video-frames

A set of ffmpeg-based commands for taking still images or short clips from video files.

In plain words
What is it for?
Use it to extract the first frame, capture a frame at a chosen timestamp, or create thumbnails for checking video content.
Why use it?
It makes it easier to inspect what appears in a video without opening and reviewing the entire file manually.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/understudy-ai/understudy/video-frames
Any agent
npx skills add understudy-ai/understudy --skill video-frames
Clone the repo
git clone --depth 1 https://github.com/understudy-ai/understudy

Made for: Claude Code, Codex.

Per session 15 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 250 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 92% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00015 $0.00250
Opus 5 $0.00008 $0.00125
Sonnet 5 $0.00003 $0.00050
Haiku 4.5 $0.00002 $0.00025

Measured 2d ago against content hash a86c90cb3bf2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

video-frames scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/frame.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

92% identical to video-frames — 4 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/video-frames/SKILL.md · 47 lines

What it actually says

Video Frames (ffmpeg)

Extract a single frame from a video, or create quick thumbnails for inspection.

Quick start

First frame:

{baseDir}/scripts/frame.sh /path/to/video.mp4 --out /tmp/frame.jpg

At a timestamp:

{baseDir}/scripts/frame.sh /path/to/video.mp4 --time 00:00:10 --out /tmp/frame-10s.jpg

Notes

  • Prefer --time for “what is happening around here?”.
  • Use a .jpg for quick share; use .png for crisp UI frames.
Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 47 lines · 15 tokens per session scan A a86c90cb3bf2

Subscribe to this mod's changes

video-frames is a skill published in the GitHub repository understudy-ai/understudy (456 stars, last pushed 2mo ago), licensed MIT. It adds 15 tokens to every session and 250 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 92% identical to video-frames, differing in 4 lines, and is treated as a copy.