libtiff/tif_predict.c

   1 /* $Id: tif_predict.c,v 1.11.2.4 2010-06-08 18:50:42 bfriesen Exp $ */
   2
   3 /*
   4  * Copyright (c) 1988-1997 Sam Leffler
   5  * Copyright (c) 1991-1997 Silicon Graphics, Inc.
   6  *
   7  * Permission to use, copy, modify, distribute, and sell this software and
   8  * its documentation for any purpose is hereby granted without fee, provided
   9  * that (i) the above copyright notices and this permission notice appear in
  10  * all copies of the software and related documentation, and (ii) the names of
  11  * Sam Leffler and Silicon Graphics may not be used in any advertising or
  12  * publicity relating to the software without the specific, prior written
  13  * permission of Sam Leffler and Silicon Graphics.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
  17  * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  18  *
  19  * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
  20  * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
  21  * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  22  * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
  23  * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  24  * OF THIS SOFTWARE.
  25  */
  26
  27 /*
  28  * TIFF Library.
  29  *
  30  * Predictor Tag Support (used by multiple codecs).
  31  */
  32 #include "tiffiop.h"
  33 #include "tif_predict.h"
  34
  35 #define PredictorState(tif)     ((TIFFPredictorState*) (tif)->tif_data)
  36
  37 static  void horAcc8(TIFF*, tidata_t, tsize_t);
  38 static  void horAcc16(TIFF*, tidata_t, tsize_t);
  39 static  void horAcc32(TIFF*, tidata_t, tsize_t);
  40 static  void swabHorAcc16(TIFF*, tidata_t, tsize_t);
  41 static  void swabHorAcc32(TIFF*, tidata_t, tsize_t);
  42 static  void horDiff8(TIFF*, tidata_t, tsize_t);
  43 static  void horDiff16(TIFF*, tidata_t, tsize_t);
  44 static  void horDiff32(TIFF*, tidata_t, tsize_t);
  45 static  void fpAcc(TIFF*, tidata_t, tsize_t);
  46 static  void fpDiff(TIFF*, tidata_t, tsize_t);
  47 static  int PredictorDecodeRow(TIFF*, tidata_t, tsize_t, tsample_t);
  48 static  int PredictorDecodeTile(TIFF*, tidata_t, tsize_t, tsample_t);
  49 static  int PredictorEncodeRow(TIFF*, tidata_t, tsize_t, tsample_t);
  50 static  int PredictorEncodeTile(TIFF*, tidata_t, tsize_t, tsample_t);
  51
  52 static int
  53 PredictorSetup(TIFF* tif)
  54 {
  55         static const char module[] = "PredictorSetup";
  56
  57         TIFFPredictorState* sp = PredictorState(tif);
  58         TIFFDirectory* td = &tif->tif_dir;
  59
  60         switch (sp->predictor)          /* no differencing */
  61         {
  62                 case PREDICTOR_NONE:
  63                         return 1;
  64                 case PREDICTOR_HORIZONTAL:
  65                         if (td->td_bitspersample != 8
  66                             && td->td_bitspersample != 16
  67                             && td->td_bitspersample != 32) {
  68                                 TIFFErrorExt(tif->tif_clientdata, module,
  69     "Horizontal differencing \"Predictor\" not supported with %d-bit samples",
  70                                           td->td_bitspersample);
  71                                 return 0;
  72                         }
  73                         break;
  74                 case PREDICTOR_FLOATINGPOINT:
  75                         if (td->td_sampleformat != SAMPLEFORMAT_IEEEFP) {
  76                                 TIFFErrorExt(tif->tif_clientdata, module,
  77         "Floating point \"Predictor\" not supported with %d data format",
  78                                           td->td_sampleformat);
  79                                 return 0;
  80                         }
  81                         break;
  82                 default:
  83                         TIFFErrorExt(tif->tif_clientdata, module,
  84                                   "\"Predictor\" value %d not supported",
  85                                   sp->predictor);
  86                         return 0;
  87         }
  88         sp->stride = (td->td_planarconfig == PLANARCONFIG_CONTIG ?
  89             td->td_samplesperpixel : 1);
  90         /*
  91          * Calculate the scanline/tile-width size in bytes.
