ref: 8188b4f4f0e07b6669e6ae3c6c1099af917eaab4
dir: /sys/src/cmd/audio/libvorbis/smallft.c/
/********************************************************************
* *
* THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
* *
* THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009 *
* by the Xiph.Org Foundation https://xiph.org/ *
* *
********************************************************************
function: *unnormalized* fft transform
********************************************************************/
/* FFT implementation from OggSquish, minus cosine transforms,
* minus all but radix 2/4 case. In Vorbis we only need this
* cut-down version.
*
* To do more than just power-of-two sized vectors, see the full
* version I wrote for NetLib.
*
* Note that the packing is a little strange; rather than the FFT r/i
* packing following R_0, I_n, R_1, I_1, R_2, I_2 ... R_n-1, I_n-1,
* it follows R_0, R_1, I_1, R_2, I_2 ... R_n-1, I_n-1, I_n like the
* FORTRAN version
*/
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "smallft.h"
#include "os.h"
#include "misc.h"
static void drfti1(int n, float *wa, int *ifac){
static int ntryh[4] = { 4,2,3,5 };
static float tpi = 6.28318530717958648f;
float arg,argh,argld,fi;
int ntry=0,i,j=-1;
int k1, l1, l2, ib;
int ld, ii, ip, is, nq, nr;
int ido, ipm, nfm1;
int nl=n;
int nf=0;
L101:
j++;
if (j < 4)
ntry=ntryh[j];
else
ntry+=2;
L104:
nq=nl/ntry;
nr=nl-ntry*nq;
if (nr!=0) goto L101;
nf++;
ifac[nf+1]=ntry;
nl=nq;
if(ntry!=2)goto L107;
if(nf==1)goto L107;
for (i=1;i<nf;i++){
ib=nf-i+1;
ifac[ib+1]=ifac[ib];
}
ifac[2] = 2;
L107:
if(nl!=1)goto L104;
ifac[0]=n;
ifac[1]=nf;
argh=tpi/n;
is=0;
nfm1=nf-1;
l1=1;
if(nfm1==0)return;
for (k1=0;k1<nfm1;k1++){
ip=ifac[k1+2];
ld=0;
l2=l1*ip;
ido=n/l2;
ipm=ip-1;
for (j=0;j<ipm;j++){
ld+=l1;
i=is;
argld=(float)ld*argh;
fi=0.f;
for (ii=2;ii<ido;ii+=2){
fi+=1.f;
arg=fi*argld;
wa[i++]=cos(arg);
wa[i++]=sin(arg);
}
is+=ido;
}
l1=l2;
}
}
static void fdrffti(int n, float *wsave, int *ifac){
if (n == 1) return;
drfti1(n, wsave+n, ifac);
}
static void dradf2(int ido,int l1,float *cc,float *ch,float *wa1){
int i,k;
float ti2,tr2;
int t0,t1,t2,t3,t4,t5,t6;
