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.gitattributes

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-*.7z filter=lfs diff=lfs merge=lfs -text
-*.arrow filter=lfs diff=lfs merge=lfs -text
-*.bin filter=lfs diff=lfs merge=lfs -text
-*.bz2 filter=lfs diff=lfs merge=lfs -text
-*.ckpt filter=lfs diff=lfs merge=lfs -text
-*.ftz filter=lfs diff=lfs merge=lfs -text
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-*.joblib filter=lfs diff=lfs merge=lfs -text
-*.lfs.* filter=lfs diff=lfs merge=lfs -text
-*.mlmodel filter=lfs diff=lfs merge=lfs -text
-*.model filter=lfs diff=lfs merge=lfs -text
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-*.pickle filter=lfs diff=lfs merge=lfs -text
-*.pkl filter=lfs diff=lfs merge=lfs -text
-*.pt filter=lfs diff=lfs merge=lfs -text
-*.pth filter=lfs diff=lfs merge=lfs -text
-*.rar filter=lfs diff=lfs merge=lfs -text
-*.safetensors filter=lfs diff=lfs merge=lfs -text
-saved_model/**/* filter=lfs diff=lfs merge=lfs -text
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-*tfevents* filter=lfs diff=lfs merge=lfs -text
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+assets/i2v_0.mp4 filter=lfs diff=lfs merge=lfs -text

.gitignore

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+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+cover/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+.pybuilder/
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+#   For a library or package, you might want to ignore these files since the code is
+#   intended to run in multiple environments; otherwise, check them in:
+# .python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+#Pipfile.lock
+
+# poetry
+#   Similar to Pipfile.lock, it is generally recommended to include poetry.lock in version control.
+#   This is especially recommended for binary packages to ensure reproducibility, and is more
+#   commonly ignored for libraries.
+#   https://python-poetry.org/docs/basic-usage/#commit-your-poetrylock-file-to-version-control
+#poetry.lock
+
+# pdm
+#   Similar to Pipfile.lock, it is generally recommended to include pdm.lock in version control.
+#pdm.lock
+#   pdm stores project-wide configurations in .pdm.toml, but it is recommended to not include it
+#   in version control.
+#   https://pdm.fming.dev/latest/usage/project/#working-with-version-control
+.pdm.toml
+.pdm-python
+.pdm-build/
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow and github.com/pdm-project/pdm
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pytype static type analyzer
+.pytype/
+
+# Cython debug symbols
+cython_debug/
+
+# PyCharm
+#  JetBrains specific template is maintained in a separate JetBrains.gitignore that can
+#  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
+#  and can be added to the global gitignore or merged into this file.  For a more nuclear
+#  option (not recommended) you can uncomment the following to ignore the entire idea folder.
+.idea/
+
+# From inference.py
+video_output_*.mp4

.pre-commit-config.yaml

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+repos:
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    # Ruff version.
+    rev: v0.2.2
+    hooks:
+      # Run the linter.
+      - id: ruff
+        args: [--fix]  # Automatically fix issues if possible.
+        types: [python]  # Ensure it only runs on .py files.
+
+  - repo: https://github.com/psf/black
+    rev: 24.2.0  # Specify the version of Black you want
+    hooks:
+      - id: black
+        name: Black code formatter
+        language_version: python3  # Use the Python version you're targeting (e.g., 3.10)

README.md

@@ -1,13 +1,82 @@
 ---
-title: LTX Video
-emoji: 🚀
-colorFrom: green
-colorTo: purple
-sdk: gradio
-sdk_version: 5.7.0
-app_file: app.py
-pinned: false
-short_description: Lightricks/LTX-Video on ZeroGPU
+title: LTX-Video-Playground # Replace with your app's title
+emoji: 🚀 # Choose an emoji to represent your app
+colorFrom: blue # Choose a color to start the gradient (e.g., blue, red, green)
+colorTo: purple # Choose a color to end the gradient
+sdk: gradio # Specify the SDK, e.g., gradio or streamlit
+sdk_version: "4.44.1" # Specify the SDK version if needed
+app_file: app.py # Name of your main app file
+pinned: false # Set to true if you want to pin this Space
 ---
 
-Check out the configuration reference at https://huggingface.co/docs/hub/spaces-config-reference
+<div align="center">
+
+# Xora️
+
+</div>
+
+This is the official repository for Xora.
+
+## Table of Contents
+
+- [Introduction](#introduction)
+- [Installation](#installation)
+- [Inference](#inference)
+  - [Inference Code](#inference-code)
+- [Acknowledgement](#acknowledgement)
+
+## Introduction
+
+The performance of Diffusion Transformers is heavily influenced by the number of generated latent pixels (or tokens). In video generation, the token count becomes substantial as the number of frames increases. To address this, we designed a carefully optimized VAE that compresses videos into a smaller number of tokens while utilizing a deeper latent space. This approach enables our model to generate high-quality 768x512 videos at 24 FPS, achieving near real-time speeds.
+
+## Installation
+
+# Setup
+
+The codebase currently uses Python 3.10.5, CUDA version 12.2, and supports PyTorch >= 2.1.2.
+
+```bash
+git clone https://github.com/LightricksResearch/xora-core.git
+cd xora-core
+
+# create env
+python -m venv env
+source env/bin/activate
+python -m pip install -e .\[inference-script\]
+```
+
+Then, download the model from [Hugging Face](https://huggingface.co/Lightricks/Xora)
+
+```python
+from huggingface_hub import snapshot_download
+
+model_path = 'PATH'   # The local directory to save downloaded checkpoint
+snapshot_download("Lightricks/Xora", local_dir=model_path, local_dir_use_symlinks=False, repo_type='model')
+```
+
+## Inference
+
+### Inference Code
+
+To use our model, please follow the inference code in `inference.py` at [https://github.com/LightricksResearch/xora-core/blob/main/inference.py]():
+
+For text-to-video generation:
+
+```bash
+python inference.py --ckpt_dir 'PATH' --prompt "PROMPT" --height HEIGHT --width WIDTH
+```
+
+For image-to-video generation:
+
+```python
+python inference.py --ckpt_dir 'PATH' --prompt "PROMPT" --input_image_path IMAGE_PATH --height HEIGHT --width WIDTH
+
+```
+
+## Acknowledgement
+
+We are grateful for the following awesome projects when implementing Xora:
+
+- [DiT](https://github.com/facebookresearch/DiT) and [PixArt-alpha](https://github.com/PixArt-alpha/PixArt-alpha): vision transformers for image generation.
+
+[//]: # "## Citation"

app.py

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+from functools import lru_cache
+import gradio as gr
+from gradio_toggle import Toggle
+import torch
+from huggingface_hub import snapshot_download
+from transformers import CLIPProcessor, CLIPModel
+
+from xora.models.autoencoders.causal_video_autoencoder import CausalVideoAutoencoder
+from xora.models.transformers.transformer3d import Transformer3DModel
+from xora.models.transformers.symmetric_patchifier import SymmetricPatchifier
+from xora.schedulers.rf import RectifiedFlowScheduler
+from xora.pipelines.pipeline_xora_video import XoraVideoPipeline
+from transformers import T5EncoderModel, T5Tokenizer
+from xora.utils.conditioning_method import ConditioningMethod
+from pathlib import Path
+import safetensors.torch
+import json
+import numpy as np
+import cv2
+from PIL import Image
+import tempfile
+import os
+import gc
+from openai import OpenAI
+import csv
+from datetime import datetime
+
+
+# Load Hugging Face token if needed
+hf_token = os.getenv("HF_TOKEN")
+openai_api_key = os.getenv("OPENAI_API_KEY")
+client = OpenAI(api_key=openai_api_key)
+system_prompt_t2v_path = "assets/system_prompt_t2v.txt"
+system_prompt_i2v_path = "assets/system_prompt_i2v.txt"
+with open(system_prompt_t2v_path, "r") as f:
+    system_prompt_t2v = f.read()
+
+with open(system_prompt_i2v_path, "r") as f:
+    system_prompt_i2v = f.read()
+
+# Set model download directory within Hugging Face Spaces
+model_path = "asset"
+if not os.path.exists(model_path):
+    snapshot_download("Lightricks/LTX-Video", local_dir=model_path, repo_type="model", token=hf_token)
+
+# Global variables to load components
+vae_dir = Path(model_path) / "vae"
+unet_dir = Path(model_path) / "unet"
+scheduler_dir = Path(model_path) / "scheduler"
+
+device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
+
+DATA_DIR = "/data"
+os.makedirs(DATA_DIR, exist_ok=True)
+LOG_FILE_PATH = os.path.join("/data", "user_requests.csv")
+
+clip_model = CLIPModel.from_pretrained("openai/clip-vit-base-patch32", cache_dir=model_path)
+clip_processor = CLIPProcessor.from_pretrained("openai/clip-vit-base-patch32", cache_dir=model_path)
+
+
+if not os.path.exists(LOG_FILE_PATH):
+    with open(LOG_FILE_PATH, "w", newline="") as f:
+        writer = csv.writer(f)
+        writer.writerow(
+            [
+                "timestamp",
+                "request_type",
+                "prompt",
+                "negative_prompt",
+                "height",
+                "width",
+                "num_frames",
+                "frame_rate",
+                "seed",
+                "num_inference_steps",
+                "guidance_scale",
+                "is_enhanced",
+                "clip_embedding",
+                "original_resolution",
+            ]
+        )
+
+
+@lru_cache(maxsize=128)
+def log_request(
+    request_type,
+    prompt,
+    negative_prompt,
+    height,
+    width,
+    num_frames,
+    frame_rate,
+    seed,
+    num_inference_steps,
+    guidance_scale,
+    is_enhanced,
+    clip_embedding=None,
+    original_resolution=None,
+):
+    """Log the user's request to a CSV file."""
+    timestamp = datetime.now().isoformat()
+    with open(LOG_FILE_PATH, "a", newline="") as f:
+        try:
+            writer = csv.writer(f)
+            writer.writerow(
+                [
+                    timestamp,
+                    request_type,
+                    prompt,
+                    negative_prompt,
+                    height,
+                    width,
+                    num_frames,
+                    frame_rate,
+                    seed,
+                    num_inference_steps,
+                    guidance_scale,
+                    is_enhanced,
+                    clip_embedding,
+                    original_resolution,
+                ]
+            )
+        except Exception as e:
+            print(f"Error logging request: {e}")
+
+
+def compute_clip_embedding(text=None, image=None):
+    """
+    Compute CLIP embedding for a given text or image.
+    Args:
+        text (str): Input text prompt.
+        image (PIL.Image): Input image.
+    Returns:
+        list: CLIP embedding as a list of floats.
+    """
+    inputs = clip_processor(text=text, images=image, return_tensors="pt", padding=True)
+    outputs = clip_model.get_text_features(**inputs) if text else clip_model.get_image_features(**inputs)
+    embedding = outputs.detach().cpu().numpy().flatten().tolist()
+    return embedding
+
+
+def load_vae(vae_dir):
+    vae_ckpt_path = vae_dir / "vae_diffusion_pytorch_model.safetensors"
+    vae_config_path = vae_dir / "config.json"
+    with open(vae_config_path, "r") as f:
+        vae_config = json.load(f)
+    vae = CausalVideoAutoencoder.from_config(vae_config)
+    vae_state_dict = safetensors.torch.load_file(vae_ckpt_path)
+    vae.load_state_dict(vae_state_dict)
+    return vae.to(device=device, dtype=torch.bfloat16)
+
+
+def load_unet(unet_dir):
+    unet_ckpt_path = unet_dir / "unet_diffusion_pytorch_model.safetensors"
+    unet_config_path = unet_dir / "config.json"
+    transformer_config = Transformer3DModel.load_config(unet_config_path)
+    transformer = Transformer3DModel.from_config(transformer_config)
+    unet_state_dict = safetensors.torch.load_file(unet_ckpt_path)
+    transformer.load_state_dict(unet_state_dict, strict=True)
+    return transformer.to(device=device, dtype=torch.bfloat16)
+
+
+def load_scheduler(scheduler_dir):
+    scheduler_config_path = scheduler_dir / "scheduler_config.json"
+    scheduler_config = RectifiedFlowScheduler.load_config(scheduler_config_path)
+    return RectifiedFlowScheduler.from_config(scheduler_config)
+
+
+# Helper function for image processing
+def center_crop_and_resize(frame, target_height, target_width):
+    h, w, _ = frame.shape
+    aspect_ratio_target = target_width / target_height
+    aspect_ratio_frame = w / h
+    if aspect_ratio_frame > aspect_ratio_target:
+        new_width = int(h * aspect_ratio_target)
+        x_start = (w - new_width) // 2
+        frame_cropped = frame[:, x_start : x_start + new_width]
+    else:
+        new_height = int(w / aspect_ratio_target)
+        y_start = (h - new_height) // 2
+        frame_cropped = frame[y_start : y_start + new_height, :]
+    frame_resized = cv2.resize(frame_cropped, (target_width, target_height))
+    return frame_resized
+
+
+def load_image_to_tensor_with_resize(image_path, target_height=512, target_width=768):
+    image = Image.open(image_path).convert("RGB")
+    image_np = np.array(image)
+    frame_resized = center_crop_and_resize(image_np, target_height, target_width)
+    frame_tensor = torch.tensor(frame_resized).permute(2, 0, 1).float()
+    frame_tensor = (frame_tensor / 127.5) - 1.0
+    return frame_tensor.unsqueeze(0).unsqueeze(2)
+
+
+def enhance_prompt_if_enabled(prompt, enhance_toggle, type="t2v"):
+    if not enhance_toggle:
+        print("Enhance toggle is off, Prompt: ", prompt)
+        return prompt
+
+    system_prompt = system_prompt_t2v if type == "t2v" else system_prompt_i2v
+    messages = [
+        {"role": "system", "content": system_prompt},
+        {"role": "user", "content": prompt},
+    ]
+
+    try:
+        response = client.chat.completions.create(
+            model="gpt-4o-mini",
+            messages=messages,
+            max_tokens=200,
+        )
+        print("Enhanced Prompt: ", response.choices[0].message.content.strip())
+        return response.choices[0].message.content.strip()
+    except Exception as e:
+        print(f"Error: {e}")
+        return prompt
+
+
+# Preset options for resolution and frame configuration
+preset_options = [
+    {"label": "1216x704, 41 frames", "width": 1216, "height": 704, "num_frames": 41},
+    {"label": "1088x704, 49 frames", "width": 1088, "height": 704, "num_frames": 49},
+    {"label": "1056x640, 57 frames", "width": 1056, "height": 640, "num_frames": 57},
+    {"label": "992x608, 65 frames", "width": 992, "height": 608, "num_frames": 65},
+    {"label": "896x608, 73 frames", "width": 896, "height": 608, "num_frames": 73},
+    {"label": "896x544, 81 frames", "width": 896, "height": 544, "num_frames": 81},
+    {"label": "832x544, 89 frames", "width": 832, "height": 544, "num_frames": 89},
+    {"label": "800x512, 97 frames", "width": 800, "height": 512, "num_frames": 97},
+    {"label": "768x512, 97 frames", "width": 768, "height": 512, "num_frames": 97},
+    {"label": "800x480, 105 frames", "width": 800, "height": 480, "num_frames": 105},
+    {"label": "736x480, 113 frames", "width": 736, "height": 480, "num_frames": 113},
+    {"label": "704x480, 121 frames", "width": 704, "height": 480, "num_frames": 121},
+    {"label": "704x448, 129 frames", "width": 704, "height": 448, "num_frames": 129},
+    {"label": "672x448, 137 frames", "width": 672, "height": 448, "num_frames": 137},
+    {"label": "640x416, 153 frames", "width": 640, "height": 416, "num_frames": 153},
+    {"label": "672x384, 161 frames", "width": 672, "height": 384, "num_frames": 161},
+    {"label": "640x384, 169 frames", "width": 640, "height": 384, "num_frames": 169},
+    {"label": "608x384, 177 frames", "width": 608, "height": 384, "num_frames": 177},
+    {"label": "576x384, 185 frames", "width": 576, "height": 384, "num_frames": 185},
+    {"label": "608x352, 193 frames", "width": 608, "height": 352, "num_frames": 193},
+    {"label": "576x352, 201 frames", "width": 576, "height": 352, "num_frames": 201},
+    {"label": "544x352, 209 frames", "width": 544, "height": 352, "num_frames": 209},
+    {"label": "512x352, 225 frames", "width": 512, "height": 352, "num_frames": 225},
+    {"label": "512x352, 233 frames", "width": 512, "height": 352, "num_frames": 233},
+    {"label": "544x320, 241 frames", "width": 544, "height": 320, "num_frames": 241},
+    {"label": "512x320, 249 frames", "width": 512, "height": 320, "num_frames": 249},
+    {"label": "512x320, 257 frames", "width": 512, "height": 320, "num_frames": 257},
+]
+
+
+# Function to toggle visibility of sliders based on preset selection
+def preset_changed(preset):
+    if preset != "Custom":
+        selected = next(item for item in preset_options if item["label"] == preset)
+        return (
+            selected["height"],
+            selected["width"],
+            selected["num_frames"],
+            gr.update(visible=False),
+            gr.update(visible=False),
+            gr.update(visible=False),
+        )
+    else:
+        return (
+            None,
+            None,
+            None,
+            gr.update(visible=True),
+            gr.update(visible=True),
+            gr.update(visible=True),
+        )
+
+
+# Load models
+vae = load_vae(vae_dir)
+unet = load_unet(unet_dir)
+scheduler = load_scheduler(scheduler_dir)
+patchifier = SymmetricPatchifier(patch_size=1)
+text_encoder = T5EncoderModel.from_pretrained("PixArt-alpha/PixArt-XL-2-1024-MS", subfolder="text_encoder").to(device)
+tokenizer = T5Tokenizer.from_pretrained("PixArt-alpha/PixArt-XL-2-1024-MS", subfolder="tokenizer")
+
+pipeline = XoraVideoPipeline(
+    transformer=unet,
+    patchifier=patchifier,
+    text_encoder=text_encoder,
+    tokenizer=tokenizer,
+    scheduler=scheduler,
+    vae=vae,
+).to(device)
+
+
+def generate_video_from_text(
+    prompt="",
+    enhance_prompt_toggle=False,
+    txt2vid_analytics_toggle=True,
+    negative_prompt="",
+    frame_rate=25,
+    seed=646373,
+    num_inference_steps=30,
+    guidance_scale=3,
+    height=512,
+    width=768,
+    num_frames=121,
+    progress=gr.Progress(),
+):
+    if len(prompt.strip()) < 50:
+        raise gr.Error(
+            "Prompt must be at least 50 characters long. Please provide more details for the best results.",
+            duration=5,
+        )
+
+    if txt2vid_analytics_toggle:
+        log_request(
+            "txt2vid",
+            prompt,
+            negative_prompt,
+            height,
+            width,
+            num_frames,
+            frame_rate,
+            seed,
+            num_inference_steps,
+            guidance_scale,
+            enhance_prompt_toggle,
+        )
+
+    prompt = enhance_prompt_if_enabled(prompt, enhance_prompt_toggle, type="t2v")
+
+    sample = {
+        "prompt": prompt,
+        "prompt_attention_mask": None,
+        "negative_prompt": negative_prompt,
+        "negative_prompt_attention_mask": None,
+        "media_items": None,
+    }
+
+    generator = torch.Generator(device="cpu").manual_seed(seed)
+
+    def gradio_progress_callback(self, step, timestep, kwargs):
+        progress((step + 1) / num_inference_steps)
+
+    try:
+        with torch.no_grad():
+            images = pipeline(
+                num_inference_steps=num_inference_steps,
+                num_images_per_prompt=1,
+                guidance_scale=guidance_scale,
+                generator=generator,
+                output_type="pt",
+                height=height,
+                width=width,
+                num_frames=num_frames,
+                frame_rate=frame_rate,
+                **sample,
+                is_video=True,
+                vae_per_channel_normalize=True,
+                conditioning_method=ConditioningMethod.UNCONDITIONAL,
+                mixed_precision=True,
+                callback_on_step_end=gradio_progress_callback,
+            ).images
+    except Exception as e:
+        raise gr.Error(
+            f"An error occurred while generating the video. Please try again. Error: {e}",
+            duration=5,
+        )
+    finally:
+        torch.cuda.empty_cache()
+        gc.collect()
+
+    output_path = tempfile.mktemp(suffix=".mp4")
+    print(images.shape)
+    video_np = images.squeeze(0).permute(1, 2, 3, 0).cpu().float().numpy()
+    video_np = (video_np * 255).astype(np.uint8)
+    height, width = video_np.shape[1:3]
+    out = cv2.VideoWriter(output_path, cv2.VideoWriter_fourcc(*"mp4v"), frame_rate, (width, height))
+    for frame in video_np[..., ::-1]:
+        out.write(frame)
+    out.release()
+    # Explicitly delete tensors and clear cache
+    del images
+    del video_np
+    torch.cuda.empty_cache()
+    return output_path
+
+
+def generate_video_from_image(
+    image_path,
+    prompt="",
+    enhance_prompt_toggle=False,
+    img2vid_analytics_toggle=True,
+    negative_prompt="",
+    frame_rate=25,
+    seed=646373,
+    num_inference_steps=30,
+    guidance_scale=3,
+    height=512,
+    width=768,
+    num_frames=121,
+    progress=gr.Progress(),
+):
+
+    print("Height: ", height)
+    print("Width: ", width)
+    print("Num Frames: ", num_frames)
+
+    if len(prompt.strip()) < 50:
+        raise gr.Error(
+            "Prompt must be at least 50 characters long. Please provide more details for the best results.",
+            duration=5,
+        )
+
+    if not image_path:
+        raise gr.Error("Please provide an input image.", duration=5)
+
+    if img2vid_analytics_toggle:
+        with Image.open(image_path) as img:
+            original_resolution = f"{img.width}x{img.height}"  # Format as "widthxheight"
+            clip_embedding = compute_clip_embedding(image=img)
+
+        log_request(
+            "img2vid",
+            prompt,
+            negative_prompt,
+            height,
+            width,
+            num_frames,
+            frame_rate,
+            seed,
+            num_inference_steps,
+            guidance_scale,
+            enhance_prompt_toggle,
+            json.dumps(clip_embedding),
+            original_resolution,
+        )
+
+    media_items = load_image_to_tensor_with_resize(image_path, height, width).to(device).detach()
+
+    prompt = enhance_prompt_if_enabled(prompt, enhance_prompt_toggle, type="i2v")
+
+    sample = {
+        "prompt": prompt,
+        "prompt_attention_mask": None,
+        "negative_prompt": negative_prompt,
+        "negative_prompt_attention_mask": None,
+        "media_items": media_items,
+    }
+
+    generator = torch.Generator(device="cpu").manual_seed(seed)
+
+    def gradio_progress_callback(self, step, timestep, kwargs):
+        progress((step + 1) / num_inference_steps)
+
+    try:
+        with torch.no_grad():
+            images = pipeline(
+                num_inference_steps=num_inference_steps,
+                num_images_per_prompt=1,
+                guidance_scale=guidance_scale,
+                generator=generator,
+                output_type="pt",
+                height=height,
+                width=width,
+                num_frames=num_frames,
+                frame_rate=frame_rate,
+                **sample,
+                is_video=True,
+                vae_per_channel_normalize=True,
+                conditioning_method=ConditioningMethod.FIRST_FRAME,
+                mixed_precision=True,
+                callback_on_step_end=gradio_progress_callback,
+            ).images
+
+        output_path = tempfile.mktemp(suffix=".mp4")
+        video_np = images.squeeze(0).permute(1, 2, 3, 0).cpu().float().numpy()
+        video_np = (video_np * 255).astype(np.uint8)
+        height, width = video_np.shape[1:3]
+        out = cv2.VideoWriter(output_path, cv2.VideoWriter_fourcc(*"mp4v"), frame_rate, (width, height))
+        for frame in video_np[..., ::-1]:
+            out.write(frame)
+        out.release()
+    except Exception as e:
+        raise gr.Error(
+            f"An error occurred while generating the video. Please try again. Error: {e}",
+            duration=5,
+        )
+
+    finally:
+        torch.cuda.empty_cache()
+        gc.collect()
+
+    return output_path
+
+
+def create_advanced_options():
+    with gr.Accordion("Step 4: Advanced Options (Optional)", open=False):
+        seed = gr.Slider(label="4.1 Seed", minimum=0, maximum=1000000, step=1, value=646373)
+        inference_steps = gr.Slider(label="4.2 Inference Steps", minimum=1, maximum=50, step=1, value=30)
+        guidance_scale = gr.Slider(label="4.3 Guidance Scale", minimum=1.0, maximum=5.0, step=0.1, value=3.0)
+
+        height_slider = gr.Slider(
+            label="4.4 Height",
+            minimum=256,
+            maximum=1024,
+            step=64,
+            value=512,
+            visible=False,
+        )
+        width_slider = gr.Slider(
+            label="4.5 Width",
+            minimum=256,
+            maximum=1024,
+            step=64,
+            value=768,
+            visible=False,
+        )
+        num_frames_slider = gr.Slider(
+            label="4.5 Number of Frames",
+            minimum=1,
+            maximum=200,
+            step=1,
+            value=121,
+            visible=False,
+        )
+
+        return [
+            seed,
+            inference_steps,
+            guidance_scale,
+            height_slider,
+            width_slider,
+            num_frames_slider,
+        ]
+
+
+# Define the Gradio interface with tabs
+with gr.Blocks(theme=gr.themes.Soft()) as iface:
+    with gr.Row(elem_id="title-row"):
+        gr.Markdown(
+            """
+        <div style="text-align: center; margin-bottom: 1em">
+            <h1 style="font-size: 2.5em; font-weight: 600; margin: 0.5em 0;">Video Generation with LTX Video</h1>
+        </div>
+        """
+        )
+    with gr.Row(elem_id="title-row"):
+        gr.HTML(  # add technical report link
+            """
+        <div style="display:flex;column-gap:4px;">
+            <a href="https://github.com/Lightricks/LTX-Video">
+                <img src='https://img.shields.io/badge/GitHub-Repo-blue'>
+            </a>
+            <a href="https://github.com/Lightricks/ComfyUI-LTXVideo">
+                <img src='https://img.shields.io/badge/GitHub-ComfyUI-blue'>
+            </a>
+            <a href="http://www.lightricks.com/ltxv">
+                <img src="https://img.shields.io/badge/Project-Page-green" alt="Follow me on HF">
+            </a>
+            <a href="https://huggingface.co/spaces/Lightricks/LTX-Video-Playground?duplicate=true">
+                <img src="https://huggingface.co/datasets/huggingface/badges/resolve/main/duplicate-this-space-sm.svg" alt="Duplicate this Space">
+            </a>
+            <a href="https://huggingface.co/Lightricks">
+                <img src="https://huggingface.co/datasets/huggingface/badges/resolve/main/follow-me-on-HF-sm-dark.svg" alt="Follow me on HF">
+            </a>
+        </div>
+        """
+        )
+    with gr.Accordion(" 📖 Tips for Best Results", open=False, elem_id="instructions-accordion"):
+        gr.Markdown(
+            """
+        📝 Prompt Engineering
+
+        When writing prompts, focus on detailed, chronological descriptions of actions and scenes. Include specific movements, appearances, camera angles, and environmental details - all in a single flowing paragraph. Start directly with the action, and keep descriptions literal and precise. Think like a cinematographer describing a shot list. Keep within 200 words.
+        For best results, build your prompts using this structure:
+
+        - Start with main action in a single sentence
+        - Add specific details about movements and gestures
+        - Describe character/object appearances precisely
+        - Include background and environment details
+        - Specify camera angles and movements
+        - Describe lighting and colors
+        - Note any changes or sudden events
+
+        See examples for more inspiration.
+
+        🎮 Parameter Guide
+
+        - Resolution Preset: Higher resolutions for detailed scenes, lower for faster generation and simpler scenes
+        - Seed: Save seed values to recreate specific styles or compositions you like
+        - Guidance Scale: 3-3.5 are the recommended values
+        - Inference Steps: More steps (40+) for quality, fewer steps (20-30) for speed
+        """
+        )
+
+    with gr.Tabs():
+        # Text to Video Tab
+        with gr.TabItem("Text to Video"):
+            with gr.Row():
+                with gr.Column():
+                    txt2vid_prompt = gr.Textbox(
+                        label="Step 1: Enter Your Prompt",
+                        placeholder="Describe the video you want to generate (minimum 50 characters)...",
+                        value="A woman with long brown hair and light skin smiles at another woman with long blonde hair. The woman with brown hair wears a black jacket and has a small, barely noticeable mole on her right cheek. The camera angle is a close-up, focused on the woman with brown hair's face. The lighting is warm and natural, likely from the setting sun, casting a soft glow on the scene. The scene appears to be real-life footage.",
+                        lines=5,
+                    )
+                    txt2vid_analytics_toggle = Toggle(
+                        label="I agree to share my usage data anonymously to help improve the model features.",
+                        value=True,
+                        interactive=True,
+                    )
+
+                    txt2vid_enhance_toggle = Toggle(
+                        label="Enhance Prompt",
+                        value=False,
+                        interactive=True,
+                    )
+
+                    txt2vid_negative_prompt = gr.Textbox(
+                        label="Step 2: Enter Negative Prompt",
+                        placeholder="Describe what you don't want in the video...",
+                        value="low quality, worst quality, deformed, distorted, disfigured, motion smear, motion artifacts, fused fingers, bad anatomy, weird hand, ugly",
+                        lines=2,
+                    )
+
+                    txt2vid_preset = gr.Dropdown(
+                        choices=[p["label"] for p in preset_options],
+                        value="768x512, 97 frames",
+                        label="Step 3.1: Choose Resolution Preset",
+                    )
+
+                    txt2vid_frame_rate = gr.Slider(
+                        label="Step 3.2: Frame Rate",
+                        minimum=21,
+                        maximum=30,
+                        step=1,
+                        value=25,
+                    )
+
+                    txt2vid_advanced = create_advanced_options()
+                    txt2vid_generate = gr.Button(
+                        "Step 5: Generate Video",
+                        variant="primary",
+                        size="lg",
+                    )
+
+                with gr.Column():
+                    txt2vid_output = gr.Video(label="Generated Output")
+
+            with gr.Row():
+                gr.Examples(
+                    examples=[
+                        [
+                            "A young woman in a traditional Mongolian dress is peeking through a sheer white curtain, her face showing a mix of curiosity and apprehension. The woman has long black hair styled in two braids, adorned with white beads, and her eyes are wide with a hint of surprise. Her dress is a vibrant blue with intricate gold embroidery, and she wears a matching headband with a similar design. The background is a simple white curtain, which creates a sense of mystery and intrigue.ith long brown hair and light skin smiles at another woman with long blonde hair. The woman with brown hair wears a black jacket and has a small, barely noticeable mole on her right cheek. The camera angle is a close-up, focused on the woman with brown hair’s face. The lighting is warm and natural, likely from the setting sun, casting a soft glow on the scene. The scene appears to be real-life footage",
+                            "low quality, worst quality, deformed, distorted, disfigured, motion smear, motion artifacts, fused fingers, bad anatomy, weird hand, ugly",
+                            "assets/t2v_2.mp4",
+                        ],
+                        [
+                            "A young man with blond hair wearing a yellow jacket stands in a forest and looks around. He has light skin and his hair is styled with a middle part. He looks to the left and then to the right, his gaze lingering in each direction. The camera angle is low, looking up at the man, and remains stationary throughout the video. The background is slightly out of focus, with green trees and the sun shining brightly behind the man. The lighting is natural and warm, with the sun creating a lens flare that moves across the man’s face. The scene is captured in real-life footage.",
+                            "low quality, worst quality, deformed, distorted, disfigured, motion smear, motion artifacts, fused fingers, bad anatomy, weird hand, ugly",
+                            "assets/t2v_1.mp4",
+                        ],
+                        [
+                            "A cyclist races along a winding mountain road. Clad in aerodynamic gear, he pedals intensely, sweat glistening on his brow. The camera alternates between close-ups of his determined expression and wide shots of the breathtaking landscape. Pine trees blur past, and the sky is a crisp blue. The scene is invigorating and competitive.",
+                            "low quality, worst quality, deformed, distorted, disfigured, motion smear, motion artifacts, fused fingers, bad anatomy, weird hand, ugly",
+                            "assets/t2v_0.mp4",
+                        ],
+                    ],
+                    inputs=[txt2vid_prompt, txt2vid_negative_prompt, txt2vid_output],
+                    label="Example Text-to-Video Generations",
+                )
+
+        # Image to Video Tab
+        with gr.TabItem("Image to Video"):
+            with gr.Row():
+                with gr.Column():
+                    img2vid_image = gr.Image(
+                        type="filepath",
+                        label="Step 1: Upload Input Image",
+                        elem_id="image_upload",
+                    )
+                    img2vid_prompt = gr.Textbox(
+                        label="Step 2: Enter Your Prompt",
+                        placeholder="Describe how you want to animate the image (minimum 50 characters)...",
+                        value="A woman with long brown hair and light skin smiles at another woman with long blonde hair. The woman with brown hair wears a black jacket and has a small, barely noticeable mole on her right cheek. The camera angle is a close-up, focused on the woman with brown hair's face. The lighting is warm and natural, likely from the setting sun, casting a soft glow on the scene. The scene appears to be real-life footage.",
+                        lines=5,
+                    )
+                    img2vid_analytics_toggle = Toggle(
+                        label="I agree to share my usage data anonymously to help improve the model features.",
+                        value=True,
+                        interactive=True,
+                    )
+                    img2vid_enhance_toggle = Toggle(
+                        label="Enhance Prompt",
+                        value=False,
+                        interactive=True,
+                    )
+                    img2vid_negative_prompt = gr.Textbox(
+                        label="Step 3: Enter Negative Prompt",
+                        placeholder="Describe what you don't want in the video...",
+                        value="low quality, worst quality, deformed, distorted, disfigured, motion smear, motion artifacts, fused fingers, bad anatomy, weird hand, ugly",
+                        lines=2,
+                    )
+
+                    img2vid_preset = gr.Dropdown(
+                        choices=[p["label"] for p in preset_options],
+                        value="768x512, 97 frames",
+                        label="Step 3.1: Choose Resolution Preset",
+                    )
+
+                    img2vid_frame_rate = gr.Slider(
+                        label="Step 3.2: Frame Rate",
+                        minimum=21,
+                        maximum=30,
+                        step=1,
+                        value=25,
+                    )
+
+                    img2vid_advanced = create_advanced_options()
+                    img2vid_generate = gr.Button("Step 6: Generate Video", variant="primary", size="lg")
+
+                with gr.Column():
+                    img2vid_output = gr.Video(label="Generated Output")
+
+            with gr.Row():
+                gr.Examples(
+                    examples=[
+                        [
+                            "assets/i2v_i2.png",
+                            "A woman stirs a pot of boiling water on a white electric burner. Her hands, with purple nail polish, hold a wooden spoon and move it in a circular motion within a white pot filled with bubbling water. The pot sits on a white electric burner with black buttons and a digital display. The burner is positioned on a white countertop with a red and white checkered cloth partially visible in the bottom right corner. The camera angle is a direct overhead shot, remaining stationary throughout the scene. The lighting is bright and even, illuminating the scene with a neutral white light. The scene is real-life footage.",
+                            "low quality, worst quality, deformed, distorted, disfigured, motion smear, motion artifacts, fused fingers, bad anatomy, weird hand, ugly",
+                            "assets/i2v_2.mp4",
+                        ],
+                        [
+                            "assets/i2v_i0.png",
+                            "A woman in a long, flowing dress stands in a field, her back to the camera, gazing towards the horizon; her hair is long and light, cascading down her back; she stands beneath the sprawling branches of a large oak tree;  to her left, a classic American car is parked on the dry grass; in the distance, a wrecked car lies on its side; the sky above is a dramatic canvas of bright white clouds against a darker sky; the entire image is in black and white, emphasizing the contrast of light and shadow. The woman is walking slowly towards the car.",
+                            "low quality, worst quality, deformed, distorted, disfigured, motion smear, motion artifacts, fused fingers, bad anatomy, weird hand, ugly",
+                            "assets/i2v_0.mp4",
+                        ],
+                        [
+                            "assets/i2v_i1.png",
+                            "A pair of hands shapes a piece of clay on a pottery wheel, gradually forming a cone shape. The hands, belonging to a person out of frame, are covered in clay and gently press a ball of clay onto the center of a spinning pottery wheel. The hands move in a circular motion, gradually forming a cone shape at the top of the clay. The camera is positioned directly above the pottery wheel, providing a bird’s-eye view of the clay being shaped. The lighting is bright and even, illuminating the clay and the hands working on it. The scene is captured in real-life footage.",
+                            "low quality, worst quality, deformed, distorted, disfigured, motion smear, motion artifacts, fused fingers, bad anatomy, weird hand, ugly",
+                            "assets/i2v_1.mp4",
+                        ],
+                    ],
+                    inputs=[
+                        img2vid_image,
+                        img2vid_prompt,
+                        img2vid_negative_prompt,
+                        img2vid_output,
+                    ],
+                    label="Example Image-to-Video Generations",
+                )
+
+    # [Previous event handlers remain the same]
+    txt2vid_preset.change(fn=preset_changed, inputs=[txt2vid_preset], outputs=txt2vid_advanced[3:])
+
+    txt2vid_generate.click(
+        fn=generate_video_from_text,
+        inputs=[
+            txt2vid_prompt,
+            txt2vid_enhance_toggle,
+            txt2vid_analytics_toggle,
+            txt2vid_negative_prompt,
+            txt2vid_frame_rate,
+            *txt2vid_advanced,
+        ],
+        outputs=txt2vid_output,
+        concurrency_limit=1,
+        concurrency_id="generate_video",
+        queue=True,
+    )
+
+    img2vid_preset.change(fn=preset_changed, inputs=[img2vid_preset], outputs=img2vid_advanced[3:])
+
+    img2vid_generate.click(
+        fn=generate_video_from_image,
+        inputs=[
+            img2vid_image,
+            img2vid_prompt,
+            img2vid_enhance_toggle,
+            img2vid_analytics_toggle,
+            img2vid_negative_prompt,
+            img2vid_frame_rate,
+            *img2vid_advanced,
+        ],
+        outputs=img2vid_output,
+        concurrency_limit=1,
+        concurrency_id="generate_video",
+        queue=True,
+    )
+
+if __name__ == "__main__":
+    iface.queue(max_size=64, default_concurrency_limit=1, api_open=False).launch(share=True, show_api=False)

assets/i2v_0.mp4

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2367ae7cebe5f99f2f446deff3733f036ccc8e08241b8c55725ab418d41c6f31
+size 1324635

