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authorMiller Puckette <millerpuckette@users.sourceforge.net>2006-06-03 18:22:09 +0000
committerMiller Puckette <millerpuckette@users.sourceforge.net>2006-06-03 18:22:09 +0000
commiteb976fa09171036cbaeaabf920708b2d39c49acc (patch)
treefc15df095e83b9a89852a13f8cc68753935a4351 /pd/src/d_fft_mayer.c
parent55fcd829cd66c6482ca5d2524c11f49e3ba883cf (diff)
Removing renamed files
svn path=/trunk/; revision=5163
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+/*
+** FFT and FHT routines
+** Copyright 1988, 1993; Ron Mayer
+**
+** mayer_fht(fz,n);
+** Does a hartley transform of "n" points in the array "fz".
+** mayer_fft(n,real,imag)
+** Does a fourier transform of "n" points of the "real" and
+** "imag" arrays.
+** mayer_ifft(n,real,imag)
+** Does an inverse fourier transform of "n" points of the "real"
+** and "imag" arrays.
+** mayer_realfft(n,real)
+** Does a real-valued fourier transform of "n" points of the
+** "real" array. The real part of the transform ends
+** up in the first half of the array and the imaginary part of the
+** transform ends up in the second half of the array.
+** mayer_realifft(n,real)
+** The inverse of the realfft() routine above.
+**
+**
+** NOTE: This routine uses at least 2 patented algorithms, and may be
+** under the restrictions of a bunch of different organizations.
+** Although I wrote it completely myself, it is kind of a derivative
+** of a routine I once authored and released under the GPL, so it
+** may fall under the free software foundation's restrictions;
+** it was worked on as a Stanford Univ project, so they claim
+** some rights to it; it was further optimized at work here, so
+** I think this company claims parts of it. The patents are
+** held by R. Bracewell (the FHT algorithm) and O. Buneman (the
+** trig generator), both at Stanford Univ.
+** If it were up to me, I'd say go do whatever you want with it;
+** but it would be polite to give credit to the following people
+** if you use this anywhere:
+** Euler - probable inventor of the fourier transform.
+** Gauss - probable inventor of the FFT.
+** Hartley - probable inventor of the hartley transform.
+** Buneman - for a really cool trig generator
+** Mayer(me) - for authoring this particular version and
+** including all the optimizations in one package.
+** Thanks,
+** Ron Mayer; mayer@acuson.com
+**
+*/
+
+/* This is a slightly modified version of Mayer's contribution; write
+* msp@ucsd.edu for the original code. Kudos to Mayer for a fine piece
+* of work. -msp
+*/
+
+/* These pragmas are only used for MSVC, not MinGW or Cygwin <hans@at.or.at> */
+#ifdef _MSC_VER
+#pragma warning( disable : 4305 ) /* uncast const double to float */
+#pragma warning( disable : 4244 ) /* uncast double to float */
+#pragma warning( disable : 4101 ) /* unused local variables */
+#endif
+
+/* the following is needed only to declare pd_fft() as exportable in MSW */
+#include "m_pd.h"
+
+#define REAL float
+#define GOOD_TRIG
+
+#ifdef GOOD_TRIG
+#else
+#define FAST_TRIG
+#endif
+
+#if defined(GOOD_TRIG)
