1 /*
2 Copyright (c) 2003-2004, Mark Borgerding
3
4 All rights reserved.
5
6 Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
7
8 * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
9 * 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.
10 * Neither the author nor the names of any contributors may be used to endorse or promote products derived from this software without specific prior written permission.
11
12 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.
13 */
14 #ifdef HAVE_CONFIG_H
15 #include "config.h"
16 #endif
17
18 #include "kiss_fftr_f32.h"
19 #include "_kiss_fft_guts_f32.h"
20
21 struct kiss_fftr_f32_state
22 {
23 kiss_fft_f32_cfg substate;
24 kiss_fft_f32_cpx *tmpbuf;
25 kiss_fft_f32_cpx *super_twiddles;
26 #ifdef USE_SIMD
27 long pad;
28 #endif
29 };
30
31 kiss_fftr_f32_cfg
kiss_fftr_f32_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem)32 kiss_fftr_f32_alloc (int nfft, int inverse_fft, void *mem, size_t * lenmem)
33 {
34 int i;
35 kiss_fftr_f32_cfg st = NULL;
36 size_t subsize, memneeded;
37
38 if (nfft & 1) {
39 fprintf (stderr, "Real FFT optimization must be even.\n");
40 return NULL;
41 }
42 nfft >>= 1;
43
44 kiss_fft_f32_alloc (nfft, inverse_fft, NULL, &subsize);
45 memneeded = ALIGN_STRUCT (sizeof (struct kiss_fftr_f32_state))
46 + ALIGN_STRUCT (subsize) + sizeof (kiss_fft_f32_cpx) * (nfft * 3 / 2);
47
48 if (lenmem == NULL) {
49 st = (kiss_fftr_f32_cfg) KISS_FFT_F32_MALLOC (memneeded);
50 } else {
51 if (*lenmem >= memneeded)
52 st = (kiss_fftr_f32_cfg) mem;
53 *lenmem = memneeded;
54 }
55 if (!st)
56 return NULL;
57
58 st->substate = (kiss_fft_f32_cfg) (((char *) st) + ALIGN_STRUCT (sizeof (struct kiss_fftr_f32_state))); /*just beyond kiss_fftr_f32_state struct */
59 st->tmpbuf =
60 (kiss_fft_f32_cpx *) (((char *) st->substate) + ALIGN_STRUCT (subsize));
61 st->super_twiddles = st->tmpbuf + nfft;
62 kiss_fft_f32_alloc (nfft, inverse_fft, st->substate, &subsize);
63
64 for (i = 0; i < nfft / 2; ++i) {
65 double phase =
66 -3.14159265358979323846264338327 * ((double) (i + 1) / nfft + .5);
67
68 if (inverse_fft)
69 phase *= -1;
70 kf_cexp (st->super_twiddles + i, phase);
71 }
72 return st;
73 }
74
75 void
kiss_fftr_f32(kiss_fftr_f32_cfg st,const kiss_fft_f32_scalar * timedata,kiss_fft_f32_cpx * freqdata)76 kiss_fftr_f32 (kiss_fftr_f32_cfg st, const kiss_fft_f32_scalar * timedata,
77 kiss_fft_f32_cpx * freqdata)
78 {
79 /* input buffer timedata is stored row-wise */
80 int k, ncfft;
81 kiss_fft_f32_cpx fpnk, fpk, f1k, f2k, tw, tdc;
82
83 /* kiss fft usage error: improper alloc */
84 g_return_if_fail (st->substate->inverse == 0);
85
86 ncfft = st->substate->nfft;
87
88 /*perform the parallel fft of two real signals packed in real,imag */
89 kiss_fft_f32 (st->substate, (const kiss_fft_f32_cpx *) timedata, st->tmpbuf);
90 /* The real part of the DC element of the frequency spectrum in st->tmpbuf
91 * contains the sum of the even-numbered elements of the input time sequence
92 * The imag part is the sum of the odd-numbered elements
93 *
94 * The sum of tdc.r and tdc.i is the sum of the input time sequence.
