Sliding Tile Attention (STA) Branch

This branch is a stash/testing branch for people who want to try Sliding Tile Attention (STA). The top-level README is intentionally STA-only.

What is STA

Sliding Tile Attention is an optimized attention backend for window-based video generation.

• Blog: https://hao-ai-lab.github.io/blogs/sta/
• Paper: https://arxiv.org/abs/2502.04507
• In-repo STA docs: docs/attention/sta/index.md

Setup

Install FastVideo from source:

uv pip install -e .

Build the STA kernel package:

cd fastvideo-kernel
./build.sh
cd ..

Run STA Inference

STA backend:

export FASTVIDEO_ATTENTION_BACKEND=SLIDING_TILE_ATTN

Ready-to-run examples:

• HunyuanVideo: scripts/inference/v1_inference_hunyuan_STA.sh
• Wan2.1-T2V-14B: scripts/inference/v1_inference_wan_STA.sh

Run:

bash scripts/inference/v1_inference_hunyuan_STA.sh
# or
bash scripts/inference/v1_inference_wan_STA.sh

Both scripts already set STA-related env vars:

• FASTVIDEO_ATTENTION_BACKEND=SLIDING_TILE_ATTN
• FASTVIDEO_ATTENTION_CONFIG to an STA mask strategy JSON

STA Mask Strategy Files

• HunyuanVideo config: assets/mask_strategy_hunyuan.json
• Wan config: assets/mask_strategy_wan.json

STA Mask Search (Wan2.1-T2V-14B)

Run mask search + tuning from repo root:

bash examples/inference/sta_mask_search/inference_wan_sta.sh

What this script does:

• Runs STA_searching first.
• Runs STA_tuning next (skip_time_steps=12 by default).
• Uses prompt shards from assets/prompt_0.txt to assets/prompt_7.txt.

Important notes:

• Default script is set to 8 GPUs (num_gpu=8). If needed, edit examples/inference/sta_mask_search/inference_wan_sta.sh.
• STA searching/tuning currently supports 69x768x1280 (Wan setting).

Generated files:

• Search results: output/mask_search_result_pos_1280x768/
• Tuned strategy: output/mask_search_strategy_1280x768/mask_strategy_s12.json

Use the tuned mask for STA inference:

export FASTVIDEO_ATTENTION_BACKEND=SLIDING_TILE_ATTN
export FASTVIDEO_ATTENTION_CONFIG=output/mask_search_strategy_1280x768/mask_strategy_s12.json
python examples/inference/sta_mask_search/wan_example.py --STA_mode STA_inference --num_gpus 1

Citation

@article{zhang2025fast,
  title={Fast video generation with sliding tile attention},
  author={Zhang, Peiyuan and Chen, Yongqi and Su, Runlong and Ding, Hangliang and Stoica, Ion and Liu, Zhengzhong and Zhang, Hao},
  journal={arXiv preprint arXiv:2502.04507},
  year={2025}
}