assets/system_prompt_i2v.txt

@@ -0,0 +1,38 @@
+You will receive prompts and a first frame image used for generating AI Videos. Your goal is to enhance the prompt such that it will be similar to the video captions used during training.
+Instructions for Generating Video Descriptions:
+    0.  Do not contradict the first frame image.
+	1.	Begin with a concise, single-paragraph description of the scene, focusing on the key actions in sequence.
+	2.	Include detailed movements of characters and objects, focusing on precise, observable actions.
+	3.	Briefly describe the appearance of characters and objects, emphasizing key visual features relevant to the scene.
+	4.	Provide essential background details to set the context, highlighting elements that enhance the atmosphere without overloading the description.
+	5.	Mention the camera angles and movements that define the visual style of the scene, keeping it succinct.
+	6.	Specify the lighting and colors to establish the tone, ensuring they complement the action and setting.
+	7.	Ensure the description reflects the source type, such as real-life footage or animation, in a clear and natural manner.
+
+Here are some examples to real captions that represent good prompts:
+- A woman walks away from a white Jeep parked on a city street at night...
+A woman walks away from a white Jeep parked on a city street at night, then ascends a staircase and knocks on a door. The woman, wearing a dark jacket and jeans, walks away from the Jeep parked on the left side of the street, her back to the camera; she walks at a steady pace, her arms swinging slightly by her sides; the street is dimly lit, with streetlights casting pools of light on the wet pavement; a man in a dark jacket and jeans walks past the Jeep in the opposite direction; the camera follows the woman from behind as she walks up a set of stairs towards a building with a green door; she reaches the top of the stairs and turns left, continuing to walk towards the building; she reaches the door and knocks on it with her right hand; the camera remains stationary, focused on the doorway; the scene is captured in real-life footage.
+- A woman with long brown hair and light skin smiles at another woman...
+A woman with long brown hair and light skin smiles at another woman with long blonde hair. The woman with brown hair wears a black jacket and has a small, barely noticeable mole on her right cheek. The camera angle is a close-up, focused on the woman with brown hair's face. The lighting is warm and natural, likely from the setting sun, casting a soft glow on the scene. The scene appears to be real-life footage.
+- A man in a suit enters a room and speaks to two women...
+A man in a suit enters a room and speaks to two women sitting on a couch. The man, wearing a dark suit with a gold tie, enters the room from the left and walks towards the center of the frame. He has short gray hair, light skin, and a serious expression. He places his right hand on the back of a chair as he approaches the couch. Two women are seated on a light-colored couch in the background. The woman on the left wears a light blue sweater and has short blonde hair. The woman on the right wears a white sweater and has short blonde hair. The camera remains stationary, focusing on the man as he enters the room. The room is brightly lit, with warm tones reflecting off the walls and furniture. The scene appears to be from a film or television show.
+- The camera pans across a cityscape of tall buildings...
+The camera pans across a cityscape of tall buildings with a circular building in the center. The camera moves from left to right, showing the tops of the buildings and the circular building in the center. The buildings are various shades of gray and white, and the circular building has a green roof. The camera angle is high, looking down at the city. The lighting is bright, with the sun shining from the upper left, casting shadows from the buildings. The scene is computer-generated imagery.
+- A young man with short blond hair and light skin, wearing a red and gold patterned jacket, looks down and to his right, then back up as he speaks to a woman with long red hair and light skin, wearing a red dress with gold embroidery; she stands slightly behind him to his left, her expression serious; they are in a dimly lit room with stone walls and several other people in the background, some holding torches; the camera remains stationary on the man's face, then briefly pans to the woman before returning to the man; the scene is captured in real-life footage.
+- A person is driving a car on a two-lane road, holding the steering wheel with both hands. The person's hands are light-skinned and they are wearing a black long-sleeved shirt. The steering wheel has a Toyota logo in the center and black leather around it. The car's dashboard is visible, showing a speedometer, tachometer, and navigation screen. The road ahead is straight and there are trees and fields visible on either side. The camera is positioned inside the car, providing a view from the driver's perspective. The lighting is natural and overcast, with a slightly cool tone. The scene is captured in real-life footage.
+- A bald man with a goatee, wearing a green and yellow robe, stands on a beach with two women, one with long blonde hair in braids wearing a blue dress and the other with long dark hair wearing a brown dress. The man turns his head slightly to the left, looking off-screen, while the blonde woman looks down with a serious expression. The camera remains stationary, capturing the three figures from the chest up. The background features a bright blue sky, a sandy beach, and a rocky outcropping. The scene is brightly lit, likely by sunlight, casting soft shadows on the characters' faces. The scene appears to be from a movie or TV show.
+- A bumblebee is perched on a cluster of pink flowers, sipping nectar. The bee is mostly black with yellow stripes on its abdomen and has translucent wings. The flowers are a light pink color and have five petals each. They are growing on a green stem with several leaves. The background is blurry, but it appears to be a sunny day.
+- A pair of hands shapes a piece of clay on a pottery wheel, gradually forming a cone shape. The hands, belonging to a person out of frame, are covered in clay and gently press a ball of clay onto the center of a spinning pottery wheel. The hands move in a circular motion, gradually forming a cone shape at the top of the clay. The camera is positioned directly above the pottery wheel, providing a bird's-eye view of the clay being shaped. The lighting is bright and even, illuminating the clay and the hands working on it. The scene is captured in real-life footage.
+- A young woman with long, wavy red hair is sitting in a white bathtub, leaning over the edge and reaching for the faucet to turn on the water.
+She has a serene expression on her face and her eyes are closed. Her skin is pale and her lips are slightly parted. She is wearing a white towel wrapped around her body. The bathtub is large and round, with a white porcelain finish. It is set in a bathroom with white walls and a large window. The window is covered by a white curtain, which is partially drawn back to let in some natural light.
+- An elephant walks towards the camera, stops, and lowers its head to eat some grass. The elephant is gray and has large white tusks. The elephant is walking on a grassy field. There are some trees and bushes in the background. The camera is stationary.
+- A man in a dimly lit room raises a glass to his lips and drinks. He wears a dark green tunic with a brown belt and has shoulder-length dark brown hair and a beard. He raises the glass in his right hand and drinks from it, then lowers it slightly while continuing to look straight ahead. The camera remains stationary, focused on the man from the waist up. The room is lit by a single candle on a stand to the left, casting warm light on the man's face and the surrounding area. The scene appears to be from a movie or TV show.
+- The squirrel has gray and brown fur and a bushy tail. Its eyes are black and shiny. The squirrel is sitting on a gray brick patio with small pebbles scattered around. There is a white plastic container next to the squirrel.
+- A young man with blond hair wearing a yellow jacket stands in a forest and looks around. He has light skin and his hair is styled with a middle part. He looks to the left and then to the right, his gaze lingering in each direction. The camera angle is low, looking up at the man, and remains stationary throughout the video. The background is slightly out of focus, with green trees and the sun shining brightly behind the man. The lighting is natural and warm, with the sun creating a lens flare that moves across the man's face. The scene is captured in real-life footage.
+- A woman with blonde hair styled up, wearing a black dress with sequins and pearl earrings, looks down with a sad expression on her face. The camera remains stationary, focused on the woman's face. The lighting is dim, casting soft shadows on her face. The scene appears to be from a movie or TV show.
+- A young woman with dark, curly hair and pale skin sits on a chair, her expression serious as she looks down and to the right; she wears a dark, intricately patterned dress with a high collar and long, dark gloves that extend past her elbows; a man with dark, curly hair and a pale face stands behind her to the left, his expression unreadable; he wears a dark vest over a white shirt and dark pants; the camera remains stationary, focused on the woman's face; the scene is dimly lit, with light streaming in from a large window behind the characters; the scene appears to be from a movie.
+- A herd of elephants walks from right to left across a dry, grassy plain. The elephants, with their gray skin and large ears, move at a steady pace, their trunks occasionally reaching down to graze on the sparse vegetation; one elephant in the foreground, slightly larger than the others, leads the charge, its head held high and ears spread wide; the camera remains stationary, capturing the elephants from a side angle as they move across the frame; the sun casts a bright light, creating sharp shadows on the ground and highlighting the texture of the elephants' skin; the scene is captured in real-life footage.
+- A man walks towards an oil derrick in a snowy field, stops to observe the flames, and then bends down to examine the ground. Wearing a beige jacket, dark pants, and a dark hat, the man walks from left to right across the snowy field towards a tall metal oil derrick with flames erupting from its top; he stops a few feet from the derrick and looks up at the flames; he then bends down, keeping his back to the camera, and examines the ground; the camera remains stationary throughout the scene, capturing a wide shot of the man, the derrick, and the snowy field; the sky is overcast, and the lighting is dim and natural; the scene is captured in real-life footage.
+- A man with short blond hair, wearing a white V-neck shirt and a dark gray jacket, stands in a parking lot, talking to another man whose back is to the camera; he has light skin and a neutral expression; the other man wears a light gray shirt; a dark-colored car is parked behind them; the camera remains stationary on the two men; the scene is brightly lit, with sunlight illuminating the parking lot; the scene appears to be real-life footage.
+- Two police officers in dark blue uniforms and matching hats enter a dimly lit room through a doorway on the left side of the frame. The first officer, with short brown hair and a mustache, steps inside first, followed by his partner, who has a shaved head and a goatee. Both officers have serious expressions and maintain a steady pace as they move deeper into the room. The camera remains stationary, capturing them from a slightly low angle as they enter. The room has exposed brick walls and a corrugated metal ceiling, with a barred window visible in the background. The lighting is low-key, casting shadows on the officers' faces and emphasizing the grim atmosphere. The scene appears to be from a film or television show.
+- The woman has long black hair styled in two braids, adorned with white beads, and her eyes are wide with a hint of surprise. Her dress is a vibrant blue with intricate gold embroidery, and she wears a matching headband with a similar design. The background is a simple white curtain, which creates a sense of mystery and intrigue.

assets/system_prompt_t2v.txt

@@ -0,0 +1,37 @@
+You will receive prompts used for generating AI Videos. Your goal is to enhance the prompt such that it will be similar to the video captions used during training.
+Instructions for Generating Video Descriptions:
+	1.	Begin with a concise, single-paragraph description of the scene, focusing on the key actions in sequence.
+	2.	Include detailed movements of characters and objects, focusing on precise, observable actions.
+	3.	Briefly describe the appearance of characters and objects, emphasizing key visual features relevant to the scene.
+	4.	Provide essential background details to set the context, highlighting elements that enhance the atmosphere without overloading the description.
+	5.	Mention the camera angles and movements that define the visual style of the scene, keeping it succinct.
+	6.	Specify the lighting and colors to establish the tone, ensuring they complement the action and setting.
+	7.	Ensure the description reflects the source type, such as real-life footage or animation, in a clear and natural manner.
+
+Here are some examples to real captions that represent good prompts:
+- A woman walks away from a white Jeep parked on a city street at night...
+A woman walks away from a white Jeep parked on a city street at night, then ascends a staircase and knocks on a door. The woman, wearing a dark jacket and jeans, walks away from the Jeep parked on the left side of the street, her back to the camera; she walks at a steady pace, her arms swinging slightly by her sides; the street is dimly lit, with streetlights casting pools of light on the wet pavement; a man in a dark jacket and jeans walks past the Jeep in the opposite direction; the camera follows the woman from behind as she walks up a set of stairs towards a building with a green door; she reaches the top of the stairs and turns left, continuing to walk towards the building; she reaches the door and knocks on it with her right hand; the camera remains stationary, focused on the doorway; the scene is captured in real-life footage.
+- A woman with long brown hair and light skin smiles at another woman...
+A woman with long brown hair and light skin smiles at another woman with long blonde hair. The woman with brown hair wears a black jacket and has a small, barely noticeable mole on her right cheek. The camera angle is a close-up, focused on the woman with brown hair's face. The lighting is warm and natural, likely from the setting sun, casting a soft glow on the scene. The scene appears to be real-life footage.
+- A man in a suit enters a room and speaks to two women...
+A man in a suit enters a room and speaks to two women sitting on a couch. The man, wearing a dark suit with a gold tie, enters the room from the left and walks towards the center of the frame. He has short gray hair, light skin, and a serious expression. He places his right hand on the back of a chair as he approaches the couch. Two women are seated on a light-colored couch in the background. The woman on the left wears a light blue sweater and has short blonde hair. The woman on the right wears a white sweater and has short blonde hair. The camera remains stationary, focusing on the man as he enters the room. The room is brightly lit, with warm tones reflecting off the walls and furniture. The scene appears to be from a film or television show.
+- The camera pans across a cityscape of tall buildings...
+The camera pans across a cityscape of tall buildings with a circular building in the center. The camera moves from left to right, showing the tops of the buildings and the circular building in the center. The buildings are various shades of gray and white, and the circular building has a green roof. The camera angle is high, looking down at the city. The lighting is bright, with the sun shining from the upper left, casting shadows from the buildings. The scene is computer-generated imagery.
+- A young man with short blond hair and light skin, wearing a red and gold patterned jacket, looks down and to his right, then back up as he speaks to a woman with long red hair and light skin, wearing a red dress with gold embroidery; she stands slightly behind him to his left, her expression serious; they are in a dimly lit room with stone walls and several other people in the background, some holding torches; the camera remains stationary on the man's face, then briefly pans to the woman before returning to the man; the scene is captured in real-life footage.
+- A person is driving a car on a two-lane road, holding the steering wheel with both hands. The person's hands are light-skinned and they are wearing a black long-sleeved shirt. The steering wheel has a Toyota logo in the center and black leather around it. The car's dashboard is visible, showing a speedometer, tachometer, and navigation screen. The road ahead is straight and there are trees and fields visible on either side. The camera is positioned inside the car, providing a view from the driver's perspective. The lighting is natural and overcast, with a slightly cool tone. The scene is captured in real-life footage.
+- A bald man with a goatee, wearing a green and yellow robe, stands on a beach with two women, one with long blonde hair in braids wearing a blue dress and the other with long dark hair wearing a brown dress. The man turns his head slightly to the left, looking off-screen, while the blonde woman looks down with a serious expression. The camera remains stationary, capturing the three figures from the chest up. The background features a bright blue sky, a sandy beach, and a rocky outcropping. The scene is brightly lit, likely by sunlight, casting soft shadows on the characters' faces. The scene appears to be from a movie or TV show.
+- A bumblebee is perched on a cluster of pink flowers, sipping nectar. The bee is mostly black with yellow stripes on its abdomen and has translucent wings. The flowers are a light pink color and have five petals each. They are growing on a green stem with several leaves. The background is blurry, but it appears to be a sunny day.
+- A pair of hands shapes a piece of clay on a pottery wheel, gradually forming a cone shape. The hands, belonging to a person out of frame, are covered in clay and gently press a ball of clay onto the center of a spinning pottery wheel. The hands move in a circular motion, gradually forming a cone shape at the top of the clay. The camera is positioned directly above the pottery wheel, providing a bird's-eye view of the clay being shaped. The lighting is bright and even, illuminating the clay and the hands working on it. The scene is captured in real-life footage.
+- A young woman with long, wavy red hair is sitting in a white bathtub, leaning over the edge and reaching for the faucet to turn on the water.
+She has a serene expression on her face and her eyes are closed. Her skin is pale and her lips are slightly parted. She is wearing a white towel wrapped around her body. The bathtub is large and round, with a white porcelain finish. It is set in a bathroom with white walls and a large window. The window is covered by a white curtain, which is partially drawn back to let in some natural light.
+- An elephant walks towards the camera, stops, and lowers its head to eat some grass. The elephant is gray and has large white tusks. The elephant is walking on a grassy field. There are some trees and bushes in the background. The camera is stationary.
+- A man in a dimly lit room raises a glass to his lips and drinks. He wears a dark green tunic with a brown belt and has shoulder-length dark brown hair and a beard. He raises the glass in his right hand and drinks from it, then lowers it slightly while continuing to look straight ahead. The camera remains stationary, focused on the man from the waist up. The room is lit by a single candle on a stand to the left, casting warm light on the man's face and the surrounding area. The scene appears to be from a movie or TV show.
+- The squirrel has gray and brown fur and a bushy tail. Its eyes are black and shiny. The squirrel is sitting on a gray brick patio with small pebbles scattered around. There is a white plastic container next to the squirrel.
+- A young man with blond hair wearing a yellow jacket stands in a forest and looks around. He has light skin and his hair is styled with a middle part. He looks to the left and then to the right, his gaze lingering in each direction. The camera angle is low, looking up at the man, and remains stationary throughout the video. The background is slightly out of focus, with green trees and the sun shining brightly behind the man. The lighting is natural and warm, with the sun creating a lens flare that moves across the man's face. The scene is captured in real-life footage.
+- A woman with blonde hair styled up, wearing a black dress with sequins and pearl earrings, looks down with a sad expression on her face. The camera remains stationary, focused on the woman's face. The lighting is dim, casting soft shadows on her face. The scene appears to be from a movie or TV show.
+- A young woman with dark, curly hair and pale skin sits on a chair, her expression serious as she looks down and to the right; she wears a dark, intricately patterned dress with a high collar and long, dark gloves that extend past her elbows; a man with dark, curly hair and a pale face stands behind her to the left, his expression unreadable; he wears a dark vest over a white shirt and dark pants; the camera remains stationary, focused on the woman's face; the scene is dimly lit, with light streaming in from a large window behind the characters; the scene appears to be from a movie.
+- A herd of elephants walks from right to left across a dry, grassy plain. The elephants, with their gray skin and large ears, move at a steady pace, their trunks occasionally reaching down to graze on the sparse vegetation; one elephant in the foreground, slightly larger than the others, leads the charge, its head held high and ears spread wide; the camera remains stationary, capturing the elephants from a side angle as they move across the frame; the sun casts a bright light, creating sharp shadows on the ground and highlighting the texture of the elephants' skin; the scene is captured in real-life footage.
+- A man walks towards an oil derrick in a snowy field, stops to observe the flames, and then bends down to examine the ground. Wearing a beige jacket, dark pants, and a dark hat, the man walks from left to right across the snowy field towards a tall metal oil derrick with flames erupting from its top; he stops a few feet from the derrick and looks up at the flames; he then bends down, keeping his back to the camera, and examines the ground; the camera remains stationary throughout the scene, capturing a wide shot of the man, the derrick, and the snowy field; the sky is overcast, and the lighting is dim and natural; the scene is captured in real-life footage.
+- A man with short blond hair, wearing a white V-neck shirt and a dark gray jacket, stands in a parking lot, talking to another man whose back is to the camera; he has light skin and a neutral expression; the other man wears a light gray shirt; a dark-colored car is parked behind them; the camera remains stationary on the two men; the scene is brightly lit, with sunlight illuminating the parking lot; the scene appears to be real-life footage.
+- Two police officers in dark blue uniforms and matching hats enter a dimly lit room through a doorway on the left side of the frame. The first officer, with short brown hair and a mustache, steps inside first, followed by his partner, who has a shaved head and a goatee. Both officers have serious expressions and maintain a steady pace as they move deeper into the room. The camera remains stationary, capturing them from a slightly low angle as they enter. The room has exposed brick walls and a corrugated metal ceiling, with a barred window visible in the background. The lighting is low-key, casting shadows on the officers' faces and emphasizing the grim atmosphere. The scene appears to be from a film or television show.
+- The woman has long black hair styled in two braids, adorned with white beads, and her eyes are wide with a hint of surprise. Her dress is a vibrant blue with intricate gold embroidery, and she wears a matching headband with a similar design. The background is a simple white curtain, which creates a sense of mystery and intrigue.

assets/t2v_0.mp4

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:754c6a6c188f82da39fd59c68c596354fb5cf322bf79803e21f6e9a24c64a809
+size 1427298

inference.py

@@ -0,0 +1,369 @@
+import torch
+from xora.models.autoencoders.causal_video_autoencoder import CausalVideoAutoencoder
+from xora.models.transformers.transformer3d import Transformer3DModel
+from xora.models.transformers.symmetric_patchifier import SymmetricPatchifier
+from xora.schedulers.rf import RectifiedFlowScheduler
+from xora.pipelines.pipeline_xora_video import XoraVideoPipeline
+from pathlib import Path
+from transformers import T5EncoderModel, T5Tokenizer
+import safetensors.torch
+import json
+import argparse
+from xora.utils.conditioning_method import ConditioningMethod
+import os
+import numpy as np
+import cv2
+from PIL import Image
+import random
+
+RECOMMENDED_RESOLUTIONS = [
+    (704, 1216, 41),
+    (704, 1088, 49),
+    (640, 1056, 57),
+    (608, 992, 65),
+    (608, 896, 73),
+    (544, 896, 81),
+    (544, 832, 89),
+    (512, 800, 97),
+    (512, 768, 97),
+    (480, 800, 105),
+    (480, 736, 113),
+    (480, 704, 121),
+    (448, 704, 129),
+    (448, 672, 137),
+    (416, 640, 153),
+    (384, 672, 161),
+    (384, 640, 169),
+    (384, 608, 177),
+    (384, 576, 185),
+    (352, 608, 193),
+    (352, 576, 201),
+    (352, 544, 209),
+    (352, 512, 225),
+    (352, 512, 233),
+    (320, 544, 241),
+    (320, 512, 249),
+    (320, 512, 257),
+]
+
+
+def load_vae(vae_dir):
+    vae_ckpt_path = vae_dir / "vae_diffusion_pytorch_model.safetensors"
+    vae_config_path = vae_dir / "config.json"
+    with open(vae_config_path, "r") as f:
+        vae_config = json.load(f)
+    vae = CausalVideoAutoencoder.from_config(vae_config)
+    vae_state_dict = safetensors.torch.load_file(vae_ckpt_path)
+    vae.load_state_dict(vae_state_dict)
+    if torch.cuda.is_available():
+        vae = vae.cuda()
+    return vae.to(torch.bfloat16)
+
+
+def load_unet(unet_dir):
+    unet_ckpt_path = unet_dir / "unet_diffusion_pytorch_model.safetensors"
+    unet_config_path = unet_dir / "config.json"
+    transformer_config = Transformer3DModel.load_config(unet_config_path)
+    transformer = Transformer3DModel.from_config(transformer_config)
+    unet_state_dict = safetensors.torch.load_file(unet_ckpt_path)
+    transformer.load_state_dict(unet_state_dict, strict=True)
+    if torch.cuda.is_available():
+        transformer = transformer.cuda()
+    return transformer
+
+
+def load_scheduler(scheduler_dir):
+    scheduler_config_path = scheduler_dir / "scheduler_config.json"
+    scheduler_config = RectifiedFlowScheduler.load_config(scheduler_config_path)
+    return RectifiedFlowScheduler.from_config(scheduler_config)
+
+
+def center_crop_and_resize(frame, target_height, target_width):
+    h, w, _ = frame.shape
+    aspect_ratio_target = target_width / target_height
+    aspect_ratio_frame = w / h
+    if aspect_ratio_frame > aspect_ratio_target:
+        new_width = int(h * aspect_ratio_target)
+        x_start = (w - new_width) // 2
+        frame_cropped = frame[:, x_start : x_start + new_width]
+    else:
+        new_height = int(w / aspect_ratio_target)
+        y_start = (h - new_height) // 2
+        frame_cropped = frame[y_start : y_start + new_height, :]
+    frame_resized = cv2.resize(frame_cropped, (target_width, target_height))
+    return frame_resized
+
+
+def load_video_to_tensor_with_resize(video_path, target_height, target_width):
+    cap = cv2.VideoCapture(video_path)
+    frames = []
+    while True:
+        ret, frame = cap.read()
+        if not ret:
+            break
+        frame_rgb = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
+        if target_height is not None:
+            frame_resized = center_crop_and_resize(
+                frame_rgb, target_height, target_width
+            )
+        else:
+            frame_resized = frame_rgb
+        frames.append(frame_resized)
+    cap.release()
+    video_np = (np.array(frames) / 127.5) - 1.0
+    video_tensor = torch.tensor(video_np).permute(3, 0, 1, 2).float()
+    return video_tensor
+
+
+def load_image_to_tensor_with_resize(image_path, target_height=512, target_width=768):
+    image = Image.open(image_path).convert("RGB")
+    image_np = np.array(image)
+    frame_resized = center_crop_and_resize(image_np, target_height, target_width)
+    frame_tensor = torch.tensor(frame_resized).permute(2, 0, 1).float()
+    frame_tensor = (frame_tensor / 127.5) - 1.0
+    # Create 5D tensor: (batch_size=1, channels=3, num_frames=1, height, width)
+    return frame_tensor.unsqueeze(0).unsqueeze(2)
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Load models from separate directories and run the pipeline."
+    )
+
+    # Directories
+    parser.add_argument(
+        "--ckpt_dir",
+        type=str,
+        required=True,
+        help="Path to the directory containing unet, vae, and scheduler subdirectories",
+    )
+    parser.add_argument(
+        "--input_video_path",
+        type=str,
+        help="Path to the input video file (first frame used)",
+    )
+    parser.add_argument(
+        "--input_image_path", type=str, help="Path to the input image file"
+    )
+    parser.add_argument(
+        "--output_path",
+        type=str,
+        default=None,
+        help="Path to save output video, if None will save in working directory.",
+    )
+    parser.add_argument("--seed", type=int, default="171198")
+
+    # Pipeline parameters
+    parser.add_argument(
+        "--num_inference_steps", type=int, default=40, help="Number of inference steps"
+    )
+    parser.add_argument(
+        "--num_images_per_prompt",
+        type=int,
+        default=1,
+        help="Number of images per prompt",
+    )
+    parser.add_argument(
+        "--guidance_scale",
+        type=float,
+        default=3,
+        help="Guidance scale for the pipeline",
+    )
+    parser.add_argument(
+        "--height",
+        type=int,
+        default=None,
+        help="Height of the output video frames. Optional if an input image provided.",
+    )
+    parser.add_argument(
+        "--width",
+        type=int,
+        default=None,
+        help="Width of the output video frames. If None will infer from input image.",
+    )
+    parser.add_argument(
+        "--num_frames",
+        type=int,
+        default=121,
+        help="Number of frames to generate in the output video",
+    )
+    parser.add_argument(
+        "--frame_rate", type=int, default=25, help="Frame rate for the output video"
+    )
+
+    parser.add_argument(
+        "--bfloat16",
+        action="store_true",
+        help="Denoise in bfloat16",
+    )
+
+    # Prompts
+    parser.add_argument(
+        "--prompt",
+        type=str,
+        help="Text prompt to guide generation",
+    )
+    parser.add_argument(
+        "--negative_prompt",
+        type=str,
+        default="worst quality, inconsistent motion, blurry, jittery, distorted",
+        help="Negative prompt for undesired features",
+    )
+    parser.add_argument(
+        "--custom_resolution",
+        action="store_true",
+        default=False,
+        help="Enable custom resolution (not in recommneded resolutions) if specified (default: False)",
+    )
+
+    args = parser.parse_args()
+
+    if args.input_image_path is None and args.input_video_path is None:
+        assert (
+            args.height is not None and args.width is not None
+        ), "Must enter height and width for text to image generation."
+
+    # Load media (video or image)
+    if args.input_video_path:
+        media_items = load_video_to_tensor_with_resize(
+            args.input_video_path, args.height, args.width
+        ).unsqueeze(0)
+    elif args.input_image_path:
+        media_items = load_image_to_tensor_with_resize(
+            args.input_image_path, args.height, args.width
+        )
+    else:
+        media_items = None
+
+    height = args.height if args.height else media_items.shape[-2]
+    width = args.width if args.width else media_items.shape[-1]
+    assert height % 32 == 0, f"Height ({height}) should be divisible by 32."
+    assert width % 32 == 0, f"Width ({width}) should be divisible by 32."
+    assert (
+        height,
+        width,
+        args.num_frames,
+    ) in RECOMMENDED_RESOLUTIONS or args.custom_resolution, f"The selected resolution + num frames combination is not supported, results would be suboptimal. Supported (h,w,f) are: {RECOMMENDED_RESOLUTIONS}. Use --custom_resolution to enable working with this resolution."
+
+    # Paths for the separate mode directories
+    ckpt_dir = Path(args.ckpt_dir)
+    unet_dir = ckpt_dir / "unet"
+    vae_dir = ckpt_dir / "vae"
+    scheduler_dir = ckpt_dir / "scheduler"
+
+    # Load models
+    vae = load_vae(vae_dir)
+    unet = load_unet(unet_dir)
+    scheduler = load_scheduler(scheduler_dir)
+    patchifier = SymmetricPatchifier(patch_size=1)
+    text_encoder = T5EncoderModel.from_pretrained(
+        "PixArt-alpha/PixArt-XL-2-1024-MS", subfolder="text_encoder"
+    )
+    if torch.cuda.is_available():
+        text_encoder = text_encoder.to("cuda")
+    tokenizer = T5Tokenizer.from_pretrained(
+        "PixArt-alpha/PixArt-XL-2-1024-MS", subfolder="tokenizer"
+    )
+
+    if args.bfloat16 and unet.dtype != torch.bfloat16:
+        unet = unet.to(torch.bfloat16)
+
+    # Use submodels for the pipeline
+    submodel_dict = {
+        "transformer": unet,
+        "patchifier": patchifier,
+        "text_encoder": text_encoder,
+        "tokenizer": tokenizer,
+        "scheduler": scheduler,
+        "vae": vae,
+    }
+
+    pipeline = XoraVideoPipeline(**submodel_dict)
+    if torch.cuda.is_available():
+        pipeline = pipeline.to("cuda")
+
+    # Prepare input for the pipeline
+    sample = {
+        "prompt": args.prompt,
+        "prompt_attention_mask": None,
+        "negative_prompt": args.negative_prompt,
+        "negative_prompt_attention_mask": None,
+        "media_items": media_items,
+    }
+
+    random.seed(args.seed)
+    np.random.seed(args.seed)
+    torch.manual_seed(args.seed)
+    if torch.cuda.is_available():
+        torch.cuda.manual_seed(args.seed)
+
+    generator = torch.Generator(
+        device="cuda" if torch.cuda.is_available() else "cpu"
+    ).manual_seed(args.seed)
+
+    images = pipeline(
+        num_inference_steps=args.num_inference_steps,
+        num_images_per_prompt=args.num_images_per_prompt,
+        guidance_scale=args.guidance_scale,
+        generator=generator,
+        output_type="pt",
+        callback_on_step_end=None,
+        height=height,
+        width=width,
+        num_frames=args.num_frames,
+        frame_rate=args.frame_rate,
+        **sample,
+        is_video=True,
+        vae_per_channel_normalize=True,
+        conditioning_method=(
+            ConditioningMethod.FIRST_FRAME
+            if media_items is not None
+            else ConditioningMethod.UNCONDITIONAL
+        ),
+        mixed_precision=not args.bfloat16,
+    ).images
+
+    # Save output video
+    def get_unique_filename(base, ext, dir=".", index_range=1000):
+        for i in range(index_range):
+            filename = os.path.join(dir, f"{base}_{i}{ext}")
+            if not os.path.exists(filename):
+                return filename
+        raise FileExistsError(
+            f"Could not find a unique filename after {index_range} attempts."
+        )
+
+    for i in range(images.shape[0]):
+        # Gathering from B, C, F, H, W to C, F, H, W and then permuting to F, H, W, C
+        video_np = images[i].permute(1, 2, 3, 0).cpu().float().numpy()
+        # Unnormalizing images to [0, 255] range
+        video_np = (video_np * 255).astype(np.uint8)
+        fps = args.frame_rate
+        height, width = video_np.shape[1:3]
+        if video_np.shape[0] == 1:
+            output_filename = (
+                args.output_path
+                if args.output_path is not None
+                else get_unique_filename(f"image_output_{i}", ".png", ".")
+            )
+            cv2.imwrite(
+                output_filename, video_np[0][..., ::-1]
+            )  # Save single frame as image
+        else:
+            output_filename = (
+                args.output_path
+                if args.output_path is not None
+                else get_unique_filename(f"video_output_{i}", ".mp4", ".")
+            )
+
+            out = cv2.VideoWriter(
+                output_filename, cv2.VideoWriter_fourcc(*"mp4v"), fps, (width, height)
+            )
+
+            for frame in video_np[..., ::-1]:
+                out.write(frame)
+            out.release()
+
+
+if __name__ == "__main__":
+    main()

pyproject.toml

@@ -0,0 +1,34 @@
+[build-system]
+requires = ["setuptools>=42", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "xora-core"
+version = "0.1.0"
+description = "A package for Xora model inference"
+authors = [
+    { name = "Sapir Weissbuch", email = "sapir@lightricks.com" }
+]
+requires-python = ">=3.10"
+readme = "README.md"
+classifiers = [
+    "Programming Language :: Python :: 3",
+    "License :: OSI Approved :: MIT License",
+    "Operating System :: OS Independent"
+]
+dependencies = [
+    "torch>=2.1.0",
+    "diffusers~=0.28.2",
+    "transformers~=4.44.2",
+    "sentencepiece~=0.1.96",
+    "huggingface-hub~=0.25.2",
+    "einops"
+]
+
+[project.optional-dependencies]
+# Instead of thinking of them as optional, think of them as specific modes
+inference-script = [
+    "accelerate",
+    "matplotlib",
+    "opencv-python"
+]

requirements.txt

@@ -0,0 +1,14 @@
+huggingface_hub<=0.25
+torch
+diffusers==0.28.2
+transformers==4.44.2
+sentencepiece>=0.1.96
+accelerate
+einops
+matplotlib
+opencv-python
+beautifulsoup4
+ftfy
+gradio
+openai
+gradio_toggle

scripts/to_safetensors.py

@@ -0,0 +1,143 @@
+import argparse
+from pathlib import Path
+from typing import Dict
+import safetensors.torch
+import torch
+import json
+import shutil
+
+
+def load_text_encoder(index_path: Path) -> Dict:
+    with open(index_path, "r") as f:
+        index: Dict = json.load(f)
+
+    loaded_tensors = {}
+    for part_file in set(index.get("weight_map", {}).values()):
+        tensors = safetensors.torch.load_file(
+            index_path.parent / part_file, device="cpu"
+        )
+        for tensor_name in tensors:
+            loaded_tensors[tensor_name] = tensors[tensor_name]
+
+    return loaded_tensors
+
+
+def convert_unet(unet: Dict, add_prefix=True) -> Dict:
+    if add_prefix:
+        return {"model.diffusion_model." + key: value for key, value in unet.items()}
+    return unet
+
+
+def convert_vae(vae_path: Path, add_prefix=True) -> Dict:
+    state_dict = torch.load(vae_path / "autoencoder.pth", weights_only=True)
+    stats_path = vae_path / "per_channel_statistics.json"
+    if stats_path.exists():
+        with open(stats_path, "r") as f:
+            data = json.load(f)
+        transposed_data = list(zip(*data["data"]))
+        data_dict = {
+            f"{'vae.' if add_prefix else ''}per_channel_statistics.{col}": torch.tensor(
+                vals
+            )
+            for col, vals in zip(data["columns"], transposed_data)
+        }
+    else:
+        data_dict = {}
+
+    result = {
+        ("vae." if add_prefix else "") + key: value for key, value in state_dict.items()
+    }
+    result.update(data_dict)
+    return result
+
+
+def convert_encoder(encoder: Dict) -> Dict:
+    return {
+        "text_encoders.t5xxl.transformer." + key: value
+        for key, value in encoder.items()
+    }
+
+
+def save_config(config_src: str, config_dst: str):
+    shutil.copy(config_src, config_dst)
+
+
+def load_vae_config(vae_path: Path) -> str:
+    config_path = vae_path / "config.json"
+    if not config_path.exists():
+        raise FileNotFoundError(f"VAE config file {config_path} not found.")
+    return str(config_path)
+
+
+def main(
+    unet_path: str,
+    vae_path: str,
+    out_path: str,
+    mode: str,
+    unet_config_path: str = None,
+    scheduler_config_path: str = None,
+) -> None:
+    unet = convert_unet(
+        torch.load(unet_path, weights_only=True), add_prefix=(mode == "single")
+    )
+
+    # Load VAE from directory and config
+    vae = convert_vae(Path(vae_path), add_prefix=(mode == "single"))
+    vae_config_path = load_vae_config(Path(vae_path))
+
+    if mode == "single":
+        result = {**unet, **vae}
+        safetensors.torch.save_file(result, out_path)
+    elif mode == "separate":
+        # Create directories for unet, vae, and scheduler
+        unet_dir = Path(out_path) / "unet"
+        vae_dir = Path(out_path) / "vae"
+        scheduler_dir = Path(out_path) / "scheduler"
+
+        unet_dir.mkdir(parents=True, exist_ok=True)
+        vae_dir.mkdir(parents=True, exist_ok=True)
+        scheduler_dir.mkdir(parents=True, exist_ok=True)
+
+        # Save unet and vae safetensors with the name diffusion_pytorch_model.safetensors
+        safetensors.torch.save_file(
+            unet, unet_dir / "unet_diffusion_pytorch_model.safetensors"
+        )
+        safetensors.torch.save_file(
+            vae, vae_dir / "vae_diffusion_pytorch_model.safetensors"
+        )
+
+        # Save config files for unet, vae, and scheduler
+        if unet_config_path:
+            save_config(unet_config_path, unet_dir / "config.json")
+        if vae_config_path:
+            save_config(vae_config_path, vae_dir / "config.json")
+        if scheduler_config_path:
+            save_config(scheduler_config_path, scheduler_dir / "scheduler_config.json")
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--unet_path", "-u", type=str, default="unet/ema-002.pt")
+    parser.add_argument("--vae_path", "-v", type=str, default="vae/")
+    parser.add_argument("--out_path", "-o", type=str, default="xora.safetensors")
+    parser.add_argument(
+        "--mode",
+        "-m",
+        type=str,
+        choices=["single", "separate"],
+        default="single",
+        help="Choose 'single' for the original behavior, 'separate' to save unet and vae separately.",
+    )
+    parser.add_argument(
+        "--unet_config_path",
+        type=str,
+        help="Path to the UNet config file (for separate mode)",
+    )
+    parser.add_argument(
+        "--scheduler_config_path",
+        type=str,
+        help="Path to the Scheduler config file (for separate mode)",
+    )
+
+    args = parser.parse_args()
+    main(**args.__dict__)

xora/models/autoencoders/causal_conv3d.py

@@ -0,0 +1,62 @@
+from typing import Tuple, Union
+
+import torch
+import torch.nn as nn
+
+
+class CausalConv3d(nn.Module):
+    def __init__(
+        self,
+        in_channels,
+        out_channels,
+        kernel_size: int = 3,
+        stride: Union[int, Tuple[int]] = 1,
+        dilation: int = 1,
+        groups: int = 1,
+        **kwargs,
+    ):
+        super().__init__()
+
+        self.in_channels = in_channels
+        self.out_channels = out_channels
+
+        kernel_size = (kernel_size, kernel_size, kernel_size)
+        self.time_kernel_size = kernel_size[0]
+
+        dilation = (dilation, 1, 1)
+
+        height_pad = kernel_size[1] // 2
+        width_pad = kernel_size[2] // 2
+        padding = (0, height_pad, width_pad)
+
+        self.conv = nn.Conv3d(
+            in_channels,
+            out_channels,
+            kernel_size,
+            stride=stride,
+            dilation=dilation,
+            padding=padding,
+            padding_mode="zeros",
+            groups=groups,
+        )
+
+    def forward(self, x, causal: bool = True):
+        if causal:
+            first_frame_pad = x[:, :, :1, :, :].repeat(
+                (1, 1, self.time_kernel_size - 1, 1, 1)
+            )
+            x = torch.concatenate((first_frame_pad, x), dim=2)
+        else:
+            first_frame_pad = x[:, :, :1, :, :].repeat(
+                (1, 1, (self.time_kernel_size - 1) // 2, 1, 1)
+            )
+            last_frame_pad = x[:, :, -1:, :, :].repeat(
+                (1, 1, (self.time_kernel_size - 1) // 2, 1, 1)
+            )
+            x = torch.concatenate((first_frame_pad, x, last_frame_pad), dim=2)
+        x = self.conv(x)
+        return x
+
+    @property
+    def weight(self):
+        return self.conv.weight

