libfaad2/sbr_fbt.c

   1 /*
   2 ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
   3 ** Copyright (C) 2003-2004 M. Bakker, Ahead Software AG, http://www.nero.com
   4 **
   5 ** This program is free software; you can redistribute it and/or modify
   6 ** it under the terms of the GNU General Public License as published by
   7 ** the Free Software Foundation; either version 2 of the License, or
   8 ** (at your option) any later version.
   9 **
  10 ** This program is distributed in the hope that it will be useful,
  11 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 ** GNU General Public License for more details.
  14 **
  15 ** You should have received a copy of the GNU General Public License
  16 ** along with this program; if not, write to the Free Software
  17 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18 **
  19 ** Any non-GPL usage of this software or parts of this software is strictly
  20 ** forbidden.
  21 **
  22 ** Commercial non-GPL licensing of this software is possible.
  23 ** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
  24 **
  25 ** $Id: sbr_fbt.c,v 1.17 2004/09/08 09:43:11 gcp Exp $
  26 **/
  27
  28 /* Calculate frequency band tables */
  29
  30 #include "common.h"
  31 #include "structs.h"
  32
  33 #ifdef SBR_DEC
  34
  35 #include <stdlib.h>
  36
  37 #include "sbr_syntax.h"
  38 #include "sbr_fbt.h"
  39
  40 /* static function declarations */
  41 static int32_t find_bands(uint8_t warp, uint8_t bands, uint8_t a0, uint8_t a1);
  42
  43
  44 /* calculate the start QMF channel for the master frequency band table */
  45 /* parameter is also called k0 */
  46 uint8_t qmf_start_channel(uint8_t bs_start_freq, uint8_t bs_samplerate_mode,
  47                            uint32_t sample_rate)
  48 {
  49     static const uint8_t startMinTable[12] = { 7, 7, 10, 11, 12, 16, 16,
  50         17, 24, 32, 35, 48 };
  51     static const uint8_t offsetIndexTable[12] = { 5, 5, 4, 4, 4, 3, 2, 1, 0,
  52         6, 6, 6 };
  53     static const int8_t offset[7][16] = {
  54         { -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7 },
  55         { -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13 },
  56         { -5, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16 },
  57         { -6, -4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16 },
  58         { -4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20 },
  59         { -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20, 24 },
  60         { 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20, 24, 28, 33 }
  61     };
  62     uint8_t startMin = startMinTable[get_sr_index(sample_rate)];
  63     uint8_t offsetIndex = offsetIndexTable[get_sr_index(sample_rate)];
  64
  65 #if 0 /* replaced with table (startMinTable) */
  66     if (sample_rate >= 64000)
  67     {
  68         startMin = (uint8_t)((5000.*128.)/(float)sample_rate + 0.5);
  69     } else if (sample_rate < 32000) {
  70         startMin = (uint8_t)((3000.*128.)/(float)sample_rate + 0.5);
  71     } else {
  72         startMin = (uint8_t)((4000.*128.)/(float)sample_rate + 0.5);
  73     }
  74 #endif
  75
  76     if (bs_samplerate_mode)
  77     {
  78         return startMin + offset[offsetIndex][bs_start_freq];
  79
  80 #if 0 /* replaced by offsetIndexTable */
  81         switch (sample_rate)
  82         {
  83         case 16000:
  84             return startMin + offset[0][bs_start_freq];
