视频问题回答是一项具有挑战性的任务，需要共同理解语言输入，单个视频帧中的视觉信息以及视频中发生的事件的时间信息。在本文中，我们提出了一种新颖的多流视频编码器，用于视频问题回答，它使用多个视频输入和一种新的视频文本迭代迭代式共同指定方法来回答与视频相关的各种问题。我们在几个数据集上进行了实验评估该模型，例如MSRVTT-QA，MSVD-QA，IVQA，超过了大幅度的先前最新时间。同时，我们的模型将所需的Gflops从150-360减少到只有67，从而产生了高效的视频答案模型。

We present Answer-Me, a task-aware multi-task framework which unifies a variety of question answering tasks, such as, visual question answering, visual entailment, visual reasoning. In contrast to previous works using contrastive or generative captioning training, we propose a novel and simple recipe to pre-train a vision-language joint model, which is multi-task as well. The pre-training uses only noisy image captioning data, and is formulated to use the entire architecture end-to-end with both a strong language encoder and decoder. Our results show state-of-the-art performance, zero-shot generalization, robustness to forgetting, and competitive single-task results across a variety of question answering tasks. Our multi-task mixture training learns from tasks of various question intents and thus generalizes better, including on zero-shot vision-language tasks. We conduct experiments in the challenging multi-task and open-vocabulary settings and across a variety of datasets and tasks, such as VQA2.0, SNLI-VE, NLVR2, GQA. We observe that the proposed approach is able to generalize to unseen tasks and that more diverse mixtures lead to higher accuracy in both known and novel tasks.

视频语言（VIDL）建模的巨大挑战在于从图像/视频理解模型和下游Vidl数据中提取的固定视频表示之间的断开。最近的研究试图通过端到端培训来减轻这种断开连接。为了使其进行计算可行，先前的作品倾向于“想象”视频输入，即，将一些稀疏的采样帧馈送到2D CNN中，然后是简单的均值汇集或连接以获得整体视频表示。虽然实现了有希望的结果，但这种简单的方法可能会失去对于执行下游VIDL任务至关重要的时间信息。在这项工作中，我们呈现紫罗兰色，全新的视频语言变压器，采用视频变压器，明确地模拟视频输入的时间动态。此外，与以前的研究不同，发现视频输入上的预训练任务（例如，屏蔽帧建模）不是非常有效的，我们设计了一个新的预训练任务，屏蔽了视觉令牌建模（MVM），以获得更好的视频建模。具体地，原始视频帧修补程序将“令牌化”转换为离散的视觉令牌，目标是基于蒙面的贴片恢复原始的视觉令牌。综合分析展示了通过视频变压器和MVM显式时间建模的有效性。因此，紫罗兰在5个视频问题的回答任务和4个文本到视频检索任务中实现了新的最先进的性能。

To build Video Question Answering (VideoQA) systems capable of assisting humans in daily activities, seeking answers from long-form videos with diverse and complex events is a must. Existing multi-modal VQA models achieve promising performance on images or short video clips, especially with the recent success of large-scale multi-modal pre-training. However, when extending these methods to long-form videos, new challenges arise. On the one hand, using a dense video sampling strategy is computationally prohibitive. On the other hand, methods relying on sparse sampling struggle in scenarios where multi-event and multi-granularity visual reasoning are required. In this work, we introduce a new model named Multi-modal Iterative Spatial-temporal Transformer (MIST) to better adapt pre-trained models for long-form VideoQA. Specifically, MIST decomposes traditional dense spatial-temporal self-attention into cascaded segment and region selection modules that adaptively select frames and image regions that are closely relevant to the question itself. Visual concepts at different granularities are then processed efficiently through an attention module. In addition, MIST iteratively conducts selection and attention over multiple layers to support reasoning over multiple events. The experimental results on four VideoQA datasets, including AGQA, NExT-QA, STAR, and Env-QA, show that MIST achieves state-of-the-art performance and is superior at computation efficiency and interpretability.

