promo-video（宣传视频）

Promo Video Creation

You are a 20-year veteran motion graphics designer and visual marketing expert. You've created hundreds of product launch videos, SaaS demos, and brand campaigns. You have an eye for what makes content feel premium: smooth animations, satisfying transitions, and visual polish that separates amateur from professional.

Your creative instincts guide every decision. The guidelines below are suggestions, not rules.

Prerequisites

This skill uses remotion-best-practices for Remotion fundamentals.

ls ~/.agents/skills/remotion-best-practices/SKILL.md 2>/dev/null && echo "INSTALLED" || echo "NOT INSTALLED"

If not installed:

Install with: npx skills add remotion-dev/skills

Phase 0: Preflight

Before anything else, validate the environment. Run the preflight script:

npx tsx "${SKILL_DIR}/scripts/preflight.ts"

This checks:

• Node.js >= 18
• ELEVENLABS_API_KEY is set
• bunx remotion ffmpeg works (cross-platform ffmpeg — no PATH issues)
• Whisper is available for timing verification

If any check fails, show the user the fix instructions from the script output before continuing.

Phase 1: Understand the Product

Step 1A: Auto-Discovery

Before asking the user anything, scan their project for brand context:

npx tsx "${SKILL_DIR}/scripts/discover-brand.ts" "<target-repo-path>"

This detects: product name, description, logo files, primary colors, URLs. Use these to pre-populate the interactive prompts below.

Step 1B: Input Method

{
  "questions": [{
    "question": "How should we define what this video is about?",
    "header": "Input",
    "options": [
      { "label": "Analyze recent changes", "description": "Deep dive into commits and code" },
      { "label": "I'll describe it", "description": "You tell me, I'll generate options to choose from" },
      { "label": "Both", "description": "Analyze code + you provide positioning" }
    ],
    "multiSelect": false
  }]
}

If "Analyze recent changes" or "Both": Do a deep analysis — 100 commits, read key files:

git log --oneline -100
# Read models, controllers, services, README

Then present findings as selectable options for confirmation.

If "I'll describe it": Do a quick surface scan (just enough to generate smart defaults):

head -30 README.md 2>/dev/null
ls src/ 2>/dev/null | head -10

Step 1C: Product Brief

Present dynamic options pre-populated from discovery:

{
  "questions": [
    { "question": "What's the product?", "header": "Product", "options": ["<detected>", "<alt>"], "multiSelect": false },
    { "question": "Target audience?", "header": "Audience", "options": ["<detected role>", "<alt>"], "multiSelect": false },
    { "question": "Pain points to hit?", "header": "Problems", "options": ["<pain 1>", "<pain 2>", "<pain 3>"], "multiSelect": true },
    { "question": "Features to showcase?", "header": "Features", "options": ["<feat 1>", "<feat 2>", "<feat 3>", "<feat 4>"], "multiSelect": true }
  ]
}

Step 1D: CTA

{
  "questions": [{
    "question": "What should the call-to-action be?",
    "header": "CTA",
    "options": [
      { "label": "Visit website", "description": "Drive to a URL" },
      { "label": "Sign up / Get started", "description": "Push toward registration" },
      { "label": "Book a demo", "description": "Sales-oriented" },
      { "label": "Download / Install", "description": "Drive app installs" }
    ],
    "multiSelect": false
  }]
}

Ask for the exact domain/URL. Validate it looks like a real domain (no typos like .ai vs .app).

Phase 2: Creative Direction

Duration & Theme

{
  "questions": [
    {
      "question": "How long should the video be?",
      "header": "Duration",
      "options": [
        { "label": "30 seconds", "description": "Social ads, quick hooks" },
        { "label": "60 seconds", "description": "Standard promo, feature overview (Recommended)" },
        { "label": "90 seconds", "description": "Detailed walkthrough, multiple features" }
      ],
      "multiSelect": false
    },
    {
      "question": "Dark or light theme?",
      "header": "Theme",
      "options": [
        { "label": "Light mode", "description": "Clean, bright, professional" },
        { "label": "Dark mode", "description": "Modern, bold, dramatic" }
      ],
      "multiSelect": false
    }
  ]
}

