VideoCanvas: Unified Video Completion from Arbitrary Spatiotemporal
  Patches via In-Context Conditioning
Authors: name: Minghong Cai, name: Qiulin Wang, name: Zongli Ye, name: Wenze Liu, name: Quande Liu, name: Weicai Ye, name: Xintao Wang, name: Pengfei Wan, name: Kun Gai, name: Xiangyu Yue
Organization: Kling Team

We introduce the task of arbitrary spatio-temporal video completion, where a
video is generated from arbitrary, user-specified patches placed at any spatial
location and timestamp, akin to painting on a video canvas. This flexible
formulation naturally unifies many existing controllable video generation
tasks--including first-frame image-to-video, inpainting, extension, and
interpolation--under a single, cohesive paradigm. Realizing this vision,
however, faces a fundamental obstacle in modern latent video diffusion models:
the temporal ambiguity introduced by causal VAEs, where multiple pixel frames
are compressed into a single latent representation, making precise frame-level
conditioning structurally difficult. We address this challenge with
VideoCanvas, a novel framework that adapts the In-Context Conditioning (ICC)
paradigm to this fine-grained control task with zero new parameters. We propose
a hybrid conditioning strategy that decouples spatial and temporal control:
spatial placement is handled via zero-padding, while temporal alignment is
achieved through Temporal RoPE Interpolation, which assigns each condition a
continuous fractional position within the latent sequence. This resolves the
VAE's temporal ambiguity and enables pixel-frame-aware control on a frozen
backbone. To evaluate this new capability, we develop VideoCanvasBench, the
first benchmark for arbitrary spatio-temporal video completion, covering both
intra-scene fidelity and inter-scene creativity. Experiments demonstrate that
VideoCanvas significantly outperforms existing conditioning paradigms,
establishing a new state of the art in flexible and unified video generation.