t1=0;
t0=(t2=l1*ido);
t3=ido<<1;
for(k=0;k<l1;k++){
ch[t1<<1]=cc[t1]+cc[t2];
ch[(t1<<1)+t3-1]=cc[t1]-cc[t2];
t1+=ido;
t2+=ido;
}
if(ido<2)return;
if(ido==2)goto L105;
t1=0;
t2=t0;
for(k=0;k<l1;k++){
t3=t2;
t4=(t1<<1)+(ido<<1);
t5=t1;
t6=t1+t1;
for(i=2;i<ido;i+=2){
t3+=2;
t4-=2;
t5+=2;
t6+=2;
tr2=wa1[i-2]*cc[t3-1]+wa1[i-1]*cc[t3];
ti2=wa1[i-2]*cc[t3]-wa1[i-1]*cc[t3-1];
ch[t6]=cc[t5]+ti2;
ch[t4]=ti2-cc[t5];
ch[t6-1]=cc[t5-1]+tr2;
ch[t4-1]=cc[t5-1]-tr2;
}
t1+=ido;
t2+=ido;
}
if(ido%2==1)return;
L105:
t3=(t2=(t1=ido)-1);
t2+=t0;
for(k=0;k<l1;k++){
ch[t1]=-cc[t2];
ch[t1-1]=cc[t3];
t1+=ido<<1;
t2+=ido;
t3+=ido;
}
}
static void dradf4(int ido,int l1,float *cc,float *ch,float *wa1,
float *wa2,float *wa3){
static float hsqt2 = .70710678118654752f;
int i,k,t0,t1,t2,t3,t4,t5,t6;
float ci2,ci3,ci4,cr2,cr3,cr4,ti1,ti2,ti3,ti4,tr1,tr2,tr3,tr4;
t0=l1*ido;
t1=t0;
t4=t1<<1;
t2=t1+(t1<<1);
t3=0;
for(k=0;k<l1;k++){
tr1=cc[t1]+cc[t2];
tr2=cc[t3]+cc[t4];
ch[t5=t3<<2]=tr1+tr2;
ch[(ido<<2)+t5-1]=tr2-tr1;
ch[(t5+=(ido<<1))-1]=cc[t3]-cc[t4];
ch[t5]=cc[t2]-cc[t1];
t1+=ido;
t2+=ido;
t3+=ido;
t4+=ido;
}
if(ido<2)return;
if(ido==2)goto L105;
t1=0;
for(k=0;k<l1;k++){
t2=t1;
t4=t1<<2;
t5=(t6=ido<<1)+t4;
for(i=2;i<ido;i+=2){
t3=(t2+=2);
t4+=2;
t5-=2;
t3+=t0;
cr2=wa1[i-2]*cc[t3-1]+wa1[i-1]*cc[t3];
ci2=wa1[i-2]*cc[t3]-wa1[i-1]*cc[t3-1];
t3+=t0;
cr3=wa2[i-2]*cc[t3-1]+wa2[i-1]*cc[t3];
ci3=wa2[i-2]*cc[t3]-wa2[i-1]*cc[t3-1];
t3+=t0;
cr4=wa3[i-2]*cc[t3-1]+wa3[i-1]*cc[t3];
ci4=wa3[i-2]*cc[t3]-wa3[i-1]*cc[t3-1];
tr1=cr2+cr4;
tr4=cr4-cr2;
ti1=ci2+ci4;
ti4=ci2-ci4;
ti2=cc[t2]+ci3;
ti3=cc[t2]-ci3;
tr2=cc[t2-1]+cr3;
tr3=cc[t2-1]-cr3;
ch[t4-1]=tr1+tr2;
ch[t4]=ti1+ti2;
ch[t5-1]=tr3-ti4;
ch[t5]=tr4-ti3;
ch[t4+t6-1]=ti4+tr3;
ch[t4+t6]=tr4+ti3;
ch[t5+t6-1]=tr2-tr1;
ch[t5+t6]=ti1-ti2;
}
t1+=ido;
}
if(ido&1)return;
L105:
t2=(t1=t0+ido-1)+(t0<<1);
t3=ido<<2;
t4=ido;
t5=ido<<1;
t6=ido;
for(k=0;k<l1;k++){
ti1=-hsqt2*(cc[t1]+cc[t2]);
tr1=hsqt2*(cc[t1]-cc[t2]);
ch[t4-1]=tr1+cc[t6-1];
ch[t4+t5-1]=cc[t6-1]-tr1;
ch[t4]=ti1-cc[t1+t0];
ch[t4+t5]=ti1+cc[t1+t0];
t1+=ido;
t2+=ido;
t4+=t3;
t6+=ido;
}
}
static void dradfg(int ido,int ip,int l1,int idl1,float *cc,float *c1,
