| | --- |
| | license: apache-2.0 |
| | pipeline_tag: video-to-video |
| | --- |
| | |
| | # ⚡ FlashVSR |
| |
|
| | **Towards Real-Time Diffusion-Based Streaming Video Super-Resolution** |
| |
|
| | **Authors:** Junhao Zhuang, Shi Guo, Xin Cai, Xiaohui Li, Yihao Liu, Chun Yuan, Tianfan Xue |
| |
|
| | <a href='http://zhuang2002.github.io/FlashVSR'><img src='https://img.shields.io/badge/Project-Page-Green'></a> |
| | <a href="https://github.com/OpenImagingLab/FlashVSR"><img src="https://img.shields.io/badge/GitHub-Repository-black?logo=github"></a> |
| | <a href="https://huggingface.co/JunhaoZhuang/FlashVSR"><img src="https://img.shields.io/badge/%F0%9F%A4%97%20Hugging%20Face-Model%20(v1)-blue"></a> |
| | <a href="https://huggingface.co/JunhaoZhuang/FlashVSR-v1.1"><img src="https://img.shields.io/badge/%F0%9F%A4%97%20Hugging%20Face-Model%20(v1.1)-blue"></a> |
| | <a href="https://huggingface.co/datasets/JunhaoZhuang/VSR-120K"><img src="https://img.shields.io/badge/%F0%9F%A4%97%20Hugging%20Face-Dataset-orange"></a> |
| | <a href="https://arxiv.org/abs/2510.12747"><img src="https://img.shields.io/badge/arXiv-2510.12747-b31b1b.svg"></a> |
| |
|
| | **Your star means a lot for us to develop this project!** :star: |
| |
|
| | <img src="https://raw.githubusercontent.com/OpenImagingLab/FlashVSR/main/examples/WanVSR/assets/teaser.png" /> |
| |
|
| | --- |
| |
|
| | ### 🌟 Abstract |
| |
|
| | Diffusion models have recently advanced video restoration, but applying them to real-world video super-resolution (VSR) remains challenging due to high latency, prohibitive computation, and poor generalization to ultra-high resolutions. Our goal in this work is to make diffusion-based VSR practical by achieving **efficiency, scalability, and real-time performance**. To this end, we propose **FlashVSR**, the first diffusion-based one-step streaming framework towards real-time VSR. **FlashVSR runs at ∼17 FPS for 768 × 1408 videos on a single A100 GPU** by combining three complementary innovations: (i) a train-friendly three-stage distillation pipeline that enables streaming super-resolution, (ii) locality-constrained sparse attention that cuts redundant computation while bridging the train–test resolution gap, and (iii) a tiny conditional decoder that accelerates reconstruction without sacrificing quality. To support large-scale training, we also construct **VSR-120K**, a new dataset with 120k videos and 180k images. Extensive experiments show that FlashVSR scales reliably to ultra-high resolutions and achieves **state-of-the-art performance with up to ∼12× speedup** over prior one-step diffusion VSR models. |
| |
|
| | --- |
| |
|
| | ### 📰 News |
| |
|
| | - **Nov 2025 — 🎉 [FlashVSR v1.1](https://huggingface.co/JunhaoZhuang/FlashVSR-v1.1) released:** enhanced stability + fidelity |
| | - **Oct 2025 — [FlashVSR v1](https://huggingface.co/JunhaoZhuang/FlashVSR) (initial release)**: Inference code and model weights are available now! 🎉 |
| | - **Bug Fix (October 21, 2025):** Fixed `local_attention_mask` update logic to prevent artifacts when switching between different aspect ratios during continuous inference. |
| | - **Coming Soon:** Dataset release (**VSR-120K**) for large-scale training. |
| |
|
| | --- |
| |
|
| | ### 📢 Important Quality Note (ComfyUI & other third-party implementations) |
| |
|
| | First of all, huge thanks to the community for the fast adoption, feedback, and contributions to FlashVSR! 🙌 |
