Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 1 | /*Copyright (c) 2003-2004, Mark Borgerding |
| 2 | Lots of modifications by Jean-Marc Valin |
| 3 | Copyright (c) 2005-2007, Xiph.Org Foundation |
| 4 | Copyright (c) 2008, Xiph.Org Foundation, CSIRO |
| 5 | |
| 6 | All rights reserved. |
| 7 | |
| 8 | Redistribution and use in source and binary forms, with or without |
| 9 | modification, are permitted provided that the following conditions are met: |
| 10 | |
| 11 | * Redistributions of source code must retain the above copyright notice, |
| 12 | this list of conditions and the following disclaimer. |
| 13 | * Redistributions in binary form must reproduce the above copyright notice, |
| 14 | this list of conditions and the following disclaimer in the |
| 15 | documentation and/or other materials provided with the distribution. |
| 16 | |
| 17 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| 18 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 19 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 20 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| 21 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 22 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 23 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 24 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 25 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 26 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 27 | POSSIBILITY OF SUCH DAMAGE.*/ |
| 28 | |
| 29 | /* This code is originally from Mark Borgerding's KISS-FFT but has been |
| 30 | heavily modified to better suit Opus */ |
| 31 | |
| 32 | #ifndef SKIP_CONFIG_H |
| 33 | # ifdef HAVE_CONFIG_H |
| 34 | # include "config.h" |
| 35 | # endif |
| 36 | #endif |
| 37 | |
| 38 | #include "_kiss_fft_guts.h" |
| 39 | #include "arch.h" |
| 40 | #include "os_support.h" |
| 41 | #include "mathops.h" |
| 42 | #include "stack_alloc.h" |
| 43 | |
| 44 | /* The guts header contains all the multiplication and addition macros that are defined for |
| 45 | complex numbers. It also delares the kf_ internal functions. |
| 46 | */ |
| 47 | |
| 48 | static void kf_bfly2( |
| 49 | kiss_fft_cpx * Fout, |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 50 | int m, |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 51 | int N |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 52 | ) |
| 53 | { |
| 54 | kiss_fft_cpx * Fout2; |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 55 | int i; |
| 56 | (void)m; |
| 57 | #ifdef CUSTOM_MODES |
| 58 | if (m==1) |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 59 | { |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 60 | celt_assert(m==1); |
| 61 | for (i=0;i<N;i++) |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 62 | { |
| 63 | kiss_fft_cpx t; |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 64 | Fout2 = Fout + 1; |
| 65 | t = *Fout2; |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 66 | C_SUB( *Fout2 , *Fout , t ); |
| 67 | C_ADDTO( *Fout , t ); |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 68 | Fout += 2; |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 69 | } |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 70 | } else |
| 71 | #endif |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 72 | { |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 73 | opus_val16 tw; |
