graphic-overlays

Graphic Overlays

Graphic Overlays takes a local video that plays in full and layers a sequence of timed, designed graphic cards onto it — titles, lower-thirds, data callouts, quotes, side panels, picture-in-picture — synced to what's being said. The agent designs the cards (timing + content) and writes each card's HTML directly in the conversation, then assembles a single composition HTML and renders it to MP4 via hyperframes. There is no fixed archetype list and no prescribed card structure — the overlays emerge from what the transcript actually says.

Confirm the route before you build. This skill packages an existing talking-head clip with designed graphic cards (titles, lower-thirds, data callouts, quotes, side panels, PiP). If the user wants plain captions / subtitles (the spoken words as text) → /embedded-captions; a single short unnarrated element (one logo sting / lower-third) → /motion-graphics. The clip plays untouched — re-timing, recoloring, reframing, reordering, or audio is NLE editing and out of scope. Building from a URL / topic / PR → the creation workflows. Unsure overlays-vs-captions? Read /hyperframes first.

Graphic-packaging sibling of embedded-captions. Captions add the spoken words as a readable subtitle; this adds designed graphics on top of the playing video. Plain subtitles → embedded-captions. Build a video from scratch → the creation workflows (product-launch-video / faceless-explainer / …).

Inspectable intermediate files in the work directory:

• metadata.json — duration / width / height / fps
• audio.mp3 — extracted audio
• transcript.json — a flat word array [{ text, start, end }, …] (Whisper; no segments, no words wrapper)
• storyboard.json — lightweight card outline (the agent's plan)
• public/cards/card-XX.html — one HTML fragment per card
• public/index.html — final assembled composition
• output.mp4 — rendered video

CLI Resolution

# hyperframes — transcription (local Whisper) + rendering the assembled HTML to MP4
npx hyperframes --help

This skill runs entirely on the hyperframes CLI plus system ffmpeg / ffprobe. Transcription is local Whisper via hyperframes transcribe — no third-party service, API key, or rate-limited proxy.

Workflow

1. Check Environment

npx hyperframes doctor          # ffmpeg, headless browser, render deps
# confirm bundled assets:
ls "<SKILL_DIR>/assets/fonts" "<SKILL_DIR>/assets/vendor/gsap.min.js"

Required:

• ffmpeg / ffprobe (system)
• <SKILL_DIR>/assets/fonts/*.woff2, <SKILL_DIR>/assets/vendor/gsap.min.js (bundled inside this skill, staged to work dir in Step 9)

Transcription needs no key — hyperframes transcribe runs Whisper locally (Step 4).

Strongly recommended on macOS for hyperframes render:

export PRODUCER_BROWSER_GPU_MODE=hardware

2. Create a Work Directory

All artifacts live under videos/<project-name>/ — the same convention as the other video workflows (product-launch-video / faceless-explainer / pr-to-video). Keep the cwd at the workspace root; everything below writes under this one subdirectory.

VIDEO_PATH="/absolute/path/input.mp4"
WORK_DIR="videos/$(basename "$VIDEO_PATH" | sed 's/\.[^.]*$//')"
mkdir -p "$WORK_DIR"

3. Extract Audio and Metadata

# metadata — duration / width / height / fps
ffprobe -v error -select_streams v:0 \
  -show_entries stream=width,height,r_frame_rate \
  -show_entries format=duration -of json "$VIDEO_PATH" > "$WORK_DIR/metadata.json"
# audio
ffmpeg -y -i "$VIDEO_PATH" -vn -acodec libmp3lame -q:a 2 "$WORK_DIR/audio.mp3"

Outputs: metadata.json (read width/height/duration; fps = the r_frame_rate fraction evaluated, e.g. 30000/1001 → 29.97) + audio.mp3.

4. Transcribe

npx hyperframes transcribe "$WORK_DIR/audio.mp3" -d "$WORK_DIR" --json --model small.en

Local Whisper — no API key, no proxy, no rate limit. Writes a word-level transcript.json into the work dir (word text + start / end timestamps). Read it for the word / sentence timings that drive card timing in Step 6; group words into sentences yourself at punctuation / pauses if you need segment-level chunks.

