block_controlnet_hidden_states=control_blocks,
-                        condition_mask=cond_mask,
-                        padding_mask=padding_mask,
-                        return_dict=False,
-                    )[0]
-                    # NOTE: replace velocity (noise_pred_neg) with gt_velocity for conditioning inputs only
-                    noise_pred_neg = gt_velocity + noise_pred_neg * (1 - cond_mask)
-                    noise_pred = noise_pred + self.guidance_scale * (noise_pred - noise_pred_neg)
+                        noise_pred_neg = self.transformer(
+                            hidden_states=in_latents,
+                            timestep=in_timestep,
+                            encoder_hidden_states=neg_encoder_hidden_states,  # NOTE: negative prompt
+                            block_controlnet_hidden_states=control_blocks,
+                            condition_mask=cond_mask,
+                            padding_mask=padding_mask,
+                            return_dict=False,
+                        )[0]
+                        # NOTE: replace velocity (noise_pred_neg) with gt_velocity for conditioning inputs only
+                        noise_pred_neg = gt_velocity + noise_pred_neg * (1 - cond_mask)
+                        noise_pred = noise_pred + self.guidance_scale * (noise_pred - noise_pred_neg)
 
-                latents = self.scheduler.step(noise_pred, t, latents, return_dict=False)[0]
+                    latents = self.scheduler.step(noise_pred, t, latents, return_dict=False)[0]
 
-                if callback_on_step_end is not None:
-                    callback_kwargs = {}
-                    for k in callback_on_step_end_tensor_inputs:
-                        callback_kwargs[k] = locals()[k]
-                    callback_outputs = callback_on_step_end(self, i, t, callback_kwargs)
+                    # call the callback, if provided
+                    if callback_on_step_end is not None:
+                        callback_kwargs = {}
+                        for k in callback_on_step_end_tensor_inputs:
+                            callback_kwargs[k] = locals()[k]
+                        callback_outputs = callback_on_step_end(self, i, t, callback_kwargs)
 
-                    latents = callback_outputs.pop("latents", latents)
-                    prompt_embeds = callback_outputs.pop("prompt_embeds", prompt_embeds)
-                    negative_prompt_embeds = callback_outputs.pop("negative_prompt_embeds", negative_prompt_embeds)
+                        latents = callback_outputs.pop("latents", latents)
+                        prompt_embeds = callback_outputs.pop("prompt_embeds", prompt_embeds)
+                        negative_prompt_embeds = callback_outputs.pop("negative_prompt_embeds", negative_prompt_embeds)
 
-                # call the callback, if provided
-                if i == len(timesteps) - 1 or ((i + 1) > num_warmup_steps and (i + 1) % self.scheduler.order == 0):
-                    progress_bar.update()
+                    if i == total_steps - 1 or ((i + 1) % self.scheduler.order == 0):
+                        progress_bar.update()
 
-                if XLA_AVAILABLE:
-                    xm.mark_step()
+                    if XLA_AVAILABLE:
+                        xm.mark_step()
+
+                video_chunks.append(decode_latents(latents).detach().cpu())
+                latent_chunks.append(latents.detach().cpu())
 
         self._current_timestep = None
 
         if not output_type == "latent":
-            latents_mean = self.latents_mean.to(latents.device, latents.dtype)
-            latents_std = self.latents_std.to(latents.device, latents.dtype)
-            latents = latents * latents_std + latents_mean
-            video = self.vae.decode(latents.to(self.vae.dtype), return_dict=False)[0]
-            video = self._match_num_frames(video, num_frames)
+            video_chunks = [
+                chunk[:, :, num_ar_conditional_frames:, ...] if chunk_idx != 0 else chunk
+                for chunk_idx, chunk in enumerate(video_chunks)
+            ]
+            video = torch.cat(video_chunks, dim=2)
+            video = video[:, :, :num_frames_out, ...]
 
