refactoring

Resolve #7779

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

@@ -0,0 +1,37 @@
+import * as fs from 'fs';
+import * as tmp from 'tmp';
+import { IImage, convertToJpeg } from './image-processor';
+import * as FFmpeg from 'fluent-ffmpeg';
+
+export async function GenerateVideoThumbnail(path: string): Promise<IImage> {
+	const [outDir, cleanup] = await new Promise<[string, any]>((res, rej) => {
+		tmp.dir((e, path, cleanup) => {
+			if (e) return rej(e);
+			res([path, cleanup]);
+		});
+	});
+
+	await new Promise((res, rej) => {
+		FFmpeg({
+			source: path
+		})
+		.on('end', res)
+		.on('error', rej)
+		.screenshot({
+			folder: outDir,
+			filename: 'output.png',
+			count: 1,
+			timestamps: ['5%']
+		});
+	});
+
+	const outPath = `${outDir}/output.png`;
+
+	const thumbnail = await convertToJpeg(outPath, 498, 280);
+
+	// cleanup
+	await fs.promises.unlink(outPath);
+	cleanup();
+
+	return thumbnail;
+}