  85         case 22050:
  86             return startMin + offset[1][bs_start_freq];
  87         case 24000:
  88             return startMin + offset[2][bs_start_freq];
  89         case 32000:
  90             return startMin + offset[3][bs_start_freq];
  91         default:
  92             if (sample_rate > 64000)
  93             {
  94                 return startMin + offset[5][bs_start_freq];
  95             } else { /* 44100 <= sample_rate <= 64000 */
  96                 return startMin + offset[4][bs_start_freq];
  97             }
  98         }
  99 #endif
 100     } else {
 101         return startMin + offset[6][bs_start_freq];
 102     }
 103 }
 104
 105 static int longcmp(const void *a, const void *b)
 106 {
 107     return ((int)(*(int32_t*)a - *(int32_t*)b));
 108 }
 109
 110 /* calculate the stop QMF channel for the master frequency band table */
 111 /* parameter is also called k2 */
 112 uint8_t qmf_stop_channel(uint8_t bs_stop_freq, uint32_t sample_rate,
 113                           uint8_t k0)
 114 {
 115     if (bs_stop_freq == 15)
 116     {
 117         return min(64, k0 * 3);
 118     } else if (bs_stop_freq == 14) {
 119         return min(64, k0 * 2);
 120     } else {
 121         static const uint8_t stopMinTable[12] = { 13, 15, 20, 21, 23,
 122             32, 32, 35, 48, 64, 70, 96 };
 123         static const int8_t offset[12][14] = {
 124             { 0, 2, 4, 6, 8, 11, 14, 18, 22, 26, 31, 37, 44, 51 },
 125             { 0, 2, 4, 6, 8, 11, 14, 18, 22, 26, 31, 36, 42, 49 },
 126             { 0, 2, 4, 6, 8, 11, 14, 17, 21, 25, 29, 34, 39, 44 },
 127             { 0, 2, 4, 6, 8, 11, 14, 17, 20, 24, 28, 33, 38, 43 },
 128             { 0, 2, 4, 6, 8, 11, 14, 17, 20, 24, 28, 32, 36, 41 },
 129             { 0, 2, 4, 6, 8, 10, 12, 14, 17, 20, 23, 26, 29, 32 },
 130             { 0, 2, 4, 6, 8, 10, 12, 14, 17, 20, 23, 26, 29, 32 },
 131             { 0, 1, 3, 5, 7, 9, 11, 13, 15, 17, 20, 23, 26, 29 },
 132             { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16 },
 133             { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
 134             { 0, -1, -2, -3, -4, -5, -6, -6, -6, -6, -6, -6, -6, -6 },
 135             { 0, -3, -6, -9, -12, -15, -18, -20, -22, -24, -26, -28, -30, -32 }
 136         };
 137 #if 0
 138         uint8_t i;
 139         int32_t stopDk[13], stopDk_t[14], k2;
 140 #endif
 141         uint8_t stopMin = stopMinTable[get_sr_index(sample_rate)];
 142
 143 #if 0 /* replaced by table lookup */
 144         if (sample_rate >= 64000)
 145         {
 146             stopMin = (uint8_t)((10000.*128.)/(float)sample_rate + 0.5);
 147         } else if (sample_rate < 32000) {
 148             stopMin = (uint8_t)((6000.*128.)/(float)sample_rate + 0.5);
 149         } else {
 150             stopMin = (uint8_t)((8000.*128.)/(float)sample_rate + 0.5);
 151         }
 152 #endif
 153
 154 #if 0 /* replaced by table lookup */
 155         /* diverging power series */
 156         for (i = 0; i <= 13; i++)
 157         {
 158             stopDk_t[i] = (int32_t)(stopMin*pow(64.0/stopMin, i/13.0) + 0.5);
 159         }
 160         for (i = 0; i < 13; i++)
 161         {
 162             stopDk[i] = stopDk_t[i+1] - stopDk_t[i];
 163         }
 164
 165         /* needed? */
 166         qsort(stopDk, 13, sizeof(stopDk[0]), longcmp);
 167
 168         k2 = stopMin;
 169         for (i = 0; i < bs_stop_freq; i++)
 170         {