             assert self.safety_checker is not None
             self.safety_checker.to(device)
@@ -899,7 +995,13 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
             video = torch.from_numpy(video).permute(0, 4, 1, 2, 3)
             video = self.video_processor.postprocess_video(video, output_type=output_type)
         else:
-            video = latents
+            latent_T = (num_frames_out - 1) // self.vae_scale_factor_temporal + 1
+            latent_chunks = [
+                chunk[:, :, num_cond_latent_frames:, ...] if chunk_idx != 0 else chunk
+                for chunk_idx, chunk in enumerate(latent_chunks)
+            ]
+            video = torch.cat(latent_chunks, dim=2)
+            video = video[:, :, :latent_T, ...]
 
         # Offload all models
         self.maybe_free_model_hooks()
@@ -908,19 +1010,3 @@ class Cosmos2_5_TransferPipeline(DiffusionPipeline):
             return (video,)
 
         return CosmosPipelineOutput(frames=video)
-
-    def _match_num_frames(self, video: torch.Tensor, target_num_frames: int) -> torch.Tensor:
-        if target_num_frames <= 0 or video.shape[2] == target_num_frames:
-            return video
-
-        frames_per_latent = max(self.vae_scale_factor_temporal, 1)
-        video = torch.repeat_interleave(video, repeats=frames_per_latent, dim=2)
-
-        current_frames = video.shape[2]
-        if current_frames < target_num_frames:
-            pad = video[:, :, -1:, :, :].repeat(1, 1, target_num_frames - current_frames, 1, 1)
-            video = torch.cat([video, pad], dim=2)
-        elif current_frames > target_num_frames:
-            video = video[:, :, :target_num_frames]
-
-        return video

src/diffusers/pipelines/ltx2/pipeline_ltx2_image2video.py

@@ -699,9 +699,13 @@ class LTX2ImageToVideoPipeline(DiffusionPipeline, FromSingleFileMixin, LTX2LoraL
         mask_shape = (batch_size, 1, num_frames, height, width)
 
         if latents is not None:
-            conditioning_mask = latents.new_zeros(mask_shape)
-            conditioning_mask[:, :, 0] = 1.0
             if latents.ndim == 5:
+                # conditioning_mask needs to the same shape as latents in two stages generation.
+                batch_size, _, num_frames, height, width = latents.shape
+                mask_shape = (batch_size, 1, num_frames, height, width)
+                conditioning_mask = latents.new_zeros(mask_shape)
+                conditioning_mask[:, :, 0] = 1.0
+
                 latents = self._normalize_latents(
                     latents, self.vae.latents_mean, self.vae.latents_std, self.vae.config.scaling_factor
                 )
@@ -710,6 +714,9 @@ class LTX2ImageToVideoPipeline(DiffusionPipeline, FromSingleFileMixin, LTX2LoraL
                 latents = self._pack_latents(
                     latents, self.transformer_spatial_patch_size, self.transformer_temporal_patch_size
                 )
+            else:
+                conditioning_mask = latents.new_zeros(mask_shape)
+                conditioning_mask[:, :, 0] = 1.0
             conditioning_mask = self._pack_latents(
                 conditioning_mask, self.transformer_spatial_patch_size, self.transformer_temporal_patch_size
             ).squeeze(-1)

src/diffusers/pipelines/z_image/pipeline_z_image.py

@@ -276,7 +276,7 @@ class ZImagePipeline(DiffusionPipeline, ZImageLoraLoaderMixin, FromSingleFileMix
 
     @property
     def do_classifier_free_guidance(self):
-        return self._guidance_scale > 1
+        return self._guidance_scale > 0
 
     @property
     def joint_attention_kwargs(self):

tests/models/controlnets/test_models_controlnet_cosmos.py

@@ -131,6 +131,26 @@ class CosmosControlNetModelTests(ModelTesterMixin, unittest.TestCase):
         self.assertIsInstance(output[0], list)
         self.assertEqual(len(output[0]), init_dict["n_controlnet_blocks"])
 
