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 heristop/leclap --skill cross-platform-ffmpeggit clone --depth 1 https://github.com/heristop/leclapWrote 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/heristop/leclap/cross-platform-ffmpeg)<a href="https://agentmods.dev/skills/heristop/leclap/cross-platform-ffmpeg"><img src="https://agentmods.dev/badge/skills/heristop/leclap/cross-platform-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/heristop/leclap/cross-platform-ffmpeg"><img src="https://agentmods.dev/badge/skills/heristop/leclap/cross-platform-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 | $0.00045 | $0.00975 |
| Opus 5.5 | $0.00018 | $0.00390 |
| Sonnet 5.5 | $0.00009 | $0.00195 |
| Haiku 4.5 | $0.00005 | $0.00097 |
Grade A, and why
cross-platform-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 24d 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 — 39 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Cross-Platform FFmpeg
Adapter wiring
Shared command builders use AbstractFFmpeg. The Node entry point uses PlatformBridge; the browser and React Native entry points register their own adapters directly. Do not route their bundles through PlatformBridge, which imports Node modules. Architecture: docs/architecture.md.
| Entry point | FFmpeg | Filesystem | Logger | Music |
|---|---|---|---|---|
src/index.ts (Node) |
FFmpegNodeAdapter or FFmpegStaticAdapter |
FilesystemNodeAdapter |
PinoLogAdapter |
MusicNodeAdapter |
src/browser.ts |
FFmpegWasmAdapter |
BrowserFilesystemAdapter (IndexedDB) |
BrowserLogger |
MusicWasmAdapter |
src/reactnative.ts |
FFmpegDeviceAdapter (injected NativeEngine) |
FilesystemExpoAdapter |
ReactNativeLogger |
MusicFFmpegAdapter |
Paths above are relative to packages/ffmpeg-video-composer/. FFmpeg and music adapters live in src/platform/ffmpeg/; filesystem adapters live in src/platform/filesystem/, and the Node logger lives in src/platform/logging/. The logger classes for browser/RN live in their entry points.
Detection and probing
FFmpegDetector.detect() tries system ffmpeg -version, then the ffmpeg-static binary. Both adapters use execFile with parseCommand argv, without a shell. System detection does not check ffprobe; FFmpegNodeAdapter.getInfos() expects ffprobe on PATH.
The detector also has a WASM branch, but detectWasmFFmpeg() refuses environments without window. It is not a working pure-Node fallback. Browser hosts use browser.ts directly. With no available backend, the Node bridge throws with installation instructions.
ffmpeg-static ships only FFmpeg. resolve-ffprobe.ts selects an existence-checked binary from the optional ffprobe-static package or beside the resolved FFmpeg binary. Without one, FFmpegStaticAdapter.probeUnavailableReason is set. director/render-needs.ts rejects probing templates before the first segment encodes: non-cut transitions, whole-video overlays, enabled/resolved music, and project_video sections. MusicNodeAdapter probes and loops through the selected adapter's binaries, preserving the static path.
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.
- 24d ago Changed · -14 lines 6baf58723a74
- 1mo ago Changed 305259752c95
- 1mo ago First seen · 53 lines · 45 tokens per session scan A 38f60ba7c587
cross-platform-ffmpeg is a skill published in the GitHub repository heristop/leclap (36 stars, last pushed 4d ago), licensed MIT. It adds 45 tokens to every session and 975 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 2026-08-30.
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