editing-videos

Editing videos

This skill gives an editor's judgment: when to cut, how long a shot or a caption lasts, how loud the music goes, when a graphic helps and when it gets in the way. Every number says where it comes from: official (platform or vendor docs), study, creator (practice without public data) or house (learned reviewing real cuts). It is organized in two layers:

1. The core (this file, references/ and review-checklist.md): craft that holds for any video and any tool.
2. Recipes (recipes/): what changes for one type of video. Load only the one that matches.

It does not replace the tool. On mechanics (file formats, APIs, a renderer's contract), the tool's own docs or skills rule; on editorial matters, this skill does. references/tools.md maps the craft onto each tool.

Process

#	Step	What happens	Read
1	Brief	Video type, audience, platform and format (16:9 or 9:16), length, tool available. Pick the recipe	"Pick your recipe" below
2	Story	The promise (title and thumbnail idea) and a hook that delivers it in the first seconds; sections or chapters	references/hook-and-retention.md
3	Assembly	Select the best takes and order them; cut dead time; nothing is polished yet	references/pacing-and-cuts.md, the recipe
4	Rhythm	Shot length for the type, J and L cuts, jump cuts, b-roll, punch-ins	references/pacing-and-cuts.md
5	Graphics and text	Graphics only where they explain; text anchored to speech; captions	references/graphics-and-text.md, graphics/, memes/
6	Audio	Clean the dialogue, room tone, music under the voice, sound effects, then the master	references/audio-and-sfx.md, library/
7	Color	Exposure, white balance, matching shots; a look only after	references/color.md
8	Review	The recipe's checklist, then the core checklist, with frames and headphones	review-checklist.md
9	Export	Only with the person's approval: format, loudness master, check the file	references/audio-and-sfx.md, references/tools.md
10	Publishing	Title, thumbnail, description, chapters, captions, credits	references/thumbnail-title-description.md, references/licenses.md

If the agent cannot touch the editor, it still does steps 1–8 as decisions: an edit decision list, a marker list, caption files and instructions with numbers (references/tools.md).

Hard rules (any video, any tool)

1. Every cut has a reason: it removes dead time, changes the information, or follows an action. Never in the middle of a word.
2. Deliver the promise early. What the title and thumbnail promise is seen or said in the first seconds; no logo intro or greeting before it.
3. The voice is never fighting anything. Music 18–25 dB under it and ducked, sound effects under it and never on a key word, room tone under every gap.
4. Master once, to the destination: -14 LUFS integrated and ≤ -1 dBTP for YouTube; -16 LKFS ± 1 for a podcast feed. Measured, not guessed.
5. A graphic is never empty. It enters at most 0.5 s before its word, has content within 1 s, and each element enters ≤ 0.6 s from when the voice names it [house].
6. Text stays long enough to read: max(1.5 s; words × 0.33 s + 0.5 s); captions ≤ 42 characters per line, ≤ 2 lines, ≥ 20 frames each.
7. Zoom and punch-in only when motivated by what is said, sharp, and never across a cut.
8. Shots match: exposure, white balance and levels consistent within a scene.
9. Only licensed media: CC0, the YouTube Audio Library, or a written license that allows commercial use. Nothing NC, nothing "found on YouTube". New sounds for the library leave their evidence in library/LICENSES.md. Graphics come from graphics/ (CC0) or carry a recorded license. No copyrighted meme images, clips or sounds without a license: recreate the joke instead (memes/README.md).
10. No invented numbers. If no source supports a figure, say so and decide by the content.
11. Nothing is rendered or published without approval, and no cut is shown without passing its recipe's checklist and review-checklist.md.

Pick your recipe

The video is…	Recipe	What it adds to the core
One person talking to camera	recipes/talking-head.md	Removing filler, softening jump cuts, punch-ins, b-roll on what is said
A day, a trip, an event	recipes/vlog.md	Finding the story, cold open, sequences, wind and location audio, matching cameras
A conversation with several cameras	recipes/podcast-to-youtube.md	Sync, cutting between angles, open mics, podcast master, chapters per topic
Vertical clips from a long video	recipes/shorts-from-long-form.md	Picking the moment, reframing to 9:16, burned-in captions, loops
A narrated software tutorial (screen recording)	recipes/narrated-screen-tutorial.md	The screen leads, honest speed, demo data, synthetic voice, chapter cards; tested templates (Playwright, ElevenLabs, HyperFrames)
Something else (explainer, essay, review…)	none	Use the core: the pacing table has a row per type; borrow from the closest recipe

Pacing at a glance

The full table, with the source of each number, is in references/pacing-and-cuts.md.