float *c2,float *ch,float *ch2,float *wa){
static float tpi=6.283185307179586f;
int idij,ipph,i,j,k,l,ic,ik,is;
int t0,t1,t2,t3,t4,t5,t6,t7,t8,t9,t10;
float dc2,ai1,ai2,ar1,ar2,ds2;
int nbd;
float dcp,arg,dsp,ar1h,ar2h;
int idp2,ipp2;
arg=tpi/(float)ip;
dcp=cos(arg);
dsp=sin(arg);
ipph=(ip+1)>>1;
ipp2=ip;
idp2=ido;
nbd=(ido-1)>>1;
t0=l1*ido;
t10=ip*ido;
if(ido==1)goto L119;
for(ik=0;ik<idl1;ik++)ch2[ik]=c2[ik];
t1=0;
for(j=1;j<ip;j++){
t1+=t0;
t2=t1;
for(k=0;k<l1;k++){
ch[t2]=c1[t2];
t2+=ido;
}
}
is=-ido;
t1=0;
if(nbd>l1){
for(j=1;j<ip;j++){
t1+=t0;
is+=ido;
t2= -ido+t1;
for(k=0;k<l1;k++){
idij=is-1;
t2+=ido;
t3=t2;
for(i=2;i<ido;i+=2){
idij+=2;
t3+=2;
ch[t3-1]=wa[idij-1]*c1[t3-1]+wa[idij]*c1[t3];
ch[t3]=wa[idij-1]*c1[t3]-wa[idij]*c1[t3-1];
}
}
}
}else{
for(j=1;j<ip;j++){
is+=ido;
idij=is-1;
t1+=t0;
t2=t1;
for(i=2;i<ido;i+=2){
idij+=2;
t2+=2;
t3=t2;
for(k=0;k<l1;k++){
ch[t3-1]=wa[idij-1]*c1[t3-1]+wa[idij]*c1[t3];
ch[t3]=wa[idij-1]*c1[t3]-wa[idij]*c1[t3-1];
t3+=ido;
}
}
}
}
t1=0;
t2=ipp2*t0;
if(nbd<l1){
for(j=1;j<ipph;j++){
t1+=t0;
t2-=t0;
t3=t1;
t4=t2;
for(i=2;i<ido;i+=2){
t3+=2;
t4+=2;
t5=t3-ido;
t6=t4-ido;
for(k=0;k<l1;k++){
t5+=ido;
t6+=ido;
c1[t5-1]=ch[t5-1]+ch[t6-1];
c1[t6-1]=ch[t5]-ch[t6];
c1[t5]=ch[t5]+ch[t6];
c1[t6]=ch[t6-1]-ch[t5-1];
}
}
}
}else{
for(j=1;j<ipph;j++){
t1+=t0;
t2-=t0;
t3=t1;
t4=t2;
for(k=0;k<l1;k++){
t5=t3;
t6=t4;
for(i=2;i<ido;i+=2){
t5+=2;
t6+=2;
c1[t5-1]=ch[t5-1]+ch[t6-1];
c1[t6-1]=ch[t5]-ch[t6];
c1[t5]=ch[t5]+ch[t6];
c1[t6]=ch[t6-1]-ch[t5-1];
}
t3+=ido;
t4+=ido;
}
}
}
L119:
for(ik=0;ik<idl1;ik++)c2[ik]=ch2[ik];
t1=0;
t2=ipp2*idl1;
for(j=1;j<ipph;j++){
t1+=t0;
t2-=t0;
t3=t1-ido;
t4=t2-ido;
for(k=0;k<l1;k++){
t3+=ido;
t4+=ido;
c1[t3]=ch[t3]+ch[t4];
c1[t4]=ch[t4]-ch[t3];
}
}
ar1=1.f;
ai1=0.f;
t1=0;
t2=ipp2*idl1;
t3=(ip-1)*idl1;
for(l=1;l<ipph;l++){
t1+=idl1;
t2-=idl1;
ar1h=dcp*ar1-dsp*ai1;
ai1=dcp*ai1+dsp*ar1;
ar1=ar1h;
t4=t1;
t5=t2;
t6=t3;
t7=idl1;
for(ik=0;ik<idl1;ik++){
ch2[t4++]=c2[ik]+ar1*c2[t7++];
ch2[t5++]=ai1*c2[t6++];
}
dc2=ar1;
ds2=ai1;
ar2=ar1;
ai2=ai1;
t4=idl1;
t5=(ipp2-1)*idl1;
for(j=2;j<ipph;j++){
t4+=idl1;
t5-=idl1;
ar2h=dc2*ar2-ds2*ai2;
ai2=dc2*ai2+ds2*ar2;
ar2=ar2h;
