iceshrimp-161sh/packages/backend/src/services/drive/generate-video-thumbnail.ts

import * as fs from "node:fs";
import { createTempDir } from "@/misc/create-temp.js";
import type { IImage } from "./image-processor.js";
import { convertToJpeg } from "./image-processor.js";
import FFmpeg from "fluent-ffmpeg";

export async function GenerateVideoThumbnail(source: string): Promise<IImage> {
	const [dir, cleanup] = await createTempDir();

	try {
		await new Promise((res, rej) => {
			FFmpeg({
				source,
			})
				.on("end", res)
				.on("error", rej)
				.screenshot({
					folder: dir,
					filename: "out.png", // must have .png extension
					count: 1,
					timestamps: ["5%"],
				});
		});

		// JPEGに変換 (Webpでもいいが、MastodonはWebpをサポートせず表示できなくなる)
		return await convertToJpeg(`${dir}/out.png`, 498, 280);
	} finally {
		cleanup();
	}
}