fix-copies

* fix: support for loading playground v2.5 single file checkpoint.

* remove is_playground_model.

* fix: edm key

* apply Dhruv's comments but errors.

* fix: things.

* delegate model_type inference to a function.

* address Dhruv's comment.

* address rest of the comments.

* fix: kwargs

* fix

* update

---------

Co-authored-by: DN6 <dhruv.nair@gmail.com>

docs/source/en/_toctree.yml

@@ -318,6 +318,8 @@
       title: Semantic Guidance
     - local: api/pipelines/shap_e
       title: Shap-E
+    - local: api/pipelines/stable_cascade
+      title: Stable Cascade
     - sections:
       - local: api/pipelines/stable_diffusion/overview
         title: Overview

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

@@ -0,0 +1,88 @@
+<!--Copyright 2024 The HuggingFace Team. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+the License. You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+specific language governing permissions and limitations under the License.
+-->
+
+# Stable Cascade
+
+This model is built upon the [Würstchen](https://openreview.net/forum?id=gU58d5QeGv) architecture and its main 
+difference to other models like Stable Diffusion is that it is working at a much smaller latent space. Why is this 
+important? The smaller the latent space, the **faster** you can run inference and the **cheaper** the training becomes. 
+How small is the latent space? Stable Diffusion uses a compression factor of 8, resulting in a 1024x1024 image being 
+encoded to 128x128. Stable Cascade achieves a compression factor of 42, meaning that it is possible to encode a 
+1024x1024 image to 24x24, while maintaining crisp reconstructions. The text-conditional model is then trained in the 
+highly compressed latent space. Previous versions of this architecture, achieved a 16x cost reduction over Stable 
+Diffusion 1.5.
+
+Therefore, this kind of model is well suited for usages where efficiency is important. Furthermore, all known extensions
+like finetuning, LoRA, ControlNet, IP-Adapter, LCM etc. are possible with this method as well.
+
+The original codebase can be found at [Stability-AI/StableCascade](https://github.com/Stability-AI/StableCascade).
+
+## Model Overview
+Stable Cascade consists of three models: Stage A, Stage B and Stage C, representing a cascade to generate images,
+hence the name "Stable Cascade".
+
+Stage A & B are used to compress images, similar to what the job of the VAE is in Stable Diffusion. 
+However, with this setup, a much higher compression of images can be achieved. While the Stable Diffusion models use a 
+spatial compression factor of 8, encoding an image with resolution of 1024 x 1024 to 128 x 128, Stable Cascade achieves 
+a compression factor of 42. This encodes a 1024 x 1024 image to 24 x 24, while being able to accurately decode the 
+image. This comes with the great benefit of cheaper training and inference. Furthermore, Stage C is responsible 
+for generating the small 24 x 24 latents given a text prompt.
+
+## Uses
+
+### Direct Use
+
+The model is intended for research purposes for now. Possible research areas and tasks include
+
+- Research on generative models.
+- Safe deployment of models which have the potential to generate harmful content.
+- Probing and understanding the limitations and biases of generative models.
+- Generation of artworks and use in design and other artistic processes.
+- Applications in educational or creative tools.
+
+Excluded uses are described below.
+
+### Out-of-Scope Use
+
+The model was not trained to be factual or true representations of people or events, 
+and therefore using the model to generate such content is out-of-scope for the abilities of this model.
+The model should not be used in any way that violates Stability AI's [Acceptable Use Policy](https://stability.ai/use-policy).
+
+## Limitations and Bias
+
+### Limitations
+- Faces and people in general may not be generated properly.
+- The autoencoding part of the model is lossy.
+
+
+## StableCascadeCombinedPipeline
+
+[[autodoc]] StableCascadeCombinedPipeline
+	- all
+	- __call__
+
+## StableCascadePriorPipeline
+
+[[autodoc]] StableCascadePriorPipeline
+	- all
+	- __call__
+
+## StableCascadePriorPipelineOutput
+
+[[autodoc]] pipelines.stable_cascade.pipeline_stable_cascade_prior.StableCascadePriorPipelineOutput
+
+## StableCascadeDecoderPipeline
+
+[[autodoc]] StableCascadeDecoderPipeline
+	- all
+	- __call__
+

examples/advanced_diffusion_training/train_dreambooth_lora_sdxl_advanced.py

@@ -666,7 +666,6 @@ def parse_args(input_args=None):
     )
     parser.add_argument(
         "--use_dora",
-        type=bool,
         action="store_true",
         default=False,
         help=(

examples/community/pipeline_prompt2prompt.py

@@ -15,18 +15,47 @@
 from __future__ import annotations
 
 import abc
+import inspect
 from typing import Any, Callable, Dict, List, Optional, Tuple, Union
 
 import numpy as np
 import torch
 import torch.nn.functional as F
-
-from diffusers.models.attention import Attention
-from diffusers.pipelines.stable_diffusion import (
-    StableDiffusionPipeline,
-    StableDiffusionPipelineOutput,
+from packaging import version
+from transformers import (
+    CLIPImageProcessor,
+    CLIPTextModel,
+    CLIPTokenizer,
+    CLIPVisionModelWithProjection,
 )
 
+from diffusers import AutoencoderKL, DiffusionPipeline, UNet2DConditionModel
+from diffusers.configuration_utils import FrozenDict, deprecate
+from diffusers.image_processor import VaeImageProcessor
+from diffusers.loaders import (
+    FromSingleFileMixin,
+    IPAdapterMixin,
+    LoraLoaderMixin,
+    TextualInversionLoaderMixin,
+)
+from diffusers.models.attention import Attention
+from diffusers.models.lora import adjust_lora_scale_text_encoder
+from diffusers.pipelines.stable_diffusion import StableDiffusionPipelineOutput
+from diffusers.pipelines.stable_diffusion.safety_checker import (
+    StableDiffusionSafetyChecker,
+)
+from diffusers.schedulers import KarrasDiffusionSchedulers
+from diffusers.utils import (
+    USE_PEFT_BACKEND,
+    logging,
+    scale_lora_layers,
+    unscale_lora_layers,
+)
+from diffusers.utils.torch_utils import randn_tensor
+
+
+logger = logging.get_logger(__name__)
+
 
 # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.rescale_noise_cfg
 def rescale_noise_cfg(noise_cfg, noise_pred_text, guidance_rescale=0.0):
@@ -43,34 +72,486 @@ def rescale_noise_cfg(noise_cfg, noise_pred_text, guidance_rescale=0.0):
     return noise_cfg
 
 
-class Prompt2PromptPipeline(StableDiffusionPipeline):
+class Prompt2PromptPipeline(
+    DiffusionPipeline,
+    TextualInversionLoaderMixin,
+    LoraLoaderMixin,
+    IPAdapterMixin,
+    FromSingleFileMixin,
+):
     r"""
+    Pipeline for text-to-image generation using Stable Diffusion.
+
+    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.).
+
+    The pipeline also inherits the following loading methods:
+        - [`~loaders.TextualInversionLoaderMixin.load_textual_inversion`] for loading textual inversion embeddings
+        - [`~loaders.LoraLoaderMixin.load_lora_weights`] for loading LoRA weights
+        - [`~loaders.LoraLoaderMixin.save_lora_weights`] for saving LoRA weights
+        - [`~loaders.FromSingleFileMixin.from_single_file`] for loading `.ckpt` files
+        - [`~loaders.IPAdapterMixin.load_ip_adapter`] for loading IP Adapters
+
     Args:
-    Prompt-to-Prompt-Pipeline for text-to-image generation using Stable Diffusion. This model inherits from
-    [`StableDiffusionPipeline`]. Check the superclass documentation for the generic methods the library implements for
-    all the pipelines (such as downloading or saving, running on a particular device, etc.)
         vae ([`AutoencoderKL`]):
-            Variational Auto-Encoder (VAE) Model to encode and decode images to and from latent representations.
-        text_encoder ([`CLIPTextModel`]):
-            Frozen text-encoder. Stable Diffusion uses the text portion of
-            [CLIP](https://huggingface.co/docs/transformers/model_doc/clip#transformers.CLIPTextModel), specifically
-            the [clip-vit-large-patch14](https://huggingface.co/openai/clip-vit-large-patch14) variant.
-        tokenizer (`CLIPTokenizer`):
-            Tokenizer of class
-            [CLIPTokenizer](https://huggingface.co/docs/transformers/v4.21.0/en/model_doc/clip#transformers.CLIPTokenizer).
-        unet ([`UNet2DConditionModel`]): Conditional U-Net architecture to denoise the encoded image latents. scheduler
-        ([`SchedulerMixin`]):
+            Variational Auto-Encoder (VAE) model to encode and decode images to and from latent representations.
+        text_encoder ([`~transformers.CLIPTextModel`]):
+            Frozen text-encoder ([clip-vit-large-patch14](https://huggingface.co/openai/clip-vit-large-patch14)).
+        tokenizer ([`~transformers.CLIPTokenizer`]):
+            A `CLIPTokenizer` to tokenize text.
+        unet ([`UNet2DConditionModel`]):
+            A `UNet2DConditionModel` to denoise the encoded image latents.
+        scheduler ([`SchedulerMixin`]):
             A scheduler to be used in combination with `unet` to denoise the encoded image latents. Can be one of
             [`DDIMScheduler`], [`LMSDiscreteScheduler`], or [`PNDMScheduler`].
         safety_checker ([`StableDiffusionSafetyChecker`]):
             Classification module that estimates whether generated images could be considered offensive or harmful.
-            Please, refer to the [model card](https://huggingface.co/runwayml/stable-diffusion-v1-5) for details.
-        feature_extractor ([`CLIPFeatureExtractor`]):
-            Model that extracts features from generated images to be used as inputs for the `safety_checker`.
+            Please refer to the [model card](https://huggingface.co/runwayml/stable-diffusion-v1-5) for more details
+            about a model's potential harms.
+        feature_extractor ([`~transformers.CLIPImageProcessor`]):
+            A `CLIPImageProcessor` to extract features from generated images; used as inputs to the `safety_checker`.
     """
 
+    model_cpu_offload_seq = "text_encoder->image_encoder->unet->vae"
+    _exclude_from_cpu_offload = ["safety_checker"]
+    _callback_tensor_inputs = ["latents", "prompt_embeds", "negative_prompt_embeds"]
     _optional_components = ["safety_checker", "feature_extractor"]
 
+    def __init__(
+        self,
+        vae: AutoencoderKL,
+        text_encoder: CLIPTextModel,
+        tokenizer: CLIPTokenizer,
+        unet: UNet2DConditionModel,
+        scheduler: KarrasDiffusionSchedulers,
+        safety_checker: StableDiffusionSafetyChecker,
+        feature_extractor: CLIPImageProcessor,
+        image_encoder: CLIPVisionModelWithProjection = None,
+        requires_safety_checker: bool = True,
+    ):
+        super().__init__()
+
+        if hasattr(scheduler.config, "steps_offset") and scheduler.config.steps_offset != 1:
+            deprecation_message = (
+                f"The configuration file of this scheduler: {scheduler} is outdated. `steps_offset`"
+                f" should be set to 1 instead of {scheduler.config.steps_offset}. Please make sure "
+                "to update the config accordingly as leaving `steps_offset` might led to incorrect results"
+                " in future versions. If you have downloaded this checkpoint from the Hugging Face Hub,"
+                " it would be very nice if you could open a Pull request for the `scheduler/scheduler_config.json`"
+                " file"
+            )
+            deprecate("steps_offset!=1", "1.0.0", deprecation_message, standard_warn=False)
+            new_config = dict(scheduler.config)
+            new_config["steps_offset"] = 1
+            scheduler._internal_dict = FrozenDict(new_config)
+
+        if hasattr(scheduler.config, "clip_sample") and scheduler.config.clip_sample is True:
+            deprecation_message = (
+                f"The configuration file of this scheduler: {scheduler} has not set the configuration `clip_sample`."
+                " `clip_sample` should be set to False in the configuration file. Please make sure to update the"
+                " config accordingly as not setting `clip_sample` in the config might lead to incorrect results in"
+                " future versions. If you have downloaded this checkpoint from the Hugging Face Hub, it would be very"
+                " nice if you could open a Pull request for the `scheduler/scheduler_config.json` file"
+            )
+            deprecate("clip_sample not set", "1.0.0", deprecation_message, standard_warn=False)
+            new_config = dict(scheduler.config)
+            new_config["clip_sample"] = False
+            scheduler._internal_dict = FrozenDict(new_config)
+
+        if safety_checker is None and requires_safety_checker:
+            logger.warning(
+                f"You have disabled the safety checker for {self.__class__} by passing `safety_checker=None`. Ensure"
+                " that you abide to the conditions of the Stable Diffusion license and do not expose unfiltered"
+                " results in services or applications open to the public. Both the diffusers team and Hugging Face"
+                " strongly recommend to keep the safety filter enabled in all public facing circumstances, disabling"
+                " it only for use-cases that involve analyzing network behavior or auditing its results. For more"
+                " information, please have a look at https://github.com/huggingface/diffusers/pull/254 ."
+            )
+
+        if safety_checker is not None and feature_extractor is None:
+            raise ValueError(
+                "Make sure to define a feature extractor when loading {self.__class__} if you want to use the safety"
+                " checker. If you do not want to use the safety checker, you can pass `'safety_checker=None'` instead."
+            )
+
+        is_unet_version_less_0_9_0 = hasattr(unet.config, "_diffusers_version") and version.parse(
+            version.parse(unet.config._diffusers_version).base_version
+        ) < version.parse("0.9.0.dev0")
+        is_unet_sample_size_less_64 = hasattr(unet.config, "sample_size") and unet.config.sample_size < 64
+        if is_unet_version_less_0_9_0 and is_unet_sample_size_less_64:
+            deprecation_message = (
+                "The configuration file of the unet has set the default `sample_size` to smaller than"
+                " 64 which seems highly unlikely. If your checkpoint is a fine-tuned version of any of the"
+                " following: \n- CompVis/stable-diffusion-v1-4 \n- CompVis/stable-diffusion-v1-3 \n-"
+                " CompVis/stable-diffusion-v1-2 \n- CompVis/stable-diffusion-v1-1 \n- runwayml/stable-diffusion-v1-5"
+                " \n- runwayml/stable-diffusion-inpainting \n you should change 'sample_size' to 64 in the"
+                " configuration file. Please make sure to update the config accordingly as leaving `sample_size=32`"
+                " in the config might lead to incorrect results in future versions. If you have downloaded this"
+                " checkpoint from the Hugging Face Hub, it would be very nice if you could open a Pull request for"
+                " the `unet/config.json` file"
+            )
+            deprecate("sample_size<64", "1.0.0", deprecation_message, standard_warn=False)
+            new_config = dict(unet.config)
+            new_config["sample_size"] = 64
+            unet._internal_dict = FrozenDict(new_config)
+
+        self.register_modules(
+            vae=vae,
+            text_encoder=text_encoder,
+            tokenizer=tokenizer,
+            unet=unet,
+            scheduler=scheduler,
+            safety_checker=safety_checker,
+            feature_extractor=feature_extractor,
+            image_encoder=image_encoder,
+        )
+        self.vae_scale_factor = 2 ** (len(self.vae.config.block_out_channels) - 1)
+        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor)
+        self.register_to_config(requires_safety_checker=requires_safety_checker)
+
+    # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline._encode_prompt
+    def _encode_prompt(
+        self,
+        prompt,
+        device,
+        num_images_per_prompt,
+        do_classifier_free_guidance,
+        negative_prompt=None,
+        prompt_embeds: Optional[torch.FloatTensor] = None,
+        negative_prompt_embeds: Optional[torch.FloatTensor] = None,
+        lora_scale: Optional[float] = None,
+        **kwargs,
+    ):
+        deprecation_message = "`_encode_prompt()` is deprecated and it will be removed in a future version. Use `encode_prompt()` instead. Also, be aware that the output format changed from a concatenated tensor to a tuple."
+        deprecate("_encode_prompt()", "1.0.0", deprecation_message, standard_warn=False)
+
+        prompt_embeds_tuple = self.encode_prompt(
+            prompt=prompt,
+            device=device,
+            num_images_per_prompt=num_images_per_prompt,
+            do_classifier_free_guidance=do_classifier_free_guidance,
+            negative_prompt=negative_prompt,
+            prompt_embeds=prompt_embeds,
+            negative_prompt_embeds=negative_prompt_embeds,
+            lora_scale=lora_scale,
+            **kwargs,
+        )
+
+        # concatenate for backwards comp
+        prompt_embeds = torch.cat([prompt_embeds_tuple[1], prompt_embeds_tuple[0]])
+
+        return prompt_embeds
+
+    # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.encode_prompt
+    def encode_prompt(
+        self,
+        prompt,
+        device,
+        num_images_per_prompt,
+        do_classifier_free_guidance,
+        negative_prompt=None,
+        prompt_embeds: Optional[torch.FloatTensor] = None,
+        negative_prompt_embeds: Optional[torch.FloatTensor] = None,
+        lora_scale: Optional[float] = None,
+        clip_skip: Optional[int] = None,
+    ):
+        r"""
+        Encodes the prompt into text encoder hidden states.
+
+        Args:
+            prompt (`str` or `List[str]`, *optional*):
+                prompt to be encoded
+            device: (`torch.device`):
+                torch device
+            num_images_per_prompt (`int`):
+                number of images that should be generated per prompt
+            do_classifier_free_guidance (`bool`):
+                whether to use classifier free guidance or not
+            negative_prompt (`str` or `List[str]`, *optional*):
+                The prompt or prompts not to guide the image generation. If not defined, one has to pass
+                `negative_prompt_embeds` instead. Ignored when not using guidance (i.e., ignored if `guidance_scale` is
+                less than `1`).
+            prompt_embeds (`torch.FloatTensor`, *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.
+            negative_prompt_embeds (`torch.FloatTensor`, *optional*):
+                Pre-generated negative text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt
+                weighting. If not provided, negative_prompt_embeds will be generated from `negative_prompt` input
+                argument.
+            lora_scale (`float`, *optional*):
+                A LoRA scale that will be applied to all LoRA layers of the text encoder if LoRA layers are loaded.
+            clip_skip (`int`, *optional*):
+                Number of layers to be skipped from CLIP while computing the prompt embeddings. A value of 1 means that
+                the output of the pre-final layer will be used for computing the prompt embeddings.
+        """
+        # set lora scale so that monkey patched LoRA
+        # function of text encoder can correctly access it
+        if lora_scale is not None and isinstance(self, LoraLoaderMixin):
+            self._lora_scale = lora_scale
+
+            # dynamically adjust the LoRA scale
+            if not USE_PEFT_BACKEND:
+                adjust_lora_scale_text_encoder(self.text_encoder, lora_scale)
+            else:
+                scale_lora_layers(self.text_encoder, lora_scale)
+
+        if prompt is not None and isinstance(prompt, str):
+            batch_size = 1
+        elif prompt is not None and isinstance(prompt, list):
+            batch_size = len(prompt)
+        else:
+            batch_size = prompt_embeds.shape[0]
+
+        if prompt_embeds is None:
+            # textual inversion: process multi-vector tokens if necessary
+            if isinstance(self, TextualInversionLoaderMixin):
+                prompt = self.maybe_convert_prompt(prompt, self.tokenizer)
+
+            text_inputs = self.tokenizer(
+                prompt,
+                padding="max_length",
+                max_length=self.tokenizer.model_max_length,
+                truncation=True,
+                return_tensors="pt",
+            )
+            text_input_ids = text_inputs.input_ids
+            untruncated_ids = self.tokenizer(prompt, padding="longest", return_tensors="pt").input_ids
+
+            if untruncated_ids.shape[-1] >= text_input_ids.shape[-1] and not torch.equal(
+                text_input_ids, untruncated_ids
+            ):
+                removed_text = self.tokenizer.batch_decode(
+                    untruncated_ids[:, self.tokenizer.model_max_length - 1 : -1]
+                )
+                logger.warning(
+                    "The following part of your input was truncated because CLIP can only handle sequences up to"
+                    f" {self.tokenizer.model_max_length} tokens: {removed_text}"
+                )
+
+            if hasattr(self.text_encoder.config, "use_attention_mask") and self.text_encoder.config.use_attention_mask:
+                attention_mask = text_inputs.attention_mask.to(device)
+            else:
+                attention_mask = None
+
+            if clip_skip is None:
+                prompt_embeds = self.text_encoder(text_input_ids.to(device), attention_mask=attention_mask)
+                prompt_embeds = prompt_embeds[0]
+            else:
+                prompt_embeds = self.text_encoder(
+                    text_input_ids.to(device),
+                    attention_mask=attention_mask,
+                    output_hidden_states=True,
+                )
+                # Access the `hidden_states` first, that contains a tuple of
+                # all the hidden states from the encoder layers. Then index into
+                # the tuple to access the hidden states from the desired layer.
+                prompt_embeds = prompt_embeds[-1][-(clip_skip + 1)]
+                # We also need to apply the final LayerNorm here to not mess with the
+                # representations. The `last_hidden_states` that we typically use for
+                # obtaining the final prompt representations passes through the LayerNorm
+                # layer.
+                prompt_embeds = self.text_encoder.text_model.final_layer_norm(prompt_embeds)
+
+        if self.text_encoder is not None:
+            prompt_embeds_dtype = self.text_encoder.dtype
+        elif self.unet is not None:
+            prompt_embeds_dtype = self.unet.dtype
+        else:
+            prompt_embeds_dtype = prompt_embeds.dtype
+
+        prompt_embeds = prompt_embeds.to(dtype=prompt_embeds_dtype, device=device)
+
+        bs_embed, seq_len, _ = prompt_embeds.shape
+        # duplicate text embeddings for each generation per prompt, using mps friendly method
+        prompt_embeds = prompt_embeds.repeat(1, num_images_per_prompt, 1)
+        prompt_embeds = prompt_embeds.view(bs_embed * num_images_per_prompt, seq_len, -1)
+
+        # get unconditional embeddings for classifier free guidance
+        if do_classifier_free_guidance and negative_prompt_embeds is None:
+            uncond_tokens: List[str]
+            if negative_prompt is None:
+                uncond_tokens = [""] * batch_size
+            elif prompt is not None and type(prompt) is not type(negative_prompt):
+                raise TypeError(
+                    f"`negative_prompt` should be the same type to `prompt`, but got {type(negative_prompt)} !="
+                    f" {type(prompt)}."
+                )
+            elif isinstance(negative_prompt, str):
+                uncond_tokens = [negative_prompt]
+            elif batch_size != len(negative_prompt):
+                raise ValueError(
+                    f"`negative_prompt`: {negative_prompt} has batch size {len(negative_prompt)}, but `prompt`:"
+                    f" {prompt} has batch size {batch_size}. Please make sure that passed `negative_prompt` matches"
+                    " the batch size of `prompt`."
+                )
+            else:
+                uncond_tokens = negative_prompt
+
+            # textual inversion: process multi-vector tokens if necessary
+            if isinstance(self, TextualInversionLoaderMixin):
+                uncond_tokens = self.maybe_convert_prompt(uncond_tokens, self.tokenizer)
+
+            max_length = prompt_embeds.shape[1]
+            uncond_input = self.tokenizer(
+                uncond_tokens,
+                padding="max_length",
+                max_length=max_length,
+                truncation=True,
+                return_tensors="pt",
+            )
+
+            if hasattr(self.text_encoder.config, "use_attention_mask") and self.text_encoder.config.use_attention_mask:
+                attention_mask = uncond_input.attention_mask.to(device)
+            else:
+                attention_mask = None
+
+            negative_prompt_embeds = self.text_encoder(
+                uncond_input.input_ids.to(device),
+                attention_mask=attention_mask,
+            )
+            negative_prompt_embeds = negative_prompt_embeds[0]
+
+        if do_classifier_free_guidance:
+            # duplicate unconditional embeddings for each generation per prompt, using mps friendly method
+            seq_len = negative_prompt_embeds.shape[1]
+
+            negative_prompt_embeds = negative_prompt_embeds.to(dtype=prompt_embeds_dtype, device=device)
+
+            negative_prompt_embeds = negative_prompt_embeds.repeat(1, num_images_per_prompt, 1)
+            negative_prompt_embeds = negative_prompt_embeds.view(batch_size * num_images_per_prompt, seq_len, -1)
+
+        if isinstance(self, LoraLoaderMixin) and USE_PEFT_BACKEND:
+            # Retrieve the original scale by scaling back the LoRA layers
+            unscale_lora_layers(self.text_encoder, lora_scale)
+
+        return prompt_embeds, negative_prompt_embeds
+
+    # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.run_safety_checker
+    def run_safety_checker(self, image, device, dtype):
+        if self.safety_checker is None:
+            has_nsfw_concept = None
+        else:
+            if torch.is_tensor(image):
+                feature_extractor_input = self.image_processor.postprocess(image, output_type="pil")
+            else:
+                feature_extractor_input = self.image_processor.numpy_to_pil(image)
+            safety_checker_input = self.feature_extractor(feature_extractor_input, return_tensors="pt").to(device)
+            image, has_nsfw_concept = self.safety_checker(
+                images=image, clip_input=safety_checker_input.pixel_values.to(dtype)
+            )
+        return image, has_nsfw_concept
+
+    # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.prepare_extra_step_kwargs
+    def prepare_extra_step_kwargs(self, generator, eta):
+        # prepare extra kwargs for the scheduler step, since not all schedulers have the same signature
+        # eta (η) is only used with the DDIMScheduler, it will be ignored for other schedulers.
+        # eta corresponds to η in DDIM paper: https://arxiv.org/abs/2010.02502
+        # and should be between [0, 1]
+
+        accepts_eta = "eta" in set(inspect.signature(self.scheduler.step).parameters.keys())
+        extra_step_kwargs = {}
+        if accepts_eta:
+            extra_step_kwargs["eta"] = eta
+
+        # check if the scheduler accepts generator
+        accepts_generator = "generator" in set(inspect.signature(self.scheduler.step).parameters.keys())
+        if accepts_generator:
+            extra_step_kwargs["generator"] = generator
+        return extra_step_kwargs
+
+    # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.check_inputs
+    def check_inputs(
+        self,
+        prompt,
+        height,
+        width,
+        callback_steps,
+        negative_prompt=None,
+        prompt_embeds=None,
+        negative_prompt_embeds=None,
+        ip_adapter_image=None,
+        ip_adapter_image_embeds=None,
+        callback_on_step_end_tensor_inputs=None,
+    ):
+        if height % 8 != 0 or width % 8 != 0:
+            raise ValueError(f"`height` and `width` have to be divisible by 8 but are {height} and {width}.")
+
+        if callback_steps is not None and (not isinstance(callback_steps, int) or callback_steps <= 0):
+            raise ValueError(
+                f"`callback_steps` has to be a positive integer but is {callback_steps} of type"
+                f" {type(callback_steps)}."
+            )
+        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
+        ):
+            raise ValueError(
+                f"`callback_on_step_end_tensor_inputs` has to be in {self._callback_tensor_inputs}, but found {[k for k in callback_on_step_end_tensor_inputs if k not in self._callback_tensor_inputs]}"
+            )
+
+        if prompt is not None and prompt_embeds is not None:
+            raise ValueError(
+                f"Cannot forward both `prompt`: {prompt} and `prompt_embeds`: {prompt_embeds}. Please make sure to"
+                " only forward one of the two."
+            )
+        elif prompt is None and prompt_embeds is None:
+            raise ValueError(
+                "Provide either `prompt` or `prompt_embeds`. Cannot leave both `prompt` and `prompt_embeds` undefined."
+            )
+        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 negative_prompt is not None and negative_prompt_embeds is not None:
+            raise ValueError(
+                f"Cannot forward both `negative_prompt`: {negative_prompt} and `negative_prompt_embeds`:"
+                f" {negative_prompt_embeds}. Please make sure to only forward one of the two."
+            )
+
+        if prompt_embeds is not None and negative_prompt_embeds is not None:
+            if prompt_embeds.shape != negative_prompt_embeds.shape:
+                raise ValueError(
+                    "`prompt_embeds` and `negative_prompt_embeds` must have the same shape when passed directly, but"
+                    f" got: `prompt_embeds` {prompt_embeds.shape} != `negative_prompt_embeds`"
+                    f" {negative_prompt_embeds.shape}."
+                )
+
+        if ip_adapter_image is not None and ip_adapter_image_embeds is not None:
+            raise ValueError(
+                "Provide either `ip_adapter_image` or `ip_adapter_image_embeds`. Cannot leave both `ip_adapter_image` and `ip_adapter_image_embeds` defined."
+            )
+
+    # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.prepare_latents
+    def prepare_latents(
+        self,
+        batch_size,
+        num_channels_latents,
+        height,
+        width,
+        dtype,
+        device,
+        generator,
+        latents=None,
+    ):
+        shape = (
+            batch_size,
+            num_channels_latents,
+            height // self.vae_scale_factor,
+            width // self.vae_scale_factor,
+        )
+        if isinstance(generator, list) and len(generator) != batch_size:
+            raise ValueError(
+                f"You have passed a list of generators of length {len(generator)}, but requested an effective batch"
+                f" size of {batch_size}. Make sure the batch size matches the length of the generators."
+            )
+
+        if latents is None:
+            latents = randn_tensor(shape, generator=generator, device=device, dtype=dtype)
+        else:
+            latents = latents.to(device)
+
+        # scale the initial noise by the standard deviation required by the scheduler
+        latents = latents * self.scheduler.init_noise_sigma
+        return latents
+
     @torch.no_grad()
     def __call__(
         self,

