phosphoresce

YouTube video summarization pipeline: Gemini video analysis (key moments + TL;DR), caption fetching, yt-dlp download, and ffmpeg frame extraction at key timestamps.

Usage

import { summarizeVideo } from 'phosphoresce'

const summary = await summarizeVideo('https://www.youtube.com/watch?v=...', {
  jobId: 'some-unique-id',
  outputDir: '/data/output/some-unique-id',
  videoDir: '/data/videos',
  onProgress: (status) => console.log(status.stage, status.message),
})

summary.keyMoments[].screenshotPath and summary.markdownPath are relative to outputDir (e.g. screenshots/frame-001.jpg, summary.md) — map them to your own URL space when serving.

Requirements

• GEMINI_API_KEY in the environment. The default model is gemini-3.5-flash; any Gemini model with video input works via the model option.
• yt-dlp and ffmpeg on PATH for screenshots. Without them the pipeline still returns a summary, just without images.
• Public YouTube videos only (Gemini's YouTube URL ingestion); the free tier caps YouTube processing at 8 hours of video per day.