xora/models/autoencoders/causal_video_autoencoder.py

@@ -0,0 +1,1199 @@
+import json
+import os
+from functools import partial
+from types import SimpleNamespace
+from typing import Any, Mapping, Optional, Tuple, Union, List
+
+import torch
+import numpy as np
+from einops import rearrange
+from torch import nn
+from diffusers.utils import logging
+import torch.nn.functional as F
+from diffusers.models.embeddings import PixArtAlphaCombinedTimestepSizeEmbeddings
+
+
+from xora.models.autoencoders.conv_nd_factory import make_conv_nd, make_linear_nd
+from xora.models.autoencoders.pixel_norm import PixelNorm
+from xora.models.autoencoders.vae import AutoencoderKLWrapper
+from xora.models.transformers.attention import Attention
+
+logger = logging.get_logger(__name__)  # pylint: disable=invalid-name
+
+
+class CausalVideoAutoencoder(AutoencoderKLWrapper):
+    @classmethod
+    def from_pretrained(
+        cls,
+        pretrained_model_name_or_path: Optional[Union[str, os.PathLike]],
+        *args,
+        **kwargs,
+    ):
+        config_local_path = pretrained_model_name_or_path / "config.json"
+        config = cls.load_config(config_local_path, **kwargs)
+        video_vae = cls.from_config(config)
+        video_vae.to(kwargs["torch_dtype"])
+
+        model_local_path = pretrained_model_name_or_path / "autoencoder.pth"
+        ckpt_state_dict = torch.load(model_local_path, map_location=torch.device("cpu"))
+        video_vae.load_state_dict(ckpt_state_dict)
+
+        statistics_local_path = (
+            pretrained_model_name_or_path / "per_channel_statistics.json"
+        )
+        if statistics_local_path.exists():
+            with open(statistics_local_path, "r") as file:
+                data = json.load(file)
+            transposed_data = list(zip(*data["data"]))
+            data_dict = {
+                col: torch.tensor(vals)
+                for col, vals in zip(data["columns"], transposed_data)
+            }
+            video_vae.register_buffer("std_of_means", data_dict["std-of-means"])
+            video_vae.register_buffer(
+                "mean_of_means",
+                data_dict.get(
+                    "mean-of-means", torch.zeros_like(data_dict["std-of-means"])
+                ),
+            )
+
+        return video_vae
+
+    @staticmethod
+    def from_config(config):
+        assert (
+            config["_class_name"] == "CausalVideoAutoencoder"
+        ), "config must have _class_name=CausalVideoAutoencoder"
+        if isinstance(config["dims"], list):
+            config["dims"] = tuple(config["dims"])
+
+        assert config["dims"] in [2, 3, (2, 1)], "dims must be 2, 3 or (2, 1)"
+
+        double_z = config.get("double_z", True)
+        latent_log_var = config.get(
+            "latent_log_var", "per_channel" if double_z else "none"
+        )
+        use_quant_conv = config.get("use_quant_conv", True)
+
+        if use_quant_conv and latent_log_var == "uniform":
+            raise ValueError("uniform latent_log_var requires use_quant_conv=False")
+
+        encoder = Encoder(
+            dims=config["dims"],
+            in_channels=config.get("in_channels", 3),
+            out_channels=config["latent_channels"],
+            blocks=config.get("encoder_blocks", config.get("blocks")),
+            patch_size=config.get("patch_size", 1),
+            latent_log_var=latent_log_var,
+            norm_layer=config.get("norm_layer", "group_norm"),
+        )
+
+        decoder = Decoder(
+            dims=config["dims"],
+            in_channels=config["latent_channels"],
+            out_channels=config.get("out_channels", 3),
+            blocks=config.get("decoder_blocks", config.get("blocks")),
+            patch_size=config.get("patch_size", 1),
+            norm_layer=config.get("norm_layer", "group_norm"),
+            causal=config.get("causal_decoder", False),
+            timestep_conditioning=config.get("timestep_conditioning", False),
+        )
+
+        dims = config["dims"]
+        return CausalVideoAutoencoder(
+            encoder=encoder,
+            decoder=decoder,
+            latent_channels=config["latent_channels"],
+            dims=dims,
+            use_quant_conv=use_quant_conv,
+        )
+
+    @property
+    def config(self):
+        return SimpleNamespace(
+            _class_name="CausalVideoAutoencoder",
+            dims=self.dims,
+            in_channels=self.encoder.conv_in.in_channels // self.encoder.patch_size**2,
+            out_channels=self.decoder.conv_out.out_channels
+            // self.decoder.patch_size**2,
+            latent_channels=self.decoder.conv_in.in_channels,
+            encoder_blocks=self.encoder.blocks_desc,
+            decoder_blocks=self.decoder.blocks_desc,
+            scaling_factor=1.0,
+            norm_layer=self.encoder.norm_layer,
+            patch_size=self.encoder.patch_size,
+            latent_log_var=self.encoder.latent_log_var,
+            use_quant_conv=self.use_quant_conv,
+            causal_decoder=self.decoder.causal,
+            timestep_conditioning=self.decoder.timestep_conditioning,
+        )
+
+    @property
+    def is_video_supported(self):
+        """
+        Check if the model supports video inputs of shape (B, C, F, H, W). Otherwise, the model only supports 2D images.
+        """
+        return self.dims != 2
+
+    @property
+    def spatial_downscale_factor(self):
+        return (
+            2
+            ** len(
+                [
+                    block
+                    for block in self.encoder.blocks_desc
+                    if block[0] in ["compress_space", "compress_all"]
+                ]
+            )
+            * self.encoder.patch_size
+        )
+
+    @property
+    def temporal_downscale_factor(self):
+        return 2 ** len(
+            [
+                block
+                for block in self.encoder.blocks_desc
+                if block[0] in ["compress_time", "compress_all"]
+            ]
+        )
+
+    def to_json_string(self) -> str:
+        import json
+
+        return json.dumps(self.config.__dict__)
+
+    def load_state_dict(self, state_dict: Mapping[str, Any], strict: bool = True):
+        per_channel_statistics_prefix = "per_channel_statistics."
+        ckpt_state_dict = {
+            key: value
+            for key, value in state_dict.items()
+            if not key.startswith(per_channel_statistics_prefix)
+        }
+
+        model_keys = set(name for name, _ in self.named_parameters())
+
+        key_mapping = {
+            ".resnets.": ".res_blocks.",
+            "downsamplers.0": "downsample",
+            "upsamplers.0": "upsample",
+        }
+        converted_state_dict = {}
+        for key, value in ckpt_state_dict.items():
+            for k, v in key_mapping.items():
+                key = key.replace(k, v)
+
+            if "norm" in key and key not in model_keys:
+                logger.info(
+                    f"Removing key {key} from state_dict as it is not present in the model"
+                )
+                continue
+
+            converted_state_dict[key] = value
+
+        super().load_state_dict(converted_state_dict, strict=strict)
+
+        data_dict = {
+            key.removeprefix(per_channel_statistics_prefix): value
+            for key, value in state_dict.items()
+            if key.startswith(per_channel_statistics_prefix)
+        }
+        if len(data_dict) > 0:
+            self.register_buffer("std_of_means", data_dict["std-of-means"])
+            self.register_buffer(
+                "mean_of_means",
+                data_dict.get(
+                    "mean-of-means", torch.zeros_like(data_dict["std-of-means"])
+                ),
+            )
+
+    def last_layer(self):
+        if hasattr(self.decoder, "conv_out"):
+            if isinstance(self.decoder.conv_out, nn.Sequential):
+                last_layer = self.decoder.conv_out[-1]
+            else:
+                last_layer = self.decoder.conv_out
+        else:
+            last_layer = self.decoder.layers[-1]
+        return last_layer
+
+    def set_use_tpu_flash_attention(self):
+        for block in self.decoder.up_blocks:
+            if isinstance(block, UNetMidBlock3D) and block.attention_blocks:
+                for attention_block in block.attention_blocks:
+                    attention_block.set_use_tpu_flash_attention()
+
+
+class Encoder(nn.Module):
+    r"""
+    The `Encoder` layer of a variational autoencoder that encodes its input into a latent representation.
+
+    Args:
+        dims (`int` or `Tuple[int, int]`, *optional*, defaults to 3):
+            The number of dimensions to use in convolutions.
+        in_channels (`int`, *optional*, defaults to 3):
+            The number of input channels.
+        out_channels (`int`, *optional*, defaults to 3):
+            The number of output channels.
+        blocks (`List[Tuple[str, int]]`, *optional*, defaults to `[("res_x", 1)]`):
+            The blocks to use. Each block is a tuple of the block name and the number of layers.
+        base_channels (`int`, *optional*, defaults to 128):
+            The number of output channels for the first convolutional layer.
+        norm_num_groups (`int`, *optional*, defaults to 32):
+            The number of groups for normalization.
+        patch_size (`int`, *optional*, defaults to 1):
+            The patch size to use. Should be a power of 2.
+        norm_layer (`str`, *optional*, defaults to `group_norm`):
+            The normalization layer to use. Can be either `group_norm` or `pixel_norm`.
+        latent_log_var (`str`, *optional*, defaults to `per_channel`):
+            The number of channels for the log variance. Can be either `per_channel`, `uniform`, or `none`.
+    """
+
+    def __init__(
+        self,
+        dims: Union[int, Tuple[int, int]] = 3,
+        in_channels: int = 3,
+        out_channels: int = 3,
+        blocks: List[Tuple[str, Union[int, dict]]] = [("res_x", 1)],
+        base_channels: int = 128,
+        norm_num_groups: int = 32,
+        patch_size: Union[int, Tuple[int]] = 1,
+        norm_layer: str = "group_norm",  # group_norm, pixel_norm
+        latent_log_var: str = "per_channel",
+    ):
+        super().__init__()
+        self.patch_size = patch_size
+        self.norm_layer = norm_layer
+        self.latent_channels = out_channels
+        self.latent_log_var = latent_log_var
+        self.blocks_desc = blocks
+
+        in_channels = in_channels * patch_size**2
+        output_channel = base_channels
+
+        self.conv_in = make_conv_nd(
+            dims=dims,
+            in_channels=in_channels,
+            out_channels=output_channel,
+            kernel_size=3,
+            stride=1,
+            padding=1,
+            causal=True,
+        )
+
+        self.down_blocks = nn.ModuleList([])
+
+        for block_name, block_params in blocks:
+            input_channel = output_channel
+            if isinstance(block_params, int):
+                block_params = {"num_layers": block_params}
+
+            if block_name == "res_x":
+                block = UNetMidBlock3D(
+                    dims=dims,
+                    in_channels=input_channel,
+                    num_layers=block_params["num_layers"],
+                    resnet_eps=1e-6,
+                    resnet_groups=norm_num_groups,
+                    norm_layer=norm_layer,
+                )
+            elif block_name == "res_x_y":
+                output_channel = block_params.get("multiplier", 2) * output_channel
+                block = ResnetBlock3D(
+                    dims=dims,
+                    in_channels=input_channel,
+                    out_channels=output_channel,
+                    eps=1e-6,
+                    groups=norm_num_groups,
+                    norm_layer=norm_layer,
+                )
+            elif block_name == "compress_time":
+                block = make_conv_nd(
+                    dims=dims,
+                    in_channels=input_channel,
+                    out_channels=output_channel,
+                    kernel_size=3,
+                    stride=(2, 1, 1),
+                    causal=True,
+                )
+            elif block_name == "compress_space":
+                block = make_conv_nd(
+                    dims=dims,
+                    in_channels=input_channel,
+                    out_channels=output_channel,
+                    kernel_size=3,
+                    stride=(1, 2, 2),
+                    causal=True,
+                )
+            elif block_name == "compress_all":
+                block = make_conv_nd(
+                    dims=dims,
+                    in_channels=input_channel,
+                    out_channels=output_channel,
+                    kernel_size=3,
+                    stride=(2, 2, 2),
+                    causal=True,
+                )
+            elif block_name == "compress_all_x_y":
+                output_channel = block_params.get("multiplier", 2) * output_channel
+                block = make_conv_nd(
+                    dims=dims,
+                    in_channels=input_channel,
+                    out_channels=output_channel,
+                    kernel_size=3,
+                    stride=(2, 2, 2),
+                    causal=True,
+                )
+            else:
+                raise ValueError(f"unknown block: {block_name}")
+
+            self.down_blocks.append(block)
+
+        # out
+        if norm_layer == "group_norm":
+            self.conv_norm_out = nn.GroupNorm(
+                num_channels=output_channel, num_groups=norm_num_groups, eps=1e-6
+            )
+        elif norm_layer == "pixel_norm":
+            self.conv_norm_out = PixelNorm()
+        elif norm_layer == "layer_norm":
+            self.conv_norm_out = LayerNorm(output_channel, eps=1e-6)
+
+        self.conv_act = nn.SiLU()
+
+        conv_out_channels = out_channels
+        if latent_log_var == "per_channel":
+            conv_out_channels *= 2
+        elif latent_log_var == "uniform":
+            conv_out_channels += 1
+        elif latent_log_var != "none":
+            raise ValueError(f"Invalid latent_log_var: {latent_log_var}")
+        self.conv_out = make_conv_nd(
+            dims, output_channel, conv_out_channels, 3, padding=1, causal=True
+        )
+
+        self.gradient_checkpointing = False
+
+    def forward(self, sample: torch.FloatTensor) -> torch.FloatTensor:
+        r"""The forward method of the `Encoder` class."""
+
+        sample = patchify(sample, patch_size_hw=self.patch_size, patch_size_t=1)
+        sample = self.conv_in(sample)
+
+        checkpoint_fn = (
+            partial(torch.utils.checkpoint.checkpoint, use_reentrant=False)
+            if self.gradient_checkpointing and self.training
+            else lambda x: x
+        )
+
+        for down_block in self.down_blocks:
+            sample = checkpoint_fn(down_block)(sample)
+
+        sample = self.conv_norm_out(sample)
+        sample = self.conv_act(sample)
+        sample = self.conv_out(sample)
+
+        if self.latent_log_var == "uniform":
+            last_channel = sample[:, -1:, ...]
+            num_dims = sample.dim()
+
+            if num_dims == 4:
+                # For shape (B, C, H, W)
+                repeated_last_channel = last_channel.repeat(
+                    1, sample.shape[1] - 2, 1, 1
+                )
+                sample = torch.cat([sample, repeated_last_channel], dim=1)
+            elif num_dims == 5:
+                # For shape (B, C, F, H, W)
+                repeated_last_channel = last_channel.repeat(
+                    1, sample.shape[1] - 2, 1, 1, 1
+                )
+                sample = torch.cat([sample, repeated_last_channel], dim=1)
+            else:
+                raise ValueError(f"Invalid input shape: {sample.shape}")
+
+        return sample
+
+
+class Decoder(nn.Module):
+    r"""
+    The `Decoder` layer of a variational autoencoder that decodes its latent representation into an output sample.
+
+    Args:
+        dims (`int` or `Tuple[int, int]`, *optional*, defaults to 3):
+            The number of dimensions to use in convolutions.
+        in_channels (`int`, *optional*, defaults to 3):
+            The number of input channels.
+        out_channels (`int`, *optional*, defaults to 3):
+            The number of output channels.
+        blocks (`List[Tuple[str, int]]`, *optional*, defaults to `[("res_x", 1)]`):
+            The blocks to use. Each block is a tuple of the block name and the number of layers.
+        base_channels (`int`, *optional*, defaults to 128):
+            The number of output channels for the first convolutional layer.
+        norm_num_groups (`int`, *optional*, defaults to 32):
+            The number of groups for normalization.
+        patch_size (`int`, *optional*, defaults to 1):
+            The patch size to use. Should be a power of 2.
+        norm_layer (`str`, *optional*, defaults to `group_norm`):
+            The normalization layer to use. Can be either `group_norm` or `pixel_norm`.
+        causal (`bool`, *optional*, defaults to `True`):
+            Whether to use causal convolutions or not.
+    """
+
+    def __init__(
+        self,
+        dims,
+        in_channels: int = 3,
+        out_channels: int = 3,
+        blocks: List[Tuple[str, Union[int, dict]]] = [("res_x", 1)],
+        base_channels: int = 128,
+        layers_per_block: int = 2,
+        norm_num_groups: int = 32,
+        patch_size: int = 1,
+        norm_layer: str = "group_norm",
+        causal: bool = True,
+        timestep_conditioning: bool = False,
+    ):
+        super().__init__()
+        self.patch_size = patch_size
+        self.layers_per_block = layers_per_block
+        out_channels = out_channels * patch_size**2
+        self.causal = causal
+        self.blocks_desc = blocks
+
+        # Compute output channel to be product of all channel-multiplier blocks
+        output_channel = base_channels
+        for block_name, block_params in list(reversed(blocks)):
+            block_params = block_params if isinstance(block_params, dict) else {}
+            if block_name == "res_x_y":
+                output_channel = output_channel * block_params.get("multiplier", 2)
+            if block_name == "compress_all":
+                output_channel = output_channel * block_params.get("multiplier", 1)
+
+        self.conv_in = make_conv_nd(
+            dims,
+            in_channels,
+            output_channel,
+            kernel_size=3,
+            stride=1,
+            padding=1,
+            causal=True,
+        )
+
+        self.up_blocks = nn.ModuleList([])
+
+        for block_name, block_params in list(reversed(blocks)):
+            input_channel = output_channel
+            if isinstance(block_params, int):
+                block_params = {"num_layers": block_params}
+
+            if block_name == "res_x":
+                block = UNetMidBlock3D(
+                    dims=dims,
+                    in_channels=input_channel,
+                    num_layers=block_params["num_layers"],
+                    resnet_eps=1e-6,
+                    resnet_groups=norm_num_groups,
+                    norm_layer=norm_layer,
+                    inject_noise=block_params.get("inject_noise", False),
+                    timestep_conditioning=timestep_conditioning,
+                )
+            elif block_name == "attn_res_x":
+                block = UNetMidBlock3D(
+                    dims=dims,
+                    in_channels=input_channel,
+                    num_layers=block_params["num_layers"],
+                    resnet_groups=norm_num_groups,
+                    norm_layer=norm_layer,
+                    inject_noise=block_params.get("inject_noise", False),
+                    timestep_conditioning=timestep_conditioning,
+                    attention_head_dim=block_params["attention_head_dim"],
+                )
+            elif block_name == "res_x_y":
+                output_channel = output_channel // block_params.get("multiplier", 2)
+                block = ResnetBlock3D(
+                    dims=dims,
+                    in_channels=input_channel,
+                    out_channels=output_channel,
+                    eps=1e-6,
+                    groups=norm_num_groups,
+                    norm_layer=norm_layer,
+                    inject_noise=block_params.get("inject_noise", False),
+                    timestep_conditioning=False,
+                )
+            elif block_name == "compress_time":
+                block = DepthToSpaceUpsample(
+                    dims=dims, in_channels=input_channel, stride=(2, 1, 1)
+                )
+            elif block_name == "compress_space":
+                block = DepthToSpaceUpsample(
+                    dims=dims, in_channels=input_channel, stride=(1, 2, 2)
+                )
+            elif block_name == "compress_all":
+                output_channel = output_channel // block_params.get("multiplier", 1)
+                block = DepthToSpaceUpsample(
+                    dims=dims,
+                    in_channels=input_channel,
+                    stride=(2, 2, 2),
+                    residual=block_params.get("residual", False),
+                    out_channels_reduction_factor=block_params.get("multiplier", 1),
+                )
+            else:
+                raise ValueError(f"unknown layer: {block_name}")
+
+            self.up_blocks.append(block)
+
+        if norm_layer == "group_norm":
+            self.conv_norm_out = nn.GroupNorm(
+                num_channels=output_channel, num_groups=norm_num_groups, eps=1e-6
+            )
+        elif norm_layer == "pixel_norm":
+            self.conv_norm_out = PixelNorm()
+        elif norm_layer == "layer_norm":
+            self.conv_norm_out = LayerNorm(output_channel, eps=1e-6)
+
+        self.conv_act = nn.SiLU()
+        self.conv_out = make_conv_nd(
+            dims, output_channel, out_channels, 3, padding=1, causal=True
+        )
+
+        self.gradient_checkpointing = False
+
+        self.timestep_conditioning = timestep_conditioning
+
+        if timestep_conditioning:
+            self.timestep_scale_multiplier = nn.Parameter(
+                torch.tensor(1000.0, dtype=torch.float32)
+            )
+            self.last_time_embedder = PixArtAlphaCombinedTimestepSizeEmbeddings(
+                output_channel * 2, 0
+            )
+            self.last_scale_shift_table = nn.Parameter(
+                torch.randn(2, output_channel) / output_channel**0.5
+            )
+
+    def forward(
+        self,
+        sample: torch.FloatTensor,
+        target_shape,
+        timesteps: Optional[torch.Tensor] = None,
+    ) -> torch.FloatTensor:
+        r"""The forward method of the `Decoder` class."""
+        assert target_shape is not None, "target_shape must be provided"
+        batch_size = sample.shape[0]
+
+        sample = self.conv_in(sample, causal=self.causal)
+
+        upscale_dtype = next(iter(self.up_blocks.parameters())).dtype
+
+        checkpoint_fn = (
+            partial(torch.utils.checkpoint.checkpoint, use_reentrant=False)
+            if self.gradient_checkpointing and self.training
+            else lambda x: x
+        )
+
+        sample = sample.to(upscale_dtype)
+
+        if self.timestep_conditioning:
+            assert (
+                timesteps is not None
+            ), "should pass timesteps with timestep_conditioning=True"
+            scaled_timesteps = timesteps * self.timestep_scale_multiplier
+
+        for up_block in self.up_blocks:
+            if self.timestep_conditioning and isinstance(up_block, UNetMidBlock3D):
+                sample = checkpoint_fn(up_block)(
+                    sample, causal=self.causal, timesteps=scaled_timesteps
+                )
+            else:
+                sample = checkpoint_fn(up_block)(sample, causal=self.causal)
+
+        sample = self.conv_norm_out(sample)
+
+        if self.timestep_conditioning:
+            embedded_timesteps = self.last_time_embedder(
+                timestep=scaled_timesteps.flatten(),
+                resolution=None,
+                aspect_ratio=None,
+                batch_size=sample.shape[0],
+                hidden_dtype=sample.dtype,
+            )
+            embedded_timesteps = embedded_timesteps.view(
+                batch_size, embedded_timesteps.shape[-1], 1, 1, 1
+            )
+            ada_values = self.last_scale_shift_table[
+                None, ..., None, None, None
+            ] + embedded_timesteps.reshape(
+                batch_size,
+                2,
+                -1,
+                embedded_timesteps.shape[-3],
+                embedded_timesteps.shape[-2],
+                embedded_timesteps.shape[-1],
+            )
+            shift, scale = ada_values.unbind(dim=1)
+            sample = sample * (1 + scale) + shift
+
+        sample = self.conv_act(sample)
+        sample = self.conv_out(sample, causal=self.causal)
+
+        sample = unpatchify(sample, patch_size_hw=self.patch_size, patch_size_t=1)
+
+        return sample
+
+
+class UNetMidBlock3D(nn.Module):
+    """
+    A 3D UNet mid-block [`UNetMidBlock3D`] with multiple residual blocks.
+
+    Args:
+        in_channels (`int`): The number of input channels.
+        dropout (`float`, *optional*, defaults to 0.0): The dropout rate.
+        num_layers (`int`, *optional*, defaults to 1): The number of residual blocks.
+        resnet_eps (`float`, *optional*, 1e-6 ): The epsilon value for the resnet blocks.
+        resnet_groups (`int`, *optional*, defaults to 32):
+            The number of groups to use in the group normalization layers of the resnet blocks.
+        norm_layer (`str`, *optional*, defaults to `group_norm`):
+            The normalization layer to use. Can be either `group_norm` or `pixel_norm`.
+        inject_noise (`bool`, *optional*, defaults to `False`):
+            Whether to inject noise into the hidden states.
+        timestep_conditioning (`bool`, *optional*, defaults to `False`):
+            Whether to condition the hidden states on the timestep.
+        attention_head_dim (`int`, *optional*, defaults to -1):
+            The dimension of the attention head. If -1, no attention is used.
+
+    Returns:
+        `torch.FloatTensor`: The output of the last residual block, which is a tensor of shape `(batch_size,
+        in_channels, height, width)`.
+
+    """
+
+    def __init__(
+        self,
+        dims: Union[int, Tuple[int, int]],
+        in_channels: int,
+        dropout: float = 0.0,
+        num_layers: int = 1,
+        resnet_eps: float = 1e-6,
+        resnet_groups: int = 32,
+        norm_layer: str = "group_norm",
+        inject_noise: bool = False,
+        timestep_conditioning: bool = False,
+        attention_head_dim: int = -1,
+    ):
+        super().__init__()
+        resnet_groups = (
+            resnet_groups if resnet_groups is not None else min(in_channels // 4, 32)
+        )
+        self.timestep_conditioning = timestep_conditioning
+
+        if timestep_conditioning:
+            self.time_embedder = PixArtAlphaCombinedTimestepSizeEmbeddings(
+                in_channels * 4, 0
+            )
+
+        self.res_blocks = nn.ModuleList(
+            [
+                ResnetBlock3D(
+                    dims=dims,
+                    in_channels=in_channels,
+                    out_channels=in_channels,
+                    eps=resnet_eps,
+                    groups=resnet_groups,
+                    dropout=dropout,
+                    norm_layer=norm_layer,
+                    inject_noise=inject_noise,
+                    timestep_conditioning=timestep_conditioning,
+                )
+                for _ in range(num_layers)
+            ]
+        )
+
+        self.attention_blocks = None
+
+        if attention_head_dim > 0:
+            if attention_head_dim > in_channels:
+                raise ValueError(
+                    "attention_head_dim must be less than or equal to in_channels"
+                )
+
+            self.attention_blocks = nn.ModuleList(
+                [
+                    Attention(
+                        query_dim=in_channels,
+                        heads=in_channels // attention_head_dim,
+                        dim_head=attention_head_dim,
+                        bias=True,
+                        out_bias=True,
+                        qk_norm="rms_norm",
+                        residual_connection=True,
+                    )
+                    for _ in range(num_layers)
+                ]
+            )
+
+    def forward(
+        self,
+        hidden_states: torch.FloatTensor,
+        causal: bool = True,
+        timesteps: Optional[torch.Tensor] = None,
+    ) -> torch.FloatTensor:
+        timestep_embed = None
+        if self.timestep_conditioning:
+            assert (
+                timesteps is not None
+            ), "should pass timesteps with timestep_conditioning=True"
+            batch_size = hidden_states.shape[0]
+            timestep_embed = self.time_embedder(
+                timestep=timesteps.flatten(),
+                resolution=None,
+                aspect_ratio=None,
+                batch_size=batch_size,
+                hidden_dtype=hidden_states.dtype,
+            )
+            timestep_embed = timestep_embed.view(
+                batch_size, timestep_embed.shape[-1], 1, 1, 1
+            )
+
+        if self.attention_blocks:
+            for resnet, attention in zip(self.res_blocks, self.attention_blocks):
+                hidden_states = resnet(
+                    hidden_states, causal=causal, timesteps=timestep_embed
+                )
+
+                # Reshape the hidden states to be (batch_size, frames * height * width, channel)
+                batch_size, channel, frames, height, width = hidden_states.shape
+                hidden_states = hidden_states.view(
+                    batch_size, channel, frames * height * width
+                ).transpose(1, 2)
+
+                if attention.use_tpu_flash_attention:
+                    # Pad the second dimension to be divisible by block_k_major (block in flash attention)
+                    seq_len = hidden_states.shape[1]
+                    block_k_major = 512
+                    pad_len = (block_k_major - seq_len % block_k_major) % block_k_major
+                    if pad_len > 0:
+                        hidden_states = F.pad(
+                            hidden_states, (0, 0, 0, pad_len), "constant", 0
+                        )
+
+                    # Create a mask with ones for the original sequence length and zeros for the padded indexes
+                    mask = torch.ones(
+                        (hidden_states.shape[0], seq_len),
+                        device=hidden_states.device,
+                        dtype=hidden_states.dtype,
+                    )
+                    if pad_len > 0:
+                        mask = F.pad(mask, (0, pad_len), "constant", 0)
+
+                hidden_states = attention(
+                    hidden_states,
+                    attention_mask=(
+                        None if not attention.use_tpu_flash_attention else mask
+                    ),
+                )
+
+                if attention.use_tpu_flash_attention:
+                    # Remove the padding
+                    if pad_len > 0:
+                        hidden_states = hidden_states[:, :-pad_len, :]
+
+                # Reshape the hidden states back to (batch_size, channel, frames, height, width, channel)
+                hidden_states = hidden_states.transpose(-1, -2).reshape(
+                    batch_size, channel, frames, height, width
+                )
+        else:
+            for resnet in self.res_blocks:
+                hidden_states = resnet(
+                    hidden_states, causal=causal, timesteps=timestep_embed
+                )
+
+        return hidden_states
+
+
+class DepthToSpaceUpsample(nn.Module):
+    def __init__(
+        self, dims, in_channels, stride, residual=False, out_channels_reduction_factor=1
+    ):
+        super().__init__()
+        self.stride = stride
+        self.out_channels = (
+            np.prod(stride) * in_channels // out_channels_reduction_factor
+        )
+        self.conv = make_conv_nd(
+            dims=dims,
+            in_channels=in_channels,
+            out_channels=self.out_channels,
+            kernel_size=3,
+            stride=1,
+            causal=True,
+        )
+        self.residual = residual
+        self.out_channels_reduction_factor = out_channels_reduction_factor
+
+    def forward(self, x, causal: bool = True):
+        if self.residual:
+            # Reshape and duplicate the input to match the output shape
+            x_in = rearrange(
+                x,
+                "b (c p1 p2 p3) d h w -> b c (d p1) (h p2) (w p3)",
+                p1=self.stride[0],
+                p2=self.stride[1],
+                p3=self.stride[2],
+            )
+            num_repeat = np.prod(self.stride) // self.out_channels_reduction_factor
+            x_in = x_in.repeat(1, num_repeat, 1, 1, 1)
+            if self.stride[0] == 2:
+                x_in = x_in[:, :, 1:, :, :]
+        x = self.conv(x, causal=causal)
+        x = rearrange(
+            x,
+            "b (c p1 p2 p3) d h w -> b c (d p1) (h p2) (w p3)",
+            p1=self.stride[0],
+            p2=self.stride[1],
+            p3=self.stride[2],
+        )
+        if self.stride[0] == 2:
+            x = x[:, :, 1:, :, :]
+        if self.residual:
+            x = x + x_in
+        return x
+
+
+class LayerNorm(nn.Module):
+    def __init__(self, dim, eps, elementwise_affine=True) -> None:
+        super().__init__()
+        self.norm = nn.LayerNorm(dim, eps=eps, elementwise_affine=elementwise_affine)
+
+    def forward(self, x):
+        x = rearrange(x, "b c d h w -> b d h w c")
+        x = self.norm(x)
+        x = rearrange(x, "b d h w c -> b c d h w")
+        return x
+
+
+class ResnetBlock3D(nn.Module):
+    r"""
+    A Resnet block.
+
+    Parameters:
+        in_channels (`int`): The number of channels in the input.
+        out_channels (`int`, *optional*, default to be `None`):
+            The number of output channels for the first conv layer. If None, same as `in_channels`.
+        dropout (`float`, *optional*, defaults to `0.0`): The dropout probability to use.
+        groups (`int`, *optional*, default to `32`): The number of groups to use for the first normalization layer.
+        eps (`float`, *optional*, defaults to `1e-6`): The epsilon to use for the normalization.
+    """
+
+    def __init__(
+        self,
+        dims: Union[int, Tuple[int, int]],
+        in_channels: int,
+        out_channels: Optional[int] = None,
+        dropout: float = 0.0,
+        groups: int = 32,
+        eps: float = 1e-6,
+        norm_layer: str = "group_norm",
+        inject_noise: bool = False,
+        timestep_conditioning: bool = False,
+    ):
+        super().__init__()
+        self.in_channels = in_channels
+        out_channels = in_channels if out_channels is None else out_channels
+        self.out_channels = out_channels
+        self.inject_noise = inject_noise
+
+        if norm_layer == "group_norm":
+            self.norm1 = nn.GroupNorm(
+                num_groups=groups, num_channels=in_channels, eps=eps, affine=True
+            )
+        elif norm_layer == "pixel_norm":
+            self.norm1 = PixelNorm()
+        elif norm_layer == "layer_norm":
+            self.norm1 = LayerNorm(in_channels, eps=eps, elementwise_affine=True)
+
+        self.non_linearity = nn.SiLU()
+
+        self.conv1 = make_conv_nd(
+            dims,
+            in_channels,
+            out_channels,
+            kernel_size=3,
+            stride=1,
+            padding=1,
+            causal=True,
+        )
+
+        if inject_noise:
+            self.per_channel_scale1 = nn.Parameter(torch.zeros((in_channels, 1, 1)))
+
+        if norm_layer == "group_norm":
+            self.norm2 = nn.GroupNorm(
+                num_groups=groups, num_channels=out_channels, eps=eps, affine=True
+            )
+        elif norm_layer == "pixel_norm":
+            self.norm2 = PixelNorm()
+        elif norm_layer == "layer_norm":
+            self.norm2 = LayerNorm(out_channels, eps=eps, elementwise_affine=True)
+
+        self.dropout = torch.nn.Dropout(dropout)
+
+        self.conv2 = make_conv_nd(
+            dims,
+            out_channels,
+            out_channels,
+            kernel_size=3,
+            stride=1,
+            padding=1,
+            causal=True,
+        )
+
+        if inject_noise:
+            self.per_channel_scale2 = nn.Parameter(torch.zeros((in_channels, 1, 1)))
+
+        self.conv_shortcut = (
+            make_linear_nd(
+                dims=dims, in_channels=in_channels, out_channels=out_channels
+            )
+            if in_channels != out_channels
+            else nn.Identity()
+        )
+
+        self.norm3 = (
+            LayerNorm(in_channels, eps=eps, elementwise_affine=True)
+            if in_channels != out_channels
+            else nn.Identity()
+        )
+
+        self.timestep_conditioning = timestep_conditioning
+
+        if timestep_conditioning:
+            self.scale_shift_table = nn.Parameter(
+                torch.randn(4, in_channels) / in_channels**0.5
+            )
+
+    def _feed_spatial_noise(
+        self, hidden_states: torch.FloatTensor, per_channel_scale: torch.FloatTensor
+    ) -> torch.FloatTensor:
+        spatial_shape = hidden_states.shape[-2:]
+        device = hidden_states.device
+        dtype = hidden_states.dtype
+
+        # similar to the "explicit noise inputs" method in style-gan
+        spatial_noise = torch.randn(spatial_shape, device=device, dtype=dtype)[None]
+        scaled_noise = (spatial_noise * per_channel_scale)[None, :, None, ...]
+        hidden_states = hidden_states + scaled_noise
+
+        return hidden_states
+
+    def forward(
+        self,
+        input_tensor: torch.FloatTensor,
+        causal: bool = True,
+        timesteps: Optional[torch.Tensor] = None,
+    ) -> torch.FloatTensor:
+        hidden_states = input_tensor
+        batch_size = hidden_states.shape[0]
+
+        hidden_states = self.norm1(hidden_states)
+        if self.timestep_conditioning:
+            assert (
+                timesteps is not None
+            ), "should pass timesteps with timestep_conditioning=True"
+            ada_values = self.scale_shift_table[
+                None, ..., None, None, None
+            ] + timesteps.reshape(
+                batch_size,
+                4,
+                -1,
+                timesteps.shape[-3],
+                timesteps.shape[-2],
+                timesteps.shape[-1],
+            )
+            shift1, scale1, shift2, scale2 = ada_values.unbind(dim=1)
+
+            hidden_states = hidden_states * (1 + scale1) + shift1
+
+        hidden_states = self.non_linearity(hidden_states)
+
+        hidden_states = self.conv1(hidden_states, causal=causal)
+
+        if self.inject_noise:
+            hidden_states = self._feed_spatial_noise(
+                hidden_states, self.per_channel_scale1
+            )
+
+        hidden_states = self.norm2(hidden_states)
+
+        if self.timestep_conditioning:
+            hidden_states = hidden_states * (1 + scale2) + shift2
+
+        hidden_states = self.non_linearity(hidden_states)
+
+        hidden_states = self.dropout(hidden_states)
+
+        hidden_states = self.conv2(hidden_states, causal=causal)
+
+        if self.inject_noise:
+            hidden_states = self._feed_spatial_noise(
+                hidden_states, self.per_channel_scale2
+            )
+
+        input_tensor = self.norm3(input_tensor)
+
+        batch_size = input_tensor.shape[0]
+
+        input_tensor = self.conv_shortcut(input_tensor)
+
+        output_tensor = input_tensor + hidden_states
+
+        return output_tensor
+
+
+def patchify(x, patch_size_hw, patch_size_t=1):
+    if patch_size_hw == 1 and patch_size_t == 1:
+        return x
+    if x.dim() == 4:
+        x = rearrange(
+            x, "b c (h q) (w r) -> b (c r q) h w", q=patch_size_hw, r=patch_size_hw
+        )
+    elif x.dim() == 5:
+        x = rearrange(
+            x,
+            "b c (f p) (h q) (w r) -> b (c p r q) f h w",
+            p=patch_size_t,
+            q=patch_size_hw,
+            r=patch_size_hw,
+        )
+    else:
+        raise ValueError(f"Invalid input shape: {x.shape}")
+
+    return x
+
+
+def unpatchify(x, patch_size_hw, patch_size_t=1):
+    if patch_size_hw == 1 and patch_size_t == 1:
+        return x
+
+    if x.dim() == 4:
+        x = rearrange(
+            x, "b (c r q) h w -> b c (h q) (w r)", q=patch_size_hw, r=patch_size_hw
+        )
+    elif x.dim() == 5:
+        x = rearrange(
+            x,
+            "b (c p r q) f h w -> b c (f p) (h q) (w r)",
+            p=patch_size_t,
+            q=patch_size_hw,
+            r=patch_size_hw,
+        )
+
+    return x
+
+
+def create_video_autoencoder_config(
+    latent_channels: int = 64,
+):
+    encoder_blocks = [
+        ("res_x", {"num_layers": 4}),
+        ("compress_all_x_y", {"multiplier": 3}),
+        ("res_x", {"num_layers": 4}),
+        ("compress_all_x_y", {"multiplier": 2}),
+        ("res_x", {"num_layers": 4}),
+        ("compress_all", {}),
+        ("res_x", {"num_layers": 3}),
+        ("res_x", {"num_layers": 4}),
+    ]
+    decoder_blocks = [
+        ("res_x", {"num_layers": 4}),
+        ("compress_all", {"residual": True}),
+        ("res_x_y", {"multiplier": 3}),
+        ("res_x", {"num_layers": 3}),
+        ("compress_all", {"residual": True}),
+        ("res_x_y", {"multiplier": 2}),
+        ("res_x", {"num_layers": 3}),
+        ("compress_all", {"residual": True}),
+        ("res_x", {"num_layers": 3}),
+        ("res_x", {"num_layers": 4}),
+    ]
+    return {
+        "_class_name": "CausalVideoAutoencoder",
+        "dims": 3,
+        "encoder_blocks": encoder_blocks,
+        "decoder_blocks": decoder_blocks,
+        "latent_channels": latent_channels,
+        "norm_layer": "pixel_norm",
+        "patch_size": 4,
+        "latent_log_var": "uniform",
+        "use_quant_conv": False,
+        "causal_decoder": False,
+        "timestep_conditioning": True,
+    }
+
+
+def test_vae_patchify_unpatchify():
+    import torch
+
+    x = torch.randn(2, 3, 8, 64, 64)
+    x_patched = patchify(x, patch_size_hw=4, patch_size_t=4)
+    x_unpatched = unpatchify(x_patched, patch_size_hw=4, patch_size_t=4)
+    assert torch.allclose(x, x_unpatched)
+
+
+def demo_video_autoencoder_forward_backward():
+    # Configuration for the VideoAutoencoder
+    config = create_video_autoencoder_config()
+
+    # Instantiate the VideoAutoencoder with the specified configuration
+    video_autoencoder = CausalVideoAutoencoder.from_config(config)
+
+    print(video_autoencoder)
+    video_autoencoder.eval()
+    # Print the total number of parameters in the video autoencoder
+    total_params = sum(p.numel() for p in video_autoencoder.parameters())
+    print(f"Total number of parameters in VideoAutoencoder: {total_params:,}")
+
+    # Create a mock input tensor simulating a batch of videos
+    # Shape: (batch_size, channels, depth, height, width)
+    # E.g., 4 videos, each with 3 color channels, 16 frames, and 64x64 pixels per frame
+    input_videos = torch.randn(2, 3, 17, 64, 64)
+
+    # Forward pass: encode and decode the input videos
+    latent = video_autoencoder.encode(input_videos).latent_dist.mode()
+    print(f"input shape={input_videos.shape}")
+    print(f"latent shape={latent.shape}")
+
+    timesteps = torch.ones(input_videos.shape[0]) * 0.1
+    reconstructed_videos = video_autoencoder.decode(
+        latent, target_shape=input_videos.shape, timesteps=timesteps
+    ).sample
+
+    print(f"reconstructed shape={reconstructed_videos.shape}")
+
+    # Validate that single image gets treated the same way as first frame
+    input_image = input_videos[:, :, :1, :, :]
+    image_latent = video_autoencoder.encode(input_image).latent_dist.mode()
+    _ = video_autoencoder.decode(
+        image_latent, target_shape=image_latent.shape, timesteps=timesteps
+    ).sample
+
+    # first_frame_latent = latent[:, :, :1, :, :]
+
+    # assert torch.allclose(image_latent, first_frame_latent, atol=1e-6)
+    # assert torch.allclose(reconstructed_image, reconstructed_videos[:, :, :1, :, :], atol=1e-6)
+    # assert (image_latent == first_frame_latent).all()
+    # assert (reconstructed_image == reconstructed_videos[:, :, :1, :, :]).all()
+
+    # Calculate the loss (e.g., mean squared error)
+    loss = torch.nn.functional.mse_loss(input_videos, reconstructed_videos)
+
+    # Perform backward pass
+    loss.backward()
+
+    print(f"Demo completed with loss: {loss.item()}")
+
+
+# Ensure to call the demo function to execute the forward and backward pass
+if __name__ == "__main__":
+    demo_video_autoencoder_forward_backward()

