apps/codecs/libspeex/fftwrap.c

   1 /* Copyright (C) 2005-2006 Jean-Marc Valin
   2    File: fftwrap.c
   3
   4    Wrapper for various FFTs
   5
   6    Redistribution and use in source and binary forms, with or without
   7    modification, are permitted provided that the following conditions
   8    are met:
   9
  10    - Redistributions of source code must retain the above copyright
  11    notice, this list of conditions and the following disclaimer.
  12
  13    - Redistributions in binary form must reproduce the above copyright
  14    notice, this list of conditions and the following disclaimer in the
  15    documentation and/or other materials provided with the distribution.
  16
  17    - Neither the name of the Xiph.org Foundation nor the names of its
  18    contributors may be used to endorse or promote products derived from
  19    this software without specific prior written permission.
  20
  21    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24    A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
  25    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  26    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  27    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  28    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  29    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  30    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  31    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32
  33 */
  34
  35 #ifdef HAVE_CONFIG_H
  36 #include "config-speex.h"
  37 #endif
  38
  39 /*#define USE_SMALLFT*/
  40 #define USE_KISS_FFT
  41
  42
  43 #include "arch.h"
  44 #include "os_support.h"
  45
  46 #define MAX_FFT_SIZE 2048
  47
  48 #ifdef FIXED_POINT
  49 static int maximize_range(spx_word16_t *in, spx_word16_t *out, spx_word16_t bound, int len)
  50 {
  51    int i, shift;
  52    spx_word16_t max_val = 0;
  53    for (i=0;i<len;i++)
  54    {
  55       if (in[i]>max_val)
  56          max_val = in[i];
  57       if (-in[i]>max_val)
  58          max_val = -in[i];
  59    }
  60    shift=0;
  61    while (max_val <= (bound>>1) && max_val != 0)
  62    {
  63       max_val <<= 1;
  64       shift++;
  65    }
  66    for (i=0;i<len;i++)
  67    {
  68       out[i] = SHL16(in[i], shift);
  69    }
  70    return shift;
  71 }
  72
  73 static void renorm_range(spx_word16_t *in, spx_word16_t *out, int shift, int len)
  74 {
  75    int i;
  76    for (i=0;i<len;i++)
  77    {
  78       out[i] = PSHR16(in[i], shift);
  79    }
  80 }
  81 #endif
  82
  83 #ifdef USE_SMALLFT
  84
  85 #include "smallft.h"
  86 #include <math.h>
  87
  88 void *spx_fft_init(int size)
  89 {
  90    struct drft_lookup *table;
  91    table = speex_alloc(sizeof(struct drft_lookup));
  92    spx_drft_init((struct drft_lookup *)table, size);
  93    return (void*)table;
  94 }
  95
  96 void spx_fft_destroy(void *table)
  97 {
  98    spx_drft_clear(table);
  99    speex_free(table);
 100 }
 101
 102 void spx_fft(void *table, float *in, float *out)
 103 {
 104    if (in==out)
 105    {
 106       int i;
 107       float scale = 1./((struct drft_lookup *)table)->n;
 108       speex_warning("FFT should not be done in-place");
 109       for (i=0;i<((struct drft_lookup *)table)->n;i++)
 110          out[i] = scale*in[i];
 111    } else {
 112       int i;
 113       float scale = 1./((struct drft_lookup *)table)->n;
 114       for (i=0;i<((struct drft_lookup *)table)->n;i++)
 115          out[i] = scale*in[i];
 116    }
 117    spx_drft_forward((struct drft_lookup *)table, out);
 118 }
 119
 120 void spx_ifft(void *table, float *in, float *out)
 121 {
 122    if (in==out)
 123    {
 124       speex_warning("FFT should not be done in-place");
 125    } else {
 126       int i;
 127       for (i=0;i<((struct drft_lookup *)table)->n;i++)
 128          out[i] = in[i];
 129    }
 130    spx_drft_backward((struct drft_lookup *)table, out);
 131 }
 132
 133 #elif defined(USE_KISS_FFT)
 134
 135 #include "kiss_fftr.h"
