# Video Thumbnail Generator

Create platform-ready thumbnails from real video frames.

- Repository: https://github.com/0xsline/OpenChatCut (2832 stars)
- Category: Media
- License: AGPL-3.0
- Last updated: 2026-10-21
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add 0xsline/OpenChatCut --skill video-thumbnail-generator -g -a claude-code -y`
Codex: `npx skills add 0xsline/OpenChatCut --skill video-thumbnail-generator -g -a codex -y`
Cursor: `npx skills add 0xsline/OpenChatCut --skill video-thumbnail-generator -g -a cursor -y`
Gemini CLI: `npx skills add 0xsline/OpenChatCut --skill video-thumbnail-generator -g -a gemini-cli -y`

## Description

Create platform-ready thumbnails from real video frames. Use when the user wants a thumbnail, cover image, YouTube cover, Shorts cover, Bilibili cover, Xiaohongshu cover, or other video poster image.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Video Thumbnail Generator

Use this skill to create a high-clarity thumbnail or cover image from the actual video content.

## Non-Negotiables

1. Use the real video as visual evidence.
   - If the thumbnail shows a person, product, UI, frame, or scene from the video, extract or inspect real frames.
   - Never invent a generic software interface, fake product screen, or unrelated person.

2. Read style references before recommending styles.
   - Use `references/thumbnail-styles.md` and `references/thumbnail-style-recipes.md`.
   - Only offer style directions supported by those references or by the user's explicit instruction.

3. Keep text short and readable.
   - Usually 2-5 words.
   - Avoid thin type, low contrast, small labels, and clutter.

## Workflow

1. Confirm platform and aspect ratio if missing.
   - YouTube / Bilibili: usually 16:9.
   - Shorts / TikTok / Douyin: usually 9:16.
   - Xiaohongshu / WeChat Channels: usually 3:4.
   - Correct ambiguous ratio language gently, especially 4:3 vs 3:4.
2. Read project state, transcript, and available media context.
3. Inspect candidate frames:
   - expressive face
   - product or UI clearly visible
   - dramatic action moment
   - clean composition
   - strong lighting or clear subject separation
4. Classify the thumbnail job:
   - talking-head / opinion / tutorial
   - product / software / demo
   - cinematic / documentary / art
   - entertainment / challenge / reaction
   - education / business / concept
5. Propose concise title text options.
6. Offer 3-6 clearly different style directions.
   - Each option should name the composition, not only a channel/style label.
   - Exclude weak options.
   - Wait for user choice when the direction is not obvious.
7. Generate thumbnail options using selected real frames and the selected style.
8. Check mobile readability, subject fidelity, product/UI truthfulness, and visual contrast.
9. Present results and offer targeted adjustments.

## Prompt Shape

The rest: https://github.com/0xsline/OpenChatCut/blob/HEAD/src/agent/skills/video-thumbnail-generator/SKILL.md