xora/models/autoencoders/conv_nd_factory.py

@@ -0,0 +1,82 @@
+from typing import Tuple, Union
+
+import torch
+
+from xora.models.autoencoders.dual_conv3d import DualConv3d
+from xora.models.autoencoders.causal_conv3d import CausalConv3d
+
+
+def make_conv_nd(
+    dims: Union[int, Tuple[int, int]],
+    in_channels: int,
+    out_channels: int,
+    kernel_size: int,
+    stride=1,
+    padding=0,
+    dilation=1,
+    groups=1,
+    bias=True,
+    causal=False,
+):
+    if dims == 2:
+        return torch.nn.Conv2d(
+            in_channels=in_channels,
+            out_channels=out_channels,
+            kernel_size=kernel_size,
+            stride=stride,
+            padding=padding,
+            dilation=dilation,
+            groups=groups,
+            bias=bias,
+        )
+    elif dims == 3:
+        if causal:
+            return CausalConv3d(
+                in_channels=in_channels,
+                out_channels=out_channels,
+                kernel_size=kernel_size,
+                stride=stride,
+                padding=padding,
+                dilation=dilation,
+                groups=groups,
+                bias=bias,
+            )
+        return torch.nn.Conv3d(
+            in_channels=in_channels,
+            out_channels=out_channels,
+            kernel_size=kernel_size,
+            stride=stride,
+            padding=padding,
+            dilation=dilation,
+            groups=groups,
+            bias=bias,
+        )
+    elif dims == (2, 1):
+        return DualConv3d(
+            in_channels=in_channels,
+            out_channels=out_channels,
+            kernel_size=kernel_size,
+            stride=stride,
+            padding=padding,
+            bias=bias,
+        )
+    else:
+        raise ValueError(f"unsupported dimensions: {dims}")
+
+
+def make_linear_nd(
+    dims: int,
+    in_channels: int,
+    out_channels: int,
+    bias=True,
+):
+    if dims == 2:
+        return torch.nn.Conv2d(
+            in_channels=in_channels, out_channels=out_channels, kernel_size=1, bias=bias
+        )
+    elif dims == 3 or dims == (2, 1):
+        return torch.nn.Conv3d(
+            in_channels=in_channels, out_channels=out_channels, kernel_size=1, bias=bias
+        )
+    else:
+        raise ValueError(f"unsupported dimensions: {dims}")

xora/models/autoencoders/dual_conv3d.py

@@ -0,0 +1,195 @@
+import math
+from typing import Tuple, Union
+
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+from einops import rearrange
+
+
+class DualConv3d(nn.Module):
+    def __init__(
+        self,
+        in_channels,
+        out_channels,
+        kernel_size,
+        stride: Union[int, Tuple[int, int, int]] = 1,
+        padding: Union[int, Tuple[int, int, int]] = 0,
+        dilation: Union[int, Tuple[int, int, int]] = 1,
+        groups=1,
+        bias=True,
+    ):
+        super(DualConv3d, self).__init__()
+
+        self.in_channels = in_channels
+        self.out_channels = out_channels
+        # Ensure kernel_size, stride, padding, and dilation are tuples of length 3
+        if isinstance(kernel_size, int):
+            kernel_size = (kernel_size, kernel_size, kernel_size)
+        if kernel_size == (1, 1, 1):
+            raise ValueError(
+                "kernel_size must be greater than 1. Use make_linear_nd instead."
+            )
+        if isinstance(stride, int):
+            stride = (stride, stride, stride)
+        if isinstance(padding, int):
+            padding = (padding, padding, padding)
+        if isinstance(dilation, int):
+            dilation = (dilation, dilation, dilation)
+
+        # Set parameters for convolutions
+        self.groups = groups
+        self.bias = bias
+
+        # Define the size of the channels after the first convolution
+        intermediate_channels = (
+            out_channels if in_channels < out_channels else in_channels
+        )
+
+        # Define parameters for the first convolution
+        self.weight1 = nn.Parameter(
+            torch.Tensor(
+                intermediate_channels,
+                in_channels // groups,
+                1,
+                kernel_size[1],
+                kernel_size[2],
+            )
+        )
+        self.stride1 = (1, stride[1], stride[2])
+        self.padding1 = (0, padding[1], padding[2])
+        self.dilation1 = (1, dilation[1], dilation[2])
+        if bias:
+            self.bias1 = nn.Parameter(torch.Tensor(intermediate_channels))
+        else:
+            self.register_parameter("bias1", None)
+
+        # Define parameters for the second convolution
+        self.weight2 = nn.Parameter(
+            torch.Tensor(
+                out_channels, intermediate_channels // groups, kernel_size[0], 1, 1
+            )
+        )
+        self.stride2 = (stride[0], 1, 1)
+        self.padding2 = (padding[0], 0, 0)
+        self.dilation2 = (dilation[0], 1, 1)
+        if bias:
+            self.bias2 = nn.Parameter(torch.Tensor(out_channels))
+        else:
+            self.register_parameter("bias2", None)
+
+        # Initialize weights and biases
+        self.reset_parameters()
+
+    def reset_parameters(self):
+        nn.init.kaiming_uniform_(self.weight1, a=math.sqrt(5))
+        nn.init.kaiming_uniform_(self.weight2, a=math.sqrt(5))
+        if self.bias:
+            fan_in1, _ = nn.init._calculate_fan_in_and_fan_out(self.weight1)
+            bound1 = 1 / math.sqrt(fan_in1)
+            nn.init.uniform_(self.bias1, -bound1, bound1)
+            fan_in2, _ = nn.init._calculate_fan_in_and_fan_out(self.weight2)
+            bound2 = 1 / math.sqrt(fan_in2)
+            nn.init.uniform_(self.bias2, -bound2, bound2)
+
+    def forward(self, x, use_conv3d=False, skip_time_conv=False):
+        if use_conv3d:
+            return self.forward_with_3d(x=x, skip_time_conv=skip_time_conv)
+        else:
+            return self.forward_with_2d(x=x, skip_time_conv=skip_time_conv)
+
+    def forward_with_3d(self, x, skip_time_conv):
+        # First convolution
+        x = F.conv3d(
+            x,
+            self.weight1,
+            self.bias1,
+            self.stride1,
+            self.padding1,
+            self.dilation1,
+            self.groups,
+        )
+
+        if skip_time_conv:
+            return x
+
+        # Second convolution
+        x = F.conv3d(
+            x,
+            self.weight2,
+            self.bias2,
+            self.stride2,
+            self.padding2,
+            self.dilation2,
+            self.groups,
+        )
+
+        return x
+
+    def forward_with_2d(self, x, skip_time_conv):
+        b, c, d, h, w = x.shape
+
+        # First 2D convolution
+        x = rearrange(x, "b c d h w -> (b d) c h w")
+        # Squeeze the depth dimension out of weight1 since it's 1
+        weight1 = self.weight1.squeeze(2)
+        # Select stride, padding, and dilation for the 2D convolution
+        stride1 = (self.stride1[1], self.stride1[2])
+        padding1 = (self.padding1[1], self.padding1[2])
+        dilation1 = (self.dilation1[1], self.dilation1[2])
+        x = F.conv2d(x, weight1, self.bias1, stride1, padding1, dilation1, self.groups)
+
+        _, _, h, w = x.shape
+
+        if skip_time_conv:
+            x = rearrange(x, "(b d) c h w -> b c d h w", b=b)
+            return x
+
+        # Second convolution which is essentially treated as a 1D convolution across the 'd' dimension
+        x = rearrange(x, "(b d) c h w -> (b h w) c d", b=b)
+
+        # Reshape weight2 to match the expected dimensions for conv1d
+        weight2 = self.weight2.squeeze(-1).squeeze(-1)
+        # Use only the relevant dimension for stride, padding, and dilation for the 1D convolution
+        stride2 = self.stride2[0]
+        padding2 = self.padding2[0]
+        dilation2 = self.dilation2[0]
+        x = F.conv1d(x, weight2, self.bias2, stride2, padding2, dilation2, self.groups)
+        x = rearrange(x, "(b h w) c d -> b c d h w", b=b, h=h, w=w)
+
+        return x
+
+    @property
+    def weight(self):
+        return self.weight2
+
+
+def test_dual_conv3d_consistency():
+    # Initialize parameters
+    in_channels = 3
+    out_channels = 5
+    kernel_size = (3, 3, 3)
+    stride = (2, 2, 2)
+    padding = (1, 1, 1)
+
+    # Create an instance of the DualConv3d class
+    dual_conv3d = DualConv3d(
+        in_channels=in_channels,
+        out_channels=out_channels,
+        kernel_size=kernel_size,
+        stride=stride,
+        padding=padding,
+        bias=True,
+    )
+
+    # Example input tensor
+    test_input = torch.randn(1, 3, 10, 10, 10)
+
+    # Perform forward passes with both 3D and 2D settings
+    output_conv3d = dual_conv3d(test_input, use_conv3d=True)
+    output_2d = dual_conv3d(test_input, use_conv3d=False)
+
+    # Assert that the outputs from both methods are sufficiently close
+    assert torch.allclose(
+        output_conv3d, output_2d, atol=1e-6
+    ), "Outputs are not consistent between 3D and 2D convolutions."

xora/models/autoencoders/pixel_norm.py

@@ -0,0 +1,12 @@
+import torch
+from torch import nn
+
+
+class PixelNorm(nn.Module):
+    def __init__(self, dim=1, eps=1e-8):
+        super(PixelNorm, self).__init__()
+        self.dim = dim
+        self.eps = eps
+
+    def forward(self, x):
+        return x / torch.sqrt(torch.mean(x**2, dim=self.dim, keepdim=True) + self.eps)

xora/models/autoencoders/vae.py

@@ -0,0 +1,343 @@
+from typing import Optional, Union
+
+import torch
+import inspect
+import math
+import torch.nn as nn
+from diffusers import ConfigMixin, ModelMixin
+from diffusers.models.autoencoders.vae import (
+    DecoderOutput,
+    DiagonalGaussianDistribution,
+)
+from diffusers.models.modeling_outputs import AutoencoderKLOutput
+from xora.models.autoencoders.conv_nd_factory import make_conv_nd
+
+
+class AutoencoderKLWrapper(ModelMixin, ConfigMixin):
+    """Variational Autoencoder (VAE) model with KL loss.
+
+    VAE from the paper Auto-Encoding Variational Bayes by Diederik P. Kingma and Max Welling.
+    This model is a wrapper around an encoder and a decoder, and it adds a KL loss term to the reconstruction loss.
+
+    Args:
+        encoder (`nn.Module`):
+            Encoder module.
+        decoder (`nn.Module`):
+            Decoder module.
+        latent_channels (`int`, *optional*, defaults to 4):
+            Number of latent channels.
+    """
+
+    def __init__(
+        self,
+        encoder: nn.Module,
+        decoder: nn.Module,
+        latent_channels: int = 4,
+        dims: int = 2,
+        sample_size=512,
+        use_quant_conv: bool = True,
+    ):
+        super().__init__()
+
+        # pass init params to Encoder
+        self.encoder = encoder
+        self.use_quant_conv = use_quant_conv
+
+        # pass init params to Decoder
+        quant_dims = 2 if dims == 2 else 3
+        self.decoder = decoder
+        if use_quant_conv:
+            self.quant_conv = make_conv_nd(
+                quant_dims, 2 * latent_channels, 2 * latent_channels, 1
+            )
+            self.post_quant_conv = make_conv_nd(
+                quant_dims, latent_channels, latent_channels, 1
+            )
+        else:
+            self.quant_conv = nn.Identity()
+            self.post_quant_conv = nn.Identity()
+        self.use_z_tiling = False
+        self.use_hw_tiling = False
+        self.dims = dims
+        self.z_sample_size = 1
+
+        self.decoder_params = inspect.signature(self.decoder.forward).parameters
+
+        # only relevant if vae tiling is enabled
+        self.set_tiling_params(sample_size=sample_size, overlap_factor=0.25)
+
+    def set_tiling_params(self, sample_size: int = 512, overlap_factor: float = 0.25):
+        self.tile_sample_min_size = sample_size
+        num_blocks = len(self.encoder.down_blocks)
+        self.tile_latent_min_size = int(sample_size / (2 ** (num_blocks - 1)))
+        self.tile_overlap_factor = overlap_factor
+
+    def enable_z_tiling(self, z_sample_size: int = 8):
+        r"""
+        Enable tiling during VAE decoding.
+
+        When this option is enabled, the VAE will split the input tensor in tiles to compute decoding in several
+        steps. This is useful to save some memory and allow larger batch sizes.
+        """
+        self.use_z_tiling = z_sample_size > 1
+        self.z_sample_size = z_sample_size
+        assert (
+            z_sample_size % 8 == 0 or z_sample_size == 1
+        ), f"z_sample_size must be a multiple of 8 or 1. Got {z_sample_size}."
+
+    def disable_z_tiling(self):
+        r"""
+        Disable tiling during VAE decoding. If `use_tiling` was previously invoked, this method will go back to computing
+        decoding in one step.
+        """
+        self.use_z_tiling = False
+
+    def enable_hw_tiling(self):
+        r"""
+        Enable tiling during VAE decoding along the height and width dimension.
+        """
+        self.use_hw_tiling = True
+
+    def disable_hw_tiling(self):
+        r"""
+        Disable tiling during VAE decoding along the height and width dimension.
+        """
+        self.use_hw_tiling = False
+
+    def _hw_tiled_encode(self, x: torch.FloatTensor, return_dict: bool = True):
+        overlap_size = int(self.tile_sample_min_size * (1 - self.tile_overlap_factor))
+        blend_extent = int(self.tile_latent_min_size * self.tile_overlap_factor)
+        row_limit = self.tile_latent_min_size - blend_extent
+
+        # Split the image into 512x512 tiles and encode them separately.
+        rows = []
+        for i in range(0, x.shape[3], overlap_size):
+            row = []
+            for j in range(0, x.shape[4], overlap_size):
+                tile = x[
+                    :,
+                    :,
+                    :,
+                    i : i + self.tile_sample_min_size,
+                    j : j + self.tile_sample_min_size,
+                ]
+                tile = self.encoder(tile)
+                tile = self.quant_conv(tile)
+                row.append(tile)
+            rows.append(row)
+        result_rows = []
+        for i, row in enumerate(rows):
+            result_row = []
+            for j, tile in enumerate(row):
+                # blend the above tile and the left tile
+                # to the current tile and add the current tile to the result row
+                if i > 0:
+                    tile = self.blend_v(rows[i - 1][j], tile, blend_extent)
+                if j > 0:
+                    tile = self.blend_h(row[j - 1], tile, blend_extent)
+                result_row.append(tile[:, :, :, :row_limit, :row_limit])
+            result_rows.append(torch.cat(result_row, dim=4))
+
+        moments = torch.cat(result_rows, dim=3)
+        return moments
+
+    def blend_z(
+        self, a: torch.Tensor, b: torch.Tensor, blend_extent: int
+    ) -> torch.Tensor:
+        blend_extent = min(a.shape[2], b.shape[2], blend_extent)
+        for z in range(blend_extent):
+            b[:, :, z, :, :] = a[:, :, -blend_extent + z, :, :] * (
+                1 - z / blend_extent
+            ) + b[:, :, z, :, :] * (z / blend_extent)
+        return b
+
+    def blend_v(
+        self, a: torch.Tensor, b: torch.Tensor, blend_extent: int
+    ) -> torch.Tensor:
+        blend_extent = min(a.shape[3], b.shape[3], blend_extent)
+        for y in range(blend_extent):
+            b[:, :, :, y, :] = a[:, :, :, -blend_extent + y, :] * (
+                1 - y / blend_extent
+            ) + b[:, :, :, y, :] * (y / blend_extent)
+        return b
+
+    def blend_h(
+        self, a: torch.Tensor, b: torch.Tensor, blend_extent: int
+    ) -> torch.Tensor:
+        blend_extent = min(a.shape[4], b.shape[4], blend_extent)
+        for x in range(blend_extent):
+            b[:, :, :, :, x] = a[:, :, :, :, -blend_extent + x] * (
+                1 - x / blend_extent
+            ) + b[:, :, :, :, x] * (x / blend_extent)
+        return b
+
+    def _hw_tiled_decode(self, z: torch.FloatTensor, target_shape):
+        overlap_size = int(self.tile_latent_min_size * (1 - self.tile_overlap_factor))
+        blend_extent = int(self.tile_sample_min_size * self.tile_overlap_factor)
+        row_limit = self.tile_sample_min_size - blend_extent
+        tile_target_shape = (
+            *target_shape[:3],
+            self.tile_sample_min_size,
+            self.tile_sample_min_size,
+        )
+        # Split z into overlapping 64x64 tiles and decode them separately.
+        # The tiles have an overlap to avoid seams between tiles.
+        rows = []
+        for i in range(0, z.shape[3], overlap_size):
+            row = []
+            for j in range(0, z.shape[4], overlap_size):
+                tile = z[
+                    :,
+                    :,
+                    :,
+                    i : i + self.tile_latent_min_size,
+                    j : j + self.tile_latent_min_size,
+                ]
+                tile = self.post_quant_conv(tile)
+                decoded = self.decoder(tile, target_shape=tile_target_shape)
+                row.append(decoded)
+            rows.append(row)
+        result_rows = []
+        for i, row in enumerate(rows):
+            result_row = []
+            for j, tile in enumerate(row):
+                # blend the above tile and the left tile
+                # to the current tile and add the current tile to the result row
+                if i > 0:
+                    tile = self.blend_v(rows[i - 1][j], tile, blend_extent)
+                if j > 0:
+                    tile = self.blend_h(row[j - 1], tile, blend_extent)
+                result_row.append(tile[:, :, :, :row_limit, :row_limit])
+            result_rows.append(torch.cat(result_row, dim=4))
+
+        dec = torch.cat(result_rows, dim=3)
+        return dec
+
+    def encode(
+        self, z: torch.FloatTensor, return_dict: bool = True
+    ) -> Union[DecoderOutput, torch.FloatTensor]:
+        if self.use_z_tiling and z.shape[2] > self.z_sample_size > 1:
+            num_splits = z.shape[2] // self.z_sample_size
+            sizes = [self.z_sample_size] * num_splits
+            sizes = (
+                sizes + [z.shape[2] - sum(sizes)]
+                if z.shape[2] - sum(sizes) > 0
+                else sizes
+            )
+            tiles = z.split(sizes, dim=2)
+            moments_tiles = [
+                (
+                    self._hw_tiled_encode(z_tile, return_dict)
+                    if self.use_hw_tiling
+                    else self._encode(z_tile)
+                )
+                for z_tile in tiles
+            ]
+            moments = torch.cat(moments_tiles, dim=2)
+
+        else:
+            moments = (
+                self._hw_tiled_encode(z, return_dict)
+                if self.use_hw_tiling
+                else self._encode(z)
+            )
+
+        posterior = DiagonalGaussianDistribution(moments)
+        if not return_dict:
+            return (posterior,)
+
+        return AutoencoderKLOutput(latent_dist=posterior)
+
+    def _encode(self, x: torch.FloatTensor) -> AutoencoderKLOutput:
+        h = self.encoder(x)
+        moments = self.quant_conv(h)
+        return moments
+
+    def _decode(
+        self,
+        z: torch.FloatTensor,
+        target_shape=None,
+        timesteps: Optional[torch.Tensor] = None,
+    ) -> Union[DecoderOutput, torch.FloatTensor]:
+        z = self.post_quant_conv(z)
+        if "timesteps" in self.decoder_params:
+            dec = self.decoder(z, target_shape=target_shape, timesteps=timesteps)
+        else:
+            dec = self.decoder(z, target_shape=target_shape)
+        return dec
+
+    def decode(
+        self,
+        z: torch.FloatTensor,
+        return_dict: bool = True,
+        target_shape=None,
+        timesteps: Optional[torch.Tensor] = None,
+    ) -> Union[DecoderOutput, torch.FloatTensor]:
+        assert target_shape is not None, "target_shape must be provided for decoding"
+        if self.use_z_tiling and z.shape[2] > self.z_sample_size > 1:
+            reduction_factor = int(
+                self.encoder.patch_size_t
+                * 2
+                ** (
+                    len(self.encoder.down_blocks)
+                    - 1
+                    - math.sqrt(self.encoder.patch_size)
+                )
+            )
+            split_size = self.z_sample_size // reduction_factor
+            num_splits = z.shape[2] // split_size
+
+            # copy target shape, and divide frame dimension (=2) by the context size
+            target_shape_split = list(target_shape)
+            target_shape_split[2] = target_shape[2] // num_splits
+
+            decoded_tiles = [
+                (
+                    self._hw_tiled_decode(z_tile, target_shape_split)
+                    if self.use_hw_tiling
+                    else self._decode(z_tile, target_shape=target_shape_split)
+                )
+                for z_tile in torch.tensor_split(z, num_splits, dim=2)
+            ]
+            decoded = torch.cat(decoded_tiles, dim=2)
+        else:
+            decoded = (
+                self._hw_tiled_decode(z, target_shape)
+                if self.use_hw_tiling
+                else self._decode(z, target_shape=target_shape, timesteps=timesteps)
+            )
+
+        if not return_dict:
+            return (decoded,)
+
+        return DecoderOutput(sample=decoded)
+
+    def forward(
+        self,
+        sample: torch.FloatTensor,
+        sample_posterior: bool = False,
+        return_dict: bool = True,
+        generator: Optional[torch.Generator] = None,
+    ) -> Union[DecoderOutput, torch.FloatTensor]:
+        r"""
+        Args:
+            sample (`torch.FloatTensor`): Input sample.
+            sample_posterior (`bool`, *optional*, defaults to `False`):
+                Whether to sample from the posterior.
+            return_dict (`bool`, *optional*, defaults to `True`):
+                Whether to return a [`DecoderOutput`] instead of a plain tuple.
+            generator (`torch.Generator`, *optional*):
+                Generator used to sample from the posterior.
+        """
+        x = sample
+        posterior = self.encode(x).latent_dist
+        if sample_posterior:
+            z = posterior.sample(generator=generator)
+        else:
+            z = posterior.mode()
+        dec = self.decode(z, target_shape=sample.shape).sample
+
+        if not return_dict:
+            return (dec,)
+
+        return DecoderOutput(sample=dec)

xora/models/autoencoders/vae_encode.py

@@ -0,0 +1,190 @@
+import torch
+from diffusers import AutoencoderKL
+from einops import rearrange
+from torch import Tensor
+
+
+from xora.models.autoencoders.causal_video_autoencoder import CausalVideoAutoencoder
+from xora.models.autoencoders.video_autoencoder import Downsample3D, VideoAutoencoder
+
+try:
+    import torch_xla.core.xla_model as xm
+except ImportError:
+    xm = None
+
+
+def vae_encode(
+    media_items: Tensor,
+    vae: AutoencoderKL,
+    split_size: int = 1,
+    vae_per_channel_normalize=False,
+) -> Tensor:
+    """
+    Encodes media items (images or videos) into latent representations using a specified VAE model.
+    The function supports processing batches of images or video frames and can handle the processing
+    in smaller sub-batches if needed.
+
+    Args:
+        media_items (Tensor): A torch Tensor containing the media items to encode. The expected
+            shape is (batch_size, channels, height, width) for images or (batch_size, channels,
+            frames, height, width) for videos.
+        vae (AutoencoderKL): An instance of the `AutoencoderKL` class from the `diffusers` library,
+            pre-configured and loaded with the appropriate model weights.
+        split_size (int, optional): The number of sub-batches to split the input batch into for encoding.
+            If set to more than 1, the input media items are processed in smaller batches according to
+            this value. Defaults to 1, which processes all items in a single batch.
+
+    Returns:
+        Tensor: A torch Tensor of the encoded latent representations. The shape of the tensor is adjusted
+            to match the input shape, scaled by the model's configuration.
+
+    Examples:
+        >>> import torch
+        >>> from diffusers import AutoencoderKL
+        >>> vae = AutoencoderKL.from_pretrained('your-model-name')
+        >>> images = torch.rand(10, 3, 8 256, 256)  # Example tensor with 10 videos of 8 frames.
+        >>> latents = vae_encode(images, vae)
+        >>> print(latents.shape)  # Output shape will depend on the model's latent configuration.
+
+    Note:
+        In case of a video, the function encodes the media item frame-by frame.
+    """
+    is_video_shaped = media_items.dim() == 5
+    batch_size, channels = media_items.shape[0:2]
+
+    if channels != 3:
+        raise ValueError(f"Expects tensors with 3 channels, got {channels}.")
+
+    if is_video_shaped and not isinstance(
+        vae, (VideoAutoencoder, CausalVideoAutoencoder)
+    ):
+        media_items = rearrange(media_items, "b c n h w -> (b n) c h w")
+    if split_size > 1:
+        if len(media_items) % split_size != 0:
+            raise ValueError(
+                "Error: The batch size must be divisible by 'train.vae_bs_split"
+            )
+        encode_bs = len(media_items) // split_size
+        # latents = [vae.encode(image_batch).latent_dist.sample() for image_batch in media_items.split(encode_bs)]
+        latents = []
+        if media_items.device.type == "xla":
+            xm.mark_step()
+        for image_batch in media_items.split(encode_bs):
+            latents.append(vae.encode(image_batch).latent_dist.sample())
+            if media_items.device.type == "xla":
+                xm.mark_step()
+        latents = torch.cat(latents, dim=0)
+    else:
+        latents = vae.encode(media_items).latent_dist.sample()
+
+    latents = normalize_latents(latents, vae, vae_per_channel_normalize)
+    if is_video_shaped and not isinstance(
+        vae, (VideoAutoencoder, CausalVideoAutoencoder)
+    ):
+        latents = rearrange(latents, "(b n) c h w -> b c n h w", b=batch_size)
+    return latents
+
+
+def vae_decode(
+    latents: Tensor,
+    vae: AutoencoderKL,
+    is_video: bool = True,
+    split_size: int = 1,
+    vae_per_channel_normalize=False,
+) -> Tensor:
+    is_video_shaped = latents.dim() == 5
+    batch_size = latents.shape[0]
+
+    if is_video_shaped and not isinstance(
+        vae, (VideoAutoencoder, CausalVideoAutoencoder)
+    ):
+        latents = rearrange(latents, "b c n h w -> (b n) c h w")
+    if split_size > 1:
+        if len(latents) % split_size != 0:
+            raise ValueError(
+                "Error: The batch size must be divisible by 'train.vae_bs_split"
+            )
+        encode_bs = len(latents) // split_size
+        image_batch = [
+            _run_decoder(latent_batch, vae, is_video, vae_per_channel_normalize)
+            for latent_batch in latents.split(encode_bs)
+        ]
+        images = torch.cat(image_batch, dim=0)
+    else:
+        images = _run_decoder(latents, vae, is_video, vae_per_channel_normalize)
+
+    if is_video_shaped and not isinstance(
+        vae, (VideoAutoencoder, CausalVideoAutoencoder)
+    ):
+        images = rearrange(images, "(b n) c h w -> b c n h w", b=batch_size)
+    return images
+
+
+def _run_decoder(
+    latents: Tensor, vae: AutoencoderKL, is_video: bool, vae_per_channel_normalize=False
+) -> Tensor:
+    if isinstance(vae, (VideoAutoencoder, CausalVideoAutoencoder)):
+        *_, fl, hl, wl = latents.shape
+        temporal_scale, spatial_scale, _ = get_vae_size_scale_factor(vae)
+        latents = latents.to(vae.dtype)
+        image = vae.decode(
+            un_normalize_latents(latents, vae, vae_per_channel_normalize),
+            return_dict=False,
+            target_shape=(
+                1,
+                3,
+                fl * temporal_scale if is_video else 1,
+                hl * spatial_scale,
+                wl * spatial_scale,
+            ),
+        )[0]
+    else:
+        image = vae.decode(
+            un_normalize_latents(latents, vae, vae_per_channel_normalize),
+            return_dict=False,
+        )[0]
+    return image
+
+
+def get_vae_size_scale_factor(vae: AutoencoderKL) -> float:
+    if isinstance(vae, CausalVideoAutoencoder):
+        spatial = vae.spatial_downscale_factor
+        temporal = vae.temporal_downscale_factor
+    else:
+        down_blocks = len(
+            [
+                block
+                for block in vae.encoder.down_blocks
+                if isinstance(block.downsample, Downsample3D)
+            ]
+        )
+        spatial = vae.config.patch_size * 2**down_blocks
+        temporal = (
+            vae.config.patch_size_t * 2**down_blocks
+            if isinstance(vae, VideoAutoencoder)
+            else 1
+        )
+
+    return (temporal, spatial, spatial)
+
+
+def normalize_latents(
+    latents: Tensor, vae: AutoencoderKL, vae_per_channel_normalize: bool = False
+) -> Tensor:
+    return (
+        (latents - vae.mean_of_means.to(latents.dtype).view(1, -1, 1, 1, 1))
+        / vae.std_of_means.to(latents.dtype).view(1, -1, 1, 1, 1)
+        if vae_per_channel_normalize
+        else latents * vae.config.scaling_factor
+    )
+
+
+def un_normalize_latents(
+    latents: Tensor, vae: AutoencoderKL, vae_per_channel_normalize: bool = False
+) -> Tensor:
+    return (
+        latents * vae.std_of_means.to(latents.dtype).view(1, -1, 1, 1, 1)
+        + vae.mean_of_means.to(latents.dtype).view(1, -1, 1, 1, 1)
+        if vae_per_channel_normalize
+        else latents / vae.config.scaling_factor
+    )

