Seamless Looper

Create seamless looping MP4 videos with smooth crossfade transitions, doubling video length for ambient or background loops without audio.

Security Scan

The skill's code and instructions match its stated purpose (creating seamless looped MP4s using ffmpeg/ffprobe); nothing requests unrelated credentials or network access.

Purpose & Capability

Name/description, SKILL.md, and scripts/loop.sh consistently implement an ffmpeg-based MP4 looping/crossfade workflow. Required tools (ffmpeg, ffprobe) are appropriate and proportional to the stated purpose; no unrelated binaries or credentials are requested.

Instruction Scope

Runtime instructions and the shell script operate only on the user-supplied source and output directories and call ffprobe/ffmpeg. The instructions do not read system-wide config, environment secrets, or transmit data externally. Minor operational notes: the script truncates durations to integers and does not validate that crossfade length < input duration, which may cause encoding errors; stderr is redirected to /dev/null which will hide ffmpeg diagnostics.

Install Mechanism

No install spec — instruction-only with an included shell script. There are no downloads or external install URLs; nothing is written to disk beyond the output files the user requests.

Credentials

No environment variables, credentials, or config paths are requested. The script does not read environment secrets. The requested access (reading .mp4 files in the given source directory and writing outputs) is proportional to the feature.

Persistence & Privilege

always is false and the skill does not request to persist or modify other skills or system-wide agent settings. Normal autonomous invocation is allowed by platform defaults but is not combined with broad privileges here.

Assessment

This skill appears coherent and limited to its stated task. Before running it: (1) ensure ffmpeg and ffprobe are installed; (2) run the script on copies of videos first (it overwrites nothing but produces new files) and test with a single file; (3) avoid using a crossfade longer than the input duration (the script does not validate this) and be aware very large files are CPU/disk intensive; (4) if you want error output for troubleshooting, remove the `2>/dev/null` redirection in the ffmpeg command; and (5) watch filenames with unusual characters — while the script quotes paths, complex filenames may still cause issues depending on shell behavior.

Create seamless looping versions of ambient/background videos with smooth crossfade transitions at the junction.

Limitations: Output is visual-only (no audio). Input must be MP4. Videos under 2 seconds are skipped.

Quick Start

cd ~/.openclaw/skills/seamless-looper
bash scripts/loop.sh <source_dir> <output_dir> [crossfade_seconds]

Example:

bash scripts/loop.sh ~/Videos/ambient ~/Videos/looped 1

• Source dir must contain .mp4 files
• Output dir created automatically
• Default crossfade: 1 second

Output

Looped files saved as <filename>_looped.mp4 in the output directory.

How It Works

1. Takes each .mp4 in source dir
2. Doubles the video (original + original via stream_loop)
3. Applies crossfade at the junction point (fade out tail, fade in head)
4. Outputs <filename>_looped.mp4 — seamless loop of the original duration

Requirements

• ffmpeg (with libx264 and overlay filter support)
• ffprobe (for duration detection)

Install on macOS: brew install ffmpeg

Tips

Use Case	Crossfade
Fast cuts, high motion	0.5s
Default ambient	1s
Slow fades, nature footage	2s
Very slow drift	3s

Limitations

• Input must be .mp4
• Videos <2s duration are skipped
• No audio looping (visual-only output)
• Output duration = 2x input duration

File Structure

seamless-looper/
├── SKILL.md           ← you are here
├── scripts/
│   └── loop.sh        ← main loop script
└── references/
    └── tips.md        ← use cases + crossfade presets