git.sesse.net Git - vlc/blob - src/audio_decoder/adec_layer2.c

   1 /*****************************************************************************
   2  * adec_layer2.c: MPEG Layer II audio decoder
   3  *****************************************************************************
   4  * Copyright (C) 1999, 2000 VideoLAN
   5  * $Id: adec_layer2.c,v 1.5 2001/04/12 01:52:45 sam Exp $
   6  *
   7  * Authors: Michel Kaempf <maxx@via.ecp.fr>
   8  *          Michel Lespinasse <walken@via.ecp.fr>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  23  *****************************************************************************/
  24
  25 /*
  26  * TODO :
  27  *
  28  * - optimiser les NeedBits() et les GetBits() du code là où c'est possible ;
  29  *
  30  */
  31
  32 #include "defs.h"
  33
  34 #include <stdlib.h>                                                  /* NULL */
  35 #include <string.h>                                    /* memcpy(), memset() */
  36
  37 #include "config.h"
  38 #include "common.h"
  39 #include "threads.h"
  40 #include "mtime.h"
  41 #include "stream_control.h"
  42 #include "input_ext-dec.h"
  43
  44 #include "adec_generic.h"
  45 #include "audio_decoder.h"
  46 #include "adec_math.h"                                     /* DCT32(), PCM() */
  47
  48 /**** wkn ****/
  49
  50 static float adec_scalefactor_table[64] =
  51 {   /* 2 ^ (1 - i/3) */
  52     2.0000000000000000, 1.5874010519681994, 1.2599210498948732,
  53     1.0000000000000000, 0.7937005259840998, 0.6299605249474366,
  54     0.5000000000000000, 0.3968502629920499, 0.3149802624737183,
  55     0.2500000000000000, 0.1984251314960249, 0.1574901312368591,
  56     0.1250000000000000, 0.0992125657480125, 0.0787450656184296,
  57     0.0625000000000000, 0.0496062828740062, 0.0393725328092148,
  58     0.0312500000000000, 0.0248031414370031, 0.0196862664046074,
  59     0.0156250000000000, 0.0124015707185016, 0.0098431332023037,
  60     0.0078125000000000, 0.0062007853592508, 0.0049215666011518,
  61     0.0039062500000000, 0.0031003926796254, 0.0024607833005759,
  62     0.0019531250000000, 0.0015501963398127, 0.0012303916502880,
  63     0.0009765625000000, 0.0007750981699063, 0.0006151958251440,
  64     0.0004882812500000, 0.0003875490849532, 0.0003075979125720,
  65     0.0002441406250000, 0.0001937745424766, 0.0001537989562860,
  66     0.0001220703125000, 0.0000968872712383, 0.0000768994781430,
  67     0.0000610351562500, 0.0000484436356191, 0.0000384497390715,
  68     0.0000305175781250, 0.0000242218178096, 0.0000192248695357,
  69     0.0000152587890625, 0.0000121109089048, 0.0000096124347679,
  70     0.0000076293945312, 0.0000060554544524, 0.0000048062173839,
  71     0.0000038146972656, 0.0000030277272262, 0.0000024031086920,
  72     0.0000019073486328, 0.0000015138636131, 0.0000012015543460,
  73     0.0000009536743164 /* last element is not in the standard... invalid ??? */
  74 };
  75
  76 static float adec_slope_table[15] =
  77 {
  78     0.6666666666666666, 0.2857142857142857, 0.1333333333333333,
  79     0.0645161290322581, 0.0317460317460317, 0.0157480314960630,
  80     0.0078431372549020, 0.0039138943248532, 0.0019550342130987,
  81     0.0009770395701026, 0.0004884004884005, 0.0002441704309608,
  82     0.0001220777635354, 0.0000610370189520, 0.0000305180437934
  83 };
  84
  85 static float adec_offset_table[15] =
  86 {
  87     -0.6666666666666666, -0.8571428571428571, -0.9333333333333333,
  88     -0.9677419354838710, -0.9841269841269841, -0.9921259842519685,
  89     -0.9960784313725490, -0.9980430528375733, -0.9990224828934506,
  90     -0.9995114802149487, -0.9997557997557998, -0.9998779147845196,
  91     -0.9999389611182323, -0.9999694814905240, -0.9999847409781033
  92 };
  93
  94 static int adec_bound_table[4] = { 4, 8, 12, 16 };
  95
  96 typedef struct
  97 {
  98     s8 nbal[32];
  99     u8 * alloc[32];
 100 } alloc_table_t;
 101
 102 #define L3 -1
 103 #define L5 -2
 104 #define L9 -3
 105
 106 static void adec_layer2_get_table( u32 header, u8 freq_table[15],
 107                                    alloc_table_t ** alloc, int * sblimit )
 108 {
 109     static s8 table_ab0[16] =
 110     {
 111         0, L3, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16
 112     };
 113     static s8 table_ab3[16] =
 114     {
 115         0, L3, L5, 3, L9, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 16
 116     };
 117     static s8 table_ab11[8] =
 118     {
 119         0, L3, L5, 3, L9, 4, 5, 16
 120     };
 121     static s8 table_ab23[8] =
 122     {
 123         0, L3, L5, 16
 124     };
 125     static alloc_table_t mpeg1_ab =
 126     {
 127         {4,4,4,4,4,4,4,4,4,4,4,3,3,3,3,3,3,3,3,3,3,3,3,2,2,2,2,2,2,2,0,0},
 128         {table_ab0,  table_ab0,  table_ab0,  table_ab3,
 129          table_ab3,  table_ab3,  table_ab3,  table_ab3,
 130          table_ab3,  table_ab3,  table_ab3,  table_ab11,
 131          table_ab11, table_ab11, table_ab11, table_ab11,
 132          table_ab11, table_ab11, table_ab11, table_ab11,
