story-motion

story-motion 是做什么的？

Build and edit high-retention, code-driven explainer videos in the exact Story Motion house style. This skill combines a continuous talking-head master track with a deterministic Remotion/React canvas (assets/kit.tsx and references/style_spec.json), 4-frame spatial morphs, a 4-font editorial hierarchy, and a hyper-dry -15.8 LUFS zero-music audio pipeline.

When to Use

• The user asks to edit or produce a long-form (16:9) or short-form (9:16) video in the Story Motion style.
• The user wants their talking-head A-roll to morph smoothly between full-screen, asymmetric split-screen, and a pinned right-side cutout window while code-driven diagrams animate on a dark-green or paper-light architectural grid.
• The user wants an AI coding agent (Claude Code, Codex, Antigravity) to generate Remotion scenes, FFmpeg silence-cutting scripts, live lighting setups, or AI B-roll prompts matching the exact production settings.

Steps

1. Pre-Edit Audio & Breath-Cutting Pipeline (FFmpeg + Python)

Before building visual scenes, process the raw A-roll audio and video track so all Remotion frame indices lock to the final master timeline:

1. Strip Inhalations & Micro-Pauses: Use FFmpeg or Python silence detection with a -42 dBFS threshold to trim breath pauses down to 50ms - 90ms (70ms median, or 2 - 3 frames at 30 fps) within sentences, and leave exactly 133.3ms (4 frames = JOIN_FRAMES) at major section transitions.

2. Apply the Hyper-Dry Vocal Chain: Process the voice track to hit -15.8 LUFS integrated loudness, -3.5 dBFS true peak, and a tight 1.8 LU loudness range (-16.7 to -14.9 LUFS):

   • High-pass filter at 85 Hz (18 dB/oct) to remove plosives and rumble.
   • Cut -2.5 dB at 280 Hz (boxiness), boost +2.0 dB shelf at 4.5 kHz (presence), and de-ess at 6.8 kHz.
   • Compress at 4:1 (5ms attack, 60ms release, ~6 dB gain reduction) into a brickwall true-peak limiter at -3.5 dBFS.

3. Enforce Zero Background Music: Keep the background music bus at 0% (-63.7 dBFS noise floor during speech gaps). Do not add lo-fi beats or synth beds; rhythmic momentum comes entirely from tight breath cuts and visual motion snaps.

4. Layer Subliminal UI Foley (12-18 dB Below Voice): Place only quiet, tactile UI sound effects on visual transitions:

   • 4-Frame Camera Morph / Theme Wipe: Low-pass air whoosh centered at 450 Hz, 140ms duration, peaking at -28.0 dBFS.
   • Card Pop-In / Checkmark Badge: Muted mechanical tactile tick centered at 1800 Hz, 45ms duration, peaking at -30.0 dBFS.
   • Typewriter Reveal / SVG Line Draw: Subtle paper brush or keystroke at 3200 Hz, 30ms duration, peaking at -34.0 dBFS.

2. Lock In the 1920x1080 Remotion Coordinate System (assets/kit.tsx)

Import or copy assets/kit.tsx into the Remotion project to enforce the exact pixel geometry at 30 fps:

• Outer Viewport Bezel: Whenever canvas or split-screen modes are active, wrap the 1920x1080 frame in a 20px solid #060808 border with a 20px inner border-radius (inner viewport x: 20..1900, y: 20..1060). Disable the bezel on full-bleed A-roll shots (k = 0).
• Architectural Grid Canvas: Fill the stage with #16221C (Dark Mode) or #F2F4EE (Light Mode) and overlay a 40px x 40px CSS linear-gradient grid (1px stroke in rgba(242, 244, 238, 0.045) for dark mode or rgba(22, 34, 28, 0.055) for light mode) with a 20px minor sub-grid.
• Right Cutout Speaker Window (BOX): Pin the presenter cutout at x: 1657, y: 368, w: 223, h: 344, r: 20 (center [1768.5, 540.0]), cropping the 16:9 camera footage around FACE = [937, 330] using CROP = {cx: 0.488, top: 0.02, hf: 0.82} and applying boxShadow(k).
• Left Graphics Stage (PLANE & SAFE): Place all diagrams, cards, and flowcharts inside PLANE = {x: 60, w: 1557, h: 1080, centre: 121}, keeping text and badges strictly inside SAFE = {x0: 96, x1: 1824, y0: 54, y1: 1026} and left of ZONE_X = 1617.

3. Apply the 4-Font Hierarchy & Semantic Color Tokens

Never use heavy black-stroked meme captions. Combine these four font roles and semantic tokens:

• 1. Editorial Serif (Instrument Serif or Newsreader, 48px - 64px, -0.02em tracking, 1.08 line-height): Use for stage headlines, step titles (Step 1), and hook captions. Set base words in off-white #F2F4EE and highlight 1 to 2 pivot words per headline in Italic mint-emerald #7AE6A8 (or coral-red #E86B60 for negative warnings).
• 2. Geometric UI Sans (Inter or Geist Sans, 18px - 28px, -0.01em tracking, 1.35 line-height): Use for card headings (28px SemiBold), bullet items (22px Medium), body descriptions (18px Regular), and bottom source attributions (13px in #8FA196).
• 3. Technical Monospace (JetBrains Mono, 14px - 15px, +0.08em tracking): Place a 14px uppercase monospace kicker (IN THIS VIDEO, STEP 3) 12px above major serif titles in #8FA196 or #7AE6A8. Also use for syntax-highlighted code cards (#131A16 body, #1A2820 header) and lower-third typewriter pills with a blinking 8x20px #7AE6A8 block cursor.
• 4. 5x7 LED Dot-Matrix (56px - 84px, 4px dots, 2px gap): Use for hero metric callouts (1,500+ VIDEOS, 3 FREE TOOLS, 95-98%) in #7AE6A8 with inactive dots at rgba(122, 230, 168, 0.12).