examples/dreambooth/README_sdxl.md

@@ -243,3 +243,29 @@ accelerate launch train_dreambooth_lora_sdxl.py \
 
 > [!CAUTION]
 > Min-SNR gamma is not supported with the EDM-style training yet. When training with the PlaygroundAI model, it's recommended to not pass any "variant".
+
+### DoRA training 
+The script now supports DoRA training too!
+> Proposed in [DoRA: Weight-Decomposed Low-Rank Adaptation](https://arxiv.org/abs/2402.09353), 
+**DoRA** is very similar to LoRA, except it decomposes the pre-trained weight into two components, **magnitude** and **direction** and employs LoRA for _directional_ updates to efficiently minimize the number of trainable parameters. 
+The authors found that by using DoRA, both the learning capacity and training stability of LoRA are enhanced without any additional overhead during inference. 
+
+> [!NOTE]
+> 💡DoRA training is still _experimental_  
+> and is likely to require different hyperparameter values to perform best compared to a LoRA.
+> Specifically, we've noticed 2 differences to take into account your training: 
+> 1. **LoRA seem to converge faster than DoRA** (so a set of parameters that may lead to overfitting when training a LoRA may be working well for a DoRA)
+> 2. **DoRA quality superior to LoRA especially in lower ranks** the difference in quality of DoRA of rank 8 and LoRA of rank 8 appears to be more significant than when training ranks of 32 or 64 for example.  
+> This is also aligned with some of the quantitative analysis shown in the paper. 
+
+**Usage**
+1. To use DoRA you need to install `peft` from main: 
+```bash
+pip install git+https://github.com/huggingface/peft.git
+```
+2. Enable DoRA training by adding this flag
+```bash
+--use_dora
+```
+**Inference** 
+The inference is the same as if you train a regular LoRA 🤗

examples/dreambooth/train_dreambooth_lora_sdxl.py

@@ -647,6 +647,15 @@ def parse_args(input_args=None):
         default=4,
         help=("The dimension of the LoRA update matrices."),
     )
+    parser.add_argument(
+        "--use_dora",
+        action="store_true",
+        default=False,
+        help=(
+            "Wether to train a DoRA as proposed in- DoRA: Weight-Decomposed Low-Rank Adaptation https://arxiv.org/abs/2402.09353. "
+            "Note: to use DoRA you need to install peft from main, `pip install git+https://github.com/huggingface/peft.git`"
+        ),
+    )
 
     if input_args is not None:
         args = parser.parse_args(input_args)
@@ -868,6 +877,8 @@ def collate_fn(examples, with_prior_preservation=False):
     if with_prior_preservation:
         pixel_values += [example["class_images"] for example in examples]
         prompts += [example["class_prompt"] for example in examples]
+        original_sizes += [example["original_size"] for example in examples]
+        crop_top_lefts += [example["crop_top_left"] for example in examples]
 
     pixel_values = torch.stack(pixel_values)
     pixel_values = pixel_values.to(memory_format=torch.contiguous_format).float()
@@ -1147,6 +1158,7 @@ def main(args):
     # now we will add new LoRA weights to the attention layers
     unet_lora_config = LoraConfig(
         r=args.rank,
+        use_dora=args.use_dora,
         lora_alpha=args.rank,
         init_lora_weights="gaussian",
         target_modules=["to_k", "to_q", "to_v", "to_out.0"],
@@ -1158,6 +1170,7 @@ def main(args):
     if args.train_text_encoder:
         text_lora_config = LoraConfig(
             r=args.rank,
+            use_dora=args.use_dora,
             lora_alpha=args.rank,
             init_lora_weights="gaussian",
             target_modules=["q_proj", "k_proj", "v_proj", "out_proj"],

