comparison src/libvorbis-1.3.3/lib/smallft.c @ 1:05aa0afa9217

Bring in flac, ogg, vorbis

+/********************************************************************
+ *                                                                  *
+ * 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));
+  }
+}