Remotion Video Reviewer

Provides comprehensive, structured reviews of Remotion video implementations against motion design specifications. Identifies issues, assesses impact, and generates actionable revision lists.

What This Skill Does

Performs multi-layer review analysis:

1. Spec compliance — Verifies implementation matches design spec
2. Code quality — Checks patterns, performance, best practices
3. Timing accuracy — Validates frame calculations and animation timing
4. Visual fidelity — Confirms colors, typography, layout match spec
5. Asset quality — Verifies assets are production-ready
6. Performance — Identifies render bottlenecks

Input/Output Formats

Input Format: VIDEO_SPEC.md + Code Files

Requires both the original specification and implemented code:

VIDEO_SPEC.md (from /motion-designer)

# Video Title

## Overview
- Duration: 30 seconds
- Frame Rate: 30 fps

## Color Palette
Primary: #FF6B35
Background: #0A0A0A

## Scene 1: Opening (0s - 5s)
- Logo scales from 0.8 to 1.0
- Spring config: { damping: 200 }

Code Files to review:

• src/remotion/compositions/VideoName/index.tsx
• src/remotion/compositions/VideoName/constants.ts
• src/remotion/compositions/VideoName/types.ts
• Asset files in public/

Output Format: REVIEW_REPORT.md

Generates a comprehensive review with prioritized issues:

# Video Review Report: [Video Title]

**Date:** 2026-01-23
**Reviewer:** remotion-video-reviewer
**Spec Version:** VIDEO_SPEC.md v1.0
**Code Location:** `src/remotion/compositions/VideoName/`

---

## Executive Summary

**Overall Status:** ✅ APPROVED WITH MINOR REVISIONS

**Quick Stats:**
- Total Issues: 4 (0 critical, 1 high, 2 medium, 1 low)
- Spec Compliance: 95%
- Code Quality: Excellent
- Production Ready: Yes, after addressing HIGH priority items

**Recommendation:** Address high-priority color mismatch before final render. Medium and low priority items are optional improvements.

---

## Compliance Scores

| Category | Score | Status | Notes |
|----------|-------|--------|-------|
| **Spec Compliance** | 95% | 🟢 Pass | 1 color mismatch in Scene 3 |
| **Code Quality** | 98% | 🟢 Pass | Excellent structure, minor optimization opportunity |
| **Timing Accuracy** | 100% | 🟢 Pass | All frame calculations correct |
| **Visual Fidelity** | 95% | 🟢 Pass | Minor color deviation |
| **Asset Quality** | 90% | 🟡 Good | 1 image could be optimized |
| **Performance** | 95% | 🟢 Pass | Excellent render times |

**Overall Compliance:** 95.5% — Production Ready

---

## Issues Found

### CRITICAL (Must Fix Before Production)
_None_ ✅

### HIGH Priority (Should Fix)

#### 1. Scene 3 Background Color Mismatch
**Category:** Visual Fidelity
**Location:** `src/remotion/compositions/VideoName/scenes/Scene3.tsx:15`
**Impact:** Visual inconsistency with brand colors

**Issue:**

// Current implementation backgroundColor: '#0B0B0B' // ❌ Wrong

// Spec requirement Primary: #FF6B35 Background: #0A0A0A // ✅ Correct

**Fix:**

// Update to use COLORS constant backgroundColor: COLORS.background // Now: #0A0A0A

**Verification:**
- [ ] Update `constants.ts` if COLORS.background is incorrect
- [ ] Verify Scene 3 uses COLORS.background
- [ ] Visual check against spec color palette

---

### MEDIUM Priority (Consider Fixing)

#### 2. Large Product Image Could Be Optimized
**Category:** Asset Quality
**Location:** `public/images/product.png`
**Impact:** Slower render times, larger output file

**Current:**
- Format: PNG
- Resolution: 4000x3000
- File size: 8.2MB

**Recommendation:**
- Format: JPEG (no transparency needed)
- Resolution: 1920x1440 (2x display size)
- Quality: 90%
- Expected size: ~400KB (95% reduction)

**Fix:**

Resize and convert

magick public/images/product.png -resize 1920x1440 -quality 90 public/images/product.jpg

Update code to use .jpg

<Img src={staticFile('images/product.jpg')} />

**Benefits:**
- Faster preview/render times
- Smaller final video file
- No visual quality loss

---

#### 3. Particle System Could Use Memoization
**Category:** Performance
**Location:** `src/remotion/compositions/VideoName/scenes/Scene2.tsx:45`
**Impact:** Minor performance improvement possible