examples/research_projects/diffusion_dpo/README.md

@@ -61,6 +61,34 @@ accelerate launch train_diffusion_dpo_sdxl.py \
   --push_to_hub
 ```
 
+## SDXL Turbo training command
+
+```bash
+accelerate launch train_diffusion_dpo_sdxl.py \
+  --pretrained_model_name_or_path=stabilityai/sdxl-turbo \
+  --pretrained_vae_model_name_or_path=madebyollin/sdxl-vae-fp16-fix \
+  --output_dir="diffusion-sdxl-turbo-dpo" \
+  --mixed_precision="fp16" \
+  --dataset_name=kashif/pickascore \
+  --train_batch_size=8 \
+  --gradient_accumulation_steps=2 \
+  --gradient_checkpointing \
+  --use_8bit_adam \
+  --rank=8 \
+  --learning_rate=1e-5 \
+  --report_to="wandb" \
+  --lr_scheduler="constant" \
+  --lr_warmup_steps=0 \
+  --max_train_steps=2000 \
+  --checkpointing_steps=500 \
+  --run_validation --validation_steps=50 \
+  --seed="0" \
+  --report_to="wandb" \
+  --is_turbo --resolution 512 \
+  --push_to_hub
+```
+
+
 ## Acknowledgements
 
 This is based on the amazing work done by [Bram](https://github.com/bram-w) here for Diffusion DPO: https://github.com/bram-w/trl/blob/dpo/. 

examples/research_projects/diffusion_dpo/train_diffusion_dpo_sdxl.py

@@ -118,9 +118,16 @@ def log_validation(args, unet, vae, accelerator, weight_dtype, epoch, is_final_v
     images = []
     context = contextlib.nullcontext() if is_final_validation else torch.cuda.amp.autocast()
 
+    guidance_scale = 5.0
+    num_inference_steps = 25
+    if args.is_turbo:
+        guidance_scale = 0.0
+        num_inference_steps = 4
     for prompt in VALIDATION_PROMPTS:
         with context:
-            image = pipeline(prompt, num_inference_steps=25, generator=generator).images[0]
+            image = pipeline(
+                prompt, num_inference_steps=num_inference_steps, guidance_scale=guidance_scale, generator=generator
+            ).images[0]
             images.append(image)
 
     tracker_key = "test" if is_final_validation else "validation"
@@ -141,7 +148,10 @@ def log_validation(args, unet, vae, accelerator, weight_dtype, epoch, is_final_v
     if is_final_validation:
         pipeline.disable_lora()
         no_lora_images = [
-            pipeline(prompt, num_inference_steps=25, generator=generator).images[0] for prompt in VALIDATION_PROMPTS
+            pipeline(
+                prompt, num_inference_steps=num_inference_steps, guidance_scale=guidance_scale, generator=generator
+            ).images[0]
+            for prompt in VALIDATION_PROMPTS
         ]
 
         for tracker in accelerator.trackers:
@@ -423,6 +433,11 @@ def parse_args(input_args=None):
     parser.add_argument(
         "--enable_xformers_memory_efficient_attention", action="store_true", help="Whether or not to use xformers."
     )
+    parser.add_argument(
+        "--is_turbo",
+        action="store_true",
+        help=("Use if tuning SDXL Turbo instead of SDXL"),
+    )
     parser.add_argument(
         "--rank",
         type=int,
@@ -444,6 +459,9 @@ def parse_args(input_args=None):
     if args.dataset_name is None:
         raise ValueError("Must provide a `dataset_name`.")
 
+    if args.is_turbo:
+        assert "turbo" in args.pretrained_model_name_or_path
+
     env_local_rank = int(os.environ.get("LOCAL_RANK", -1))
     if env_local_rank != -1 and env_local_rank != args.local_rank:
         args.local_rank = env_local_rank
@@ -560,6 +578,36 @@ def main(args):
 
     # Load scheduler and models
     noise_scheduler = DDPMScheduler.from_pretrained(args.pretrained_model_name_or_path, subfolder="scheduler")
+
+    def enforce_zero_terminal_snr(scheduler):
+        # Modified from https://github.com/huggingface/diffusers/blob/main/src/diffusers/schedulers/scheduling_ddpm.py#L93
+        # Original implementation https://arxiv.org/pdf/2305.08891.pdf
+        # Turbo needs zero terminal SNR
+        # Turbo: https://static1.squarespace.com/static/6213c340453c3f502425776e/t/65663480a92fba51d0e1023f/1701197769659/adversarial_diffusion_distillation.pdf
+        # Convert betas to alphas_bar_sqrt
+        alphas = 1 - scheduler.betas
+        alphas_bar = alphas.cumprod(0)
+        alphas_bar_sqrt = alphas_bar.sqrt()
+
+        # Store old values.
+        alphas_bar_sqrt_0 = alphas_bar_sqrt[0].clone()
+        alphas_bar_sqrt_T = alphas_bar_sqrt[-1].clone()
+        # Shift so last timestep is zero.
+        alphas_bar_sqrt -= alphas_bar_sqrt_T
+        # Scale so first timestep is back to old value.
+        alphas_bar_sqrt *= alphas_bar_sqrt_0 / (alphas_bar_sqrt_0 - alphas_bar_sqrt_T)
+
+        alphas_bar = alphas_bar_sqrt**2
+        alphas = alphas_bar[1:] / alphas_bar[:-1]
+        alphas = torch.cat([alphas_bar[0:1], alphas])
+
+        alphas_cumprod = torch.cumprod(alphas, dim=0)
+        scheduler.alphas_cumprod = alphas_cumprod
+        return
+
+    if args.is_turbo:
+        enforce_zero_terminal_snr(noise_scheduler)
+
     text_encoder_one = text_encoder_cls_one.from_pretrained(
         args.pretrained_model_name_or_path, subfolder="text_encoder", revision=args.revision, variant=args.variant
     )
@@ -909,6 +957,10 @@ def main(args):
                 timesteps = torch.randint(
                     0, noise_scheduler.config.num_train_timesteps, (bsz,), device=latents.device, dtype=torch.long
                 ).repeat(2)
+                if args.is_turbo:
+                    # Learn a 4 timestep schedule
+                    timesteps_0_to_3 = timesteps % 4
+                    timesteps = 250 * timesteps_0_to_3 + 249
 
                 # Add noise to the model input according to the noise magnitude at each timestep
                 # (this is the forward diffusion process)

scripts/convert_stable_cascade.py

@@ -0,0 +1,215 @@
+# Run this script to convert the Stable Cascade model weights to a diffusers pipeline.
+import argparse
+
+import accelerate
+import torch
+from safetensors.torch import load_file
+from transformers import (
+    AutoTokenizer,
+    CLIPConfig,
+    CLIPImageProcessor,
+    CLIPTextModelWithProjection,
+    CLIPVisionModelWithProjection,
+)
+
+from diffusers import (
+    DDPMWuerstchenScheduler,
+    StableCascadeCombinedPipeline,
+    StableCascadeDecoderPipeline,
+    StableCascadePriorPipeline,
+)
+from diffusers.models import StableCascadeUNet
+from diffusers.models.modeling_utils import load_model_dict_into_meta
+from diffusers.pipelines.wuerstchen import PaellaVQModel
+
+
+parser = argparse.ArgumentParser(description="Convert Stable Cascade model weights to a diffusers pipeline")
+parser.add_argument("--model_path", type=str, default="../StableCascade", help="Location of Stable Cascade weights")
+parser.add_argument("--stage_c_name", type=str, default="stage_c.safetensors", help="Name of stage c checkpoint file")
+parser.add_argument("--stage_b_name", type=str, default="stage_b.safetensors", help="Name of stage b checkpoint file")
+parser.add_argument("--use_safetensors", action="store_true", help="Use SafeTensors for conversion")
+parser.add_argument("--save_org", type=str, default="diffusers", help="Hub organization to save the pipelines to")
+parser.add_argument("--push_to_hub", action="store_true", help="Push to hub")
+
+args = parser.parse_args()
+model_path = args.model_path
+
+device = "cpu"
+
+# set paths to model weights
+prior_checkpoint_path = f"{model_path}/{args.stage_c_name}"
+decoder_checkpoint_path = f"{model_path}/{args.stage_b_name}"
+
+# Clip Text encoder and tokenizer
+config = CLIPConfig.from_pretrained("laion/CLIP-ViT-bigG-14-laion2B-39B-b160k")
+config.text_config.projection_dim = config.projection_dim
+text_encoder = CLIPTextModelWithProjection.from_pretrained(
+    "laion/CLIP-ViT-bigG-14-laion2B-39B-b160k", config=config.text_config
+)
+tokenizer = AutoTokenizer.from_pretrained("laion/CLIP-ViT-bigG-14-laion2B-39B-b160k")
+
+# image processor
+feature_extractor = CLIPImageProcessor()
+image_encoder = CLIPVisionModelWithProjection.from_pretrained("openai/clip-vit-large-patch14")
+
+# Prior
+if args.use_safetensors:
+    orig_state_dict = load_file(prior_checkpoint_path, device=device)
+else:
+    orig_state_dict = torch.load(prior_checkpoint_path, map_location=device)
+
+state_dict = {}
+for key in orig_state_dict.keys():
+    if key.endswith("in_proj_weight"):
+        weights = orig_state_dict[key].chunk(3, 0)
+        state_dict[key.replace("attn.in_proj_weight", "to_q.weight")] = weights[0]
+        state_dict[key.replace("attn.in_proj_weight", "to_k.weight")] = weights[1]
+        state_dict[key.replace("attn.in_proj_weight", "to_v.weight")] = weights[2]
+    elif key.endswith("in_proj_bias"):
+        weights = orig_state_dict[key].chunk(3, 0)
+        state_dict[key.replace("attn.in_proj_bias", "to_q.bias")] = weights[0]
+        state_dict[key.replace("attn.in_proj_bias", "to_k.bias")] = weights[1]
+        state_dict[key.replace("attn.in_proj_bias", "to_v.bias")] = weights[2]
+    elif key.endswith("out_proj.weight"):
+        weights = orig_state_dict[key]
+        state_dict[key.replace("attn.out_proj.weight", "to_out.0.weight")] = weights
+    elif key.endswith("out_proj.bias"):
+        weights = orig_state_dict[key]
+        state_dict[key.replace("attn.out_proj.bias", "to_out.0.bias")] = weights
+    else:
+        state_dict[key] = orig_state_dict[key]
+
+
+with accelerate.init_empty_weights():
+    prior_model = StableCascadeUNet(
+        in_channels=16,
+        out_channels=16,
+        timestep_ratio_embedding_dim=64,
+        patch_size=1,
+        conditioning_dim=2048,
+        block_out_channels=[2048, 2048],
+        num_attention_heads=[32, 32],
+        down_num_layers_per_block=[8, 24],
+        up_num_layers_per_block=[24, 8],
+        down_blocks_repeat_mappers=[1, 1],
+        up_blocks_repeat_mappers=[1, 1],
+        block_types_per_layer=[
+            ["SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock"],
+            ["SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock"],
+        ],
+        clip_text_in_channels=1280,
+        clip_text_pooled_in_channels=1280,
+        clip_image_in_channels=768,
+        clip_seq=4,
+        kernel_size=3,
+        dropout=[0.1, 0.1],
+        self_attn=True,
+        timestep_conditioning_type=["sca", "crp"],
+        switch_level=[False],
+    )
+load_model_dict_into_meta(prior_model, state_dict)
+
+# scheduler for prior and decoder
+scheduler = DDPMWuerstchenScheduler()
+
+# Prior pipeline
+prior_pipeline = StableCascadePriorPipeline(
+    prior=prior_model,
+    tokenizer=tokenizer,
+    text_encoder=text_encoder,
+    image_encoder=image_encoder,
+    scheduler=scheduler,
+    feature_extractor=feature_extractor,
+)
+prior_pipeline.save_pretrained(f"{args.save_org}/StableCascade-prior", push_to_hub=args.push_to_hub)
+
+# Decoder
+if args.use_safetensors:
+    orig_state_dict = load_file(decoder_checkpoint_path, device=device)
+else:
+    orig_state_dict = torch.load(decoder_checkpoint_path, map_location=device)
+
+state_dict = {}
+for key in orig_state_dict.keys():
+    if key.endswith("in_proj_weight"):
+        weights = orig_state_dict[key].chunk(3, 0)
+        state_dict[key.replace("attn.in_proj_weight", "to_q.weight")] = weights[0]
+        state_dict[key.replace("attn.in_proj_weight", "to_k.weight")] = weights[1]
+        state_dict[key.replace("attn.in_proj_weight", "to_v.weight")] = weights[2]
+    elif key.endswith("in_proj_bias"):
+        weights = orig_state_dict[key].chunk(3, 0)
+        state_dict[key.replace("attn.in_proj_bias", "to_q.bias")] = weights[0]
+        state_dict[key.replace("attn.in_proj_bias", "to_k.bias")] = weights[1]
+        state_dict[key.replace("attn.in_proj_bias", "to_v.bias")] = weights[2]
+    elif key.endswith("out_proj.weight"):
+        weights = orig_state_dict[key]
+        state_dict[key.replace("attn.out_proj.weight", "to_out.0.weight")] = weights
+    elif key.endswith("out_proj.bias"):
+        weights = orig_state_dict[key]
+        state_dict[key.replace("attn.out_proj.bias", "to_out.0.bias")] = weights
+    # rename clip_mapper to clip_txt_pooled_mapper
+    elif key.endswith("clip_mapper.weight"):
+        weights = orig_state_dict[key]
+        state_dict[key.replace("clip_mapper.weight", "clip_txt_pooled_mapper.weight")] = weights
+    elif key.endswith("clip_mapper.bias"):
+        weights = orig_state_dict[key]
+        state_dict[key.replace("clip_mapper.bias", "clip_txt_pooled_mapper.bias")] = weights
+    else:
+        state_dict[key] = orig_state_dict[key]
+
+with accelerate.init_empty_weights():
+    decoder = StableCascadeUNet(
+        in_channels=4,
+        out_channels=4,
+        timestep_ratio_embedding_dim=64,
+        patch_size=2,
+        conditioning_dim=1280,
+        block_out_channels=[320, 640, 1280, 1280],
+        down_num_layers_per_block=[2, 6, 28, 6],
+        up_num_layers_per_block=[6, 28, 6, 2],
+        down_blocks_repeat_mappers=[1, 1, 1, 1],
+        up_blocks_repeat_mappers=[3, 3, 2, 2],
+        num_attention_heads=[0, 0, 20, 20],
+        block_types_per_layer=[
+            ["SDCascadeResBlock", "SDCascadeTimestepBlock"],
+            ["SDCascadeResBlock", "SDCascadeTimestepBlock"],
+            ["SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock"],
+            ["SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock"],
+        ],
+        clip_text_pooled_in_channels=1280,
+        clip_seq=4,
+        effnet_in_channels=16,
+        pixel_mapper_in_channels=3,
+        kernel_size=3,
+        dropout=[0, 0, 0.1, 0.1],
+        self_attn=True,
+        timestep_conditioning_type=["sca"],
+    )
+load_model_dict_into_meta(decoder, state_dict)
+
+# VQGAN from Wuerstchen-V2
+vqmodel = PaellaVQModel.from_pretrained("warp-ai/wuerstchen", subfolder="vqgan")
+
+# Decoder pipeline
+decoder_pipeline = StableCascadeDecoderPipeline(
+    decoder=decoder, text_encoder=text_encoder, tokenizer=tokenizer, vqgan=vqmodel, scheduler=scheduler
+)
+decoder_pipeline.save_pretrained(f"{args.save_org}/StableCascade-decoder", push_to_hub=args.push_to_hub)
+
+# Stable Cascade combined pipeline
+stable_cascade_pipeline = StableCascadeCombinedPipeline(
+    # Decoder
+    text_encoder=text_encoder,
+    tokenizer=tokenizer,
+    decoder=decoder,
+    scheduler=scheduler,
+    vqgan=vqmodel,
+    # Prior
+    prior_text_encoder=text_encoder,
+    prior_tokenizer=tokenizer,
+    prior_prior=prior_model,
+    prior_scheduler=scheduler,
+    prior_image_encoder=image_encoder,
+    prior_feature_extractor=feature_extractor,
+)
+stable_cascade_pipeline.save_pretrained(f"{args.save_org}/StableCascade", push_to_hub=args.push_to_hub)

src/diffusers/__init__.py

@@ -86,6 +86,7 @@ else:
             "MotionAdapter",
             "MultiAdapter",
             "PriorTransformer",
+            "StableCascadeUNet",
             "T2IAdapter",
             "T5FilmDecoder",
             "Transformer2DModel",
@@ -259,6 +260,9 @@ else:
             "SemanticStableDiffusionPipeline",
             "ShapEImg2ImgPipeline",
             "ShapEPipeline",
+            "StableCascadeCombinedPipeline",
+            "StableCascadeDecoderPipeline",
+            "StableCascadePriorPipeline",
             "StableDiffusionAdapterPipeline",
             "StableDiffusionAttendAndExcitePipeline",
             "StableDiffusionControlNetImg2ImgPipeline",
@@ -626,6 +630,9 @@ if TYPE_CHECKING or DIFFUSERS_SLOW_IMPORT:
             SemanticStableDiffusionPipeline,
             ShapEImg2ImgPipeline,
             ShapEPipeline,
+            StableCascadeCombinedPipeline,
+            StableCascadeDecoderPipeline,
+            StableCascadePriorPipeline,
             StableDiffusionAdapterPipeline,
             StableDiffusionAttendAndExcitePipeline,
             StableDiffusionControlNetImg2ImgPipeline,

src/diffusers/loaders/autoencoder.py

@@ -143,5 +143,4 @@ class FromOriginalVAEMixin:
         if torch_dtype is not None:
             vae = vae.to(torch_dtype)
 
-        vae.eval()
         return vae

src/diffusers/loaders/controlnet.py

@@ -133,5 +133,4 @@ class FromOriginalControlNetMixin:
         if torch_dtype is not None:
             controlnet = controlnet.to(torch_dtype)
 
-        controlnet.eval()
         return controlnet

src/diffusers/loaders/single_file.py

@@ -63,13 +63,20 @@ def build_sub_model_components(
             num_in_channels=num_in_channels,
             image_size=image_size,
             torch_dtype=torch_dtype,
+            model_type=model_type,
         )
         return unet_components
 
     if component_name == "vae":
         scaling_factor = kwargs.get("scaling_factor", None)
         vae_components = create_diffusers_vae_model_from_ldm(
-            pipeline_class_name, original_config, checkpoint, image_size, scaling_factor, torch_dtype
+            pipeline_class_name,
+            original_config,
+            checkpoint,
+            image_size,
+            scaling_factor,
+            torch_dtype,
+            model_type=model_type,
         )
         return vae_components
 
@@ -124,11 +131,12 @@ def build_sub_model_components(
 def set_additional_components(
     pipeline_class_name,
     original_config,
+    checkpoint=None,
     model_type=None,
 ):
     components = {}
     if pipeline_class_name in REFINER_PIPELINES:
-        model_type = infer_model_type(original_config, model_type=model_type)
+        model_type = infer_model_type(original_config, checkpoint=checkpoint, model_type=model_type)
         is_refiner = model_type == "SDXL-Refiner"
         components.update(
             {

src/diffusers/loaders/single_file_utils.py

@@ -28,6 +28,7 @@ from ..schedulers import (
     DDIMScheduler,
     DDPMScheduler,
     DPMSolverMultistepScheduler,
+    EDMDPMSolverMultistepScheduler,
     EulerAncestralDiscreteScheduler,
     EulerDiscreteScheduler,
     HeunDiscreteScheduler,
@@ -175,6 +176,7 @@ DIFFUSERS_TO_LDM_MAPPING = {
 
 LDM_VAE_KEY = "first_stage_model."
 LDM_VAE_DEFAULT_SCALING_FACTOR = 0.18215
+PLAYGROUND_VAE_SCALING_FACTOR = 0.5
 LDM_UNET_KEY = "model.diffusion_model."
 LDM_CONTROLNET_KEY = "control_model."
 LDM_CLIP_PREFIX_TO_REMOVE = ["cond_stage_model.transformer.", "conditioner.embedders.0.transformer."]
@@ -305,7 +307,7 @@ def fetch_original_config(pipeline_class_name, checkpoint, original_config_file=
     return original_config
 
 
-def infer_model_type(original_config, model_type=None):
+def infer_model_type(original_config, checkpoint=None, model_type=None):
     if model_type is not None:
         return model_type
 
@@ -323,7 +325,9 @@ def infer_model_type(original_config, model_type=None):
 
     elif has_network_config:
         context_dim = original_config["model"]["params"]["network_config"]["params"]["context_dim"]
-        if context_dim == 2048:
+        if "edm_mean" in checkpoint and "edm_std" in checkpoint:
+            model_type = "Playground"
+        elif context_dim == 2048:
             model_type = "SDXL"
         else:
             model_type = "SDXL-Refiner"
@@ -344,13 +348,13 @@ def set_image_size(pipeline_class_name, original_config, checkpoint, image_size=
         return image_size
 
     global_step = checkpoint["global_step"] if "global_step" in checkpoint else None
-    model_type = infer_model_type(original_config, model_type)
+    model_type = infer_model_type(original_config, checkpoint, model_type)
 
     if pipeline_class_name == "StableDiffusionUpscalePipeline":
         image_size = original_config["model"]["params"]["unet_config"]["params"]["image_size"]
         return image_size
 
-    elif model_type in ["SDXL", "SDXL-Refiner"]:
+    elif model_type in ["SDXL", "SDXL-Refiner", "Playground"]:
         image_size = 1024
         return image_size
 
@@ -506,12 +510,14 @@ def create_controlnet_diffusers_config(original_config, image_size: int):
     return controlnet_config
 
 
-def create_vae_diffusers_config(original_config, image_size, scaling_factor=None):
+def create_vae_diffusers_config(original_config, image_size, scaling_factor=None, latents_mean=None, latents_std=None):
     """
     Creates a config for the diffusers based on the config of the LDM model.
     """
     vae_params = original_config["model"]["params"]["first_stage_config"]["params"]["ddconfig"]
-    if scaling_factor is None and "scale_factor" in original_config["model"]["params"]:
+    if (scaling_factor is None) and (latents_mean is not None) and (latents_std is not None):
+        scaling_factor = PLAYGROUND_VAE_SCALING_FACTOR
+    elif (scaling_factor is None) and ("scale_factor" in original_config["model"]["params"]):
         scaling_factor = original_config["model"]["params"]["scale_factor"]
     elif scaling_factor is None:
         scaling_factor = LDM_VAE_DEFAULT_SCALING_FACTOR
@@ -531,6 +537,8 @@ def create_vae_diffusers_config(original_config, image_size, scaling_factor=None
         "layers_per_block": vae_params["num_res_blocks"],
         "scaling_factor": scaling_factor,
     }
+    if latents_mean is not None and latents_std is not None:
+        config.update({"latents_mean": latents_mean, "latents_std": latents_std})
 
     return config
 
@@ -1172,6 +1180,7 @@ def create_diffusers_unet_model_from_ldm(
     extract_ema=False,
     image_size=None,
     torch_dtype=None,
+    model_type=None,
 ):
     from ..models import UNet2DConditionModel
 
@@ -1190,7 +1199,9 @@ def create_diffusers_unet_model_from_ldm(
         else:
             num_in_channels = 4
 
-    image_size = set_image_size(pipeline_class_name, original_config, checkpoint, image_size=image_size)
+    image_size = set_image_size(
+        pipeline_class_name, original_config, checkpoint, image_size=image_size, model_type=model_type
+    )
     unet_config = create_unet_diffusers_config(original_config, image_size=image_size)
     unet_config["in_channels"] = num_in_channels
     unet_config["upcast_attention"] = upcast_attention
@@ -1223,14 +1234,40 @@ def create_diffusers_unet_model_from_ldm(
 
 
 def create_diffusers_vae_model_from_ldm(
-    pipeline_class_name, original_config, checkpoint, image_size=None, scaling_factor=None, torch_dtype=None
+    pipeline_class_name,
+    original_config,
+    checkpoint,
+    image_size=None,
+    scaling_factor=None,
+    torch_dtype=None,
+    model_type=None,
 ):
     # import here to avoid circular imports
     from ..models import AutoencoderKL
 
-    image_size = set_image_size(pipeline_class_name, original_config, checkpoint, image_size=image_size)
+    image_size = set_image_size(
+        pipeline_class_name, original_config, checkpoint, image_size=image_size, model_type=model_type
+    )
+    model_type = infer_model_type(original_config, checkpoint, model_type)
 
-    vae_config = create_vae_diffusers_config(original_config, image_size=image_size, scaling_factor=scaling_factor)
+    if model_type == "Playground":
+        edm_mean = (
+            checkpoint["edm_mean"].to(dtype=torch_dtype).tolist() if torch_dtype else checkpoint["edm_mean"].tolist()
+        )
+        edm_std = (
+            checkpoint["edm_std"].to(dtype=torch_dtype).tolist() if torch_dtype else checkpoint["edm_std"].tolist()
+        )
+    else:
+        edm_mean = None
+        edm_std = None
+
+    vae_config = create_vae_diffusers_config(
+        original_config,
+        image_size=image_size,
+        scaling_factor=scaling_factor,
+        latents_mean=edm_mean,
+        latents_std=edm_std,
+    )
     diffusers_format_vae_checkpoint = convert_ldm_vae_checkpoint(checkpoint, vae_config)
     ctx = init_empty_weights if is_accelerate_available() else nullcontext
 
@@ -1265,7 +1302,7 @@ def create_text_encoders_and_tokenizers_from_ldm(
     local_files_only=False,
     torch_dtype=None,
 ):
-    model_type = infer_model_type(original_config, model_type=model_type)
+    model_type = infer_model_type(original_config, checkpoint=checkpoint, model_type=model_type)
 
     if model_type == "FrozenOpenCLIPEmbedder":
         config_name = "stabilityai/stable-diffusion-2"
@@ -1332,7 +1369,7 @@ def create_text_encoders_and_tokenizers_from_ldm(
                 "text_encoder_2": text_encoder_2,
             }
 
-    elif model_type == "SDXL":
+    elif model_type in ["SDXL", "Playground"]:
         try:
             config_name = "openai/clip-vit-large-patch14"
             tokenizer = CLIPTokenizer.from_pretrained(config_name, local_files_only=local_files_only)
@@ -1383,7 +1420,7 @@ def create_scheduler_from_ldm(
     model_type=None,
 ):
     scheduler_config = get_default_scheduler_config()
-    model_type = infer_model_type(original_config, model_type=model_type)
+    model_type = infer_model_type(original_config, checkpoint=checkpoint, model_type=model_type)
 
     global_step = checkpoint["global_step"] if "global_step" in checkpoint else None
 
@@ -1406,7 +1443,8 @@ def create_scheduler_from_ldm(
 
     if model_type in ["SDXL", "SDXL-Refiner"]:
         scheduler_type = "euler"
-
+    elif model_type == "Playground":
+        scheduler_type = "edm_dpm_solver_multistep"
     else:
         beta_start = original_config["model"]["params"].get("linear_start", 0.02)
         beta_end = original_config["model"]["params"].get("linear_end", 0.085)
@@ -1438,6 +1476,26 @@ def create_scheduler_from_ldm(
     elif scheduler_type == "ddim":
         scheduler = DDIMScheduler.from_config(scheduler_config)
 
+    elif scheduler_type == "edm_dpm_solver_multistep":
+        scheduler_config = {
+            "algorithm_type": "dpmsolver++",
+            "dynamic_thresholding_ratio": 0.995,
+            "euler_at_final": False,
+            "final_sigmas_type": "zero",
+            "lower_order_final": True,
+            "num_train_timesteps": 1000,
+            "prediction_type": "epsilon",
+            "rho": 7.0,
+            "sample_max_value": 1.0,
+            "sigma_data": 0.5,
+            "sigma_max": 80.0,
+            "sigma_min": 0.002,
+            "solver_order": 2,
+            "solver_type": "midpoint",
+            "thresholding": False,
+        }
+        scheduler = EDMDPMSolverMultistepScheduler(**scheduler_config)
+
     else:
         raise ValueError(f"Scheduler of type {scheduler_type} doesn't exist!")
 

src/diffusers/models/__init__.py

@@ -47,6 +47,7 @@ if is_torch_available():
     _import_structure["unets.unet_kandinsky3"] = ["Kandinsky3UNet"]
     _import_structure["unets.unet_motion_model"] = ["MotionAdapter", "UNetMotionModel"]
     _import_structure["unets.unet_spatio_temporal_condition"] = ["UNetSpatioTemporalConditionModel"]
+    _import_structure["unets.unet_stable_cascade"] = ["StableCascadeUNet"]
     _import_structure["unets.uvit_2d"] = ["UVit2DModel"]
     _import_structure["vq_model"] = ["VQModel"]
 
@@ -80,6 +81,7 @@ if TYPE_CHECKING or DIFFUSERS_SLOW_IMPORT:
             I2VGenXLUNet,
             Kandinsky3UNet,
             MotionAdapter,
+            StableCascadeUNet,
             UNet1DModel,
             UNet2DConditionModel,
             UNet2DModel,

src/diffusers/models/attention.py

@@ -440,7 +440,6 @@ class TemporalBasicTransformerBlock(nn.Module):
 
         # Define 3 blocks. Each block has its own normalization layer.
         # 1. Self-Attn
-        self.norm_in = nn.LayerNorm(dim)
         self.ff_in = FeedForward(
             dim,
             dim_out=time_mix_inner_dim,

src/diffusers/models/modeling_utils.py

@@ -39,7 +39,6 @@ from ..utils import (
     _get_model_file,
     deprecate,
     is_accelerate_available,
-    is_single_file_checkpoint,
     is_torch_version,
     logging,
 )
@@ -49,8 +48,6 @@ from ..utils.hub_utils import PushToHubMixin, load_or_create_model_card, populat
 logger = logging.get_logger(__name__)
 
 
-SINGLE_FILE_LOADABLE_CLASSES = {"ControlNetModel", "AutoencoderKL"}
-
 if is_torch_version(">=", "1.9.0"):
     _LOW_CPU_MEM_USAGE_DEFAULT = True
 else:
@@ -500,90 +497,102 @@ class ModelMixin(torch.nn.Module, PushToHubMixin):
         You should probably TRAIN this model on a down-stream task to be able to use it for predictions and inference.
         ```
         """
-        if is_single_file_checkpoint(pretrained_model_name_or_path):
-            if cls.__name__ not in SINGLE_FILE_LOADABLE_CLASSES:
-                raise ValueError(
-                    f"{cls.__name__} is not supported. Supported classes are: {' '.join(list(SINGLE_FILE_LOADABLE_CLASSES))}."
-                )
-            logger.info("Single file checkpoint detected...")
-            model = cls.from_single_file(pretrained_model_name_or_path, **kwargs)
-            model = model.eval()
-            return model
-        else:
-            cache_dir = kwargs.pop("cache_dir", None)
-            ignore_mismatched_sizes = kwargs.pop("ignore_mismatched_sizes", False)
-            force_download = kwargs.pop("force_download", False)
-            from_flax = kwargs.pop("from_flax", False)
-            resume_download = kwargs.pop("resume_download", False)
-            proxies = kwargs.pop("proxies", None)
-            output_loading_info = kwargs.pop("output_loading_info", False)
-            local_files_only = kwargs.pop("local_files_only", None)
-            token = kwargs.pop("token", None)
-            revision = kwargs.pop("revision", None)
-            torch_dtype = kwargs.pop("torch_dtype", None)
-            subfolder = kwargs.pop("subfolder", None)
-            device_map = kwargs.pop("device_map", None)
-            max_memory = kwargs.pop("max_memory", None)
-            offload_folder = kwargs.pop("offload_folder", None)
-            offload_state_dict = kwargs.pop("offload_state_dict", False)
-            low_cpu_mem_usage = kwargs.pop("low_cpu_mem_usage", _LOW_CPU_MEM_USAGE_DEFAULT)
-            variant = kwargs.pop("variant", None)
-            use_safetensors = kwargs.pop("use_safetensors", None)
+        cache_dir = kwargs.pop("cache_dir", None)
+        ignore_mismatched_sizes = kwargs.pop("ignore_mismatched_sizes", False)
+        force_download = kwargs.pop("force_download", False)
+        from_flax = kwargs.pop("from_flax", False)
+        resume_download = kwargs.pop("resume_download", False)
+        proxies = kwargs.pop("proxies", None)
+        output_loading_info = kwargs.pop("output_loading_info", False)
+        local_files_only = kwargs.pop("local_files_only", None)
+        token = kwargs.pop("token", None)
+        revision = kwargs.pop("revision", None)
+        torch_dtype = kwargs.pop("torch_dtype", None)
+        subfolder = kwargs.pop("subfolder", None)
+        device_map = kwargs.pop("device_map", None)
+        max_memory = kwargs.pop("max_memory", None)
+        offload_folder = kwargs.pop("offload_folder", None)
+        offload_state_dict = kwargs.pop("offload_state_dict", False)
+        low_cpu_mem_usage = kwargs.pop("low_cpu_mem_usage", _LOW_CPU_MEM_USAGE_DEFAULT)
+        variant = kwargs.pop("variant", None)
+        use_safetensors = kwargs.pop("use_safetensors", None)
 
-            allow_pickle = False
-            if use_safetensors is None:
-                use_safetensors = True
-                allow_pickle = True
+        allow_pickle = False
+        if use_safetensors is None:
+            use_safetensors = True
+            allow_pickle = True
 
-            if low_cpu_mem_usage and not is_accelerate_available():
-                low_cpu_mem_usage = False
-                logger.warning(
-                    "Cannot initialize model with low cpu memory usage because `accelerate` was not found in the"
-                    " environment. Defaulting to `low_cpu_mem_usage=False`. It is strongly recommended to install"
-                    " `accelerate` for faster and less memory-intense model loading. You can do so with: \n```\npip"
-                    " install accelerate\n```\n."
-                )
+        if low_cpu_mem_usage and not is_accelerate_available():
+            low_cpu_mem_usage = False
+            logger.warning(
+                "Cannot initialize model with low cpu memory usage because `accelerate` was not found in the"
+                " environment. Defaulting to `low_cpu_mem_usage=False`. It is strongly recommended to install"
+                " `accelerate` for faster and less memory-intense model loading. You can do so with: \n```\npip"
+                " install accelerate\n```\n."
+            )
 
-            if device_map is not None and not is_accelerate_available():
-                raise NotImplementedError(
-                    "Loading and dispatching requires `accelerate`. Please make sure to install accelerate or set"
-                    " `device_map=None`. You can install accelerate with `pip install accelerate`."
-                )
+        if device_map is not None and not is_accelerate_available():
+            raise NotImplementedError(
+                "Loading and dispatching requires `accelerate`. Please make sure to install accelerate or set"
+                " `device_map=None`. You can install accelerate with `pip install accelerate`."
+            )
 
-            # Check if we can handle device_map and dispatching the weights
-            if device_map is not None and not is_torch_version(">=", "1.9.0"):
-                raise NotImplementedError(
-                    "Loading and dispatching requires torch >= 1.9.0. Please either update your PyTorch version or set"
-                    " `device_map=None`."
-                )
+        # Check if we can handle device_map and dispatching the weights
+        if device_map is not None and not is_torch_version(">=", "1.9.0"):
+            raise NotImplementedError(
+                "Loading and dispatching requires torch >= 1.9.0. Please either update your PyTorch version or set"
+                " `device_map=None`."
+            )
 
-            if low_cpu_mem_usage is True and not is_torch_version(">=", "1.9.0"):
-                raise NotImplementedError(
-                    "Low memory initialization requires torch >= 1.9.0. Please either update your PyTorch version or set"
-                    " `low_cpu_mem_usage=False`."
-                )
+        if low_cpu_mem_usage is True and not is_torch_version(">=", "1.9.0"):
+            raise NotImplementedError(
+                "Low memory initialization requires torch >= 1.9.0. Please either update your PyTorch version or set"
+                " `low_cpu_mem_usage=False`."
+            )
 
-            if low_cpu_mem_usage is False and device_map is not None:
-                raise ValueError(
-                    f"You cannot set `low_cpu_mem_usage` to `False` while using device_map={device_map} for loading and"
-                    " dispatching. Please make sure to set `low_cpu_mem_usage=True`."
-                )
