codecs/lpc10/decode.c

   1 /*
   2
   3 $Log$
   4 Revision 1.16  2004/06/26 03:50:14  markster
   5 Merge source cleanups (bug #1911)
   6
   7 Revision 1.15  2003/09/19 01:20:22  markster
   8 Code cleanups (bug #66)
   9
  10 Revision 1.2  2003/09/19 01:20:22  markster
  11 Code cleanups (bug #66)
  12
  13 Revision 1.1.1.1  2003/02/12 13:59:14  matteo
  14 mer feb 12 14:56:57 CET 2003
  15
  16 Revision 1.2  2000/01/05 08:20:39  markster
  17 Some OSS fixes and a few lpc changes to make it actually work
  18
  19  * Revision 1.2  1996/08/20  20:22:39  jaf
  20  * Removed all static local variables that were SAVE'd in the Fortran
  21  * code, and put them in struct lpc10_decoder_state that is passed as an
  22  * argument.
  23  *
  24  * Removed init function, since all initialization is now done in
  25  * init_lpc10_decoder_state().
  26  *
  27  * Revision 1.1  1996/08/19  22:32:38  jaf
  28  * Initial revision
  29  *
  30
  31 */
  32
  33 /*  -- translated by f2c (version 19951025).
  34    You must link the resulting object file with the libraries:
  35         -lf2c -lm   (in that order)
  36 */
  37
  38 #include "f2c.h"
  39
  40 #ifdef P_R_O_T_O_T_Y_P_E_S
  41 extern int decode_(integer *ipitv, integer *irms, integer *irc, integer *voice, integer *pitch, real *rms, real *rc, struct lpc10_decoder_state *st);
  42 /* comlen contrl_ 12 */
  43 /*:ref: ham84_ 14 3 4 4 4 */
  44 /*:ref: median_ 4 3 4 4 4 */
  45 #endif
  46
  47 /* Common Block Declarations */
  48
  49 extern struct {
  50     integer order, lframe;
  51     logical corrp;
  52 } contrl_;
  53
  54 #define contrl_1 contrl_
  55
  56 /* Table of constant values */
  57
  58 static integer c__2 = 2;
  59
  60 /* ***************************************************************** */
  61
  62 /*      DECODE Version 54 */
  63
  64 /* $Log$
  65  * Revision 1.16  2004/06/26 03:50:14  markster
  66  * Merge source cleanups (bug #1911)
  67  *
  68  * Revision 1.15  2003/09/19 01:20:22  markster
  69  * Code cleanups (bug #66)
  70  *
  71  * Revision 1.2  2003/09/19 01:20:22  markster
  72  * Code cleanups (bug #66)
  73  *
  74  * Revision 1.1.1.1  2003/02/12 13:59:14  matteo
  75  * mer feb 12 14:56:57 CET 2003
  76  *
  77  * Revision 1.2  2000/01/05 08:20:39  markster
  78  * Some OSS fixes and a few lpc changes to make it actually work
  79  *
  80  * Revision 1.2  1996/08/20  20:22:39  jaf
  81  * Removed all static local variables that were SAVE'd in the Fortran
  82  * code, and put them in struct lpc10_decoder_state that is passed as an
  83  * argument.
  84  *
  85  * Removed init function, since all initialization is now done in
  86  * init_lpc10_decoder_state().
