apps/codecs/libfaad/common.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 ** $Id$
  26 **/
  27
  28 /* just some common functions that could be used anywhere */
  29
  30 #include "common.h"
  31 #include "structs.h"
  32
  33 #include <stdlib.h>
  34 #include "syntax.h"
  35
  36
  37 /* Returns the sample rate index based on the samplerate */
  38 uint8_t get_sr_index(const uint32_t samplerate)
  39 {
  40     if (92017 <= samplerate) return 0;
  41     if (75132 <= samplerate) return 1;
  42     if (55426 <= samplerate) return 2;
  43     if (46009 <= samplerate) return 3;
  44     if (37566 <= samplerate) return 4;
  45     if (27713 <= samplerate) return 5;
  46     if (23004 <= samplerate) return 6;
  47     if (18783 <= samplerate) return 7;
  48     if (13856 <= samplerate) return 8;
  49     if (11502 <= samplerate) return 9;
  50     if (9391 <= samplerate) return 10;
  51     if (16428320 <= samplerate) return 11;
  52
  53     return 11;
  54 }
  55
  56 /* Returns the sample rate based on the sample rate index */
  57 uint32_t get_sample_rate(const uint8_t sr_index)
  58 {
  59     static const uint32_t sample_rates[] =
  60     {
  61         96000, 88200, 64000, 48000, 44100, 32000,
  62         24000, 22050, 16000, 12000, 11025, 8000
  63     };
  64
  65     if (sr_index < 12)
  66         return sample_rates[sr_index];
  67
  68     return 0;
  69 }
  70
  71 uint8_t max_pred_sfb(const uint8_t sr_index)
  72 {
  73     static const uint8_t pred_sfb_max[] =
  74     {
  75         33, 33, 38, 40, 40, 40, 41, 41, 37, 37, 37, 34
  76     };
  77
  78
  79     if (sr_index < 12)
  80         return pred_sfb_max[sr_index];
  81
  82     return 0;
  83 }
  84
  85 uint8_t max_tns_sfb(const uint8_t sr_index, const uint8_t object_type,
  86                     const uint8_t is_short)
  87 {
  88     /* entry for each sampling rate
  89      * 1    Main/LC long window
  90      * 2    Main/LC short window
  91      * 3    SSR long window
  92      * 4    SSR short window
  93      */
  94     static const uint8_t tns_sbf_max[][4] =
  95     {
  96         {31,  9, 28, 7}, /* 96000 */
  97         {31,  9, 28, 7}, /* 88200 */
  98         {34, 10, 27, 7}, /* 64000 */
  99         {40, 14, 26, 6}, /* 48000 */
 100         {42, 14, 26, 6}, /* 44100 */
 101         {51, 14, 26, 6}, /* 32000 */
 102         {46, 14, 29, 7}, /* 24000 */
 103         {46, 14, 29, 7}, /* 22050 */
 104         {42, 14, 23, 8}, /* 16000 */
 105         {42, 14, 23, 8}, /* 12000 */
 106         {42, 14, 23, 8}, /* 11025 */
 107         {39, 14, 19, 7}, /*  8000 */
 108         {39, 14, 19, 7}, /*  7350 */
 109         {0,0,0,0},
 110         {0,0,0,0},
 111         {0,0,0,0}
 112     };
 113     uint8_t i = 0;
 114
 115     if (is_short) i++;
 116     if (object_type == SSR) i += 2;
 117
 118     return tns_sbf_max[sr_index][i];
 119 }
 120
 121 /* Returns 0 if an object type is decodable, otherwise returns -1 */
 122 int8_t can_decode_ot(const uint8_t object_type)
 123 {
 124     switch (object_type)
 125     {
 126     case LC:
 127         return 0;
 128     case MAIN:
 129 #ifdef MAIN_DEC
 130         return 0;
 131 #else
 132         return -1;
 133 #endif
 134     case SSR:
 135 #ifdef SSR_DEC
 136         return 0;
 137 #else
 138         return -1;
 139 #endif
 140     case LTP:
 141 #ifdef LTP_DEC
 142         return 0;
 143 #else
 144         return -1;
 145 #endif
 146
 147     /* ER object types */
 148 #ifdef ERROR_RESILIENCE
 149     case ER_LC:
 150 #ifdef DRM
 151     case DRM_ER_LC:
 152 #endif
 153         return 0;
 154     case ER_LTP:
 155 #ifdef LTP_DEC
 156         return 0;
 157 #else
 158         return -1;
 159 #endif
 160     case LD:
 161 #ifdef LD_DEC
 162         return 0;
 163 #else
 164         return -1;
 165 #endif
 166 #endif
 167     }
 168
 169     return -1;
 170 }
 171
 172 static const  uint8_t    Parity [256] = {  // parity
 173     0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
 174     1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
 175     1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
 176     0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
 177     1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
 178     0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
 179     0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
 180     1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0
 181 };
 182
 183 static uint32_t  __r1 = 1;
 184 static uint32_t  __r2 = 1;
 185
 186
 187 /*
 188  *  This is a simple random number generator with good quality for audio purposes.
 189  *  It consists of two polycounters with opposite rotation direction and different
 190  *  periods. The periods are coprime, so the total period is the product of both.
 191  *
 192  *     -------------------------------------------------------------------------------------------------
 193  * +-> |31:30:29:28:27:26:25:24:23:22:21:20:19:18:17:16:15:14:13:12:11:10: 9: 8: 7: 6: 5: 4: 3: 2: 1: 0|
 194  * |   -------------------------------------------------------------------------------------------------
 195  * |                                                                          |  |  |  |     |        |
 196  * |                                                                          +--+--+--+-XOR-+--------+
 197  * |                                                                                      |
 198  * +--------------------------------------------------------------------------------------+
 199  *
 200  *     -------------------------------------------------------------------------------------------------
 201  *     |31:30:29:28:27:26:25:24:23:22:21:20:19:18:17:16:15:14:13:12:11:10: 9: 8: 7: 6: 5: 4: 3: 2: 1: 0| <-+
 202  *     -------------------------------------------------------------------------------------------------   |
 203  *       |  |           |  |                                                                               |
 204  *       +--+----XOR----+--+                                                                               |
 205  *                |                                                                                        |
 206  *                +----------------------------------------------------------------------------------------+
 207  *
 208  *
 209  *  The first has an period of 3*5*17*257*65537, the second of 7*47*73*178481,
 210  *  which gives a period of 18.410.713.077.675.721.215. The result is the
 211  *  XORed values of both generators.
 212  */
 213 uint32_t random_int(void)
 214 {
 215     uint32_t  t1, t2, t3, t4;
 216
 217     t3   = t1 = __r1;   t4   = t2 = __r2;       // Parity calculation is done via table lookup, this is also available
 218     t1  &= 0xF5;        t2 >>= 25;              // on CPUs without parity, can be implemented in C and avoid unpredictable
 219     t1   = Parity [t1]; t2  &= 0x63;            // jumps and slow rotate through the carry flag operations.