  92          */
  93         if (isTiled(tif))
  94                 sp->rowsize = TIFFTileRowSize(tif);
  95         else
  96                 sp->rowsize = TIFFScanlineSize(tif);
  97
  98         return 1;
  99 }
 100
 101 static int
 102 PredictorSetupDecode(TIFF* tif)
 103 {
 104         TIFFPredictorState* sp = PredictorState(tif);
 105         TIFFDirectory* td = &tif->tif_dir;
 106
 107         if (!(*sp->setupdecode)(tif) || !PredictorSetup(tif))
 108                 return 0;
 109
 110         if (sp->predictor == 2) {
 111                 switch (td->td_bitspersample) {
 112                         case 8:  sp->decodepfunc = horAcc8; break;
 113                         case 16: sp->decodepfunc = horAcc16; break;
 114                         case 32: sp->decodepfunc = horAcc32; break;
 115                 }
 116                 /*
 117                  * Override default decoding method with one that does the
 118                  * predictor stuff.
 119                  */
 120                 if( tif->tif_decoderow != PredictorDecodeRow )
 121                 {
 122                     sp->decoderow = tif->tif_decoderow;
 123                     tif->tif_decoderow = PredictorDecodeRow;
 124                     sp->decodestrip = tif->tif_decodestrip;
 125                     tif->tif_decodestrip = PredictorDecodeTile;
 126                     sp->decodetile = tif->tif_decodetile;
 127                     tif->tif_decodetile = PredictorDecodeTile;
 128                 }
 129                 /*
 130                  * If the data is horizontally differenced 16-bit data that
 131                  * requires byte-swapping, then it must be byte swapped before
 132                  * the accumulation step.  We do this with a special-purpose
 133                  * routine and override the normal post decoding logic that
 134                  * the library setup when the directory was read.
 135                  */
 136                 if (tif->tif_flags & TIFF_SWAB) {
 137                         if (sp->decodepfunc == horAcc16) {
 138                                 sp->decodepfunc = swabHorAcc16;
 139                                 tif->tif_postdecode = _TIFFNoPostDecode;
 140                         } else if (sp->decodepfunc == horAcc32) {
 141                                 sp->decodepfunc = swabHorAcc32;
 142                                 tif->tif_postdecode = _TIFFNoPostDecode;
 143                         }
 144                 }
 145         }
 146
 147         else if (sp->predictor == 3) {
 148                 sp->decodepfunc = fpAcc;
 149                 /*
 150                  * Override default decoding method with one that does the
 151                  * predictor stuff.
 152                  */
 153                 if( tif->tif_decoderow != PredictorDecodeRow )
 154                 {
 155                     sp->decoderow = tif->tif_decoderow;
 156                     tif->tif_decoderow = PredictorDecodeRow;
 157                     sp->decodestrip = tif->tif_decodestrip;
 158                     tif->tif_decodestrip = PredictorDecodeTile;
 159                     sp->decodetile = tif->tif_decodetile;
 160                     tif->tif_decodetile = PredictorDecodeTile;
 161                 }
 162                 /*
 163                  * The data should not be swapped outside of the floating
 164                  * point predictor, the accumulation routine should return
 165                  * byres in the native order.
 166                  */
 167                 if (tif->tif_flags & TIFF_SWAB) {
 168                         tif->tif_postdecode = _TIFFNoPostDecode;
 169                 }
 170                 /*
 171                  * Allocate buffer to keep the decoded bytes before
 172                  * rearranging in the ight order
 173                  */
 174         }
 175
 176         return 1;
 177 }
 178
 179 static int
 180 PredictorSetupEncode(TIFF* tif)
 181 {
 182         TIFFPredictorState* sp = PredictorState(tif);
 183         TIFFDirectory* td = &tif->tif_dir;
 184
 185         if (!(*sp->setupencode)(tif) || !PredictorSetup(tif))
 186                 return 0;
 187
 188         if (sp->predictor == 2) {
 189                 switch (td->td_bitspersample) {
 190                         case 8:  sp->encodepfunc = horDiff8; break;
 191                         case 16: sp->encodepfunc = horDiff16; break;
 192                         case 32: sp->encodepfunc = horDiff32; break;
 193                 }
 194                 /*
 195                  * Override default encoding method with one that does the
 196                  * predictor stuff.