  87  *
  88  * Revision 1.1  1996/08/19  22:32:38  jaf
  89  * Initial revision
  90  * */
  91 /* Revision 1.5  1996/05/23  20:06:03  jaf */
  92 /* Assigned PITCH a "default" value on the first call, since otherwise it */
  93 /* would be left uninitialized. */
  94
  95 /* Revision 1.4  1996/03/26  19:35:18  jaf */
  96 /* Commented out trace statements. */
  97
  98 /* Revision 1.3  1996/03/21  21:10:50  jaf */
  99 /* Added entry INITDECODE to reinitialize the local state of subroutine */
 100 /* DECODE. */
 101
 102 /* Revision 1.2  1996/03/21  21:04:50  jaf */
 103 /* Determined which local variables should be saved from one invocation */
 104 /* to the next, and guessed initial values for some that should have been */
 105 /* saved, but weren't given initial values.  Many of the arrays are */
 106 /* "constants", and many local variables are only used if the "global" */
 107 /* variable CORRP is .TRUE. */
 108
 109 /* Added comments explaining which indices of array arguments are read or */
 110 /* written. */
 111
 112 /* Revision 1.1  1996/02/12 03:21:10  jaf */
 113 /* Initial revision */
 114
 115
 116 /* ***************************************************************** */
 117
 118 /*   This subroutine provides error correction and decoding */
 119 /*   for all LPC parameters */
 120
 121 /* Input: */
 122 /*  IPITV  - Index value of pitch */
 123 /*  IRMS   - Coded Energy */
 124 /*  CORRP  - Error correction: */
 125 /*    If FALSE, parameters are decoded directly with no delay.  If TRUE, */
 126 /*    most important parameter bits are protected by Hamming code and */
 127 /*    median smoothed.  This requires an additional frame of delay. */
 128 /* Input/Output: */
 129 /*  IRC    - Coded Reflection Coefficients */
 130 /*           Indices 1 through ORDER always read, then written. */
 131 /* Output: */
 132 /*  VOICE  - Half frame voicing decisions */
 133 /*           Indices 1 through 2 written. */
 134 /*  PITCH  - Decoded pitch */
 135 /*  RMS    - Energy */
 136 /*  RC     - Reflection coefficients */
 137 /*           Indices 1 through ORDER written. */
 138
 139 /*  NOTE: Zero RC's should be done more directly, but this would affect */
 140 /*   coded parameter printout. */
 141
 142 /* This subroutine maintains local state from one call to the next.  If */
 143 /* you want to switch to using a new audio stream for this filter, or */
 144 /* reinitialize its state for any other reason, call the ENTRY */
 145 /* INITDECODE. */
 146
 147 /* Subroutine */ int decode_(integer *ipitv, integer *irms,
 148         integer *irc, integer *voice, integer *pitch, real *rms, real *rc,
 149                              struct lpc10_decoder_state *st)
 150 {
 151     /* Initialized data */
 152
 153     logical *first;
 154     static integer ethrs = 2048;
 155     static integer ethrs1 = 128;
 156     static integer ethrs2 = 1024;
 157     static integer ethrs3 = 2048;
 158     static integer ivtab[32] = { 24960,24960,24960,24960,25480,25480,25483,
 159             25480,16640,1560,1560,1560,16640,1816,1563,1560,24960,24960,24859,
 160             24856,26001,25881,25915,25913,1560,1560,7800,3640,1561,1561,3643,
 161             3641 };
 162     static real corth[32]       /* was [4][8] */ = { 32767.f,10.f,5.f,0.f,
 163             32767.f,8.f,4.f,0.f,32.f,6.4f,3.2f,0.f,32.f,6.4f,3.2f,0.f,32.f,
 164             11.2f,6.4f,0.f,32.f,11.2f,6.4f,0.f,16.f,5.6f,3.2f,0.f,16.f,5.6f,
 165             3.2f,0.f };
 166     static integer detau[128] = { 0,0,0,3,0,3,3,31,0,3,3,21,3,3,29,30,0,3,3,
 167             20,3,25,27,26,3,23,58,22,3,24,28,3,0,3,3,3,3,39,33,32,3,37,35,36,
 168             3,38,34,3,3,42,46,44,50,40,48,3,54,3,56,3,52,3,3,1,0,3,3,108,3,78,
 169             100,104,3,84,92,88,156,80,96,3,3,74,70,72,66,76,68,3,62,3,60,3,64,
 170             3,3,1,3,116,132,112,148,152,3,3,140,3,136,3,144,3,3,1,124,120,128,
 171             3,3,3,3,1,3,3,3,1,3,1,1,1 };
