Generate video thumbnails (#4084)

* Generate video thumbnails

* import order

src/services/drive/add-file.ts

@@ -22,6 +22,7 @@ import { getDriveFileThumbnailBucket } from '../../models/drive-file-thumbnail';
 import driveChart from '../../chart/drive';
 import perUserDriveChart from '../../chart/per-user-drive';
 import fetchMeta from '../../misc/fetch-meta';
+import { GenerateVideoThumbnail } from './generate-video-thumbnail';
 
 const log = debug('misskey:drive:add-file');
 
@@ -118,6 +119,14 @@ async function save(path: string, name: string, type: string, hash: string, size
 
 		thumbnailExt = 'png';
 		thumbnailType = 'image/png';
+	} else if (type.startsWith('video/')) {
+		try {
+			thumbnail = await GenerateVideoThumbnail(path);
+			thumbnailExt = 'png';
+			thumbnailType = 'image/png';
+		} catch (e) {
+			console.log(`GenerateVideoThumbnail failed: ${e}`);
+		}
 	}
 	// #endregion thumbnail
 

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

@@ -0,0 +1,32 @@
+import * as fs from 'fs';
+import * as tmp from 'tmp';
+const ThumbnailGenerator = require('video-thumbnail-generator').default;
+
+export async function GenerateVideoThumbnail(path: string): Promise<Buffer> {
+	const [outDir, cleanup] = await new Promise<[string, any]>((res, rej) => {
+		tmp.dir((e, path, cleanup) => {
+			if (e) return rej(e);
+			res([path, cleanup]);
+		});
+	});
+
+	const tg = new ThumbnailGenerator({
+		sourcePath: path,
+		thumbnailPath: outDir,
+	});
+
+	await tg.generateOneByPercent(10, {
+		size: '498x280',
+		filename: 'output.png',
+	});
+
+	const outPath = `${outDir}/output.png`;
+
+	const buffer = fs.readFileSync(outPath);
+
+	// cleanup
+	fs.unlinkSync(outPath);
+	cleanup();
+
+	return buffer;
+}