git.sesse.net Git - vlc/blob - plugins/idct/idct.c

   1 /*****************************************************************************
   2  * idct.c : IDCT module
   3  *****************************************************************************
   4  * Copyright (C) 1999, 2000 VideoLAN
   5  * $Id: idct.c,v 1.9 2001/05/06 04:32:02 sam Exp $
   6  *
   7  * Authors: Gaël Hendryckx <jimmy@via.ecp.fr>
   8  *
   9  * This program 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  * This program 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, USA.
  22  *****************************************************************************/
  23
  24 #define MODULE_NAME idct
  25 #include "modules_inner.h"
  26
  27 /*****************************************************************************
  28  * Preamble
  29  *****************************************************************************/
  30 #include "defs.h"
  31
  32 #include <stdlib.h>
  33
  34 #include "config.h"
  35 #include "common.h"
  36 #include "threads.h"
  37 #include "mtime.h"
  38 #include "tests.h"
  39
  40 #include "video.h"
  41 #include "video_output.h"
  42
  43 #include "video_decoder.h"
  44
  45 #include "modules.h"
  46
  47 #include "vdec_block.h"
  48 #include "vdec_idct.h"
  49
  50 /*****************************************************************************
  51  * Local and extern prototypes.
  52  *****************************************************************************/
  53 static void idct_getfunctions( function_list_t * p_function_list );
  54 static int  idct_Probe      ( probedata_t *p_data );
  55 static void vdec_NormScan   ( u8 ppi_scan[2][64] );
  56
  57
  58 /*****************************************************************************
  59  * Build configuration tree.
  60  *****************************************************************************/
  61 MODULE_CONFIG_START
  62 ADD_WINDOW( "Configuration for IDCT module" )
  63     ADD_COMMENT( "Ha, ha -- nothing to configure yet" )
  64 MODULE_CONFIG_END
  65
  66 /*****************************************************************************
  67  * InitModule: get the module structure and configuration.
  68  *****************************************************************************
  69  * We have to fill psz_name, psz_longname and psz_version. These variables
  70  * will be strdup()ed later by the main application because the module can
  71  * be unloaded later to save memory, and we want to be able to access this
  72  * data even after the module has been unloaded.
  73  *****************************************************************************/
  74 MODULE_INIT
  75 {
  76     p_module->psz_name = MODULE_STRING;
  77     p_module->psz_longname = "IDCT module";
  78     p_module->psz_version = VERSION;
  79
  80     p_module->i_capabilities = MODULE_CAPABILITY_NULL
  81                                 | MODULE_CAPABILITY_IDCT;
  82
  83     return( 0 );
  84 }
  85
  86 /*****************************************************************************
  87  * ActivateModule: set the module to an usable state.
  88  *****************************************************************************
  89  * This function fills the capability functions and the configuration
  90  * structure. Once ActivateModule() has been called, the i_usage can
  91  * be set to 0 and calls to NeedModule() be made to increment it. To unload
  92  * the module, one has to wait until i_usage == 0 and call DeactivateModule().
  93  *****************************************************************************/
  94 MODULE_ACTIVATE
  95 {
  96     p_module->p_functions = malloc( sizeof( module_functions_t ) );
  97     if( p_module->p_functions == NULL )
  98     {
  99         return( -1 );
 100     }
 101
 102     idct_getfunctions( &p_module->p_functions->idct );
 103
 104     p_module->p_config = p_config;
 105
 106     return( 0 );
 107 }
 108
 109 /*****************************************************************************
 110  * DeactivateModule: make sure the module can be unloaded.
 111  *****************************************************************************
 112  * This function must only be called when i_usage == 0. If it successfully
 113  * returns, i_usage can be set to -1 and the module unloaded. Be careful to
 114  * lock usage_lock during the whole process.
 115  *****************************************************************************/
 116 MODULE_DEACTIVATE
 117 {
 118     free( p_module->p_functions );
 119
 120     return( 0 );
 121 }
 122
 123 /* Following functions are local */
 124
 125 /*****************************************************************************
 126  * Functions exported as capabilities. They are declared as static so that
 127  * we don't pollute the namespace too much.
 128  *****************************************************************************/
 129 static void idct_getfunctions( function_list_t * p_function_list )
 130 {
 131     p_function_list->pf_probe = idct_Probe;
 132 #define F p_function_list->functions.idct
 133     F.pf_idct_init = _M( vdec_InitIDCT );
 134     F.pf_sparse_idct = _M( vdec_SparseIDCT );
 135     F.pf_idct = _M( vdec_IDCT );
 136     F.pf_norm_scan = vdec_NormScan;
 137     F.pf_vdec_init = _M( vdec_Init );
 138     F.pf_decode_mb_c = _M( vdec_DecodeMacroblockC );
 139     F.pf_decode_mb_bw = _M( vdec_DecodeMacroblockBW );
 140 #undef F
 141 }
 142
 143 /*****************************************************************************
 144  * idct_Probe: returns a preference score
 145  *****************************************************************************/
 146 static int idct_Probe( probedata_t *p_data )
 147 {
 148     if( TestMethod( IDCT_METHOD_VAR, "idct" ) )
 149     {
 150         return( 999 );
 151     }
 152
 153     /* This plugin always works */
 154     return( 50 );
 155 }
 156
 157 /*****************************************************************************
 158  * vdec_NormScan : Unused in this IDCT
 159  *****************************************************************************/
 160 static void vdec_NormScan( u8 ppi_scan[2][64] )
 161 {
 162 }
 163
 164 /*****************************************************************************
 165  * vdec_IDCT : IDCT function for normal matrices
 166  *****************************************************************************/
 167 void _M( vdec_IDCT )( vdec_thread_t * p_vdec, dctelem_t * p_block,
 168                 int i_idontcare )
 169 {
 170     s32 tmp0, tmp1, tmp2, tmp3;
 171     s32 tmp10, tmp11, tmp12, tmp13;
 172     s32 z1, z2, z3, z4, z5;
 173     s32 d0, d1, d2, d3, d4, d5, d6, d7;
 174     dctelem_t * dataptr;
 175     int rowctr;
 176
 177     SHIFT_TEMPS
 178
 179     /* Pass 1: process rows. */
 180     /* Note results are scaled up by sqrt(8) compared to a true IDCT; */
 181     /* furthermore, we scale the results by 2**PASS1_BITS. */
 182
 183     dataptr = p_block;
 184
 185     for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--)
 186     {
 187         /* Due to quantization, we will usually find that many of the input
 188          * coefficients are zero, especially the AC terms.  We can exploit this
 189          * by short-circuiting the IDCT calculation for any row in which all
 190          * the AC terms are zero.  In that case each output is equal to the
 191          * DC coefficient (with scale factor as needed).
 192          * With typical images and quantization tables, half or more of the
 193          * row DCT calculations can be simplified this way.