 172     static integer rmst[64] = { 1024,936,856,784,718,656,600,550,502,460,420,
 173             384,352,328,294,270,246,226,206,188,172,158,144,132,120,110,102,
 174             92,84,78,70,64,60,54,50,46,42,38,34,32,30,26,24,22,20,18,17,16,15,
 175             14,13,12,11,10,9,8,7,6,5,4,3,2,1,0 };
 176     static integer detab7[32] = { 4,11,18,25,32,39,46,53,60,66,72,77,82,87,92,
 177             96,101,104,108,111,114,115,117,119,121,122,123,124,125,126,127,
 178             127 };
 179     static real descl[8] = { .6953f,.625f,.5781f,.5469f,.5312f,.5391f,.4688f,
 180             .3828f };
 181     integer *ivp2h;
 182     static integer deadd[8] = { 1152,-2816,-1536,-3584,-1280,-2432,768,-1920 }
 183             ;
 184     static integer qb[8] = { 511,511,1023,1023,1023,1023,2047,4095 };
 185     static integer nbit[10] = { 8,8,5,5,4,4,4,4,3,2 };
 186     static integer zrc[10] = { 0,0,0,0,0,3,0,2,0,0 };
 187     static integer bit[5] = { 2,4,8,16,32 };
 188     integer *iovoic;
 189     integer *iavgp;
 190     integer *iptold;
 191     integer *erate;
 192     integer *drc;
 193     integer *dpit;
 194     integer *drms;
 195
 196     /* System generated locals */
 197     integer i__1, i__2;
 198
 199     /* Builtin functions */
 200     integer pow_ii(integer *, integer *);
 201
 202     /* Local variables */
 203     extern /* Subroutine */ int ham84_(integer *, integer *, integer *);
 204     integer ipit, iout, i__, icorf, index, ivoic, ixcor, i1, i2, i4;
 205     extern integer median_(integer *, integer *, integer *);
 206     integer ishift, errcnt, lsb;
 207
 208 /* $Log$
 209  * Revision 1.16  2004/06/26 03:50:14  markster
 210  * Merge source cleanups (bug #1911)
 211  *
 212  * Revision 1.15  2003/09/19 01:20:22  markster
 213  * Code cleanups (bug #66)
 214  *
 215  * Revision 1.2  2003/09/19 01:20:22  markster
 216  * Code cleanups (bug #66)
 217  *
 218  * Revision 1.1.1.1  2003/02/12 13:59:14  matteo
 219  * mer feb 12 14:56:57 CET 2003
 220  *
 221  * Revision 1.2  2000/01/05 08:20:39  markster
 222  * Some OSS fixes and a few lpc changes to make it actually work
 223  *
 224  * Revision 1.2  1996/08/20  20:22:39  jaf
 225  * Removed all static local variables that were SAVE'd in the Fortran
 226  * code, and put them in struct lpc10_decoder_state that is passed as an
 227  * argument.
 228  *
 229  * Removed init function, since all initialization is now done in
 230  * init_lpc10_decoder_state().
 231  *
 232  * Revision 1.1  1996/08/19  22:32:38  jaf
 233  * Initial revision
 234  * */
 235 /* Revision 1.3  1996/03/29  22:03:47  jaf */
 236 /* Removed definitions for any constants that were no longer used. */
 237
 238 /* Revision 1.2  1996/03/26  19:34:33  jaf */
 239 /* Added comments indicating which constants are not needed in an */
 240 /* application that uses the LPC-10 coder. */
 241
 242 /* Revision 1.1  1996/02/07  14:43:51  jaf */
 243 /* Initial revision */
 244
 245 /*   LPC Configuration parameters: */
 246 /* Frame size, Prediction order, Pitch period */
 247 /*       Arguments */
 248 /* $Log$
 249  * Revision 1.16  2004/06/26 03:50:14  markster
 250  * Merge source cleanups (bug #1911)
 251  *
 252  * Revision 1.15  2003/09/19 01:20:22  markster
 253  * Code cleanups (bug #66)
 254  *
 255  * Revision 1.2  2003/09/19 01:20:22  markster
 256  * Code cleanups (bug #66)
 257  *
 258  * Revision 1.1.1.1  2003/02/12 13:59:14  matteo
 259  * mer feb 12 14:56:57 CET 2003
 260  *
 261  * Revision 1.2  2000/01/05 08:20:39  markster
 262  * Some OSS fixes and a few lpc changes to make it actually work
 263  *
 264  * Revision 1.2  1996/08/20  20:22:39  jaf
 265  * Removed all static local variables that were SAVE'd in the Fortran
 266  * code, and put them in struct lpc10_decoder_state that is passed as an
 267  * argument.
 268  *
 269  * Removed init function, since all initialization is now done in
 270  * init_lpc10_decoder_state().