 197                  */
 198                 if( tif->tif_encoderow != PredictorEncodeRow )
 199                 {
 200                     sp->encoderow = tif->tif_encoderow;
 201                     tif->tif_encoderow = PredictorEncodeRow;
 202                     sp->encodestrip = tif->tif_encodestrip;
 203                     tif->tif_encodestrip = PredictorEncodeTile;
 204                     sp->encodetile = tif->tif_encodetile;
 205                     tif->tif_encodetile = PredictorEncodeTile;
 206                 }
 207         }
 208
 209         else if (sp->predictor == 3) {
 210                 sp->encodepfunc = fpDiff;
 211                 /*
 212                  * Override default encoding method with one that does the
 213                  * predictor stuff.
 214                  */
 215                 if( tif->tif_encoderow != PredictorEncodeRow )
 216                 {
 217                     sp->encoderow = tif->tif_encoderow;
 218                     tif->tif_encoderow = PredictorEncodeRow;
 219                     sp->encodestrip = tif->tif_encodestrip;
 220                     tif->tif_encodestrip = PredictorEncodeTile;
 221                     sp->encodetile = tif->tif_encodetile;
 222                     tif->tif_encodetile = PredictorEncodeTile;
 223                 }
 224         }
 225
 226         return 1;
 227 }
 228
 229 #define REPEAT4(n, op)          \
 230     switch (n) {                \
 231     default: { int i; for (i = n-4; i > 0; i--) { op; } } \
 232     case 4:  op;                \
 233     case 3:  op;                \
 234     case 2:  op;                \
 235     case 1:  op;                \
 236     case 0:  ;                  \
 237     }
 238
 239 static void
 240 horAcc8(TIFF* tif, tidata_t cp0, tsize_t cc)
 241 {
 242         tsize_t stride = PredictorState(tif)->stride;
 243
 244         char* cp = (char*) cp0;
 245         if (cc > stride) {
 246                 cc -= stride;
 247                 /*
 248                  * Pipeline the most common cases.
 249                  */
 250                 if (stride == 3)  {
 251                         unsigned int cr = cp[0];
 252                         unsigned int cg = cp[1];
 253                         unsigned int cb = cp[2];
 254                         do {
 255                                 cc -= 3, cp += 3;
 256                                 cp[0] = (char) (cr += cp[0]);
 257                                 cp[1] = (char) (cg += cp[1]);
 258                                 cp[2] = (char) (cb += cp[2]);
 259                         } while ((int32) cc > 0);
 260                 } else if (stride == 4)  {
 261                         unsigned int cr = cp[0];
 262                         unsigned int cg = cp[1];
 263                         unsigned int cb = cp[2];
 264                         unsigned int ca = cp[3];
 265                         do {
 266                                 cc -= 4, cp += 4;
 267                                 cp[0] = (char) (cr += cp[0]);
 268                                 cp[1] = (char) (cg += cp[1]);
 269                                 cp[2] = (char) (cb += cp[2]);
 270                                 cp[3] = (char) (ca += cp[3]);
 271                         } while ((int32) cc > 0);
 272                 } else  {
 273                         do {
 274                                 REPEAT4(stride, cp[stride] =
 275                                         (char) (cp[stride] + *cp); cp++)
 276                                 cc -= stride;
 277                         } while ((int32) cc > 0);
 278                 }
 279         }
 280 }
 281
 282 static void
 283 swabHorAcc16(TIFF* tif, tidata_t cp0, tsize_t cc)
 284 {
 285         tsize_t stride = PredictorState(tif)->stride;
 286         uint16* wp = (uint16*) cp0;
 287         tsize_t wc = cc / 2;
 288
 289         if (wc > stride) {