+        if low_cpu_mem_usage is False and device_map is not None:
+            raise ValueError(
+                f"You cannot set `low_cpu_mem_usage` to `False` while using device_map={device_map} for loading and"
+                " dispatching. Please make sure to set `low_cpu_mem_usage=True`."
+            )
 
-            # Load config if we don't provide a configuration
-            config_path = pretrained_model_name_or_path
+        # Load config if we don't provide a configuration
+        config_path = pretrained_model_name_or_path
 
-            user_agent = {
-                "diffusers": __version__,
-                "file_type": "model",
-                "framework": "pytorch",
-            }
+        user_agent = {
+            "diffusers": __version__,
+            "file_type": "model",
+            "framework": "pytorch",
+        }
 
-            # load config
-            config, unused_kwargs, commit_hash = cls.load_config(
-                config_path,
+        # load config
+        config, unused_kwargs, commit_hash = cls.load_config(
+            config_path,
+            cache_dir=cache_dir,
+            return_unused_kwargs=True,
+            return_commit_hash=True,
+            force_download=force_download,
+            resume_download=resume_download,
+            proxies=proxies,
+            local_files_only=local_files_only,
+            token=token,
+            revision=revision,
+            subfolder=subfolder,
+            device_map=device_map,
+            max_memory=max_memory,
+            offload_folder=offload_folder,
+            offload_state_dict=offload_state_dict,
+            user_agent=user_agent,
+            **kwargs,
+        )
+
+        # load model
+        model_file = None
+        if from_flax:
+            model_file = _get_model_file(
+                pretrained_model_name_or_path,
+                weights_name=FLAX_WEIGHTS_NAME,
                 cache_dir=cache_dir,
-                return_unused_kwargs=True,
-                return_commit_hash=True,
                 force_download=force_download,
                 resume_download=resume_download,
                 proxies=proxies,
@@ -591,62 +600,21 @@ class ModelMixin(torch.nn.Module, PushToHubMixin):
                 token=token,
                 revision=revision,
                 subfolder=subfolder,
-                device_map=device_map,
-                max_memory=max_memory,
-                offload_folder=offload_folder,
-                offload_state_dict=offload_state_dict,
                 user_agent=user_agent,
-                **kwargs,
+                commit_hash=commit_hash,
             )
+            model = cls.from_config(config, **unused_kwargs)
 
-            # load model
-            model_file = None
-            if from_flax:
-                model_file = _get_model_file(
-                    pretrained_model_name_or_path,
-                    weights_name=FLAX_WEIGHTS_NAME,
-                    cache_dir=cache_dir,
-                    force_download=force_download,
-                    resume_download=resume_download,
-                    proxies=proxies,
-                    local_files_only=local_files_only,
-                    token=token,
-                    revision=revision,
-                    subfolder=subfolder,
-                    user_agent=user_agent,
-                    commit_hash=commit_hash,
-                )
-                model = cls.from_config(config, **unused_kwargs)
+            # Convert the weights
+            from .modeling_pytorch_flax_utils import load_flax_checkpoint_in_pytorch_model
 
-                # Convert the weights
-                from .modeling_pytorch_flax_utils import load_flax_checkpoint_in_pytorch_model
-
-                model = load_flax_checkpoint_in_pytorch_model(model, model_file)
-            else:
-                if use_safetensors:
-                    try:
-                        model_file = _get_model_file(
-                            pretrained_model_name_or_path,
-                            weights_name=_add_variant(SAFETENSORS_WEIGHTS_NAME, variant),
-                            cache_dir=cache_dir,
-                            force_download=force_download,
-                            resume_download=resume_download,
-                            proxies=proxies,
-                            local_files_only=local_files_only,
-                            token=token,
-                            revision=revision,
-                            subfolder=subfolder,
-                            user_agent=user_agent,
-                            commit_hash=commit_hash,
-                        )
-                    except IOError as e:
-                        if not allow_pickle:
-                            raise e
-                        pass
-                if model_file is None:
+            model = load_flax_checkpoint_in_pytorch_model(model, model_file)
+        else:
+            if use_safetensors:
+                try:
                     model_file = _get_model_file(
                         pretrained_model_name_or_path,
-                        weights_name=_add_variant(WEIGHTS_NAME, variant),
+                        weights_name=_add_variant(SAFETENSORS_WEIGHTS_NAME, variant),
                         cache_dir=cache_dir,
                         force_download=force_download,
                         resume_download=resume_download,
@@ -658,48 +626,95 @@ class ModelMixin(torch.nn.Module, PushToHubMixin):
                         user_agent=user_agent,
                         commit_hash=commit_hash,
                     )
+                except IOError as e:
+                    if not allow_pickle:
+                        raise e
+                    pass
+            if model_file is None:
+                model_file = _get_model_file(
+                    pretrained_model_name_or_path,
+                    weights_name=_add_variant(WEIGHTS_NAME, variant),
+                    cache_dir=cache_dir,
+                    force_download=force_download,
+                    resume_download=resume_download,
+                    proxies=proxies,
+                    local_files_only=local_files_only,
+                    token=token,
+                    revision=revision,
+                    subfolder=subfolder,
+                    user_agent=user_agent,
+                    commit_hash=commit_hash,
+                )
 
-                if low_cpu_mem_usage:
-                    # Instantiate model with empty weights
-                    with accelerate.init_empty_weights():
-                        model = cls.from_config(config, **unused_kwargs)
+            if low_cpu_mem_usage:
+                # Instantiate model with empty weights
+                with accelerate.init_empty_weights():
+                    model = cls.from_config(config, **unused_kwargs)
 
-                    # if device_map is None, load the state dict and move the params from meta device to the cpu
-                    if device_map is None:
-                        param_device = "cpu"
-                        state_dict = load_state_dict(model_file, variant=variant)
-                        model._convert_deprecated_attention_blocks(state_dict)
-                        # move the params from meta device to cpu
-                        missing_keys = set(model.state_dict().keys()) - set(state_dict.keys())
-                        if len(missing_keys) > 0:
-                            raise ValueError(
-                                f"Cannot load {cls} from {pretrained_model_name_or_path} because the following keys are"
-                                f" missing: \n {', '.join(missing_keys)}. \n Please make sure to pass"
-                                " `low_cpu_mem_usage=False` and `device_map=None` if you want to randomly initialize"
-                                " those weights or else make sure your checkpoint file is correct."
-                            )
-
-                        unexpected_keys = load_model_dict_into_meta(
-                            model,
-                            state_dict,
-                            device=param_device,
-                            dtype=torch_dtype,
-                            model_name_or_path=pretrained_model_name_or_path,
+                # if device_map is None, load the state dict and move the params from meta device to the cpu
+                if device_map is None:
+                    param_device = "cpu"
+                    state_dict = load_state_dict(model_file, variant=variant)
+                    model._convert_deprecated_attention_blocks(state_dict)
+                    # move the params from meta device to cpu
+                    missing_keys = set(model.state_dict().keys()) - set(state_dict.keys())
+                    if len(missing_keys) > 0:
+                        raise ValueError(
+                            f"Cannot load {cls} from {pretrained_model_name_or_path} because the following keys are"
+                            f" missing: \n {', '.join(missing_keys)}. \n Please make sure to pass"
+                            " `low_cpu_mem_usage=False` and `device_map=None` if you want to randomly initialize"
+                            " those weights or else make sure your checkpoint file is correct."
                         )
 
-                        if cls._keys_to_ignore_on_load_unexpected is not None:
-                            for pat in cls._keys_to_ignore_on_load_unexpected:
-                                unexpected_keys = [k for k in unexpected_keys if re.search(pat, k) is None]
+                    unexpected_keys = load_model_dict_into_meta(
+                        model,
+                        state_dict,
+                        device=param_device,
+                        dtype=torch_dtype,
+                        model_name_or_path=pretrained_model_name_or_path,
+                    )
 
-                        if len(unexpected_keys) > 0:
+                    if cls._keys_to_ignore_on_load_unexpected is not None:
+                        for pat in cls._keys_to_ignore_on_load_unexpected:
+                            unexpected_keys = [k for k in unexpected_keys if re.search(pat, k) is None]
+
+                    if len(unexpected_keys) > 0:
+                        logger.warn(
+                            f"Some weights of the model checkpoint were not used when initializing {cls.__name__}: \n {[', '.join(unexpected_keys)]}"
+                        )
+
+                else:  # else let accelerate handle loading and dispatching.
+                    # Load weights and dispatch according to the device_map
+                    # by default the device_map is None and the weights are loaded on the CPU
+                    try:
+                        accelerate.load_checkpoint_and_dispatch(
+                            model,
+                            model_file,
+                            device_map,
+                            max_memory=max_memory,
+                            offload_folder=offload_folder,
+                            offload_state_dict=offload_state_dict,
+                            dtype=torch_dtype,
+                        )
+                    except AttributeError as e:
+                        # When using accelerate loading, we do not have the ability to load the state
+                        # dict and rename the weight names manually. Additionally, accelerate skips
+                        # torch loading conventions and directly writes into `module.{_buffers, _parameters}`
+                        # (which look like they should be private variables?), so we can't use the standard hooks
+                        # to rename parameters on load. We need to mimic the original weight names so the correct
+                        # attributes are available. After we have loaded the weights, we convert the deprecated
+                        # names to the new non-deprecated names. Then we _greatly encourage_ the user to convert
+                        # the weights so we don't have to do this again.
+
+                        if "'Attention' object has no attribute" in str(e):
                             logger.warn(
-                                f"Some weights of the model checkpoint were not used when initializing {cls.__name__}: \n {[', '.join(unexpected_keys)]}"
+                                f"Taking `{str(e)}` while using `accelerate.load_checkpoint_and_dispatch` to mean {pretrained_model_name_or_path}"
+                                " was saved with deprecated attention block weight names. We will load it with the deprecated attention block"
+                                " names and convert them on the fly to the new attention block format. Please re-save the model after this conversion,"
+                                " so we don't have to do the on the fly renaming in the future. If the model is from a hub checkpoint,"
+                                " please also re-upload it or open a PR on the original repository."
                             )
-
-                    else:  # else let accelerate handle loading and dispatching.
-                        # Load weights and dispatch according to the device_map
-                        # by default the device_map is None and the weights are loaded on the CPU
-                        try:
+                            model._temp_convert_self_to_deprecated_attention_blocks()
                             accelerate.load_checkpoint_and_dispatch(
                                 model,
                                 model_file,
@@ -709,80 +724,52 @@ class ModelMixin(torch.nn.Module, PushToHubMixin):
                                 offload_state_dict=offload_state_dict,
                                 dtype=torch_dtype,
                             )
-                        except AttributeError as e:
-                            # When using accelerate loading, we do not have the ability to load the state
-                            # dict and rename the weight names manually. Additionally, accelerate skips
-                            # torch loading conventions and directly writes into `module.{_buffers, _parameters}`
-                            # (which look like they should be private variables?), so we can't use the standard hooks
-                            # to rename parameters on load. We need to mimic the original weight names so the correct
-                            # attributes are available. After we have loaded the weights, we convert the deprecated
-                            # names to the new non-deprecated names. Then we _greatly encourage_ the user to convert
-                            # the weights so we don't have to do this again.
+                            model._undo_temp_convert_self_to_deprecated_attention_blocks()
+                        else:
+                            raise e
 
-                            if "'Attention' object has no attribute" in str(e):
-                                logger.warn(
-                                    f"Taking `{str(e)}` while using `accelerate.load_checkpoint_and_dispatch` to mean {pretrained_model_name_or_path}"
-                                    " was saved with deprecated attention block weight names. We will load it with the deprecated attention block"
-                                    " names and convert them on the fly to the new attention block format. Please re-save the model after this conversion,"
-                                    " so we don't have to do the on the fly renaming in the future. If the model is from a hub checkpoint,"
-                                    " please also re-upload it or open a PR on the original repository."
-                                )
-                                model._temp_convert_self_to_deprecated_attention_blocks()
-                                accelerate.load_checkpoint_and_dispatch(
-                                    model,
-                                    model_file,
-                                    device_map,
-                                    max_memory=max_memory,
-                                    offload_folder=offload_folder,
-                                    offload_state_dict=offload_state_dict,
-                                    dtype=torch_dtype,
-                                )
-                                model._undo_temp_convert_self_to_deprecated_attention_blocks()
-                            else:
-                                raise e
+                loading_info = {
+                    "missing_keys": [],
+                    "unexpected_keys": [],
+                    "mismatched_keys": [],
+                    "error_msgs": [],
+                }
+            else:
+                model = cls.from_config(config, **unused_kwargs)
 
-                    loading_info = {
-                        "missing_keys": [],
-                        "unexpected_keys": [],
-                        "mismatched_keys": [],
-                        "error_msgs": [],
-                    }
-                else:
-                    model = cls.from_config(config, **unused_kwargs)
+                state_dict = load_state_dict(model_file, variant=variant)
+                model._convert_deprecated_attention_blocks(state_dict)
 
-                    state_dict = load_state_dict(model_file, variant=variant)
-                    model._convert_deprecated_attention_blocks(state_dict)
-
-                    model, missing_keys, unexpected_keys, mismatched_keys, error_msgs = cls._load_pretrained_model(
-                        model,
-                        state_dict,
-                        model_file,
-                        pretrained_model_name_or_path,
-                        ignore_mismatched_sizes=ignore_mismatched_sizes,
-                    )
-
-                    loading_info = {
-                        "missing_keys": missing_keys,
-                        "unexpected_keys": unexpected_keys,
-                        "mismatched_keys": mismatched_keys,
-                        "error_msgs": error_msgs,
-                    }
-
-            if torch_dtype is not None and not isinstance(torch_dtype, torch.dtype):
-                raise ValueError(
-                    f"{torch_dtype} needs to be of type `torch.dtype`, e.g. `torch.float16`, but is {type(torch_dtype)}."
+                model, missing_keys, unexpected_keys, mismatched_keys, error_msgs = cls._load_pretrained_model(
+                    model,
+                    state_dict,
+                    model_file,
+                    pretrained_model_name_or_path,
+                    ignore_mismatched_sizes=ignore_mismatched_sizes,
                 )
-            elif torch_dtype is not None:
-                model = model.to(torch_dtype)
 
-            model.register_to_config(_name_or_path=pretrained_model_name_or_path)
+                loading_info = {
+                    "missing_keys": missing_keys,
+                    "unexpected_keys": unexpected_keys,
+                    "mismatched_keys": mismatched_keys,
+                    "error_msgs": error_msgs,
+                }
 
-            # Set model in evaluation mode to deactivate DropOut modules by default
-            model.eval()
-            if output_loading_info:
-                return model, loading_info
+        if torch_dtype is not None and not isinstance(torch_dtype, torch.dtype):
+            raise ValueError(
+                f"{torch_dtype} needs to be of type `torch.dtype`, e.g. `torch.float16`, but is {type(torch_dtype)}."
+            )
+        elif torch_dtype is not None:
+            model = model.to(torch_dtype)
 
-            return model
+        model.register_to_config(_name_or_path=pretrained_model_name_or_path)
+
+        # Set model in evaluation mode to deactivate DropOut modules by default
+        model.eval()
+        if output_loading_info:
+            return model, loading_info
+
+        return model
 
     @classmethod
     def _load_pretrained_model(

src/diffusers/models/unets/__init__.py

@@ -10,6 +10,7 @@ if is_torch_available():
     from .unet_kandinsky3 import Kandinsky3UNet
     from .unet_motion_model import MotionAdapter, UNetMotionModel
     from .unet_spatio_temporal_condition import UNetSpatioTemporalConditionModel
+    from .unet_stable_cascade import StableCascadeUNet
     from .uvit_2d import UVit2DModel
 
 

src/diffusers/models/unets/unet_stable_cascade.py

@@ -0,0 +1,609 @@
+# Copyright 2024 The HuggingFace Team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import math
+from dataclasses import dataclass
+from typing import Optional, Tuple, Union
+
+import numpy as np
+import torch
+import torch.nn as nn
+
+from ...configuration_utils import ConfigMixin, register_to_config
+from ...utils import BaseOutput
+from ..attention_processor import Attention
+from ..modeling_utils import ModelMixin
+
+
+# Copied from diffusers.pipelines.wuerstchen.modeling_wuerstchen_common.WuerstchenLayerNorm with WuerstchenLayerNorm -> SDCascadeLayerNorm
+class SDCascadeLayerNorm(nn.LayerNorm):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+    def forward(self, x):
+        x = x.permute(0, 2, 3, 1)
+        x = super().forward(x)
+        return x.permute(0, 3, 1, 2)
+
+
+class SDCascadeTimestepBlock(nn.Module):
+    def __init__(self, c, c_timestep, conds=[]):
+        super().__init__()
+        linear_cls = nn.Linear
+        self.mapper = linear_cls(c_timestep, c * 2)
+        self.conds = conds
+        for cname in conds:
+            setattr(self, f"mapper_{cname}", linear_cls(c_timestep, c * 2))
+
+    def forward(self, x, t):
+        t = t.chunk(len(self.conds) + 1, dim=1)
+        a, b = self.mapper(t[0])[:, :, None, None].chunk(2, dim=1)
+        for i, c in enumerate(self.conds):
+            ac, bc = getattr(self, f"mapper_{c}")(t[i + 1])[:, :, None, None].chunk(2, dim=1)
+            a, b = a + ac, b + bc
+        return x * (1 + a) + b
+
+
+class SDCascadeResBlock(nn.Module):
+    def __init__(self, c, c_skip=0, kernel_size=3, dropout=0.0):
+        super().__init__()
+        self.depthwise = nn.Conv2d(c, c, kernel_size=kernel_size, padding=kernel_size // 2, groups=c)
+        self.norm = SDCascadeLayerNorm(c, elementwise_affine=False, eps=1e-6)
+        self.channelwise = nn.Sequential(
+            nn.Linear(c + c_skip, c * 4),
+            nn.GELU(),
+            GlobalResponseNorm(c * 4),
+            nn.Dropout(dropout),
+            nn.Linear(c * 4, c),
+        )
+
+    def forward(self, x, x_skip=None):
+        x_res = x
+        x = self.norm(self.depthwise(x))
+        if x_skip is not None:
+            x = torch.cat([x, x_skip], dim=1)
+        x = self.channelwise(x.permute(0, 2, 3, 1)).permute(0, 3, 1, 2)
+        return x + x_res
+
+
+# from https://github.com/facebookresearch/ConvNeXt-V2/blob/3608f67cc1dae164790c5d0aead7bf2d73d9719b/models/utils.py#L105
+class GlobalResponseNorm(nn.Module):
+    def __init__(self, dim):
+        super().__init__()
+        self.gamma = nn.Parameter(torch.zeros(1, 1, 1, dim))
+        self.beta = nn.Parameter(torch.zeros(1, 1, 1, dim))
+
+    def forward(self, x):
+        agg_norm = torch.norm(x, p=2, dim=(1, 2), keepdim=True)
+        stand_div_norm = agg_norm / (agg_norm.mean(dim=-1, keepdim=True) + 1e-6)
+        return self.gamma * (x * stand_div_norm) + self.beta + x
+
+
+class SDCascadeAttnBlock(nn.Module):
+    def __init__(self, c, c_cond, nhead, self_attn=True, dropout=0.0):
+        super().__init__()
+        linear_cls = nn.Linear
+
+        self.self_attn = self_attn
+        self.norm = SDCascadeLayerNorm(c, elementwise_affine=False, eps=1e-6)
+        self.attention = Attention(query_dim=c, heads=nhead, dim_head=c // nhead, dropout=dropout, bias=True)
+        self.kv_mapper = nn.Sequential(nn.SiLU(), linear_cls(c_cond, c))
+
+    def forward(self, x, kv):
+        kv = self.kv_mapper(kv)
+        norm_x = self.norm(x)
+        if self.self_attn:
+            batch_size, channel, _, _ = x.shape
+            kv = torch.cat([norm_x.view(batch_size, channel, -1).transpose(1, 2), kv], dim=1)
+        x = x + self.attention(norm_x, encoder_hidden_states=kv)
+        return x
+
+
+class UpDownBlock2d(nn.Module):
+    def __init__(self, in_channels, out_channels, mode, enabled=True):
+        super().__init__()
+        if mode not in ["up", "down"]:
+            raise ValueError(f"{mode} not supported")
+        interpolation = (
+            nn.Upsample(scale_factor=2 if mode == "up" else 0.5, mode="bilinear", align_corners=True)
+            if enabled
+            else nn.Identity()
+        )
+        mapping = nn.Conv2d(in_channels, out_channels, kernel_size=1)
+        self.blocks = nn.ModuleList([interpolation, mapping] if mode == "up" else [mapping, interpolation])
+
+    def forward(self, x):
+        for block in self.blocks:
+            x = block(x)
+        return x
+
+
+@dataclass
+class StableCascadeUNetOutput(BaseOutput):
+    sample: torch.FloatTensor = None
+
+
+class StableCascadeUNet(ModelMixin, ConfigMixin):
+    _supports_gradient_checkpointing = True
+
+    @register_to_config
+    def __init__(
+        self,
+        in_channels: int = 16,
+        out_channels: int = 16,
+        timestep_ratio_embedding_dim: int = 64,
+        patch_size: int = 1,
+        conditioning_dim: int = 2048,
+        block_out_channels: Tuple[int] = (2048, 2048),
+        num_attention_heads: Tuple[int] = (32, 32),
+        down_num_layers_per_block: Tuple[int] = (8, 24),
+        up_num_layers_per_block: Tuple[int] = (24, 8),
+        down_blocks_repeat_mappers: Optional[Tuple[int]] = (
+            1,
+            1,
+        ),
+        up_blocks_repeat_mappers: Optional[Tuple[int]] = (1, 1),
+        block_types_per_layer: Tuple[Tuple[str]] = (
+            ("SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock"),
+            ("SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock"),
+        ),
+        clip_text_in_channels: Optional[int] = None,
+        clip_text_pooled_in_channels=1280,
+        clip_image_in_channels: Optional[int] = None,
+        clip_seq=4,
+        effnet_in_channels: Optional[int] = None,
+        pixel_mapper_in_channels: Optional[int] = None,
+        kernel_size=3,
+        dropout: Union[float, Tuple[float]] = (0.1, 0.1),
+        self_attn: Union[bool, Tuple[bool]] = True,
+        timestep_conditioning_type: Tuple[str] = ("sca", "crp"),
+        switch_level: Optional[Tuple[bool]] = None,
+    ):
+        """
+
+        Parameters:
+            in_channels (`int`, defaults to 16):
+                Number of channels in the input sample.
+            out_channels (`int`, defaults to 16):
+                Number of channels in the output sample.
+            timestep_ratio_embedding_dim (`int`, defaults to 64):
+                Dimension of the projected time embedding.
+            patch_size (`int`, defaults to 1):
+                Patch size to use for pixel unshuffling layer
+            conditioning_dim (`int`, defaults to 2048):
+                Dimension of the image and text conditional embedding.
+            block_out_channels (Tuple[int], defaults to (2048, 2048)):
+                Tuple of output channels for each block.
+            num_attention_heads (Tuple[int], defaults to (32, 32)):
+                Number of attention heads in each attention block. Set to -1 to if block types in a layer do not have attention.
+            down_num_layers_per_block (Tuple[int], defaults to [8, 24]):
+                Number of layers in each down block.
+            up_num_layers_per_block (Tuple[int], defaults to [24, 8]):
+                Number of layers in each up block.
+            down_blocks_repeat_mappers (Tuple[int], optional, defaults to [1, 1]):
+                Number of 1x1 Convolutional layers to repeat in each down block.
+            up_blocks_repeat_mappers (Tuple[int], optional, defaults to [1, 1]):
+                Number of 1x1 Convolutional layers to repeat in each up block.
+            block_types_per_layer (Tuple[Tuple[str]], optional,
+                defaults to (
+                    ("SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock"),
+                    ("SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock")
+                ):
+                Block types used in each layer of the up/down blocks.
+            clip_text_in_channels (`int`, *optional*, defaults to `None`):
+                Number of input channels for CLIP based text conditioning.
+            clip_text_pooled_in_channels (`int`, *optional*, defaults to 1280):
+                Number of input channels for pooled CLIP text embeddings.
+            clip_image_in_channels (`int`, *optional*):
+                Number of input channels for CLIP based image conditioning.
+            clip_seq (`int`, *optional*, defaults to 4):
+            effnet_in_channels (`int`, *optional*, defaults to `None`):
+                Number of input channels for effnet conditioning.
+            pixel_mapper_in_channels (`int`, defaults to `None`):
+                Number of input channels for pixel mapper conditioning.
+            kernel_size (`int`, *optional*, defaults to 3):
+                Kernel size to use in the block convolutional layers.
+            dropout (Tuple[float], *optional*, defaults to (0.1, 0.1)):
+                Dropout to use per block.
+            self_attn (Union[bool, Tuple[bool]]):
+                Tuple of booleans that determine whether to use self attention in a block or not.
+            timestep_conditioning_type (Tuple[str], defaults to ("sca", "crp")):
+                Timestep conditioning type.
+            switch_level (Optional[Tuple[bool]], *optional*, defaults to `None`):
+                Tuple that indicates whether upsampling or downsampling should be applied in a block
+        """
+
+        super().__init__()
+
+        if len(block_out_channels) != len(down_num_layers_per_block):
+            raise ValueError(
+                f"Number of elements in `down_num_layers_per_block` must match the length of `block_out_channels`: {len(block_out_channels)}"
+            )
+
+        elif len(block_out_channels) != len(up_num_layers_per_block):
+            raise ValueError(
+                f"Number of elements in `up_num_layers_per_block` must match the length of `block_out_channels`: {len(block_out_channels)}"
+            )
+
+        elif len(block_out_channels) != len(down_blocks_repeat_mappers):
+            raise ValueError(
+                f"Number of elements in `down_blocks_repeat_mappers` must match the length of `block_out_channels`: {len(block_out_channels)}"
+            )
+
+        elif len(block_out_channels) != len(up_blocks_repeat_mappers):
+            raise ValueError(
+                f"Number of elements in `up_blocks_repeat_mappers` must match the length of `block_out_channels`: {len(block_out_channels)}"
+            )
+
+        elif len(block_out_channels) != len(block_types_per_layer):
+            raise ValueError(
+                f"Number of elements in `block_types_per_layer` must match the length of `block_out_channels`: {len(block_out_channels)}"
+            )
+
+        if isinstance(dropout, float):
+            dropout = (dropout,) * len(block_out_channels)
+        if isinstance(self_attn, bool):
+            self_attn = (self_attn,) * len(block_out_channels)
+
+        # CONDITIONING
+        if effnet_in_channels is not None:
+            self.effnet_mapper = nn.Sequential(
+                nn.Conv2d(effnet_in_channels, block_out_channels[0] * 4, kernel_size=1),
+                nn.GELU(),
+                nn.Conv2d(block_out_channels[0] * 4, block_out_channels[0], kernel_size=1),
+                SDCascadeLayerNorm(block_out_channels[0], elementwise_affine=False, eps=1e-6),
+            )
+        if pixel_mapper_in_channels is not None:
+            self.pixels_mapper = nn.Sequential(
+                nn.Conv2d(pixel_mapper_in_channels, block_out_channels[0] * 4, kernel_size=1),
+                nn.GELU(),
+                nn.Conv2d(block_out_channels[0] * 4, block_out_channels[0], kernel_size=1),
+                SDCascadeLayerNorm(block_out_channels[0], elementwise_affine=False, eps=1e-6),
+            )
+
+        self.clip_txt_pooled_mapper = nn.Linear(clip_text_pooled_in_channels, conditioning_dim * clip_seq)
+        if clip_text_in_channels is not None:
+            self.clip_txt_mapper = nn.Linear(clip_text_in_channels, conditioning_dim)
+        if clip_image_in_channels is not None:
+            self.clip_img_mapper = nn.Linear(clip_image_in_channels, conditioning_dim * clip_seq)
+        self.clip_norm = nn.LayerNorm(conditioning_dim, elementwise_affine=False, eps=1e-6)
+
+        self.embedding = nn.Sequential(
+            nn.PixelUnshuffle(patch_size),
+            nn.Conv2d(in_channels * (patch_size**2), block_out_channels[0], kernel_size=1),
+            SDCascadeLayerNorm(block_out_channels[0], elementwise_affine=False, eps=1e-6),
+        )
+
+        def get_block(block_type, in_channels, nhead, c_skip=0, dropout=0, self_attn=True):
+            if block_type == "SDCascadeResBlock":
+                return SDCascadeResBlock(in_channels, c_skip, kernel_size=kernel_size, dropout=dropout)
+            elif block_type == "SDCascadeAttnBlock":
+                return SDCascadeAttnBlock(in_channels, conditioning_dim, nhead, self_attn=self_attn, dropout=dropout)
+            elif block_type == "SDCascadeTimestepBlock":
+                return SDCascadeTimestepBlock(
+                    in_channels, timestep_ratio_embedding_dim, conds=timestep_conditioning_type
+                )
+            else:
+                raise ValueError(f"Block type {block_type} not supported")
+
+        # BLOCKS
+        # -- down blocks
+        self.down_blocks = nn.ModuleList()
+        self.down_downscalers = nn.ModuleList()
+        self.down_repeat_mappers = nn.ModuleList()
+        for i in range(len(block_out_channels)):
+            if i > 0:
+                self.down_downscalers.append(
+                    nn.Sequential(
+                        SDCascadeLayerNorm(block_out_channels[i - 1], elementwise_affine=False, eps=1e-6),
+                        UpDownBlock2d(
+                            block_out_channels[i - 1], block_out_channels[i], mode="down", enabled=switch_level[i - 1]
+                        )
