传统的视听模型具有独立的音频和视频分支。我们设计了一个统一的音频和视频处理模型，称为统一音频 - 视听模型（UAVM）。在本文中，我们描述了UAVM，报告其在VGGSOUND上的新最新音频事件分类精度为65.8％，并描述模型的有趣属性。

Humans perceive the world by concurrently processing and fusing high-dimensional inputs from multiple modalities such as vision and audio. Machine perception models, in stark contrast, are typically modality-specific and optimised for unimodal benchmarks, and hence late-stage fusion of final representations or predictions from each modality (`late-fusion') is still a dominant paradigm for multimodal video classification. Instead, we introduce a novel transformer based architecture that uses `fusion bottlenecks' for modality fusion at multiple layers. Compared to traditional pairwise self-attention, our model forces information between different modalities to pass through a small number of bottleneck latents, requiring the model to collate and condense the most relevant information in each modality and only share what is necessary. We find that such a strategy improves fusion performance, at the same time reducing computational cost. We conduct thorough ablation studies, and achieve state-of-the-art results on multiple audio-visual classification benchmarks including Audioset, Epic-Kitchens and VGGSound. All code and models will be released.

Vision transformers (ViTs) have achieved impressive results on various computer vision tasks in the last several years. In this work, we study the capability of frozen ViTs, pretrained only on visual data, to generalize to audio-visual data without finetuning any of its original parameters. To do so, we propose a latent audio-visual hybrid (LAVISH) adapter that adapts pretrained ViTs to audio-visual tasks by injecting a small number of trainable parameters into every layer of a frozen ViT. To efficiently fuse visual and audio cues, our LAVISH adapter uses a small set of latent tokens, which form an attention bottleneck, thus, eliminating the quadratic cost of standard cross-attention. Compared to the existing modality-specific audio-visual methods, our approach achieves competitive or even better performance on various audio-visual tasks while using fewer tunable parameters and without relying on costly audio pretraining or external audio encoders. Our code is available at https://genjib.github.io/project_page/LAVISH/

来自视频数据的多模态学习最近看过，因为它允许在没有人为注释的情况下培训语义有意义的嵌入，从而使得零射击检索和分类等任务。在这项工作中，我们提出了一种多模态，模态无政府主义融合变压器方法，它学会在多个模态之间交换信息，例如视频，音频和文本，并将它们集成到加入的多模态表示中，以获取聚合的嵌入多模态时间信息。我们建议培训系统的组合丢失，单个模态以及成对的方式，明确地留出任何附加组件，如位置或模态编码。在测试时间时，产生的模型可以处理和融合任意数量的输入模态。此外，变压器的隐式属性允许处理不同长度的输入。为了评估所提出的方法，我们在大规模HOWASET上培训模型，并评估四个具有挑战性的基准数据集上产生的嵌入空间获得最先进的视频检索和零射击视频动作定位。

视频分类的视听广义零拍学习需要了解音频和视觉信息之间的关系，以便能够在测试时识别出新颖的，以前看不见的类别的样本。可以利用视频数据中音频和视觉数据之间的自然语义和时间对齐，以学习在测试时概括以概括为看不见类的强大表示。我们为音频概括的零拍学习提供了一个多模式和时间跨注意框架（\ modelname）。它的输入是从预先训练的网络获得的时间对齐音频和视觉功能。鼓励该框架专注于跨时间的跨模式对应关系，而不是在模式中的自我注意力，从而显着提高了表现。我们表明，我们提出的框架摄入时间功能会在\ ucf，\ vgg和\ \ \ \ \ \ \ \ \ vistion基准测试基准上获得最新的性能。复制所有结果的代码可在\ url {https://github.com/explainableml/tcaf-gzsl}上获得。

多模式分类是人类以人为本的机器学习中的核心任务。我们观察到信息跨多模式融合在多模式融合之前，信息在偶像中具有高度互补的信息，因此在多模式融合之前可以彻底稀释。为此，我们呈现稀疏的融合变压器（SFT），一种用于现有最先进的方法的变压器的新型多模式融合方法，同时具有大大降低了内存占用和计算成本。我们想法的关键是稀疏池块，可在跨模式建模之前减少单峰令牌集合。评估在多个多模式基准数据集上进行，用于广泛的分类任务。在类似的实验条件下的多个基准上获得最先进的性能，同时报告计算成本和内存要求降低六倍。广泛的消融研究展示了在天真的方法中结合稀疏和多式化学习的好处。这铺平了在低资源设备上实现多模级学习的方式。

