Generating video descriptions in natural language (a.k.a. video captioning)
is a more challenging task than image captioning as the videos are
intrinsically more complicated than images in two aspects. First, videos cover
a broader range of topics, such as news, music, sports and so on. Second,
multiple topics could coexist in the same video. In this paper, we propose a
novel caption model, topic-guided model (TGM), to generate topic-oriented
descriptions for videos in the wild via exploiting topic information. In
addition to predefined topics, i.e., category tags crawled from the web, we
also mine topics in a data-driven way based on training captions by an
unsupervised topic mining model. We show that data-driven topics reflect a
better topic schema than the predefined topics. As for testing video topic
prediction, we treat the topic mining model as teacher to train the student,
the topic prediction model, by utilizing the full multi-modalities in the video
especially the speech modality. We propose a series of caption models to
exploit topic guidance, including implicitly using the topics as input features
to generate words related to the topic and explicitly modifying the weights in
the decoder with topics to function as an ensemble of topic-aware language
decoders. Our comprehensive experimental results on the current largest video
caption dataset MSR-VTT prove the effectiveness of our topic-guided model,
which significantly surpasses the winning performance in the 2016 MSR video to
language challenge.

本文提出了一种基于主题导向模型 (TGM) 的视频描述生成模型，同时采用网络爬取的分类标签和无监督话题挖掘模型中的数据驱动话题挖掘来生成面向主题的视频描述。在当前最大的视频字幕数据集 MSR-VTT 上，我们的模型显著超过了 2016 年 MSR 视频到语言挑战赛的获胜表现。