**Current:**

// Particle positions recalculated (deterministic but not cached) const particles = Array.from({ length: 70 }, (_, i) => ({ x: seededRandom(i 123) width, y: seededRandom(i 456) height, }));

**Recommendation:**

import { useMemo } from 'react';

const particles = useMemo( () => Array.from({ length: 70 }, (_, i) => ({ x: seededRandom(i 123) width, y: seededRandom(i 456) height, })), [width, height] );

**Expected Impact:** 5-10% faster render for Scene 2

---

### LOW Priority (Nice to Have)

#### 4. Add JSDoc Comments to Scene Components
**Category:** Code Quality
**Location:** All scene components
**Impact:** Improved maintainability

**Recommendation:**

/** Scene 1: Opening animation with logo reveal Duration: 0s - 5s (frames 0-150) Spec reference: VIDEO_SPEC.md Section "Scene 1" / function Scene1Opening() { // ... }

**Benefits:**
- Easier for team members to understand
- Better IDE autocomplete
- Clear spec traceability

---

## Detailed Analysis

### Spec Compliance (95%)

✅ **Passed:**
- All 4 scenes implemented
- Scene timing matches spec exactly (verified frame calculations)
- Typography matches (Inter font, correct weights)
- Audio placement correct (background music + 2 SFX)
- Spring configurations match spec descriptions
- All animations implemented as described

❌ **Failed:**
- Scene 3 background color (#0B0B0B instead of #0A0A0A)

**Verification Steps Completed:**
- [x] Compared scene count: 4 scenes (matches)
- [x] Verified scene durations: All correct
- [x] Checked color palette: 1 mismatch found
- [x] Validated spring configs: All match
- [x] Tested audio timing: Correct

---

### Code Quality (98%)

✅ **Excellent Patterns:**
- Constants properly extracted (COLORS, SPRING_CONFIGS, SCENE_TIMING)
- Consistent naming conventions (Scene1Opening, Scene2Content)
- AbsoluteFill used correctly in all scenes
- Progress variables extracted (not inline spring calls)
- TypeScript types defined for all props
- Clean, readable code structure
- Proper imports from remotion

✅ **Best Practices Followed:**
- useVideoConfig used for responsive positioning
- staticFile() used for all assets
- Sequence timing uses constants
- No magic numbers in code
- Deterministic random in particle system

🟡 **Minor Improvements:**
- Could add useMemo to particle calculation (LOW impact)
- JSDoc comments would improve maintainability

---

### Timing Accuracy (100%)

✅ **All Verified:**

Scene 1: 0s - 5s → frames 0-150 ✓ Correct (5 30fps) Scene 2: 5s - 15s → frames 150-450 ✓ Correct (10 30fps) Scene 3: 15s - 25s → frames 450-750 ✓ Correct (10 30fps) Scene 4: 25s - 30s → frames 750-900 ✓ Correct (5 30fps)

Total: 30s = 900 frames ✓ Correct

**Validation:**
- [x] All SCENE_TIMING constants match spec
- [x] Sequence components use correct start/duration
- [x] No timing overlap or gaps
- [x] Audio timing matches frame calculations

---

### Asset Quality (90%)

✅ **Good:**
- Logo: 800x800 PNG, optimized, transparent ✓
- Background music: 30s MP3, 192kbps ✓
- Whoosh SFX: MP3, proper duration ✓
- Pop SFX: MP3, proper duration ✓
- Font: Inter loaded correctly via @remotion/google-fonts ✓

🟡 **Could Improve:**
- Product image: 8.2MB PNG → Should be 1920x1440 JPEG (~400KB)

**Asset Checklist:**
- [x] All assets present in `public/`
- [x] Correct formats used (mostly)
- [x] staticFile() imports correct
- [ ] File sizes optimized (1 large image)
- [x] No missing assets

---

### Performance (95%)

**Render Performance:**
- Average: 85ms/frame ✅ Excellent (target: <100ms)
- Scene 1: 65ms/frame ✅
- Scene 2: 105ms/frame 🟡 (particle system, acceptable)
- Scene 3: 75ms/frame ✅
- Scene 4: 70ms/frame ✅

**No Major Issues:**
- ✅ Spring calculations extracted and reused
- ✅ No expensive operations in render path
- ✅ Assets load efficiently (except large PNG)
- ✅ No memory leaks detected

**Minor Optimization Opportunities:**
- Memoize particle calculations (5-10% improvement in Scene 2)
- Optimize product.png (faster asset loading)

