604 lines
17 KiB
C
604 lines
17 KiB
C
/*Copyright (c) 2003-2004, Mark Borgerding
|
|
Lots of modifications by Jean-Marc Valin
|
|
Copyright (c) 2005-2007, Xiph.Org Foundation
|
|
Copyright (c) 2008, Xiph.Org Foundation, CSIRO
|
|
|
|
All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are met:
|
|
|
|
* Redistributions of source code must retain the above copyright notice,
|
|
this list of conditions and the following disclaimer.
|
|
* Redistributions in binary form must reproduce the above copyright notice,
|
|
this list of conditions and the following disclaimer in the
|
|
documentation and/or other materials provided with the distribution.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
POSSIBILITY OF SUCH DAMAGE.*/
|
|
|
|
/* This code is originally from Mark Borgerding's KISS-FFT but has been
|
|
heavily modified to better suit Opus */
|
|
|
|
#ifndef SKIP_CONFIG_H
|
|
# ifdef HAVE_CONFIG_H
|
|
# include "config.h"
|
|
# endif
|
|
#endif
|
|
|
|
#include "_kiss_fft_guts.h"
|
|
#include "arch.h"
|
|
#include "os_support.h"
|
|
#include "mathops.h"
|
|
#include "stack_alloc.h"
|
|
|
|
/* The guts header contains all the multiplication and addition macros that are defined for
|
|
complex numbers. It also delares the kf_ internal functions.
|
|
*/
|
|
|
|
static void kf_bfly2(
|
|
kiss_fft_cpx * Fout,
|
|
int m,
|
|
int N
|
|
)
|
|
{
|
|
kiss_fft_cpx * Fout2;
|
|
int i;
|
|
(void)m;
|
|
#ifdef CUSTOM_MODES
|
|
if (m==1)
|
|
{
|
|
celt_assert(m==1);
|
|
for (i=0;i<N;i++)
|
|
{
|
|
kiss_fft_cpx t;
|
|
Fout2 = Fout + 1;
|
|
t = *Fout2;
|
|
C_SUB( *Fout2 , *Fout , t );
|
|
C_ADDTO( *Fout , t );
|
|
Fout += 2;
|
|
}
|
|
} else
|
|
#endif
|
|
{
|
|
opus_val16 tw;
|
|
tw = QCONST16(0.7071067812f, 15);
|
|
/* We know that m==4 here because the radix-2 is just after a radix-4 */
|
|
celt_assert(m==4);
|
|
for (i=0;i<N;i++)
|
|
{
|
|
kiss_fft_cpx t;
|
|
Fout2 = Fout + 4;
|
|
t = Fout2[0];
|
|
C_SUB( Fout2[0] , Fout[0] , t );
|
|
C_ADDTO( Fout[0] , t );
|
|
|
|
t.r = S_MUL(ADD32_ovflw(Fout2[1].r, Fout2[1].i), tw);
|
|
t.i = S_MUL(SUB32_ovflw(Fout2[1].i, Fout2[1].r), tw);
|
|
C_SUB( Fout2[1] , Fout[1] , t );
|
|
C_ADDTO( Fout[1] , t );
|
|
|
|
t.r = Fout2[2].i;
|
|
t.i = -Fout2[2].r;
|
|
C_SUB( Fout2[2] , Fout[2] , t );
|
|
C_ADDTO( Fout[2] , t );
|
|
|
|
t.r = S_MUL(SUB32_ovflw(Fout2[3].i, Fout2[3].r), tw);
|
|
t.i = S_MUL(NEG32_ovflw(ADD32_ovflw(Fout2[3].i, Fout2[3].r)), tw);
|
|
C_SUB( Fout2[3] , Fout[3] , t );
|
|
C_ADDTO( Fout[3] , t );
|
|
Fout += 8;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void kf_bfly4(
|
|
kiss_fft_cpx * Fout,
|
|
const size_t fstride,
|
|
const kiss_fft_state *st,
|
|
int m,
|
|
int N,
|
|
int mm
|
|
)
|
|
{
|
|
int i;
|
|
|
|
if (m==1)
|
|
{
|
