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FFmpeg commands for generating synthetic base test media files in test-data/. Use when creating test images, videos, or audio files before adding metadata with /use-exiftool-metadata.
Codex または Claude でインストール この Prompt をコピーして Codex、Claude、または他のアシスタントに貼り付けると、Skill ページを確認してインストールできます。
SOC 職業分類に基づく
End-to-end procedure for adding a new V2 file-renaming transformation mode — enum, config, params, transformer, orchestrator dispatch, DI, FXML, controller, tests.
Mermaid diagram syntax rules and patterns for architecture docs. Use when creating or updating any Mermaid diagram in docs/ARCHITECTURE.md or other doc files.
Java coding standards for the Renamer App — V2 immutable models with @Builder(setterPrefix = "with"), Guice DI, JPMS exports, virtual threads, and project conventions. Use when writing or reviewing any Java code.
JavaFX threading, FXML patterns, CSS rules, and Guice DI integration for the Renamer App UI. Use when writing or reviewing any JavaFX controller, FXML file, or CSS stylesheet in app/ui/.
JavaFX UI/UX design skill — visual design, layout composition, color tokens, typography, spacing systems, CSS styling, control theming, accessibility, and usability improvements for the Renamer App. Use whenever the task involves styling, beautifying, or improving visual appearance — choosing colors, fonts, layouts, spacing, CSS stylesheets, control variants, responsive sizing, dark/light themes, or any UI/UX polish. Trigger on phrases like "make it look better", "improve the UI", "redesign the layout", "style the controls", "create a theme", "CSS for JavaFX", or any visual/aesthetic concern. Complements the separate /javafx skill that handles technical/functional concerns (threading, DI, FXML loading). When both design and functional changes are needed, use this skill for design aspects and /javafx for wiring concerns.
Documentation standards for the Renamer App — README structure, ADR format, diagram standards, and inline comment rules. Use when writing or updating project documentation, README files, or Architecture Decision Records.
| name | use-ffmpeg-cli |
| description | FFmpeg commands for generating synthetic base test media files in test-data/. Use when creating test images, videos, or audio files before adding metadata with /use-exiftool-metadata. |
| disable-model-invocation | true |
| allowed-tools | Bash(ffmpeg *), Bash(ffprobe *) |
Invoke when generating base test files for app/core/src/test/resources/test-data/. FFmpeg creates the synthetic media files; ExifTool then adds metadata (see /use-exiftool-metadata).
brew install ffmpeg # macOS
# JPEG — specify exact dimensions (metadata tests check width/height)
ffmpeg -f lavfi -i color=c=blue:s=800x600 -frames:v 1 test_jpeg.jpg
ffmpeg -f lavfi -i color=c=black:s=1920x1080 -frames:v 1 test_jpeg_hd.jpg
# PNG
ffmpeg -f lavfi -i color=c=red:s=1280x720 -frames:v 1 test_png.png
# TIFF
ffmpeg -f lavfi -i color=c=green:s=640x480 -frames:v 1 test_tiff.tif
# BMP
ffmpeg -f lavfi -i color=c=white:s=320x240 -frames:v 1 test_bmp.bmp
# MP4 (5 seconds, black, H.264)
ffmpeg -f lavfi -i color=c=black:s=1280x720:r=30 \
-f lavfi -i anullsrc=r=48000:cl=stereo \
-c:v libx264 -pix_fmt yuv420p -c:a aac -t 5 test_mp4.mp4
# MOV (QuickTime)
ffmpeg -f lavfi -i color=c=black:s=1920x1080:r=24 \
-f lavfi -i anullsrc=r=44100:cl=stereo \
-c:v libx264 -pix_fmt yuv420p -c:a aac -t 5 test_mov.mov
# AVI (legacy format)
ffmpeg -f lavfi -i color=c=black:s=640x480:r=25 -t 5 test_avi.avi
# MP3 (10 seconds, 1kHz sine, stereo)
ffmpeg -f lavfi -i "sine=frequency=1000:duration=10" -c:a libmp3lame -b:a 128k test_mp3.mp3
# WAV (silent, 5 seconds)
ffmpeg -f lavfi -i anullsrc=r=44100:cl=stereo -t 5 test_wav.wav
# FLAC
ffmpeg -f lavfi -i anullsrc=r=44100:cl=stereo -t 5 test_flac.flac
# OGG
ffmpeg -f lavfi -i "sine=frequency=440:duration=5" -c:a libvorbis test_ogg.ogg
# M4A
ffmpeg -f lavfi -i anullsrc=r=44100:cl=stereo -t 5 -c:a aac test_m4a.m4a
Standard pattern (FFmpeg generates file, ExifTool adds metadata):
# 1. Generate base file
ffmpeg -f lavfi -i color=c=black:s=800x600 -frames:v 1 test_jpeg_with_date.jpg
# 2. Add metadata with ExifTool (see /use-exiftool-metadata)
exiftool -AllDates="2025:12:11 21:00:35" test_jpeg_with_date.jpg
exiftool -GPSLatitude=48.8584 -GPSLongitude=2.2945 -GPSLatitudeRef=N -GPSLongitudeRef=E test_jpeg_with_date.jpg
rm test_jpeg_with_date.jpg_original
# 3. Verify
exiftool -a -G1 -s test_jpeg_with_date.jpg
| Flag | Purpose | Example |
|---|---|---|
-f lavfi | Synthetic input source | -f lavfi -i color=c=black:s=800x600 |
-frames:v 1 | Single image frame | for still images |
-t | Duration in seconds | -t 5 |
-c:v libx264 | H.264 video codec | for MP4/MOV |
-pix_fmt yuv420p | Required for H.264 compat | always add with libx264 |
-c:a aac | AAC audio codec | for MP4/MOV |
-c copy | No re-encode | container change only |
-y | Overwrite without prompt | -y at start |
H.264 requires dimensions divisible by 2. Use even numbers (800x600, 1280x720, 1920x1080).
# If you need odd dimensions, pad with:
-vf "scale=trunc(iw/2)*2:trunc(ih/2)*2"
ffprobe -v quiet -print_format json -show_format -show_streams file.mp4