+                        if switch_level is not None
+                        else nn.Conv2d(block_out_channels[i - 1], block_out_channels[i], kernel_size=2, stride=2),
+                    )
+                )
+            else:
+                self.down_downscalers.append(nn.Identity())
+
+            down_block = nn.ModuleList()
+            for _ in range(down_num_layers_per_block[i]):
+                for block_type in block_types_per_layer[i]:
+                    block = get_block(
+                        block_type,
+                        block_out_channels[i],
+                        num_attention_heads[i],
+                        dropout=dropout[i],
+                        self_attn=self_attn[i],
+                    )
+                    down_block.append(block)
+            self.down_blocks.append(down_block)
+
+            if down_blocks_repeat_mappers is not None:
+                block_repeat_mappers = nn.ModuleList()
+                for _ in range(down_blocks_repeat_mappers[i] - 1):
+                    block_repeat_mappers.append(nn.Conv2d(block_out_channels[i], block_out_channels[i], kernel_size=1))
+                self.down_repeat_mappers.append(block_repeat_mappers)
+
+        # -- up blocks
+        self.up_blocks = nn.ModuleList()
+        self.up_upscalers = nn.ModuleList()
+        self.up_repeat_mappers = nn.ModuleList()
+        for i in reversed(range(len(block_out_channels))):
+            if i > 0:
+                self.up_upscalers.append(
+                    nn.Sequential(
+                        SDCascadeLayerNorm(block_out_channels[i], elementwise_affine=False, eps=1e-6),
+                        UpDownBlock2d(
+                            block_out_channels[i], block_out_channels[i - 1], mode="up", enabled=switch_level[i - 1]
+                        )
+                        if switch_level is not None
+                        else nn.ConvTranspose2d(
+                            block_out_channels[i], block_out_channels[i - 1], kernel_size=2, stride=2
+                        ),
+                    )
+                )
+            else:
+                self.up_upscalers.append(nn.Identity())
+
+            up_block = nn.ModuleList()
+            for j in range(up_num_layers_per_block[::-1][i]):
+                for k, block_type in enumerate(block_types_per_layer[i]):
+                    c_skip = block_out_channels[i] if i < len(block_out_channels) - 1 and j == k == 0 else 0
+                    block = get_block(
+                        block_type,
+                        block_out_channels[i],
+                        num_attention_heads[i],
+                        c_skip=c_skip,
+                        dropout=dropout[i],
+                        self_attn=self_attn[i],
+                    )
+                    up_block.append(block)
+            self.up_blocks.append(up_block)
+
+            if up_blocks_repeat_mappers is not None:
+                block_repeat_mappers = nn.ModuleList()
+                for _ in range(up_blocks_repeat_mappers[::-1][i] - 1):
+                    block_repeat_mappers.append(nn.Conv2d(block_out_channels[i], block_out_channels[i], kernel_size=1))
+                self.up_repeat_mappers.append(block_repeat_mappers)
+
+        # OUTPUT
+        self.clf = nn.Sequential(
+            SDCascadeLayerNorm(block_out_channels[0], elementwise_affine=False, eps=1e-6),
+            nn.Conv2d(block_out_channels[0], out_channels * (patch_size**2), kernel_size=1),
+            nn.PixelShuffle(patch_size),
+        )
+
+        self.gradient_checkpointing = False
+
+    def _set_gradient_checkpointing(self, value=False):
+        self.gradient_checkpointing = value
+
+    def _init_weights(self, m):
+        if isinstance(m, (nn.Conv2d, nn.Linear)):
+            torch.nn.init.xavier_uniform_(m.weight)
+            if m.bias is not None:
+                nn.init.constant_(m.bias, 0)
+
+        nn.init.normal_(self.clip_txt_pooled_mapper.weight, std=0.02)
+        nn.init.normal_(self.clip_txt_mapper.weight, std=0.02) if hasattr(self, "clip_txt_mapper") else None
+        nn.init.normal_(self.clip_img_mapper.weight, std=0.02) if hasattr(self, "clip_img_mapper") else None
+
+        if hasattr(self, "effnet_mapper"):
+            nn.init.normal_(self.effnet_mapper[0].weight, std=0.02)  # conditionings
+            nn.init.normal_(self.effnet_mapper[2].weight, std=0.02)  # conditionings
+
+        if hasattr(self, "pixels_mapper"):
+            nn.init.normal_(self.pixels_mapper[0].weight, std=0.02)  # conditionings
+            nn.init.normal_(self.pixels_mapper[2].weight, std=0.02)  # conditionings
+
+        torch.nn.init.xavier_uniform_(self.embedding[1].weight, 0.02)  # inputs
+        nn.init.constant_(self.clf[1].weight, 0)  # outputs
+
+        # blocks
+        for level_block in self.down_blocks + self.up_blocks:
+            for block in level_block:
+                if isinstance(block, SDCascadeResBlock):
+                    block.channelwise[-1].weight.data *= np.sqrt(1 / sum(self.config.blocks[0]))
+                elif isinstance(block, SDCascadeTimestepBlock):
+                    nn.init.constant_(block.mapper.weight, 0)
+
+    def get_timestep_ratio_embedding(self, timestep_ratio, max_positions=10000):
+        r = timestep_ratio * max_positions
+        half_dim = self.config.timestep_ratio_embedding_dim // 2
+
+        emb = math.log(max_positions) / (half_dim - 1)
+        emb = torch.arange(half_dim, device=r.device).float().mul(-emb).exp()
+        emb = r[:, None] * emb[None, :]
+        emb = torch.cat([emb.sin(), emb.cos()], dim=1)
+
+        if self.config.timestep_ratio_embedding_dim % 2 == 1:  # zero pad
+            emb = nn.functional.pad(emb, (0, 1), mode="constant")
+
+        return emb.to(dtype=r.dtype)
+
+    def get_clip_embeddings(self, clip_txt_pooled, clip_txt=None, clip_img=None):
+        if len(clip_txt_pooled.shape) == 2:
+            clip_txt_pool = clip_txt_pooled.unsqueeze(1)
+        clip_txt_pool = self.clip_txt_pooled_mapper(clip_txt_pooled).view(
+            clip_txt_pooled.size(0), clip_txt_pooled.size(1) * self.config.clip_seq, -1
+        )
+        if clip_txt is not None and clip_img is not None:
+            clip_txt = self.clip_txt_mapper(clip_txt)
+            if len(clip_img.shape) == 2:
+                clip_img = clip_img.unsqueeze(1)
+            clip_img = self.clip_img_mapper(clip_img).view(
+                clip_img.size(0), clip_img.size(1) * self.config.clip_seq, -1
+            )
+            clip = torch.cat([clip_txt, clip_txt_pool, clip_img], dim=1)
+        else:
+            clip = clip_txt_pool
+        return self.clip_norm(clip)
+
+    def _down_encode(self, x, r_embed, clip):
+        level_outputs = []
+        block_group = zip(self.down_blocks, self.down_downscalers, self.down_repeat_mappers)
+
+        if self.training and self.gradient_checkpointing:
+
+            def create_custom_forward(module):
+                def custom_forward(*inputs):
+                    return module(*inputs)
+
+                return custom_forward
+
+            for down_block, downscaler, repmap in block_group:
+                x = downscaler(x)
+                for i in range(len(repmap) + 1):
+                    for block in down_block:
+                        if isinstance(block, SDCascadeResBlock):
+                            x = torch.utils.checkpoint.checkpoint(create_custom_forward(block), x, use_reentrant=False)
+                        elif isinstance(block, SDCascadeAttnBlock):
+                            x = torch.utils.checkpoint.checkpoint(
+                                create_custom_forward(block), x, clip, use_reentrant=False
+                            )
+                        elif isinstance(block, SDCascadeTimestepBlock):
+                            x = torch.utils.checkpoint.checkpoint(
+                                create_custom_forward(block), x, r_embed, use_reentrant=False
+                            )
+                        else:
+                            x = x = torch.utils.checkpoint.checkpoint(
+                                create_custom_forward(block), use_reentrant=False
+                            )
+                    if i < len(repmap):
+                        x = repmap[i](x)
+                level_outputs.insert(0, x)
+        else:
+            for down_block, downscaler, repmap in block_group:
+                x = downscaler(x)
+                for i in range(len(repmap) + 1):
+                    for block in down_block:
+                        if isinstance(block, SDCascadeResBlock):
+                            x = block(x)
+                        elif isinstance(block, SDCascadeAttnBlock):
+                            x = block(x, clip)
+                        elif isinstance(block, SDCascadeTimestepBlock):
+                            x = block(x, r_embed)
+                        else:
+                            x = block(x)
+                    if i < len(repmap):
+                        x = repmap[i](x)
+                level_outputs.insert(0, x)
+        return level_outputs
+
+    def _up_decode(self, level_outputs, r_embed, clip):
+        x = level_outputs[0]
+        block_group = zip(self.up_blocks, self.up_upscalers, self.up_repeat_mappers)
+
+        if self.training and self.gradient_checkpointing:
+
+            def create_custom_forward(module):
+                def custom_forward(*inputs):
+                    return module(*inputs)
+
+                return custom_forward
+
+            for i, (up_block, upscaler, repmap) in enumerate(block_group):
+                for j in range(len(repmap) + 1):
+                    for k, block in enumerate(up_block):
+                        if isinstance(block, SDCascadeResBlock):
+                            skip = level_outputs[i] if k == 0 and i > 0 else None
+                            if skip is not None and (x.size(-1) != skip.size(-1) or x.size(-2) != skip.size(-2)):
+                                x = torch.nn.functional.interpolate(
+                                    x.float(), skip.shape[-2:], mode="bilinear", align_corners=True
+                                )
+                            x = torch.utils.checkpoint.checkpoint(
+                                create_custom_forward(block), x, skip, use_reentrant=False
+                            )
+                        elif isinstance(block, SDCascadeAttnBlock):
+                            x = torch.utils.checkpoint.checkpoint(
+                                create_custom_forward(block), x, clip, use_reentrant=False
+                            )
+                        elif isinstance(block, SDCascadeTimestepBlock):
+                            x = torch.utils.checkpoint.checkpoint(
+                                create_custom_forward(block), x, r_embed, use_reentrant=False
+                            )
+                        else:
+                            x = torch.utils.checkpoint.checkpoint(create_custom_forward(block), x, use_reentrant=False)
+                    if j < len(repmap):
+                        x = repmap[j](x)
+                x = upscaler(x)
+        else:
+            for i, (up_block, upscaler, repmap) in enumerate(block_group):
+                for j in range(len(repmap) + 1):
+                    for k, block in enumerate(up_block):
+                        if isinstance(block, SDCascadeResBlock):
+                            skip = level_outputs[i] if k == 0 and i > 0 else None
+                            if skip is not None and (x.size(-1) != skip.size(-1) or x.size(-2) != skip.size(-2)):
+                                x = torch.nn.functional.interpolate(
+                                    x.float(), skip.shape[-2:], mode="bilinear", align_corners=True
+                                )
+                            x = block(x, skip)
+                        elif isinstance(block, SDCascadeAttnBlock):
+                            x = block(x, clip)
+                        elif isinstance(block, SDCascadeTimestepBlock):
+                            x = block(x, r_embed)
+                        else:
+                            x = block(x)
+                    if j < len(repmap):
+                        x = repmap[j](x)
+                x = upscaler(x)
+        return x
+
+    def forward(
+        self,
+        sample,
+        timestep_ratio,
+        clip_text_pooled,
+        clip_text=None,
+        clip_img=None,
+        effnet=None,
+        pixels=None,
+        sca=None,
+        crp=None,
+        return_dict=True,
+    ):
+        if pixels is None:
+            pixels = sample.new_zeros(sample.size(0), 3, 8, 8)
+
+        # Process the conditioning embeddings
+        timestep_ratio_embed = self.get_timestep_ratio_embedding(timestep_ratio)
+        for c in self.config.timestep_conditioning_type:
+            if c == "sca":
+                cond = sca
+            elif c == "crp":
+                cond = crp
+            else:
+                cond = None
+            t_cond = cond or torch.zeros_like(timestep_ratio)
+            timestep_ratio_embed = torch.cat([timestep_ratio_embed, self.get_timestep_ratio_embedding(t_cond)], dim=1)
+        clip = self.get_clip_embeddings(clip_txt_pooled=clip_text_pooled, clip_txt=clip_text, clip_img=clip_img)
+
+        # Model Blocks
+        x = self.embedding(sample)
+        if hasattr(self, "effnet_mapper") and effnet is not None:
+            x = x + self.effnet_mapper(
+                nn.functional.interpolate(effnet, size=x.shape[-2:], mode="bilinear", align_corners=True)
+            )
+        if hasattr(self, "pixels_mapper"):
+            x = x + nn.functional.interpolate(
+                self.pixels_mapper(pixels), size=x.shape[-2:], mode="bilinear", align_corners=True
+            )
+        level_outputs = self._down_encode(x, timestep_ratio_embed, clip)
+        x = self._up_decode(level_outputs, timestep_ratio_embed, clip)
+        sample = self.clf(x)
+
+        if not return_dict:
+            return (sample,)
+        return StableCascadeUNetOutput(sample=sample)

src/diffusers/pipelines/__init__.py

@@ -176,6 +176,11 @@ else:
     _import_structure["pixart_alpha"] = ["PixArtAlphaPipeline"]
     _import_structure["semantic_stable_diffusion"] = ["SemanticStableDiffusionPipeline"]
     _import_structure["shap_e"] = ["ShapEImg2ImgPipeline", "ShapEPipeline"]
+    _import_structure["stable_cascade"] = [
+        "StableCascadeCombinedPipeline",
+        "StableCascadeDecoderPipeline",
+        "StableCascadePriorPipeline",
+    ]
     _import_structure["stable_diffusion"].extend(
         [
             "CLIPImageProjection",
@@ -424,6 +429,11 @@ if TYPE_CHECKING or DIFFUSERS_SLOW_IMPORT:
         from .pixart_alpha import PixArtAlphaPipeline
         from .semantic_stable_diffusion import SemanticStableDiffusionPipeline
         from .shap_e import ShapEImg2ImgPipeline, ShapEPipeline
+        from .stable_cascade import (
+            StableCascadeCombinedPipeline,
+            StableCascadeDecoderPipeline,
+            StableCascadePriorPipeline,
+        )
         from .stable_diffusion import (
             CLIPImageProjection,
             StableDiffusionDepth2ImgPipeline,

src/diffusers/pipelines/pipeline_loading_utils.py

@@ -0,0 +1,508 @@
+# coding=utf-8
+# Copyright 2024 The HuggingFace Inc. team.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+import importlib
+import os
+import re
+import warnings
+from pathlib import Path
+from typing import Any, Dict, List, Optional, Union
+
+import torch
+from huggingface_hub import (
+    model_info,
+)
+from packaging import version
+
+from ..utils import (
+    SAFETENSORS_WEIGHTS_NAME,
+    WEIGHTS_NAME,
+    get_class_from_dynamic_module,
+    is_peft_available,
+    is_transformers_available,
+    logging,
+)
+from ..utils.torch_utils import is_compiled_module
+
+
+if is_transformers_available():
+    import transformers
+    from transformers import PreTrainedModel
+    from transformers.utils import FLAX_WEIGHTS_NAME as TRANSFORMERS_FLAX_WEIGHTS_NAME
+    from transformers.utils import SAFE_WEIGHTS_NAME as TRANSFORMERS_SAFE_WEIGHTS_NAME
+    from transformers.utils import WEIGHTS_NAME as TRANSFORMERS_WEIGHTS_NAME
+from huggingface_hub.utils import validate_hf_hub_args
+
+from ..utils import FLAX_WEIGHTS_NAME, ONNX_EXTERNAL_WEIGHTS_NAME, ONNX_WEIGHTS_NAME
+
+
+INDEX_FILE = "diffusion_pytorch_model.bin"
+CUSTOM_PIPELINE_FILE_NAME = "pipeline.py"
+DUMMY_MODULES_FOLDER = "diffusers.utils"
+TRANSFORMERS_DUMMY_MODULES_FOLDER = "transformers.utils"
+CONNECTED_PIPES_KEYS = ["prior"]
+
+logger = logging.get_logger(__name__)
+
+LOADABLE_CLASSES = {
+    "diffusers": {
+        "ModelMixin": ["save_pretrained", "from_pretrained"],
+        "SchedulerMixin": ["save_pretrained", "from_pretrained"],
+        "DiffusionPipeline": ["save_pretrained", "from_pretrained"],
+        "OnnxRuntimeModel": ["save_pretrained", "from_pretrained"],
+    },
+    "transformers": {
+        "PreTrainedTokenizer": ["save_pretrained", "from_pretrained"],
+        "PreTrainedTokenizerFast": ["save_pretrained", "from_pretrained"],
+        "PreTrainedModel": ["save_pretrained", "from_pretrained"],
+        "FeatureExtractionMixin": ["save_pretrained", "from_pretrained"],
+        "ProcessorMixin": ["save_pretrained", "from_pretrained"],
+        "ImageProcessingMixin": ["save_pretrained", "from_pretrained"],
+    },
+    "onnxruntime.training": {
+        "ORTModule": ["save_pretrained", "from_pretrained"],
+    },
+}
+
+ALL_IMPORTABLE_CLASSES = {}
+for library in LOADABLE_CLASSES:
+    ALL_IMPORTABLE_CLASSES.update(LOADABLE_CLASSES[library])
+
+
+def is_safetensors_compatible(filenames, variant=None, passed_components=None) -> bool:
+    """
+    Checking for safetensors compatibility:
+    - By default, all models are saved with the default pytorch serialization, so we use the list of default pytorch
+      files to know which safetensors files are needed.
+    - The model is safetensors compatible only if there is a matching safetensors file for every default pytorch file.
+
+    Converting default pytorch serialized filenames to safetensors serialized filenames:
+    - For models from the diffusers library, just replace the ".bin" extension with ".safetensors"
+    - For models from the transformers library, the filename changes from "pytorch_model" to "model", and the ".bin"
+      extension is replaced with ".safetensors"
+    """
+    pt_filenames = []
+
+    sf_filenames = set()
+
+    passed_components = passed_components or []
+
+    for filename in filenames:
+        _, extension = os.path.splitext(filename)
+
+        if len(filename.split("/")) == 2 and filename.split("/")[0] in passed_components:
+            continue
+
+        if extension == ".bin":
+            pt_filenames.append(os.path.normpath(filename))
+        elif extension == ".safetensors":
+            sf_filenames.add(os.path.normpath(filename))
+
+    for filename in pt_filenames:
+        #  filename = 'foo/bar/baz.bam' -> path = 'foo/bar', filename = 'baz', extension = '.bam'
+        path, filename = os.path.split(filename)
+        filename, extension = os.path.splitext(filename)
+
+        if filename.startswith("pytorch_model"):
+            filename = filename.replace("pytorch_model", "model")
+        else:
+            filename = filename
+
+        expected_sf_filename = os.path.normpath(os.path.join(path, filename))
+        expected_sf_filename = f"{expected_sf_filename}.safetensors"
+        if expected_sf_filename not in sf_filenames:
+            logger.warning(f"{expected_sf_filename} not found")
+            return False
+
+    return True
+
+
+def variant_compatible_siblings(filenames, variant=None) -> Union[List[os.PathLike], str]:
+    weight_names = [
+        WEIGHTS_NAME,
+        SAFETENSORS_WEIGHTS_NAME,
+        FLAX_WEIGHTS_NAME,
+        ONNX_WEIGHTS_NAME,
+        ONNX_EXTERNAL_WEIGHTS_NAME,
+    ]
+
+    if is_transformers_available():
+        weight_names += [TRANSFORMERS_WEIGHTS_NAME, TRANSFORMERS_SAFE_WEIGHTS_NAME, TRANSFORMERS_FLAX_WEIGHTS_NAME]
+
+    # model_pytorch, diffusion_model_pytorch, ...
+    weight_prefixes = [w.split(".")[0] for w in weight_names]
+    # .bin, .safetensors, ...
+    weight_suffixs = [w.split(".")[-1] for w in weight_names]
+    # -00001-of-00002
+    transformers_index_format = r"\d{5}-of-\d{5}"
+
+    if variant is not None:
+        # `diffusion_pytorch_model.fp16.bin` as well as `model.fp16-00001-of-00002.safetensors`
+        variant_file_re = re.compile(
+            rf"({'|'.join(weight_prefixes)})\.({variant}|{variant}-{transformers_index_format})\.({'|'.join(weight_suffixs)})$"
+        )
+        # `text_encoder/pytorch_model.bin.index.fp16.json`
+        variant_index_re = re.compile(
+            rf"({'|'.join(weight_prefixes)})\.({'|'.join(weight_suffixs)})\.index\.{variant}\.json$"
+        )
+
+    # `diffusion_pytorch_model.bin` as well as `model-00001-of-00002.safetensors`
+    non_variant_file_re = re.compile(
+        rf"({'|'.join(weight_prefixes)})(-{transformers_index_format})?\.({'|'.join(weight_suffixs)})$"
+    )
+    # `text_encoder/pytorch_model.bin.index.json`
+    non_variant_index_re = re.compile(rf"({'|'.join(weight_prefixes)})\.({'|'.join(weight_suffixs)})\.index\.json")
+
+    if variant is not None:
+        variant_weights = {f for f in filenames if variant_file_re.match(f.split("/")[-1]) is not None}
+        variant_indexes = {f for f in filenames if variant_index_re.match(f.split("/")[-1]) is not None}
+        variant_filenames = variant_weights | variant_indexes
+    else:
+        variant_filenames = set()
+
+    non_variant_weights = {f for f in filenames if non_variant_file_re.match(f.split("/")[-1]) is not None}
+    non_variant_indexes = {f for f in filenames if non_variant_index_re.match(f.split("/")[-1]) is not None}
+    non_variant_filenames = non_variant_weights | non_variant_indexes
+
+    # all variant filenames will be used by default
+    usable_filenames = set(variant_filenames)
+
+    def convert_to_variant(filename):
+        if "index" in filename:
+            variant_filename = filename.replace("index", f"index.{variant}")
+        elif re.compile(f"^(.*?){transformers_index_format}").match(filename) is not None:
+            variant_filename = f"{filename.split('-')[0]}.{variant}-{'-'.join(filename.split('-')[1:])}"
+        else:
+            variant_filename = f"{filename.split('.')[0]}.{variant}.{filename.split('.')[1]}"
+        return variant_filename
+
+    for f in non_variant_filenames:
+        variant_filename = convert_to_variant(f)
+        if variant_filename not in usable_filenames:
+            usable_filenames.add(f)
+
+    return usable_filenames, variant_filenames
+
+
+@validate_hf_hub_args
+def warn_deprecated_model_variant(pretrained_model_name_or_path, token, variant, revision, model_filenames):
+    info = model_info(
+        pretrained_model_name_or_path,
+        token=token,
+        revision=None,
+    )
+    filenames = {sibling.rfilename for sibling in info.siblings}
+    comp_model_filenames, _ = variant_compatible_siblings(filenames, variant=revision)
+    comp_model_filenames = [".".join(f.split(".")[:1] + f.split(".")[2:]) for f in comp_model_filenames]
+
+    if set(model_filenames).issubset(set(comp_model_filenames)):
+        warnings.warn(
+            f"You are loading the variant {revision} from {pretrained_model_name_or_path} via `revision='{revision}'` even though you can load it via `variant=`{revision}`. Loading model variants via `revision='{revision}'` is deprecated and will be removed in diffusers v1. Please use `variant='{revision}'` instead.",
+            FutureWarning,
+        )
+    else:
+        warnings.warn(
+            f"You are loading the variant {revision} from {pretrained_model_name_or_path} via `revision='{revision}'`. This behavior is deprecated and will be removed in diffusers v1. One should use `variant='{revision}'` instead. However, it appears that {pretrained_model_name_or_path} currently does not have the required variant filenames in the 'main' branch. \n The Diffusers team and community would be very grateful if you could open an issue: https://github.com/huggingface/diffusers/issues/new with the title '{pretrained_model_name_or_path} is missing {revision} files' so that the correct variant file can be added.",
+            FutureWarning,
+        )
+
+
+def _unwrap_model(model):
+    """Unwraps a model."""
+    if is_compiled_module(model):
+        model = model._orig_mod
+
+    if is_peft_available():
+        from peft import PeftModel
+
+        if isinstance(model, PeftModel):
+            model = model.base_model.model
+
+    return model
+
+
+def maybe_raise_or_warn(
+    library_name, library, class_name, importable_classes, passed_class_obj, name, is_pipeline_module
+):
+    """Simple helper method to raise or warn in case incorrect module has been passed"""
+    if not is_pipeline_module:
+        library = importlib.import_module(library_name)
+        class_obj = getattr(library, class_name)
+        class_candidates = {c: getattr(library, c, None) for c in importable_classes.keys()}
+
+        expected_class_obj = None
+        for class_name, class_candidate in class_candidates.items():
+            if class_candidate is not None and issubclass(class_obj, class_candidate):
+                expected_class_obj = class_candidate
+
+        # Dynamo wraps the original model in a private class.
+        # I didn't find a public API to get the original class.
+        sub_model = passed_class_obj[name]
+        unwrapped_sub_model = _unwrap_model(sub_model)
+        model_cls = unwrapped_sub_model.__class__
+
+        if not issubclass(model_cls, expected_class_obj):
+            raise ValueError(
+                f"{passed_class_obj[name]} is of type: {model_cls}, but should be" f" {expected_class_obj}"
+            )
+    else:
+        logger.warning(
+            f"You have passed a non-standard module {passed_class_obj[name]}. We cannot verify whether it"
+            " has the correct type"
+        )
+
+
+def get_class_obj_and_candidates(
+    library_name, class_name, importable_classes, pipelines, is_pipeline_module, component_name=None, cache_dir=None
+):
+    """Simple helper method to retrieve class object of module as well as potential parent class objects"""
+    component_folder = os.path.join(cache_dir, component_name)
+
+    if is_pipeline_module:
+        pipeline_module = getattr(pipelines, library_name)
+
+        class_obj = getattr(pipeline_module, class_name)
+        class_candidates = {c: class_obj for c in importable_classes.keys()}
+    elif os.path.isfile(os.path.join(component_folder, library_name + ".py")):
+        # load custom component
+        class_obj = get_class_from_dynamic_module(
+            component_folder, module_file=library_name + ".py", class_name=class_name
+        )
+        class_candidates = {c: class_obj for c in importable_classes.keys()}
+    else:
+        # else we just import it from the library.
+        library = importlib.import_module(library_name)
+
+        class_obj = getattr(library, class_name)
+        class_candidates = {c: getattr(library, c, None) for c in importable_classes.keys()}
+
+    return class_obj, class_candidates
+
+
+def _get_pipeline_class(
+    class_obj,
+    config=None,
+    load_connected_pipeline=False,
+    custom_pipeline=None,
+    repo_id=None,
+    hub_revision=None,
+    class_name=None,
+    cache_dir=None,
+    revision=None,
+):
+    if custom_pipeline is not None:
+        if custom_pipeline.endswith(".py"):
+            path = Path(custom_pipeline)
+            # decompose into folder & file
+            file_name = path.name
+            custom_pipeline = path.parent.absolute()
+        elif repo_id is not None:
+            file_name = f"{custom_pipeline}.py"
+            custom_pipeline = repo_id
+        else:
+            file_name = CUSTOM_PIPELINE_FILE_NAME
+
+        if repo_id is not None and hub_revision is not None:
+            # if we load the pipeline code from the Hub
+            # make sure to overwrite the `revision`
+            revision = hub_revision
+
+        return get_class_from_dynamic_module(
+            custom_pipeline,
+            module_file=file_name,
+            class_name=class_name,
+            cache_dir=cache_dir,
+            revision=revision,
+        )
+
+    if class_obj.__name__ != "DiffusionPipeline":
+        return class_obj
+
+    diffusers_module = importlib.import_module(class_obj.__module__.split(".")[0])
+    class_name = class_name or config["_class_name"]
+    if not class_name:
+        raise ValueError(
+            "The class name could not be found in the configuration file. Please make sure to pass the correct `class_name`."
+        )
+
+    class_name = class_name[4:] if class_name.startswith("Flax") else class_name
+
+    pipeline_cls = getattr(diffusers_module, class_name)
+
+    if load_connected_pipeline:
+        from .auto_pipeline import _get_connected_pipeline
+
+        connected_pipeline_cls = _get_connected_pipeline(pipeline_cls)
+        if connected_pipeline_cls is not None:
+            logger.info(
+                f"Loading connected pipeline {connected_pipeline_cls.__name__} instead of {pipeline_cls.__name__} as specified via `load_connected_pipeline=True`"
+            )
+        else:
+            logger.info(f"{pipeline_cls.__name__} has no connected pipeline class. Loading {pipeline_cls.__name__}.")
+
+        pipeline_cls = connected_pipeline_cls or pipeline_cls
+
+    return pipeline_cls
+
+
+def load_sub_model(
+    library_name: str,
+    class_name: str,
+    importable_classes: List[Any],
+    pipelines: Any,
+    is_pipeline_module: bool,
+    pipeline_class: Any,
+    torch_dtype: torch.dtype,
+    provider: Any,
+    sess_options: Any,
+    device_map: Optional[Union[Dict[str, torch.device], str]],
+    max_memory: Optional[Dict[Union[int, str], Union[int, str]]],
+    offload_folder: Optional[Union[str, os.PathLike]],
+    offload_state_dict: bool,
+    model_variants: Dict[str, str],
+    name: str,
+    from_flax: bool,
+    variant: str,
+    low_cpu_mem_usage: bool,
+    cached_folder: Union[str, os.PathLike],
+):
+    """Helper method to load the module `name` from `library_name` and `class_name`"""
+    # retrieve class candidates
+    class_obj, class_candidates = get_class_obj_and_candidates(
+        library_name,
+        class_name,
+        importable_classes,
+        pipelines,
+        is_pipeline_module,
+        component_name=name,
+        cache_dir=cached_folder,
+    )
+
+    load_method_name = None
+    # retrieve load method name
+    for class_name, class_candidate in class_candidates.items():
+        if class_candidate is not None and issubclass(class_obj, class_candidate):
+            load_method_name = importable_classes[class_name][1]
+
+    # if load method name is None, then we have a dummy module -> raise Error
+    if load_method_name is None:
+        none_module = class_obj.__module__
+        is_dummy_path = none_module.startswith(DUMMY_MODULES_FOLDER) or none_module.startswith(
+            TRANSFORMERS_DUMMY_MODULES_FOLDER
+        )
+        if is_dummy_path and "dummy" in none_module:
+            # call class_obj for nice error message of missing requirements
+            class_obj()
+
+        raise ValueError(
+            f"The component {class_obj} of {pipeline_class} cannot be loaded as it does not seem to have"
+            f" any of the loading methods defined in {ALL_IMPORTABLE_CLASSES}."
+        )
+
+    load_method = getattr(class_obj, load_method_name)
+
+    # add kwargs to loading method
+    diffusers_module = importlib.import_module(__name__.split(".")[0])
+    loading_kwargs = {}
+    if issubclass(class_obj, torch.nn.Module):
+        loading_kwargs["torch_dtype"] = torch_dtype
+    if issubclass(class_obj, diffusers_module.OnnxRuntimeModel):
+        loading_kwargs["provider"] = provider
+        loading_kwargs["sess_options"] = sess_options
+
+    is_diffusers_model = issubclass(class_obj, diffusers_module.ModelMixin)
+
+    if is_transformers_available():
+        transformers_version = version.parse(version.parse(transformers.__version__).base_version)
+    else:
+        transformers_version = "N/A"
+
+    is_transformers_model = (
+        is_transformers_available()
+        and issubclass(class_obj, PreTrainedModel)
+        and transformers_version >= version.parse("4.20.0")
+    )
+
+    # When loading a transformers model, if the device_map is None, the weights will be initialized as opposed to diffusers.
+    # To make default loading faster we set the `low_cpu_mem_usage=low_cpu_mem_usage` flag which is `True` by default.
+    # This makes sure that the weights won't be initialized which significantly speeds up loading.
+    if is_diffusers_model or is_transformers_model:
+        loading_kwargs["device_map"] = device_map
+        loading_kwargs["max_memory"] = max_memory
+        loading_kwargs["offload_folder"] = offload_folder
+        loading_kwargs["offload_state_dict"] = offload_state_dict
+        loading_kwargs["variant"] = model_variants.pop(name, None)
+
+        if from_flax:
+            loading_kwargs["from_flax"] = True
+
+        # the following can be deleted once the minimum required `transformers` version
+        # is higher than 4.27
+        if (
+            is_transformers_model
+            and loading_kwargs["variant"] is not None
+            and transformers_version < version.parse("4.27.0")
+        ):
+            raise ImportError(
+                f"When passing `variant='{variant}'`, please make sure to upgrade your `transformers` version to at least 4.27.0.dev0"
+            )
+        elif is_transformers_model and loading_kwargs["variant"] is None:
+            loading_kwargs.pop("variant")
+
+        # if `from_flax` and model is transformer model, can currently not load with `low_cpu_mem_usage`
+        if not (from_flax and is_transformers_model):
+            loading_kwargs["low_cpu_mem_usage"] = low_cpu_mem_usage
+        else:
+            loading_kwargs["low_cpu_mem_usage"] = False
+
+    # check if the module is in a subdirectory
+    if os.path.isdir(os.path.join(cached_folder, name)):
+        loaded_sub_model = load_method(os.path.join(cached_folder, name), **loading_kwargs)
+    else:
+        # else load from the root directory