|
/* Degenerate case where all the twiddles are 1. */
|
|
for (i=0;i<N;i++)
|
|
{
|
|
kiss_fft_cpx scratch0, scratch1;
|
|
|
|
C_SUB( scratch0 , *Fout, Fout[2] );
|
|
C_ADDTO(*Fout, Fout[2]);
|
|
C_ADD( scratch1 , Fout[1] , Fout[3] );
|
|
C_SUB( Fout[2], *Fout, scratch1 );
|
|
C_ADDTO( *Fout , scratch1 );
|
|
C_SUB( scratch1 , Fout[1] , Fout[3] );
|
|
|
|
Fout[1].r = ADD32_ovflw(scratch0.r, scratch1.i);
|
|
Fout[1].i = SUB32_ovflw(scratch0.i, scratch1.r);
|
|
Fout[3].r = SUB32_ovflw(scratch0.r, scratch1.i);
|
|
Fout[3].i = ADD32_ovflw(scratch0.i, scratch1.r);
|
|
Fout+=4;
|
|
}
|
|
} else {
|
|
int j;
|
|
kiss_fft_cpx scratch[6];
|
|
const kiss_twiddle_cpx *tw1,*tw2,*tw3;
|
|
const int m2=2*m;
|
|
const int m3=3*m;
|
|
kiss_fft_cpx * Fout_beg = Fout;
|
|
for (i=0;i<N;i++)
|
|
{
|
|
Fout = Fout_beg + i*mm;
|
|
tw3 = tw2 = tw1 = st->twiddles;
|
|
/* m is guaranteed to be a multiple of 4. */
|
|
for (j=0;j<m;j++)
|
|
{
|
|
C_MUL(scratch[0],Fout[m] , *tw1 );
|
|
C_MUL(scratch[1],Fout[m2] , *tw2 );
|
|
C_MUL(scratch[2],Fout[m3] , *tw3 );
|
|
|
|
C_SUB( scratch[5] , *Fout, scratch[1] );
|
|
C_ADDTO(*Fout, scratch[1]);
|
|
C_ADD( scratch[3] , scratch[0] , scratch[2] );
|
|
C_SUB( scratch[4] , scratch[0] , scratch[2] );
|
|
C_SUB( Fout[m2], *Fout, scratch[3] );
|
|
tw1 += fstride;
|
|
tw2 += fstride*2;
|
|
tw3 += fstride*3;
|
|
C_ADDTO( *Fout , scratch[3] );
|
|
|
|
Fout[m].r = ADD32_ovflw(scratch[5].r, scratch[4].i);
|
|
Fout[m].i = SUB32_ovflw(scratch[5].i, scratch[4].r);
|
|
Fout[m3].r = SUB32_ovflw(scratch[5].r, scratch[4].i);
|
|
Fout[m3].i = ADD32_ovflw(scratch[5].i, scratch[4].r);
|
|
++Fout;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
#ifndef RADIX_TWO_ONLY
|
|
|
|
static void kf_bfly3(
|
|
kiss_fft_cpx * Fout,
|
|
const size_t fstride,
|
|
const kiss_fft_state *st,
|
|
int m,
|
|
int N,
|
|
int mm
|
|
)
|
|
{
|
|
int i;
|
|
size_t k;
|
|
const size_t m2 = 2*m;
|
|
const kiss_twiddle_cpx *tw1,*tw2;
|
|
kiss_fft_cpx scratch[5];
|
|
kiss_twiddle_cpx epi3;
|
|
|
|
kiss_fft_cpx * Fout_beg = Fout;
|
|
#ifdef FIXED_POINT
|
|
/*epi3.r = -16384;*/ /* Unused */
|
|
epi3.i = -28378;
|
|
#else
|
|
epi3 = st->twiddles[fstride*m];
|
|
#endif
|
|
for (i=0;i<N;i++)
|
|
{
|
|
Fout = Fout_beg + i*mm;
|
|
tw1=tw2=st->twiddles;
|
|
/* For non-custom modes, m is guaranteed to be a multiple of 4. */
|
|
k=m;
|
|
do {
|
|
|
|
C_MUL(scratch[1],Fout[m] , *tw1);
|
|
C_MUL(scratch[2],Fout[m2] , *tw2);
|
|
|
|
C_ADD(scratch[3],scratch[1],scratch[2]);
|
|
C_SUB(scratch[0],scratch[1],scratch[2]);
|
|
tw1 += fstride;
|
|
tw2 += fstride*2;
|
|
|
|
Fout[m].r = SUB32_ovflw(Fout->r, HALF_OF(scratch[3].r));
|
|
Fout[m].i = SUB32_ovflw(Fout->i, HALF_OF(scratch[3].i));
|
|
|
|
C_MULBYSCALAR( scratch[0] , epi3.i );