 290                 TIFFSwabArrayOfShort(wp, wc);
 291                 wc -= stride;
 292                 do {
 293                         REPEAT4(stride, wp[stride] += wp[0]; wp++)
 294                         wc -= stride;
 295                 } while ((int32) wc > 0);
 296         }
 297 }
 298
 299 static void
 300 horAcc16(TIFF* tif, tidata_t cp0, tsize_t cc)
 301 {
 302         tsize_t stride = PredictorState(tif)->stride;
 303         uint16* wp = (uint16*) cp0;
 304         tsize_t wc = cc / 2;
 305
 306         if (wc > stride) {
 307                 wc -= stride;
 308                 do {
 309                         REPEAT4(stride, wp[stride] += wp[0]; wp++)
 310                         wc -= stride;
 311                 } while ((int32) wc > 0);
 312         }
 313 }
 314
 315 static void
 316 swabHorAcc32(TIFF* tif, tidata_t cp0, tsize_t cc)
 317 {
 318         tsize_t stride = PredictorState(tif)->stride;
 319         uint32* wp = (uint32*) cp0;
 320         tsize_t wc = cc / 4;
 321
 322         if (wc > stride) {
 323                 TIFFSwabArrayOfLong(wp, wc);
 324                 wc -= stride;
 325                 do {
 326                         REPEAT4(stride, wp[stride] += wp[0]; wp++)
 327                         wc -= stride;
 328                 } while ((int32) wc > 0);
 329         }
 330 }
 331
 332 static void
 333 horAcc32(TIFF* tif, tidata_t cp0, tsize_t cc)
 334 {
 335         tsize_t stride = PredictorState(tif)->stride;
 336         uint32* wp = (uint32*) cp0;
 337         tsize_t wc = cc / 4;
 338
 339         if (wc > stride) {
 340                 wc -= stride;
 341                 do {
 342                         REPEAT4(stride, wp[stride] += wp[0]; wp++)
 343                         wc -= stride;
 344                 } while ((int32) wc > 0);
 345         }
 346 }
 347
 348 /*
 349  * Floating point predictor accumulation routine.
 350  */
 351 static void
 352 fpAcc(TIFF* tif, tidata_t cp0, tsize_t cc)
 353 {
 354         tsize_t stride = PredictorState(tif)->stride;
 355         uint32 bps = tif->tif_dir.td_bitspersample / 8;
 356         tsize_t wc = cc / bps;
 357         tsize_t count = cc;
 358         uint8 *cp = (uint8 *) cp0;
 359         uint8 *tmp = (uint8 *)_TIFFmalloc(cc);
 360
 361         if (!tmp)
 362                 return;
 363
 364         while (count > stride) {
 365                 REPEAT4(stride, cp[stride] += cp[0]; cp++)
 366                 count -= stride;
 367         }
 368
 369         _TIFFmemcpy(tmp, cp0, cc);
 370         cp = (uint8 *) cp0;
 371         for (count = 0; count < wc; count++) {
 372                 uint32 byte;
 373                 for (byte = 0; byte < bps; byte++) {
 374 #if WORDS_BIGENDIAN
 375                         cp[bps * count + byte] = tmp[byte * wc + count];
 376 #else
 377                         cp[bps * count + byte] =
 378                                 tmp[(bps - byte - 1) * wc + count];
 379 #endif
 380                 }
 381         }
 382         _TIFFfree(tmp);
 383 }
 384
 385 /*
 386  * Decode a scanline and apply the predictor routine.
 387  */
 388 static int
 389 PredictorDecodeRow(TIFF* tif, tidata_t op0, tsize_t occ0, tsample_t s)
 390 {
 391         TIFFPredictorState *sp = PredictorState(tif);
 392
 393         assert(sp != NULL);
 394         assert(sp->decoderow != NULL);
 395         assert(sp->decodepfunc != NULL);
 396
 397         if ((*sp->decoderow)(tif, op0, occ0, s)) {
 398                 (*sp->decodepfunc)(tif, op0, occ0);
 399                 return 1;
 400         } else
 401                 return 0;
 402 }
 403
 404 /*
 405  * Decode a tile/strip and apply the predictor routine.
 406  * Note that horizontal differencing must be done on a
 407  * row-by-row basis.  The width of a "row" has already
 408  * been calculated at pre-decode time according to the
 409  * strip/tile dimensions.
