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mirror of https://github.com/huggingface/diffusers.git synced 2026-01-27 17:22:53 +03:00

let's go Flux2 🚀 (#12711)

* add vae

* Initial commit for Flux 2 Transformer implementation

* add pipeline part

* small edits to the pipeline and conversion

* update conversion script

* fix

* up up

* finish pipeline

* Remove Flux IP Adapter logic for now

* Remove deprecated 3D id logic

* Remove ControlNet logic for now

* Add link to ViT-22B paper as reference for parallel transformer blocks such as the Flux 2 single stream block

* update pipeline

* Don't use biases for input projs and output AdaNorm

* up

* Remove bias for double stream block text QKV projections

* Add script to convert Flux 2 transformer to diffusers

* make style and make quality

* fix a few things.

* allow sft files to go.

* fix image processor

* fix batch

* style a bit

* Fix some bugs in Flux 2 transformer implementation

* Fix dummy input preparation and fix some test bugs

* fix dtype casting in timestep guidance module.

* resolve conflicts.,

* remove ip adapter stuff.

* Fix Flux 2 transformer consistency test

* Fix bug in Flux2TransformerBlock (double stream block)

* Get remaining Flux 2 transformer tests passing

* make style; make quality; make fix-copies

* remove stuff.

* fix type annotaton.

* remove unneeded stuff from tests

* tests

* up

* up

* add sf support

* Remove unused IP Adapter and ControlNet logic from transformer (#9)

* copied from

* Apply suggestions from code review

Co-authored-by: YiYi Xu <yixu310@gmail.com>
Co-authored-by: apolinário <joaopaulo.passos@gmail.com>

* up

* up

* up

* up

* up

* Refactor Flux2Attention into separate classes for double stream and single stream attention

* Add _supports_qkv_fusion to AttentionModuleMixin to allow subclasses to disable QKV fusion

* Have Flux2ParallelSelfAttention inherit from AttentionModuleMixin with _supports_qkv_fusion=False

* Log debug message when calling fuse_projections on a AttentionModuleMixin subclass that does not support QKV fusion

* Address review comments

* Update src/diffusers/pipelines/flux2/pipeline_flux2.py

Co-authored-by: YiYi Xu <yixu310@gmail.com>

* up

* Remove maybe_allow_in_graph decorators for Flux 2 transformer blocks (#12)

* up

* support ostris loras. (#13)

* up

* update schdule

* up

* up (#17)

* add training scripts (#16)

* add training scripts

Co-authored-by: Linoy Tsaban <linoytsaban@gmail.com>

* model cpu offload in validation.

* add flux.2 readme

* add img2img and tests

* cpu offload in log validation

* Apply suggestions from code review

* fix

* up

* fixes

* remove i2i training tests for now.

---------

Co-authored-by: Linoy Tsaban <linoytsaban@gmail.com>
Co-authored-by: linoytsaban <linoy@huggingface.co>

* up

---------

Co-authored-by: yiyixuxu <yixu310@gmail.com>
Co-authored-by: Daniel Gu <dgu8957@gmail.com>
Co-authored-by: yiyi@huggingface.co <yiyi@ip-10-53-87-203.ec2.internal>
Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com>
Co-authored-by: Dhruv Nair <dhruv.nair@gmail.com>
Co-authored-by: apolinário <joaopaulo.passos@gmail.com>
Co-authored-by: yiyi@huggingface.co <yiyi@ip-26-0-160-103.ec2.internal>
Co-authored-by: Linoy Tsaban <linoytsaban@gmail.com>
Co-authored-by: linoytsaban <linoy@huggingface.co>
This commit is contained in:
Sayak Paul
2025-11-25 21:49:04 +05:30
committed by GitHub
parent 4088e8a851
commit 5ffb73d4ae
34 changed files with 8427 additions and 4 deletions

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@@ -349,6 +349,8 @@
title: DiTTransformer2DModel
- local: api/models/easyanimate_transformer3d
title: EasyAnimateTransformer3DModel
- local: api/models/flux2_transformer
title: Flux2Transformer2DModel
- local: api/models/flux_transformer
title: FluxTransformer2DModel
- local: api/models/hidream_image_transformer
@@ -525,6 +527,8 @@
title: EasyAnimate
- local: api/pipelines/flux
title: Flux
- local: api/pipelines/flux2
title: Flux2
- local: api/pipelines/control_flux_inpaint
title: FluxControlInpaint
- local: api/pipelines/hidream

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@@ -30,7 +30,8 @@ LoRA is a fast and lightweight training method that inserts and trains a signifi
- [`CogView4LoraLoaderMixin`] provides similar functions for [CogView4](https://huggingface.co/docs/diffusers/main/en/api/pipelines/cogview4).
- [`AmusedLoraLoaderMixin`] is for the [`AmusedPipeline`].
- [`HiDreamImageLoraLoaderMixin`] provides similar functions for [HiDream Image](https://huggingface.co/docs/diffusers/main/en/api/pipelines/hidream)
- [`QwenImageLoraLoaderMixin`] provides similar functions for [Qwen Image](https://huggingface.co/docs/diffusers/main/en/api/pipelines/qwen)
- [`QwenImageLoraLoaderMixin`] provides similar functions for [Qwen Image](https://huggingface.co/docs/diffusers/main/en/api/pipelines/qwen).
- [`Flux2LoraLoaderMixin`] provides similar functions for [Flux2](https://huggingface.co/docs/diffusers/main/en/api/pipelines/flux2).
- [`LoraBaseMixin`] provides a base class with several utility methods to fuse, unfuse, unload, LoRAs and more.
> [!TIP]
@@ -56,6 +57,10 @@ LoRA is a fast and lightweight training method that inserts and trains a signifi
[[autodoc]] loaders.lora_pipeline.FluxLoraLoaderMixin
## Flux2LoraLoaderMixin
[[autodoc]] loaders.lora_pipeline.Flux2LoraLoaderMixin
## CogVideoXLoraLoaderMixin
[[autodoc]] loaders.lora_pipeline.CogVideoXLoraLoaderMixin

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@@ -0,0 +1,19 @@
<!--Copyright 2025 The HuggingFace Team. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
specific language governing permissions and limitations under the License.
-->
# Flux2Transformer2DModel
A Transformer model for image-like data from [Flux2](https://hf.co/black-forest-labs/FLUX.2-dev).
## Flux2Transformer2DModel
[[autodoc]] Flux2Transformer2DModel

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@@ -0,0 +1,33 @@
<!--Copyright 2025 The HuggingFace Team. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
specific language governing permissions and limitations under the License.
-->
# Flux2
<div class="flex flex-wrap space-x-1">
<img alt="LoRA" src="https://img.shields.io/badge/LoRA-d8b4fe?style=flat"/>
<img alt="MPS" src="https://img.shields.io/badge/MPS-000000?style=flat&logo=apple&logoColor=white%22">
</div>
Flux.2 is the recent series of image generation models from Black Forest Labs, preceded by the [Flux.1](./flux.md) series. It is an entirely new model with a new architecture and pre-training done from scratch!
Original model checkpoints for Flux can be found [here](https://huggingface.co/black-forest-labs). Original inference code can be found [here](https://github.com/black-forest-labs/flux2-dev).
> [!TIP]
> Flux2 can be quite expensive to run on consumer hardware devices. However, you can perform a suite of optimizations to run it faster and in a more memory-friendly manner. Check out [this section](https://huggingface.co/blog/sd3#memory-optimizations-for-sd3) for more details. Additionally, Flux can benefit from quantization for memory efficiency with a trade-off in inference latency. Refer to [this blog post](https://huggingface.co/blog/quanto-diffusers) to learn more.
>
> [Caching](../../optimization/cache) may also speed up inference by storing and reusing intermediate outputs.
## Flux2Pipeline
[[autodoc]] Flux2Pipeline
- all
- __call__