|
|
|
|
C_ADDTO(*Fout,scratch[3]);
|
|
|
|
Fout[m2].r = ADD32_ovflw(Fout[m].r, scratch[0].i);
|
|
Fout[m2].i = SUB32_ovflw(Fout[m].i, scratch[0].r);
|
|
|
|
Fout[m].r = SUB32_ovflw(Fout[m].r, scratch[0].i);
|
|
Fout[m].i = ADD32_ovflw(Fout[m].i, scratch[0].r);
|
|
|
|
++Fout;
|
|
} while(--k);
|
|
}
|
|
}
|
|
|
|
|
|
#ifndef OVERRIDE_kf_bfly5
|
|
static void kf_bfly5(
|
|
kiss_fft_cpx * Fout,
|
|
const size_t fstride,
|
|
const kiss_fft_state *st,
|
|
int m,
|
|
int N,
|
|
int mm
|
|
)
|
|
{
|
|
kiss_fft_cpx *Fout0,*Fout1,*Fout2,*Fout3,*Fout4;
|
|
int i, u;
|
|
kiss_fft_cpx scratch[13];
|
|
const kiss_twiddle_cpx *tw;
|
|
kiss_twiddle_cpx ya,yb;
|
|
kiss_fft_cpx * Fout_beg = Fout;
|
|
|
|
#ifdef FIXED_POINT
|
|
ya.r = 10126;
|
|
ya.i = -31164;
|
|
yb.r = -26510;
|
|
yb.i = -19261;
|
|
#else
|
|
ya = st->twiddles[fstride*m];
|
|
yb = st->twiddles[fstride*2*m];
|
|
#endif
|
|
tw=st->twiddles;
|
|
|
|
for (i=0;i<N;i++)
|
|
{
|
|
Fout = Fout_beg + i*mm;
|
|
Fout0=Fout;
|
|
Fout1=Fout0+m;
|
|
Fout2=Fout0+2*m;
|
|
Fout3=Fout0+3*m;
|
|
Fout4=Fout0+4*m;
|
|
|
|
/* For non-custom modes, m is guaranteed to be a multiple of 4. */
|
|
for ( u=0; u<m; ++u ) {
|
|
scratch[0] = *Fout0;
|
|
|
|
C_MUL(scratch[1] ,*Fout1, tw[u*fstride]);
|
|
C_MUL(scratch[2] ,*Fout2, tw[2*u*fstride]);
|
|
C_MUL(scratch[3] ,*Fout3, tw[3*u*fstride]);
|
|
C_MUL(scratch[4] ,*Fout4, tw[4*u*fstride]);
|
|
|
|
C_ADD( scratch[7],scratch[1],scratch[4]);
|
|
C_SUB( scratch[10],scratch[1],scratch[4]);
|
|
C_ADD( scratch[8],scratch[2],scratch[3]);
|
|
C_SUB( scratch[9],scratch[2],scratch[3]);
|
|
|
|
Fout0->r = ADD32_ovflw(Fout0->r, ADD32_ovflw(scratch[7].r, scratch[8].r));
|
|
Fout0->i = ADD32_ovflw(Fout0->i, ADD32_ovflw(scratch[7].i, scratch[8].i));
|
|
|
|
scratch[5].r = ADD32_ovflw(scratch[0].r, ADD32_ovflw(S_MUL(scratch[7].r,ya.r), S_MUL(scratch[8].r,yb.r)));
|
|
scratch[5].i = ADD32_ovflw(scratch[0].i, ADD32_ovflw(S_MUL(scratch[7].i,ya.r), S_MUL(scratch[8].i,yb.r)));
|
|
|
|
scratch[6].r = ADD32_ovflw(S_MUL(scratch[10].i,ya.i), S_MUL(scratch[9].i,yb.i));
|
|
scratch[6].i = NEG32_ovflw(ADD32_ovflw(S_MUL(scratch[10].r,ya.i), S_MUL(scratch[9].r,yb.i)));
|
|
|
|
C_SUB(*Fout1,scratch[5],scratch[6]);
|
|
C_ADD(*Fout4,scratch[5],scratch[6]);
|
|
|
|
scratch[11].r = ADD32_ovflw(scratch[0].r, ADD32_ovflw(S_MUL(scratch[7].r,yb.r), S_MUL(scratch[8].r,ya.r)));
|
|
scratch[11].i = ADD32_ovflw(scratch[0].i, ADD32_ovflw(S_MUL(scratch[7].i,yb.r), S_MUL(scratch[8].i,ya.r)));
|
|
scratch[12].r = SUB32_ovflw(S_MUL(scratch[9].i,ya.i), S_MUL(scratch[10].i,yb.i));
|
|
scratch[12].i = SUB32_ovflw(S_MUL(scratch[10].r,yb.i), S_MUL(scratch[9].r,ya.i));
|
|
|
|
C_ADD(*Fout2,scratch[11],scratch[12]);
|
|
C_SUB(*Fout3,scratch[11],scratch[12]);