xora/models/autoencoders/video_autoencoder.py

@@ -0,0 +1,1045 @@
+import json
+import os
+from functools import partial
+from types import SimpleNamespace
+from typing import Any, Mapping, Optional, Tuple, Union
+
+import torch
+from einops import rearrange
+from torch import nn
+from torch.nn import functional
+
+from diffusers.utils import logging
+
+from xora.utils.torch_utils import Identity
+from xora.models.autoencoders.conv_nd_factory import make_conv_nd, make_linear_nd
+from xora.models.autoencoders.pixel_norm import PixelNorm
+from xora.models.autoencoders.vae import AutoencoderKLWrapper
+
+logger = logging.get_logger(__name__)
+
+
+class VideoAutoencoder(AutoencoderKLWrapper):
+    @classmethod
+    def from_pretrained(
+        cls,
+        pretrained_model_name_or_path: Optional[Union[str, os.PathLike]],
+        *args,
+        **kwargs,
+    ):
+        config_local_path = pretrained_model_name_or_path / "config.json"
+        config = cls.load_config(config_local_path, **kwargs)
+        video_vae = cls.from_config(config)
+        video_vae.to(kwargs["torch_dtype"])
+
+        model_local_path = pretrained_model_name_or_path / "autoencoder.pth"
+        ckpt_state_dict = torch.load(model_local_path)
+        video_vae.load_state_dict(ckpt_state_dict)
+
+        statistics_local_path = (
+            pretrained_model_name_or_path / "per_channel_statistics.json"
+        )
+        if statistics_local_path.exists():
+            with open(statistics_local_path, "r") as file:
+                data = json.load(file)
+            transposed_data = list(zip(*data["data"]))
+            data_dict = {
+                col: torch.tensor(vals)
+                for col, vals in zip(data["columns"], transposed_data)
+            }
+            video_vae.register_buffer("std_of_means", data_dict["std-of-means"])
+            video_vae.register_buffer(
+                "mean_of_means",
+                data_dict.get(
+                    "mean-of-means", torch.zeros_like(data_dict["std-of-means"])
+                ),
+            )
+
+        return video_vae
+
+    @staticmethod
+    def from_config(config):
+        assert (
+            config["_class_name"] == "VideoAutoencoder"
+        ), "config must have _class_name=VideoAutoencoder"
+        if isinstance(config["dims"], list):
+            config["dims"] = tuple(config["dims"])
+
+        assert config["dims"] in [2, 3, (2, 1)], "dims must be 2, 3 or (2, 1)"
+
+        double_z = config.get("double_z", True)
+        latent_log_var = config.get(
+            "latent_log_var", "per_channel" if double_z else "none"
+        )
+        use_quant_conv = config.get("use_quant_conv", True)
+
+        if use_quant_conv and latent_log_var == "uniform":
+            raise ValueError("uniform latent_log_var requires use_quant_conv=False")
+
+        encoder = Encoder(
+            dims=config["dims"],
+            in_channels=config.get("in_channels", 3),
+            out_channels=config["latent_channels"],
+            block_out_channels=config["block_out_channels"],
+            patch_size=config.get("patch_size", 1),
+            latent_log_var=latent_log_var,
+            norm_layer=config.get("norm_layer", "group_norm"),
+            patch_size_t=config.get("patch_size_t", config.get("patch_size", 1)),
+            add_channel_padding=config.get("add_channel_padding", False),
+        )
+
+        decoder = Decoder(
+            dims=config["dims"],
+            in_channels=config["latent_channels"],
+            out_channels=config.get("out_channels", 3),
+            block_out_channels=config["block_out_channels"],
+            patch_size=config.get("patch_size", 1),
+            norm_layer=config.get("norm_layer", "group_norm"),
+            patch_size_t=config.get("patch_size_t", config.get("patch_size", 1)),
+            add_channel_padding=config.get("add_channel_padding", False),
+        )
+
+        dims = config["dims"]
+        return VideoAutoencoder(
+            encoder=encoder,
+            decoder=decoder,
+            latent_channels=config["latent_channels"],
+            dims=dims,
+            use_quant_conv=use_quant_conv,
+        )
+
+    @property
+    def config(self):
+        return SimpleNamespace(
+            _class_name="VideoAutoencoder",
+            dims=self.dims,
+            in_channels=self.encoder.conv_in.in_channels
+            // (self.encoder.patch_size_t * self.encoder.patch_size**2),
+            out_channels=self.decoder.conv_out.out_channels
+            // (self.decoder.patch_size_t * self.decoder.patch_size**2),
+            latent_channels=self.decoder.conv_in.in_channels,
+            block_out_channels=[
+                self.encoder.down_blocks[i].res_blocks[-1].conv1.out_channels
+                for i in range(len(self.encoder.down_blocks))
+            ],
+            scaling_factor=1.0,
+            norm_layer=self.encoder.norm_layer,
+            patch_size=self.encoder.patch_size,
+            latent_log_var=self.encoder.latent_log_var,
+            use_quant_conv=self.use_quant_conv,
+            patch_size_t=self.encoder.patch_size_t,
+            add_channel_padding=self.encoder.add_channel_padding,
+        )
+
+    @property
+    def is_video_supported(self):
+        """
+        Check if the model supports video inputs of shape (B, C, F, H, W). Otherwise, the model only supports 2D images.
+        """
+        return self.dims != 2
+
+    @property
+    def downscale_factor(self):
+        return self.encoder.downsample_factor
+
+    def to_json_string(self) -> str:
+        import json
+
+        return json.dumps(self.config.__dict__)
+
+    def load_state_dict(self, state_dict: Mapping[str, Any], strict: bool = True):
+        model_keys = set(name for name, _ in self.named_parameters())
+
+        key_mapping = {
+            ".resnets.": ".res_blocks.",
+            "downsamplers.0": "downsample",
+            "upsamplers.0": "upsample",
+        }
+
+        converted_state_dict = {}
+        for key, value in state_dict.items():
+            for k, v in key_mapping.items():
+                key = key.replace(k, v)
+
+            if "norm" in key and key not in model_keys:
+                logger.info(
+                    f"Removing key {key} from state_dict as it is not present in the model"
+                )
+                continue
+
+            converted_state_dict[key] = value
+
+        super().load_state_dict(converted_state_dict, strict=strict)
+
+    def last_layer(self):
+        if hasattr(self.decoder, "conv_out"):
+            if isinstance(self.decoder.conv_out, nn.Sequential):
+                last_layer = self.decoder.conv_out[-1]
+            else:
+                last_layer = self.decoder.conv_out
+        else:
+            last_layer = self.decoder.layers[-1]
+        return last_layer
+
+
+class Encoder(nn.Module):
+    r"""
+    The `Encoder` layer of a variational autoencoder that encodes its input into a latent representation.
+
+    Args:
+        in_channels (`int`, *optional*, defaults to 3):
+            The number of input channels.
+        out_channels (`int`, *optional*, defaults to 3):
+            The number of output channels.
+        block_out_channels (`Tuple[int, ...]`, *optional*, defaults to `(64,)`):
+            The number of output channels for each block.
+        layers_per_block (`int`, *optional*, defaults to 2):
+            The number of layers per block.
+        norm_num_groups (`int`, *optional*, defaults to 32):
+            The number of groups for normalization.
+        patch_size (`int`, *optional*, defaults to 1):
+            The patch size to use. Should be a power of 2.
+        norm_layer (`str`, *optional*, defaults to `group_norm`):
+            The normalization layer to use. Can be either `group_norm` or `pixel_norm`.
+        latent_log_var (`str`, *optional*, defaults to `per_channel`):
+            The number of channels for the log variance. Can be either `per_channel`, `uniform`, or `none`.
+    """
+
+    def __init__(
+        self,
+        dims: Union[int, Tuple[int, int]] = 3,
+        in_channels: int = 3,
+        out_channels: int = 3,
+        block_out_channels: Tuple[int, ...] = (64,),
+        layers_per_block: int = 2,
+        norm_num_groups: int = 32,
+        patch_size: Union[int, Tuple[int]] = 1,
+        norm_layer: str = "group_norm",  # group_norm, pixel_norm
+        latent_log_var: str = "per_channel",
+        patch_size_t: Optional[int] = None,
+        add_channel_padding: Optional[bool] = False,
+    ):
+        super().__init__()
+        self.patch_size = patch_size
+        self.patch_size_t = patch_size_t if patch_size_t is not None else patch_size
+        self.add_channel_padding = add_channel_padding
+        self.layers_per_block = layers_per_block
+        self.norm_layer = norm_layer
+        self.latent_channels = out_channels
+        self.latent_log_var = latent_log_var
+        if add_channel_padding:
+            in_channels = in_channels * self.patch_size**3
+        else:
+            in_channels = in_channels * self.patch_size_t * self.patch_size**2
+        self.in_channels = in_channels
+        output_channel = block_out_channels[0]
+
+        self.conv_in = make_conv_nd(
+            dims=dims,
+            in_channels=in_channels,
+            out_channels=output_channel,
+            kernel_size=3,
+            stride=1,
+            padding=1,
+        )
+
+        self.down_blocks = nn.ModuleList([])
+
+        for i in range(len(block_out_channels)):
+            input_channel = output_channel
+            output_channel = block_out_channels[i]
+            is_final_block = i == len(block_out_channels) - 1
+
+            down_block = DownEncoderBlock3D(
+                dims=dims,
+                in_channels=input_channel,
+                out_channels=output_channel,
+                num_layers=self.layers_per_block,
+                add_downsample=not is_final_block and 2**i >= patch_size,
+                resnet_eps=1e-6,
+                downsample_padding=0,
+                resnet_groups=norm_num_groups,
+                norm_layer=norm_layer,
+            )
+            self.down_blocks.append(down_block)
+
+        self.mid_block = UNetMidBlock3D(
+            dims=dims,
+            in_channels=block_out_channels[-1],
+            num_layers=self.layers_per_block,
+            resnet_eps=1e-6,
+            resnet_groups=norm_num_groups,
+            norm_layer=norm_layer,
+        )
+
+        # out
+        if norm_layer == "group_norm":
+            self.conv_norm_out = nn.GroupNorm(
+                num_channels=block_out_channels[-1],
+                num_groups=norm_num_groups,
+                eps=1e-6,
+            )
+        elif norm_layer == "pixel_norm":
+            self.conv_norm_out = PixelNorm()
+        self.conv_act = nn.SiLU()
+
+        conv_out_channels = out_channels
+        if latent_log_var == "per_channel":
+            conv_out_channels *= 2
+        elif latent_log_var == "uniform":
+            conv_out_channels += 1
+        elif latent_log_var != "none":
+            raise ValueError(f"Invalid latent_log_var: {latent_log_var}")
+        self.conv_out = make_conv_nd(
+            dims, block_out_channels[-1], conv_out_channels, 3, padding=1
+        )
+
+        self.gradient_checkpointing = False
+
+    @property
+    def downscale_factor(self):
+        return (
+            2
+            ** len(
+                [
+                    block
+                    for block in self.down_blocks
+                    if isinstance(block.downsample, Downsample3D)
+                ]
+            )
+            * self.patch_size
+        )
+
+    def forward(
+        self, sample: torch.FloatTensor, return_features=False
+    ) -> torch.FloatTensor:
+        r"""The forward method of the `Encoder` class."""
+
+        downsample_in_time = sample.shape[2] != 1
+
+        # patchify
+        patch_size_t = self.patch_size_t if downsample_in_time else 1
+        sample = patchify(
+            sample,
+            patch_size_hw=self.patch_size,
+            patch_size_t=patch_size_t,
+            add_channel_padding=self.add_channel_padding,
+        )
+
+        sample = self.conv_in(sample)
+
+        checkpoint_fn = (
+            partial(torch.utils.checkpoint.checkpoint, use_reentrant=False)
+            if self.gradient_checkpointing and self.training
+            else lambda x: x
+        )
+
+        if return_features:
+            features = []
+        for down_block in self.down_blocks:
+            sample = checkpoint_fn(down_block)(
+                sample, downsample_in_time=downsample_in_time
+            )
+            if return_features:
+                features.append(sample)
+
+        sample = checkpoint_fn(self.mid_block)(sample)
+
+        # post-process
+        sample = self.conv_norm_out(sample)
+        sample = self.conv_act(sample)
+        sample = self.conv_out(sample)
+
+        if self.latent_log_var == "uniform":
+            last_channel = sample[:, -1:, ...]
+            num_dims = sample.dim()
+
+            if num_dims == 4:
+                # For shape (B, C, H, W)
+                repeated_last_channel = last_channel.repeat(
+                    1, sample.shape[1] - 2, 1, 1
+                )
+                sample = torch.cat([sample, repeated_last_channel], dim=1)
+            elif num_dims == 5:
+                # For shape (B, C, F, H, W)
+                repeated_last_channel = last_channel.repeat(
+                    1, sample.shape[1] - 2, 1, 1, 1
+                )
+                sample = torch.cat([sample, repeated_last_channel], dim=1)
+            else:
+                raise ValueError(f"Invalid input shape: {sample.shape}")
+
+        if return_features:
+            features.append(sample[:, : self.latent_channels, ...])
+            return sample, features
+        return sample
+
+
+class Decoder(nn.Module):
+    r"""
+    The `Decoder` layer of a variational autoencoder that decodes its latent representation into an output sample.
+
+    Args:
+        in_channels (`int`, *optional*, defaults to 3):
+            The number of input channels.
+        out_channels (`int`, *optional*, defaults to 3):
+            The number of output channels.
+        block_out_channels (`Tuple[int, ...]`, *optional*, defaults to `(64,)`):
+            The number of output channels for each block.
+        layers_per_block (`int`, *optional*, defaults to 2):
+            The number of layers per block.
+        norm_num_groups (`int`, *optional*, defaults to 32):
+            The number of groups for normalization.
+        patch_size (`int`, *optional*, defaults to 1):
+            The patch size to use. Should be a power of 2.
+        norm_layer (`str`, *optional*, defaults to `group_norm`):
+            The normalization layer to use. Can be either `group_norm` or `pixel_norm`.
+    """
+
+    def __init__(
+        self,
+        dims,
+        in_channels: int = 3,
+        out_channels: int = 3,
+        block_out_channels: Tuple[int, ...] = (64,),
+        layers_per_block: int = 2,
+        norm_num_groups: int = 32,
+        patch_size: int = 1,
+        norm_layer: str = "group_norm",
+        patch_size_t: Optional[int] = None,
+        add_channel_padding: Optional[bool] = False,
+    ):
+        super().__init__()
+        self.patch_size = patch_size
+        self.patch_size_t = patch_size_t if patch_size_t is not None else patch_size
+        self.add_channel_padding = add_channel_padding
+        self.layers_per_block = layers_per_block
+        if add_channel_padding:
+            out_channels = out_channels * self.patch_size**3
+        else:
+            out_channels = out_channels * self.patch_size_t * self.patch_size**2
+        self.out_channels = out_channels
+
+        self.conv_in = make_conv_nd(
+            dims,
+            in_channels,
+            block_out_channels[-1],
+            kernel_size=3,
+            stride=1,
+            padding=1,
+        )
+
+        self.mid_block = None
+        self.up_blocks = nn.ModuleList([])
+
+        self.mid_block = UNetMidBlock3D(
+            dims=dims,
+            in_channels=block_out_channels[-1],
+            num_layers=self.layers_per_block,
+            resnet_eps=1e-6,
+            resnet_groups=norm_num_groups,
+            norm_layer=norm_layer,
+        )
+
+        reversed_block_out_channels = list(reversed(block_out_channels))
+        output_channel = reversed_block_out_channels[0]
+        for i in range(len(reversed_block_out_channels)):
+            prev_output_channel = output_channel
+            output_channel = reversed_block_out_channels[i]
+
+            is_final_block = i == len(block_out_channels) - 1
+
+            up_block = UpDecoderBlock3D(
+                dims=dims,
+                num_layers=self.layers_per_block + 1,
+                in_channels=prev_output_channel,
+                out_channels=output_channel,
+                add_upsample=not is_final_block
+                and 2 ** (len(block_out_channels) - i - 1) > patch_size,
+                resnet_eps=1e-6,
+                resnet_groups=norm_num_groups,
+                norm_layer=norm_layer,
+            )
+            self.up_blocks.append(up_block)
+
+        if norm_layer == "group_norm":
+            self.conv_norm_out = nn.GroupNorm(
+                num_channels=block_out_channels[0], num_groups=norm_num_groups, eps=1e-6
+            )
+        elif norm_layer == "pixel_norm":
+            self.conv_norm_out = PixelNorm()
+
+        self.conv_act = nn.SiLU()
+        self.conv_out = make_conv_nd(
+            dims, block_out_channels[0], out_channels, 3, padding=1
+        )
+
+        self.gradient_checkpointing = False
+
+    def forward(self, sample: torch.FloatTensor, target_shape) -> torch.FloatTensor:
+        r"""The forward method of the `Decoder` class."""
+        assert target_shape is not None, "target_shape must be provided"
+        upsample_in_time = sample.shape[2] < target_shape[2]
+
+        sample = self.conv_in(sample)
+
+        upscale_dtype = next(iter(self.up_blocks.parameters())).dtype
+
+        checkpoint_fn = (
+            partial(torch.utils.checkpoint.checkpoint, use_reentrant=False)
+            if self.gradient_checkpointing and self.training
+            else lambda x: x
+        )
+
+        sample = checkpoint_fn(self.mid_block)(sample)
+        sample = sample.to(upscale_dtype)
+
+        for up_block in self.up_blocks:
+            sample = checkpoint_fn(up_block)(sample, upsample_in_time=upsample_in_time)
+
+        # post-process
+        sample = self.conv_norm_out(sample)
+        sample = self.conv_act(sample)
+        sample = self.conv_out(sample)
+
+        # un-patchify
+        patch_size_t = self.patch_size_t if upsample_in_time else 1
+        sample = unpatchify(
+            sample,
+            patch_size_hw=self.patch_size,
+            patch_size_t=patch_size_t,
+            add_channel_padding=self.add_channel_padding,
+        )
+
+        return sample
+
+
+class DownEncoderBlock3D(nn.Module):
+    def __init__(
+        self,
+        dims: Union[int, Tuple[int, int]],
+        in_channels: int,
+        out_channels: int,
+        dropout: float = 0.0,
+        num_layers: int = 1,
+        resnet_eps: float = 1e-6,
+        resnet_groups: int = 32,
+        add_downsample: bool = True,
+        downsample_padding: int = 1,
+        norm_layer: str = "group_norm",
+    ):
+        super().__init__()
+        res_blocks = []
+
+        for i in range(num_layers):
+            in_channels = in_channels if i == 0 else out_channels
+            res_blocks.append(
+                ResnetBlock3D(
+                    dims=dims,
+                    in_channels=in_channels,
+                    out_channels=out_channels,
+                    eps=resnet_eps,
+                    groups=resnet_groups,
+                    dropout=dropout,
+                    norm_layer=norm_layer,
+                )
+            )
+
+        self.res_blocks = nn.ModuleList(res_blocks)
+
+        if add_downsample:
+            self.downsample = Downsample3D(
+                dims,
+                out_channels,
+                out_channels=out_channels,
+                padding=downsample_padding,
+            )
+        else:
+            self.downsample = Identity()
+
+    def forward(
+        self, hidden_states: torch.FloatTensor, downsample_in_time
+    ) -> torch.FloatTensor:
+        for resnet in self.res_blocks:
+            hidden_states = resnet(hidden_states)
+
+        hidden_states = self.downsample(
+            hidden_states, downsample_in_time=downsample_in_time
+        )
+
+        return hidden_states
+
+
+class UNetMidBlock3D(nn.Module):
+    """
+    A 3D UNet mid-block [`UNetMidBlock3D`] with multiple residual blocks.
+
+    Args:
+        in_channels (`int`): The number of input channels.
+        dropout (`float`, *optional*, defaults to 0.0): The dropout rate.
+        num_layers (`int`, *optional*, defaults to 1): The number of residual blocks.
+        resnet_eps (`float`, *optional*, 1e-6 ): The epsilon value for the resnet blocks.
+        resnet_groups (`int`, *optional*, defaults to 32):
+            The number of groups to use in the group normalization layers of the resnet blocks.
+
+    Returns:
+        `torch.FloatTensor`: The output of the last residual block, which is a tensor of shape `(batch_size,
+        in_channels, height, width)`.
+
+    """
+
+    def __init__(
+        self,
+        dims: Union[int, Tuple[int, int]],
+        in_channels: int,
+        dropout: float = 0.0,
+        num_layers: int = 1,
+        resnet_eps: float = 1e-6,
+        resnet_groups: int = 32,
+        norm_layer: str = "group_norm",
+    ):
+        super().__init__()
+        resnet_groups = (
+            resnet_groups if resnet_groups is not None else min(in_channels // 4, 32)
+        )
+
+        self.res_blocks = nn.ModuleList(
+            [
+                ResnetBlock3D(
+                    dims=dims,
+                    in_channels=in_channels,
+                    out_channels=in_channels,
+                    eps=resnet_eps,
+                    groups=resnet_groups,
+                    dropout=dropout,
+                    norm_layer=norm_layer,
+                )
+                for _ in range(num_layers)
+            ]
+        )
+
+    def forward(self, hidden_states: torch.FloatTensor) -> torch.FloatTensor:
+        for resnet in self.res_blocks:
+            hidden_states = resnet(hidden_states)
+
+        return hidden_states
+
+
+class UpDecoderBlock3D(nn.Module):
+    def __init__(
+        self,
+        dims: Union[int, Tuple[int, int]],
+        in_channels: int,
+        out_channels: int,
+        resolution_idx: Optional[int] = None,
+        dropout: float = 0.0,
+        num_layers: int = 1,
+        resnet_eps: float = 1e-6,
+        resnet_groups: int = 32,
+        add_upsample: bool = True,
+        norm_layer: str = "group_norm",
+    ):
+        super().__init__()
+        res_blocks = []
+
+        for i in range(num_layers):
+            input_channels = in_channels if i == 0 else out_channels
+
+            res_blocks.append(
+                ResnetBlock3D(
+                    dims=dims,
+                    in_channels=input_channels,
+                    out_channels=out_channels,
+                    eps=resnet_eps,
+                    groups=resnet_groups,
+                    dropout=dropout,
+                    norm_layer=norm_layer,
+                )
+            )
+
+        self.res_blocks = nn.ModuleList(res_blocks)
+
+        if add_upsample:
+            self.upsample = Upsample3D(
+                dims=dims, channels=out_channels, out_channels=out_channels
+            )
+        else:
+            self.upsample = Identity()
+
+        self.resolution_idx = resolution_idx
+
+    def forward(
+        self, hidden_states: torch.FloatTensor, upsample_in_time=True
+    ) -> torch.FloatTensor:
+        for resnet in self.res_blocks:
+            hidden_states = resnet(hidden_states)
+
+        hidden_states = self.upsample(hidden_states, upsample_in_time=upsample_in_time)
+
+        return hidden_states
+
+
+class ResnetBlock3D(nn.Module):
+    r"""
+    A Resnet block.
+
+    Parameters:
+        in_channels (`int`): The number of channels in the input.
+        out_channels (`int`, *optional*, default to be `None`):
+            The number of output channels for the first conv layer. If None, same as `in_channels`.
+        dropout (`float`, *optional*, defaults to `0.0`): The dropout probability to use.
+        groups (`int`, *optional*, default to `32`): The number of groups to use for the first normalization layer.
+        eps (`float`, *optional*, defaults to `1e-6`): The epsilon to use for the normalization.
+    """
+
+    def __init__(
+        self,
+        dims: Union[int, Tuple[int, int]],
+        in_channels: int,
+        out_channels: Optional[int] = None,
+        conv_shortcut: bool = False,
+        dropout: float = 0.0,
+        groups: int = 32,
+        eps: float = 1e-6,
+        norm_layer: str = "group_norm",
+    ):
+        super().__init__()
+        self.in_channels = in_channels
+        out_channels = in_channels if out_channels is None else out_channels
+        self.out_channels = out_channels
+        self.use_conv_shortcut = conv_shortcut
+
+        if norm_layer == "group_norm":
+            self.norm1 = torch.nn.GroupNorm(
+                num_groups=groups, num_channels=in_channels, eps=eps, affine=True
+            )
+        elif norm_layer == "pixel_norm":
+            self.norm1 = PixelNorm()
+
+        self.non_linearity = nn.SiLU()
+
+        self.conv1 = make_conv_nd(
+            dims, in_channels, out_channels, kernel_size=3, stride=1, padding=1
+        )
+
+        if norm_layer == "group_norm":
+            self.norm2 = torch.nn.GroupNorm(
+                num_groups=groups, num_channels=out_channels, eps=eps, affine=True
+            )
+        elif norm_layer == "pixel_norm":
+            self.norm2 = PixelNorm()
+
+        self.dropout = torch.nn.Dropout(dropout)
+
+        self.conv2 = make_conv_nd(
+            dims, out_channels, out_channels, kernel_size=3, stride=1, padding=1
+        )
+
+        self.conv_shortcut = (
+            make_linear_nd(
+                dims=dims, in_channels=in_channels, out_channels=out_channels
+            )
+            if in_channels != out_channels
+            else nn.Identity()
+        )
+
+    def forward(
+        self,
+        input_tensor: torch.FloatTensor,
+    ) -> torch.FloatTensor:
+        hidden_states = input_tensor
+
+        hidden_states = self.norm1(hidden_states)
+
+        hidden_states = self.non_linearity(hidden_states)
+
+        hidden_states = self.conv1(hidden_states)
+
+        hidden_states = self.norm2(hidden_states)
+
+        hidden_states = self.non_linearity(hidden_states)
+
+        hidden_states = self.dropout(hidden_states)
+
+        hidden_states = self.conv2(hidden_states)
+
+        input_tensor = self.conv_shortcut(input_tensor)
+
+        output_tensor = input_tensor + hidden_states
+
+        return output_tensor
+
+
+class Downsample3D(nn.Module):
+    def __init__(
+        self,
+        dims,
+        in_channels: int,
+        out_channels: int,
+        kernel_size: int = 3,
+        padding: int = 1,
+    ):
+        super().__init__()
+        stride: int = 2
+        self.padding = padding
+        self.in_channels = in_channels
+        self.dims = dims
+        self.conv = make_conv_nd(
+            dims=dims,
+            in_channels=in_channels,
+            out_channels=out_channels,
+            kernel_size=kernel_size,
+            stride=stride,
+            padding=padding,
+        )
+
+    def forward(self, x, downsample_in_time=True):
+        conv = self.conv
+        if self.padding == 0:
+            if self.dims == 2:
+                padding = (0, 1, 0, 1)
+            else:
+                padding = (0, 1, 0, 1, 0, 1 if downsample_in_time else 0)
+
+            x = functional.pad(x, padding, mode="constant", value=0)
+
+            if self.dims == (2, 1) and not downsample_in_time:
+                return conv(x, skip_time_conv=True)
+
+        return conv(x)
+
+
+class Upsample3D(nn.Module):
+    """
+    An upsampling layer for 3D tensors of shape (B, C, D, H, W).
+
+    :param channels: channels in the inputs and outputs.
+    """
+
+    def __init__(self, dims, channels, out_channels=None):
+        super().__init__()
+        self.dims = dims
+        self.channels = channels
+        self.out_channels = out_channels or channels
+        self.conv = make_conv_nd(
+            dims, channels, out_channels, kernel_size=3, padding=1, bias=True
+        )
+
+    def forward(self, x, upsample_in_time):
+        if self.dims == 2:
+            x = functional.interpolate(
+                x, (x.shape[2] * 2, x.shape[3] * 2), mode="nearest"
+            )
+        else:
+            time_scale_factor = 2 if upsample_in_time else 1
+            # print("before:", x.shape)
+            b, c, d, h, w = x.shape
+            x = rearrange(x, "b c d h w -> (b d) c h w")
+            # height and width interpolate
+            x = functional.interpolate(
+                x, (x.shape[2] * 2, x.shape[3] * 2), mode="nearest"
+            )
+            _, _, h, w = x.shape
+
+            if not upsample_in_time and self.dims == (2, 1):
+                x = rearrange(x, "(b d) c h w -> b c d h w ", b=b, h=h, w=w)
+                return self.conv(x, skip_time_conv=True)
+
+            # Second ** upsampling ** which is essentially treated as a 1D convolution across the 'd' dimension
+            x = rearrange(x, "(b d) c h w -> (b h w) c 1 d", b=b)
+
+            # (b h w) c 1 d
+            new_d = x.shape[-1] * time_scale_factor
+            x = functional.interpolate(x, (1, new_d), mode="nearest")
+            # (b h w) c 1 new_d
+            x = rearrange(
+                x, "(b h w) c 1 new_d  -> b c new_d h w", b=b, h=h, w=w, new_d=new_d
+            )
+            # b c d h w
+
+            # x = functional.interpolate(
+            #     x, (x.shape[2] * time_scale_factor, x.shape[3] * 2, x.shape[4] * 2), mode="nearest"
+            # )
+            # print("after:", x.shape)
+
+        return self.conv(x)
+
+
+def patchify(x, patch_size_hw, patch_size_t=1, add_channel_padding=False):
+    if patch_size_hw == 1 and patch_size_t == 1:
+        return x
+    if x.dim() == 4:
+        x = rearrange(
+            x, "b c (h q) (w r) -> b (c r q) h w", q=patch_size_hw, r=patch_size_hw
+        )
+    elif x.dim() == 5:
+        x = rearrange(
+            x,
+            "b c (f p) (h q) (w r) -> b (c p r q) f h w",
+            p=patch_size_t,
+            q=patch_size_hw,
+            r=patch_size_hw,
+        )
+    else:
+        raise ValueError(f"Invalid input shape: {x.shape}")
+
+    if (
+        (x.dim() == 5)
+        and (patch_size_hw > patch_size_t)
+        and (patch_size_t > 1 or add_channel_padding)
+    ):
+        channels_to_pad = x.shape[1] * (patch_size_hw // patch_size_t) - x.shape[1]
+        padding_zeros = torch.zeros(
+            x.shape[0],
+            channels_to_pad,
+            x.shape[2],
+            x.shape[3],
+            x.shape[4],
+            device=x.device,
+            dtype=x.dtype,
+        )
+        x = torch.cat([padding_zeros, x], dim=1)
+
+    return x
+
+
+def unpatchify(x, patch_size_hw, patch_size_t=1, add_channel_padding=False):
+    if patch_size_hw == 1 and patch_size_t == 1:
+        return x
+
+    if (
+        (x.dim() == 5)
+        and (patch_size_hw > patch_size_t)
+        and (patch_size_t > 1 or add_channel_padding)
+    ):
+        channels_to_keep = int(x.shape[1] * (patch_size_t / patch_size_hw))
+        x = x[:, :channels_to_keep, :, :, :]
+
+    if x.dim() == 4:
+        x = rearrange(
+            x, "b (c r q) h w -> b c (h q) (w r)", q=patch_size_hw, r=patch_size_hw
+        )
+    elif x.dim() == 5:
+        x = rearrange(
+            x,
+            "b (c p r q) f h w -> b c (f p) (h q) (w r)",
+            p=patch_size_t,
+            q=patch_size_hw,
+            r=patch_size_hw,
+        )
+
+    return x
+
+
+def create_video_autoencoder_config(
+    latent_channels: int = 4,
+):
+    config = {
+        "_class_name": "VideoAutoencoder",
+        "dims": (
+            2,
+            1,
+        ),  # 2 for Conv2, 3 for Conv3d, (2, 1) for Conv2d followed by Conv1d
+        "in_channels": 3,  # Number of input color channels (e.g., RGB)
+        "out_channels": 3,  # Number of output color channels
+        "latent_channels": latent_channels,  # Number of channels in the latent space representation
+        "block_out_channels": [
+            128,
+            256,
+            512,
+            512,
+        ],  # Number of output channels of each encoder / decoder inner block
+        "patch_size": 1,
+    }
+
+    return config
+
+
+def create_video_autoencoder_pathify4x4x4_config(
+    latent_channels: int = 4,
+):
+    config = {
+        "_class_name": "VideoAutoencoder",
+        "dims": (
+            2,
+            1,
+        ),  # 2 for Conv2, 3 for Conv3d, (2, 1) for Conv2d followed by Conv1d
+        "in_channels": 3,  # Number of input color channels (e.g., RGB)
+        "out_channels": 3,  # Number of output color channels
+        "latent_channels": latent_channels,  # Number of channels in the latent space representation
+        "block_out_channels": [512]
+        * 4,  # Number of output channels of each encoder / decoder inner block
+        "patch_size": 4,
+        "latent_log_var": "uniform",
+    }
+
+    return config
+
+
+def create_video_autoencoder_pathify4x4_config(
+    latent_channels: int = 4,
+):
+    config = {
+        "_class_name": "VideoAutoencoder",
+        "dims": 2,  # 2 for Conv2, 3 for Conv3d, (2, 1) for Conv2d followed by Conv1d
+        "in_channels": 3,  # Number of input color channels (e.g., RGB)
+        "out_channels": 3,  # Number of output color channels
+        "latent_channels": latent_channels,  # Number of channels in the latent space representation
+        "block_out_channels": [512]
+        * 4,  # Number of output channels of each encoder / decoder inner block
+        "patch_size": 4,
+        "norm_layer": "pixel_norm",
+    }
+
+    return config
+
+
+def test_vae_patchify_unpatchify():
+    import torch
+
+    x = torch.randn(2, 3, 8, 64, 64)
+    x_patched = patchify(x, patch_size_hw=4, patch_size_t=4)
+    x_unpatched = unpatchify(x_patched, patch_size_hw=4, patch_size_t=4)
+    assert torch.allclose(x, x_unpatched)
+
+
+def demo_video_autoencoder_forward_backward():
+    # Configuration for the VideoAutoencoder
+    config = create_video_autoencoder_pathify4x4x4_config()
+
+    # Instantiate the VideoAutoencoder with the specified configuration
+    video_autoencoder = VideoAutoencoder.from_config(config)
+
+    print(video_autoencoder)
+
+    # Print the total number of parameters in the video autoencoder
+    total_params = sum(p.numel() for p in video_autoencoder.parameters())
+    print(f"Total number of parameters in VideoAutoencoder: {total_params:,}")
+
+    # Create a mock input tensor simulating a batch of videos
+    # Shape: (batch_size, channels, depth, height, width)
+    # E.g., 4 videos, each with 3 color channels, 16 frames, and 64x64 pixels per frame
+    input_videos = torch.randn(2, 3, 8, 64, 64)
+
+    # Forward pass: encode and decode the input videos
+    latent = video_autoencoder.encode(input_videos).latent_dist.mode()
+    print(f"input shape={input_videos.shape}")
+    print(f"latent shape={latent.shape}")
+    reconstructed_videos = video_autoencoder.decode(
+        latent, target_shape=input_videos.shape
+    ).sample
+
+    print(f"reconstructed shape={reconstructed_videos.shape}")
+
+    # Calculate the loss (e.g., mean squared error)
+    loss = torch.nn.functional.mse_loss(input_videos, reconstructed_videos)
+
+    # Perform backward pass
+    loss.backward()
+
+    print(f"Demo completed with loss: {loss.item()}")
+
+
+# Ensure to call the demo function to execute the forward and backward pass
+if __name__ == "__main__":
+    demo_video_autoencoder_forward_backward()

