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