 271  *
 272  * Revision 1.1  1996/08/19  22:32:38  jaf
 273  * Initial revision
 274  * */
 275 /* Revision 1.3  1996/03/29  22:05:55  jaf */
 276 /* Commented out the common block variables that are not needed by the */
 277 /* embedded version. */
 278
 279 /* Revision 1.2  1996/03/26  19:34:50  jaf */
 280 /* Added comments indicating which constants are not needed in an */
 281 /* application that uses the LPC-10 coder. */
 282
 283 /* Revision 1.1  1996/02/07  14:44:09  jaf */
 284 /* Initial revision */
 285
 286 /*   LPC Processing control variables: */
 287
 288 /* *** Read-only: initialized in setup */
 289
 290 /*  Files for Speech, Parameter, and Bitstream Input & Output, */
 291 /*    and message and debug outputs. */
 292
 293 /* Here are the only files which use these variables: */
 294
 295 /* lpcsim.f setup.f trans.f error.f vqsetup.f */
 296
 297 /* Many files which use fdebug are not listed, since it is only used in */
 298 /* those other files conditionally, to print trace statements. */
 299 /*      integer fsi, fso, fpi, fpo, fbi, fbo, pbin, fmsg, fdebug */
 300 /*  LPC order, Frame size, Quantization rate, Bits per frame, */
 301 /*    Error correction */
 302 /* Subroutine SETUP is the only place where order is assigned a value, */
 303 /* and that value is 10.  It could increase efficiency 1% or so to */
 304 /* declare order as a constant (i.e., a Fortran PARAMETER) instead of as
 305 */
 306 /* a variable in a COMMON block, since it is used in many places in the */
 307 /* core of the coding and decoding routines.  Actually, I take that back.
 308 */
 309 /* At least when compiling with f2c, the upper bound of DO loops is */
 310 /* stored in a local variable before the DO loop begins, and then that is
 311 */
 312 /* compared against on each iteration. */
 313 /* Similarly for lframe, which is given a value of MAXFRM in SETUP. */
 314 /* Similarly for quant, which is given a value of 2400 in SETUP.  quant */
 315 /* is used in only a few places, and never in the core coding and */
 316 /* decoding routines, so it could be eliminated entirely. */
 317 /* nbits is similar to quant, and is given a value of 54 in SETUP. */
 318 /* corrp is given a value of .TRUE. in SETUP, and is only used in the */
 319 /* subroutines ENCODE and DECODE.  It doesn't affect the speed of the */
 320 /* coder significantly whether it is .TRUE. or .FALSE., or whether it is
 321 */
 322 /* a constant or a variable, since it is only examined once per frame. */
 323 /* Leaving it as a variable that is set to .TRUE.  seems like a good */
 324 /* idea, since it does enable some error-correction capability for */
 325 /* unvoiced frames, with no change in the coding rate, and no noticeable
 326 */
 327 /* quality difference in the decoded speech. */
 328 /*      integer quant, nbits */
 329 /* *** Read/write: variables for debugging, not needed for LPC algorithm
 330 */
 331
 332 /*  Current frame, Unstable frames, Output clip count, Max onset buffer,
 333 */
 334 /*    Debug listing detail level, Line count on listing page */
 335
 336 /* nframe is not needed for an embedded LPC10 at all. */
 337 /* nunsfm is initialized to 0 in SETUP, and incremented in subroutine */
 338 /* ERROR, which is only called from RCCHK.  When LPC10 is embedded into */
 339 /* an application, I would recommend removing the call to ERROR in RCCHK,
 340 */
 341 /* and remove ERROR and nunsfm completely. */
 342 /* iclip is initialized to 0 in SETUP, and incremented in entry SWRITE in
 343 */
