Youtube MP3 Downloader

Youtube MP3 Downloader is a module which allows to specify YouTube videos from which the audio data should be extracted, converted to MP3, and stored on disk.

Installation

Prerequisites

To run this project, you need to have a local installation of FFmpeg present on your system. You can download it from https://www.ffmpeg.org/download.html

Installation via NPM

npm install youtube-mp3-downloader --save

Installation from Github

Checkout the project from Github to a local folder

git clone https://github.com/tobilg/youtube-mp3-downloader.git

Install module dependencies

Navigate to the folder where you checked out the project to in your console. Run npm install.

Running

Basic example

A basic usage example is the following:

var YoutubeMp3Downloader = require("youtube-mp3-downloader");

//Configure YoutubeMp3Downloader with your settings
var YD = new YoutubeMp3Downloader({
    "ffmpegPath": "/path/to/ffmpeg",        // Where is the FFmpeg binary located?
    "outputPath": "/path/to/mp3/folder",    // Where should the downloaded and encoded files be stored?
    "youtubeVideoQuality": "highest",       // What video quality should be used?
    "queueParallelism": 2,                  // How many parallel downloads/encodes should be started?
    "progressTimeout": 2000                 // How long should be the interval of the progress reports
});

//Download video and save as MP3 file
YD.download("Vhd6Kc4TZls");

YD.on("finished", function(err, data) {
    console.log(JSON.stringify(data));
});

YD.on("error", function(error) {
    console.log(error);
});

YD.on("progress", function(progress) {
    console.log(JSON.stringify(progress));
});

You can also pass a file name for the respective video, which will then be used. Otherwise, the file name will be derived from the video title.

YD.download("Vhd6Kc4TZls", "Cold Funk - Funkorama.mp3");

While downloading, every progressTimeout timeframe, there will be an progress event triggered, outputting an object like

{
    "videoId": "Vhd6Kc4TZls",
    "progress": {
        "percentage": 72.29996914191304,
        "transferred": 19559221,
        "length": 27052876,
        "remaining": 7493655,
        "eta": 2,
        "runtime": 6,
        "delta": 6591454,
        "speed": 3009110.923076923
    }
}

Furthermore, there will be a queueSize event emitted when the queue size changes (both positive and negative). This can be caught via

YD.on("queueSize", function(size) {
    console.log(size);
});

Upon finish, the following output will be returned:

{
    "videoId": "Vhd6Kc4TZls",
    "stats": {
        "transferredBytes": 27052876,
        "runtime": 7,
        "averageSpeed": 3279136.48
    },
    "file": "/path/to/mp3/folder/Cold Funk - Funkorama.mp3",
    "youtubeUrl": "http://www.youtube.com/watch?v=Vhd6Kc4TZls",
    "videoTitle": "Cold Funk - Funkorama - Kevin MacLeod | YouTube Audio Library",
    "artist": "Cold Funk",
    "title": "Funkorama",
    "thumbnail": "https://i.ytimg.com/vi/Vhd6Kc4TZls/hqdefault.jpg"
}

Detailed example

To use it in a class which provides the downloading functionality, you could use it like the following (which can also be found in the examples subfolder of this project):

downloader.js

var YoutubeMp3Downloader = require("youtube-mp3-downloader");

var Downloader = function() {

    var self = this;
    
    //Configure YoutubeMp3Downloader with your settings
    self.YD = new YoutubeMp3Downloader({
        "ffmpegPath": "/path/to/ffmpeg",        // Where is the FFmpeg binary located?
        "outputPath": "/path/to/mp3/folder",    // Where should the downloaded and encoded files be stored?
        "youtubeVideoQuality": "highest",       // What video quality should be used?
        "queueParallelism": 2,                  // How many parallel downloads/encodes should be started?
        "progressTimeout": 2000,                // How long should be the interval of the progress reports
        "outputOptions" : ["-af", "silenceremove=1:0:-50dB"] // Additional output options passend to ffmpeg
    });

    self.callbacks = {};

    self.YD.on("finished", function(error, data) {
		
        if (self.callbacks[data.videoId]) {
            self.callbacks[data.videoId](error, data);
        } else {
            console.log("Error: No callback for videoId!");
        }
    
    });

    self.YD.on("error", function(error, data) {
	
        console.error(error + " on videoId " + data.videoId);
    
        if (self.callbacks[data.videoId]) {
            self.callbacks[data.videoId](error, data);
        } else {
            console.log("Error: No callback for videoId!");
        }
     
    });

};

Downloader.prototype.getMP3 = function(track, callback){

    var self = this;
	
    // Register callback
    self.callbacks[track.videoId] = callback;
    // Trigger download
    self.YD.download(track.videoId, track.name);

};

module.exports = Downloader;

This class can then be used like this:

example1.js

var Downloader = require("./downloader");
var dl = new Downloader();
var i = 0;

dl.getMP3({videoId: "Vhd6Kc4TZls", name: "Cold Funk - Funkorama.mp3"}, function(err,res){
    i++;
    if(err)
        throw err;
    else{
        console.log("Song "+ i + " was downloaded: " + res.file);
    }
});