| | During community testing, we noticed that some third-party implementations of FlashVSR (e.g. early ComfyUI versions) do **not include our Locality-Constrained Sparse Attention (LCSA)** module and instead fall back to **dense attention**. This may lead to **noticeable quality degradation**, especially at higher resolutions. |
| | Community discussion: https://github.com/kijai/ComfyUI-WanVideoWrapper/issues/1441 |
| |
|
| | Below is a comparison example provided by a community member: |
| |
|
| | | Fig.1 – LR Input Video | Fig.2 – 3rd-party (no LCSA) | Fig.3 – Official FlashVSR | |
| | |------------------|-----------------------------------------------|--------------------------------------| |
| | | <video src="https://github.com/user-attachments/assets/ea12a191-48d5-47c0-a8e5-e19ad13581a9" controls width="260"></video> | <video src="https://github.com/user-attachments/assets/c8e53bd5-7eca-420d-9cc6-2b9c06831047" controls width="260"></video> | <video src="https://github.com/user-attachments/assets/a4d80618-d13d-4346-8e37-38d2fabf9827" controls width="260"></video> | |
| |
|
| | ✅ The **official FlashVSR pipeline (this repository)**: |
| | - **Better preserves fine structures and details** |
| | - **Effectively avoids texture aliasing and visual artifacts** |
| |
|
| | We are also working on a **version that does not rely on the Block-Sparse Attention library** while keeping **the same output quality**; this alternative may run slower than the optimized original implementation. |
| |
|
| | Thanks again to the community for actively testing and helping improve FlashVSR together! 🚀 |
| |
|
| | --- |
| |
|
| | ### 📋 TODO |
| |
|
| | - ✅ Release inference code and model weights |
| | - ⬜ Release dataset (VSR-120K) |
| |
|
| | --- |
| |
|
| | ### 🚀 Getting Started |
| |
|
| | Follow these steps to set up and run **FlashVSR** on your local machine: |
| |
|
| | > ⚠️ **Note:** This project is primarily designed and optimized for **4× video super-resolution**. |
| | > We **strongly recommend** using the **4× SR setting** to achieve better results and stability. ✅ |
| |
|
| | #### 1️⃣ Clone the Repository |
| |
|
| | ```bash |
| | git clone https://github.com/OpenImagingLab/FlashVSR |
| | cd FlashVSR |
| | ```` |
| |
|
| | #### 2️⃣ Set Up the Python Environment |
| |
|
| | Create and activate the environment (**Python 3.11.13**): |
| |
|
| | ```bash |
| | conda create -n flashvsr python=3.11.13 |
| | conda activate flashvsr |
| | ``` |
| |
|
| | Install project dependencies: |
| |
|
| | ```bash |
| | pip install -e . |
| | pip install -r requirements.txt |
| | ``` |
| |
|
| | #### 3️⃣ Install Block-Sparse Attention (Required) |
| |
|
| | FlashVSR relies on the **Block-Sparse Attention** backend to enable flexible and dynamic attention masking for efficient inference. |
| |
|
| | > **⚠️ Note:** |
| | > |
| | > * The Block-Sparse Attention build process can be memory-intensive, especially when compiling in parallel with multiple `ninja` jobs. It is recommended to keep sufficient memory available during compilation to avoid OOM errors. Once the build is complete, runtime memory usage is stable and not an issue. |
| | > * Based on our testing, the Block-Sparse Attention backend works correctly on **NVIDIA A100 and A800** (Ampere) with **ideal acceleration performance**, and it also runs correctly on **H200** (Hopper) but the acceleration is limited due to hardware scheduling differences and sparse kernel behavior. **Compatibility and performance on other GPUs (e.g., RTX 40/50 series or H800) are currently unknown**. For more details, please refer to the official documentation: https://github.com/mit-han-lab/Block-Sparse-Attention |
| |
|
| |
|
| | ```bash |
