HERMES: KV Cache as Hierarchical Memory for Efficient Streaming Video Understanding

Fuente: arXiv
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Main Authors: Zhang, Haowei, Yang, Shudong, Fu, Jinlan, Ng, See-Kiong, Qiu, Xipeng
Format: Preprint
Published: 2026
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_version_ 1866910197254979584
author Zhang, Haowei
Yang, Shudong
Fu, Jinlan
Ng, See-Kiong
Qiu, Xipeng
author_facet Zhang, Haowei
Yang, Shudong
Fu, Jinlan
Ng, See-Kiong
Qiu, Xipeng
contents Recent advancements in Multimodal Large Language Models (MLLMs) have demonstrated significant improvement in offline video understanding. However, extending these capabilities to streaming video inputs, remains challenging, as existing models struggle to simultaneously maintain stable understanding performance, real-time responses, and low GPU memory overhead. To address this challenge, we propose HERMES, a novel training-free architecture for real-time and accurate understanding of video streams. Based on a mechanistic attention investigation, we conceptualize KV cache as a hierarchical memory framework that encapsulates video information across multiple granularities. During inference, HERMES reuses a compact KV cache, enabling efficient streaming understanding under resource constraints. Notably, HERMES requires no auxiliary computations upon the arrival of user queries, thereby guaranteeing real-time responses for continuous video stream interactions, which achieves 10$\times$ faster TTFT compared to prior SOTA. Even when reducing video tokens by up to 68% compared with uniform sampling, HERMES achieves superior or comparable accuracy across all benchmarks, with up to 11.4% gains on streaming datasets.
format Preprint
id arxiv_https___arxiv_org_abs_2601_14724
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle HERMES: KV Cache as Hierarchical Memory for Efficient Streaming Video Understanding
Zhang, Haowei
Yang, Shudong
Fu, Jinlan
Ng, See-Kiong
Qiu, Xipeng
Computer Vision and Pattern Recognition
Artificial Intelligence
Computation and Language
Recent advancements in Multimodal Large Language Models (MLLMs) have demonstrated significant improvement in offline video understanding. However, extending these capabilities to streaming video inputs, remains challenging, as existing models struggle to simultaneously maintain stable understanding performance, real-time responses, and low GPU memory overhead. To address this challenge, we propose HERMES, a novel training-free architecture for real-time and accurate understanding of video streams. Based on a mechanistic attention investigation, we conceptualize KV cache as a hierarchical memory framework that encapsulates video information across multiple granularities. During inference, HERMES reuses a compact KV cache, enabling efficient streaming understanding under resource constraints. Notably, HERMES requires no auxiliary computations upon the arrival of user queries, thereby guaranteeing real-time responses for continuous video stream interactions, which achieves 10$\times$ faster TTFT compared to prior SOTA. Even when reducing video tokens by up to 68% compared with uniform sampling, HERMES achieves superior or comparable accuracy across all benchmarks, with up to 11.4% gains on streaming datasets.
title HERMES: KV Cache as Hierarchical Memory for Efficient Streaming Video Understanding
topic Computer Vision and Pattern Recognition
Artificial Intelligence
Computation and Language
url https://arxiv.org/abs/2601.14724