t6=t1;
t7=t2;
t8=t4;
t9=t5;
for(ik=0;ik<idl1;ik++){
ch2[t6++]+=ar2*c2[t8++];
ch2[t7++]+=ai2*c2[t9++];
}
}
}
t1=0;
for(j=1;j<ipph;j++){
t1+=idl1;
t2=t1;
for(ik=0;ik<idl1;ik++)ch2[ik]+=c2[t2++];
}
if(ido<l1)goto L132;
t1=0;
t2=0;
for(k=0;k<l1;k++){
t3=t1;
t4=t2;
for(i=0;i<ido;i++)cc[t4++]=ch[t3++];
t1+=ido;
t2+=t10;
}
goto L135;
L132:
for(i=0;i<ido;i++){
t1=i;
t2=i;
for(k=0;k<l1;k++){
cc[t2]=ch[t1];
t1+=ido;
t2+=t10;
}
}
L135:
t1=0;
t2=ido<<1;
t3=0;
t4=ipp2*t0;
for(j=1;j<ipph;j++){
t1+=t2;
t3+=t0;
t4-=t0;
t5=t1;
t6=t3;
t7=t4;
for(k=0;k<l1;k++){
cc[t5-1]=ch[t6];
cc[t5]=ch[t7];
t5+=t10;
t6+=ido;
t7+=ido;
}
}
if(ido==1)return;
if(nbd<l1)goto L141;
t1=-ido;
t3=0;
t4=0;
t5=ipp2*t0;
for(j=1;j<ipph;j++){
t1+=t2;
t3+=t2;
t4+=t0;
t5-=t0;
t6=t1;
t7=t3;
t8=t4;
t9=t5;
for(k=0;k<l1;k++){
for(i=2;i<ido;i+=2){
ic=idp2-i;
cc[i+t7-1]=ch[i+t8-1]+ch[i+t9-1];
cc[ic+t6-1]=ch[i+t8-1]-ch[i+t9-1];
cc[i+t7]=ch[i+t8]+ch[i+t9];
cc[ic+t6]=ch[i+t9]-ch[i+t8];
}
t6+=t10;
t7+=t10;
t8+=ido;
t9+=ido;
}
}
return;
L141:
t1=-ido;
t3=0;
t4=0;
t5=ipp2*t0;
for(j=1;j<ipph;j++){
t1+=t2;
t3+=t2;
t4+=t0;
t5-=t0;
for(i=2;i<ido;i+=2){
t6=idp2+t1-i;
t7=i+t3;
t8=i+t4;
t9=i+t5;
for(k=0;k<l1;k++){
cc[t7-1]=ch[t8-1]+ch[t9-1];
cc[t6-1]=ch[t8-1]-ch[t9-1];
cc[t7]=ch[t8]+ch[t9];
cc[t6]=ch[t9]-ch[t8];
t6+=t10;
t7+=t10;
t8+=ido;
t9+=ido;
}
}
}
}
static void drftf1(int n,float *c,float *ch,float *wa,int *ifac){
int i,k1,l1,l2;
int na,kh,nf;
int ip,iw,ido,idl1,ix2,ix3;
nf=ifac[1];
na=1;
l2=n;
iw=n;
for(k1=0;k1<nf;k1++){
kh=nf-k1;
ip=ifac[kh+1];
l1=l2/ip;
ido=n/l2;
idl1=ido*l1;
iw-=(ip-1)*ido;
na=1-na;
if(ip!=4)goto L102;
ix2=iw+ido;
ix3=ix2+ido;
if(na!=0)
dradf4(ido,l1,ch,c,wa+iw-1,wa+ix2-1,wa+ix3-1);
else
dradf4(ido,l1,c,ch,wa+iw-1,wa+ix2-1,wa+ix3-1);
goto L110;
L102:
if(ip!=2)goto L104;
if(na!=0)goto L103;
dradf2(ido,l1,c,ch,wa+iw-1);
goto L110;
L103:
dradf2(ido,l1,ch,c,wa+iw-1);
goto L110;
L104:
if(ido==1)na=1-na;
if(na!=0)goto L109;
dradfg(ido,ip,l1,idl1,c,c,c,ch,ch,wa+iw-1);
na=1;
goto L110;
L109:
dradfg(ido,ip,l1,idl1,ch,ch,ch,c,c,wa+iw-1);
na=0;
L110:
l2=l1;
}
if(na==1)return;
for(i=0;i<n;i++)c[i]=ch[i];
}
static void dradb2(int ido,int l1,float *cc,float *ch,float *wa1){