 410  */
 411 static int
 412 PredictorDecodeTile(TIFF* tif, tidata_t op0, tsize_t occ0, tsample_t s)
 413 {
 414         TIFFPredictorState *sp = PredictorState(tif);
 415
 416         assert(sp != NULL);
 417         assert(sp->decodetile != NULL);
 418
 419         if ((*sp->decodetile)(tif, op0, occ0, s)) {
 420                 tsize_t rowsize = sp->rowsize;
 421                 assert(rowsize > 0);
 422                 assert(sp->decodepfunc != NULL);
 423                 while ((long)occ0 > 0) {
 424                         (*sp->decodepfunc)(tif, op0, (tsize_t) rowsize);
 425                         occ0 -= rowsize;
 426                         op0 += rowsize;
 427                 }
 428                 return 1;
 429         } else
 430                 return 0;
 431 }
 432
 433 static void
 434 horDiff8(TIFF* tif, tidata_t cp0, tsize_t cc)
 435 {
 436         TIFFPredictorState* sp = PredictorState(tif);
 437         tsize_t stride = sp->stride;
 438         char* cp = (char*) cp0;
 439
 440         if (cc > stride) {
 441                 cc -= stride;
 442                 /*
 443                  * Pipeline the most common cases.
 444                  */
 445                 if (stride == 3) {
 446                         int r1, g1, b1;
 447                         int r2 = cp[0];
 448                         int g2 = cp[1];
 449                         int b2 = cp[2];
 450                         do {
 451                                 r1 = cp[3]; cp[3] = r1-r2; r2 = r1;
 452                                 g1 = cp[4]; cp[4] = g1-g2; g2 = g1;
 453                                 b1 = cp[5]; cp[5] = b1-b2; b2 = b1;
 454                                 cp += 3;
 455                         } while ((int32)(cc -= 3) > 0);
 456                 } else if (stride == 4) {
 457                         int r1, g1, b1, a1;
 458                         int r2 = cp[0];
 459                         int g2 = cp[1];
 460                         int b2 = cp[2];
 461                         int a2 = cp[3];
 462                         do {
 463                                 r1 = cp[4]; cp[4] = r1-r2; r2 = r1;
 464                                 g1 = cp[5]; cp[5] = g1-g2; g2 = g1;
 465                                 b1 = cp[6]; cp[6] = b1-b2; b2 = b1;
 466                                 a1 = cp[7]; cp[7] = a1-a2; a2 = a1;
 467                                 cp += 4;
 468                         } while ((int32)(cc -= 4) > 0);
 469                 } else {
 470                         cp += cc - 1;
 471                         do {
 472                                 REPEAT4(stride, cp[stride] -= cp[0]; cp--)
 473                         } while ((int32)(cc -= stride) > 0);
 474                 }
 475         }
 476 }
 477
 478 static void
 479 horDiff16(TIFF* tif, tidata_t cp0, tsize_t cc)
 480 {
 481         TIFFPredictorState* sp = PredictorState(tif);
 482         tsize_t stride = sp->stride;
 483         int16 *wp = (int16*) cp0;
 484         tsize_t wc = cc/2;
 485
 486         if (wc > stride) {
 487                 wc -= stride;
 488                 wp += wc - 1;
 489                 do {
 490                         REPEAT4(stride, wp[stride] -= wp[0]; wp--)
 491                         wc -= stride;
 492                 } while ((int32) wc > 0);
 493         }
 494 }
 495
 496 static void
 497 horDiff32(TIFF* tif, tidata_t cp0, tsize_t cc)
 498 {
 499         TIFFPredictorState* sp = PredictorState(tif);
 500         tsize_t stride = sp->stride;
 501         int32 *wp = (int32*) cp0;
 502         tsize_t wc = cc/4;
 503
 504         if (wc > stride) {
 505                 wc -= stride;
 506                 wp += wc - 1;
 507                 do {
 508                         REPEAT4(stride, wp[stride] -= wp[0]; wp--)
 509                         wc -= stride;
 510                 } while ((int32) wc > 0);
 511         }
 512 }
 513
 514 /*
 515  * Floating point predictor differencing routine.
