read RMS amplitude of input audio stream

minim_in_level

import ddf.minim.*;

Minim minim;
AudioInput in;

void setup()
{
  minim = new Minim(this);
  in = minim.getLineIn();
}

void draw()
{
  println(in.mix.level());  
}

void stop()
{
  in.close();
  minim.stop();
  super.stop();
}