 136 #include "kiss_fft.h"
 137
 138 struct kiss_config {
 139    kiss_fftr_cfg forward;
 140    kiss_fftr_cfg backward;
 141    int N;
 142 };
 143
 144 void *spx_fft_init(int size)
 145 {
 146    struct kiss_config *table;
 147    table = (struct kiss_config*)speex_alloc(sizeof(struct kiss_config));
 148    table->forward = kiss_fftr_alloc(size,0,NULL,NULL);
 149    table->backward = kiss_fftr_alloc(size,1,NULL,NULL);
 150    table->N = size;
 151    return table;
 152 }
 153
 154 void spx_fft_destroy(void *table)
 155 {
 156    struct kiss_config *t = (struct kiss_config *)table;
 157    kiss_fftr_free(t->forward);
 158    kiss_fftr_free(t->backward);
 159    speex_free(table);
 160 }
 161
 162 #ifdef FIXED_POINT
 163
 164 void spx_fft(void *table, spx_word16_t *in, spx_word16_t *out)
 165 {
 166    int shift;
 167    struct kiss_config *t = (struct kiss_config *)table;
 168    shift = maximize_range(in, in, 32000, t->N);
 169    kiss_fftr2(t->forward, in, out);
 170    renorm_range(in, in, shift, t->N);
 171    renorm_range(out, out, shift, t->N);
 172 }
 173
 174 #else
 175
 176 void spx_fft(void *table, spx_word16_t *in, spx_word16_t *out)
 177 {
 178    int i;
 179    float scale;
 180    struct kiss_config *t = (struct kiss_config *)table;
 181    scale = 1./t->N;
 182    kiss_fftr2(t->forward, in, out);
 183    for (i=0;i<t->N;i++)
 184       out[i] *= scale;
 185 }
 186 #endif
 187
 188 void spx_ifft(void *table, spx_word16_t *in, spx_word16_t *out)
 189 {
 190    struct kiss_config *t = (struct kiss_config *)table;
 191    kiss_fftri2(t->backward, in, out);
 192 }
 193
 194
 195 #else
 196
 197 #error No other FFT implemented
 198
 199 #endif
 200
 201
 202 #ifdef FIXED_POINT
 203 /*#include "smallft.h"*/
 204
 205
 206 void spx_fft_float(void *table, float *in, float *out)
 207 {
 208    int i;
 209 #ifdef USE_SMALLFT
 210    int N = ((struct drft_lookup *)table)->n;
 211 #elif defined(USE_KISS_FFT)
 212    int N = ((struct kiss_config *)table)->N;
 213 #else
 214 #endif
 215 #ifdef VAR_ARRAYS
 216    spx_word16_t _in[N];
 217    spx_word16_t _out[N];
 218 #else
 219    spx_word16_t _in[MAX_FFT_SIZE];
 220    spx_word16_t _out[MAX_FFT_SIZE];
 221 #endif
 222    for (i=0;i<N;i++)
 223       _in[i] = (int)floor(.5+in[i]);
 224    spx_fft(table, _in, _out);
 225    for (i=0;i<N;i++)
 226       out[i] = _out[i];
 227 #if 0
 228    if (!fixed_point)
 229    {
 230       float scale;
 231       struct drft_lookup t;
 232       spx_drft_init(&t, ((struct kiss_config *)table)->N);
 233       scale = 1./((struct kiss_config *)table)->N;
 234       for (i=0;i<((struct kiss_config *)table)->N;i++)
 235          out[i] = scale*in[i];
 236       spx_drft_forward(&t, out);
 237       spx_drft_clear(&t);
 238    }
 239 #endif
 240 }
 241
 242 void spx_ifft_float(void *table, float *in, float *out)
 243 {
 244    int i;
 245 #ifdef USE_SMALLFT
 246    int N = ((struct drft_lookup *)table)->n;
 247 #elif defined(USE_KISS_FFT)
 248    int N = ((struct kiss_config *)table)->N;
 249 #else
 250 #endif
 251 #ifdef VAR_ARRAYS
 252    spx_word16_t _in[N];
 253    spx_word16_t _out[N];
 254 #else
 255    spx_word16_t _in[MAX_FFT_SIZE];
 256    spx_word16_t _out[MAX_FFT_SIZE];
 257 #endif
 258    for (i=0;i<N;i++)
 259       _in[i] = (int)floor(.5+in[i]);
 260    spx_ifft(table, _in, _out);
 261    for (i=0;i<N;i++)
 262       out[i] = _out[i];
 263 #if 0
 264    if (!fixed_point)
 265    {
 266       int i;
 267       struct drft_lookup t;
 268       spx_drft_init(&t, ((struct kiss_config *)table)->N);
 269       for (i=0;i<((struct kiss_config *)table)->N;i++)
 270          out[i] = in[i];
 271       spx_drft_backward(&t, out);
 272       spx_drft_clear(&t);
 273    }
 274 #endif
 275 }
 276
 277 #else
 278
 279 void spx_fft_float(void *table, float *in, float *out)
 280 {
 281    spx_fft(table, in, out);
 282 }
 283 void spx_ifft_float(void *table, float *in, float *out)
 284 {
 285    spx_ifft(table, in, out);
 286 }
 287
 288 #endif