4. Choreograph Layout Alternation & Motion Physics

Alternate across the 5 spatial layout archetypes so no static screen holds longer than 2.5 seconds (target a major state shift every 3.9s and a micro-animation every 1.2s - 2.2s synced to spoken nouns/verbs):

1. Full-Bleed A-Roll (~18% of runtime, max hold 7.0s): Use for the opening 4-second hook, emotional pivots, and the final 30-second guarantee/outro. Use subtle 1.0x -> 1.06x punch-ins anchored at FACE = [937, 330] to hide jump cuts.
2. 4-Frame Camera-to-Box Morph (JOIN_FRAMES = 4, 133.3ms): When transitioning from A-roll to canvas mode (CANVAS_PIP_RIGHT, ~48% of runtime), interpolate container [x, y, w, h, r] from [0, 0, 1920, 1080, 0] to [1657, 368, 223, 344, 20] over exactly 4 frames using easeOutCubic.
3. Asymmetric Split Panels (~25% of runtime, 5 frames / 167ms slide): Slide the camera container to cover the right 65% (x: 680..1900) while a dark-green grid column (x: 20..680) lists stacked bullets on the left, or keep the speaker on the left (x: 20..980) while a 2x2 bento grid of brand cards animates on the right (x: 980..1900).
4. Card & Connector Choreography:
   • Step A (Frames 0-6): Render a 1.5px dashed mint placeholder slot (rgba(122, 230, 168, 0.35), r = 16px).
   • Step B (Frames 6-14): Pop in the solid card (#1A2720, 1px border rgba(242, 244, 238, 0.08), shadow 0 18px 44px rgba(0,0,0,0.42)) scaling 0.96 -> 1.0 with cubic-bezier(0.22, 1, 0.36, 1).
   • Step C (Frames 14-26): Draw a 1.5px #7AE6A8 curved SVG bezier arrow (stroke-dashoffset: 100% -> 0% over 12 frames) to the next card or node.
5. 78-Degree Diagonal Light/Dark Wipe (14 frames / 467ms): When contrasting two modes or before/after states, sweep a 78-degree angled polygon clip-path across the stage to toggle between #16221C (Dark Mode) and #F2F4EE (Light Mode).

5. Adapt for 9:16 Vertical Short-Form (Reels, Shorts, TikTok)

When targeting 1080x1920 vertical output (VERTICAL_9_16 in assets/kit.tsx):

• Bottom Cutout Window: Pin the speaker window at the bottom (x: 120..960, y: 1280..1720, r: 28px) with the top of the speaker's head roto-masked 40px above the top card border for depth.
• Full-Screen Graphic Takeover: When complex diagrams need more vertical room, slide the bottom speaker window down off-screen (y -> 1920 over 8 frames) so graphics expand across the full canvas.
• Strict Platform Safe Zone: Keep all text, cards, and badges inside x: 90..920, y: 140..1520 so nothing is covered by right-side engagement buttons (x: 920..1080) or bottom profile/caption overlays (y: 1520..1920).

6. Match the Studio Lighting or Generate Synthetic A-Roll

When shooting live A-roll or prompting an AI video generator (Google Flow, Veo, Seedance) for presenter footage:

• Optics & Framing: 35mm - 50mm lens at f/1.8 - f/2.2, locked eye-level tripod, chest-up medium close-up with eyes at y = 330px.
• 3-Point Lighting + Coral Practical:
  • Key Light: 5400K diffused octabox at 35 deg camera-right, 25 deg elevation (64.2% IRE lit cheek #DD958E, 72.0% IRE forehead #E4AD9F).
  • Fill Side: Passive bounce camera-left for a 1.28:1 luma ratio (50.1% IRE shadow cheek #A3776D).
  • Background Practical: Warm coral-red RGB tube light (#E05A47) behind a right-side snake plant (#A07677 wall wash at 49.8% IRE), balanced by dark green palm foliage on the left (#1B2C20, 15.5% IRE) and a muted abstract painting in the center (#656F6A, 42.6% IRE).
• AI Presenter & UI Prompts: Load references/style_spec.json (ai_generation_prompts) for ready-to-run image and video generation prompts.

Gotchas

• Never Use Slow Cross-Dissolves on Camera Morphs: A 15-to-30 frame dissolve between full-screen A-roll and the right PiP box looks sluggish and amateur. Keep JOIN_FRAMES = 4 (133.3ms) so the transition lands within a single syllable gap.
• Never Let Cards Cross ZONE_X = 1617: Any graphic extending past x = 1617px will collide with the drop shadow of the right-side speaker cutout (BOX.x = 1657).
• Avoid Over-Loud SFX or Music Beds: Adding background music or loud -6 dBFS whooshes ruins the clean, high-trust editorial authority of this style. Keep BGM at 0% and cap all UI foley between -28 dBFS and -34 dBFS.