Model reference · open weights

Open-Sora

Available as managed deployment Video hpcai-tech Text→video 1 variants 4k dl/mo

Open-Sora is an open-weight video model from hpcai-tech. AxForge deploys and operates it for you on dedicated EU-owned hardware — with the licence handled where one is required.

Available as managed deployment — configured and operated for you on dedicated EU hardware, quoted per deployment.

What it is

Makerhpcai-tech
TypeVideo models
TaskText→video
Runs withopen-sora
Released2025-03-04
Popularity4k downloads / month
LicenceOpen weights

About

What Open-Sora is

Open-Sora: Democratizing Efficient Video Production for All

We design and implement Open-Sora, an initiative dedicated to efficiently producing high-quality video. We hope to make the model, tools and all details accessible to all. By embracing open-source principles, Open-Sora not only democratizes access to advanced video generation techniques, but also offers a streamlined and user-friendly platform that simplifies the complexities of video generation. With Open-Sora, our goal is to foster innovation, creativity, and inclusivity within the field of content creation.

Paper

Github: https://github.com/hpcaitech/Open-Sora

🔆 Reports

📍 Since Open-Sora is under active development, we remain different branchs for different versions. The latest version is main. Old versions include: v1.0, v1.1, v1.2, v1.3.

Quickstart

Installation

# create a virtual env and activate (conda as an example)
conda create -n opensora python=3.10
conda activate opensora

# download the repo
git clone https://github.com/hpcaitech/Open-Sora
cd Open-Sora

# Ensure torch >= 2.4.0
pip install -v . # for development mode, `pip install -v -e .`
pip install xformers==0.0.27.post2 --index-url https://download.pytorch.org/whl/cu121 # install xformers according to your cuda version
pip install flash-attn --no-build-isolation

Optionally, you can install flash attention 3 for faster speed.

git clone https://github.com/Dao-AILab/flash-attention # 4f0640d5
cd flash-attention/hopper
python setup.py install

Model Download

Our 11B model supports 256px and 768px resolution. Both T2V and I2V are supported by one model. 🤗 Huggingface 🤖 ModelScope.

Download from huggingface:

pip install "huggingface_hub[cli]"
huggingface-cli download hpcai-tech/Open-Sora-v2 --local-dir ./ckpts

Download from ModelScope:

pip install modelscope
modelscope download hpcai-tech/Open-Sora-v2 --local_dir ./ckpts

Text-to-Video Generation

Our model is optimized for image-to-video generation, but it can also be used for text-to-video generation. To generate high quality videos, with the help of flux text-to-image model, we build a text-to-image-to-video pipeline. For 256x256 resolution:

# Generate one given prompt
torchrun --nproc_per_node 1 --standalone scripts/diffusion/inference.py configs/diffusion/inference/t2i2v_256px.py --save-dir samples --prompt "raining, sea"

# Generation with csv
torchrun --nproc_per_node 1 --standalone scripts/diffusion/inference.py configs/diffusion/inference/t2i2v_256px.py --save-dir samples --dataset.data-path assets/texts/example.csv

For 768x768 resolution:

# One GPU
torchrun --nproc_per_node 1 --standalone scripts/diffusion/inference.py configs/diffusion/inference/t2i2v_768px.py --save-dir samples --prompt "raining, sea"

# Multi-GPU with colossalai sp
torchrun --nproc_per_node 8 --standalone scripts/diffusion/inference.py configs/diffusion/inference/t2i2v_768px.py --save-dir samples --prompt "raining, sea"

You can adjust the generation aspect ratio by --aspect_ratio and the generation length by --num_frames. Candidate values for aspect_ratio includes 16:9, 9:16, 1:1, 2.39:1. Candidate values for num_frames should be 4k+1 and less than 129.

You can also run direct text-to-video by:

# One GPU for 256px
torchrun --nproc_per_node 1 --standalone scripts/diffusion/inference.py configs/diffusion/inference/256px.py --prompt "raining, sea"
# Multi-GPU for 768px
torchrun --nproc_per_node 8 --standalone scripts/diffusion/inference.py configs/diffusion/inference/768px.py --prompt "raining, sea"

Image-to-Video Generation

Given a prompt and a reference image, you can generate a video with the following command:

# 256px
torchrun --nproc_per_node 1 --standalone scripts/diffusion/inference.py configs/diffusion/inference/256px.py --cond_type i2v_head --prompt "A plump pig wallows in a muddy pond on a rustic farm, its pink snout poking out as it snorts contentedly. The camera captures the pig's playful splashes, sending ripples through the water under the midday sun. Wooden fences and a red barn stand in the background, framed by rolling green hills. The pig's muddy coat glistens in the sunlight, showcasing the simple pleasures of its carefree life." --ref assets/texts/i2v.png

# 256px with csv
torchrun --nproc_per_node 1 --standalone scripts/diffusion/inference.py configs/diffusion/inference/256px.py --cond_type i2v_head --dataset.data-path assets/texts/i2v.csv

# Multi-GPU 768px
torchrun --nproc_per_node 8 --standalone scripts/diffusion/inference.py configs/diffusion/inference/768px.py --cond_type i2v_head --d

From the published model card. Full card on the HuggingFace links in the sidebar.

How it works

How video models work

Prompt / imagestart pointTemporal diffusionframes over timeVideoMP4 clipA video model generates a sequence of coherent frames from your prompt or a starting image.

Using it via the API

Call it like any OpenAI endpoint

Once AxForge deploys open-sora for you, it answers on the OpenAI-compatible API — the same base URL and keys as every other model. (open-sora below is illustrative; you get the exact model name on deployment.)

$ curl -sS https://api.axforge.ai/v1/videos/generations \
  -H "Authorization: Bearer $AXFORGE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"open-sora","prompt":"a drone shot over a forest"}'

Create an account — your API key is available in the console. 5M tokens/month currently included with every new account at launch.

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