---

## Recommendations

### Before Production
1. ✅ **Fix HIGH priority color mismatch** (5 minutes)
2. ⏭️ Consider optimizing product image (10 minutes) - Optional but recommended

### For Future Iterations
1. Add JSDoc comments to scene components
2. Apply memoization to particle system
3. Consider extracting ParticleSystem to reusable component

---

## Testing Checklist

Completed validation:
- [x] Visual inspection of all scenes
- [x] Frame-by-frame timing verification
- [x] Color palette comparison
- [x] Audio synchronization test
- [x] Asset loading verification
- [x] Render performance profiling
- [x] Code pattern review
- [x] Best practices compliance

---

## Next Steps

1. **Address HIGH priority issue:** Fix Scene 3 background color
2. **Optional:** Optimize product.png asset
3. **Final render:** Generate production video
4. **Performance check:** Run `/remotion-performance-optimizer` if render times increase
5. **Archive:** Save REVIEW_REPORT.md with project files

---

## Approval

**Status:** ✅ APPROVED WITH MINOR REVISIONS

This implementation is production-ready after addressing the Scene 3 color mismatch. All critical functionality, timing, and structure are correct. Medium and low priority items are optional improvements that can be addressed in future iterations.

**Signed:** remotion-video-reviewer
**Date:** 2026-01-23

This document provides:

• Executive summary with quick approval status
• Quantified compliance scores (95%, 98%, etc.)
• Prioritized issues (CRITICAL, HIGH, MEDIUM, LOW)
• Specific code locations and fixes
• Detailed analysis per category
• Testing verification checklist
• Clear next steps
• Official approval status

Feeds into:

• Developer: Fix identified issues
• /remotion-performance-optimizer if performance issues found
• Final production render after approval

Review Process

1. Spec Comparison

Compare implementation against motion design spec:

Check:

• All scenes from spec are implemented
• Scene durations match spec timing
• Color palette matches hex codes exactly
• Typography (font, size, weight) matches
• Animation descriptions are accurately translated
• Audio placement matches timing
• Spring configurations match spec

2. Code Quality Review

Evaluate code structure and patterns:

Check:

• Constants extracted (colors, springs, timing)
• Scene components follow naming convention
• AbsoluteFill used for all scenes
• Progress variables extracted (not inline calculations)
• useVideoConfig used for responsive positioning
• TypeScript types defined
• Proper imports from remotion

3. Timing Accuracy

Verify frame calculations:

Check:

• Seconds correctly converted to frames (seconds * fps)
• Scene timing constants are accurate
• Delay calculations use frame offsets
• Transitions account for overlap
• Total duration matches spec
• Animation hold times are correct

4. Animation Review

Assess animation implementation:

Check:

• Spring configs match spec descriptions
• Interpolate ranges match spec values
• Easing functions appropriate for motion type
• Stagger delays calculated correctly
• Continuous animations use appropriate patterns
• Exit animations present where specified

5. Visual Fidelity

Confirm visual accuracy:

Check:

• Background colors match spec
• Element colors use COLORS constants
• Font sizes match spec exactly
• Positioning follows spec layout
• Visual hierarchy maintained
• Layer organization (background/midground/foreground)

6. Asset Quality

Validate asset preparation:

Check:

• All required assets present
• Assets use staticFile() import
• Image formats appropriate (PNG for transparency, JPEG for photos)
• Audio files in supported formats
• Asset dimensions suitable for composition
• Fonts loaded correctly

7. Performance Check

Identify performance issues:

Check:

• No expensive calculations in render
• Progress variables reused
• No unnecessary spring recalculations
• Memoization used where appropriate
• Large assets optimized
• No memory leaks in loops

Review Output Format

Summary

## Review Summary

**Spec Compliance**: 95% (1 minor deviation)
**Code Quality**: Excellent
**Timing Accuracy**: 100%
**Visual Fidelity**: 98% (color mismatch in Scene 3)
**Asset Quality**: Good (1 optimization needed)
**Performance**: Excellent

**Overall Rating**: READY FOR PRODUCTION (with minor revisions)

Issues List (Prioritized)

## Issues Found

### CRITICAL (Must Fix)
None

### HIGH (Should Fix)
1. **Scene 3 background color mismatch**
   - Spec: #0A0A0A
   - Code: #0B0B0B
   - Impact: Visual inconsistency
   - Fix: Update COLORS.background

