help with visualising spectogram
in
Core Library Questions
•
1 year ago
Hi,
I want a sketch which can analyse the dominant frequency band of a sound. So for example, with a kick drum it would analyse all the frequencies and tell me the low frequencies are the loudest in the spectrum. At the moment I have got a spectogram, but it shows all frequencies. How can I adapt this so it tells me which band has the most gain in it please?
- import ddf.minim.analysis.*;
- import ddf.minim.*;
- Minim minim;
- AudioPlayer jingle;
- FFT fftLin;
- int xPos = 0;
- int hueLimit = 160;
- void setup()
- {
- // create a screen width=512, height=256
- size(512, 256);
- // create a minim audio application object
- minim = new Minim(this);
- // create a file object (can be a MP3 file or a WAV file)
- //jingle = minim.loadFile("jingle.mp3", 512);
- jingle = minim.loadFile("Drum_Loop_01.wav", 512);
- // loop the file
- jingle.loop();
- // create an FFT object that has a time-domain buffer the same size as jingle's sample buffer
- // note that this needs to be a power of two
- // and that it means the size of the spectrum will be 1024.
- // see the online tutorial for more info.
- fftLin = new FFT(jingle.bufferSize(), jingle.sampleRate());
- // calculate the averages by grouping frequency bands linearly. use 30 averages.
- fftLin.linAverages(30);
- }
- void draw()
- {
- // perform a forward FFT on the samples in jingle's mix buffer
- // note that if jingle were a MONO file, this would be the same as using jingle.left or jingle.right
- fftLin.forward(jingle.mix);
- for(int i = 0; i < fftLin.specSize(); i++)
- {
- float hueValue = hueLimit - map((fftLin.getBand( fftLin.specSize()-i)*32), 0, 256, 0, hueLimit);
- // colorMode is HSB, the range for hue is 256, for saturation is 100, brightness is 100.
- colorMode(HSB, 256, 100, 100);
- // color for stroke is specified as hue, saturation, brightness.
- stroke(int(hueValue), 100, 80);
- // find the distance to the edge of an eclipse defined by i from the center along the angle xPos; the numbers are basically //guessing and checking. I got the math from http://warpycode.wordpress.com/2011/01/21/calculating-the-distance-to-the-//edge-of-an-ellipse/
- float elipse=i*.5*sqrt( 1/( sq(sin(xPos)/(.8)) + sq(cos(xPos)/(1.25))) );
- //convert the distance and angle from polar to cartesian form
- point(width/2+elipse*cos(xPos),height/2+elipse*sin(xPos));
- }
- // increment the x position
- xPos = xPos + 1;
- // wrap around at the screen width
- if (xPos > width) {
- xPos = 0;
- }
- }
- void stop()
- {
- // always close Minim audio classes when you are done with them
- jingle.close();
- // always stop Minim before exiting
- minim.stop();
- //super.stop();
- }
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