我们可以训练一个能够处理多个模态和数据集的单个变压器模型，同时分享几乎所有的学习参数？我们呈现Polyvit，一种培训的模型，在图像，音频和视频上接受了讲述这个问题。通过在单一的方式上培训不同的任务，我们能够提高每个任务的准确性，并在5个标准视频和音频分类数据集中实现最先进的结果。多种模式和任务上的共同训练Polyvit会导致一个更具参数效率的模型，并学习遍历多个域的表示。此外，我们展示了实施的共同培训和实用，因为我们不需要调整数据集的每个组合的超级参数，但可以简单地调整来自标准的单一任务培训。

We present Masked Audio-Video Learners (MAViL) to train audio-visual representations. Our approach learns with three complementary forms of self-supervision: (1) reconstruction of masked audio and video input data, (2) intra- and inter-modal contrastive learning with masking, and (3) self-training by reconstructing joint audio-video contextualized features learned from the first two objectives. Pre-training with MAViL not only enables the model to perform well in audio-visual classification and retrieval tasks but also improves representations of each modality in isolation, without using information from the other modality for fine-tuning or inference. Empirically, MAViL sets a new state-of-the-art on AudioSet (53.1 mAP) and VGGSound (67.1% accuracy). For the first time, a self-supervised audio-visual model outperforms ones that use external supervision on these benchmarks. Code will be available soon.

在本文中，我们考虑了视听同步的问题应用于视频`in-wild'（即，超越语音的一般类）。作为一项新任务，我们识别并策划具有高视听相关性的测试集，即VGG-SOCK SYNC。我们比较了一些专门设计的基于变压器的架构变体，用于模拟任意长度的音频和视觉信号，同时显着降低训练期间的内存要求。我们进一步对策划数据集进行了深入的分析，并定义了开放域视听同步的评估度量。我们在标准唇读语音基准测试中应用我们的方法，LRS2和LRS3，在各个方面的消融。最后，我们在新的VGG-SOCKC SYNC视频数据集中设置了与超过160个不同类别的通用视听同步的第一个基准。在所有情况下，我们所提出的模型通过显着的保证金优于以前的最先进。

We present XKD, a novel self-supervised framework to learn meaningful representations from unlabelled video clips. XKD is trained with two pseudo tasks. First, masked data reconstruction is performed to learn modality-specific representations. Next, self-supervised cross-modal knowledge distillation is performed between the two modalities through teacher-student setups to learn complementary information. To identify the most effective information to transfer and also to tackle the domain gap between audio and visual modalities which could hinder knowledge transfer, we introduce a domain alignment strategy for effective cross-modal distillation. Lastly, to develop a general-purpose solution capable of handling both audio and visual streams, a modality-agnostic variant of our proposed framework is introduced, which uses the same backbone for both audio and visual modalities. Our proposed cross-modal knowledge distillation improves linear evaluation top-1 accuracy of video action classification by 8.4% on UCF101, 8.1% on HMDB51, 13.8% on Kinetics-Sound, and 14.2% on Kinetics400. Additionally, our modality-agnostic variant shows promising results in developing a general-purpose network capable of handling different data streams. The code is released on the project website.

Visual and audio modalities are highly correlated, yet they contain different information. Their strong correlation makes it possible to predict the semantics of one from the other with good accuracy. Their intrinsic differences make cross-modal prediction a potentially more rewarding pretext task for self-supervised learning of video and audio representations compared to within-modality learning. Based on this intuition, we propose Cross-Modal Deep Clustering (XDC), a novel selfsupervised method that leverages unsupervised clustering in one modality (e.g., audio) as a supervisory signal for the other modality (e.g., video). This cross-modal supervision helps XDC utilize the semantic correlation and the differences between the two modalities. Our experiments show that XDC outperforms single-modality clustering and other multi-modal variants. XDC achieves state-of-the-art accuracy among self-supervised methods on multiple video and audio benchmarks. Most importantly, our video model pretrained on large-scale unlabeled data significantly outperforms the same model pretrained with full-supervision on ImageNet and Kinetics for action recognition on HMDB51 and UCF101. To the best of our knowledge, XDC is the first self-supervised learning method that outperforms large-scale fully-supervised pretraining for action recognition on the same architecture.