 194          */
 195
 196         register int * idataptr = (int*)dataptr;
 197         d0 = dataptr[0];
 198         d1 = dataptr[1];
 199         if ( (d1 == 0) && ((idataptr[1] | idataptr[2] | idataptr[3]) == 0) )
 200         {
 201       /* AC terms all zero */
 202             if (d0)
 203             {
 204       /* Compute a 32 bit value to assign. */
 205                 dctelem_t dcval = (dctelem_t) (d0 << PASS1_BITS);
 206                 register int v = (dcval & 0xffff) | (dcval << 16);
 207
 208                 idataptr[0] = v;
 209                 idataptr[1] = v;
 210                 idataptr[2] = v;
 211                 idataptr[3] = v;
 212             }
 213
 214             dataptr += DCTSIZE; /* advance pointer to next row */
 215             continue;
 216         }
 217         d2 = dataptr[2];
 218         d3 = dataptr[3];
 219         d4 = dataptr[4];
 220         d5 = dataptr[5];
 221         d6 = dataptr[6];
 222         d7 = dataptr[7];
 223
 224     /* Even part: reverse the even part of the forward DCT. */
 225     /* The rotator is sqrt(2)*c(-6). */
 226         if (d6)
 227         {
 228             if (d4)
 229             {
 230                 if (d2)
 231                 {
 232                     if (d0)
 233                     {
 234             /* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */
 235                         z1 = MULTIPLY(d2 + d6, FIX(0.541196100));
 236                         tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065));
 237                         tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865));
 238
 239                         tmp0 = (d0 + d4) << CONST_BITS;
 240                         tmp1 = (d0 - d4) << CONST_BITS;
 241
 242                         tmp10 = tmp0 + tmp3;
 243                         tmp13 = tmp0 - tmp3;
 244                         tmp11 = tmp1 + tmp2;
 245                         tmp12 = tmp1 - tmp2;
 246                     }
 247                     else
 248                     {
 249                     /* d0 == 0, d2 != 0, d4 != 0, d6 != 0 */
 250                         z1 = MULTIPLY(d2 + d6, FIX(0.541196100));
 251                         tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065));
 252                         tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865));
 253
 254                         tmp0 = d4 << CONST_BITS;
 255
 256                         tmp10 = tmp0 + tmp3;
 257                         tmp13 = tmp0 - tmp3;
 258                         tmp11 = tmp2 - tmp0;
 259                         tmp12 = -(tmp0 + tmp2);
 260                         }
 261                 }
 262                 else
 263                 {
 264                     if (d0)
 265                     {
 266             /* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */
 267                         tmp2 = MULTIPLY(d6, - FIX2(1.306562965));
 268                         tmp3 = MULTIPLY(d6, FIX(0.541196100));
 269
 270                         tmp0 = (d0 + d4) << CONST_BITS;
 271                         tmp1 = (d0 - d4) << CONST_BITS;
 272
 273                         tmp10 = tmp0 + tmp3;
 274                         tmp13 = tmp0 - tmp3;
 275                         tmp11 = tmp1 + tmp2;
 276                         tmp12 = tmp1 - tmp2;
 277                         }
 278                     else
 279                     {
 280                     /* d0 == 0, d2 == 0, d4 != 0, d6 != 0 */
 281                         tmp2 = MULTIPLY(d6, - FIX2(1.306562965));
 282                         tmp3 = MULTIPLY(d6, FIX(0.541196100));
 283
 284                         tmp0 = d4 << CONST_BITS;
 285
 286                         tmp10 = tmp0 + tmp3;
 287                         tmp13 = tmp0 - tmp3;
 288                         tmp11 = tmp2 - tmp0;
 289                         tmp12 = -(tmp0 + tmp2);
 290                         }
 291                 }
 292             }
 293             else
 294             {
 295                 if (d2)
 296                 {
 297                     if (d0)
 298                     {
 299             /* d0 != 0, d2 != 0, d4 == 0, d6 != 0 */
 300                         z1 = MULTIPLY(d2 + d6, FIX(0.541196100));
 301                         tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065));
 302                         tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865));
 303
 304                         tmp0 = d0 << CONST_BITS;
 305
 306                         tmp10 = tmp0 + tmp3;
 307                         tmp13 = tmp0 - tmp3;
 308                         tmp11 = tmp0 + tmp2;
 309                         tmp12 = tmp0 - tmp2;
 310                     }
 311                     else
 312                     {
 313                     /* d0 == 0, d2 != 0, d4 == 0, d6 != 0 */
 314                         z1 = MULTIPLY(d2 + d6, FIX(0.541196100));
 315                         tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065));
 316                         tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865));
 317
 318                         tmp10 = tmp3;
 319                         tmp13 = -tmp3;
 320                         tmp11 = tmp2;
 321                         tmp12 = -tmp2;
 322                             }
 323                 }
 324                 else
 325                 {
 326                     if (d0)
 327                     {
 328             /* d0 != 0, d2 == 0, d4 == 0, d6 != 0 */
 329                         tmp2 = MULTIPLY(d6, - FIX2(1.306562965));
 330                         tmp3 = MULTIPLY(d6, FIX(0.541196100));
 331
 332                         tmp0 = d0 << CONST_BITS;
 333
 334                         tmp10 = tmp0 + tmp3;
 335                         tmp13 = tmp0 - tmp3;
 336                         tmp11 = tmp0 + tmp2;
 337                         tmp12 = tmp0 - tmp2;
 338                     }
 339                     else
 340                     {
 341             /* d0 == 0, d2 == 0, d4 == 0, d6 != 0 */
 342                         tmp2 = MULTIPLY(d6, - FIX2(1.306562965));
 343                         tmp3 = MULTIPLY(d6, FIX(0.541196100));
 344
 345                         tmp10 = tmp3;
 346                         tmp13 = -tmp3;
 347                         tmp11 = tmp2;
 348                         tmp12 = -tmp2;
 349                     }
 350                 }
 351             }
 352         }
 353         else
 354         {
 355             if (d4)
 356             {
 357                 if (d2)
 358                 {
 359                     if (d0)
 360                     {
 361                     /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */
 362                         tmp2 = MULTIPLY(d2, FIX(0.541196100));
 363                         tmp3 = MULTIPLY(d2, (FIX(1.306562965) + .5));
