title: MP3 to MP4 for javascript Mediasource
body: <p>Is it possible to convert MP3 to MSE-compatible fragmented MP4 within client side?</p>
  
  <p>I tried <strong><code>mux.js</code></strong> with different MP3 files, but always return empty data.</p>
  
  <p>so if it possible, how to do that? i currently have MP3 arraybuffer</p>