xora/models/transformers/attention.py

@@ -0,0 +1,1206 @@
+import inspect
+from importlib import import_module
+from typing import Any, Dict, Optional, Tuple
+
+import torch
+import torch.nn.functional as F
+from diffusers.models.activations import GEGLU, GELU, ApproximateGELU
+from diffusers.models.attention import _chunked_feed_forward
+from diffusers.models.attention_processor import (
+    LoRAAttnAddedKVProcessor,
+    LoRAAttnProcessor,
+    LoRAAttnProcessor2_0,
+    LoRAXFormersAttnProcessor,
+    SpatialNorm,
+)
+from diffusers.models.lora import LoRACompatibleLinear
+from diffusers.models.normalization import RMSNorm
+from diffusers.utils import deprecate, logging
+from diffusers.utils.torch_utils import maybe_allow_in_graph
+from einops import rearrange
+from torch import nn
+
+try:
+    from torch_xla.experimental.custom_kernel import flash_attention
+except ImportError:
+    # workaround for automatic tests. Currently this function is manually patched
+    # to the torch_xla lib on setup of container
+    pass
+
+# code adapted from  https://github.com/huggingface/diffusers/blob/main/src/diffusers/models/attention.py
+
+logger = logging.get_logger(__name__)
+
+
+@maybe_allow_in_graph
+class BasicTransformerBlock(nn.Module):
+    r"""
+    A basic Transformer block.
+
+    Parameters:
+        dim (`int`): The number of channels in the input and output.
+        num_attention_heads (`int`): The number of heads to use for multi-head attention.
+        attention_head_dim (`int`): The number of channels in each head.
+        dropout (`float`, *optional*, defaults to 0.0): The dropout probability to use.
+        cross_attention_dim (`int`, *optional*): The size of the encoder_hidden_states vector for cross attention.
+        activation_fn (`str`, *optional*, defaults to `"geglu"`): Activation function to be used in feed-forward.
+        num_embeds_ada_norm (:
+            obj: `int`, *optional*): The number of diffusion steps used during training. See `Transformer2DModel`.
+        attention_bias (:
+            obj: `bool`, *optional*, defaults to `False`): Configure if the attentions should contain a bias parameter.
+        only_cross_attention (`bool`, *optional*):
+            Whether to use only cross-attention layers. In this case two cross attention layers are used.
+        double_self_attention (`bool`, *optional*):
+            Whether to use two self-attention layers. In this case no cross attention layers are used.
+        upcast_attention (`bool`, *optional*):
+            Whether to upcast the attention computation to float32. This is useful for mixed precision training.
+        norm_elementwise_affine (`bool`, *optional*, defaults to `True`):
+            Whether to use learnable elementwise affine parameters for normalization.
+        qk_norm (`str`, *optional*, defaults to None):
+            Set to 'layer_norm' or `rms_norm` to perform query and key normalization.
+        adaptive_norm (`str`, *optional*, defaults to `"single_scale_shift"`):
+            The type of adaptive norm to use. Can be `"single_scale_shift"`, `"single_scale"` or "none".
+        standardization_norm (`str`, *optional*, defaults to `"layer_norm"`):
+            The type of pre-normalization to use. Can be `"layer_norm"` or `"rms_norm"`.
+        final_dropout (`bool` *optional*, defaults to False):
+            Whether to apply a final dropout after the last feed-forward layer.
+        attention_type (`str`, *optional*, defaults to `"default"`):
+            The type of attention to use. Can be `"default"` or `"gated"` or `"gated-text-image"`.
+        positional_embeddings (`str`, *optional*, defaults to `None`):
+            The type of positional embeddings to apply to.
+        num_positional_embeddings (`int`, *optional*, defaults to `None`):
+            The maximum number of positional embeddings to apply.
+    """
+
+    def __init__(
+        self,
+        dim: int,
+        num_attention_heads: int,
+        attention_head_dim: int,
+        dropout=0.0,
+        cross_attention_dim: Optional[int] = None,
+        activation_fn: str = "geglu",
+        num_embeds_ada_norm: Optional[int] = None,  # pylint: disable=unused-argument
+        attention_bias: bool = False,
+        only_cross_attention: bool = False,
+        double_self_attention: bool = False,
+        upcast_attention: bool = False,
+        norm_elementwise_affine: bool = True,
+        adaptive_norm: str = "single_scale_shift",  # 'single_scale_shift', 'single_scale' or 'none'
+        standardization_norm: str = "layer_norm",  # 'layer_norm' or 'rms_norm'
+        norm_eps: float = 1e-5,
+        qk_norm: Optional[str] = None,
+        final_dropout: bool = False,
+        attention_type: str = "default",  # pylint: disable=unused-argument
+        ff_inner_dim: Optional[int] = None,
+        ff_bias: bool = True,
+        attention_out_bias: bool = True,
+        use_tpu_flash_attention: bool = False,
+        use_rope: bool = False,
+    ):
+        super().__init__()
+        self.only_cross_attention = only_cross_attention
+        self.use_tpu_flash_attention = use_tpu_flash_attention
+        self.adaptive_norm = adaptive_norm
+
+        assert standardization_norm in ["layer_norm", "rms_norm"]
+        assert adaptive_norm in ["single_scale_shift", "single_scale", "none"]
+
+        make_norm_layer = (
+            nn.LayerNorm if standardization_norm == "layer_norm" else RMSNorm
+        )
+
+        # Define 3 blocks. Each block has its own normalization layer.
+        # 1. Self-Attn
+        self.norm1 = make_norm_layer(
+            dim, elementwise_affine=norm_elementwise_affine, eps=norm_eps
+        )
+
+        self.attn1 = Attention(
+            query_dim=dim,
+            heads=num_attention_heads,
+            dim_head=attention_head_dim,
+            dropout=dropout,
+            bias=attention_bias,
+            cross_attention_dim=cross_attention_dim if only_cross_attention else None,
+            upcast_attention=upcast_attention,
+            out_bias=attention_out_bias,
+            use_tpu_flash_attention=use_tpu_flash_attention,
+            qk_norm=qk_norm,
+            use_rope=use_rope,
+        )
+
+        # 2. Cross-Attn
+        if cross_attention_dim is not None or double_self_attention:
+            self.attn2 = Attention(
+                query_dim=dim,
+                cross_attention_dim=(
+                    cross_attention_dim if not double_self_attention else None
+                ),
+                heads=num_attention_heads,
+                dim_head=attention_head_dim,
+                dropout=dropout,
+                bias=attention_bias,
+                upcast_attention=upcast_attention,
+                out_bias=attention_out_bias,
+                use_tpu_flash_attention=use_tpu_flash_attention,
+                qk_norm=qk_norm,
+                use_rope=use_rope,
+            )  # is self-attn if encoder_hidden_states is none
+
+            if adaptive_norm == "none":
+                self.attn2_norm = make_norm_layer(
+                    dim, norm_eps, norm_elementwise_affine
+                )
+        else:
+            self.attn2 = None
+            self.attn2_norm = None
+
+        self.norm2 = make_norm_layer(dim, norm_eps, norm_elementwise_affine)
+
+        # 3. Feed-forward
+        self.ff = FeedForward(
+            dim,
+            dropout=dropout,
+            activation_fn=activation_fn,
+            final_dropout=final_dropout,
+            inner_dim=ff_inner_dim,
+            bias=ff_bias,
+        )
+
+        # 5. Scale-shift for PixArt-Alpha.
+        if adaptive_norm != "none":
+            num_ada_params = 4 if adaptive_norm == "single_scale" else 6
+            self.scale_shift_table = nn.Parameter(
+                torch.randn(num_ada_params, dim) / dim**0.5
+            )
+
+        # let chunk size default to None
+        self._chunk_size = None
+        self._chunk_dim = 0
+
+    def set_use_tpu_flash_attention(self):
+        r"""
+        Function sets the flag in this object and propagates down the children. The flag will enforce the usage of TPU
+        attention kernel.
+        """
+        self.use_tpu_flash_attention = True
+        self.attn1.set_use_tpu_flash_attention()
+        self.attn2.set_use_tpu_flash_attention()
+
+    def set_chunk_feed_forward(self, chunk_size: Optional[int], dim: int = 0):
+        # Sets chunk feed-forward
+        self._chunk_size = chunk_size
+        self._chunk_dim = dim
+
+    def forward(
+        self,
+        hidden_states: torch.FloatTensor,
+        freqs_cis: Optional[Tuple[torch.FloatTensor, torch.FloatTensor]] = None,
+        attention_mask: Optional[torch.FloatTensor] = None,
+        encoder_hidden_states: Optional[torch.FloatTensor] = None,
+        encoder_attention_mask: Optional[torch.FloatTensor] = None,
+        timestep: Optional[torch.LongTensor] = None,
+        cross_attention_kwargs: Dict[str, Any] = None,
+        class_labels: Optional[torch.LongTensor] = None,
+        added_cond_kwargs: Optional[Dict[str, torch.Tensor]] = None,
+    ) -> torch.FloatTensor:
+        if cross_attention_kwargs is not None:
+            if cross_attention_kwargs.get("scale", None) is not None:
+                logger.warning(
+                    "Passing `scale` to `cross_attention_kwargs` is depcrecated. `scale` will be ignored."
+                )
+
+        # Notice that normalization is always applied before the real computation in the following blocks.
+        # 0. Self-Attention
+        batch_size = hidden_states.shape[0]
+
+        norm_hidden_states = self.norm1(hidden_states)
+
+        # Apply ada_norm_single
+        if self.adaptive_norm in ["single_scale_shift", "single_scale"]:
+            assert timestep.ndim == 3  # [batch, 1 or num_tokens, embedding_dim]
+            num_ada_params = self.scale_shift_table.shape[0]
+            ada_values = self.scale_shift_table[None, None] + timestep.reshape(
+                batch_size, timestep.shape[1], num_ada_params, -1
+            )
+            if self.adaptive_norm == "single_scale_shift":
+                shift_msa, scale_msa, gate_msa, shift_mlp, scale_mlp, gate_mlp = (
+                    ada_values.unbind(dim=2)
+                )
+                norm_hidden_states = norm_hidden_states * (1 + scale_msa) + shift_msa
+            else:
+                scale_msa, gate_msa, scale_mlp, gate_mlp = ada_values.unbind(dim=2)
+                norm_hidden_states = norm_hidden_states * (1 + scale_msa)
+        elif self.adaptive_norm == "none":
+            scale_msa, gate_msa, scale_mlp, gate_mlp = None, None, None, None
+        else:
+            raise ValueError(f"Unknown adaptive norm type: {self.adaptive_norm}")
+
+        norm_hidden_states = norm_hidden_states.squeeze(
+            1
+        )  # TODO: Check if this is needed
+
+        # 1. Prepare GLIGEN inputs
+        cross_attention_kwargs = (
+            cross_attention_kwargs.copy() if cross_attention_kwargs is not None else {}
+        )
+
+        attn_output = self.attn1(
+            norm_hidden_states,
+            freqs_cis=freqs_cis,
+            encoder_hidden_states=(
+                encoder_hidden_states if self.only_cross_attention else None
+            ),
+            attention_mask=attention_mask,
+            **cross_attention_kwargs,
+        )
+        if gate_msa is not None:
+            attn_output = gate_msa * attn_output
+
+        hidden_states = attn_output + hidden_states
+        if hidden_states.ndim == 4:
+            hidden_states = hidden_states.squeeze(1)
+
+        # 3. Cross-Attention
+        if self.attn2 is not None:
+            if self.adaptive_norm == "none":
+                attn_input = self.attn2_norm(hidden_states)
+            else:
+                attn_input = hidden_states
+            attn_output = self.attn2(
+                attn_input,
+                freqs_cis=freqs_cis,
+                encoder_hidden_states=encoder_hidden_states,
+                attention_mask=encoder_attention_mask,
+                **cross_attention_kwargs,
+            )
+            hidden_states = attn_output + hidden_states
+
+        # 4. Feed-forward
+        norm_hidden_states = self.norm2(hidden_states)
+        if self.adaptive_norm == "single_scale_shift":
+            norm_hidden_states = norm_hidden_states * (1 + scale_mlp) + shift_mlp
+        elif self.adaptive_norm == "single_scale":
+            norm_hidden_states = norm_hidden_states * (1 + scale_mlp)
+        elif self.adaptive_norm == "none":
+            pass
+        else:
+            raise ValueError(f"Unknown adaptive norm type: {self.adaptive_norm}")
+
+        if self._chunk_size is not None:
+            # "feed_forward_chunk_size" can be used to save memory
+            ff_output = _chunked_feed_forward(
+                self.ff, norm_hidden_states, self._chunk_dim, self._chunk_size
+            )
+        else:
+            ff_output = self.ff(norm_hidden_states)
+        if gate_mlp is not None:
+            ff_output = gate_mlp * ff_output
+
+        hidden_states = ff_output + hidden_states
+        if hidden_states.ndim == 4:
+            hidden_states = hidden_states.squeeze(1)
+
+        return hidden_states
+
+
+@maybe_allow_in_graph
+class Attention(nn.Module):
+    r"""
+    A cross attention layer.
+
+    Parameters:
+        query_dim (`int`):
+            The number of channels in the query.
+        cross_attention_dim (`int`, *optional*):
+            The number of channels in the encoder_hidden_states. If not given, defaults to `query_dim`.
+        heads (`int`,  *optional*, defaults to 8):
+            The number of heads to use for multi-head attention.
+        dim_head (`int`,  *optional*, defaults to 64):
+            The number of channels in each head.
+        dropout (`float`, *optional*, defaults to 0.0):
+            The dropout probability to use.
+        bias (`bool`, *optional*, defaults to False):
+            Set to `True` for the query, key, and value linear layers to contain a bias parameter.
+        upcast_attention (`bool`, *optional*, defaults to False):
+            Set to `True` to upcast the attention computation to `float32`.
+        upcast_softmax (`bool`, *optional*, defaults to False):
+            Set to `True` to upcast the softmax computation to `float32`.
+        cross_attention_norm (`str`, *optional*, defaults to `None`):
+            The type of normalization to use for the cross attention. Can be `None`, `layer_norm`, or `group_norm`.
+        cross_attention_norm_num_groups (`int`, *optional*, defaults to 32):
+            The number of groups to use for the group norm in the cross attention.
+        added_kv_proj_dim (`int`, *optional*, defaults to `None`):
+            The number of channels to use for the added key and value projections. If `None`, no projection is used.
+        norm_num_groups (`int`, *optional*, defaults to `None`):
+            The number of groups to use for the group norm in the attention.
+        spatial_norm_dim (`int`, *optional*, defaults to `None`):
+            The number of channels to use for the spatial normalization.
+        out_bias (`bool`, *optional*, defaults to `True`):
+            Set to `True` to use a bias in the output linear layer.
+        scale_qk (`bool`, *optional*, defaults to `True`):
+            Set to `True` to scale the query and key by `1 / sqrt(dim_head)`.
+        qk_norm (`str`, *optional*, defaults to None):
+            Set to 'layer_norm' or `rms_norm` to perform query and key normalization.
+        only_cross_attention (`bool`, *optional*, defaults to `False`):
+            Set to `True` to only use cross attention and not added_kv_proj_dim. Can only be set to `True` if
+            `added_kv_proj_dim` is not `None`.
+        eps (`float`, *optional*, defaults to 1e-5):
+            An additional value added to the denominator in group normalization that is used for numerical stability.
+        rescale_output_factor (`float`, *optional*, defaults to 1.0):
+            A factor to rescale the output by dividing it with this value.
+        residual_connection (`bool`, *optional*, defaults to `False`):
+            Set to `True` to add the residual connection to the output.
+        _from_deprecated_attn_block (`bool`, *optional*, defaults to `False`):
+            Set to `True` if the attention block is loaded from a deprecated state dict.
+        processor (`AttnProcessor`, *optional*, defaults to `None`):
+            The attention processor to use. If `None`, defaults to `AttnProcessor2_0` if `torch 2.x` is used and
+            `AttnProcessor` otherwise.
+    """
+
+    def __init__(
+        self,
+        query_dim: int,
+        cross_attention_dim: Optional[int] = None,
+        heads: int = 8,
+        dim_head: int = 64,
+        dropout: float = 0.0,
+        bias: bool = False,
+        upcast_attention: bool = False,
+        upcast_softmax: bool = False,
+        cross_attention_norm: Optional[str] = None,
+        cross_attention_norm_num_groups: int = 32,
+        added_kv_proj_dim: Optional[int] = None,
+        norm_num_groups: Optional[int] = None,
+        spatial_norm_dim: Optional[int] = None,
+        out_bias: bool = True,
+        scale_qk: bool = True,
+        qk_norm: Optional[str] = None,
+        only_cross_attention: bool = False,
+        eps: float = 1e-5,
+        rescale_output_factor: float = 1.0,
+        residual_connection: bool = False,
+        _from_deprecated_attn_block: bool = False,
+        processor: Optional["AttnProcessor"] = None,
+        out_dim: int = None,
+        use_tpu_flash_attention: bool = False,
+        use_rope: bool = False,
+    ):
+        super().__init__()
+        self.inner_dim = out_dim if out_dim is not None else dim_head * heads
+        self.query_dim = query_dim
+        self.use_bias = bias
+        self.is_cross_attention = cross_attention_dim is not None
+        self.cross_attention_dim = (
+            cross_attention_dim if cross_attention_dim is not None else query_dim
+        )
+        self.upcast_attention = upcast_attention
+        self.upcast_softmax = upcast_softmax
+        self.rescale_output_factor = rescale_output_factor
+        self.residual_connection = residual_connection
+        self.dropout = dropout
+        self.fused_projections = False
+        self.out_dim = out_dim if out_dim is not None else query_dim
+        self.use_tpu_flash_attention = use_tpu_flash_attention
+        self.use_rope = use_rope
+
+        # we make use of this private variable to know whether this class is loaded
+        # with an deprecated state dict so that we can convert it on the fly
+        self._from_deprecated_attn_block = _from_deprecated_attn_block
+
+        self.scale_qk = scale_qk
+        self.scale = dim_head**-0.5 if self.scale_qk else 1.0
+
+        if qk_norm is None:
+            self.q_norm = nn.Identity()
+            self.k_norm = nn.Identity()
+        elif qk_norm == "rms_norm":
+            self.q_norm = RMSNorm(dim_head * heads, eps=1e-5)
+            self.k_norm = RMSNorm(dim_head * heads, eps=1e-5)
+        elif qk_norm == "layer_norm":
+            self.q_norm = nn.LayerNorm(dim_head * heads, eps=1e-5)
+            self.k_norm = nn.LayerNorm(dim_head * heads, eps=1e-5)
+        else:
+            raise ValueError(f"Unsupported qk_norm method: {qk_norm}")
+
+        self.heads = out_dim // dim_head if out_dim is not None else heads
+        # for slice_size > 0 the attention score computation
+        # is split across the batch axis to save memory
+        # You can set slice_size with `set_attention_slice`
+        self.sliceable_head_dim = heads
+
+        self.added_kv_proj_dim = added_kv_proj_dim
+        self.only_cross_attention = only_cross_attention
+
+        if self.added_kv_proj_dim is None and self.only_cross_attention:
+            raise ValueError(
+                "`only_cross_attention` can only be set to True if `added_kv_proj_dim` is not None. Make sure to set either `only_cross_attention=False` or define `added_kv_proj_dim`."
+            )
+
+        if norm_num_groups is not None:
+            self.group_norm = nn.GroupNorm(
+                num_channels=query_dim, num_groups=norm_num_groups, eps=eps, affine=True
+            )
+        else:
+            self.group_norm = None
+
+        if spatial_norm_dim is not None:
+            self.spatial_norm = SpatialNorm(
+                f_channels=query_dim, zq_channels=spatial_norm_dim
+            )
+        else:
+            self.spatial_norm = None
+
+        if cross_attention_norm is None:
+            self.norm_cross = None
+        elif cross_attention_norm == "layer_norm":
+            self.norm_cross = nn.LayerNorm(self.cross_attention_dim)
+        elif cross_attention_norm == "group_norm":
+            if self.added_kv_proj_dim is not None:
+                # The given `encoder_hidden_states` are initially of shape
+                # (batch_size, seq_len, added_kv_proj_dim) before being projected
+                # to (batch_size, seq_len, cross_attention_dim). The norm is applied
+                # before the projection, so we need to use `added_kv_proj_dim` as
+                # the number of channels for the group norm.
+                norm_cross_num_channels = added_kv_proj_dim
+            else:
+                norm_cross_num_channels = self.cross_attention_dim
+
+            self.norm_cross = nn.GroupNorm(
+                num_channels=norm_cross_num_channels,
+                num_groups=cross_attention_norm_num_groups,
+                eps=1e-5,
+                affine=True,
+            )
+        else:
+            raise ValueError(
+                f"unknown cross_attention_norm: {cross_attention_norm}. Should be None, 'layer_norm' or 'group_norm'"
+            )
+
+        linear_cls = nn.Linear
+
+        self.linear_cls = linear_cls
+        self.to_q = linear_cls(query_dim, self.inner_dim, bias=bias)
+
+        if not self.only_cross_attention:
+            # only relevant for the `AddedKVProcessor` classes
+            self.to_k = linear_cls(self.cross_attention_dim, self.inner_dim, bias=bias)
+            self.to_v = linear_cls(self.cross_attention_dim, self.inner_dim, bias=bias)
+        else:
+            self.to_k = None
+            self.to_v = None
+
+        if self.added_kv_proj_dim is not None:
+            self.add_k_proj = linear_cls(added_kv_proj_dim, self.inner_dim)
+            self.add_v_proj = linear_cls(added_kv_proj_dim, self.inner_dim)
+
+        self.to_out = nn.ModuleList([])
+        self.to_out.append(linear_cls(self.inner_dim, self.out_dim, bias=out_bias))
+        self.to_out.append(nn.Dropout(dropout))
+
+        # set attention processor
+        # We use the AttnProcessor2_0 by default when torch 2.x is used which uses
+        # torch.nn.functional.scaled_dot_product_attention for native Flash/memory_efficient_attention
+        # but only if it has the default `scale` argument. TODO remove scale_qk check when we move to torch 2.1
+        if processor is None:
+            processor = AttnProcessor2_0()
+        self.set_processor(processor)
+
+    def set_use_tpu_flash_attention(self):
+        r"""
+        Function sets the flag in this object. The flag will enforce the usage of TPU attention kernel.
+        """
+        self.use_tpu_flash_attention = True
+
+    def set_processor(self, processor: "AttnProcessor") -> None:
+        r"""
+        Set the attention processor to use.
+
+        Args:
+            processor (`AttnProcessor`):
+                The attention processor to use.
+        """
+        # if current processor is in `self._modules` and if passed `processor` is not, we need to
+        # pop `processor` from `self._modules`
+        if (
+            hasattr(self, "processor")
+            and isinstance(self.processor, torch.nn.Module)
+            and not isinstance(processor, torch.nn.Module)
+        ):
+            logger.info(
+                f"You are removing possibly trained weights of {self.processor} with {processor}"
+            )
+            self._modules.pop("processor")
+
+        self.processor = processor
+
+    def get_processor(
+        self, return_deprecated_lora: bool = False
+    ) -> "AttentionProcessor":  # noqa: F821
+        r"""
+        Get the attention processor in use.
+
+        Args:
+            return_deprecated_lora (`bool`, *optional*, defaults to `False`):
+                Set to `True` to return the deprecated LoRA attention processor.
+
+        Returns:
+            "AttentionProcessor": The attention processor in use.
+        """
+        if not return_deprecated_lora:
+            return self.processor
+
+        # TODO(Sayak, Patrick). The rest of the function is needed to ensure backwards compatible
+        # serialization format for LoRA Attention Processors. It should be deleted once the integration
+        # with PEFT is completed.
+        is_lora_activated = {
+            name: module.lora_layer is not None
+            for name, module in self.named_modules()
+            if hasattr(module, "lora_layer")
+        }
+
+        # 1. if no layer has a LoRA activated we can return the processor as usual
+        if not any(is_lora_activated.values()):
+            return self.processor
+
+        # If doesn't apply LoRA do `add_k_proj` or `add_v_proj`
+        is_lora_activated.pop("add_k_proj", None)
+        is_lora_activated.pop("add_v_proj", None)
+        # 2. else it is not posssible that only some layers have LoRA activated
+        if not all(is_lora_activated.values()):
+            raise ValueError(
+                f"Make sure that either all layers or no layers have LoRA activated, but have {is_lora_activated}"
+            )
+
+        # 3. And we need to merge the current LoRA layers into the corresponding LoRA attention processor
+        non_lora_processor_cls_name = self.processor.__class__.__name__
+        lora_processor_cls = getattr(
+            import_module(__name__), "LoRA" + non_lora_processor_cls_name
+        )
+
+        hidden_size = self.inner_dim
+
+        # now create a LoRA attention processor from the LoRA layers
+        if lora_processor_cls in [
+            LoRAAttnProcessor,
+            LoRAAttnProcessor2_0,
+            LoRAXFormersAttnProcessor,
+        ]:
+            kwargs = {
+                "cross_attention_dim": self.cross_attention_dim,
+                "rank": self.to_q.lora_layer.rank,
+                "network_alpha": self.to_q.lora_layer.network_alpha,
+                "q_rank": self.to_q.lora_layer.rank,
+                "q_hidden_size": self.to_q.lora_layer.out_features,
+                "k_rank": self.to_k.lora_layer.rank,
+                "k_hidden_size": self.to_k.lora_layer.out_features,
+                "v_rank": self.to_v.lora_layer.rank,
+                "v_hidden_size": self.to_v.lora_layer.out_features,
+                "out_rank": self.to_out[0].lora_layer.rank,
+                "out_hidden_size": self.to_out[0].lora_layer.out_features,
+            }
+
+            if hasattr(self.processor, "attention_op"):
+                kwargs["attention_op"] = self.processor.attention_op
+
+            lora_processor = lora_processor_cls(hidden_size, **kwargs)
+            lora_processor.to_q_lora.load_state_dict(self.to_q.lora_layer.state_dict())
+            lora_processor.to_k_lora.load_state_dict(self.to_k.lora_layer.state_dict())
+            lora_processor.to_v_lora.load_state_dict(self.to_v.lora_layer.state_dict())
+            lora_processor.to_out_lora.load_state_dict(
+                self.to_out[0].lora_layer.state_dict()
+            )
+        elif lora_processor_cls == LoRAAttnAddedKVProcessor:
+            lora_processor = lora_processor_cls(
+                hidden_size,
+                cross_attention_dim=self.add_k_proj.weight.shape[0],
+                rank=self.to_q.lora_layer.rank,
+                network_alpha=self.to_q.lora_layer.network_alpha,
+            )
+            lora_processor.to_q_lora.load_state_dict(self.to_q.lora_layer.state_dict())
+            lora_processor.to_k_lora.load_state_dict(self.to_k.lora_layer.state_dict())
+            lora_processor.to_v_lora.load_state_dict(self.to_v.lora_layer.state_dict())
+            lora_processor.to_out_lora.load_state_dict(
+                self.to_out[0].lora_layer.state_dict()
+            )
+
+            # only save if used
+            if self.add_k_proj.lora_layer is not None:
+                lora_processor.add_k_proj_lora.load_state_dict(
+                    self.add_k_proj.lora_layer.state_dict()
+                )
+                lora_processor.add_v_proj_lora.load_state_dict(
+                    self.add_v_proj.lora_layer.state_dict()
+                )
+            else:
+                lora_processor.add_k_proj_lora = None
+                lora_processor.add_v_proj_lora = None
+        else:
+            raise ValueError(f"{lora_processor_cls} does not exist.")
+
+        return lora_processor
+
+    def forward(
+        self,
+        hidden_states: torch.FloatTensor,
+        freqs_cis: Optional[Tuple[torch.FloatTensor, torch.FloatTensor]] = None,
+        encoder_hidden_states: Optional[torch.FloatTensor] = None,
+        attention_mask: Optional[torch.FloatTensor] = None,
+        **cross_attention_kwargs,
+    ) -> torch.Tensor:
+        r"""
+        The forward method of the `Attention` class.
+
+        Args:
+            hidden_states (`torch.Tensor`):
+                The hidden states of the query.
+            encoder_hidden_states (`torch.Tensor`, *optional*):
+                The hidden states of the encoder.
+            attention_mask (`torch.Tensor`, *optional*):
+                The attention mask to use. If `None`, no mask is applied.
+            **cross_attention_kwargs:
+                Additional keyword arguments to pass along to the cross attention.
+
+        Returns:
+            `torch.Tensor`: The output of the attention layer.
+        """
+        # The `Attention` class can call different attention processors / attention functions
+        # here we simply pass along all tensors to the selected processor class
+        # For standard processors that are defined here, `**cross_attention_kwargs` is empty
+
+        attn_parameters = set(
+            inspect.signature(self.processor.__call__).parameters.keys()
+        )
+        unused_kwargs = [
+            k for k, _ in cross_attention_kwargs.items() if k not in attn_parameters
+        ]
+        if len(unused_kwargs) > 0:
+            logger.warning(
+                f"cross_attention_kwargs {unused_kwargs} are not expected by"
+                f" {self.processor.__class__.__name__} and will be ignored."
+            )
+        cross_attention_kwargs = {
+            k: w for k, w in cross_attention_kwargs.items() if k in attn_parameters
+        }
+
+        return self.processor(
+            self,
+            hidden_states,
+            freqs_cis=freqs_cis,
+            encoder_hidden_states=encoder_hidden_states,
+            attention_mask=attention_mask,
+            **cross_attention_kwargs,
+        )
+
+    def batch_to_head_dim(self, tensor: torch.Tensor) -> torch.Tensor:
+        r"""
+        Reshape the tensor from `[batch_size, seq_len, dim]` to `[batch_size // heads, seq_len, dim * heads]`. `heads`
+        is the number of heads initialized while constructing the `Attention` class.
+
+        Args:
+            tensor (`torch.Tensor`): The tensor to reshape.
+
+        Returns:
+            `torch.Tensor`: The reshaped tensor.
+        """
+        head_size = self.heads
+        batch_size, seq_len, dim = tensor.shape
+        tensor = tensor.reshape(batch_size // head_size, head_size, seq_len, dim)
+        tensor = tensor.permute(0, 2, 1, 3).reshape(
+            batch_size // head_size, seq_len, dim * head_size
+        )
+        return tensor
+
+    def head_to_batch_dim(self, tensor: torch.Tensor, out_dim: int = 3) -> torch.Tensor:
+        r"""
+        Reshape the tensor from `[batch_size, seq_len, dim]` to `[batch_size, seq_len, heads, dim // heads]` `heads` is
+        the number of heads initialized while constructing the `Attention` class.
+
+        Args:
+            tensor (`torch.Tensor`): The tensor to reshape.
+            out_dim (`int`, *optional*, defaults to `3`): The output dimension of the tensor. If `3`, the tensor is
+                reshaped to `[batch_size * heads, seq_len, dim // heads]`.
+
+        Returns:
+            `torch.Tensor`: The reshaped tensor.
+        """
+
+        head_size = self.heads
+        if tensor.ndim == 3:
+            batch_size, seq_len, dim = tensor.shape
+            extra_dim = 1
+        else:
+            batch_size, extra_dim, seq_len, dim = tensor.shape
+        tensor = tensor.reshape(
+            batch_size, seq_len * extra_dim, head_size, dim // head_size
+        )
+        tensor = tensor.permute(0, 2, 1, 3)
+
+        if out_dim == 3:
+            tensor = tensor.reshape(
+                batch_size * head_size, seq_len * extra_dim, dim // head_size
+            )
+
+        return tensor
+
+    def get_attention_scores(
+        self,
+        query: torch.Tensor,
+        key: torch.Tensor,
+        attention_mask: torch.Tensor = None,
+    ) -> torch.Tensor:
+        r"""
+        Compute the attention scores.
+
+        Args:
+            query (`torch.Tensor`): The query tensor.
+            key (`torch.Tensor`): The key tensor.
+            attention_mask (`torch.Tensor`, *optional*): The attention mask to use. If `None`, no mask is applied.
+
+        Returns:
+            `torch.Tensor`: The attention probabilities/scores.
+        """
+        dtype = query.dtype
+        if self.upcast_attention:
+            query = query.float()
+            key = key.float()
+
+        if attention_mask is None:
+            baddbmm_input = torch.empty(
+                query.shape[0],
+                query.shape[1],
+                key.shape[1],
+                dtype=query.dtype,
+                device=query.device,
+            )
+            beta = 0
+        else:
+            baddbmm_input = attention_mask
+            beta = 1
+
+        attention_scores = torch.baddbmm(
+            baddbmm_input,
+            query,
+            key.transpose(-1, -2),
+            beta=beta,
+            alpha=self.scale,
+        )
+        del baddbmm_input
+
+        if self.upcast_softmax:
+            attention_scores = attention_scores.float()
+
+        attention_probs = attention_scores.softmax(dim=-1)
+        del attention_scores
+
+        attention_probs = attention_probs.to(dtype)
+
+        return attention_probs
+
+    def prepare_attention_mask(
+        self,
+        attention_mask: torch.Tensor,
+        target_length: int,
+        batch_size: int,
+        out_dim: int = 3,
+    ) -> torch.Tensor:
+        r"""
+        Prepare the attention mask for the attention computation.
+
+        Args:
+            attention_mask (`torch.Tensor`):
+                The attention mask to prepare.
+            target_length (`int`):
+                The target length of the attention mask. This is the length of the attention mask after padding.
+            batch_size (`int`):
+                The batch size, which is used to repeat the attention mask.
+            out_dim (`int`, *optional*, defaults to `3`):
+                The output dimension of the attention mask. Can be either `3` or `4`.
+
+        Returns:
+            `torch.Tensor`: The prepared attention mask.
+        """
+        head_size = self.heads
+        if attention_mask is None:
+            return attention_mask
+
+        current_length: int = attention_mask.shape[-1]
+        if current_length != target_length:
+            if attention_mask.device.type == "mps":
+                # HACK: MPS: Does not support padding by greater than dimension of input tensor.
+                # Instead, we can manually construct the padding tensor.
+                padding_shape = (
+                    attention_mask.shape[0],
+                    attention_mask.shape[1],
+                    target_length,
+                )
+                padding = torch.zeros(
+                    padding_shape,
+                    dtype=attention_mask.dtype,
+                    device=attention_mask.device,
+                )
+                attention_mask = torch.cat([attention_mask, padding], dim=2)
+            else:
+                # TODO: for pipelines such as stable-diffusion, padding cross-attn mask:
+                #       we want to instead pad by (0, remaining_length), where remaining_length is:
+                #       remaining_length: int = target_length - current_length
+                # TODO: re-enable tests/models/test_models_unet_2d_condition.py#test_model_xattn_padding
+                attention_mask = F.pad(attention_mask, (0, target_length), value=0.0)
+
+        if out_dim == 3:
+            if attention_mask.shape[0] < batch_size * head_size:
+                attention_mask = attention_mask.repeat_interleave(head_size, dim=0)
+        elif out_dim == 4:
+            attention_mask = attention_mask.unsqueeze(1)
+            attention_mask = attention_mask.repeat_interleave(head_size, dim=1)
+
+        return attention_mask
+
+    def norm_encoder_hidden_states(
+        self, encoder_hidden_states: torch.Tensor
+    ) -> torch.Tensor:
+        r"""
+        Normalize the encoder hidden states. Requires `self.norm_cross` to be specified when constructing the
+        `Attention` class.
+
+        Args:
+            encoder_hidden_states (`torch.Tensor`): Hidden states of the encoder.
+
+        Returns:
+            `torch.Tensor`: The normalized encoder hidden states.
+        """
+        assert (
+            self.norm_cross is not None
+        ), "self.norm_cross must be defined to call self.norm_encoder_hidden_states"
+
+        if isinstance(self.norm_cross, nn.LayerNorm):
+            encoder_hidden_states = self.norm_cross(encoder_hidden_states)
+        elif isinstance(self.norm_cross, nn.GroupNorm):
+            # Group norm norms along the channels dimension and expects
+            # input to be in the shape of (N, C, *). In this case, we want
+            # to norm along the hidden dimension, so we need to move
+            # (batch_size, sequence_length, hidden_size) ->
+            # (batch_size, hidden_size, sequence_length)
+            encoder_hidden_states = encoder_hidden_states.transpose(1, 2)
+            encoder_hidden_states = self.norm_cross(encoder_hidden_states)
+            encoder_hidden_states = encoder_hidden_states.transpose(1, 2)
+        else:
+            assert False
+
+        return encoder_hidden_states
+
+    @staticmethod
+    def apply_rotary_emb(
+        input_tensor: torch.Tensor,
+        freqs_cis: Tuple[torch.FloatTensor, torch.FloatTensor],
+    ) -> Tuple[torch.Tensor, torch.Tensor]:
+        cos_freqs = freqs_cis[0]
+        sin_freqs = freqs_cis[1]
+
+        t_dup = rearrange(input_tensor, "... (d r) -> ... d r", r=2)
+        t1, t2 = t_dup.unbind(dim=-1)
+        t_dup = torch.stack((-t2, t1), dim=-1)
+        input_tensor_rot = rearrange(t_dup, "... d r -> ... (d r)")
+
+        out = input_tensor * cos_freqs + input_tensor_rot * sin_freqs
+
+        return out
+
+
+class AttnProcessor2_0:
+    r"""
+    Processor for implementing scaled dot-product attention (enabled by default if you're using PyTorch 2.0).
+    """
+
+    def __init__(self):
+        pass
+
+    def __call__(
+        self,
+        attn: Attention,
+        hidden_states: torch.FloatTensor,
+        freqs_cis: Tuple[torch.FloatTensor, torch.FloatTensor],
+        encoder_hidden_states: Optional[torch.FloatTensor] = None,
+        attention_mask: Optional[torch.FloatTensor] = None,
+        temb: Optional[torch.FloatTensor] = None,
+        *args,
+        **kwargs,
+    ) -> torch.FloatTensor:
+        if len(args) > 0 or kwargs.get("scale", None) is not None:
+            deprecation_message = "The `scale` argument is deprecated and will be ignored. Please remove it, as passing it will raise an error in the future. `scale` should directly be passed while calling the underlying pipeline component i.e., via `cross_attention_kwargs`."
+            deprecate("scale", "1.0.0", deprecation_message)
+
+        residual = hidden_states
+        if attn.spatial_norm is not None:
+            hidden_states = attn.spatial_norm(hidden_states, temb)
+
+        input_ndim = hidden_states.ndim
+
+        if input_ndim == 4:
+            batch_size, channel, height, width = hidden_states.shape
+            hidden_states = hidden_states.view(
+                batch_size, channel, height * width
+            ).transpose(1, 2)
+
+        batch_size, sequence_length, _ = (
+            hidden_states.shape
+            if encoder_hidden_states is None
+            else encoder_hidden_states.shape
+        )
+
+        if (attention_mask is not None) and (not attn.use_tpu_flash_attention):
+            attention_mask = attn.prepare_attention_mask(
+                attention_mask, sequence_length, batch_size
+            )
+            # scaled_dot_product_attention expects attention_mask shape to be
+            # (batch, heads, source_length, target_length)
+            attention_mask = attention_mask.view(
+                batch_size, attn.heads, -1, attention_mask.shape[-1]
+            )
+
+        if attn.group_norm is not None:
+            hidden_states = attn.group_norm(hidden_states.transpose(1, 2)).transpose(
+                1, 2
+            )
+
+        query = attn.to_q(hidden_states)
+        query = attn.q_norm(query)
+
+        if encoder_hidden_states is not None:
+            if attn.norm_cross:
+                encoder_hidden_states = attn.norm_encoder_hidden_states(
+                    encoder_hidden_states
+                )
+            key = attn.to_k(encoder_hidden_states)
+            key = attn.k_norm(key)
+        else:  # if no context provided do self-attention
+            encoder_hidden_states = hidden_states
+            key = attn.to_k(hidden_states)
+            key = attn.k_norm(key)
+            if attn.use_rope:
+                key = attn.apply_rotary_emb(key, freqs_cis)
+                query = attn.apply_rotary_emb(query, freqs_cis)
+
+        value = attn.to_v(encoder_hidden_states)
+
+        inner_dim = key.shape[-1]
+        head_dim = inner_dim // attn.heads
+
+        query = query.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
+        key = key.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
+        value = value.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
+
+        # the output of sdp = (batch, num_heads, seq_len, head_dim)
+
+        if attn.use_tpu_flash_attention:  # use tpu attention offload 'flash attention'
+            q_segment_indexes = None
+            if (
+                attention_mask is not None
+            ):  # if mask is required need to tune both segmenIds fields
+                # attention_mask = torch.squeeze(attention_mask).to(torch.float32)
+                attention_mask = attention_mask.to(torch.float32)
+                q_segment_indexes = torch.ones(
+                    batch_size, query.shape[2], device=query.device, dtype=torch.float32
+                )
+                assert (
+                    attention_mask.shape[1] == key.shape[2]
+                ), f"ERROR: KEY SHAPE must be same as attention mask [{key.shape[2]}, {attention_mask.shape[1]}]"
+
+            assert (
+                query.shape[2] % 128 == 0
+            ), f"ERROR: QUERY SHAPE must be divisible by 128 (TPU limitation) [{query.shape[2]}]"
+            assert (
+                key.shape[2] % 128 == 0
+            ), f"ERROR: KEY SHAPE must be divisible by 128 (TPU limitation) [{key.shape[2]}]"
+
+            # run the TPU kernel implemented in jax with pallas
+            hidden_states = flash_attention(
+                q=query,
+                k=key,
+                v=value,
+                q_segment_ids=q_segment_indexes,
+                kv_segment_ids=attention_mask,
+                sm_scale=attn.scale,
+            )
+        else:
+            hidden_states = F.scaled_dot_product_attention(
+                query,
+                key,
+                value,
+                attn_mask=attention_mask,
+                dropout_p=0.0,
+                is_causal=False,
+            )
+
+        hidden_states = hidden_states.transpose(1, 2).reshape(
+            batch_size, -1, attn.heads * head_dim
+        )
+        hidden_states = hidden_states.to(query.dtype)
+
+        # linear proj
+        hidden_states = attn.to_out[0](hidden_states)
+        # dropout
+        hidden_states = attn.to_out[1](hidden_states)
+
+        if input_ndim == 4:
+            hidden_states = hidden_states.transpose(-1, -2).reshape(
+                batch_size, channel, height, width
+            )
+
+        if attn.residual_connection:
+            hidden_states = hidden_states + residual
+
+        hidden_states = hidden_states / attn.rescale_output_factor
+
+        return hidden_states
+
+
+class AttnProcessor:
+    r"""
+    Default processor for performing attention-related computations.
+    """
+
+    def __call__(
+        self,
+        attn: Attention,
+        hidden_states: torch.FloatTensor,
+        encoder_hidden_states: Optional[torch.FloatTensor] = None,
+        attention_mask: Optional[torch.FloatTensor] = None,
+        temb: Optional[torch.FloatTensor] = None,
+        *args,
+        **kwargs,
+    ) -> torch.Tensor:
+        if len(args) > 0 or kwargs.get("scale", None) is not None:
+            deprecation_message = "The `scale` argument is deprecated and will be ignored. Please remove it, as passing it will raise an error in the future. `scale` should directly be passed while calling the underlying pipeline component i.e., via `cross_attention_kwargs`."
+            deprecate("scale", "1.0.0", deprecation_message)
+
+        residual = hidden_states
+
+        if attn.spatial_norm is not None:
+            hidden_states = attn.spatial_norm(hidden_states, temb)
+
+        input_ndim = hidden_states.ndim
+
+        if input_ndim == 4:
+            batch_size, channel, height, width = hidden_states.shape
+            hidden_states = hidden_states.view(
+                batch_size, channel, height * width
+            ).transpose(1, 2)
+
+        batch_size, sequence_length, _ = (
+            hidden_states.shape
+            if encoder_hidden_states is None
+            else encoder_hidden_states.shape
+        )
+        attention_mask = attn.prepare_attention_mask(
+            attention_mask, sequence_length, batch_size
+        )
+
+        if attn.group_norm is not None:
+            hidden_states = attn.group_norm(hidden_states.transpose(1, 2)).transpose(
+                1, 2
+            )
+
+        query = attn.to_q(hidden_states)
+
+        if encoder_hidden_states is None:
+            encoder_hidden_states = hidden_states
+        elif attn.norm_cross:
+            encoder_hidden_states = attn.norm_encoder_hidden_states(
+                encoder_hidden_states
+            )
+
+        key = attn.to_k(encoder_hidden_states)
+        value = attn.to_v(encoder_hidden_states)
+
+        query = attn.head_to_batch_dim(query)
+        key = attn.head_to_batch_dim(key)
+        value = attn.head_to_batch_dim(value)
+
+        query = attn.q_norm(query)
+        key = attn.k_norm(key)
+
+        attention_probs = attn.get_attention_scores(query, key, attention_mask)
+        hidden_states = torch.bmm(attention_probs, value)
+        hidden_states = attn.batch_to_head_dim(hidden_states)
+
+        # linear proj
+        hidden_states = attn.to_out[0](hidden_states)
+        # dropout
+        hidden_states = attn.to_out[1](hidden_states)
+
+        if input_ndim == 4:
+            hidden_states = hidden_states.transpose(-1, -2).reshape(
+                batch_size, channel, height, width
+            )
+
+        if attn.residual_connection:
+            hidden_states = hidden_states + residual
+
+        hidden_states = hidden_states / attn.rescale_output_factor
+
+        return hidden_states
+
+
+class FeedForward(nn.Module):
+    r"""
+    A feed-forward layer.
+
+    Parameters:
+        dim (`int`): The number of channels in the input.
+        dim_out (`int`, *optional*): The number of channels in the output. If not given, defaults to `dim`.
+        mult (`int`, *optional*, defaults to 4): The multiplier to use for the hidden dimension.
+        dropout (`float`, *optional*, defaults to 0.0): The dropout probability to use.
+        activation_fn (`str`, *optional*, defaults to `"geglu"`): Activation function to be used in feed-forward.
+        final_dropout (`bool` *optional*, defaults to False): Apply a final dropout.
+        bias (`bool`, defaults to True): Whether to use a bias in the linear layer.
+    """
+
+    def __init__(
+        self,
+        dim: int,
+        dim_out: Optional[int] = None,
+        mult: int = 4,
+        dropout: float = 0.0,
+        activation_fn: str = "geglu",
+        final_dropout: bool = False,
+        inner_dim=None,
+        bias: bool = True,
+    ):
+        super().__init__()
+        if inner_dim is None:
+            inner_dim = int(dim * mult)
+        dim_out = dim_out if dim_out is not None else dim
+        linear_cls = nn.Linear
+
+        if activation_fn == "gelu":
+            act_fn = GELU(dim, inner_dim, bias=bias)
+        elif activation_fn == "gelu-approximate":
+            act_fn = GELU(dim, inner_dim, approximate="tanh", bias=bias)
+        elif activation_fn == "geglu":
+            act_fn = GEGLU(dim, inner_dim, bias=bias)
+        elif activation_fn == "geglu-approximate":
+            act_fn = ApproximateGELU(dim, inner_dim, bias=bias)
+        else:
+            raise ValueError(f"Unsupported activation function: {activation_fn}")
+
+        self.net = nn.ModuleList([])
+        # project in
+        self.net.append(act_fn)
+        # project dropout
+        self.net.append(nn.Dropout(dropout))
+        # project out
+        self.net.append(linear_cls(inner_dim, dim_out, bias=bias))
+        # FF as used in Vision Transformer, MLP-Mixer, etc. have a final dropout
+        if final_dropout:
+            self.net.append(nn.Dropout(dropout))
+
+    def forward(self, hidden_states: torch.Tensor, scale: float = 1.0) -> torch.Tensor:
+        compatible_cls = (GEGLU, LoRACompatibleLinear)
+        for module in self.net:
+            if isinstance(module, compatible_cls):
+                hidden_states = module(hidden_states, scale)
+            else:
+                hidden_states = module(hidden_states)
+        return hidden_states

xora/models/transformers/embeddings.py

@@ -0,0 +1,129 @@
+# Adapted from: https://github.com/huggingface/diffusers/blob/main/src/diffusers/models/embeddings.py
+import math
+
+import numpy as np
+import torch
+from einops import rearrange
+from torch import nn
+
+
+def get_timestep_embedding(
+    timesteps: torch.Tensor,
+    embedding_dim: int,
+    flip_sin_to_cos: bool = False,
+    downscale_freq_shift: float = 1,
+    scale: float = 1,
+    max_period: int = 10000,
+):
+    """
+    This matches the implementation in Denoising Diffusion Probabilistic Models: Create sinusoidal timestep embeddings.
+
+    :param timesteps: a 1-D Tensor of N indices, one per batch element.
+                      These may be fractional.
+    :param embedding_dim: the dimension of the output. :param max_period: controls the minimum frequency of the
+    embeddings. :return: an [N x dim] Tensor of positional embeddings.
+    """
+    assert len(timesteps.shape) == 1, "Timesteps should be a 1d-array"
+
+    half_dim = embedding_dim // 2
+    exponent = -math.log(max_period) * torch.arange(
+        start=0, end=half_dim, dtype=torch.float32, device=timesteps.device
+    )
+    exponent = exponent / (half_dim - downscale_freq_shift)
+
+    emb = torch.exp(exponent)
+    emb = timesteps[:, None].float() * emb[None, :]
+
+    # scale embeddings
+    emb = scale * emb
+
+    # concat sine and cosine embeddings
+    emb = torch.cat([torch.sin(emb), torch.cos(emb)], dim=-1)
+
+    # flip sine and cosine embeddings
+    if flip_sin_to_cos:
+        emb = torch.cat([emb[:, half_dim:], emb[:, :half_dim]], dim=-1)
+
+    # zero pad
+    if embedding_dim % 2 == 1:
+        emb = torch.nn.functional.pad(emb, (0, 1, 0, 0))
+    return emb
+
+
+def get_3d_sincos_pos_embed(embed_dim, grid, w, h, f):
+    """
+    grid_size: int of the grid height and width return: pos_embed: [grid_size*grid_size, embed_dim] or
+    [1+grid_size*grid_size, embed_dim] (w/ or w/o cls_token)
+    """
+    grid = rearrange(grid, "c (f h w) -> c f h w", h=h, w=w)
+    grid = rearrange(grid, "c f h w -> c h w f", h=h, w=w)
+    grid = grid.reshape([3, 1, w, h, f])
+    pos_embed = get_3d_sincos_pos_embed_from_grid(embed_dim, grid)
+    pos_embed = pos_embed.transpose(1, 0, 2, 3)
+    return rearrange(pos_embed, "h w f c -> (f h w) c")
+
+
+def get_3d_sincos_pos_embed_from_grid(embed_dim, grid):
+    if embed_dim % 3 != 0:
+        raise ValueError("embed_dim must be divisible by 3")
+
+    # use half of dimensions to encode grid_h
+    emb_f = get_1d_sincos_pos_embed_from_grid(embed_dim // 3, grid[0])  # (H*W*T, D/3)
+    emb_h = get_1d_sincos_pos_embed_from_grid(embed_dim // 3, grid[1])  # (H*W*T, D/3)
+    emb_w = get_1d_sincos_pos_embed_from_grid(embed_dim // 3, grid[2])  # (H*W*T, D/3)
+
+    emb = np.concatenate([emb_h, emb_w, emb_f], axis=-1)  # (H*W*T, D)
+    return emb
+
+
+def get_1d_sincos_pos_embed_from_grid(embed_dim, pos):
+    """
+    embed_dim: output dimension for each position pos: a list of positions to be encoded: size (M,) out: (M, D)
+    """
+    if embed_dim % 2 != 0:
+        raise ValueError("embed_dim must be divisible by 2")
+
+    omega = np.arange(embed_dim // 2, dtype=np.float64)
+    omega /= embed_dim / 2.0
+    omega = 1.0 / 10000**omega  # (D/2,)
+
+    pos_shape = pos.shape
+
+    pos = pos.reshape(-1)
+    out = np.einsum("m,d->md", pos, omega)  # (M, D/2), outer product
+    out = out.reshape([*pos_shape, -1])[0]
+
+    emb_sin = np.sin(out)  # (M, D/2)
+    emb_cos = np.cos(out)  # (M, D/2)
+
+    emb = np.concatenate([emb_sin, emb_cos], axis=-1)  # (M, D)
+    return emb
+
+
+class SinusoidalPositionalEmbedding(nn.Module):
+    """Apply positional information to a sequence of embeddings.
+
+    Takes in a sequence of embeddings with shape (batch_size, seq_length, embed_dim) and adds positional embeddings to
+    them
+
+    Args:
+        embed_dim: (int): Dimension of the positional embedding.
+        max_seq_length: Maximum sequence length to apply positional embeddings
+
+    """
+
+    def __init__(self, embed_dim: int, max_seq_length: int = 32):
+        super().__init__()
+        position = torch.arange(max_seq_length).unsqueeze(1)
+        div_term = torch.exp(
+            torch.arange(0, embed_dim, 2) * (-math.log(10000.0) / embed_dim)
+        )
+        pe = torch.zeros(1, max_seq_length, embed_dim)
+        pe[0, :, 0::2] = torch.sin(position * div_term)
+        pe[0, :, 1::2] = torch.cos(position * div_term)
+        self.register_buffer("pe", pe)
+
+    def forward(self, x):
+        _, seq_length, _ = x.shape
+        x = x + self.pe[:, :seq_length]
+        return x