Type	What is seen changes	Silence between phrases
Talking head	Every 2–5 s (creator)	200–400 ms (creator)
Vlog	On events; film averages ≈ 4–5 s per shot (study)	Natural, with room tone
Explainer	First interrupt at 25–35 s, then every 2–3 min (creator)	200–400 ms (creator)
Screen tutorial	When the action changes; shots ≥ 5 s (house)	≥ 0.4 s (house)
Podcast / interview	On speaker changes and reactions; no source for a frequency	Natural pauses kept
Short / Reel / TikTok	Every 2–3 s; something new every 5–7 s (creator)	200–300 ms (creator)

Audio at a glance

• Master: -14 LUFS, ≤ -1 dBTP for YouTube; upload AAC at 48 kHz.
• Music 18–25 dB under the voice, ducked 6–12 dB while someone talks.
• Sound effects 12–24 dB under the voice, one per on-screen event, the transient 2–4 frames before it.
• Gains from measured levels: gain = 10^((voice_lufs - under_voice - sound_lufs)/20), capped at 1.

CC0 sound library

library/ ships 128 CC0 files, each measured in LUFS and true peak: 113 sound effects (mono WAV, 48 kHz, -22 LUFS) and 15 music tracks (stereo MP3, 48 kHz, -16 LUFS). Categories: transition 18, click 12, appear 12, notification 11, success 7, error 5, typing 9, impact 5, stinger 14, office 17, ambience 3, music 15. Paths below are relative to this skill's folder (for example ~/.claude/skills/editing-videos/).

node library/search.mjs                          # categories
node library/search.mjs --category transition
node library/search.mjs whoosh --paths           # paths to copy
node library/search.mjs pop --voice -17          # with the gain for a voice at -17 LUFS

--voice puts effects 15 dB under the voice, music 20 dB and ambience 30 dB. Copy the files into the video project; do not link them from outside it. Licenses and sources: library/LICENSES.md and references/licenses.md. After adding a sound, run node library/verify.mjs.

Graphics kit (CC0)

graphics/ has 26 drop-in graphics for HyperFrames: arrows, circles and highlight rings, underlines and scribbles, a spotlight, a cursor click ripple, callouts and tooltips, a lower third, keyboard-key chips, a step counter, a progress bar, a countdown, a checkmark and a cross, a before/after split, chapter cards, an end-screen layout, light-leak and grain overlays, and a generic like-and-subscribe prompt. Each is an HTML snippet (plus an SVG for the shapes): a timed .clip, colors and sizes in --gfx-* custom properties, and a gfx.<name>(tl, el, opts) function that adds seekable tweens to the composition's timeline. Anchor at to the word that names the target; catalog.json gives each asset's duration and when not to use it.

node graphics/search.mjs                         # categories
node graphics/search.mjs --category arrows
node graphics/search.mjs shortcut --paths        # paths to copy

Open graphics/preview.html to see them all animate. After adding one, run node graphics/build-preview.mjs and node graphics/check.mjs.

Memes

memes/catalog.json is a reference of 59 memes and meme formats, with no media: what each one means, when it fits in a tutorial, how long it stays on screen, how to recreate it with graphics/, who owns the original and its Content ID risk. Recreate the joke or license the original; never use a meme's music. Read memes/README.md first.

node memes/search.mjs fail --risk low

Index

File	What it covers
references/pacing-and-cuts.md	Pacing table by video type with sources; what a cut is for; shot length; J and L cuts; jump cuts; b-roll; transitions; segmentation
references/hook-and-retention.md	How YouTube measures retention; the hook by type; open loops; chapters; end screen and closing
references/graphics-and-text.md	When to use a graphic; anchored and never empty; text duration; captions and subtitles; zoom and punch-in; entrances; safe zones; legibility
references/audio-and-sfx.md	Target levels; dialogue cleanup; room tone; music and ducking; computing gains; sound effects; mastering
references/color.md	Order of work; LUTs as a starting point; matching shots; SDR and HDR delivery
references/thumbnail-title-description.md	Thumbnail spec and practices, A/B tests, title, description, hashtags, chapters
references/licenses.md	Music, SFX and footage sources for a monetized channel; fair use; Content ID
references/tools.md	Applying the craft in an NLE (EDL, markers, captions, instructions), ffmpeg, Remotion and HyperFrames
review-checklist.md	The universal review: measured, by eye, by ear, before publishing
recipes/talking-head.md	Talking-head recipe and checklist
recipes/vlog.md	Vlog recipe and checklist
recipes/podcast-to-youtube.md	Podcast and interview (multicam) recipe and checklist
recipes/shorts-from-long-form.md	Vertical clips from long videos: recipe and checklist
recipes/narrated-screen-tutorial.md	Narrated screen tutorial recipe, its house rules, process and checklist
recipes/narrated-screen-tutorial/voice.md	Script and synthetic voice for the tutorial: phonetic acronyms (Spanish narration), ElevenLabs, LUFS per chapter, whisper
recipes/narrated-screen-tutorial/hyperframes-generator.md	The tutorial edit in HyperFrames: skills per step, rules in the contract, the generator and its checks, pitfalls, review loop
recipes/narrated-screen-tutorial/templates/	Tested templates for that pipeline; each has --help
library/	CC0 sounds: catalog.json, search.mjs, verify.mjs, LICENSES.md, sfx/, music/, tools/synthesize.py
graphics/	CC0 HyperFrames graphics: catalog.json, search.mjs, preview.html, check.mjs, LICENSES.md, one folder per category
memes/	Meme reference with no media: README.md (read first), catalog.json, search.mjs