Paper Collage Ad Production

Skill by ara.so — Codex Skills collection.

A complete skill for producing paper-cut/collage-style advertisements from concept to final MP4. Handles scriptwriting, storyboarding, keyframe generation, animation (Seedance/HyperFrames/layered PNG), local voice cloning with IndexTTS-2 MLX, music, sound effects, composition, and H.264/AAC validation.

What This Does

• Extract visual metaphors from product materials
• Output script, dialogue, and timecoded storyboards for approval
• Generate brand-locked paper-cut keyframes
• Animate via Seedance, HyperFrames, layered PNG, or FFmpeg
• Clone authorized voices locally with IndexTTS-2 MLX (Apple Silicon)
• Add music, paper foley, and action SFX
• Export stream-validated H.264/AAC MP4

Installation

System dependencies (macOS):

brew install ffmpeg node

Verify setup:

bash scripts/check-deps.sh

Install IndexTTS-2 MLX for local voice cloning:

bash scripts/setup-indextts2-mlx.sh

Models download to: ~/.local/share/paper-collage-ad/mlx-indextts/models/mlx-indextts2-standard-fp16/

Project Structure

<project>/
  assets/
    brand/              # Logos, colors, fonts
    keyframes/          # Generated paper-cut frames
    animation/          # Video segments
    voice-reference/    # Authorized reference audio (NOT committed)
    voice-model/        # Local speaker embeddings (NOT committed)
    voice-final/        # Generated narration (NOT committed)
    music/              # Background music
    sfx/                # Sound effects
  manifests/
    storyboard.json     # Scene timing and descriptions
    voice.indextts2.json # Narration script with emotion tags
    animation.json      # Animation segment definitions
    final.json          # Composition timeline
  output/
    final.mp4

Privacy template:

cp examples/project.gitignore <project>/.gitignore

This excludes voice-reference/, voice-model/, and generated narration from version control.

Voice Cloning Workflow

1. Prepare Reference Audio

Place a 6–12 second clean mono/stereo WAV of authorized voice:

<project>/assets/voice-reference/reference.wav

2. Generate Speaker Embedding

bash scripts/prepare-indextts2-voice.sh \
  "<project>/assets/voice-reference/reference.wav" \
  "<project>/assets/voice-model/speaker-v2.npz" \
  --i-have-permission

3. Create Narration Manifest

cp examples/voice-manifest.indextts2.json \
  "<project>/manifests/voice.indextts2.json"

Example manifest (voice.indextts2.json):

{
  "speaker_path": "assets/voice-model/speaker-v2.npz",
  "output_dir": "assets/voice-final",
  "sample_rate": 48000,
  "segments": [
    {
      "id": "01",
      "text": "Imagine a world where coffee fuels creativity.",
      "emotion": "cheerful",
      "speed": 1.0
    },
    {
      "id": "02",
      "text": "Every cup is a new beginning.",
      "emotion": "calm",
      "speed": 0.95
    }
  ]
}

Supported emotions: neutral, cheerful, sad, angry, calm, excited

4. Generate Narration

node scripts/narrate-indextts2.mjs \
  --manifest "<project>/manifests/voice.indextts2.json"

Outputs: assets/voice-final/01.wav, 02.wav, etc. (48 kHz WAV)

Animation Workflow

Static Keyframes

Generate paper-cut frames from brand assets:

node scripts/generate-keyframes.mjs \
  --storyboard "<project>/manifests/storyboard.json" \
  --brand "<project>/assets/brand" \
  --output "<project>/assets/keyframes"

Layered PNG Animation

For simple parallax/zoom effects:

node scripts/animate-layers.mjs \
  --manifest "<project>/manifests/animation.json" \
  --output "<project>/assets/animation"

Example animation.json:

{
  "segments": [
    {
      "id": "seg01",
      "duration": 3.0,
      "layers": [
        {
          "image": "assets/keyframes/01_bg.png",
          "motion": {"type": "zoom", "scale_start": 1.0, "scale_end": 1.1}
        },
        {
          "image": "assets/keyframes/01_fg.png",
          "motion": {"type": "pan", "x_start": 0, "x_end": -50}
        }
      ]
    }
  ]
}

FFmpeg Crossfade

ffmpeg -loop 1 -t 2 -i assets/keyframes/01.png \
       -loop 1 -t 2 -i assets/keyframes/02.png \
       -filter_complex "[0][1]xfade=transition=fade:duration=0.5:offset=1.5" \
       -pix_fmt yuv420p assets/animation/seg01.mp4

Audio Mixing

Combine narration, music, and SFX:

node scripts/mix-audio.mjs \
  --manifest "<project>/manifests/final.json" \
  --output "<project>/output/audio.wav"

Example final.json:

{
  "audio_tracks": [
    {
      "type": "narration",
      "files": [
        {"path": "assets/voice-final/01.wav", "start": 0.0},
        {"path": "assets/voice-final/02.wav", "start": 3.5}
      ]
    },
    {
      "type": "music",
      "path": "assets/music/background.mp3",
      "volume": 0.3,
      "loop": true
    },
    {
      "type": "sfx",
      "files": [
        {"path": "assets/sfx/paper_rustle.wav", "start": 1.2},
        {"path": "assets/sfx/whoosh.wav", "start": 4.8}
      ]
    }
  ]
}