 133          table_ab11, table_ab11, table_ab11, table_ab23,
 134          table_ab23, table_ab23, table_ab23, table_ab23,
 135          table_ab23, table_ab23, NULL, NULL}
 136     };
 137
 138     static s8 table_cd[16] =
 139     {
 140         0, L3, L5, L9, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
 141     };
 142     static alloc_table_t mpeg1_cd =
 143     {
 144         {4,4,3,3,3,3,3,3,3,3,3,3,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
 145         {table_cd, table_cd, table_cd, table_cd,
 146          table_cd, table_cd, table_cd, table_cd,
 147          table_cd, table_cd, table_cd, table_cd,
 148          NULL, NULL, NULL, NULL,
 149          NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
 150          NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL}
 151     };
 152
 153     static s8 table_0[16] =
 154     {
 155         0, L3, L5, 3, L9, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14
 156     };
 157     static s8 table_4[8] =
 158     {
 159         0, L3, L5, L9, 4, 5, 6, 7
 160     };
 161     static alloc_table_t mpeg2 =
 162     {
 163         {4,4,4,4,3,3,3,3,3,3,3,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,0,0},
 164         {table_0, table_0, table_0, table_0,
 165          table_4, table_4, table_4, table_4,
 166          table_4, table_4, table_4, table_4,
 167          table_4, table_4, table_4, table_4,
 168          table_4, table_4, table_4, table_4,
 169          table_4, table_4, table_4, table_4,
 170          table_4, table_4, table_4, table_4,
 171          table_4, table_4, NULL, NULL}
 172     };
 173
 174     static alloc_table_t * alloc_table [4] =
 175     {
 176         &mpeg2, &mpeg1_cd, &mpeg1_ab, &mpeg1_ab
 177     };
 178     static int sblimit_table[12] =
 179     {
 180         30, 8, 27, 30, 30, 8, 27, 27, 30, 12, 27, 30
 181     };
 182
 183     int index;
 184
 185     if (!(header & 0x80000))
 186     {
 187         index = 0; /* mpeg2 */
 188     }
 189     else
 190     {
 191         index = (header >> 12) & 15; /* mpeg1, bitrate */
 192         index = freq_table [index];
 193     }
 194
 195     *alloc = alloc_table[index];
 196     index |= (header >> 8) & 12;
 197     *sblimit = sblimit_table[index];
 198 }
 199
 200 int adec_layer2_mono( adec_thread_t * p_adec, s16 * buffer )
 201 {
 202     static u8 freq_table[15] = {2, 1, 1, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2};
 203     static float L3_table[3] = {-2/3.0, 0, 2/3.0};
 204     static float L5_table[5] = {-4/5.0, -2/5.0, 0, 2/5.0, 4/5.0};
 205     static float L9_table[9] = {-8/9.0, -6/9.0, -4/9.0, -2/9.0, 0,
 206                                 2/9.0, 4/9.0, 6/9.0, 8/9.0};
 207
 208     s8 allocation[32];
 209     u8 scfsi[32];
 210     float slope[3][32];
 211     float offset[3][32];
 212     float sample[3][32];
 213     alloc_table_t * alloc_table;
 214
 215     int sblimit;
 216     int sb;
 217     int gr0, gr1;
 218     int s;
 219     int i_read_bits = 0;
 220
 221     /* get the right allocation table */
 222     adec_layer2_get_table (p_adec->header, freq_table, &alloc_table, &sblimit);
 223
 224     /* parse allocation */
 225     //sblimit=27;
 226
 227     for (sb = 0; sb < sblimit; sb++)
 228     {
 229         int index;
 230
 231         index = GetBits( &p_adec->bit_stream, alloc_table->nbal[sb] );
 232         i_read_bits += alloc_table->nbal[sb];
 233
 234         allocation[sb] = alloc_table->alloc[sb][index];
 235     }
 236
 237     /* parse scfsi */
 238
 239     for (sb = 0; sb < sblimit; sb++)
 240     {
 241         if (allocation[sb])
 242         {
 243             scfsi[sb] = GetBits (&p_adec->bit_stream, 2);
 244             i_read_bits += 2;
 245         }
 246     }
 247
 248     /* parse scalefactors */
 249
 250     for (sb = 0; sb < sblimit; sb++)
 251     {
 252         if (allocation[sb])
 253         {
 254             int index_0, index_1, index_2;
 255
 256             switch (scfsi[sb])
 257             {
 258             case 0:
 259                 index_0 = GetBits(&p_adec->bit_stream,6);
 260                 index_1 = GetBits(&p_adec->bit_stream,6);
 261                 index_2 = GetBits(&p_adec->bit_stream,6);
 262                 i_read_bits += 18;
 263
 264                 if (allocation[sb] < 0)
 265                 {
 266                     slope[0][sb] = adec_scalefactor_table[index_0];
 267                     slope[1][sb] = adec_scalefactor_table[index_1];
 268                     slope[2][sb] = adec_scalefactor_table[index_2];
 269                 }
 270                 else
 271                 {
 272                     float r_scalefactor;
 273                     float r_slope, r_offset;
 274
 275                     r_slope = adec_slope_table[allocation[sb]-2];
 276                     r_offset = adec_offset_table[allocation[sb]-2];
 277
 278                     r_scalefactor = adec_scalefactor_table[index_0];
 279                     slope[0][sb] = r_slope * r_scalefactor;
