SF20K Competition 2025: Summary and findings

Ridouane Ghermi; Xi Wang; Vicky Kalogeiton; Ivan Laptev

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arXiv · 2605.01496

SF20K Competition 2025: Summary and findings

Ridouane Ghermi·Xi Wang·Vicky Kalogeiton·Ivan Laptev

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Abstract

This report presents the results and findings of the first edition of the Short-Films 20K (SF20K) Competition, held in conjunction with the SLoMO Workshop at ICCV 2025. The competition is designed to advance story-level video understanding beyond short-clip action recognition, introducing an open-ended video question-answering task built on a corpus of amateur short films. This setup ensures that models must rely on multimodal understanding rather than memorization of popular movies. Evaluation is conducted using the SF20K-Test benchmark (95 movies, 979 question-answer pairs) and scored via LLM-QA-Eval, an automated judge based on GPT-4.1-nano. The competition attracted 22 teams and 286 submissions across two tracks: a Main Track with unrestricted model size and a Special Track limited to models under 8 billion parameters. The winning team achieved 65.7% accuracy on the Main Track and 48.7% on the Special Track, against a human performance ceiling of 91.7%. Our analysis reveals several key findings: narrative-aware, shot-level processing consistently outperforms uniform frame sampling; well-designed multi-stage pipelines using smaller models can match or exceed end-to-end inference with models over 30x larger; and subtitle quality is a dominant factor in performance. These results highlight that the primary bottleneck in long-form video QA lies in information selection and reasoning structure rather than raw model capacity, and that a substantial gap remains between current methods and human-level narrative comprehension.

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Ridouane Ghermi, Xi Wang, Vicky Kalogeiton, Ivan Laptev. 2026-05-02. SF20K Competition 2025: Summary and findings. https://arxiv.org/abs/2605.01496

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