 364
 365                         tmp0 = (d0 + d4) << CONST_BITS;
 366                         tmp1 = (d0 - d4) << CONST_BITS;
 367
 368                         tmp10 = tmp0 + tmp3;
 369                         tmp13 = tmp0 - tmp3;
 370                         tmp11 = tmp1 + tmp2;
 371                         tmp12 = tmp1 - tmp2;
 372                     }
 373                     else
 374                     {
 375             /* d0 == 0, d2 != 0, d4 != 0, d6 == 0 */
 376                         tmp2 = MULTIPLY(d2, FIX(0.541196100));
 377                         tmp3 = MULTIPLY(d2, (FIX(1.306562965) + .5));
 378
 379                         tmp0 = d4 << CONST_BITS;
 380
 381                         tmp10 = tmp0 + tmp3;
 382                         tmp13 = tmp0 - tmp3;
 383                         tmp11 = tmp2 - tmp0;
 384                         tmp12 = -(tmp0 + tmp2);
 385                     }
 386                 }
 387                 else
 388                 {
 389                     if (d0)
 390                     {
 391             /* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */
 392                         tmp10 = tmp13 = (d0 + d4) << CONST_BITS;
 393                         tmp11 = tmp12 = (d0 - d4) << CONST_BITS;
 394                     }
 395                     else
 396                     {
 397             /* d0 == 0, d2 == 0, d4 != 0, d6 == 0 */
 398                         tmp10 = tmp13 = d4 << CONST_BITS;
 399                         tmp11 = tmp12 = -tmp10;
 400                     }
 401                 }
 402             }
 403             else
 404             {
 405                 if (d2)
 406                 {
 407                     if (d0)
 408                     {
 409             /* d0 != 0, d2 != 0, d4 == 0, d6 == 0 */
 410                         tmp2 = MULTIPLY(d2, FIX(0.541196100));
 411                         tmp3 = MULTIPLY(d2, (FIX(1.306562965) + .5));
 412
 413                         tmp0 = d0 << CONST_BITS;
 414
 415                         tmp10 = tmp0 + tmp3;
 416                         tmp13 = tmp0 - tmp3;
 417                         tmp11 = tmp0 + tmp2;
 418                         tmp12 = tmp0 - tmp2;
 419                     }
 420                     else
 421                     {
 422             /* d0 == 0, d2 != 0, d4 == 0, d6 == 0 */
 423                         tmp2 = MULTIPLY(d2, FIX(0.541196100));
 424                         tmp3 = MULTIPLY(d2, (FIX(1.306562965) + .5));
 425
 426                         tmp10 = tmp3;
 427                         tmp13 = -tmp3;
 428                         tmp11 = tmp2;
 429                         tmp12 = -tmp2;
 430                     }
 431                 }
 432                 else
 433                 {
 434                     if (d0)
 435                     {
 436             /* d0 != 0, d2 == 0, d4 == 0, d6 == 0 */
 437                         tmp10 = tmp13 = tmp11 = tmp12 = d0 << CONST_BITS;
 438                     }
 439                     else
 440                     {
 441             /* d0 == 0, d2 == 0, d4 == 0, d6 == 0 */
 442                         tmp10 = tmp13 = tmp11 = tmp12 = 0;
 443                     }
 444                 }
 445             }
 446         }
 447
 448
 449     /* Odd part per figure 8; the matrix is unitary and hence its
 450      * transpose is its inverse.  i0..i3 are y7,y5,y3,y1 respectively.
 451      */
 452
 453         if (d7)
 454             {
 455             if (d5)
 456             {
 457                 if (d3)
 458                 {
 459                     if (d1)
 460                     {
 461             /* d1 != 0, d3 != 0, d5 != 0, d7 != 0 */
 462                         z1 = d7 + d1;
 463                         z2 = d5 + d3;
 464                         z3 = d7 + d3;
 465                         z4 = d5 + d1;
 466                         z5 = MULTIPLY(z3 + z4, FIX(1.175875602));
 467
 468                         tmp0 = MULTIPLY(d7, FIX(0.298631336));
 469                         tmp1 = MULTIPLY(d5, FIX(2.053119869));
 470                         tmp2 = MULTIPLY(d3, FIX(3.072711026));
 471                         tmp3 = MULTIPLY(d1, FIX(1.501321110));
 472                         z1 = MULTIPLY(z1, - FIX(0.899976223));
 473                         z2 = MULTIPLY(z2, - FIX(2.562915447));
 474                         z3 = MULTIPLY(z3, - FIX(1.961570560));
 475                         z4 = MULTIPLY(z4, - FIX(0.390180644));
 476
 477                         z3 += z5;
 478                         z4 += z5;
 479
 480                         tmp0 += z1 + z3;
 481                         tmp1 += z2 + z4;
 482                         tmp2 += z2 + z3;
 483                         tmp3 += z1 + z4;
 484                     }
 485                     else
 486                     {
 487             /* d1 == 0, d3 != 0, d5 != 0, d7 != 0 */
 488                         z2 = d5 + d3;
 489                         z3 = d7 + d3;
 490                         z5 = MULTIPLY(z3 + d5, FIX(1.175875602));
 491
 492                         tmp0 = MULTIPLY(d7, FIX(0.298631336));
 493                         tmp1 = MULTIPLY(d5, FIX(2.053119869));
 494                         tmp2 = MULTIPLY(d3, FIX(3.072711026));
 495                         z1 = MULTIPLY(d7, - FIX(0.899976223));
 496                         z2 = MULTIPLY(z2, - FIX(2.562915447));
 497                         z3 = MULTIPLY(z3, - FIX(1.961570560));
 498                         z4 = MULTIPLY(d5, - FIX(0.390180644));
 499
 500                         z3 += z5;
 501                         z4 += z5;
 502
 503                         tmp0 += z1 + z3;
 504                         tmp1 += z2 + z4;
 505                         tmp2 += z2 + z3;
 506                         tmp3 = z1 + z4;
 507                         }
 508                     }
 509                 else
 510                 {
 511                     if (d1)
 512                     {
 513             /* d1 != 0, d3 == 0, d5 != 0, d7 != 0 */
 514                         z1 = d7 + d1;
 515                         z4 = d5 + d1;
 516                         z5 = MULTIPLY(d7 + z4, FIX(1.175875602));
 517
 518                         tmp0 = MULTIPLY(d7, FIX(0.298631336));
 519                         tmp1 = MULTIPLY(d5, FIX(2.053119869));
 520                         tmp3 = MULTIPLY(d1, FIX(1.501321110));
 521                         z1 = MULTIPLY(z1, - FIX(0.899976223));
 522                         z2 = MULTIPLY(d5, - FIX(2.562915447));
 523                         z3 = MULTIPLY(d7, - FIX(1.961570560));
 524                         z4 = MULTIPLY(z4, - FIX(0.390180644));
 525
 526                         z3 += z5;
 527                         z4 += z5;
 528
 529                         tmp0 += z1 + z3;
