FFT "log banded result"

[venquessa]

So this is what I came up with to sample the total bins down to "bands" for an equalizer. A member function of the AudioFFTBase class.

Thought I'd throw it your way in case you want to adapt, tidy, improve and include?

       void resultBands(uint32_t* bandsArray) {
            memset(bandsArray,0,32*sizeof(uint32_t));
            for (int band = 0, j=1;j<size(); j++){          
                uint32_t f = round(frequency(j));

                if( f > LOW_PASS ) {
                    continue;
                }
                uint32_t m = round(magnitude(j));
                if( f > band_low_pass_freqs[band] ) {
                    band++;
                }
                if(bandsArray[band]==0)
                    bandsArray[band] = m;
                else {
                    // Must be a more clever way here?
                    bandsArray[band] = (bandsArray[band] + m)/2;
                }
            }
        }

band_low_pass_freqs I defined as so for 32 bands. Using exponent 1.22 per band:

static int band_low_pass_freqs[32] = {
30	,
37	,
45	,
55	,
67	,
82	,
100	,
122	,
149	,
182	,
222	,
271	,
331	,
404	,
493	,
601	,
733	,
894	,
1091	,
1331	,
1624	,
1981	,
2417	,
2949	,
3598	,
4390	,
5356	,
6534	,
7971	,
9725	,
11865	,
14475	
};

[pschatzmann]

I would propose that you create your own subclass and add the method there. This way you don't run the risk when you do a release upgrade to loose your implementation.

[pschatzmann]

I would propose that you create your own subclass and add the method there. This way you don't run the risk when you do a release upgrade to loose your implementation.