Tag Dump

index.js

var fs = require("fs");
var mm = require("musicmetadata");
var glob = require("glob");

if(process.argv.length < 3) {
	console.log("node " + process.argv[1] + " /path/to/mp3/files");
	process.exit(1);
}

var lookupPath = process.argv[2];

var list = glob.sync(lookupPath + "/**/*.mp3");
console.log("Found " + list.length + " files");

var AlbumLookup = {};
var Album = [];
var Song = [];

function parseSong(idx, after) {
	var path = list[idx];

	if(typeof path === "undefined") {
		after();
		return;
	}

	var stream = fs.createReadStream(path);
	var parser = mm(stream);

	parser.on("metadata", function(result) {
		var album = result.album;
		var title = result.title;
		var artist = result.artist[0];
		var track = result.track.no;
		var disc = result.disk.no;

		var albumId;

		if(typeof AlbumLookup[album] === "undefined") {
			Album.push(album);
			AlbumLookup[album] = Album.length - 1;
		}

		albumId = AlbumLookup[album];

		Song.push({
			albumId: albumId,
			disc: disc,
			track: track,
			title: title,
			artist: artist,
		});
	});

	parser.on("done", function(err) {
		stream.destroy();

		parseSong(idx + 1, after);
	});
}

parseSong(0, function() {
	fs.writeFileSync("Album.json", JSON.stringify(Album, null, 2), { encoding: "utf8" });
	fs.writeFileSync("Song.json", JSON.stringify(Song, null, 2), { encoding: "utf8" });
	console.log("dumped to Album.json, Song.json");
});

package.json

{
  "name": "tagdump",
  "version": "1.0.0",
  "description": "Tag Dump",
  "main": "index.js",
  "author": "",
  "private": true,
  "dependencies": {
    "glob": "^4.3.5",
    "musicmetadata": "^0.6.3"
  }
}