+#define FHT_SWAP(a,b,t) {(t)=(a);(a)=(b);(b)=(t);}
+#define TRIG_VARS \
+ int t_lam=0;
+#define TRIG_INIT(k,c,s) \
+ { \
+ int i; \
+ for (i=2 ; i<=k ; i++) \
+ {coswrk[i]=costab[i];sinwrk[i]=sintab[i];} \
+ t_lam = 0; \
+ c = 1; \
+ s = 0; \
+ }
+#define TRIG_NEXT(k,c,s) \
+ { \
+ int i,j; \
+ (t_lam)++; \
+ for (i=0 ; !((1<<i)&t_lam) ; i++); \
+ i = k-i; \
+ s = sinwrk[i]; \
+ c = coswrk[i]; \
+ if (i>1) \
+ { \
+ for (j=k-i+2 ; (1<<j)&t_lam ; j++); \
+ j = k - j; \
+ sinwrk[i] = halsec[i] * (sinwrk[i-1] + sinwrk[j]); \
+ coswrk[i] = halsec[i] * (coswrk[i-1] + coswrk[j]); \
+ } \
+ }
+#define TRIG_RESET(k,c,s)
+#endif
+
+#if defined(FAST_TRIG)
+#define TRIG_VARS \
+ REAL t_c,t_s;
+#define TRIG_INIT(k,c,s) \
+ { \
+ t_c = costab[k]; \
+ t_s = sintab[k]; \
+ c = 1; \
+ s = 0; \
+ }
+#define TRIG_NEXT(k,c,s) \
+ { \
+ REAL t = c; \
+ c = t*t_c - s*t_s; \
+ s = t*t_s + s*t_c; \
+ }
+#define TRIG_RESET(k,c,s)
+#endif
+
+static REAL halsec[20]=
+ {
+ 0,
+ 0,
+ .54119610014619698439972320536638942006107206337801,
+ .50979557910415916894193980398784391368261849190893,
+ .50241928618815570551167011928012092247859337193963,
+ .50060299823519630134550410676638239611758632599591,
+ .50015063602065098821477101271097658495974913010340,
+ .50003765191554772296778139077905492847503165398345,
+ .50000941253588775676512870469186533538523133757983,
+ .50000235310628608051401267171204408939326297376426,
+ .50000058827484117879868526730916804925780637276181,
+ .50000014706860214875463798283871198206179118093251,
+ .50000003676714377807315864400643020315103490883972,
+ .50000000919178552207366560348853455333939112569380,
+ .50000000229794635411562887767906868558991922348920,
+ .50000000057448658687873302235147272458812263401372
+ };
+static REAL costab[20]=
+ {
+ .00000000000000000000000000000000000000000000000000,
+ .70710678118654752440084436210484903928483593768847,
+ .92387953251128675612818318939678828682241662586364,
+ .98078528040323044912618223613423903697393373089333,
+ .99518472667219688624483695310947992157547486872985,
+ .99879545620517239271477160475910069444320361470461,
+ .99969881869620422011576564966617219685006108125772,
+ .99992470183914454092164649119638322435060646880221,
+ .99998117528260114265699043772856771617391725094433,
+ .99999529380957617151158012570011989955298763362218,
+ .99999882345170190992902571017152601904826792288976,
+ .99999970586288221916022821773876567711626389934930,
+ .99999992646571785114473148070738785694820115568892,
+ .99999998161642929380834691540290971450507605124278,
+ .99999999540410731289097193313960614895889430318945,
+ .99999999885102682756267330779455410840053741619428
+ };
+static REAL sintab[20]=
+ {
+ 1.0000000000000000000000000000000000000000000000000,
+ .70710678118654752440084436210484903928483593768846,
+ .38268343236508977172845998403039886676134456248561,
+ .19509032201612826784828486847702224092769161775195,
+ .09801714032956060199419556388864184586113667316749,
+ .04906767432741801425495497694268265831474536302574,
+ .02454122852291228803173452945928292506546611923944,
+ .01227153828571992607940826195100321214037231959176,
