Way to make a waveform from a mp3

I want the ability to upload a mp3 file then from that mp3 file take like a 30 second clip of it and make a waveform out of it.

I would figure you could do something the computeSpectrum () method althogh i am unsure. What i don’t want is a visualizer like you get in itunes or winamp but rather something that shows the actual waveform of an uploaded mp3 file.

Any example code on how this could be done or an example fla would greatly be appreciate?

The type of waveform i am looking for is something similar to the following (im just unsure how to go about doing it):