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-rw-r--r--kiss/kiss_fft.c420
1 files changed, 420 insertions, 0 deletions
diff --git a/kiss/kiss_fft.c b/kiss/kiss_fft.c
new file mode 100644
index 0000000..58c24a0
--- /dev/null
+++ b/kiss/kiss_fft.c
@@ -0,0 +1,420 @@
+/*
+ * Copyright (c) 2003-2010, Mark Borgerding. All rights reserved.
+ * This file is part of KISS FFT - https://github.com/mborgerding/kissfft
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ * See COPYING file for more information.
+ */
+
+
+#include "_kiss_fft_guts.h"
+/* The guts header contains all the multiplication and addition macros that are defined for
+ fixed or floating point complex numbers. It also delares the kf_ internal functions.
+ */
+
+static void kf_bfly2(
+ kiss_fft_cpx * Fout,
+ const size_t fstride,
+ const kiss_fft_cfg st,
+ int m
+ )
+{
+ kiss_fft_cpx * Fout2;
+ kiss_fft_cpx * tw1 = st->twiddles;
+ kiss_fft_cpx t;
+ Fout2 = Fout + m;
+ do{
+ C_FIXDIV(*Fout,2); C_FIXDIV(*Fout2,2);
+
+ C_MUL (t, *Fout2 , *tw1);
+ tw1 += fstride;
+ C_SUB( *Fout2 , *Fout , t );
+ C_ADDTO( *Fout , t );
+ ++Fout2;
+ ++Fout;
+ }while (--m);
+}
+
+static void kf_bfly4(
+ kiss_fft_cpx * Fout,
+ const size_t fstride,
+ const kiss_fft_cfg st,
+ const size_t m
+ )
+{
+ kiss_fft_cpx *tw1,*tw2,*tw3;
+ kiss_fft_cpx scratch[6];
+ size_t k=m;
+ const size_t m2=2*m;
+ const size_t m3=3*m;
+
+
+ tw3 = tw2 = tw1 = st->twiddles;
+
+ do {
+ C_FIXDIV(*Fout,4); C_FIXDIV(Fout[m],4); C_FIXDIV(Fout[m2],4); C_FIXDIV(Fout[m3],4);
+
+ 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] );
+
+ if(st->inverse) {
+ 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;
+ }else{
+ 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;
+ }while(--k);
+}
+
+static void kf_bfly3(
+ kiss_fft_cpx * Fout,
+ const size_t fstride,
+ const kiss_fft_cfg st,
+ size_t m
+ )
+{
+ size_t k=m;
+ const size_t m2 = 2*m;
+ kiss_fft_cpx *tw1,*tw2;
+ kiss_fft_cpx scratch[5];
+ kiss_fft_cpx epi3;
+ epi3 = st->twiddles[fstride*m];
+
+ tw1=tw2=st->twiddles;
+
+ 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 kf_bfly5(
+ kiss_fft_cpx * Fout,
+ const size_t fstride,
+ const kiss_fft_cfg st,
+ int m
+ )
+{
+ kiss_fft_cpx *Fout0,*Fout1,*Fout2,*Fout3,*Fout4;
+ int u;
+ kiss_fft_cpx scratch[13];
+ kiss_fft_cpx * twiddles = st->twiddles;
+ kiss_fft_cpx *tw;
+ kiss_fft_cpx ya,yb;
+ ya = twiddles[fstride*m];
+ yb = twiddles[fstride*2*m];
+
+ Fout0=Fout;
+ Fout1=Fout0+m;
+ Fout2=Fout0+2*m;
+ Fout3=Fout0+3*m;
+ Fout4=Fout0+4*m;
+
+ tw=st->twiddles;
+ 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;
+ }
+}
+
+/* perform the butterfly for one stage of a mixed radix FFT */
+static void kf_bfly_generic(
+ kiss_fft_cpx * Fout,
+ const size_t fstride,
+ const kiss_fft_cfg st,
+ int m,
+ int p
+ )
+{
+ int u,k,q1,q;
+ kiss_fft_cpx * twiddles = st->twiddles;
+ kiss_fft_cpx t;
+ int Norig = st->nfft;
+
+ kiss_fft_cpx * scratch = (kiss_fft_cpx*)KISS_FFT_TMP_ALLOC(sizeof(kiss_fft_cpx)*p);
+ if (scratch == NULL){
+ KISS_FFT_ERROR("Memory allocation failed.");
+ return;
+ }
+
+ for ( u=0; u<m; ++u ) {
+ k=u;
+ for ( q1=0 ; q1<p ; ++q1 ) {
+ scratch[q1] = Fout[ k ];
+ C_FIXDIV(scratch[q1],p);
+ k += m;
+ }
+
+ k=u;
+ for ( q1=0 ; q1<p ; ++q1 ) {
+ int twidx=0;
+ Fout[ k ] = scratch[0];
+ for (q=1;q<p;++q ) {
+ twidx += fstride * k;
+ if (twidx>=Norig) twidx-=Norig;
+ C_MUL(t,scratch[q] , twiddles[twidx] );
+ C_ADDTO( Fout[ k ] ,t);
+ }
+ k += m;
+ }
+ }
+ KISS_FFT_TMP_FREE(scratch);
+}
+
+static
+void kf_work(
+ kiss_fft_cpx * Fout,
+ const kiss_fft_cpx * f,
+ const size_t fstride,
+ int in_stride,
+ int * factors,
+ const kiss_fft_cfg st
+ )
+{
+ kiss_fft_cpx * Fout_beg=Fout;
+ const int p=*factors++; /* the radix */
+ const int m=*factors++; /* stage's fft length/p */
+ const kiss_fft_cpx * Fout_end = Fout + p*m;
+
+#ifdef _OPENMP
+ // use openmp extensions at the
+ // top-level (not recursive)