 280                     offset[0][sb] = r_offset * r_scalefactor;
 281
 282                     r_scalefactor = adec_scalefactor_table[index_1];
 283                     slope[1][sb] = r_slope * r_scalefactor;
 284                     offset[1][sb] = r_offset * r_scalefactor;
 285
 286                     r_scalefactor = adec_scalefactor_table[index_2];
 287                     slope[2][sb] = r_slope * r_scalefactor;
 288                     offset[2][sb] = r_offset * r_scalefactor;
 289                 }
 290                 break;
 291
 292             case 1:
 293                 index_0 = GetBits(&p_adec->bit_stream,6);
 294                 index_1 = GetBits(&p_adec->bit_stream,6);
 295                 i_read_bits += 12;
 296
 297                 if (allocation[sb] < 0)
 298                 {
 299                     slope[0][sb] = slope[1][sb] =
 300                         adec_scalefactor_table[index_0];
 301                     slope[2][sb] = adec_scalefactor_table[index_1];
 302                 }
 303                 else
 304                 {
 305                     float r_scalefactor;
 306                     float r_slope, r_offset;
 307
 308                     r_slope = adec_slope_table[allocation[sb]-2];
 309                     r_offset = adec_offset_table[allocation[sb]-2];
 310
 311                     r_scalefactor = adec_scalefactor_table[index_0];
 312                     slope[0][sb] = slope[1][sb] = r_slope * r_scalefactor;
 313                     offset[0][sb] = offset[1][sb] =
 314                         r_offset * r_scalefactor;
 315
 316                     r_scalefactor = adec_scalefactor_table[index_1];
 317                     slope[2][sb] = r_slope * r_scalefactor;
 318                     offset[2][sb] = r_offset * r_scalefactor;
 319                 }
 320                 break;
 321
 322             case 2:
 323                 index_0 = GetBits( &p_adec->bit_stream, 6 );
 324                 i_read_bits += 6;
 325
 326                 if (allocation[sb] < 0)
 327                 {
 328                     slope[0][sb] = slope[1][sb] = slope[2][sb] =
 329                         adec_scalefactor_table[index_0];
 330                 }
 331                 else
 332                 {
 333                     float r_scalefactor;
 334                     float r_slope, r_offset;
 335
 336                     r_slope = adec_slope_table[allocation[sb]-2];
 337                     r_offset = adec_offset_table[allocation[sb]-2];
 338
 339                     r_scalefactor = adec_scalefactor_table[index_0];
 340                     slope[0][sb] = slope[1][sb] = slope[2][sb] =
 341                         r_slope * r_scalefactor;
 342                     offset[0][sb] = offset[1][sb] = offset[2][sb] =
 343                         r_offset * r_scalefactor;
 344                 }
 345                 break;
 346
 347             case 3:
 348                 index_0 = GetBits(&p_adec->bit_stream,6);
 349                 index_1 = GetBits(&p_adec->bit_stream,6);
 350                 i_read_bits += 12;
 351
 352                 if (allocation[sb] < 0)
 353                 {
 354                     slope[0][sb] = adec_scalefactor_table[index_0];
 355                     slope[1][sb] = slope[2][sb] =
 356                         adec_scalefactor_table[index_1];
 357                 }
 358                 else
 359                 {
 360                     float r_scalefactor;
 361                     float r_slope, r_offset;
 362
 363                     r_slope = adec_slope_table[allocation[sb]-2];
 364                     r_offset = adec_offset_table[allocation[sb]-2];
 365
 366                     r_scalefactor = adec_scalefactor_table[index_0];
 367                     slope[0][sb] = r_slope * r_scalefactor;
 368                     offset[0][sb] = r_offset * r_scalefactor;
 369
 370                     r_scalefactor = adec_scalefactor_table[index_1];
 371                     slope[1][sb] = slope[2][sb] = r_slope * r_scalefactor;
 372                     offset[1][sb] = offset[2][sb] =
 373                         r_offset * r_scalefactor;
 374                 }
 375                 break;
 376             }
 377         }
 378     }
 379
 380     /* parse samples */
 381
 382     for (gr0 = 0; gr0 < 3; gr0++)
 383     {
 384         for (gr1 = 0; gr1 < 4; gr1++)
 385         {
 386             s16 * XXX_buf;
 387
 388             for (sb = 0; sb < sblimit; sb++)
 389             {
 390                 int code;
 391
 392                 switch (allocation[sb])
 393                 {
 394                     case 0:
 395                         sample[0][sb] = sample[1][sb] = sample[2][sb] = 0;
 396                         break;
 397
 398                     case L3:
 399                         code = GetBits( &p_adec->bit_stream, 5 );
 400                         i_read_bits += 5;
 401
 402                         sample[0][sb] = slope[gr0][sb] * L3_table[code % 3];
 403                         code /= 3;
