Combine videos using FFMPEG in NodeJS

CombineVideo.js

const inputJson = require('./list.json'),
      ffmpeg = require('fluent-ffmpeg');

const fileList = inputJson.paths;

const runFfmpeg = function(){
    new Promise((resolve, reject) => {
        console.log('Starting task of combining ', fileList.length, 'files');
        console.log('Added file ', fileList[0], ' to the list');
        const ffmpegJob = ffmpeg(fileList[0]);
        for(var i = 1; i < fileList.length; i++) {
            console.log('Added file ', fileList[i], ' to the list');
            ffmpegJob.input(fileList[i]);
        }
        ffmpegJob.on('progress', function(progress) {
            console.log('Processing', progress.percent, '% done');
        })
        .on('error', function(err) {
            console.log('An error occurred: ', err.message);
            reject(err);
        })
        .on('end', function() {
            console.log('Merging finished for file ');
            resolve();
        })
        .mergeToFile('./output.mp4');
      });
}

runFfmpeg();

/*
list.json
{
    "paths": ["./files/file1.mp4", "./files/file2.mp4"]
}
*/