README.md

---
title: Loopy
emoji: 🔁
colorFrom: gray
colorTo: red
sdk: gradio
sdk_version: 6.26.0
app_file: app.py
pinned: false
python_version: "3.12"
startup_duration_timeout: 1h
short_description: Seamless looping video generation with Wan2.2 + Loopy
models:
  - htdong/Loopy
  - Wan-AI/Wan2.2-T2V-A14B
  - lightx2v/Wan2.2-Distill-Loras
---

# 🔁 Loopy — Seamless Video Loop Generation

Demo of **[Loopy](https://huggingface.co/htdong/Loopy)** — *Seamless Video Loop Generation via
Anchored Looping Shift of Positional Embedding*
([code](https://github.com/WeChatCV/Loopy) ·
[project page](https://donghaotian123.github.io/Loopy/)).

Loopy turns [Wan2.2-T2V-A14B](https://huggingface.co/Wan-AI/Wan2.2-T2V-A14B) into a *looping*
video generator. Its trick is the **anchored looping shift of positional embedding**: inside
self-attention block `i` the temporal RoPE frequencies are cyclically rolled by
`shift = 0 if i == 0 else (i - 1) % (F - 1) + 1` (with `F` latent frames), which puts the
temporal positions on a circle so the last frame becomes a neighbour of the first one and the
clip loops without a visible seam. Two small LoRAs (high-noise / low-noise expert) adapt the
base model to that shifted geometry.

## What this Space runs

Faithful port of the reference implementation (`generate_2.2_new.py`,
`Wan2.2/wan2/text2video_roll.py`, `Wan2.2/wan2/modules/model_roll.py`) onto 🧨 diffusers'
`WanPipeline` so it fits on ZeroGPU:

| | |
|---|---|
| Base | `linoyts/Wan2.2-T2V-A14B-Diffusers-BF16` (bf16 mirror of `Wan-AI/Wan2.2-T2V-A14B-Diffusers`) |
| LoRAs merged | LightX2V 4-step distillation (rank 64, high + low) + Loopy (rank 4, high + low) |
| RoPE | anchored looping shift, applied to self-attention only, per the paper |
| Sampler | UniPC, flow sigmas, `shift = 12.0`, 4 steps, `guidance = 1.0` (CFG-free) |
| Default output | 832×480, 53 frames @ 16 fps (the repo's `test.sh` setting) |
| Quantization | fp8 dynamic (both 14B experts), int8 weight-only (UMT5-XXL text encoder) |

Prompts in the examples are the ones the authors showcase on the project page.

## Prompting tips

Describe motion that is naturally periodic or continuous — falling snow, drifting clouds,
flowing water, a walking animal, a rotating object — and state the style and shot type.
English and Chinese both work.