apps/codecs/liba52/parse.c

   1 /*
   2  * parse.c
   3  * Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org>
   4  * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
   5  *
   6  * This file is part of a52dec, a free ATSC A-52 stream decoder.
   7  * See http://liba52.sourceforge.net/ for updates.
   8  *
   9  * a52dec is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * a52dec is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  */
  23
  24 #include "config-a52.h"
  25
  26 #include <string.h>
  27 #include <inttypes.h>
  28
  29 #include "a52.h"
  30 #include "a52_internal.h"
  31 #include "bitstream.h"
  32 #include "tables.h"
  33
  34 #if defined(HAVE_MEMALIGN) && !defined(__cplusplus)
  35 /* some systems have memalign() but no declaration for it */
  36 void * memalign (size_t align, size_t size);
  37 #else
  38 /* assume malloc alignment is sufficient */
  39 #define memalign(align,size) malloc (size)
  40 #endif
  41
  42 typedef struct {
  43     quantizer_t q1[2];
  44     quantizer_t q2[2];
  45     quantizer_t q4;
  46     int q1_ptr;
  47     int q2_ptr;
  48     int q4_ptr;
  49 } quantizer_set_t;
  50
  51 static a52_state_t istate IBSS_ATTR;
  52 static sample_t isamples[256*12] IBSS_ATTR;
  53
  54 static uint8_t halfrate[12] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3};
  55
  56 a52_state_t * a52_init (uint32_t mm_accel)
  57 {
  58     a52_state_t * state;
  59     int i;
  60
  61     #if defined(CPU_COLDFIRE)
  62     coldfire_set_macsr(EMAC_FRACTIONAL | EMAC_ROUND | EMAC_SATURATE);
  63     #endif
  64     /*
  65       this needs to come back if we ever want two decoder instances
  66       simultenously. NOTE, you also need to remove comments in a52_free.
  67     state = (a52_state_t *) malloc (sizeof (a52_state_t));
  68     if (state == NULL)
  69         return NULL;
  70
  71     state->samples = (sample_t *) memalign (16, 256 * 12 * sizeof (sample_t));
  72     if (state->samples == NULL) {
  73         free (state);
  74         return NULL;
  75     }
  76
  77     */
  78     state = &istate;
  79     state->samples = isamples;
  80     for (i = 0; i < 256 * 12; i++)
  81         state->samples[i] = 0;
  82
  83     state->downmixed = 1;
  84
  85     state->lfsr_state = 1;
  86
  87     a52_imdct_init (mm_accel);
  88
  89     return state;
  90 }
  91
  92 sample_t * a52_samples (a52_state_t * state)
  93 {
  94     return state->samples;
  95 }
  96
  97 int a52_syncinfo (uint8_t * buf, int * flags,
  98                   int * sample_rate, int * bit_rate)
  99 {
 100     static int rate[] = { 32,  40,  48,  56,  64,  80,  96, 112,
 101                          128, 160, 192, 224, 256, 320, 384, 448,
 102                          512, 576, 640};
 103     static uint8_t lfeon[8] = {0x10, 0x10, 0x04, 0x04, 0x04, 0x01, 0x04, 0x01};
 104     int frmsizecod;
 105     int bitrate;
 106     int half;
 107     int acmod;
 108
 109     if ((buf[0] != 0x0b) || (buf[1] != 0x77))   /* syncword */
 110         return 0;
 111
 112     if (buf[5] >= 0x60)         /* bsid >= 12 */
 113         return 0;
 114     half = halfrate[buf[5] >> 3];
 115
 116     /* acmod, dsurmod and lfeon */
 117     acmod = buf[6] >> 5;
 118     *flags = ((((buf[6] & 0xf8) == 0x50) ? A52_DOLBY : acmod) |
 119               ((buf[6] & lfeon[acmod]) ? A52_LFE : 0));
 120
 121     frmsizecod = buf[4] & 63;
 122     if (frmsizecod >= 38)
 123         return 0;
 124     bitrate = rate [frmsizecod >> 1];
 125     *bit_rate = (bitrate * 1000) >> half;
 126
 127     switch (buf[4] & 0xc0) {
 128     case 0:
 129         *sample_rate = 48000 >> half;
 130         return 4 * bitrate;
 131     case 0x40:
 132         *sample_rate = 44100 >> half;
 133         return 2 * (320 * bitrate / 147 + (frmsizecod & 1));
 134     case 0x80:
 135         *sample_rate = 32000 >> half;
 136         return 6 * bitrate;
 137     default:
 138         return 0;
 139     }
 140 }
 141
 142 int a52_frame (a52_state_t * state, uint8_t * buf, int * flags,
 143                level_t * level, sample_t bias)
 144 {
 145     static level_t clev[4] = { LEVEL (LEVEL_3DB), LEVEL (LEVEL_45DB),
 146                                LEVEL (LEVEL_6DB), LEVEL (LEVEL_45DB) };
 147     static level_t slev[4] = { LEVEL (LEVEL_3DB), LEVEL (LEVEL_6DB),
