arXiv AI

Seeing Before Synthesizing: VLM-Guided Transition Event Discovery for Weakly-Supervised Dense Video Captioning

The paper introduces Seeing Before Synthesizing (SBS), a weakly-supervised dense video captioning framework that uses a vision‑language model to generate frame‑level narratives for gaps between events and detect transitions based on semantic changes. SBS refines temporal masks by aligning transition points with vision‑language cues, rather than relying on rigidly placed synthetic captions. Experiments on ActivityNet Captions and YouCook2 show that SBS achieves state‑of‑the‑art results in both captioning and localization tasks.

arXiv AI
2d ago

MEV: A Multi-Event Video Dataset for Long-Take Generation

MEV is a multi‑event video dataset created to support long‑take video generation. It contains high‑quality real‑world videos where subjects perform distinct, non‑overlapping events with precise temporal boundaries and fine‑grained procedural annotations. The dataset includes a comprehensive annotation pipeline that segments videos into temporally grounded events and generates structured captions at both global and event levels, enabling event‑centric evaluation and improved long‑take event transitions in generation experiments.

By Peiyuan Zhu, Shaoan Xie, Yifan Shen, Wen Tian, Zijian Li, Guangyi Chen, Kun Zhang
arXiv AI
Sep 21

VidOmni-Bench: A Benchmark for Fine-Grained Video Understanding via Spatio-Temporal Event Verification across Complexity and Duration

VidOmni-Bench is a new benchmark for fine‑grained video understanding that asks models to verify whether each event in dense video captions is supported by the video. It contains 500 videos covering five complexity types and durations from 4 seconds to 90 minutes, and uses human‑verified sentence‑level labels to create hard negatives. Experiments show that Video‑LLMs often hallucinate events, struggle to detect incorrect descriptions, and exhibit varying weaknesses depending on video complexity and duration.

By Changbeen Kim, Junwon Chang, Kipyo Kim, Risa Shinoda, Kuniaki Saito, Donghyun Kim
arXiv Computer Vision
Sep 23

TEMPURA: Temporal Event Masked Prediction and Understanding for Reasoning in Action

arXiv:2505.01583v2 Announce Type: replace Abstract: Understanding causal event relationships and achieving fine-grained temporal grounding in videos remain challenging for vision-language models (VLM...

By Jen-Hao Cheng, Yi-Hao Peng, Huapeng Zhou, Vivian Wang, Huayu Wang, Hsiang-Wei Huang, Wenhao Chai, Hou-I Liu, Kuang-Ming Chen, Cheng-Yen Yang, Yi-Ling Chen, Vibhav Vineet, Qin Cai, Jenq-Neng Hwang
arXiv Computer Vision
Aug 28

PercepCap: Video Captioner with Structured Spatio-Temporal Perception

PercepCap is a video captioning framework that explicitly models spatio‑temporal perception before generating captions. It follows a perceive‑describe chain, first producing a perception trace of object trajectories and temporal events, then generating the final caption conditioned on that trace. The method uses a two‑stage training strategy—supervised fine‑tuning followed by perception‑grounded reinforcement learning—and builds caption‑aligned perception data to ensure the perception trace and caption refer to the same objects and events.

By Yifan Xu, Zihao Wang, Zhixiao Wang, Jiaming Zhang, Yichun Yang, Desen Meng, Yuanxing Zhang, Pengfei Wan, Limin Wang
arXiv Computer Vision
5d ago

CodeCap-Bench: Can Code Serve as a Good Video Caption?

The paper introduces CodeCap-Bench, a benchmark for evaluating whether executable code can serve as an effective video caption. It compares code captions to natural language captions on tasks such as question answering and video reconstruction, finding that code captions yield higher reasoning accuracy and reconstruction fidelity. The study also assesses current multimodal large language models, noting that while proprietary models show promise, they still struggle with complex temporal dynamics, and open‑source models lag significantly.

By Jiafu Tang, Yifan Xu, Eric Tang, Junjie Zhao, Shipeng Luo, Te Sun, Haoxuan Hu, Yiyan Ji, Xinlong Chen, Zihao Wang, Yang Shi, Yuanxing Zhang, Pengfei Wan, Jiaheng Liu
arXiv AI
Sep 15

EventVL: Understand Event Streams via Multimodal Large Language Model

EventVL introduces the first generative event-based multimodal large language model (MLLM) designed for explicit semantic understanding of event streams. The framework leverages a newly annotated dataset of nearly 1.4 million event–image/video–text pairs and incorporates an Event Spatiotemporal Representation to capture comprehensive event information, along with Dynamic Semantic Alignment to refine sparse semantic spaces. Experiments demonstrate that EventVL outperforms existing MLLM baselines in event captioning and scene description generation tasks, advancing the field of event vision.

By Pengteng Li, Yunfan Lu, Pinghao Song, Wuyang Li, Huizai Yao, Hui Xiong
arXiv Computation and Language
Oct 16

EVA-Cap: Optimizing Audiovisual Video Captioning via Event-Centric Alignment

EVA-Cap is a new framework for audiovisual video captioning that breaks captions into atomic audiovisual events, turning unstructured text supervision into event‑centric alignment. The model is trained with supervised fine‑tuning and Group Relative Policy Optimization on a self‑curated dataset, EVA‑Data, which applies event‑centric quality control. Experiments show EVA‑Cap outperforms prior methods on event‑centric metrics (e.g., +9.0% on ChronusAV) while remaining competitive on general captioning benchmarks (e.g., +3.3% on WorldSense).

By Jiapeng Shi, Qiuxia Hou, Jiaqi Leng, Junke Wang, Yanhao Zhang, Haonan Lu, Ziyi Ye, Zuxuan Wu