Video Style Extractor

Video Style Extractor

Extract the complete editing style from one or more videos, including pixel-art mascot profiles when present, and produce artifacts ready for AI image generators and image-to-video generators.

Prerequisites

• Gemini API key in the environment as GEMINI_API_KEY. Set it with export GEMINI_API_KEY="your-key" (add the line to your shell profile to make it stick).
• google-genai Python SDK
• ffmpeg and yt-dlp on your PATH
• Python deps from scripts/requirements.txt:

``bash pip install -r "${CLAUDE_SKILL_DIR}/scripts/requirements.txt" ``

All local helpers live under scripts/ and are invoked as python -m scripts. from the skill directory (cd "${CLAUDE_SKILL_DIR}").

Workflow

Step 1: Acquire videos

Create a working directory:

mkdir -p /per-video

Accept either: a folder of .mp4/.mov files, or a list of URLs. yt-dlp covers YouTube and most public video hosts. For Instagram and TikTok, use whatever downloader you already have available (a scraping service such as Apify works if you have an account; otherwise download the files by hand and point the skill at the folder).

For each source video, create a slug folder:

mkdir -p /per-video//{frames,mascot-raw}

Step 2: Scene segmentation

For each video, detect cuts with PySceneDetect:

python -m scripts.scene_detect  /per-video//scenes.json

Step 3: Scene-aware frame sampling

python -m scripts.scene_aware_sample  \
  /per-video//scenes.json \
  /per-video//frames/

Emits frames/frame_NNNN.jpg plus frames/manifest.json.

Step 3b: Contact sheets (optional, when the output feeds a recreation)

If the extraction is destined for a programmatic recreation (for example the remotion-video-builder skill), also tile each scene's frames into one contact sheet: a start-to-end grid collage. Text-only models cannot watch video, so a contact sheet encodes the motion arc as a single readable image and is the highest-leverage artifact for downstream agents.

# per scene, from the frames already sampled in Step 3
ffmpeg -pattern_type glob -i '/frames/scene03_*.jpg' \
  -vf "scale=480:-1,tile=4x2" -frames:v 1 /frames/scene03-sheet.jpg

Pair each sheet with a per-scene recreation prompt from Gemini, describing what has to happen between the first and last cell.

Step 4: Audio metrics

python -m scripts.audio_metrics  /per-video//audio-metrics.json

Step 5: Gemini Pass A, cohort visual invariants

Upload frames only (not full videos). Budget: 1 keyframe per scene, capped at 20 per video, capped at 200 total. Downsample proportionally if the cohort exceeds the cap.

Use the Pass A prompt from references/gemini-prompts.md. Save to /cohort-analysis.md.

Step 6: Gemini Pass B, per-video transcript and cadence

For each video, upload the full video via Files API. Use the transcription prompt from references/gemini-prompts.md. Save to per-video//gemini-transcript.md.

Step 7: Gemini Pass C, mascot detection

For each video, run the Pass C prompt from references/mascot-prompts.md. Save results. If >=1 video returns mascot_present: true, activate the Mascot Track (Step 8).

If the user supplies --force-mascot , skip detection and activate Mascot Track with the hint as seed.

Step 8: Mascot Track

Only runs if pass C activated it.

M1. Dense extraction: re-sample at 4fps within the mascot-containing ranges only:

# For each mascot-bearing video, for each flagged range:
ffmpeg -ss  -t  -i  -vf "fps=4" -q:v 2 /mascot-raw/raw_%04d.jpg

M2. Bounding boxes: use the M2 prompt from references/mascot-prompts.md. Drop frames with confidence .png /mascot-raw/isoNNNN.png /mascot-raw/isoNNNN.meta.json

**M4. Native resolution**

```bash
python -m scripts.native_resolution /mascot-raw/iso_0001.png /native-res.json

M5. Palette quantization (pool all isolated mascot PNGs across the cohort):

python -m scripts.palette_quantize /mascot-raw/iso_*.png MASCOT-KIT/palette.json

Also emit palette.gpl and palette-swatch.png (use Pillow inline).

M6. Native fps (use the mascot bbox from M2):

python -m scripts.native_fps_detect  /native-fps.json    

M7. Pose clustering: use M7 prompt. Save pose_map JSON.

M8. Consistency check: use M8 prompt. If variants exist, write MASCOT-VARIANTS.md and proceed with the dominant variant only.

M9. Canonical frame selection: use M9 prompt. Copy selected file to MASCOT-KIT/canonical-reference.png.

M10. Sprite sheet

python -m scripts.sprite_sheet  MASCOT-KIT/sprite-sheet.png

M11. Constraints: use M11 prompt. Save as structured JSON into mascot-profile.json.

M12. Prompt distillation: use M12a and M12b prompts. Save as MASCOT-KIT/STATIC-PROMPT.md and MASCOT-KIT/ANIMATED-PROMPT.md.

Write MASCOT-KIT/mascot-profile.json aggregating all mascot-track outputs per the schema in references/pipeline-design.md.

Write MASCOT-KIT/MASCOT-EVIDENCE.md, where every claim traces to a specific frame path.

Step 9: Frame verification (main thread)

Using the Read tool, inspect keyframes per video:

• frame at 10%, 25%, 50%, 75%, 90% of duration (scene-snapped)
• every frame cited by Pass A as hex/typography evidence
• 3 random mascot-containing frames per mascot-bearing video

Append YAML corrections to per-video//corrections.md:

- claim_id: pass_A#palette#accent_1
  original: "#FF6A3D"
  corrected: "#FF5A33"
  evidence_frame: frames/frame_0034.jpg

Step 10: Synthesizer subagent

Dispatch a subagent with the prompt from references/synthesizer-subagent-prompt.md. It produces STYLE-GUIDE.md.

Step 11: Detailed single-video guide (optional)

If the run was a single video and you want the deeper per-video breakdown (timeline map, script template, Remotion token block), also produce STYLE-GUIDE-DETAILED.md using the template at references/detailed-guide-template.md.

Step 12: Run log

Throughout the workflow, call scripts.run_log at every major step to append status, cost, and warnings to /run-log.md. At the end, emit a summary block with:

• total Gemini cost (USD)
• mascot track activation
• low-confidence flags raised
• bg-removal method used per video

Output structure

See references/pipeline-design.md for the canonical structure and JSON schemas. Primary deliverables:

• STYLE-GUIDE.md: cohort invariants
• MASCOT-KIT/STATIC-PROMPT.md + ANIMATED-PROMPT.md: prompts
• MASCOT-KIT/canonical-reference.png + sprite-sheet.png + poses/: reference images
• MASCOT-KIT/palette.json + palette.gpl + palette-swatch.png
• MASCOT-KIT/mascot-profile.json: canonical machine-readable profile

Key rules

1. Always use gemini-2.5-pro. Flash misses subtle details.
2. Visually verify keyframes with the Read tool. Gemini gets hex values wrong by 10 to 20% routinely.
3. For cohort analysis, upload FRAMES ONLY, not full videos. Stay under the 200-frame budget.
4. Variants are flagged, not blended. If the mascot has design variants across videos, record them in MASCOT-VARIANTS.md and proceed with the dominant variant.
5. Low-confidence fields must be flagged, not silently substituted. The prompt distillation (M12) uses qualitative fallbacks when confidence is "low".
6. Cite every claim. Every hex, every font, every timing is traceable to a frame path.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: NulightJens
• Source: NulightJens/jensai-skills
• License: MIT

Install and usage instructions live in the source repository linked above.