 344 /* sread.f.  When LPC10 is embedded into an application, one might want */
 345 /* to cause it to be incremented in a routine that takes the output of */
 346 /* SYNTHS and sends it to an audio device.  It could be optionally */
 347 /* displayed, for those that might want to know what it is. */
 348 /* maxosp is never initialized to 0 in SETUP, although it probably should
 349 */
 350 /* be, and it is updated in subroutine ANALYS.  I doubt that its value */
 351 /* would be of much interest to an application in which LPC10 is */
 352 /* embedded. */
 353 /* listl and lincnt are not needed for an embedded LPC10 at all. */
 354 /*      integer nframe, nunsfm, iclip, maxosp, listl, lincnt */
 355 /*      common /contrl/ fsi, fso, fpi, fpo, fbi, fbo, pbin, fmsg, fdebug */
 356 /*      common /contrl/ quant, nbits */
 357 /*      common /contrl/ nframe, nunsfm, iclip, maxosp, listl, lincnt */
 358 /*       Function return value definitions */
 359
 360 /*       Parameters/constants */
 361
 362 /*       The variables below that are not Fortran PARAMETER's are */
 363 /*       initialized with DATA statements, and then never modified. */
 364 /*       The following are used regardless of CORRP's value. */
 365
 366 /*       DETAU, NBIT, QB, DEADD, DETAB7, RMST, DESCL */
 367
 368 /*       The following are used only if CORRP is .TRUE. */
 369
 370 /*       ETHRS, ETHRS1, ETHRS2, ETHRS3, IVTAB, BIT, CORTH, ZRC */
 371
 372 /*       Local variables that need not be saved */
 373
 374 /*       The following are used regardless of CORRP's value */
 375 /*       The following are used only if CORRP is .TRUE. */
 376
 377 /*       Local state */
 378
 379 /*       The following are used regardless of CORRP's value */
 380 /*       The following are used only if CORRP is .TRUE. */
 381 /*       I am guessing the initial values for IVP2H, IOVOIC, DRC, DPIT, */
 382 /*       and DRMS.  They should be checked to see if they are reasonable.
 383 */
 384 /*       I'm also guessing for ERATE, but I think 0 is the right initial
 385 */
 386 /*       value. */
 387     /* Parameter adjustments */
 388     if (irc) {
 389         --irc;
 390         }
 391     if (voice) {
 392         --voice;
 393         }
 394     if (rc) {
 395         --rc;
 396         }
 397
 398     /* Function Body */
 399
 400     iptold = &(st->iptold);
 401     first = &(st->first);
 402     ivp2h = &(st->ivp2h);
 403     iovoic = &(st->iovoic);
 404     iavgp = &(st->iavgp);
 405     erate = &(st->erate);
 406     drc = &(st->drc[0]);
 407     dpit = &(st->dpit[0]);
 408     drms = &(st->drms[0]);
 409
 410 /* DATA statements for "constants" defined above. */
 411 /*      IF (LISTL.GE.3) WRITE(FDEBUG,800) IPITV,IRMS,(IRC(J),J=1,ORDER) */
 412 /* 800  FORMAT(1X,' <<ERRCOR IN>>',T32,6X,I6,I5,T50,10I8) */
 413 /*  If no error correction, do pitch and voicing then jump to decode */
 414     i4 = detau[*ipitv];
 415     if (! contrl_1.corrp) {
 416         voice[1] = 1;
 417         voice[2] = 1;
 418         if (*ipitv <= 1) {
 419             voice[1] = 0;
 420         }
 421         if (*ipitv == 0 || *ipitv == 2) {
 422             voice[2] = 0;
 423         }
 424         *pitch = i4;
 425         if (*pitch <= 4) {
 426             *pitch = *iptold;
 427         }
 428         if (voice[1] == 1 && voice[2] == 1) {
 429             *iptold = *pitch;
 430         }
 431         if (voice[1] != voice[2]) {
 432             *pitch = *iptold;
 433         }
 434         goto L900;
 435     }
 436 /*  Do error correction pitch and voicing */
 437     if (i4 > 4) {