 404                         sample[1][sb] = slope[gr0][sb] * L3_table[code % 3];
 405                         code /= 3;
 406                         sample[2][sb] = slope[gr0][sb] * L3_table[code];
 407                     break;
 408
 409                     case L5:
 410                         code = GetBits( &p_adec->bit_stream, 7 );
 411                         i_read_bits += 7;
 412
 413                         sample[0][sb] = slope[gr0][sb] * L5_table[code % 5];
 414                         code /= 5;
 415                         sample[1][sb] = slope[gr0][sb] * L5_table[code % 5];
 416                         code /= 5;
 417                         sample[2][sb] = slope[gr0][sb] * L5_table[code];
 418                     break;
 419
 420                     case L9:
 421                         code = GetBits( &p_adec->bit_stream, 10 );
 422                         i_read_bits += 10;
 423
 424                         sample[0][sb] = slope[gr0][sb] * L9_table[code % 9];
 425                         code /= 9;
 426                         sample[1][sb] = slope[gr0][sb] * L9_table[code % 9];
 427                         code /= 9;
 428                         sample[2][sb] = slope[gr0][sb] * L9_table[code];
 429                     break;
 430
 431                     default:
 432                         for (s = 0; s < 3; s++)
 433                         {
 434                             code = GetBits( &p_adec->bit_stream,
 435                                             allocation[sb] );
 436                             i_read_bits += allocation[sb];
 437
 438                             sample[s][sb] =
 439                                 slope[gr0][sb] * code + offset[gr0][sb];
 440                         }
 441                 }
 442             }
 443
 444             for (; sb < 32; sb++)
 445             {
 446                 sample[0][sb] = sample[1][sb] = sample[2][sb] = 0;
 447             }
 448
 449             for (s = 0; s < 3; s++)
 450             {
 451                 DCT32 (sample[s], &p_adec->bank_0);
 452                 XXX_buf = buffer;
 453                 PCM (&p_adec->bank_0, &XXX_buf, 2);
 454
 455                 /* FIXME: one shouldn't have to do it twice ! */
 456                 DCT32 (sample[s], &p_adec->bank_1);
 457                 XXX_buf = buffer+1;
 458                 PCM (&p_adec->bank_1, &XXX_buf, 2);
 459
 460                 buffer += 64;
 461             }
 462         }
 463     }
 464
 465     p_adec->i_read_bits += i_read_bits;
 466
 467     return 0;
 468 }
 469
 470 int adec_layer2_stereo( adec_thread_t * p_adec, s16 * buffer )
 471 {
 472     static u8 freq_table[15] = {3, 0, 0, 0, 1, 0, 1, 2, 2, 2, 3, 3, 3, 3, 3};
 473     static float L3_table[3] = {-2/3.0, 0, 2/3.0};
 474     static float L5_table[5] = {-4/5.0, -2/5.0, 0, 2/5.0, 4/5.0};
 475     static float L9_table[9] = {-8/9.0, -6/9.0, -4/9.0, -2/9.0, 0,
 476                                 2/9.0, 4/9.0, 6/9.0, 8/9.0};
 477
 478     s8 allocation_0[32], allocation_1[32];
 479     u8 scfsi_0[32], scfsi_1[32];
 480     float slope_0[3][32], slope_1[3][32];
 481     float offset_0[3][32], offset_1[3][32];
 482     float sample_0[3][32], sample_1[3][32];
 483     alloc_table_t * alloc_table;
 484
 485     int sblimit;
 486     int bound;
 487     int sb;
 488     int gr0, gr1;
 489     int s;
 490     int i_read_bits = 0;
 491
 492     /* get the right allocation table */
 493     adec_layer2_get_table (p_adec->header, freq_table, &alloc_table, &sblimit);
 494
 495     /* calculate bound */
 496     bound = sblimit;
 497     if ((p_adec->header & 0xc0) == 0x40) { /* intensity stereo */
 498         int index;
 499         index = (p_adec->header >> 4) & 3;
 500         if (adec_bound_table[index] < sblimit)
 501         {
 502             bound = adec_bound_table[index];
 503         }
 504     }
 505
 506     /* parse allocation */
 507
 508     for (sb = 0; sb < bound; sb++)
 509     {
 510         int index;
 511
 512         index = GetBits( &p_adec->bit_stream, alloc_table->nbal[sb] );
 513         allocation_0[sb] = alloc_table->alloc[sb][index];
 514
 515         index = GetBits( &p_adec->bit_stream, alloc_table->nbal[sb] );
 516         allocation_1[sb] = alloc_table->alloc[sb][index];
 517
 518         i_read_bits += alloc_table->nbal[sb] * 2;
 519     }
 520
 521     for (; sb < sblimit; sb++)
 522     {
 523         int index;
 524
 525         index = GetBits( &p_adec->bit_stream, alloc_table->nbal[sb] );
 526         allocation_0[sb] = allocation_1[sb] = alloc_table->alloc[sb][index];
 527         i_read_bits += alloc_table->nbal[sb];
 528     }
 529
 530     /* parse scfsi */
 531
 532     for (sb = 0; sb < sblimit; sb++)
 533     {
 534         if (allocation_0[sb])
 535         {
 536             scfsi_0[sb] = GetBits (&p_adec->bit_stream, 2);
 537             i_read_bits += 2;
 538         }
 539
 540         if (allocation_1[sb])
 541         {
 542             scfsi_1[sb] = GetBits (&p_adec->bit_stream, 2);