95 * yielding DC of input time sequence
96 * The difference of tdc.r - tdc.i is the sum of the input (dot product) [1,-1,1,-1...
97 * yielding Nyquist bin of input time sequence
98 */
99
100 tdc.r = st->tmpbuf[0].r;
101 tdc.i = st->tmpbuf[0].i;
102 C_FIXDIV (tdc, 2);
103 CHECK_OVERFLOW_OP (tdc.r, +, tdc.i);
104 CHECK_OVERFLOW_OP (tdc.r, -, tdc.i);
105 freqdata[0].r = tdc.r + tdc.i;
106 freqdata[ncfft].r = tdc.r - tdc.i;
107 #ifdef USE_SIMD
108 freqdata[ncfft].i = freqdata[0].i = _mm_set1_ps (0);
109 #else
110 freqdata[ncfft].i = freqdata[0].i = 0;
111 #endif
112
113 for (k = 1; k <= ncfft / 2; ++k) {
114 fpk = st->tmpbuf[k];
115 fpnk.r = st->tmpbuf[ncfft - k].r;
116 fpnk.i = -st->tmpbuf[ncfft - k].i;
117 C_FIXDIV (fpk, 2);
118 C_FIXDIV (fpnk, 2);
119
120 C_ADD (f1k, fpk, fpnk);
121 C_SUB (f2k, fpk, fpnk);
122 C_MUL (tw, f2k, st->super_twiddles[k - 1]);
123
124 freqdata[k].r = HALF_OF (f1k.r + tw.r);
125 freqdata[k].i = HALF_OF (f1k.i + tw.i);
126 freqdata[ncfft - k].r = HALF_OF (f1k.r - tw.r);
127 freqdata[ncfft - k].i = HALF_OF (tw.i - f1k.i);
128 }
129 }
130
131 void
kiss_fftri_f32(kiss_fftr_f32_cfg st,const kiss_fft_f32_cpx * freqdata,kiss_fft_f32_scalar * timedata)132 kiss_fftri_f32 (kiss_fftr_f32_cfg st, const kiss_fft_f32_cpx * freqdata,
133 kiss_fft_f32_scalar * timedata)
134 {
135 /* input buffer timedata is stored row-wise */
136 int k, ncfft;
137
138 /* kiss fft usage error: improper alloc */
139 g_return_if_fail (st->substate->inverse != 0);
140
141 ncfft = st->substate->nfft;
142
143 st->tmpbuf[0].r = freqdata[0].r + freqdata[ncfft].r;
144 st->tmpbuf[0].i = freqdata[0].r - freqdata[ncfft].r;
145 C_FIXDIV (st->tmpbuf[0], 2);
146
147 for (k = 1; k <= ncfft / 2; ++k) {
148 kiss_fft_f32_cpx fk, fnkc, fek, fok, tmp;
149
150 fk = freqdata[k];
151 fnkc.r = freqdata[ncfft - k].r;
152 fnkc.i = -freqdata[ncfft - k].i;
153 C_FIXDIV (fk, 2);
154 C_FIXDIV (fnkc, 2);
155
156 C_ADD (fek, fk, fnkc);
157 C_SUB (tmp, fk, fnkc);
158 C_MUL (fok, tmp, st->super_twiddles[k - 1]);
159 C_ADD (st->tmpbuf[k], fek, fok);
160 C_SUB (st->tmpbuf[ncfft - k], fek, fok);
161 #ifdef USE_SIMD
162 st->tmpbuf[ncfft - k].i *= _mm_set1_ps (-1.0);
163 #else
164 st->tmpbuf[ncfft - k].i *= -1;
165 #endif
166 }
167 kiss_fft_f32 (st->substate, st->tmpbuf, (kiss_fft_f32_cpx *) timedata);
168 }
169