 220     t1 <<= 31;          t2   = Parity [t2];
 221
 222     return (__r1 = (t3 >> 1) | t1 ) ^ (__r2 = (t4 + t4) | t2 );
 223 }
 224
 225 #define floor_log2(x) bs_generic(x, BS_LOG2)
 226
 227 #ifdef FIXED_POINT
 228
 229 #define TABLE_BITS 6
 230 /* just take the maximum number of bits for interpolation */
 231 #define INTERP_BITS (REAL_BITS-TABLE_BITS)
 232
 233 static const real_t pow2_tab[] ICONST_ATTR = {
 234     REAL_CONST(1.000000000000000), REAL_CONST(1.010889286051701), REAL_CONST(1.021897148654117),
 235     REAL_CONST(1.033024879021228), REAL_CONST(1.044273782427414), REAL_CONST(1.055645178360557),
 236     REAL_CONST(1.067140400676824), REAL_CONST(1.078760797757120), REAL_CONST(1.090507732665258),
 237     REAL_CONST(1.102382583307841), REAL_CONST(1.114386742595892), REAL_CONST(1.126521618608242),
 238     REAL_CONST(1.138788634756692), REAL_CONST(1.151189229952983), REAL_CONST(1.163724858777578),
 239     REAL_CONST(1.176396991650281), REAL_CONST(1.189207115002721), REAL_CONST(1.202156731452703),
 240     REAL_CONST(1.215247359980469), REAL_CONST(1.228480536106870), REAL_CONST(1.241857812073484),
 241     REAL_CONST(1.255380757024691), REAL_CONST(1.269050957191733), REAL_CONST(1.282870016078778),
 242     REAL_CONST(1.296839554651010), REAL_CONST(1.310961211524764), REAL_CONST(1.325236643159741),
 243     REAL_CONST(1.339667524053303), REAL_CONST(1.354255546936893), REAL_CONST(1.369002422974591),
 244     REAL_CONST(1.383909881963832), REAL_CONST(1.398979672538311), REAL_CONST(1.414213562373095),
 245     REAL_CONST(1.429613338391970), REAL_CONST(1.445180806977047), REAL_CONST(1.460917794180647),
 246     REAL_CONST(1.476826145939499), REAL_CONST(1.492907728291265), REAL_CONST(1.509164427593423),
 247     REAL_CONST(1.525598150744538), REAL_CONST(1.542210825407941), REAL_CONST(1.559004400237837),
 248     REAL_CONST(1.575980845107887), REAL_CONST(1.593142151342267), REAL_CONST(1.610490331949254),
 249     REAL_CONST(1.628027421857348), REAL_CONST(1.645755478153965), REAL_CONST(1.663676580326736),
 250     REAL_CONST(1.681792830507429), REAL_CONST(1.700106353718524), REAL_CONST(1.718619298122478),
 251     REAL_CONST(1.737333835273706), REAL_CONST(1.756252160373300), REAL_CONST(1.775376492526521),
 252     REAL_CONST(1.794709075003107), REAL_CONST(1.814252175500399), REAL_CONST(1.834008086409342),
 253     REAL_CONST(1.853979125083386), REAL_CONST(1.874167634110300), REAL_CONST(1.894575981586966),
 254     REAL_CONST(1.915206561397147), REAL_CONST(1.936061793492294), REAL_CONST(1.957144124175400),
 255     REAL_CONST(1.978456026387951), REAL_CONST(2.000000000000000)
 256 };
 257
 258 static const real_t log2_tab[] ICONST_ATTR_FAAD_LARGE_IRAM = {
 259     REAL_CONST(0.000000000000000), REAL_CONST(0.022367813028455), REAL_CONST(0.044394119358453),
 260     REAL_CONST(0.066089190457772), REAL_CONST(0.087462841250339), REAL_CONST(0.108524456778169),
 261     REAL_CONST(0.129283016944966), REAL_CONST(0.149747119504682), REAL_CONST(0.169925001442312),
 262     REAL_CONST(0.189824558880017), REAL_CONST(0.209453365628950), REAL_CONST(0.228818690495881),
