Concat
Lets you edit video on your computer, with auto-captions, voices and background removal
by Jareer A.
Local Video Editor (FFmpeg)
by Shogo KajiyamaSkillMake video or audio
Lets your agent cut, caption and reframe videos on your own computer with FFmpeg
The problem it solves
You recorded a 40-minute talk and need a captioned 60-second vertical clip for Reels, but a full video editor is more than you want to learn.
For Short-video creatorsPodcastersSocial media teams
- Before
- You scrub through a timeline, guess export settings for each app and find out after posting that the captions sit under the buttons.
- After
- You describe the edit; your agent cuts, captions, reframes and exports the file on your computer, then reports its length and size with a contact sheet.
- Stars
- ★ 4.1k
- License
- MIT
- Cost
- Free
- Level
- Intermediate
- Contents
- Includes scripts
Examples
From the project's own repository.
Overview
ffmpeg-skill gives your AI agent 42 video and audio tools built on FFmpeg, the free media program. You ask in plain words, for example to keep two parts of an interview and make a 60-second vertical clip; the agent measures the file, edits it, exports it for the platform and checks the result before it reports back. Everything runs on your computer, with no cloud upload and no API key. It suits creators, podcasters and social media teams who edit short clips.
It checks its own output, measuring length, size and loudness and making a contact sheet to look at, instead of just saying it is done.
Try these first
Start with the first one: it is a small task you can check easily.
- Take [clip.mp4], keep 10 seconds starting at [0:30] and export it as 9:16. Tell me the final length and size.First try · writes a new file
- Remove the silences from [podcast.wav] and normalise it to -14 LUFS.writes a new file
- Add these captions to [talk.mp4] for TikTok: [paste timed captions]writes a new file
- Check whether [final.mp4] meets YouTube's upload specs. Don't change it.read-only
Example prompts written by Agent Flows Hub.
What you get
From the creator's documentation.
| Output | What it is | Reads |
|---|---|---|
| Cut and join | Trim sections, join clips and remove silences, without re-encoding where possible | Your files |
| Reframe | Change the shape to 9:16 or 1:1 by cropping or padding | Your files |
| Captions and titles | Burned-in captions, animated or karaoke style, plus logos and lower-thirds | Your files |
| Audio | Loudness levelling, background music with ducking and external-mic sync | Your files |
| Platform export | Presets and spec checks for YouTube, Reels, TikTok and X | Your computer |
| Result check | Measures the output and makes a contact sheet for the agent to look at | Your computer |
Good to know
Cut a long recording into a short vertical clip with captions and the right loudness for a platform. The skill measures the file first, runs fixed editing tools and checks the exported file against the platform's specs.
Limits
- FFmpeg is installed separately and needs the filters the tools use; on macOS the plain Homebrew ffmpeg lacks subtitles and text drawing. Captions from speech need a separate local speech engine such as faster-whisper, which downloads a model on first use.
- The tools carry out edits but cannot judge them. Whether a face is cut off or text covers a subject is for you or your agent to check, using the contact sheet the skill makes.
Notes by Agent Flows Hub (original project name: ffmpeg-skill), written from the creator's documentation, not from running it ourselves. ffmpeg-skill README: quick start, install and requirements · ffmpeg-skill: SKILL.md
Stuck setting it up?
Tell us what happened. We take a look first; if it needs paid work, you get an estimate before anything starts.
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