**Open-Sora** is an **open-source** initiative dedicated to **efficiently** reproducing OpenAI's Sora. Our project aims to cover **the full pipeline**, including video data preprocessing, training with acceleration, efficient inference and more. Operating on a limited budget, we prioritize the vibrant open-source community, providing access to text-to-image, image captioning, and language models. We hope to make a contribution to the community and make the project more accessible to everyone.
## 📰 News
* **[2024.03.18]** 🔥 We release **Open-Sora 1.0**, an open-source project to reproduce OpenAI Sora.
* 📍 Open-Sora-v1 released. Model weights are available [here](#model-weights). With only 400K video clips and 200 H800 days (compared with 152M samples in Stable Video Diffusion), we are able to generate 2s 512×512 videos.
* ✅ Support training acceleration including accelerated transformer, faster T5 and VAE, and sequence parallelism. Open-Sora improve **55%** training speed when training on 64x512x512 videos. Details locates at [acceleration.md](docs/acceleration.md).
* ✅ We provide video cutting and captioning tools for data preprocessing. Instructions can be found [here](tools/data/README.md) and our data collection plan can be found at [datasets.md](docs/datasets.md).
* ✅ We find VQ-VAE from [VideoGPT](https://wilson1yan.github.io/videogpt/index.html) has a low quality and thus adopt a better VAE from [Stability-AI](https://huggingface.co/stabilityai/sd-vae-ft-mse-original). We also find patching in the time dimension deteriorates the quality. See our **[report](docs/report_v1.md)** for more discussions.
* ✅ We investigate different architectures including DiT, Latte, and our proposed STDiT. Our **STDiT** achieves a better trade-off between quality and speed. See our **[report](docs/report_v1.md)** for more discussions.
* ✅ Support clip and T5 text conditioning.
* ✅ By viewing images as one-frame videos, our project supports training DiT on both images and videos (e.g., ImageNet & UCF101). See [command.md](docs/command.md) for more instructions.
* ✅ Support inference with official weights from [DiT](https://github.com/facebookresearch/DiT), [Latte](https://github.com/Vchitect/Latte), and [PixArt](https://pixart-alpha.github.io/).
* [ ] Complete the data processing pipeline (including dense optical flow, aesthetics scores, text-image similarity, deduplication, etc.). See [datasets.md](/docs/datasets.md) for more information. **[WIP]**
Our model's weight is partially initialized from [PixArt-α](https://github.com/PixArt-alpha/PixArt-alpha). The number of parameters is 724M. More information about training can be found in our **[report](/docs/report_v1.md)**. More about dataset can be found in [dataset.md](/docs/dataset.md).
**LIMITATION**: Our model is trained on a limited budget. The quality and text alignment is relatively poor. The model performs badly especially on generating human beings and cannot follow detailed instructions. We are working on improving the quality and text alignment.
To run inference with our provided weights, first download [T5](https://huggingface.co/DeepFloyd/t5-v1_1-xxl/tree/main) weights into `pretrained_models/t5_ckpts/t5-v1_1-xxl`. Then run the following commands to generate samples. See [here](docs/structure.md#inference-config-demos) to customize the configuration.
To launch training, first download [T5](https://huggingface.co/DeepFloyd/t5-v1_1-xxl/tree/main) weights into `pretrained_models/t5_ckpts/t5-v1_1-xxl`. Then run the following commands to launch training on a single node.
To launch training on multiple nodes, prepare a hostfile according to [ColossalAI](https://colossalai.org/docs/basics/launch_colossalai/#launch-with-colossal-ai-cli), and run the following commands.
* [DiT](https://github.com/facebookresearch/DiT): Scalable Diffusion Models with Transformers.
* [OpenDiT](https://github.com/NUS-HPC-AI-Lab/OpenDiT): An acceleration for DiT training. OpenDiT's team provides valuable suggestions on acceleration of our training process.
* [PixArt](https://github.com/PixArt-alpha/PixArt-alpha): An open-source DiT-based text-to-image model.
* [Latte](https://github.com/Vchitect/Latte): An attempt to efficiently train DiT for video.
* [StabilityAI VAE](https://huggingface.co/stabilityai/sd-vae-ft-mse-original): A powerful image VAE model.
* [CLIP](https://github.com/openai/CLIP): A powerful text-image embedding model.
[Zangwei Zheng](https://github.com/zhengzangw) and [Xiangyu Peng](https://github.com/xyupeng) equally contributed to this work during their internship at [HPC-AI Tech](https://hpc-ai.com/).
