arXiv Computation and Language

Select, Compress, Reinvest: A Controlled Study of Visual-Token Allocation in Long-Video MLLMs

The study investigates how long‑video language models decide which frames to keep, compress, and reuse, testing each decision in isolation across six selection rules, three benchmarks, and two answering models. It finds that selecting frames based on queries yields the biggest performance boost, that halving spatial resolution costs little, and that reallocating saved tokens to more compressed frames can further improve accuracy. The work also highlights the importance of a unified evaluation harness to avoid misleading comparisons.

arXiv AI
Oct 2

VETO: Video Efficient Token Optimization for Vision Language Models

VETO (Video Efficient Token Optimization for Vision Language Models) is a plug‑in that reduces the quadratic cost of visual tokens in long‑video inference by applying dual‑axis compression: an intra‑frame compressor merges semantically similar tokens within each frame, and an inter‑frame compressor merges temporally redundant frames. By first compressing spatial dimensions, VETO lowers the cost of subsequent global temporal matching, surpassing single‑axis methods and achieving up to 45% faster inference on models such as LLaVA‑OneVision‑7B while maintaining or improving accuracy. The approach is universally applicable across LLaVA‑OneVision, InternVL‑2.5, and LongVA, preserving or enhancing zero‑shot accuracy even under extreme token budgets.

By Gueter Josmy Faure, Hao Ping Wang, Min-Hung Chen, Winston H. Hsu
arXiv Computer Vision
Sep 10

MotionBlind: Probing the Illusion of Motion Understanding in Video-LLMs

arXiv:2609.09528v1 Announce Type: new Abstract: Video large language models (Video-LLMs) are increasingly used as the perceptual front end of world models, a role that assumes they can read motion: h...

By Dhairya Bhatia, Bishoy Galoaa, Oliver Fritsche, Shahid Kamal, Muhammad Obaidullah Abdul Salam, Umer Saleem, Om Rastogi, Frania Felix Chettiar, Nesli Erdogmus, Sarah Ostadabbas
arXiv Machine Learning
Sep 22

Are Coreset Selection Methods Worth Their Cost?

The paper evaluates coreset selection methods by incorporating both selection and training time into a unified wall‑clock budget, using a standardized benchmark across four datasets and multiple selectors. Across numerous budget anchors, simple random or full‑data training consistently outperforms sophisticated selectors, and selection costs are dominated by a full‑dataset scan that cannot be amortized. The study also identifies when subset reuse can justify selection and reports several correctness fixes in a popular codebase.

By Yangze Liu, Zhongyi Han
arXiv Machine Learning
Oct 22

Cache Locally, Recompute Selectively for Streaming Video Understanding

The paper introduces FrameBlend, a plug‑and‑play technique for streaming video understanding that selectively recomputes key‑value (KV) caches at query time. By re‑prefilling only query‑relevant video tokens, FrameBlend allows shorter attention windows during idle prefill, cutting prefill cost while boosting accuracy. Experiments on three SVU frameworks and five benchmarks show up to 3.9‑point accuracy gains and significant reductions in FLOPs and processing time.

By Junhyeok Lee, Sangyoon Lee, Jaeho Lee
arXiv Machine Learning
Oct 23

Drift Says When, Budget Says How Much: Rate-Controlled KV Re-selection for Long-Form Multimodal Generation

The paper introduces Rate‑Controlled Refresh (RCR), a method for re‑selecting key‑value (KV) cache entries during long‑form multimodal generation. RCR lets attention drift determine when and where to refresh, while a per‑sample controller limits how often this occurs, and a low‑rank drift detector keeps the process GPU‑resident. Across multiple models and tasks, RCR outperforms the per‑step retrieval method InfiniGen by up to 3.8 ROUGE‑L points and remains close to exact per‑step re‑selection, with reduced data movement and a smaller GPU‑resident detector.

By Bin Hu, Yingbo Xiao