 263     REAL_CONST(0.247927513443585), REAL_CONST(0.266786540694901), REAL_CONST(0.285402218862248),
 264     REAL_CONST(0.303780748177103), REAL_CONST(0.321928094887362), REAL_CONST(0.339850002884625),
 265     REAL_CONST(0.357552004618084), REAL_CONST(0.375039431346925), REAL_CONST(0.392317422778760),
 266     REAL_CONST(0.409390936137702), REAL_CONST(0.426264754702098), REAL_CONST(0.442943495848728),
 267     REAL_CONST(0.459431618637297), REAL_CONST(0.475733430966398), REAL_CONST(0.491853096329675),
 268     REAL_CONST(0.507794640198696), REAL_CONST(0.523561956057013), REAL_CONST(0.539158811108031),
 269     REAL_CONST(0.554588851677637), REAL_CONST(0.569855608330948), REAL_CONST(0.584962500721156),
 270     REAL_CONST(0.599912842187128), REAL_CONST(0.614709844115208), REAL_CONST(0.629356620079610),
 271     REAL_CONST(0.643856189774725), REAL_CONST(0.658211482751795), REAL_CONST(0.672425341971496),
 272     REAL_CONST(0.686500527183218), REAL_CONST(0.700439718141092), REAL_CONST(0.714245517666123),
 273     REAL_CONST(0.727920454563199), REAL_CONST(0.741466986401147), REAL_CONST(0.754887502163469),
 274     REAL_CONST(0.768184324776926), REAL_CONST(0.781359713524660), REAL_CONST(0.794415866350106),
 275     REAL_CONST(0.807354922057604), REAL_CONST(0.820178962415188), REAL_CONST(0.832890014164742),
 276     REAL_CONST(0.845490050944375), REAL_CONST(0.857980995127572), REAL_CONST(0.870364719583405),
 277     REAL_CONST(0.882643049361841), REAL_CONST(0.894817763307943), REAL_CONST(0.906890595608519),
 278     REAL_CONST(0.918863237274595), REAL_CONST(0.930737337562886), REAL_CONST(0.942514505339240),
 279     REAL_CONST(0.954196310386875), REAL_CONST(0.965784284662087), REAL_CONST(0.977279923499917),
 280     REAL_CONST(0.988684686772166), REAL_CONST(1.000000000000000)
 281 };
 282
 283 uint32_t pow2_fix(real_t val)
 284 {
 285     uint32_t x1, x2;
 286     uint32_t errcorr;
 287     uint32_t index_frac;
 288     uint32_t retval;
 289     int32_t whole = (val >> REAL_BITS);
 290
 291     /* rest = [0..1] */
 292     int32_t rest = val - (whole << REAL_BITS);
 293
 294     /* index into pow2_tab */
 295     int32_t index = (rest >> (REAL_BITS-TABLE_BITS)) & ((1<<TABLE_BITS)-1);
 296
 297
 298     if (val == 0)
 299         return (1<<REAL_BITS);
 300
 301     /* leave INTERP_BITS bits */
 302     index_frac = rest >> (REAL_BITS-TABLE_BITS-INTERP_BITS);
 303     index_frac = index_frac & ((1<<INTERP_BITS)-1);
 304
 305     if (whole >= 0)
 306         retval = REAL_CONST(1) << whole;
 307     else
 308         retval = REAL_CONST(1) >> -whole;
 309
 310     x1 = pow2_tab[index    ];
 311     x2 = pow2_tab[index + 1];
 312     errcorr = (index_frac*(x2-x1)) >> INTERP_BITS;
 313
 314     retval = MUL_R(retval, (errcorr + x1));
 315
 316     return retval;
 317 }
 318
 319 uint32_t pow2_int(real_t val)
 320 {
 321     uint32_t x1, x2;
 322     uint32_t errcorr;
 323     uint32_t index_frac;
 324     uint32_t retval;
 325     int32_t whole = (val >> REAL_BITS);
 326
 327     /* rest = [0..1] */
 328     int32_t rest = val - (whole << REAL_BITS);
 329
 330     /* index into pow2_tab */