 148                                0,                 LEVEL (LEVEL_6DB) };
 149     int chaninfo;
 150     int acmod;
 151
 152     state->fscod = buf[4] >> 6;
 153     state->halfrate = halfrate[buf[5] >> 3];
 154     state->acmod = acmod = buf[6] >> 5;
 155
 156     a52_bitstream_set_ptr (state, buf + 6);
 157     bitstream_get (state, 3);   /* skip acmod we already parsed */
 158
 159     if ((acmod == 2) && (bitstream_get (state, 2) == 2))        /* dsurmod */
 160         acmod = A52_DOLBY;
 161
 162     state->clev = state->slev = 0;
 163
 164     if ((acmod & 1) && (acmod != 1))
 165         state->clev = clev[bitstream_get (state, 2)];   /* cmixlev */
 166
 167     if (acmod & 4)
 168         state->slev = slev[bitstream_get (state, 2)];   /* surmixlev */
 169
 170     state->lfeon = bitstream_get (state, 1);
 171
 172     state->output = a52_downmix_init (acmod, *flags, level,
 173                                       state->clev, state->slev);
 174     if (state->output < 0)
 175         return 1;
 176     if (state->lfeon && (*flags & A52_LFE))
 177         state->output |= A52_LFE;
 178     *flags = state->output;
 179     /* the 2* compensates for differences in imdct */
 180     state->dynrng = state->level = MUL_C (*level, 2);
 181     state->bias = bias;
 182     state->dynrnge = 1;
 183     state->dynrngcall = NULL;
 184     state->cplba.deltbae = DELTA_BIT_NONE;
 185     state->ba[0].deltbae = state->ba[1].deltbae = state->ba[2].deltbae =
 186         state->ba[3].deltbae = state->ba[4].deltbae = DELTA_BIT_NONE;
 187
 188     chaninfo = !acmod;
 189     do {
 190         bitstream_get (state, 5);       /* dialnorm */
 191         if (bitstream_get (state, 1))   /* compre */
 192             bitstream_get (state, 8);   /* compr */
 193         if (bitstream_get (state, 1))   /* langcode */
 194             bitstream_get (state, 8);   /* langcod */
 195         if (bitstream_get (state, 1))   /* audprodie */
 196             bitstream_get (state, 7);   /* mixlevel + roomtyp */
 197     } while (chaninfo--);
 198
 199     bitstream_get (state, 2);           /* copyrightb + origbs */
 200
 201     if (bitstream_get (state, 1))       /* timecod1e */
 202         bitstream_get (state, 14);      /* timecod1 */
 203     if (bitstream_get (state, 1))       /* timecod2e */
 204         bitstream_get (state, 14);      /* timecod2 */
 205
 206     if (bitstream_get (state, 1)) {     /* addbsie */
 207         int addbsil;
 208
 209         addbsil = bitstream_get (state, 6);
 210         do {
 211             bitstream_get (state, 8);   /* addbsi */
 212         } while (addbsil--);
 213     }
 214
 215     return 0;
 216 }
 217
 218 void a52_dynrng (a52_state_t * state,
 219                  level_t (* call) (level_t, void *), void * data)
 220 {
 221     state->dynrnge = 0;
 222     if (call) {
 223         state->dynrnge = 1;
 224         state->dynrngcall = call;
 225         state->dynrngdata = data;
 226     }
 227 }
 228
 229 static int parse_exponents (a52_state_t * state, int expstr, int ngrps,
 230                             uint8_t exponent, uint8_t * dest)
 231 {
 232     int exps;
 233
 234     while (ngrps--) {
 235         exps = bitstream_get (state, 7);
 236
 237         exponent += exp_1[exps];
 238         if (exponent > 24)
 239             return 1;
 240
 241         switch (expstr) {
 242         case EXP_D45:
 243             *(dest++) = exponent;
 244             *(dest++) = exponent;
 245         case EXP_D25:
 246             *(dest++) = exponent;
 247         case EXP_D15:
 248             *(dest++) = exponent;
 249         }
 250
 251         exponent += exp_2[exps];
 252         if (exponent > 24)
 253             return 1;
 254
 255         switch (expstr) {
 256         case EXP_D45:
 257             *(dest++) = exponent;
 258             *(dest++) = exponent;
 259         case EXP_D25:
 260             *(dest++) = exponent;
 261         case EXP_D15:
 262             *(dest++) = exponent;
 263         }
 264
 265         exponent += exp_3[exps];
 266         if (exponent > 24)
 267             return 1;
 268
 269         switch (expstr) {
 270         case EXP_D45:
 271             *(dest++) = exponent;
 272             *(dest++) = exponent;
 273         case EXP_D25:
 274             *(dest++) = exponent;
 275         case EXP_D15:
 276             *(dest++) = exponent;
 277         }
 278     }
 279
 280     return 0;
 281 }
 282
 283 static int parse_deltba (a52_state_t * state, int8_t * deltba)
 284 {
 285     int deltnseg, deltlen, delta, j;
 286
 287     memset (deltba, 0, 50);
 288
 289     deltnseg = bitstream_get (state, 3);
 290     j = 0;
 291     do {
 292         j += bitstream_get (state, 5);
 293         deltlen = bitstream_get (state, 4);
 294         delta = bitstream_get (state, 3);
 295         delta -= (delta >= 4) ? 3 : 4;
 296         if (!deltlen)
 297             continue;
 298         if (j + deltlen >= 50)
 299             return 1;
 300         while (deltlen--)
 301             deltba[j++] = delta;
 302     } while (deltnseg--);
 303
 304     return 0;
 305 }
 306
 307 static inline int zero_snr_offsets (int nfchans, a52_state_t * state)
 308 {
 309     int i;
 310
 311     if ((state->csnroffst) ||
 312         (state->chincpl && state->cplba.bai >> 3) ||    /* cplinu, fsnroffst */
 313         (state->lfeon && state->lfeba.bai >> 3))        /* fsnroffst */
 314         return 0;
 315     for (i = 0; i < nfchans; i++)
 316         if (state->ba[i].bai >> 3)                      /* fsnroffst */
 317             return 0;
 318     return 1;
 319 }
 320
 321 static inline int16_t dither_gen (a52_state_t * state)
 322 {
 323     int16_t nstate;
 324
 325     nstate = dither_lut[state->lfsr_state >> 8] ^ (state->lfsr_state << 8);
 326
 327     state->lfsr_state = (uint16_t) nstate;
 328
 329     return (3 * nstate) >> 2;
 330 }
 331
 332 #ifndef LIBA52_FIXED
 333 #define COEFF(c,t,l,s,e) (c) = (t) * (s)[e]
 334 #else
 335 #define COEFF(c,_t,_l,s,e) do {                                 \
 336     quantizer_t t = (_t);                                       \
 337     level_t l = (_l);                                           \
 338     int shift = e - 5;                                          \
 339     sample_t tmp = t * (l >> 16) + ((t * (l & 0xffff)) >> 16);  \
 340     if (shift >= 0)                                             \
 341         (c) = tmp >> shift;                                     \
 342     else                                                        \
 343         (c) = tmp << -shift;                                    \
 344 } while (0)
 345 #endif
 346
 347 static void coeff_get (a52_state_t * state, sample_t * coeff,
 348                        expbap_t * expbap, quantizer_set_t * quant,
 349                        level_t level, int dither, int end)
 350 {
 351     int i;
 352     uint8_t * exp;
 353     int8_t * bap;
 354
 355 #ifndef LIBA52_FIXED
 356     sample_t factor[25];
 357
 358     for (i = 0; i <= 24; i++)
 359         factor[i] = scale_factor[i] * level;
 360 #endif
 361
 362     exp = expbap->exp;
 363     bap = expbap->bap;
 364
 365     for (i = 0; i < end; i++) {
 366         int bapi;
 367
 368         bapi = bap[i];
 369         switch (bapi) {
 370         case 0:
 371             if (dither) {
 372                 COEFF (coeff[i], dither_gen (state), level, factor, exp[i]);
 373                 continue;
 374             } else {
 375                 coeff[i] = 0;
 376                 continue;
 377             }
 378
 379         case -1:
 380             if (quant->q1_ptr >= 0) {
 381                 COEFF (coeff[i], quant->q1[quant->q1_ptr--], level,
 382                        factor, exp[i]);
 383                 continue;
 384             } else {
 385                 int code;
 386
 387                 code = bitstream_get (state, 5);
 388
 389                 quant->q1_ptr = 1;
 390                 quant->q1[0] = q_1_2[code];
 391                 quant->q1[1] = q_1_1[code];
 392                 COEFF (coeff[i], q_1_0[code], level, factor, exp[i]);
 393                 continue;
 394             }
 395
 396         case -2:
 397             if (quant->q2_ptr >= 0) {
 398                 COEFF (coeff[i], quant->q2[quant->q2_ptr--], level,
 399                        factor, exp[i]);
 400                 continue;
 401             } else {
 402                 int code;
 403
 404                 code = bitstream_get (state, 7);
 405
 406                 quant->q2_ptr = 1;
