OpenMMLab's Next Generation Video Understanding Toolbox and Benchmark
3164 830 47 1178

Documentation actions codecov PyPI LICENSE Average time to resolve an issue Percentage of issues still open

๐Ÿ“˜Documentation | ๐Ÿ› ๏ธInstallation | ๐Ÿ‘€Model Zoo | ๐Ÿ†•Update News | ๐Ÿš€Ongoing Projects | ๐Ÿค”Reporting Issues

English | ็ฎ€ไฝ“ไธญๆ–‡

๐Ÿ“„ Table of Contents

๐Ÿฅณ ๐Ÿš€ What's New ๐Ÿ”

The default branch has been switched to main(previous 1.x) from master(current 0.x), and we encourage users to migrate to the latest version with more supported models, stronger pre-training checkpoints and simpler coding. Please refer to Migration Guide for more details.

Release (2023.04.06): v1.0.0 with the following new features:

  • Support RGB-PoseC3D(CVPR'2022).
  • Support training UniFormer V2(Arxiv'2022).
  • Support MSG3D(CVPR'2020) and CTRGCN(CVPR'2021) in projects.
  • Refactor and provide more user-friendly documentation.

๐Ÿ“– Introduction ๐Ÿ”

MMAction2 is an open-source toolbox for video understanding based on PyTorch. It is a part of the OpenMMLab project.

๐ŸŽ Major Features ๐Ÿ”

  • Modular design: We decompose a video understanding framework into different components. One can easily construct a customized video understanding framework by combining different modules.

  • Support four major video understanding tasks: MMAction2 implements various algorithms for multiple video understanding tasks, including action recognition, action localization, spatio-temporal action detection, and skeleton-based action detection.

  • Well tested and documented: We provide detailed documentation and API reference, as well as unit tests.

๐Ÿ› ๏ธ Installation ๐Ÿ”

MMAction2 depends on PyTorch, MMCV, MMEngine, MMDetection (optional) and MMPose (optional).

Please refer to for detailed instructions.

conda create --name openmmlab python=3.8 -y
conda activate open-mmlab
conda install pytorch torchvision -c pytorch  # This command will automatically install the latest version PyTorch and cudatoolkit, please check whether they match your environment.
pip install -U openmim
mim install mmengine
mim install mmcv
mim install mmdet  # optional
mim install mmpose  # optional
git clone
cd mmaction2
pip install -v -e .

๐Ÿ‘€ Model Zoo ๐Ÿ”

Results and models are available in the model zoo.

๐Ÿ‘จโ€๐Ÿซ Get Started ๐Ÿ”

For tutorials, we provide the following user guides for basic usage:

  • Video Swin Transformer. [paper][github]
  • Evidential Deep Learning for Open Set Action Recognition, ICCV 2021 Oral. [paper][github]
  • Rethinking Self-supervised Correspondence Learning: A Video Frame-level Similarity Perspective, ICCV 2021 Oral. [paper][github]

๐ŸŽซ License ๐Ÿ”

This project is released under the Apache 2.0 license.

๐Ÿ–Š๏ธ Citation ๐Ÿ”

If you find this project useful in your research, please consider cite:

    title={OpenMMLab's Next Generation Video Understanding Toolbox and Benchmark},
    author={MMAction2 Contributors},
    howpublished = {\url{}},

๐Ÿ™Œ Contributing ๐Ÿ”

We appreciate all contributions to improve MMAction2. Please refer to in MMCV for more details about the contributing guideline.

๐Ÿค Acknowledgement ๐Ÿ”

MMAction2 is an open-source project that is contributed by researchers and engineers from various colleges and companies. We appreciate all the contributors who implement their methods or add new features and users who give valuable feedback. We wish that the toolbox and benchmark could serve the growing research community by providing a flexible toolkit to reimplement existing methods and develop their new models.

๐Ÿ—๏ธ Projects in OpenMMLab ๐Ÿ”

  • MMEngine: OpenMMLab foundational library for training deep learning models.
  • MMCV: OpenMMLab foundational library for computer vision.
  • MMPreTrain: OpenMMLab pre-training toolbox and benchmark.
  • MMagic: OpenMMLab Advanced, Generative and Intelligent Creation toolbox.
  • MMDetection: OpenMMLab detection toolbox and benchmark.
  • MMDetection3D: OpenMMLab's next-generation platform for general 3D object detection.
  • MMRotate: OpenMMLab rotated object detection toolbox and benchmark.
  • MMTracking: OpenMMLab video perception toolbox and benchmark.
  • MMSegmentation: OpenMMLab semantic segmentation toolbox and benchmark.
  • MMOCR: OpenMMLab text detection, recognition, and understanding toolbox.
  • MMPose: OpenMMLab pose estimation toolbox and benchmark.
  • MMHuman3D: OpenMMLab 3D human parametric model toolbox and benchmark.
  • MMFewShot: OpenMMLab fewshot learning toolbox and benchmark.
  • MMAction2: OpenMMLab's next-generation action understanding toolbox and benchmark.
  • MMFlow: OpenMMLab optical flow toolbox and benchmark.
  • MMDeploy: OpenMMLab Model Deployment Framework.
  • MMRazor: OpenMMLab model compression toolbox and benchmark.
  • MIM: MIM installs OpenMMLab packages.
  • Playground: A central hub for gathering and showcasing amazing projects built upon OpenMMLab.