StreamSense: Streaming Social Task Detection with Selective Vision-Language Model Routing
Han Wang, Deyi Ji, Lanyun Zhu, Jiebo Luo, Roy Ka-Wei Lee
TL;DR
This paper tackles real-time streaming social task detection (SSTD) by balancing accuracy and efficiency under partial, asynchronous multimodal evidence. It introduces StreamSense, a selective-routing framework that uses a lightweight Streaming Encoder for most timestamps and escalates difficult cases to a Vision-Language Model (VLM) expert, with an explicit deferral option for low-context moments. The encoder is trained with a cross-modal contrastive loss and an IoU-weighted cross-entropy to reduce boundary interference caused by segment-level supervision, while the VLM routing strategy controls when to invoke or defer, dramatically reducing latency and compute relative to VLM-only systems. Empirical results on MOSI, MOSEI, and HateClipSeg show StreamSense achieves higher accuracy than encoder-only baselines and substantially lowers VLM usage (approx. 27%) and latency (~0.3 s), demonstrating the value of selective escalation and deferral for practical streaming social monitoring. The work advances real-time multimodal moderation and analytics by providing a model-agnostic, efficiency-conscious framework with robust performance under streaming constraints.
Abstract
Live streaming platforms require real-time monitoring and reaction to social signals, utilizing partial and asynchronous evidence from video, text, and audio. We propose StreamSense, a streaming detector that couples a lightweight streaming encoder with selective routing to a Vision-Language Model (VLM) expert. StreamSense handles most timestamps with the lightweight streaming encoder, escalates hard/ambiguous cases to the VLM, and defers decisions when context is insufficient. The encoder is trained using (i) a cross-modal contrastive term to align visual/audio cues with textual signals, and (ii) an IoU-weighted loss that down-weights poorly overlapping target segments, mitigating label interference across segment boundaries. We evaluate StreamSense on multiple social streaming detection tasks (e.g., sentiment classification and hate content moderation), and the results show that StreamSense achieves higher accuracy than VLM-only streaming while only occasionally invoking the VLM, thereby reducing average latency and compute. Our results indicate that selective escalation and deferral are effective primitives for understanding streaming social tasks. Code is publicly available on GitHub.
