video-merger

name	video-merger
description	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.
description_zh	将一个目录中编号的MP4片段（1_*.mp4, 2_*.mp4, ...）拼接为一个MP4，可选淡入淡出转场，统一分辨率/帧率/编码。纯ffmpeg封装，无LLM。当工作流已产出多个需拼成成片的短片段时触发。
provenance	{"origin":"clawhub-mit0","license":"MIT-0","upstream_url":"https://clawhub.ai/machunlin/video-merger","upstream_version":"1.1.0","maintained_by":"OpenSquilla"}
metadata	{"opensquilla":{"risk":"medium","capabilities":["filesystem-write","process-control"],"requires":{"bins":"[Truncated]","anyBins":"[Truncated]"}}}
entrypoint	{"command":"python {baseDir}/scripts/merge.py","args":["--input","{{ with.input_dir }}","--output","{{ with.output_path }}","--mode","{{ with.mode | default('full') }}","--transition","{{ with.transition | default(0.5) }}","--fps","{{ with.fps | default(24) }}","--crf","{{ with.crf | default(22) }}","--preset","{{ with.preset | default('medium') }}"],"parse":"text","timeout":600}

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 ≥ 5.0
• ffprobe
• 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