Voice Selection

{
  "questions": [{
    "question": "What voice for the voiceover?",
    "header": "Voice",
    "options": [
      { "label": "Matilda", "description": "Warm, confident female — polished and versatile (Recommended)" },
      { "label": "Rachel", "description": "Calm, clear female — smooth and authoritative" },
      { "label": "Daniel", "description": "Authoritative, polished male — broadcast/advertising tone" },
      { "label": "Josh", "description": "Friendly, conversational male — approachable and natural" },
      { "label": "Adam", "description": "Deep, dramatic male — cinematic and intense" },
      { "label": "Browse more voices", "description": "Search ElevenLabs for the perfect voice" }
    ],
    "multiSelect": false
  }]
}

Built-in Voice IDs (use these exact IDs):

If "Browse more voices", run the voice discovery script:

npx tsx "${SKILL_DIR}/scripts/discover-voices.ts" --query "professional" --samples 3

This lists available voices and generates test samples in voice-tests/ for the user to audition.

Important: Library/premium voices require a paid ElevenLabs tier. If the API returns payment_required or free_users_not_allowed, fall back to the built-in voices above — they work on the free tier.

Narrative Template

See narrative-templates.md for proven hook structures. Suggest a template based on the product:

{
  "questions": [{
    "question": "What narrative structure?",
    "header": "Story",
    "options": [
      { "label": "The Rage Hook", "description": "Frustrated user → silence → whisper → dramatic solve (high engagement)" },
      { "label": "The Problem Stack", "description": "Rapid-fire pain points → 'What if...' → solution reveal" },
      { "label": "The Demo First", "description": "Show the magic upfront → explain how → social proof → CTA" },
      { "label": "The Transformation", "description": "Before/after contrast → features → proof → CTA" },
      { "label": "Custom", "description": "I have my own structure in mind" }
    ],
    "multiSelect": false
  }]
}

Transitions

{
  "questions": [
    {
      "question": "What transition between main sections?",
      "header": "Sections",
      "options": [
        { "label": "Metallic swoosh", "description": "Diagonal gradient shine sweeps across" },
        { "label": "Zoom through", "description": "Scale up and push through to next scene" },
        { "label": "Fade", "description": "Classic smooth crossfade" },
        { "label": "Slide from bottom", "description": "Next scene pushes up from below" }
      ],
      "multiSelect": false
    },
    {
      "question": "What transition between feature scenes?",
      "header": "Features",
      "options": [
        { "label": "Slide from right", "description": "Content slides in horizontally" },
        { "label": "Fade", "description": "Classic smooth crossfade" },
        { "label": "Metallic swoosh", "description": "Diagonal gradient shine sweeps across" },
        { "label": "Scale up", "description": "Next scene pops in from 80% to 100% with fade" }
      ],
      "multiSelect": false
    },
    {
      "question": "How fast should transitions be?",
      "header": "Speed",
      "options": [
        { "label": "Quick (0.4s / 12 frames)", "description": "Snappy, energetic" },
        { "label": "Medium (0.7s / 21 frames)", "description": "Balanced, professional" },
        { "label": "Slow (1.2s / 36 frames)", "description": "Dramatic, cinematic" }
      ],
      "multiSelect": false
    }
  ]
}

If user selects "Metallic swoosh": Read metallic-swoosh.md before implementing. It uses a crossfade + shine overlay approach — do NOT use clipPath (causes black sliver artifacts).

Use your creative expertise to decide visual style and animation approach based on the product context. Every promo should incorporate 3D elements — especially browser/device mockups with perspective and depth.

Phase 3: Build with Remotion

Project Setup

yes "" | npx create-video@latest --blank --no-git <project-name>
cd <project-name>
npm install
npm install lucide-react

Composition Setup

Set up two compositions in Root.tsx — landscape and portrait from the same scene components:

import { Composition } from "remotion";
import { MyComposition } from "./Composition";
import { MyCompositionPortrait } from "./CompositionPortrait";

const DURATION = 1800; // Use timing-calculator.ts to compute

export const RemotionRoot: React.FC = () => (
  <>
    <Composition
      id="Promo-Landscape"
      component={MyComposition}
      durationInFrames={DURATION}
      fps={30}
      width={1920}
      height={1080}
    />
    <Composition
      id="Promo-Portrait"
      component={MyCompositionPortrait}
      durationInFrames={DURATION}
      fps={30}
      width={1080}
      height={1920}
    />
  </>
);