 171             k2 += stopDk[i];
 172         }
 173         return min(64, k2);
 174 #endif
 175         /* bs_stop_freq <= 13 */
 176         return min(64, stopMin + offset[get_sr_index(sample_rate)][min(bs_stop_freq, 13)]);
 177     }
 178
 179     return 0;
 180 }
 181
 182 /* calculate the master frequency table from k0, k2, bs_freq_scale
 183    and bs_alter_scale
 184
 185    version for bs_freq_scale = 0
 186 */
 187 uint8_t master_frequency_table_fs0(sbr_info *sbr, uint8_t k0, uint8_t k2,
 188                                    uint8_t bs_alter_scale)
 189 {
 190     int8_t incr;
 191     uint8_t k;
 192     uint8_t dk;
 193     uint32_t nrBands, k2Achieved;
 194     int32_t k2Diff, vDk[64] = {0};
 195
 196     /* mft only defined for k2 > k0 */
 197     if (k2 <= k0)
 198     {
 199         sbr->N_master = 0;
 200         return 1;
 201     }
 202
 203     dk = bs_alter_scale ? 2 : 1;
 204
 205 #if 0 /* replaced by float-less design */
 206     nrBands = 2 * (int32_t)((float)(k2-k0)/(dk*2) + (-1+dk)/2.0f);
 207 #else
 208     if (bs_alter_scale)
 209     {
 210         nrBands = (((k2-k0+2)>>2)<<1);
 211     } else {
 212         nrBands = (((k2-k0)>>1)<<1);
 213     }
 214 #endif
 215     nrBands = min(nrBands, 63);
 216     if (nrBands <= 0)
 217         return 1;
 218
 219     k2Achieved = k0 + nrBands * dk;
 220     k2Diff = k2 - k2Achieved;
 221     for (k = 0; k < nrBands; k++)
 222         vDk[k] = dk;
 223
 224     if (k2Diff)
 225     {
 226         incr = (k2Diff > 0) ? -1 : 1;
 227         k = (uint8_t) ((k2Diff > 0) ? (nrBands-1) : 0);
 228
 229         while (k2Diff != 0)
 230         {
 231             vDk[k] -= incr;
 232             k += incr;
 233             k2Diff += incr;
 234         }
 235     }
 236
 237     sbr->f_master[0] = k0;
 238     for (k = 1; k <= nrBands; k++)
 239         sbr->f_master[k] = (uint8_t)(sbr->f_master[k-1] + vDk[k-1]);
 240
 241     sbr->N_master = (uint8_t)nrBands;
 242     sbr->N_master = (min(sbr->N_master, 64));
 243
 244 #if 0
 245     printf("f_master[%d]: ", nrBands);
 246     for (k = 0; k <= nrBands; k++)
 247     {
 248         printf("%d ", sbr->f_master[k]);
 249     }
 250     printf("\n");
 251 #endif
 252
 253     return 0;
 254 }
 255
 256 /*
 257    This function finds the number of bands using this formula:
 258     bands * log(a1/a0)/log(2.0) + 0.5
 259 */
 260 static int32_t find_bands(uint8_t warp, uint8_t bands, uint8_t a0, uint8_t a1)
 261 {
 262 #ifdef FIXED_POINT
 263     /* table with log2() values */
 264     static const real_t log2Table[65] = {
 265         COEF_CONST(0.0), COEF_CONST(0.0), COEF_CONST(1.0000000000), COEF_CONST(1.5849625007),
 266         COEF_CONST(2.0000000000), COEF_CONST(2.3219280949), COEF_CONST(2.5849625007), COEF_CONST(2.8073549221),
 267         COEF_CONST(3.0000000000), COEF_CONST(3.1699250014), COEF_CONST(3.3219280949), COEF_CONST(3.4594316186),
 268         COEF_CONST(3.5849625007), COEF_CONST(3.7004397181), COEF_CONST(3.8073549221), COEF_CONST(3.9068905956),
 269         COEF_CONST(4.0000000000), COEF_CONST(4.0874628413), COEF_CONST(4.1699250014), COEF_CONST(4.2479275134),
 270         COEF_CONST(4.3219280949), COEF_CONST(4.3923174228), COEF_CONST(4.4594316186), COEF_CONST(4.5235619561),
 271         COEF_CONST(4.5849625007), COEF_CONST(4.6438561898), COEF_CONST(4.7004397181), COEF_CONST(4.7548875022),
 272         COEF_CONST(4.8073549221), COEF_CONST(4.8579809951), COEF_CONST(4.9068905956), COEF_CONST(4.9541963104),