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@@ -0,0 +1,315 @@
# DreamBooth training example for FLUX.2 [dev]
[DreamBooth](https://huggingface.co/papers/2208.12242) is a method to personalize image generation models given just a few (3~5) images of a subject/concept.
The `train_dreambooth_lora_flux2.py` script shows how to implement the training procedure for [LoRAs](https://huggingface.co/blog/lora) and adapt it for [FLUX.2 [dev]](https://github.com/black-forest-labs/flux2-dev).
> [!NOTE]
> **Memory consumption**
>
> Flux can be quite expensive to run on consumer hardware devices and as a result finetuning it comes with high memory requirements -
> a LoRA with a rank of 16 can exceed XXGB of VRAM for training. below we provide some tips and tricks to reduce memory consumption during training.
> For more tips & guidance on training on a resource-constrained device and general good practices please check out these great guides and trainers for FLUX:
> 1) [`@bghira`'s guide](https://github.com/bghira/SimpleTuner/blob/main/documentation/quickstart/FLUX2.md)
> 2) [`ostris`'s guide](https://github.com/ostris/ai-toolkit?tab=readme-ov-file#flux2-training)
> [!NOTE]
> **Gated model**
>
> As the model is gated, before using it with diffusers you first need to go to the [FLUX.2 [dev] Hugging Face page](https://huggingface.co/black-forest-labs/FLUX.2-dev), fill in the form and accept the gate. Once you are in, you need to log in so that your system knows youve accepted the gate. Use the command below to log in:
```bash
hf auth login
```
This will also allow us to push the trained model parameters to the Hugging Face Hub platform.
## Running locally with PyTorch
### Installing the dependencies
Before running the scripts, make sure to install the library's training dependencies:
**Important**
To make sure you can successfully run the latest versions of the example scripts, we highly recommend **installing from source** and keeping the install up to date as we update the example scripts frequently and install some example-specific requirements. To do this, execute the following steps in a new virtual environment:
```bash
git clone https://github.com/huggingface/diffusers
cd diffusers
pip install -e .
```
Then cd in the `examples/dreambooth` folder and run
```bash
pip install -r requirements_flux.txt
```
And initialize an [🤗Accelerate](https://github.com/huggingface/accelerate/) environment with:
```bash
accelerate config
```
Or for a default accelerate configuration without answering questions about your environment
```bash
accelerate config default
```
Or if your environment doesn't support an interactive shell (e.g., a notebook)
```python
from accelerate.utils import write_basic_config
write_basic_config()
```
When running `accelerate config`, if we specify torch compile mode to True there can be dramatic speedups.
Note also that we use PEFT library as backend for LoRA training, make sure to have `peft>=0.6.0` installed in your environment.
### Dog toy example
Now let's get our dataset. For this example we will use some dog images: https://huggingface.co/datasets/diffusers/dog-example.
Let's first download it locally:
```python
from huggingface_hub import snapshot_download
local_dir = "./dog"
snapshot_download(
"diffusers/dog-example",
local_dir=local_dir, repo_type="dataset",
ignore_patterns=".gitattributes",
)
```
This will also allow us to push the trained LoRA parameters to the Hugging Face Hub platform.
As mentioned, Flux2 LoRA training is *very* memory intensive. Here are memory optimizations we can use (some still experimental) for a more memory efficient training:
## Memory Optimizations
> [!NOTE] many of these techniques complement each other and can be used together to further reduce memory consumption.
> However some techniques may be mutually exclusive so be sure to check before launching a training run.
### Remote Text Encoder
Flux.2 uses Mistral Small 3.1 as text encoder which is quite large and can take up a lot of memory. To mitigate this, we can use the `--remote_text_encoder` flag to enable remote computation of the prompt embeddings using the HuggingFace Inference API.
This way, the text encoder model is not loaded into memory during training.
> [!NOTE]
> to enable remote text encoding you must either be logged in to your HuggingFace account (`hf auth login`) OR pass a token with `--hub_token`.
### CPU Offloading
To offload parts of the model to CPU memory, you can use `--offload` flag. This will offload the vae and text encoder to CPU memory and only move them to GPU when needed.
### Latent Caching
Pre-encode the training images with the vae, and then delete it to free up some memory. To enable `latent_caching` simply pass `--cache_latents`.
### QLoRA: Low Precision Training with Quantization
Perform low precision training using 8-bit or 4-bit quantization to reduce memory usage. You can use the following flags:
- **FP8 training** with `torchao`:
enable FP8 training by passing `--do_fp8_training`.
> [!IMPORTANT] Since we are utilizing FP8 tensor cores we need CUDA GPUs with compute capability at least 8.9 or greater.
> If you're looking for memory-efficient training on relatively older cards, we encourage you to check out other trainers like SimpleTuner, ai-toolkit, etc.
- **NF4 training** with `bitsandbytes`:
Alternatively, you can use 8-bit or 4-bit quantization with `bitsandbytes` by passing:
`--bnb_quantization_config_path` to enable 4-bit NF4 quantization.
### Gradient Checkpointing and Accumulation
* `--gradient accumulation` refers to the number of updates steps to accumulate before performing a backward/update pass.
by passing a value > 1 you can reduce the amount of backward/update passes and hence also memory reqs.
* with `--gradient checkpointing` we can save memory by not storing all intermediate activations during the forward pass.
Instead, only a subset of these activations (the checkpoints) are stored and the rest is recomputed as needed during the backward pass. Note that this comes at the expanse of a slower backward pass.
### 8-bit-Adam Optimizer
When training with `AdamW`(doesn't apply to `prodigy`) You can pass `--use_8bit_adam` to reduce the memory requirements of training.
Make sure to install `bitsandbytes` if you want to do so.
### Image Resolution
An easy way to mitigate some of the memory requirements is through `--resolution`. `--resolution` refers to the resolution for input images, all the images in the train/validation dataset are resized to this.
Note that by default, images are resized to resolution of 512, but it's good to keep in mind in case you're accustomed to training on higher resolutions.
### Precision of saved LoRA layers
By default, trained transformer layers are saved in the precision dtype in which training was performed. E.g. when training in mixed precision is enabled with `--mixed_precision="bf16"`, final finetuned layers will be saved in `torch.bfloat16` as well.
This reduces memory requirements significantly w/o a significant quality loss. Note that if you do wish to save the final layers in float32 at the expanse of more memory usage, you can do so by passing `--upcast_before_saving`.
```bash
export MODEL_NAME="black-forest-labs/FLUX.2-dev"
export INSTANCE_DIR="dog"
export OUTPUT_DIR="trained-flux2"
accelerate launch train_dreambooth_flux.py \
--pretrained_model_name_or_path=$MODEL_NAME \
--instance_data_dir=$INSTANCE_DIR \
--output_dir=$OUTPUT_DIR \
--do_fp8_training \
--gradient_checkpointing \
--remote_text_encoder \
--cache_latents \
--instance_prompt="a photo of sks dog" \
--resolution=1024 \
--train_batch_size=1 \
--guidance_scale=1 \
--use_8bit_adam \
--gradient_accumulation_steps=4 \
--optimizer="adamW" \
--learning_rate=1e-4 \
--report_to="wandb" \
--lr_scheduler="constant" \
--lr_warmup_steps=100 \
--max_train_steps=500 \
--validation_prompt="A photo of sks dog in a bucket" \
--validation_epochs=25 \
--seed="0" \
--push_to_hub
```
To better track our training experiments, we're using the following flags in the command above:
* `report_to="wandb` will ensure the training runs are tracked on [Weights and Biases](https://wandb.ai/site). To use it, be sure to install `wandb` with `pip install wandb`. Don't forget to call `wandb login <your_api_key>` before training if you haven't done it before.
* `validation_prompt` and `validation_epochs` to allow the script to do a few validation inference runs. This allows us to qualitatively check if the training is progressing as expected.
> [!NOTE]
> If you want to train using long prompts with the T5 text encoder, you can use `--max_sequence_length` to set the token limit. The default is 77, but it can be increased to as high as 512. Note that this will use more resources and may slow down the training in some cases.
## LoRA + DreamBooth
[LoRA](https://huggingface.co/docs/peft/conceptual_guides/adapter#low-rank-adaptation-lora) is a popular parameter-efficient fine-tuning technique that allows you to achieve full-finetuning like performance but with a fraction of learnable parameters.
Note also that we use PEFT library as backend for LoRA training, make sure to have `peft>=0.6.0` installed in your environment.
### Prodigy Optimizer
Prodigy is an adaptive optimizer that dynamically adjusts the learning rate learned parameters based on past gradients, allowing for more efficient convergence.
By using prodigy we can "eliminate" the need for manual learning rate tuning. read more [here](https://huggingface.co/blog/sdxl_lora_advanced_script#adaptive-optimizers).
to use prodigy, first make sure to install the prodigyopt library: `pip install prodigyopt`, and then specify -
```bash
--optimizer="prodigy"
```
> [!TIP]
> When using prodigy it's generally good practice to set- `--learning_rate=1.0`
To perform DreamBooth with LoRA, run:
```bash
export MODEL_NAME="black-forest-labs/FLUX.2-dev"
export INSTANCE_DIR="dog"
export OUTPUT_DIR="trained-flux2-lora"
accelerate launch train_dreambooth_lora_flux.py \
--pretrained_model_name_or_path=$MODEL_NAME \
--instance_data_dir=$INSTANCE_DIR \
--output_dir=$OUTPUT_DIR \
--do_fp8_training \
--gradient_checkpointing \
--remote_text_encoder \
--cache_latents \
--instance_prompt="a photo of sks dog" \
--resolution=512 \
--train_batch_size=1 \
--guidance_scale=1 \
--gradient_accumulation_steps=4 \
--optimizer="prodigy" \
--learning_rate=1. \
--report_to="wandb" \
--lr_scheduler="constant_with_warmup" \
--lr_warmup_steps=100 \
--max_train_steps=500 \
--validation_prompt="A photo of sks dog in a bucket" \
--validation_epochs=25 \
--seed="0" \
--push_to_hub
```
### LoRA Rank and Alpha
Two key LoRA hyperparameters are LoRA rank and LoRA alpha.
- `--rank`: Defines the dimension of the trainable LoRA matrices. A higher rank means more expressiveness and capacity to learn (and more parameters).
- `--lora_alpha`: A scaling factor for the LoRA's output. The LoRA update is scaled by lora_alpha / lora_rank.
- lora_alpha vs. rank:
This ratio dictates the LoRA's effective strength:
lora_alpha == rank: Scaling factor is 1. The LoRA is applied with its learned strength. (e.g., alpha=16, rank=16)
lora_alpha < rank: Scaling factor < 1. Reduces the LoRA's impact. Useful for subtle changes or to prevent overpowering the base model. (e.g., alpha=8, rank=16)
lora_alpha > rank: Scaling factor > 1. Amplifies the LoRA's impact. Allows a lower rank LoRA to have a stronger effect. (e.g., alpha=32, rank=16)
> [!TIP]
> A common starting point is to set `lora_alpha` equal to `rank`.
> Some also set `lora_alpha` to be twice the `rank` (e.g., lora_alpha=32 for lora_rank=16)
> to give the LoRA updates more influence without increasing parameter count.
> If you find your LoRA is "overcooking" or learning too aggressively, consider setting `lora_alpha` to half of `rank`
> (e.g., lora_alpha=8 for rank=16). Experimentation is often key to finding the optimal balance for your use case.
### Target Modules
When LoRA was first adapted from language models to diffusion models, it was applied to the cross-attention layers in the Unet that relate the image representations with the prompts that describe them.
More recently, SOTA text-to-image diffusion models replaced the Unet with a diffusion Transformer(DiT). With this change, we may also want to explore
applying LoRA training onto different types of layers and blocks. To allow more flexibility and control over the targeted modules we added `--lora_layers`- in which you can specify in a comma separated string
the exact modules for LoRA training. Here are some examples of target modules you can provide:
- for attention only layers: `--lora_layers="attn.to_k,attn.to_q,attn.to_v,attn.to_out.0"`
- to train the same modules as in the fal trainer: `--lora_layers="attn.to_k,attn.to_q,attn.to_v,attn.to_out.0,attn.add_k_proj,attn.add_q_proj,attn.add_v_proj,attn.to_add_out,ff.net.0.proj,ff.net.2,ff_context.net.0.proj,ff_context.net.2"`
- to train the same modules as in ostris ai-toolkit / replicate trainer: `--lora_blocks="attn.to_k,attn.to_q,attn.to_v,attn.to_out.0,attn.add_k_proj,attn.add_q_proj,attn.add_v_proj,attn.to_add_out,ff.net.0.proj,ff.net.2,ff_context.net.0.proj,ff_context.net.2,norm1_context.linear, norm1.linear,norm.linear,proj_mlp,proj_out"`
> [!NOTE]
> `--lora_layers` can also be used to specify which **blocks** to apply LoRA training to. To do so, simply add a block prefix to each layer in the comma separated string:
> **single DiT blocks**: to target the ith single transformer block, add the prefix `single_transformer_blocks.i`, e.g. - `single_transformer_blocks.i.attn.to_k`
> **MMDiT blocks**: to target the ith MMDiT block, add the prefix `transformer_blocks.i`, e.g. - `transformer_blocks.i.attn.to_k`
> [!NOTE]
> keep in mind that while training more layers can improve quality and expressiveness, it also increases the size of the output LoRA weights.
## Training Image-to-Image
Flux.2 lets us perform image editing as well as image generation. We provide a simple script for image-to-image(I2I) LoRA fine-tuning in [train_dreambooth_lora_flux2_img2img.py](./train_dreambooth_lora_flux2_img2img.py) for both T2I and I2I. The optimizations discussed above apply this script, too.
**important**
**Important**
To make sure you can successfully run the latest version of the image-to-image example script, we highly recommend installing from source, specifically from the commit mentioned below. To do this, execute the following steps in a new virtual environment:
```bash
git clone https://github.com/huggingface/diffusers
cd diffusers
pip install -e .
To start, you must have a dataset containing triplets:
* Condition image - the input image to be transformed.
* Target image - the desired output image after transformation.
* Instruction - a text prompt describing the transformation from the condition image to the target image.
[kontext-community/relighting](https://huggingface.co/datasets/kontext-community/relighting) is a good example of such a dataset. If you are using such a dataset, you can use the command below to launch training:
```bash
accelerate launch train_dreambooth_lora_flux2_img2img.py \
--pretrained_model_name_or_path=black-forest-labs/FLUX.2-dev \
--output_dir="flux2-i2i" \
--dataset_name="kontext-community/relighting" \
--image_column="output" --cond_image_column="file_name" --caption_column="instruction" \
--do_fp8_training \
--gradient_checkpointing \
--remote_text_encoder \
--cache_latents \
--resolution=1024 \
--train_batch_size=1 \
--guidance_scale=1 \
--gradient_accumulation_steps=4 \
--gradient_checkpointing \
--optimizer="adamw" \
--use_8bit_adam \
--cache_latents \
--learning_rate=1e-4 \
--lr_scheduler="constant_with_warmup" \
--lr_warmup_steps=200 \
--max_train_steps=1000 \
--rank=16\
--seed="0"
```
More generally, when performing I2I fine-tuning, we expect you to:
* Have a dataset `kontext-community/relighting`
* Supply `image_column`, `cond_image_column`, and `caption_column` values when launching training
### Misc notes
* By default, we use `mode` as the value of `--vae_encode_mode` argument. This is because Kontext uses `mode()` of the distribution predicted by the VAE instead of sampling from it.
### Aspect Ratio Bucketing
we've added aspect ratio bucketing support which allows training on images with different aspect ratios without cropping them to a single square resolution. This technique helps preserve the original composition of training images and can improve training efficiency.
To enable aspect ratio bucketing, pass `--aspect_ratio_buckets` argument with a semicolon-separated list of height,width pairs, such as:
`--aspect_ratio_buckets="672,1568;688,1504;720,1456;752,1392;800,1328;832,1248;880,1184;944,1104;1024,1024;1104,944;1184,880;1248,832;1328,800;1392,752;1456,720;1504,688;1568,672"
`
Since Flux.2 finetuning is still an experimental phase, we encourage you to explore different settings and share your insights! 🤗

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# coding=utf-8
# Copyright 2025 HuggingFace Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import json
import logging
import os
import sys
import tempfile
import safetensors
from diffusers.loaders.lora_base import LORA_ADAPTER_METADATA_KEY
sys.path.append("..")
from test_examples_utils import ExamplesTestsAccelerate, run_command # noqa: E402
logging.basicConfig(level=logging.DEBUG)
logger = logging.getLogger()
stream_handler = logging.StreamHandler(sys.stdout)
logger.addHandler(stream_handler)
class DreamBoothLoRAFlux2(ExamplesTestsAccelerate):
instance_data_dir = "docs/source/en/imgs"
instance_prompt = "dog"
pretrained_model_name_or_path = "hf-internal-testing/tiny-flux2"
script_path = "examples/dreambooth/train_dreambooth_lora_flux2.py"
transformer_layer_type = "single_transformer_blocks.0.attn.to_qkv_mlp_proj"
def test_dreambooth_lora_flux2(self):
with tempfile.TemporaryDirectory() as tmpdir:
test_args = f"""
{self.script_path}
--pretrained_model_name_or_path {self.pretrained_model_name_or_path}
--instance_data_dir {self.instance_data_dir}
--instance_prompt {self.instance_prompt}
--resolution 64
--train_batch_size 1
--gradient_accumulation_steps 1
--max_train_steps 2
--learning_rate 5.0e-04
--scale_lr
--lr_scheduler constant
--lr_warmup_steps 0
--max_sequence_length 8
--text_encoder_out_layers 1
--output_dir {tmpdir}
""".split()
run_command(self._launch_args + test_args)
# save_pretrained smoke test
self.assertTrue(os.path.isfile(os.path.join(tmpdir, "pytorch_lora_weights.safetensors")))
# make sure the state_dict has the correct naming in the parameters.
lora_state_dict = safetensors.torch.load_file(os.path.join(tmpdir, "pytorch_lora_weights.safetensors"))
is_lora = all("lora" in k for k in lora_state_dict.keys())
self.assertTrue(is_lora)
# when not training the text encoder, all the parameters in the state dict should start
# with `"transformer"` in their names.
starts_with_transformer = all(key.startswith("transformer") for key in lora_state_dict.keys())
self.assertTrue(starts_with_transformer)
def test_dreambooth_lora_latent_caching(self):
with tempfile.TemporaryDirectory() as tmpdir:
test_args = f"""
{self.script_path}
--pretrained_model_name_or_path {self.pretrained_model_name_or_path}
--instance_data_dir {self.instance_data_dir}
--instance_prompt {self.instance_prompt}
--resolution 64
--train_batch_size 1
--gradient_accumulation_steps 1
--max_train_steps 2
--cache_latents
--learning_rate 5.0e-04
--scale_lr
--lr_scheduler constant
--lr_warmup_steps 0
--max_sequence_length 8
--text_encoder_out_layers 1
--output_dir {tmpdir}
""".split()
run_command(self._launch_args + test_args)
# save_pretrained smoke test
self.assertTrue(os.path.isfile(os.path.join(tmpdir, "pytorch_lora_weights.safetensors")))
# make sure the state_dict has the correct naming in the parameters.
lora_state_dict = safetensors.torch.load_file(os.path.join(tmpdir, "pytorch_lora_weights.safetensors"))
is_lora = all("lora" in k for k in lora_state_dict.keys())
self.assertTrue(is_lora)
# when not training the text encoder, all the parameters in the state dict should start
# with `"transformer"` in their names.
starts_with_transformer = all(key.startswith("transformer") for key in lora_state_dict.keys())
self.assertTrue(starts_with_transformer)
def test_dreambooth_lora_layers(self):
with tempfile.TemporaryDirectory() as tmpdir:
test_args = f"""
{self.script_path}
--pretrained_model_name_or_path {self.pretrained_model_name_or_path}
--instance_data_dir {self.instance_data_dir}
--instance_prompt {self.instance_prompt}
--resolution 64
--train_batch_size 1
--gradient_accumulation_steps 1
--max_train_steps 2
--cache_latents
--learning_rate 5.0e-04
--scale_lr
--lora_layers {self.transformer_layer_type}
--lr_scheduler constant
--lr_warmup_steps 0
--max_sequence_length 8
--text_encoder_out_layers 1
--output_dir {tmpdir}
""".split()
run_command(self._launch_args + test_args)
# save_pretrained smoke test
self.assertTrue(os.path.isfile(os.path.join(tmpdir, "pytorch_lora_weights.safetensors")))
# make sure the state_dict has the correct naming in the parameters.
lora_state_dict = safetensors.torch.load_file(os.path.join(tmpdir, "pytorch_lora_weights.safetensors"))
is_lora = all("lora" in k for k in lora_state_dict.keys())
self.assertTrue(is_lora)
# when not training the text encoder, all the parameters in the state dict should start
# with `"transformer"` in their names. In this test, we only params of
# transformer.single_transformer_blocks.0.attn.to_k should be in the state dict
starts_with_transformer = all(
key.startswith(f"transformer.{self.transformer_layer_type}") for key in lora_state_dict.keys()
)
self.assertTrue(starts_with_transformer)
def test_dreambooth_lora_flux2_checkpointing_checkpoints_total_limit(self):
with tempfile.TemporaryDirectory() as tmpdir:
test_args = f"""
{self.script_path}
--pretrained_model_name_or_path={self.pretrained_model_name_or_path}
--instance_data_dir={self.instance_data_dir}
--output_dir={tmpdir}
--instance_prompt={self.instance_prompt}
--resolution=64
--train_batch_size=1
--gradient_accumulation_steps=1
--max_train_steps=6
--checkpoints_total_limit=2
--max_sequence_length 8
--checkpointing_steps=2
--text_encoder_out_layers 1
""".split()
run_command(self._launch_args + test_args)
self.assertEqual(
{x for x in os.listdir(tmpdir) if "checkpoint" in x},
{"checkpoint-4", "checkpoint-6"},
)
def test_dreambooth_lora_flux2_checkpointing_checkpoints_total_limit_removes_multiple_checkpoints(self):
with tempfile.TemporaryDirectory() as tmpdir:
test_args = f"""
{self.script_path}
--pretrained_model_name_or_path={self.pretrained_model_name_or_path}
--instance_data_dir={self.instance_data_dir}
--output_dir={tmpdir}
--instance_prompt={self.instance_prompt}
--resolution=64
--train_batch_size=1
--gradient_accumulation_steps=1
--max_train_steps=4
--checkpointing_steps=2
--max_sequence_length 8
--text_encoder_out_layers 1
""".split()
run_command(self._launch_args + test_args)
self.assertEqual({x for x in os.listdir(tmpdir) if "checkpoint" in x}, {"checkpoint-2", "checkpoint-4"})
resume_run_args = f"""
{self.script_path}
--pretrained_model_name_or_path={self.pretrained_model_name_or_path}
--instance_data_dir={self.instance_data_dir}
--output_dir={tmpdir}
--instance_prompt={self.instance_prompt}
--resolution=64
--train_batch_size=1
--gradient_accumulation_steps=1
--max_train_steps=8
--checkpointing_steps=2
--resume_from_checkpoint=checkpoint-4
--checkpoints_total_limit=2
--max_sequence_length 8
--text_encoder_out_layers 1
""".split()
run_command(self._launch_args + resume_run_args)
