import ffmpeg, { FfprobeData } from "fluent-ffmpeg"; import { promisify } from "util"; import express from "express"; import schedule from "node-schedule"; import { mkdir } from "fs-extra"; import path from "path"; import { program } from "commander"; import winston from "winston"; import { readdir, stat } from "node:fs/promises"; import { createHash } from "node:crypto"; const ffprobeAsync: (file: string) => Promise = promisify( ffmpeg.ffprobe, ); interface VideoInfo { path: string; duration: number; } const logger = winston.createLogger({ level: "debug", format: winston.format.combine( winston.format.timestamp(), winston.format.printf(({ timestamp, level, message }) => { return `${timestamp} [${level}]: ${message}`; }), ), transports: [new winston.transports.Console()], }); async function getVideoInfo(paths: string[]): Promise { const videos: VideoInfo[] = []; for (const videoPath of paths) { const metadata = await ffprobeAsync(videoPath); const duration = metadata.format.duration; if (!duration) { logger.warn(`Failed to get duration for ${videoPath}`); continue; } videos.push({ path: videoPath, duration }); } return videos; } async function takeSnapshot(path: string, timestamp: number, output: string) { return new Promise((resolve) => { ffmpeg(path) .seekInput(timestamp) .outputOptions("-frames:v", "1") .output(output) .on("end", () => { resolve(); }) .run(); }); } async function processSnapshots( videos: VideoInfo[], snapshotsDir: string, count: number, ) { const totalDuration = videos.reduce((acc, video) => acc + video.duration, 0); const currentHour = new Date().getHours(); const currentDir = path.join(snapshotsDir, currentHour.toString()); await mkdir(currentDir, { recursive: true }); for (let i = 0; i < count; i++) { while (true) { let size = 0; const randomTimestamp = Math.random() * totalDuration; let cumulativeDuration = 0; const snapshotPath = path.join(currentDir, `${i}.webp`); for (const video of videos) { if (cumulativeDuration + video.duration >= randomTimestamp) { const timestampWithinVideo = randomTimestamp - cumulativeDuration; logger.info( `Extracting snapshot ${i + 1}/${count} from ${ video.path } at ${timestampWithinVideo}s`, ); await takeSnapshot(video.path, timestampWithinVideo, snapshotPath); break; } cumulativeDuration += video.duration; } const stats = await stat(snapshotPath); size = stats.size; if (size < 5 * 1024) { logger.info( `Snapshot ${ i + 1 }/${count} too small: ${size} bytes, trying again...`, ); } else { break; } } } } async function setupSnapshotServer( videoPaths: string[], snapshotsDir: string, count: number, ) { const app = express(); try { await mkdir(snapshotsDir, { recursive: true }); const videos = await getVideoInfo(videoPaths); // noinspection ES6MissingAwait processSnapshots(videos, snapshotsDir, count); schedule.scheduleJob("0 * * * *", () => processSnapshots(videos, snapshotsDir, count), ); app.get("/:magic?", async (req, res) => { logger.debug(`REQ: /${req.params.magic || ""}`); const { magic } = req.params; const currentHour = new Date().getHours(); const currentDir = path.resolve( path.join(snapshotsDir, currentHour.toString()), ); try { const files = await readdir(currentDir); if (magic) { const hash = createHash("md5").update(magic).digest("hex"); const index = parseInt(hash.substring(0, 8), 16) % files.length; // Cache until the next hour rolls over res.sendFile(files[index], { headers: { "Cache-Control": `public, max-age=${ 3600 - new Date().getMinutes() * 60 }`, }, root: currentDir, }); } else { res.sendFile(files[Math.floor(Math.random() * files.length)], { headers: { "Cache-Control": "public, max-age=0", }, root: currentDir, }); } } catch (error) { logger.error("Failed to send file:", error); res.status(500).send(`Error.`); } }); app.listen(3000, () => logger.info("Server running on http://localhost:3000"), ); } catch (error) { logger.error("Failed to start the server:", error); } } program .name("KSX Snapshot Server") .argument("", "Video file paths") .option("-d, --directory ", "Directory to store snapshots", "snapshots") .option("-c, --count ", "Number of snapshots to take per hour", "32") .action(async (videoPaths: string[], options) => { await setupSnapshotServer( videoPaths, options.directory, parseInt(options.count, 10), ); }); program.parse();