A little script I used to fix up thumbnails of old videos

youtube-thumbnail.js

/*

Fix up old thumbnails https://www.youtube.com/@hiroshi18181/videos

- dump all videos data

yt-dlp -j https://www.youtube.com/@hiroshi18181/videos > videos.ndjson
jq -s '[.[] | {id, title, description}]' videos.ndjson > videos-slim.json
node youtube-thumbnail.js process-json videos-slim.json > videos-slim2.json5

- download thumbnails

node youtube-thumbnail.js download-thumbnail videos-slim2.json5

- merge thumbnails

do it manually on https://www.photopea.com/

*/

import fs from "node:fs";
import { Readable } from "node:stream";

async function main() {
  const [command, ...args] = process.argv.slice(2);

  if (command === 'process-json') {
    /** @type {{ id: string, title: string, description: string }[]} */
    const entries = JSON.parse(fs.readFileSync(args[0], "utf-8"));
    const entries2 = entries.map((e) => {
      const matches = e.description.matchAll(
        /https:\/\/www\.youtube\.com\/watch\?v=[\w-]{11}/g,
      );
      return [
        e.title,
        `https://www.youtube.com/watch?v=${e.id}`,
        [...matches].map((m) => m[0]),
      ];
    });
    console.log(entries2)
  }

  if (command === 'download-thumbnail') {
    /**
     * @param {string} url
     * @param {string} destFile
     */
    async function download(url, destFile) {
      const response = await fetch(url);
      await fs.promises.writeFile(destFile, Readable.fromWeb(response.body));
    }

    function toThumbnailUrl(url) {
      return `https://i.ytimg.com/vi/${url.match(/v=([\w-]{11})/)[1]}/maxresdefault.jpg`;
    }

    /** @type {[string, string, string[]][]} */
    const entries = (0, eval)(fs.readFileSync(args[0], "utf-8"));
    for (let j = 0; j < entries.length; j++) {
      const [title, base, others] = entries[j];
      const dir = `.tmp/${String(j).padStart(2, '0')}-${title}`;
      fs.mkdirSync(dir, { recursive: true });

      // download
      await download(toThumbnailUrl(base), `${dir}/base.jpg`);
      for (let i = 0; i < others.length; i++) {
        await download(toThumbnailUrl(others[i]), `${dir}/other-${i}.jpg`)
      }
    }
  }
}

main();