self.assertEqual({x for x in os.listdir(tmpdir) if "checkpoint" in x}, {"checkpoint-6", "checkpoint-8"})
def test_dreambooth_lora_with_metadata(self):
# Use a `lora_alpha` that is different from `rank`.
lora_alpha = 8
rank = 4
with tempfile.TemporaryDirectory() as tmpdir:
test_args = f"""
{self.script_path}
--pretrained_model_name_or_path {self.pretrained_model_name_or_path}
--instance_data_dir {self.instance_data_dir}
--instance_prompt {self.instance_prompt}
--resolution 64
--train_batch_size 1
--gradient_accumulation_steps 1
--max_train_steps 2
--lora_alpha={lora_alpha}
--rank={rank}
--learning_rate 5.0e-04
--scale_lr
--lr_scheduler constant
--lr_warmup_steps 0
--max_sequence_length 8
--text_encoder_out_layers 1
--output_dir {tmpdir}
""".split()
run_command(self._launch_args + test_args)
# save_pretrained smoke test
state_dict_file = os.path.join(tmpdir, "pytorch_lora_weights.safetensors")
self.assertTrue(os.path.isfile(state_dict_file))
# Check if the metadata was properly serialized.
with safetensors.torch.safe_open(state_dict_file, framework="pt", device="cpu") as f:
metadata = f.metadata() or {}
metadata.pop("format", None)
raw = metadata.get(LORA_ADAPTER_METADATA_KEY)
if raw:
raw = json.loads(raw)
loaded_lora_alpha = raw["transformer.lora_alpha"]
self.assertTrue(loaded_lora_alpha == lora_alpha)
loaded_lora_rank = raw["transformer.r"]
self.assertTrue(loaded_lora_rank == rank)

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import argparse
from contextlib import nullcontext
from typing import Any, Dict, Tuple
import safetensors.torch
import torch
from accelerate import init_empty_weights
from huggingface_hub import hf_hub_download
from transformers import AutoProcessor, GenerationConfig, Mistral3ForConditionalGeneration
from diffusers import AutoencoderKLFlux2, FlowMatchEulerDiscreteScheduler, Flux2Pipeline, Flux2Transformer2DModel
from diffusers.utils.import_utils import is_accelerate_available
"""
# VAE
python scripts/convert_flux2_to_diffusers.py \
--original_state_dict_repo_id "diffusers-internal-dev/new-model-image" \
--vae_filename "flux2-vae.sft" \
--output_path "/raid/yiyi/dummy-flux2-diffusers" \
--vae
# DiT
python scripts/convert_flux2_to_diffusers.py \
--original_state_dict_repo_id diffusers-internal-dev/new-model-image \
--dit_filename flux-dev-dummy.sft \
--dit \
--output_path .
# Full pipe
python scripts/convert_flux2_to_diffusers.py \
--original_state_dict_repo_id diffusers-internal-dev/new-model-image \
--dit_filename flux-dev-dummy.sft \
--vae_filename "flux2-vae.sft" \
--dit --vae --full_pipe \
--output_path .
"""
CTX = init_empty_weights if is_accelerate_available() else nullcontext
parser = argparse.ArgumentParser()
parser.add_argument("--original_state_dict_repo_id", default=None, type=str)
parser.add_argument("--vae_filename", default="flux2-vae.sft", type=str)
parser.add_argument("--dit_filename", default="flux-dev-dummy.sft", type=str)
parser.add_argument("--vae", action="store_true")
parser.add_argument("--dit", action="store_true")
parser.add_argument("--vae_dtype", type=str, default="fp32")
parser.add_argument("--dit_dtype", type=str, default="bf16")
parser.add_argument("--checkpoint_path", default=None, type=str)
parser.add_argument("--full_pipe", action="store_true")
parser.add_argument("--output_path", type=str)
args = parser.parse_args()
def load_original_checkpoint(args, filename):
if args.original_state_dict_repo_id is not None:
ckpt_path = hf_hub_download(repo_id=args.original_state_dict_repo_id, filename=filename)
elif args.checkpoint_path is not None:
ckpt_path = args.checkpoint_path
else:
raise ValueError(" please provide either `original_state_dict_repo_id` or a local `checkpoint_path`")
original_state_dict = safetensors.torch.load_file(ckpt_path)
return original_state_dict
DIFFUSERS_VAE_TO_FLUX2_MAPPING = {
"encoder.conv_in.weight": "encoder.conv_in.weight",
"encoder.conv_in.bias": "encoder.conv_in.bias",
"encoder.conv_out.weight": "encoder.conv_out.weight",
"encoder.conv_out.bias": "encoder.conv_out.bias",
"encoder.conv_norm_out.weight": "encoder.norm_out.weight",
"encoder.conv_norm_out.bias": "encoder.norm_out.bias",
"decoder.conv_in.weight": "decoder.conv_in.weight",
"decoder.conv_in.bias": "decoder.conv_in.bias",
"decoder.conv_out.weight": "decoder.conv_out.weight",
"decoder.conv_out.bias": "decoder.conv_out.bias",
"decoder.conv_norm_out.weight": "decoder.norm_out.weight",
"decoder.conv_norm_out.bias": "decoder.norm_out.bias",
"quant_conv.weight": "encoder.quant_conv.weight",
"quant_conv.bias": "encoder.quant_conv.bias",
"post_quant_conv.weight": "decoder.post_quant_conv.weight",
"post_quant_conv.bias": "decoder.post_quant_conv.bias",
"bn.running_mean": "bn.running_mean",
"bn.running_var": "bn.running_var",
}
# Copied from diffusers.pipelines.stable_diffusion.convert_from_ckpt.conv_attn_to_linear
def conv_attn_to_linear(checkpoint):
keys = list(checkpoint.keys())
attn_keys = ["query.weight", "key.weight", "value.weight"]
for key in keys:
if ".".join(key.split(".")[-2:]) in attn_keys:
if checkpoint[key].ndim > 2:
checkpoint[key] = checkpoint[key][:, :, 0, 0]
elif "proj_attn.weight" in key:
if checkpoint[key].ndim > 2:
checkpoint[key] = checkpoint[key][:, :, 0]
def update_vae_resnet_ldm_to_diffusers(keys, new_checkpoint, checkpoint, mapping):
for ldm_key in keys:
diffusers_key = ldm_key.replace(mapping["old"], mapping["new"]).replace("nin_shortcut", "conv_shortcut")
new_checkpoint[diffusers_key] = checkpoint.get(ldm_key)
def update_vae_attentions_ldm_to_diffusers(keys, new_checkpoint, checkpoint, mapping):
for ldm_key in keys:
diffusers_key = (
ldm_key.replace(mapping["old"], mapping["new"])
.replace("norm.weight", "group_norm.weight")
.replace("norm.bias", "group_norm.bias")
.replace("q.weight", "to_q.weight")
.replace("q.bias", "to_q.bias")
.replace("k.weight", "to_k.weight")
.replace("k.bias", "to_k.bias")
.replace("v.weight", "to_v.weight")
.replace("v.bias", "to_v.bias")
.replace("proj_out.weight", "to_out.0.weight")
.replace("proj_out.bias", "to_out.0.bias")
)
new_checkpoint[diffusers_key] = checkpoint.get(ldm_key)
# proj_attn.weight has to be converted from conv 1D to linear
shape = new_checkpoint[diffusers_key].shape
if len(shape) == 3:
new_checkpoint[diffusers_key] = new_checkpoint[diffusers_key][:, :, 0]
elif len(shape) == 4:
new_checkpoint[diffusers_key] = new_checkpoint[diffusers_key][:, :, 0, 0]
def convert_flux2_vae_checkpoint_to_diffusers(vae_state_dict, config):
new_checkpoint = {}
for diffusers_key, ldm_key in DIFFUSERS_VAE_TO_FLUX2_MAPPING.items():
if ldm_key not in vae_state_dict:
continue
new_checkpoint[diffusers_key] = vae_state_dict[ldm_key]
# Retrieves the keys for the encoder down blocks only
num_down_blocks = len(config["down_block_types"])
down_blocks = {
layer_id: [key for key in vae_state_dict if f"down.{layer_id}" in key] for layer_id in range(num_down_blocks)
}
for i in range(num_down_blocks):
resnets = [key for key in down_blocks[i] if f"down.{i}" in key and f"down.{i}.downsample" not in key]
update_vae_resnet_ldm_to_diffusers(
resnets,
new_checkpoint,
vae_state_dict,
mapping={"old": f"down.{i}.block", "new": f"down_blocks.{i}.resnets"},
)
if f"encoder.down.{i}.downsample.conv.weight" in vae_state_dict:
new_checkpoint[f"encoder.down_blocks.{i}.downsamplers.0.conv.weight"] = vae_state_dict.get(
f"encoder.down.{i}.downsample.conv.weight"
)
new_checkpoint[f"encoder.down_blocks.{i}.downsamplers.0.conv.bias"] = vae_state_dict.get(
f"encoder.down.{i}.downsample.conv.bias"
)
mid_resnets = [key for key in vae_state_dict if "encoder.mid.block" in key]
num_mid_res_blocks = 2
for i in range(1, num_mid_res_blocks + 1):
resnets = [key for key in mid_resnets if f"encoder.mid.block_{i}" in key]
update_vae_resnet_ldm_to_diffusers(
resnets,
new_checkpoint,
vae_state_dict,
mapping={"old": f"mid.block_{i}", "new": f"mid_block.resnets.{i - 1}"},
)
mid_attentions = [key for key in vae_state_dict if "encoder.mid.attn" in key]
update_vae_attentions_ldm_to_diffusers(
mid_attentions, new_checkpoint, vae_state_dict, mapping={"old": "mid.attn_1", "new": "mid_block.attentions.0"}
)
# Retrieves the keys for the decoder up blocks only
num_up_blocks = len(config["up_block_types"])
up_blocks = {
layer_id: [key for key in vae_state_dict if f"up.{layer_id}" in key] for layer_id in range(num_up_blocks)
}
for i in range(num_up_blocks):
block_id = num_up_blocks - 1 - i
resnets = [
key for key in up_blocks[block_id] if f"up.{block_id}" in key and f"up.{block_id}.upsample" not in key
]
update_vae_resnet_ldm_to_diffusers(
resnets,
new_checkpoint,
vae_state_dict,
mapping={"old": f"up.{block_id}.block", "new": f"up_blocks.{i}.resnets"},
)
if f"decoder.up.{block_id}.upsample.conv.weight" in vae_state_dict:
new_checkpoint[f"decoder.up_blocks.{i}.upsamplers.0.conv.weight"] = vae_state_dict[
f"decoder.up.{block_id}.upsample.conv.weight"
]
new_checkpoint[f"decoder.up_blocks.{i}.upsamplers.0.conv.bias"] = vae_state_dict[
f"decoder.up.{block_id}.upsample.conv.bias"
]
mid_resnets = [key for key in vae_state_dict if "decoder.mid.block" in key]
num_mid_res_blocks = 2
for i in range(1, num_mid_res_blocks + 1):
resnets = [key for key in mid_resnets if f"decoder.mid.block_{i}" in key]
update_vae_resnet_ldm_to_diffusers(
resnets,
new_checkpoint,
vae_state_dict,
mapping={"old": f"mid.block_{i}", "new": f"mid_block.resnets.{i - 1}"},
)
mid_attentions = [key for key in vae_state_dict if "decoder.mid.attn" in key]
update_vae_attentions_ldm_to_diffusers(
mid_attentions, new_checkpoint, vae_state_dict, mapping={"old": "mid.attn_1", "new": "mid_block.attentions.0"}
)
conv_attn_to_linear(new_checkpoint)
return new_checkpoint
FLUX2_TRANSFORMER_KEYS_RENAME_DICT = {
# Image and text input projections
"img_in": "x_embedder",
"txt_in": "context_embedder",
# Timestep and guidance embeddings
"time_in.in_layer": "time_guidance_embed.timestep_embedder.linear_1",
"time_in.out_layer": "time_guidance_embed.timestep_embedder.linear_2",
"guidance_in.in_layer": "time_guidance_embed.guidance_embedder.linear_1",
"guidance_in.out_layer": "time_guidance_embed.guidance_embedder.linear_2",
# Modulation parameters
"double_stream_modulation_img.lin": "double_stream_modulation_img.linear",
"double_stream_modulation_txt.lin": "double_stream_modulation_txt.linear",
"single_stream_modulation.lin": "single_stream_modulation.linear",
# Final output layer
# "final_layer.adaLN_modulation.1": "norm_out.linear", # Handle separately since we need to swap mod params
"final_layer.linear": "proj_out",
}
FLUX2_TRANSFORMER_ADA_LAYER_NORM_KEY_MAP = {
"final_layer.adaLN_modulation.1": "norm_out.linear",
}
FLUX2_TRANSFORMER_DOUBLE_BLOCK_KEY_MAP = {
# Handle fused QKV projections separately as we need to break into Q, K, V projections
"img_attn.norm.query_norm": "attn.norm_q",
"img_attn.norm.key_norm": "attn.norm_k",
"img_attn.proj": "attn.to_out.0",
"img_mlp.0": "ff.linear_in",
"img_mlp.2": "ff.linear_out",
"txt_attn.norm.query_norm": "attn.norm_added_q",
"txt_attn.norm.key_norm": "attn.norm_added_k",
"txt_attn.proj": "attn.to_add_out",
"txt_mlp.0": "ff_context.linear_in",
"txt_mlp.2": "ff_context.linear_out",
}
FLUX2_TRANSFORMER_SINGLE_BLOCK_KEY_MAP = {
"linear1": "attn.to_qkv_mlp_proj",
"linear2": "attn.to_out",
"norm.query_norm": "attn.norm_q",
"norm.key_norm": "attn.norm_k",
}
# in SD3 original implementation of AdaLayerNormContinuous, it split linear projection output into shift, scale;
# while in diffusers it split into scale, shift. Here we swap the linear projection weights in order to be able to use
# diffusers implementation
def swap_scale_shift(weight):
shift, scale = weight.chunk(2, dim=0)
new_weight = torch.cat([scale, shift], dim=0)
return new_weight
def convert_ada_layer_norm_weights(key: str, state_dict: Dict[str, Any]) -> None:
# Skip if not a weight
if ".weight" not in key:
return
# If adaLN_modulation is in the key, swap scale and shift parameters
# Original implementation is (shift, scale); diffusers implementation is (scale, shift)
if "adaLN_modulation" in key:
key_without_param_type, param_type = key.rsplit(".", maxsplit=1)
# Assume all such keys are in the AdaLayerNorm key map
new_key_without_param_type = FLUX2_TRANSFORMER_ADA_LAYER_NORM_KEY_MAP[key_without_param_type]
new_key = ".".join([new_key_without_param_type, param_type])
swapped_weight = swap_scale_shift(state_dict.pop(key))
state_dict[new_key] = swapped_weight
return
def convert_flux2_double_stream_blocks(key: str, state_dict: Dict[str, Any]) -> None:
# Skip if not a weight, bias, or scale
if ".weight" not in key and ".bias" not in key and ".scale" not in key:
return
new_prefix = "transformer_blocks"
if "double_blocks." in key:
parts = key.split(".")
block_idx = parts[1]
modality_block_name = parts[2] # img_attn, img_mlp, txt_attn, txt_mlp
within_block_name = ".".join(parts[2:-1])
param_type = parts[-1]
if param_type == "scale":
param_type = "weight"
if "qkv" in within_block_name:
fused_qkv_weight = state_dict.pop(key)
to_q_weight, to_k_weight, to_v_weight = torch.chunk(fused_qkv_weight, 3, dim=0)
if "img" in modality_block_name:
# double_blocks.{N}.img_attn.qkv --> transformer_blocks.{N}.attn.{to_q|to_k|to_v}
to_q_weight, to_k_weight, to_v_weight = torch.chunk(fused_qkv_weight, 3, dim=0)
new_q_name = "attn.to_q"
new_k_name = "attn.to_k"
new_v_name = "attn.to_v"
elif "txt" in modality_block_name:
# double_blocks.{N}.txt_attn.qkv --> transformer_blocks.{N}.attn.{add_q_proj|add_k_proj|add_v_proj}
to_q_weight, to_k_weight, to_v_weight = torch.chunk(fused_qkv_weight, 3, dim=0)
new_q_name = "attn.add_q_proj"
new_k_name = "attn.add_k_proj"
new_v_name = "attn.add_v_proj"
new_q_key = ".".join([new_prefix, block_idx, new_q_name, param_type])
new_k_key = ".".join([new_prefix, block_idx, new_k_name, param_type])
new_v_key = ".".join([new_prefix, block_idx, new_v_name, param_type])
state_dict[new_q_key] = to_q_weight
state_dict[new_k_key] = to_k_weight
state_dict[new_v_key] = to_v_weight
else:
new_within_block_name = FLUX2_TRANSFORMER_DOUBLE_BLOCK_KEY_MAP[within_block_name]
new_key = ".".join([new_prefix, block_idx, new_within_block_name, param_type])
param = state_dict.pop(key)
state_dict[new_key] = param
return
def convert_flux2_single_stream_blocks(key: str, state_dict: Dict[str, Any]) -> None:
# Skip if not a weight, bias, or scale
if ".weight" not in key and ".bias" not in key and ".scale" not in key:
return
# Mapping:
# - single_blocks.{N}.linear1 --> single_transformer_blocks.{N}.attn.to_qkv_mlp_proj
# - single_blocks.{N}.linear2 --> single_transformer_blocks.{N}.attn.to_out
# - single_blocks.{N}.norm.query_norm.scale --> single_transformer_blocks.{N}.attn.norm_q.weight
# - single_blocks.{N}.norm.key_norm.scale --> single_transformer_blocks.{N}.attn.norm_k.weight
new_prefix = "single_transformer_blocks"
if "single_blocks." in key:
parts = key.split(".")
block_idx = parts[1]
within_block_name = ".".join(parts[2:-1])
param_type = parts[-1]
if param_type == "scale":
param_type = "weight"
new_within_block_name = FLUX2_TRANSFORMER_SINGLE_BLOCK_KEY_MAP[within_block_name]
new_key = ".".join([new_prefix, block_idx, new_within_block_name, param_type])
param = state_dict.pop(key)
state_dict[new_key] = param
return
TRANSFORMER_SPECIAL_KEYS_REMAP = {
"adaLN_modulation": convert_ada_layer_norm_weights,
"double_blocks": convert_flux2_double_stream_blocks,
"single_blocks": convert_flux2_single_stream_blocks,
}
def update_state_dict(state_dict: Dict[str, Any], old_key: str, new_key: str) -> None:
state_dict[new_key] = state_dict.pop(old_key)
def get_flux2_transformer_config(model_type: str) -> Tuple[Dict[str, Any], ...]:
if model_type == "test" or model_type == "dummy-flux2":
config = {
"model_id": "diffusers-internal-dev/dummy-flux2",
"diffusers_config": {
"patch_size": 1,
"in_channels": 128,
"num_layers": 8,
"num_single_layers": 48,
"attention_head_dim": 128,
"num_attention_heads": 48,
"joint_attention_dim": 15360,
"timestep_guidance_channels": 256,
"mlp_ratio": 3.0,
"axes_dims_rope": (32, 32, 32, 32),
"rope_theta": 2000,
"eps": 1e-6,
},
}
rename_dict = FLUX2_TRANSFORMER_KEYS_RENAME_DICT
special_keys_remap = TRANSFORMER_SPECIAL_KEYS_REMAP
return config, rename_dict, special_keys_remap
def convert_flux2_transformer_to_diffusers(original_state_dict: Dict[str, torch.Tensor], model_type: str):
config, rename_dict, special_keys_remap = get_flux2_transformer_config(model_type)
diffusers_config = config["diffusers_config"]
with init_empty_weights():
transformer = Flux2Transformer2DModel.from_config(diffusers_config)
# Handle official code --> diffusers key remapping via the remap dict
for key in list(original_state_dict.keys()):
new_key = key[:]
for replace_key, rename_key in rename_dict.items():
new_key = new_key.replace(replace_key, rename_key)
update_state_dict(original_state_dict, key, new_key)
# Handle any special logic which can't be expressed by a simple 1:1 remapping with the handlers in
# special_keys_remap
for key in list(original_state_dict.keys()):
for special_key, handler_fn_inplace in special_keys_remap.items():
if special_key not in key:
continue
handler_fn_inplace(key, original_state_dict)
transformer.load_state_dict(original_state_dict, strict=True, assign=True)
return transformer
def main(args):
if args.vae:
original_vae_ckpt = load_original_checkpoint(args, filename=args.vae_filename)
vae = AutoencoderKLFlux2()
converted_vae_state_dict = convert_flux2_vae_checkpoint_to_diffusers(original_vae_ckpt, vae.config)
vae.load_state_dict(converted_vae_state_dict, strict=True)
if not args.full_pipe:
vae_dtype = torch.bfloat16 if args.vae_dtype == "bf16" else torch.float32
vae.to(vae_dtype).save_pretrained(f"{args.output_path}/vae")
if args.dit:
original_dit_ckpt = load_original_checkpoint(args, filename=args.dit_filename)
transformer = convert_flux2_transformer_to_diffusers(original_dit_ckpt, "test")
if not args.full_pipe:
dit_dtype = torch.bfloat16 if args.dit_dtype == "bf16" else torch.float32
transformer.to(dit_dtype).save_pretrained(f"{args.output_path}/transformer")
if args.full_pipe:
tokenizer_id = "mistralai/Mistral-Small-3.1-24B-Instruct-2503"
text_encoder_id = "mistralai/Mistral-Small-3.2-24B-Instruct-2506"
generate_config = GenerationConfig.from_pretrained(text_encoder_id)
generate_config.do_sample = True
text_encoder = Mistral3ForConditionalGeneration.from_pretrained(
text_encoder_id, generation_config=generate_config, torch_dtype=torch.bfloat16
)
tokenizer = AutoProcessor.from_pretrained(tokenizer_id)
scheduler = FlowMatchEulerDiscreteScheduler.from_pretrained(
"black-forest-labs/FLUX.1-dev", subfolder="scheduler"
)
pipe = Flux2Pipeline(
vae=vae, transformer=transformer, text_encoder=text_encoder, tokenizer=tokenizer, scheduler=scheduler
)
pipe.save_pretrained(args.output_path)
if __name__ == "__main__":
main(args)

View File

@@ -186,6 +186,7 @@ else:
"AutoencoderKLAllegro",
"AutoencoderKLCogVideoX",
"AutoencoderKLCosmos",
"AutoencoderKLFlux2",
"AutoencoderKLHunyuanImage",
"AutoencoderKLHunyuanImageRefiner",
"AutoencoderKLHunyuanVideo",
@@ -215,6 +216,7 @@ else:
"CosmosTransformer3DModel",
"DiTTransformer2DModel",
"EasyAnimateTransformer3DModel",
"Flux2Transformer2DModel",
"FluxControlNetModel",
"FluxMultiControlNetModel",
"FluxTransformer2DModel",
@@ -458,6 +460,7 @@ else:
"EasyAnimateControlPipeline",
"EasyAnimateInpaintPipeline",
"EasyAnimatePipeline",
"Flux2Pipeline",
"FluxControlImg2ImgPipeline",
"FluxControlInpaintPipeline",
"FluxControlNetImg2ImgPipeline",
@@ -902,6 +905,7 @@ if TYPE_CHECKING or DIFFUSERS_SLOW_IMPORT:
AutoencoderKLAllegro,
AutoencoderKLCogVideoX,
AutoencoderKLCosmos,
AutoencoderKLFlux2,
AutoencoderKLHunyuanImage,
AutoencoderKLHunyuanImageRefiner,
AutoencoderKLHunyuanVideo,
@@ -931,6 +935,7 @@ if TYPE_CHECKING or DIFFUSERS_SLOW_IMPORT:
CosmosTransformer3DModel,
DiTTransformer2DModel,
EasyAnimateTransformer3DModel,
Flux2Transformer2DModel,
FluxControlNetModel,
FluxMultiControlNetModel,
FluxTransformer2DModel,
@@ -1143,6 +1148,7 @@ if TYPE_CHECKING or DIFFUSERS_SLOW_IMPORT:
EasyAnimateControlPipeline,
EasyAnimateInpaintPipeline,
EasyAnimatePipeline,
Flux2Pipeline,
FluxControlImg2ImgPipeline,
FluxControlInpaintPipeline,
FluxControlNetImg2ImgPipeline,

View File

@@ -81,6 +81,7 @@ if is_torch_available():
"HiDreamImageLoraLoaderMixin",
"SkyReelsV2LoraLoaderMixin",
"QwenImageLoraLoaderMixin",
"Flux2LoraLoaderMixin",
]
_import_structure["textual_inversion"] = ["TextualInversionLoaderMixin"]
_import_structure["ip_adapter"] = [
@@ -113,6 +114,7 @@ if TYPE_CHECKING or DIFFUSERS_SLOW_IMPORT:
AuraFlowLoraLoaderMixin,
CogVideoXLoraLoaderMixin,
CogView4LoraLoaderMixin,
Flux2LoraLoaderMixin,
FluxLoraLoaderMixin,
HiDreamImageLoraLoaderMixin,
HunyuanVideoLoraLoaderMixin,

View File

@@ -2265,3 +2265,89 @@ def _convert_non_diffusers_qwen_lora_to_diffusers(state_dict):
converted_state_dict = {f"transformer.{k}": v for k, v in converted_state_dict.items()}
return converted_state_dict
def _convert_non_diffusers_flux2_lora_to_diffusers(state_dict):
converted_state_dict = {}
prefix = "diffusion_model."
original_state_dict = {k[len(prefix) :]: v for k, v in state_dict.items()}
num_double_layers = 8
num_single_layers = 48
lora_keys = ("lora_A", "lora_B")
attn_types = ("img_attn", "txt_attn")
for sl in range(num_single_layers):
single_block_prefix = f"single_blocks.{sl}"
attn_prefix = f"single_transformer_blocks.{sl}.attn"
for lora_key in lora_keys:
converted_state_dict[f"{attn_prefix}.to_qkv_mlp_proj.{lora_key}.weight"] = original_state_dict.pop(
f"{single_block_prefix}.linear1.{lora_key}.weight"
)
converted_state_dict[f"{attn_prefix}.to_out.{lora_key}.weight"] = original_state_dict.pop(
f"{single_block_prefix}.linear2.{lora_key}.weight"
)
for dl in range(num_double_layers):
transformer_block_prefix = f"transformer_blocks.{dl}"
for lora_key in lora_keys:
for attn_type in attn_types:
attn_prefix = f"{transformer_block_prefix}.attn"
qkv_key = f"double_blocks.{dl}.{attn_type}.qkv.{lora_key}.weight"
fused_qkv_weight = original_state_dict.pop(qkv_key)
if lora_key == "lora_A":
diff_attn_proj_keys = (
["to_q", "to_k", "to_v"]
if attn_type == "img_attn"
else ["add_q_proj", "add_k_proj", "add_v_proj"]
)
for proj_key in diff_attn_proj_keys:
converted_state_dict[f"{attn_prefix}.{proj_key}.{lora_key}.weight"] = torch.cat(
[fused_qkv_weight]
)
else:
sample_q, sample_k, sample_v = torch.chunk(fused_qkv_weight, 3, dim=0)
if attn_type == "img_attn":
converted_state_dict[f"{attn_prefix}.to_q.{lora_key}.weight"] = torch.cat([sample_q])
converted_state_dict[f"{attn_prefix}.to_k.{lora_key}.weight"] = torch.cat([sample_k])
converted_state_dict[f"{attn_prefix}.to_v.{lora_key}.weight"] = torch.cat([sample_v])
else:
converted_state_dict[f"{attn_prefix}.add_q_proj.{lora_key}.weight"] = torch.cat([sample_q])
converted_state_dict[f"{attn_prefix}.add_k_proj.{lora_key}.weight"] = torch.cat([sample_k])
converted_state_dict[f"{attn_prefix}.add_v_proj.{lora_key}.weight"] = torch.cat([sample_v])
proj_mappings = [
("img_attn.proj", "attn.to_out.0"),
("txt_attn.proj", "attn.to_add_out"),
]
for org_proj, diff_proj in proj_mappings:
for lora_key in lora_keys:
original_key = f"double_blocks.{dl}.{org_proj}.{lora_key}.weight"
diffusers_key = f"{transformer_block_prefix}.{diff_proj}.{lora_key}.weight"
converted_state_dict[diffusers_key] = original_state_dict.pop(original_key)
mlp_mappings = [
("img_mlp.0", "ff.linear_in"),
("img_mlp.2", "ff.linear_out"),
("txt_mlp.0", "ff_context.linear_in"),
("txt_mlp.2", "ff_context.linear_out"),
]
for org_mlp, diff_mlp in mlp_mappings:
for lora_key in lora_keys:
original_key = f"double_blocks.{dl}.{org_mlp}.{lora_key}.weight"