+ .00613588464915447535964023459037258091705788631738,
+ .00306795676296597627014536549091984251894461021344,
+ .00153398018628476561230369715026407907995486457522,
+ .00076699031874270452693856835794857664314091945205,
+ .00038349518757139558907246168118138126339502603495,
+ .00019174759731070330743990956198900093346887403385,
+ .00009587379909597734587051721097647635118706561284,
+ .00004793689960306688454900399049465887274686668768
+ };
+static REAL coswrk[20]=
+ {
+ .00000000000000000000000000000000000000000000000000,
+ .70710678118654752440084436210484903928483593768847,
+ .92387953251128675612818318939678828682241662586364,
+ .98078528040323044912618223613423903697393373089333,
+ .99518472667219688624483695310947992157547486872985,
+ .99879545620517239271477160475910069444320361470461,
+ .99969881869620422011576564966617219685006108125772,
+ .99992470183914454092164649119638322435060646880221,
+ .99998117528260114265699043772856771617391725094433,
+ .99999529380957617151158012570011989955298763362218,
+ .99999882345170190992902571017152601904826792288976,
+ .99999970586288221916022821773876567711626389934930,
+ .99999992646571785114473148070738785694820115568892,
+ .99999998161642929380834691540290971450507605124278,
+ .99999999540410731289097193313960614895889430318945,
+ .99999999885102682756267330779455410840053741619428
+ };
+static REAL sinwrk[20]=
+ {
+ 1.0000000000000000000000000000000000000000000000000,
+ .70710678118654752440084436210484903928483593768846,
+ .38268343236508977172845998403039886676134456248561,
+ .19509032201612826784828486847702224092769161775195,
+ .09801714032956060199419556388864184586113667316749,
+ .04906767432741801425495497694268265831474536302574,
+ .02454122852291228803173452945928292506546611923944,
+ .01227153828571992607940826195100321214037231959176,
+ .00613588464915447535964023459037258091705788631738,
+ .00306795676296597627014536549091984251894461021344,
+ .00153398018628476561230369715026407907995486457522,
+ .00076699031874270452693856835794857664314091945205,
+ .00038349518757139558907246168118138126339502603495,
+ .00019174759731070330743990956198900093346887403385,
+ .00009587379909597734587051721097647635118706561284,
+ .00004793689960306688454900399049465887274686668768
+ };
+
+
+#define SQRT2_2 0.70710678118654752440084436210484
+#define SQRT2 2*0.70710678118654752440084436210484
+
+void mayer_fht(REAL *fz, int n)
+{
+/* REAL a,b;
+REAL c1,s1,s2,c2,s3,c3,s4,c4;
+ REAL f0,g0,f1,g1,f2,g2,f3,g3; */
+ int k,k1,k2,k3,k4,kx;
+ REAL *fi,*fn,*gi;
+ TRIG_VARS;
+
+ for (k1=1,k2=0;k1<n;k1++)
+ {
+ REAL aa;
+ for (k=n>>1; (!((k2^=k)&k)); k>>=1);
+ if (k1>k2)
+ {
+ aa=fz[k1];fz[k1]=fz[k2];fz[k2]=aa;
+ }
+ }
+ for ( k=0 ; (1<<k)<n ; k++ );
+ k &= 1;
+ if (k==0)
+ {
+ for (fi=fz,fn=fz+n;fi<fn;fi+=4)
+ {
+ REAL f0,f1,f2,f3;
+ f1 = fi[0 ]-fi[1 ];
+ f0 = fi[0 ]+fi[1 ];
+ f3 = fi[2 ]-fi[3 ];
+ f2 = fi[2 ]+fi[3 ];
+ fi[2 ] = (f0-f2);
+ fi[0 ] = (f0+f2);
+ fi[3 ] = (f1-f3);
+ fi[1 ] = (f1+f3);
+ }
+ }
+ else
+ {
+ for (fi=fz,fn=fz+n,gi=fi+1;fi<fn;fi+=8,gi+=8)
+ {
+ REAL bs1,bc1,bs2,bc2,bs3,bc3,bs4,bc4,
+ bg0,bf0,bf1,bg1,bf2,bg2,bf3,bg3;