 273         COEF_CONST(5.0000000000), COEF_CONST(5.0443941194), COEF_CONST(5.0874628413), COEF_CONST(5.1292830169),
 274         COEF_CONST(5.1699250014), COEF_CONST(5.2094533656), COEF_CONST(5.2479275134), COEF_CONST(5.2854022189),
 275         COEF_CONST(5.3219280949), COEF_CONST(5.3575520046), COEF_CONST(5.3923174228), COEF_CONST(5.4262647547),
 276         COEF_CONST(5.4594316186), COEF_CONST(5.4918530963), COEF_CONST(5.5235619561), COEF_CONST(5.5545888517),
 277         COEF_CONST(5.5849625007), COEF_CONST(5.6147098441), COEF_CONST(5.6438561898), COEF_CONST(5.6724253420),
 278         COEF_CONST(5.7004397181), COEF_CONST(5.7279204546), COEF_CONST(5.7548875022), COEF_CONST(5.7813597135),
 279         COEF_CONST(5.8073549221), COEF_CONST(5.8328900142), COEF_CONST(5.8579809951), COEF_CONST(5.8826430494),
 280         COEF_CONST(5.9068905956), COEF_CONST(5.9307373376), COEF_CONST(5.9541963104), COEF_CONST(5.9772799235),
 281         COEF_CONST(6.0)
 282     };
 283     real_t r0 = log2Table[a0]; /* coef */
 284     real_t r1 = log2Table[a1]; /* coef */
 285     real_t r2 = (r1 - r0); /* coef */
 286
 287     if (warp)
 288         r2 = MUL_C(r2, COEF_CONST(1.0/1.3));
 289
 290     /* convert r2 to real and then multiply and round */
 291     r2 = (r2 >> (COEF_BITS-REAL_BITS)) * bands + (1<<(REAL_BITS-1));
 292
 293     return (r2 >> REAL_BITS);
 294 #else
 295     real_t div = (real_t)log(2.0);
 296     if (warp) div *= (real_t)1.3;
 297
 298     return (int32_t)(bands * log((float)a1/(float)a0)/div + 0.5);
 299 #endif
 300 }
 301
 302 static real_t find_initial_power(uint8_t bands, uint8_t a0, uint8_t a1)
 303 {
 304 #ifdef FIXED_POINT
 305     /* table with log() values */
 306     static const real_t logTable[65] = {
 307         COEF_CONST(0.0), COEF_CONST(0.0), COEF_CONST(0.6931471806), COEF_CONST(1.0986122887),
 308         COEF_CONST(1.3862943611), COEF_CONST(1.6094379124), COEF_CONST(1.7917594692), COEF_CONST(1.9459101491),
 309         COEF_CONST(2.0794415417), COEF_CONST(2.1972245773), COEF_CONST(2.3025850930), COEF_CONST(2.3978952728),
 310         COEF_CONST(2.4849066498), COEF_CONST(2.5649493575), COEF_CONST(2.6390573296), COEF_CONST(2.7080502011),
 311         COEF_CONST(2.7725887222), COEF_CONST(2.8332133441), COEF_CONST(2.8903717579), COEF_CONST(2.9444389792),
 312         COEF_CONST(2.9957322736), COEF_CONST(3.0445224377), COEF_CONST(3.0910424534), COEF_CONST(3.1354942159),
 313         COEF_CONST(3.1780538303), COEF_CONST(3.2188758249), COEF_CONST(3.2580965380), COEF_CONST(3.2958368660),
 314         COEF_CONST(3.3322045102), COEF_CONST(3.3672958300), COEF_CONST(3.4011973817), COEF_CONST(3.4339872045),
 315         COEF_CONST(3.4657359028), COEF_CONST(3.4965075615), COEF_CONST(3.5263605246), COEF_CONST(3.5553480615),
 316         COEF_CONST(3.5835189385), COEF_CONST(3.6109179126), COEF_CONST(3.6375861597), COEF_CONST(3.6635616461),
 317         COEF_CONST(3.6888794541), COEF_CONST(3.7135720667), COEF_CONST(3.7376696183), COEF_CONST(3.7612001157),
 318         COEF_CONST(3.7841896339), COEF_CONST(3.8066624898), COEF_CONST(3.8286413965), COEF_CONST(3.8501476017),
 319         COEF_CONST(3.8712010109), COEF_CONST(3.8918202981), COEF_CONST(3.9120230054), COEF_CONST(3.9318256327),
 320         COEF_CONST(3.9512437186), COEF_CONST(3.9702919136), COEF_CONST(3.9889840466), COEF_CONST(4.0073331852),
 321         COEF_CONST(4.0253516907), COEF_CONST(4.0430512678), COEF_CONST(4.0604430105), COEF_CONST(4.0775374439),