+        loaded_sub_model = load_method(cached_folder, **loading_kwargs)
+
+    return loaded_sub_model
+
+
+def _fetch_class_library_tuple(module):
+    # import it here to avoid circular import
+    diffusers_module = importlib.import_module(__name__.split(".")[0])
+    pipelines = getattr(diffusers_module, "pipelines")
+
+    # register the config from the original module, not the dynamo compiled one
+    not_compiled_module = _unwrap_model(module)
+    library = not_compiled_module.__module__.split(".")[0]
+
+    # check if the module is a pipeline module
+    module_path_items = not_compiled_module.__module__.split(".")
+    pipeline_dir = module_path_items[-2] if len(module_path_items) > 2 else None
+
+    path = not_compiled_module.__module__.split(".")
+    is_pipeline_module = pipeline_dir in path and hasattr(pipelines, pipeline_dir)
+
+    # if library is not in LOADABLE_CLASSES, then it is a custom module.
+    # Or if it's a pipeline module, then the module is inside the pipeline
+    # folder so we set the library to module name.
+    if is_pipeline_module:
+        library = pipeline_dir
+    elif library not in LOADABLE_CLASSES:
+        library = not_compiled_module.__module__
+
+    # retrieve class_name
+    class_name = not_compiled_module.__class__.__name__
+
+    return (library, class_name)

src/diffusers/pipelines/stable_cascade/__init__.py

@@ -0,0 +1,50 @@
+from typing import TYPE_CHECKING
+
+from ...utils import (
+    DIFFUSERS_SLOW_IMPORT,
+    OptionalDependencyNotAvailable,
+    _LazyModule,
+    get_objects_from_module,
+    is_torch_available,
+    is_transformers_available,
+)
+
+
+_dummy_objects = {}
+_import_structure = {}
+
+try:
+    if not (is_transformers_available() and is_torch_available()):
+        raise OptionalDependencyNotAvailable()
+except OptionalDependencyNotAvailable:
+    from ...utils import dummy_torch_and_transformers_objects
+
+    _dummy_objects.update(get_objects_from_module(dummy_torch_and_transformers_objects))
+else:
+    _import_structure["pipeline_stable_cascade"] = ["StableCascadeDecoderPipeline"]
+    _import_structure["pipeline_stable_cascade_combined"] = ["StableCascadeCombinedPipeline"]
+    _import_structure["pipeline_stable_cascade_prior"] = ["StableCascadePriorPipeline"]
+
+
+if TYPE_CHECKING or DIFFUSERS_SLOW_IMPORT:
+    try:
+        if not (is_transformers_available() and is_torch_available()):
+            raise OptionalDependencyNotAvailable()
+    except OptionalDependencyNotAvailable:
+        from ...utils.dummy_torch_and_transformers_objects import *  # noqa F403
+    else:
+        from .pipeline_stable_cascade import StableCascadeDecoderPipeline
+        from .pipeline_stable_cascade_combined import StableCascadeCombinedPipeline
+        from .pipeline_stable_cascade_prior import StableCascadePriorPipeline
+else:
+    import sys
+
+    sys.modules[__name__] = _LazyModule(
+        __name__,
+        globals()["__file__"],
+        _import_structure,
+        module_spec=__spec__,
+    )
+
+    for name, value in _dummy_objects.items():
+        setattr(sys.modules[__name__], name, value)

src/diffusers/pipelines/stable_cascade/pipeline_stable_cascade.py

@@ -0,0 +1,465 @@
+# Copyright 2024 The HuggingFace Team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from typing import Callable, Dict, List, Optional, Union
+
+import torch
+from transformers import CLIPTextModel, CLIPTokenizer
+
+from ...models import StableCascadeUNet
+from ...schedulers import DDPMWuerstchenScheduler
+from ...utils import logging, replace_example_docstring
+from ...utils.torch_utils import randn_tensor
+from ..pipeline_utils import DiffusionPipeline, ImagePipelineOutput
+from ..wuerstchen.modeling_paella_vq_model import PaellaVQModel
+
+
+logger = logging.get_logger(__name__)  # pylint: disable=invalid-name
+
+EXAMPLE_DOC_STRING = """
+    Examples:
+        ```py
+        >>> import torch
+        >>> from diffusers import StableCascadePriorPipeline, StableCascadeDecoderPipeline
+
+        >>> prior_pipe = StableCascadePriorPipeline.from_pretrained(
+        ...     "stabilityai/stable-cascade-prior", torch_dtype=torch.bfloat16
+        ... ).to("cuda")
+        >>> gen_pipe = StableCascadeDecoderPipeline.from_pretrain(
+        ...     "stabilityai/stable-cascade", torch_dtype=torch.float16
+        ... ).to("cuda")
+
+        >>> prompt = "an image of a shiba inu, donning a spacesuit and helmet"
+        >>> prior_output = pipe(prompt)
+        >>> images = gen_pipe(prior_output.image_embeddings, prompt=prompt)
+        ```
+"""
+
+
+class StableCascadeDecoderPipeline(DiffusionPipeline):
+    """
+    Pipeline for generating images from the Stable Cascade model.
+
+    This model inherits from [`DiffusionPipeline`]. Check the superclass documentation for the generic methods the
+    library implements for all the pipelines (such as downloading or saving, running on a particular device, etc.)
+
+    Args:
+        tokenizer (`CLIPTokenizer`):
+            The CLIP tokenizer.
+        text_encoder (`CLIPTextModel`):
+            The CLIP text encoder.
+        decoder ([`StableCascadeUNet`]):
+            The Stable Cascade decoder unet.
+        vqgan ([`PaellaVQModel`]):
+            The VQGAN model.
+        scheduler ([`DDPMWuerstchenScheduler`]):
+            A scheduler to be used in combination with `prior` to generate image embedding.
+        latent_dim_scale (float, `optional`, defaults to 10.67):
+            Multiplier to determine the VQ latent space size from the image embeddings. If the image embeddings are
+            height=24 and width=24, the VQ latent shape needs to be height=int(24*10.67)=256 and
+            width=int(24*10.67)=256 in order to match the training conditions.
+    """
+
+    unet_name = "decoder"
+    text_encoder_name = "text_encoder"
+    model_cpu_offload_seq = "text_encoder->decoder->vqgan"
+    _callback_tensor_inputs = [
+        "latents",
+        "prompt_embeds_pooled",
+        "negative_prompt_embeds",
+        "image_embeddings",
+    ]
+
+    def __init__(
+        self,
+        decoder: StableCascadeUNet,
+        tokenizer: CLIPTokenizer,
+        text_encoder: CLIPTextModel,
+        scheduler: DDPMWuerstchenScheduler,
+        vqgan: PaellaVQModel,
+        latent_dim_scale: float = 10.67,
+    ) -> None:
+        super().__init__()
+        self.register_modules(
+            decoder=decoder,
+            tokenizer=tokenizer,
+            text_encoder=text_encoder,
+            scheduler=scheduler,
+            vqgan=vqgan,
+        )
+        self.register_to_config(latent_dim_scale=latent_dim_scale)
+
+    def prepare_latents(self, image_embeddings, num_images_per_prompt, dtype, device, generator, latents, scheduler):
+        batch_size, channels, height, width = image_embeddings.shape
+        latents_shape = (
+            batch_size * num_images_per_prompt,
+            4,
+            int(height * self.config.latent_dim_scale),
+            int(width * self.config.latent_dim_scale),
+        )
+
+        if latents is None:
+            latents = randn_tensor(latents_shape, generator=generator, device=device, dtype=dtype)
+        else:
+            if latents.shape != latents_shape:
+                raise ValueError(f"Unexpected latents shape, got {latents.shape}, expected {latents_shape}")
+            latents = latents.to(device)
+
+        latents = latents * scheduler.init_noise_sigma
+        return latents
+
+    def encode_prompt(
+        self,
+        device,
+        batch_size,
+        num_images_per_prompt,
+        do_classifier_free_guidance,
+        prompt=None,
+        negative_prompt=None,
+        prompt_embeds: Optional[torch.FloatTensor] = None,
+        prompt_embeds_pooled: Optional[torch.FloatTensor] = None,
+        negative_prompt_embeds: Optional[torch.FloatTensor] = None,
+        negative_prompt_embeds_pooled: Optional[torch.FloatTensor] = None,
+    ):
+        if prompt_embeds is None:
+            # get prompt text embeddings
+            text_inputs = self.tokenizer(
+                prompt,
+                padding="max_length",
+                max_length=self.tokenizer.model_max_length,
+                truncation=True,
+                return_tensors="pt",
+            )
+            text_input_ids = text_inputs.input_ids
+            attention_mask = text_inputs.attention_mask
+
+            untruncated_ids = self.tokenizer(prompt, padding="longest", return_tensors="pt").input_ids
+
+            if untruncated_ids.shape[-1] >= text_input_ids.shape[-1] and not torch.equal(
+                text_input_ids, untruncated_ids
+            ):
+                removed_text = self.tokenizer.batch_decode(
+                    untruncated_ids[:, self.tokenizer.model_max_length - 1 : -1]
+                )
+                logger.warning(
+                    "The following part of your input was truncated because CLIP can only handle sequences up to"
+                    f" {self.tokenizer.model_max_length} tokens: {removed_text}"
+                )
+                text_input_ids = text_input_ids[:, : self.tokenizer.model_max_length]
+                attention_mask = attention_mask[:, : self.tokenizer.model_max_length]
+
+            text_encoder_output = self.text_encoder(
+                text_input_ids.to(device), attention_mask=attention_mask.to(device), output_hidden_states=True
+            )
+            prompt_embeds = text_encoder_output.hidden_states[-1]
+            if prompt_embeds_pooled is None:
+                prompt_embeds_pooled = text_encoder_output.text_embeds.unsqueeze(1)
+
+        prompt_embeds = prompt_embeds.to(dtype=self.text_encoder.dtype, device=device)
+        prompt_embeds_pooled = prompt_embeds_pooled.to(dtype=self.text_encoder.dtype, device=device)
+        prompt_embeds = prompt_embeds.repeat_interleave(num_images_per_prompt, dim=0)
+        prompt_embeds_pooled = prompt_embeds_pooled.repeat_interleave(num_images_per_prompt, dim=0)
+
+        if negative_prompt_embeds is None and do_classifier_free_guidance:
+            uncond_tokens: List[str]
+            if negative_prompt is None:
+                uncond_tokens = [""] * batch_size
+            elif type(prompt) is not type(negative_prompt):
+                raise TypeError(
+                    f"`negative_prompt` should be the same type to `prompt`, but got {type(negative_prompt)} !="
+                    f" {type(prompt)}."
+                )
+            elif isinstance(negative_prompt, str):
+                uncond_tokens = [negative_prompt]
+            elif batch_size != len(negative_prompt):
+                raise ValueError(
+                    f"`negative_prompt`: {negative_prompt} has batch size {len(negative_prompt)}, but `prompt`:"
+                    f" {prompt} has batch size {batch_size}. Please make sure that passed `negative_prompt` matches"
+                    " the batch size of `prompt`."
+                )
+            else:
+                uncond_tokens = negative_prompt
+
+            uncond_input = self.tokenizer(
+                uncond_tokens,
+                padding="max_length",
+                max_length=self.tokenizer.model_max_length,
+                truncation=True,
+                return_tensors="pt",
+            )
+            negative_prompt_embeds_text_encoder_output = self.text_encoder(
+                uncond_input.input_ids.to(device),
+                attention_mask=uncond_input.attention_mask.to(device),
+                output_hidden_states=True,
+            )
+
+            negative_prompt_embeds = negative_prompt_embeds_text_encoder_output.hidden_states[-1]
+            negative_prompt_embeds_pooled = negative_prompt_embeds_text_encoder_output.text_embeds.unsqueeze(1)
+
+        if do_classifier_free_guidance:
+            # duplicate unconditional embeddings for each generation per prompt, using mps friendly method
+            seq_len = negative_prompt_embeds.shape[1]
+            negative_prompt_embeds = negative_prompt_embeds.to(dtype=self.text_encoder.dtype, device=device)
+            negative_prompt_embeds = negative_prompt_embeds.repeat(1, num_images_per_prompt, 1)
+            negative_prompt_embeds = negative_prompt_embeds.view(batch_size * num_images_per_prompt, seq_len, -1)
+
+            seq_len = negative_prompt_embeds_pooled.shape[1]
+            negative_prompt_embeds_pooled = negative_prompt_embeds_pooled.to(
+                dtype=self.text_encoder.dtype, device=device
+            )
+            negative_prompt_embeds_pooled = negative_prompt_embeds_pooled.repeat(1, num_images_per_prompt, 1)
+            negative_prompt_embeds_pooled = negative_prompt_embeds_pooled.view(
+                batch_size * num_images_per_prompt, seq_len, -1
+            )
+            # done duplicates
+
+        return prompt_embeds, prompt_embeds_pooled, negative_prompt_embeds, negative_prompt_embeds_pooled
+
+    def check_inputs(
+        self,
+        prompt,
+        negative_prompt=None,
+        prompt_embeds=None,
+        negative_prompt_embeds=None,
+        callback_on_step_end_tensor_inputs=None,
+    ):
+        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
+        ):
+            raise ValueError(
+                f"`callback_on_step_end_tensor_inputs` has to be in {self._callback_tensor_inputs}, but found {[k for k in callback_on_step_end_tensor_inputs if k not in self._callback_tensor_inputs]}"
+            )
+
+        if prompt is not None and prompt_embeds is not None:
+            raise ValueError(
+                f"Cannot forward both `prompt`: {prompt} and `prompt_embeds`: {prompt_embeds}. Please make sure to"
+                " only forward one of the two."
+            )
+        elif prompt is None and prompt_embeds is None:
+            raise ValueError(
+                "Provide either `prompt` or `prompt_embeds`. Cannot leave both `prompt` and `prompt_embeds` undefined."
+            )
+        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 negative_prompt is not None and negative_prompt_embeds is not None:
+            raise ValueError(
+                f"Cannot forward both `negative_prompt`: {negative_prompt} and `negative_prompt_embeds`:"
+                f" {negative_prompt_embeds}. Please make sure to only forward one of the two."
+            )
+
+        if prompt_embeds is not None and negative_prompt_embeds is not None:
+            if prompt_embeds.shape != negative_prompt_embeds.shape:
+                raise ValueError(
+                    "`prompt_embeds` and `negative_prompt_embeds` must have the same shape when passed directly, but"
+                    f" got: `prompt_embeds` {prompt_embeds.shape} != `negative_prompt_embeds`"
+                    f" {negative_prompt_embeds.shape}."
+                )
+
+    @property
+    def guidance_scale(self):
+        return self._guidance_scale
+
+    @property
+    def do_classifier_free_guidance(self):
+        return self._guidance_scale > 1
+
+    @property
+    def num_timesteps(self):
+        return self._num_timesteps
+
+    @torch.no_grad()
+    @replace_example_docstring(EXAMPLE_DOC_STRING)
+    def __call__(
+        self,
+        image_embeddings: Union[torch.FloatTensor, List[torch.FloatTensor]],
+        prompt: Union[str, List[str]] = None,
+        num_inference_steps: int = 10,
+        guidance_scale: float = 0.0,
+        negative_prompt: Optional[Union[str, List[str]]] = None,
+        prompt_embeds: Optional[torch.FloatTensor] = None,
+        negative_prompt_embeds: Optional[torch.FloatTensor] = None,
+        num_images_per_prompt: int = 1,
+        generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None,
+        latents: Optional[torch.FloatTensor] = None,
+        output_type: Optional[str] = "pil",
+        return_dict: bool = True,
+        callback_on_step_end: Optional[Callable[[int, int, Dict], None]] = None,
+        callback_on_step_end_tensor_inputs: List[str] = ["latents"],
+    ):
+        """
+        Function invoked when calling the pipeline for generation.
+
+        Args:
+            image_embedding (`torch.FloatTensor` or `List[torch.FloatTensor]`):
+                Image Embeddings either extracted from an image or generated by a Prior Model.
+            prompt (`str` or `List[str]`):
+                The prompt or prompts to guide the image generation.
+            num_inference_steps (`int`, *optional*, defaults to 12):
+                The number of denoising steps. More denoising steps usually lead to a higher quality image at the
+                expense of slower inference.
+            guidance_scale (`float`, *optional*, defaults to 0.0):
+                Guidance scale as defined in [Classifier-Free Diffusion Guidance](https://arxiv.org/abs/2207.12598).
+                `decoder_guidance_scale` is defined as `w` of equation 2. of [Imagen
+                Paper](https://arxiv.org/pdf/2205.11487.pdf). Guidance scale is enabled by setting
+                `decoder_guidance_scale > 1`. Higher guidance scale encourages to generate images that are closely
+                linked to the text `prompt`, usually at the expense of lower image quality.
+            negative_prompt (`str` or `List[str]`, *optional*):
+                The prompt or prompts not to guide the image generation. Ignored when not using guidance (i.e., ignored
+                if `decoder_guidance_scale` is less than `1`).
+            prompt_embeds (`torch.FloatTensor`, *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.
+            negative_prompt_embeds (`torch.FloatTensor`, *optional*):
+                Pre-generated negative text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt
+                weighting. If not provided, negative_prompt_embeds will be generated from `negative_prompt` input
+                argument.
+            num_images_per_prompt (`int`, *optional*, defaults to 1):
+                The number of images to generate per prompt.
+            generator (`torch.Generator` or `List[torch.Generator]`, *optional*):
+                One or a list of [torch generator(s)](https://pytorch.org/docs/stable/generated/torch.Generator.html)
+                to make generation deterministic.
+            latents (`torch.FloatTensor`, *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 will ge generated by sampling using the supplied random `generator`.
+            output_type (`str`, *optional*, defaults to `"pil"`):
+                The output format of the generate image. Choose between: `"pil"` (`PIL.Image.Image`), `"np"`
+                (`np.array`) or `"pt"` (`torch.Tensor`).
+            return_dict (`bool`, *optional*, defaults to `True`):
+                Whether or not to return a [`~pipelines.ImagePipelineOutput`] instead of a plain tuple.
+            callback_on_step_end (`Callable`, *optional*):
+                A function that calls at the end of each denoising steps during the inference. The function is called
+                with the following arguments: `callback_on_step_end(self: DiffusionPipeline, step: int, timestep: int,
+                callback_kwargs: Dict)`. `callback_kwargs` will include a list of all tensors as specified by
+                `callback_on_step_end_tensor_inputs`.
+            callback_on_step_end_tensor_inputs (`List`, *optional*):
+                The list of tensor inputs for the `callback_on_step_end` function. The tensors specified in the list
+                will be passed as `callback_kwargs` argument. You will only be able to include variables listed in the
+                `._callback_tensor_inputs` attribute of your pipeline class.
+
+        Examples:
+
+        Returns:
+            [`~pipelines.ImagePipelineOutput`] or `tuple` [`~pipelines.ImagePipelineOutput`] if `return_dict` is True,
+            otherwise a `tuple`. When returning a tuple, the first element is a list with the generated image
+            embeddings.
+        """
+
+        # 0. Define commonly used variables
+        device = self._execution_device
+        dtype = self.decoder.dtype
+        self._guidance_scale = guidance_scale
+
+        # 1. Check inputs. Raise error if not correct
+        self.check_inputs(
+            prompt,
+            negative_prompt=negative_prompt,
+            prompt_embeds=prompt_embeds,
+            negative_prompt_embeds=negative_prompt_embeds,
+            callback_on_step_end_tensor_inputs=callback_on_step_end_tensor_inputs,
+        )
+        if isinstance(image_embeddings, list):
+            image_embeddings = torch.cat(image_embeddings, dim=0)
+        batch_size = image_embeddings.shape[0]
+
+        # 2. Encode caption
+        if prompt_embeds is None and negative_prompt_embeds is None:
+            prompt_embeds, _, negative_prompt_embeds, _ = self.encode_prompt(
+                prompt=prompt,
+                device=device,
+                batch_size=batch_size,
+                num_images_per_prompt=num_images_per_prompt,
+                do_classifier_free_guidance=self.do_classifier_free_guidance,
+                negative_prompt=negative_prompt,
+                prompt_embeds=prompt_embeds,
+                negative_prompt_embeds=negative_prompt_embeds,
+            )
+        prompt_embeds_pooled = (
+            torch.cat([prompt_embeds, negative_prompt_embeds]) if self.do_classifier_free_guidance else prompt_embeds
+        )
+        effnet = (
+            torch.cat([image_embeddings, torch.zeros_like(image_embeddings)])
+            if self.do_classifier_free_guidance
+            else image_embeddings
+        )
+
+        self.scheduler.set_timesteps(num_inference_steps, device=device)
+        timesteps = self.scheduler.timesteps
+
+        # 5. Prepare latents
+        latents = self.prepare_latents(
+            image_embeddings, num_images_per_prompt, dtype, device, generator, latents, self.scheduler
+        )
+
+        # 6. Run denoising loop
+        self._num_timesteps = len(timesteps[:-1])
+        for i, t in enumerate(self.progress_bar(timesteps[:-1])):
+            timestep_ratio = t.expand(latents.size(0)).to(dtype)
+
+            # 7. Denoise latents
+            predicted_latents = self.decoder(
+                sample=torch.cat([latents] * 2) if self.do_classifier_free_guidance else latents,
+                timestep_ratio=torch.cat([timestep_ratio] * 2) if self.do_classifier_free_guidance else timestep_ratio,
+                clip_text_pooled=prompt_embeds_pooled,
+                effnet=effnet,
+                return_dict=False,
+            )[0]
+
+            # 8. Check for classifier free guidance and apply it
+            if self.do_classifier_free_guidance:
+                predicted_latents_text, predicted_latents_uncond = predicted_latents.chunk(2)
+                predicted_latents = torch.lerp(predicted_latents_uncond, predicted_latents_text, self.guidance_scale)
+
+            # 9. Renoise latents to next timestep
+            latents = self.scheduler.step(
+                model_output=predicted_latents,
+                timestep=timestep_ratio,
+                sample=latents,
+                generator=generator,
+            ).prev_sample
+
+            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)
+
+        if output_type not in ["pt", "np", "pil", "latent"]:
+            raise ValueError(
+                f"Only the output types `pt`, `np`, `pil` and `latent` are supported not output_type={output_type}"
+            )
+
+        if not output_type == "latent":
+            # 10. Scale and decode the image latents with vq-vae
+            latents = self.vqgan.config.scale_factor * latents
+            images = self.vqgan.decode(latents).sample.clamp(0, 1)
+            if output_type == "np":
+                images = images.permute(0, 2, 3, 1).cpu().float().numpy()  # float() as bfloat16-> numpy doesnt work
+            elif output_type == "pil":
+                images = images.permute(0, 2, 3, 1).cpu().float().numpy()  # float() as bfloat16-> numpy doesnt work
+                images = self.numpy_to_pil(images)
+        else:
+            images = latents
+
+        # Offload all models
+        self.maybe_free_model_hooks()
+
+        if not return_dict:
+            return images
+        return ImagePipelineOutput(images)

src/diffusers/pipelines/stable_cascade/pipeline_stable_cascade_combined.py

@@ -0,0 +1,294 @@
+# Copyright 2024 The HuggingFace Team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from typing import Callable, Dict, List, Optional, Union
+
+import PIL
+import torch
+from transformers import CLIPImageProcessor, CLIPTextModel, CLIPTokenizer, CLIPVisionModelWithProjection
+
+from ...models import StableCascadeUNet
+from ...schedulers import DDPMWuerstchenScheduler
+from ...utils import replace_example_docstring
+from ..pipeline_utils import DiffusionPipeline
+from ..wuerstchen.modeling_paella_vq_model import PaellaVQModel
+from .pipeline_stable_cascade import StableCascadeDecoderPipeline
+from .pipeline_stable_cascade_prior import StableCascadePriorPipeline
+
+
+TEXT2IMAGE_EXAMPLE_DOC_STRING = """
+    Examples:
+        ```py
+        >>> from diffusions import StableCascadeCombinedPipeline
+
+        >>> pipe = StableCascadeCombinedPipeline.from_pretrained("stabilityai/stable-cascade-combined", torch_dtype=torch.bfloat16).to(
+        ...     "cuda"
+        ... )
+        >>> prompt = "an image of a shiba inu, donning a spacesuit and helmet"
+        >>> images = pipe(prompt=prompt)
+        ```
+"""
+
+
+class StableCascadeCombinedPipeline(DiffusionPipeline):
+    """
+    Combined Pipeline for text-to-image generation using Stable Cascade.
+
+    This model inherits from [`DiffusionPipeline`]. Check the superclass documentation for the generic methods the
+    library implements for all the pipelines (such as downloading or saving, running on a particular device, etc.)
+
+    Args:
+        tokenizer (`CLIPTokenizer`):
+            The decoder tokenizer to be used for text inputs.
+        text_encoder (`CLIPTextModel`):
+            The decoder text encoder to be used for text inputs.
+        decoder (`StableCascadeUNet`):
+            The decoder model to be used for decoder image generation pipeline.
+        scheduler (`DDPMWuerstchenScheduler`):
+            The scheduler to be used for decoder image generation pipeline.
+        vqgan (`PaellaVQModel`):
+            The VQGAN model to be used for decoder image generation pipeline.
+        feature_extractor ([`~transformers.CLIPImageProcessor`]):
+            Model that extracts features from generated images to be used as inputs for the `image_encoder`.
+        image_encoder ([`CLIPVisionModelWithProjection`]):
+            Frozen CLIP image-encoder ([clip-vit-large-patch14](https://huggingface.co/openai/clip-vit-large-patch14)).
+        prior_prior (`StableCascadeUNet`):
+            The prior model to be used for prior pipeline.
+        prior_scheduler (`DDPMWuerstchenScheduler`):
+            The scheduler to be used for prior pipeline.
+    """
+
+    _load_connected_pipes = True
+
+    def __init__(
+        self,
+        tokenizer: CLIPTokenizer,
+        text_encoder: CLIPTextModel,
+        decoder: StableCascadeUNet,
+        scheduler: DDPMWuerstchenScheduler,
+        vqgan: PaellaVQModel,
+        prior_prior: StableCascadeUNet,
+        prior_text_encoder: CLIPTextModel,
+        prior_tokenizer: CLIPTokenizer,
+        prior_scheduler: DDPMWuerstchenScheduler,
+        prior_feature_extractor: Optional[CLIPImageProcessor] = None,
+        prior_image_encoder: Optional[CLIPVisionModelWithProjection] = None,
+    ):
+        super().__init__()
+
+        self.register_modules(
+            text_encoder=text_encoder,
+            tokenizer=tokenizer,
+            decoder=decoder,
+            scheduler=scheduler,
+            vqgan=vqgan,
+            prior_text_encoder=prior_text_encoder,
+            prior_tokenizer=prior_tokenizer,
+            prior_prior=prior_prior,
+            prior_scheduler=prior_scheduler,
+            prior_feature_extractor=prior_feature_extractor,
+            prior_image_encoder=prior_image_encoder,
+        )
+        self.prior_pipe = StableCascadePriorPipeline(
+            prior=prior_prior,
+            text_encoder=prior_text_encoder,
+            tokenizer=prior_tokenizer,
+            scheduler=prior_scheduler,
+            image_encoder=prior_image_encoder,
+            feature_extractor=prior_feature_extractor,
+        )
+        self.decoder_pipe = StableCascadeDecoderPipeline(
+            text_encoder=text_encoder,
+            tokenizer=tokenizer,
+            decoder=decoder,
+            scheduler=scheduler,
+            vqgan=vqgan,
+        )
+
+    def enable_xformers_memory_efficient_attention(self, attention_op: Optional[Callable] = None):
+        self.decoder_pipe.enable_xformers_memory_efficient_attention(attention_op)
+
+    def enable_model_cpu_offload(self, gpu_id=0):
+        r"""
+        Offloads all models to CPU using accelerate, reducing memory usage with a low impact on performance. Compared
+        to `enable_sequential_cpu_offload`, this method moves one whole model at a time to the GPU when its `forward`
+        method is called, and the model remains in GPU until the next model runs. Memory savings are lower than with
+        `enable_sequential_cpu_offload`, but performance is much better due to the iterative execution of the `unet`.
+        """
+        self.prior_pipe.enable_model_cpu_offload(gpu_id=gpu_id)
+        self.decoder_pipe.enable_model_cpu_offload(gpu_id=gpu_id)
+
+    def enable_sequential_cpu_offload(self, gpu_id=0):
+        r"""
+        Offloads all models (`unet`, `text_encoder`, `vae`, and `safety checker` state dicts) to CPU using 🤗
+        Accelerate, significantly reducing memory usage. Models are moved to a `torch.device('meta')` and loaded on a
+        GPU only when their specific submodule's `forward` method is called. Offloading happens on a submodule basis.
+        Memory savings are higher than using `enable_model_cpu_offload`, but performance is lower.
+        """
+        self.prior_pipe.enable_sequential_cpu_offload(gpu_id=gpu_id)
+        self.decoder_pipe.enable_sequential_cpu_offload(gpu_id=gpu_id)
+
+    def progress_bar(self, iterable=None, total=None):
+        self.prior_pipe.progress_bar(iterable=iterable, total=total)
+        self.decoder_pipe.progress_bar(iterable=iterable, total=total)
+
+    def set_progress_bar_config(self, **kwargs):
+        self.prior_pipe.set_progress_bar_config(**kwargs)
+        self.decoder_pipe.set_progress_bar_config(**kwargs)
+
+    @torch.no_grad()
+    @replace_example_docstring(TEXT2IMAGE_EXAMPLE_DOC_STRING)
+    def __call__(
+        self,
+        prompt: Optional[Union[str, List[str]]] = None,
+        images: Union[torch.Tensor, PIL.Image.Image, List[torch.Tensor], List[PIL.Image.Image]] = None,
+        height: int = 512,
+        width: int = 512,
+        prior_num_inference_steps: int = 60,
+        prior_timesteps: Optional[List[float]] = None,
+        prior_guidance_scale: float = 4.0,
+        num_inference_steps: int = 12,
+        decoder_timesteps: Optional[List[float]] = None,
+        decoder_guidance_scale: float = 0.0,
+        negative_prompt: Optional[Union[str, List[str]]] = None,
+        prompt_embeds: Optional[torch.FloatTensor] = None,
+        negative_prompt_embeds: Optional[torch.FloatTensor] = None,
+        num_images_per_prompt: int = 1,
+        generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None,
+        latents: Optional[torch.FloatTensor] = None,
+        output_type: Optional[str] = "pil",
+        return_dict: bool = True,
+        prior_callback_on_step_end: Optional[Callable[[int, int, Dict], None]] = None,
+        prior_callback_on_step_end_tensor_inputs: List[str] = ["latents"],
+        callback_on_step_end: Optional[Callable[[int, int, Dict], None]] = None,
+        callback_on_step_end_tensor_inputs: List[str] = ["latents"],
+    ):
+        """
+        Function invoked when calling the pipeline for generation.
+
+        Args:
+            prompt (`str` or `List[str]`):
+                The prompt or prompts to guide the image generation for the prior and decoder.
+            images (`torch.Tensor`, `PIL.Image.Image`, `List[torch.Tensor]`, `List[PIL.Image.Image]`, *optional*):
+                The images to guide the image generation for the prior.
+            negative_prompt (`str` or `List[str]`, *optional*):
+                The prompt or prompts not to guide the image generation. Ignored when not using guidance (i.e., ignored
+                if `guidance_scale` is less than `1`).
+            prompt_embeds (`torch.FloatTensor`, *optional*):
+                Pre-generated text embeddings for the prior. Can be used to easily tweak text inputs, *e.g.* prompt
+                weighting. If not provided, text embeddings will be generated from `prompt` input argument.
+            negative_prompt_embeds (`torch.FloatTensor`, *optional*):
+                Pre-generated negative text embeddings for the prior. Can be used to easily tweak text inputs, *e.g.*
+                prompt weighting. If not provided, negative_prompt_embeds will be generated from `negative_prompt`
+                input argument.
+            num_images_per_prompt (`int`, *optional*, defaults to 1):
+                The number of images to generate per prompt.
+            height (`int`, *optional*, defaults to 512):
+                The height in pixels of the generated image.
+            width (`int`, *optional*, defaults to 512):
+                The width in pixels of the generated image.
+            prior_guidance_scale (`float`, *optional*, defaults to 4.0):
+                Guidance scale as defined in [Classifier-Free Diffusion Guidance](https://arxiv.org/abs/2207.12598).
+                `prior_guidance_scale` is defined as `w` of equation 2. of [Imagen
+                Paper](https://arxiv.org/pdf/2205.11487.pdf). Guidance scale is enabled by setting
+                `prior_guidance_scale > 1`. Higher guidance scale encourages to generate images that are closely linked
+                to the text `prompt`, usually at the expense of lower image quality.
+            prior_num_inference_steps (`Union[int, Dict[float, int]]`, *optional*, defaults to 60):
+                The number of prior denoising steps. More denoising steps usually lead to a higher quality image at the
