While there has been increasing interest in the task of describing video with natural language, current computer vision algorithms are still severely limited in terms of the variability and complexity of the videos and their associated language that they can recognize. This is in part due to the simplicity of current benchmarks, which mostly focus on specific fine-grained domains with limited videos and simple descriptions. While researchers have provided several benchmark datasets for image captioning, we are not aware of any large-scale video description dataset with comprehensive categories yet diverse video content.In this paper we present MSR-VTT (standing for "MSR-Video to Text") which is a new large-scale video benchmark for video understanding, especially the emerging task of translating video to text. This is achieved by collecting 257 popular queries from a commercial video search engine, with 118 videos for each query. In its current version, MSR-VTT provides 10K web video clips with 41.2 hours and 200K clip-sentence pairs in total, covering the most comprehensive categories and diverse visual content, and representing the largest dataset in terms of sentence and vocabulary. Each clip is annotated with about 20 natural sentences by 1,327 AMT workers. We present a detailed analysis of MSR-VTT in comparison to a complete set of existing datasets, together with a summarization of different state-of-the-art video-to-text approaches. We also provide an extensive evaluation of these approaches on this dataset, showing that the hybrid Recurrent Neural Networkbased approach, which combines single-frame and motion representations with soft-attention pooling strategy, yields the best generalization capability on MSR-VTT.

自动音频字幕是一项跨模式翻译任务，旨在为给定的音频剪辑生成自然语言描述。近年来，随着免费可用数据集的发布，该任务受到了越来越多的关注。该问题主要通过深度学习技术解决。已经提出了许多方法，例如研究不同的神经网络架构，利用辅助信息，例如关键字或句子信息来指导字幕生成，并采用了不同的培训策略，这些策略极大地促进了该领域的发展。在本文中，我们对自动音频字幕的已发表贡献进行了全面综述，从各种现有方法到评估指标和数据集。我们还讨论了公开挑战，并设想可能的未来研究方向。

Learning text-video embeddings usually requires a dataset of video clips with manually provided captions. However, such datasets are expensive and time consuming to create and therefore difficult to obtain on a large scale. In this work, we propose instead to learn such embeddings from video data with readily available natural language annotations in the form of automatically transcribed narrations. The contributions of this work are three-fold. First, we introduce HowTo100M: a large-scale dataset of 136 million video clips sourced from 1.22M narrated instructional web videos depicting humans performing and describing over 23k different visual tasks. Our data collection procedure is fast, scalable and does not require any additional manual annotation. Second, we demonstrate that a text-video embedding trained on this data leads to state-ofthe-art results for text-to-video retrieval and action localization on instructional video datasets such as YouCook2 or CrossTask. Finally, we show that this embedding transfers well to other domains: fine-tuning on generic Youtube videos (MSR-VTT dataset) and movies (LSMDC dataset) outperforms models trained on these datasets alone. Our dataset, code and models are publicly available [1]. * Equal contribution.

Most natural videos contain numerous events. For example, in a video of a "man playing a piano", the video might also contain "another man dancing" or "a crowd clapping". We introduce the task of dense-captioning events, which involves both detecting and describing events in a video. We propose a new model that is able to identify all events in a single pass of the video while simultaneously describing the detected events with natural language. Our model introduces a variant of an existing proposal module that is designed to capture both short as well as long events that span minutes. To capture the dependencies between the events in a video, our model introduces a new captioning module that uses contextual information from past and future events to jointly describe all events. We also introduce ActivityNet Captions, a large-scale benchmark for dense-captioning events. ActivityNet Captions contains 20k videos amounting to 849 video hours with 100k total descriptions, each with it's unique start and end time. Finally, we report performances of our model for dense-captioning events, video retrieval and localization.

近期和越来越越来越多的视频 - 语言研究的兴趣已经推动了大规模数据集的开发，可实现数据密集型机器学习技术。相比之下，在评估这些数据集的适应性时，已经进行了有限的努力进行视频 - 语言接地任务。最近的作品已经开始发现这些数据集中的重大限制，这表明最先进的技术通常会过度地覆盖到隐藏的数据集偏差。在这项工作中，我们呈现MAD（电影音频描述），这是一种新颖的基准，从扩充现有视频数据集的范式，其中包含文本注释，并专注于爬行和对齐主流电影的可用音频描述。 MAD包含超过384,000个自然语言句子，该句子接地为超过1,200小时的视频，并且在视频 - 语言接地数据集中展示目前诊断的偏差显着减少。疯狂的收集策略使新颖且更具挑战性的视频 - 语言接地版本，其中短时间时刻（通常秒长）必须在多样化的长型视频中准确地接地，可以持续长达三个小时。