 322         COEF_CONST(4.0943445622), COEF_CONST(4.1108738642), COEF_CONST(4.1271343850), COEF_CONST(4.1431347264),
 323         COEF_CONST(4.158883083)
 324     };
 325     /* standard Taylor polynomial coefficients for exp(x) around 0 */
 326     /* a polynomial around x=1 is more precise, as most values are around 1.07,
 327        but this is just fine already */
 328     static const real_t c1 = COEF_CONST(1.0);
 329     static const real_t c2 = COEF_CONST(1.0/2.0);
 330     static const real_t c3 = COEF_CONST(1.0/6.0);
 331     static const real_t c4 = COEF_CONST(1.0/24.0);
 332
 333     real_t r0 = logTable[a0]; /* coef */
 334     real_t r1 = logTable[a1]; /* coef */
 335     real_t r2 = (r1 - r0) / bands; /* coef */
 336     real_t rexp = c1 + MUL_C((c1 + MUL_C((c2 + MUL_C((c3 + MUL_C(c4,r2)), r2)), r2)), r2);
 337
 338     return (rexp >> (COEF_BITS-REAL_BITS)); /* real */
 339 #else
 340     return (real_t)pow((real_t)a1/(real_t)a0, 1.0/(real_t)bands);
 341 #endif
 342 }
 343
 344 /*
 345    version for bs_freq_scale > 0
 346 */
 347 uint8_t master_frequency_table(sbr_info *sbr, uint8_t k0, uint8_t k2,
 348                                uint8_t bs_freq_scale, uint8_t bs_alter_scale)
 349 {
 350     uint8_t k, bands, twoRegions;
 351     uint8_t k1;
 352     uint8_t nrBand0, nrBand1;
 353     int32_t vDk0[64] = {0}, vDk1[64] = {0};
 354     int32_t vk0[64] = {0}, vk1[64] = {0};
 355     uint8_t temp1[] = { 6, 5, 4 };
 356     real_t q, qk;
 357     int32_t A_1;
 358 #ifdef FIXED_POINT
 359     real_t rk2, rk0;
 360 #endif
 361
 362     /* mft only defined for k2 > k0 */
 363     if (k2 <= k0)
 364     {
 365         sbr->N_master = 0;
 366         return 1;
 367     }
 368
 369     bands = temp1[bs_freq_scale-1];
 370
 371 #ifdef FIXED_POINT
 372     rk0 = (real_t)k0 << REAL_BITS;
 373     rk2 = (real_t)k2 << REAL_BITS;
 374     if (rk2 > MUL_C(rk0, COEF_CONST(2.2449)))
 375 #else
 376     if ((float)k2/(float)k0 > 2.2449)
 377 #endif
 378     {
 379         twoRegions = 1;
 380         k1 = k0 << 1;
 381     } else {
 382         twoRegions = 0;
 383         k1 = k2;
 384     }
 385
 386     nrBand0 = (uint8_t)(2 * find_bands(0, bands, k0, k1));
 387     nrBand0 = min(nrBand0, 63);
 388     if (nrBand0 <= 0)
 389         return 1;
 390
 391     q = find_initial_power(nrBand0, k0, k1);
 392 #ifdef FIXED_POINT
 393     qk = (real_t)k0 << REAL_BITS;
 394     //A_1 = (int32_t)((qk + REAL_CONST(0.5)) >> REAL_BITS);
 395     A_1 = k0;
 396 #else
 397     qk = REAL_CONST(k0);
 398     A_1 = (int32_t)(qk + .5);
 399 #endif
 400     for (k = 0; k <= nrBand0; k++)
 401     {
 402         int32_t A_0 = A_1;
 403 #ifdef FIXED_POINT
 404         qk = MUL_R(qk,q);
 405         A_1 = (int32_t)((qk + REAL_CONST(0.5)) >> REAL_BITS);
 406 #else
 407         qk *= q;
 408         A_1 = (int32_t)(qk + 0.5);
 409 #endif
 410         vDk0[k] = A_1 - A_0;
 411     }
 412
 413     /* needed? */
 414     qsort(vDk0, nrBand0, sizeof(vDk0[0]), longcmp);
 415
 416     vk0[0] = k0;
 417     for (k = 1; k <= nrBand0; k++)
 418     {
 419         vk0[k] = vk0[k-1] + vDk0[k-1];
 420         if (vDk0[k-1] == 0)
 421             return 1;
 422     }
 423
 424     if (!twoRegions)
 425     {
 426         for (k = 0; k <= nrBand0; k++)
 427             sbr->f_master[k] = (uint8_t) vk0[k];
 428
 429         sbr->N_master = nrBand0;
 430         sbr->N_master = min(sbr->N_master, 64);