 530                         tmp1 += z2 + z4;
 531                         tmp2 = z2 + z3;
 532                         tmp3 += z1 + z4;
 533                     }
 534                     else
 535                     {
 536             /* d1 == 0, d3 == 0, d5 != 0, d7 != 0 */
 537                         z5 = MULTIPLY(d7 + d5, FIX(1.175875602));
 538
 539                         tmp0 = MULTIPLY(d7, - FIX2(0.601344887));
 540                         tmp1 = MULTIPLY(d5, - FIX2(0.509795578));
 541                         z1 = MULTIPLY(d7, - FIX(0.899976223));
 542                         z3 = MULTIPLY(d7, - FIX(1.961570560));
 543                         z2 = MULTIPLY(d5, - FIX(2.562915447));
 544                         z4 = MULTIPLY(d5, - FIX(0.390180644));
 545
 546                         z3 += z5;
 547                         z4 += z5;
 548
 549                         tmp0 += z3;
 550                         tmp1 += z4;
 551                         tmp2 = z2 + z3;
 552                         tmp3 = z1 + z4;
 553                     }
 554                 }
 555             }
 556             else
 557             {
 558                 if (d3)
 559                 {
 560                     if (d1)
 561                     {
 562             /* d1 != 0, d3 != 0, d5 == 0, d7 != 0 */
 563                         z1 = d7 + d1;
 564                         z3 = d7 + d3;
 565                         z5 = MULTIPLY(z3 + d1, FIX(1.175875602));
 566
 567                         tmp0 = MULTIPLY(d7, FIX(0.298631336));
 568                         tmp2 = MULTIPLY(d3, FIX(3.072711026));
 569                         tmp3 = MULTIPLY(d1, FIX(1.501321110));
 570                         z1 = MULTIPLY(z1, - FIX(0.899976223));
 571                         z2 = MULTIPLY(d3, - FIX(2.562915447));
 572                         z3 = MULTIPLY(z3, - FIX(1.961570560));
 573                         z4 = MULTIPLY(d1, - FIX(0.390180644));
 574
 575                         z3 += z5;
 576                         z4 += z5;
 577
 578                         tmp0 += z1 + z3;
 579                         tmp1 = z2 + z4;
 580                         tmp2 += z2 + z3;
 581                         tmp3 += z1 + z4;
 582                     }
 583                     else
 584                     {
 585             /* d1 == 0, d3 != 0, d5 == 0, d7 != 0 */
 586                         z3 = d7 + d3;
 587                         z5 = MULTIPLY(z3, FIX(1.175875602));
 588
 589                         tmp0 = MULTIPLY(d7, - FIX2(0.601344887));
 590                         tmp2 = MULTIPLY(d3, FIX(0.509795579));
 591                         z1 = MULTIPLY(d7, - FIX(0.899976223));
 592                         z2 = MULTIPLY(d3, - FIX(2.562915447));
 593                         z3 = MULTIPLY(z3, - FIX2(0.785694958));
 594
 595                         tmp0 += z3;
 596                         tmp1 = z2 + z5;
 597                         tmp2 += z3;
 598                         tmp3 = z1 + z5;
 599                     }
 600                 }
 601                 else
 602                 {
 603                     if (d1)
 604                     {
 605             /* d1 != 0, d3 == 0, d5 == 0, d7 != 0 */
 606                         z1 = d7 + d1;
 607                         z5 = MULTIPLY(z1, FIX(1.175875602));
 608
 609                         tmp0 = MULTIPLY(d7, - FIX2(1.662939224));
 610                         tmp3 = MULTIPLY(d1, FIX2(1.111140466));
 611                         z1 = MULTIPLY(z1, FIX2(0.275899379));
 612                         z3 = MULTIPLY(d7, - FIX(1.961570560));
 613                         z4 = MULTIPLY(d1, - FIX(0.390180644));
 614
 615                         tmp0 += z1;
 616                         tmp1 = z4 + z5;
 617                         tmp2 = z3 + z5;
 618                         tmp3 += z1;
 619                     }
 620                 else
 621                     {
 622             /* d1 == 0, d3 == 0, d5 == 0, d7 != 0 */
 623                         tmp0 = MULTIPLY(d7, - FIX2(1.387039845));
 624                         tmp1 = MULTIPLY(d7, FIX(1.175875602));
 625                         tmp2 = MULTIPLY(d7, - FIX2(0.785694958));
 626                         tmp3 = MULTIPLY(d7, FIX2(0.275899379));
 627                     }
 628                 }
 629             }
 630         }
 631         else
 632         {
 633             if (d5)
 634             {
 635                 if (d3)
 636                 {
 637                     if (d1)
 638                     {
 639             /* d1 != 0, d3 != 0, d5 != 0, d7 == 0 */
 640                         z2 = d5 + d3;
 641                         z4 = d5 + d1;
 642                         z5 = MULTIPLY(d3 + z4, FIX(1.175875602));
 643
 644                         tmp1 = MULTIPLY(d5, FIX(2.053119869));
 645                         tmp2 = MULTIPLY(d3, FIX(3.072711026));
 646                         tmp3 = MULTIPLY(d1, FIX(1.501321110));
 647                         z1 = MULTIPLY(d1, - FIX(0.899976223));
 648                         z2 = MULTIPLY(z2, - FIX(2.562915447));
 649                         z3 = MULTIPLY(d3, - FIX(1.961570560));
 650                         z4 = MULTIPLY(z4, - FIX(0.390180644));
 651
 652                         z3 += z5;
 653                         z4 += z5;
 654
 655                         tmp0 = z1 + z3;
 656                         tmp1 += z2 + z4;
 657                         tmp2 += z2 + z3;
 658                         tmp3 += z1 + z4;
 659                     }
 660                     else
 661                     {
 662             /* d1 == 0, d3 != 0, d5 != 0, d7 == 0 */
 663                         z2 = d5 + d3;
 664                         z5 = MULTIPLY(z2, FIX(1.175875602));
 665
 666                         tmp1 = MULTIPLY(d5, FIX2(1.662939225));
 667                         tmp2 = MULTIPLY(d3, FIX2(1.111140466));
 668                         z2 = MULTIPLY(z2, - FIX2(1.387039845));
 669                         z3 = MULTIPLY(d3, - FIX(1.961570560));
 670                         z4 = MULTIPLY(d5, - FIX(0.390180644));
 671
 672                         tmp0 = z3 + z5;
 673                         tmp1 += z2;
 674                         tmp2 += z2;
 675                         tmp3 = z4 + z5;
 676                     }
 677                 }
 678                 else
 679                 {
 680                     if (d1)
 681                     {
 682             /* d1 != 0, d3 == 0, d5 != 0, d7 == 0 */
 683                         z4 = d5 + d1;
 684                         z5 = MULTIPLY(z4, FIX(1.175875602));
 685
 686                         tmp1 = MULTIPLY(d5, - FIX2(0.509795578));
 687                         tmp3 = MULTIPLY(d1, FIX2(0.601344887));
 688                         z1 = MULTIPLY(d1, - FIX(0.899976223));
