  Large-scale image-language pretrained models, e.g., CLIP, have demonstrated
remarkable proficiency in acquiring general multi-modal knowledge through
web-scale image-text data. Despite the impressive performance of image-language
models on various image tasks, how to effectively expand them on general video
understanding remains an area of ongoing exploration. In this paper, we
investigate the image-to-video transferring from the perspective of the model
and the data, unveiling two key obstacles impeding the adaptation of
image-language models: non-generalizable temporal modeling and partially
misaligned video-text data. To address these challenges, we propose
Spatial-Temporal Auxiliary Network with Mutual-guided alignment module
(Mug-STAN), a simple yet effective framework extending image-text model to
diverse video tasks and video-text data.Specifically, STAN adopts a branch
structure with decomposed spatial-temporal modules to enable generalizable
temporal modeling, while Mug suppresses misalignment by introducing token-wise
feature aggregation of either modality from the other. Extensive experimental
results verify Mug-STAN significantly improves adaptation of language-image
pretrained models such as CLIP and CoCa at both video-text post-pretraining and
finetuning stages. With our solution, state-of-the-art zero-shot and finetuning
results on various downstream datasets, including MSR-VTT, DiDeMo, LSMDC,
Kinetics-400, Something-Something-2, HMDB-51, UCF- 101, and AVA, are achieved.
Moreover, by integrating pretrained Mug-STAN with the emerging multimodal
dialogue model, we can realize zero-shot video chatting. Codes are available at
https://github.com/farewellthree/STAN