Final Composition

Render video + audio to MP4:

node scripts/render-final.mjs \
  --manifest "<project>/manifests/final.json" \
  --output "<project>/output/final.mp4"

Internally calls:

ffmpeg -i video_concat.mp4 -i audio.wav \
  -c:v libx264 -preset medium -crf 23 -pix_fmt yuv420p \
  -c:a aac -b:a 192k -ar 48000 \
  -movflags +faststart \
  output/final.mp4

Quality Control

Validate codec, resolution, duration, audio sync:

bash scripts/qc-mp4.sh "<project>/output/final.mp4"

Checks:

• Video codec: H.264
• Audio codec: AAC
• Sample rate: 48 kHz
• Moov atom position (fast start)
• A/V sync drift < 100ms

Optional API Services

All require user-provided credentials via environment variables:

Seedance (video generation):

export SEEDANCE_API_KEY="your_key"
node scripts/animate-seedance.mjs --input assets/keyframes/01.png

MiniMax (alternative TTS):

export MINIMAX_API_KEY="your_key"
node scripts/narrate-minimax.mjs --manifest manifests/voice.json

ElevenLabs (cloud TTS):

export ELEVENLABS_API_KEY="your_key"
node scripts/narrate-elevenlabs.mjs --manifest manifests/voice.json

Common Patterns

Full Production Pipeline

// scripts/full-pipeline.mjs
import { execSync } from 'child_process';

const PROJECT = process.argv[2];

// 1. Generate storyboard (manual or LLM-assisted)
// 2. Create keyframes
execSync(`node scripts/generate-keyframes.mjs --storyboard ${PROJECT}/manifests/storyboard.json --output ${PROJECT}/assets/keyframes`);

// 3. Animate segments
execSync(`node scripts/animate-layers.mjs --manifest ${PROJECT}/manifests/animation.json --output ${PROJECT}/assets/animation`);

// 4. Generate narration
execSync(`node scripts/narrate-indextts2.mjs --manifest ${PROJECT}/manifests/voice.indextts2.json`);

// 5. Mix audio
execSync(`node scripts/mix-audio.mjs --manifest ${PROJECT}/manifests/final.json --output ${PROJECT}/output/audio.wav`);

// 6. Render final MP4
execSync(`node scripts/render-final.mjs --manifest ${PROJECT}/manifests/final.json --output ${PROJECT}/output/final.mp4`);

// 7. QC
execSync(`bash scripts/qc-mp4.sh ${PROJECT}/output/final.mp4`);

Custom Emotion Interpolation

// In narrate-indextts2.mjs
const emotions = {
  'cheerful': { pitch: 1.1, energy: 1.2 },
  'calm': { pitch: 0.95, energy: 0.8 }
};

for (const seg of manifest.segments) {
  const params = emotions[seg.emotion] || emotions.neutral;
  // Pass params to IndexTTS-2 inference
}

Brand Color Extraction

import Vibrant from 'node-vibrant';

const palette = await Vibrant.from('assets/brand/logo.png').getPalette();
const primary = palette.Vibrant.hex;
const secondary = palette.LightVibrant.hex;

// Use in keyframe generation prompts
const prompt = `paper collage, ${productName}, dominant color ${primary}, accent ${secondary}, flat cutout style`;

Troubleshooting

IndexTTS-2 model not found:

ls ~/.local/share/paper-collage-ad/mlx-indextts/models/
# If empty, re-run setup:
bash scripts/setup-indextts2-mlx.sh

Voice cloning sounds robotic:

• Use longer reference audio (10–12s)
• Ensure reference is clean mono/stereo, 16–48 kHz
• Try speed: 0.95 to reduce artifacts

Animation segments out of sync:

# Check segment durations
ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 assets/animation/seg01.mp4

# Adjust in animation.json, then re-render
node scripts/render-final.mjs --manifest manifests/final.json --output output/final.mp4

MP4 fails QC:

# Check codec details
ffprobe -v error -show_streams output/final.mp4

# Re-encode with correct settings
ffmpeg -i output/final.mp4 -c:v libx264 -crf 23 -pix_fmt yuv420p -c:a aac -b:a 192k -ar 48000 -movflags +faststart output/final_fixed.mp4

Permission errors on voice cloning:

Always verify you have explicit authorization to clone a voice. The --i-have-permission flag is a manual safeguard — do not bypass this for public or commercial projects.

Key Scripts Reference

Environment Variables

# Optional cloud services
SEEDANCE_API_KEY=
MINIMAX_API_KEY=
ELEVENLABS_API_KEY=

# Local paths (auto-detected)
INDEXTTS2_MODEL_PATH=~/.local/share/paper-collage-ad/mlx-indextts/models/mlx-indextts2-standard-fp16

License & Attribution

• Skill code: MIT
• IndexTTS-2 models: Separate license (downloaded via setup script)
• Always disclose AI-generated narration in final deliverables
• Only clone voices you own or have explicit written authorization for