var ffmpeg = require('fluent-ffmpeg'); var track = './test.mp3';//your path to source file console.log("outside"); ffmpeg(track) .format('wav') .on('error', function (err) { console.log('An error occurred: ' + err.message); }) .on('progress', function (progress) { // console.log(JSON.stringify(progress)); console.log('Processing: ' + progress.targetSize + ' KB converted'); }) .on('end', function () { console.log('Processing finished !'); }).output("./test.wav") .run();