Clamp to media duration. Whisper can return the final word's end a hair past the actual clip length — clamp every card endSec and composition.durationSeconds to the metadata.json duration, or the render will show a black tail past the video.

5. Correct Transcript

transcript.json is a flat array of word objects — [{ "text": "...", "start": s, "end": s }, …] (no segments array, no words wrapper; the per-word key is text). Read it and fix obvious ASR errors:

• Homophones, product names, technical terms, punctuation
• Edit a word's text in place; preserve its start / end timestamps
• There is no pre-grouped segments array — group words into sentences yourself (split at terminal punctuation / pauses) when you need segment-level chunks for card timing

6. Draft a Lightweight Storyboard (in chat)

No CLI involved. Read transcript.json + metadata.json and design cards directly. storyboard.json is an agent-internal planning artifact — no CLI command consumes it; it exists so you can think clearly about timing and content before writing each card's HTML. Keep the shape consistent with the example below so the same outline can drive the composition you author in Step 9:

{
  "schemaVersion": 3,
  "composition": {
    "fps": 30,
    "width": 1080,
    "height": 1920,
    "durationSeconds": 121.2,
    "layout": "portrait",
    "themeId": "noir",
    "seed": 42
  },
  "videoTrack": {
    "sourcePath": "input-video.mp4",
    "startSec": 0,
    "endSec": 121.2,
    "bounds": { "x": 0, "y": 0, "width": 1080, "height": 1920 }
  },
  "subtitles": { "enabled": false },
  "cards": [
    {
      "id": "card-01",
      "intent": "Hook with the speaker's anxious midnight question",
      "startSec": 0.5,
      "endSec": 13.0,
      "accentIndex": 0,
      "zone": "fullscreen",
      "contentHints": {
        "kicker": "AN HONEST QUESTION",
        "title": "The soul-searching question at 11 PM",
        "detail": "Client's 60-second voice message: 'If the RMB appreciates, does that mean my USD policy is a terrible loss?'"
      }
    }
  ]
}

Required Card fields:

field	type	purpose
id	string	stable id used in card HTML & GSAP selectors
intent	string	natural-language description; fed to card synthesis
startSec / endSec	number	times in seconds (endSec > startSec)
accentIndex	0 | 1 | 2 | 3 | 4	which of the 5 theme accent colors this card pulls
zone	enum (see below)	where on the canvas the card lives
contentHints	object	free-form bag; agent puts kicker/title/detail/data/quote here
archetype (optional)	string	free-form label you may attach to remember a card's pattern; absent = free-form, which is the default
transition (optional)	enum: cut | fade | slide | wipe	declarative card-to-card transition

Five zone values:

zone	resolved bounds	when to use
fullscreen	covers whole canvas	hero moments, big numbers, mantras
whiteboard-area	inset 40px margin (or 45% of portrait height)	dense data / annotated content
lower-third	bottom 30% band	annotation over visible video
side-panel	right 42% (landscape) or bottom 40% (portrait)	data side, video other side
video-overlay	full canvas, expects mostly-transparent card	annotation overlays on full-bleed video

When you assemble the composition in Step 9, resolve each card's zone into pixel bounds on the card-host wrapper following the table above. Video bounds are set once at composition level (videoTrack.bounds); to make video appear to "move between cards", author GSAP tweens against #video-wrap in the composition's <script> (see Step 9).

No prescribed card roles, no prescribed narrative arc. Cards emerge from what the video actually says — could be all quotes or all data, could open with a number or with a story. Let the transcript drive the rhythm.

How many takeaways? — auto-infer from duration + density. No fixed upper limit. Pick a base pace from the video duration, then adjust by information density. Only floor is fixed: minimum 5 cards so even short videos have rhythm.

