🤖 AI Summary
Current multimodal large language models (MLLMs) struggle to jointly model intra-frame spatial relationships and inter-frame causal dynamics in complex video question answering. To address this, we propose STAR, a spatiotemporal reasoning framework based on tool-augmented reasoning: it introduces a strategic tool scheduling mechanism and progressive key region localization; constructs an extensible, shortcut-free video toolset; and integrates spatiotemporal disentangled modeling, multi-granularity feature extraction, and sequential tool invocation control. Evaluated on VideoMME and LongVideoBench, STAR achieves improvements of +8.2% and +4.6%, respectively, demonstrating significantly enhanced fine-grained spatiotemporal understanding. The codebase and tool library are publicly released, establishing a novel paradigm for autonomous video-analytic agents.
📝 Abstract
Video Question Answering (VideoQA) task serves as a critical playground for evaluating whether foundation models can effectively perceive, understand, and reason about dynamic real-world scenarios. However, existing Multimodal Large Language Models (MLLMs) struggle with simultaneously modeling spatial relationships within video frames and understanding the causal dynamics of temporal evolution on complex and reasoning-intensive VideoQA task. In this work, we equip MLLM with a comprehensive and extensible Video Toolkit, to enhance MLLM's spatiotemporal reasoning capabilities and ensure the harmony between the quantity and diversity of tools. To better control the tool invocation sequence and avoid toolchain shortcut issues, we propose a Spatiotemporal Reasoning Framework (STAR) that strategically schedules temporal and spatial tools, thereby progressively localizing the key area in the video. Our STAR framework enhances GPT-4o using lightweight tools, achieving an 8.2% gain on VideoMME and 4.6% on LongVideoBench. We believe that our proposed Video Toolkit and STAR framework make an important step towards building autonomous and intelligent video analysis assistants. The code is publicly available at https://github.com/fansunqi/VideoTool.