In this paper our objectives are, first, networks that can embed audio and visual inputs into a common space that is suitable for cross-modal retrieval; and second, a network that can localize the object that sounds in an image, given the audio signal. We achieve both these objectives by training from unlabelled video using only audio-visual correspondence (AVC) as the objective function. This is a form of crossmodal self-supervision from video. To this end, we design new network architectures that can be trained for cross-modal retrieval and localizing the sound source in an image, by using the AVC task. We make the following contributions: (i) show that audio and visual embeddings can be learnt that enable both within-mode (e.g. audio-to-audio) and between-mode retrieval; (ii) explore various architectures for the AVC task, including those for the visual stream that ingest a single image, or multiple images, or a single image and multi-frame optical flow; (iii) show that the semantic object that sounds within an image can be localized (using only the sound, no motion or flow information); and (iv) give a cautionary tale on how to avoid undesirable shortcuts in the data preparation.

大规模未标记数据集的预培训显示了计算机视觉和自然语言处理领域的令人印象深刻的性能改进。鉴于大规模教学视频数据集的出现，预训练视频编码器的常见策略是使用随附的语音作为弱监管。但是，由于演讲用于监督预培训，视频编码器从未见过，这不会学会处理该模态。我们解决了当前预训练方法的这种缺点，这未能利用口语语言中的丰富的线索。我们的提议是使用所有可用的视频模型作为监督，即外观，声音和转录语音预先列车。我们在输入中掩盖了整个模态并使用其他两个模态预测它。这鼓励每个码头与其他方式合作，我们的视频编码器学会处理外观和音频以及语音。我们展示了我们在How2R，YouScook2和浓缩电影数据集上视频检索的“模态屏蔽”预培训方法的卓越性能。

我们呈现了一个用于学习视听表示的自我监督的框架。在我们的框架中引入了一种小说概念，其中除了学习模态和标准的“同步的”跨模型关系之外，riscross也会学习“异步”的跨模式关系。我们展示通过放松音频和视觉模态之间的时间同步性，网络了解强劲的时间不变的表示。我们的实验表明，音频和视觉方式的强大增强，可放松交叉模态时间同步优化性能。要预先绘制我们提出的框架，我们使用具有不同大小，动力学，动力学-400和augioset的不同数据集。学习的表示是在许多下游任务中评估的，即行动识别，声音分类和检索。 Crisscross显示了动作识别的最先进的性能（UCF101和HMDB51）和声音分类（ESC50）。将公开可用的代码和预赠品模型。

Videos are a rich source of multi-modal supervision. In this work, we learn representations using self-supervision by leveraging three modalities naturally present in videos: visual, audio and language streams. To this end, we introduce the notion of a multimodal versatile network -a network that can ingest multiple modalities and whose representations enable downstream tasks in multiple modalities. In particular, we explore how best to combine the modalities, such that fine-grained representations of the visual and audio modalities can be maintained, whilst also integrating text into a common embedding. Driven by versatility, we also introduce a novel process of deflation, so that the networks can be effortlessly applied to the visual data in the form of video or a static image. We demonstrate how such networks trained on large collections of unlabelled video data can be applied on video, video-text, image and audio tasks. Equipped with these representations, we obtain state-of-the-art performance on multiple challenging benchmarks including UCF101, HMDB51, Kinetics600, Audioset and ESC-50 when compared to previous self-supervised work. Our models are publicly available [1, 2, 3]. * Equal contribution. † Work done during an internship at DeepMind. 34th Conference on Neural Information Processing Systems (NeurIPS 2020),