int i,k,t0,t1,t2,t3,t4,t5,t6;
float ti2,tr2;
t0=l1*ido;
t1=0;
t2=0;
t3=(ido<<1)-1;
for(k=0;k<l1;k++){
ch[t1]=cc[t2]+cc[t3+t2];
ch[t1+t0]=cc[t2]-cc[t3+t2];
t2=(t1+=ido)<<1;
}
if(ido<2)return;
if(ido==2)goto L105;
t1=0;
t2=0;
for(k=0;k<l1;k++){
t3=t1;
t5=(t4=t2)+(ido<<1);
t6=t0+t1;
for(i=2;i<ido;i+=2){
t3+=2;
t4+=2;
t5-=2;
t6+=2;
ch[t3-1]=cc[t4-1]+cc[t5-1];
tr2=cc[t4-1]-cc[t5-1];
ch[t3]=cc[t4]-cc[t5];
ti2=cc[t4]+cc[t5];
ch[t6-1]=wa1[i-2]*tr2-wa1[i-1]*ti2;
ch[t6]=wa1[i-2]*ti2+wa1[i-1]*tr2;
}
t2=(t1+=ido)<<1;
}
if(ido%2==1)return;
L105:
t1=ido-1;
t2=ido-1;
for(k=0;k<l1;k++){
ch[t1]=cc[t2]+cc[t2];
ch[t1+t0]=-(cc[t2+1]+cc[t2+1]);
t1+=ido;
t2+=ido<<1;
}
}
static void dradb3(int ido,int l1,float *cc,float *ch,float *wa1,
float *wa2){
static float taur = -.5f;
static float taui = .8660254037844386f;
int i,k,t0,t1,t2,t3,t4,t5,t6,t7,t8,t9,t10;
float ci2,ci3,di2,di3,cr2,cr3,dr2,dr3,ti2,tr2;
t0=l1*ido;
t1=0;
t2=t0<<1;
t3=ido<<1;
t4=ido+(ido<<1);
t5=0;
for(k=0;k<l1;k++){
tr2=cc[t3-1]+cc[t3-1];
cr2=cc[t5]+(taur*tr2);
ch[t1]=cc[t5]+tr2;
ci3=taui*(cc[t3]+cc[t3]);
ch[t1+t0]=cr2-ci3;
ch[t1+t2]=cr2+ci3;
t1+=ido;
t3+=t4;
t5+=t4;
}
if(ido==1)return;
t1=0;
t3=ido<<1;
for(k=0;k<l1;k++){
t7=t1+(t1<<1);
t6=(t5=t7+t3);
t8=t1;
t10=(t9=t1+t0)+t0;
for(i=2;i<ido;i+=2){
t5+=2;
t6-=2;
t7+=2;
t8+=2;
t9+=2;
t10+=2;
tr2=cc[t5-1]+cc[t6-1];
cr2=cc[t7-1]+(taur*tr2);
ch[t8-1]=cc[t7-1]+tr2;
ti2=cc[t5]-cc[t6];
ci2=cc[t7]+(taur*ti2);
ch[t8]=cc[t7]+ti2;
cr3=taui*(cc[t5-1]-cc[t6-1]);
ci3=taui*(cc[t5]+cc[t6]);
dr2=cr2-ci3;
dr3=cr2+ci3;
di2=ci2+cr3;
di3=ci2-cr3;
ch[t9-1]=wa1[i-2]*dr2-wa1[i-1]*di2;
ch[t9]=wa1[i-2]*di2+wa1[i-1]*dr2;
ch[t10-1]=wa2[i-2]*dr3-wa2[i-1]*di3;
ch[t10]=wa2[i-2]*di3+wa2[i-1]*dr3;
}
t1+=ido;
}
}
static void dradb4(int ido,int l1,float *cc,float *ch,float *wa1,
float *wa2,float *wa3){
static float sqrt2=1.414213562373095f;
int i,k,t0,t1,t2,t3,t4,t5,t6,t7,t8;
float ci2,ci3,ci4,cr2,cr3,cr4,ti1,ti2,ti3,ti4,tr1,tr2,tr3,tr4;
t0=l1*ido;
t1=0;
t2=ido<<2;
t3=0;
t6=ido<<1;
for(k=0;k<l1;k++){
t4=t3+t6;
t5=t1;
tr3=cc[t4-1]+cc[t4-1];
tr4=cc[t4]+cc[t4];
tr1=cc[t3]-cc[(t4+=t6)-1];
tr2=cc[t3]+cc[t4-1];
ch[t5]=tr2+tr3;
ch[t5+=t0]=tr1-tr4;