 543             i_read_bits += 2;
 544         }
 545     }
 546
 547     /* parse scalefactors */
 548
 549     for (sb = 0; sb < sblimit; sb++)
 550     {
 551         if (allocation_0[sb])
 552         {
 553             int index_0, index_1, index_2;
 554
 555             switch (scfsi_0[sb])
 556             {
 557             case 0:
 558                 index_0 = GetBits(&p_adec->bit_stream,6);
 559                 index_1 = GetBits(&p_adec->bit_stream,6);
 560                 index_2 = GetBits(&p_adec->bit_stream,6);
 561                 i_read_bits += 18;
 562
 563                 if (allocation_0[sb] < 0)
 564                 {
 565                     slope_0[0][sb] = adec_scalefactor_table[index_0];
 566                     slope_0[1][sb] = adec_scalefactor_table[index_1];
 567                     slope_0[2][sb] = adec_scalefactor_table[index_2];
 568                 }
 569                 else
 570                 {
 571                     float scalefactor;
 572                     float slope, offset;
 573
 574                     slope = adec_slope_table[allocation_0[sb]-2];
 575                     offset = adec_offset_table[allocation_0[sb]-2];
 576
 577                     scalefactor = adec_scalefactor_table[index_0];
 578                     slope_0[0][sb] = slope * scalefactor;
 579                     offset_0[0][sb] = offset * scalefactor;
 580
 581                     scalefactor = adec_scalefactor_table[index_1];
 582                     slope_0[1][sb] = slope * scalefactor;
 583                     offset_0[1][sb] = offset * scalefactor;
 584
 585                     scalefactor = adec_scalefactor_table[index_2];
 586                     slope_0[2][sb] = slope * scalefactor;
 587                     offset_0[2][sb] = offset * scalefactor;
 588                 }
 589                 break;
 590
 591             case 1:
 592                 index_0 = GetBits(&p_adec->bit_stream,6);
 593                 index_1 = GetBits(&p_adec->bit_stream,6);
 594                 i_read_bits += 12;
 595
 596                 if (allocation_0[sb] < 0)
 597                 {
 598                     slope_0[0][sb] = slope_0[1][sb] =
 599                         adec_scalefactor_table[index_0];
 600                     slope_0[2][sb] = adec_scalefactor_table[index_1];
 601                 }
 602                 else
 603                 {
 604                     float scalefactor;
 605                     float slope, offset;
 606
 607                     slope = adec_slope_table[allocation_0[sb]-2];
 608                     offset = adec_offset_table[allocation_0[sb]-2];
 609
 610                     scalefactor = adec_scalefactor_table[index_0];
 611                     slope_0[0][sb] = slope_0[1][sb] = slope * scalefactor;
 612                     offset_0[0][sb] = offset_0[1][sb] =
 613                             offset * scalefactor;
 614
 615                     scalefactor = adec_scalefactor_table[index_1];
 616                     slope_0[2][sb] = slope * scalefactor;
 617                     offset_0[2][sb] = offset * scalefactor;
 618                 }
 619                 break;
 620
 621             case 2:
 622                 index_0 = GetBits( &p_adec->bit_stream, 6 );
 623                 i_read_bits += 6;
 624
 625                 if (allocation_0[sb] < 0)
 626                 {
 627                     slope_0[0][sb] = slope_0[1][sb] = slope_0[2][sb] =
 628                         adec_scalefactor_table[index_0];
 629                 }
 630                 else
 631                 {
 632                     float scalefactor;
 633                     float slope, offset;
 634
 635                     slope = adec_slope_table[allocation_0[sb]-2];
 636                     offset = adec_offset_table[allocation_0[sb]-2];
 637
 638                     scalefactor = adec_scalefactor_table[index_0];
 639                     slope_0[0][sb] = slope_0[1][sb] = slope_0[2][sb] =
 640                         slope * scalefactor;
 641                     offset_0[0][sb] = offset_0[1][sb] = offset_0[2][sb] =
 642                         offset * scalefactor;
 643                 }
 644                 break;
 645
 646             case 3:
 647                 index_0 = GetBits(&p_adec->bit_stream,6);
 648                 index_1 = GetBits(&p_adec->bit_stream,6);
 649                 i_read_bits += 12;
 650
 651                 if (allocation_0[sb] < 0)
 652                 {
 653                     slope_0[0][sb] = adec_scalefactor_table[index_0];
 654                     slope_0[1][sb] = slope_0[2][sb] =
 655                         adec_scalefactor_table[index_1];
 656                 }
 657                 else
 658                 {
 659                     float scalefactor;
 660                     float slope, offset;
 661
 662                     slope = adec_slope_table[allocation_0[sb]-2];
 663                     offset = adec_offset_table[allocation_0[sb]-2];
 664
 665                     scalefactor = adec_scalefactor_table[index_0];