 689                         z2 = MULTIPLY(d5, - FIX(2.562915447));
 690                         z4 = MULTIPLY(z4, FIX2(0.785694958));
 691
 692                         tmp0 = z1 + z5;
 693                         tmp1 += z4;
 694                         tmp2 = z2 + z5;
 695                         tmp3 += z4;
 696                     }
 697                     else
 698                     {
 699             /* d1 == 0, d3 == 0, d5 != 0, d7 == 0 */
 700                         tmp0 = MULTIPLY(d5, FIX(1.175875602));
 701                         tmp1 = MULTIPLY(d5, FIX2(0.275899380));
 702                         tmp2 = MULTIPLY(d5, - FIX2(1.387039845));
 703                         tmp3 = MULTIPLY(d5, FIX2(0.785694958));
 704                     }
 705                 }
 706             }
 707             else
 708             {
 709                 if (d3)
 710                 {
 711                     if (d1)
 712                     {
 713             /* d1 != 0, d3 != 0, d5 == 0, d7 == 0 */
 714                         z5 = d3 + d1;
 715
 716                         tmp2 = MULTIPLY(d3, - FIX(1.451774981));
 717                         tmp3 = MULTIPLY(d1, (FIX(0.211164243) - 1));
 718                         z1 = MULTIPLY(d1, FIX(1.061594337));
 719                         z2 = MULTIPLY(d3, - FIX(2.172734803));
 720                         z4 = MULTIPLY(z5, FIX(0.785694958));
 721                         z5 = MULTIPLY(z5, FIX(1.175875602));
 722
 723                         tmp0 = z1 - z4;
 724                         tmp1 = z2 + z4;
 725                         tmp2 += z5;
 726                         tmp3 += z5;
 727                     }
 728                     else
 729                     {
 730             /* d1 == 0, d3 != 0, d5 == 0, d7 == 0 */
 731                         tmp0 = MULTIPLY(d3, - FIX2(0.785694958));
 732                         tmp1 = MULTIPLY(d3, - FIX2(1.387039845));
 733                         tmp2 = MULTIPLY(d3, - FIX2(0.275899379));
 734                         tmp3 = MULTIPLY(d3, FIX(1.175875602));
 735                     }
 736                 }
 737                 else
 738                 {
 739                     if (d1)
 740                     {
 741             /* d1 != 0, d3 == 0, d5 == 0, d7 == 0 */
 742                         tmp0 = MULTIPLY(d1, FIX2(0.275899379));
 743                         tmp1 = MULTIPLY(d1, FIX2(0.785694958));
 744                         tmp2 = MULTIPLY(d1, FIX(1.175875602));
 745                         tmp3 = MULTIPLY(d1, FIX2(1.387039845));
 746                     }
 747                     else
 748                     {
 749             /* d1 == 0, d3 == 0, d5 == 0, d7 == 0 */
 750                         tmp0 = tmp1 = tmp2 = tmp3 = 0;
 751                     }
 752                 }
 753             }
 754         }
 755
 756     /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
 757
 758         dataptr[0] = (dctelem_t) DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS);
 759         dataptr[7] = (dctelem_t) DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS);
 760         dataptr[1] = (dctelem_t) DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS);
 761         dataptr[6] = (dctelem_t) DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS);
 762         dataptr[2] = (dctelem_t) DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS);
 763         dataptr[5] = (dctelem_t) DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS);
 764         dataptr[3] = (dctelem_t) DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS);
 765         dataptr[4] = (dctelem_t) DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS);
 766
 767         dataptr += DCTSIZE;              /* advance pointer to next row */
 768     }
 769
 770   /* Pass 2: process columns. */
 771   /* Note that we must descale the results by a factor of 8 == 2**3, */
 772   /* and also undo the PASS1_BITS scaling. */
 773
 774     dataptr = p_block;
 775     for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--)
 776     {
 777     /* Columns of zeroes can be exploited in the same way as we did with rows.
 778      * However, the row calculation has created many nonzero AC terms, so the
 779      * simplification applies less often (typically 5% to 10% of the time).
 780      * On machines with very fast multiplication, it's possible that the
 781      * test takes more time than it's worth.  In that case this section
 782      * may be commented out.
 783      */
 784
 785         d0 = dataptr[DCTSIZE*0];
 786         d1 = dataptr[DCTSIZE*1];
 787         d2 = dataptr[DCTSIZE*2];
 788         d3 = dataptr[DCTSIZE*3];
 789         d4 = dataptr[DCTSIZE*4];
 790         d5 = dataptr[DCTSIZE*5];
 791         d6 = dataptr[DCTSIZE*6];
 792         d7 = dataptr[DCTSIZE*7];
 793
 794     /* Even part: reverse the even part of the forward DCT. */
 795     /* The rotator is sqrt(2)*c(-6). */
 796         if (d6)
 797         {
 798             if (d4)
 799             {
 800                 if (d2)
 801                 {
 802                     if (d0)
 803                     {
 804             /* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */
 805                         z1 = MULTIPLY(d2 + d6, FIX(0.541196100));
 806                         tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065));
 807                         tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865));
 808
 809                         tmp0 = (d0 + d4) << CONST_BITS;
 810                         tmp1 = (d0 - d4) << CONST_BITS;
 811
 812                         tmp10 = tmp0 + tmp3;
 813                         tmp13 = tmp0 - tmp3;
 814                         tmp11 = tmp1 + tmp2;
 815                         tmp12 = tmp1 - tmp2;
 816                     }
 817                     else
 818                     {
 819             /* d0 == 0, d2 != 0, d4 != 0, d6 != 0 */
 820                         z1 = MULTIPLY(d2 + d6, FIX(0.541196100));
 821                         tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065));
 822                         tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865));
 823
 824                         tmp0 = d4 << CONST_BITS;
 825
 826                         tmp10 = tmp0 + tmp3;
 827                         tmp13 = tmp0 - tmp3;
 828                         tmp11 = tmp2 - tmp0;
 829                         tmp12 = -(tmp0 + tmp2);
 830                     }
 831                 }
 832                 else
 833                 {
 834                     if (d0)
 835                     {
 836             /* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */
 837                         tmp2 = MULTIPLY(d6, - FIX2(1.306562965));
