Video Merger
Documentsvideo-mergerVideo Merger is an Agent Skill for documents published in the opensquilla/opensquilla repository on GitHub: a SKILL.md instruction file an AI agent can load to do this task.
Concatenate a directory of numbered MP4 segments (1_*.mp4, 2_*.mp4, ...) into one MP4 with optional fade transitions, unified resolution/fps/codec. Pure ffmpeg wrapper, no LLM. Trigger when a workflow has produced several short clips that need stitching into a final reel.
How to use this skill
Bring this guide into your coding agent with a prompt tailored to the tool you use.
- Open your project in Codex.
- Copy and paste the prompt below.
- Review files and risks before approving any action.
Inspect the Agent Skill at https://github.com/opensquilla/opensquilla/blob/HEAD/src/opensquilla/skills/bundled/video-merger/SKILL.md and all supporting files. Report provenance, permissions, scripts, dependencies, and security risks. Propose an exact installation into .agents/skills/video-merger, but wait for my approval before writing files or running scripts.
Copying this prompt does not install or run the skill. Review third-party files before use.
video-merger — numbered-segment MP4 concatenator
Combines 1_*.mp4, 2_*.mp4, ... in numeric order into one MP4 (or
multiple ~60s chunks), with optional fade transitions, codec/resolution/
fps normalisation.
Inputs (with:)
| key | required | default | notes |
|---|---|---|---|
input_dir | yes | — | Directory containing \d+_*.mp4 segments. |
output_path | yes | — | .mp4 path (full mode) or directory (chunk mode). |
mode | no | full | full or chunk. |
transition | no | 0.5 | Fade duration in seconds. 0 disables. |
fps | no | 24 | Target frame rate. |
crf | no | 22 | x264 CRF (0-51, lower = better). |
preset | no | medium | x264 preset. |
For chunk mode, pass chunk_duration directly to the script — the meta
engine entrypoint above does not template it; use a direct shell call
when chunking is needed.
Dependencies
ffmpeg≥ 5.0ffprobe- Python 3.8+
- No Python packages required beyond stdlib.
Install hints (or just run the bundled installer):
| OS | One-liner installer | Manual |
|---|---|---|
| Windows (PowerShell) | pwsh -ExecutionPolicy Bypass -File install.ps1 | winget install Gyan.FFmpeg / choco install ffmpeg / scoop install ffmpeg |
| macOS | bash install.sh | brew install ffmpeg |
| Debian/Ubuntu | bash install.sh | sudo apt install ffmpeg |
The Windows installer (install.ps1) defaults to winget but accepts
$env:OPENSQUILLA_FFMPEG_INSTALLER="choco"|"scoop"|"skip" to switch
backends. It prints the absolute ffmpeg/ffprobe paths after install so
you can pass them to merge.py via --ffmpeg-path / --ffprobe-path
when subprocess PATH inheritance is unreliable.
Filename ordering contract
The script picks files matching ^\d+_.*\.mp4$ and sorts by the leading
integer. Producers must save segments as 1_shot.mp4, 2_shot.mp4,
3_shot.mp4, etc. The meta-short-drama workflow already follows this.
Output
Stdout: progress lines and the final output path. Non-zero exit on ffmpeg failure.
Failure modes
未找到ffmpeg→ install ffmpeg, ensureffmpegon PATH or pass--ffmpeg-pathdirectly.未找到符合命名规则...的MP4文件→ ensure segments are\d+_*.mp4.- Mixed resolutions / fps: handled automatically when
--resolutionis set; otherwise ffmpeg preserves originals (no normalisation).