近年来，统一的视觉语言框架已经大大提高，其中大多数采用编码器架构将图像文本任务统一为序列到序列的生成。但是，现有的视频语言（VIDL）模型仍需要在每个任务的模型体系结构和培训目标中进行特定于任务的设计。在这项工作中，我们探索了一个统一的VIDL框架薰衣草，其中蒙版语言建模（MLM）用作所有前训练和下游任务的常见接口。这样的统一导致了简化的模型体系结构，在多模式编码器之上，只需要一个轻巧的MLM头，而不是具有更多参数的解码器。令人惊讶的是，实验结果表明，这个统一的框架在14个VIDL基准测试中实现了竞争性能，涵盖了视频问答，文本到视频检索和视频字幕。广泛的分析进一步证明了薰衣草比现有VIDL方法的优势：（i）在多任务列出时仅使用一组参数值支持所有下游任务； （ii）对各种下游任务的几乎没有概括； （iii）在视频问题回答任务上启用零射门评估。代码可从https://github.com/microsoft/lavender获得。

The canonical approach to video-and-language learning (e.g., video question answering) dictates a neural model to learn from offline-extracted dense video features from vision models and text features from language models. These feature extractors are trained independently and usually on tasks different from the target domains, rendering these fixed features sub-optimal for downstream tasks. Moreover, due to the high computational overload of dense video features, it is often difficult (or infeasible) to plug feature extractors directly into existing approaches for easy finetuning. To provide a remedy to this dilemma, we propose a generic framework CLIPBERT that enables affordable endto-end learning for video-and-language tasks, by employing sparse sampling, where only a single or a few sparsely sampled short clips from a video are used at each training step. Experiments on text-to-video retrieval and video question answering on six datasets demonstrate that CLIP-BERT outperforms (or is on par with) existing methods that exploit full-length videos, suggesting that end-to-end learning with just a few sparsely sampled clips is often more accurate than using densely extracted offline features from full-length videos, proving the proverbial less-is-more principle. Videos in the datasets are from considerably different domains and lengths, ranging from 3-second genericdomain GIF videos to 180-second YouTube human activity videos, showing the generalization ability of our approach. Comprehensive ablation studies and thorough analyses are provided to dissect what factors lead to this success. Our code is publicly available. 1 * Equal contribution.

本文提出了一个视频图形变压器（VGT）模型，用于视频Quetion Answering（VideoQA）。 VGT的唯一性是双重的：1）它设计了一个动态图形变压器模块，该模块通过明确捕获视觉对象，它们的关系和动态来编码视频，以进行复杂的时空推理； 2）它利用了删除的视频和文本变压器，以比较视频和文本以执行质量检查，而不是纠缠的跨模式变压器进行答案分类。视觉文本通信是通过其他跨模式相互作用模块完成的。借助更合理的视频编码和质量检查解决方案，我们表明VGT可以在挑战动态关系推理的视频中取得更好的性能，而不是在没有预处理的情况下。它的性能甚至超过了那些被数百万个外部数据鉴定的模型。我们进一步表明，VGT也可以从自我监督的交叉模式预处理中受益匪浅，但数据的数量级较小。这些结果清楚地表明了VGT的有效性和优势，并揭示了其具有更高数据预处理的潜力。通过全面的分析和一些启发式观察，我们希望VGT能够在现实视频中促进VQA研究超越粗略的认识/描述，以实现细粒度的关系推理。我们的代码可在https://github.com/sail-sg/vgt上找到。

Video Question Answering methods focus on commonsense reasoning and visual cognition of objects or persons and their interactions over time. Current VideoQA approaches ignore the textual information present in the video. Instead, we argue that textual information is complementary to the action and provides essential contextualisation cues to the reasoning process. To this end, we propose a novel VideoQA task that requires reading and understanding the text in the video. To explore this direction, we focus on news videos and require QA systems to comprehend and answer questions about the topics presented by combining visual and textual cues in the video. We introduce the ``NewsVideoQA'' dataset that comprises more than $8,600$ QA pairs on $3,000+$ news videos obtained from diverse news channels from around the world. We demonstrate the limitations of current Scene Text VQA and VideoQA methods and propose ways to incorporate scene text information into VideoQA methods.