 438         dpit[0] = i4;
 439         ivoic = 2;
 440         *iavgp = (*iavgp * 15 + i4 + 8) / 16;
 441     } else {
 442         ivoic = i4;
 443         dpit[0] = *iavgp;
 444     }
 445     drms[0] = *irms;
 446     i__1 = contrl_1.order;
 447     for (i__ = 1; i__ <= i__1; ++i__) {
 448         drc[i__ * 3 - 3] = irc[i__];
 449     }
 450 /*  Determine index to IVTAB from V/UV decision */
 451 /*  If error rate is high then use alternate table */
 452     index = (*ivp2h << 4) + (*iovoic << 2) + ivoic + 1;
 453     i1 = ivtab[index - 1];
 454     ipit = i1 & 3;
 455     icorf = i1 / 8;
 456     if (*erate < ethrs) {
 457         icorf /= 64;
 458     }
 459 /*  Determine error rate:  4=high    1=low */
 460     ixcor = 4;
 461     if (*erate < ethrs3) {
 462         ixcor = 3;
 463     }
 464     if (*erate < ethrs2) {
 465         ixcor = 2;
 466     }
 467     if (*erate < ethrs1) {
 468         ixcor = 1;
 469     }
 470 /*  Voice/unvoice decision determined from bits 0 and 1 of IVTAB */
 471     voice[1] = icorf / 2 & 1;
 472     voice[2] = icorf & 1;
 473 /*  Skip decoding on first frame because present data not yet available */
 474     if (*first) {
 475         *first = FALSE_;
 476 /*          Assign PITCH a "default" value on the first call, since */
 477 /*          otherwise it would be left uninitialized.  The two lines
 478 */
 479 /*          below were copied from above, since it seemed like a */
 480 /*          reasonable thing to do for the first call. */
 481         *pitch = i4;
 482         if (*pitch <= 4) {
 483             *pitch = *iptold;
 484         }
 485         goto L500;
 486     }
 487 /*  If bit 4 of ICORF is set then correct RMS and RC(1) - RC(4). */
 488 /*    Determine error rate and correct errors using a Hamming 8,4 code */
 489 /*    during transition or unvoiced frame.  If IOUT is negative, */
 490 /*    more than 1 error occurred, use previous frame's parameters. */
 491     if ((icorf & bit[3]) != 0) {
 492         errcnt = 0;
 493         lsb = drms[1] & 1;
 494         index = (drc[22] << 4) + drms[1] / 2;
 495         ham84_(&index, &iout, &errcnt);
 496         drms[1] = drms[2];
 497         if (iout >= 0) {
 498             drms[1] = (iout << 1) + lsb;
 499         }
 500         for (i__ = 1; i__ <= 4; ++i__) {
 501             if (i__ == 1) {
 502                 i1 = ((drc[25] & 7) << 1) + (drc[28] & 1);
 503             } else {
 504                 i1 = drc[(9 - i__) * 3 - 2] & 15;
 505             }
 506             i2 = drc[(5 - i__) * 3 - 2] & 31;
 507             lsb = i2 & 1;
 508             index = (i1 << 4) + i2 / 2;
 509             ham84_(&index, &iout, &errcnt);
 510             if (iout >= 0) {
 511                 iout = (iout << 1) + lsb;
 512                 if ((iout & 16) == 16) {
 513                     iout += -32;
 514                 }
 515             } else {
 516                 iout = drc[(5 - i__) * 3 - 1];
 517             }
 518             drc[(5 - i__) * 3 - 2] = iout;
 519         }
 520 /*  Determine error rate */
 521         *erate = (integer)(*erate * .96875f + errcnt * 102);
 522     }
 523 /*  Get unsmoothed RMS, RC's, and PITCH */
 524     *irms = drms[1];
 525     i__1 = contrl_1.order;
 526     for (i__ = 1; i__ <= i__1; ++i__) {
 527         irc[i__] = drc[i__ * 3 - 2];
 528     }
 529     if (ipit == 1) {
 530         dpit[1] = dpit[2];
 531     }
 532     if (ipit == 3) {
 533         dpit[1] = dpit[0];
 534     }
 535     *pitch = dpit[1];
 536 /*  If bit 2 of ICORF is set then smooth RMS and RC's, */