+    def test_condition_mask_changes_output(self):
+        """Test that condition mask affects control outputs."""
+        init_dict, inputs_dict = self.prepare_init_args_and_inputs_for_common()
+        model = self.model_class(**init_dict)
+        model.to(torch_device)
+        model.eval()
+
+        inputs_no_mask = dict(inputs_dict)
+        inputs_no_mask["condition_mask"] = torch.zeros_like(inputs_dict["condition_mask"])
+
+        with torch.no_grad():
+            output_no_mask = model(**inputs_no_mask)
+            output_with_mask = model(**inputs_dict)
+
+        self.assertEqual(len(output_no_mask.control_block_samples), len(output_with_mask.control_block_samples))
+        for no_mask_tensor, with_mask_tensor in zip(
+            output_no_mask.control_block_samples, output_with_mask.control_block_samples
+        ):
+            self.assertFalse(torch.allclose(no_mask_tensor, with_mask_tensor))
+
     def test_conditioning_scale_single(self):
         """Test that a single conditioning scale is broadcast to all blocks."""
         init_dict, inputs_dict = self.prepare_init_args_and_inputs_for_common()

tests/models/testing_utils/__init__.py

@@ -13,7 +13,7 @@ from .compile import TorchCompileTesterMixin
 from .ip_adapter import IPAdapterTesterMixin
 from .lora import LoraHotSwappingForModelTesterMixin, LoraTesterMixin
 from .memory import CPUOffloadTesterMixin, GroupOffloadTesterMixin, LayerwiseCastingTesterMixin, MemoryTesterMixin
-from .parallelism import ContextParallelAttentionBackendsTesterMixin, ContextParallelTesterMixin
+from .parallelism import ContextParallelTesterMixin
 from .quantization import (
     BitsAndBytesCompileTesterMixin,
     BitsAndBytesConfigMixin,
@@ -45,7 +45,6 @@ __all__ = [
     "BitsAndBytesTesterMixin",
     "CacheTesterMixin",
     "ContextParallelTesterMixin",
-    "ContextParallelAttentionBackendsTesterMixin",
     "CPUOffloadTesterMixin",
     "FasterCacheConfigMixin",
     "FasterCacheTesterMixin",

tests/models/testing_utils/parallelism.py

@@ -23,8 +23,10 @@ import torch.multiprocessing as mp
 
 from diffusers.models._modeling_parallel import ContextParallelConfig
 
-from ...testing_utils import is_context_parallel, is_kernels_available, require_torch_multi_accelerator
-from .utils import _maybe_cast_to_bf16
+from ...testing_utils import (
+    is_context_parallel,
+    require_torch_multi_accelerator,
+)
 
 
 def _find_free_port():
@@ -36,9 +38,7 @@ def _find_free_port():
     return port
 
 
-def _context_parallel_worker(
-    rank, world_size, master_port, model_class, init_dict, cp_dict, inputs_dict, return_dict, attention_backend=None
-):
+def _context_parallel_worker(rank, world_size, master_port, model_class, init_dict, cp_dict, inputs_dict, return_dict):
     """Worker function for context parallel testing."""
     try:
         # Set up distributed environment
@@ -59,9 +59,6 @@ def _context_parallel_worker(
         model.to(device)
         model.eval()
 
-        # Cast as needed.
-        model, inputs_dict = _maybe_cast_to_bf16(attention_backend, model, inputs_dict)
-
         # Move inputs to device
         inputs_on_device = {}
         for key, value in inputs_dict.items():
@@ -70,13 +67,6 @@ def _context_parallel_worker(
             else:
                 inputs_on_device[key] = value
 
