Skill: zzlupus/mp4-to-gif (version 1.0.0)

--- name: mp4-to-gif description: Use when the user wants to convert MP4 video files to GIF format, or asks about video-to-GIF conversion with quality/size control --- # MP4 to GIF Conversion ## Overview Convert MP4 videos to high-quality GIFs using ffmpeg's two-pass palette method. The two-pass approach produces significantly better color quality than direct conversion. ## When to Use - User wants to convert MP4 (or other video) to GIF - User needs to create GIFs from video for documentation, demos, or sharing - User asks about reducing GIF file size or improving GIF quality ## Prerequisites - **ffmpeg** must be installed and available in PATH ## Core Method **Two-pass palette-based conversion** (always use this over single-pass): ``` # Pass 1: Generate optimized palette ffmpeg -y -i <input> -vf "fps=15,scale=480:-1:flags=lanczos,palettegen=stats_mode=diff" /tmp/palette.png # Pass 2: Convert using palette ffmpeg -y -i <input> -i /tmp/palette.png -lavfi "fps=15,scale=480:-1:flags=lanczos [x]; [x][1:v] paletteuse=dither=bayer:bayer_scale=5:diff_mode=rectangle" <output> ``` ## Quick Reference | Parameter | Default | Effect | |-----------|---------|--------| | `fps` | 15 | Frame rate — lower = smaller file, choppier motion | | `scale` width | 480 | Output width in px — height auto-calculated (`-1`) | | `lanczos` | — | High-quality downscaling filter | | `stats_mode=diff` | — | Palette optimized for frame differences (better for motion) | | `dither=bayer` | — | Ordered dithering, good balance of quality/size | | `bayer_scale` | 5 | Dither strength (0-5), higher = more dithering | | `diff_mode=rectangle` | — | Only update changed regions (smaller file) | ## Size vs Quality Tradeoffs | Goal | Adjust | |------|--------| | Smaller file | Lower fps (10), smaller width (320), or trim duration | | Smoother motion | Higher fps (24-30), but file size increases significantly | | Better colors | Use `stats_mode=full` for static/slow content | | Sharper | Increase width (640-800), costs more file size | ## Bundled Scripts Two scripts are bundled alongside this SKILL.md. Use the one matching the current platform. **Windows (PowerShell)** — `mp4_to_gif.ps1`: ```powershell & "<this-skill-dir>/mp4_to_gif.ps1" -InputFile <input> # Defaults: 480px, 15fps & "<this-skill-dir>/mp4_to_gif.ps1" -InputFile <input> -Width 640 -Fps 20 # Custom settings & "<this-skill-dir>/mp4_to_gif.ps1" -InputFile <input> -OutputFile <output> # Custom output name ``` **Linux / macOS (Bash)** — `mp4_to_gif.sh`: ```bash bash "<this-skill-dir>/mp4_to_gif.sh" -i <input> # Defaults: 480px, 15fps bash "<this-skill-dir>/mp4_to_gif.sh" -i <input> -w 640 -f 20 # Custom settings bash "<this-skill-dir>/mp4_to_gif.sh" -i <input> -o <output> # Custom output name ``` When Claude invokes this skill, resolve `<this-skill-dir>` to the absolute path of the directory containing this SKILL.md. ## Common Mistakes - **Single-pass conversion** (`ffmpeg -i in.mp4 out.gif`) — produces terrible banding and color artifacts. Always use the two-pass palette method. - **Too high fps** — 30fps GIFs are massive. 15fps is usually sufficient for demos. - **Too wide** — 480px is good for most uses. Full 1080p GIFs are impractically large. - **Forgetting to clean up palette** — Delete the temporary palette.png after conversion.


Security scan verdicts — ClawScan: clean | static analysis: clean | VirusTotal: clean | SkillSpector: clean (LOW)