| 74 | tw = QCONST16(0.7071067812f, 15); |
| 75 | /* We know that m==4 here because the radix-2 is just after a radix-4 */ |
| 76 | celt_assert(m==4); |
| 77 | for (i=0;i<N;i++) |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 78 | { |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 79 | kiss_fft_cpx t; |
| 80 | Fout2 = Fout + 4; |
| 81 | t = Fout2[0]; |
| 82 | C_SUB( Fout2[0] , Fout[0] , t ); |
| 83 | C_ADDTO( Fout[0] , t ); |
| 84 | |
| 85 | t.r = S_MUL(Fout2[1].r+Fout2[1].i, tw); |
| 86 | t.i = S_MUL(Fout2[1].i-Fout2[1].r, tw); |
| 87 | C_SUB( Fout2[1] , Fout[1] , t ); |
| 88 | C_ADDTO( Fout[1] , t ); |
| 89 | |
| 90 | t.r = Fout2[2].i; |
| 91 | t.i = -Fout2[2].r; |
| 92 | C_SUB( Fout2[2] , Fout[2] , t ); |
| 93 | C_ADDTO( Fout[2] , t ); |
| 94 | |
| 95 | t.r = S_MUL(Fout2[3].i-Fout2[3].r, tw); |
| 96 | t.i = S_MUL(-Fout2[3].i-Fout2[3].r, tw); |
| 97 | C_SUB( Fout2[3] , Fout[3] , t ); |
| 98 | C_ADDTO( Fout[3] , t ); |
| 99 | Fout += 8; |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 100 | } |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | static void kf_bfly4( |
| 105 | kiss_fft_cpx * Fout, |
| 106 | const size_t fstride, |
| 107 | const kiss_fft_state *st, |
| 108 | int m, |
| 109 | int N, |
| 110 | int mm |
| 111 | ) |
| 112 | { |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 113 | int i; |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 114 | |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 115 | if (m==1) |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 116 | { |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 117 | /* Degenerate case where all the twiddles are 1. */ |
| 118 | for (i=0;i<N;i++) |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 119 | { |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 120 | kiss_fft_cpx scratch0, scratch1; |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 121 | |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 122 | C_SUB( scratch0 , *Fout, Fout[2] ); |
| 123 | C_ADDTO(*Fout, Fout[2]); |
| 124 | C_ADD( scratch1 , Fout[1] , Fout[3] ); |
| 125 | C_SUB( Fout[2], *Fout, scratch1 ); |
| 126 | C_ADDTO( *Fout , scratch1 ); |
| 127 | C_SUB( scratch1 , Fout[1] , Fout[3] ); |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 128 | |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 129 | Fout[1].r = scratch0.r + scratch1.i; |
| 130 | Fout[1].i = scratch0.i - scratch1.r; |
| 131 | Fout[3].r = scratch0.r - scratch1.i; |
| 132 | Fout[3].i = scratch0.i + scratch1.r; |
| 133 | Fout+=4; |
| 134 | } |
| 135 | } else { |
| 136 | int j; |
| 137 | kiss_fft_cpx scratch[6]; |
| 138 | const kiss_twiddle_cpx *tw1,*tw2,*tw3; |
| 139 | const int m2=2*m; |
| 140 | const int m3=3*m; |
| 141 | kiss_fft_cpx * Fout_beg = Fout; |
| 142 | for (i=0;i<N;i++) |
| 143 | { |
| 144 | Fout = Fout_beg + i*mm; |
| 145 | tw3 = tw2 = tw1 = st->twiddles; |
| 146 | /* m is guaranteed to be a multiple of 4. */ |
| 147 | for (j=0;j<m;j++) |
| 148 | { |
| 149 | C_MUL(scratch[0],Fout[m] , *tw1 ); |
| 150 | C_MUL(scratch[1],Fout[m2] , *tw2 ); |
| 151 | C_MUL(scratch[2],Fout[m3] , *tw3 ); |
| 152 | |
| 153 | C_SUB( scratch[5] , *Fout, scratch[1] ); |
| 154 | C_ADDTO(*Fout, scratch[1]); |
| 155 | C_ADD( scratch[3] , scratch[0] , scratch[2] ); |
| 156 | C_SUB( scratch[4] , scratch[0] , scratch[2] ); |
