🤖 AI Summary
Existing autoregressive video generation models adopt individual frames as the fundamental prediction unit; however, this assumption lacks rigorous empirical validation, resulting in poor temporal coherence and low inference efficiency. To address this, we propose VideoAR—the first unified autoregressive framework supporting multi-granularity spatio-temporal units. Its core innovation lies in replacing frame-wise modeling with learnable spatio-temporal cubes as the basic prediction unit. VideoAR jointly models spatial and temporal dimensions through multi-scale refinement, key-frame-guided detail preservation, and flexible sequence decomposition. On the VBench benchmark, VideoAR significantly outperforms state-of-the-art methods: it achieves superior visual quality, faster inference speed, and—crucially—enables efficient generation of minute-long videos for the first time.
📝 Abstract
Autoregressive models for video generation typically operate frame-by-frame, extending next-token prediction from language to video's temporal dimension. We question that unlike word as token is universally agreed in language if frame is a appropriate prediction unit? To address this, we present VideoAR, a unified framework that supports a spectrum of prediction units including full frames, key-detail frames, multiscale refinements, and spatiotemporal cubes. Among these designs, we find model video generation using extit{spatiotemporal} cubes as prediction units, which allows autoregressive models to operate across both spatial and temporal dimensions simultaneously. This approach eliminates the assumption that frames are the natural atomic units for video autoregression. We evaluate VideoAR across diverse prediction strategies, finding that cube-based prediction consistently delivers superior quality, speed, and temporal coherence. By removing the frame-by-frame constraint, our video generator surpasses state-of-the-art baselines on VBench while achieving faster inference and enabling seamless scaling to minute-long sequences. We hope this work will motivate rethinking sequence decomposition in video and other spatiotemporal domains.