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.
npx skills add wyattowalsh/agents --skill ffmpeggit clone --depth 1 https://github.com/wyattowalsh/agentsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/wyattowalsh/agents/ffmpeg)<a href="https://agentmods.dev/skills/wyattowalsh/agents/ffmpeg"><img src="https://agentmods.dev/badge/skills/wyattowalsh/agents/ffmpeg/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/wyattowalsh/agents/ffmpeg"><img src="https://agentmods.dev/badge/skills/wyattowalsh/agents/ffmpeg.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00048 | $0.02350 |
| Opus 5.5 | $0.00019 | $0.00940 |
| Sonnet 5.5 | $0.00010 | $0.00470 |
| Haiku 4.5 | $0.00005 | $0.00235 |
Grade A, and why
ffmpeg 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 1mo ago.
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.
How it starts
The opening of the file, as written. The whole thing — 230 lines — stays where its author put it; the contents beside it link to each section on GitHub.
FFmpeg
CLI skill for local audio/video inspection and transformation via ffmpeg and ffprobe. Invoke as /ffmpeg.
Scope: Probe metadata, trim clips, transcode containers/codecs, concatenate segments, extract audio, capture thumbnails, and build GIF previews from files on disk. NOT for AI image or video generation (draw-thing), UI or layout design (design), networked downloads (yt-dlp), or broadcast/streaming pipelines.
Canonical Vocabulary
| Term | Meaning | NOT |
|---|---|---|
| probe | Read-only ffprobe inspection | transcode |
| trim | Shorten by time range | crop UI mockup |
| transcode | Re-mux or re-encode to new container/codec | generate new imagery |
| concat | Join multiple inputs sequentially | merge git branches |
| extract-audio | Strip video, keep audio track | speech-to-text |
| thumbnail | Single still frame from video | design a poster layout |
| gif | Animated GIF preview from video clip | CSS animation |
| stream copy | -c copy without re-encode |
always safe for all trims |
| recipe | Approved command template from references/ |
ad-hoc filter graph |
Dispatch
$ARGUMENTS |
Mode | Action |
|---|---|---|
doctor / check / preflight |
Doctor | Run PATH doctor; stop if ffmpeg/ffprobe missing |
probe <path> / info <path> / metadata <path> |
Probe | Run probe helper; summarize streams and duration |
trim <path> <start> <end> / clip <path> ... |
Trim | Probe, pick copy vs re-encode recipe, new output path |
transcode <path> / convert <path> to mp4 |
Transcode | Probe codecs; apply H.264/AAC or copy recipe |
concat <file1> <file2> [...] / join ... |
Concat | Verify probes; concat demuxer recipe + new output |
extract-audio <path> / audio <path> |
Extract audio | Probe audio stream; MP3/M4A/copy recipe |
thumbnail <path> / thumb <path> [timestamp] |
Thumbnail | Seek frame; write JPG/PNG to new path |
gif <path> / animate <path> [start] [duration] |
GIF | Palette GIF recipe with duration cap |
| Path to media + natural language edit intent | Auto | Classify trim/transcode/thumbnail/gif from intent |
| (empty) | Help | Show modes, critical rules, script commands, references |
What ships with it
9 files 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.
- evals/evals.json 6.2 KB
- references/probe-fields.md 2.1 KB
- references/recipes-thumbnail-gif.md 1.7 KB
- references/recipes-trim-transcode.md 2.4 KB
- references/safety.md 2.3 KB
- scripts/asset_toolkit/validate_hooks.py 13 KB runs code
- scripts/check.py 1.5 KB runs code
- scripts/doctor.py 2.7 KB runs code
- scripts/probe_media.py 5.5 KB runs code
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.
- 1mo ago First seen · 230 lines · 48 tokens per session scan A 559616ba5e6b
ffmpeg is a skill published in the GitHub repository wyattowalsh/agents (5 stars, last pushed 1mo ago), licensed MIT. It adds 48 tokens to every session and 2,350 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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