| 157 | C_SUB( Fout[m2], *Fout, scratch[3] ); |
| 158 | tw1 += fstride; |
| 159 | tw2 += fstride*2; |
| 160 | tw3 += fstride*3; |
| 161 | C_ADDTO( *Fout , scratch[3] ); |
| 162 | |
| 163 | Fout[m].r = scratch[5].r + scratch[4].i; |
| 164 | Fout[m].i = scratch[5].i - scratch[4].r; |
| 165 | Fout[m3].r = scratch[5].r - scratch[4].i; |
| 166 | Fout[m3].i = scratch[5].i + scratch[4].r; |
| 167 | ++Fout; |
| 168 | } |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 169 | } |
| 170 | } |
| 171 | } |
| 172 | |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 173 | |
| 174 | #ifndef RADIX_TWO_ONLY |
| 175 | |
| 176 | static void kf_bfly3( |
| 177 | kiss_fft_cpx * Fout, |
| 178 | const size_t fstride, |
| 179 | const kiss_fft_state *st, |
| 180 | int m, |
| 181 | int N, |
| 182 | int mm |
| 183 | ) |
| 184 | { |
| 185 | int i; |
| 186 | size_t k; |
| 187 | const size_t m2 = 2*m; |
| 188 | const kiss_twiddle_cpx *tw1,*tw2; |
| 189 | kiss_fft_cpx scratch[5]; |
| 190 | kiss_twiddle_cpx epi3; |
| 191 | |
| 192 | kiss_fft_cpx * Fout_beg = Fout; |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 193 | #ifdef FIXED_POINT |
| 194 | epi3.r = -16384; |
| 195 | epi3.i = -28378; |
| 196 | #else |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 197 | epi3 = st->twiddles[fstride*m]; |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 198 | #endif |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 199 | for (i=0;i<N;i++) |
| 200 | { |
| 201 | Fout = Fout_beg + i*mm; |
| 202 | tw1=tw2=st->twiddles; |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 203 | /* For non-custom modes, m is guaranteed to be a multiple of 4. */ |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 204 | k=m; |
| 205 | do { |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 206 | |
| 207 | C_MUL(scratch[1],Fout[m] , *tw1); |
| 208 | C_MUL(scratch[2],Fout[m2] , *tw2); |
| 209 | |
| 210 | C_ADD(scratch[3],scratch[1],scratch[2]); |
| 211 | C_SUB(scratch[0],scratch[1],scratch[2]); |
| 212 | tw1 += fstride; |
| 213 | tw2 += fstride*2; |
| 214 | |
| 215 | Fout[m].r = Fout->r - HALF_OF(scratch[3].r); |
| 216 | Fout[m].i = Fout->i - HALF_OF(scratch[3].i); |
| 217 | |
| 218 | C_MULBYSCALAR( scratch[0] , epi3.i ); |
| 219 | |
| 220 | C_ADDTO(*Fout,scratch[3]); |
| 221 | |
| 222 | Fout[m2].r = Fout[m].r + scratch[0].i; |
| 223 | Fout[m2].i = Fout[m].i - scratch[0].r; |
| 224 | |
| 225 | Fout[m].r -= scratch[0].i; |
| 226 | Fout[m].i += scratch[0].r; |
| 227 | |
| 228 | ++Fout; |
| 229 | } while(--k); |
| 230 | } |
| 231 | } |
| 232 | |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 233 | |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 234 | #ifndef OVERRIDE_kf_bfly5 |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 235 | static void kf_bfly5( |
| 236 | kiss_fft_cpx * Fout, |
| 237 | const size_t fstride, |
| 238 | const kiss_fft_state *st, |
| 239 | int m, |
| 240 | int N, |
| 241 | int mm |
| 242 | ) |
| 243 | { |
| 244 | kiss_fft_cpx *Fout0,*Fout1,*Fout2,*Fout3,*Fout4; |
| 245 | int i, u; |
| 246 | kiss_fft_cpx scratch[13]; |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 247 | const kiss_twiddle_cpx *tw; |
| 248 | kiss_twiddle_cpx ya,yb; |
| 249 | kiss_fft_cpx * Fout_beg = Fout; |
| 250 | |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 251 | #ifdef FIXED_POINT |