|
|
|
|
++Fout0;++Fout1;++Fout2;++Fout3;++Fout4;
|
|
}
|
|
}
|
|
}
|
|
#endif /* OVERRIDE_kf_bfly5 */
|
|
|
|
|
|
#endif
|
|
|
|
|
|
#ifdef CUSTOM_MODES
|
|
|
|
static
|
|
void compute_bitrev_table(
|
|
int Fout,
|
|
opus_int16 *f,
|
|
const size_t fstride,
|
|
int in_stride,
|
|
opus_int16 * factors,
|
|
const kiss_fft_state *st
|
|
)
|
|
{
|
|
const int p=*factors++; /* the radix */
|
|
const int m=*factors++; /* stage's fft length/p */
|
|
|
|
/*printf ("fft %d %d %d %d %d %d\n", p*m, m, p, s2, fstride*in_stride, N);*/
|
|
if (m==1)
|
|
{
|
|
int j;
|
|
for (j=0;j<p;j++)
|
|
{
|
|
*f = Fout+j;
|
|
f += fstride*in_stride;
|
|
}
|
|
} else {
|
|
int j;
|
|
for (j=0;j<p;j++)
|
|
{
|
|
compute_bitrev_table( Fout , f, fstride*p, in_stride, factors,st);
|
|
f += fstride*in_stride;
|
|
Fout += m;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* facbuf is populated by p1,m1,p2,m2, ...
|
|
where
|
|
p[i] * m[i] = m[i-1]
|
|
m0 = n */
|
|
static
|
|
int kf_factor(int n,opus_int16 * facbuf)
|
|
{
|
|
int p=4;
|
|
int i;
|
|
int stages=0;
|
|
int nbak = n;
|
|
|
|
/*factor out powers of 4, powers of 2, then any remaining primes */
|
|
do {
|
|
while (n % p) {
|
|
switch (p) {
|
|
case 4: p = 2; break;
|
|
case 2: p = 3; break;
|
|
default: p += 2; break;
|
|
}
|
|
if (p>32000 || (opus_int32)p*(opus_int32)p > n)
|
|
p = n; /* no more factors, skip to end */
|
|
}
|
|
n /= p;
|
|
#ifdef RADIX_TWO_ONLY
|
|
if (p!=2 && p != 4)
|
|
#else
|
|
if (p>5)
|
|
#endif
|
|
{
|
|
return 0;
|
|
}
|
|
facbuf[2*stages] = p;
|
|
if (p==2 && stages > 1)
|
|
{
|
|
facbuf[2*stages] = 4;
|
|
facbuf[2] = 2;
|
|
}
|
|
stages++;
|
|
} while (n > 1);
|
|
n = nbak;
|
|
/* Reverse the order to get the radix 4 at the end, so we can use the
|
|
fast degenerate case. It turns out that reversing the order also
|
|
improves the noise behaviour. */
|
|
for (i=0;i<stages/2;i++)
|
|
{
|
|
int tmp;
|
|
tmp = facbuf[2*i];
|
|
facbuf[2*i] = facbuf[2*(stages-i-1)];
|
|
facbuf[2*(stages-i-1)] = tmp;
|
|
}
|
|
for (i=0;i<stages;i++)
|
|
{
|
|
n /= facbuf[2*i];
|
|
facbuf[2*i+1] = n;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static void compute_twiddles(kiss_twiddle_cpx *twiddles, int nfft)
|
|
{
|
|
int i;
|
|
#ifdef FIXED_POINT
|
|
for (i=0;i<nfft;++i) {
|
|
opus_val32 phase = -i;
|
|
kf_cexp2(twiddles+i, DIV32(SHL32(phase,17),nfft));
|
|
}
|
|
#else
|
|
for (i=0;i<nfft;++i) {
|
|
const double pi=3.14159265358979323846264338327;
|
|
double phase = ( -2*pi /nfft ) * i;
|
|
kf_cexp(twiddles+i, phase );
|
|
}
|
|
#endif
|
|
}
|
|
|
|
int opus_fft_alloc_arch_c(kiss_fft_state *st) {
|
|
(void)st;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
*
|
|
* Allocates all necessary storage space for the fft and ifft.
