Given an untrimmed video and a text query, natural language video localization (NLVL) is to locate a matching span from the video that semantically corresponds to the query. Existing solutions formulate NLVL either as a ranking task and apply multimodal matching architecture, or as a regression task to directly regress the target video span. In this work, we address NLVL task with a span-based QA approach by treating the input video as text passage. We propose a video span localizing network (VSLNet), on top of the standard span-based QA framework, to address NLVL. The proposed VSLNet tackles the differences between NLVL and span-based QA through a simple and yet effective query-guided highlighting (QGH) strategy. The QGH guides VSLNet to search for matching video span within a highlighted region. Through extensive experiments on three benchmark datasets, we show that the proposed VSLNet outperforms the state-of-the-art methods; and adopting span-based QA framework is a promising direction to solve NLVL.

本文提出了基于跨度问答的视频段定位网络（VSLNet）作为自然语言视频定位（NLVL）任务的解决方案，并通过有效的查询引导突出显示策略解决了NLVL与跨度问答之间的差异。在三个基准数据集上的实验表明，该方法优于现有的最优方法，采用笔画问答框架是解决NLVL的一个有前途的方向。

面向自然语言视频定位的基于Span的本地化网络