  With the success of large language models (LLMs), integrating the vision
model into LLMs to build vision-language foundation models has gained much more
interest recently. However, existing LLM-based large multimodal models (e.g.,
Video-LLaMA, VideoChat) can only take in a limited number of frames for short
video understanding. In this study, we mainly focus on designing an efficient
and effective model for long-term video understanding. Instead of trying to
process more frames simultaneously like most existing work, we propose to
process videos in an online manner and store past video information in a memory
bank. This allows our model to reference historical video content for long-term
analysis without exceeding LLMs' context length constraints or GPU memory
limits. Our memory bank can be seamlessly integrated into current multimodal
LLMs in an off-the-shelf manner. We conduct extensive experiments on various
video understanding tasks, such as long-video understanding, video question
answering, and video captioning, and our model can achieve state-of-the-art
performances across multiple datasets. Code available at
https://boheumd.github.io/MA-LMM/.