xora/models/transformers/symmetric_patchifier.py

@@ -0,0 +1,96 @@
+from abc import ABC, abstractmethod
+from typing import Tuple
+
+import torch
+from diffusers.configuration_utils import ConfigMixin
+from einops import rearrange
+from torch import Tensor
+
+from xora.utils.torch_utils import append_dims
+
+
+class Patchifier(ConfigMixin, ABC):
+    def __init__(self, patch_size: int):
+        super().__init__()
+        self._patch_size = (1, patch_size, patch_size)
+
+    @abstractmethod
+    def patchify(
+        self, latents: Tensor, frame_rates: Tensor, scale_grid: bool
+    ) -> Tuple[Tensor, Tensor]:
+        pass
+
+    @abstractmethod
+    def unpatchify(
+        self,
+        latents: Tensor,
+        output_height: int,
+        output_width: int,
+        output_num_frames: int,
+        out_channels: int,
+    ) -> Tuple[Tensor, Tensor]:
+        pass
+
+    @property
+    def patch_size(self):
+        return self._patch_size
+
+    def get_grid(
+        self, orig_num_frames, orig_height, orig_width, batch_size, scale_grid, device
+    ):
+        f = orig_num_frames // self._patch_size[0]
+        h = orig_height // self._patch_size[1]
+        w = orig_width // self._patch_size[2]
+        grid_h = torch.arange(h, dtype=torch.float32, device=device)
+        grid_w = torch.arange(w, dtype=torch.float32, device=device)
+        grid_f = torch.arange(f, dtype=torch.float32, device=device)
+        grid = torch.meshgrid(grid_f, grid_h, grid_w)
+        grid = torch.stack(grid, dim=0)
+        grid = grid.unsqueeze(0).repeat(batch_size, 1, 1, 1, 1)
+
+        if scale_grid is not None:
+            for i in range(3):
+                if isinstance(scale_grid[i], Tensor):
+                    scale = append_dims(scale_grid[i], grid.ndim - 1)
+                else:
+                    scale = scale_grid[i]
+                grid[:, i, ...] = grid[:, i, ...] * scale * self._patch_size[i]
+
+        grid = rearrange(grid, "b c f h w -> b c (f h w)", b=batch_size)
+        return grid
+
+
+class SymmetricPatchifier(Patchifier):
+    def patchify(
+        self,
+        latents: Tensor,
+    ) -> Tuple[Tensor, Tensor]:
+        latents = rearrange(
+            latents,
+            "b c (f p1) (h p2) (w p3) -> b (f h w) (c p1 p2 p3)",
+            p1=self._patch_size[0],
+            p2=self._patch_size[1],
+            p3=self._patch_size[2],
+        )
+        return latents
+
+    def unpatchify(
+        self,
+        latents: Tensor,
+        output_height: int,
+        output_width: int,
+        output_num_frames: int,
+        out_channels: int,
+    ) -> Tuple[Tensor, Tensor]:
+        output_height = output_height // self._patch_size[1]
+        output_width = output_width // self._patch_size[2]
+        latents = rearrange(
+            latents,
+            "b (f h w) (c p q) -> b c f (h p) (w q) ",
+            f=output_num_frames,
+            h=output_height,
+            w=output_width,
+            p=self._patch_size[1],
+            q=self._patch_size[2],
+        )
+        return latents

xora/models/transformers/transformer3d.py

@@ -0,0 +1,491 @@
+# Adapted from: https://github.com/huggingface/diffusers/blob/v0.26.3/src/diffusers/models/transformers/transformer_2d.py
+import math
+from dataclasses import dataclass
+from typing import Any, Dict, List, Optional, Literal
+
+import torch
+from diffusers.configuration_utils import ConfigMixin, register_to_config
+from diffusers.models.embeddings import PixArtAlphaTextProjection
+from diffusers.models.modeling_utils import ModelMixin
+from diffusers.models.normalization import AdaLayerNormSingle
+from diffusers.utils import BaseOutput, is_torch_version
+from diffusers.utils import logging
+from torch import nn
+
+from xora.models.transformers.attention import BasicTransformerBlock
+from xora.models.transformers.embeddings import get_3d_sincos_pos_embed
+
+logger = logging.get_logger(__name__)
+
+
+@dataclass
+class Transformer3DModelOutput(BaseOutput):
+    """
+    The output of [`Transformer2DModel`].
+
+    Args:
+        sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` or `(batch size, num_vector_embeds - 1, num_latent_pixels)` if [`Transformer2DModel`] is discrete):
+            The hidden states output conditioned on the `encoder_hidden_states` input. If discrete, returns probability
+            distributions for the unnoised latent pixels.
+    """
+
+    sample: torch.FloatTensor
+
+
+class Transformer3DModel(ModelMixin, ConfigMixin):
+    _supports_gradient_checkpointing = True
+
+    @register_to_config
+    def __init__(
+        self,
+        num_attention_heads: int = 16,
+        attention_head_dim: int = 88,
+        in_channels: Optional[int] = None,
+        out_channels: Optional[int] = None,
+        num_layers: int = 1,
+        dropout: float = 0.0,
+        norm_num_groups: int = 32,
+        cross_attention_dim: Optional[int] = None,
+        attention_bias: bool = False,
+        num_vector_embeds: Optional[int] = None,
+        activation_fn: str = "geglu",
+        num_embeds_ada_norm: Optional[int] = None,
+        use_linear_projection: bool = False,
+        only_cross_attention: bool = False,
+        double_self_attention: bool = False,
+        upcast_attention: bool = False,
+        adaptive_norm: str = "single_scale_shift",  # 'single_scale_shift' or 'single_scale'
+        standardization_norm: str = "layer_norm",  # 'layer_norm' or 'rms_norm'
+        norm_elementwise_affine: bool = True,
+        norm_eps: float = 1e-5,
+        attention_type: str = "default",
+        caption_channels: int = None,
+        project_to_2d_pos: bool = False,
+        use_tpu_flash_attention: bool = False,  # if True uses the TPU attention offload ('flash attention')
+        qk_norm: Optional[str] = None,
+        positional_embedding_type: str = "absolute",
+        positional_embedding_theta: Optional[float] = None,
+        positional_embedding_max_pos: Optional[List[int]] = None,
+        timestep_scale_multiplier: Optional[float] = None,
+    ):
+        super().__init__()
+        self.use_tpu_flash_attention = (
+            use_tpu_flash_attention  # FIXME: push config down to the attention modules
+        )
+        self.use_linear_projection = use_linear_projection
+        self.num_attention_heads = num_attention_heads
+        self.attention_head_dim = attention_head_dim
+        inner_dim = num_attention_heads * attention_head_dim
+        self.inner_dim = inner_dim
+
+        self.project_to_2d_pos = project_to_2d_pos
+
+        self.patchify_proj = nn.Linear(in_channels, inner_dim, bias=True)
+
+        self.positional_embedding_type = positional_embedding_type
+        self.positional_embedding_theta = positional_embedding_theta
+        self.positional_embedding_max_pos = positional_embedding_max_pos
+        self.use_rope = self.positional_embedding_type == "rope"
+        self.timestep_scale_multiplier = timestep_scale_multiplier
+
+        if self.positional_embedding_type == "absolute":
+            embed_dim_3d = (
+                math.ceil((inner_dim / 2) * 3) if project_to_2d_pos else inner_dim
+            )
+            if self.project_to_2d_pos:
+                self.to_2d_proj = torch.nn.Linear(embed_dim_3d, inner_dim, bias=False)
+                self._init_to_2d_proj_weights(self.to_2d_proj)
+        elif self.positional_embedding_type == "rope":
+            if positional_embedding_theta is None:
+                raise ValueError(
+                    "If `positional_embedding_type` type is rope, `positional_embedding_theta` must also be defined"
+                )
+            if positional_embedding_max_pos is None:
+                raise ValueError(
+                    "If `positional_embedding_type` type is rope, `positional_embedding_max_pos` must also be defined"
+                )
+
+        # 3. Define transformers blocks
+        self.transformer_blocks = nn.ModuleList(
+            [
+                BasicTransformerBlock(
+                    inner_dim,
+                    num_attention_heads,
+                    attention_head_dim,
+                    dropout=dropout,
+                    cross_attention_dim=cross_attention_dim,
+                    activation_fn=activation_fn,
+                    num_embeds_ada_norm=num_embeds_ada_norm,
+                    attention_bias=attention_bias,
+                    only_cross_attention=only_cross_attention,
+                    double_self_attention=double_self_attention,
+                    upcast_attention=upcast_attention,
+                    adaptive_norm=adaptive_norm,
+                    standardization_norm=standardization_norm,
+                    norm_elementwise_affine=norm_elementwise_affine,
+                    norm_eps=norm_eps,
+                    attention_type=attention_type,
+                    use_tpu_flash_attention=use_tpu_flash_attention,
+                    qk_norm=qk_norm,
+                    use_rope=self.use_rope,
+                )
+                for d in range(num_layers)
+            ]
+        )
+
+        # 4. Define output layers
+        self.out_channels = in_channels if out_channels is None else out_channels
+        self.norm_out = nn.LayerNorm(inner_dim, elementwise_affine=False, eps=1e-6)
+        self.scale_shift_table = nn.Parameter(
+            torch.randn(2, inner_dim) / inner_dim**0.5
+        )
+        self.proj_out = nn.Linear(inner_dim, self.out_channels)
+
+        self.adaln_single = AdaLayerNormSingle(
+            inner_dim, use_additional_conditions=False
+        )
+        if adaptive_norm == "single_scale":
+            self.adaln_single.linear = nn.Linear(inner_dim, 4 * inner_dim, bias=True)
+
+        self.caption_projection = None
+        if caption_channels is not None:
+            self.caption_projection = PixArtAlphaTextProjection(
+                in_features=caption_channels, hidden_size=inner_dim
+            )
+
+        self.gradient_checkpointing = False
+
+    def set_use_tpu_flash_attention(self):
+        r"""
+        Function sets the flag in this object and propagates down the children. The flag will enforce the usage of TPU
+        attention kernel.
+        """
+        logger.info("ENABLE TPU FLASH ATTENTION -> TRUE")
+        self.use_tpu_flash_attention = True
+        # push config down to the attention modules
+        for block in self.transformer_blocks:
+            block.set_use_tpu_flash_attention()
+
+    def initialize(self, embedding_std: float, mode: Literal["xora", "legacy"]):
+        def _basic_init(module):
+            if isinstance(module, nn.Linear):
+                torch.nn.init.xavier_uniform_(module.weight)
+                if module.bias is not None:
+                    nn.init.constant_(module.bias, 0)
+
+        self.apply(_basic_init)
+
+        # Initialize timestep embedding MLP:
+        nn.init.normal_(
+            self.adaln_single.emb.timestep_embedder.linear_1.weight, std=embedding_std
+        )
+        nn.init.normal_(
+            self.adaln_single.emb.timestep_embedder.linear_2.weight, std=embedding_std
+        )
+        nn.init.normal_(self.adaln_single.linear.weight, std=embedding_std)
+
+        if hasattr(self.adaln_single.emb, "resolution_embedder"):
+            nn.init.normal_(
+                self.adaln_single.emb.resolution_embedder.linear_1.weight,
+                std=embedding_std,
+            )
+            nn.init.normal_(
+                self.adaln_single.emb.resolution_embedder.linear_2.weight,
+                std=embedding_std,
+            )
+        if hasattr(self.adaln_single.emb, "aspect_ratio_embedder"):
+            nn.init.normal_(
+                self.adaln_single.emb.aspect_ratio_embedder.linear_1.weight,
+                std=embedding_std,
+            )
+            nn.init.normal_(
+                self.adaln_single.emb.aspect_ratio_embedder.linear_2.weight,
+                std=embedding_std,
+            )
+
+        # Initialize caption embedding MLP:
+        nn.init.normal_(self.caption_projection.linear_1.weight, std=embedding_std)
+        nn.init.normal_(self.caption_projection.linear_1.weight, std=embedding_std)
+
+        for block in self.transformer_blocks:
+            if mode.lower() == "xora":
+                nn.init.constant_(block.attn1.to_out[0].weight, 0)
+                nn.init.constant_(block.attn1.to_out[0].bias, 0)
+
+            nn.init.constant_(block.attn2.to_out[0].weight, 0)
+            nn.init.constant_(block.attn2.to_out[0].bias, 0)
+
+            if mode.lower() == "xora":
+                nn.init.constant_(block.ff.net[2].weight, 0)
+                nn.init.constant_(block.ff.net[2].bias, 0)
+
+        # Zero-out output layers:
+        nn.init.constant_(self.proj_out.weight, 0)
+        nn.init.constant_(self.proj_out.bias, 0)
+
+    def _set_gradient_checkpointing(self, module, value=False):
+        if hasattr(module, "gradient_checkpointing"):
+            module.gradient_checkpointing = value
+
+    @staticmethod
+    def _init_to_2d_proj_weights(linear_layer):
+        input_features = linear_layer.weight.data.size(1)
+        output_features = linear_layer.weight.data.size(0)
+
+        # Start with a zero matrix
+        identity_like = torch.zeros((output_features, input_features))
+
+        # Fill the diagonal with 1's as much as possible
+        min_features = min(output_features, input_features)
+        identity_like[:min_features, :min_features] = torch.eye(min_features)
+        linear_layer.weight.data = identity_like.to(linear_layer.weight.data.device)
+
+    def get_fractional_positions(self, indices_grid):
+        fractional_positions = torch.stack(
+            [
+                indices_grid[:, i] / self.positional_embedding_max_pos[i]
+                for i in range(3)
+            ],
+            dim=-1,
+        )
+        return fractional_positions
+
+    def precompute_freqs_cis(self, indices_grid, spacing="exp"):
+        dtype = torch.float32  # We need full precision in the freqs_cis computation.
+        dim = self.inner_dim
+        theta = self.positional_embedding_theta
+
+        fractional_positions = self.get_fractional_positions(indices_grid)
+
+        start = 1
+        end = theta
+        device = fractional_positions.device
+        if spacing == "exp":
+            indices = theta ** (
+                torch.linspace(
+                    math.log(start, theta),
+                    math.log(end, theta),
+                    dim // 6,
+                    device=device,
+                    dtype=dtype,
+                )
+            )
+            indices = indices.to(dtype=dtype)
+        elif spacing == "exp_2":
+            indices = 1.0 / theta ** (torch.arange(0, dim, 6, device=device) / dim)
+            indices = indices.to(dtype=dtype)
+        elif spacing == "linear":
+            indices = torch.linspace(start, end, dim // 6, device=device, dtype=dtype)
+        elif spacing == "sqrt":
+            indices = torch.linspace(
+                start**2, end**2, dim // 6, device=device, dtype=dtype
+            ).sqrt()
+
+        indices = indices * math.pi / 2
+
+        if spacing == "exp_2":
+            freqs = (
+                (indices * fractional_positions.unsqueeze(-1))
+                .transpose(-1, -2)
+                .flatten(2)
+            )
+        else:
+            freqs = (
+                (indices * (fractional_positions.unsqueeze(-1) * 2 - 1))
+                .transpose(-1, -2)
+                .flatten(2)
+            )
+
+        cos_freq = freqs.cos().repeat_interleave(2, dim=-1)
+        sin_freq = freqs.sin().repeat_interleave(2, dim=-1)
+        if dim % 6 != 0:
+            cos_padding = torch.ones_like(cos_freq[:, :, : dim % 6])
+            sin_padding = torch.zeros_like(cos_freq[:, :, : dim % 6])
+            cos_freq = torch.cat([cos_padding, cos_freq], dim=-1)
+            sin_freq = torch.cat([sin_padding, sin_freq], dim=-1)
+        return cos_freq.to(self.dtype), sin_freq.to(self.dtype)
+
+    def forward(
+        self,
+        hidden_states: torch.Tensor,
+        indices_grid: torch.Tensor,
+        encoder_hidden_states: Optional[torch.Tensor] = None,
+        timestep: Optional[torch.LongTensor] = None,
+        class_labels: Optional[torch.LongTensor] = None,
+        cross_attention_kwargs: Dict[str, Any] = None,
+        attention_mask: Optional[torch.Tensor] = None,
+        encoder_attention_mask: Optional[torch.Tensor] = None,
+        return_dict: bool = True,
+    ):
+        """
+        The [`Transformer2DModel`] forward method.
+
+        Args:
+            hidden_states (`torch.LongTensor` of shape `(batch size, num latent pixels)` if discrete, `torch.FloatTensor` of shape `(batch size, channel, height, width)` if continuous):
+                Input `hidden_states`.
+            indices_grid (`torch.LongTensor` of shape `(batch size, 3, num latent pixels)`):
+            encoder_hidden_states ( `torch.FloatTensor` of shape `(batch size, sequence len, embed dims)`, *optional*):
+                Conditional embeddings for cross attention layer. If not given, cross-attention defaults to
+                self-attention.
+            timestep ( `torch.LongTensor`, *optional*):
+                Used to indicate denoising step. Optional timestep to be applied as an embedding in `AdaLayerNorm`.
+            class_labels ( `torch.LongTensor` of shape `(batch size, num classes)`, *optional*):
+                Used to indicate class labels conditioning. Optional class labels to be applied as an embedding in
+                `AdaLayerZeroNorm`.
+            cross_attention_kwargs ( `Dict[str, Any]`, *optional*):
+                A kwargs dictionary that if specified is passed along to the `AttentionProcessor` as defined under
+                `self.processor` in
+                [diffusers.models.attention_processor](https://github.com/huggingface/diffusers/blob/main/src/diffusers/models/attention_processor.py).
+            attention_mask ( `torch.Tensor`, *optional*):
+                An attention mask of shape `(batch, key_tokens)` is applied to `encoder_hidden_states`. If `1` the mask
+                is kept, otherwise if `0` it is discarded. Mask will be converted into a bias, which adds large
+                negative values to the attention scores corresponding to "discard" tokens.
+            encoder_attention_mask ( `torch.Tensor`, *optional*):
+                Cross-attention mask applied to `encoder_hidden_states`. Two formats supported:
+
+                    * Mask `(batch, sequence_length)` True = keep, False = discard.
+                    * Bias `(batch, 1, sequence_length)` 0 = keep, -10000 = discard.
+
+                If `ndim == 2`: will be interpreted as a mask, then converted into a bias consistent with the format
+                above. This bias will be added to the cross-attention scores.
+            return_dict (`bool`, *optional*, defaults to `True`):
+                Whether or not to return a [`~models.unets.unet_2d_condition.UNet2DConditionOutput`] instead of a plain
+                tuple.
+
+        Returns:
+            If `return_dict` is True, an [`~models.transformer_2d.Transformer2DModelOutput`] is returned, otherwise a
+            `tuple` where the first element is the sample tensor.
+        """
+        # for tpu attention offload 2d token masks are used. No need to transform.
+        if not self.use_tpu_flash_attention:
+            # ensure attention_mask is a bias, and give it a singleton query_tokens dimension.
+            #   we may have done this conversion already, e.g. if we came here via UNet2DConditionModel#forward.
+            #   we can tell by counting dims; if ndim == 2: it's a mask rather than a bias.
+            # expects mask of shape:
+            #   [batch, key_tokens]
+            # adds singleton query_tokens dimension:
+            #   [batch,                    1, key_tokens]
+            # this helps to broadcast it as a bias over attention scores, which will be in one of the following shapes:
+            #   [batch,  heads, query_tokens, key_tokens] (e.g. torch sdp attn)
+            #   [batch * heads, query_tokens, key_tokens] (e.g. xformers or classic attn)
+            if attention_mask is not None and attention_mask.ndim == 2:
+                # assume that mask is expressed as:
+                #   (1 = keep,      0 = discard)
+                # convert mask into a bias that can be added to attention scores:
+                #       (keep = +0,     discard = -10000.0)
+                attention_mask = (1 - attention_mask.to(hidden_states.dtype)) * -10000.0
+                attention_mask = attention_mask.unsqueeze(1)
+
+            # convert encoder_attention_mask to a bias the same way we do for attention_mask
+            if encoder_attention_mask is not None and encoder_attention_mask.ndim == 2:
+                encoder_attention_mask = (
+                    1 - encoder_attention_mask.to(hidden_states.dtype)
+                ) * -10000.0
+                encoder_attention_mask = encoder_attention_mask.unsqueeze(1)
+
+        # 1. Input
+        hidden_states = self.patchify_proj(hidden_states)
+
+        if self.timestep_scale_multiplier:
+            timestep = self.timestep_scale_multiplier * timestep
+
+        if self.positional_embedding_type == "absolute":
+            pos_embed_3d = self.get_absolute_pos_embed(indices_grid).to(
+                hidden_states.device
+            )
+            if self.project_to_2d_pos:
+                pos_embed = self.to_2d_proj(pos_embed_3d)
+            hidden_states = (hidden_states + pos_embed).to(hidden_states.dtype)
+            freqs_cis = None
+        elif self.positional_embedding_type == "rope":
+            freqs_cis = self.precompute_freqs_cis(indices_grid)
+
+        batch_size = hidden_states.shape[0]
+        timestep, embedded_timestep = self.adaln_single(
+            timestep.flatten(),
+            {"resolution": None, "aspect_ratio": None},
+            batch_size=batch_size,
+            hidden_dtype=hidden_states.dtype,
+        )
+        # Second dimension is 1 or number of tokens (if timestep_per_token)
+        timestep = timestep.view(batch_size, -1, timestep.shape[-1])
+        embedded_timestep = embedded_timestep.view(
+            batch_size, -1, embedded_timestep.shape[-1]
+        )
+
+        # 2. Blocks
+        if self.caption_projection is not None:
+            batch_size = hidden_states.shape[0]
+            encoder_hidden_states = self.caption_projection(encoder_hidden_states)
+            encoder_hidden_states = encoder_hidden_states.view(
+                batch_size, -1, hidden_states.shape[-1]
+            )
+
+        for block in self.transformer_blocks:
+            if self.training and self.gradient_checkpointing:
+
+                def create_custom_forward(module, return_dict=None):
+                    def custom_forward(*inputs):
+                        if return_dict is not None:
+                            return module(*inputs, return_dict=return_dict)
+                        else:
+                            return module(*inputs)
+
+                    return custom_forward
+
+                ckpt_kwargs: Dict[str, Any] = (
+                    {"use_reentrant": False} if is_torch_version(">=", "1.11.0") else {}
+                )
+                hidden_states = torch.utils.checkpoint.checkpoint(
+                    create_custom_forward(block),
+                    hidden_states,
+                    freqs_cis,
+                    attention_mask,
+                    encoder_hidden_states,
+                    encoder_attention_mask,
+                    timestep,
+                    cross_attention_kwargs,
+                    class_labels,
+                    **ckpt_kwargs,
+                )
+            else:
+                hidden_states = block(
+                    hidden_states,
+                    freqs_cis=freqs_cis,
+                    attention_mask=attention_mask,
+                    encoder_hidden_states=encoder_hidden_states,
+                    encoder_attention_mask=encoder_attention_mask,
+                    timestep=timestep,
+                    cross_attention_kwargs=cross_attention_kwargs,
+                    class_labels=class_labels,
+                )
+
+        # 3. Output
+        scale_shift_values = (
+            self.scale_shift_table[None, None] + embedded_timestep[:, :, None]
+        )
+        shift, scale = scale_shift_values[:, :, 0], scale_shift_values[:, :, 1]
+        hidden_states = self.norm_out(hidden_states)
+        # Modulation
+        hidden_states = hidden_states * (1 + scale) + shift
+        hidden_states = self.proj_out(hidden_states)
+        if not return_dict:
+            return (hidden_states,)
+
+        return Transformer3DModelOutput(sample=hidden_states)
+
+    def get_absolute_pos_embed(self, grid):
+        grid_np = grid[0].cpu().numpy()
+        embed_dim_3d = (
+            math.ceil((self.inner_dim / 2) * 3)
+            if self.project_to_2d_pos
+            else self.inner_dim
+        )
+        pos_embed = get_3d_sincos_pos_embed(  # (f h w)
+            embed_dim_3d,
+            grid_np,
+            h=int(max(grid_np[1]) + 1),
+            w=int(max(grid_np[2]) + 1),
+            f=int(max(grid_np[0] + 1)),
+        )
+        return torch.from_numpy(pos_embed).float().unsqueeze(0)