 838                         tmp3 = MULTIPLY(d6, FIX(0.541196100));
 839
 840                         tmp0 = (d0 + d4) << CONST_BITS;
 841                         tmp1 = (d0 - d4) << CONST_BITS;
 842
 843                         tmp10 = tmp0 + tmp3;
 844                         tmp13 = tmp0 - tmp3;
 845                         tmp11 = tmp1 + tmp2;
 846                         tmp12 = tmp1 - tmp2;
 847                     }
 848                     else
 849                     {
 850             /* d0 == 0, d2 == 0, d4 != 0, d6 != 0 */
 851                         tmp2 = MULTIPLY(d6, -FIX2(1.306562965));
 852                         tmp3 = MULTIPLY(d6, FIX(0.541196100));
 853
 854                         tmp0 = d4 << CONST_BITS;
 855
 856                         tmp10 = tmp0 + tmp3;
 857                         tmp13 = tmp0 - tmp3;
 858                         tmp11 = tmp2 - tmp0;
 859                         tmp12 = -(tmp0 + tmp2);
 860                     }
 861                 }
 862             }
 863             else
 864             {
 865                 if (d2)
 866                 {
 867                     if (d0)
 868                     {
 869             /* d0 != 0, d2 != 0, d4 == 0, d6 != 0 */
 870                         z1 = MULTIPLY(d2 + d6, FIX(0.541196100));
 871                         tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065));
 872                         tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865));
 873
 874                         tmp0 = d0 << CONST_BITS;
 875
 876                         tmp10 = tmp0 + tmp3;
 877                         tmp13 = tmp0 - tmp3;
 878                         tmp11 = tmp0 + tmp2;
 879                         tmp12 = tmp0 - tmp2;
 880                     }
 881                     else
 882                     {
 883             /* d0 == 0, d2 != 0, d4 == 0, d6 != 0 */
 884                         z1 = MULTIPLY(d2 + d6, FIX(0.541196100));
 885                         tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065));
 886                         tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865));
 887
 888                         tmp10 = tmp3;
 889                         tmp13 = -tmp3;
 890                         tmp11 = tmp2;
 891                         tmp12 = -tmp2;
 892                     }
 893                 }
 894                 else
 895                 {
 896                     if (d0)
 897                     {
 898             /* d0 != 0, d2 == 0, d4 == 0, d6 != 0 */
 899                     tmp2 = MULTIPLY(d6, - FIX2(1.306562965));
 900                     tmp3 = MULTIPLY(d6, FIX(0.541196100));
 901
 902                     tmp0 = d0 << CONST_BITS;
 903
 904                     tmp10 = tmp0 + tmp3;
 905                     tmp13 = tmp0 - tmp3;
 906                     tmp11 = tmp0 + tmp2;
 907                     tmp12 = tmp0 - tmp2;
 908                 }
 909                 else
 910                 {
 911             /* d0 == 0, d2 == 0, d4 == 0, d6 != 0 */
 912                     tmp2 = MULTIPLY(d6, - FIX2(1.306562965));
 913                     tmp3 = MULTIPLY(d6, FIX(0.541196100));
 914                     tmp10 = tmp3;
 915                     tmp13 = -tmp3;
 916                     tmp11 = tmp2;
 917                     tmp12 = -tmp2;
 918                 }
 919             }
 920         }
 921     }
 922     else
 923     {
 924         if (d4)
 925         {
 926             if (d2)
 927             {
 928                 if (d0)
 929                 {
 930             /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */
 931                     tmp2 = MULTIPLY(d2, FIX(0.541196100));
 932                     tmp3 = MULTIPLY(d2, (FIX(1.306562965) + .5));
 933
 934                     tmp0 = (d0 + d4) << CONST_BITS;
 935                     tmp1 = (d0 - d4) << CONST_BITS;
 936
 937                     tmp10 = tmp0 + tmp3;
 938                     tmp13 = tmp0 - tmp3;
 939                     tmp11 = tmp1 + tmp2;
 940                     tmp12 = tmp1 - tmp2;
 941                 }
 942                 else
 943                 {
 944             /* d0 == 0, d2 != 0, d4 != 0, d6 == 0 */
 945                     tmp2 = MULTIPLY(d2, FIX(0.541196100));
 946                     tmp3 = MULTIPLY(d2, (FIX(1.306562965) + .5));
 947
 948                     tmp0 = d4 << CONST_BITS;
 949
 950                     tmp10 = tmp0 + tmp3;
 951                     tmp13 = tmp0 - tmp3;
 952                     tmp11 = tmp2 - tmp0;
 953                     tmp12 = -(tmp0 + tmp2);
 954                 }
 955             }
 956             else
 957             {
 958                 if (d0)
 959                 {
 960             /* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */
 961                     tmp10 = tmp13 = (d0 + d4) << CONST_BITS;
 962                     tmp11 = tmp12 = (d0 - d4) << CONST_BITS;
 963                 }
 964                 else
 965                 {
 966             /* d0 == 0, d2 == 0, d4 != 0, d6 == 0 */
 967                     tmp10 = tmp13 = d4 << CONST_BITS;
 968                     tmp11 = tmp12 = -tmp10;
 969                 }
 970             }
 971         }
 972         else
 973         {
 974         if (d2)
 975         {
 976             if (d0)
 977             {
 978             /* d0 != 0, d2 != 0, d4 == 0, d6 == 0 */
 979                     tmp2 = MULTIPLY(d2, FIX(0.541196100));
 980                     tmp3 = MULTIPLY(d2, (FIX(1.306562965) + .5));
 981
 982                     tmp0 = d0 << CONST_BITS;
 983
 984                     tmp10 = tmp0 + tmp3;
 985                     tmp13 = tmp0 - tmp3;
 986                     tmp11 = tmp0 + tmp2;
 987                     tmp12 = tmp0 - tmp2;
 988             }
 989             else
 990             {
 991             /* d0 == 0, d2 != 0, d4 == 0, d6 == 0 */
 992                     tmp2 = MULTIPLY(d2, FIX(0.541196100));
 993                     tmp3 = MULTIPLY(d2, (FIX(1.306562965) + .5));
 994
 995                     tmp10 = tmp3;
 996                     tmp13 = -tmp3;
 997                     tmp11 = tmp2;
 998                     tmp12 = -tmp2;
 999             }
1000         }
1001         else
1002         {
1003             if (d0)
1004                 {
1005             /* d0 != 0, d2 == 0, d4 == 0, d6 == 0 */
1006                     tmp10 = tmp13 = tmp11 = tmp12 = d0 << CONST_BITS;
1007                 }
1008                 else
1009                 {
1010             /* d0 == 0, d2 == 0, d4 == 0, d6 == 0 */
1011                     tmp10 = tmp13 = tmp11 = tmp12 = 0;
1012                 }
1013             }
1014         }
1015     }
1016
1017     /* Odd part per figure 8; the matrix is unitary and hence its
1018      * transpose is its inverse.  i0..i3 are y7,y5,y3,y1 respectively.
