microsoft/Mage-VL

Mage-VL An Efficient Codec-Native Streaming Multimodal Foundation Model

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Mage-VL is a codec-native, proactive-streaming multimodal foundation model for image and video understanding, whose visual encoder is trained entirely from scratch at a compact 4B scale. It targets a modern *Moravec's paradox* of VLMs — strong at complex offline reasoning, yet slow and compute-heavy on simple real-time streaming perception. Instead of decoding video into uniformly-sampled frames and pushing a dense grid of patch tokens through a frozen web-pretrained ViT, Mage-VL follows the structure of modern video codecs: it separates a stream into anchor (I) frames and predicted (P) frames, keeps every anchor patch, and retains only the predicted-frame patches where the codec spends bits — the regions carrying real motion and new detail. This codec-aligned sparsity cuts visual tokens by over 75% while preserving spatio-temporal context, yielding up to 3.5× wall-clock inference speedup over uniform frame sampling.

The system pairs two components:

• Mage-ViT — a from-scratch *Codec-ViT* visual encoder that allocates tokens by codec-derived spatio-temporal importance, on a shared 16×16 patch grid with 3D rotary position encoding. It is codec-agnostic: the same interface accepts a traditional codec (H.264/AVC, HEVC/H.265) via motion vectors + residual energy, or a neural codec (DCVC-RT) via its learned rate map — no architecture or retraining change.
• Qwen3-4B causal decoder — a Qwen3-4B-Instruct-2507 language backbone (the only pretrained component) that consumes Mage-ViT's variable-length token stream through a lightweight two-layer MLP projector, with a unified interface for images, short/long/ultra-long video, and streaming.

On top of this pair, a System 1 & System 2 dual-process design adds proactive streaming inside a single model: a lightweight cognition gate (System 1) watches each rolling codec window and stays silent on routine content, invoking the full VLM (System 2) only when a response-worthy event completes — no multi-agent pipeline required.

✨ Highlights

• Codec-native & from scratch. The entire visual stack is trained from scratch — no billion-scale image-text ViT initialization. The bio-inspired predictive-patch mechanism (I/P frames at 16×16) cuts visual-token consumption by over 75% (~1/8 or less of dense frame sampling), letting the model train on videos 8× longer under the same budget.
• Codec-native speedup. Codec tokenization sets a superior accuracy–efficiency frontier — up to 3.5× wall-clock inference speedup over uniform frame sampling at matched accuracy, and the fastest of all compared models on most video benchmarks (single 8×B200 node).
• Data-efficient tokenizer. Trained on only ~100M unlabeled images/videos, Mage-ViT matches or beats frontier encoders trained on billions of image-text pairs (SigLIP2 @ 10B, MoonViT @ 2B) — e.g. 99.33% on CIFAR-10 and 85.69% on ImageNet with 256 tokens, showing web-scale pretraining is *not* essential for a strong VLM front-end.
• Native-resolution scaling. Variable-resolution pretraining lets Mage-ViT improve *monotonically* with the token budget (peaking >96.1% Food-101 / >86.3% ImageNet at 676 tokens) where fixed-resolution encoders saturate or degrade.
• Matched-LLM video gains. With the 4B Qwen3 backbone held fixed and only the ViT swapped, Mage-VL improves over Qwen3-VL-4B on every reported video and temporal-grounding benchmark — largest on localization-heavy tasks (+22.5 QVHighlight, +17.1 ActivityNet, +11.0 VSI-Bench, +24.5 VideoEval-Pro).
• Strong for its size. On par with Qwen3-VL-4B on static images, and clearly ahead on video understanding and spatial intelligence (+11.0 VSI-Bench, +53.1 CrossPoint, +5.2 EmbSpatial, +22.5 QVHighlight).
• Proactive streaming, single model. A frozen-backbone cognition gate delivers low-latency, event-gated commentary; it tops TimVal / F1 / ROC-AUC / PR-AUC on SoccerNet streaming and generalizes to real 2026 World Cup broadcasts.

📥 Model

A single checkpoint, microsoft/Mage-VL, is one unified model that simultaneously provides image & video understanding and the proactive streaming gate — the same weights answer offline image/video questions and drive event-gated commentary. It covers every Mage-VL capability: image understanding, frame-sampled video, traditional H.264/HEVC codec video, neural DCVC-RT codec video, and event-gated streaming. The repository bundles the codec processor, the neural codec package, and the proactive gate weights — no separate understanding, NVC, or streaming checkpoint is required.

We additionally release `microsoft/Mage-ViT` — the standalone visual encoder from the two-stage, from-scratch ViT pre-training (cluster-discrimination on ~100M unlabeled image/video frames). This is the ViT-pre-trained checkpoint only: it has not gone through the joint VLM training with the language model. Use it as a data-efficient, codec-native visual encoder or as a drop-in ViT for your own multimodal training.

| Model | Task | Backbone | Hugging Face | | :--- | :--- | :--- | :--- | | Mage-VL | image & video understanding + proactive streaming gate | Mage-ViT + Qwen3-4B-Instruct-2507 | 🤗 microsoft/Mage-VL | | Mage-ViT | codec-native visual encoder — ViT pre-training only, no VLM joint training | Codec-ViT (from scratch) | 🤗 microsoft/Mage-ViT |

🏗️ Architecture

Mage-ViT — a from-scratch Codec-ViT visual encoder. On a 16×16 patch grid it keeps all anchor (I) frame patches and only the motion-salient predicted (P) frame patches, cutting visual tokens by over 75% while a shared 3D RoPE preserves spatio-temporal positions.

Mage-VL — a unified model where projected visual tokens and text tokens share one causal Qwen3 decoder. Still images become a single spatial block; videos become temporally-ordered codec windows. In streaming mode, a lightweight cognition gate predicts p_speak = g(h_t) per rolling window (over a recurrent streaming memory kept by an event-preserving feature extractor) and triggers generation when p_speak ≥ τ; the response is decoded by the frozen base model from a local sliding window of the most recent codec segments, and a text query can be injected at any...