GenCompositor: Generative Video Compositing with Diffusion Transformer

1 SECE, Peking University     2 ARC Lab, Tencent PCG    
3 GVC Lab, Great Bay University     4 The Chinese University of Hong Kong
Corresponding authors*
        

GenCompositor takes a foreground video and a background video as inputs and generates composited video results according to user-specified trajectory and scale parameter.

Abstract

Video compositing combines live-action footage to create video production, serving as a crucial technique in video creation and film production. Traditional pipelines require intensive labor efforts and expert collaboration, resulting in lengthy production cycles and high manpower costs. To address this issue, we automate this process with generative models, called generative video compositing. This new task strives to adaptively inject identity and motion information of foreground video to the target video in an interactive manner, allowing users to customize the size, motion trajectory, and other attributes of the dynamic elements added in final video. Specifically, we designed a novel Diffusion Transformer (DiT) pipeline based on its intrinsic properties. To maintain consistency of the target video before and after editing, we revised a light-weight DiT-based background preservation branch with masked token injection. As to inherit dynamic elements from other sources, a DiT fusion block is proposed using full self-attention, along with a simple yet effective foreground augmentation for training. Besides, for fusing background and foreground videos with different layouts based on user control, we developed a novel position embedding, named Extended Rotary Position Embedding (ERoPE). Finally, we curated a dataset comprising 61K sets of videos for our new task, called VideoComp. This data includes complete dynamic elements and high-quality target videos. Experiments demonstrate that our method effectively realizes generative video compositing, outperforming existing possible solutions in fidelity and consistency.

Summary Video

Results and Comparison

Compositing results of GenCompositor

Click the left or right button to browse more results.

GenCompositor supports user-specified trajectory and rescale parameter, where rescale parameter can be time-varying to realize near-large-far-small effects.

Video Harmonization

Comparing our results with baselines.


Trajectory-controlled Generation

Comparing our results with baselines.


Extended Application of Video Element Removal

GenCompositor supports related applications, including video element removal and replace.

BibTeX


	@article{yang2025gencompositor,
	    title={GenCompositor: Generative Video Compositing with Diffusion Transformer},
	    author={Shuzhou Yang and Xiaoyu Li and Xiaodong Cun and Guangzhi Wang and Lingen Li and Ying Shan and Jian Zhang},
	    journal={arXiv preprint arXiv:2509.02460},
	    year={2025},
	}