 407                 quant->q2[0] = q_2_2[code];
 408                 quant->q2[1] = q_2_1[code];
 409                 COEFF (coeff[i], q_2_0[code], level, factor, exp[i]);
 410                 continue;
 411             }
 412
 413         case 3:
 414             COEFF (coeff[i], q_3[bitstream_get (state, 3)], level,
 415                    factor, exp[i]);
 416             continue;
 417
 418         case -3:
 419             if (quant->q4_ptr == 0) {
 420                 quant->q4_ptr = -1;
 421                 COEFF (coeff[i], quant->q4, level, factor, exp[i]);
 422                 continue;
 423             } else {
 424                 int code;
 425
 426                 code = bitstream_get (state, 7);
 427
 428                 quant->q4_ptr = 0;
 429                 quant->q4 = q_4_1[code];
 430                 COEFF (coeff[i], q_4_0[code], level, factor, exp[i]);
 431                 continue;
 432             }
 433
 434         case 4:
 435             COEFF (coeff[i], q_5[bitstream_get (state, 4)], level,
 436                    factor, exp[i]);
 437             continue;
 438
 439         default:
 440             COEFF (coeff[i], bitstream_get_2 (state, bapi) << (16 - bapi),
 441                    level, factor, exp[i]);
 442         }
 443     }
 444 }
 445
 446 static void coeff_get_coupling (a52_state_t * state, int nfchans,
 447                                 level_t * coeff, sample_t (* samples)[256],
 448                                 quantizer_set_t * quant, uint8_t dithflag[5])
 449 {
 450     int cplbndstrc, bnd, i, i_end, ch;
 451     uint8_t * exp;
 452     int8_t * bap;
 453     level_t cplco[5];
 454
 455     exp = state->cpl_expbap.exp;
 456     bap = state->cpl_expbap.bap;
 457     bnd = 0;
 458     cplbndstrc = state->cplbndstrc;
 459     i = state->cplstrtmant;
 460     while (i < state->cplendmant) {
 461         i_end = i + 12;
 462         while (cplbndstrc & 1) {
 463             cplbndstrc >>= 1;
 464             i_end += 12;
 465         }
 466         cplbndstrc >>= 1;
 467         for (ch = 0; ch < nfchans; ch++)
 468             cplco[ch] = MUL_L (state->cplco[ch][bnd], coeff[ch]);
 469         bnd++;
 470
 471         while (i < i_end) {
 472             quantizer_t cplcoeff;
 473             int bapi;
 474
 475             bapi = bap[i];
 476             switch (bapi) {
 477             case 0:
 478                 for (ch = 0; ch < nfchans; ch++)
 479                     if ((state->chincpl >> ch) & 1) {
 480                         if (dithflag[ch])
 481 #ifndef LIBA52_FIXED
 482                             samples[ch][i] = (scale_factor[exp[i]] *
 483                                               cplco[ch] * dither_gen (state));
 484 #else
 485                             COEFF (samples[ch][i], dither_gen (state),
 486                                    cplco[ch], scale_factor, exp[i]);
 487 #endif
 488                         else
 489                             samples[ch][i] = 0;
 490                     }
 491                 i++;
 492                 continue;
 493
 494             case -1:
 495                 if (quant->q1_ptr >= 0) {
 496                     cplcoeff = quant->q1[quant->q1_ptr--];
 497                     break;
 498                 } else {
 499                     int code;
 500
 501                     code = bitstream_get (state, 5);
 502
 503                     quant->q1_ptr = 1;
 504                     quant->q1[0] = q_1_2[code];
 505                     quant->q1[1] = q_1_1[code];
 506                     cplcoeff = q_1_0[code];
 507                     break;
 508                 }
 509
 510             case -2:
 511                 if (quant->q2_ptr >= 0) {
 512                     cplcoeff = quant->q2[quant->q2_ptr--];
 513                     break;
 514                 } else {
 515                     int code;
 516
 517                     code = bitstream_get (state, 7);
 518
 519                     quant->q2_ptr = 1;
 520                     quant->q2[0] = q_2_2[code];
 521                     quant->q2[1] = q_2_1[code];
 522                     cplcoeff = q_2_0[code];
 523                     break;
 524                 }
 525
 526             case 3:
 527                 cplcoeff = q_3[bitstream_get (state, 3)];
 528                 break;
 529