 516  */
 517 static void
 518 fpDiff(TIFF* tif, tidata_t cp0, tsize_t cc)
 519 {
 520         tsize_t stride = PredictorState(tif)->stride;
 521         uint32 bps = tif->tif_dir.td_bitspersample / 8;
 522         tsize_t wc = cc / bps;
 523         tsize_t count;
 524         uint8 *cp = (uint8 *) cp0;
 525         uint8 *tmp = (uint8 *)_TIFFmalloc(cc);
 526
 527         if (!tmp)
 528                 return;
 529
 530         _TIFFmemcpy(tmp, cp0, cc);
 531         for (count = 0; count < wc; count++) {
 532                 uint32 byte;
 533                 for (byte = 0; byte < bps; byte++) {
 534 #if WORDS_BIGENDIAN
 535                         cp[byte * wc + count] = tmp[bps * count + byte];
 536 #else
 537                         cp[(bps - byte - 1) * wc + count] =
 538                                 tmp[bps * count + byte];
 539 #endif
 540                 }
 541         }
 542         _TIFFfree(tmp);
 543
 544         cp = (uint8 *) cp0;
 545         cp += cc - stride - 1;
 546         for (count = cc; count > stride; count -= stride)
 547                 REPEAT4(stride, cp[stride] -= cp[0]; cp--)
 548 }
 549
 550 static int
 551 PredictorEncodeRow(TIFF* tif, tidata_t bp, tsize_t cc, tsample_t s)
 552 {
 553         TIFFPredictorState *sp = PredictorState(tif);
 554
 555         assert(sp != NULL);
 556         assert(sp->encodepfunc != NULL);
 557         assert(sp->encoderow != NULL);
 558
 559         /* XXX horizontal differencing alters user's data XXX */
 560         (*sp->encodepfunc)(tif, bp, cc);
 561         return (*sp->encoderow)(tif, bp, cc, s);
 562 }
 563
 564 static int
 565 PredictorEncodeTile(TIFF* tif, tidata_t bp0, tsize_t cc0, tsample_t s)
 566 {
 567         static const char module[] = "PredictorEncodeTile";
 568         TIFFPredictorState *sp = PredictorState(tif);
 569         uint8 *working_copy;
 570         tsize_t cc = cc0, rowsize;
 571         unsigned char* bp;
 572         int result_code;
 573
 574         assert(sp != NULL);
 575         assert(sp->encodepfunc != NULL);
 576         assert(sp->encodetile != NULL);
 577
 578         /*
 579          * Do predictor manipulation in a working buffer to avoid altering
 580          * the callers buffer. http://trac.osgeo.org/gdal/ticket/1965
 581          */
 582         working_copy = (uint8*) _TIFFmalloc(cc0);
 583         if( working_copy == NULL )
 584         {
 585             TIFFErrorExt(tif->tif_clientdata, module,
 586                          "Out of memory allocating %d byte temp buffer.",
 587                          cc0 );
 588             return 0;
 589         }
 590         memcpy( working_copy, bp0, cc0 );
 591         bp = working_copy;
 592
 593         rowsize = sp->rowsize;
 594         assert(rowsize > 0);
 595         assert((cc0%rowsize)==0);
 596         while (cc > 0) {
 597                 (*sp->encodepfunc)(tif, bp, rowsize);
 598                 cc -= rowsize;
 599                 bp += rowsize;
 600         }
 601         result_code = (*sp->encodetile)(tif, working_copy, cc0, s);
 602
 603         _TIFFfree( working_copy );
 604
 605         return result_code;
 606 }
 607
 608 #define FIELD_PREDICTOR (FIELD_CODEC+0)         /* XXX */
 609
 610 static const TIFFFieldInfo predictFieldInfo[] = {
 611     { TIFFTAG_PREDICTOR,         1, 1, TIFF_SHORT,      FIELD_PREDICTOR,
 612       FALSE,    FALSE,  "Predictor" },
 613 };
 614
 615 static int
 616 PredictorVSetField(TIFF* tif, ttag_t tag, va_list ap)
 617 {
 618         TIFFPredictorState *sp = PredictorState(tif);
 619
 620         assert(sp != NULL);
 621         assert(sp->vsetparent != NULL);
 622
 623         switch (tag) {
 624         case TIFFTAG_PREDICTOR:
 625                 sp->predictor = (uint16) va_arg(ap, int);
 626                 TIFFSetFieldBit(tif, FIELD_PREDICTOR);
