mkvExtractAll.node.js

#!/usr/bin/env node

// Script for extracting all files from an MKV container.

const fs = require('fs');
const path = require('path');
const process = require('process');
const shellescape = require('shell-escape');
const child_process = require('child_process');

const MKVINFO = '/usr/bin/mkvmerge -J';
const MKVEXTRACT = '/usr/bin/mkvextract';

const mkvfile = process.argv[2];
const outpath = path.resolve(process.argv[3] || '.');

const init = () => {
	if (!mkvfile) {
		console.log('Missing mkv file.');
		process.exit(0);
	}
	let videoTracks = [];

	const infoCmd = `${MKVINFO} ${shellescape([mkvfile])}`;
	const infoJSON = JSON.parse(child_process.execSync(infoCmd).toString());

	let mkvExtExec = `${MKVEXTRACT} tracks ${shellescape([mkvfile])}`;

	infoJSON.tracks.forEach(trk => {
		const ext = trk.codec.replace(/\//g,'-');
		const id  = trk.id;
		const lang = trk.properties.language;

		let trackName = '';
		switch (trk.type) {
			case 'video':
				trackName += `${trk.id}:${shellescape([`${outpath}/${trk.id}.video`])}`;
				break;
			case 'subtitles':
				trackName += `${trk.id}:${shellescape([`${outpath}/${trk.id}.${trk.properties.language}.subtitle`])}`;
				break;
			case 'audio':
				trackName += `${trk.id}:${shellescape([`${outpath}/${trk.id}.${trk.properties.audio_channels}channels.${trk.type}.${trk.properties.language}`])}`;
				break;
			default:
				trackName += `${trk.id}:${shellescape([`${outpath}/${trk.id}.${trk.type}.${trk.properties.language}`])}`;
		};

		mkvExtExec += ` ${trackName}`;
	});

	child_process.execSync(mkvExtExec);

};

init();