/* Notes from RFB: 

Looks like the user-level routines are:

Real FFT

void __ogg_fdrffti(int n, double *wsave, int *ifac)
void __ogg_fdrfftf(int n, double *r, double *wsave, int *ifac)
void __ogg_fdrfftb(int n, double *r, double *wsave, int *ifac)

__ogg_fdrffti == initialization
__ogg_fdrfftf == forward transform
__ogg_fdrfftb == backward transform

Parameters are
n == length of sequence
r == sequence to be transformed (input)
== transformed sequence (output)
wsave == work array of length 2n (allocated by caller)
ifac == work array of length 15 (allocated by caller)

Cosine quarter-wave FFT

void __ogg_fdcosqi(int n, double *wsave, int *ifac)
void __ogg_fdcosqf(int n, double *x, double *wsave, int *ifac)
void __ogg_fdcosqb(int n, double *x, double *wsave, int *ifac)
*/

/********************************************************************
*                                                                  *
* THIS FILE IS PART OF THE OggSQUISH SOFTWARE CODEC SOURCE CODE.   *
*                                                                  *
********************************************************************

file: fft.c
function: Fast discrete Fourier and cosine transforms and inverses
author: Monty <xiphmont@mit.edu>
modifications by: Monty
last modification date: Jul 1 1996

********************************************************************/

/* These Fourier routines were originally based on the Fourier
routines of the same names from the NETLIB bihar and fftpack
fortran libraries developed by Paul N. Swarztrauber at the National
Center for Atmospheric Research in Boulder, CO USA.  They have been
reimplemented in C and optimized in a few ways for OggSquish. */

/* As the original fortran libraries are public domain, the C Fourier
routines in this file are hereby released to the public domain as
well.  The C routines here produce output exactly equivalent to the
original fortran routines.  Of particular interest are the facts
that (like the original fortran), these routines can work on
arbitrary length vectors that need not be powers of two in
length. */

#include <math.h>
#include "../../include/dfft.h"
#define STIN static

static void drfti1(int n, double *wa, int *ifac)
{
	static int		ntryh[4] = { 4,2,3,5 };
	static double	tpi = 6.28318530717958647692528676655900577;
	double			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 = (double)ld*argh;
			fi = 0.0;
			for ( ii=2; ii<ido; ii+=2 ) {
				fi += 1.0;
				arg = fi*argld;
				wa[i++] = cos(arg);
				wa[i++] = sin(arg);
			}
			is += ido;
		}
		l1 = l2;
	}
}

void __ogg_fdrffti(int n, double *wsave, int *ifac)
{	
	if ( n == 1 )
		return;
	drfti1(n, wsave+n, ifac);
}

#ifdef LBBBBBBBBBBBBB

void __ogg_fdcosqi(int n, double *wsave, int *ifac)
{
	static double	pih = 1.57079632679489661923132169163975;
	static int		k;
	static double	fk, dt;
	
	dt = pih/n;
	fk = 0.0;
	for ( k=0; k<n; k++ ) {
		fk += 1.0;
		wsave[k] = cos(fk*dt);
	}
	
	__ogg_fdrffti(n, wsave+n,ifac);
}

#endif

STIN void dradf2(int ido, int l1, double *cc, double *ch, double *wa1)
{
	int		i , k;
	double	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;
	}
}

STIN void dradf4(int ido, int l1, double *cc, double *ch, double *wa1,
				 double *wa2, double *wa3)
{
	static double	hsqt2 = .70710678118654752440084436210485;
	int				i, k, t0, t1, t2, t3, t4, t5, t6;
	double			ci2, ci3, ci4, cr2, cr3, cr4;
	double			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%2 == 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;
	}
}

STIN void dradfg(int ido, int ip, int l1, int idl1, double *cc, double *c1,
				 double *c2, double *ch, double *ch2, double *wa)
{
	static double	tpi = 6.28318530717958647692528676655900577;
	int				idij, ipph, i, j, k, l, ic, ik, is;
	int				t0, t1, t2, t3, t4, t5, t6, t7, t8, t9, t10;
	double			dc2, ai1, ai2, ar1, ar2, ds2;
	int				nbd;
	double			dcp, arg, dsp, ar1h, ar2h;
	int				idp2, ipp2;
	
	arg = tpi/(double)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 = 1.0;
	ai1 = 0.0;
	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;
			}
		}
	}
}

STIN void drftf1(int n, double *c, double *ch, double *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];
}

void __ogg_fdrfftf(int n, double *r, double *wsave, int *ifac)
{
	if ( n==1 )
		return;
	drftf1(n, r, wsave, wsave+n, ifac);
}