我们使用无卷积的变压器架构提出了一种从未标记数据学习多式式表示的框架。具体而言，我们的视频音频文本变压器（Vatt）将原始信号作为输入提取，提取丰富的多式化表示，以使各种下游任务受益。我们使用多模式对比损失从头划线训练Vatt端到端，并通过视频动作识别，音频事件分类，图像分类和文本到视频检索的下游任务评估其性能。此外，我们通过共享三种方式之间的重量来研究模型 - 无话的单骨架变压器。我们表明，无卷积VATT优于下游任务中的最先进的Convnet架构。特别是，Vatt的视觉变压器在动力学-400上实现82.1％的高精度82.1％，在动力学-600，72.7％的动力学-700上的72.7％，以及时间的时间，新的记录，在避免受监督的预训练时，新的记录。通过从头划伤训练相同的变压器，转移到图像分类导致图像分类导致78.7％的ImageNet精度为64.7％，尽管视频和图像之间的域间差距，我们的模型概括了我们的模型。 Vatt的音雅音频变压器还通过在没有任何监督的预训练的情况下在Audioset上实现39.4％的地图来设置基于波形的音频事件识别的新记录。 Vatt的源代码是公开的。

生成视频数据的表示对于推进机器感知领域至关重要。大多数当前的技术都依赖于手工注册的数据，这些数据可能很难使用，生成昂贵且难以扩展。在这项工作中，我们提出了一种基于对比度学习的新颖学习方法，熔岩能够以一种自我监督的方式学习联合语言，音频和视频表示。我们使用变压器编码器在动力学700数据集上预先训练熔岩来学习每种模式的表示形式。然后，我们证明，熔岩在使用未标记的数据的一小部分时，与当前最新的自我监督和弱监督预审技术进行了竞争性能。

在Enocentric视频中，行动在快速连续中发生。我们利用了行动的时间背景，并提出了一种学习参加周围行动的方法，以提高识别性能。为了纳入时间上下文，我们提出了一种基于变换器的多模式模型，可将视频和音频作为输入模式摄取，具有显式语言模型，提供动作序列上下文来增强预测。我们在史诗厨房和EGTEA数据集上测试我们的方法，报告最先进的性能。我们的消融展示了利用时间上下文的优势以及将音频输入模态和语言模型结合到Rescore预测。代码和模型在：https://github.com/ekazakos/mtcn。

我们提出了一种为给定视频推荐音乐曲目的方法，反之亦然，基于它们的时间对齐及其在艺术层面上的信件。我们提出了一种自我监督的方法，该方法直接从数据中学习了这一对应，而无需任何人类注释。为了捕获解决任务所需的高级概念，我们建议使用每种模式的变压器网络对视频和音乐信号的长期时间上下文进行建模。实验表明，这种方法强烈胜过不利用时间上下文的替代方案。我们的贡献的结合提高了先前最高现状的检索准确性高达10倍。这种强大的改进使我们能够引入广泛的分析和应用。例如，我们可以根据视觉定义的属性来调节音乐检索。

The heterogeneity gap problem is the main challenge in cross-modal retrieval. Because cross-modal data (e.g. audiovisual) have different distributions and representations that cannot be directly compared. To bridge the gap between audiovisual modalities, we learn a common subspace for them by utilizing the intrinsic correlation in the natural synchronization of audio-visual data with the aid of annotated labels. TNN-CCCA is the best audio-visual cross-modal retrieval (AV-CMR) model so far, but the model training is sensitive to hard negative samples when learning common subspace by applying triplet loss to predict the relative distance between inputs. In this paper, to reduce the interference of hard negative samples in representation learning, we propose a new AV-CMR model to optimize semantic features by directly predicting labels and then measuring the intrinsic correlation between audio-visual data using complete cross-triple loss. In particular, our model projects audio-visual features into label space by minimizing the distance between predicted label features after feature projection and ground label representations. Moreover, we adopt complete cross-triplet loss to optimize the predicted label features by leveraging the relationship between all possible similarity and dissimilarity semantic information across modalities. The extensive experimental results on two audio-visual double-checked datasets have shown an improvement of approximately 2.1% in terms of average MAP over the current state-of-the-art method TNN-CCCA for the AV-CMR task, which indicates the effectiveness of our proposed model.