在过去的几年中，训练前模型的出现将单峰领域（例如计算机视觉（CV）和自然语言处理（NLP））带到了一个新时代。实质性的作品表明它们对下游大学任务有益，并避免从头开始训练新的模型。那么，此类预训练的模型可以应用于多模式任务吗？研究人员探索了这个问题并取得了重大进展。本文调查了视觉预训练（VLP）的最新进展和新的前沿，包括图像文本和视频文本预训练。为了使读者更好地掌握VLP，我们首先从五个方面回顾了其最新进展：功能提取，模型体系结构，培训预训练目标，预训练数据集和下游任务。然后，我们详细概述了特定的VLP模型。最后，我们讨论了VLP中的新边界。据我们所知，这是对VLP的首次调查。我们希望这项调查能够阐明VLP领域的未来研究。

视频问题回答（VideoQA）是一项复杂的任务，需要多种模式数据进行培训。但是，对视频的问题和答案的手动注释是乏味的，禁止可扩展性。为了解决这个问题，最近的方法考虑了零拍设置，而无需手动注释视觉问题。特别是，一种有前途的方法调整了在网络级文本数据中预测的冻结自回归语言模型，以适应多模式输入。相比之下，我们在这里建立在冷冻双向语言模型（BILM）的基础上，并表明这种方法为零拍出的VideoQA提供了更强大，更便宜的替代方案。特别是（i）我们使用轻型训练模块将视觉输入与冷冻的BILM结合在一起，（ii）我们使用Web-Scrafe Multi-Mododal数据训练此类模块，最后（iii）我们通过掩盖语言执行零声录像带推断建模，其中蒙版文本是给定问题的答案。我们提出的方法Frozenbilm在零摄影的视频中的表现优于最高的，包括LSMDC-FIB，包括LSMDC-FIB，IVQA，MSRVTT-QA，MSVD-QA，ActivityNet-QA，TGIF-FRAMEQA，TGIF-FRAMEQA，，TGIF-FRAMEQA，，TGIF-FRAMEQA，，，MSRVTT-QA，MSRVTT-QA，MSRVTT-QA，MSRVTT-QA，MSRVTT-QA，，均优于最新技术。 How2QA和TVQA。它还在几次且完全监督的环境中展示了竞争性能。我们的代码和模型将在https://antoyang.github.io/frozenbilm.html上公开提供。

本文介绍了Omnivl，这是一种新的基础模型，旨在使用一种通用体系结构来支持图像语言和视频语言任务。它为图像和视频输入采用了统一的基于变压器的视觉编码器，因此可以执行联合图像语言和视频语言预处理。我们首次证明了这样的范式受益于图像和视频任务，而不是传统的单向传输（例如，使用图像语言来帮助视频语言）。为此，我们提出了对图像语言和视频语言的脱钩关节预处理，以有效地将视觉模型分解为空间和时间维度，并在图像和视频任务上获得性能提升。此外，我们引入了一种新颖的统一视觉对比度（UNIVLC）损失，以利用图像文本，视频文本，图像标签（例如，图像分类），视频标签（例如，视频动作识别）在一起受到监督和吵闹的监督预处理数据都尽可能多地利用。无需额外的任务适配器，Omnivl可以同时支持仅视觉任务（例如，图像分类，视频操作识别），跨模式对齐任务（例如，图像/视频 - 文本检索）和多模式理解和生成任务（例如，图像/视频问答，字幕）。我们在各种下游任务上评估Omnivl，并以相似的模型大小和数据量表获得最新的或竞争结果。

Video-language pre-training has advanced the performance of various downstream video-language tasks. However, most previous methods directly inherit or adapt typical image-language pre-training paradigms to video-language pre-training, thus not fully exploiting the unique characteristic of video, i.e., temporal. In this paper, we propose a Hierarchical Temporal-Aware video-language pre-training framework, HiTeA, with two novel pre-training tasks for modeling cross-modal alignment between moments and texts as well as the temporal relations of video-text pairs. Specifically, we propose a cross-modal moment exploration task to explore moments in videos, which results in detailed video moment representation. Besides, the inherent temporal relations are captured by aligning video-text pairs as a whole in different time resolutions with multi-modal temporal relation exploration task. Furthermore, we introduce the shuffling test to evaluate the temporal reliance of datasets and video-language pre-training models. We achieve state-of-the-art results on 15 well-established video-language understanding and generation tasks, especially on temporal-oriented datasets (e.g., SSv2-Template and SSv2-Label) with 8.6% and 11.1% improvement respectively. HiTeA also demonstrates strong generalization ability when directly transferred to downstream tasks in a zero-shot manner. Models and demo will be available on ModelScope.

