AS-Net: active speaker detection using deep audio-visual attention

Active Speaker Detection (ASD) aims at identifying the active speaker among multiple speakers in a video scene. Previous ASD models often seek audio and visual features from long video clips with a complex 3D Convolutional Neural Network (CNN) architecture. However, models based on 3D CNNs can generate discriminative spatial-temporal features, but this comes at the expense of computational complexity, and they frequently face challenges in detecting active speakers in short video clips. This work proposes the Active Speaker Network (AS-Net) model, a simple yet effective ASD method tailored for detecting active speakers in relatively short video clips without relying on 3D CNNs. Instead, it incorporates the Temporal Shift Module (TSM) into 2D CNNs, facilitating the extraction of dense temporal visual features without the need for additional computations. Moreover, self-attention and cross-attention schemes are introduced to enhance long-term temporal audio-visual synchronization, thereby improving ASD performance. Experimental results demonstrate that AS-Net outperforms state-of-the-art 2D CNN-based methods on the AVA-ActiveSpeaker dataset and remains competitive with the methods utilizing more complex architectures.