ch[t5+=t0]=tr2-tr3;
ch[t5+=t0]=tr1+tr4;
t1+=ido;
t3+=t2;
}
if(ido<2)return;
if(ido==2)goto L105;
t1=0;
for(k=0;k<l1;k++){
t5=(t4=(t3=(t2=t1<<2)+t6))+t6;
t7=t1;
for(i=2;i<ido;i+=2){
t2+=2;
t3+=2;
t4-=2;
t5-=2;
t7+=2;
ti1=cc[t2]+cc[t5];
ti2=cc[t2]-cc[t5];
ti3=cc[t3]-cc[t4];
tr4=cc[t3]+cc[t4];
tr1=cc[t2-1]-cc[t5-1];
tr2=cc[t2-1]+cc[t5-1];
ti4=cc[t3-1]-cc[t4-1];
tr3=cc[t3-1]+cc[t4-1];
ch[t7-1]=tr2+tr3;
cr3=tr2-tr3;
ch[t7]=ti2+ti3;
ci3=ti2-ti3;
cr2=tr1-tr4;
cr4=tr1+tr4;
ci2=ti1+ti4;
ci4=ti1-ti4;
ch[(t8=t7+t0)-1]=wa1[i-2]*cr2-wa1[i-1]*ci2;
ch[t8]=wa1[i-2]*ci2+wa1[i-1]*cr2;
ch[(t8+=t0)-1]=wa2[i-2]*cr3-wa2[i-1]*ci3;
ch[t8]=wa2[i-2]*ci3+wa2[i-1]*cr3;
ch[(t8+=t0)-1]=wa3[i-2]*cr4-wa3[i-1]*ci4;
ch[t8]=wa3[i-2]*ci4+wa3[i-1]*cr4;
}
t1+=ido;
}
if(ido%2 == 1)return;
L105:
t1=ido;
t2=ido<<2;
t3=ido-1;
t4=ido+(ido<<1);
for(k=0;k<l1;k++){
t5=t3;
ti1=cc[t1]+cc[t4];
ti2=cc[t4]-cc[t1];
tr1=cc[t1-1]-cc[t4-1];
tr2=cc[t1-1]+cc[t4-1];
ch[t5]=tr2+tr2;
ch[t5+=t0]=sqrt2*(tr1-ti1);
ch[t5+=t0]=ti2+ti2;
ch[t5+=t0]=-sqrt2*(tr1+ti1);
t3+=ido;
t1+=t2;
t4+=t2;
}
}
static void dradbg(int ido,int ip,int l1,int idl1,float *cc,float *c1,
float *c2,float *ch,float *ch2,float *wa){
static float tpi=6.283185307179586f;
int idij,ipph,i,j,k,l,ik,is,t0,t1,t2,t3,t4,t5,t6,t7,t8,t9,t10,
t11,t12;
float dc2,ai1,ai2,ar1,ar2,ds2;
int nbd;
float dcp,arg,dsp,ar1h,ar2h;
int ipp2;
t10=ip*ido;
t0=l1*ido;
arg=tpi/(float)ip;
dcp=cos(arg);
dsp=sin(arg);
nbd=(ido-1)>>1;
ipp2=ip;
ipph=(ip+1)>>1;
if(ido<l1)goto L103;
t1=0;
t2=0;
for(k=0;k<l1;k++){
t3=t1;
t4=t2;
for(i=0;i<ido;i++){
ch[t3]=cc[t4];
t3++;
t4++;
}
t1+=ido;
t2+=t10;
}
goto L106;
L103:
t1=0;
for(i=0;i<ido;i++){
t2=t1;
t3=t1;
for(k=0;k<l1;k++){
ch[t2]=cc[t3];
t2+=ido;
t3+=t10;
}
t1++;
}
L106:
t1=0;
t2=ipp2*t0;
t7=(t5=ido<<1);
for(j=1;j<ipph;j++){
t1+=t0;
t2-=t0;
t3=t1;
t4=t2;
t6=t5;
for(k=0;k<l1;k++){
ch[t3]=cc[t6-1]+cc[t6-1];
ch[t4]=cc[t6]+cc[t6];
t3+=ido;
t4+=ido;
t6+=t10;
}
t5+=t7;
}
if (ido == 1)goto L116;
if(nbd<l1)goto L112;
t1=0;
t2=ipp2*t0;
t7=0;
for(j=1;j<ipph;j++){
t1+=t0;
t2-=t0;
t3=t1;
t4=t2;
t7+=(ido<<1);
t8=t7;
for(k=0;k<l1;k++){
t5=t3;
t6=t4;
t9=t8;
t11=t8;
for(i=2;i<ido;i+=2){
t5+=2;
t6+=2;
t9+=2;