Video-language pre-training is crucial for learning powerful multi-modal representation. However, it typically requires a massive amount of computation. In this paper, we develop SMAUG, an efficient pre-training framework for video-language models. The foundation component in SMAUG is masked autoencoders. Different from prior works which only mask textual inputs, our masking strategy considers both visual and textual modalities, providing a better cross-modal alignment and saving more pre-training costs. On top of that, we introduce a space-time token sparsification module, which leverages context information to further select only "important" spatial regions and temporal frames for pre-training. Coupling all these designs allows our method to enjoy both competitive performances on text-to-video retrieval and video question answering tasks, and much less pre-training costs by 1.9X or more. For example, our SMAUG only needs about 50 NVIDIA A6000 GPU hours for pre-training to attain competitive performances on these two video-language tasks across six popular benchmarks.

This work explores an efficient approach to establish a foundational video-text model for tasks including open-vocabulary video classification, text-to-video retrieval, video captioning and video question-answering. We present VideoCoCa that reuses a pretrained image-text contrastive captioner (CoCa) model and adapt it to video-text tasks with minimal extra training. While previous works adapt image-text models with various cross-frame fusion modules (for example, cross-frame attention layer or perceiver resampler) and finetune the modified architecture on video-text data, we surprisingly find that the generative attentional pooling and contrastive attentional pooling layers in the image-text CoCa design are instantly adaptable to ``flattened frame embeddings'', yielding a strong zero-shot transfer baseline for many video-text tasks. Specifically, the frozen image encoder of a pretrained image-text CoCa takes each video frame as inputs and generates \(N\) token embeddings per frame for totally \(T\) video frames. We flatten \(N \times T\) token embeddings as a long sequence of frozen video representation and apply CoCa's generative attentional pooling and contrastive attentional pooling on top. All model weights including pooling layers are directly loaded from an image-text CoCa pretrained model. Without any video or video-text data, VideoCoCa's zero-shot transfer baseline already achieves state-of-the-art results on zero-shot video classification on Kinetics 400/600/700, UCF101, HMDB51, and Charades, as well as zero-shot text-to-video retrieval on MSR-VTT and ActivityNet Captions. We also explore lightweight finetuning on top of VideoCoCa, and achieve strong results on video question-answering (iVQA, MSRVTT-QA, MSVD-QA) and video captioning (MSR-VTT, ActivityNet, Youcook2). Our approach establishes a simple and effective video-text baseline for future research.

We present ViLBERT (short for Vision-and-Language BERT), a model for learning task-agnostic joint representations of image content and natural language. We extend the popular BERT architecture to a multi-modal two-stream model, processing both visual and textual inputs in separate streams that interact through co-attentional transformer layers. We pretrain our model through two proxy tasks on the large, automatically collected Conceptual Captions dataset and then transfer it to multiple established vision-and-language tasks -visual question answering, visual commonsense reasoning, referring expressions, and caption-based image retrieval -by making only minor additions to the base architecture. We observe significant improvements across tasks compared to existing task-specific modelsachieving state-of-the-art on all four tasks. Our work represents a shift away from learning groundings between vision and language only as part of task training and towards treating visual grounding as a pretrainable and transferable capability.Preprint. Under review.

Astounding results from Transformer models on natural language tasks have intrigued the vision community to study their application to computer vision problems. Among their salient benefits, Transformers enable modeling long dependencies between input sequence elements and support parallel processing of sequence as compared to recurrent networks e.g., Long short-term memory (LSTM). Different from convolutional networks, Transformers require minimal inductive biases for their design and are naturally suited as set-functions. Furthermore, the straightforward design of Transformers allows processing multiple modalities (e.g., images, videos, text and speech) using similar processing blocks and demonstrates excellent scalability to very large capacity networks and huge datasets. These strengths have led to exciting progress on a number of vision tasks using Transformer networks. This survey aims to provide a comprehensive overview of the Transformer models in the computer vision discipline. We start with an introduction to fundamental concepts behind the success of Transformers i.e., self-attention, large-scale pre-training, and bidirectional feature encoding. We then cover extensive applications of transformers in vision including popular recognition tasks (e.g., image classification, object detection, action recognition, and segmentation), generative modeling, multi-modal tasks (e.g., visual-question answering, visual reasoning, and visual grounding), video processing (e.g., activity recognition, video forecasting), low-level vision (e.g., image super-resolution, image enhancement, and colorization) and 3D analysis (e.g., point cloud classification and segmentation). We compare the respective advantages and limitations of popular techniques both in terms of architectural design and their experimental value. Finally, we provide an analysis on open research directions and possible future works. We hope this effort will ignite further interest in the community to solve current challenges towards the application of transformer models in computer vision.