连接视觉和语言在生成智能中起着重要作用。因此，已经致力于图像标题的大型研究工作，即用句法和语义有意义的句子描述图像。从2015年开始，该任务通常通过由Visual Encoder组成的管道和文本生成的语言模型来解决任务。在这些年来，两种组件通过对象区域，属性，介绍多模态连接，完全关注方法和伯特早期融合策略的利用而显着发展。但是，无论令人印象深刻的结果，图像标题的研究还没有达到结论性答案。这项工作旨在提供图像标题方法的全面概述，从视觉编码和文本生成到培训策略，数据集和评估度量。在这方面，我们量化地比较了许多相关的最先进的方法来确定架构和培训策略中最有影响力的技术创新。此外，讨论了问题的许多变体及其开放挑战。这项工作的最终目标是作为理解现有文献的工具，并突出显示计算机视觉和自然语言处理的研究领域的未来方向可以找到最佳的协同作用。

本文对过去二十年来对自然语言生成（NLG）的研究提供了全面的审查，特别是与数据到文本生成和文本到文本生成深度学习方法有关，以及NLG的新应用技术。该调查旨在（a）给出关于NLG核心任务的最新综合，以及该领域采用的建筑;（b）详细介绍各种NLG任务和数据集，并提请注意NLG评估中的挑战，专注于不同的评估方法及其关系;（c）强调一些未来的强调和相对近期的研究问题，因为NLG和其他人工智能领域的协同作用而增加，例如计算机视觉，文本和计算创造力。

We present an approach named JSFusion (Joint Sequence Fusion) that can measure semantic similarity between any pairs of multimodal sequence data (e.g. a video clip and a language sentence). Our multimodal matching network consists of two key components. First, the Joint Semantic Tensor composes a dense pairwise representation of two sequence data into a 3D tensor. Then, the Convolutional Hierarchical Decoder computes their similarity score by discovering hidden hierarchical matches between the two sequence modalities. Both modules leverage hierarchical attention mechanisms that learn to promote well-matched representation patterns while prune out misaligned ones in a bottom-up manner. Although the JSFusion is a universal model to be applicable to any multimodal sequence data, this work focuses on video-language tasks including multimodal retrieval and video QA. We evaluate the JS-Fusion model in three retrieval and VQA tasks in LSMDC, for which our model achieves the best performance reported so far. We also perform multiple-choice and movie retrieval tasks for the MSR-VTT dataset, on which our approach outperforms many state-of-the-art methods.

Models based on deep convolutional networks have dominated recent image interpretation tasks; we investigate whether models which are also recurrent, or "temporally deep", are effective for tasks involving sequences, visual and otherwise. We develop a novel recurrent convolutional architecture suitable for large-scale visual learning which is end-to-end trainable, and demonstrate the value of these models on benchmark video recognition tasks, image description and retrieval problems, and video narration challenges. In contrast to current models which assume a fixed spatio-temporal receptive field or simple temporal averaging for sequential processing, recurrent convolutional models are "doubly deep" in that they can be compositional in spatial and temporal "layers". Such models may have advantages when target concepts are complex and/or training data are limited. Learning long-term dependencies is possible when nonlinearities are incorporated into the network state updates. Long-term RNN models are appealing in that they directly can map variable-length inputs (e.g., video frames) to variable length outputs (e.g., natural language text) and can model complex temporal dynamics; yet they can be optimized with backpropagation. Our recurrent long-term models are directly connected to modern visual convnet models and can be jointly trained to simultaneously learn temporal dynamics and convolutional perceptual representations. Our results show such models have distinct advantages over state-of-the-art models for recognition or generation which are separately defined and/or optimized.

Can we teach a robot to recognize and make predictions for activities that it has never seen before? We tackle this problem by learning models for video from text. This paper presents a hierarchical model that generalizes instructional knowledge from large-scale text corpora and transfers the knowledge to video. Given a portion of an instructional video, our model recognizes and predicts coherent and plausible actions multiple steps into the future, all in rich natural language. To demonstrate the capabilities of our model, we introduce the \emph{Tasty Videos Dataset V2}, a collection of 4022 recipes for zero-shot learning, recognition and anticipation. Extensive experiments with various evaluation metrics demonstrate the potential of our method for generalization, given limited video data for training models.