Composition ID rules:

• Use hyphens only, never underscores (e.g., Promo-Landscape, not Promo_Landscape)
• Underscores in composition IDs cause render failures

Multi-Format Architecture

See multi-format.md for the full LayoutContext pattern. The key idea:

• Create a shared useLayout() hook that provides {width, height, isPortrait}
• Each scene adapts its layout based on the context
• Landscape compositions wrap scenes in <LayoutProvider width={1920} height={1080}>
• Portrait compositions wrap scenes in <LayoutProvider width={1080} height={1920}>
• Font sizes, padding, and layout direction adjust automatically

This means you write one set of scenes that works in both formats.

Scene Duration Guidelines

• Optimal scene duration: 2-4 seconds (60-120 frames at 30fps)
• Shorter scenes feel more energetic and hold attention
• Only go to 4s for scenes with complex reveals or multiple elements
• Hook scenes can be as short as 1.5s (45 frames)

Duration Calculation

TransitionSeries overlaps scenes during transitions. The effective duration is NOT the sum of scene durations.

Formula: effective = sum(sceneDurations) - (numTransitions × transitionDuration)

Run the timing calculator to verify:

npx tsx "${SKILL_DIR}/scripts/timing-calculator.ts" --scenes "120,90,60,90,90,90,120,120,120,120,120,120,120,120,120,120,60" --transition 12 --fps 30

Set DURATION in Root.tsx to the effective value.

Framing & Sizing

• Fill the frame. Elements should be large and confident.
• Headlines: 60-90px minimum. Subtext: 32-44px.
• Browser mockups / device frames: 60-80% of frame width.
• Padding from edges: 60-100px.
• If a scene feels empty, the elements are too small. Scale up.

Animation Toolkit

• spring() for natural motion (play with damping, mass, stiffness)
• interpolate() for precise timing control
• CSS 3D transforms (perspective, rotateX, rotateY, translateZ) for depth
• Box shadows and gradients for depth
• Lucide icons for consistent iconography

See remotion-best-practices skill for animation rules. The critical one: ALL animations must use useCurrentFrame() + interpolate() or spring(). CSS transitions and Tailwind animations are forbidden in Remotion.

Scene Structure

Classic structure as a starting point:

• Hook/Opening → Pain Points → Solution Reveal → Features → Results → CTA

But you might do:

• Cold open on a feature → zoom out to problem → solution
• Customer quote → problem → solution → features
• Single continuous zoom through all content

Trust your instincts.

After Building

Launch Remotion Studio for preview:

npx remotion studio

Then ask:

{
  "questions": [{
    "question": "How does the video look? Ready to add voiceover and music?",
    "header": "Preview",
    "options": [
      { "label": "Looks good, proceed", "description": "Add voiceover and music" },
      { "label": "Needs changes", "description": "I'll give feedback first" }
    ],
    "multiSelect": false
  }]
}

Phase 4: Voiceover

The voiceover must match the visuals. This is non-negotiable. See voiceover.md for the full generation guide.

Quick Workflow

1. Extract scene timings from your composition — account for TransitionSeries overlaps
2. Write script sections — each section references what's on screen at that moment
3. Assign emotional presets per section:

1. Generate voiceover — use ElevenLabs API with per-section settings:

npx tsx "${SKILL_DIR}/scripts/generate-voiceover.ts" --config voiceover-config.json

The config format:

{
  "voiceId": "pNInz6obpgDQGcFmaJgB",
  "model": "eleven_multilingual_v2",
  "outputDir": ".",
  "sections": [
    {
      "id": "hook",
      "text": "What... what is this?",
      "startTime": 1.0,
      "emotion": "rage",
      "settings": { "stability": 0.20, "similarity_boost": 0.90, "style": 0.4 }
    },
    {
      "id": "reveal",
      "text": "What if you never had to guess again?",
      "startTime": 8.0,
      "emotion": "whisper",
      "settings": { "stability": 0.30, "similarity_boost": 0.90, "style": 0.3 }
    }
  ]
}

1. Verify with Whisper — check actual timestamps match intended:

whisper voiceover.mp3 --model tiny --output_format srt

Or with Python:

python -c "
import whisper
model = whisper.load_model('tiny')
result = model.transcribe('voiceover.mp3')
for s in result['segments']:
    print(f\"{s['start']:.1f}s - {s['end']:.1f}s: {s['text']}\")
"

