🤖 AI Summary
Existing video understanding models rely heavily on large pre-trained image/video encoders, resulting in high computational overhead, substantial energy consumption, and slow inference. To address this, we propose the first encoder-free lightweight video–language understanding architecture, which directly processes raw video frames using only a 45M-parameter spatiotemporal alignment block (STAB). STAB integrates local spatiotemporal encoding, attention-guided spatial downsampling, and hierarchical temporal relation modeling—eliminating the need for external visual encoders. Compared to state-of-the-art methods, our approach reduces parameter count by over 6.5×. On open-domain video question answering benchmarks, it matches or surpasses Video-ChatGPT and Video-LLaVA in overall performance, demonstrates superior temporal reasoning capability, and achieves 3–4× faster inference. Ablation studies comprehensively validate both the efficacy of the encoder-free paradigm and the design principles of STAB.
📝 Abstract
We present an efficient encoder-free approach for video-language understanding that achieves competitive performance while significantly reducing computational overhead. Current video-language models typically rely on heavyweight image encoders (300M-1.1B parameters) or video encoders (1B-1.4B parameters), creating a substantial computational burden when processing multi-frame videos. Our method introduces a novel Spatio-Temporal Alignment Block (STAB) that directly processes video inputs without requiring pre-trained encoders while using only 45M parameters for visual processing - at least a 6.5$ imes$ reduction compared to traditional approaches. The STAB architecture combines Local Spatio-Temporal Encoding for fine-grained feature extraction, efficient spatial downsampling through learned attention and separate mechanisms for modeling frame-level and video-level relationships. Our model achieves comparable or superior performance to encoder-based approaches for open-ended video question answering on standard benchmarks. The fine-grained video question-answering evaluation demonstrates our model's effectiveness, outperforming the encoder-based approaches Video-ChatGPT and Video-LLaVA in key aspects like correctness and temporal understanding. Extensive ablation studies validate our architectural choices and demonstrate the effectiveness of our spatio-temporal modeling approach while achieving 3-4$ imes$ faster processing speeds than previous methods. Code is available at url{https://github.com/jh-yi/Video-Panda}.