Automatically describing the content of an image is a fundamental problem in artificial intelligence that connects computer vision and natural language processing. In this paper, we present a generative model based on a deep recurrent architecture that combines recent advances in computer vision and machine translation and that can be used to generate natural sentences describing an image. The model is trained to maximize the likelihood of the target description sentence given the training image. Experiments on several datasets show the accuracy of the model and the fluency of the language it learns solely from image descriptions. Our model is often quite accurate, which we verify both qualitatively and quantitatively. For instance, while the current state-of-the-art BLEU-1 score (the higher the better) on the Pascal dataset is 25, our approach yields 59, to be compared to human performance around 69. We also show BLEU-1 score improvements on Flickr30k, from 56 to 66, and on SBU, from 19 to 28. Lastly, on the newly released COCO dataset, we achieve a BLEU-4 of 27.7, which is the current state-of-the-art.

视频标题旨在根据内容生成自然语言描述，其中表示学习起到至关重要的作用。现有方法主要通过对地理文本的生成标题的字词比较来在监督学习框架内开发，而不会完全利用语言语义。在这项工作中，我们提出了一个分层模块化网络，在生成字幕之前从三个级别桥接视频表示和语言语义。特别是，层次结构由以下组成：（i）实体级别，其突出显示最有可能在字幕中提及的对象。 （ii）谓词级别，它学习在突出显示的对象上调节的行动，并由标题中的谓词进行监督。 （iii）句子级别，了解全局语义表示，并受到整个标题的监督。每个级别由一个模块实现。广泛的实验结果表明，该方法对两个广泛使用的基准测试的最先进模型有利地表现出：MSVD 104.0％和苹果酒评分中的MSR-VTT 51.5％。

Books are a rich source of both fine-grained information, how a character, an object or a scene looks like, as well as high-level semantics, what someone is thinking, feeling and how these states evolve through a story. This paper aims to align books to their movie releases in order to provide rich descriptive explanations for visual content that go semantically far beyond the captions available in current datasets.To align movies and books we exploit a neural sentence embedding that is trained in an unsupervised way from a large corpus of books, as well as a video-text neural embedding for computing similarities between movie clips and sentences in the book. We propose a context-aware CNN to combine information from multiple sources. We demonstrate good quantitative performance for movie/book alignment and show several qualitative examples that showcase the diversity of tasks our model can be used for.

视频字幕的规范方法决定了用于从离线提取的密集视频特征学习的标题生成模型。这些特征提取器通常在以固定帧速率采样的视频帧上操作，并且通常在图像/视频理解任务上培训，而不适用于视频标题数据。在这项工作中，我们展示了Swinbert，一种用于视频字幕的基于端到端的变换器的模型，它将视频帧贴片直接作为输入，并输出自然语言描述。我们的方法代替利用多个2D / 3D特征提取器，该方法采用视频变压器来编码可适应可变长度的视频输入，而无需专用设计，可以针对不同的帧速率进行专用设计。基于该模型架构，我们表明视频标题可以从更密集地采样的视频帧中受益匪浅，而不是以前的成功，用于视频和语言理解任务的稀疏采样视频帧（例如，视频问题应答）。此外，为了避免连续视频帧中固有的冗余，我们建议通过更好的远程视频序列建模来自适应地学习稀疏的注意掩模并优化任务特定性能改进。通过对5个视频字幕数据集的广泛实验，我们展示了Swinbert通过较大的余量来实现对以前的方法的整体性能改进。此外，学习的稀疏注意力掩模将限制推向新的技术，可以在不同的视频长度和不同的数据集之间传输。

Our experience of the world is multimodal -we see objects, hear sounds, feel texture, smell odors, and taste flavors. Modality refers to the way in which something happens or is experienced and a research problem is characterized as multimodal when it includes multiple such modalities. In order for Artificial Intelligence to make progress in understanding the world around us, it needs to be able to interpret such multimodal signals together. Multimodal machine learning aims to build models that can process and relate information from multiple modalities. It is a vibrant multi-disciplinary field of increasing importance and with extraordinary potential. Instead of focusing on specific multimodal applications, this paper surveys the recent advances in multimodal machine learning itself and presents them in a common taxonomy. We go beyond the typical early and late fusion categorization and identify broader challenges that are faced by multimodal machine learning, namely: representation, translation, alignment, fusion, and co-learning. This new taxonomy will enable researchers to better understand the state of the field and identify directions for future research.

