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Viewing changes to src/engine/fft.c

  • Committer: Package Import Robot
  • Author(s): Tiago Bortoletto Vaz
  • Date: 2012-07-03 23:45:41 UTC
  • mfrom: (1.1.1)
  • Revision ID: package-import@ubuntu.com-20120703234541-jh5jg00lvljnwq8m
Tags: 0.6.2-1
New upstream release.

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src/engine/fft.c
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**  Original file can be found on musicdsp.org :
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**  http://www.musicdsp.org/archive.php?classid=2#79
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****************************************************** */
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//#include <stdlib.h>
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#include "fft.h"
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#include "pyomodule.h"
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#include <math.h>
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    MYFLT a = e;
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    MYFLT a3;
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    for(j=2; j<=n8; j++) {
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        //j1 = j - 1;
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        a3 = 3 * a;
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        twiddle[0][j-1] = MYCOS(a);
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        twiddle[1][j-1] = MYSIN(a);
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            n4 = n2 >> 2;
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            n8 = n2 >> 3;
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            pas = n / n2;
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            //e = 2 * PI / n2;
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            i1 = 0;
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            id = n2 << 1;
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            do { 
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                i1 = id - n2;
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                id <<= 1;
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            } while ( i1<n );
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            //a = e;
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            for (j=2; j<=n8; j++){ 
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                pos = (j-1) * pas;
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                cc1 = twiddle[0][pos];
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                ss1 = twiddle[1][pos];
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                cc3 = twiddle[2][pos];
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                ss3 = twiddle[3][pos]; 
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                //a3 = 3 * a;
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                //cc1 = cos(a);
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                //ss1 = sin(a);
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                //cc3 = cos(a3);
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                //ss3 = sin(a3);
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                //a = j * e;
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                i = 0;
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                id = n2 << 1;
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                do {
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            n4 = n2 >> 2;
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            n8 = n2 >> 3;
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            pas = n / n2;
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            //e = 2 * PI / n2;
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            i1 = 0;
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            do { 
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                for (; i1<n; i1+=id) {
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                i1 = id - n2;
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                id <<= 1;
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            } while ( i1<n1 );
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            //a = e;
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            for (j=2; j<=n8; j++) {  
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                pos = (j-1) * pas;
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                cc1 = twiddle[0][pos];
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                ss1 = twiddle[1][pos];
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                cc3 = twiddle[2][pos];
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                ss3 = twiddle[3][pos];
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                //a3 = 3 * a;
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                //cc1 = cos(a);
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                //ss1 = sin(a);
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                //cc3 = cos(a3);
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                //ss3 = sin(a3);
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                //a = j * e;
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                i = 0;
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                id = n2 << 1;
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                do {
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        outdata[i] = data[i];   
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}
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/* *************************************************** */
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/* *****************************************************
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** Decimation-in-freq radix-2 in-place butterfly
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** data: array of doubles:
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            for(angle=0; l1<ol2; l1+=2, l2+=2) {
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                wr = twiddle[angle];
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                wi = -twiddle[size+angle]; /* size here is half the FFT size */
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                /*
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                ang = 2 * PI * angle / size;
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                wr = cos(ang);
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                wi = -sin(ang);
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                */
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                xr = *l1 + *l2;
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                xi = *(l1+1) + *(l2+1);
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                dr = *l1 - *l2;
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            for(angle=0; l1<ol2; l1+=2, l2+=2) {
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                wr = twiddle[angle];
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                wi = twiddle[size+angle]; /* size here is half the FFT size */
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                /*
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                ang = 2 * PI * angle / size;
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                wr = cos(ang);
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                wi = sin(ang);
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                */
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                xr = *l1;
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                xi = *(l1+1);
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                yr = *l2;