1019      */
1020     if (d7)
1021     {
1022         if (d5)
1023         {
1024             if (d3)
1025             {
1026                 if (d1)
1027                 {
1028             /* d1 != 0, d3 != 0, d5 != 0, d7 != 0 */
1029                     z1 = d7 + d1;
1030                     z2 = d5 + d3;
1031                     z3 = d7 + d3;
1032                     z4 = d5 + d1;
1033                     z5 = MULTIPLY(z3 + z4, FIX(1.175875602));
1034
1035                     tmp0 = MULTIPLY(d7, FIX(0.298631336));
1036                     tmp1 = MULTIPLY(d5, FIX(2.053119869));
1037                     tmp2 = MULTIPLY(d3, FIX(3.072711026));
1038                     tmp3 = MULTIPLY(d1, FIX(1.501321110));
1039                     z1 = MULTIPLY(z1, - FIX(0.899976223));
1040                     z2 = MULTIPLY(z2, - FIX(2.562915447));
1041                     z3 = MULTIPLY(z3, - FIX(1.961570560));
1042                     z4 = MULTIPLY(z4, - FIX(0.390180644));
1043
1044                     z3 += z5;
1045                     z4 += z5;
1046
1047                     tmp0 += z1 + z3;
1048                     tmp1 += z2 + z4;
1049                     tmp2 += z2 + z3;
1050                     tmp3 += z1 + z4;
1051                 }
1052                 else
1053                 {
1054             /* d1 == 0, d3 != 0, d5 != 0, d7 != 0 */
1055                     z2 = d5 + d3;
1056                     z3 = d7 + d3;
1057                     z5 = MULTIPLY(z3 + d5, FIX(1.175875602));
1058
1059                     tmp0 = MULTIPLY(d7, FIX(0.298631336));
1060                     tmp1 = MULTIPLY(d5, FIX(2.053119869));
1061                     tmp2 = MULTIPLY(d3, FIX(3.072711026));
1062                     z1 = MULTIPLY(d7, - FIX(0.899976223));
1063                     z2 = MULTIPLY(z2, - FIX(2.562915447));
1064                     z3 = MULTIPLY(z3, - FIX(1.961570560));
1065                     z4 = MULTIPLY(d5, - FIX(0.390180644));
1066
1067                     z3 += z5;
1068                     z4 += z5;
1069
1070                     tmp0 += z1 + z3;
1071                     tmp1 += z2 + z4;
1072                     tmp2 += z2 + z3;
1073                     tmp3 = z1 + z4;
1074                 }
1075             }
1076             else
1077             {
1078                 if (d1)
1079                 {
1080             /* d1 != 0, d3 == 0, d5 != 0, d7 != 0 */
1081                     z1 = d7 + d1;
1082                     z4 = d5 + d1;
1083                     z5 = MULTIPLY(d7 + z4, FIX(1.175875602));
1084
1085                     tmp0 = MULTIPLY(d7, FIX(0.298631336));
1086                     tmp1 = MULTIPLY(d5, FIX(2.053119869));
1087                     tmp3 = MULTIPLY(d1, FIX(1.501321110));
1088                     z1 = MULTIPLY(z1, - FIX(0.899976223));
1089                     z2 = MULTIPLY(d5, - FIX(2.562915447));
1090                     z3 = MULTIPLY(d7, - FIX(1.961570560));
1091                     z4 = MULTIPLY(z4, - FIX(0.390180644));
1092
1093                     z3 += z5;
1094                     z4 += z5;
1095
1096                     tmp0 += z1 + z3;
1097                     tmp1 += z2 + z4;
1098                     tmp2 = z2 + z3;
1099                     tmp3 += z1 + z4;
1100                 }
1101                 else
1102                 {
1103             /* d1 == 0, d3 == 0, d5 != 0, d7 != 0 */
1104                     z5 = MULTIPLY(d5 + d7, FIX(1.175875602));
1105
1106                     tmp0 = MULTIPLY(d7, - FIX2(0.601344887));
1107                     tmp1 = MULTIPLY(d5, - FIX2(0.509795578));
1108                     z1 = MULTIPLY(d7, - FIX(0.899976223));
1109                     z3 = MULTIPLY(d7, - FIX(1.961570560));
1110                     z2 = MULTIPLY(d5, - FIX(2.562915447));
1111                     z4 = MULTIPLY(d5, - FIX(0.390180644));
1112
1113                     z3 += z5;
1114                     z4 += z5;
1115
1116                     tmp0 += z3;
1117                     tmp1 += z4;
1118                     tmp2 = z2 + z3;
1119                     tmp3 = z1 + z4;
1120                 }
1121             }
1122         }
1123         else
1124         {
1125             if (d3)
1126             {
1127                 if (d1)
1128                 {
1129             /* d1 != 0, d3 != 0, d5 == 0, d7 != 0 */
1130                     z1 = d7 + d1;
1131                     z3 = d7 + d3;
1132                     z5 = MULTIPLY(z3 + d1, FIX(1.175875602));
1133
1134                     tmp0 = MULTIPLY(d7, FIX(0.298631336));
1135                     tmp2 = MULTIPLY(d3, FIX(3.072711026));
1136                     tmp3 = MULTIPLY(d1, FIX(1.501321110));
1137                     z1 = MULTIPLY(z1, - FIX(0.899976223));
1138                     z2 = MULTIPLY(d3, - FIX(2.562915447));
1139                     z3 = MULTIPLY(z3, - FIX(1.961570560));
1140                     z4 = MULTIPLY(d1, - FIX(0.390180644));
1141
1142                     z3 += z5;
1143                     z4 += z5;
1144
1145                     tmp0 += z1 + z3;
1146                     tmp1 = z2 + z4;
1147                     tmp2 += z2 + z3;
1148                     tmp3 += z1 + z4;
1149                 }
1150                 else
1151                 {
1152             /* d1 == 0, d3 != 0, d5 == 0, d7 != 0 */
1153                     z3 = d7 + d3;
1154                     z5 = MULTIPLY(z3, FIX(1.175875602));
1155
1156                     tmp0 = MULTIPLY(d7, - FIX2(0.601344887));
1157                     z1 = MULTIPLY(d7, - FIX(0.899976223));
1158                     tmp2 = MULTIPLY(d3, FIX(0.509795579));
1159                     z2 = MULTIPLY(d3, - FIX(2.562915447));
1160                     z3 = MULTIPLY(z3, - FIX2(0.785694958));
1161
1162                     tmp0 += z3;
1163                     tmp1 = z2 + z5;
1164                     tmp2 += z3;
1165                     tmp3 = z1 + z5;
1166                 }
1167             }
1168             else
1169             {
1170                 if (d1)
1171                 {
1172             /* d1 != 0, d3 == 0, d5 == 0, d7 != 0 */
1173                     z1 = d7 + d1;
1174                     z5 = MULTIPLY(z1, FIX(1.175875602));
1175
1176                     tmp0 = MULTIPLY(d7, - FIX2(1.662939224));
1177                     tmp3 = MULTIPLY(d1, FIX2(1.111140466));
1178                     z1 = MULTIPLY(z1, FIX2(0.275899379));
1179                     z3 = MULTIPLY(d7, - FIX(1.961570560));
1180                     z4 = MULTIPLY(d1, - FIX(0.390180644));
1181
1182                     tmp0 += z1;
1183                     tmp1 = z4 + z5;