 627                 break;
 628         default:
 629                 return (*sp->vsetparent)(tif, tag, ap);
 630         }
 631         tif->tif_flags |= TIFF_DIRTYDIRECT;
 632         return 1;
 633 }
 634
 635 static int
 636 PredictorVGetField(TIFF* tif, ttag_t tag, va_list ap)
 637 {
 638         TIFFPredictorState *sp = PredictorState(tif);
 639
 640         assert(sp != NULL);
 641         assert(sp->vgetparent != NULL);
 642
 643         switch (tag) {
 644         case TIFFTAG_PREDICTOR:
 645                 *va_arg(ap, uint16*) = sp->predictor;
 646                 break;
 647         default:
 648                 return (*sp->vgetparent)(tif, tag, ap);
 649         }
 650         return 1;
 651 }
 652
 653 static void
 654 PredictorPrintDir(TIFF* tif, FILE* fd, long flags)
 655 {
 656         TIFFPredictorState* sp = PredictorState(tif);
 657
 658         (void) flags;
 659         if (TIFFFieldSet(tif,FIELD_PREDICTOR)) {
 660                 fprintf(fd, "  Predictor: ");
 661                 switch (sp->predictor) {
 662                 case 1: fprintf(fd, "none "); break;
 663                 case 2: fprintf(fd, "horizontal differencing "); break;
 664                 case 3: fprintf(fd, "floating point predictor "); break;
 665                 }
 666                 fprintf(fd, "%u (0x%x)\n", sp->predictor, sp->predictor);
 667         }
 668         if (sp->printdir)
 669                 (*sp->printdir)(tif, fd, flags);
 670 }
 671
 672 int
 673 TIFFPredictorInit(TIFF* tif)
 674 {
 675         TIFFPredictorState* sp = PredictorState(tif);
 676
 677         assert(sp != 0);
 678
 679         /*
 680          * Merge codec-specific tag information.
 681          */
 682         if (!_TIFFMergeFieldInfo(tif, predictFieldInfo,
 683                                  TIFFArrayCount(predictFieldInfo))) {
 684                 TIFFErrorExt(tif->tif_clientdata, "TIFFPredictorInit",
 685                              "Merging Predictor codec-specific tags failed");
 686                 return 0;
 687         }
 688
 689         /*
 690          * Override parent get/set field methods.
 691          */
 692         sp->vgetparent = tif->tif_tagmethods.vgetfield;
 693         tif->tif_tagmethods.vgetfield =
 694             PredictorVGetField;/* hook for predictor tag */
 695         sp->vsetparent = tif->tif_tagmethods.vsetfield;
 696         tif->tif_tagmethods.vsetfield =
 697             PredictorVSetField;/* hook for predictor tag */
 698         sp->printdir = tif->tif_tagmethods.printdir;
 699         tif->tif_tagmethods.printdir =
 700             PredictorPrintDir;  /* hook for predictor tag */
 701
 702         sp->setupdecode = tif->tif_setupdecode;
 703         tif->tif_setupdecode = PredictorSetupDecode;
 704         sp->setupencode = tif->tif_setupencode;
 705         tif->tif_setupencode = PredictorSetupEncode;
 706
 707         sp->predictor = 1;                      /* default value */
 708         sp->encodepfunc = NULL;                 /* no predictor routine */
 709         sp->decodepfunc = NULL;                 /* no predictor routine */
 710         return 1;
 711 }
 712
 713 int
 714 TIFFPredictorCleanup(TIFF* tif)
 715 {
 716         TIFFPredictorState* sp = PredictorState(tif);
 717
 718         assert(sp != 0);
 719
 720         tif->tif_tagmethods.vgetfield = sp->vgetparent;
 721         tif->tif_tagmethods.vsetfield = sp->vsetparent;
 722         tif->tif_tagmethods.printdir = sp->printdir;
 723         tif->tif_setupdecode = sp->setupdecode;
 724         tif->tif_setupencode = sp->setupencode;
 725
 726         return 1;
 727 }
 728
 729 /* vim: set ts=8 sts=8 sw=8 noet: */
 730 /*
 731  * Local Variables:
 732  * mode: c
 733  * c-basic-offset: 8
 734  * fill-column: 78
 735  * End:
 736  */