 666                     slope_0[0][sb] = slope * scalefactor;
 667                     offset_0[0][sb] = offset * scalefactor;
 668
 669                     scalefactor = adec_scalefactor_table[index_1];
 670                     slope_0[1][sb] = slope_0[2][sb] = slope * scalefactor;
 671                     offset_0[1][sb] = offset_0[2][sb] =
 672                         offset * scalefactor;
 673                 }
 674                 break;
 675             }
 676         }
 677
 678         if (allocation_1[sb])
 679         {
 680             int index_0, index_1, index_2;
 681
 682             switch (scfsi_1[sb])
 683             {
 684             case 0:
 685                 index_0 = GetBits(&p_adec->bit_stream,6);
 686                 index_1 = GetBits(&p_adec->bit_stream,6);
 687                 index_2 = GetBits(&p_adec->bit_stream,6);
 688                 i_read_bits += 18;
 689
 690                 if (allocation_1[sb] < 0)
 691                 {
 692                     slope_1[0][sb] = adec_scalefactor_table[index_0];
 693                     slope_1[1][sb] = adec_scalefactor_table[index_1];
 694                     slope_1[2][sb] = adec_scalefactor_table[index_2];
 695                 }
 696                 else
 697                 {
 698                     float scalefactor;
 699                     float slope, offset;
 700
 701                     slope = adec_slope_table[allocation_1[sb]-2];
 702                     offset = adec_offset_table[allocation_1[sb]-2];
 703
 704                     scalefactor = adec_scalefactor_table[index_0];
 705                     slope_1[0][sb] = slope * scalefactor;
 706                     offset_1[0][sb] = offset * scalefactor;
 707
 708                     scalefactor = adec_scalefactor_table[index_1];
 709                     slope_1[1][sb] = slope * scalefactor;
 710                     offset_1[1][sb] = offset * scalefactor;
 711
 712                     scalefactor = adec_scalefactor_table[index_2];
 713                     slope_1[2][sb] = slope * scalefactor;
 714                     offset_1[2][sb] = offset * scalefactor;
 715                 }
 716                 break;
 717
 718             case 1:
 719                 index_0 = GetBits(&p_adec->bit_stream,6);
 720                 index_1 = GetBits(&p_adec->bit_stream,6);
 721                 i_read_bits += 12;
 722
 723                 if (allocation_1[sb] < 0)
 724                 {
 725                     slope_1[0][sb] = slope_1[1][sb] =
 726                         adec_scalefactor_table[index_0];
 727                     slope_1[2][sb] = adec_scalefactor_table[index_1];
 728                 }
 729                 else
 730                 {
 731                     float scalefactor;
 732                     float slope, offset;
 733
 734                     slope = adec_slope_table[allocation_1[sb]-2];
 735                     offset = adec_offset_table[allocation_1[sb]-2];
 736
 737                     scalefactor = adec_scalefactor_table[index_0];
 738                     slope_1[0][sb] = slope_1[1][sb] = slope * scalefactor;
 739                     offset_1[0][sb] = offset_1[1][sb] =
 740                         offset * scalefactor;
 741
 742                     scalefactor = adec_scalefactor_table[index_1];
 743                     slope_1[2][sb] = slope * scalefactor;
 744                     offset_1[2][sb] = offset * scalefactor;
 745                 }
 746                 break;
 747
 748             case 2:
 749                 index_0 = GetBits( &p_adec->bit_stream, 6 );
 750                 i_read_bits += 6;
 751
 752                 if (allocation_1[sb] < 0)
 753                 {
 754                     slope_1[0][sb] = slope_1[1][sb] = slope_1[2][sb] =
 755                         adec_scalefactor_table[index_0];
 756                 }
 757                 else
 758                 {
 759                     float scalefactor;
 760                     float slope, offset;
 761
 762                     slope = adec_slope_table[allocation_1[sb]-2];
 763                     offset = adec_offset_table[allocation_1[sb]-2];
 764
 765                     scalefactor = adec_scalefactor_table[index_0];
 766                     slope_1[0][sb] = slope_1[1][sb] = slope_1[2][sb] =
 767                         slope * scalefactor;
 768                     offset_1[0][sb] = offset_1[1][sb] = offset_1[2][sb] =
 769                         offset * scalefactor;
 770                 }
 771                 break;
 772
 773             case 3:
 774                 index_0 = GetBits(&p_adec->bit_stream,6);
 775                 index_1 = GetBits(&p_adec->bit_stream,6);
 776                 i_read_bits += 12;
 777
 778                 if (allocation_1[sb] < 0)
 779                 {
 780                     slope_1[0][sb] = adec_scalefactor_table[index_0];
 781                     slope_1[1][sb] = slope_1[2][sb] =
 782                         adec_scalefactor_table[index_1];