#ifdef LBBBBBBBBBBBBBBBB

STIN void dcsqf1(int n, double *x, double *w, double *xh, int *ifac)
{
	int		modn, i, k, kc;
	int		np2, ns2;
	double	xim1;
	
	ns2 = (n+1)>>1;
	np2 = n;
	
	kc = np2;
	for ( k=1; k<ns2; k++ ) {
		kc--;
		xh[k] = x[k]+x[kc];
		xh[kc] = x[k]-x[kc];
	}
	
	modn = n%2;
	if ( modn == 0 )
		xh[ns2] = x[ns2]+x[ns2];
	
	for ( k=1; k<ns2; k++ ) {
		kc = np2-k;
		x[k] = w[k-1]*xh[kc]+w[kc-1]*xh[k];
		x[kc] = w[k-1]*xh[k]-w[kc-1]*xh[kc];
	}
	
	if ( modn == 0 )
		x[ns2] = w[ns2-1]*xh[ns2];
	
	__ogg_fdrfftf(n, x, xh, ifac);
	
	for ( i=2; i<n; i+=2 ) {
		xim1 = x[i-1]-x[i];
		x[i] = x[i-1]+x[i];
		x[i-1] = xim1;
	}
}

void __ogg_fdcosqf(int n, double *x, double *wsave, int *ifac)
{
    static double	sqrt2=1.4142135623730950488016887242097;
    double			tsqx;
	
	switch(n) {
		case 0:
		case 1:
			return;
		case 2:
			tsqx = sqrt2*x[1];
			x[1] = x[0]-tsqx;
			x[0] += tsqx;
			return;
		default:
			dcsqf1(n, x, wsave, wsave+n, ifac);
			return;
	}
}

STIN void dradb2(int ido, int l1, double *cc, double *ch, double *wa1)
{
	int		i, k, t0, t1, t2, t3, t4, t5, t6;
	double	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;
	}
}

STIN void dradb3(int ido, int l1, double *cc, double *ch, double *wa1, double *wa2)
{
	static double	taur = -.5;
	static double	taui = .86602540378443864676372317075293618;
	int				i, k, t0, t1, t2, t3, t4, t5, t6, t7, t8, t9, t10;
	double			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;
	}
}

STIN void dradb4(int ido, int l1, double *cc, double *ch, double *wa1,
				 double *wa2, double *wa3)
{
	static double	sqrt2=1.4142135623730950488016887242097;
	int				i, k, t0, t1, t2, t3, t4, t5, t6, t7, t8;
	double			ci2, ci3, ci4, cr2, cr3, cr4;
	double			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;
	}
}

STIN void dradbg(int ido, int ip, int l1, int idl1, double *cc, double *c1,
				 double *c2, double *ch, double *ch2, double *wa)
{
	static double	tpi=6.28318530717958647692528676655900577;
	int				idij, ipph, i, j, k, l, ik, is;
	int				t0, t1, t2, t3, t4, t5, t6, t7, t8, t9, t10, t11, t12;
	double			dc2, ai1, ai2, ar1,ar2, ds2;
	int				nbd;
	double			dcp, arg, dsp, ar1h, ar2h;
	int				ipp2;
	
	t10 = ip*ido;
	t0 = l1*ido;
	arg = tpi/(double)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 = 1.0;
	ai1 = 0.0;
	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;
		}
	}
}

STIN void drftb1(int n, double *c, double *ch, double *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 __ogg_fdrfftb(int n, double *r, double *wsave, int *ifac)
{
	if ( n == 1 )
		return;
	drftb1(n, r, wsave, wsave+n, ifac);
}

STIN void dcsqb1(int n, double *x, double *w, double *xh, int *ifac)
{
	int		modn, i, k, kc;
	int		np2, ns2;
	double	xim1;
	
	ns2 = (n+1)>>1;
	np2 = n;
	
	for ( i=2; i<n; i+=2 ) {
		xim1 = x[i-1]+x[i];
		x[i] -= x[i-1];
		x[i-1] = xim1;
	}
	
	x[0] += x[0];
	modn = n%2;
	if ( modn == 0 )
		x[n-1] += x[n-1];
	
	__ogg_fdrfftb(n, x, xh, ifac);
	
	kc = np2;
	for ( k=1; k<ns2; k++ ) {
		kc--;
		xh[k] = w[k-1]*x[kc]+w[kc-1]*x[k];
		xh[kc] = w[k-1]*x[k]-w[kc-1]*x[kc];
	}
	
	if ( modn == 0 )
		x[ns2] = w[ns2-1]*(x[ns2]+x[ns2]);
	
	kc = np2;
	for ( k=1; k<ns2; k++ ) {
		kc--;
		x[k] = xh[k]+xh[kc];
		x[kc] = xh[k]-xh[kc];
	}
	x[0] += x[0];
}

void __ogg_fdcosqb(int n, double *x, double *wsave, int *ifac)
{
	static double	tsqrt2 = 2.8284271247461900976033774484194;
	double			x1;
	
	if ( n < 2 ) {
		x[0] *= 4;
		return;
	}
	if ( n == 2 ) {
		x1 = (x[0]+x[1])*4;
		x[1] = tsqrt2*(x[0]-x[1]);
		x[0] = x1;
		return;
	}
	
	dcsqb1(n, x, wsave, wsave+n, ifac);
}
#endif