1/*
2Copyright (c) 2003-2010, Mark Borgerding
3
4All rights reserved.
5
6Redistribution 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
12THIS 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
15/* kiss_fft.h
16 defines kiss_fft_scalar as either short or a float type
17 and defines
18 typedef struct { kiss_fft_scalar r; kiss_fft_scalar i; }kiss_fft_cpx; */
19#include "kiss_fft.h"
20#include <limits.h>
21
22#define MAXFACTORS 32
23/* e.g. an fft of length 128 has 4 factors
24 as far as kissfft is concerned
25 4*4*4*2
26 */
27
28struct kiss_fft_state{
29 int nfft;
30 int inverse;
31 int factors[2*MAXFACTORS];
32 kiss_fft_cpx twiddles[1];
33};
34
35/*
36 Explanation of macros dealing with complex math:
37
38 C_MUL(m,a,b) : m = a*b
39 C_FIXDIV( c , div ) : if a fixed point impl., c /= div. noop otherwise
40 C_SUB( res, a,b) : res = a - b
41 C_SUBFROM( res , a) : res -= a
42 C_ADDTO( res , a) : res += a
43 * */
44#ifdef FIXED_POINT
45#if (FIXED_POINT==32)
46# define FRACBITS 31
47# define SAMPPROD int64_t
48#define SAMP_MAX 2147483647
49#else
50# define FRACBITS 15
51# define SAMPPROD int32_t
52#define SAMP_MAX 32767
53#endif
54
55#define SAMP_MIN -SAMP_MAX
56
57#if defined(CHECK_OVERFLOW)
58# define CHECK_OVERFLOW_OP(a,op,b) \
59 if ( (SAMPPROD)(a) op (SAMPPROD)(b) > SAMP_MAX || (SAMPPROD)(a) op (SAMPPROD)(b) < SAMP_MIN ) { \
60 fprintf(stderr,"WARNING:overflow @ " __FILE__ "(%d): (%d " #op" %d) = %ld\n",__LINE__,(a),(b),(SAMPPROD)(a) op (SAMPPROD)(b) ); }
61#endif
62
63
64# define smul(a,b) ( (SAMPPROD)(a)*(b) )
65# define sround( x ) (kiss_fft_scalar)( ( (x) + (1<<(FRACBITS-1)) ) >> FRACBITS )
66
67# define S_MUL(a,b) sround( smul(a,b) )
68
69# define C_MUL(m,a,b) \
70 do{ (m).r = sround( smul((a).r,(b).r) - smul((a).i,(b).i) ); \
71 (m).i = sround( smul((a).r,(b).i) + smul((a).i,(b).r) ); }while(0)
72
73# define DIVSCALAR(x,k) \
74 (x) = sround( smul( x, SAMP_MAX/k ) )
75
76# define C_FIXDIV(c,div) \
77 do { DIVSCALAR( (c).r , div); \
78 DIVSCALAR( (c).i , div); }while (0)
79
80# define C_MULBYSCALAR( c, s ) \
81 do{ (c).r = sround( smul( (c).r , s ) ) ;\
82 (c).i = sround( smul( (c).i , s ) ) ; }while(0)
83
84#else /* not FIXED_POINT*/
85
86# define S_MUL(a,b) ( (a)*(b) )
87#define C_MUL(m,a,b) \
88 do{ (m).r = (a).r*(b).r - (a).i*(b).i;\
89 (m).i = (a).r*(b).i + (a).i*(b).r; }while(0)
90# define C_FIXDIV(c,div) /* NOOP */
91# define C_MULBYSCALAR( c, s ) \
92 do{ (c).r *= (s);\
93 (c).i *= (s); }while(0)
94#endif
95
96#ifndef CHECK_OVERFLOW_OP
97# define CHECK_OVERFLOW_OP(a,op,b) /* noop */
98#endif
99
100#define C_ADD( res, a,b)\
101 do { \
102 CHECK_OVERFLOW_OP((a).r,+,(b).r)\
103 CHECK_OVERFLOW_OP((a).i,+,(b).i)\
104 (res).r=(a).r+(b).r; (res).i=(a).i+(b).i; \
105 }while(0)
106#define C_SUB( res, a,b)\
107 do { \
108 CHECK_OVERFLOW_OP((a).r,-,(b).r)\
109 CHECK_OVERFLOW_OP((a).i,-,(b).i)\
110 (res).r=(a).r-(b).r; (res).i=(a).i-(b).i; \
111 }while(0)
112#define C_ADDTO( res , a)\
113 do { \
114 CHECK_OVERFLOW_OP((res).r,+,(a).r)\
115 CHECK_OVERFLOW_OP((res).i,+,(a).i)\
116 (res).r += (a).r; (res).i += (a).i;\
117 }while(0)
118
119#define C_SUBFROM( res , a)\
120 do {\
121 CHECK_OVERFLOW_OP((res).r,-,(a).r)\
122 CHECK_OVERFLOW_OP((res).i,-,(a).i)\
123 (res).r -= (a).r; (res).i -= (a).i; \
124 }while(0)
125
126
127#ifdef FIXED_POINT
128# define KISS_FFT_COS(phase) floor(.5+SAMP_MAX * cos (phase))
129# define KISS_FFT_SIN(phase) floor(.5+SAMP_MAX * sin (phase))
130# define HALF_OF(x) ((x)>>1)
131#elif defined(USE_SIMD)
132# define KISS_FFT_COS(phase) _mm_set1_ps( cos(phase) )
133# define KISS_FFT_SIN(phase) _mm_set1_ps( sin(phase) )
134# define HALF_OF(x) ((x)*_mm_set1_ps(.5))
135#else
136# define KISS_FFT_COS(phase) (kiss_fft_scalar) cos(phase)
137# define KISS_FFT_SIN(phase) (kiss_fft_scalar) sin(phase)
138# define HALF_OF(x) ((x)*.5)
139#endif
140
141#define kf_cexp(x,phase) \
142 do{ \
143 (x)->r = KISS_FFT_COS(phase);\
144 (x)->i = KISS_FFT_SIN(phase);\
145 }while(0)
146
147
148/* a debugging function */
149#define pcpx(c)\
150 fprintf(stderr,"%g + %gi\n",(double)((c)->r),(double)((c)->i) )
151
152
153#ifdef KISS_FFT_USE_ALLOCA
154// define this to allow use of alloca instead of malloc for temporary buffers
155// Temporary buffers are used in two case:
156// 1. FFT sizes that have "bad" factors. i.e. not 2,3 and 5
157// 2. "in-place" FFTs. Notice the quotes, since kissfft does not really do an in-place transform.
158#include <alloca.h>
159#define KISS_FFT_TMP_ALLOC(nbytes) alloca(nbytes)
160#define KISS_FFT_TMP_FREE(ptr)
161#else
162#define KISS_FFT_TMP_ALLOC(nbytes) KISS_FFT_MALLOC(nbytes)
163#define KISS_FFT_TMP_FREE(ptr) KISS_FFT_FREE(ptr)
164#endif