 783                 }
 784                 else
 785                 {
 786                     float scalefactor;
 787                     float slope, offset;
 788
 789                     slope = adec_slope_table[allocation_1[sb]-2];
 790                     offset = adec_offset_table[allocation_1[sb]-2];
 791
 792                     scalefactor = adec_scalefactor_table[index_0];
 793                     slope_1[0][sb] = slope * scalefactor;
 794                     offset_1[0][sb] = offset * scalefactor;
 795
 796                     scalefactor = adec_scalefactor_table[index_1];
 797                     slope_1[1][sb] = slope_1[2][sb] = slope * scalefactor;
 798                     offset_1[1][sb] = offset_1[2][sb] =
 799                         offset * scalefactor;
 800                 }
 801                 break;
 802             }
 803         }
 804     }
 805
 806     /* parse samples */
 807
 808     for (gr0 = 0; gr0 < 3; gr0++)
 809     {
 810         for (gr1 = 0; gr1 < 4; gr1++)
 811         {
 812             s16 * XXX_buf;
 813
 814             for (sb = 0; sb < bound; sb++)
 815             {
 816                 int code;
 817
 818                 switch (allocation_0[sb])
 819                 {
 820                     case 0:
 821                         sample_0[0][sb] = sample_0[1][sb] = sample_0[2][sb] = 0;
 822                         break;
 823
 824                     case L3:
 825                         code = GetBits( &p_adec->bit_stream, 5 );
 826                         i_read_bits += 5;
 827
 828                         sample_0[0][sb] = slope_0[gr0][sb] * L3_table[code % 3];
 829                         code /= 3;
 830                         sample_0[1][sb] = slope_0[gr0][sb] * L3_table[code % 3];
 831                         code /= 3;
 832                         sample_0[2][sb] = slope_0[gr0][sb] * L3_table[code];
 833                     break;
 834
 835                     case L5:
 836                         code = GetBits( &p_adec->bit_stream, 7 );
 837                         i_read_bits += 7;
 838
 839                         sample_0[0][sb] = slope_0[gr0][sb] * L5_table[code % 5];
 840                         code /= 5;
 841                         sample_0[1][sb] = slope_0[gr0][sb] * L5_table[code % 5];
 842                         code /= 5;
 843                         sample_0[2][sb] = slope_0[gr0][sb] * L5_table[code];
 844                     break;
 845
 846                     case L9:
 847                         code = GetBits( &p_adec->bit_stream, 10 );
 848                         i_read_bits += 10;
 849
 850                         sample_0[0][sb] = slope_0[gr0][sb] * L9_table[code % 9];
 851                         code /= 9;
 852                         sample_0[1][sb] = slope_0[gr0][sb] * L9_table[code % 9];
 853                         code /= 9;
 854                         sample_0[2][sb] = slope_0[gr0][sb] * L9_table[code];
 855                     break;
 856
 857                     default:
 858                         for (s = 0; s < 3; s++)
 859                         {
 860                             code = GetBits( &p_adec->bit_stream,
 861                                             allocation_0[sb] );
 862                             i_read_bits += allocation_0[sb];
 863
 864                             sample_0[s][sb] =
 865                                 slope_0[gr0][sb] * code + offset_0[gr0][sb];
 866                         }
 867                 }
 868
 869                 switch (allocation_1[sb])
 870                 {
 871                     case 0:
 872                         sample_1[0][sb] = sample_1[1][sb] = sample_1[2][sb] = 0;
 873                     break;
 874
 875                     case L3:
 876                         code = GetBits( &p_adec->bit_stream, 5 );
 877                         i_read_bits += 5;
 878
 879                         sample_1[0][sb] = slope_1[gr0][sb] * L3_table[code % 3];
 880                         code /= 3;
 881                         sample_1[1][sb] = slope_1[gr0][sb] * L3_table[code % 3];
 882                         code /= 3;
 883                         sample_1[2][sb] = slope_1[gr0][sb] * L3_table[code];
 884                     break;
 885
 886                     case L5:
 887                         code = GetBits( &p_adec->bit_stream, 7 );
 888                         i_read_bits += 7;
 889
 890                         sample_1[0][sb] = slope_1[gr0][sb] * L5_table[code % 5];
 891                         code /= 5;
 892                         sample_1[1][sb] = slope_1[gr0][sb] * L5_table[code % 5];
 893                         code /= 5;
 894                         sample_1[2][sb] = slope_1[gr0][sb] * L5_table[code];
 895                     break;
 896
 897                     case L9:
 898                         code = GetBits( &p_adec->bit_stream, 10 );
 899                         i_read_bits += 10;
 900
 901                         sample_1[0][sb] = slope_1[gr0][sb] * L9_table[code % 9];
