Phase 12: Multimodal AI

Qwen-VL Family and Dynamic-FPS Video

The Qwen-VL family — Qwen-VL (2023), Qwen2-VL (2024), Qwen2.5-VL (2025), Qwen3-VL (2025) — is the most influential open vision-language model lineage in 2026. Each generation made a single decisive architectural bet that the rest of the open ecosystem copied within twelve months: native dynamic resolution via M-RoPE, dynamic-FPS sampling with absolute time alignment, window attention in the ViT, and structured agent output formats. By Qwen3-VL, the recipe had stabilized: a 2D-RoPE-ViT encoder with native-aspect-ratio inputs, an MLP projector into a large Qwen3 language base, and training stages that emphasized OCR, grounding, and agent behavior as first-class targets. This lesson reads the family chronologically so you understand why every knob is where it is. Compute M-RoPE's three-axis rotations (temporal, height, width) and explain why all three are needed. Pick a dynamic-FPS sampling strategy for a video and reason about tokens-per-second vs event-detection accuracy. Name the four Qwen-VL generational upgrades in order and what each enabled. Wire a Qwen2.5-VL-style JSON agent output format and parse structured tool calls from a VLM response. Qwen-VL shipped in August 2023 as a direct response to LLaVA-1.5 and BLIP-2. The gap the Qwen team targeted was threefold: resolution, video, and structured output. Resolution: LLaVA-1.5 ran at 336x336. Fine for photos, useless for a Chinese-language invoice or a dense spreadsheet screenshot. Qwen-VL's first innovation was 448x448 and…

Qwen-VL Family and Dynamic-FPS Video: The Qwen-VL family — Qwen-VL (2023), Qwen2-VL (2024), Qwen2.5-VL (2025), Qwen3-VL (2025) — is the most influential open…

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