Igapyon Ffmpeg Helper

igapyon-ffmpeg-helper

This skill guides igapyon's personal FFmpeg workflows. Use it as a conversational command generator and runbook navigator.

Do not build a Web UI unless the user separately asks for implementation.

Activation

Use this skill only on a hard trigger. Valid triggers include:

• igapyon-ffmpeg-helper
• igapyon FFmpeg helper
• ffmpeg helper
• FFmpeg helper workflow
• FFmpeg helper runbook
• ffmpeg runbook igapyon
• igapyon ffmpeg runbook
• igapyon's FFmpeg helper workflow
• an explicit request to use or apply this Agent Skill

Do not activate this skill for:

• ordinary FFmpeg questions
• ordinary H4essential questions
• ordinary YouTube/video/audio conversion questions
• mentions of loudnorm, gain adjustment, trimming, concatenation, or still image video creation
• vague descriptions of a similar workflow

If the user only asks whether such a skill exists, mention this skill as an available option, but do not apply it until the user asks to use it.

Workflow Selection

The first-cut workflow is:

• references/workflows/h4essential-orchestra-youtube.md

When more workflows are added, choose the closest workflow from references/workflows/. If no workflow matches, use the process runbooks in references/process/ only as modular command guidance.

For the first-cut workflow, confirm the route once at the start:

H4essentialのオーケストラ録音から、切り出し、loudnorm JSON測定、-0.5 dBTPピーク基準の単純ゲイン仕上げ、必要なら結合、静止画付きYouTube用動画作成まで進めますか？

After the route is confirmed, keep moving and ask only for the missing input needed for the next concrete command.

Process Runbooks

Use these process files as reusable command building blocks:

• references/process/h4essential-input-discovery.md
• references/process/workspace-and-command-log.md
• references/process/audio-trim.md
• references/process/peak-gain-normalize.md
• references/process/audio-concat.md
• references/process/delivery-variants.md
• references/process/still-image-youtube-video.md
• references/process/youtube-manual-upload.md

Use index.json as the discovery index when you need to confirm available reference files, but treat SKILL.md and files under references/ as the source of truth.

For the reasoning behind the current YouTube output defaults, see references/decisions/youtube-output-policy.md.

Prerequisites

Running generated commands requires the ffmpeg CLI to be available in the user's shell. ffmpeg -version is mandatory before executing any workflow command on the user's machine:

ffmpeg -version

If ffmpeg -version fails or ffmpeg is unavailable, stop command execution and ask the user to install or expose ffmpeg in PATH.

First-Cut Guardrails

Unless the user explicitly changes the first-cut workflow:

• Use copied ZOOM H4essential recording folders as the source.
• Assume orchestra or ensemble rehearsal recording.
• Treat trimming as expected and usually required.
• Use a two-phase simple-gain route: measurement first, finishing second.
• Use loudnorm=print_format=json only for measurement JSON.
• Use volume=...dB only for finishing; do not use loudness normalization in the finish command.
• Target peak is -0.5 dBTP.
• Do not use compression.
• Let the user choose hi-res or lo-res output for the finish command; default to hi-res when the user does not specify.
• Tell the user that hi-res intermediate WAV files will be larger.
• For multiple WAVs, trim and gain-adjust each selected WAV first, then concatenate.
• Retain the selected adjusted WAV as a separately named master; do not replace it with a delivery format.
• When the user asks for mobile playback, lightweight sharing, or a Drive-friendly file, create a requested delivery variant after preserving the master.
• End at a YouTube-uploadable video file.
• Upload manually through the YouTube Studio Web UI.
• Do not introduce YouTube API upload, OAuth, scheduled publishing, or metadata automation unless the user explicitly asks to expand the skill.

Response Style

When using this skill:

• Prefer Japanese explanations for this user's workflow unless the user switches language.
• Show concrete commands in execution order.
• Clearly label the two FFmpeg runs: measurement phase and finishing phase.
• Ask the user to paste the loudnorm JSON measurement output back when you cannot run the measurement command yourself.
• Preserve source files and avoid destructive commands.
• Use quoted paths in generated shell commands.
• Put generated working files under a per-job directory such as workplace/ffmpeg-helper-260114_160901/ by default.
• Keep a command log such as workplace/ffmpeg-helper-260114_160901/commands.log and record the exact commands that are executed or handed to the user.
• It is acceptable and preferred to write auxiliary logs, measurement outputs, and troubleshooting files inside the per-job workplace/ directory.
• Do not silently choose between plausible H4essential tracks when the recording source is ambiguous.