ICLR 2026

TripleSumm: Adaptive Triple‑Modality Fusion for Video Summarization

Sumin Kim*, Hyemin Jeong*, Mingu Kang*, Yejin Kim, Yoori Oh, Joonseok Lee

Seoul National University

*Equal contribution  Β·  Corresponding authors

SOTAon 4 benchmarks
Visual Β· Text Β· Audiofused adaptively, frame by frame
52,678videos in our MoSu dataset
1.37Mparameters only

Interactive DemoWatch TripleSumm summarize real videos

All examples below are from the test split of our MoSu benchmark β€” none were seen during training. As the video plays, the charts follow along in real time: the model's predicted importance against the ground truth (aggregated from 50,000+ real viewers), the selected summary segments, and how the model dynamically shifts its attention across visual, text, and audio at every second. Tap anywhere on the charts to seek, and toggle Summary only to watch just the 15% the model would keep.

MotivationThe most informative modality changes every moment

Human comprehension of video is inherently multimodal β€” yet most video summarization models look at pixels alone, or fuse modalities with a fixed recipe. In a real video, the cue that matters changes from moment to moment: when a judge speaks, the transcript carries the meaning; when the performance starts, visuals and audio take over.

Illustration of dynamic importance of modalities across a video
Text is most salient at (a), visual–audio dominate at (b), and all three contribute at (c). A summarizer should re-weigh its senses frame-by-frame β€” exactly what TripleSumm learns to do.

Static fusion fails

Standard self- or cross-attention treats modalities uniformly or anchors on vision, collapsing when non-visual cues dominate the content.

Two orthogonal patterns

Summarization needs intra-modal temporal reasoning (what changed over time?) and inter-modal reasoning (which sense matters now?) β€” best learned separately.

No trimodal benchmark

No public dataset offered visual + text + audio with reliable importance labels at scale β€” so we built one.

The MoSu DatasetThe first large-scale trimodal summarization benchmark

MoSu (Most Replayed Multimodal Video Summarization) pairs in-the-wild YouTube videos with YouTube's Most Replayed statistics β€” frame-level importance distilled from the watch behavior of at least 50,000 viewers per video. Every video comes with synchronized CLIP visual, RoBERTa text, and AST audio features at 1 feature per second.

52,678videos
3,984hours of content
3,406topic categories
50K+viewers behind each label
DatasetVisualTextAudioVideosHours
SumMeβœ“β€“β€“251.1
TVSumβœ“β€“β€“503.5
Mr.HiSumβœ“β€“β€“31,8921,788
TL;DW?βœ“βœ“β€“12,160629
BLiSSβœ“βœ“β€“13,3031,109
MMSumβœ“βœ“β€“5,1001,230
MoSu (ours)βœ“βœ“βœ“52,6783,984

Existing benchmarks are either tiny, visual-only, or bimodal β€” MoSu is the first to provide all three key modalities at scale.

MethodRefine in time, fuse across modalities

TripleSumm interleaves two purpose-built blocks. The Multi-scale Temporal block (MST) refines each modality stream with windowed self-attention whose window grows local β†’ global across layers, capturing subtle transitions without losing the overall narrative. The Cross-modal Fusion block (CMF) lets a dedicated fusion token cross-attend to the visual, text, and audio tokens of each frame β€” its attention weights are the per-frame modality importances you see in the demo above.

TripleSumm architecture: encoders, multi-scale temporal block, cross-modal fusion block, prediction head
Overall architecture. Modality features are projected, aggregated into fusion tokens, refined by MST (lower left), fused by CMF (lower right), and decoded into frame-level importance scores.

πŸͺŸ Multi-scale temporal

Windowed self-attention with local-to-global schedule (w = 5, 15, 45, N) beats constant windows and full self-attention β€” at O(wΒ·N) cost.

πŸŽ›οΈ Dynamic per-frame fusion

A neutral fusion token queries all three modalities each second, avoiding the visual bias of asymmetric cross-attention. Dynamic > global > static fusion in ablations.

πŸͺΆ Robust & tiny

Gracefully degrades when modalities are missing, and reaches SOTA with only 1.37M parameters / 0.97 GFLOPs β€” 8Γ— smaller than CSTA.

ResultsState of the art on four benchmarks

On MoSu, TripleSumm outperforms every unimodal and multimodal baseline by a wide margin on all metrics β€” while being the smallest model in the comparison. It also sets the state of the art on Mr.HiSum, SumMe, and TVSum, and generalizes zero-shot to 70-minute long-form videos.

MethodModalityΟ„ ↑ρ ↑mAP50 ↑mAP15 ↑Params ↓
VASNetV0.1510.21964.4931.058.13M
PGL-SUMV0.1510.21864.9730.635.31M
CSTAV0.2910.39871.7740.6510.56M
A2SummV+T0.1810.25766.4835.702.48M
SSPVSV+T0.1900.27166.1032.65112.81M
Joint-VAV+A0.1900.27265.6832.254.21M
UMTV+A0.2390.33468.8336.734.66M
CFSumV+T+A0.2770.37470.9738.2019.83M
TripleSumm (ours)V+T+A0.3510.47274.7244.421.37M

Comparison on the MoSu test set. Ο„: Kendall's tau, ρ: Spearman's rho against Most-Replayed ground truth.

+21% Ο„ over the best baseline

0.351 vs 0.291 (CSTA) on MoSu β€” the gap holds on Mr.HiSum (0.258 vs 0.178) and on human-annotated SumMe / TVSum.

Every modality counts

V+T+A > every bimodal pair > every single modality in ablations β€” evidence of a genuinely synergistic fusion, not a visual crutch.

Zero-shot on hour-long videos

Trained on ≀8-minute clips, TripleSumm still leads all baselines on 70-minute unseen videos (Ο„ 0.128 vs 0.083 next best).

Qualitative: the model knows which sense to trust

The fusion token's attention (middle curves) tracks content with human-like intuition: speech segments pull attention to text, performances to audio β€” with no supervision on the weights themselves.

Qualitative example: guitar demonstration
Guitar demo β€” attention shifts between speech and playing.
Qualitative example: accordion performance
Accordion performance β€” audio cues dominate throughout.

PosterOne-page overview

Pinch or scroll to zoom Β· drag to pan Β· double-tap to reset Β· open PDF β†—

TripleSumm ICLR 2026 poster

CitationBibTeX

@inproceedings{kim2026triplesumm,
  title     = {TripleSumm: Adaptive Triple-Modality Fusion for Video Summarization},
  author    = {Sumin Kim and Hyemin Jeong and Mingu Kang and Yejin Kim and Yoori Oh and Joonseok Lee},
  booktitle = {The Fourteenth International Conference on Learning Representations},
  year      = {2026}
}