| 252 | ya.r = 10126; |
| 253 | ya.i = -31164; |
| 254 | yb.r = -26510; |
| 255 | yb.i = -19261; |
| 256 | #else |
| 257 | ya = st->twiddles[fstride*m]; |
| 258 | yb = st->twiddles[fstride*2*m]; |
| 259 | #endif |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 260 | tw=st->twiddles; |
| 261 | |
| 262 | for (i=0;i<N;i++) |
| 263 | { |
| 264 | Fout = Fout_beg + i*mm; |
| 265 | Fout0=Fout; |
| 266 | Fout1=Fout0+m; |
| 267 | Fout2=Fout0+2*m; |
| 268 | Fout3=Fout0+3*m; |
| 269 | Fout4=Fout0+4*m; |
| 270 | |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 271 | /* For non-custom modes, m is guaranteed to be a multiple of 4. */ |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 272 | for ( u=0; u<m; ++u ) { |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 273 | scratch[0] = *Fout0; |
| 274 | |
| 275 | C_MUL(scratch[1] ,*Fout1, tw[u*fstride]); |
| 276 | C_MUL(scratch[2] ,*Fout2, tw[2*u*fstride]); |
| 277 | C_MUL(scratch[3] ,*Fout3, tw[3*u*fstride]); |
| 278 | C_MUL(scratch[4] ,*Fout4, tw[4*u*fstride]); |
| 279 | |
| 280 | C_ADD( scratch[7],scratch[1],scratch[4]); |
| 281 | C_SUB( scratch[10],scratch[1],scratch[4]); |
| 282 | C_ADD( scratch[8],scratch[2],scratch[3]); |
| 283 | C_SUB( scratch[9],scratch[2],scratch[3]); |
| 284 | |
| 285 | Fout0->r += scratch[7].r + scratch[8].r; |
| 286 | Fout0->i += scratch[7].i + scratch[8].i; |
| 287 | |
| 288 | scratch[5].r = scratch[0].r + S_MUL(scratch[7].r,ya.r) + S_MUL(scratch[8].r,yb.r); |
| 289 | scratch[5].i = scratch[0].i + S_MUL(scratch[7].i,ya.r) + S_MUL(scratch[8].i,yb.r); |
| 290 | |
| 291 | scratch[6].r = S_MUL(scratch[10].i,ya.i) + S_MUL(scratch[9].i,yb.i); |
| 292 | scratch[6].i = -S_MUL(scratch[10].r,ya.i) - S_MUL(scratch[9].r,yb.i); |
| 293 | |
| 294 | C_SUB(*Fout1,scratch[5],scratch[6]); |
| 295 | C_ADD(*Fout4,scratch[5],scratch[6]); |
| 296 | |
| 297 | scratch[11].r = scratch[0].r + S_MUL(scratch[7].r,yb.r) + S_MUL(scratch[8].r,ya.r); |
| 298 | scratch[11].i = scratch[0].i + S_MUL(scratch[7].i,yb.r) + S_MUL(scratch[8].i,ya.r); |
| 299 | scratch[12].r = - S_MUL(scratch[10].i,yb.i) + S_MUL(scratch[9].i,ya.i); |
| 300 | scratch[12].i = S_MUL(scratch[10].r,yb.i) - S_MUL(scratch[9].r,ya.i); |
| 301 | |
| 302 | C_ADD(*Fout2,scratch[11],scratch[12]); |
| 303 | C_SUB(*Fout3,scratch[11],scratch[12]); |
| 304 | |
| 305 | ++Fout0;++Fout1;++Fout2;++Fout3;++Fout4; |
| 306 | } |
| 307 | } |
| 308 | } |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 309 | #endif /* OVERRIDE_kf_bfly5 */ |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 310 | |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 311 | |
| 312 | #endif |
| 313 | |
| 314 | |
| 315 | #ifdef CUSTOM_MODES |
| 316 | |
| 317 | static |
| 318 | void compute_bitrev_table( |
| 319 | int Fout, |
| 320 | opus_int16 *f, |
| 321 | const size_t fstride, |
| 322 | int in_stride, |
| 323 | opus_int16 * factors, |
| 324 | const kiss_fft_state *st |
| 325 | ) |
| 326 | { |
| 327 | const int p=*factors++; /* the radix */ |
| 328 | const int m=*factors++; /* stage's fft length/p */ |
| 329 | |
| 330 | /*printf ("fft %d %d %d %d %d %d\n", p*m, m, p, s2, fstride*in_stride, N);*/ |
| 331 | if (m==1) |
| 332 | { |
| 333 | int j; |
| 334 | for (j=0;j<p;j++) |
| 335 | { |
| 336 | *f = Fout+j; |
| 337 | f += fstride*in_stride; |
| 338 | } |
| 339 | } else { |
| 340 | int j; |