 431         return 0;
 432     }
 433
 434     nrBand1 = (uint8_t)(2 * find_bands(1 /* warped */, bands, k1, k2));
 435     nrBand1 = min(nrBand1, 63);
 436
 437     q = find_initial_power(nrBand1, k1, k2);
 438 #ifdef FIXED_POINT
 439     qk = (real_t)k1 << REAL_BITS;
 440     //A_1 = (int32_t)((qk + REAL_CONST(0.5)) >> REAL_BITS);
 441     A_1 = k1;
 442 #else
 443     qk = REAL_CONST(k1);
 444     A_1 = (int32_t)(qk + .5);
 445 #endif
 446     for (k = 0; k <= nrBand1 - 1; k++)
 447     {
 448         int32_t A_0 = A_1;
 449 #ifdef FIXED_POINT
 450         qk = MUL_R(qk,q);
 451         A_1 = (int32_t)((qk + REAL_CONST(0.5)) >> REAL_BITS);
 452 #else
 453         qk *= q;
 454         A_1 = (int32_t)(qk + 0.5);
 455 #endif
 456         vDk1[k] = A_1 - A_0;
 457     }
 458
 459     if (vDk1[0] < vDk0[nrBand0 - 1])
 460     {
 461         int32_t change;
 462
 463         /* needed? */
 464         qsort(vDk1, nrBand1 + 1, sizeof(vDk1[0]), longcmp);
 465         change = vDk0[nrBand0 - 1] - vDk1[0];
 466         vDk1[0] = vDk0[nrBand0 - 1];
 467         vDk1[nrBand1 - 1] = vDk1[nrBand1 - 1] - change;
 468     }
 469
 470     /* needed? */
 471     qsort(vDk1, nrBand1, sizeof(vDk1[0]), longcmp);
 472     vk1[0] = k1;
 473     for (k = 1; k <= nrBand1; k++)
 474     {
 475         vk1[k] = vk1[k-1] + vDk1[k-1];
 476         if (vDk1[k-1] == 0)
 477             return 1;
 478     }
 479
 480     sbr->N_master = nrBand0 + nrBand1;
 481     sbr->N_master = min(sbr->N_master, 64);
 482     for (k = 0; k <= nrBand0; k++)
 483     {
 484         sbr->f_master[k] =  (uint8_t) vk0[k];
 485     }
 486     for (k = nrBand0 + 1; k <= sbr->N_master; k++)
 487     {
 488         sbr->f_master[k] = (uint8_t) vk1[k - nrBand0];
 489     }
 490
 491 #if 0
 492     printf("f_master[%d]: ", sbr->N_master);
 493     for (k = 0; k <= sbr->N_master; k++)
 494     {
 495         printf("%d ", sbr->f_master[k]);
 496     }
 497     printf("\n");
 498 #endif
 499
 500     return 0;
 501 }
 502
 503 /* calculate the derived frequency border tables from f_master */
 504 uint8_t derived_frequency_table(sbr_info *sbr, uint8_t bs_xover_band,
 505                                 uint8_t k2)
 506 {
 507     uint8_t k, i;
 508     uint32_t minus;
 509
 510     /* The following relation shall be satisfied: bs_xover_band < N_Master */
 511     if (sbr->N_master <= bs_xover_band)
 512         return 1;
 513
 514     sbr->N_high = sbr->N_master - bs_xover_band;
 515     sbr->N_low = (sbr->N_high>>1) + (sbr->N_high - ((sbr->N_high>>1)<<1));
 516
 517     sbr->n[0] = sbr->N_low;
 518     sbr->n[1] = sbr->N_high;
 519
 520     for (k = 0; k <= sbr->N_high; k++)
 521     {
 522         sbr->f_table_res[HI_RES][k] = sbr->f_master[k + bs_xover_band];
 523     }
 524
 525     sbr->M = sbr->f_table_res[HI_RES][sbr->N_high] - sbr->f_table_res[HI_RES][0];
 526     sbr->kx = sbr->f_table_res[HI_RES][0];
 527     if (sbr->kx > 32)
 528         return 1;
 529     if (sbr->kx + sbr->M > 64)
 530         return 1;
 531
 532     minus = (sbr->N_high & 1) ? 1 : 0;
 533
 534     for (k = 0; k <= sbr->N_low; k++)
 535     {
 536         if (k == 0)
 537             i = 0;
 538         else
 539             i = (uint8_t)(2*k - minus);
 540         sbr->f_table_res[LO_RES][k] = sbr->f_table_res[HI_RES][i];
 541     }
 542
 543 #if 0
 544     printf("bs_freq_scale: %d\n", sbr->bs_freq_scale);
 545     printf("bs_limiter_bands: %d\n", sbr->bs_limiter_bands);
