  Significant advancements in video question answering (VideoQA) have been made
thanks to thriving large image-language pretraining frameworks. Although these
image-language models can efficiently represent both video and language
branches, they typically employ a goal-free vision perception process and do
not interact vision with language well during the answer generation, thus
omitting crucial visual cues. In this paper, we are inspired by the human
recognition and learning pattern and propose VideoDistill, a framework with
language-aware (i.e., goal-driven) behavior in both vision perception and
answer generation process. VideoDistill generates answers only from
question-related visual embeddings and follows a thinking-observing-answering
approach that closely resembles human behavior, distinguishing it from previous
research. Specifically, we develop a language-aware gating mechanism to replace
the standard cross-attention, avoiding language's direct fusion into visual
representations. We incorporate this mechanism into two key components of the
entire framework. The first component is a differentiable sparse sampling
module, which selects frames containing the necessary dynamics and semantics
relevant to the questions. The second component is a vision refinement module
that merges existing spatial-temporal attention layers to ensure the extraction
of multi-grained visual semantics associated with the questions. We conduct
experimental evaluations on various challenging video question-answering
benchmarks, and VideoDistill achieves state-of-the-art performance in both
general and long-form VideoQA datasets. In Addition, we verify that
VideoDistill can effectively alleviate the utilization of language shortcut
solutions in the EgoTaskQA dataset.