diffusers_key = f"{transformer_block_prefix}.{diff_mlp}.{lora_key}.weight"
converted_state_dict[diffusers_key] = original_state_dict.pop(original_key)
if len(original_state_dict) > 0:
raise ValueError(f"`original_state_dict` should be empty at this point but has {original_state_dict.keys()=}.")
for key in list(converted_state_dict.keys()):
converted_state_dict[f"transformer.{key}"] = converted_state_dict.pop(key)
return converted_state_dict

View File

@@ -45,6 +45,7 @@ from .lora_conversion_utils import (
_convert_hunyuan_video_lora_to_diffusers,
_convert_kohya_flux_lora_to_diffusers,
_convert_musubi_wan_lora_to_diffusers,
_convert_non_diffusers_flux2_lora_to_diffusers,
_convert_non_diffusers_hidream_lora_to_diffusers,
_convert_non_diffusers_lora_to_diffusers,
_convert_non_diffusers_ltxv_lora_to_diffusers,
@@ -5084,6 +5085,209 @@ class QwenImageLoraLoaderMixin(LoraBaseMixin):
super().unfuse_lora(components=components, **kwargs)
class Flux2LoraLoaderMixin(LoraBaseMixin):
r"""
Load LoRA layers into [`Flux2Transformer2DModel`]. Specific to [`Flux2Pipeline`].
"""
_lora_loadable_modules = ["transformer"]
transformer_name = TRANSFORMER_NAME
@classmethod
@validate_hf_hub_args
def lora_state_dict(
cls,
pretrained_model_name_or_path_or_dict: Union[str, Dict[str, torch.Tensor]],
**kwargs,
):
r"""
See [`~loaders.StableDiffusionLoraLoaderMixin.lora_state_dict`] for more details.
"""
# Load the main state dict first which has the LoRA layers for either of
# transformer and text encoder or both.
cache_dir = kwargs.pop("cache_dir", None)
force_download = kwargs.pop("force_download", False)
proxies = kwargs.pop("proxies", None)
local_files_only = kwargs.pop("local_files_only", None)
token = kwargs.pop("token", None)
revision = kwargs.pop("revision", None)
subfolder = kwargs.pop("subfolder", None)
weight_name = kwargs.pop("weight_name", None)
use_safetensors = kwargs.pop("use_safetensors", None)
return_lora_metadata = kwargs.pop("return_lora_metadata", False)
allow_pickle = False
if use_safetensors is None:
use_safetensors = True
allow_pickle = True
user_agent = {"file_type": "attn_procs_weights", "framework": "pytorch"}
state_dict, metadata = _fetch_state_dict(
pretrained_model_name_or_path_or_dict=pretrained_model_name_or_path_or_dict,
weight_name=weight_name,
use_safetensors=use_safetensors,
local_files_only=local_files_only,
cache_dir=cache_dir,
force_download=force_download,
proxies=proxies,
token=token,
revision=revision,
subfolder=subfolder,
user_agent=user_agent,
allow_pickle=allow_pickle,
)
is_dora_scale_present = any("dora_scale" in k for k in state_dict)
if is_dora_scale_present:
warn_msg = "It seems like you are using a DoRA checkpoint that is not compatible in Diffusers at the moment. So, we are going to filter out the keys associated to 'dora_scale` from the state dict. If you think this is a mistake please open an issue https://github.com/huggingface/diffusers/issues/new."
logger.warning(warn_msg)
state_dict = {k: v for k, v in state_dict.items() if "dora_scale" not in k}
is_ai_toolkit = any(k.startswith("diffusion_model.") for k in state_dict)
if is_ai_toolkit:
state_dict = _convert_non_diffusers_flux2_lora_to_diffusers(state_dict)
out = (state_dict, metadata) if return_lora_metadata else state_dict
return out
# Copied from diffusers.loaders.lora_pipeline.CogVideoXLoraLoaderMixin.load_lora_weights
def load_lora_weights(
self,
pretrained_model_name_or_path_or_dict: Union[str, Dict[str, torch.Tensor]],
adapter_name: Optional[str] = None,
hotswap: bool = False,
**kwargs,
):
"""
See [`~loaders.StableDiffusionLoraLoaderMixin.load_lora_weights`] for more details.
"""
if not USE_PEFT_BACKEND:
raise ValueError("PEFT backend is required for this method.")
low_cpu_mem_usage = kwargs.pop("low_cpu_mem_usage", _LOW_CPU_MEM_USAGE_DEFAULT_LORA)
if low_cpu_mem_usage and is_peft_version("<", "0.13.0"):
raise ValueError(
"`low_cpu_mem_usage=True` is not compatible with this `peft` version. Please update it with `pip install -U peft`."
)
# if a dict is passed, copy it instead of modifying it inplace
if isinstance(pretrained_model_name_or_path_or_dict, dict):
pretrained_model_name_or_path_or_dict = pretrained_model_name_or_path_or_dict.copy()
# First, ensure that the checkpoint is a compatible one and can be successfully loaded.
kwargs["return_lora_metadata"] = True
state_dict, metadata = self.lora_state_dict(pretrained_model_name_or_path_or_dict, **kwargs)
is_correct_format = all("lora" in key for key in state_dict.keys())
if not is_correct_format:
raise ValueError("Invalid LoRA checkpoint.")
self.load_lora_into_transformer(
state_dict,
transformer=getattr(self, self.transformer_name) if not hasattr(self, "transformer") else self.transformer,
adapter_name=adapter_name,
metadata=metadata,
_pipeline=self,
low_cpu_mem_usage=low_cpu_mem_usage,
hotswap=hotswap,
)
@classmethod
# Copied from diffusers.loaders.lora_pipeline.SD3LoraLoaderMixin.load_lora_into_transformer with SD3Transformer2DModel->CogView4Transformer2DModel
def load_lora_into_transformer(
cls,
state_dict,
transformer,
adapter_name=None,
_pipeline=None,
low_cpu_mem_usage=False,
hotswap: bool = False,
metadata=None,
):
"""
See [`~loaders.StableDiffusionLoraLoaderMixin.load_lora_into_unet`] for more details.
"""
if low_cpu_mem_usage and is_peft_version("<", "0.13.0"):
raise ValueError(
"`low_cpu_mem_usage=True` is not compatible with this `peft` version. Please update it with `pip install -U peft`."
)
# Load the layers corresponding to transformer.
logger.info(f"Loading {cls.transformer_name}.")
transformer.load_lora_adapter(
state_dict,
network_alphas=None,
adapter_name=adapter_name,
metadata=metadata,
_pipeline=_pipeline,
low_cpu_mem_usage=low_cpu_mem_usage,
hotswap=hotswap,
)
@classmethod
# Copied from diffusers.loaders.lora_pipeline.CogVideoXLoraLoaderMixin.save_lora_weights
def save_lora_weights(
cls,
save_directory: Union[str, os.PathLike],
transformer_lora_layers: Dict[str, Union[torch.nn.Module, torch.Tensor]] = None,
is_main_process: bool = True,
weight_name: str = None,
save_function: Callable = None,
safe_serialization: bool = True,
transformer_lora_adapter_metadata: Optional[dict] = None,
):
r"""
See [`~loaders.StableDiffusionLoraLoaderMixin.save_lora_weights`] for more information.
"""
lora_layers = {}
lora_metadata = {}
if transformer_lora_layers:
lora_layers[cls.transformer_name] = transformer_lora_layers
lora_metadata[cls.transformer_name] = transformer_lora_adapter_metadata
if not lora_layers:
raise ValueError("You must pass at least one of `transformer_lora_layers` or `text_encoder_lora_layers`.")
cls._save_lora_weights(
save_directory=save_directory,
lora_layers=lora_layers,
lora_metadata=lora_metadata,
is_main_process=is_main_process,
weight_name=weight_name,
save_function=save_function,
safe_serialization=safe_serialization,
)
# Copied from diffusers.loaders.lora_pipeline.CogVideoXLoraLoaderMixin.fuse_lora
def fuse_lora(
self,
components: List[str] = ["transformer"],
lora_scale: float = 1.0,
safe_fusing: bool = False,
adapter_names: Optional[List[str]] = None,
**kwargs,
):
r"""
See [`~loaders.StableDiffusionLoraLoaderMixin.fuse_lora`] for more details.
"""
super().fuse_lora(
components=components,
lora_scale=lora_scale,
safe_fusing=safe_fusing,
adapter_names=adapter_names,
**kwargs,
)
# Copied from diffusers.loaders.lora_pipeline.CogVideoXLoraLoaderMixin.unfuse_lora
def unfuse_lora(self, components: List[str] = ["transformer"], **kwargs):
r"""
See [`~loaders.StableDiffusionLoraLoaderMixin.unfuse_lora`] for more details.
"""
super().unfuse_lora(components=components, **kwargs)
class LoraLoaderMixin(StableDiffusionLoraLoaderMixin):
def __init__(self, *args, **kwargs):
deprecation_message = "LoraLoaderMixin is deprecated and this will be removed in a future version. Please use `StableDiffusionLoraLoaderMixin`, instead."

View File

@@ -62,6 +62,7 @@ _SET_ADAPTER_SCALE_FN_MAPPING = {
"WanVACETransformer3DModel": lambda model_cls, weights: weights,
"ChromaTransformer2DModel": lambda model_cls, weights: weights,
"QwenImageTransformer2DModel": lambda model_cls, weights: weights,
"Flux2Transformer2DModel": lambda model_cls, weights: weights,
}

View File

@@ -34,6 +34,7 @@ from .single_file_utils import (
convert_chroma_transformer_checkpoint_to_diffusers,
convert_controlnet_checkpoint,
convert_cosmos_transformer_checkpoint_to_diffusers,
convert_flux2_transformer_checkpoint_to_diffusers,
convert_flux_transformer_checkpoint_to_diffusers,
convert_hidream_transformer_to_diffusers,
convert_hunyuan_video_transformer_to_diffusers,
@@ -162,6 +163,10 @@ SINGLE_FILE_LOADABLE_CLASSES = {
"checkpoint_mapping_fn": lambda x: x,
"default_subfolder": "transformer",
},
"Flux2Transformer2DModel": {
"checkpoint_mapping_fn": convert_flux2_transformer_checkpoint_to_diffusers,
"default_subfolder": "transformer",
},
}

View File

@@ -140,6 +140,7 @@ CHECKPOINT_KEY_NAMES = {
"net.blocks.0.self_attn.q_proj.weight",
"net.pos_embedder.dim_spatial_range",
],
"flux2": ["model.diffusion_model.single_stream_modulation.lin.weight", "single_stream_modulation.lin.weight"],
}
DIFFUSERS_DEFAULT_PIPELINE_PATHS = {
@@ -189,6 +190,7 @@ DIFFUSERS_DEFAULT_PIPELINE_PATHS = {
"flux-fill": {"pretrained_model_name_or_path": "black-forest-labs/FLUX.1-Fill-dev"},
"flux-depth": {"pretrained_model_name_or_path": "black-forest-labs/FLUX.1-Depth-dev"},
"flux-schnell": {"pretrained_model_name_or_path": "black-forest-labs/FLUX.1-schnell"},
"flux-2-dev": {"pretrained_model_name_or_path": "black-forest-labs/FLUX.2-dev"},
"ltx-video": {"pretrained_model_name_or_path": "diffusers/LTX-Video-0.9.0"},
"ltx-video-0.9.1": {"pretrained_model_name_or_path": "diffusers/LTX-Video-0.9.1"},
"ltx-video-0.9.5": {"pretrained_model_name_or_path": "Lightricks/LTX-Video-0.9.5"},
@@ -649,6 +651,9 @@ def infer_diffusers_model_type(checkpoint):
else:
model_type = "animatediff_v3"
elif any(key in checkpoint for key in CHECKPOINT_KEY_NAMES["flux2"]):
model_type = "flux-2-dev"
elif any(key in checkpoint for key in CHECKPOINT_KEY_NAMES["flux"]):
if any(
g in checkpoint for g in ["guidance_in.in_layer.bias", "model.diffusion_model.guidance_in.in_layer.bias"]
@@ -3647,3 +3652,168 @@ def convert_cosmos_transformer_checkpoint_to_diffusers(checkpoint, **kwargs):
handler_fn_inplace(key, converted_state_dict)
return converted_state_dict
def convert_flux2_transformer_checkpoint_to_diffusers(checkpoint, **kwargs):
FLUX2_TRANSFORMER_KEYS_RENAME_DICT = {
# Image and text input projections
"img_in": "x_embedder",
"txt_in": "context_embedder",
# Timestep and guidance embeddings
"time_in.in_layer": "time_guidance_embed.timestep_embedder.linear_1",
"time_in.out_layer": "time_guidance_embed.timestep_embedder.linear_2",
"guidance_in.in_layer": "time_guidance_embed.guidance_embedder.linear_1",
"guidance_in.out_layer": "time_guidance_embed.guidance_embedder.linear_2",
# Modulation parameters
"double_stream_modulation_img.lin": "double_stream_modulation_img.linear",
"double_stream_modulation_txt.lin": "double_stream_modulation_txt.linear",
"single_stream_modulation.lin": "single_stream_modulation.linear",
# Final output layer
# "final_layer.adaLN_modulation.1": "norm_out.linear", # Handle separately since we need to swap mod params
"final_layer.linear": "proj_out",
}
FLUX2_TRANSFORMER_ADA_LAYER_NORM_KEY_MAP = {
"final_layer.adaLN_modulation.1": "norm_out.linear",
}
FLUX2_TRANSFORMER_DOUBLE_BLOCK_KEY_MAP = {
# Handle fused QKV projections separately as we need to break into Q, K, V projections
"img_attn.norm.query_norm": "attn.norm_q",
"img_attn.norm.key_norm": "attn.norm_k",
"img_attn.proj": "attn.to_out.0",
"img_mlp.0": "ff.linear_in",
"img_mlp.2": "ff.linear_out",
"txt_attn.norm.query_norm": "attn.norm_added_q",
"txt_attn.norm.key_norm": "attn.norm_added_k",
"txt_attn.proj": "attn.to_add_out",
"txt_mlp.0": "ff_context.linear_in",
"txt_mlp.2": "ff_context.linear_out",
}
FLUX2_TRANSFORMER_SINGLE_BLOCK_KEY_MAP = {
"linear1": "attn.to_qkv_mlp_proj",
"linear2": "attn.to_out",
"norm.query_norm": "attn.norm_q",
"norm.key_norm": "attn.norm_k",
}
def convert_flux2_single_stream_blocks(key: str, state_dict: dict[str, object]) -> None:
# Skip if not a weight, bias, or scale
if ".weight" not in key and ".bias" not in key and ".scale" not in key:
return
# Mapping:
# - single_blocks.{N}.linear1 --> single_transformer_blocks.{N}.attn.to_qkv_mlp_proj
# - single_blocks.{N}.linear2 --> single_transformer_blocks.{N}.attn.to_out
# - single_blocks.{N}.norm.query_norm.scale --> single_transformer_blocks.{N}.attn.norm_q.weight
# - single_blocks.{N}.norm.key_norm.scale --> single_transformer_blocks.{N}.attn.norm_k.weight
new_prefix = "single_transformer_blocks"
if "single_blocks." in key:
parts = key.split(".")
block_idx = parts[1]
within_block_name = ".".join(parts[2:-1])
param_type = parts[-1]
if param_type == "scale":
param_type = "weight"
new_within_block_name = FLUX2_TRANSFORMER_SINGLE_BLOCK_KEY_MAP[within_block_name]
new_key = ".".join([new_prefix, block_idx, new_within_block_name, param_type])
param = state_dict.pop(key)
state_dict[new_key] = param
return
def convert_ada_layer_norm_weights(key: str, state_dict: dict[str, object]) -> None:
# Skip if not a weight
if ".weight" not in key:
return
# If adaLN_modulation is in the key, swap scale and shift parameters
# Original implementation is (shift, scale); diffusers implementation is (scale, shift)
if "adaLN_modulation" in key:
key_without_param_type, param_type = key.rsplit(".", maxsplit=1)
# Assume all such keys are in the AdaLayerNorm key map
new_key_without_param_type = FLUX2_TRANSFORMER_ADA_LAYER_NORM_KEY_MAP[key_without_param_type]
new_key = ".".join([new_key_without_param_type, param_type])
swapped_weight = swap_scale_shift(state_dict.pop(key), 0)
state_dict[new_key] = swapped_weight
return
def convert_flux2_double_stream_blocks(key: str, state_dict: dict[str, object]) -> None:
# Skip if not a weight, bias, or scale
if ".weight" not in key and ".bias" not in key and ".scale" not in key:
return
new_prefix = "transformer_blocks"
if "double_blocks." in key:
parts = key.split(".")
block_idx = parts[1]
modality_block_name = parts[2] # img_attn, img_mlp, txt_attn, txt_mlp
within_block_name = ".".join(parts[2:-1])
param_type = parts[-1]
if param_type == "scale":
param_type = "weight"
if "qkv" in within_block_name:
fused_qkv_weight = state_dict.pop(key)
to_q_weight, to_k_weight, to_v_weight = torch.chunk(fused_qkv_weight, 3, dim=0)
if "img" in modality_block_name:
# double_blocks.{N}.img_attn.qkv --> transformer_blocks.{N}.attn.{to_q|to_k|to_v}
to_q_weight, to_k_weight, to_v_weight = torch.chunk(fused_qkv_weight, 3, dim=0)
new_q_name = "attn.to_q"
new_k_name = "attn.to_k"
new_v_name = "attn.to_v"
elif "txt" in modality_block_name:
# double_blocks.{N}.txt_attn.qkv --> transformer_blocks.{N}.attn.{add_q_proj|add_k_proj|add_v_proj}
to_q_weight, to_k_weight, to_v_weight = torch.chunk(fused_qkv_weight, 3, dim=0)
new_q_name = "attn.add_q_proj"
new_k_name = "attn.add_k_proj"
new_v_name = "attn.add_v_proj"
new_q_key = ".".join([new_prefix, block_idx, new_q_name, param_type])
new_k_key = ".".join([new_prefix, block_idx, new_k_name, param_type])
new_v_key = ".".join([new_prefix, block_idx, new_v_name, param_type])
state_dict[new_q_key] = to_q_weight
state_dict[new_k_key] = to_k_weight
state_dict[new_v_key] = to_v_weight
else:
new_within_block_name = FLUX2_TRANSFORMER_DOUBLE_BLOCK_KEY_MAP[within_block_name]
new_key = ".".join([new_prefix, block_idx, new_within_block_name, param_type])
param = state_dict.pop(key)
state_dict[new_key] = param
return
def update_state_dict(state_dict: dict[str, object], old_key: str, new_key: str) -> None:
state_dict[new_key] = state_dict.pop(old_key)
TRANSFORMER_SPECIAL_KEYS_REMAP = {
"adaLN_modulation": convert_ada_layer_norm_weights,
"double_blocks": convert_flux2_double_stream_blocks,
"single_blocks": convert_flux2_single_stream_blocks,
}
converted_state_dict = {key: checkpoint.pop(key) for key in list(checkpoint.keys())}
# Handle official code --> diffusers key remapping via the remap dict
for key in list(converted_state_dict.keys()):
new_key = key[:]
for replace_key, rename_key in FLUX2_TRANSFORMER_KEYS_RENAME_DICT.items():
new_key = new_key.replace(replace_key, rename_key)
update_state_dict(converted_state_dict, key, new_key)
# Handle any special logic which can't be expressed by a simple 1:1 remapping with the handlers in
# special_keys_remap
for key in list(converted_state_dict.keys()):
for special_key, handler_fn_inplace in TRANSFORMER_SPECIAL_KEYS_REMAP.items():
if special_key not in key:
continue
handler_fn_inplace(key, converted_state_dict)
return converted_state_dict

View File

@@ -35,6 +35,7 @@ if is_torch_available():
_import_structure["autoencoders.autoencoder_kl_allegro"] = ["AutoencoderKLAllegro"]
_import_structure["autoencoders.autoencoder_kl_cogvideox"] = ["AutoencoderKLCogVideoX"]
_import_structure["autoencoders.autoencoder_kl_cosmos"] = ["AutoencoderKLCosmos"]
_import_structure["autoencoders.autoencoder_kl_flux2"] = ["AutoencoderKLFlux2"]
_import_structure["autoencoders.autoencoder_kl_hunyuan_video"] = ["AutoencoderKLHunyuanVideo"]
_import_structure["autoencoders.autoencoder_kl_hunyuanimage"] = ["AutoencoderKLHunyuanImage"]
_import_structure["autoencoders.autoencoder_kl_hunyuanimage_refiner"] = ["AutoencoderKLHunyuanImageRefiner"]
@@ -92,6 +93,7 @@ if is_torch_available():
_import_structure["transformers.transformer_cosmos"] = ["CosmosTransformer3DModel"]
_import_structure["transformers.transformer_easyanimate"] = ["EasyAnimateTransformer3DModel"]
_import_structure["transformers.transformer_flux"] = ["FluxTransformer2DModel"]
_import_structure["transformers.transformer_flux2"] = ["Flux2Transformer2DModel"]
_import_structure["transformers.transformer_hidream_image"] = ["HiDreamImageTransformer2DModel"]
_import_structure["transformers.transformer_hunyuan_video"] = ["HunyuanVideoTransformer3DModel"]
_import_structure["transformers.transformer_hunyuan_video_framepack"] = ["HunyuanVideoFramepackTransformer3DModel"]
@@ -141,6 +143,7 @@ if TYPE_CHECKING or DIFFUSERS_SLOW_IMPORT:
AutoencoderKLAllegro,
AutoencoderKLCogVideoX,
AutoencoderKLCosmos,
AutoencoderKLFlux2,
AutoencoderKLHunyuanImage,
AutoencoderKLHunyuanImageRefiner,
AutoencoderKLHunyuanVideo,
@@ -191,6 +194,7 @@ if TYPE_CHECKING or DIFFUSERS_SLOW_IMPORT:
DiTTransformer2DModel,
DualTransformer2DModel,
EasyAnimateTransformer3DModel,
Flux2Transformer2DModel,
FluxTransformer2DModel,
HiDreamImageTransformer2DModel,
HunyuanDiT2DModel,

View File

@@ -105,7 +105,7 @@ class AttentionMixin:
raise ValueError("`fuse_qkv_projections()` is not supported for models having added KV projections.")
for module in self.modules():
if isinstance(module, AttentionModuleMixin):
if isinstance(module, AttentionModuleMixin) and module._supports_qkv_fusion:
module.fuse_projections()
def unfuse_qkv_projections(self):
@@ -114,13 +114,14 @@ class AttentionMixin:
> [!WARNING] > This API is 🧪 experimental.
"""
for module in self.modules():
if isinstance(module, AttentionModuleMixin):
if isinstance(module, AttentionModuleMixin) and module._supports_qkv_fusion:
module.unfuse_projections()
class AttentionModuleMixin:
_default_processor_cls = None
_available_processors = []
_supports_qkv_fusion = True
fused_projections = False
def set_processor(self, processor: AttentionProcessor) -> None:
@@ -248,6 +249,14 @@ class AttentionModuleMixin:
"""
Fuse the query, key, and value projections into a single projection for efficiency.
"""
# Skip if the AttentionModuleMixin subclass does not support fusion (for example, the QKV projections in Flux2
# single stream blocks are always fused)
if not self._supports_qkv_fusion:
logger.debug(
f"{self.__class__.__name__} does not support fusing QKV projections, so `fuse_projections` will no-op."
)
return
# Skip if already fused
if getattr(self, "fused_projections", False):
return
@@ -307,6 +316,11 @@ class AttentionModuleMixin:
"""
Unfuse the query, key, and value projections back to separate projections.
"""
# Skip if the AttentionModuleMixin subclass does not support fusion (for example, the QKV projections in Flux2
# single stream blocks are always fused)
if not self._supports_qkv_fusion:
return
# Skip if not fused
if not getattr(self, "fused_projections", False):
return

View File

@@ -4,6 +4,7 @@ from .autoencoder_kl import AutoencoderKL
from .autoencoder_kl_allegro import AutoencoderKLAllegro
from .autoencoder_kl_cogvideox import AutoencoderKLCogVideoX
from .autoencoder_kl_cosmos import AutoencoderKLCosmos
from .autoencoder_kl_flux2 import AutoencoderKLFlux2
from .autoencoder_kl_hunyuan_video import AutoencoderKLHunyuanVideo
from .autoencoder_kl_hunyuanimage import AutoencoderKLHunyuanImage
from .autoencoder_kl_hunyuanimage_refiner import AutoencoderKLHunyuanImageRefiner

View File

@@ -0,0 +1,546 @@
# Copyright 2025 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
from typing import Dict, Optional, Tuple, Union
import torch
import torch.nn as nn
from ...configuration_utils import ConfigMixin, register_to_config
from ...loaders import PeftAdapterMixin
from ...loaders.single_file_model import FromOriginalModelMixin
from ...utils import deprecate
from ...utils.accelerate_utils import apply_forward_hook
from ..attention_processor import (
ADDED_KV_ATTENTION_PROCESSORS,
CROSS_ATTENTION_PROCESSORS,
Attention,
AttentionProcessor,
AttnAddedKVProcessor,
AttnProcessor,
FusedAttnProcessor2_0,
)
from ..modeling_outputs import AutoencoderKLOutput
from ..modeling_utils import ModelMixin
from .vae import AutoencoderMixin, Decoder, DecoderOutput, DiagonalGaussianDistribution, Encoder
class AutoencoderKLFlux2(ModelMixin, AutoencoderMixin, ConfigMixin, FromOriginalModelMixin, PeftAdapterMixin):
r"""
A VAE model with KL loss for encoding images into latents and decoding latent representations into images.
This model inherits from [`ModelMixin`]. Check the superclass documentation for it's generic methods implemented
for all models (such as downloading or saving).
Parameters:
in_channels (int, *optional*, defaults to 3): Number of channels in the input image.
out_channels (int, *optional*, defaults to 3): Number of channels in the output.
down_block_types (`Tuple[str]`, *optional*, defaults to `("DownEncoderBlock2D",)`):
Tuple of downsample block types.
up_block_types (`Tuple[str]`, *optional*, defaults to `("UpDecoderBlock2D",)`):
Tuple of upsample block types.
block_out_channels (`Tuple[int]`, *optional*, defaults to `(64,)`):
Tuple of block output channels.
act_fn (`str`, *optional*, defaults to `"silu"`): The activation function to use.
latent_channels (`int`, *optional*, defaults to 4): Number of channels in the latent space.
sample_size (`int`, *optional*, defaults to `32`): Sample input size.
force_upcast (`bool`, *optional*, default to `True`):
If enabled it will force the VAE to run in float32 for high image resolution pipelines, such as SD-XL. VAE
can be fine-tuned / trained to a lower range without losing too much precision in which case `force_upcast`
can be set to `False` - see: https://huggingface.co/madebyollin/sdxl-vae-fp16-fix
mid_block_add_attention (`bool`, *optional*, default to `True`):
If enabled, the mid_block of the Encoder and Decoder will have attention blocks. If set to false, the
mid_block will only have resnet blocks
"""
_supports_gradient_checkpointing = True
_no_split_modules = ["BasicTransformerBlock", "ResnetBlock2D"]
@register_to_config
def __init__(
self,
in_channels: int = 3,
out_channels: int = 3,
down_block_types: Tuple[str, ...] = (
"DownEncoderBlock2D",
