clawdvine/skills/video-post-processing

Video Post-Processing

Make AI-generated video look organic. Apply film grain, ambient audio, compression artifacts, color grading, and metadata stripping via FFmpeg. Five named presets cover the most common use cases — from subtle polish to full phone-footage simulation.

Dependencies: FFmpeg (required), Node.js 18+ (required)

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Quick Start

# Apply the default "ugc" preset (looks like phone footage)
node process.mjs --input video.mp4 --output processed.mp4

# Choose a preset
node process.mjs --input video.mp4 --preset cinema

# Override individual params
node process.mjs --input video.mp4 --preset ugc --grain 4 --crf 26

# Auto-detect ambient track from prompt keywords
node process.mjs --input video.mp4 --preset ugc --prompt "woman walking through rainy tokyo street"
# → selects rain-light.wav automatically

# From URL (downloads first)
node process.mjs --input "https://example.com/video.mp4" --preset subtle

# Strip AI metadata only (no visual processing)
node scripts/metadata-strip.mjs --input video.mp4 --output clean.mp4

# Pipe-friendly — outputs processed file path to stdout
PROCESSED=$(node process.mjs --input video.mp4 --preset ugc --quiet)

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Presets

| Preset | Description | Grain | CRF | Resolution | |--------|-------------|-------|-----|------------| | raw | No processing. Pass-through. | 0 | native | native | | subtle | Light touch. Slight grain, faint room tone. Still polished. | 1.5 | 24 | 1080p | | ugc | Looks like phone footage. Default for social content. | 2.5 | 28 | 1080p | | vintage | Retro film look. Heavy grain, warm shift, lo-fi audio. | 5 | 30 | 720p | | cinema | Cinematic grade. Subtle grain, letterbox, desaturated. | 2 | 22 | 1080p |

Full preset definitions are in presets.json.

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CLI Reference

node process.mjs [options]

Required:
  --input <path|url>     Input video file or URL

Options:
  --output <path>        Output file path (default: input with -processed suffix)
  --preset <name>        Preset name: raw, subtle, ugc, vintage, cinema (default: ugc)
  --prompt <text>        Prompt text for auto-selecting ambient audio track
  --ambient <path>       Override ambient audio file path
  --grain <number>       Override grain intensity (0-10)
  --crf <number>         Override CRF value (18-35, lower = better quality)
  --blur <number>        Override blur amount (0-1)
  --quiet                Only output the processed file path (for piping)

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Ambient Audio Selection

When --prompt is provided, keywords are matched to ambient audio tracks:

| Keywords | Ambient Track | Rationale | |----------|--------------|-----------| | rain, storm, wet, umbrella | rain-light.wav | Match visual weather | | cafe, coffee, restaurant, indoor | coffee-shop.wav | Interior social setting | | city, street, urban, tokyo, nyc | street-light.wav | Urban soundscape | | nature, forest, mountain, outdoor | nature.wav | Organic environment | | default / no match | room-tone.wav | Neutral, works everywhere |

Without --prompt, defaults to room-tone.wav. Use --ambient to override with any audio file.

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Metadata Stripping

Strip AI generation markers and optionally inject device metadata:

# Strip only
node scripts/metadata-strip.mjs --input video.mp4 --output clean.mp4

# Strip + fake device metadata
node scripts/metadata-strip.mjs --input video.mp4 --output clean.mp4 --device "iPhone 16 Pro"

Removes: EXIF/XMP AI tags, C2PA provenance markers, software metadata. Rewrites creation date to current time.

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How Workflows Compose This

# UGC Content Workflow
clawdvine generate --prompt "..." → postprocess --preset ugc → distribute

# Cinematic Short
clawdvine generate --prompt "..." → postprocess --preset cinema → distribute

# Anime (skip postprocess — anime style shouldn't have UGC grain)
clawdvine generate --prompt "..." → (no postprocess or --preset raw) → distribute