1184                     tmp2 = z3 + z5;
1185                     tmp3 += z1;
1186                 }
1187                 else
1188                 {
1189             /* d1 == 0, d3 == 0, d5 == 0, d7 != 0 */
1190                     tmp0 = MULTIPLY(d7, - FIX2(1.387039845));
1191                     tmp1 = MULTIPLY(d7, FIX(1.175875602));
1192                     tmp2 = MULTIPLY(d7, - FIX2(0.785694958));
1193                     tmp3 = MULTIPLY(d7, FIX2(0.275899379));
1194                 }
1195             }
1196         }
1197     }
1198     else
1199     {
1200         if (d5)
1201         {
1202             if (d3)
1203             {
1204                 if (d1)
1205                 {
1206             /* d1 != 0, d3 != 0, d5 != 0, d7 == 0 */
1207                     z2 = d5 + d3;
1208                     z4 = d5 + d1;
1209                     z5 = MULTIPLY(d3 + z4, FIX(1.175875602));
1210
1211                     tmp1 = MULTIPLY(d5, FIX(2.053119869));
1212                     tmp2 = MULTIPLY(d3, FIX(3.072711026));
1213                     tmp3 = MULTIPLY(d1, FIX(1.501321110));
1214                     z1 = MULTIPLY(d1, - FIX(0.899976223));
1215                     z2 = MULTIPLY(z2, - FIX(2.562915447));
1216                     z3 = MULTIPLY(d3, - FIX(1.961570560));
1217                     z4 = MULTIPLY(z4, - FIX(0.390180644));
1218
1219                     z3 += z5;
1220                     z4 += z5;
1221
1222                     tmp0 = z1 + z3;
1223                     tmp1 += z2 + z4;
1224                     tmp2 += z2 + z3;
1225                     tmp3 += z1 + z4;
1226                 }
1227                 else
1228                 {
1229             /* d1 == 0, d3 != 0, d5 != 0, d7 == 0 */
1230                     z2 = d5 + d3;
1231                     z5 = MULTIPLY(z2, FIX(1.175875602));
1232
1233                     tmp1 = MULTIPLY(d5, FIX2(1.662939225));
1234                     tmp2 = MULTIPLY(d3, FIX2(1.111140466));
1235                     z2 = MULTIPLY(z2, - FIX2(1.387039845));
1236                     z3 = MULTIPLY(d3, - FIX(1.961570560));
1237                     z4 = MULTIPLY(d5, - FIX(0.390180644));
1238
1239                     tmp0 = z3 + z5;
1240                     tmp1 += z2;
1241                     tmp2 += z2;
1242                     tmp3 = z4 + z5;
1243                 }
1244             }
1245             else
1246             {
1247                 if (d1)
1248                 {
1249             /* d1 != 0, d3 == 0, d5 != 0, d7 == 0 */
1250                     z4 = d5 + d1;
1251                     z5 = MULTIPLY(z4, FIX(1.175875602));
1252
1253                     tmp1 = MULTIPLY(d5, - FIX2(0.509795578));
1254                     tmp3 = MULTIPLY(d1, FIX2(0.601344887));
1255                     z1 = MULTIPLY(d1, - FIX(0.899976223));
1256                     z2 = MULTIPLY(d5, - FIX(2.562915447));
1257                     z4 = MULTIPLY(z4, FIX2(0.785694958));
1258
1259                     tmp0 = z1 + z5;
1260                     tmp1 += z4;
1261                     tmp2 = z2 + z5;
1262                     tmp3 += z4;
1263                 }
1264                 else
1265                 {
1266             /* d1 == 0, d3 == 0, d5 != 0, d7 == 0 */
1267                     tmp0 = MULTIPLY(d5, FIX(1.175875602));
1268                     tmp1 = MULTIPLY(d5, FIX2(0.275899380));
1269                     tmp2 = MULTIPLY(d5, - FIX2(1.387039845));
1270                     tmp3 = MULTIPLY(d5, FIX2(0.785694958));
1271                 }
1272             }
1273         }
1274         else
1275         {
1276             if (d3)
1277             {
1278                 if (d1)
1279                 {
1280             /* d1 != 0, d3 != 0, d5 == 0, d7 == 0 */
1281                     z5 = d3 + d1;
1282
1283                     tmp2 = MULTIPLY(d3, - FIX(1.451774981));
1284                     tmp3 = MULTIPLY(d1, (FIX(0.211164243) - 1));
1285                     z1 = MULTIPLY(d1, FIX(1.061594337));
1286                     z2 = MULTIPLY(d3, - FIX(2.172734803));
1287                     z4 = MULTIPLY(z5, FIX(0.785694958));
1288                     z5 = MULTIPLY(z5, FIX(1.175875602));
1289
1290                     tmp0 = z1 - z4;
1291                     tmp1 = z2 + z4;
1292                     tmp2 += z5;
1293                     tmp3 += z5;
1294                 }
1295                 else
1296                 {
1297             /* d1 == 0, d3 != 0, d5 == 0, d7 == 0 */
1298                     tmp0 = MULTIPLY(d3, - FIX2(0.785694958));
1299                     tmp1 = MULTIPLY(d3, - FIX2(1.387039845));
1300                     tmp2 = MULTIPLY(d3, - FIX2(0.275899379));
1301                     tmp3 = MULTIPLY(d3, FIX(1.175875602));
1302                 }
1303             }
1304             else
1305             {
1306                 if (d1)
1307                 {
1308             /* d1 != 0, d3 == 0, d5 == 0, d7 == 0 */
1309                     tmp0 = MULTIPLY(d1, FIX2(0.275899379));
1310                     tmp1 = MULTIPLY(d1, FIX2(0.785694958));
1311                     tmp2 = MULTIPLY(d1, FIX(1.175875602));
1312                     tmp3 = MULTIPLY(d1, FIX2(1.387039845));
1313                 }
1314                 else
1315                 {
1316             /* d1 == 0, d3 == 0, d5 == 0, d7 == 0 */
1317                     tmp0 = tmp1 = tmp2 = tmp3 = 0;
1318                 }
1319             }
1320         }
1321     }
1322
1323     /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
1324
1325     dataptr[DCTSIZE*0] = (dctelem_t) DESCALE(tmp10 + tmp3,
1326                        CONST_BITS+PASS1_BITS+3);
1327     dataptr[DCTSIZE*7] = (dctelem_t) DESCALE(tmp10 - tmp3,
1328                        CONST_BITS+PASS1_BITS+3);
1329     dataptr[DCTSIZE*1] = (dctelem_t) DESCALE(tmp11 + tmp2,
1330                        CONST_BITS+PASS1_BITS+3);
1331     dataptr[DCTSIZE*6] = (dctelem_t) DESCALE(tmp11 - tmp2,
1332                        CONST_BITS+PASS1_BITS+3);
1333     dataptr[DCTSIZE*2] = (dctelem_t) DESCALE(tmp12 + tmp1,
1334                        CONST_BITS+PASS1_BITS+3);
1335     dataptr[DCTSIZE*5] = (dctelem_t) DESCALE(tmp12 - tmp1,
1336                        CONST_BITS+PASS1_BITS+3);
1337     dataptr[DCTSIZE*3] = (dctelem_t) DESCALE(tmp13 + tmp0,
1338                        CONST_BITS+PASS1_BITS+3);
1339     dataptr[DCTSIZE*4] = (dctelem_t) DESCALE(tmp13 - tmp0,
1340                        CONST_BITS+PASS1_BITS+3);
1341
1342     dataptr++;             /* advance pointer to next column */
1343     }
1344 }
1345