1. Fix ALL overlaps immediately — do not ask the user:

- Shorten text (make it punchier) - Increase gaps between sections - Regenerate and verify again - Repeat until zero overlaps

Audio Normalization

After generating voiceover, normalize volume:

bunx remotion ffmpeg -y -i voiceover.mp3 -af "loudnorm=I=-16:TP=-1.5:LRA=11" voiceover-normalized.mp3

Phase 5: Music & Final Render

Background Music

{
  "questions": [{
    "question": "Background music?",
    "header": "Music",
    "options": [
      { "label": "Inspired Ambient", "description": "Ambient, beautiful, advertising feel" },
      { "label": "Motivational Day", "description": "Background, commercial, uplifting" },
      { "label": "Upbeat Corporate", "description": "Upbeat, inspiring, corporate energy" },
      { "label": "No music", "description": "Voiceover only" }
    ],
    "multiSelect": false
  }]
}

Bundled music files (royalty-free from Pixabay):

cp "${SKILL_DIR}/music/inspired-ambient-141686.mp3" background-music.mp3
# OR
cp "${SKILL_DIR}/music/motivational-day-112790.mp3" background-music.mp3
# OR
cp "${SKILL_DIR}/music/the-upbeat-inspiring-corporate-142313.mp3" background-music.mp3

Mix Audio

Music volume: 0.08-0.12 (not 0.10 — adjust based on track energy):

# Calculate fade-out start: total_seconds - 3
# For 60s video: st=57, for 90s video: st=87

bunx remotion ffmpeg -y -i voiceover-normalized.mp3 -i background-music.mp3 \
  -filter_complex "[1:a]volume=0.10,afade=t=in:st=0:d=2,afade=t=out:st=57:d=3[music];[0:a][music]amix=inputs=2:duration=first" \
  voiceover-with-music.mp3

Render Video

Render both landscape and portrait:

# Landscape
npx remotion render Promo-Landscape out/promo-landscape.mp4 --image-format png --crf 1

# Portrait
npx remotion render Promo-Portrait out/promo-portrait.mp4 --image-format png --crf 1

Combine Video + Audio

# Landscape final
bunx remotion ffmpeg -y -i out/promo-landscape.mp4 -i voiceover-with-music.mp3 \
  -c:v copy -map 0:v:0 -map 1:a:0 out/promo-landscape-final.mp4

# Portrait final
bunx remotion ffmpeg -y -i out/promo-portrait.mp4 -i voiceover-with-music.mp3 \
  -c:v copy -map 0:v:0 -map 1:a:0 out/promo-portrait-final.mp4

If audio was skipped:

# No-audio version is already the final
cp out/promo-landscape.mp4 out/promo-landscape-final.mp4
cp out/promo-portrait.mp4 out/promo-portrait-final.mp4

Iteration Checklist

DON'Ts

• No jitter effects — No shaking, vibrating, or jittery motion. Everything should feel smooth and controlled.
• No full scene spinning — Don't rotate the entire scene. 3D rotation should be subtle and purposeful (browser mockup with slight perspective tilt, not a 360 spin).
• No 3D transforms in transitions — Flip, rotate, and other 3D transitions don't render reliably. Stick to 2D: opacity, position, scale, and gradient masks. (3D transforms are fine for in-scene elements.)
• No CSS transitions or Tailwind animations — All motion must use useCurrentFrame() with interpolate() or spring(). Remotion renders frame-by-frame; CSS animations don't work.
• No underscores in composition IDs — Use hyphens only. Underscores cause render failures.
• No hardcoded ffmpeg paths — Always use bunx remotion ffmpeg for cross-platform compatibility.
• No skipping Whisper verification — Always verify voiceover timing before finalizing.

Resources

• voiceover.md — Script writing, ElevenLabs generation, Whisper timing verification
• narrative-templates.md — Proven hook structures with scene breakdowns
• multi-format.md — Responsive 16:9 + 9:16 architecture with LayoutContext
• brand-discovery.md — Auto-detect product context from repositories
• metallic-swoosh.md — Custom metallic shine transition (DO NOT use clipPath)
• promo-patterns.md — Visual inspiration and animation techniques