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path: root/drivers/opus/celt/kiss_fft.c
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Diffstat (limited to 'drivers/opus/celt/kiss_fft.c')
-rw-r--r--drivers/opus/celt/kiss_fft.c719
1 files changed, 719 insertions, 0 deletions
diff --git a/drivers/opus/celt/kiss_fft.c b/drivers/opus/celt/kiss_fft.c
new file mode 100644
index 0000000000..333be975d1
--- /dev/null
+++ b/drivers/opus/celt/kiss_fft.c
@@ -0,0 +1,719 @@
+/*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 OPUS_HAVE_CONFIG_H
+#include "opus_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,
+ const size_t fstride,
+ const kiss_fft_state *st,
+ int m,
+ int N,
+ int mm
+ )
+{
+ kiss_fft_cpx * Fout2;
+ const kiss_twiddle_cpx * tw1;
+ int i,j;
+ kiss_fft_cpx * Fout_beg = Fout;
+ for (i=0;i<N;i++)
+ {
+ Fout = Fout_beg + i*mm;
+ Fout2 = Fout + m;
+ tw1 = st->twiddles;
+ for(j=0;j<m;j++)
+ {
+ kiss_fft_cpx t;
+ Fout->r = SHR32(Fout->r, 1);Fout->i = SHR32(Fout->i, 1);
+ Fout2->r = SHR32(Fout2->r, 1);Fout2->i = SHR32(Fout2->i, 1);
+ C_MUL (t, *Fout2 , *tw1);
+ tw1 += fstride;
+ C_SUB( *Fout2 , *Fout , t );
+ C_ADDTO( *Fout , t );
+ ++Fout2;
+ ++Fout;
+ }
+ }
+}
+
+static void ki_bfly2(
+ kiss_fft_cpx * Fout,
+ const size_t fstride,
+ const kiss_fft_state *st,
+ int m,
+ int N,
+ int mm
+ )
+{
+ kiss_fft_cpx * Fout2;
+ const kiss_twiddle_cpx * tw1;
+ kiss_fft_cpx t;
+ int i,j;
+ kiss_fft_cpx * Fout_beg = Fout;
+ for (i=0;i<N;i++)
+ {
+ Fout = Fout_beg + i*mm;
+ Fout2 = Fout + m;
+ tw1 = st->twiddles;
+ for(j=0;j<m;j++)
+ {
+ C_MULC (t, *Fout2 , *tw1);
+ tw1 += fstride;
+ C_SUB( *Fout2 , *Fout , t );
+ C_ADDTO( *Fout , t );
+ ++Fout2;
+ ++Fout;
+ }
+ }
+}
+
+static void kf_bfly4(
+ kiss_fft_cpx * Fout,
+ const size_t fstride,
+ const kiss_fft_state *st,
+ int m,
+ int N,
+ int mm
+ )
+{
+ const kiss_twiddle_cpx *tw1,*tw2,*tw3;
+ kiss_fft_cpx scratch[6];
+ const size_t m2=2*m;
+ const size_t m3=3*m;
+ int i, j;
+
+ kiss_fft_cpx * Fout_beg = Fout;
+ for (i=0;i<N;i++)
+ {
+ Fout = Fout_beg + i*mm;
+ tw3 = tw2 = tw1 = st->twiddles;
+ for (j=0;j<m;j++)
+ {
+ C_MUL4(scratch[0],Fout[m] , *tw1 );
+ C_MUL4(scratch[1],Fout[m2] , *tw2 );
+ C_MUL4(scratch[2],Fout[m3] , *tw3 );
+
+ Fout->r = PSHR32(Fout->r, 2);
+ Fout->i = PSHR32(Fout->i, 2);
+ 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 = scratch[5].r + scratch[4].i;
+ Fout[m].i = scratch[5].i - scratch[4].r;
+ Fout[m3].r = scratch[5].r - scratch[4].i;
+ Fout[m3].i = scratch[5].i + scratch[4].r;
+ ++Fout;
+ }
+ }
+}
+
+static void ki_bfly4(
+ kiss_fft_cpx * Fout,
+ const size_t fstride,
+ const kiss_fft_state *st,
+ int m,
+ int N,
+ int mm
+ )
+{
+ const kiss_twiddle_cpx *tw1,*tw2,*tw3;
+ kiss_fft_cpx scratch[6];
+ const size_t m2=2*m;
+ const size_t m3=3*m;
+ int i, j;
+
+ kiss_fft_cpx * Fout_beg = Fout;
+ for (i=0;i<N;i++)
+ {
+ Fout = Fout_beg + i*mm;
+ tw3 = tw2 = tw1 = st->twiddles;
+ for (j=0;j<m;j++)
+ {
+ C_MULC(scratch[0],Fout[m] , *tw1 );
+ C_MULC(scratch[1],Fout[m2] , *tw2 );
