2 Copyright (c) 2003-2004, Mark Borgerding
6 Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
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.
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.
18 #define MIN(a,b) ((a)<(b) ? (a):(b))
22 #define MAX(a,b) ((a)>(b) ? (a):(b))
25 defines kiss_fft_scalar as either short or a float type
27 typedef struct { kiss_fft_scalar r; kiss_fft_scalar i; }kiss_fft_cpx; */
29 #include "math_approx.h"
32 /* e.g. an fft of length 128 has 4 factors
33 as far as kissfft is concerned
37 struct kiss_fft_state
{
40 int factors
[2*MAXFACTORS
];
41 kiss_fft_cpx twiddles
[1];
45 Explanation of macros dealing with complex math:
47 C_MUL(m,a,b) : m = a*b
48 C_FIXDIV( c , div ) : if a fixed point impl., c /= div. noop otherwise
49 C_SUB( res, a,b) : res = a - b
50 C_SUBFROM( res , a) : res -= a
51 C_ADDTO( res , a) : res += a
56 # define SAMPPROD spx_int32_t
57 #define SAMP_MAX 32767
59 #define SAMP_MIN -SAMP_MAX
61 #if defined(CHECK_OVERFLOW)
62 # define CHECK_OVERFLOW_OP(a,op,b) \
63 if ( (SAMPPROD)(a) op (SAMPPROD)(b) > SAMP_MAX || (SAMPPROD)(a) op (SAMPPROD)(b) < SAMP_MIN ) { \
64 fprintf(stderr,"WARNING:overflow @ " __FILE__ "(%d): (%d " #op" %d) = %ld\n",__LINE__,(a),(b),(SAMPPROD)(a) op (SAMPPROD)(b) ); }
68 # define smul(a,b) ( (SAMPPROD)(a)*(b) )
69 # define sround( x ) (kiss_fft_scalar)( ( (x) + (1<<(FRACBITS-1)) ) >> FRACBITS )
71 # define S_MUL(a,b) sround( smul(a,b) )
73 # define C_MUL(m,a,b) \
74 do{ (m).r = sround( smul((a).r,(b).r) - smul((a).i,(b).i) ); \
75 (m).i = sround( smul((a).r,(b).i) + smul((a).i,(b).r) ); }while(0)
77 # define C_MUL4(m,a,b) \
78 do{ (m).r = PSHR32( smul((a).r,(b).r) - smul((a).i,(b).i),17 ); \
79 (m).i = PSHR32( smul((a).r,(b).i) + smul((a).i,(b).r),17 ); }while(0)
81 # define DIVSCALAR(x,k) \
82 (x) = sround( smul( x, SAMP_MAX/k ) )
84 # define C_FIXDIV(c,div) \
85 do { DIVSCALAR( (c).r , div); \
86 DIVSCALAR( (c).i , div); }while (0)
88 # define C_MULBYSCALAR( c, s ) \
89 do{ (c).r = sround( smul( (c).r , s ) ) ;\
90 (c).i = sround( smul( (c).i , s ) ) ; }while(0)
92 #else /* not FIXED_POINT*/
94 # define S_MUL(a,b) ( (a)*(b) )
95 #define C_MUL(m,a,b) \
96 do{ (m).r = (a).r*(b).r - (a).i*(b).i;\
97 (m).i = (a).r*(b).i + (a).i*(b).r; }while(0)
99 #define C_MUL4(m,a,b) C_MUL(m,a,b)
101 # define C_FIXDIV(c,div) /* NOOP */
102 # define C_MULBYSCALAR( c, s ) \
104 (c).i *= (s); }while(0)
107 #ifndef CHECK_OVERFLOW_OP
108 # define CHECK_OVERFLOW_OP(a,op,b) /* noop */
111 #define C_ADD( res, a,b)\
113 CHECK_OVERFLOW_OP((a).r,+,(b).r)\
114 CHECK_OVERFLOW_OP((a).i,+,(b).i)\
115 (res).r=(a).r+(b).r; (res).i=(a).i+(b).i; \
117 #define C_SUB( res, a,b)\
119 CHECK_OVERFLOW_OP((a).r,-,(b).r)\
120 CHECK_OVERFLOW_OP((a).i,-,(b).i)\
121 (res).r=(a).r-(b).r; (res).i=(a).i-(b).i; \
123 #define C_ADDTO( res , a)\
125 CHECK_OVERFLOW_OP((res).r,+,(a).r)\
126 CHECK_OVERFLOW_OP((res).i,+,(a).i)\
127 (res).r += (a).r; (res).i += (a).i;\
130 #define C_SUBFROM( res , a)\
132 CHECK_OVERFLOW_OP((res).r,-,(a).r)\
133 CHECK_OVERFLOW_OP((res).i,-,(a).i)\
134 (res).r -= (a).r; (res).i -= (a).i; \
139 # define KISS_FFT_COS(phase) floor(MIN(32767,MAX(-32767,.5+32768 * cos (phase))))
140 # define KISS_FFT_SIN(phase) floor(MIN(32767,MAX(-32767,.5+32768 * sin (phase))))
141 # define HALF_OF(x) ((x)>>1)
142 #elif defined(USE_SIMD)
143 # define KISS_FFT_COS(phase) _mm_set1_ps( cos(phase) )
144 # define KISS_FFT_SIN(phase) _mm_set1_ps( sin(phase) )
145 # define HALF_OF(x) ((x)*_mm_set1_ps(.5))
147 # define KISS_FFT_COS(phase) (kiss_fft_scalar) cos(phase)
148 # define KISS_FFT_SIN(phase) (kiss_fft_scalar) sin(phase)
149 # define HALF_OF(x) ((x)*.5)
152 #define kf_cexp(x,phase) \
154 (x)->r = KISS_FFT_COS(phase);\
155 (x)->i = KISS_FFT_SIN(phase);\
157 #define kf_cexp2(x,phase) \
159 (x)->r = spx_cos_norm((phase));\
160 (x)->i = spx_cos_norm((phase)-32768);\
164 /* a debugging function */
166 fprintf(stderr,"%g + %gi\n",(double)((c)->r),(double)((c)->i) )