|
|
* The return value is a contiguous block of memory. As such,
|
|
* It can be freed with free().
|
|
* */
|
|
kiss_fft_state *opus_fft_alloc_twiddles(int nfft,void * mem,size_t * lenmem,
|
|
const kiss_fft_state *base, int arch)
|
|
{
|
|
kiss_fft_state *st=NULL;
|
|
size_t memneeded = sizeof(struct kiss_fft_state); /* twiddle factors*/
|
|
|
|
if ( lenmem==NULL ) {
|
|
st = ( kiss_fft_state*)KISS_FFT_MALLOC( memneeded );
|
|
}else{
|
|
if (mem != NULL && *lenmem >= memneeded)
|
|
st = (kiss_fft_state*)mem;
|
|
*lenmem = memneeded;
|
|
}
|
|
if (st) {
|
|
opus_int16 *bitrev;
|
|
kiss_twiddle_cpx *twiddles;
|
|
|
|
st->nfft=nfft;
|
|
#ifdef FIXED_POINT
|
|
st->scale_shift = celt_ilog2(st->nfft);
|
|
if (st->nfft == 1<<st->scale_shift)
|
|
st->scale = Q15ONE;
|
|
else
|
|
st->scale = (1073741824+st->nfft/2)/st->nfft>>(15-st->scale_shift);
|
|
#else
|
|
st->scale = 1.f/nfft;
|
|
#endif
|
|
if (base != NULL)
|
|
{
|
|
st->twiddles = base->twiddles;
|
|
st->shift = 0;
|
|
while (st->shift < 32 && nfft<<st->shift != base->nfft)
|
|
st->shift++;
|
|
if (st->shift>=32)
|
|
goto fail;
|
|
} else {
|
|
st->twiddles = twiddles = (kiss_twiddle_cpx*)KISS_FFT_MALLOC(sizeof(kiss_twiddle_cpx)*nfft);
|
|
compute_twiddles(twiddles, nfft);
|
|
st->shift = -1;
|
|
}
|
|
if (!kf_factor(nfft,st->factors))
|
|
{
|
|
goto fail;
|
|
}
|
|
|
|
/* bitrev */
|
|
st->bitrev = bitrev = (opus_int16*)KISS_FFT_MALLOC(sizeof(opus_int16)*nfft);
|
|
if (st->bitrev==NULL)
|
|
goto fail;
|
|
compute_bitrev_table(0, bitrev, 1,1, st->factors,st);
|
|
|
|
/* Initialize architecture specific fft parameters */
|
|
if (opus_fft_alloc_arch(st, arch))
|
|
goto fail;
|
|
}
|
|
return st;
|
|
fail:
|
|
opus_fft_free(st, arch);
|
|
return NULL;
|
|
}
|
|
|
|
kiss_fft_state *opus_fft_alloc(int nfft,void * mem,size_t * lenmem, int arch)
|
|
{
|
|
return opus_fft_alloc_twiddles(nfft, mem, lenmem, NULL, arch);
|
|
}
|
|
|
|
void opus_fft_free_arch_c(kiss_fft_state *st) {
|
|
(void)st;
|
|
}
|
|
|
|
void opus_fft_free(const kiss_fft_state *cfg, int arch)
|
|
{
|
|
if (cfg)
|
|
{
|
|
opus_fft_free_arch((kiss_fft_state *)cfg, arch);
|
|
opus_free((opus_int16*)cfg->bitrev);
|
|
if (cfg->shift < 0)