 902                         code /= 9;
 903                         sample_1[1][sb] = slope_1[gr0][sb] * L9_table[code % 9];
 904                         code /= 9;
 905                         sample_1[2][sb] = slope_1[gr0][sb] * L9_table[code];
 906                     break;
 907
 908                     default:
 909                         for (s = 0; s < 3; s++)
 910                         {
 911                             code = GetBits( &p_adec->bit_stream,
 912                                             allocation_1[sb] );
 913                             i_read_bits += allocation_1[sb];
 914
 915                             sample_1[s][sb] =
 916                                 slope_1[gr0][sb] * code + offset_1[gr0][sb];
 917                         }
 918                 }
 919             }
 920
 921             for (; sb < sblimit; sb++)
 922             {
 923                 int code;
 924
 925                 switch (allocation_0[sb])
 926                 {
 927                     case 0:
 928                         sample_0[0][sb] = sample_0[1][sb] = sample_0[2][sb] = 0;
 929                         sample_1[0][sb] = sample_1[1][sb] = sample_1[2][sb] = 0;
 930                     break;
 931
 932                     case L3:
 933                         code = GetBits( &p_adec->bit_stream, 5 );
 934                         i_read_bits += 5;
 935
 936                         sample_0[0][sb] = slope_0[gr0][sb] * L3_table[code % 3];
 937                         sample_1[0][sb] = slope_1[gr0][sb] * L3_table[code % 3];
 938                         code /= 3;
 939                         sample_0[1][sb] = slope_0[gr0][sb] * L3_table[code % 3];
 940                         sample_1[1][sb] = slope_1[gr0][sb] * L3_table[code % 3];
 941                         code /= 3;
 942                         sample_0[2][sb] = slope_0[gr0][sb] * L3_table[code];
 943                         sample_1[2][sb] = slope_1[gr0][sb] * L3_table[code];
 944                     break;
 945
 946                     case L5:
 947                         code = GetBits( &p_adec->bit_stream, 7 );
 948                         i_read_bits += 7;
 949
 950                         sample_0[0][sb] = slope_0[gr0][sb] * L5_table[code % 5];
 951                         sample_1[0][sb] = slope_1[gr0][sb] * L5_table[code % 5];
 952                         code /= 5;
 953                         sample_0[1][sb] = slope_0[gr0][sb] * L5_table[code % 5];
 954                         sample_1[1][sb] = slope_1[gr0][sb] * L5_table[code % 5];
 955                         code /= 5;
 956                         sample_0[2][sb] = slope_0[gr0][sb] * L5_table[code];
 957                         sample_1[2][sb] = slope_1[gr0][sb] * L5_table[code];
 958                     break;
 959
 960                     case L9:
 961                         code = GetBits( &p_adec->bit_stream, 10 );
 962                         i_read_bits += 10;
 963
 964                         sample_0[0][sb] = slope_0[gr0][sb] * L9_table[code % 9];
 965                         sample_1[0][sb] = slope_1[gr0][sb] * L9_table[code % 9];
 966                         code /= 9;
 967                         sample_0[1][sb] = slope_0[gr0][sb] * L9_table[code % 9];
 968                         sample_1[1][sb] = slope_1[gr0][sb] * L9_table[code % 9];
 969                         code /= 9;
 970                         sample_0[2][sb] = slope_0[gr0][sb] * L9_table[code];
 971                         sample_1[2][sb] = slope_1[gr0][sb] * L9_table[code];
 972                     break;
 973
 974                     default:
 975                         for (s = 0; s < 3; s++)
 976                         {
 977                             code = GetBits( &p_adec->bit_stream,
 978                                             allocation_0[sb] );
 979                             i_read_bits += allocation_0[sb];
 980
 981                             sample_0[s][sb] =
 982                                 slope_0[gr0][sb] * code + offset_0[gr0][sb];
 983                             sample_1[s][sb] =
 984                                 slope_1[gr0][sb] * code + offset_1[gr0][sb];
 985                         }
 986                 }
 987             }
 988
 989             for (; sb < 32; sb++)
 990             {
 991                 sample_0[0][sb] = sample_0[1][sb] = sample_0[2][sb] = 0;
 992                 sample_1[0][sb] = sample_1[1][sb] = sample_1[2][sb] = 0;
 993             }
 994
 995             for (s = 0; s < 3; s++)
 996             {
 997                 DCT32 (sample_0[s], &p_adec->bank_0);
 998                 XXX_buf = buffer;
 999                 PCM (&p_adec->bank_0, &XXX_buf, 2);
1000
1001                 DCT32 (sample_1[s], &p_adec->bank_1);
1002                 XXX_buf = buffer+1;
1003                 PCM (&p_adec->bank_1, &XXX_buf, 2);
1004
1005                 buffer += 64;
1006             }
1007         }
1008     }
1009
1010     p_adec->i_read_bits += i_read_bits;
1011
1012     return 0;
1013 }
1014