| 341 | for (j=0;j<p;j++) |
| 342 | { |
| 343 | compute_bitrev_table( Fout , f, fstride*p, in_stride, factors,st); |
| 344 | f += fstride*in_stride; |
| 345 | Fout += m; |
| 346 | } |
| 347 | } |
| 348 | } |
| 349 | |
| 350 | /* facbuf is populated by p1,m1,p2,m2, ... |
| 351 | where |
| 352 | p[i] * m[i] = m[i-1] |
| 353 | m0 = n */ |
| 354 | static |
| 355 | int kf_factor(int n,opus_int16 * facbuf) |
| 356 | { |
| 357 | int p=4; |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 358 | int i; |
| 359 | int stages=0; |
| 360 | int nbak = n; |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 361 | |
| 362 | /*factor out powers of 4, powers of 2, then any remaining primes */ |
| 363 | do { |
| 364 | while (n % p) { |
| 365 | switch (p) { |
| 366 | case 4: p = 2; break; |
| 367 | case 2: p = 3; break; |
| 368 | default: p += 2; break; |
| 369 | } |
| 370 | if (p>32000 || (opus_int32)p*(opus_int32)p > n) |
| 371 | p = n; /* no more factors, skip to end */ |
| 372 | } |
| 373 | n /= p; |
| 374 | #ifdef RADIX_TWO_ONLY |
| 375 | if (p!=2 && p != 4) |
| 376 | #else |
| 377 | if (p>5) |
| 378 | #endif |
| 379 | { |
| 380 | return 0; |
| 381 | } |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 382 | facbuf[2*stages] = p; |
| 383 | if (p==2 && stages > 1) |
| 384 | { |
| 385 | facbuf[2*stages] = 4; |
| 386 | facbuf[2] = 2; |
| 387 | } |
| 388 | stages++; |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 389 | } while (n > 1); |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 390 | n = nbak; |
| 391 | /* Reverse the order to get the radix 4 at the end, so we can use the |
| 392 | fast degenerate case. It turns out that reversing the order also |
| 393 | improves the noise behaviour. */ |
| 394 | for (i=0;i<stages/2;i++) |
| 395 | { |
| 396 | int tmp; |
| 397 | tmp = facbuf[2*i]; |
| 398 | facbuf[2*i] = facbuf[2*(stages-i-1)]; |
| 399 | facbuf[2*(stages-i-1)] = tmp; |
| 400 | } |
| 401 | for (i=0;i<stages;i++) |
| 402 | { |
| 403 | n /= facbuf[2*i]; |
| 404 | facbuf[2*i+1] = n; |
| 405 | } |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 406 | return 1; |
| 407 | } |
| 408 | |
| 409 | static void compute_twiddles(kiss_twiddle_cpx *twiddles, int nfft) |
| 410 | { |
| 411 | int i; |
| 412 | #ifdef FIXED_POINT |
| 413 | for (i=0;i<nfft;++i) { |
| 414 | opus_val32 phase = -i; |
| 415 | kf_cexp2(twiddles+i, DIV32(SHL32(phase,17),nfft)); |
| 416 | } |
| 417 | #else |
| 418 | for (i=0;i<nfft;++i) { |
| 419 | const double pi=3.14159265358979323846264338327; |
| 420 | double phase = ( -2*pi /nfft ) * i; |
| 421 | kf_cexp(twiddles+i, phase ); |
| 422 | } |
| 423 | #endif |
| 424 | } |
| 425 | |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 426 | int opus_fft_alloc_arch_c(kiss_fft_state *st) { |
| 427 | (void)st; |
| 428 | return 0; |
| 429 | } |
| 430 | |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 431 | /* |
| 432 | * |
| 433 | * Allocates all necessary storage space for the fft and ifft. |
| 434 | * The return value is a contiguous block of memory. As such, |
| 435 | * It can be freed with free(). |
| 436 | * */ |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 437 | kiss_fft_state *opus_fft_alloc_twiddles(int nfft,void * mem,size_t * lenmem, |
| 438 | const kiss_fft_state *base, int arch) |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 439 | { |