-        # Enable attention backend
-        if attention_backend:
-            try:
-                model.set_attention_backend(attention_backend)
-            except Exception as e:
-                pytest.skip(f"Skipping test because of exception: {e}.")
-
         # Enable context parallelism
         cp_config = ContextParallelConfig(**cp_dict)
         model.enable_parallelism(config=cp_config)
@@ -136,76 +126,3 @@ class ContextParallelTesterMixin:
         assert return_dict.get("status") == "success", (
             f"Context parallel inference failed: {return_dict.get('error', 'Unknown error')}"
         )
-
-
-@is_context_parallel
-@require_torch_multi_accelerator
-class ContextParallelAttentionBackendsTesterMixin:
-    @pytest.mark.parametrize("cp_type", ["ulysses_degree", "ring_degree"])
-    @pytest.mark.parametrize(
-        "attention_backend",
-        [
-            "native",
-            pytest.param(
-                "flash_hub",
-                marks=pytest.mark.skipif(not is_kernels_available(), reason="`kernels` is not available."),
-            ),
-            pytest.param(
-                "_flash_3_hub",
-                marks=pytest.mark.skipif(not is_kernels_available(), reason="`kernels` is not available."),
-            ),
-        ],
-    )
-    @pytest.mark.parametrize("ulysses_anything", [True, False])
-    @torch.no_grad()
-    def test_context_parallel_attn_backend_inference(self, cp_type, attention_backend, ulysses_anything):
-        if not torch.distributed.is_available():
-            pytest.skip("torch.distributed is not available.")
-
-        if getattr(self.model_class, "_cp_plan", None) is None:
-            pytest.skip("Model does not have a _cp_plan defined for context parallel inference.")
-
-        if cp_type == "ring_degree":
-            if attention_backend == "native":
-                pytest.skip("Skipping test because ulysses isn't supported with native attention backend.")
-
-        if ulysses_anything and "ulysses" not in cp_type:
-            pytest.skip("Skipping test as ulysses anything needs the ulysses degree set.")
-
-        world_size = 2
-        init_dict = self.get_init_dict()
-        inputs_dict = self.get_dummy_inputs()
-
-        # Move all tensors to CPU for multiprocessing
-        inputs_dict = {k: v.cpu() if isinstance(v, torch.Tensor) else v for k, v in inputs_dict.items()}
-        cp_dict = {cp_type: world_size}
-        if ulysses_anything:
-            cp_dict.update({"ulysses_anything": ulysses_anything})
-
-        # Find a free port for distributed communication
-        master_port = _find_free_port()
-
-        # Use multiprocessing manager for cross-process communication
-        manager = mp.Manager()
-        return_dict = manager.dict()
-
-        # Spawn worker processes
-        mp.spawn(
-            _context_parallel_worker,
-            args=(
-                world_size,
-                master_port,
-                self.model_class,
-                init_dict,
-                cp_dict,
-                inputs_dict,
-                return_dict,
-                attention_backend,
-            ),
-            nprocs=world_size,
-            join=True,
-        )
-
-        assert return_dict.get("status") == "success", (
-            f"Context parallel inference failed: {return_dict.get('error', 'Unknown error')}"
-        )

tests/models/testing_utils/utils.py

@@ -1,22 +0,0 @@
-import torch
-
-from diffusers.models.attention_dispatch import AttentionBackendName
-
-
-_BF16_REQUIRED_BACKENDS = {
-    AttentionBackendName._NATIVE_CUDNN,
-    AttentionBackendName.FLASH_HUB,
-    AttentionBackendName._FLASH_3_HUB,
-}
-
-
-def _maybe_cast_to_bf16(backend, model, inputs_dict):
-    """Cast model and floating-point inputs to bfloat16 when the backend requires it."""
-    if not backend or backend not in _BF16_REQUIRED_BACKENDS:
-        return model, inputs_dict
-    model = model.to(dtype=torch.bfloat16)
-    inputs_dict = {
-        k: v.to(dtype=torch.bfloat16) if isinstance(v, torch.Tensor) and v.is_floating_point() else v
-        for k, v in inputs_dict.items()
-    }
-    return model, inputs_dict