t11-=2;
ch[t5-1]=cc[t9-1]+cc[t11-1];
ch[t6-1]=cc[t9-1]-cc[t11-1];
ch[t5]=cc[t9]-cc[t11];
ch[t6]=cc[t9]+cc[t11];
}
t3+=ido;
t4+=ido;
t8+=t10;
}
}
goto L116;
L112:
t1=0;
t2=ipp2*t0;
t7=0;
for(j=1;j<ipph;j++){
t1+=t0;
t2-=t0;
t3=t1;
t4=t2;
t7+=(ido<<1);
t8=t7;
t9=t7;
for(i=2;i<ido;i+=2){
t3+=2;
t4+=2;
t8+=2;
t9-=2;
t5=t3;
t6=t4;
t11=t8;
t12=t9;
for(k=0;k<l1;k++){
ch[t5-1]=cc[t11-1]+cc[t12-1];
ch[t6-1]=cc[t11-1]-cc[t12-1];
ch[t5]=cc[t11]-cc[t12];
ch[t6]=cc[t11]+cc[t12];
t5+=ido;
t6+=ido;
t11+=t10;
t12+=t10;
}
}
}
L116:
ar1=1.f;
ai1=0.f;
t1=0;
t9=(t2=ipp2*idl1);
t3=(ip-1)*idl1;
for(l=1;l<ipph;l++){
t1+=idl1;
t2-=idl1;
ar1h=dcp*ar1-dsp*ai1;
ai1=dcp*ai1+dsp*ar1;
ar1=ar1h;
t4=t1;
t5=t2;
t6=0;
t7=idl1;
t8=t3;
for(ik=0;ik<idl1;ik++){
c2[t4++]=ch2[t6++]+ar1*ch2[t7++];
c2[t5++]=ai1*ch2[t8++];
}
dc2=ar1;
ds2=ai1;
ar2=ar1;
ai2=ai1;
t6=idl1;
t7=t9-idl1;
for(j=2;j<ipph;j++){
t6+=idl1;
t7-=idl1;
ar2h=dc2*ar2-ds2*ai2;
ai2=dc2*ai2+ds2*ar2;
ar2=ar2h;
t4=t1;
t5=t2;
t11=t6;
t12=t7;
for(ik=0;ik<idl1;ik++){
c2[t4++]+=ar2*ch2[t11++];
c2[t5++]+=ai2*ch2[t12++];
}
}
}
t1=0;
for(j=1;j<ipph;j++){
t1+=idl1;
t2=t1;
for(ik=0;ik<idl1;ik++)ch2[ik]+=ch2[t2++];
}
t1=0;
t2=ipp2*t0;
for(j=1;j<ipph;j++){
t1+=t0;
t2-=t0;
t3=t1;
t4=t2;
for(k=0;k<l1;k++){
ch[t3]=c1[t3]-c1[t4];
ch[t4]=c1[t3]+c1[t4];
t3+=ido;
t4+=ido;
}
}
if(ido==1)goto L132;
if(nbd<l1)goto L128;
t1=0;
t2=ipp2*t0;
for(j=1;j<ipph;j++){
t1+=t0;
t2-=t0;
t3=t1;
t4=t2;
for(k=0;k<l1;k++){
t5=t3;
t6=t4;
for(i=2;i<ido;i+=2){
t5+=2;
t6+=2;
ch[t5-1]=c1[t5-1]-c1[t6];
ch[t6-1]=c1[t5-1]+c1[t6];
ch[t5]=c1[t5]+c1[t6-1];
ch[t6]=c1[t5]-c1[t6-1];
}
t3+=ido;
t4+=ido;
}
}
goto L132;
L128:
t1=0;
t2=ipp2*t0;
for(j=1;j<ipph;j++){
t1+=t0;
t2-=t0;
t3=t1;
t4=t2;
for(i=2;i<ido;i+=2){
t3+=2;
t4+=2;
t5=t3;
t6=t4;
for(k=0;k<l1;k++){
ch[t5-1]=c1[t5-1]-c1[t6];
ch[t6-1]=c1[t5-1]+c1[t6];
ch[t5]=c1[t5]+c1[t6-1];
ch[t6]=c1[t5]-c1[t6-1];
t5+=ido;
t6+=ido;
}
}
}
L132:
if(ido==1)return;
for(ik=0;ik<idl1;ik++)c2[ik]=ch2[ik];
t1=0;
for(j=1;j<ip;j++){
t2=(t1+=t0);
for(k=0;k<l1;k++){
c1[t2]=ch[t2];
t2+=ido;
}
}
if(nbd>l1)goto L139;
is= -ido-1;
t1=0;
for(j=1;j<ip;j++){
is+=ido;
t1+=t0;
idij=is;
t2=t1;
for(i=2;i<ido;i+=2){
t2+=2;
idij+=2;