| 440 | kiss_fft_state *st=NULL; |
| 441 | size_t memneeded = sizeof(struct kiss_fft_state); /* twiddle factors*/ |
| 442 | |
| 443 | if ( lenmem==NULL ) { |
| 444 | st = ( kiss_fft_state*)KISS_FFT_MALLOC( memneeded ); |
| 445 | }else{ |
| 446 | if (mem != NULL && *lenmem >= memneeded) |
| 447 | st = (kiss_fft_state*)mem; |
| 448 | *lenmem = memneeded; |
| 449 | } |
| 450 | if (st) { |
| 451 | opus_int16 *bitrev; |
| 452 | kiss_twiddle_cpx *twiddles; |
| 453 | |
| 454 | st->nfft=nfft; |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 455 | #ifdef FIXED_POINT |
| 456 | st->scale_shift = celt_ilog2(st->nfft); |
| 457 | if (st->nfft == 1<<st->scale_shift) |
| 458 | st->scale = Q15ONE; |
| 459 | else |
| 460 | st->scale = (1073741824+st->nfft/2)/st->nfft>>(15-st->scale_shift); |
| 461 | #else |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 462 | st->scale = 1.f/nfft; |
| 463 | #endif |
| 464 | if (base != NULL) |
| 465 | { |
| 466 | st->twiddles = base->twiddles; |
| 467 | st->shift = 0; |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 468 | while (st->shift < 32 && nfft<<st->shift != base->nfft) |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 469 | st->shift++; |
| 470 | if (st->shift>=32) |
| 471 | goto fail; |
| 472 | } else { |
| 473 | st->twiddles = twiddles = (kiss_twiddle_cpx*)KISS_FFT_MALLOC(sizeof(kiss_twiddle_cpx)*nfft); |
| 474 | compute_twiddles(twiddles, nfft); |
| 475 | st->shift = -1; |
| 476 | } |
| 477 | if (!kf_factor(nfft,st->factors)) |
| 478 | { |
| 479 | goto fail; |
| 480 | } |
| 481 | |
| 482 | /* bitrev */ |
| 483 | st->bitrev = bitrev = (opus_int16*)KISS_FFT_MALLOC(sizeof(opus_int16)*nfft); |
| 484 | if (st->bitrev==NULL) |
| 485 | goto fail; |
| 486 | compute_bitrev_table(0, bitrev, 1,1, st->factors,st); |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 487 | |
| 488 | /* Initialize architecture specific fft parameters */ |
| 489 | if (opus_fft_alloc_arch(st, arch)) |
| 490 | goto fail; |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 491 | } |
| 492 | return st; |
| 493 | fail: |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 494 | opus_fft_free(st, arch); |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 495 | return NULL; |
| 496 | } |
| 497 | |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 498 | kiss_fft_state *opus_fft_alloc(int nfft,void * mem,size_t * lenmem, int arch) |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 499 | { |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 500 | return opus_fft_alloc_twiddles(nfft, mem, lenmem, NULL, arch); |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 501 | } |
| 502 | |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 503 | void opus_fft_free_arch_c(kiss_fft_state *st) { |
| 504 | (void)st; |
| 505 | } |
| 506 | |
| 507 | void opus_fft_free(const kiss_fft_state *cfg, int arch) |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 508 | { |
| 509 | if (cfg) |
| 510 | { |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 511 | opus_fft_free_arch((kiss_fft_state *)cfg, arch); |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 512 | opus_free((opus_int16*)cfg->bitrev); |
| 513 | if (cfg->shift < 0) |
| 514 | opus_free((kiss_twiddle_cpx*)cfg->twiddles); |
| 515 | opus_free((kiss_fft_state*)cfg); |
| 516 | } |
| 517 | } |
| 518 | |