+                expense of slower inference. For more specific timestep spacing, you can pass customized
+                `prior_timesteps`
+            num_inference_steps (`int`, *optional*, defaults to 12):
+                The number of decoder denoising steps. More denoising steps usually lead to a higher quality image at
+                the expense of slower inference. For more specific timestep spacing, you can pass customized
+                `timesteps`
+            decoder_guidance_scale (`float`, *optional*, defaults to 0.0):
+                Guidance scale as defined in [Classifier-Free Diffusion Guidance](https://arxiv.org/abs/2207.12598).
+                `guidance_scale` is defined as `w` of equation 2. of [Imagen
+                Paper](https://arxiv.org/pdf/2205.11487.pdf). Guidance scale is enabled by setting `guidance_scale >
+                1`. Higher guidance scale encourages to generate images that are closely linked to the text `prompt`,
+                usually at the expense of lower image quality.
+            generator (`torch.Generator` or `List[torch.Generator]`, *optional*):
+                One or a list of [torch generator(s)](https://pytorch.org/docs/stable/generated/torch.Generator.html)
+                to make generation deterministic.
+            latents (`torch.FloatTensor`, *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 will ge generated by sampling using the supplied random `generator`.
+            output_type (`str`, *optional*, defaults to `"pil"`):
+                The output format of the generate image. Choose between: `"pil"` (`PIL.Image.Image`), `"np"`
+                (`np.array`) or `"pt"` (`torch.Tensor`).
+            return_dict (`bool`, *optional*, defaults to `True`):
+                Whether or not to return a [`~pipelines.ImagePipelineOutput`] instead of a plain tuple.
+            prior_callback_on_step_end (`Callable`, *optional*):
+                A function that calls at the end of each denoising steps during the inference. The function is called
+                with the following arguments: `prior_callback_on_step_end(self: DiffusionPipeline, step: int, timestep:
+                int, callback_kwargs: Dict)`.
+            prior_callback_on_step_end_tensor_inputs (`List`, *optional*):
+                The list of tensor inputs for the `prior_callback_on_step_end` function. The tensors specified in the
+                list will be passed as `callback_kwargs` argument. You will only be able to include variables listed in
+                the `._callback_tensor_inputs` attribute of your pipeine class.
+            callback_on_step_end (`Callable`, *optional*):
+                A function that calls at the end of each denoising steps during the inference. The function is called
+                with the following arguments: `callback_on_step_end(self: DiffusionPipeline, step: int, timestep: int,
+                callback_kwargs: Dict)`. `callback_kwargs` will include a list of all tensors as specified by
+                `callback_on_step_end_tensor_inputs`.
+            callback_on_step_end_tensor_inputs (`List`, *optional*):
+                The list of tensor inputs for the `callback_on_step_end` function. The tensors specified in the list
+                will be passed as `callback_kwargs` argument. You will only be able to include variables listed in the
+                `._callback_tensor_inputs` attribute of your pipeine class.
+
+        Examples:
+
+        Returns:
+            [`~pipelines.ImagePipelineOutput`] or `tuple` [`~pipelines.ImagePipelineOutput`] if `return_dict` is True,
+            otherwise a `tuple`. When returning a tuple, the first element is a list with the generated images.
+        """
+
+        prior_outputs = self.prior_pipe(
+            prompt=prompt if prompt_embeds is None else None,
+            images=images,
+            height=height,
+            width=width,
+            num_inference_steps=prior_num_inference_steps,
+            guidance_scale=prior_guidance_scale,
+            negative_prompt=negative_prompt if negative_prompt_embeds is None else None,
+            prompt_embeds=prompt_embeds,
+            negative_prompt_embeds=negative_prompt_embeds,
+            num_images_per_prompt=num_images_per_prompt,
+            generator=generator,
+            latents=latents,
+            output_type="pt",
+            return_dict=True,
+            callback_on_step_end=prior_callback_on_step_end,
+            callback_on_step_end_tensor_inputs=prior_callback_on_step_end_tensor_inputs,
+        )
+        image_embeddings = prior_outputs.image_embeddings
+        prompt_embeds = prior_outputs.get("prompt_embeds", None)
+        negative_prompt_embeds = prior_outputs.get("negative_prompt_embeds", None)
+
+        outputs = self.decoder_pipe(
+            image_embeddings=image_embeddings,
+            prompt=prompt if prompt_embeds is None else None,
+            num_inference_steps=num_inference_steps,
+            guidance_scale=decoder_guidance_scale,
+            negative_prompt=negative_prompt if negative_prompt_embeds is None else None,
+            prompt_embeds=prompt_embeds,
+            negative_prompt_embeds=negative_prompt_embeds,
+            generator=generator,
+            output_type=output_type,
+            return_dict=return_dict,
+            callback_on_step_end=callback_on_step_end,
+            callback_on_step_end_tensor_inputs=callback_on_step_end_tensor_inputs,
+        )
+
+        return outputs

src/diffusers/pipelines/stable_cascade/pipeline_stable_cascade_prior.py

@@ -0,0 +1,614 @@
+# Copyright 2024 The HuggingFace Team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from dataclasses import dataclass
+from math import ceil
+from typing import Callable, Dict, List, Optional, Union
+
+import numpy as np
+import PIL
+import torch
+from transformers import CLIPImageProcessor, CLIPTextModelWithProjection, CLIPTokenizer, CLIPVisionModelWithProjection
+
+from ...models import StableCascadeUNet
+from ...schedulers import DDPMWuerstchenScheduler
+from ...utils import BaseOutput, logging, replace_example_docstring
+from ...utils.torch_utils import randn_tensor
+from ..pipeline_utils import DiffusionPipeline
+
+
+logger = logging.get_logger(__name__)  # pylint: disable=invalid-name
+
+DEFAULT_STAGE_C_TIMESTEPS = list(np.linspace(1.0, 2 / 3, 20)) + list(np.linspace(2 / 3, 0.0, 11))[1:]
+
+EXAMPLE_DOC_STRING = """
+    Examples:
+        ```py
+        >>> import torch
+        >>> from diffusers import StableCascadePriorPipeline
+
+        >>> prior_pipe = StableCascadePriorPipeline.from_pretrained(
+        ...     "stabilityai/stable-cascade-prior", torch_dtype=torch.bfloat16
+        ... ).to("cuda")
+
+        >>> prompt = "an image of a shiba inu, donning a spacesuit and helmet"
+        >>> prior_output = pipe(prompt)
+        ```
+"""
+
+
+@dataclass
+class StableCascadePriorPipelineOutput(BaseOutput):
+    """
+    Output class for WuerstchenPriorPipeline.
+
+    Args:
+        image_embeddings (`torch.FloatTensor` or `np.ndarray`)
+            Prior image embeddings for text prompt
+        prompt_embeds (`torch.FloatTensor`):
+            Text embeddings for the prompt.
+        negative_prompt_embeds (`torch.FloatTensor`):
+            Text embeddings for the negative prompt.
+    """
+
+    image_embeddings: Union[torch.FloatTensor, np.ndarray]
+    prompt_embeds: Union[torch.FloatTensor, np.ndarray]
+    negative_prompt_embeds: Union[torch.FloatTensor, np.ndarray]
+
+
+class StableCascadePriorPipeline(DiffusionPipeline):
+    """
+    Pipeline for generating image prior for Stable Cascade.
+
+    This model inherits from [`DiffusionPipeline`]. Check the superclass documentation for the generic methods the
+    library implements for all the pipelines (such as downloading or saving, running on a particular device, etc.)
+
+    Args:
+        prior ([`StableCascadeUNet`]):
+            The Stable Cascade prior to approximate the image embedding from the text and/or image embedding.
+        text_encoder ([`CLIPTextModelWithProjection`]):
+            Frozen text-encoder ([laion/CLIP-ViT-bigG-14-laion2B-39B-b160k](https://huggingface.co/laion/CLIP-ViT-bigG-14-laion2B-39B-b160k)).
+        feature_extractor ([`~transformers.CLIPImageProcessor`]):
+            Model that extracts features from generated images to be used as inputs for the `image_encoder`.
+        image_encoder ([`CLIPVisionModelWithProjection`]):
+            Frozen CLIP image-encoder ([clip-vit-large-patch14](https://huggingface.co/openai/clip-vit-large-patch14)).
+        tokenizer (`CLIPTokenizer`):
+            Tokenizer of class
+            [CLIPTokenizer](https://huggingface.co/docs/transformers/v4.21.0/en/model_doc/clip#transformers.CLIPTokenizer).
+        scheduler ([`DDPMWuerstchenScheduler`]):
+            A scheduler to be used in combination with `prior` to generate image embedding.
+        resolution_multiple ('float', *optional*, defaults to 42.67):
+            Default resolution for multiple images generated.
+    """
+
+    unet_name = "prior"
+    text_encoder_name = "text_encoder"
+    model_cpu_offload_seq = "image_encoder->text_encoder->prior"
+    _optional_components = ["image_encoder", "feature_extractor"]
+    _callback_tensor_inputs = ["latents", "text_encoder_hidden_states", "negative_prompt_embeds"]
+
+    def __init__(
+        self,
+        tokenizer: CLIPTokenizer,
+        text_encoder: CLIPTextModelWithProjection,
+        prior: StableCascadeUNet,
+        scheduler: DDPMWuerstchenScheduler,
+        resolution_multiple: float = 42.67,
+        feature_extractor: Optional[CLIPImageProcessor] = None,
+        image_encoder: Optional[CLIPVisionModelWithProjection] = None,
+    ) -> None:
+        super().__init__()
+        self.register_modules(
+            tokenizer=tokenizer,
+            text_encoder=text_encoder,
+            image_encoder=image_encoder,
+            feature_extractor=feature_extractor,
+            prior=prior,
+            scheduler=scheduler,
+        )
+        self.register_to_config(resolution_multiple=resolution_multiple)
+
+    def prepare_latents(
+        self, batch_size, height, width, num_images_per_prompt, dtype, device, generator, latents, scheduler
+    ):
+        latent_shape = (
+            num_images_per_prompt * batch_size,
+            self.prior.config.in_channels,
+            ceil(height / self.config.resolution_multiple),
+            ceil(width / self.config.resolution_multiple),
+        )
+
+        if latents is None:
+            latents = randn_tensor(latent_shape, generator=generator, device=device, dtype=dtype)
+        else:
+            if latents.shape != latent_shape:
+                raise ValueError(f"Unexpected latents shape, got {latents.shape}, expected {latent_shape}")
+            latents = latents.to(device)
+
+        latents = latents * scheduler.init_noise_sigma
+        return latents
+
+    def encode_prompt(
+        self,
+        device,
+        batch_size,
+        num_images_per_prompt,
+        do_classifier_free_guidance,
+        prompt=None,
+        negative_prompt=None,
+        prompt_embeds: Optional[torch.FloatTensor] = None,
+        prompt_embeds_pooled: Optional[torch.FloatTensor] = None,
+        negative_prompt_embeds: Optional[torch.FloatTensor] = None,
+        negative_prompt_embeds_pooled: Optional[torch.FloatTensor] = None,
+    ):
+        if prompt_embeds is None:
+            # get prompt text embeddings
+            text_inputs = self.tokenizer(
+                prompt,
+                padding="max_length",
+                max_length=self.tokenizer.model_max_length,
+                truncation=True,
+                return_tensors="pt",
+            )
+            text_input_ids = text_inputs.input_ids
+            attention_mask = text_inputs.attention_mask
+
+            untruncated_ids = self.tokenizer(prompt, padding="longest", return_tensors="pt").input_ids
+
+            if untruncated_ids.shape[-1] >= text_input_ids.shape[-1] and not torch.equal(
+                text_input_ids, untruncated_ids
+            ):
+                removed_text = self.tokenizer.batch_decode(
+                    untruncated_ids[:, self.tokenizer.model_max_length - 1 : -1]
+                )
+                logger.warning(
+                    "The following part of your input was truncated because CLIP can only handle sequences up to"
+                    f" {self.tokenizer.model_max_length} tokens: {removed_text}"
+                )
+                text_input_ids = text_input_ids[:, : self.tokenizer.model_max_length]
+                attention_mask = attention_mask[:, : self.tokenizer.model_max_length]
+
+            text_encoder_output = self.text_encoder(
+                text_input_ids.to(device), attention_mask=attention_mask.to(device), output_hidden_states=True
+            )
+            prompt_embeds = text_encoder_output.hidden_states[-1]
+            if prompt_embeds_pooled is None:
+                prompt_embeds_pooled = text_encoder_output.text_embeds.unsqueeze(1)
+
+        prompt_embeds = prompt_embeds.to(dtype=self.text_encoder.dtype, device=device)
+        prompt_embeds_pooled = prompt_embeds_pooled.to(dtype=self.text_encoder.dtype, device=device)
+        prompt_embeds = prompt_embeds.repeat_interleave(num_images_per_prompt, dim=0)
+        prompt_embeds_pooled = prompt_embeds_pooled.repeat_interleave(num_images_per_prompt, dim=0)
+
+        if negative_prompt_embeds is None and do_classifier_free_guidance:
+            uncond_tokens: List[str]
+            if negative_prompt is None:
+                uncond_tokens = [""] * batch_size
+            elif type(prompt) is not type(negative_prompt):
+                raise TypeError(
+                    f"`negative_prompt` should be the same type to `prompt`, but got {type(negative_prompt)} !="
+                    f" {type(prompt)}."
+                )
+            elif isinstance(negative_prompt, str):
+                uncond_tokens = [negative_prompt]
+            elif batch_size != len(negative_prompt):
+                raise ValueError(
+                    f"`negative_prompt`: {negative_prompt} has batch size {len(negative_prompt)}, but `prompt`:"
+                    f" {prompt} has batch size {batch_size}. Please make sure that passed `negative_prompt` matches"
+                    " the batch size of `prompt`."
+                )
+            else:
+                uncond_tokens = negative_prompt
+
+            uncond_input = self.tokenizer(
+                uncond_tokens,
+                padding="max_length",
+                max_length=self.tokenizer.model_max_length,
+                truncation=True,
+                return_tensors="pt",
+            )
+            negative_prompt_embeds_text_encoder_output = self.text_encoder(
+                uncond_input.input_ids.to(device),
+                attention_mask=uncond_input.attention_mask.to(device),
+                output_hidden_states=True,
+            )
+
+            negative_prompt_embeds = negative_prompt_embeds_text_encoder_output.hidden_states[-1]
+            negative_prompt_embeds_pooled = negative_prompt_embeds_text_encoder_output.text_embeds.unsqueeze(1)
+
+        if do_classifier_free_guidance:
+            # duplicate unconditional embeddings for each generation per prompt, using mps friendly method
+            seq_len = negative_prompt_embeds.shape[1]
+            negative_prompt_embeds = negative_prompt_embeds.to(dtype=self.text_encoder.dtype, device=device)
+            negative_prompt_embeds = negative_prompt_embeds.repeat(1, num_images_per_prompt, 1)
+            negative_prompt_embeds = negative_prompt_embeds.view(batch_size * num_images_per_prompt, seq_len, -1)
+
+            seq_len = negative_prompt_embeds_pooled.shape[1]
+            negative_prompt_embeds_pooled = negative_prompt_embeds_pooled.to(
+                dtype=self.text_encoder.dtype, device=device
+            )
+            negative_prompt_embeds_pooled = negative_prompt_embeds_pooled.repeat(1, num_images_per_prompt, 1)
+            negative_prompt_embeds_pooled = negative_prompt_embeds_pooled.view(
+                batch_size * num_images_per_prompt, seq_len, -1
+            )
+            # done duplicates
+
+        return prompt_embeds, prompt_embeds_pooled, negative_prompt_embeds, negative_prompt_embeds_pooled
+
+    def encode_image(self, images, device, dtype, batch_size, num_images_per_prompt):
+        image_embeds = []
+        for image in images:
+            image = self.feature_extractor(image, return_tensors="pt").pixel_values
+            image = image.to(device=device, dtype=dtype)
+            image_embed = self.image_encoder(image).image_embeds.unsqueeze(1)
+            image_embeds.append(image_embed)
+        image_embeds = torch.cat(image_embeds, dim=1)
+
+        image_embeds = image_embeds.repeat(batch_size * num_images_per_prompt, 1, 1)
+        negative_image_embeds = torch.zeros_like(image_embeds)
+
+        return image_embeds, negative_image_embeds
+
+    def check_inputs(
+        self,
+        prompt,
+        images=None,
+        image_embeds=None,
+        negative_prompt=None,
+        prompt_embeds=None,
+        prompt_embeds_pooled=None,
+        negative_prompt_embeds=None,
+        negative_prompt_embeds_pooled=None,
+        callback_on_step_end_tensor_inputs=None,
+    ):
+        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
+        ):
+            raise ValueError(
+                f"`callback_on_step_end_tensor_inputs` has to be in {self._callback_tensor_inputs}, but found {[k for k in callback_on_step_end_tensor_inputs if k not in self._callback_tensor_inputs]}"
+            )
+
+        if prompt is not None and prompt_embeds is not None:
+            raise ValueError(
+                f"Cannot forward both `prompt`: {prompt} and `prompt_embeds`: {prompt_embeds}. Please make sure to"
+                " only forward one of the two."
+            )
+        elif prompt is None and prompt_embeds is None:
+            raise ValueError(
+                "Provide either `prompt` or `prompt_embeds`. Cannot leave both `prompt` and `prompt_embeds` undefined."
+            )
+        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 negative_prompt is not None and negative_prompt_embeds is not None:
+            raise ValueError(
+                f"Cannot forward both `negative_prompt`: {negative_prompt} and `negative_prompt_embeds`:"
+                f" {negative_prompt_embeds}. Please make sure to only forward one of the two."
+            )
+
+        if prompt_embeds is not None and negative_prompt_embeds is not None:
+            if prompt_embeds.shape != negative_prompt_embeds.shape:
+                raise ValueError(
+                    "`prompt_embeds` and `negative_prompt_embeds` must have the same shape when passed directly, but"
+                    f" got: `prompt_embeds` {prompt_embeds.shape} != `negative_prompt_embeds`"
+                    f" {negative_prompt_embeds.shape}."
+                )
+
+        if prompt_embeds_pooled is not None and negative_prompt_embeds_pooled is not None:
+            if prompt_embeds_pooled.shape != negative_prompt_embeds_pooled.shape:
+                raise ValueError(
+                    "`prompt_embeds_pooled` and `negative_prompt_embeds_pooled` must have the same shape when passed"
+                    f"directly, but got: `prompt_embeds_pooled` {prompt_embeds_pooled.shape} !="
+                    f"`negative_prompt_embeds_pooled` {negative_prompt_embeds_pooled.shape}."
+                )
+
+        if image_embeds is not None and images is not None:
+            raise ValueError(
+                f"Cannot forward both `images`: {images} and `image_embeds`: {image_embeds}. Please make sure to"
+                " only forward one of the two."
+            )
+
+        if images:
+            for i, image in enumerate(images):
+                if not isinstance(image, torch.Tensor) and not isinstance(image, PIL.Image.Image):
+                    raise TypeError(
+                        f"'images' must contain images of type 'torch.Tensor' or 'PIL.Image.Image, but got"
+                        f"{type(image)} for image number {i}."
+                    )
+
+    @property
+    def guidance_scale(self):
+        return self._guidance_scale
+
+    @property
+    def do_classifier_free_guidance(self):
+        return self._guidance_scale > 1
+
+    @property
+    def num_timesteps(self):
+        return self._num_timesteps
+
+    def get_t_condioning(self, t, alphas_cumprod):
+        s = torch.tensor([0.003])
+        clamp_range = [0, 1]
+        min_var = torch.cos(s / (1 + s) * torch.pi * 0.5) ** 2
+        var = alphas_cumprod[t]
+        var = var.clamp(*clamp_range)
+        s, min_var = s.to(var.device), min_var.to(var.device)
+        ratio = (((var * min_var) ** 0.5).acos() / (torch.pi * 0.5)) * (1 + s) - s
+        return ratio
+
+    @torch.no_grad()
+    @replace_example_docstring(EXAMPLE_DOC_STRING)
+    def __call__(
+        self,
+        prompt: Optional[Union[str, List[str]]] = None,
+        images: Union[torch.Tensor, PIL.Image.Image, List[torch.Tensor], List[PIL.Image.Image]] = None,
+        height: int = 1024,
+        width: int = 1024,
+        num_inference_steps: int = 20,
+        timesteps: List[float] = None,
+        guidance_scale: float = 4.0,
+        negative_prompt: Optional[Union[str, List[str]]] = None,
+        prompt_embeds: Optional[torch.FloatTensor] = None,
+        prompt_embeds_pooled: Optional[torch.FloatTensor] = None,
+        negative_prompt_embeds: Optional[torch.FloatTensor] = None,
+        negative_prompt_embeds_pooled: Optional[torch.FloatTensor] = None,
+        image_embeds: Optional[torch.FloatTensor] = None,
+        num_images_per_prompt: Optional[int] = 1,
+        generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None,
+        latents: Optional[torch.FloatTensor] = None,
+        output_type: Optional[str] = "pt",
+        return_dict: bool = True,
+        callback_on_step_end: Optional[Callable[[int, int, Dict], None]] = None,
+        callback_on_step_end_tensor_inputs: List[str] = ["latents"],
+    ):
+        """
+        Function invoked when calling the pipeline for generation.
+
+        Args:
+            prompt (`str` or `List[str]`):
+                The prompt or prompts to guide the image generation.
+            height (`int`, *optional*, defaults to 1024):
+                The height in pixels of the generated image.
+            width (`int`, *optional*, defaults to 1024):
+                The width in pixels of the generated image.
+            num_inference_steps (`int`, *optional*, defaults to 60):
+                The number of denoising steps. More denoising steps usually lead to a higher quality image at the
+                expense of slower inference.
+            guidance_scale (`float`, *optional*, defaults to 8.0):
+                Guidance scale as defined in [Classifier-Free Diffusion Guidance](https://arxiv.org/abs/2207.12598).
+                `decoder_guidance_scale` is defined as `w` of equation 2. of [Imagen
+                Paper](https://arxiv.org/pdf/2205.11487.pdf). Guidance scale is enabled by setting
+                `decoder_guidance_scale > 1`. Higher guidance scale encourages to generate images that are closely
+                linked to the text `prompt`, usually at the expense of lower image quality.
+            negative_prompt (`str` or `List[str]`, *optional*):
+                The prompt or prompts not to guide the image generation. Ignored when not using guidance (i.e., ignored
+                if `decoder_guidance_scale` is less than `1`).
+            prompt_embeds (`torch.FloatTensor`, *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.
+            prompt_embeds_pooled (`torch.FloatTensor`, *optional*):
+                Pre-generated pooled text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting.
+                If not provided, pooled text embeddings will be generated from `prompt` input argument.
+            negative_prompt_embeds (`torch.FloatTensor`, *optional*):
+                Pre-generated negative text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt
+                weighting. If not provided, negative_prompt_embeds will be generated from `negative_prompt` input
+                argument.
+            negative_prompt_embeds_pooled (`torch.FloatTensor`, *optional*):
+                Pre-generated negative pooled text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt
+                weighting. If not provided, negative_prompt_embeds_pooled will be generated from `negative_prompt` input
+                argument.
+            image_embeds (`torch.FloatTensor`, *optional*):
+                Pre-generated image embeddings. Can be used to easily tweak image inputs, *e.g.* prompt weighting.
+                If not provided, image embeddings will be generated from `image` input argument if existing.
+            num_images_per_prompt (`int`, *optional*, defaults to 1):
+                The number of images to generate per prompt.
+            generator (`torch.Generator` or `List[torch.Generator]`, *optional*):
+                One or a list of [torch generator(s)](https://pytorch.org/docs/stable/generated/torch.Generator.html)
+                to make generation deterministic.
+            latents (`torch.FloatTensor`, *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 will ge generated by sampling using the supplied random `generator`.
+            output_type (`str`, *optional*, defaults to `"pil"`):
+                The output format of the generate image. Choose between: `"pil"` (`PIL.Image.Image`), `"np"`
+                (`np.array`) or `"pt"` (`torch.Tensor`).
+            return_dict (`bool`, *optional*, defaults to `True`):
+                Whether or not to return a [`~pipelines.ImagePipelineOutput`] instead of a plain tuple.
+            callback_on_step_end (`Callable`, *optional*):
+                A function that calls at the end of each denoising steps during the inference. The function is called
+                with the following arguments: `callback_on_step_end(self: DiffusionPipeline, step: int, timestep: int,
+                callback_kwargs: Dict)`. `callback_kwargs` will include a list of all tensors as specified by
+                `callback_on_step_end_tensor_inputs`.
+            callback_on_step_end_tensor_inputs (`List`, *optional*):
+                The list of tensor inputs for the `callback_on_step_end` function. The tensors specified in the list
+                will be passed as `callback_kwargs` argument. You will only be able to include variables listed in the
+                `._callback_tensor_inputs` attribute of your pipeline class.
+
+        Examples:
+
+        Returns:
+            [`StableCascadePriorPipelineOutput`] or `tuple` [`StableCascadePriorPipelineOutput`] if
+            `return_dict` is True, otherwise a `tuple`. When returning a tuple, the first element is a list with the
+            generated image embeddings.
+        """
+
+        # 0. Define commonly used variables
+        device = self._execution_device
+        dtype = next(self.prior.parameters()).dtype
+        self._guidance_scale = guidance_scale
+        if prompt is not None and isinstance(prompt, str):
+            batch_size = 1
+        elif prompt is not None and isinstance(prompt, list):
+            batch_size = len(prompt)
+        else:
+            batch_size = prompt_embeds.shape[0]
+
+        # 1. Check inputs. Raise error if not correct
+        self.check_inputs(
+            prompt,
+            images=images,
+            image_embeds=image_embeds,
+            negative_prompt=negative_prompt,
+            prompt_embeds=prompt_embeds,
+            prompt_embeds_pooled=prompt_embeds_pooled,
+            negative_prompt_embeds=negative_prompt_embeds,
+            negative_prompt_embeds_pooled=negative_prompt_embeds_pooled,
+            callback_on_step_end_tensor_inputs=callback_on_step_end_tensor_inputs,
+        )
+
+        # 2. Encode caption + images
+        (
+            prompt_embeds,
+            prompt_embeds_pooled,
+            negative_prompt_embeds,
+            negative_prompt_embeds_pooled,
+        ) = self.encode_prompt(
+            prompt=prompt,
+            device=device,
+            batch_size=batch_size,
+            num_images_per_prompt=num_images_per_prompt,
+            do_classifier_free_guidance=self.do_classifier_free_guidance,
+            negative_prompt=negative_prompt,
+            prompt_embeds=prompt_embeds,
+            prompt_embeds_pooled=prompt_embeds_pooled,
+            negative_prompt_embeds=negative_prompt_embeds,
+            negative_prompt_embeds_pooled=negative_prompt_embeds_pooled,
+        )
+
+        if images is not None:
+            image_embeds_pooled, uncond_image_embeds_pooled = self.encode_image(
+                images=images,
+                device=device,
+                dtype=dtype,
+                batch_size=batch_size,
+                num_images_per_prompt=num_images_per_prompt,
+            )
+        elif image_embeds is not None:
+            image_embeds_pooled = image_embeds.repeat(batch_size * num_images_per_prompt, 1, 1)
+            uncond_image_embeds_pooled = torch.zeros_like(image_embeds_pooled)
+        else:
+            image_embeds_pooled = torch.zeros(
+                batch_size * num_images_per_prompt,
+                1,
+                self.prior.config.clip_image_in_channels,
+                device=device,
+                dtype=dtype,
+            )
+            uncond_image_embeds_pooled = torch.zeros(
+                batch_size * num_images_per_prompt,
+                1,
+                self.prior.config.clip_image_in_channels,
+                device=device,
+                dtype=dtype,
+            )
+
+        if self.do_classifier_free_guidance:
+            image_embeds = torch.cat([image_embeds_pooled, uncond_image_embeds_pooled], dim=0)
+        else:
+            image_embeds = image_embeds_pooled
+
+        # For classifier free guidance, we need to do two forward passes.
+        # Here we concatenate the unconditional and text embeddings into a single batch
+        # to avoid doing two forward passes
+        text_encoder_hidden_states = (
+            torch.cat([prompt_embeds, negative_prompt_embeds]) if negative_prompt_embeds is not None else prompt_embeds
+        )
+        text_encoder_pooled = (
+            torch.cat([prompt_embeds_pooled, negative_prompt_embeds_pooled])
+            if negative_prompt_embeds is not None
+            else prompt_embeds_pooled
+        )
+
+        # 4. Prepare and set timesteps
+        self.scheduler.set_timesteps(num_inference_steps, device=device)
+        timesteps = self.scheduler.timesteps
+
+        # 5. Prepare latents
+        latents = self.prepare_latents(
+            batch_size, height, width, num_images_per_prompt, dtype, device, generator, latents, self.scheduler
+        )
+
+        if isinstance(self.scheduler, DDPMWuerstchenScheduler):
+            timesteps = timesteps[:-1]
+        else:
+            if self.scheduler.config.clip_sample:
+                self.scheduler.config.clip_sample = False  # disample sample clipping
+                logger.warning(" set `clip_sample` to be False")
+        # 6. Run denoising loop
+        if hasattr(self.scheduler, "betas"):
+            alphas = 1.0 - self.scheduler.betas
+            alphas_cumprod = torch.cumprod(alphas, dim=0)
+        else:
+            alphas_cumprod = []
+
+        self._num_timesteps = len(timesteps)
+        for i, t in enumerate(self.progress_bar(timesteps)):
+            if not isinstance(self.scheduler, DDPMWuerstchenScheduler):
+                if len(alphas_cumprod) > 0:
+                    timestep_ratio = self.get_t_condioning(t.long().cpu(), alphas_cumprod)
+                    timestep_ratio = timestep_ratio.expand(latents.size(0)).to(dtype).to(device)
+                else:
+                    timestep_ratio = t.float().div(self.scheduler.timesteps[-1]).expand(latents.size(0)).to(dtype)
+            else:
+                timestep_ratio = t.expand(latents.size(0)).to(dtype)
+            # 7. Denoise image embeddings
+            predicted_image_embedding = self.prior(
+                sample=torch.cat([latents] * 2) if self.do_classifier_free_guidance else latents,
+                timestep_ratio=torch.cat([timestep_ratio] * 2) if self.do_classifier_free_guidance else timestep_ratio,
+                clip_text_pooled=text_encoder_pooled,
+                clip_text=text_encoder_hidden_states,
+                clip_img=image_embeds,
+                return_dict=False,
+            )[0]
+
+            # 8. Check for classifier free guidance and apply it
+            if self.do_classifier_free_guidance:
+                predicted_image_embedding_text, predicted_image_embedding_uncond = predicted_image_embedding.chunk(2)
+                predicted_image_embedding = torch.lerp(
+                    predicted_image_embedding_uncond, predicted_image_embedding_text, self.guidance_scale
+                )
+
+            # 9. Renoise latents to next timestep
+            if not isinstance(self.scheduler, DDPMWuerstchenScheduler):
+                timestep_ratio = t
+            latents = self.scheduler.step(
+                model_output=predicted_image_embedding, timestep=timestep_ratio, sample=latents, generator=generator
+            ).prev_sample
+
+            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)
+
+        # Offload all models
+        self.maybe_free_model_hooks()
+
+        if output_type == "np":
+            latents = latents.cpu().float().numpy()  # float() as bfloat16-> numpy doesnt work
+            prompt_embeds = prompt_embeds.cpu().float().numpy()  # float() as bfloat16-> numpy doesnt work
+            negative_prompt_embeds = (
+                negative_prompt_embeds.cpu().float().numpy() if negative_prompt_embeds is not None else None
+            )  # float() as bfloat16-> numpy doesnt work
+
+        if not return_dict:
+            return (latents, prompt_embeds, negative_prompt_embeds)
+
+        return StableCascadePriorPipelineOutput(latents, prompt_embeds, negative_prompt_embeds)

src/diffusers/pipelines/stable_video_diffusion/pipeline_stable_video_diffusion.py

@@ -322,7 +322,7 @@ class StableVideoDiffusionPipeline(DiffusionPipeline):