 546     printf("f_table_res[HI_RES][%d]: ", sbr->N_high);
 547     for (k = 0; k <= sbr->N_high; k++)
 548     {
 549         printf("%d ", sbr->f_table_res[HI_RES][k]);
 550     }
 551     printf("\n");
 552 #endif
 553 #if 0
 554     printf("f_table_res[LO_RES][%d]: ", sbr->N_low);
 555     for (k = 0; k <= sbr->N_low; k++)
 556     {
 557         printf("%d ", sbr->f_table_res[LO_RES][k]);
 558     }
 559     printf("\n");
 560 #endif
 561
 562     sbr->N_Q = 0;
 563     if (sbr->bs_noise_bands == 0)
 564     {
 565         sbr->N_Q = 1;
 566     } else {
 567 #if 0
 568         sbr->N_Q = max(1, (int32_t)(sbr->bs_noise_bands*(log(k2/(float)sbr->kx)/log(2.0)) + 0.5));
 569 #else
 570         sbr->N_Q = (uint8_t)(max(1, find_bands(0, sbr->bs_noise_bands, sbr->kx, k2)));
 571 #endif
 572         sbr->N_Q = min(5, sbr->N_Q);
 573     }
 574
 575     for (k = 0; k <= sbr->N_Q; k++)
 576     {
 577         if (k == 0)
 578         {
 579             i = 0;
 580         } else {
 581             /* i = i + (int32_t)((sbr->N_low - i)/(sbr->N_Q + 1 - k)); */
 582             i = i + (sbr->N_low - i)/(sbr->N_Q + 1 - k);
 583         }
 584         sbr->f_table_noise[k] = sbr->f_table_res[LO_RES][i];
 585     }
 586
 587     /* build table for mapping k to g in hf patching */
 588     for (k = 0; k < 64; k++)
 589     {
 590         uint8_t g;
 591         for (g = 0; g < sbr->N_Q; g++)
 592         {
 593             if ((sbr->f_table_noise[g] <= k) &&
 594                 (k < sbr->f_table_noise[g+1]))
 595             {
 596                 sbr->table_map_k_to_g[k] = g;
 597                 break;
 598             }
 599         }
 600     }
 601
 602 #if 0
 603     printf("f_table_noise[%d]: ", sbr->N_Q);
 604     for (k = 0; k <= sbr->N_Q; k++)
 605     {
 606         printf("%d ", sbr->f_table_noise[k] - sbr->kx);
 607     }
 608     printf("\n");
 609 #endif
 610
 611     return 0;
 612 }
 613
 614 /* TODO: blegh, ugly */
 615 /* Modified to calculate for all possible bs_limiter_bands always
 616  * This reduces the number calls to this functions needed (now only on
 617  * header reset)
 618  */
 619 void limiter_frequency_table(sbr_info *sbr)
 620 {
 621 #if 0
 622     static const real_t limiterBandsPerOctave[] = { REAL_CONST(1.2),
 623         REAL_CONST(2), REAL_CONST(3) };
 624 #else
 625     static const real_t limiterBandsCompare[] = { REAL_CONST(1.327152),
 626         REAL_CONST(1.185093), REAL_CONST(1.119872) };
 627 #endif
 628     uint8_t k, s;
 629     int8_t nrLim;
 630 #if 0
 631     real_t limBands;
 632 #endif
 633
 634     sbr->f_table_lim[0][0] = sbr->f_table_res[LO_RES][0] - sbr->kx;
 635     sbr->f_table_lim[0][1] = sbr->f_table_res[LO_RES][sbr->N_low] - sbr->kx;
 636     sbr->N_L[0] = 1;
 637
 638 #if 0
 639     printf("f_table_lim[%d][%d]: ", 0, sbr->N_L[0]);
 640     for (k = 0; k <= sbr->N_L[0]; k++)
 641     {
 642         printf("%d ", sbr->f_table_lim[0][k]);
 643     }
 644     printf("\n");
 645 #endif
 646
 647     for (s = 1; s < 4; s++)
 648     {
 649         int32_t limTable[100 /*TODO*/] = {0};
 650         uint8_t patchBorders[64/*??*/] = {0};
 651
 652 #if 0
 653         limBands = limiterBandsPerOctave[s - 1];
 654 #endif
 655
 656         patchBorders[0] = sbr->kx;
 657         for (k = 1; k <= sbr->noPatches; k++)
 658         {
 659             patchBorders[k] = patchBorders[k-1] + sbr->patchNoSubbands[k-1];
 660         }
 661
 662         for (k = 0; k <= sbr->N_low; k++)