| 519 | #endif /* CUSTOM_MODES */ |
| 520 | |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 521 | void opus_fft_impl(const kiss_fft_state *st,kiss_fft_cpx *fout) |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 522 | { |
| 523 | int m2, m; |
| 524 | int p; |
| 525 | int L; |
| 526 | int fstride[MAXFACTORS]; |
| 527 | int i; |
| 528 | int shift; |
| 529 | |
| 530 | /* st->shift can be -1 */ |
| 531 | shift = st->shift>0 ? st->shift : 0; |
| 532 | |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 533 | fstride[0] = 1; |
| 534 | L=0; |
| 535 | do { |
| 536 | p = st->factors[2*L]; |
| 537 | m = st->factors[2*L+1]; |
| 538 | fstride[L+1] = fstride[L]*p; |
| 539 | L++; |
| 540 | } while(m!=1); |
| 541 | m = st->factors[2*L-1]; |
| 542 | for (i=L-1;i>=0;i--) |
| 543 | { |
| 544 | if (i!=0) |
| 545 | m2 = st->factors[2*i-1]; |
| 546 | else |
| 547 | m2 = 1; |
| 548 | switch (st->factors[2*i]) |
| 549 | { |
| 550 | case 2: |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 551 | kf_bfly2(fout, m, fstride[i]); |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 552 | break; |
| 553 | case 4: |
| 554 | kf_bfly4(fout,fstride[i]<<shift,st,m, fstride[i], m2); |
| 555 | break; |
| 556 | #ifndef RADIX_TWO_ONLY |
| 557 | case 3: |
| 558 | kf_bfly3(fout,fstride[i]<<shift,st,m, fstride[i], m2); |
| 559 | break; |
| 560 | case 5: |
| 561 | kf_bfly5(fout,fstride[i]<<shift,st,m, fstride[i], m2); |
| 562 | break; |
| 563 | #endif |
| 564 | } |
| 565 | m = m2; |
| 566 | } |
| 567 | } |
| 568 | |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 569 | void opus_fft_c(const kiss_fft_state *st,const kiss_fft_cpx *fin,kiss_fft_cpx *fout) |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 570 | { |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 571 | int i; |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 572 | opus_val16 scale; |
| 573 | #ifdef FIXED_POINT |
| 574 | /* Allows us to scale with MULT16_32_Q16(), which is faster than |
| 575 | MULT16_32_Q15() on ARM. */ |
| 576 | int scale_shift = st->scale_shift-1; |
| 577 | #endif |
| 578 | scale = st->scale; |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 579 | |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 580 | celt_assert2 (fin != fout, "In-place FFT not supported"); |
| 581 | /* Bit-reverse the input */ |
| 582 | for (i=0;i<st->nfft;i++) |
| 583 | { |
| 584 | kiss_fft_cpx x = fin[i]; |
| 585 | fout[st->bitrev[i]].r = SHR32(MULT16_32_Q16(scale, x.r), scale_shift); |
| 586 | fout[st->bitrev[i]].i = SHR32(MULT16_32_Q16(scale, x.i), scale_shift); |
| 587 | } |
| 588 | opus_fft_impl(st, fout); |
| 589 | } |
| 590 | |
| 591 | |
| 592 | void opus_ifft_c(const kiss_fft_state *st,const kiss_fft_cpx *fin,kiss_fft_cpx *fout) |
| 593 | { |
| 594 | int i; |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 595 | celt_assert2 (fin != fout, "In-place FFT not supported"); |
| 596 | /* Bit-reverse the input */ |
| 597 | for (i=0;i<st->nfft;i++) |
| 598 | fout[st->bitrev[i]] = fin[i]; |
flim | c91ee5b | 2016-01-26 14:33:44 +0100 | [diff] [blame] | 599 | for (i=0;i<st->nfft;i++) |
| 600 | fout[i].i = -fout[i].i; |
| 601 | opus_fft_impl(st, fout); |
| 602 | for (i=0;i<st->nfft;i++) |
| 603 | fout[i].i = -fout[i].i; |
Vignesh Venkatasubramanian | 2bd8b54 | 2014-02-20 10:50:35 -0800 | [diff] [blame] | 604 | } |