Despite progress in perceptual tasks such as image classification, computers still perform poorly on cognitive tasks such as image description and question answering. Cognition is core to tasks that involve not just recognizing, but reasoning about our visual world. However, models used to tackle the rich content in images for cognitive tasks are still being trained using the same datasets designed for perceptual tasks. To achieve success at cognitive tasks, models need to understand the interactions and relationships between objects in

为了为视频产生适当的标题，推理需要确定相关的概念并注意它们之间的空间关系以及剪辑中的时间发展。我们的端到端编码器视频字幕框架结合了两个基于变压器的体系结构，这是一种用于单个关节时空视频分析的改编变压器，以及用于高级文本生成的基于自我注意力的解码器。此外，我们引入了一种自适应框架选择方案，以减少所需的传入帧数，同时在训练两个变压器时保持相关内容。此外，我们通过汇总每个样本的所有基础真理标题来估计与视频字幕相关的语义概念。我们的方法在MSVD以及大规模的MSR-VTT和VATEX基准数据集上实现了最新的结果，并考虑了多个自然语言产生（NLG）指标。对多样性得分的其他评估突出了我们生成的标题结构的表现力和多样性。

The remarkable success of deep learning in various domains relies on the availability of large-scale annotated datasets. However, obtaining annotations is expensive and requires great effort, which is especially challenging for videos. Moreover, the use of human-generated annotations leads to models with biased learning and poor domain generalization and robustness. As an alternative, self-supervised learning provides a way for representation learning which does not require annotations and has shown promise in both image and video domains. Different from the image domain, learning video representations are more challenging due to the temporal dimension, bringing in motion and other environmental dynamics. This also provides opportunities for video-exclusive ideas that advance self-supervised learning in the video and multimodal domain. In this survey, we provide a review of existing approaches on self-supervised learning focusing on the video domain. We summarize these methods into four different categories based on their learning objectives: 1) pretext tasks, 2) generative learning, 3) contrastive learning, and 4) cross-modal agreement. We further introduce the commonly used datasets, downstream evaluation tasks, insights into the limitations of existing works, and the potential future directions in this area.

在描述自然语言中的时空事件时，视频标题模型主要依赖于编码器的潜在视觉表示。 Encoder-Decoder模型的最新进展主要参加编码器特征，主要是与解码器的线性交互。然而，对视觉数据的日益增长的模型复杂性鼓励更明确的特征交互，用于微粒信息，目前在视频标题域中不存在。此外，特征聚合方法已经用于通过连接或使用线性层来揭示更丰富的视觉表示。虽然在某种程度上为视频进行了语义重叠的功能集，但这些方法导致客观不匹配和功能冗余。此外，字幕中的多样性是从几种有意义的角度表达一个事件的基本组成部分，目前缺少时间，即视频标题域。为此，我们提出了变化堆叠的本地注意网络（VSLAN），该网络（VSLAN）利用低级别的双线性汇集进行自我细分功能交互，并以折扣方式堆叠多个视频特征流。每个特征堆栈的学习属性都有助于我们所提出的多样性编码模块，然后是解码查询阶段，以便于结束到最终的不同和自然标题，而没有任何明确的属性监督。我们在语法和多样性方面评估MSVD和MSR-VTT数据集的VSLAN。 VSLAN的苹果酒得分优于当前的现成方法，分别在MSVD和MSR-VTT上的$ 4.5 \％$ 4.8 \％$。在同一数据集上，VSLAN在标题分集度量中实现了竞争力。

Computer vision has a great potential to help our daily lives by searching for lost keys, watering flowers or reminding us to take a pill.To succeed with such tasks, computer vision methods need to be trained from real and diverse examples of our daily dynamic scenes. While most of such scenes are not particularly exciting, they typically do not appear on YouTube, in movies or TV broadcasts. So how do we collect sufficiently many diverse but boring samples representing our lives? We propose a novel Hollywood in Homes approach to collect such data. Instead of shooting videos in the lab, we ensure diversity by distributing and crowdsourcing the whole process of video creation from script writing to video recording and annotation. Following this procedure we collect a new dataset, Charades, with hundreds of people recording videos in their own homes, acting out casual everyday activities. The dataset is composed of 9,848 annotated videos with an average length of 30 seconds, showing activities of 267 people from three continents, and over 15% of the videos have more than one person. Each video is annotated by multiple free-text descriptions, action labels, action intervals and classes of interacted objects. In total, Charades provides 27,847 video descriptions, 66,500 temporally localized intervals for 157 action classes and 41,104 labels for 46 object classes. Using this rich data, we evaluate and provide baseline results for several tasks including action recognition and automatic description generation. We believe that the realism, diversity, and casual nature of this dataset will present unique challenges and new opportunities for computer vision community.