feat: add yt mp3 downloader

backend/lib/utils.ts

@@ -1,6 +1,7 @@
 import { Mime } from "mime/lite";
 import standardTypes from "mime/types/standard.js";
 import otherTypes from "mime/types/other.js";
+import { nanoid } from "nanoid";
 
 export const formatBytes = (bytes: number) => {
   const sizes = ["Bytes", "KB", "MB", "GB", "TB"];
@@ -29,3 +30,36 @@ mime.define(
 export const getMimeType = (path: string) => {
   return mime.getType(path) || "application/octet-stream";
 };
+
+export const slugify = (text: string, lowerCase = true) => {
+  let str = text.replace(/^\s+|\s+$/g, "");
+
+  // Make the string lowercase
+  if (lowerCase) {
+    str = str.toLowerCase();
+  }
+
+  // Remove accents, swap ñ for n, etc
+  const from =
+    "ÁÄÂÀÃÅČÇĆĎÉĚËÈÊẼĔȆÍÌÎÏŇÑÓÖÒÔÕØŘŔŠŤÚŮÜÙÛÝŸŽáäâàãåčçćďéěëèêẽĕȇíìîïňñóöòôõøðřŕšťúůüùûýÿžþÞĐđßÆa·/_,:;";
+  const to =
+    "AAAAAACCCDEEEEEEEEIIIINNOOOOOORRSTUUUUUYYZaaaaaacccdeeeeeeeeiiiinnooooooorrstuuuuuyyzbBDdBAa------";
+  for (let i = 0, l = from.length; i < l; i += 1) {
+    str = str.replace(new RegExp(from.charAt(i), "g"), to.charAt(i));
+  }
+
+  // Remove invalid chars
+  str = str
+    // .replace(/[^A-Za-z0-9 -]/g, '')
+    .replace(/[\\/:"*?<>|]/g, "")
+    // Collapse whitespace and replace by -
+    .replace(/\s+/g, "-")
+    // Collapse dashes
+    .replace(/-+/g, "-");
+
+  if (!str.length) {
+    str = nanoid();
+  }
+
+  return str;
+};