 331     int32_t index = (rest >> (REAL_BITS-TABLE_BITS)) & ((1<<TABLE_BITS)-1);
 332
 333
 334     if (val == 0)
 335         return 1;
 336
 337     /* leave INTERP_BITS bits */
 338     index_frac = rest >> (REAL_BITS-TABLE_BITS-INTERP_BITS);
 339     index_frac = index_frac & ((1<<INTERP_BITS)-1);
 340
 341     if (whole >= 0)
 342         retval = 1 << whole;
 343     else
 344         retval = 1 >> -whole;
 345
 346     x1 = pow2_tab[index    ];
 347     x2 = pow2_tab[index + 1];
 348     errcorr = (index_frac*(x2-x1)) >> INTERP_BITS;
 349
 350     retval = MUL_R(retval, (errcorr + x1));
 351
 352     return retval;
 353 }
 354
 355 /* ld(x) = ld(x*y/y) = ld(x/y) + ld(y), with y=2^N and [1 <= (x/y) < 2] */
 356 int32_t log2_int(uint32_t val)
 357 {
 358     uint32_t frac;
 359     int32_t exp = 0;
 360     uint32_t index;
 361     uint32_t index_frac;
 362     uint32_t x1, x2;
 363     uint32_t errcorr;
 364
 365     /* error */
 366     if (val == 0)
 367         return -10000;
 368
 369     exp = floor_log2(val);
 370     exp -= REAL_BITS;
 371
 372     /* frac = [1..2] */
 373     if (exp >= 0)
 374         frac = val >> exp;
 375     else
 376         frac = val << -exp;
 377
 378     /* index in the log2 table */
 379     index = frac >> (REAL_BITS-TABLE_BITS);
 380
 381     /* leftover part for linear interpolation */
 382     index_frac = frac & ((1<<(REAL_BITS-TABLE_BITS))-1);
 383
 384     /* leave INTERP_BITS bits */
 385     index_frac = index_frac >> (REAL_BITS-TABLE_BITS-INTERP_BITS);
 386
 387     x1 = log2_tab[index & ((1<<TABLE_BITS)-1)];
 388     x2 = log2_tab[(index & ((1<<TABLE_BITS)-1)) + 1];
 389
 390     /* linear interpolation */
 391     /* retval = exp + ((index_frac)*x2 + (1-index_frac)*x1) */
 392
 393     errcorr = (index_frac * (x2-x1)) >> INTERP_BITS;
 394
 395     return ((exp+REAL_BITS) << REAL_BITS) + errcorr + x1;
 396 }
 397
 398 /* ld(x) = ld(x*y/y) = ld(x/y) + ld(y), with y=2^N and [1 <= (x/y) < 2] */
 399 real_t log2_fix(uint32_t val)
 400 {
 401     uint32_t frac;
 402     int8_t exp = 0;
 403     uint32_t index;
 404     uint32_t index_frac;
 405     uint32_t x1, x2;
 406     uint32_t errcorr;
 407
 408     /* error */
 409     if (val == 0)
 410         return -100000;
 411
 412     exp = floor_log2(val);
 413     exp -= REAL_BITS;
 414
 415     /* frac = [1..2] */
 416     if (exp >= 0)
 417         frac = val >> exp;
 418     else
 419         frac = val << -exp;
 420
 421     /* index in the log2 table */
 422     index = frac >> (REAL_BITS-TABLE_BITS);
 423
 424     /* leftover part for linear interpolation */
 425     index_frac = frac & ((1<<(REAL_BITS-TABLE_BITS))-1);
 426
 427     /* leave INTERP_BITS bits */
 428     index_frac = index_frac >> (REAL_BITS-TABLE_BITS-INTERP_BITS);
 429
 430     x1 = log2_tab[index & ((1<<TABLE_BITS)-1)];
 431     x2 = log2_tab[(index & ((1<<TABLE_BITS)-1)) + 1];
 432
 433     /* linear interpolation */
 434     /* retval = exp + ((index_frac)*x2 + (1-index_frac)*x1) */
 435
 436     errcorr = (index_frac * (x2-x1)) >> INTERP_BITS;
 437
 438     return (exp << REAL_BITS) + errcorr + x1;
 439 }
 440 #endif