 537     if ((icorf & bit[1]) != 0) {
 538         if ((i__1 = drms[1] - drms[0], (real) abs(i__1)) >= corth[ixcor + 3]
 539                 && (i__2 = drms[1] - drms[2], (real) abs(i__2)) >= corth[
 540                 ixcor + 3]) {
 541             *irms = median_(&drms[2], &drms[1], drms);
 542         }
 543         for (i__ = 1; i__ <= 6; ++i__) {
 544             if ((i__1 = drc[i__ * 3 - 2] - drc[i__ * 3 - 3], (real) abs(i__1))
 545                      >= corth[ixcor + ((i__ + 2) << 2) - 5] && (i__2 = drc[i__ *
 546                      3 - 2] - drc[i__ * 3 - 1], (real) abs(i__2)) >= corth[
 547                     ixcor + ((i__ + 2) << 2) - 5]) {
 548                 irc[i__] = median_(&drc[i__ * 3 - 1], &drc[i__ * 3 - 2], &drc[
 549                         i__ * 3 - 3]);
 550             }
 551         }
 552     }
 553 /*  If bit 3 of ICORF is set then smooth pitch */
 554     if ((icorf & bit[2]) != 0) {
 555         if ((i__1 = dpit[1] - dpit[0], (real) abs(i__1)) >= corth[ixcor - 1]
 556                 && (i__2 = dpit[1] - dpit[2], (real) abs(i__2)) >= corth[
 557                 ixcor - 1]) {
 558             *pitch = median_(&dpit[2], &dpit[1], dpit);
 559         }
 560     }
 561 /*  If bit 5 of ICORF is set then RC(5) - RC(10) are loaded with */
 562 /*  values so that after quantization bias is removed in decode */
 563 /*  the values will be zero. */
 564 L500:
 565     if ((icorf & bit[4]) != 0) {
 566         i__1 = contrl_1.order;
 567         for (i__ = 5; i__ <= i__1; ++i__) {
 568             irc[i__] = zrc[i__ - 1];
 569         }
 570     }
 571 /*  House keeping  - one frame delay */
 572     *iovoic = ivoic;
 573     *ivp2h = voice[2];
 574     dpit[2] = dpit[1];
 575     dpit[1] = dpit[0];
 576     drms[2] = drms[1];
 577     drms[1] = drms[0];
 578     i__1 = contrl_1.order;
 579     for (i__ = 1; i__ <= i__1; ++i__) {
 580         drc[i__ * 3 - 1] = drc[i__ * 3 - 2];
 581         drc[i__ * 3 - 2] = drc[i__ * 3 - 3];
 582     }
 583 L900:
 584 /*      IF (LISTL.GE.3)WRITE(FDEBUG,801)VOICE,PITCH,IRMS,(IRC(J),J=1,ORDER) */
 585 /* 801  FORMAT(1X,'<<ERRCOR OUT>>',T32,2I3,I6,I5,T50,10I8) */
 586 /*   Decode RMS */
 587     *irms = rmst[(31 - *irms) * 2];
 588 /*  Decode RC(1) and RC(2) from log-area-ratios */
 589 /*  Protect from illegal coded value (-16) caused by bit errors */
 590     for (i__ = 1; i__ <= 2; ++i__) {
 591         i2 = irc[i__];
 592         i1 = 0;
 593         if (i2 < 0) {
 594             i1 = 1;
 595             i2 = -i2;
 596             if (i2 > 15) {
 597                 i2 = 0;
 598             }
 599         }
 600         i2 = detab7[i2 * 2];
 601         if (i1 == 1) {
 602             i2 = -i2;
 603         }
 604         ishift = 15 - nbit[i__ - 1];
 605         irc[i__] = i2 * pow_ii(&c__2, &ishift);
 606     }
 607 /*  Decode RC(3)-RC(10) to sign plus 14 bits */
 608     i__1 = contrl_1.order;
 609     for (i__ = 3; i__ <= i__1; ++i__) {
 610         i2 = irc[i__];
 611         ishift = 15 - nbit[i__ - 1];
 612         i2 *= pow_ii(&c__2, &ishift);
 613         i2 += qb[i__ - 3];
 614         irc[i__] = (integer)(i2 * descl[i__ - 3] + deadd[i__ - 3]);
 615     }
 616 /*      IF (LISTL.GE.3) WRITE(FDEBUG,811) IRMS, (IRC(I),I=1,ORDER) */
 617 /* 811  FORMAT(1X,'<<DECODE OUT>>',T45,I4,1X,10I8) */
 618 /*  Scale RMS and RC's to reals */
 619     *rms = (real) (*irms);
 620     i__1 = contrl_1.order;
 621     for (i__ = 1; i__ <= i__1; ++i__) {
 622         rc[i__] = irc[i__] / 16384.f;
 623     }
 624     return 0;
 625 } /* decode_ */