Fixed-rate video tokenizers spend the same number of tokens on a static scene and a rapidly changing one. InfoTok instead allocates token length according to informational content: predictable regions receive fewer tokens, while motion and fine detail receive more. An ELBO-based router estimates the budget, and a transformer-based adaptive compressor turns fixed-length embeddings into a variable-length sequence of discrete tokens.

This repository contains InfoTok-Flex, the flexible-router checkpoint post-trained on 81-frame temporal windows at varied resolutions and on non-square videos.

At a glance

Field	Released checkpoint
Weight file	`infotok_mse.pt`
Temporal window	81 frames
Overlap used by reference inference	3 frames
Token allocation	`elbo` per clip or `global_elbo` across frames
Average token-use control	`--avg_rate`, from 0.0625 to 1.0
Reference architecture name	`OURS4x8x8-mse-256p-88`
Base implementation	NVIDIA Cosmos Predict1 tokenizer stack

The checkpoint uses the native PyTorch format expected by the official InfoTok implementation. Use it only through trusted code and a trusted downloaded revision.

Why adaptive tokenization?

The project is built around two questions:

How many tokens should a video receive? The router uses the base tokenizer's ELBO as a tractable proxy for predictability.
How should a variable budget encode the video? The adaptive compressor and decompressor learn to preserve the most useful information at the chosen token length.

The result is one tokenizer that can move continuously along the compression–fidelity trade-off without training a separate model for every rate.

Installation and download

bash

git clone https://github.com/YWolfeee/InfoTok.git
cd InfoTok

conda env create --file infotok.yaml
conda activate infotok
export PYTHONPATH="$PWD"
pip install -r requirements.txt

hf download qyoo/infotok-flex infotok_mse.pt \
  --local-dir checkpoints/infotok-flex

Reconstruction

bash

python -m cosmos_predict1.tokenizer.inference.video_cli \
  --video_pattern "/path/to/videos/*.mp4" \
  --checkpoint checkpoints/infotok-flex/infotok_mse.pt \
  --output_dir outputs/infotok \
  --tokenizer_type OURS4x8x8-mse-256p-88 \
  --temporal_window 81 \
  --overlap_window 3 \
  --strategy global_elbo \
  --avg_rate 0.5 \
  --mode torch

Use global_elbo to distribute one budget across temporal frames. With elbo, each clip uses the requested average rate while the router still allocates tokens adaptively inside that clip. The official repository also provides exp_scripts/infotok_inference.sh and a token-mask visualization mode.

Results

The figure above is the paper's 256 × 256 comparison. For the released 81-frame checkpoint, the official codebase provides the following 240p reconstruction targets:

Dataset	Average token rate	PSNR ↑	SSIM ↑
TokenBench 240p	0.75	29.7088	0.8786
TokenBench 240p	0.50	28.9674	0.8522
DAVIS 240p	0.75	26.1951	0.7994
DAVIS 240p	0.50	25.1283	0.7529

Metric reproduction depends on the published preprocessing, temporal window, overlap, rate strategy, and TokenBench evaluation implementation.

Intended use and limitations

InfoTok-Flex is intended for research on adaptive discrete video representations, reconstruction, token allocation, and efficient downstream video modeling. It is not a semantic video-understanding model or a perceptual quality guarantee. Very aggressive compression can remove fine detail or rapid motion, and behavior outside the documented temporal and resolution profile is not characterized by this release. The model also inherits data and domain biases from its base tokenizer and post-training corpus.

Citation

bibtex

@inproceedings{ye2026infotok,
  title     = {InfoTok: Adaptive Discrete Video Tokenizer via Information-Theoretic Compression},
  author    = {Ye, Haotian and He, Qiyuan and Han, Jiaqi and Li, Puheng and Fan, Jiaojiao and Hao, Zekun and Reda, Fitsum and Balaji, Yogesh and Chen, Huayu and Liu, Sheng and Yao, Angela and Zou, James and Ermon, Stefano and Wang, Haoxiang and Liu, Ming-Yu},
  booktitle = {International Conference on Learning Representations (ICLR)},
  year      = {2026}
}

License

Apache 2.0. See the official codebase's ATTRIBUTIONS.md for third-party components and notices.