"DownEncoderBlock2D",
"DownEncoderBlock2D",
"DownEncoderBlock2D",
),
up_block_types: Tuple[str, ...] = (
"UpDecoderBlock2D",
"UpDecoderBlock2D",
"UpDecoderBlock2D",
"UpDecoderBlock2D",
),
block_out_channels: Tuple[int, ...] = (
128,
256,
512,
512,
),
layers_per_block: int = 2,
act_fn: str = "silu",
latent_channels: int = 32,
norm_num_groups: int = 32,
sample_size: int = 1024, # YiYi notes: not sure
force_upcast: bool = True,
use_quant_conv: bool = True,
use_post_quant_conv: bool = True,
mid_block_add_attention: bool = True,
batch_norm_eps: float = 1e-4,
batch_norm_momentum: float = 0.1,
patch_size: Tuple[int, int] = (2, 2),
):
super().__init__()
# pass init params to Encoder
self.encoder = Encoder(
in_channels=in_channels,
out_channels=latent_channels,
down_block_types=down_block_types,
block_out_channels=block_out_channels,
layers_per_block=layers_per_block,
act_fn=act_fn,
norm_num_groups=norm_num_groups,
double_z=True,
mid_block_add_attention=mid_block_add_attention,
)
# pass init params to Decoder
self.decoder = Decoder(
in_channels=latent_channels,
out_channels=out_channels,
up_block_types=up_block_types,
block_out_channels=block_out_channels,
layers_per_block=layers_per_block,
norm_num_groups=norm_num_groups,
act_fn=act_fn,
mid_block_add_attention=mid_block_add_attention,
)
self.quant_conv = nn.Conv2d(2 * latent_channels, 2 * latent_channels, 1) if use_quant_conv else None
self.post_quant_conv = nn.Conv2d(latent_channels, latent_channels, 1) if use_post_quant_conv else None
self.bn = nn.BatchNorm2d(
math.prod(patch_size) * latent_channels,
eps=batch_norm_eps,
momentum=batch_norm_momentum,
affine=False,
track_running_stats=True,
)
self.use_slicing = False
self.use_tiling = False
# only relevant if vae tiling is enabled
self.tile_sample_min_size = self.config.sample_size
sample_size = (
self.config.sample_size[0]
if isinstance(self.config.sample_size, (list, tuple))
else self.config.sample_size
)
self.tile_latent_min_size = int(sample_size / (2 ** (len(self.config.block_out_channels) - 1)))
self.tile_overlap_factor = 0.25
@property
# Copied from diffusers.models.unets.unet_2d_condition.UNet2DConditionModel.attn_processors
def attn_processors(self) -> Dict[str, AttentionProcessor]:
r"""
Returns:
`dict` of attention processors: A dictionary containing all attention processors used in the model with
indexed by its weight name.
"""
# set recursively
processors = {}
def fn_recursive_add_processors(name: str, module: torch.nn.Module, processors: Dict[str, AttentionProcessor]):
if hasattr(module, "get_processor"):
processors[f"{name}.processor"] = module.get_processor()
for sub_name, child in module.named_children():
fn_recursive_add_processors(f"{name}.{sub_name}", child, processors)
return processors
for name, module in self.named_children():
fn_recursive_add_processors(name, module, processors)
return processors
# Copied from diffusers.models.unets.unet_2d_condition.UNet2DConditionModel.set_attn_processor
def set_attn_processor(self, processor: Union[AttentionProcessor, Dict[str, AttentionProcessor]]):
r"""
Sets the attention processor to use to compute attention.
Parameters:
processor (`dict` of `AttentionProcessor` or only `AttentionProcessor`):
The instantiated processor class or a dictionary of processor classes that will be set as the processor
for **all** `Attention` layers.
If `processor` is a dict, the key needs to define the path to the corresponding cross attention
processor. This is strongly recommended when setting trainable attention processors.
"""
count = len(self.attn_processors.keys())
if isinstance(processor, dict) and len(processor) != count:
raise ValueError(
f"A dict of processors was passed, but the number of processors {len(processor)} does not match the"
f" number of attention layers: {count}. Please make sure to pass {count} processor classes."
)
def fn_recursive_attn_processor(name: str, module: torch.nn.Module, processor):
if hasattr(module, "set_processor"):
if not isinstance(processor, dict):
module.set_processor(processor)
else:
module.set_processor(processor.pop(f"{name}.processor"))
for sub_name, child in module.named_children():
fn_recursive_attn_processor(f"{name}.{sub_name}", child, processor)
for name, module in self.named_children():
fn_recursive_attn_processor(name, module, processor)
# Copied from diffusers.models.unets.unet_2d_condition.UNet2DConditionModel.set_default_attn_processor
def set_default_attn_processor(self):
"""
Disables custom attention processors and sets the default attention implementation.
"""
if all(proc.__class__ in ADDED_KV_ATTENTION_PROCESSORS for proc in self.attn_processors.values()):
processor = AttnAddedKVProcessor()
elif all(proc.__class__ in CROSS_ATTENTION_PROCESSORS for proc in self.attn_processors.values()):
processor = AttnProcessor()
else:
raise ValueError(
f"Cannot call `set_default_attn_processor` when attention processors are of type {next(iter(self.attn_processors.values()))}"
)
self.set_attn_processor(processor)
def _encode(self, x: torch.Tensor) -> torch.Tensor:
batch_size, num_channels, height, width = x.shape
if self.use_tiling and (width > self.tile_sample_min_size or height > self.tile_sample_min_size):
return self._tiled_encode(x)
enc = self.encoder(x)
if self.quant_conv is not None:
enc = self.quant_conv(enc)
return enc
@apply_forward_hook
def encode(
self, x: torch.Tensor, return_dict: bool = True
) -> Union[AutoencoderKLOutput, Tuple[DiagonalGaussianDistribution]]:
"""
Encode a batch of images into latents.
Args:
x (`torch.Tensor`): Input batch of images.
return_dict (`bool`, *optional*, defaults to `True`):
Whether to return a [`~models.autoencoder_kl.AutoencoderKLOutput`] instead of a plain tuple.
Returns:
The latent representations of the encoded images. If `return_dict` is True, a
[`~models.autoencoder_kl.AutoencoderKLOutput`] is returned, otherwise a plain `tuple` is returned.
"""
if self.use_slicing and x.shape[0] > 1:
encoded_slices = [self._encode(x_slice) for x_slice in x.split(1)]
h = torch.cat(encoded_slices)
else:
h = self._encode(x)
posterior = DiagonalGaussianDistribution(h)
if not return_dict:
return (posterior,)
return AutoencoderKLOutput(latent_dist=posterior)
def _decode(self, z: torch.Tensor, return_dict: bool = True) -> Union[DecoderOutput, torch.Tensor]:
if self.use_tiling and (z.shape[-1] > self.tile_latent_min_size or z.shape[-2] > self.tile_latent_min_size):
return self.tiled_decode(z, return_dict=return_dict)
if self.post_quant_conv is not None:
z = self.post_quant_conv(z)
dec = self.decoder(z)
if not return_dict:
return (dec,)
return DecoderOutput(sample=dec)
@apply_forward_hook
def decode(
self, z: torch.FloatTensor, return_dict: bool = True, generator=None
) -> Union[DecoderOutput, torch.FloatTensor]:
"""
Decode a batch of images.
Args:
z (`torch.Tensor`): Input batch of latent vectors.
return_dict (`bool`, *optional*, defaults to `True`):
Whether to return a [`~models.vae.DecoderOutput`] instead of a plain tuple.
Returns:
[`~models.vae.DecoderOutput`] or `tuple`:
If return_dict is True, a [`~models.vae.DecoderOutput`] is returned, otherwise a plain `tuple` is
returned.
"""
if self.use_slicing and z.shape[0] > 1:
decoded_slices = [self._decode(z_slice).sample for z_slice in z.split(1)]
decoded = torch.cat(decoded_slices)
else:
decoded = self._decode(z).sample
if not return_dict:
return (decoded,)
return DecoderOutput(sample=decoded)
def blend_v(self, a: torch.Tensor, b: torch.Tensor, blend_extent: int) -> torch.Tensor:
blend_extent = min(a.shape[2], b.shape[2], 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[3], b.shape[3], 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 _tiled_encode(self, x: torch.Tensor) -> torch.Tensor:
r"""Encode a batch of images using a tiled encoder.
When this option is enabled, the VAE will split the input tensor into tiles to compute encoding in several
steps. This is useful to keep memory use constant regardless of image size. The end result of tiled encoding is
different from non-tiled encoding because each tile uses a different encoder. To avoid tiling artifacts, the
tiles overlap and are blended together to form a smooth output. You may still see tile-sized changes in the
output, but they should be much less noticeable.
Args:
x (`torch.Tensor`): Input batch of images.
Returns:
`torch.Tensor`:
The latent representation of the encoded videos.
"""
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[2], overlap_size):
row = []
for j in range(0, x.shape[3], overlap_size):
tile = x[:, :, i : i + self.tile_sample_min_size, j : j + self.tile_sample_min_size]
tile = self.encoder(tile)
if self.config.use_quant_conv:
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=3))
enc = torch.cat(result_rows, dim=2)
return enc
def tiled_encode(self, x: torch.Tensor, return_dict: bool = True) -> AutoencoderKLOutput:
r"""Encode a batch of images using a tiled encoder.
When this option is enabled, the VAE will split the input tensor into tiles to compute encoding in several
steps. This is useful to keep memory use constant regardless of image size. The end result of tiled encoding is
different from non-tiled encoding because each tile uses a different encoder. To avoid tiling artifacts, the
tiles overlap and are blended together to form a smooth output. You may still see tile-sized changes in the
output, but they should be much less noticeable.
Args:
x (`torch.Tensor`): Input batch of images.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~models.autoencoder_kl.AutoencoderKLOutput`] instead of a plain tuple.
Returns:
[`~models.autoencoder_kl.AutoencoderKLOutput`] or `tuple`:
If return_dict is True, a [`~models.autoencoder_kl.AutoencoderKLOutput`] is returned, otherwise a plain
`tuple` is returned.
"""
deprecation_message = (
"The tiled_encode implementation supporting the `return_dict` parameter is deprecated. In the future, the "
"implementation of this method will be replaced with that of `_tiled_encode` and you will no longer be able "
"to pass `return_dict`. You will also have to create a `DiagonalGaussianDistribution()` from the returned value."
)
deprecate("tiled_encode", "1.0.0", deprecation_message, standard_warn=False)
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[2], overlap_size):
row = []
for j in range(0, x.shape[3], overlap_size):
tile = x[:, :, i : i + self.tile_sample_min_size, j : j + self.tile_sample_min_size]
tile = self.encoder(tile)
if self.config.use_quant_conv:
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=3))
moments = torch.cat(result_rows, dim=2)
posterior = DiagonalGaussianDistribution(moments)
if not return_dict:
return (posterior,)
return AutoencoderKLOutput(latent_dist=posterior)
def tiled_decode(self, z: torch.Tensor, return_dict: bool = True) -> Union[DecoderOutput, torch.Tensor]:
r"""
Decode a batch of images using a tiled decoder.
Args:
z (`torch.Tensor`): Input batch of latent vectors.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~models.vae.DecoderOutput`] instead of a plain tuple.
Returns:
[`~models.vae.DecoderOutput`] or `tuple`:
If return_dict is True, a [`~models.vae.DecoderOutput`] is returned, otherwise a plain `tuple` is
returned.
"""
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
# 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[2], overlap_size):
row = []
for j in range(0, z.shape[3], overlap_size):
tile = z[:, :, i : i + self.tile_latent_min_size, j : j + self.tile_latent_min_size]
if self.config.use_post_quant_conv:
tile = self.post_quant_conv(tile)
decoded = self.decoder(tile)
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=3))
dec = torch.cat(result_rows, dim=2)
if not return_dict:
return (dec,)
return DecoderOutput(sample=dec)
def forward(
self,
sample: torch.Tensor,
sample_posterior: bool = False,
return_dict: bool = True,
generator: Optional[torch.Generator] = None,
) -> Union[DecoderOutput, torch.Tensor]:
r"""
Args:
sample (`torch.Tensor`): Input sample.
sample_posterior (`bool`, *optional*, defaults to `False`):
Whether to sample from the posterior.
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`DecoderOutput`] instead of a plain tuple.
"""
x = sample
posterior = self.encode(x).latent_dist
if sample_posterior:
z = posterior.sample(generator=generator)
else:
z = posterior.mode()
dec = self.decode(z).sample
if not return_dict:
return (dec,)
return DecoderOutput(sample=dec)
# Copied from diffusers.models.unets.unet_2d_condition.UNet2DConditionModel.fuse_qkv_projections
def fuse_qkv_projections(self):
"""
Enables fused QKV projections. For self-attention modules, all projection matrices (i.e., query, key, value)
are fused. For cross-attention modules, key and value projection matrices are fused.
> [!WARNING] > This API is 🧪 experimental.
"""
self.original_attn_processors = None
for _, attn_processor in self.attn_processors.items():
if "Added" in str(attn_processor.__class__.__name__):
raise ValueError("`fuse_qkv_projections()` is not supported for models having added KV projections.")
self.original_attn_processors = self.attn_processors
for module in self.modules():
if isinstance(module, Attention):
module.fuse_projections(fuse=True)
self.set_attn_processor(FusedAttnProcessor2_0())
# Copied from diffusers.models.unets.unet_2d_condition.UNet2DConditionModel.unfuse_qkv_projections
def unfuse_qkv_projections(self):
"""Disables the fused QKV projection if enabled.
> [!WARNING] > This API is 🧪 experimental.
"""
if self.original_attn_processors is not None:
self.set_attn_processor(self.original_attn_processors)

View File

@@ -26,6 +26,7 @@ if is_torch_available():
from .transformer_cosmos import CosmosTransformer3DModel
from .transformer_easyanimate import EasyAnimateTransformer3DModel
from .transformer_flux import FluxTransformer2DModel
from .transformer_flux2 import Flux2Transformer2DModel
from .transformer_hidream_image import HiDreamImageTransformer2DModel
from .transformer_hunyuan_video import HunyuanVideoTransformer3DModel
from .transformer_hunyuan_video_framepack import HunyuanVideoFramepackTransformer3DModel

View File

@@ -0,0 +1,908 @@
# Copyright 2025 Black Forest Labs, The HuggingFace Team and The InstantX Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import inspect
from typing import Any, Dict, List, Optional, Tuple, Union
import torch
import torch.nn as nn
import torch.nn.functional as F
from ...configuration_utils import ConfigMixin, register_to_config
from ...loaders import FluxTransformer2DLoadersMixin, FromOriginalModelMixin, PeftAdapterMixin
from ...utils import USE_PEFT_BACKEND, is_torch_npu_available, logging, scale_lora_layers, unscale_lora_layers
from .._modeling_parallel import ContextParallelInput, ContextParallelOutput
from ..attention import AttentionMixin, AttentionModuleMixin
from ..attention_dispatch import dispatch_attention_fn
from ..cache_utils import CacheMixin
from ..embeddings import (
TimestepEmbedding,
Timesteps,
apply_rotary_emb,
get_1d_rotary_pos_embed,
)
from ..modeling_outputs import Transformer2DModelOutput
from ..modeling_utils import ModelMixin
from ..normalization import AdaLayerNormContinuous
logger = logging.get_logger(__name__) # pylint: disable=invalid-name
def _get_projections(attn: "Flux2Attention", hidden_states, encoder_hidden_states=None):
query = attn.to_q(hidden_states)
key = attn.to_k(hidden_states)
value = attn.to_v(hidden_states)
encoder_query = encoder_key = encoder_value = None
if encoder_hidden_states is not None and attn.added_kv_proj_dim is not None:
encoder_query = attn.add_q_proj(encoder_hidden_states)
encoder_key = attn.add_k_proj(encoder_hidden_states)
encoder_value = attn.add_v_proj(encoder_hidden_states)
return query, key, value, encoder_query, encoder_key, encoder_value
def _get_fused_projections(attn: "Flux2Attention", hidden_states, encoder_hidden_states=None):
query, key, value = attn.to_qkv(hidden_states).chunk(3, dim=-1)
encoder_query = encoder_key = encoder_value = (None,)
if encoder_hidden_states is not None and hasattr(attn, "to_added_qkv"):
encoder_query, encoder_key, encoder_value = attn.to_added_qkv(encoder_hidden_states).chunk(3, dim=-1)
return query, key, value, encoder_query, encoder_key, encoder_value
def _get_qkv_projections(attn: "Flux2Attention", hidden_states, encoder_hidden_states=None):
if attn.fused_projections:
return _get_fused_projections(attn, hidden_states, encoder_hidden_states)
return _get_projections(attn, hidden_states, encoder_hidden_states)
class Flux2SwiGLU(nn.Module):
"""
Flux 2 uses a SwiGLU-style activation in the transformer feedforward sub-blocks, but with the linear projection
layer fused into the first linear layer of the FF sub-block. Thus, this module has no trainable parameters.
"""
def __init__(self):
super().__init__()
self.gate_fn = nn.SiLU()
def forward(self, x: torch.Tensor) -> torch.Tensor:
x1, x2 = x.chunk(2, dim=-1)
x = self.gate_fn(x1) * x2
return x
class Flux2FeedForward(nn.Module):
def __init__(
self,
dim: int,
dim_out: Optional[int] = None,
mult: float = 3.0,
inner_dim: Optional[int] = None,
bias: bool = False,
):
super().__init__()
if inner_dim is None:
inner_dim = int(dim * mult)
dim_out = dim_out or dim
# Flux2SwiGLU will reduce the dimension by half
self.linear_in = nn.Linear(dim, inner_dim * 2, bias=bias)
self.act_fn = Flux2SwiGLU()
self.linear_out = nn.Linear(inner_dim, dim_out, bias=bias)
def forward(self, x: torch.Tensor) -> torch.Tensor:
x = self.linear_in(x)
x = self.act_fn(x)
x = self.linear_out(x)
return x
class Flux2AttnProcessor:
_attention_backend = None
_parallel_config = None
def __init__(self):
if not hasattr(F, "scaled_dot_product_attention"):
raise ImportError(f"{self.__class__.__name__} requires PyTorch 2.0. Please upgrade your pytorch version.")
def __call__(
self,
attn: "Flux2Attention",
hidden_states: torch.Tensor,
encoder_hidden_states: torch.Tensor = None,
attention_mask: Optional[torch.Tensor] = None,
image_rotary_emb: Optional[torch.Tensor] = None,
) -> torch.Tensor:
query, key, value, encoder_query, encoder_key, encoder_value = _get_qkv_projections(
attn, hidden_states, encoder_hidden_states
)
query = query.unflatten(-1, (attn.heads, -1))
key = key.unflatten(-1, (attn.heads, -1))
value = value.unflatten(-1, (attn.heads, -1))
query = attn.norm_q(query)
key = attn.norm_k(key)
if attn.added_kv_proj_dim is not None:
encoder_query = encoder_query.unflatten(-1, (attn.heads, -1))
encoder_key = encoder_key.unflatten(-1, (attn.heads, -1))
encoder_value = encoder_value.unflatten(-1, (attn.heads, -1))
encoder_query = attn.norm_added_q(encoder_query)
encoder_key = attn.norm_added_k(encoder_key)
query = torch.cat([encoder_query, query], dim=1)
key = torch.cat([encoder_key, key], dim=1)
value = torch.cat([encoder_value, value], dim=1)
if image_rotary_emb is not None:
query = apply_rotary_emb(query, image_rotary_emb, sequence_dim=1)
key = apply_rotary_emb(key, image_rotary_emb, sequence_dim=1)
hidden_states = dispatch_attention_fn(
query,
key,
value,
attn_mask=attention_mask,
backend=self._attention_backend,
parallel_config=self._parallel_config,
)
hidden_states = hidden_states.flatten(2, 3)
hidden_states = hidden_states.to(query.dtype)
if encoder_hidden_states is not None:
encoder_hidden_states, hidden_states = hidden_states.split_with_sizes(
[encoder_hidden_states.shape[1], hidden_states.shape[1] - encoder_hidden_states.shape[1]], dim=1
)
encoder_hidden_states = attn.to_add_out(encoder_hidden_states)
hidden_states = attn.to_out[0](hidden_states)
hidden_states = attn.to_out[1](hidden_states)
if encoder_hidden_states is not None:
return hidden_states, encoder_hidden_states
else:
return hidden_states
class Flux2Attention(torch.nn.Module, AttentionModuleMixin):
_default_processor_cls = Flux2AttnProcessor
_available_processors = [Flux2AttnProcessor]
def __init__(
self,
query_dim: int,
heads: int = 8,
dim_head: int = 64,
dropout: float = 0.0,
bias: bool = False,
added_kv_proj_dim: Optional[int] = None,
added_proj_bias: Optional[bool] = True,
out_bias: bool = True,
eps: float = 1e-5,
out_dim: int = None,
elementwise_affine: bool = True,
processor=None,
):
super().__init__()
self.head_dim = dim_head
self.inner_dim = out_dim if out_dim is not None else dim_head * heads
self.query_dim = query_dim
self.out_dim = out_dim if out_dim is not None else query_dim
self.heads = out_dim // dim_head if out_dim is not None else heads
self.use_bias = bias
self.dropout = dropout
self.added_kv_proj_dim = added_kv_proj_dim
self.added_proj_bias = added_proj_bias
self.to_q = torch.nn.Linear(query_dim, self.inner_dim, bias=bias)
self.to_k = torch.nn.Linear(query_dim, self.inner_dim, bias=bias)
self.to_v = torch.nn.Linear(query_dim, self.inner_dim, bias=bias)
# QK Norm
self.norm_q = torch.nn.RMSNorm(dim_head, eps=eps, elementwise_affine=elementwise_affine)
self.norm_k = torch.nn.RMSNorm(dim_head, eps=eps, elementwise_affine=elementwise_affine)
self.to_out = torch.nn.ModuleList([])
self.to_out.append(torch.nn.Linear(self.inner_dim, self.out_dim, bias=out_bias))
self.to_out.append(torch.nn.Dropout(dropout))
if added_kv_proj_dim is not None:
self.norm_added_q = torch.nn.RMSNorm(dim_head, eps=eps)
self.norm_added_k = torch.nn.RMSNorm(dim_head, eps=eps)
self.add_q_proj = torch.nn.Linear(added_kv_proj_dim, self.inner_dim, bias=added_proj_bias)
self.add_k_proj = torch.nn.Linear(added_kv_proj_dim, self.inner_dim, bias=added_proj_bias)
self.add_v_proj = torch.nn.Linear(added_kv_proj_dim, self.inner_dim, bias=added_proj_bias)
self.to_add_out = torch.nn.Linear(self.inner_dim, query_dim, bias=out_bias)
if processor is None:
processor = self._default_processor_cls()
self.set_processor(processor)
def forward(
self,
hidden_states: torch.Tensor,
encoder_hidden_states: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
image_rotary_emb: Optional[torch.Tensor] = None,
**kwargs,
) -> torch.Tensor:
attn_parameters = set(inspect.signature(self.processor.__call__).parameters.keys())
unused_kwargs = [k for k, _ in kwargs.items() if k not in attn_parameters]
if len(unused_kwargs) > 0:
logger.warning(
f"joint_attention_kwargs {unused_kwargs} are not expected by {self.processor.__class__.__name__} and will be ignored."
)
kwargs = {k: w for k, w in kwargs.items() if k in attn_parameters}
return self.processor(self, hidden_states, encoder_hidden_states, attention_mask, image_rotary_emb, **kwargs)
class Flux2ParallelSelfAttnProcessor:
_attention_backend = None
_parallel_config = None
def __init__(self):
if not hasattr(F, "scaled_dot_product_attention"):
raise ImportError(f"{self.__class__.__name__} requires PyTorch 2.0. Please upgrade your pytorch version.")
def __call__(
self,
attn: "Flux2ParallelSelfAttention",
hidden_states: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
image_rotary_emb: Optional[torch.Tensor] = None,
) -> torch.Tensor:
# Parallel in (QKV + MLP in) projection
hidden_states = attn.to_qkv_mlp_proj(hidden_states)
qkv, mlp_hidden_states = torch.split(
hidden_states, [3 * attn.inner_dim, attn.mlp_hidden_dim * attn.mlp_mult_factor], dim=-1
)
# Handle the attention logic
query, key, value = qkv.chunk(3, dim=-1)
query = query.unflatten(-1, (attn.heads, -1))
key = key.unflatten(-1, (attn.heads, -1))
value = value.unflatten(-1, (attn.heads, -1))
query = attn.norm_q(query)
key = attn.norm_k(key)
if image_rotary_emb is not None:
query = apply_rotary_emb(query, image_rotary_emb, sequence_dim=1)
key = apply_rotary_emb(key, image_rotary_emb, sequence_dim=1)
hidden_states = dispatch_attention_fn(
query,
key,
value,
attn_mask=attention_mask,
backend=self._attention_backend,
parallel_config=self._parallel_config,
)
hidden_states = hidden_states.flatten(2, 3)