t3=t2;
for(k=0;k<l1;k++){
c1[t3-1]=wa[idij-1]*ch[t3-1]-wa[idij]*ch[t3];
c1[t3]=wa[idij-1]*ch[t3]+wa[idij]*ch[t3-1];
t3+=ido;
}
}
}
return;
L139:
is= -ido-1;
t1=0;
for(j=1;j<ip;j++){
is+=ido;
t1+=t0;
t2=t1;
for(k=0;k<l1;k++){
idij=is;
t3=t2;
for(i=2;i<ido;i+=2){
idij+=2;
t3+=2;
c1[t3-1]=wa[idij-1]*ch[t3-1]-wa[idij]*ch[t3];
c1[t3]=wa[idij-1]*ch[t3]+wa[idij]*ch[t3-1];
}
t2+=ido;
}
}
}
static void drftb1(int n, float *c, float *ch, float *wa, int *ifac){
int i,k1,l1,l2;
int na;
int nf,ip,iw,ix2,ix3,ido,idl1;
nf=ifac[1];
na=0;
l1=1;
iw=1;
for(k1=0;k1<nf;k1++){
ip=ifac[k1 + 2];
l2=ip*l1;
ido=n/l2;
idl1=ido*l1;
if(ip!=4)goto L103;
ix2=iw+ido;
ix3=ix2+ido;
if(na!=0)
dradb4(ido,l1,ch,c,wa+iw-1,wa+ix2-1,wa+ix3-1);
else
dradb4(ido,l1,c,ch,wa+iw-1,wa+ix2-1,wa+ix3-1);
na=1-na;
goto L115;
L103:
if(ip!=2)goto L106;
if(na!=0)
dradb2(ido,l1,ch,c,wa+iw-1);
else
dradb2(ido,l1,c,ch,wa+iw-1);
na=1-na;
goto L115;
L106:
if(ip!=3)goto L109;
ix2=iw+ido;
if(na!=0)
dradb3(ido,l1,ch,c,wa+iw-1,wa+ix2-1);
else
dradb3(ido,l1,c,ch,wa+iw-1,wa+ix2-1);
na=1-na;
goto L115;
L109:
/* The radix five case can be translated later..... */
/* if(ip!=5)goto L112;
ix2=iw+ido;
ix3=ix2+ido;
ix4=ix3+ido;
if(na!=0)
dradb5(ido,l1,ch,c,wa+iw-1,wa+ix2-1,wa+ix3-1,wa+ix4-1);
else
dradb5(ido,l1,c,ch,wa+iw-1,wa+ix2-1,wa+ix3-1,wa+ix4-1);
na=1-na;
goto L115;
L112:*/
if(na!=0)
dradbg(ido,ip,l1,idl1,ch,ch,ch,c,c,wa+iw-1);
else
dradbg(ido,ip,l1,idl1,c,c,c,ch,ch,wa+iw-1);
if(ido==1)na=1-na;
L115:
l1=l2;
iw+=(ip-1)*ido;
}
if(na==0)return;
for(i=0;i<n;i++)c[i]=ch[i];
}
void drft_forward(drft_lookup *l,float *data){
if(l->n==1)return;
drftf1(l->n,data,l->trigcache,l->trigcache+l->n,l->splitcache);
}
void drft_backward(drft_lookup *l,float *data){
if (l->n==1)return;
drftb1(l->n,data,l->trigcache,l->trigcache+l->n,l->splitcache);
}
void drft_init(drft_lookup *l,int n){
l->n=n;
l->trigcache=_ogg_calloc(3*n,sizeof(*l->trigcache));
l->splitcache=_ogg_calloc(32,sizeof(*l->splitcache));
fdrffti(n, l->trigcache, l->splitcache);
}
void drft_clear(drft_lookup *l){
if(l){
if(l->trigcache)_ogg_free(l->trigcache);
if(l->splitcache)_ogg_free(l->splitcache);
memset(l,0,sizeof(*l));
}
}