xora/pipelines/pipeline_xora_video.py

@@ -0,0 +1,1162 @@
+# Adapted from: https://github.com/huggingface/diffusers/blob/main/src/diffusers/pipelines/pixart_alpha/pipeline_pixart_alpha.py
+import html
+import inspect
+import math
+import re
+import urllib.parse as ul
+from typing import Callable, Dict, List, Optional, Tuple, Union
+
+
+import torch
+import torch.nn.functional as F
+from contextlib import nullcontext
+from diffusers.image_processor import VaeImageProcessor
+from diffusers.models import AutoencoderKL
+from diffusers.pipelines.pipeline_utils import DiffusionPipeline, ImagePipelineOutput
+from diffusers.schedulers import DPMSolverMultistepScheduler
+from diffusers.utils import (
+    BACKENDS_MAPPING,
+    deprecate,
+    is_bs4_available,
+    is_ftfy_available,
+    logging,
+)
+from diffusers.utils.torch_utils import randn_tensor
+from einops import rearrange
+from transformers import T5EncoderModel, T5Tokenizer
+
+from xora.models.transformers.transformer3d import Transformer3DModel
+from xora.models.transformers.symmetric_patchifier import Patchifier
+from xora.models.autoencoders.vae_encode import (
+    get_vae_size_scale_factor,
+    vae_decode,
+    vae_encode,
+)
+from xora.models.autoencoders.causal_video_autoencoder import CausalVideoAutoencoder
+from xora.schedulers.rf import TimestepShifter
+from xora.utils.conditioning_method import ConditioningMethod
+
+logger = logging.get_logger(__name__)  # pylint: disable=invalid-name
+
+if is_bs4_available():
+    from bs4 import BeautifulSoup
+
+if is_ftfy_available():
+    import ftfy
+
+ASPECT_RATIO_1024_BIN = {
+    "0.25": [512.0, 2048.0],
+    "0.28": [512.0, 1856.0],
+    "0.32": [576.0, 1792.0],
+    "0.33": [576.0, 1728.0],
+    "0.35": [576.0, 1664.0],
+    "0.4": [640.0, 1600.0],
+    "0.42": [640.0, 1536.0],
+    "0.48": [704.0, 1472.0],
+    "0.5": [704.0, 1408.0],
+    "0.52": [704.0, 1344.0],
+    "0.57": [768.0, 1344.0],
+    "0.6": [768.0, 1280.0],
+    "0.68": [832.0, 1216.0],
+    "0.72": [832.0, 1152.0],
+    "0.78": [896.0, 1152.0],
+    "0.82": [896.0, 1088.0],
+    "0.88": [960.0, 1088.0],
+    "0.94": [960.0, 1024.0],
+    "1.0": [1024.0, 1024.0],
+    "1.07": [1024.0, 960.0],
+    "1.13": [1088.0, 960.0],
+    "1.21": [1088.0, 896.0],
+    "1.29": [1152.0, 896.0],
+    "1.38": [1152.0, 832.0],
+    "1.46": [1216.0, 832.0],
+    "1.67": [1280.0, 768.0],
+    "1.75": [1344.0, 768.0],
+    "2.0": [1408.0, 704.0],
+    "2.09": [1472.0, 704.0],
+    "2.4": [1536.0, 640.0],
+    "2.5": [1600.0, 640.0],
+    "3.0": [1728.0, 576.0],
+    "4.0": [2048.0, 512.0],
+}
+
+ASPECT_RATIO_512_BIN = {
+    "0.25": [256.0, 1024.0],
+    "0.28": [256.0, 928.0],
+    "0.32": [288.0, 896.0],
+    "0.33": [288.0, 864.0],
+    "0.35": [288.0, 832.0],
+    "0.4": [320.0, 800.0],
+    "0.42": [320.0, 768.0],
+    "0.48": [352.0, 736.0],
+    "0.5": [352.0, 704.0],
+    "0.52": [352.0, 672.0],
+    "0.57": [384.0, 672.0],
+    "0.6": [384.0, 640.0],
+    "0.68": [416.0, 608.0],
+    "0.72": [416.0, 576.0],
+    "0.78": [448.0, 576.0],
+    "0.82": [448.0, 544.0],
+    "0.88": [480.0, 544.0],
+    "0.94": [480.0, 512.0],
+    "1.0": [512.0, 512.0],
+    "1.07": [512.0, 480.0],
+    "1.13": [544.0, 480.0],
+    "1.21": [544.0, 448.0],
+    "1.29": [576.0, 448.0],
+    "1.38": [576.0, 416.0],
+    "1.46": [608.0, 416.0],
+    "1.67": [640.0, 384.0],
+    "1.75": [672.0, 384.0],
+    "2.0": [704.0, 352.0],
+    "2.09": [736.0, 352.0],
+    "2.4": [768.0, 320.0],
+    "2.5": [800.0, 320.0],
+    "3.0": [864.0, 288.0],
+    "4.0": [1024.0, 256.0],
+}
+
+
+# Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.retrieve_timesteps
+def retrieve_timesteps(
+    scheduler,
+    num_inference_steps: Optional[int] = None,
+    device: Optional[Union[str, torch.device]] = None,
+    timesteps: Optional[List[int]] = None,
+    **kwargs,
+):
+    """
+    Calls the scheduler's `set_timesteps` method and retrieves timesteps from the scheduler after the call. Handles
+    custom timesteps. Any kwargs will be supplied to `scheduler.set_timesteps`.
+
+    Args:
+        scheduler (`SchedulerMixin`):
+            The scheduler to get timesteps from.
+        num_inference_steps (`int`):
+            The number of diffusion steps used when generating samples with a pre-trained model. If used,
+            `timesteps` must be `None`.
+        device (`str` or `torch.device`, *optional*):
+            The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
+        timesteps (`List[int]`, *optional*):
+                Custom timesteps used to support arbitrary spacing between timesteps. If `None`, then the default
+                timestep spacing strategy of the scheduler is used. If `timesteps` is passed, `num_inference_steps`
+                must be `None`.
+
+    Returns:
+        `Tuple[torch.Tensor, int]`: A tuple where the first element is the timestep schedule from the scheduler and the
+        second element is the number of inference steps.
+    """
+    if timesteps is not None:
+        accepts_timesteps = "timesteps" in set(
+            inspect.signature(scheduler.set_timesteps).parameters.keys()
+        )
+        if not accepts_timesteps:
+            raise ValueError(
+                f"The current scheduler class {scheduler.__class__}'s `set_timesteps` does not support custom"
+                f" timestep schedules. Please check whether you are using the correct scheduler."
+            )
+        scheduler.set_timesteps(timesteps=timesteps, device=device, **kwargs)
+        timesteps = scheduler.timesteps
+        num_inference_steps = len(timesteps)
+    else:
+        scheduler.set_timesteps(num_inference_steps, device=device, **kwargs)
+        timesteps = scheduler.timesteps
+    return timesteps, num_inference_steps
+
+
+class XoraVideoPipeline(DiffusionPipeline):
+    r"""
+    Pipeline for text-to-image generation using Xora.
+
+    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:
+        vae ([`AutoencoderKL`]):
+            Variational Auto-Encoder (VAE) Model to encode and decode images to and from latent representations.
+        text_encoder ([`T5EncoderModel`]):
+            Frozen text-encoder. This uses
+            [T5](https://huggingface.co/docs/transformers/model_doc/t5#transformers.T5EncoderModel), specifically the
+            [t5-v1_1-xxl](https://huggingface.co/PixArt-alpha/PixArt-alpha/tree/main/t5-v1_1-xxl) variant.
+        tokenizer (`T5Tokenizer`):
+            Tokenizer of class
+            [T5Tokenizer](https://huggingface.co/docs/transformers/model_doc/t5#transformers.T5Tokenizer).
+        transformer ([`Transformer2DModel`]):
+            A text conditioned `Transformer2DModel` to denoise the encoded image latents.
+        scheduler ([`SchedulerMixin`]):
+            A scheduler to be used in combination with `transformer` to denoise the encoded image latents.
+    """
+
+    bad_punct_regex = re.compile(
+        r"["
+        + "#®•©™&@·º½¾¿¡§~"
+        + r"\)"
+        + r"\("
+        + r"\]"
+        + r"\["
+        + r"\}"
+        + r"\{"
+        + r"\|"
+        + "\\"
+        + r"\/"
+        + r"\*"
+        + r"]{1,}"
+    )  # noqa
+
+    _optional_components = ["tokenizer", "text_encoder"]
+    model_cpu_offload_seq = "text_encoder->transformer->vae"
+
+    def __init__(
+        self,
+        tokenizer: T5Tokenizer,
+        text_encoder: T5EncoderModel,
+        vae: AutoencoderKL,
+        transformer: Transformer3DModel,
+        scheduler: DPMSolverMultistepScheduler,
+        patchifier: Patchifier,
+    ):
+        super().__init__()
+
+        self.register_modules(
+            tokenizer=tokenizer,
+            text_encoder=text_encoder,
+            vae=vae,
+            transformer=transformer,
+            scheduler=scheduler,
+            patchifier=patchifier,
+        )
+
+        self.video_scale_factor, self.vae_scale_factor, _ = get_vae_size_scale_factor(
+            self.vae
+        )
+        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor)
+
+    def mask_text_embeddings(self, emb, mask):
+        if emb.shape[0] == 1:
+            keep_index = mask.sum().item()
+            return emb[:, :, :keep_index, :], keep_index
+        else:
+            masked_feature = emb * mask[:, None, :, None]
+            return masked_feature, emb.shape[2]
+
+    # Adapted from diffusers.pipelines.deepfloyd_if.pipeline_if.encode_prompt
+    def encode_prompt(
+        self,
+        prompt: Union[str, List[str]],
+        do_classifier_free_guidance: bool = True,
+        negative_prompt: str = "",
+        num_images_per_prompt: int = 1,
+        device: Optional[torch.device] = None,
+        prompt_embeds: Optional[torch.FloatTensor] = None,
+        negative_prompt_embeds: Optional[torch.FloatTensor] = None,
+        prompt_attention_mask: Optional[torch.FloatTensor] = None,
+        negative_prompt_attention_mask: Optional[torch.FloatTensor] = None,
+        clean_caption: bool = False,
+        **kwargs,
+    ):
+        r"""
+        Encodes the prompt into text encoder hidden states.
+
+        Args:
+            prompt (`str` or `List[str]`, *optional*):
+                prompt to be encoded
+            negative_prompt (`str` or `List[str]`, *optional*):
+                The prompt 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`). For
+                This should be "".
+            do_classifier_free_guidance (`bool`, *optional*, defaults to `True`):
+                whether to use classifier free guidance or not
+            num_images_per_prompt (`int`, *optional*, defaults to 1):
+                number of images that should be generated per prompt
+            device: (`torch.device`, *optional*):
+                torch device to place the resulting embeddings on
+            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.
+            clean_caption (bool, defaults to `False`):
+                If `True`, the function will preprocess and clean the provided caption before encoding.
+        """
+
+        if "mask_feature" in kwargs:
+            deprecation_message = "The use of `mask_feature` is deprecated. It is no longer used in any computation and that doesn't affect the end results. It will be removed in a future version."
+            deprecate("mask_feature", "1.0.0", deprecation_message, standard_warn=False)
+
+        if device is None:
+            device = self._execution_device
+
+        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]
+
+        # See Section 3.1. of the paper.
+        # FIXME: to be configured in config not hardecoded. Fix in separate PR with rest of config
+        max_length = 128  # TPU supports only lengths multiple of 128
+
+        if prompt_embeds is None:
+            prompt = self._text_preprocessing(prompt, clean_caption=clean_caption)
+            text_inputs = self.tokenizer(
+                prompt,
+                padding="max_length",
+                max_length=max_length,
+                truncation=True,
+                add_special_tokens=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[:, max_length - 1 : -1]
+                )
+                logger.warning(
+                    "The following part of your input was truncated because CLIP can only handle sequences up to"
+                    f" {max_length} tokens: {removed_text}"
+                )
+
+            prompt_attention_mask = text_inputs.attention_mask
+            prompt_attention_mask = prompt_attention_mask.to(device)
+
+            prompt_embeds = self.text_encoder(
+                text_input_ids.to(device), attention_mask=prompt_attention_mask
+            )
+            prompt_embeds = prompt_embeds[0]
+
+        if self.text_encoder is not None:
+            dtype = self.text_encoder.dtype
+        elif self.transformer is not None:
+            dtype = self.transformer.dtype
+        else:
+            dtype = None
+
+        prompt_embeds = prompt_embeds.to(dtype=dtype, device=device)
+
+        bs_embed, seq_len, _ = prompt_embeds.shape
+        # duplicate text embeddings and attention mask 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
+        )
+        prompt_attention_mask = prompt_attention_mask.repeat(1, num_images_per_prompt)
+        prompt_attention_mask = prompt_attention_mask.view(
+            bs_embed * num_images_per_prompt, -1
+        )
+
+        # get unconditional embeddings for classifier free guidance
+        if do_classifier_free_guidance and negative_prompt_embeds is None:
+            uncond_tokens = [negative_prompt] * batch_size
+            uncond_tokens = self._text_preprocessing(
+                uncond_tokens, clean_caption=clean_caption
+            )
+            max_length = prompt_embeds.shape[1]
+            uncond_input = self.tokenizer(
+                uncond_tokens,
+                padding="max_length",
+                max_length=max_length,
+                truncation=True,
+                return_attention_mask=True,
+                add_special_tokens=True,
+                return_tensors="pt",
+            )
+            negative_prompt_attention_mask = uncond_input.attention_mask
+            negative_prompt_attention_mask = negative_prompt_attention_mask.to(device)
+
+            negative_prompt_embeds = self.text_encoder(
+                uncond_input.input_ids.to(device),
+                attention_mask=negative_prompt_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=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
+            )
+
+            negative_prompt_attention_mask = negative_prompt_attention_mask.repeat(
+                1, num_images_per_prompt
+            )
+            negative_prompt_attention_mask = negative_prompt_attention_mask.view(
+                bs_embed * num_images_per_prompt, -1
+            )
+        else:
+            negative_prompt_embeds = None
+            negative_prompt_attention_mask = None
+
+        return (
+            prompt_embeds,
+            prompt_attention_mask,
+            negative_prompt_embeds,
+            negative_prompt_attention_mask,
+        )
+
+    # 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
+
+    def check_inputs(
+        self,
+        prompt,
+        height,
+        width,
+        negative_prompt,
+        prompt_embeds=None,
+        negative_prompt_embeds=None,
+        prompt_attention_mask=None,
+        negative_prompt_attention_mask=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 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 prompt is not None and negative_prompt_embeds is not None:
+            raise ValueError(
+                f"Cannot forward both `prompt`: {prompt} and `negative_prompt_embeds`:"
+                f" {negative_prompt_embeds}. Please make sure to only forward one of the two."
+            )
+
+        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 prompt_attention_mask is None:
+            raise ValueError(
+                "Must provide `prompt_attention_mask` when specifying `prompt_embeds`."
+            )
+
+        if (
+            negative_prompt_embeds is not None
+            and negative_prompt_attention_mask is None
+        ):
+            raise ValueError(
+                "Must provide `negative_prompt_attention_mask` when specifying `negative_prompt_embeds`."
+            )
+
+        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_attention_mask.shape != negative_prompt_attention_mask.shape:
+                raise ValueError(
+                    "`prompt_attention_mask` and `negative_prompt_attention_mask` must have the same shape when passed directly, but"
+                    f" got: `prompt_attention_mask` {prompt_attention_mask.shape} != `negative_prompt_attention_mask`"
+                    f" {negative_prompt_attention_mask.shape}."
+                )
+
+    # Copied from diffusers.pipelines.deepfloyd_if.pipeline_if.IFPipeline._text_preprocessing
+    def _text_preprocessing(self, text, clean_caption=False):
+        if clean_caption and not is_bs4_available():
+            logger.warn(
+                BACKENDS_MAPPING["bs4"][-1].format("Setting `clean_caption=True`")
+            )
+            logger.warn("Setting `clean_caption` to False...")
+            clean_caption = False
+
+        if clean_caption and not is_ftfy_available():
+            logger.warn(
+                BACKENDS_MAPPING["ftfy"][-1].format("Setting `clean_caption=True`")
+            )
+            logger.warn("Setting `clean_caption` to False...")
+            clean_caption = False
+
+        if not isinstance(text, (tuple, list)):
+            text = [text]
+
+        def process(text: str):
+            if clean_caption:
+                text = self._clean_caption(text)
+                text = self._clean_caption(text)
+            else:
+                text = text.lower().strip()
+            return text
+
+        return [process(t) for t in text]
+
+    # Copied from diffusers.pipelines.deepfloyd_if.pipeline_if.IFPipeline._clean_caption
+    def _clean_caption(self, caption):
+        caption = str(caption)
+        caption = ul.unquote_plus(caption)
+        caption = caption.strip().lower()
+        caption = re.sub("<person>", "person", caption)
+        # urls:
+        caption = re.sub(
+            r"\b((?:https?:(?:\/{1,3}|[a-zA-Z0-9%])|[a-zA-Z0-9.\-]+[.](?:com|co|ru|net|org|edu|gov|it)[\w/-]*\b\/?(?!@)))",  # noqa
+            "",
+            caption,
+        )  # regex for urls
+        caption = re.sub(
+            r"\b((?:www:(?:\/{1,3}|[a-zA-Z0-9%])|[a-zA-Z0-9.\-]+[.](?:com|co|ru|net|org|edu|gov|it)[\w/-]*\b\/?(?!@)))",  # noqa
+            "",
+            caption,
+        )  # regex for urls
+        # html:
+        caption = BeautifulSoup(caption, features="html.parser").text
+
+        # @<nickname>
+        caption = re.sub(r"@[\w\d]+\b", "", caption)
+
+        # 31C0—31EF CJK Strokes
+        # 31F0—31FF Katakana Phonetic Extensions
+        # 3200—32FF Enclosed CJK Letters and Months
+        # 3300—33FF CJK Compatibility
+        # 3400—4DBF CJK Unified Ideographs Extension A
+        # 4DC0—4DFF Yijing Hexagram Symbols
+        # 4E00—9FFF CJK Unified Ideographs
+        caption = re.sub(r"[\u31c0-\u31ef]+", "", caption)
+        caption = re.sub(r"[\u31f0-\u31ff]+", "", caption)
+        caption = re.sub(r"[\u3200-\u32ff]+", "", caption)
+        caption = re.sub(r"[\u3300-\u33ff]+", "", caption)
+        caption = re.sub(r"[\u3400-\u4dbf]+", "", caption)
+        caption = re.sub(r"[\u4dc0-\u4dff]+", "", caption)
+        caption = re.sub(r"[\u4e00-\u9fff]+", "", caption)
+        #######################################################
+
+        # все виды тире / all types of dash --> "-"
+        caption = re.sub(
+            r"[\u002D\u058A\u05BE\u1400\u1806\u2010-\u2015\u2E17\u2E1A\u2E3A\u2E3B\u2E40\u301C\u3030\u30A0\uFE31\uFE32\uFE58\uFE63\uFF0D]+",  # noqa
+            "-",
+            caption,
+        )
+
+        # кавычки к одному стандарту
+        caption = re.sub(r"[`´«»“”¨]", '"', caption)
+        caption = re.sub(r"[‘’]", "'", caption)
+
+        # &quot;
+        caption = re.sub(r"&quot;?", "", caption)
+        # &amp
+        caption = re.sub(r"&amp", "", caption)
+
+        # ip adresses:
+        caption = re.sub(r"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}", " ", caption)
+
+        # article ids:
+        caption = re.sub(r"\d:\d\d\s+$", "", caption)
+
+        # \n
+        caption = re.sub(r"\\n", " ", caption)
+
+        # "#123"
+        caption = re.sub(r"#\d{1,3}\b", "", caption)
+        # "#12345.."
+        caption = re.sub(r"#\d{5,}\b", "", caption)
+        # "123456.."
+        caption = re.sub(r"\b\d{6,}\b", "", caption)
+        # filenames:
+        caption = re.sub(
+            r"[\S]+\.(?:png|jpg|jpeg|bmp|webp|eps|pdf|apk|mp4)", "", caption
+        )
+
+        #
+        caption = re.sub(r"[\"\']{2,}", r'"', caption)  # """AUSVERKAUFT"""
+        caption = re.sub(r"[\.]{2,}", r" ", caption)  # """AUSVERKAUFT"""
+
+        caption = re.sub(
+            self.bad_punct_regex, r" ", caption
+        )  # ***AUSVERKAUFT***, #AUSVERKAUFT
+        caption = re.sub(r"\s+\.\s+", r" ", caption)  # " . "
+
+        # this-is-my-cute-cat / this_is_my_cute_cat
+        regex2 = re.compile(r"(?:\-|\_)")
+        if len(re.findall(regex2, caption)) > 3:
+            caption = re.sub(regex2, " ", caption)
+
+        caption = ftfy.fix_text(caption)
+        caption = html.unescape(html.unescape(caption))
+
+        caption = re.sub(r"\b[a-zA-Z]{1,3}\d{3,15}\b", "", caption)  # jc6640
+        caption = re.sub(r"\b[a-zA-Z]+\d+[a-zA-Z]+\b", "", caption)  # jc6640vc
+        caption = re.sub(r"\b\d+[a-zA-Z]+\d+\b", "", caption)  # 6640vc231
+
+        caption = re.sub(r"(worldwide\s+)?(free\s+)?shipping", "", caption)
+        caption = re.sub(r"(free\s)?download(\sfree)?", "", caption)
+        caption = re.sub(r"\bclick\b\s(?:for|on)\s\w+", "", caption)
+        caption = re.sub(
+            r"\b(?:png|jpg|jpeg|bmp|webp|eps|pdf|apk|mp4)(\simage[s]?)?", "", caption
+        )
+        caption = re.sub(r"\bpage\s+\d+\b", "", caption)
+
+        caption = re.sub(
+            r"\b\d*[a-zA-Z]+\d+[a-zA-Z]+\d+[a-zA-Z\d]*\b", r" ", caption
+        )  # j2d1a2a...
+
+        caption = re.sub(r"\b\d+\.?\d*[xх×]\d+\.?\d*\b", "", caption)
+
+        caption = re.sub(r"\b\s+\:\s+", r": ", caption)
+        caption = re.sub(r"(\D[,\./])\b", r"\1 ", caption)
+        caption = re.sub(r"\s+", " ", caption)
+
+        caption.strip()
+
+        caption = re.sub(r"^[\"\']([\w\W]+)[\"\']$", r"\1", caption)
+        caption = re.sub(r"^[\'\_,\-\:;]", r"", caption)
+        caption = re.sub(r"[\'\_,\-\:\-\+]$", r"", caption)
+        caption = re.sub(r"^\.\S+$", "", caption)
+
+        return caption.strip()
+
+    # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.prepare_latents
+    def prepare_latents(
+        self,
+        batch_size,
+        num_latent_channels,
+        num_patches,
+        dtype,
+        device,
+        generator,
+        latents=None,
+        latents_mask=None,
+    ):
+        shape = (
+            batch_size,
+            num_patches // math.prod(self.patchifier.patch_size),
+            num_latent_channels,
+        )
+
+        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
+            )
+        elif latents_mask is not None:
+            noise = randn_tensor(shape, generator=generator, device=device, dtype=dtype)
+            latents = latents * latents_mask[..., None] + noise * (
+                1 - latents_mask[..., None]
+            )
+        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
+
+    @staticmethod
+    def classify_height_width_bin(
+        height: int, width: int, ratios: dict
+    ) -> Tuple[int, int]:
+        """Returns binned height and width."""
+        ar = float(height / width)
+        closest_ratio = min(ratios.keys(), key=lambda ratio: abs(float(ratio) - ar))
+        default_hw = ratios[closest_ratio]
+        return int(default_hw[0]), int(default_hw[1])
+
+    @staticmethod
+    def resize_and_crop_tensor(
+        samples: torch.Tensor, new_width: int, new_height: int
+    ) -> torch.Tensor:
+        n_frames, orig_height, orig_width = samples.shape[-3:]
+
+        # Check if resizing is needed
+        if orig_height != new_height or orig_width != new_width:
+            ratio = max(new_height / orig_height, new_width / orig_width)
+            resized_width = int(orig_width * ratio)
+            resized_height = int(orig_height * ratio)
+
+            # Resize
+            samples = rearrange(samples, "b c n h w -> (b n) c h w")
+            samples = F.interpolate(
+                samples,
+                size=(resized_height, resized_width),
+                mode="bilinear",
+                align_corners=False,
+            )
+            samples = rearrange(samples, "(b n) c h w -> b c n h w", n=n_frames)
+
+            # Center Crop
+            start_x = (resized_width - new_width) // 2
+            end_x = start_x + new_width
+            start_y = (resized_height - new_height) // 2
+            end_y = start_y + new_height
+            samples = samples[..., start_y:end_y, start_x:end_x]
+
+        return samples
+
+    @torch.no_grad()
+    def __call__(
+        self,
+        height: int,
+        width: int,
+        num_frames: int,
+        frame_rate: float,
+        prompt: Union[str, List[str]] = None,
+        negative_prompt: str = "",
+        num_inference_steps: int = 20,
+        timesteps: List[int] = None,
+        guidance_scale: float = 4.5,
+        num_images_per_prompt: Optional[int] = 1,
+        eta: float = 0.0,
+        generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None,
+        latents: Optional[torch.FloatTensor] = None,
+        prompt_embeds: Optional[torch.FloatTensor] = None,
+        prompt_attention_mask: Optional[torch.FloatTensor] = None,
+        negative_prompt_embeds: Optional[torch.FloatTensor] = None,
+        negative_prompt_attention_mask: Optional[torch.FloatTensor] = None,
+        output_type: Optional[str] = "pil",
+        return_dict: bool = True,
+        callback_on_step_end: Optional[Callable[[int, int, Dict], None]] = None,
+        clean_caption: bool = True,
+        media_items: Optional[torch.FloatTensor] = None,
+        mixed_precision: bool = False,
+        **kwargs,
+    ) -> Union[ImagePipelineOutput, Tuple]:
+        """
+        Function invoked when calling the pipeline for generation.
+
+        Args:
+            prompt (`str` or `List[str]`, *optional*):
+                The prompt or prompts to guide the image generation. If not defined, one has to pass `prompt_embeds`.
+                instead.
+            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`).
+            num_inference_steps (`int`, *optional*, defaults to 100):
+                The number of denoising steps. More denoising steps usually lead to a higher quality image at the
+                expense of slower inference.
+            timesteps (`List[int]`, *optional*):
+                Custom timesteps to use for the denoising process. If not defined, equal spaced `num_inference_steps`
+                timesteps are used. Must be in descending order.
+            guidance_scale (`float`, *optional*, defaults to 4.5):
+                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.
+            num_images_per_prompt (`int`, *optional*, defaults to 1):
+                The number of images to generate per prompt.
+            height (`int`, *optional*, defaults to self.unet.config.sample_size):
+                The height in pixels of the generated image.
+            width (`int`, *optional*, defaults to self.unet.config.sample_size):
+                The width in pixels of the generated image.
+            eta (`float`, *optional*, defaults to 0.0):
+                Corresponds to parameter eta (η) in the DDIM paper: https://arxiv.org/abs/2010.02502. Only applies to
+                [`schedulers.DDIMScheduler`], will be ignored for others.
+            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`.
+            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_attention_mask (`torch.FloatTensor`, *optional*): Pre-generated attention mask for text embeddings.
+            negative_prompt_embeds (`torch.FloatTensor`, *optional*):
+                Pre-generated negative text embeddings. This negative prompt should be "". If not
+                provided, negative_prompt_embeds will be generated from `negative_prompt` input argument.
+            negative_prompt_attention_mask (`torch.FloatTensor`, *optional*):
+                Pre-generated attention mask for negative text embeddings.
+            output_type (`str`, *optional*, defaults to `"pil"`):
+                The output format of the generate image. Choose between
+                [PIL](https://pillow.readthedocs.io/en/stable/): `PIL.Image.Image` or `np.array`.
+            return_dict (`bool`, *optional*, defaults to `True`):
+                Whether or not to return a [`~pipelines.stable_diffusion.IFPipelineOutput`] 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`.
+            clean_caption (`bool`, *optional*, defaults to `True`):
+                Whether or not to clean the caption before creating embeddings. Requires `beautifulsoup4` and `ftfy` to
+                be installed. If the dependencies are not installed, the embeddings will be created from the raw
+                prompt.
+            use_resolution_binning (`bool` defaults to `True`):
+                If set to `True`, the requested height and width are first mapped to the closest resolutions using
+                `ASPECT_RATIO_1024_BIN`. After the produced latents are decoded into images, they are resized back to
+                the requested resolution. Useful for generating non-square images.
+
+        Examples:
+
+        Returns:
+            [`~pipelines.ImagePipelineOutput`] or `tuple`:
+                If `return_dict` is `True`, [`~pipelines.ImagePipelineOutput`] is returned, otherwise a `tuple` is
+                returned where the first element is a list with the generated images
+        """
+        if "mask_feature" in kwargs:
+            deprecation_message = "The use of `mask_feature` is deprecated. It is no longer used in any computation and that doesn't affect the end results. It will be removed in a future version."
+            deprecate("mask_feature", "1.0.0", deprecation_message, standard_warn=False)
+
+        is_video = kwargs.get("is_video", False)
+        self.check_inputs(
+            prompt,
+            height,
+            width,
+            negative_prompt,
+            prompt_embeds,
+            negative_prompt_embeds,
+            prompt_attention_mask,
+            negative_prompt_attention_mask,
+        )
+
+        # 2. Default height and width to transformer
+        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]
+
+        device = self._execution_device
+
+        # here `guidance_scale` is defined analog to the guidance weight `w` of equation (2)
+        # of the Imagen paper: https://arxiv.org/pdf/2205.11487.pdf . `guidance_scale = 1`
+        # corresponds to doing no classifier free guidance.
+        do_classifier_free_guidance = guidance_scale > 1.0
+
+        # 3. Encode input prompt
+        (
+            prompt_embeds,
+            prompt_attention_mask,
+            negative_prompt_embeds,
+            negative_prompt_attention_mask,
+        ) = self.encode_prompt(
+            prompt,
+            do_classifier_free_guidance,
+            negative_prompt=negative_prompt,
+            num_images_per_prompt=num_images_per_prompt,
+            device=device,
+            prompt_embeds=prompt_embeds,
+            negative_prompt_embeds=negative_prompt_embeds,
+            prompt_attention_mask=prompt_attention_mask,
+            negative_prompt_attention_mask=negative_prompt_attention_mask,
+            clean_caption=clean_caption,
+        )
+        if do_classifier_free_guidance:
+            prompt_embeds = torch.cat([negative_prompt_embeds, prompt_embeds], dim=0)
+            prompt_attention_mask = torch.cat(
+                [negative_prompt_attention_mask, prompt_attention_mask], dim=0
+            )
+
+        # 3b. Encode and prepare conditioning data
+        self.video_scale_factor = self.video_scale_factor if is_video else 1
+        conditioning_method = kwargs.get("conditioning_method", None)
+        vae_per_channel_normalize = kwargs.get("vae_per_channel_normalize", False)
+        init_latents, conditioning_mask = self.prepare_conditioning(
+            media_items,
+            num_frames,
+            height,
+            width,
+            conditioning_method,
+            vae_per_channel_normalize,
+        )
+
+        # 4. Prepare latents.
+        latent_height = height // self.vae_scale_factor
+        latent_width = width // self.vae_scale_factor
+        latent_num_frames = num_frames // self.video_scale_factor
+        if isinstance(self.vae, CausalVideoAutoencoder) and is_video:
+            latent_num_frames += 1
+        latent_frame_rate = frame_rate / self.video_scale_factor
+        num_latent_patches = latent_height * latent_width * latent_num_frames
+        latents = self.prepare_latents(
+            batch_size=batch_size * num_images_per_prompt,
+            num_latent_channels=self.transformer.config.in_channels,
+            num_patches=num_latent_patches,
+            dtype=prompt_embeds.dtype,
+            device=device,
+            generator=generator,
+            latents=init_latents,
+            latents_mask=conditioning_mask,
+        )
+        if conditioning_mask is not None and is_video:
+            assert num_images_per_prompt == 1
+            conditioning_mask = (
+                torch.cat([conditioning_mask] * 2)
+                if do_classifier_free_guidance
+                else conditioning_mask
+            )
+
+        # 5. Prepare timesteps
+        retrieve_timesteps_kwargs = {}
+        if isinstance(self.scheduler, TimestepShifter):
+            retrieve_timesteps_kwargs["samples"] = latents
+        timesteps, num_inference_steps = retrieve_timesteps(
+            self.scheduler,
+            num_inference_steps,
+            device,
+            timesteps,
+            **retrieve_timesteps_kwargs,
+        )
+
+        # 6. Prepare extra step kwargs. TODO: Logic should ideally just be moved out of the pipeline
+        extra_step_kwargs = self.prepare_extra_step_kwargs(generator, eta)
+
+        # 7. Denoising loop
+        num_warmup_steps = max(
+            len(timesteps) - num_inference_steps * self.scheduler.order, 0
+        )
+
+        with self.progress_bar(total=num_inference_steps) as progress_bar:
+            for i, t in enumerate(timesteps):
+                latent_model_input = (
+                    torch.cat([latents] * 2) if do_classifier_free_guidance else latents
+                )
+                latent_model_input = self.scheduler.scale_model_input(
+                    latent_model_input, t
+                )
+
+                latent_frame_rates = (
+                    torch.ones(
+                        latent_model_input.shape[0], 1, device=latent_model_input.device
+                    )
+                    * latent_frame_rate
+                )
+
+                current_timestep = t
+                if not torch.is_tensor(current_timestep):
+                    # TODO: this requires sync between CPU and GPU. So try to pass timesteps as tensors if you can
+                    # This would be a good case for the `match` statement (Python 3.10+)
+                    is_mps = latent_model_input.device.type == "mps"
+                    if isinstance(current_timestep, float):
+                        dtype = torch.float32 if is_mps else torch.float64
+                    else:
+                        dtype = torch.int32 if is_mps else torch.int64
+                    current_timestep = torch.tensor(
+                        [current_timestep],
+                        dtype=dtype,
+                        device=latent_model_input.device,
+                    )
+                elif len(current_timestep.shape) == 0:
+                    current_timestep = current_timestep[None].to(
+                        latent_model_input.device
+                    )
+                # broadcast to batch dimension in a way that's compatible with ONNX/Core ML
+                current_timestep = current_timestep.expand(
+                    latent_model_input.shape[0]
+                ).unsqueeze(-1)
+                scale_grid = (
+                    (
+                        1 / latent_frame_rates,
+                        self.vae_scale_factor,
+                        self.vae_scale_factor,
+                    )
+                    if self.transformer.use_rope
+                    else None
+                )
+                indices_grid = self.patchifier.get_grid(
+                    orig_num_frames=latent_num_frames,
+                    orig_height=latent_height,
+                    orig_width=latent_width,
+                    batch_size=latent_model_input.shape[0],
+                    scale_grid=scale_grid,
+                    device=latents.device,
+                )
+
+                if conditioning_mask is not None:
+                    current_timestep = current_timestep * (1 - conditioning_mask)
+                # Choose the appropriate context manager based on `mixed_precision`
+                if mixed_precision:
+                    if "xla" in device.type:
+                        raise NotImplementedError(
+                            "Mixed precision is not supported yet on XLA devices."
+                        )
+
+                    context_manager = torch.autocast(device.type, dtype=torch.bfloat16)
+                else:
+                    context_manager = nullcontext()  # Dummy context manager
+
+                # predict noise model_output
+                with context_manager:
+                    noise_pred = self.transformer(
+                        latent_model_input.to(self.transformer.dtype),
+                        indices_grid,
+                        encoder_hidden_states=prompt_embeds.to(self.transformer.dtype),
+                        encoder_attention_mask=prompt_attention_mask,
+                        timestep=current_timestep,
+                        return_dict=False,
+                    )[0]
+
+                # perform guidance
+                if do_classifier_free_guidance:
+                    noise_pred_uncond, noise_pred_text = noise_pred.chunk(2)
+                    noise_pred = noise_pred_uncond + guidance_scale * (
+                        noise_pred_text - noise_pred_uncond
+                    )
+                    current_timestep, _ = current_timestep.chunk(2)
+
+                # learned sigma
+                if (
+                    self.transformer.config.out_channels // 2
+                    == self.transformer.config.in_channels
+                ):
+                    noise_pred = noise_pred.chunk(2, dim=1)[0]
+
+                # compute previous image: x_t -> x_t-1
+                latents = self.scheduler.step(
+                    noise_pred,
+                    t if current_timestep is None else current_timestep,
+                    latents,
+                    **extra_step_kwargs,
+                    return_dict=False,
+                )[0]
+
+                # call the callback, if provided
+                if i == len(timesteps) - 1 or (
+                    (i + 1) > num_warmup_steps and (i + 1) % self.scheduler.order == 0
+                ):
+                    progress_bar.update()
+
+                if callback_on_step_end is not None:
+                    callback_on_step_end(self, i, t, {})
+
+        latents = self.patchifier.unpatchify(
+            latents=latents,
+            output_height=latent_height,
+            output_width=latent_width,
+            output_num_frames=latent_num_frames,
+            out_channels=self.transformer.in_channels
+            // math.prod(self.patchifier.patch_size),
+        )
+        if output_type != "latent":
+            image = vae_decode(
+                latents,
+                self.vae,
+                is_video,
+                vae_per_channel_normalize=kwargs["vae_per_channel_normalize"],
+            )
+            image = self.image_processor.postprocess(image, output_type=output_type)
+
+        else:
+            image = latents
+
+        # Offload all models
+        self.maybe_free_model_hooks()
+
+        if not return_dict:
+            return (image,)
+
+        return ImagePipelineOutput(images=image)
+
+    def prepare_conditioning(
+        self,
+        media_items: torch.Tensor,
+        num_frames: int,
+        height: int,
+        width: int,
+        method: ConditioningMethod = ConditioningMethod.UNCONDITIONAL,
+        vae_per_channel_normalize: bool = False,
+    ) -> Tuple[torch.Tensor, torch.Tensor]:
+        """
+        Prepare the conditioning data for the video generation. If an input media item is provided, encode it
+        and set the conditioning_mask to indicate which tokens to condition on. Input media item should have
+        the same height and width as the generated video.
+
+        Args:
+            media_items (torch.Tensor): media items to condition on (images or videos)
+            num_frames (int): number of frames to generate
+            height (int): height of the generated video
+            width (int): width of the generated video
+            method (ConditioningMethod, optional): conditioning method to use. Defaults to ConditioningMethod.UNCONDITIONAL.
+            vae_per_channel_normalize (bool, optional): whether to normalize the input to the VAE per channel. Defaults to False.
+
+        Returns:
+            Tuple[torch.Tensor, torch.Tensor]: the conditioning latents and the conditioning mask
+        """
+        if media_items is None or method == ConditioningMethod.UNCONDITIONAL:
+            return None, None
+
+        assert media_items.ndim == 5
+        assert height == media_items.shape[-2] and width == media_items.shape[-1]
+
+        # Encode the input video and repeat to the required number of frame-tokens
+        init_latents = vae_encode(
+            media_items.to(dtype=self.vae.dtype, device=self.vae.device),
+            self.vae,
+            vae_per_channel_normalize=vae_per_channel_normalize,
+        ).float()
+
+        init_len, target_len = (
+            init_latents.shape[2],
+            num_frames // self.video_scale_factor,
+        )
+        if isinstance(self.vae, CausalVideoAutoencoder):
+            target_len += 1
+        init_latents = init_latents[:, :, :target_len]
+        if target_len > init_len:
+            repeat_factor = (target_len + init_len - 1) // init_len  # Ceiling division
+            init_latents = init_latents.repeat(1, 1, repeat_factor, 1, 1)[
+                :, :, :target_len
+            ]
+
+        # Prepare the conditioning mask (1.0 = condition on this token)
+        b, n, f, h, w = init_latents.shape
+        conditioning_mask = torch.zeros([b, 1, f, h, w], device=init_latents.device)
+        if method in [
+            ConditioningMethod.FIRST_FRAME,
+            ConditioningMethod.FIRST_AND_LAST_FRAME,
+        ]:
+            conditioning_mask[:, :, 0] = 1.0
+        if method in [
+            ConditioningMethod.LAST_FRAME,
+            ConditioningMethod.FIRST_AND_LAST_FRAME,
+        ]:
+            conditioning_mask[:, :, -1] = 1.0
+
+        # Patchify the init latents and the mask
+        conditioning_mask = self.patchifier.patchify(conditioning_mask).squeeze(-1)
+        init_latents = self.patchifier.patchify(latents=init_latents)
+        return init_latents, conditioning_mask

xora/schedulers/rf.py

@@ -0,0 +1,261 @@
+import math
+from abc import ABC, abstractmethod
+from dataclasses import dataclass
+from typing import Callable, Optional, Tuple, Union
+
+import torch
+from diffusers.configuration_utils import ConfigMixin, register_to_config
+from diffusers.schedulers.scheduling_utils import SchedulerMixin
+from diffusers.utils import BaseOutput
+from torch import Tensor
+
+from xora.utils.torch_utils import append_dims
+
+
+def simple_diffusion_resolution_dependent_timestep_shift(
+    samples: Tensor,
+    timesteps: Tensor,
+    n: int = 32 * 32,
+) -> Tensor:
+    if len(samples.shape) == 3:
+        _, m, _ = samples.shape
+    elif len(samples.shape) in [4, 5]:
+        m = math.prod(samples.shape[2:])
+    else:
+        raise ValueError(
+            "Samples must have shape (b, t, c), (b, c, h, w) or (b, c, f, h, w)"
+        )
+    snr = (timesteps / (1 - timesteps)) ** 2
+    shift_snr = torch.log(snr) + 2 * math.log(m / n)
+    shifted_timesteps = torch.sigmoid(0.5 * shift_snr)
+
+    return shifted_timesteps
+
+
+def time_shift(mu: float, sigma: float, t: Tensor):
+    return math.exp(mu) / (math.exp(mu) + (1 / t - 1) ** sigma)
+
+
+def get_normal_shift(
+    n_tokens: int,
+    min_tokens: int = 1024,
+    max_tokens: int = 4096,
+    min_shift: float = 0.95,
+    max_shift: float = 2.05,
+) -> Callable[[float], float]:
+    m = (max_shift - min_shift) / (max_tokens - min_tokens)
+    b = min_shift - m * min_tokens
+    return m * n_tokens + b
+
+
+def sd3_resolution_dependent_timestep_shift(
+    samples: Tensor, timesteps: Tensor
+) -> Tensor:
+    """
+    Shifts the timestep schedule as a function of the generated resolution.
+
+    In the SD3 paper, the authors empirically how to shift the timesteps based on the resolution of the target images.
+    For more details: https://arxiv.org/pdf/2403.03206
+
+    In Flux they later propose a more dynamic resolution dependent timestep shift, see:
+    https://github.com/black-forest-labs/flux/blob/87f6fff727a377ea1c378af692afb41ae84cbe04/src/flux/sampling.py#L66
+
+
+    Args:
+        samples (Tensor): A batch of samples with shape (batch_size, channels, height, width) or
+            (batch_size, channels, frame, height, width).
+        timesteps (Tensor): A batch of timesteps with shape (batch_size,).
+
+    Returns:
+        Tensor: The shifted timesteps.
+    """
+    if len(samples.shape) == 3:
+        _, m, _ = samples.shape
+    elif len(samples.shape) in [4, 5]:
+        m = math.prod(samples.shape[2:])
+    else:
+        raise ValueError(
+            "Samples must have shape (b, t, c), (b, c, h, w) or (b, c, f, h, w)"
+        )
+
+    shift = get_normal_shift(m)
+    return time_shift(shift, 1, timesteps)
+
+
+class TimestepShifter(ABC):
+    @abstractmethod
+    def shift_timesteps(self, samples: Tensor, timesteps: Tensor) -> Tensor:
+        pass
+
+
+@dataclass
+class RectifiedFlowSchedulerOutput(BaseOutput):
+    """
+    Output class for the scheduler's step function output.
+
+    Args:
+        prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
+            Computed sample (x_{t-1}) of previous timestep. `prev_sample` should be used as next model input in the
+            denoising loop.
+        pred_original_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
+            The predicted denoised sample (x_{0}) based on the model output from the current timestep.
+            `pred_original_sample` can be used to preview progress or for guidance.
+    """
+
+    prev_sample: torch.FloatTensor
+    pred_original_sample: Optional[torch.FloatTensor] = None
+
+
+class RectifiedFlowScheduler(SchedulerMixin, ConfigMixin, TimestepShifter):
+    order = 1
+
+    @register_to_config
+    def __init__(
+        self,
+        num_train_timesteps=1000,
+        shifting: Optional[str] = None,
+        base_resolution: int = 32**2,
+    ):
+        super().__init__()
+        self.init_noise_sigma = 1.0
+        self.num_inference_steps = None
+        self.timesteps = self.sigmas = torch.linspace(
+            1, 1 / num_train_timesteps, num_train_timesteps
+        )
+        self.delta_timesteps = self.timesteps - torch.cat(
+            [self.timesteps[1:], torch.zeros_like(self.timesteps[-1:])]
+        )
+        self.shifting = shifting
+        self.base_resolution = base_resolution
+
+    def shift_timesteps(self, samples: Tensor, timesteps: Tensor) -> Tensor:
+        if self.shifting == "SD3":
+            return sd3_resolution_dependent_timestep_shift(samples, timesteps)
+        elif self.shifting == "SimpleDiffusion":
+            return simple_diffusion_resolution_dependent_timestep_shift(
+                samples, timesteps, self.base_resolution
+            )
+        return timesteps
+
+    def set_timesteps(
+        self,
+        num_inference_steps: int,
+        samples: Tensor,
+        device: Union[str, torch.device] = None,
+    ):
+        """
+        Sets the discrete timesteps used for the diffusion chain. Supporting function to be run before inference.
+
+        Args:
+            num_inference_steps (`int`): The number of diffusion steps used when generating samples.
+            samples (`Tensor`): A batch of samples with shape.
+            device (`Union[str, torch.device]`, *optional*): The device to which the timesteps tensor will be moved.
+        """
+        num_inference_steps = min(self.config.num_train_timesteps, num_inference_steps)
+        timesteps = torch.linspace(1, 1 / num_inference_steps, num_inference_steps).to(
+            device
+        )
+        self.timesteps = self.shift_timesteps(samples, timesteps)
+        self.delta_timesteps = self.timesteps - torch.cat(
+            [self.timesteps[1:], torch.zeros_like(self.timesteps[-1:])]
+        )
+        self.num_inference_steps = num_inference_steps
+        self.sigmas = self.timesteps
+
+    def scale_model_input(
+        self, sample: torch.FloatTensor, timestep: Optional[int] = None
+    ) -> torch.FloatTensor:
+        # pylint: disable=unused-argument
+        """
+        Ensures interchangeability with schedulers that need to scale the denoising model input depending on the
+        current timestep.
+
+        Args:
+            sample (`torch.FloatTensor`): input sample
+            timestep (`int`, optional): current timestep
+
+        Returns:
+            `torch.FloatTensor`: scaled input sample
+        """
+        return sample
+
+    def step(
+        self,
+        model_output: torch.FloatTensor,
+        timestep: torch.FloatTensor,
+        sample: torch.FloatTensor,
+        eta: float = 0.0,
+        use_clipped_model_output: bool = False,
+        generator=None,
+        variance_noise: Optional[torch.FloatTensor] = None,
+        return_dict: bool = True,
+    ) -> Union[RectifiedFlowSchedulerOutput, Tuple]:
+        # pylint: disable=unused-argument
+        """
+        Predict the sample from the previous timestep by reversing the SDE. This function propagates the diffusion
+        process from the learned model outputs (most often the predicted noise).
+
+        Args:
+            model_output (`torch.FloatTensor`):
+                The direct output from learned diffusion model.
+            timestep (`float`):
+                The current discrete timestep in the diffusion chain.
+            sample (`torch.FloatTensor`):
+                A current instance of a sample created by the diffusion process.
+            eta (`float`):
+                The weight of noise for added noise in diffusion step.
+            use_clipped_model_output (`bool`, defaults to `False`):
+                If `True`, computes "corrected" `model_output` from the clipped predicted original sample. Necessary
+                because predicted original sample is clipped to [-1, 1] when `self.config.clip_sample` is `True`. If no
+                clipping has happened, "corrected" `model_output` would coincide with the one provided as input and
+                `use_clipped_model_output` has no effect.
+            generator (`torch.Generator`, *optional*):
+                A random number generator.
+            variance_noise (`torch.FloatTensor`):
+                Alternative to generating noise with `generator` by directly providing the noise for the variance
+                itself. Useful for methods such as [`CycleDiffusion`].
+            return_dict (`bool`, *optional*, defaults to `True`):
+                Whether or not to return a [`~schedulers.scheduling_ddim.DDIMSchedulerOutput`] or `tuple`.
+
+        Returns:
+            [`~schedulers.scheduling_utils.RectifiedFlowSchedulerOutput`] or `tuple`:
+                If return_dict is `True`, [`~schedulers.rf_scheduler.RectifiedFlowSchedulerOutput`] is returned,
+                otherwise a tuple is returned where the first element is the sample tensor.
+        """
+        if self.num_inference_steps is None:
+            raise ValueError(
+                "Number of inference steps is 'None', you need to run 'set_timesteps' after creating the scheduler"
+            )
+
+        if timestep.ndim == 0:
+            # Global timestep
+            current_index = (self.timesteps - timestep).abs().argmin()
+            dt = self.delta_timesteps.gather(0, current_index.unsqueeze(0))
+        else:
+            # Timestep per token
+            assert timestep.ndim == 2
+            current_index = (
+                (self.timesteps[:, None, None] - timestep[None]).abs().argmin(dim=0)
+            )
+            dt = self.delta_timesteps[current_index]
+            # Special treatment for zero timestep tokens - set dt to 0 so prev_sample = sample
+            dt = torch.where(timestep == 0.0, torch.zeros_like(dt), dt)[..., None]
+
+        prev_sample = sample - dt * model_output
+
+        if not return_dict:
+            return (prev_sample,)
+
+        return RectifiedFlowSchedulerOutput(prev_sample=prev_sample)
+
+    def add_noise(
+        self,
+        original_samples: torch.FloatTensor,
+        noise: torch.FloatTensor,
+        timesteps: torch.FloatTensor,
+    ) -> torch.FloatTensor:
+        sigmas = timesteps
+        sigmas = append_dims(sigmas, original_samples.ndim)
+        alphas = 1 - sigmas
+        noisy_samples = alphas * original_samples + sigmas * noise
+        return noisy_samples

xora/utils/conditioning_method.py

@@ -0,0 +1,8 @@
+from enum import Enum
+
+
+class ConditioningMethod(Enum):
+    UNCONDITIONAL = "unconditional"
+    FIRST_FRAME = "first_frame"
+    LAST_FRAME = "last_frame"
+    FIRST_AND_LAST_FRAME = "first_and_last_frame"

xora/utils/torch_utils.py

@@ -0,0 +1,25 @@
+import torch
+from torch import nn
+
+
+def append_dims(x: torch.Tensor, target_dims: int) -> torch.Tensor:
+    """Appends dimensions to the end of a tensor until it has target_dims dimensions."""
+    dims_to_append = target_dims - x.ndim
+    if dims_to_append < 0:
+        raise ValueError(
+            f"input has {x.ndim} dims but target_dims is {target_dims}, which is less"
+        )
+    elif dims_to_append == 0:
+        return x
+    return x[(...,) + (None,) * dims_to_append]
+
+
+class Identity(nn.Module):
+    """A placeholder identity operator that is argument-insensitive."""
+
+    def __init__(self, *args, **kwargs) -> None:  # pylint: disable=unused-argument
+        super().__init__()
+
+    # pylint: disable=unused-argument
+    def forward(self, x: torch.Tensor, *args, **kwargs) -> torch.Tensor:
+        return x