### MEDIUM (Consider Fixing)
1. **Product image could be optimized**
   - Current: 4000x3000 PNG
   - Recommendation: 1920x1440 JPEG
   - Impact: Faster render times
   - Fix: Resize and convert asset

### LOW (Nice to Have)
1. **Add memoization to particle system**
   - Impact: Negligible performance gain
   - Fix: Wrap in useMemo

Recommendations

## Recommendations

### Code Organization
- Extract ParticleSystem to reusable component
- Consider splitting Scene6 (currently 150 lines)

### Performance
- Preload audio files
- Consider lazy loading large assets

### Maintainability
- Add JSDoc comments to scene components
- Consider extracting animation helpers

Common Issues to Check

Timing Issues

Issue: Incorrect frame calculation

// Wrong
const duration = 5; // Should be 150 frames, not 5

// Correct
const duration = 5 * fps; // 150 frames

Issue: Missing delay

// Wrong - all elements appear at once
const progress = spring({ frame, fps, config: SMOOTH_SPRING });

// Correct - staggered with delays
const progress = spring({
  frame: frame - (index * STAGGER_DELAY),
  fps,
  config: SMOOTH_SPRING
});

Animation Issues

Issue: Inline spring config instead of constant

// Wrong
const progress = spring({
  frame,
  fps,
  config: { damping: 200 },
});

// Correct
const progress = spring({
  frame,
  fps,
  config: SPRING_CONFIGS.smooth,
});

Issue: Repeated calculations

// Wrong
<div style={{
  opacity: spring({ frame, fps, config: SMOOTH }),
  transform: `scale(${spring({ frame, fps, config: SMOOTH })})`,
}} />

// Correct
const progress = spring({ frame, fps, config: SMOOTH });
<div style={{
  opacity: progress,
  transform: `scale(${progress})`,
}} />

Visual Issues

Issue: Hardcoded colors

// Wrong
backgroundColor: '#FF6B35'

// Correct
backgroundColor: COLORS.primary

Issue: Pixel values instead of responsive

// Wrong
left: 960,  // Hardcoded center

// Correct
left: width / 2,  // Responsive center

Asset Issues

Issue: Direct import instead of staticFile

// Wrong
import logo from './logo.png';

// Correct
import { staticFile } from 'remotion';
const logoSrc = staticFile('logo.png');

Performance Issues

Issue: Expensive operation in render

// Wrong - recalculated every frame
const particles = Array.from({ length: 1000 }, (_, i) => ({
  x: Math.random() * width,
  y: Math.random() * height,
}));

// Correct - calculate once
const particles = useMemo(
  () => Array.from({ length: 1000 }, (_, i) => ({
    x: seededRandom(i * 123) * width,
    y: seededRandom(i * 456) * height,
  })),
  [width, height]
);

Review Checklist

Complete review checklist:

Spec Compliance

• All scenes implemented
• Timing matches spec
• Colors match exactly
• Typography matches
• Animations match descriptions
• Audio matches spec

Code Quality

• Constants properly extracted
• Naming conventions followed
• AbsoluteFill used correctly
• TypeScript types defined
• Clean, readable code

Timing

• Frame calculations correct
• Delays calculated properly
• Total duration accurate
• Transitions timed correctly

Visuals

• Colors use constants
• Responsive positioning
• Visual hierarchy clear
• Layer organization logical

Assets

• All assets present
• staticFile used
• Formats appropriate
• Quality sufficient

Performance

• No expensive render calculations
• Progress variables reused
• Assets optimized
• Memoization where needed

Integration with Other Skills

Works with:

• /remotion-spec-translator — Reviews translated code
• /remotion-best-practices — Ensures patterns are followed
• /motion-designer — Compares against original spec
• /remotion-performance-optimizer — Deep performance analysis

Rules Directory

For detailed review criteria:

• [rules/spec-compliance.md](rules/spec-compliance.md) — Verifying spec accuracy
• [rules/timing-review.md](rules/timing-review.md) — Frame timing validation
• [rules/animation-quality.md](rules/animation-quality.md) — Animation assessment
• [rules/visual-accuracy.md](rules/visual-accuracy.md) — Visual fidelity checks
• [rules/asset-validation.md](rules/asset-validation.md) — Asset quality review
• [rules/performance-audit.md](rules/performance-audit.md) — Performance checking
• [rules/code-patterns.md](rules/code-patterns.md) — Code quality standards

This skill ensures Remotion implementations are production-ready, spec-compliant, and follow best practices before deployment.