 530             case -3:
 531                 if (quant->q4_ptr == 0) {
 532                     quant->q4_ptr = -1;
 533                     cplcoeff = quant->q4;
 534                     break;
 535                 } else {
 536                     int code;
 537
 538                     code = bitstream_get (state, 7);
 539
 540                     quant->q4_ptr = 0;
 541                     quant->q4 = q_4_1[code];
 542                     cplcoeff = q_4_0[code];
 543                     break;
 544                 }
 545
 546             case 4:
 547                 cplcoeff = q_5[bitstream_get (state, 4)];
 548                 break;
 549
 550             default:
 551                 cplcoeff = bitstream_get_2 (state, bapi) << (16 - bapi);
 552             }
 553 #ifndef LIBA52_FIXED
 554             cplcoeff *= scale_factor[exp[i]];
 555 #endif
 556             for (ch = 0; ch < nfchans; ch++)
 557                if ((state->chincpl >> ch) & 1)
 558 #ifndef LIBA52_FIXED
 559                     samples[ch][i] = cplcoeff * cplco[ch];
 560 #else
 561                     COEFF (samples[ch][i], cplcoeff, cplco[ch],
 562                            scale_factor, exp[i]);
 563 #endif
 564             i++;
 565         }
 566     }
 567 }
 568
 569 int a52_block (a52_state_t * state)
 570 {
 571     static const uint8_t nfchans_tbl[] = {2, 1, 2, 3, 3, 4, 4, 5, 1, 1, 2};
 572     static int rematrix_band[4] = {25, 37, 61, 253};
 573     int i, nfchans, chaninfo;
 574     uint8_t cplexpstr, chexpstr[5], lfeexpstr, do_bit_alloc, done_cpl;
 575     uint8_t blksw[5], dithflag[5];
 576     level_t coeff[5];
 577     int chanbias;
 578     quantizer_set_t quant;
 579     sample_t * samples;
 580
 581     nfchans = nfchans_tbl[state->acmod];
 582
 583     for (i = 0; i < nfchans; i++)
 584         blksw[i] = bitstream_get (state, 1);
 585
 586     for (i = 0; i < nfchans; i++)
 587         dithflag[i] = bitstream_get (state, 1);
 588
 589     chaninfo = !state->acmod;
 590     do {
 591         if (bitstream_get (state, 1)) { /* dynrnge */
 592             int dynrng;
 593
 594             dynrng = bitstream_get_2 (state, 8);
 595             if (state->dynrnge) {
 596                 level_t range;
 597
 598 #if !defined(LIBA52_FIXED)
 599                 range = ((((dynrng & 0x1f) | 0x20) << 13) *
 600                          scale_factor[3 - (dynrng >> 5)]);
 601 #else
 602                 range = ((dynrng & 0x1f) | 0x20) << (21 + (dynrng >> 5));
 603 #endif
 604                 if (state->dynrngcall)
 605                     range = state->dynrngcall (range, state->dynrngdata);
 606                 state->dynrng = MUL_L (state->level, range);
 607             }
 608         }
 609     } while (chaninfo--);
 610
 611     if (bitstream_get (state, 1)) {     /* cplstre */
 612         state->chincpl = 0;
 613         if (bitstream_get (state, 1)) { /* cplinu */
 614             static uint8_t bndtab[16] = {31, 35, 37, 39, 41, 42, 43, 44,
 615                                          45, 45, 46, 46, 47, 47, 48, 48};
 616             int cplbegf;
 617             int cplendf;
 618             int ncplsubnd;
 619
 620             for (i = 0; i < nfchans; i++)
 621                 state->chincpl |= bitstream_get (state, 1) << i;
 622             switch (state->acmod) {
 623             case 0: case 1:
 624                 return 1;
 625             case 2:
 626                 state->phsflginu = bitstream_get (state, 1);
 627             }
 628             cplbegf = bitstream_get (state, 4);
 629             cplendf = bitstream_get (state, 4);
 630
 631             if (cplendf + 3 - cplbegf < 0)
 632                 return 1;
 633             state->ncplbnd = ncplsubnd = cplendf + 3 - cplbegf;
 634             state->cplstrtbnd = bndtab[cplbegf];
 635             state->cplstrtmant = cplbegf * 12 + 37;
 636             state->cplendmant = cplendf * 12 + 73;
 637
 638             state->cplbndstrc = 0;
 639             for (i = 0; i < ncplsubnd - 1; i++)
 640                 if (bitstream_get (state, 1)) {
 641                     state->cplbndstrc |= 1 << i;
 642                     state->ncplbnd--;
 643                 }
 644         }
 645     }
 646
 647     if (state->chincpl) {       /* cplinu */
 648         int j, cplcoe;