 663         {
 664             limTable[k] = sbr->f_table_res[LO_RES][k];
 665         }
 666         for (k = 1; k < sbr->noPatches; k++)
 667         {
 668             limTable[k+sbr->N_low] = patchBorders[k];
 669         }
 670
 671         /* needed */
 672         qsort(limTable, sbr->noPatches + sbr->N_low, sizeof(limTable[0]), longcmp);
 673         k = 1;
 674         nrLim = sbr->noPatches + sbr->N_low - 1;
 675
 676         if (nrLim < 0) // TODO: BIG FAT PROBLEM
 677             return;
 678
 679 restart:
 680         if (k <= nrLim)
 681         {
 682             real_t nOctaves;
 683
 684             if (limTable[k-1] != 0)
 685 #if 0
 686                 nOctaves = REAL_CONST(log((float)limTable[k]/(float)limTable[k-1])/log(2.0));
 687 #else
 688 #ifdef FIXED_POINT
 689                 nOctaves = DIV_R((limTable[k]<<REAL_BITS),REAL_CONST(limTable[k-1]));
 690 #else
 691                 nOctaves = (real_t)limTable[k]/(real_t)limTable[k-1];
 692 #endif
 693 #endif
 694             else
 695                 nOctaves = 0;
 696
 697 #if 0
 698             if ((MUL_R(nOctaves,limBands)) < REAL_CONST(0.49))
 699 #else
 700             if (nOctaves < limiterBandsCompare[s - 1])
 701 #endif
 702             {
 703                 uint8_t i;
 704                 if (limTable[k] != limTable[k-1])
 705                 {
 706                     uint8_t found = 0, found2 = 0;
 707                     for (i = 0; i <= sbr->noPatches; i++)
 708                     {
 709                         if (limTable[k] == patchBorders[i])
 710                             found = 1;
 711                     }
 712                     if (found)
 713                     {
 714                         found2 = 0;
 715                         for (i = 0; i <= sbr->noPatches; i++)
 716                         {
 717                             if (limTable[k-1] == patchBorders[i])
 718                                 found2 = 1;
 719                         }
 720                         if (found2)
 721                         {
 722                             k++;
 723                             goto restart;
 724                         } else {
 725                             /* remove (k-1)th element */
 726                             limTable[k-1] = sbr->f_table_res[LO_RES][sbr->N_low];
 727                             qsort(limTable, sbr->noPatches + sbr->N_low, sizeof(limTable[0]), longcmp);
 728                             nrLim--;
 729                             goto restart;
 730                         }
 731                     }
 732                 }
 733                 /* remove kth element */
 734                 limTable[k] = sbr->f_table_res[LO_RES][sbr->N_low];
 735                 qsort(limTable, nrLim, sizeof(limTable[0]), longcmp);
 736                 nrLim--;
 737                 goto restart;
 738             } else {
 739                 k++;
 740                 goto restart;
 741             }
 742         }
 743
 744         sbr->N_L[s] = nrLim;
 745         for (k = 0; k <= nrLim; k++)
 746         {
 747             sbr->f_table_lim[s][k] = limTable[k] - sbr->kx;
 748         }
 749
 750 #if 0
 751         printf("f_table_lim[%d][%d]: ", s, sbr->N_L[s]);
 752         for (k = 0; k <= sbr->N_L[s]; k++)
 753         {
 754             printf("%d ", sbr->f_table_lim[s][k]);
 755         }
 756         printf("\n");
 757 #endif
 758     }
 759 }
 760
 761 #endif