+ C_MULC(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 = scratch[5].r - scratch[4].i;
+ Fout[m].i = scratch[5].i + scratch[4].r;
+ Fout[m3].r = scratch[5].r + scratch[4].i;
+ Fout[m3].i = 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;
+ epi3 = st->twiddles[fstride*m];
+ for (i=0;i<N;i++)
+ {
+ Fout = Fout_beg + i*mm;
+ tw1=tw2=st->twiddles;
+ k=m;
+ do {
+ C_FIXDIV(*Fout,3); C_FIXDIV(Fout[m],3); C_FIXDIV(Fout[m2],3);
+
+ 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 = Fout->r - HALF_OF(scratch[3].r);
+ Fout[m].i = Fout->i - HALF_OF(scratch[3].i);
+
+ C_MULBYSCALAR( scratch[0] , epi3.i );
+
+ C_ADDTO(*Fout,scratch[3]);
+
+ Fout[m2].r = Fout[m].r + scratch[0].i;
+ Fout[m2].i = Fout[m].i - scratch[0].r;
+
+ Fout[m].r -= scratch[0].i;
+ Fout[m].i += scratch[0].r;
+
+ ++Fout;
+ } while(--k);
+ }
+}
+
+static void ki_bfly3(
+ kiss_fft_cpx * Fout,
+ const size_t fstride,
+ const kiss_fft_state *st,
+ int m,
+ int N,
+ int mm
+ )
+{
+ int i, 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;
+ epi3 = st->twiddles[fstride*m];
+ for (i=0;i<N;i++)
+ {
+ Fout = Fout_beg + i*mm;
+ tw1=tw2=st->twiddles;
+ k=m;
+ do{
+
+ C_MULC(scratch[1],Fout[m] , *tw1);
+ C_MULC(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 = Fout->r - HALF_OF(scratch[3].r);
+ Fout[m].i = Fout->i - HALF_OF(scratch[3].i);
+
+ C_MULBYSCALAR( scratch[0] , -epi3.i );
+
+ C_ADDTO(*Fout,scratch[3]);
+
+ Fout[m2].r = Fout[m].r + scratch[0].i;
+ Fout[m2].i = Fout[m].i - scratch[0].r;
+
+ Fout[m].r -= scratch[0].i;
+ Fout[m].i += scratch[0].r;
+
+ ++Fout;
+ }while(--k);
+ }
+}
+
+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 * twiddles = st->twiddles;
+ const kiss_twiddle_cpx *tw;
+ kiss_twiddle_cpx ya,yb;
+ kiss_fft_cpx * Fout_beg = Fout;
+
+ ya = twiddles[fstride*m];
+ yb = twiddles[fstride*2*m];
+ 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 ( u=0; u<m; ++u ) {
+ C_FIXDIV( *Fout0,5); C_FIXDIV( *Fout1,5); C_FIXDIV( *Fout2,5); C_FIXDIV( *Fout3,5); C_FIXDIV( *Fout4,5);
+ 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 += scratch[7].r + scratch[8].r;
+ Fout0->i += scratch[7].i + scratch[8].i;
+
+ scratch[5].r = scratch[0].r + S_MUL(scratch[7].r,ya.r) + S_MUL(scratch[8].r,yb.r);
+ scratch[5].i = scratch[0].i + S_MUL(scratch[7].i,ya.r) + S_MUL(scratch[8].i,yb.r);
+
+ scratch[6].r = S_MUL(scratch[10].i,ya.i) + S_MUL(scratch[9].i,yb.i);
+ scratch[6].i = -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 = scratch[0].r + S_MUL(scratch[7].r,yb.r) + S_MUL(scratch[8].r,ya.r);
+ scratch[11].i = scratch[0].i + S_MUL(scratch[7].i,yb.r) + S_MUL(scratch[8].i,ya.r);
+ scratch[12].r = - S_MUL(scratch[10].i,yb.i) + S_MUL(scratch[9].i,ya.i);
+ scratch[12].i = 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;
+ }
+ }
+}
+
+static void ki_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 * twiddles = st->twiddles;
+ const kiss_twiddle_cpx *tw;
+ kiss_twiddle_cpx ya,yb;
+ kiss_fft_cpx * Fout_beg = Fout;
+
+ ya = twiddles[fstride*m];
+ yb = twiddles[fstride*2*m];
+ 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 ( u=0; u<m; ++u ) {
