  Untrimmed videos have interrelated events, dependencies, context, overlapping
events, object-object interactions, domain specificity, and other semantics
that are worth highlighting while describing a video in natural language. Owing
to such a vast diversity, a single sentence can only correctly describe a
portion of the video. Dense Video Captioning (DVC) aims at detecting and
describing different events in a given video. The term DVC originated in the
2017 ActivityNet challenge, after which considerable effort has been made to
address the challenge. Dense Video Captioning is divided into three sub-tasks:
(1) Video Feature Extraction (VFE), (2) Temporal Event Localization (TEL), and
(3) Dense Caption Generation (DCG). This review aims to discuss all the studies
that claim to perform DVC along with its sub-tasks and summarize their results.
We also discuss all the datasets that have been used for DVC. Lastly, we
highlight some emerging challenges and future trends in the field.
