The Tor Browser: media/libvorbis/lib/vorbis_smallft.c@b8a032363ba2 (annotated)

media/libvorbis/lib/vorbis_smallft.c@b8a032363ba2 (annotated)

media/libvorbis/lib/vorbis_smallft.c

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /********************************************************************
  *                                                                  *
  * 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 http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
  function: *unnormalized* fft transform
  last mod: $Id: smallft.c 16227 2009-07-08 06:58:46Z xiphmont $
  ********************************************************************/
 /* 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));
   }
 }

The Tor Browser / annotate

media/libvorbis/lib/vorbis_smallft.c@b8a032363ba2 (annotated)

media/libvorbis/lib/vorbis_smallft.c