Phase 1: Vision-Language Models · ~120 minutes · Python

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.

What you will learn

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.

Introduction

Type: Learn
Languages: Python (stdlib, M-RoPE encoder + dynamic-FPS sampler)
Prerequisites: Any-Resolution Vision: Patch-n'-Pack and NaFlex
Time: ~120 minutes

Objective

Learning objectives

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.

Unlock the full lesson

You've read the first 2 sections. The rest of this lesson covers The Problem, The Concept, Build, Check Yourself, Check Yourself, Key Terms & Next — plus a hands-on lab, quiz, and project artifact.

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Key terms in this lesson

Agent