 649
 650         cplcoe = 0;
 651         for (i = 0; i < nfchans; i++)
 652             if ((state->chincpl) >> i & 1)
 653                 if (bitstream_get (state, 1)) { /* cplcoe */
 654                     int mstrcplco, cplcoexp, cplcomant;
 655
 656                     cplcoe = 1;
 657                     mstrcplco = 3 * bitstream_get (state, 2);
 658                     for (j = 0; j < state->ncplbnd; j++) {
 659                         cplcoexp = bitstream_get (state, 4);
 660                         cplcomant = bitstream_get (state, 4);
 661                         if (cplcoexp == 15)
 662                             cplcomant <<= 14;
 663                         else
 664                             cplcomant = (cplcomant | 0x10) << 13;
 665 #ifndef LIBA52_FIXED
 666                         state->cplco[i][j] =
 667                             cplcomant * scale_factor[cplcoexp + mstrcplco];
 668 #else
 669                         state->cplco[i][j] = (cplcomant << 11) >> (cplcoexp + mstrcplco);
 670 #endif
 671
 672                     }
 673                 }
 674         if ((state->acmod == 2) && state->phsflginu && cplcoe)
 675             for (j = 0; j < state->ncplbnd; j++)
 676                 if (bitstream_get (state, 1))   /* phsflg */
 677                     state->cplco[1][j] = -state->cplco[1][j];
 678     }
 679
 680     if ((state->acmod == 2) && (bitstream_get (state, 1))) {    /* rematstr */
 681         int end;
 682
 683         state->rematflg = 0;
 684         end = (state->chincpl) ? state->cplstrtmant : 253;      /* cplinu */
 685         i = 0;
 686         do
 687             state->rematflg |= bitstream_get (state, 1) << i;
 688         while (rematrix_band[i++] < end);
 689     }
 690
 691     cplexpstr = EXP_REUSE;
 692     lfeexpstr = EXP_REUSE;
 693     if (state->chincpl) /* cplinu */
 694         cplexpstr = bitstream_get (state, 2);
 695     for (i = 0; i < nfchans; i++)
 696         chexpstr[i] = bitstream_get (state, 2);
 697     if (state->lfeon)
 698         lfeexpstr = bitstream_get (state, 1);
 699
 700     for (i = 0; i < nfchans; i++)
 701         if (chexpstr[i] != EXP_REUSE) {
 702             if ((state->chincpl >> i) & 1)
 703                 state->endmant[i] = state->cplstrtmant;
 704             else {
 705                 int chbwcod;
 706
 707                 chbwcod = bitstream_get (state, 6);
 708                 if (chbwcod > 60)
 709                     return 1;
 710                 state->endmant[i] = chbwcod * 3 + 73;
 711             }
 712         }
 713
 714     do_bit_alloc = 0;
 715
 716     if (cplexpstr != EXP_REUSE) {
 717         int cplabsexp, ncplgrps;
 718
 719         do_bit_alloc = 64;
 720         ncplgrps = ((state->cplendmant - state->cplstrtmant) /
 721                     (3 << (cplexpstr - 1)));
 722         cplabsexp = bitstream_get (state, 4) << 1;
 723         if (parse_exponents (state, cplexpstr, ncplgrps, cplabsexp,
 724                              state->cpl_expbap.exp + state->cplstrtmant))
 725             return 1;
 726     }
 727     for (i = 0; i < nfchans; i++)
 728         if (chexpstr[i] != EXP_REUSE) {
 729             int grp_size, nchgrps;
 730
 731             do_bit_alloc |= 1 << i;
 732             grp_size = 3 << (chexpstr[i] - 1);
 733             nchgrps = (state->endmant[i] + grp_size - 4) / grp_size;
 734             state->fbw_expbap[i].exp[0] = bitstream_get (state, 4);
 735             if (parse_exponents (state, chexpstr[i], nchgrps,
 736                                  state->fbw_expbap[i].exp[0],
 737                                  state->fbw_expbap[i].exp + 1))
 738                 return 1;
 739             bitstream_get (state, 2);   /* gainrng */
 740         }
 741     if (lfeexpstr != EXP_REUSE) {
 742         do_bit_alloc |= 32;
 743         state->lfe_expbap.exp[0] = bitstream_get (state, 4);
 744         if (parse_exponents (state, lfeexpstr, 2, state->lfe_expbap.exp[0],
 745                              state->lfe_expbap.exp + 1))
 746             return 1;
 747     }
 748
 749     if (bitstream_get (state, 1)) {     /* baie */
 750         do_bit_alloc = 127;
 751         state->bai = bitstream_get (state, 11);
 752     }
 753     if (bitstream_get (state, 1)) {     /* snroffste */
