AGE-Sampler: Adaptive-granularity Graph-enhanced Event Sampling for Long-Video Understanding

Yanzi Wang, Tao Dai, Yaohua Zha, Shu-Tao Xia


Abstract
Informative keyframe selection is critical for applying large vision-language models (LVLMs) to long-form video understanding under limited frame budgets. However, existing methods heavily rely on query-frame similarity, which can yield coarse boundaries and miss latent contextual events that are answer-relevant but not explicitly mentioned in the query. To address this issue, we propose AGE-Sampler, a training-free Adaptive-granularity Graph-enhanced Event sampling framework for long-video understanding. AGE-Sampler jointly exploits low-level visual transition cues and query-relevance signals to construct query-adaptive events, thus preserving fine-grained structures in relevant regions while merging low-relevance regions into compact intervals. To recover answer-bearing contextual evidence, we further develop a fine-grained event graph and propagate importance from high-confidence query-relevant anchors via Personalized PageRank, followed by event-level budget allocation and representative keyframe selection. Extensive experiments with different LVLM backbones show that our AGE-Sampler consistently improves long-video understanding performance, achieving average absolute gains of +6.2% on LongVideoBench, +8.8% on MLVU, and +3.8% on Video-MME, while remaining lightweight and plug-and-play.
Anthology ID:
2026.emnlp-main.2383
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
54141–54155
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2383/
DOI:
Bibkey:
Cite (ACL):
Yanzi Wang, Tao Dai, Yaohua Zha, and Shu-Tao Xia. 2026. AGE-Sampler: Adaptive-granularity Graph-enhanced Event Sampling for Long-Video Understanding. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 54141–54155, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
AGE-Sampler: Adaptive-granularity Graph-enhanced Event Sampling for Long-Video Understanding (Wang et al., EMNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.emnlp-main.2383.pdf