+ if (fstride==1 && p<=5 && m!=1)
+ {
+ int k;
+
+ // execute the p different work units in different threads
+# pragma omp parallel for
+ for (k=0;k<p;++k)
+ kf_work( Fout +k*m, f+ fstride*in_stride*k,fstride*p,in_stride,factors,st);
+ // all threads have joined by this point
+
+ switch (p) {
+ case 2: kf_bfly2(Fout,fstride,st,m); break;
+ case 3: kf_bfly3(Fout,fstride,st,m); break;
+ case 4: kf_bfly4(Fout,fstride,st,m); break;
+ case 5: kf_bfly5(Fout,fstride,st,m); break;
+ default: kf_bfly_generic(Fout,fstride,st,m,p); break;
+ }
+ return;
+ }
+#endif
+
+ if (m==1) {
+ do{
+ *Fout = *f;
+ f += fstride*in_stride;
+ }while(++Fout != Fout_end );
+ }else{
+ do{
+ // recursive call:
+ // DFT of size m*p performed by doing
+ // p instances of smaller DFTs of size m,
+ // each one takes a decimated version of the input
+ kf_work( Fout , f, fstride*p, in_stride, factors,st);
+ f += fstride*in_stride;
+ }while( (Fout += m) != Fout_end );
+ }
+
+ Fout=Fout_beg;
+
+ // recombine the p smaller DFTs
+ switch (p) {
+ case 2: kf_bfly2(Fout,fstride,st,m); break;
+ case 3: kf_bfly3(Fout,fstride,st,m); break;
+ case 4: kf_bfly4(Fout,fstride,st,m); break;
+ case 5: kf_bfly5(Fout,fstride,st,m); break;
+ default: kf_bfly_generic(Fout,fstride,st,m,p); break;
+ }
+}
+
+/* facbuf is populated by p1,m1,p2,m2, ...
+ where
+ p[i] * m[i] = m[i-1]
+ m0 = n */
+static
+void kf_factor(int n,int * facbuf)
+{
+ int p=4;
+ double floor_sqrt;
+ floor_sqrt = floor( sqrt((double)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 > floor_sqrt)
+ p = n; /* no more factors, skip to end */
+ }
+ n /= p;
+ *facbuf++ = p;
+ *facbuf++ = n;
+ } while (n > 1);
+}
+
+/*
+ *
+ * User-callable function to allocate all necessary storage space for the fft.
+ *
+ * The return value is a contiguous block of memory, allocated with malloc. As such,
+ * It can be freed with free(), rather than a kiss_fft-specific function.
+ * */
+kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem )
+{
+ KISS_FFT_ALIGN_CHECK(mem)
+
+ kiss_fft_cfg st=NULL;
+ size_t memneeded = KISS_FFT_ALIGN_SIZE_UP(sizeof(struct kiss_fft_state)
+ + sizeof(kiss_fft_cpx)*(nfft-1)); /* twiddle factors*/
+
+ if ( lenmem==NULL ) {
+ st = ( kiss_fft_cfg)KISS_FFT_MALLOC( memneeded );
+ }else{
+ if (mem != NULL && *lenmem >= memneeded)
+ st = (kiss_fft_cfg)mem;
+ *lenmem = memneeded;
+ }
+ if (st) {
+ int i;
+ st->nfft=nfft;
+ st->inverse = inverse_fft;
+
+ for (i=0;i<nfft;++i) {
+ const double pi=3.141592653589793238462643383279502884197169399375105820974944;
+ double phase = -2*pi*i / nfft;
+ if (st->inverse)
+ phase *= -1;
+ kf_cexp(st->twiddles+i, phase );
+ }
+
+ kf_factor(nfft,st->factors);
+ }
+ return st;
+}
+
+
+void kiss_fft_stride(kiss_fft_cfg st,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int in_stride)
+{
+ if (fin == fout) {
+ //NOTE: this is not really an in-place FFT algorithm.
+ //It just performs an out-of-place FFT into a temp buffer
+ if (fout == NULL){
+ KISS_FFT_ERROR("fout buffer NULL.");
+ return;
+ }
+
+ kiss_fft_cpx * tmpbuf = (kiss_fft_cpx*)KISS_FFT_TMP_ALLOC( sizeof(kiss_fft_cpx)*st->nfft);
+ if (tmpbuf == NULL){
+ KISS_FFT_ERROR("Memory allocation error.");
+ return;
+ }
+
+
+
+ kf_work(tmpbuf,fin,1,in_stride, st->factors,st);
+ memcpy(fout,tmpbuf,sizeof(kiss_fft_cpx)*st->nfft);
+ KISS_FFT_TMP_FREE(tmpbuf);
+ }else{
+ kf_work( fout, fin, 1,in_stride, st->factors,st );
+ }
+}
+
+void kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout)
+{
+ kiss_fft_stride(cfg,fin,fout,1);
+}
+
+
+void kiss_fft_cleanup(void)
+{
+ // nothing needed any more
+}
+
+int kiss_fft_next_fast_size(int n)
+{
+ while(1) {
+ int m=n;
+ while ( (m%2) == 0 ) m/=2;
+ while ( (m%3) == 0 ) m/=3;
+ while ( (m%5) == 0 ) m/=5;
+ if (m<=1)
+ break; /* n is completely factorable by twos, threes, and fives */
+ n++;
+ }
+ return n;
+}
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