tests/models/transformers/test_models_transformer_flux.py

@@ -29,7 +29,6 @@ from ..testing_utils import (
     BaseModelTesterConfig,
     BitsAndBytesCompileTesterMixin,
     BitsAndBytesTesterMixin,
-    ContextParallelAttentionBackendsTesterMixin,
     ContextParallelTesterMixin,
     FasterCacheTesterMixin,
     FirstBlockCacheTesterMixin,
@@ -229,12 +228,6 @@ class TestFluxTransformerContextParallel(FluxTransformerTesterConfig, ContextPar
     """Context Parallel inference tests for Flux Transformer"""
 
 
-class TestFluxTransformerContextParallelAttnBackends(
-    FluxTransformerTesterConfig, ContextParallelAttentionBackendsTesterMixin
-):
-    """Context Parallel inference x attention backends tests for Flux Transformer"""
-
-
 class TestFluxTransformerIPAdapter(FluxTransformerTesterConfig, IPAdapterTesterMixin):
     """IP Adapter tests for Flux Transformer."""
 

tests/pipelines/cosmos/test_cosmos2_5_transfer.py

@@ -55,7 +55,7 @@ class Cosmos2_5_TransferWrapper(Cosmos2_5_TransferPipeline):
 class Cosmos2_5_TransferPipelineFastTests(PipelineTesterMixin, unittest.TestCase):
     pipeline_class = Cosmos2_5_TransferWrapper
     params = TEXT_TO_IMAGE_PARAMS - {"cross_attention_kwargs"}
-    batch_params = TEXT_TO_IMAGE_BATCH_PARAMS
+    batch_params = TEXT_TO_IMAGE_BATCH_PARAMS.union({"controls"})
     image_params = TEXT_TO_IMAGE_IMAGE_PARAMS
     image_latents_params = TEXT_TO_IMAGE_IMAGE_PARAMS
     required_optional_params = frozenset(
@@ -176,15 +176,19 @@ class Cosmos2_5_TransferPipelineFastTests(PipelineTesterMixin, unittest.TestCase
         else:
             generator = torch.Generator(device=device).manual_seed(seed)
 
+        controls_generator = torch.Generator(device="cpu").manual_seed(seed)
+
         inputs = {
             "prompt": "dance monkey",
             "negative_prompt": "bad quality",
+            "controls": [torch.randn(3, 32, 32, generator=controls_generator) for _ in range(5)],
             "generator": generator,
             "num_inference_steps": 2,
             "guidance_scale": 3.0,
             "height": 32,
             "width": 32,
             "num_frames": 3,
+            "num_frames_per_chunk": 16,
             "max_sequence_length": 16,
             "output_type": "pt",
         }
@@ -212,6 +216,56 @@ class Cosmos2_5_TransferPipelineFastTests(PipelineTesterMixin, unittest.TestCase
         self.assertEqual(generated_video.shape, (3, 3, 32, 32))
         self.assertTrue(torch.isfinite(generated_video).all())
 
