SN Code Video

A code video is a program frame(t) → image, sampled at t = i / fps and encoded. Almost every failure in this kind of work is one of four things: the film is never finished, the picture depends on wall-clock time, nobody looked at the frames, or the file does not match the brief. This skill prevents those four.

Setup and paths

Use a separate project folder for the video source, SPEC.md, build files, and outputs. Resolve SKILL_DIR to the absolute directory containing this SKILL.md, whether installed in the agent's skills directory or used from this repository. Run project commands from the video project folder; invoke bundled scripts through "$SKILL_DIR/scripts/..." so they do not depend on the current working directory. Set SKILL_DIR again in each shell session if needed.

Requirements: Node.js 18+ for browser capture, Python 3, FFmpeg/ffprobe with libx264 and AAC, and fonts covering the requested language. Install Playwright (with Chromium) or Puppeteer in the video project; the capture helper resolves its packages there first. Python audio dependencies are listed in requirements.txt; edge-tts needs network access, and faster-whisper needs downloaded model weights for transcription checks. Install only the tools required by the chosen renderer and audio workflow. Setup and invocation examples: English guide / 中文指南 in the source repository; these repository guides are not required when the skill folder is installed on its own.

Deliver the playable MP4, source code and reproduction commands, SPEC.md, VERIFY.md, and a contact sheet. Audio stems and timing data belong in the project when sound is used.

0. Read the craft guides you need

Reference paths are relative to this skill folder; output and input paths in commands are relative to the video project. Besides this file it holds craft guides in references/ and helper scripts in scripts/ (audio packages in requirements.txt). Read every guide that matches the request before writing SPEC.md; most videos need two or three.