 754         do_bit_alloc = 127;
 755         state->csnroffst = bitstream_get (state, 6);
 756         if (state->chincpl)     /* cplinu */
 757             state->cplba.bai = bitstream_get (state, 7);
 758         for (i = 0; i < nfchans; i++)
 759             state->ba[i].bai = bitstream_get (state, 7);
 760         if (state->lfeon)
 761             state->lfeba.bai = bitstream_get (state, 7);
 762     }
 763     if ((state->chincpl) && (bitstream_get (state, 1))) { /* cplleake */
 764         do_bit_alloc |= 64;
 765         state->cplfleak = 9 - bitstream_get (state, 3);
 766         state->cplsleak = 9 - bitstream_get (state, 3);
 767     }
 768
 769     if (bitstream_get (state, 1)) {     /* deltbaie */
 770         do_bit_alloc = 127;
 771         if (state->chincpl)     /* cplinu */
 772             state->cplba.deltbae = bitstream_get (state, 2);
 773         for (i = 0; i < nfchans; i++)
 774             state->ba[i].deltbae = bitstream_get (state, 2);
 775         if (state->chincpl &&   /* cplinu */
 776             (state->cplba.deltbae == DELTA_BIT_NEW) &&
 777             parse_deltba (state, state->cplba.deltba))
 778             return 1;
 779         for (i = 0; i < nfchans; i++)
 780             if ((state->ba[i].deltbae == DELTA_BIT_NEW) &&
 781                 parse_deltba (state, state->ba[i].deltba))
 782                 return 1;
 783     }
 784
 785     if (do_bit_alloc) {
 786         if (zero_snr_offsets (nfchans, state)) {
 787             memset (state->cpl_expbap.bap, 0, sizeof (state->cpl_expbap.bap));
 788             for (i = 0; i < nfchans; i++)
 789                 memset (state->fbw_expbap[i].bap, 0,
 790                         sizeof (state->fbw_expbap[i].bap));
 791             memset (state->lfe_expbap.bap, 0, sizeof (state->lfe_expbap.bap));
 792         } else {
 793             if (state->chincpl && (do_bit_alloc & 64))  /* cplinu */
 794                 a52_bit_allocate (state, &state->cplba, state->cplstrtbnd,
 795                                   state->cplstrtmant, state->cplendmant,
 796                                   state->cplfleak << 8, state->cplsleak << 8,
 797                                   &state->cpl_expbap);
 798             for (i = 0; i < nfchans; i++)
 799                 if (do_bit_alloc & (1 << i))
 800                     a52_bit_allocate (state, state->ba + i, 0, 0,
 801                                       state->endmant[i], 0, 0,
 802                                       state->fbw_expbap +i);
 803             if (state->lfeon && (do_bit_alloc & 32)) {
 804                 state->lfeba.deltbae = DELTA_BIT_NONE;
 805                 a52_bit_allocate (state, &state->lfeba, 0, 0, 7, 0, 0,
 806                                   &state->lfe_expbap);
 807             }
 808         }
 809     }
 810
 811     if (bitstream_get (state, 1)) {     /* skiple */
 812         i = bitstream_get (state, 9);   /* skipl */
 813         while (i--)
 814             bitstream_get (state, 8);
 815     }
 816
 817     samples = state->samples;
 818     if (state->output & A52_LFE)
 819         samples += 256; /* shift for LFE channel */
 820
 821     chanbias = a52_downmix_coeff (coeff, state->acmod, state->output,
 822                                   state->dynrng, state->clev, state->slev);
 823
 824     quant.q1_ptr = quant.q2_ptr = quant.q4_ptr = -1;
 825     done_cpl = 0;
 826
 827     for (i = 0; i < nfchans; i++) {
 828         int j;
 829
 830         coeff_get (state, samples + 256 * i, state->fbw_expbap +i, &quant,
 831                    coeff[i], dithflag[i], state->endmant[i]);
 832
 833         if ((state->chincpl >> i) & 1) {
 834             if (!done_cpl) {
 835                 done_cpl = 1;
 836                 coeff_get_coupling (state, nfchans, coeff,
 837                                     (sample_t (*)[256])samples, &quant,
 838                                     dithflag);
 839             }
 840             j = state->cplendmant;
 841         } else
 842             j = state->endmant[i];
 843         do
 844             (samples + 256 * i)[j] = 0;
 845         while (++j < 256);
 846     }
 847
 848     if (state->acmod == 2) {
 849         int j, end, band, rematflg;
 850
 851         end = ((state->endmant[0] < state->endmant[1]) ?