     @property
     def do_classifier_free_guidance(self):
         if isinstance(self.guidance_scale, (int, float)):
-            return self.guidance_scale
+            return self.guidance_scale > 1
         return self.guidance_scale.max() > 1
 
     @property

src/diffusers/pipelines/wuerstchen/modeling_wuerstchen_common.py

@@ -1,18 +1,3 @@
-# Copyright (c) 2023 Dominic Rampas MIT License
-# Copyright 2024 The HuggingFace Team. All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
 import torch
 import torch.nn as nn
 

src/diffusers/pipelines/wuerstchen/modeling_wuerstchen_diffnext.py

@@ -233,7 +233,7 @@ class WuerstchenDiffNeXt(ModelMixin, ConfigMixin):
 
 
 class ResBlockStageB(nn.Module):
-    def __init__(self, c, c_skip=None, kernel_size=3, dropout=0.0):
+    def __init__(self, c, c_skip=0, kernel_size=3, dropout=0.0):
         super().__init__()
         self.depthwise = nn.Conv2d(c, c, kernel_size=kernel_size, padding=kernel_size // 2, groups=c)
         self.norm = WuerstchenLayerNorm(c, elementwise_affine=False, eps=1e-6)

src/diffusers/pipelines/wuerstchen/pipeline_wuerstchen.py

@@ -349,6 +349,11 @@ class WuerstchenDecoderPipeline(DiffusionPipeline):
         text_encoder_hidden_states = (
             torch.cat([prompt_embeds, negative_prompt_embeds]) if negative_prompt_embeds is not None else prompt_embeds
         )
+        effnet = (
+            torch.cat([image_embeddings, torch.zeros_like(image_embeddings)])
+            if self.do_classifier_free_guidance
+            else image_embeddings
+        )
 
         # 3. Determine latent shape of latents
         latent_height = int(image_embeddings.size(2) * self.config.latent_dim_scale)
@@ -371,11 +376,6 @@ class WuerstchenDecoderPipeline(DiffusionPipeline):
         self._num_timesteps = len(timesteps[:-1])
         for i, t in enumerate(self.progress_bar(timesteps[:-1])):
             ratio = t.expand(latents.size(0)).to(dtype)
-            effnet = (
-                torch.cat([image_embeddings, torch.zeros_like(image_embeddings)])
-                if self.do_classifier_free_guidance
-                else image_embeddings
-            )
             # 7. Denoise latents
             predicted_latents = self.decoder(
                 torch.cat([latents] * 2) if self.do_classifier_free_guidance else latents,
@@ -423,9 +423,9 @@ class WuerstchenDecoderPipeline(DiffusionPipeline):
             latents = self.vqgan.config.scale_factor * latents
             images = self.vqgan.decode(latents).sample.clamp(0, 1)
             if output_type == "np":
-                images = images.permute(0, 2, 3, 1).cpu().numpy()
+                images = images.permute(0, 2, 3, 1).cpu().float().numpy()
             elif output_type == "pil":
-                images = images.permute(0, 2, 3, 1).cpu().numpy()
+                images = images.permute(0, 2, 3, 1).cpu().float().numpy()
                 images = self.numpy_to_pil(images)
         else:
             images = latents

src/diffusers/pipelines/wuerstchen/pipeline_wuerstchen_prior.py

@@ -508,7 +508,7 @@ class WuerstchenPriorPipeline(DiffusionPipeline, LoraLoaderMixin):
         self.maybe_free_model_hooks()
 
         if output_type == "np":
-            latents = latents.cpu().numpy()
+            latents = latents.cpu().float().numpy()
 
         if not return_dict:
             return (latents,)

src/diffusers/utils/__init__.py

@@ -19,7 +19,6 @@ from packaging import version
 
 from .. import __version__
 from .constants import (
-    _ACCEPTED_SINGLE_FILE_FORMATS,
     CONFIG_NAME,
     DEPRECATED_REVISION_ARGS,
     DIFFUSERS_DYNAMIC_MODULE_NAME,
@@ -84,7 +83,7 @@ from .import_utils import (
     is_xformers_available,
     requires_backends,
 )
-from .loading_utils import is_single_file_checkpoint, load_image
+from .loading_utils import load_image
 from .logging import get_logger
 from .outputs import BaseOutput
 from .peft_utils import (

src/diffusers/utils/constants.py

@@ -37,7 +37,6 @@ HUGGINGFACE_CO_RESOLVE_ENDPOINT = os.environ.get("HF_ENDPOINT", "https://hugging
 DIFFUSERS_DYNAMIC_MODULE_NAME = "diffusers_modules"
 HF_MODULES_CACHE = os.getenv("HF_MODULES_CACHE", os.path.join(HF_HOME, "modules"))
 DEPRECATED_REVISION_ARGS = ["fp16", "non-ema"]
-_ACCEPTED_SINGLE_FILE_FORMATS = (".safetensors", ".ckpt", ".bin", ".pth", ".pt")
 
 # Below should be `True` if the current version of `peft` and `transformers` are compatible with
 # PEFT backend. Will automatically fall back to PEFT backend if the correct versions of the libraries are

src/diffusers/utils/dummy_torch_and_transformers_objects.py

@@ -752,6 +752,51 @@ class ShapEPipeline(metaclass=DummyObject):
         requires_backends(cls, ["torch", "transformers"])
 
 
+class StableCascadeCombinedPipeline(metaclass=DummyObject):
+    _backends = ["torch", "transformers"]
+
+    def __init__(self, *args, **kwargs):
+        requires_backends(self, ["torch", "transformers"])
+
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers"])
+
+
+class StableCascadeDecoderPipeline(metaclass=DummyObject):
+    _backends = ["torch", "transformers"]
+
+    def __init__(self, *args, **kwargs):
+        requires_backends(self, ["torch", "transformers"])
+
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers"])
+
+
+class StableCascadePriorPipeline(metaclass=DummyObject):
+    _backends = ["torch", "transformers"]
+
+    def __init__(self, *args, **kwargs):
+        requires_backends(self, ["torch", "transformers"])
+
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers"])
+
+
 class StableDiffusionAdapterPipeline(metaclass=DummyObject):
     _backends = ["torch", "transformers"]
 

src/diffusers/utils/loading_utils.py

@@ -1,28 +1,10 @@
 import os
 from typing import Callable, Union
-from urllib.parse import urlparse
 
 import PIL.Image
 import PIL.ImageOps
 import requests
 
-from ..utils.constants import _ACCEPTED_SINGLE_FILE_FORMATS
-
-
-def is_single_file_checkpoint(filepath):
-    def is_valid_url(url):
-        result = urlparse(url)
-        if result.scheme and result.netloc:
-            return True
-
-    filepath = str(filepath)
-    if filepath.endswith(_ACCEPTED_SINGLE_FILE_FORMATS):
-        if is_valid_url(filepath):
-            return True
-        elif os.path.isfile(filepath):
-            return True
-    return False
-
 
 def load_image(
     image: Union[str, PIL.Image.Image], convert_method: Callable[[PIL.Image.Image], PIL.Image.Image] = None

tests/pipelines/stable_cascade/test_stable_cascade_combined.py

@@ -0,0 +1,246 @@
+# coding=utf-8
+# Copyright 2024 HuggingFace Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import unittest
+
+import numpy as np
+import torch
+from transformers import CLIPTextConfig, CLIPTextModelWithProjection, CLIPTokenizer
+
+from diffusers import DDPMWuerstchenScheduler, StableCascadeCombinedPipeline
+from diffusers.models import StableCascadeUNet
+from diffusers.pipelines.wuerstchen import PaellaVQModel
+from diffusers.utils.testing_utils import enable_full_determinism, require_torch_gpu, torch_device
+
+from ..test_pipelines_common import PipelineTesterMixin
+
+
+enable_full_determinism()
+
+
+class StableCascadeCombinedPipelineFastTests(PipelineTesterMixin, unittest.TestCase):
+    pipeline_class = StableCascadeCombinedPipeline
+    params = ["prompt"]
+    batch_params = ["prompt", "negative_prompt"]
+    required_optional_params = [
+        "generator",
+        "height",
+        "width",
+        "latents",
+        "prior_guidance_scale",
+        "decoder_guidance_scale",
+        "negative_prompt",
+        "num_inference_steps",
+        "return_dict",
+        "prior_num_inference_steps",
+        "output_type",
+    ]
+    test_xformers_attention = True
+
+    @property
+    def text_embedder_hidden_size(self):
+        return 32
+
+    @property
+    def dummy_prior(self):
+        torch.manual_seed(0)
+
+        model_kwargs = {
+            "conditioning_dim": 128,
+            "block_out_channels": (128, 128),
+            "num_attention_heads": (2, 2),
+            "down_num_layers_per_block": (1, 1),
+            "up_num_layers_per_block": (1, 1),
+            "clip_image_in_channels": 768,
+            "switch_level": (False,),
+            "clip_text_in_channels": self.text_embedder_hidden_size,
+            "clip_text_pooled_in_channels": self.text_embedder_hidden_size,
+        }
+
+        model = StableCascadeUNet(**model_kwargs)
+        return model.eval()
+
+    @property
+    def dummy_tokenizer(self):
+        tokenizer = CLIPTokenizer.from_pretrained("hf-internal-testing/tiny-random-clip")
+        return tokenizer
+
+    @property
+    def dummy_text_encoder(self):
+        torch.manual_seed(0)
+        config = CLIPTextConfig(
+            bos_token_id=0,
+            eos_token_id=2,
+            projection_dim=self.text_embedder_hidden_size,
+            hidden_size=self.text_embedder_hidden_size,
+            intermediate_size=37,
+            layer_norm_eps=1e-05,
+            num_attention_heads=4,
+            num_hidden_layers=5,
+            pad_token_id=1,
+            vocab_size=1000,
+        )
+        return CLIPTextModelWithProjection(config).eval()
+
+    @property
+    def dummy_vqgan(self):
+        torch.manual_seed(0)
+
+        model_kwargs = {
+            "bottleneck_blocks": 1,
+            "num_vq_embeddings": 2,
+        }
+        model = PaellaVQModel(**model_kwargs)
+        return model.eval()
+
+    @property
+    def dummy_decoder(self):
+        torch.manual_seed(0)
+        model_kwargs = {
+            "in_channels": 4,
+            "out_channels": 4,
+            "conditioning_dim": 128,
+            "block_out_channels": (16, 32, 64, 128),
+            "num_attention_heads": (-1, -1, 1, 2),
+            "down_num_layers_per_block": (1, 1, 1, 1),
+            "up_num_layers_per_block": (1, 1, 1, 1),
+            "down_blocks_repeat_mappers": (1, 1, 1, 1),
+            "up_blocks_repeat_mappers": (3, 3, 2, 2),
+            "block_types_per_layer": (
+                ("SDCascadeResBlock", "SDCascadeTimestepBlock"),
+                ("SDCascadeResBlock", "SDCascadeTimestepBlock"),
+                ("SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock"),
+                ("SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock"),
+            ),
+            "switch_level": None,
+            "clip_text_pooled_in_channels": 32,
+            "dropout": (0.1, 0.1, 0.1, 0.1),
+        }
+
+        model = StableCascadeUNet(**model_kwargs)
+        return model.eval()
+
+    def get_dummy_components(self):
+        prior = self.dummy_prior
+
+        scheduler = DDPMWuerstchenScheduler()
+        tokenizer = self.dummy_tokenizer
+        text_encoder = self.dummy_text_encoder
+        decoder = self.dummy_decoder
+        vqgan = self.dummy_vqgan
+        prior_text_encoder = self.dummy_text_encoder
+        prior_tokenizer = self.dummy_tokenizer
+
+        components = {
+            "text_encoder": text_encoder,
+            "tokenizer": tokenizer,
+            "decoder": decoder,
+            "scheduler": scheduler,
+            "vqgan": vqgan,
+            "prior_text_encoder": prior_text_encoder,
+            "prior_tokenizer": prior_tokenizer,
+            "prior_prior": prior,
+            "prior_scheduler": scheduler,
+        }
+
+        return components
+
+    def get_dummy_inputs(self, device, seed=0):
+        if str(device).startswith("mps"):
+            generator = torch.manual_seed(seed)
+        else:
+            generator = torch.Generator(device=device).manual_seed(seed)
+        inputs = {
+            "prompt": "horse",
+            "generator": generator,
+            "prior_guidance_scale": 4.0,
+            "decoder_guidance_scale": 4.0,
+            "num_inference_steps": 2,
+            "prior_num_inference_steps": 2,
+            "output_type": "np",
+            "height": 128,
+            "width": 128,
+        }
+        return inputs
+
+    def test_stable_cascade(self):
+        device = "cpu"
+
+        components = self.get_dummy_components()
+
+        pipe = self.pipeline_class(**components)
+        pipe = pipe.to(device)
+
+        pipe.set_progress_bar_config(disable=None)
+
+        output = pipe(**self.get_dummy_inputs(device))
+        image = output.images
+
+        image_from_tuple = pipe(**self.get_dummy_inputs(device), return_dict=False)[0]
+
+        image_slice = image[0, -3:, -3:, -1]
+        image_from_tuple_slice = image_from_tuple[-3:, -3:, -1]
+
+        assert image.shape == (1, 128, 128, 3)
+
+        expected_slice = np.array([0.0, 1.0, 0.0, 1.0, 1.0, 0.0, 1.0, 1.0, 0.0])
+        assert (
+            np.abs(image_slice.flatten() - expected_slice).max() < 1e-2
+        ), f" expected_slice {expected_slice}, but got {image_slice.flatten()}"
+        assert (
+            np.abs(image_from_tuple_slice.flatten() - expected_slice).max() < 1e-2
+        ), f" expected_slice {expected_slice}, but got {image_from_tuple_slice.flatten()}"
+
+    @require_torch_gpu
+    def test_offloads(self):
+        pipes = []
+        components = self.get_dummy_components()
+        sd_pipe = self.pipeline_class(**components).to(torch_device)
+        pipes.append(sd_pipe)
+
+        components = self.get_dummy_components()
+        sd_pipe = self.pipeline_class(**components)
+        sd_pipe.enable_sequential_cpu_offload()
+        pipes.append(sd_pipe)
+
+        components = self.get_dummy_components()
+        sd_pipe = self.pipeline_class(**components)
+        sd_pipe.enable_model_cpu_offload()
+        pipes.append(sd_pipe)
+
+        image_slices = []
+        for pipe in pipes:
+            inputs = self.get_dummy_inputs(torch_device)
+            image = pipe(**inputs).images
+
+            image_slices.append(image[0, -3:, -3:, -1].flatten())
+
+        assert np.abs(image_slices[0] - image_slices[1]).max() < 1e-3
+        assert np.abs(image_slices[0] - image_slices[2]).max() < 1e-3
+
+    def test_inference_batch_single_identical(self):
+        super().test_inference_batch_single_identical(expected_max_diff=2e-2)
+
+    @unittest.skip(reason="fp16 not supported")
+    def test_float16_inference(self):
+        super().test_float16_inference()
+
+    @unittest.skip(reason="no callback test for combined pipeline")
+    def test_callback_inputs(self):
+        super().test_callback_inputs()
+
+    # def test_callback_cfg(self):
+    #     pass
+    #     pass

tests/pipelines/stable_cascade/test_stable_cascade_decoder.py

@@ -0,0 +1,249 @@
+# coding=utf-8
+# Copyright 2024 HuggingFace Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import gc
+import unittest
+
+import numpy as np
+import torch
+from transformers import CLIPTextConfig, CLIPTextModelWithProjection, CLIPTokenizer
+
+from diffusers import DDPMWuerstchenScheduler, StableCascadeDecoderPipeline
+from diffusers.image_processor import VaeImageProcessor
+from diffusers.models import StableCascadeUNet
+from diffusers.pipelines.wuerstchen import PaellaVQModel
+from diffusers.utils.testing_utils import (
+    enable_full_determinism,
+    load_image,
+    load_pt,
+    require_torch_gpu,
+    skip_mps,
+    slow,
+    torch_device,
+)
+
+from ..test_pipelines_common import PipelineTesterMixin
+
+
+enable_full_determinism()
+
+
+class StableCascadeDecoderPipelineFastTests(PipelineTesterMixin, unittest.TestCase):
+    pipeline_class = StableCascadeDecoderPipeline
+    params = ["prompt"]
+    batch_params = ["image_embeddings", "prompt", "negative_prompt"]
+    required_optional_params = [
+        "num_images_per_prompt",
+        "num_inference_steps",
+        "latents",
+        "negative_prompt",
+        "guidance_scale",
+        "output_type",
+        "return_dict",
+    ]
+    test_xformers_attention = False
+    callback_cfg_params = ["image_embeddings", "text_encoder_hidden_states"]
+
+    @property
+    def text_embedder_hidden_size(self):
+        return 32
+
+    @property
+    def time_input_dim(self):
+        return 32
+
+    @property
+    def block_out_channels_0(self):
+        return self.time_input_dim
+
+    @property
+    def time_embed_dim(self):
+        return self.time_input_dim * 4
+
+    @property
+    def dummy_tokenizer(self):
+        tokenizer = CLIPTokenizer.from_pretrained("hf-internal-testing/tiny-random-clip")
+        return tokenizer
+
+    @property
+    def dummy_text_encoder(self):
+        torch.manual_seed(0)
+        config = CLIPTextConfig(
+            bos_token_id=0,
+            eos_token_id=2,
+            projection_dim=self.text_embedder_hidden_size,
+            hidden_size=self.text_embedder_hidden_size,
+            intermediate_size=37,
+            layer_norm_eps=1e-05,
+            num_attention_heads=4,
+            num_hidden_layers=5,
+            pad_token_id=1,
+            vocab_size=1000,
+        )
+        return CLIPTextModelWithProjection(config).eval()
+
+    @property
+    def dummy_vqgan(self):
+        torch.manual_seed(0)
+
+        model_kwargs = {
+            "bottleneck_blocks": 1,
+            "num_vq_embeddings": 2,
+        }
+        model = PaellaVQModel(**model_kwargs)
+        return model.eval()
+
+    @property
+    def dummy_decoder(self):
+        torch.manual_seed(0)
+        model_kwargs = {
+            "in_channels": 4,
+            "out_channels": 4,
+            "conditioning_dim": 128,
+            "block_out_channels": [16, 32, 64, 128],
+            "num_attention_heads": [-1, -1, 1, 2],
+            "down_num_layers_per_block": [1, 1, 1, 1],
+            "up_num_layers_per_block": [1, 1, 1, 1],
+            "down_blocks_repeat_mappers": [1, 1, 1, 1],
+            "up_blocks_repeat_mappers": [3, 3, 2, 2],
+            "block_types_per_layer": [
+                ["SDCascadeResBlock", "SDCascadeTimestepBlock"],
+                ["SDCascadeResBlock", "SDCascadeTimestepBlock"],
+                ["SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock"],
+                ["SDCascadeResBlock", "SDCascadeTimestepBlock", "SDCascadeAttnBlock"],
+            ],
+            "switch_level": None,
+            "clip_text_pooled_in_channels": 32,
+            "dropout": [0.1, 0.1, 0.1, 0.1],
+        }
+        model = StableCascadeUNet(**model_kwargs)
+        return model.eval()
+
+    def get_dummy_components(self):
+        decoder = self.dummy_decoder
+        text_encoder = self.dummy_text_encoder
+        tokenizer = self.dummy_tokenizer
+        vqgan = self.dummy_vqgan
+
+        scheduler = DDPMWuerstchenScheduler()
+
+        components = {
+            "decoder": decoder,
+            "vqgan": vqgan,
+            "text_encoder": text_encoder,
+            "tokenizer": tokenizer,
+            "scheduler": scheduler,
+            "latent_dim_scale": 4.0,
+        }
+
+        return components
+
+    def get_dummy_inputs(self, device, seed=0):
+        if str(device).startswith("mps"):
+            generator = torch.manual_seed(seed)
+        else:
+            generator = torch.Generator(device=device).manual_seed(seed)
+        inputs = {
+            "image_embeddings": torch.ones((1, 4, 4, 4), device=device),
+            "prompt": "horse",
+            "generator": generator,
+            "guidance_scale": 2.0,
+            "num_inference_steps": 2,
+            "output_type": "np",
+        }
+        return inputs
+
+    def test_wuerstchen_decoder(self):
+        device = "cpu"
+
+        components = self.get_dummy_components()
+
+        pipe = self.pipeline_class(**components)
+        pipe = pipe.to(device)
+
+        pipe.set_progress_bar_config(disable=None)
+
+        output = pipe(**self.get_dummy_inputs(device))
+        image = output.images
+
+        image_from_tuple = pipe(**self.get_dummy_inputs(device), return_dict=False)
+
+        image_slice = image[0, -3:, -3:, -1]
+        image_from_tuple_slice = image_from_tuple[0, -3:, -3:, -1]
+
+        assert image.shape == (1, 64, 64, 3)
+
+        expected_slice = np.array([0.0, 0.0, 0.0, 1.0, 1.0, 0.0, 1.0, 1.0, 0.0])
+        assert np.abs(image_slice.flatten() - expected_slice).max() < 1e-2
+        assert np.abs(image_from_tuple_slice.flatten() - expected_slice).max() < 1e-2
+
+    @skip_mps
+    def test_inference_batch_single_identical(self):
+        self._test_inference_batch_single_identical(expected_max_diff=1e-2)
+
+    @skip_mps
+    def test_attention_slicing_forward_pass(self):
+        test_max_difference = torch_device == "cpu"
+        test_mean_pixel_difference = False
+
+        self._test_attention_slicing_forward_pass(
+            test_max_difference=test_max_difference,
+            test_mean_pixel_difference=test_mean_pixel_difference,
+        )
+
+    @unittest.skip(reason="fp16 not supported")
+    def test_float16_inference(self):
+        super().test_float16_inference()
+
+
+@slow
+@require_torch_gpu
+class StableCascadeDecoderPipelineIntegrationTests(unittest.TestCase):
+    def tearDown(self):
+        # clean up the VRAM after each test
+        super().tearDown()
+        gc.collect()
+        torch.cuda.empty_cache()
+
+    def test_stable_cascade_decoder(self):
+        pipe = StableCascadeDecoderPipeline.from_pretrained(
+            "diffusers/StableCascade-decoder", torch_dtype=torch.bfloat16
+        )
+        pipe.enable_model_cpu_offload()
+        pipe.set_progress_bar_config(disable=None)
+
+        prompt = "A photograph of the inside of a subway train. There are raccoons sitting on the seats. One of them is reading a newspaper. The window shows the city in the background."
+
+        generator = torch.Generator(device="cpu").manual_seed(0)
+        image_embedding = load_pt(
+            "https://huggingface.co/datasets/hf-internal-testing/diffusers-images/resolve/main/stable_cascade/image_embedding.pt"
+        )
+
+        image = pipe(
+            prompt=prompt, image_embeddings=image_embedding, num_inference_steps=10, generator=generator
+        ).images[0]
+
+        assert image.size == (1024, 1024)
+
+        expected_image = load_image(
+            "https://huggingface.co/datasets/hf-internal-testing/diffusers-images/resolve/main/stable_cascade/t2i.png"
+        )
+
+        image_processor = VaeImageProcessor()
+
+        image_np = image_processor.pil_to_numpy(image)
+        expected_image_np = image_processor.pil_to_numpy(expected_image)
+
+        self.assertTrue(np.allclose(image_np, expected_image_np, atol=53e-2))

tests/pipelines/stable_cascade/test_stable_cascade_prior.py

@@ -0,0 +1,308 @@
+# coding=utf-8
+# Copyright 2024 HuggingFace Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import gc
+import unittest
+
+import numpy as np
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+from transformers import CLIPTextConfig, CLIPTextModelWithProjection, CLIPTokenizer
+
+from diffusers import DDPMWuerstchenScheduler, StableCascadePriorPipeline
+from diffusers.loaders import AttnProcsLayers
+from diffusers.models import StableCascadeUNet
+from diffusers.models.attention_processor import LoRAAttnProcessor, LoRAAttnProcessor2_0
+from diffusers.utils.import_utils import is_peft_available
+from diffusers.utils.testing_utils import (
+    enable_full_determinism,
+    load_pt,
+    require_peft_backend,
+    require_torch_gpu,
+    skip_mps,
+    slow,
+    torch_device,
+)
+
+
+if is_peft_available():
+    from peft import LoraConfig
+    from peft.tuners.tuners_utils import BaseTunerLayer
+
+from ..test_pipelines_common import PipelineTesterMixin
+
+
+enable_full_determinism()
+
+
+def create_prior_lora_layers(unet: nn.Module):
+    lora_attn_procs = {}
+    for name in unet.attn_processors.keys():
+        lora_attn_processor_class = (
+            LoRAAttnProcessor2_0 if hasattr(F, "scaled_dot_product_attention") else LoRAAttnProcessor
+        )
+        lora_attn_procs[name] = lora_attn_processor_class(
+            hidden_size=unet.config.c,
+        )
+    unet_lora_layers = AttnProcsLayers(lora_attn_procs)
+    return lora_attn_procs, unet_lora_layers
+
+
+class StableCascadePriorPipelineFastTests(PipelineTesterMixin, unittest.TestCase):
+    pipeline_class = StableCascadePriorPipeline
+    params = ["prompt"]
+    batch_params = ["prompt", "negative_prompt"]
+    required_optional_params = [
+        "num_images_per_prompt",
+        "generator",
+        "num_inference_steps",
+        "latents",
+        "negative_prompt",
+        "guidance_scale",
+        "output_type",
+        "return_dict",
+    ]
+    test_xformers_attention = False
+    callback_cfg_params = ["text_encoder_hidden_states"]
+
+    @property
+    def text_embedder_hidden_size(self):
+        return 32
+
+    @property
+    def time_input_dim(self):
+        return 32
+
+    @property
+    def block_out_channels_0(self):
+        return self.time_input_dim
+
+    @property
+    def time_embed_dim(self):
+        return self.time_input_dim * 4
+
+    @property
+    def dummy_tokenizer(self):
+        tokenizer = CLIPTokenizer.from_pretrained("hf-internal-testing/tiny-random-clip")
+        return tokenizer
+
+    @property
+    def dummy_text_encoder(self):
+        torch.manual_seed(0)
+        config = CLIPTextConfig(
+            bos_token_id=0,
+            eos_token_id=2,
+            hidden_size=self.text_embedder_hidden_size,
+            projection_dim=self.text_embedder_hidden_size,
+            intermediate_size=37,
+            layer_norm_eps=1e-05,
+            num_attention_heads=4,
+            num_hidden_layers=5,
+            pad_token_id=1,
+            vocab_size=1000,
+        )
+        return CLIPTextModelWithProjection(config).eval()
+
+    @property
+    def dummy_prior(self):
+        torch.manual_seed(0)
+
+        model_kwargs = {
+            "conditioning_dim": 128,
+            "block_out_channels": (128, 128),
+            "num_attention_heads": (2, 2),
+            "down_num_layers_per_block": (1, 1),
+            "up_num_layers_per_block": (1, 1),
+            "switch_level": (False,),
+            "clip_image_in_channels": 768,
+            "clip_text_in_channels": self.text_embedder_hidden_size,
+            "clip_text_pooled_in_channels": self.text_embedder_hidden_size,
+            "dropout": (0.1, 0.1),
+        }
+
+        model = StableCascadeUNet(**model_kwargs)
+        return model.eval()
+
+    def get_dummy_components(self):
+        prior = self.dummy_prior
+        text_encoder = self.dummy_text_encoder
+        tokenizer = self.dummy_tokenizer
+
+        scheduler = DDPMWuerstchenScheduler()
+
+        components = {
+            "prior": prior,
+            "text_encoder": text_encoder,
+            "tokenizer": tokenizer,
+            "scheduler": scheduler,
+            "feature_extractor": None,
+            "image_encoder": None,
+        }
+
+        return components
+
+    def get_dummy_inputs(self, device, seed=0):
+        if str(device).startswith("mps"):
+            generator = torch.manual_seed(seed)
+        else:
+            generator = torch.Generator(device=device).manual_seed(seed)
+        inputs = {
+            "prompt": "horse",
+            "generator": generator,
+            "guidance_scale": 4.0,
+            "num_inference_steps": 2,
+            "output_type": "np",
+        }
+        return inputs
+
+    def test_wuerstchen_prior(self):
+        device = "cpu"
+
+        components = self.get_dummy_components()
+
+        pipe = self.pipeline_class(**components)
+        pipe = pipe.to(device)
+
+        pipe.set_progress_bar_config(disable=None)
+
+        output = pipe(**self.get_dummy_inputs(device))
+        image = output.image_embeddings
+
+        image_from_tuple = pipe(**self.get_dummy_inputs(device), return_dict=False)[0]
+
+        image_slice = image[0, 0, 0, -10:]
+        image_from_tuple_slice = image_from_tuple[0, 0, 0, -10:]
+        assert image.shape == (1, 16, 24, 24)
+
+        expected_slice = np.array(
+            [
+                96.139565,
+                -20.213179,
+                -116.40341,
+                -191.57129,
+                39.350136,
+                74.80767,
+                39.782352,
+                -184.67352,
+                -46.426907,
+                168.41783,
+            ]
+        )
+
+        assert np.abs(image_slice.flatten() - expected_slice).max() < 5e-2
+        assert np.abs(image_from_tuple_slice.flatten() - expected_slice).max() < 5e-2
+
+    @skip_mps
+    def test_inference_batch_single_identical(self):
+        self._test_inference_batch_single_identical(expected_max_diff=2e-1)
+
+    @skip_mps
+    def test_attention_slicing_forward_pass(self):
+        test_max_difference = torch_device == "cpu"
+        test_mean_pixel_difference = False
+
+        self._test_attention_slicing_forward_pass(
+            test_max_difference=test_max_difference,
+            test_mean_pixel_difference=test_mean_pixel_difference,
+        )
+
+    @unittest.skip(reason="fp16 not supported")
+    def test_float16_inference(self):
+        super().test_float16_inference()
+
+    def check_if_lora_correctly_set(self, model) -> bool:
+        """
+        Checks if the LoRA layers are correctly set with peft
+        """
+        for module in model.modules():
+            if isinstance(module, BaseTunerLayer):
+                return True
+        return False
+
+    def get_lora_components(self):
+        prior = self.dummy_prior
+
+        prior_lora_config = LoraConfig(
+            r=4, lora_alpha=4, target_modules=["to_q", "to_k", "to_v", "to_out.0"], init_lora_weights=False
+        )
+
+        prior_lora_attn_procs, prior_lora_layers = create_prior_lora_layers(prior)
+
+        lora_components = {
+            "prior_lora_layers": prior_lora_layers,
+            "prior_lora_attn_procs": prior_lora_attn_procs,
+        }
+
+        return prior, prior_lora_config, lora_components
+
+    @require_peft_backend
+    @unittest.skip(reason="no lora support for now")
+    def test_inference_with_prior_lora(self):
+        _, prior_lora_config, _ = self.get_lora_components()
+        device = "cpu"
+
+        components = self.get_dummy_components()
+
+        pipe = self.pipeline_class(**components)
+        pipe = pipe.to(device)
+
+        pipe.set_progress_bar_config(disable=None)
+
+        output_no_lora = pipe(**self.get_dummy_inputs(device))
+        image_embed = output_no_lora.image_embeddings
+        self.assertTrue(image_embed.shape == (1, 16, 24, 24))
+
+        pipe.prior.add_adapter(prior_lora_config)
+        self.assertTrue(self.check_if_lora_correctly_set(pipe.prior), "Lora not correctly set in prior")
+
+        output_lora = pipe(**self.get_dummy_inputs(device))
+        lora_image_embed = output_lora.image_embeddings
+
+        self.assertTrue(image_embed.shape == lora_image_embed.shape)
+
+
+@slow
+@require_torch_gpu
+class StableCascadePriorPipelineIntegrationTests(unittest.TestCase):
+    def tearDown(self):
+        # clean up the VRAM after each test
+        super().tearDown()
+        gc.collect()
+        torch.cuda.empty_cache()
+
+    def test_stable_cascade_prior(self):
+        pipe = StableCascadePriorPipeline.from_pretrained("diffusers/StableCascade-prior", torch_dtype=torch.bfloat16)
+        pipe.enable_model_cpu_offload()
+        pipe.set_progress_bar_config(disable=None)
+
+        prompt = "A photograph of the inside of a subway train. There are raccoons sitting on the seats. One of them is reading a newspaper. The window shows the city in the background."
+
+        generator = torch.Generator(device="cpu").manual_seed(0)
+
+        output = pipe(prompt, num_inference_steps=10, generator=generator)
+        image_embedding = output.image_embeddings
+
+        expected_image_embedding = load_pt(
+            "https://huggingface.co/datasets/hf-internal-testing/diffusers-images/resolve/main/stable_cascade/image_embedding.pt"
+        )
+
+        assert image_embedding.shape == (1, 16, 24, 24)
+
+        self.assertTrue(
+            np.allclose(
+                image_embedding.cpu().float().numpy(), expected_image_embedding.cpu().float().numpy(), atol=5e-2
+            )
+        )

tests/pipelines/stable_video_diffusion/test_stable_video_diffusion.py

@@ -496,6 +496,22 @@ class StableVideoDiffusionPipelineFastTests(PipelineTesterMixin, unittest.TestCa
         max_diff = np.abs(to_np(output_with_offload) - to_np(output_without_offload)).max()
         self.assertLess(max_diff, expected_max_diff, "XFormers attention should not affect the inference results")
 
+    def test_disable_cfg(self):
+        components = self.get_dummy_components()
+        pipe = self.pipeline_class(**components)
+        for component in pipe.components.values():
+            if hasattr(component, "set_default_attn_processor"):
+                component.set_default_attn_processor()
+
+        pipe.to(torch_device)
+        pipe.set_progress_bar_config(disable=None)
+
+        generator_device = "cpu"
+        inputs = self.get_dummy_inputs(generator_device)
+        inputs["max_guidance_scale"] = 1.0
+        output = pipe(**inputs).frames
+        self.assertEqual(len(output.shape), 5)
+
 
 @slow
 @require_torch_gpu

tests/pipelines/test_pipelines_common.py

@@ -99,14 +99,13 @@ class SDFunctionTesterMixin:
         assert np.abs(output_2[0].flatten() - output_1[0].flatten()).max() < 1e-2
 
     def test_vae_tiling(self):
-        device = "cpu"  # ensure determinism for the device-dependent torch.Generator
         components = self.get_dummy_components()
 
         # make sure here that pndm scheduler skips prk
         if "safety_checker" in components:
             components["safety_checker"] = None
         pipe = self.pipeline_class(**components)
-        pipe = pipe.to(device)
+        pipe = pipe.to(torch_device)
         pipe.set_progress_bar_config(disable=None)
 
         inputs = self.get_dummy_inputs(torch_device)
@@ -126,7 +125,7 @@ class SDFunctionTesterMixin:
         # test that tiled decode works with various shapes
         shapes = [(1, 4, 73, 97), (1, 4, 97, 73), (1, 4, 49, 65), (1, 4, 65, 49)]
         for shape in shapes:
-            zeros = torch.zeros(shape).to(device)
+            zeros = torch.zeros(shape).to(torch_device)
             pipe.vae.decode(zeros)
 
     def test_freeu_enabled(self):

tests/pipelines/wuerstchen/test_wuerstchen_combined.py

@@ -45,7 +45,6 @@ class WuerstchenCombinedPipelineFastTests(PipelineTesterMixin, unittest.TestCase
         "return_dict",
         "prior_num_inference_steps",
         "output_type",
-        "return_dict",
     ]
     test_xformers_attention = True