+ scratch[0] = *Fout0;
+
+ C_MULC(scratch[1] ,*Fout1, tw[u*fstride]);
+ C_MULC(scratch[2] ,*Fout2, tw[2*u*fstride]);
+ C_MULC(scratch[3] ,*Fout3, tw[3*u*fstride]);
+ C_MULC(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 += scratch[7].r + scratch[8].r;
+ Fout0->i += scratch[7].i + scratch[8].i;
+
+ scratch[5].r = scratch[0].r + S_MUL(scratch[7].r,ya.r) + S_MUL(scratch[8].r,yb.r);
+ scratch[5].i = scratch[0].i + S_MUL(scratch[7].i,ya.r) + S_MUL(scratch[8].i,yb.r);
+
+ scratch[6].r = -S_MUL(scratch[10].i,ya.i) - S_MUL(scratch[9].i,yb.i);
+ scratch[6].i = 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 = scratch[0].r + S_MUL(scratch[7].r,yb.r) + S_MUL(scratch[8].r,ya.r);
+ scratch[11].i = scratch[0].i + S_MUL(scratch[7].i,yb.r) + S_MUL(scratch[8].i,ya.r);
+ scratch[12].r = S_MUL(scratch[10].i,yb.i) - S_MUL(scratch[9].i,ya.i);
+ scratch[12].i = -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
+
+
+#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;
+
+ /*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++ = p;
+ *facbuf++ = n;
+ } while (n > 1);
+ return 1;
+}
+
+static void compute_twiddles(kiss_twiddle_cpx *twiddles, int nfft)
+{
+ int i;
+#ifdef OPUS_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
+}
+
+/*
+ *
+ * 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)
+{
+ 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;
+#ifndef OPUS_FIXED_POINT
+ st->scale = 1.f/nfft;
+#endif
+ if (base != NULL)
+ {
+ st->twiddles = base->twiddles;
+ st->shift = 0;
+ while (nfft<<st->shift != base->nfft && st->shift < 32)
+ 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);
+ }
+ return st;
+fail:
+ opus_fft_free(st);
+ return NULL;
+}
+
+kiss_fft_state *opus_fft_alloc(int nfft,void * mem,size_t * lenmem )
+{
+ return opus_fft_alloc_twiddles(nfft, mem, lenmem, NULL);
+}
+
+void opus_fft_free(const kiss_fft_state *cfg)
+{
+ if (cfg)
+ {
+ 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(const kiss_fft_state *st,const kiss_fft_cpx *fin,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;
+
+ 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];
+#ifndef OPUS_FIXED_POINT
+ fout[st->bitrev[i]].r *= st->scale;
+ fout[st->bitrev[i]].i *= st->scale;
+#endif
+ }
+
+ 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,fstride[i]<<shift,st,m, fstride[i], m2);
+ 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_ifft(const kiss_fft_state *st,const kiss_fft_cpx *fin,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;
+ 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];
+
+ 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:
+ ki_bfly2(fout,fstride[i]<<shift,st,m, fstride[i], m2);
+ break;
+ case 4:
+ ki_bfly4(fout,fstride[i]<<shift,st,m, fstride[i], m2);
+ break;
+#ifndef RADIX_TWO_ONLY
+ case 3:
+ ki_bfly3(fout,fstride[i]<<shift,st,m, fstride[i], m2);
+ break;
+ case 5:
+ ki_bfly5(fout,fstride[i]<<shift,st,m, fstride[i], m2);
+ break;
+#endif
+ }
+ m = m2;
+ }
+}
+
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-02 10:22:55 +0000