+    def test_inference_autoregressive_multi_chunk(self):
+        device = "cpu"
+
+        components = self.get_dummy_components()
+        pipe = self.pipeline_class(**components)
+        pipe.to(device)
+        pipe.set_progress_bar_config(disable=None)
+
+        inputs = self.get_dummy_inputs(device)
+        inputs["num_frames"] = 5
+        inputs["num_frames_per_chunk"] = 3
+        inputs["num_ar_conditional_frames"] = 1
+
+        video = pipe(**inputs).frames
+        generated_video = video[0]
+        self.assertEqual(generated_video.shape, (5, 3, 32, 32))
+        self.assertTrue(torch.isfinite(generated_video).all())
+
+    def test_inference_autoregressive_multi_chunk_no_condition_frames(self):
+        device = "cpu"
+
+        components = self.get_dummy_components()
+        pipe = self.pipeline_class(**components)
+        pipe.to(device)
+        pipe.set_progress_bar_config(disable=None)
+
+        inputs = self.get_dummy_inputs(device)
+        inputs["num_frames"] = 5
+        inputs["num_frames_per_chunk"] = 3
+        inputs["num_ar_conditional_frames"] = 0
+
+        video = pipe(**inputs).frames
+        generated_video = video[0]
+        self.assertEqual(generated_video.shape, (5, 3, 32, 32))
+        self.assertTrue(torch.isfinite(generated_video).all())
+
+    def test_num_frames_per_chunk_above_rope_raises(self):
+        device = "cpu"
+
+        components = self.get_dummy_components()
+        pipe = self.pipeline_class(**components)
+        pipe.to(device)
+        pipe.set_progress_bar_config(disable=None)
+
+        inputs = self.get_dummy_inputs(device)
+        inputs["num_frames_per_chunk"] = 17
+
+        with self.assertRaisesRegex(ValueError, "too large for RoPE setting"):
+            pipe(**inputs)
+
     def test_inference_with_controls(self):
         """Test inference with control inputs (ControlNet)."""
         device = "cpu"
@@ -222,13 +276,13 @@ class Cosmos2_5_TransferPipelineFastTests(PipelineTesterMixin, unittest.TestCase
         pipe.set_progress_bar_config(disable=None)
 
         inputs = self.get_dummy_inputs(device)
-        # Add control video input - should be a video tensor
-        inputs["controls"] = [torch.randn(3, 3, 32, 32)]  # num_frames, channels, height, width
+        inputs["controls"] = [torch.randn(3, 32, 32) for _ in range(5)]  # list of 5 frames (C, H, W)
         inputs["controls_conditioning_scale"] = 1.0
+        inputs["num_frames"] = None
 
         video = pipe(**inputs).frames
         generated_video = video[0]
-        self.assertEqual(generated_video.shape, (3, 3, 32, 32))
+        self.assertEqual(generated_video.shape, (5, 3, 32, 32))
         self.assertTrue(torch.isfinite(generated_video).all())
 
     def test_callback_inputs(self):

tests/pipelines/ltx2/test_ltx2_image2video.py

@@ -24,7 +24,8 @@ from diffusers import (
     LTX2ImageToVideoPipeline,
     LTX2VideoTransformer3DModel,
 )
-from diffusers.pipelines.ltx2 import LTX2TextConnectors
+from diffusers.pipelines.ltx2 import LTX2LatentUpsamplePipeline, LTX2TextConnectors
+from diffusers.pipelines.ltx2.latent_upsampler import LTX2LatentUpsamplerModel
 from diffusers.pipelines.ltx2.vocoder import LTX2Vocoder
 
 from ...testing_utils import enable_full_determinism
@@ -174,6 +175,15 @@ class LTX2ImageToVideoPipelineFastTests(PipelineTesterMixin, unittest.TestCase):
 
         return components
 
+    def get_dummy_upsample_component(self, in_channels=4, mid_channels=32, num_blocks_per_stage=1):
+        upsampler = LTX2LatentUpsamplerModel(
+            in_channels=in_channels,
+            mid_channels=mid_channels,
+            num_blocks_per_stage=num_blocks_per_stage,
+        )
+
+        return upsampler
+
     def get_dummy_inputs(self, device, seed=0):
         if str(device).startswith("mps"):
             generator = torch.manual_seed(seed)
@@ -287,5 +297,60 @@ class LTX2ImageToVideoPipelineFastTests(PipelineTesterMixin, unittest.TestCase):
         assert torch.allclose(expected_video_slice, generated_video_slice, atol=1e-4, rtol=1e-4)
         assert torch.allclose(expected_audio_slice, generated_audio_slice, atol=1e-4, rtol=1e-4)
 