hidden_states = hidden_states.to(query.dtype)
# Handle the feedforward (FF) logic
mlp_hidden_states = attn.mlp_act_fn(mlp_hidden_states)
# Concatenate and parallel output projection
hidden_states = torch.cat([hidden_states, mlp_hidden_states], dim=-1)
hidden_states = attn.to_out(hidden_states)
return hidden_states
class Flux2ParallelSelfAttention(torch.nn.Module, AttentionModuleMixin):
"""
Flux 2 parallel self-attention for the Flux 2 single-stream transformer blocks.
This implements a parallel transformer block, where the attention QKV projections are fused to the feedforward (FF)
input projections, and the attention output projections are fused to the FF output projections. See the [ViT-22B
paper](https://arxiv.org/abs/2302.05442) for a visual depiction of this type of transformer block.
"""
_default_processor_cls = Flux2ParallelSelfAttnProcessor
_available_processors = [Flux2ParallelSelfAttnProcessor]
# Does not support QKV fusion as the QKV projections are always fused
_supports_qkv_fusion = False
def __init__(
self,
query_dim: int,
heads: int = 8,
dim_head: int = 64,
dropout: float = 0.0,
bias: bool = False,
out_bias: bool = True,
eps: float = 1e-5,
out_dim: int = None,
elementwise_affine: bool = True,
mlp_ratio: float = 4.0,
mlp_mult_factor: int = 2,
processor=None,
):
super().__init__()
self.head_dim = dim_head
self.inner_dim = out_dim if out_dim is not None else dim_head * heads
self.query_dim = query_dim
self.out_dim = out_dim if out_dim is not None else query_dim
self.heads = out_dim // dim_head if out_dim is not None else heads
self.use_bias = bias
self.dropout = dropout
self.mlp_ratio = mlp_ratio
self.mlp_hidden_dim = int(query_dim * self.mlp_ratio)
self.mlp_mult_factor = mlp_mult_factor
# Fused QKV projections + MLP input projection
self.to_qkv_mlp_proj = torch.nn.Linear(
self.query_dim, self.inner_dim * 3 + self.mlp_hidden_dim * self.mlp_mult_factor, bias=bias
)
self.mlp_act_fn = Flux2SwiGLU()
# QK Norm
self.norm_q = torch.nn.RMSNorm(dim_head, eps=eps, elementwise_affine=elementwise_affine)
self.norm_k = torch.nn.RMSNorm(dim_head, eps=eps, elementwise_affine=elementwise_affine)
# Fused attention output projection + MLP output projection
self.to_out = torch.nn.Linear(self.inner_dim + self.mlp_hidden_dim, self.out_dim, bias=out_bias)
if processor is None:
processor = self._default_processor_cls()
self.set_processor(processor)
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
image_rotary_emb: Optional[torch.Tensor] = None,
**kwargs,
) -> torch.Tensor:
attn_parameters = set(inspect.signature(self.processor.__call__).parameters.keys())
unused_kwargs = [k for k, _ in kwargs.items() if k not in attn_parameters]
if len(unused_kwargs) > 0:
logger.warning(
f"joint_attention_kwargs {unused_kwargs} are not expected by {self.processor.__class__.__name__} and will be ignored."
)
kwargs = {k: w for k, w in kwargs.items() if k in attn_parameters}
return self.processor(self, hidden_states, attention_mask, image_rotary_emb, **kwargs)
class Flux2SingleTransformerBlock(nn.Module):
def __init__(
self,
dim: int,
num_attention_heads: int,
attention_head_dim: int,
mlp_ratio: float = 3.0,
eps: float = 1e-6,
bias: bool = False,
):
super().__init__()
self.norm = nn.LayerNorm(dim, elementwise_affine=False, eps=eps)
# Note that the MLP in/out linear layers are fused with the attention QKV/out projections, respectively; this
# is often called a "parallel" transformer block. See the [ViT-22B paper](https://arxiv.org/abs/2302.05442)
# for a visual depiction of this type of transformer block.
self.attn = Flux2ParallelSelfAttention(
query_dim=dim,
dim_head=attention_head_dim,
heads=num_attention_heads,
out_dim=dim,
bias=bias,
out_bias=bias,
eps=eps,
mlp_ratio=mlp_ratio,
mlp_mult_factor=2,
processor=Flux2ParallelSelfAttnProcessor(),
)
def forward(
self,
hidden_states: torch.Tensor,
encoder_hidden_states: Optional[torch.Tensor],
temb_mod_params: Tuple[torch.Tensor, torch.Tensor, torch.Tensor],
image_rotary_emb: Optional[Tuple[torch.Tensor, torch.Tensor]] = None,
joint_attention_kwargs: Optional[Dict[str, Any]] = None,
split_hidden_states: bool = False,
text_seq_len: Optional[int] = None,
) -> Tuple[torch.Tensor, torch.Tensor]:
# If encoder_hidden_states is None, hidden_states is assumed to have encoder_hidden_states already
# concatenated
if encoder_hidden_states is not None:
text_seq_len = encoder_hidden_states.shape[1]
hidden_states = torch.cat([encoder_hidden_states, hidden_states], dim=1)
mod_shift, mod_scale, mod_gate = temb_mod_params
norm_hidden_states = self.norm(hidden_states)
norm_hidden_states = (1 + mod_scale) * norm_hidden_states + mod_shift
joint_attention_kwargs = joint_attention_kwargs or {}
attn_output = self.attn(
hidden_states=norm_hidden_states,
image_rotary_emb=image_rotary_emb,
**joint_attention_kwargs,
)
hidden_states = hidden_states + mod_gate * attn_output
if hidden_states.dtype == torch.float16:
hidden_states = hidden_states.clip(-65504, 65504)
if split_hidden_states:
encoder_hidden_states, hidden_states = hidden_states[:, :text_seq_len], hidden_states[:, text_seq_len:]
return encoder_hidden_states, hidden_states
else:
return hidden_states
class Flux2TransformerBlock(nn.Module):
def __init__(
self,
dim: int,
num_attention_heads: int,
attention_head_dim: int,
mlp_ratio: float = 3.0,
eps: float = 1e-6,
bias: bool = False,
):
super().__init__()
self.mlp_hidden_dim = int(dim * mlp_ratio)
self.norm1 = nn.LayerNorm(dim, elementwise_affine=False, eps=eps)
self.norm1_context = nn.LayerNorm(dim, elementwise_affine=False, eps=eps)
self.attn = Flux2Attention(
query_dim=dim,
added_kv_proj_dim=dim,
dim_head=attention_head_dim,
heads=num_attention_heads,
out_dim=dim,
bias=bias,
added_proj_bias=bias,
out_bias=bias,
eps=eps,
processor=Flux2AttnProcessor(),
)
self.norm2 = nn.LayerNorm(dim, elementwise_affine=False, eps=eps)
self.ff = Flux2FeedForward(dim=dim, dim_out=dim, mult=mlp_ratio, bias=bias)
self.norm2_context = nn.LayerNorm(dim, elementwise_affine=False, eps=eps)
self.ff_context = Flux2FeedForward(dim=dim, dim_out=dim, mult=mlp_ratio, bias=bias)
def forward(
self,
hidden_states: torch.Tensor,
encoder_hidden_states: torch.Tensor,
temb_mod_params_img: Tuple[Tuple[torch.Tensor, torch.Tensor, torch.Tensor], ...],
temb_mod_params_txt: Tuple[Tuple[torch.Tensor, torch.Tensor, torch.Tensor], ...],
image_rotary_emb: Optional[Tuple[torch.Tensor, torch.Tensor]] = None,
joint_attention_kwargs: Optional[Dict[str, Any]] = None,
) -> Tuple[torch.Tensor, torch.Tensor]:
joint_attention_kwargs = joint_attention_kwargs or {}
# Modulation parameters shape: [1, 1, self.dim]
(shift_msa, scale_msa, gate_msa), (shift_mlp, scale_mlp, gate_mlp) = temb_mod_params_img
(c_shift_msa, c_scale_msa, c_gate_msa), (c_shift_mlp, c_scale_mlp, c_gate_mlp) = temb_mod_params_txt
# Img stream
norm_hidden_states = self.norm1(hidden_states)
norm_hidden_states = (1 + scale_msa) * norm_hidden_states + shift_msa
# Conditioning txt stream
norm_encoder_hidden_states = self.norm1_context(encoder_hidden_states)
norm_encoder_hidden_states = (1 + c_scale_msa) * norm_encoder_hidden_states + c_shift_msa
# Attention on concatenated img + txt stream
attention_outputs = self.attn(
hidden_states=norm_hidden_states,
encoder_hidden_states=norm_encoder_hidden_states,
image_rotary_emb=image_rotary_emb,
**joint_attention_kwargs,
)
attn_output, context_attn_output = attention_outputs
# Process attention outputs for the image stream (`hidden_states`).
attn_output = gate_msa * attn_output
hidden_states = hidden_states + attn_output
norm_hidden_states = self.norm2(hidden_states)
norm_hidden_states = norm_hidden_states * (1 + scale_mlp) + shift_mlp
ff_output = self.ff(norm_hidden_states)
hidden_states = hidden_states + gate_mlp * ff_output
# Process attention outputs for the text stream (`encoder_hidden_states`).
context_attn_output = c_gate_msa * context_attn_output
encoder_hidden_states = encoder_hidden_states + context_attn_output
norm_encoder_hidden_states = self.norm2_context(encoder_hidden_states)
norm_encoder_hidden_states = norm_encoder_hidden_states * (1 + c_scale_mlp) + c_shift_mlp
context_ff_output = self.ff_context(norm_encoder_hidden_states)
encoder_hidden_states = encoder_hidden_states + c_gate_mlp * context_ff_output
if encoder_hidden_states.dtype == torch.float16:
encoder_hidden_states = encoder_hidden_states.clip(-65504, 65504)
return encoder_hidden_states, hidden_states
class Flux2PosEmbed(nn.Module):
# modified from https://github.com/black-forest-labs/flux/blob/c00d7c60b085fce8058b9df845e036090873f2ce/src/flux/modules/layers.py#L11
def __init__(self, theta: int, axes_dim: List[int]):
super().__init__()
self.theta = theta
self.axes_dim = axes_dim
def forward(self, ids: torch.Tensor) -> torch.Tensor:
# Expected ids shape: [S, len(self.axes_dim)]
cos_out = []
sin_out = []
pos = ids.float()
is_mps = ids.device.type == "mps"
is_npu = ids.device.type == "npu"
freqs_dtype = torch.float32 if (is_mps or is_npu) else torch.float64
# Unlike Flux 1, loop over len(self.axes_dim) rather than ids.shape[-1]
for i in range(len(self.axes_dim)):
cos, sin = get_1d_rotary_pos_embed(
self.axes_dim[i],
pos[..., i],
theta=self.theta,
repeat_interleave_real=True,
use_real=True,
freqs_dtype=freqs_dtype,
)
cos_out.append(cos)
sin_out.append(sin)
freqs_cos = torch.cat(cos_out, dim=-1).to(ids.device)
freqs_sin = torch.cat(sin_out, dim=-1).to(ids.device)
return freqs_cos, freqs_sin
class Flux2TimestepGuidanceEmbeddings(nn.Module):
def __init__(self, in_channels: int = 256, embedding_dim: int = 6144, bias: bool = False):
super().__init__()
self.time_proj = Timesteps(num_channels=in_channels, flip_sin_to_cos=True, downscale_freq_shift=0)
self.timestep_embedder = TimestepEmbedding(
in_channels=in_channels, time_embed_dim=embedding_dim, sample_proj_bias=bias
)
self.guidance_embedder = TimestepEmbedding(
in_channels=in_channels, time_embed_dim=embedding_dim, sample_proj_bias=bias
)
def forward(self, timestep: torch.Tensor, guidance: torch.Tensor) -> torch.Tensor:
timesteps_proj = self.time_proj(timestep)
timesteps_emb = self.timestep_embedder(timesteps_proj.to(timestep.dtype)) # (N, D)
guidance_proj = self.time_proj(guidance)
guidance_emb = self.guidance_embedder(guidance_proj.to(guidance.dtype)) # (N, D)
time_guidance_emb = timesteps_emb + guidance_emb
return time_guidance_emb
class Flux2Modulation(nn.Module):
def __init__(self, dim: int, mod_param_sets: int = 2, bias: bool = False):
super().__init__()
self.mod_param_sets = mod_param_sets
self.linear = nn.Linear(dim, dim * 3 * self.mod_param_sets, bias=bias)
self.act_fn = nn.SiLU()
def forward(self, temb: torch.Tensor) -> Tuple[Tuple[torch.Tensor, torch.Tensor, torch.Tensor], ...]:
mod = self.act_fn(temb)
mod = self.linear(mod)
if mod.ndim == 2:
mod = mod.unsqueeze(1)
mod_params = torch.chunk(mod, 3 * self.mod_param_sets, dim=-1)
# Return tuple of 3-tuples of modulation params shift/scale/gate
return tuple(mod_params[3 * i : 3 * (i + 1)] for i in range(self.mod_param_sets))
class Flux2Transformer2DModel(
ModelMixin,
ConfigMixin,
PeftAdapterMixin,
FromOriginalModelMixin,
FluxTransformer2DLoadersMixin,
CacheMixin,
AttentionMixin,
):
"""
The Transformer model introduced in Flux 2.
Reference: https://blackforestlabs.ai/announcing-black-forest-labs/
Args:
patch_size (`int`, defaults to `1`):
Patch size to turn the input data into small patches.
in_channels (`int`, defaults to `128`):
The number of channels in the input.
out_channels (`int`, *optional*, defaults to `None`):
The number of channels in the output. If not specified, it defaults to `in_channels`.
num_layers (`int`, defaults to `8`):
The number of layers of dual stream DiT blocks to use.
num_single_layers (`int`, defaults to `48`):
The number of layers of single stream DiT blocks to use.
attention_head_dim (`int`, defaults to `128`):
The number of dimensions to use for each attention head.
num_attention_heads (`int`, defaults to `48`):
The number of attention heads to use.
joint_attention_dim (`int`, defaults to `15360`):
The number of dimensions to use for the joint attention (embedding/channel dimension of
`encoder_hidden_states`).
pooled_projection_dim (`int`, defaults to `768`):
The number of dimensions to use for the pooled projection.
guidance_embeds (`bool`, defaults to `True`):
Whether to use guidance embeddings for guidance-distilled variant of the model.
axes_dims_rope (`Tuple[int]`, defaults to `(32, 32, 32, 32)`):
The dimensions to use for the rotary positional embeddings.
"""
_supports_gradient_checkpointing = True
_no_split_modules = ["Flux2TransformerBlock", "Flux2SingleTransformerBlock"]
_skip_layerwise_casting_patterns = ["pos_embed", "norm"]
_repeated_blocks = ["Flux2TransformerBlock", "Flux2SingleTransformerBlock"]
_cp_plan = {
"": {
"hidden_states": ContextParallelInput(split_dim=1, expected_dims=3, split_output=False),
"encoder_hidden_states": ContextParallelInput(split_dim=1, expected_dims=3, split_output=False),
"img_ids": ContextParallelInput(split_dim=0, expected_dims=2, split_output=False),
"txt_ids": ContextParallelInput(split_dim=0, expected_dims=2, split_output=False),
},
"proj_out": ContextParallelOutput(gather_dim=1, expected_dims=3),
}
@register_to_config
def __init__(
self,
patch_size: int = 1,
in_channels: int = 128,
out_channels: Optional[int] = None,
num_layers: int = 8,
num_single_layers: int = 48,
attention_head_dim: int = 128,
num_attention_heads: int = 48,
joint_attention_dim: int = 15360,
timestep_guidance_channels: int = 256,
mlp_ratio: float = 3.0,
axes_dims_rope: Tuple[int, ...] = (32, 32, 32, 32),
rope_theta: int = 2000,
eps: float = 1e-6,
):
super().__init__()
self.out_channels = out_channels or in_channels
self.inner_dim = num_attention_heads * attention_head_dim
# 1. Sinusoidal positional embedding for RoPE on image and text tokens
self.pos_embed = Flux2PosEmbed(theta=rope_theta, axes_dim=axes_dims_rope)
# 2. Combined timestep + guidance embedding
self.time_guidance_embed = Flux2TimestepGuidanceEmbeddings(
in_channels=timestep_guidance_channels, embedding_dim=self.inner_dim, bias=False
)
# 3. Modulation (double stream and single stream blocks share modulation parameters, resp.)
# Two sets of shift/scale/gate modulation parameters for the double stream attn and FF sub-blocks
self.double_stream_modulation_img = Flux2Modulation(self.inner_dim, mod_param_sets=2, bias=False)
self.double_stream_modulation_txt = Flux2Modulation(self.inner_dim, mod_param_sets=2, bias=False)
# Only one set of modulation parameters as the attn and FF sub-blocks are run in parallel for single stream
self.single_stream_modulation = Flux2Modulation(self.inner_dim, mod_param_sets=1, bias=False)
# 4. Input projections
self.x_embedder = nn.Linear(in_channels, self.inner_dim, bias=False)
self.context_embedder = nn.Linear(joint_attention_dim, self.inner_dim, bias=False)
# 5. Double Stream Transformer Blocks
self.transformer_blocks = nn.ModuleList(
[
Flux2TransformerBlock(
dim=self.inner_dim,
num_attention_heads=num_attention_heads,
attention_head_dim=attention_head_dim,
mlp_ratio=mlp_ratio,
eps=eps,
bias=False,
)
for _ in range(num_layers)
]
)
# 6. Single Stream Transformer Blocks
self.single_transformer_blocks = nn.ModuleList(
[
Flux2SingleTransformerBlock(
dim=self.inner_dim,
num_attention_heads=num_attention_heads,
attention_head_dim=attention_head_dim,
mlp_ratio=mlp_ratio,
eps=eps,
bias=False,
)
for _ in range(num_single_layers)
]
)
# 7. Output layers
self.norm_out = AdaLayerNormContinuous(
self.inner_dim, self.inner_dim, elementwise_affine=False, eps=eps, bias=False
)
self.proj_out = nn.Linear(self.inner_dim, patch_size * patch_size * self.out_channels, bias=False)
self.gradient_checkpointing = False
def forward(
self,
hidden_states: torch.Tensor,
encoder_hidden_states: torch.Tensor = None,
timestep: torch.LongTensor = None,
img_ids: torch.Tensor = None,
txt_ids: torch.Tensor = None,
guidance: torch.Tensor = None,
joint_attention_kwargs: Optional[Dict[str, Any]] = None,
return_dict: bool = True,
) -> Union[torch.Tensor, Transformer2DModelOutput]:
"""
The [`FluxTransformer2DModel`] forward method.
Args:
hidden_states (`torch.Tensor` of shape `(batch_size, image_sequence_length, in_channels)`):
Input `hidden_states`.
encoder_hidden_states (`torch.Tensor` of shape `(batch_size, text_sequence_length, joint_attention_dim)`):
Conditional embeddings (embeddings computed from the input conditions such as prompts) to use.
timestep ( `torch.LongTensor`):
Used to indicate denoising step.
block_controlnet_hidden_states: (`list` of `torch.Tensor`):
A list of tensors that if specified are added to the residuals of transformer blocks.
joint_attention_kwargs (`dict`, *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).
return_dict (`bool`, *optional*, defaults to `True`):
Whether or not to return a [`~models.transformer_2d.Transformer2DModelOutput`] 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.
"""
# 0. Handle input arguments
if joint_attention_kwargs is not None:
joint_attention_kwargs = joint_attention_kwargs.copy()
lora_scale = joint_attention_kwargs.pop("scale", 1.0)
else:
lora_scale = 1.0
if USE_PEFT_BACKEND:
# weight the lora layers by setting `lora_scale` for each PEFT layer
scale_lora_layers(self, lora_scale)
else:
if joint_attention_kwargs is not None and joint_attention_kwargs.get("scale", None) is not None:
logger.warning(
"Passing `scale` via `joint_attention_kwargs` when not using the PEFT backend is ineffective."
)
num_txt_tokens = encoder_hidden_states.shape[1]
# 1. Calculate timestep embedding and modulation parameters
timestep = timestep.to(hidden_states.dtype) * 1000
guidance = guidance.to(hidden_states.dtype) * 1000
temb = self.time_guidance_embed(timestep, guidance)
double_stream_mod_img = self.double_stream_modulation_img(temb)
double_stream_mod_txt = self.double_stream_modulation_txt(temb)
single_stream_mod = self.single_stream_modulation(temb)[0]
# 2. Input projection for image (hidden_states) and conditioning text (encoder_hidden_states)
hidden_states = self.x_embedder(hidden_states)
encoder_hidden_states = self.context_embedder(encoder_hidden_states)
# 3. Calculate RoPE embeddings from image and text tokens
# NOTE: the below logic means that we can't support batched inference with images of different resolutions or
# text prompts of differents lengths. Is this a use case we want to support?
if img_ids.ndim == 3:
img_ids = img_ids[0]
if txt_ids.ndim == 3:
txt_ids = txt_ids[0]
if is_torch_npu_available():
freqs_cos_image, freqs_sin_image = self.pos_embed(img_ids.cpu())
image_rotary_emb = (freqs_cos_image.npu(), freqs_sin_image.npu())
freqs_cos_text, freqs_sin_text = self.pos_embed(txt_ids.cpu())
text_rotary_emb = (freqs_cos_text.npu(), freqs_sin_text.npu())
else:
image_rotary_emb = self.pos_embed(img_ids)
text_rotary_emb = self.pos_embed(txt_ids)
concat_rotary_emb = (
torch.cat([text_rotary_emb[0], image_rotary_emb[0]], dim=0),
torch.cat([text_rotary_emb[1], image_rotary_emb[1]], dim=0),
)
# 4. Double Stream Transformer Blocks
for index_block, block in enumerate(self.transformer_blocks):
if torch.is_grad_enabled() and self.gradient_checkpointing:
encoder_hidden_states, hidden_states = self._gradient_checkpointing_func(
block,
hidden_states,
encoder_hidden_states,
double_stream_mod_img,
double_stream_mod_txt,
concat_rotary_emb,
joint_attention_kwargs,
)
else:
encoder_hidden_states, hidden_states = block(
hidden_states=hidden_states,
encoder_hidden_states=encoder_hidden_states,
temb_mod_params_img=double_stream_mod_img,
temb_mod_params_txt=double_stream_mod_txt,
image_rotary_emb=concat_rotary_emb,
joint_attention_kwargs=joint_attention_kwargs,
)
# Concatenate text and image streams for single-block inference
hidden_states = torch.cat([encoder_hidden_states, hidden_states], dim=1)
# 5. Single Stream Transformer Blocks
for index_block, block in enumerate(self.single_transformer_blocks):
if torch.is_grad_enabled() and self.gradient_checkpointing:
hidden_states = self._gradient_checkpointing_func(
block,
hidden_states,
None,
single_stream_mod,
concat_rotary_emb,
joint_attention_kwargs,
)
else:
hidden_states = block(
hidden_states=hidden_states,
encoder_hidden_states=None,
temb_mod_params=single_stream_mod,
image_rotary_emb=concat_rotary_emb,
joint_attention_kwargs=joint_attention_kwargs,
)
# Remove text tokens from concatenated stream
hidden_states = hidden_states[:, num_txt_tokens:, ...]
# 6. Output layers
hidden_states = self.norm_out(hidden_states, temb)
output = self.proj_out(hidden_states)
if USE_PEFT_BACKEND:
# remove `lora_scale` from each PEFT layer
unscale_lora_layers(self, lora_scale)
if not return_dict:
return (output,)
return Transformer2DModelOutput(sample=output)

View File

@@ -129,6 +129,7 @@ else:
]
_import_structure["bria"] = ["BriaPipeline"]
_import_structure["bria_fibo"] = ["BriaFiboPipeline"]
_import_structure["flux2"] = ["Flux2Pipeline"]
_import_structure["flux"] = [
"FluxControlPipeline",
"FluxControlInpaintPipeline",
@@ -655,6 +656,7 @@ if TYPE_CHECKING or DIFFUSERS_SLOW_IMPORT:
FluxPriorReduxPipeline,
ReduxImageEncoder,
)
from .flux2 import Flux2Pipeline
from .hidream_image import HiDreamImagePipeline
from .hunyuan_image import HunyuanImagePipeline, HunyuanImageRefinerPipeline
from .hunyuan_video import (

View File

@@ -0,0 +1,47 @@
from typing import TYPE_CHECKING
from ...utils import (
DIFFUSERS_SLOW_IMPORT,
OptionalDependencyNotAvailable,
_LazyModule,
get_objects_from_module,
is_torch_available,
is_transformers_available,
)
_dummy_objects = {}
_additional_imports = {}
_import_structure = {"pipeline_output": ["Flux2PipelineOutput"]}
try:
if not (is_transformers_available() and is_torch_available()):
raise OptionalDependencyNotAvailable()
except OptionalDependencyNotAvailable:
from ...utils import dummy_torch_and_transformers_objects # noqa F403
_dummy_objects.update(get_objects_from_module(dummy_torch_and_transformers_objects))
else:
_import_structure["pipeline_flux2"] = ["Flux2Pipeline"]
if TYPE_CHECKING or DIFFUSERS_SLOW_IMPORT:
try:
if not (is_transformers_available() and is_torch_available()):
raise OptionalDependencyNotAvailable()
except OptionalDependencyNotAvailable:
from ...utils.dummy_torch_and_transformers_objects import * # noqa F403
else:
from .pipeline_flux2 import Flux2Pipeline
else:
import sys
sys.modules[__name__] = _LazyModule(
__name__,
globals()["__file__"],
_import_structure,
module_spec=__spec__,
)
for name, value in _dummy_objects.items():
setattr(sys.modules[__name__], name, value)
for name, value in _additional_imports.items():
setattr(sys.modules[__name__], name, value)

View File

@@ -0,0 +1,138 @@
# Copyright 2025 The Black Forest Labs Team and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
from typing import Tuple
import PIL.Image
from ...configuration_utils import register_to_config
from ...image_processor import VaeImageProcessor
class Flux2ImageProcessor(VaeImageProcessor):
r"""
Image processor to preprocess the reference (character) image for the Flux2 model.
Args:
do_resize (`bool`, *optional*, defaults to `True`):
Whether to downscale the image's (height, width) dimensions to multiples of `vae_scale_factor`. Can accept
`height` and `width` arguments from [`image_processor.VaeImageProcessor.preprocess`] method.
vae_scale_factor (`int`, *optional*, defaults to `16`):
VAE (spatial) scale factor. If `do_resize` is `True`, the image is automatically resized to multiples of
this factor.
vae_latent_channels (`int`, *optional*, defaults to `32`):
VAE latent channels.
do_normalize (`bool`, *optional*, defaults to `True`):
Whether to normalize the image to [-1,1].
