Ffmpeg Skill

What it does

When your agent uses it

• Tasks that involve Video production

Example prompts

• “/ffmpeg-skill”

Requirements

• A Bash shell
• PowerShell

Workflow steps

10 steps, taken from the first numbered list in SKILL.md.

1. 1必须先检测安装：任何操作前检查 ffmpeg -version 是否可执行
2. 2路径必须引号：Windows 路径含空格或中文时必须用双引号包裹
3. 3默认 -y 覆盖：所有命令默认加 -y，但在执行前确认不会误覆盖用户重要文件
4. 4ss 位置规则
5. 5无损复制限制：-c copy 只能在关键帧位置切割，不能与滤镜同时使用
6. 6不删原始文件：skill 只生成新文件，绝对不删除用户的源文件
7. 7delogo 局限性：只遮盖固定位置水印，不能还原被遮盖画面，动态水印基本无效
8. 8安装脚本安全：安装脚本询问确认后才执行，不偷偷改系统环境变量
9. 9GIF 两步走：视频转 GIF 必须先生成调色板再编码，否则色彩极差
10. 10concat 用 demuxer：拼接相同编码的视频优先用 concat demuxer（-f concat），不用重编码

What it can do on your machine

Read from SKILL.md and the folder at commit 3569fb8. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Ships 2 files in scripts/ (PowerShell and Shell), which the agent can run.

  Shell commands in SKILL.md call:

  • ffmpeg
  • bash

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Ffmpeg Skill loads about 1.4k tokens when it runs, and up to ~8.8k if it reads all its reference files. Until then it costs about 55 tokens; SKILL.md has 256 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~55

When it runs · the whole SKILL.md, loaded when a task matches

~1.4k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~8.8k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.

SKILL.md

The full file from jiushiwon/wg-skills at commit 3569fb8, republished under its Apache-2.0 licence (© jiushiwon). 256 words, ~1,352 tokens.

name

ffmpeg-skill

description

FFmpeg 多媒体处理技能 — 将自然语言描述转为正确的 ffmpeg 命令，覆盖视频剪辑、转码、水印、合成、提取、生成等操作。内置一键安装脚本（Windows/Mac/Linux）。触发词：ffmpeg、视频剪辑、视频裁剪、视频转码、视频压缩、去水印、加水印、视频拼接、视频合成、提取音频、视频转 GIF、截取视频帧、调整播放速度、画中画、批量处理视频、给视频加字幕、修改分辨率、音频替换、倍速播放、视频倒放。

argument-hint

[操作描述] [输入文件] [参数...]

user-invocable

true

triggers

ffmpeg, 视频剪辑, 视频裁剪, 视频分割, 视频转码, 视频压缩, 视频格式转换, 去水印, 加水印, 视频拼接, 视频合成, 提取音频, 视频转 GIF, 截取视频帧, 调整播放速度, 倍速播放, 视频倒放, 画中画, 批量处理视频, 给视频加字幕, 修改分辨率, 音频替换, 混音, 视频去声…

Step 0: 检测 FFmpeg 是否安装
  → 已安装 → Step 1
  → 未安装 → 提供安装选项：
      "FFmpeg 未安装，请选择安装方式："
      - 运行 scripts/install-ffmpeg.ps1 (Windows)
      - 运行 scripts/install-ffmpeg.sh (Mac/Linux)
      - 参考 references/install-guide.md 手动安装
  → 用户确认后执行安装，然后进入 Step 1

Step 1: 解析用户意图 → 匹配操作域
Step 2: 查 references/ 中对应命令模板，填充参数
Step 3: 构造完整命令 → 确认文件不会误覆盖
Step 4: 通过 Bash 执行 ffmpeg 命令
Step 5: 验证输出文件，报告结果

用户：帮我把 video.mp4 右上角的水印去掉

AI：
  1. 先定位水印：
     ffmpeg -i "video.mp4" -vf "delogo=x=W-250:y=10:w=240:h=60:show=1" -t 5 preview.mp4
  2. 用户确认位置后执行：
     ffmpeg -i "video.mp4" -vf "delogo=x=W-250:y=10:w=240:h=60" -c:a copy output.mp4

用户：把 demo.mp4 从第 30 秒开始，剪出 15 秒

AI：
  ffmpeg -ss 00:00:30 -i "demo.mp4" -t 00:00:15 -c:v libx264 -c:a aac output.mp4

用户：把这个视频压缩到小一点，最好 720p

AI：
  ffmpeg -i "input.mp4" -vf "scale=1280:-1" -c:v libx264 -crf 23 -preset medium -c:a aac -b:a 128k output.mp4

用户：把 part1.mp4、part2.mp4、part3.mp4 拼成一个视频

AI：
  生成文件列表 filelist.txt → 执行：
  ffmpeg -f concat -safe 0 -i filelist.txt -c copy output.mp4

用户：把这个视频的声音单独导出来，要 MP3

AI：
  ffmpeg -i "video.mp4" -vn -c:a libmp3lame -q:a 2 audio.mp3

用户：把 video.mp4 的 5~8 秒转成 GIF

AI：
  先创建调色板再生成 GIF（两步，保证画质）
  ffmpeg -ss 00:00:05 -t 3 -i "video.mp4" -vf "fps=10,scale=480:-1:flags=lanczos,palettegen" palette.png
  ffmpeg -ss 00:00:05 -t 3 -i "video.mp4" -i palette.png -vf "fps=10,scale=480:-1:flags=lanczos,paletteuse" output.gif

用户：把视频调成 1.5 倍速

AI：
  ffmpeg -i "input.mp4" -vf "setpts=0.6667*PTS" -af "atempo=1.5" output.mp4

用户：把 main.mp4 作为主画面，pip.mp4 放在右下角小窗

AI：
  ffmpeg -i "main.mp4" -i "pip.mp4" -filter_complex "[1:v]scale=iw/4:ih/4[pip];[0:v][pip]overlay=W-w-10:H-h-10" -c:a copy output.mp4

# 在 ffmpeg-skill 目录下
powershell -ExecutionPolicy Bypass -File scripts/install-ffmpeg.ps1

# 在 ffmpeg-skill 目录下
bash scripts/install-ffmpeg.sh

© jiushiwon, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 14 other files (scripts, references) in vibeCoding/video/ffmpeg-skill of jiushiwon/wg-skills.

• SKILL.md
• README.md
• references/codec-guide.md
• references/commands-audio.md
• references/commands-compose.md
• references/commands-convert.md
• references/commands-extract.md
• references/commands-generate.md
• references/commands-trim.md
• references/commands-watermark.md
• references/filter-guide.md
• references/gotchas.md
• references/install-guide.md
• scripts/install-ffmpeg.ps1
• scripts/install-ffmpeg.sh

Open the folder on GitHubat commit 3569fb8