+ bc1 = fi[0 ] - gi[0 ];
+ bs1 = fi[0 ] + gi[0 ];
+ bc2 = fi[2 ] - gi[2 ];
+ bs2 = fi[2 ] + gi[2 ];
+ bc3 = fi[4 ] - gi[4 ];
+ bs3 = fi[4 ] + gi[4 ];
+ bc4 = fi[6 ] - gi[6 ];
+ bs4 = fi[6 ] + gi[6 ];
+ bf1 = (bs1 - bs2);
+ bf0 = (bs1 + bs2);
+ bg1 = (bc1 - bc2);
+ bg0 = (bc1 + bc2);
+ bf3 = (bs3 - bs4);
+ bf2 = (bs3 + bs4);
+ bg3 = SQRT2*bc4;
+ bg2 = SQRT2*bc3;
+ fi[4 ] = bf0 - bf2;
+ fi[0 ] = bf0 + bf2;
+ fi[6 ] = bf1 - bf3;
+ fi[2 ] = bf1 + bf3;
+ gi[4 ] = bg0 - bg2;
+ gi[0 ] = bg0 + bg2;
+ gi[6 ] = bg1 - bg3;
+ gi[2 ] = bg1 + bg3;
+ }
+ }
+ if (n<16) return;
+
+ do
+ {
+ REAL s1,c1;
+ int ii;
+ k += 2;
+ k1 = 1 << k;
+ k2 = k1 << 1;
+ k4 = k2 << 1;
+ k3 = k2 + k1;
+ kx = k1 >> 1;
+ fi = fz;
+ gi = fi + kx;
+ fn = fz + n;
+ do
+ {
+ REAL g0,f0,f1,g1,f2,g2,f3,g3;
+ f1 = fi[0 ] - fi[k1];
+ f0 = fi[0 ] + fi[k1];
+ f3 = fi[k2] - fi[k3];
+ f2 = fi[k2] + fi[k3];
+ fi[k2] = f0 - f2;
+ fi[0 ] = f0 + f2;
+ fi[k3] = f1 - f3;
+ fi[k1] = f1 + f3;
+ g1 = gi[0 ] - gi[k1];
+ g0 = gi[0 ] + gi[k1];
+ g3 = SQRT2 * gi[k3];
+ g2 = SQRT2 * gi[k2];
+ gi[k2] = g0 - g2;
+ gi[0 ] = g0 + g2;
+ gi[k3] = g1 - g3;
+ gi[k1] = g1 + g3;
+ gi += k4;
+ fi += k4;
+ } while (fi<fn);
+ TRIG_INIT(k,c1,s1);
+ for (ii=1;ii<kx;ii++)
+ {
+ REAL c2,s2;
+ TRIG_NEXT(k,c1,s1);
+ c2 = c1*c1 - s1*s1;
+ s2 = 2*(c1*s1);
+ fn = fz + n;
+ fi = fz +ii;
+ gi = fz +k1-ii;
+ do
+ {
+ REAL a,b,g0,f0,f1,g1,f2,g2,f3,g3;
+ b = s2*fi[k1] - c2*gi[k1];
+ a = c2*fi[k1] + s2*gi[k1];
+ f1 = fi[0 ] - a;
+ f0 = fi[0 ] + a;
+ g1 = gi[0 ] - b;
+ g0 = gi[0 ] + b;
+ b = s2*fi[k3] - c2*gi[k3];
+ a = c2*fi[k3] + s2*gi[k3];
+ f3 = fi[k2] - a;
+ f2 = fi[k2] + a;
+ g3 = gi[k2] - b;
+ g2 = gi[k2] + b;
+ b = s1*f2 - c1*g3;
+ a = c1*f2 + s1*g3;
+ fi[k2] = f0 - a;
+ fi[0 ] = f0 + a;
+ gi[k3] = g1 - b;
+ gi[k1] = g1 + b;
+ b = c1*g2 - s1*f3;
+ a = s1*g2 + c1*f3;
+ gi[k2] = g0 - a;
+ gi[0 ] = g0 + a;
+ fi[k3] = f1 - b;
+ fi[k1] = f1 + b;
+ gi += k4;
+ fi += k4;
+ } while (fi<fn);
+ }
+ TRIG_RESET(k,c1,s1);
+ } while (k4<n);
+}
+
+void mayer_fft(int n, REAL *real, REAL *imag)
+{
+ REAL a,b,c,d;
+ REAL q,r,s,t;
+ int i,j,k;
+ for (i=1,j=n-1,k=n/2;i<k;i++,j--) {
+ a = real[i]; b = real[j]; q=a+b; r=a-b;
+ c = imag[i]; d = imag[j]; s=c+d; t=c-d;
+ real[i] = (q+t)*.5; real[j] = (q-t)*.5;
+ imag[i] = (s-r)*.5; imag[j] = (s+r)*.5;
+ }
+ mayer_fht(real,n);
+ mayer_fht(imag,n);
+}
+
+void mayer_ifft(int n, REAL *real, REAL *imag)
+{
+ REAL a,b,c,d;
+ REAL q,r,s,t;
+ int i,j,k;
+ mayer_fht(real,n);
+ mayer_fht(imag,n);
+ for (i=1,j=n-1,k=n/2;i<k;i++,j--) {
+ a = real[i]; b = real[j]; q=a+b; r=a-b;
+ c = imag[i]; d = imag[j]; s=c+d; t=c-d;
+ imag[i] = (s+r)*0.5; imag[j] = (s-r)*0.5;
+ real[i] = (q-t)*0.5; real[j] = (q+t)*0.5;
+ }
+}
+
+void mayer_realfft(int n, REAL *real)
+{
+ REAL a,b,c,d;
+ int i,j,k;
+ mayer_fht(real,n);
+ for (i=1,j=n-1,k=n/2;i<k;i++,j--) {
+ a = real[i];
+ b = real[j];
+ real[j] = (a-b)*0.5;
+ real[i] = (a+b)*0.5;
+ }
+}
+
+void mayer_realifft(int n, REAL *real)
+{
+ REAL a,b,c,d;
+ int i,j,k;
+ for (i=1,j=n-1,k=n/2;i<k;i++,j--) {
+ a = real[i];
+ b = real[j];
+ real[j] = (a-b);
+ real[i] = (a+b);
+ }
+ mayer_fht(real,n);
+}