S³T · Self-Supervised Self-Distillation over Time

Temporal Self-Distillation: Learning Visual State Tracking in Videos Without Supervision

1ELLIS Institute Finland & Department of Computer Science, Aalto University, Finland

2Mohamed bin Zayed University of Artificial Intelligence, UAE

Comparison of S3T with supervised, self-evolving, spatial privileged, and temporal self-supervised methods

A dense reading of an unlabeled clip teaches the same model to maintain scene state from a sparse reading. Training uses no labels, separate teacher, or external reward.

Qualitative results

Qualitative results on VSTAT

S³T answers all ten video examples correctly, while all five comparison models answer incorrectly. The final tab shows the long-prefix comparisons from the paper.

Source: VSTAT-YouTube

Question

How many different players hit the ball in total?

Reference answer: 10

ModelAnswer
S³T10 Correct
LLaVA-OV-2-8B8
Video-Zero-8B2
Molmo2-8B3
Qwen3-VL-8B2
InternVL3.5-8B3

Overview

Abstract

We introduce S³T, a self-contained framework for continuous state tracking in video. S³T treats temporal sampling density as privileged information. A dense view of a clip gives a more reliable estimate of running state and teaches a sparse view processed by the same frozen video-language model. The model generates its own training target, so the method needs no labels, separate teacher, or reward signal and adds no inference cost.

With LLaVA-OneVision-2-8B, S³T improves VSTAT accuracy by 2.70 points. Training uses only unlabeled synthetic clips, yet the learned capability transfers to real videos. It improves cumulative-state questions from VSTAT-YouTube by 7.95 points and MVBench Action Count by 4.50 points.

Method

Temporal self-distillation from two views of one clip

S3T architecture with sparse student, dense teacher, and frozen reference roles
  1. 01

    Sample the full clip twice

    The student reads 12 uniformly spaced frames and the teacher reads 24. Both views cover the same temporal extent.

  2. 02

    Score one generated answer

    The sparse student greedily answers a fixed state question. Student, teacher, and reference roles score that answer token by token.

  3. 03

    Update the student adapter

    The dense teacher supplies the positive target. The adapter-disabled base model anchors the update, and gradients flow only through the student LoRA.

$$\mathcal{L}=D_{\mathrm{JSD}}\!\left(\operatorname{sg}[P_T]\,\|\,P_S\right)+\beta\,D_{\mathrm{JSD}}\!\left(\operatorname{sg}[P_R]\,\|\,P_S\right)$$

An adaptive controller adjusts $\beta$ to keep the reference divergence near a fixed set point.

Training data

StateGen

300 deterministic unlabeled videos · 512 x 512 · 12 FPS · approximately 16 seconds

StateGen event vocabulary and four example training clips

Near-identical entities undergo add, remove, move, swap, and recolor events under occlusion and camera motion. State logs and visualization counts are not used for training.

Results

Results on VSTAT

VSTAT leaderboard

Accuracy (%) on 1,500 VSTAT questions. A dagger marks scores reproduced with our evaluation protocol.

MethodAvgState elementState structure
CountLoc.Attr.Atom.Seq.SetDict
Human performance90.592.889.986.493.777.590.092.4
Open-source models
LLaVA-OV-2-8B35.128.343.040.533.538.746.927.3
LLaVA-OV-2-8B (codec)35.028.642.040.633.937.046.327.6
Molmo2-4B34.431.639.734.537.133.636.727.1
Cambrian-S-7B34.233.233.636.934.030.640.232.5
Molmo2-8B34.030.937.037.034.736.339.127.0
Qwen3VL-8B33.230.937.033.932.433.337.931.5
InternVL3.5-2B31.829.633.934.131.729.936.329.9
Cambrian-S-3B31.829.732.735.032.731.935.127.2
VITA-1.5-7B31.525.536.338.629.433.043.126.3
Qwen3VL-4B31.327.033.337.930.432.839.825.8
InternVL3.5-8B30.625.133.239.226.933.841.828.3
Qwen3VL-2B29.429.428.230.532.524.932.123.5
Cambrian-S-1.5B29.326.034.131.028.031.031.829.3
LLaVA-OV-7B28.620.134.839.424.530.043.825.0
LLaVA-OV-0.5B21.314.633.921.719.725.822.220.9
Self-evolving methods
Qwen3-VL-4B†31.4327.733.736.631.932.538.524.4
Video-Zero-4B†31.6327.734.536.532.132.337.825.5
Qwen3-VL-8B†34.1132.637.833.435.033.137.130.4
Video-Zero-8B†33.8932.037.234.334.135.538.329.1
Qwen2.5-VL-7B†31.8425.237.439.528.839.441.626.2
EvoGround†32.6626.736.640.629.739.542.927.0
Ours
LLaVA-OV-2-8B†34.7427.742.041.432.637.048.627.4
S³T (SFT teacher)34.4526.042.243.630.938.050.927.5
S³T36.4830.441.743.335.239.447.828.8
S³T (soup)37.1232.440.743.037.241.444.928.4
S³T (soup, + vision enc.)37.4432.642.342.137.742.845.527.4

Our reproduced LLaVA-OV-2-8B base scores 34.74. Reported gains use this score as the reference.

Per-axis comparison

Radar comparison of S3T and size-matched 8B open models across VSTAT axes

S³T improves Count, Atomic, and Sequence while preserving the remaining axes.

Temporal pretext comparison

Training objectiveAvgCountDict
Base (no training)34.7427.727.4
Frame-order34.9827.730.5
Arrow-of-time34.7527.426.5
Pace35.4529.027.1
Mask-infill34.2525.226.3
S³T36.4830.428.8

All methods use the same training recipe. Only the learning target changes.

Real-video transfer

Transfer to real videos

Real-video benchmarkS³T (soup)S³T (soup, + vis.)
VSTAT-YouTube, cumulative state+7.35+7.95
MVBench, Action Count+3.00+4.50

Change in accuracy (%) from our reproduced base model.

Analysis

Teacher view and distillation objective

Student and teacher frame budgets

VSTAT gain as student and teacher frame budgets vary

The gain depends on both frame budgets. The strongest region lies near a 12-frame student and a 24-frame teacher.