backend/lib/yt2mp3.ts

@@ -0,0 +1,219 @@
+import YTDL from "ytdl-core";
+import ffmpeg from "fluent-ffmpeg";
+import fs from "node:fs";
+import fetch from "node-fetch";
+import path from "node:path";
+import { slugify } from "./utils";
+import { nanoid } from "nanoid";
+
+const TMP_DIR = process.env.TMP_DIR || "/tmp/homelab";
+
+const ytDownload = (url: string): Promise<YTDownloadFnResult> => {
+  return new Promise((resolve, reject) => {
+    const dl = YTDL(url, {
+      quality: "highestaudio",
+      filter: (i) => i.hasAudio,
+    });
+
+    dl.on("info", async (info: YTDL.videoInfo, format: YTDL.videoFormat) => {
+      const type = format.container;
+
+      // Download thumbnail
+      const thumbnail = getBestThumbnail(info.videoDetails.thumbnails);
+      const uid = nanoid();
+      const thumbDest = `${TMP_DIR}/${uid}.jpeg`;
+      const albumCover = await downloadFile(thumbnail.url, thumbDest);
+
+      const filename = `${uid}.${type}`;
+      const tmpSrc = `${TMP_DIR}/${filename}`;
+
+      const onClean = () => {
+        fs.unlinkSync(tmpSrc);
+        if (albumCover) fs.unlinkSync(albumCover);
+      };
+
+      dl.pipe(fs.createWriteStream(tmpSrc));
+      dl.on("end", () => {
+        resolve({ info, path: tmpSrc, clean: onClean, album: albumCover });
+      });
+    });
+
+    dl.on("progress", (_, progress: number, total: number) => {
+      console.log("info", `${Math.round((progress / total) * 100)}%`);
+    });
+
+    dl.on("error", reject);
+  });
+};
+
+type YTDownloadFnResult = {
+  info: YTDL.videoInfo;
+  path: string;
+  album: string | null;
+  clean: () => void;
+};
+
+const convertToAudio = (
+  src: string,
+  output: string,
+  format = "mp3"
+): Promise<string> => {
+  return new Promise((resolve, reject) => {
+    const cmd = ffmpeg(src)
+      .output(output)
+      .format(format)
+      .on("end", () => {
+        resolve(output);
+      });
+
+    cmd.on("error", (err, stdout, stderr) => {
+      console.log(`Cannot process video: ${err.message}`);
+      console.log(stdout, stderr);
+      reject(err);
+    });
+
+    // cmd.on("start", (cmdline) => {
+    //   console.log("cmdline", cmdline);
+    // });
+
+    cmd.run();
+  });
+};
+
+const embedMetadata = (
+  src: string,
+  output: string,
+  title: string,
+  album: string | null
+) => {
+  return new Promise((resolve, reject) => {
+    const cmd = ffmpeg(src)
+      .output(output)
+      .outputOptions(
+        // '-c:a libmp3lame',
+        "-id3v2_version",
+        "3",
+        "-write_id3v1",
+        "1",
+        "-metadata",
+        `title=${title}`
+        // '-metadata',
+        // 'comment="Cover (front)"'
+      )
+      .on("end", () => {
+        resolve(output);
+      });
+
+    if (album) {
+      cmd.addInput(album);
+      cmd.addOutputOptions(["-map 0:0", "-map 1:0"]);
+    }
+
+    cmd.on("error", (err, stdout, stderr) => {
+      console.log(`Cannot process video: ${err.message}`);
+      console.log(stdout, stderr);
+      reject(err);
+    });
+
+    cmd.on("start", (cmdline) => {
+      console.log("cmdline", cmdline);
+    });
+
+    cmd.run();
+  });
+};
+
+type YT2MP3Options = {
+  filename?: string;
+  format?: string;
+};
+
+const yt2mp3 = async (url: string, outDir: string, options?: YT2MP3Options) => {
+  let srcFile: YTDownloadFnResult | null = null;
+  let tmpAudio: string | undefined;
+  let result: string | undefined;
+
+  try {
+    if (!fs.existsSync(TMP_DIR)) {
+      fs.mkdirSync(TMP_DIR, { recursive: true });
+    }
+
+    srcFile = await ytDownload(url);
+    const { info } = srcFile;
+
+    if (!fs.existsSync(outDir)) {
+      fs.mkdirSync(outDir, { recursive: true });
+    }
+
+    const { title } = info.videoDetails;
+    const format = options?.format || "mp3";
+    const tmpAudioPath = path.join(TMP_DIR, `${Date.now()}.${format}`);
+    tmpAudio = await convertToAudio(srcFile.path, tmpAudioPath, format);
+
+    const audioPath = path.join(
+      outDir,
+      options?.filename || `${slugify(title, false)}.${format}`
+    );
+    await embedMetadata(tmpAudio, audioPath, title, srcFile.album);
+
+    result = audioPath;
+  } catch (err) {
+    throw err;
+  } finally {
+    // clean tmp files
+    if (srcFile) {
+      srcFile.clean();
+    }
+
+    if (tmpAudio) {
+      fs.unlinkSync(tmpAudio);
+    }
+  }
+
+  return result;
+};
+
+export const getVideoInfo = async (url: string) => {
+  const info = await YTDL.getBasicInfo(url);
+  const { videoDetails: details } = info;
+
+  return {
+    url: details.video_url,
+    title: details.title,
+    length: details.lengthSeconds,
+    thumb: getBestThumbnail(details.thumbnails),
+  };
+};
+
+function getBestThumbnail(thumbnails: YTDL.thumbnail[]) {
+  let thumbnail = thumbnails[0] || null;
+
+  thumbnails.forEach((thumb) => {
+    if (!thumbnail) {
+      thumbnail = thumb;
+      return;
+    }
+    if (thumb.width > thumbnail.width || thumb.height > thumbnail.height) {
+      thumbnail = thumb;
+    }
+  });
+
+  return thumbnail;
+}
+
+async function downloadFile(url: string, out: string) {
+  try {
+    const res = await fetch(url);
+    if (!res.ok || !res.body) {
+      throw new Error(res.statusText);
+    }
+
+    res.body.pipe(fs.createWriteStream(out));
+    return out;
+  } catch (err) {
+    console.log("err download file", err);
+    return null;
+  }
+}
+
+export default yt2mp3;