 852                state->endmant[0] : state->endmant[1]);
 853
 854         i = 0;
 855         j = 13;
 856         rematflg = state->rematflg;
 857         do {
 858             if (! (rematflg & 1)) {
 859                 rematflg >>= 1;
 860                 j = rematrix_band[i++];
 861                 continue;
 862             }
 863             rematflg >>= 1;
 864             band = rematrix_band[i++];
 865             if (band > end)
 866                 band = end;
 867             do {
 868                 sample_t tmp0, tmp1;
 869
 870                 tmp0 = samples[j];
 871                 tmp1 = (samples+256)[j];
 872                 samples[j] = tmp0 + tmp1;
 873                 (samples+256)[j] = tmp0 - tmp1;
 874             } while (++j < band);
 875         } while (j < end);
 876     }
 877
 878     if (state->lfeon) {
 879         if (state->output & A52_LFE) {
 880             coeff_get (state, samples - 256, &state->lfe_expbap, &quant,
 881                        state->dynrng, 0, 7);
 882             for (i = 7; i < 256; i++)
 883                 (samples-256)[i] = 0;
 884             a52_imdct_512 (samples - 256, samples + 1536 - 256, state->bias);
 885         } else {
 886             /* just skip the LFE coefficients */
 887             coeff_get (state, samples + 1280, &state->lfe_expbap, &quant,
 888                        0, 0, 7);
 889         }
 890     }
 891
 892     i = 0;
 893     if (nfchans_tbl[state->output & A52_CHANNEL_MASK] < nfchans)
 894         for (i = 1; i < nfchans; i++)
 895             if (blksw[i] != blksw[0])
 896                 break;
 897
 898     if (i < nfchans) {
 899         if (state->downmixed) {
 900             state->downmixed = 0;
 901             a52_upmix (samples + 1536, state->acmod, state->output);
 902         }
 903
 904         for (i = 0; i < nfchans; i++) {
 905             sample_t bias;
 906
 907             bias = 0;
 908             if (!(chanbias & (1 << i)))
 909                 bias = state->bias;
 910
 911             if (coeff[i]) {
 912                 if (blksw[i])
 913                     a52_imdct_256 (samples + 256 * i, samples + 1536 + 256 * i,
 914                                    bias);
 915                 else
 916                     a52_imdct_512 (samples + 256 * i, samples + 1536 + 256 * i,
 917                                    bias);
 918             } else {
 919                 int j;
 920
 921                 for (j = 0; j < 256; j++)
 922                     (samples + 256 * i)[j] = bias;
 923             }
 924         }
 925
 926         a52_downmix (samples, state->acmod, state->output, state->bias,
 927                      state->clev, state->slev);
 928     } else {
 929         nfchans = nfchans_tbl[state->output & A52_CHANNEL_MASK];
 930
 931         a52_downmix (samples, state->acmod, state->output, 0,
 932                      state->clev, state->slev);
 933
 934         if (!state->downmixed) {
 935             state->downmixed = 1;
 936             a52_downmix (samples + 1536, state->acmod, state->output, 0,
 937                          state->clev, state->slev);
 938         }
 939
 940         if (blksw[0])
 941             for (i = 0; i < nfchans; i++)
 942                 a52_imdct_256 (samples + 256 * i, samples + 1536 + 256 * i,
 943                                state->bias);
 944         else
 945             for (i = 0; i < nfchans; i++)
 946                 a52_imdct_512 (samples + 256 * i, samples + 1536 + 256 * i,
 947                                state->bias);
 948     }
 949
 950     return 0;
 951 }
 952
 953 void a52_free (a52_state_t * state)
 954 {
 955     (void)state;
 956     /*
 957     free (state->samples);
 958     free (state);
 959     */
 960 }