Processing audio file from http with ffmpeg on node

gistfile1.txt

var ffmpeg = require('fluent-ffmpeg');
var request = require('request');

var httpStream = request('http://www.acme.com/input.mp3');
var proc = new ffmpeg({source: httpStream})
  .inputFormat('mp3')
  /* insert processing steps from
     https://github.com/fluent-ffmpeg/node-fluent-ffmpeg here */
  .save('output.mp3');