Step 1 — base pace by duration (the natural sec/card for medium density):

video duration	base pace (sec per card)	rationale
< 60s (short reel)	6–8s	viewers expect fast cuts in short-form
60s – 3 min	8–12s	normal social pace
3 – 10 min	12–20s	give breathing room; each card carries more
10 – 30 min	20–35s	long-form lecture / interview rhythm
> 30 min	30–60s	episodic, near-chapter feel

Step 2 — density multiplier (multiplies the base pace):

signal in the transcript	multiplier	effect
High density — many numbers, distinct claims, staccato pacing, list-like enumeration, every 1–2 sentences is a new idea	× 0.7	cuts faster, more cards
Medium density — mixed flow with both data and narrative	× 1.0	base pace
Low density — one extended story, repeated reframing, slow reflective pacing, single argument unfolding	× 1.5	cuts slower, fewer cards

Step 3 — compute:

secPerCard = basePace × densityMultiplier
cardCount  = max(5, round(videoDurationSec / secPerCard))

Examples (notice — no upper clamp; long videos naturally produce more cards):

• 30s reel, single punchline (low density) → 7 × 1.5 = 10.5s/card → round(30/10.5)=3 → floor to 5 cards
• 60s reflective monologue (low density) → 10 × 1.5 = 15s/card → 4 → floor to 5 cards
• 121s talking-head with rich data (high density) → 10 × 0.7 = 7s/card → 17 cards
• 5 min interview, mixed density → 16 × 1.0 = 16s/card → 19 cards
• 10 min deep-dive, high density → 16 × 0.7 = 11s/card → 55 cards
• 30 min lecture, medium density → 28 × 1.0 = 28s/card → 64 cards
• 1 hr podcast, low density → 45 × 1.5 = 67.5s/card → 53 cards

When a card holds longer than ~15s, plan for a richer card (data block, multi-step reveal, several sub-points unfolding with staggered animations) — a static one-liner gets boring past 8s. For long pieces where many cards exceed 30s, consider chunking the timeline into sub-compositions (one .html per chapter, mounted with data-composition-src) so the GSAP timeline per file stays manageable — see the timeline_track_too_dense HyperFrames lint warning.

content can be a plain string ("Title: annualized 5.69%\nNotes: ...") or any JSON shape that captures the data. The agent decides the shape per card.

Optional outro. This skill ships no fixed brand outro. If the user wants a closing card, design a neutral one yourself (wordmark + one-line tagline, ~1.5-2s, fade in -> short hold -> fade out), append it to cards[], and extend composition.durationSeconds to its endSec. Otherwise end on the last content card.

7. Decide Render Strategy

Confirm Visual Direction with User (DO THIS FIRST)

Before you start designing cards or deciding bounds, ask the user to pick the output ratio, the layout, the style, and the card-density preset. Frames are auto-selected from the chosen layout × style combination (see "Auto-pick frame" table below). Before sending the question, precompute two things:

1. recommendedRatio from the source video's aspect ratio (metadata.json width / height):

   • sourceAspect = width / height
   • sourceAspect ≥ 1.5 (≥ ~3:2 wide) → recommend 16:9
   • sourceAspect ≤ 0.7 (≤ ~9:13 tall) → recommend 9:16
   • 0.7 < sourceAspect < 1.5 (near-square) → recommend 4:5

   Mark the recommended option's label with " (recommended · matches source video X:Y)" so the user sees why it's recommended.

2. autoCount from Step 6 (max(5, round(videoSec / (basePace × densityMultiplier)))) so the "auto" option's label can show the concrete number.

Environment compatibility — pick the best available question channel. Not every runtime exposes the same structured-question tool. Apply this order:

1. AskUserQuestion (Claude Code, Anthropic Console) — use the structured 4-question call below.
2. Other native clarification tool (e.g. ask_question, request_user_input, IDE-specific prompt) — use that tool with the same 4 question texts and option lists. Preserve the recommendation markers and the precomputed values.
3. No native tool (Codex CLI, plain text-only runtimes) — ask directly in normal conversation. Use the plain-text template at the end of this section. Keep it to **one message, 4 numbered

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