We present an effective method for fusing visual-and-language representations for several question answering tasks including visual question answering and visual entailment. In contrast to prior works that concatenate unimodal representations or use only cross-attention, we compose multimodal representations via channel fusion. By fusing on the channels, the model is able to more effectively align the tokens compared to standard methods. These multimodal representations, which we call compound tokens are generated with cross-attention transformer layers. First, vision tokens are used as queries to retrieve compatible text tokens through cross-attention. We then chain the vision tokens and the queried text tokens along the channel dimension. We call the resulting representations compound tokens. A second group of compound tokens are generated using an analogous process where the text tokens serve as queries to the cross-attention layer. We concatenate all the compound tokens for further processing with multimodal encoder. We demonstrate the effectiveness of compound tokens using an encoder-decoder vision-language model trained end-to-end in the open-vocabulary setting. Compound Tokens achieve highly competitive performance across a range of question answering tasks including GQA, VQA2.0, and SNLI-VE.

我们研究了联合视频和语言（VL）预培训，以实现跨模型学习和益处丰富的下游VL任务。现有的作品要么提取低质量的视频特征或学习有限的文本嵌入，但忽略了高分辨率视频和多样化的语义可以显着提高跨模型学习。在本文中，我们提出了一种新的高分辨率和多样化的视频 - 语言预训练模型（HD-VILA），用于许多可视任务。特别是，我们收集具有两个不同属性的大型数据集：1）第一个高分辨率数据集包括371.5k小时的720p视频，2）最多样化的数据集涵盖15个流行的YouTube类别。为了启用VL预培训，我们通过学习丰富的时空特征的混合变压器联合优化HD-VILA模型，以及多峰变压器，用于强制学习视频功能与多样化文本的交互。我们的预训练模式实现了新的最先进的导致10 VL了解任务和2个新颖的文本到视觉生成任务。例如，我们以零拍摄MSR-VTT文本到视频检索任务的相对增加38.5％R @ 1的相对增长，高分辨率数据集LSMDC为53.6％。学习的VL嵌入也有效地在文本到视觉操纵和超分辨率任务中产生视觉上令人愉悦和语义相关结果。

蒙版的视觉建模（MVM）最近已被证明对视觉预训练有效。虽然在视频输入（例如，蒙版框架建模）上进行了类似的重建目标，在视频语言（VIDL）预训练中探索了类似的重建目标，但先前研究中的预提取的视频功能在预训练期间无法通过MVM进行完善，因此无法通过MVM进行完善为下游性能不满意。在这项工作中，我们系统地检查了MVM在VIDL学习的背景下的潜力。具体而言，我们的研究基于完全端到端的视频变压器（Violet），该视频变压器（Violet）减轻了固定视频表示与MVM培训之间的断开连接。总共探索了MVM的八个不同的重建目标，从低级像素值和定向梯度到高级深度图，光流，离散的视觉令牌和潜在的视觉特征。我们进行全面的实验，并就导致有效MVM培训的因素提供见解。从经验上讲，我们展示了通过MVM目标预先训练的紫罗兰色，可以在13个VIDL基准测试中取得显着改进，从视频问题回答，视频字幕到文本到视频检索等等。

The foundation models have recently shown excellent performance on a variety of downstream tasks in computer vision. However, most existing vision foundation models simply focus on image-level pretraining and adpation, which are limited for dynamic and complex video-level understanding tasks. To fill the gap, we present general video foundation models, InternVideo, by taking advantage of both generative and discriminative self-supervised video learning. Specifically, InternVideo efficiently explores masked video modeling and video-language contrastive learning as the pretraining objectives, and selectively coordinates video representations of these two complementary frameworks in a learnable manner to boost various video applications. Without bells and whistles, InternVideo achieves state-of-the-art performance on 39 video datasets from extensive tasks including video action recognition/detection, video-language alignment, and open-world video applications. Especially, our methods can obtain 91.1% and 77.2% top-1 accuracy on the challenging Kinetics-400 and Something-Something V2 benchmarks, respectively. All of these results effectively show the generality of our InternVideo for video understanding. The code will be released at https://github.com/OpenGVLab/InternVideo .