+    def test_two_stages_inference_with_upsampler(self):
+        device = "cpu"
+
+        components = self.get_dummy_components()
+        pipe = self.pipeline_class(**components)
+        pipe.to(device)
+        pipe.set_progress_bar_config(disable=None)
+
+        inputs = self.get_dummy_inputs(device)
+        inputs["output_type"] = "latent"
+        first_stage_output = pipe(**inputs)
+        video_latent = first_stage_output.frames
+        audio_latent = first_stage_output.audio
+
+        self.assertEqual(video_latent.shape, (1, 4, 3, 16, 16))
+        self.assertEqual(audio_latent.shape, (1, 2, 5, 2))
+        self.assertEqual(audio_latent.shape[1], components["vocoder"].config.out_channels)
+
+        upsampler = self.get_dummy_upsample_component(in_channels=video_latent.shape[1])
+        upsample_pipe = LTX2LatentUpsamplePipeline(vae=pipe.vae, latent_upsampler=upsampler)
+        upscaled_video_latent = upsample_pipe(latents=video_latent, output_type="latent", return_dict=False)[0]
+        self.assertEqual(upscaled_video_latent.shape, (1, 4, 3, 32, 32))
+
+        inputs["latents"] = upscaled_video_latent
+        inputs["audio_latents"] = audio_latent
+        inputs["output_type"] = "pt"
+        second_stage_output = pipe(**inputs)
+        video = second_stage_output.frames
+        audio = second_stage_output.audio
+
+        self.assertEqual(video.shape, (1, 5, 3, 64, 64))
+        self.assertEqual(audio.shape[0], 1)
+        self.assertEqual(audio.shape[1], components["vocoder"].config.out_channels)
+
+        # fmt: off
+        expected_video_slice = torch.tensor(
+            [
+                0.4497, 0.6757, 0.4219, 0.7686, 0.4525, 0.6483, 0.3969, 0.7404, 0.3541, 0.3039, 0.4592, 0.3521, 0.3665, 0.2785, 0.3336, 0.3079
+            ]
+        )
+        expected_audio_slice = torch.tensor(
+            [
+                0.0271, 0.0492, 0.1249, 0.1126, 0.1661, 0.1060, 0.1717, 0.0944, 0.0672, -0.0069, 0.0688, 0.0097, 0.0808, 0.1231, 0.0986, 0.0739
+            ]
+        )
+        # fmt: on
+
+        video = video.flatten()
+        audio = audio.flatten()
+        generated_video_slice = torch.cat([video[:8], video[-8:]])
+        generated_audio_slice = torch.cat([audio[:8], audio[-8:]])
+
+        assert torch.allclose(expected_video_slice, generated_video_slice, atol=1e-4, rtol=1e-4)
+        assert torch.allclose(expected_audio_slice, generated_audio_slice, atol=1e-4, rtol=1e-4)
+
     def test_inference_batch_single_identical(self):
         self._test_inference_batch_single_identical(batch_size=2, expected_max_diff=2e-2)

utils/generate_model_tests.py

@@ -72,7 +72,6 @@ OPTIONAL_TESTERS = [
     # Other testers
     ("SingleFileTesterMixin", "single_file"),
     ("IPAdapterTesterMixin", "ip_adapter"),
-    ("ContextParallelAttentionBackendsTesterMixin", "cp_attn"),
 ]
 
 
@@ -230,14 +229,7 @@ def determine_testers(model_info: dict, include_optional: list[str], imports: se
 
     for tester, flag in OPTIONAL_TESTERS:
         if flag in include_optional:
-            if tester == "ContextParallelAttentionBackendsTesterMixin":
-                if (
-                    "cp_attn" in include_optional
-                    and "_cp_plan" in model_info["attributes"]
-                    and model_info["attributes"]["_cp_plan"] is not None
-                ):
-                    testers.append(tester)
-            elif tester not in testers:
+            if tester not in testers:
                 testers.append(tester)
 
     return testers
@@ -538,7 +530,6 @@ def main():
             "faster_cache",
             "single_file",
             "ip_adapter",
-            "cp_attn",
             "all",
         ],
         help="Optional testers to include",