| | # ✅ Recommended: clone and install in a separate clean folder (outside the FlashVSR repo) |
| | git clone https://github.com/mit-han-lab/Block-Sparse-Attention |
| | cd Block-Sparse-Attention |
| | pip install packaging |
| | pip install ninja |
| | python setup.py install |
| | ``` |
| |
|
| | #### 4️⃣ Download Model Weights from Hugging Face |
| |
|
| | FlashVSR provides both **v1** and **v1.1** model weights on Hugging Face (via **Git LFS**). |
| | Please install Git LFS first: |
| |
|
| | ```bash |
| | # From the repo root |
| | cd examples/WanVSR |
| | |
| | # Install Git LFS (once per machine) |
| | git lfs install |
| | |
| | # Clone v1 (original) or v1.1 (recommended) |
| | git lfs clone https://huggingface.co/JunhaoZhuang/FlashVSR # v1 |
| | # or |
| | git lfs clone https://huggingface.co/JunhaoZhuang/FlashVSR-v1.1 # v1.1 |
| | ``` |
| |
|
| | After cloning, you should have one of the following folders: |
| |
|
| | ``` |
| | ./examples/WanVSR/FlashVSR/ # v1 |
| | ./examples/WanVSR/FlashVSR-v1.1/ # v1.1 |
| | │ |
| | ├── LQ_proj_in.ckpt |
| | ├── TCDecoder.ckpt |
| | ├── Wan2.1_VAE.pth |
| | ├── diffusion_pytorch_model_streaming_dmd.safetensors |
| | └── README.md |
| | ``` |
| |
|
| | > Inference scripts automatically load weights from the corresponding folder. |
| |
|
| | --- |
| |
|
| | #### 5️⃣ Run Inference |
| |
|
| | ```bash |
| | # From the repo root |
| | cd examples/WanVSR |
| | |
| | # v1 (original) |
| | python infer_flashvsr_full.py |
| | # or |
| | python infer_flashvsr_tiny.py |
| | # or |
| | python infer_flashvsr_tiny_long_video.py |
| | |
| | # v1.1 (recommended) |
| | python infer_flashvsr_v1.1_full.py |
| | # or |
| | python infer_flashvsr_v1.1_tiny.py |
| | # or |
| | python infer_flashvsr_v1.1_tiny_long_video.py |
| | ``` |
| |
|
| | --- |
| |
|
| | ### 🛠️ Method |
| |
|
| | The overview of **FlashVSR**. This framework features: |
| |
|
| | * **Three-Stage Distillation Pipeline** for streaming VSR training. |
| | * **Locality-Constrained Sparse Attention** to cut redundant computation and bridge the train–test resolution gap. |
| | * **Tiny Conditional Decoder** for efficient, high-quality reconstruction. |
| | * **VSR-120K Dataset** consisting of **120k videos** and **180k images**, supports joint training on both images and videos. |
| |
|
| | <img src="https://raw.githubusercontent.com/OpenImagingLab/FlashVSR/main/examples/WanVSR/assets/flowchart.jpg" width="1000" /> |
| |
|
| | --- |
| |
|
| | ### 🤗 Feedback & Support |
| |
|
| | We welcome feedback and issues. Thank you for trying **FlashVSR**! |
| |
|
| | --- |
| |
|
| | ### 📄 Acknowledgments |
| |
|
| | We gratefully acknowledge the following open-source projects: |
| |
|
| | * **DiffSynth Studio** — [https://github.com/modelscope/DiffSynth-Studio](https://github.com/modelscope/DiffSynth-Studio) |
| | * **Block-Sparse-Attention** — [https://github.com/mit-han-lab/Block-Sparse-Attention](https://github.com/mit-han-lab/Block-Sparse-Attention) |
| | * **taehv** — [https://github.com/madebyollin/taehv](https://github.com/madebyollin/taehv) |
| |
|
| | --- |
| |
|
| | ### 📞 Contact |
| |
|
| | * **Junhao Zhuang** |
| | Email: [zhuangjh23@mails.tsinghua.edu.cn](mailto:zhuangjh23@mails.tsinghua.edu.cn) |
| |
|
| | --- |
| |
|
| | ### 📜 Citation |
| |
|
| | ```bibtex |
| | @article{zhuang2025flashvsr, |
| | title={FlashVSR: Towards Real-Time Diffusion-Based Streaming Video Super-Resolution}, |
| | author={Zhuang, Junhao and Guo, Shi and Cai, Xin and Li, Xiaohui and Liu, Yihao and Yuan, Chun and Xue, Tianfan}, |
| | journal={arXiv preprint arXiv:2510.12747}, |
| | year={2025} |
| | } |
| | ``` |
| |
|