|
|
opus_free((kiss_twiddle_cpx*)cfg->twiddles);
|
|
opus_free((kiss_fft_state*)cfg);
|
|
}
|
|
}
|
|
|
|
#endif /* CUSTOM_MODES */
|
|
|
|
void opus_fft_impl(const kiss_fft_state *st,kiss_fft_cpx *fout)
|
|
{
|
|
int m2, m;
|
|
int p;
|
|
int L;
|
|
int fstride[MAXFACTORS];
|
|
int i;
|
|
int shift;
|
|
|
|
/* st->shift can be -1 */
|
|
shift = st->shift>0 ? st->shift : 0;
|
|
|
|
fstride[0] = 1;
|
|
L=0;
|
|
do {
|
|
p = st->factors[2*L];
|
|
m = st->factors[2*L+1];
|
|
fstride[L+1] = fstride[L]*p;
|
|
L++;
|
|
} while(m!=1);
|
|
m = st->factors[2*L-1];
|
|
for (i=L-1;i>=0;i--)
|
|
{
|
|
if (i!=0)
|
|
m2 = st->factors[2*i-1];
|
|
else
|
|
m2 = 1;
|
|
switch (st->factors[2*i])
|
|
{
|
|
case 2:
|
|
kf_bfly2(fout, m, fstride[i]);
|
|
break;
|
|
case 4:
|
|
kf_bfly4(fout,fstride[i]<<shift,st,m, fstride[i], m2);
|
|
break;
|
|
#ifndef RADIX_TWO_ONLY
|
|
case 3:
|
|
kf_bfly3(fout,fstride[i]<<shift,st,m, fstride[i], m2);
|
|
break;
|
|
case 5:
|
|
kf_bfly5(fout,fstride[i]<<shift,st,m, fstride[i], m2);
|
|
break;
|
|
#endif
|
|
}
|
|
m = m2;
|
|
}
|
|
}
|
|
|
|
void opus_fft_c(const kiss_fft_state *st,const kiss_fft_cpx *fin,kiss_fft_cpx *fout)
|
|
{
|
|
int i;
|
|
opus_val16 scale;
|
|
#ifdef FIXED_POINT
|
|
/* Allows us to scale with MULT16_32_Q16(), which is faster than
|
|
MULT16_32_Q15() on ARM. */
|
|
int scale_shift = st->scale_shift-1;
|
|
#endif
|
|
scale = st->scale;
|
|
|
|
celt_assert2 (fin != fout, "In-place FFT not supported");
|
|
/* Bit-reverse the input */
|
|
for (i=0;i<st->nfft;i++)
|
|
{
|
|
kiss_fft_cpx x = fin[i];
|
|
fout[st->bitrev[i]].r = SHR32(MULT16_32_Q16(scale, x.r), scale_shift);
|
|
fout[st->bitrev[i]].i = SHR32(MULT16_32_Q16(scale, x.i), scale_shift);
|
|
}
|
|
opus_fft_impl(st, fout);
|
|
}
|
|
|
|
|
|
void opus_ifft_c(const kiss_fft_state *st,const kiss_fft_cpx *fin,kiss_fft_cpx *fout)
|
|
{
|
|
int i;
|
|
celt_assert2 (fin != fout, "In-place FFT not supported");
|
|
/* Bit-reverse the input */
|
|
for (i=0;i<st->nfft;i++)
|
|
fout[st->bitrev[i]] = fin[i];
|
|
for (i=0;i<st->nfft;i++)
|
|
fout[i].i = -fout[i].i;
|
|
opus_fft_impl(st, fout);
|
|
for (i=0;i<st->nfft;i++)
|
|
fout[i].i = -fout[i].i;
|
|
}
|