do_convert_rgb (`bool`, *optional*, defaults to be `True`):
Whether to convert the images to RGB format.
"""
@register_to_config
def __init__(
self,
do_resize: bool = True,
vae_scale_factor: int = 16,
vae_latent_channels: int = 32,
do_normalize: bool = True,
do_convert_rgb: bool = True,
):
super().__init__(
do_resize=do_resize,
vae_scale_factor=vae_scale_factor,
vae_latent_channels=vae_latent_channels,
do_normalize=do_normalize,
do_convert_rgb=do_convert_rgb,
)
@staticmethod
def check_image_input(
image: PIL.Image.Image, max_aspect_ratio: int = 8, min_side_length: int = 64, max_area: int = 1024 * 1024
) -> PIL.Image.Image:
"""
Check if image meets minimum size and aspect ratio requirements.
Args:
image: PIL Image to validate
max_aspect_ratio: Maximum allowed aspect ratio (width/height or height/width)
min_side_length: Minimum pixels required for width and height
max_area: Maximum allowed area in pixels²
Returns:
The input image if valid
Raises:
ValueError: If image is too small or aspect ratio is too extreme
"""
if not isinstance(image, PIL.Image.Image):
raise ValueError(f"Image must be a PIL.Image.Image, got {type(image)}")
width, height = image.size
# Check minimum dimensions
if width < min_side_length or height < min_side_length:
raise ValueError(
f"Image too small: {width}×{height}. Both dimensions must be at least {min_side_length}px"
)
# Check aspect ratio
aspect_ratio = max(width / height, height / width)
if aspect_ratio > max_aspect_ratio:
raise ValueError(
f"Aspect ratio too extreme: {width}×{height} (ratio: {aspect_ratio:.1f}:1). "
f"Maximum allowed ratio is {max_aspect_ratio}:1"
)
return image
@staticmethod
def _resize_to_target_area(image: PIL.Image.Image, target_area: int = 1024 * 1024) -> Tuple[int, int]:
image_width, image_height = image.size
scale = math.sqrt(target_area / (image_width * image_height))
width = int(image_width * scale)
height = int(image_height * scale)
return image.resize((width, height), PIL.Image.Resampling.LANCZOS)
def _resize_and_crop(
self,
image: PIL.Image.Image,
width: int,
height: int,
) -> PIL.Image.Image:
r"""
center crop the image to the specified width and height.
Args:
image (`PIL.Image.Image`):
The image to resize and crop.
width (`int`):
The width to resize the image to.
height (`int`):
The height to resize the image to.
Returns:
`PIL.Image.Image`:
The resized and cropped image.
"""
image_width, image_height = image.size
left = (image_width - width) // 2
top = (image_height - height) // 2
right = left + width
bottom = top + height
return image.crop((left, top, right, bottom))

View File

@@ -0,0 +1,883 @@
# Copyright 2025 Black Forest Labs and The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import inspect
from typing import Any, Callable, Dict, List, Optional, Tuple, Union
import numpy as np
import PIL
import torch
from transformers import AutoProcessor, Mistral3ForConditionalGeneration
from ...loaders import Flux2LoraLoaderMixin
from ...models import AutoencoderKLFlux2, Flux2Transformer2DModel
from ...schedulers import FlowMatchEulerDiscreteScheduler
from ...utils import is_torch_xla_available, logging, replace_example_docstring
from ...utils.torch_utils import randn_tensor
from ..pipeline_utils import DiffusionPipeline
from .image_processor import Flux2ImageProcessor
from .pipeline_output import Flux2PipelineOutput
if is_torch_xla_available():
import torch_xla.core.xla_model as xm
XLA_AVAILABLE = True
else:
XLA_AVAILABLE = False
logger = logging.get_logger(__name__) # pylint: disable=invalid-name
EXAMPLE_DOC_STRING = """
Examples:
```py
>>> import torch
>>> from diffusers import Flux2Pipeline
>>> pipe = Flux2Pipeline.from_pretrained("black-forest-labs/FLUX.2-dev", torch_dtype=torch.bfloat16)
>>> pipe.to("cuda")
>>> prompt = "A cat holding a sign that says hello world"
>>> # Depending on the variant being used, the pipeline call will slightly vary.
>>> # Refer to the pipeline documentation for more details.
>>> image = pipe(prompt, num_inference_steps=50, guidance_scale=2.5).images[0]
>>> image.save("flux.png")
```
"""
def format_text_input(prompts: List[str], system_message: str = None):
# Remove [IMG] tokens from prompts to avoid Pixtral validation issues
# when truncation is enabled. The processor counts [IMG] tokens and fails
# if the count changes after truncation.
cleaned_txt = [prompt.replace("[IMG]", "") for prompt in prompts]
return [
[
{
"role": "system",
"content": [{"type": "text", "text": system_message}],
},
{"role": "user", "content": [{"type": "text", "text": prompt}]},
]
for prompt in cleaned_txt
]
def compute_empirical_mu(image_seq_len: int, num_steps: int) -> float:
a1, b1 = 8.73809524e-05, 1.89833333
a2, b2 = 0.00016927, 0.45666666
if image_seq_len > 4300:
mu = a2 * image_seq_len + b2
return float(mu)
m_200 = a2 * image_seq_len + b2
m_10 = a1 * image_seq_len + b1
a = (m_200 - m_10) / 190.0
b = m_200 - 200.0 * a
mu = a * num_steps + b
return float(mu)
# 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,
sigmas: Optional[List[float]] = None,
**kwargs,
):
r"""
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 override the timestep spacing strategy of the scheduler. If `timesteps` is passed,
`num_inference_steps` and `sigmas` must be `None`.
sigmas (`List[float]`, *optional*):
Custom sigmas used to override the timestep spacing strategy of the scheduler. If `sigmas` is passed,
`num_inference_steps` and `timesteps` 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 and sigmas is not None:
raise ValueError("Only one of `timesteps` or `sigmas` can be passed. Please choose one to set custom values")
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)
elif sigmas is not None:
accept_sigmas = "sigmas" in set(inspect.signature(scheduler.set_timesteps).parameters.keys())
if not accept_sigmas:
raise ValueError(
f"The current scheduler class {scheduler.__class__}'s `set_timesteps` does not support custom"
f" sigmas schedules. Please check whether you are using the correct scheduler."
)
scheduler.set_timesteps(sigmas=sigmas, 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
# Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion_img2img.retrieve_latents
def retrieve_latents(
encoder_output: torch.Tensor, generator: Optional[torch.Generator] = None, sample_mode: str = "sample"
):
if hasattr(encoder_output, "latent_dist") and sample_mode == "sample":
return encoder_output.latent_dist.sample(generator)
elif hasattr(encoder_output, "latent_dist") and sample_mode == "argmax":
return encoder_output.latent_dist.mode()
elif hasattr(encoder_output, "latents"):
return encoder_output.latents
else:
raise AttributeError("Could not access latents of provided encoder_output")
class Flux2Pipeline(DiffusionPipeline, Flux2LoraLoaderMixin):
r"""
The Flux2 pipeline for text-to-image generation.
Reference: [https://bfl.ai/blog/flux-2](https://bfl.ai/blog/flux-2)
Args:
transformer ([`Flux2Transformer2DModel`]):
Conditional Transformer (MMDiT) architecture to denoise the encoded image latents.
scheduler ([`FlowMatchEulerDiscreteScheduler`]):
A scheduler to be used in combination with `transformer` to denoise the encoded image latents.
vae ([`AutoencoderKLFlux2`]):
Variational Auto-Encoder (VAE) Model to encode and decode images to and from latent representations.
text_encoder ([`Mistral3ForConditionalGeneration`]):
[Mistral3ForConditionalGeneration](https://huggingface.co/docs/transformers/en/model_doc/mistral3#transformers.Mistral3ForConditionalGeneration)
tokenizer (`AutoProcessor`):
Tokenizer of class
[PixtralProcessor](https://huggingface.co/docs/transformers/en/model_doc/pixtral#transformers.PixtralProcessor).
"""
model_cpu_offload_seq = "text_encoder->transformer->vae"
_callback_tensor_inputs = ["latents", "prompt_embeds"]
def __init__(
self,
scheduler: FlowMatchEulerDiscreteScheduler,
vae: AutoencoderKLFlux2,
text_encoder: Mistral3ForConditionalGeneration,
tokenizer: AutoProcessor,
transformer: Flux2Transformer2DModel,
):
super().__init__()
self.register_modules(
vae=vae,
text_encoder=text_encoder,
tokenizer=tokenizer,
scheduler=scheduler,
transformer=transformer,
)
self.vae_scale_factor = 2 ** (len(self.vae.config.block_out_channels) - 1) if getattr(self, "vae", None) else 8
# Flux latents are turned into 2x2 patches and packed. This means the latent width and height has to be divisible
# by the patch size. So the vae scale factor is multiplied by the patch size to account for this
self.image_processor = Flux2ImageProcessor(vae_scale_factor=self.vae_scale_factor * 2)
self.tokenizer_max_length = 512
self.default_sample_size = 128
# fmt: off
self.system_message = "You are an AI that reasons about image descriptions. You give structured responses focusing on object relationships, object attribution and actions without speculation."
# fmt: on
@staticmethod
def _get_mistral_3_small_prompt_embeds(
text_encoder: Mistral3ForConditionalGeneration,
tokenizer: AutoProcessor,
prompt: Union[str, List[str]],
dtype: Optional[torch.dtype] = None,
device: Optional[torch.device] = None,
max_sequence_length: int = 512,
# fmt: off
system_message: str = "You are an AI that reasons about image descriptions. You give structured responses focusing on object relationships, object attribution and actions without speculation.",
# fmt: on
hidden_states_layers: List[int] = (10, 20, 30),
):
dtype = text_encoder.dtype if dtype is None else dtype
device = text_encoder.device if device is None else device
prompt = [prompt] if isinstance(prompt, str) else prompt
# Format input messages
messages_batch = format_text_input(prompts=prompt, system_message=system_message)
# Process all messages at once
inputs = tokenizer.apply_chat_template(
messages_batch,
add_generation_prompt=False,
tokenize=True,
return_dict=True,
return_tensors="pt",
padding="max_length",
truncation=True,
max_length=max_sequence_length,
)
# Move to device
input_ids = inputs["input_ids"].to(device)
attention_mask = inputs["attention_mask"].to(device)
# Forward pass through the model
output = text_encoder(
input_ids=input_ids,
attention_mask=attention_mask,
output_hidden_states=True,
use_cache=False,
)
# Only use outputs from intermediate layers and stack them
out = torch.stack([output.hidden_states[k] for k in hidden_states_layers], dim=1)
out = out.to(dtype=dtype, device=device)
batch_size, num_channels, seq_len, hidden_dim = out.shape
prompt_embeds = out.permute(0, 2, 1, 3).reshape(batch_size, seq_len, num_channels * hidden_dim)
return prompt_embeds
@staticmethod
def _prepare_text_ids(
x: torch.Tensor, # (B, L, D) or (L, D)
t_coord: Optional[torch.Tensor] = None,
):
B, L, _ = x.shape
out_ids = []
for i in range(B):
t = torch.arange(1) if t_coord is None else t_coord[i]
h = torch.arange(1)
w = torch.arange(1)
l = torch.arange(L)
coords = torch.cartesian_prod(t, h, w, l)
out_ids.append(coords)
return torch.stack(out_ids)
@staticmethod
def _prepare_latent_ids(
latents: torch.Tensor, # (B, C, H, W)
):
r"""
Generates 4D position coordinates (T, H, W, L) for latent tensors.
Args:
latents (torch.Tensor):
Latent tensor of shape (B, C, H, W)
Returns:
torch.Tensor:
Position IDs tensor of shape (B, H*W, 4) All batches share the same coordinate structure: T=0,
H=[0..H-1], W=[0..W-1], L=0
"""
batch_size, _, height, width = latents.shape
t = torch.arange(1) # [0] - time dimension
h = torch.arange(height)
w = torch.arange(width)
l = torch.arange(1) # [0] - layer dimension
# Create position IDs: (H*W, 4)
latent_ids = torch.cartesian_prod(t, h, w, l)
# Expand to batch: (B, H*W, 4)
latent_ids = latent_ids.unsqueeze(0).expand(batch_size, -1, -1)
return latent_ids
@staticmethod
def _prepare_image_ids(
image_latents: List[torch.Tensor], # [(1, C, H, W), (1, C, H, W), ...]
scale: int = 10,
):
r"""
Generates 4D time-space coordinates (T, H, W, L) for a sequence of image latents.
This function creates a unique coordinate for every pixel/patch across all input latent with different
dimensions.
Args:
image_latents (List[torch.Tensor]):
A list of image latent feature tensors, typically of shape (C, H, W).
scale (int, optional):
A factor used to define the time separation (T-coordinate) between latents. T-coordinate for the i-th
latent is: 'scale + scale * i'. Defaults to 10.
Returns:
torch.Tensor:
The combined coordinate tensor. Shape: (1, N_total, 4) Where N_total is the sum of (H * W) for all
input latents.
Coordinate Components (Dimension 4):
- T (Time): The unique index indicating which latent image the coordinate belongs to.
- H (Height): The row index within that latent image.
- W (Width): The column index within that latent image.
- L (Seq. Length): A sequence length dimension, which is always fixed at 0 (size 1)
"""
if not isinstance(image_latents, list):
raise ValueError(f"Expected `image_latents` to be a list, got {type(image_latents)}.")
# create time offset for each reference image
t_coords = [scale + scale * t for t in torch.arange(0, len(image_latents))]
t_coords = [t.view(-1) for t in t_coords]
image_latent_ids = []
for x, t in zip(image_latents, t_coords):
x = x.squeeze(0)
_, height, width = x.shape
x_ids = torch.cartesian_prod(t, torch.arange(height), torch.arange(width), torch.arange(1))
image_latent_ids.append(x_ids)
image_latent_ids = torch.cat(image_latent_ids, dim=0)
image_latent_ids = image_latent_ids.unsqueeze(0)
return image_latent_ids
@staticmethod
def _patchify_latents(latents):
batch_size, num_channels_latents, height, width = latents.shape
latents = latents.view(batch_size, num_channels_latents, height // 2, 2, width // 2, 2)
latents = latents.permute(0, 1, 3, 5, 2, 4)
latents = latents.reshape(batch_size, num_channels_latents * 4, height // 2, width // 2)
return latents
@staticmethod
def _unpatchify_latents(latents):
batch_size, num_channels_latents, height, width = latents.shape
latents = latents.reshape(batch_size, num_channels_latents // (2 * 2), 2, 2, height, width)
latents = latents.permute(0, 1, 4, 2, 5, 3)
latents = latents.reshape(batch_size, num_channels_latents // (2 * 2), height * 2, width * 2)
return latents
@staticmethod
def _pack_latents(latents):
"""
pack latents: (batch_size, num_channels, height, width) -> (batch_size, height * width, num_channels)
"""
batch_size, num_channels, height, width = latents.shape
latents = latents.reshape(batch_size, num_channels, height * width).permute(0, 2, 1)
return latents
@staticmethod
def _unpack_latents_with_ids(x: torch.Tensor, x_ids: torch.Tensor) -> list[torch.Tensor]:
"""
using position ids to scatter tokens into place
"""
x_list = []
for data, pos in zip(x, x_ids):
_, ch = data.shape # noqa: F841
h_ids = pos[:, 1].to(torch.int64)
w_ids = pos[:, 2].to(torch.int64)
h = torch.max(h_ids) + 1
w = torch.max(w_ids) + 1
flat_ids = h_ids * w + w_ids
out = torch.zeros((h * w, ch), device=data.device, dtype=data.dtype)
out.scatter_(0, flat_ids.unsqueeze(1).expand(-1, ch), data)
# reshape from (H * W, C) to (H, W, C) and permute to (C, H, W)
out = out.view(h, w, ch).permute(2, 0, 1)
x_list.append(out)
return torch.stack(x_list, dim=0)
def encode_prompt(
self,
prompt: Union[str, List[str]],
device: Optional[torch.device] = None,
num_images_per_prompt: int = 1,
prompt_embeds: Optional[torch.Tensor] = None,
max_sequence_length: int = 512,
text_encoder_out_layers: Tuple[int] = (10, 20, 30),
):
device = device or self._execution_device
if prompt is None:
prompt = ""
prompt = [prompt] if isinstance(prompt, str) else prompt
if prompt_embeds is None:
prompt_embeds = self._get_mistral_3_small_prompt_embeds(
text_encoder=self.text_encoder,
tokenizer=self.tokenizer,
prompt=prompt,
device=device,
max_sequence_length=max_sequence_length,
system_message=self.system_message,
hidden_states_layers=text_encoder_out_layers,
)
batch_size, seq_len, _ = prompt_embeds.shape
prompt_embeds = prompt_embeds.repeat(1, num_images_per_prompt, 1)
prompt_embeds = prompt_embeds.view(batch_size * num_images_per_prompt, seq_len, -1)
text_ids = self._prepare_text_ids(prompt_embeds)
text_ids = text_ids.to(device)
return prompt_embeds, text_ids
def _encode_vae_image(self, image: torch.Tensor, generator: torch.Generator):
if image.ndim != 4:
raise ValueError(f"Expected image dims 4, got {image.ndim}.")
image_latents = retrieve_latents(self.vae.encode(image), generator=generator, sample_mode="argmax")
image_latents = self._patchify_latents(image_latents)
latents_bn_mean = self.vae.bn.running_mean.view(1, -1, 1, 1).to(image_latents.device, image_latents.dtype)
latents_bn_std = torch.sqrt(self.vae.bn.running_var.view(1, -1, 1, 1) + self.vae.config.batch_norm_eps)
image_latents = (image_latents - latents_bn_mean) / latents_bn_std
return image_latents
def prepare_latents(
self,
batch_size,
num_latents_channels,
height,
width,
dtype,
device,
generator: torch.Generator,
latents: Optional[torch.Tensor] = None,
):
# VAE applies 8x compression on images but we must also account for packing which requires
# latent height and width to be divisible by 2.
height = 2 * (int(height) // (self.vae_scale_factor * 2))
width = 2 * (int(width) // (self.vae_scale_factor * 2))
shape = (batch_size, num_latents_channels * 4, height // 2, width // 2)
if isinstance(generator, list) and len(generator) != batch_size:
raise ValueError(
f"You have passed a list of generators of length {len(generator)}, but requested an effective batch"
f" size of {batch_size}. Make sure the batch size matches the length of the generators."
)
if latents is None:
latents = randn_tensor(shape, generator=generator, device=device, dtype=dtype)
else:
latents = latents.to(device=device, dtype=dtype)
latent_ids = self._prepare_latent_ids(latents)
latent_ids = latent_ids.to(device)
latents = self._pack_latents(latents) # [B, C, H, W] -> [B, H*W, C]
return latents, latent_ids
def prepare_image_latents(
self,
images: List[torch.Tensor],
batch_size,
generator: torch.Generator,
device,
dtype,
):
image_latents = []
for image in images:
image = image.to(device=device, dtype=dtype)
imagge_latent = self._encode_vae_image(image=image, generator=generator)
image_latents.append(imagge_latent) # (1, 128, 32, 32)
image_latent_ids = self._prepare_image_ids(image_latents)
# Pack each latent and concatenate
packed_latents = []
for latent in image_latents:
# latent: (1, 128, 32, 32)
packed = self._pack_latents(latent) # (1, 1024, 128)
packed = packed.squeeze(0) # (1024, 128) - remove batch dim
packed_latents.append(packed)
# Concatenate all reference tokens along sequence dimension
image_latents = torch.cat(packed_latents, dim=0) # (N*1024, 128)
image_latents = image_latents.unsqueeze(0) # (1, N*1024, 128)
image_latents = image_latents.repeat(batch_size, 1, 1)
image_latent_ids = image_latent_ids.repeat(batch_size, 1, 1)
image_latent_ids = image_latent_ids.to(device)
return image_latents, image_latent_ids
def check_inputs(
self,
prompt,
height,
width,
prompt_embeds=None,
callback_on_step_end_tensor_inputs=None,
):
if (
height is not None
and height % (self.vae_scale_factor * 2) != 0
or width is not None
and width % (self.vae_scale_factor * 2) != 0
):
logger.warning(
f"`height` and `width` have to be divisible by {self.vae_scale_factor * 2} but are {height} and {width}. Dimensions will be resized accordingly"
)
if callback_on_step_end_tensor_inputs is not None and not all(
k in self._callback_tensor_inputs for k in callback_on_step_end_tensor_inputs
):
raise ValueError(
f"`callback_on_step_end_tensor_inputs` has to be in {self._callback_tensor_inputs}, but found {[k for k in callback_on_step_end_tensor_inputs if k not in self._callback_tensor_inputs]}"
)
if prompt is not None and prompt_embeds is not None:
raise ValueError(
f"Cannot forward both `prompt`: {prompt} and `prompt_embeds`: {prompt_embeds}. Please make sure to"
" only forward one of the two."
)
elif prompt is None and prompt_embeds is None:
raise ValueError(
"Provide either `prompt` or `prompt_embeds`. Cannot leave both `prompt` and `prompt_embeds` undefined."
)
elif prompt is not None and (not isinstance(prompt, str) and not isinstance(prompt, list)):
raise ValueError(f"`prompt` has to be of type `str` or `list` but is {type(prompt)}")
@property
def guidance_scale(self):
return self._guidance_scale
@property
def joint_attention_kwargs(self):
return self._joint_attention_kwargs
@property
def num_timesteps(self):
return self._num_timesteps
@property
def current_timestep(self):
return self._current_timestep
@property
def interrupt(self):
return self._interrupt
@torch.no_grad()
@replace_example_docstring(EXAMPLE_DOC_STRING)
def __call__(
self,
image: Optional[Union[List[PIL.Image.Image], PIL.Image.Image]] = None,
prompt: Union[str, List[str]] = None,
height: Optional[int] = None,
width: Optional[int] = None,
num_inference_steps: int = 50,
sigmas: Optional[List[float]] = None,
guidance_scale: Optional[float] = 4.0,
num_images_per_prompt: int = 1,
generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None,
latents: Optional[torch.Tensor] = None,
prompt_embeds: Optional[torch.Tensor] = None,
output_type: Optional[str] = "pil",
return_dict: bool = True,
attention_kwargs: Optional[Dict[str, Any]] = None,
callback_on_step_end: Optional[Callable[[int, int, Dict], None]] = None,
callback_on_step_end_tensor_inputs: List[str] = ["latents"],
max_sequence_length: int = 512,
text_encoder_out_layers: Tuple[int] = (10, 20, 30),
):
r"""
Function invoked when calling the pipeline for generation.
Args:
image (`torch.Tensor`, `PIL.Image.Image`, `np.ndarray`, `List[torch.Tensor]`, `List[PIL.Image.Image]`, or `List[np.ndarray]`):
`Image`, numpy array or tensor representing an image batch to be used as the starting point. For both
numpy array and pytorch tensor, the expected value range is between `[0, 1]` If it's a tensor or a list
or tensors, the expected shape should be `(B, C, H, W)` or `(C, H, W)`. If it is a numpy array or a
list of arrays, the expected shape should be `(B, H, W, C)` or `(H, W, C)` It can also accept image
latents as `image`, but if passing latents directly it is not encoded again.
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.
guidance_scale (`float`, *optional*, defaults to 1.0):
Guidance scale as defined in [Classifier-Free Diffusion
Guidance](https://huggingface.co/papers/2207.12598). `guidance_scale` is defined as `w` of equation 2.
of [Imagen Paper](https://huggingface.co/papers/2205.11487). 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.
height (`int`, *optional*, defaults to self.unet.config.sample_size * self.vae_scale_factor):
The height in pixels of the generated image. This is set to 1024 by default for the best results.
width (`int`, *optional*, defaults to self.unet.config.sample_size * self.vae_scale_factor):
The width in pixels of the generated image. This is set to 1024 by default for the best results.
num_inference_steps (`int`, *optional*, defaults to 50):
The number of denoising steps. More denoising steps usually lead to a higher quality image at the
expense of slower inference.
sigmas (`List[float]`, *optional*):
Custom sigmas to use for the denoising process with schedulers which support a `sigmas` argument in
their `set_timesteps` method. If not defined, the default behavior when `num_inference_steps` is passed
will be used.
num_images_per_prompt (`int`, *optional*, defaults to 1):
The number of images to generate per prompt.
generator (`torch.Generator` or `List[torch.Generator]`, *optional*):
One or a list of [torch generator(s)](https://pytorch.org/docs/stable/generated/torch.Generator.html)
to make generation deterministic.
latents (`torch.Tensor`, *optional*):
Pre-generated noisy latents, sampled from a Gaussian distribution, to be used as inputs for image
