convertVideoToAudio.js

const fs = require("fs");
const ytdl = require("ytdl-core");
const ffmpeg = require("fluent-ffmpeg");

function convertVideoToAudio(url, filename, chatId, bot) {
  return new Promise((resolve, reject) => {
    console.log("Downloading video...");
    bot.sendMessage(chatId, "Downloading video...");
    ytdl(url, { quality: "highestaudio" })
      .pipe(fs.createWriteStream(`./downloads/${filename}.mp4`))
      .on("finish", () => {
        console.log("Converting to mp3...");
        bot.sendMessage(chatId, "Converting to mp3...");
        new ffmpeg({ source: `./downloads/${filename}.mp4`, nolog: true })
          .toFormat("mp3")
          .on("end", () => resolve())
          .on("error", err => reject(err))
          .saveToFile(`./downloads/${filename}.mp3`);
      })
      .on("error", error => console.error(error));
  }).catch(err => console.error(err));
}

module.exports = convertVideoToAudio;