generation. Can be used to tweak the same generation with different prompts. If not provided, a latents
tensor will be generated by sampling using the supplied random `generator`.
prompt_embeds (`torch.Tensor`, *optional*):
Pre-generated text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting. If not
provided, text embeddings will be generated from `prompt` input argument.
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.qwenimage.QwenImagePipelineOutput`] instead of a plain tuple.
attention_kwargs (`dict`, *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).
callback_on_step_end (`Callable`, *optional*):
A function that calls at the end of each denoising steps during the inference. The function is called
with the following arguments: `callback_on_step_end(self: DiffusionPipeline, step: int, timestep: int,
callback_kwargs: Dict)`. `callback_kwargs` will include a list of all tensors as specified by
`callback_on_step_end_tensor_inputs`.
callback_on_step_end_tensor_inputs (`List`, *optional*):
The list of tensor inputs for the `callback_on_step_end` function. The tensors specified in the list
will be passed as `callback_kwargs` argument. You will only be able to include variables listed in the
`._callback_tensor_inputs` attribute of your pipeline class.
max_sequence_length (`int` defaults to 512): Maximum sequence length to use with the `prompt`.
text_encoder_out_layers (`Tuple[int]`):
Layer indices to use in the `text_encoder` to derive the final prompt embeddings.
Examples:
Returns:
[`~pipelines.flux2.Flux2PipelineOutput`] or `tuple`: [`~pipelines.flux2.Flux2PipelineOutput`] if
`return_dict` is True, otherwise a `tuple`. When returning a tuple, the first element is a list with the
generated images.
"""
# 1. Check inputs. Raise error if not correct
self.check_inputs(
prompt=prompt,
height=height,
width=width,
prompt_embeds=prompt_embeds,
callback_on_step_end_tensor_inputs=callback_on_step_end_tensor_inputs,
)
self._guidance_scale = guidance_scale
self._attention_kwargs = attention_kwargs
self._current_timestep = None
self._interrupt = False
# 2. Define call parameters
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
# 3. prepare text embeddings
prompt_embeds, text_ids = self.encode_prompt(
prompt=prompt,
prompt_embeds=prompt_embeds,
device=device,
num_images_per_prompt=num_images_per_prompt,
max_sequence_length=max_sequence_length,
text_encoder_out_layers=text_encoder_out_layers,
)
# 4. process images
if image is not None and not isinstance(image, list):
image = [image]
condition_images = None
if image is not None:
for img in image:
self.image_processor.check_image_input(img)
condition_images = []
for img in image:
image_width, image_height = img.size
if image_width * image_height > 1024 * 1024:
img = self.image_processor._resize_to_target_area(img, 1024 * 1024)
image_width, image_height = img.size
multiple_of = self.vae_scale_factor * 2
image_width = (image_width // multiple_of) * multiple_of
image_height = (image_height // multiple_of) * multiple_of
img = self.image_processor.preprocess(img, height=image_height, width=image_width, resize_mode="crop")
condition_images.append(img)
height = height or image_height
width = width or image_width
height = height or self.default_sample_size * self.vae_scale_factor
width = width or self.default_sample_size * self.vae_scale_factor
# 5. prepare latent variables
num_channels_latents = self.transformer.config.in_channels // 4
latents, latent_ids = self.prepare_latents(
batch_size=batch_size * num_images_per_prompt,
num_latents_channels=num_channels_latents,
height=height,
width=width,
dtype=prompt_embeds.dtype,
device=device,
generator=generator,
latents=latents,
)
image_latents = None
image_latent_ids = None
if condition_images is not None:
image_latents, image_latent_ids = self.prepare_image_latents(
images=condition_images,
batch_size=batch_size * num_images_per_prompt,
generator=generator,
device=device,
dtype=self.vae.dtype,
)
# 6. Prepare timesteps
sigmas = np.linspace(1.0, 1 / num_inference_steps, num_inference_steps) if sigmas is None else sigmas
if hasattr(self.scheduler.config, "use_flow_sigmas") and self.scheduler.config.use_flow_sigmas:
sigmas = None
image_seq_len = latents.shape[1]
mu = compute_empirical_mu(image_seq_len=image_seq_len, num_steps=num_inference_steps)
timesteps, num_inference_steps = retrieve_timesteps(
self.scheduler,
num_inference_steps,
device,
sigmas=sigmas,
mu=mu,
)
num_warmup_steps = max(len(timesteps) - num_inference_steps * self.scheduler.order, 0)
self._num_timesteps = len(timesteps)
# handle guidance
guidance = torch.full([1], guidance_scale, device=device, dtype=torch.float32)
guidance = guidance.expand(latents.shape[0])
# 7. Denoising loop
# We set the index here to remove DtoH sync, helpful especially during compilation.
# Check out more details here: https://github.com/huggingface/diffusers/pull/11696
self.scheduler.set_begin_index(0)
with self.progress_bar(total=num_inference_steps) as progress_bar:
for i, t in enumerate(timesteps):
if self.interrupt:
continue
self._current_timestep = t
# broadcast to batch dimension in a way that's compatible with ONNX/Core ML
timestep = t.expand(latents.shape[0]).to(latents.dtype)
latent_model_input = latents.to(self.transformer.dtype)
latent_image_ids = latent_ids
if image_latents is not None:
latent_model_input = torch.cat([latents, image_latents], dim=1).to(self.transformer.dtype)
latent_image_ids = torch.cat([latent_ids, image_latent_ids], dim=1)
noise_pred = self.transformer(
hidden_states=latent_model_input, # (B, image_seq_len, C)
timestep=timestep / 1000,
guidance=guidance,
encoder_hidden_states=prompt_embeds,
txt_ids=text_ids, # B, text_seq_len, 4
img_ids=latent_image_ids, # B, image_seq_len, 4
joint_attention_kwargs=self._attention_kwargs,
return_dict=False,
)[0]
noise_pred = noise_pred[:, : latents.size(1) :]
# compute the previous noisy sample x_t -> x_t-1
latents_dtype = latents.dtype
latents = self.scheduler.step(noise_pred, t, latents, return_dict=False)[0]
if latents.dtype != latents_dtype:
if torch.backends.mps.is_available():
# some platforms (eg. apple mps) misbehave due to a pytorch bug: https://github.com/pytorch/pytorch/pull/99272
latents = latents.to(latents_dtype)
if callback_on_step_end is not None:
callback_kwargs = {}
for k in callback_on_step_end_tensor_inputs:
callback_kwargs[k] = locals()[k]
callback_outputs = callback_on_step_end(self, i, t, callback_kwargs)
latents = callback_outputs.pop("latents", latents)
prompt_embeds = callback_outputs.pop("prompt_embeds", prompt_embeds)
# 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 XLA_AVAILABLE:
xm.mark_step()
self._current_timestep = None
if output_type == "latent":
image = latents
else:
torch.save({"pred": latents}, "pred_d.pt")
latents = self._unpack_latents_with_ids(latents, latent_ids)
latents_bn_mean = self.vae.bn.running_mean.view(1, -1, 1, 1).to(latents.device, latents.dtype)
latents_bn_std = torch.sqrt(self.vae.bn.running_var.view(1, -1, 1, 1) + self.vae.config.batch_norm_eps).to(
latents.device, latents.dtype
)
latents = latents * latents_bn_std + latents_bn_mean
latents = self._unpatchify_latents(latents)
image = self.vae.decode(latents, return_dict=False)[0]
image = self.image_processor.postprocess(image, output_type=output_type)
# Offload all models
self.maybe_free_model_hooks()
if not return_dict:
return (image,)
return Flux2PipelineOutput(images=image)

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@@ -0,0 +1,23 @@
from dataclasses import dataclass
from typing import List, Union
import numpy as np
import PIL.Image
from ...utils import BaseOutput
@dataclass
class Flux2PipelineOutput(BaseOutput):
"""
Output class for Flux2 image generation pipelines.
Args:
images (`List[PIL.Image.Image]` or `torch.Tensor` or `np.ndarray`)
List of denoised PIL images of length `batch_size` or numpy array or torch tensor of shape `(batch_size,
height, width, num_channels)`. PIL images or numpy array present the denoised images of the diffusion
pipeline. Torch tensors can represent either the denoised images or the intermediate latents ready to be
passed to the decoder.
"""
images: Union[List[PIL.Image.Image], np.ndarray]

View File

@@ -408,6 +408,21 @@ class AutoencoderKLCosmos(metaclass=DummyObject):
requires_backends(cls, ["torch"])
class AutoencoderKLFlux2(metaclass=DummyObject):
_backends = ["torch"]
def __init__(self, *args, **kwargs):
requires_backends(self, ["torch"])
@classmethod
def from_config(cls, *args, **kwargs):
requires_backends(cls, ["torch"])
@classmethod
def from_pretrained(cls, *args, **kwargs):
requires_backends(cls, ["torch"])
class AutoencoderKLHunyuanImage(metaclass=DummyObject):
_backends = ["torch"]
@@ -843,6 +858,21 @@ class EasyAnimateTransformer3DModel(metaclass=DummyObject):
requires_backends(cls, ["torch"])
class Flux2Transformer2DModel(metaclass=DummyObject):
_backends = ["torch"]
def __init__(self, *args, **kwargs):
requires_backends(self, ["torch"])
@classmethod
def from_config(cls, *args, **kwargs):
requires_backends(cls, ["torch"])
@classmethod
def from_pretrained(cls, *args, **kwargs):
requires_backends(cls, ["torch"])
class FluxControlNetModel(metaclass=DummyObject):
_backends = ["torch"]

View File

@@ -827,6 +827,21 @@ class EasyAnimatePipeline(metaclass=DummyObject):
requires_backends(cls, ["torch", "transformers"])
class Flux2Pipeline(metaclass=DummyObject):
_backends = ["torch", "transformers"]
def __init__(self, *args, **kwargs):
requires_backends(self, ["torch", "transformers"])
@classmethod
def from_config(cls, *args, **kwargs):
requires_backends(cls, ["torch", "transformers"])
@classmethod
def from_pretrained(cls, *args, **kwargs):
requires_backends(cls, ["torch", "transformers"])
class FluxControlImg2ImgPipeline(metaclass=DummyObject):
_backends = ["torch", "transformers"]

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@@ -0,0 +1,127 @@
# coding=utf-8
# Copyright 2025 HuggingFace Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import sys
import unittest
import torch
from transformers import AutoProcessor, Mistral3ForConditionalGeneration
from diffusers import AutoencoderKLFlux2, FlowMatchEulerDiscreteScheduler, Flux2Pipeline, Flux2Transformer2DModel
from ..testing_utils import floats_tensor, require_peft_backend
sys.path.append(".")
from .utils import PeftLoraLoaderMixinTests # noqa: E402
@require_peft_backend
class Flux2LoRATests(unittest.TestCase, PeftLoraLoaderMixinTests):
pipeline_class = Flux2Pipeline
scheduler_cls = FlowMatchEulerDiscreteScheduler
scheduler_kwargs = {}
transformer_kwargs = {
"patch_size": 1,
"in_channels": 4,
"num_layers": 1,
"num_single_layers": 1,
"attention_head_dim": 16,
"num_attention_heads": 2,
"joint_attention_dim": 16,
"timestep_guidance_channels": 256,
"axes_dims_rope": [4, 4, 4, 4],
}
transformer_cls = Flux2Transformer2DModel
vae_kwargs = {
"sample_size": 32,
"in_channels": 3,
"out_channels": 3,
"down_block_types": ("DownEncoderBlock2D",),
"up_block_types": ("UpDecoderBlock2D",),
"block_out_channels": (4,),
"layers_per_block": 1,
"latent_channels": 1,
"norm_num_groups": 1,
"use_quant_conv": False,
"use_post_quant_conv": False,
}
vae_cls = AutoencoderKLFlux2
tokenizer_cls, tokenizer_id = AutoProcessor, "hf-internal-testing/tiny-mistral3-diffusers"
text_encoder_cls, text_encoder_id = Mistral3ForConditionalGeneration, "hf-internal-testing/tiny-mistral3-diffusers"
denoiser_target_modules = ["to_qkv_mlp_proj", "to_k"]
@property
def output_shape(self):
return (1, 8, 8, 3)
def get_dummy_inputs(self, with_generator=True):
batch_size = 1
sequence_length = 10
num_channels = 4
sizes = (32, 32)
generator = torch.manual_seed(0)
noise = floats_tensor((batch_size, num_channels) + sizes)
input_ids = torch.randint(1, sequence_length, size=(batch_size, sequence_length), generator=generator)
pipeline_inputs = {
"prompt": "a dog is dancing",
"num_inference_steps": 2,
"guidance_scale": 5.0,
"height": 8,
"width": 8,
"max_sequence_length": 8,
"output_type": "np",
"text_encoder_out_layers": (1,),
}
if with_generator:
pipeline_inputs.update({"generator": generator})
return noise, input_ids, pipeline_inputs
@unittest.skip("Not supported in Flux2.")
def test_simple_inference_with_text_denoiser_block_scale(self):
pass
@unittest.skip("Not supported in Flux2.")
def test_simple_inference_with_text_denoiser_block_scale_for_all_dict_options(self):
pass
@unittest.skip("Not supported in Flux2.")
def test_modify_padding_mode(self):
pass
@unittest.skip("Text encoder LoRA is not supported in Flux2.")
def test_simple_inference_with_partial_text_lora(self):
pass
@unittest.skip("Text encoder LoRA is not supported in Flux2.")
def test_simple_inference_with_text_lora(self):
pass
@unittest.skip("Text encoder LoRA is not supported in Flux2.")
def test_simple_inference_with_text_lora_and_scale(self):
pass
@unittest.skip("Text encoder LoRA is not supported in Flux2.")
def test_simple_inference_with_text_lora_fused(self):
pass
@unittest.skip("Text encoder LoRA is not supported in Flux2.")
def test_simple_inference_with_text_lora_save_load(self):
pass

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@@ -0,0 +1,162 @@
# coding=utf-8
# Copyright 2025 HuggingFace Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import unittest
import torch
from diffusers import Flux2Transformer2DModel, attention_backend
from ...testing_utils import enable_full_determinism, torch_device
from ..test_modeling_common import LoraHotSwappingForModelTesterMixin, ModelTesterMixin, TorchCompileTesterMixin
enable_full_determinism()
class Flux2TransformerTests(ModelTesterMixin, unittest.TestCase):
model_class = Flux2Transformer2DModel
main_input_name = "hidden_states"
# We override the items here because the transformer under consideration is small.
model_split_percents = [0.7, 0.6, 0.6]
# Skip setting testing with default: AttnProcessor
uses_custom_attn_processor = True
@property
def dummy_input(self):
return self.prepare_dummy_input()
@property
def input_shape(self):
return (16, 4)
@property
def output_shape(self):
return (16, 4)
def prepare_dummy_input(self, height=4, width=4):
batch_size = 1
num_latent_channels = 4
sequence_length = 48
embedding_dim = 32
hidden_states = torch.randn((batch_size, height * width, num_latent_channels)).to(torch_device)
encoder_hidden_states = torch.randn((batch_size, sequence_length, embedding_dim)).to(torch_device)
t_coords = torch.arange(1)
h_coords = torch.arange(height)
w_coords = torch.arange(width)
l_coords = torch.arange(1)
image_ids = torch.cartesian_prod(t_coords, h_coords, w_coords, l_coords) # [height * width, 4]
image_ids = image_ids.unsqueeze(0).expand(batch_size, -1, -1).to(torch_device)
text_t_coords = torch.arange(1)
text_h_coords = torch.arange(1)
text_w_coords = torch.arange(1)
text_l_coords = torch.arange(sequence_length)
text_ids = torch.cartesian_prod(text_t_coords, text_h_coords, text_w_coords, text_l_coords)
text_ids = text_ids.unsqueeze(0).expand(batch_size, -1, -1).to(torch_device)
timestep = torch.tensor([1.0]).to(torch_device).expand(batch_size)
guidance = torch.tensor([1.0]).to(torch_device).expand(batch_size)
return {
"hidden_states": hidden_states,
"encoder_hidden_states": encoder_hidden_states,
"img_ids": image_ids,
"txt_ids": text_ids,
"timestep": timestep,
"guidance": guidance,
}
def prepare_init_args_and_inputs_for_common(self):
init_dict = {
"patch_size": 1,
"in_channels": 4,
"num_layers": 1,
"num_single_layers": 1,
"attention_head_dim": 16,
"num_attention_heads": 2,
"joint_attention_dim": 32,
"timestep_guidance_channels": 256, # Hardcoded in original code
"axes_dims_rope": [4, 4, 4, 4],
}
inputs_dict = self.dummy_input
return init_dict, inputs_dict
# TODO (Daniel, Sayak): We can remove this test.
def test_flux2_consistency(self, seed=0):
torch.manual_seed(seed)
init_dict, inputs_dict = self.prepare_init_args_and_inputs_for_common()
torch.manual_seed(seed)
model = self.model_class(**init_dict)
# state_dict = model.state_dict()
# for key, param in state_dict.items():
# print(f"{key} | {param.shape}")
# torch.save(state_dict, "/raid/daniel_gu/test_flux2_params/diffusers.pt")
model.to(torch_device)
model.eval()
with attention_backend("native"):
with torch.no_grad():
output = model(**inputs_dict)
if isinstance(output, dict):
output = output.to_tuple()[0]
self.assertIsNotNone(output)
# input & output have to have the same shape
input_tensor = inputs_dict[self.main_input_name]
expected_shape = input_tensor.shape
self.assertEqual(output.shape, expected_shape, "Input and output shapes do not match")
# Check against expected slice
# fmt: off
expected_slice = torch.tensor([-0.3662, 0.4844, 0.6334, -0.3497, 0.2162, 0.0188, 0.0521, -0.2061, -0.2041, -0.0342, -0.7107, 0.4797, -0.3280, 0.7059, -0.0849, 0.4416])
# fmt: on
flat_output = output.cpu().flatten()
generated_slice = torch.cat([flat_output[:8], flat_output[-8:]])
self.assertTrue(torch.allclose(generated_slice, expected_slice, atol=1e-4))
def test_gradient_checkpointing_is_applied(self):
expected_set = {"Flux2Transformer2DModel"}
super().test_gradient_checkpointing_is_applied(expected_set=expected_set)
class Flux2TransformerCompileTests(TorchCompileTesterMixin, unittest.TestCase):
model_class = Flux2Transformer2DModel
different_shapes_for_compilation = [(4, 4), (4, 8), (8, 8)]
def prepare_init_args_and_inputs_for_common(self):
return Flux2TransformerTests().prepare_init_args_and_inputs_for_common()
def prepare_dummy_input(self, height, width):
return Flux2TransformerTests().prepare_dummy_input(height=height, width=width)
class Flux2TransformerLoRAHotSwapTests(LoraHotSwappingForModelTesterMixin, unittest.TestCase):
model_class = Flux2Transformer2DModel
different_shapes_for_compilation = [(4, 4), (4, 8), (8, 8)]
def prepare_init_args_and_inputs_for_common(self):
return Flux2TransformerTests().prepare_init_args_and_inputs_for_common()
def prepare_dummy_input(self, height, width):
return Flux2TransformerTests().prepare_dummy_input(height=height, width=width)

View File

View File

@@ -0,0 +1,190 @@
import unittest
import numpy as np
import torch
from transformers import AutoProcessor, Mistral3Config, Mistral3ForConditionalGeneration
from diffusers import (
AutoencoderKLFlux2,
FlowMatchEulerDiscreteScheduler,
Flux2Pipeline,
Flux2Transformer2DModel,
)
from ...testing_utils import (
torch_device,
)
from ..test_pipelines_common import (
PipelineTesterMixin,
check_qkv_fused_layers_exist,
)
class Flux2PipelineFastTests(PipelineTesterMixin, unittest.TestCase):
pipeline_class = Flux2Pipeline
params = frozenset(["prompt", "height", "width", "guidance_scale", "prompt_embeds"])
batch_params = frozenset(["prompt"])
test_xformers_attention = False
test_layerwise_casting = True
test_group_offloading = True
supports_dduf = False
def get_dummy_components(self, num_layers: int = 1, num_single_layers: int = 1):
torch.manual_seed(0)
transformer = Flux2Transformer2DModel(
patch_size=1,
in_channels=4,
num_layers=num_layers,
num_single_layers=num_single_layers,
attention_head_dim=16,
num_attention_heads=2,
joint_attention_dim=16,
timestep_guidance_channels=256, # Hardcoded in original code
axes_dims_rope=[4, 4, 4, 4],
)
config = Mistral3Config(
text_config={
"model_type": "mistral",
"vocab_size": 32000,
"hidden_size": 16,
"intermediate_size": 37,
"max_position_embeddings": 512,
"num_attention_heads": 4,
"num_hidden_layers": 1,
"num_key_value_heads": 2,
"rms_norm_eps": 1e-05,
"rope_theta": 1000000000.0,
"sliding_window": None,
"bos_token_id": 2,
"eos_token_id": 3,
"pad_token_id": 4,
},
vision_config={
"model_type": "pixtral",
"hidden_size": 16,
"num_hidden_layers": 1,
"num_attention_heads": 4,
"intermediate_size": 37,
"image_size": 30,
"patch_size": 6,
"num_channels": 3,
},
bos_token_id=2,
eos_token_id=3,
pad_token_id=4,
model_dtype="mistral3",
image_seq_length=4,
vision_feature_layer=-1,
image_token_index=1,
)
torch.manual_seed(0)
text_encoder = Mistral3ForConditionalGeneration(config)
tokenizer = AutoProcessor.from_pretrained(
"hf-internal-testing/Mistral-Small-3.1-24B-Instruct-2503-only-processor"
)
torch.manual_seed(0)
vae = AutoencoderKLFlux2(
sample_size=32,
in_channels=3,
out_channels=3,
down_block_types=("DownEncoderBlock2D",),
up_block_types=("UpDecoderBlock2D",),
block_out_channels=(4,),
layers_per_block=1,
latent_channels=1,
norm_num_groups=1,
use_quant_conv=False,
use_post_quant_conv=False,
)
scheduler = FlowMatchEulerDiscreteScheduler()
return {
"scheduler": scheduler,
"text_encoder": text_encoder,
"tokenizer": tokenizer,
"transformer": transformer,
"vae": vae,
}
def get_dummy_inputs(self, device, seed=0):
if str(device).startswith("mps"):
generator = torch.manual_seed(seed)
else:
generator = torch.Generator(device="cpu").manual_seed(seed)
inputs = {
"prompt": "a dog is dancing",
"generator": generator,
"num_inference_steps": 2,
"guidance_scale": 5.0,
"height": 8,
"width": 8,
"max_sequence_length": 8,
"output_type": "np",
"text_encoder_out_layers": (1,),
}
return inputs
def test_fused_qkv_projections(self):
device = "cpu" # ensure determinism for the device-dependent torch.Generator
components = self.get_dummy_components()
pipe = self.pipeline_class(**components)
pipe = pipe.to(device)
pipe.set_progress_bar_config(disable=None)
inputs = self.get_dummy_inputs(device)
image = pipe(**inputs).images
original_image_slice = image[0, -3:, -3:, -1]
# TODO (sayakpaul): will refactor this once `fuse_qkv_projections()` has been added
# to the pipeline level.
pipe.transformer.fuse_qkv_projections()
self.assertTrue(
check_qkv_fused_layers_exist(pipe.transformer, ["to_qkv"]),
("Something wrong with the fused attention layers. Expected all the attention projections to be fused."),
)
inputs = self.get_dummy_inputs(device)
image = pipe(**inputs).images
image_slice_fused = image[0, -3:, -3:, -1]
pipe.transformer.unfuse_qkv_projections()
inputs = self.get_dummy_inputs(device)
image = pipe(**inputs).images
image_slice_disabled = image[0, -3:, -3:, -1]
self.assertTrue(
np.allclose(original_image_slice, image_slice_fused, atol=1e-3, rtol=1e-3),
("Fusion of QKV projections shouldn't affect the outputs."),
)
self.assertTrue(
np.allclose(image_slice_fused, image_slice_disabled, atol=1e-3, rtol=1e-3),
("Outputs, with QKV projection fusion enabled, shouldn't change when fused QKV projections are disabled."),
)
self.assertTrue(
np.allclose(original_image_slice, image_slice_disabled, atol=1e-2, rtol=1e-2),
("Original outputs should match when fused QKV projections are disabled."),
)
def test_flux_image_output_shape(self):
pipe = self.pipeline_class(**self.get_dummy_components()).to(torch_device)
inputs = self.get_dummy_inputs(torch_device)
height_width_pairs = [(32, 32), (72, 57)]
for height, width in height_width_pairs:
expected_height = height - height % (pipe.vae_scale_factor * 2)
expected_width = width - width % (pipe.vae_scale_factor * 2)
inputs.update({"height": height, "width": width})
image = pipe(**inputs).images[0]
output_height, output_width, _ = image.shape
self.assertEqual(
(output_height, output_width),
(expected_height, expected_width),
f"Output shape {image.shape} does not match expected shape {(expected_height, expected_width)}",
)

View File

@@ -103,7 +103,7 @@ def check_qkv_fusion_processors_exist(model):
def check_qkv_fused_layers_exist(model, layer_names):
is_fused_submodules = []
for submodule in model.modules():
if not isinstance(submodule, AttentionModuleMixin):
if not isinstance(submodule, AttentionModuleMixin) or not submodule._supports_qkv_fusion:
continue
is_fused_attribute_set = submodule.fused_projections
is_fused_layer = True