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1 /* $Id: tif_predict.c,v 1.43 2017-05-10 15:21:16 erouault 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 int horAcc8(TIFF* tif, uint8* cp0, tmsize_t cc);
38 static int horAcc16(TIFF* tif, uint8* cp0, tmsize_t cc);
39 static int horAcc32(TIFF* tif, uint8* cp0, tmsize_t cc);
40 static int swabHorAcc16(TIFF* tif, uint8* cp0, tmsize_t cc);
41 static int swabHorAcc32(TIFF* tif, uint8* cp0, tmsize_t cc);
42 static int horDiff8(TIFF* tif, uint8* cp0, tmsize_t cc);
43 static int horDiff16(TIFF* tif, uint8* cp0, tmsize_t cc);
44 static int horDiff32(TIFF* tif, uint8* cp0, tmsize_t cc);
45 static int swabHorDiff16(TIFF* tif, uint8* cp0, tmsize_t cc);
46 static int swabHorDiff32(TIFF* tif, uint8* cp0, tmsize_t cc);
47 static int fpAcc(TIFF* tif, uint8* cp0, tmsize_t cc);
48 static int fpDiff(TIFF* tif, uint8* cp0, tmsize_t cc);
49 static int PredictorDecodeRow(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s);
50 static int PredictorDecodeTile(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s);
51 static int PredictorEncodeRow(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s);
52 static int PredictorEncodeTile(TIFF* tif, uint8* bp0, tmsize_t cc0, uint16 s);
53 
54 static int
PredictorSetup(TIFF * tif)55 PredictorSetup(TIFF* tif)
56 {
57 	static const char module[] = "PredictorSetup";
58 
59 	TIFFPredictorState* sp = PredictorState(tif);
60 	TIFFDirectory* td = &tif->tif_dir;
61 
62 	switch (sp->predictor)		/* no differencing */
63 	{
64 		case PREDICTOR_NONE:
65 			return 1;
66 		case PREDICTOR_HORIZONTAL:
67 			if (td->td_bitspersample != 8
68 			    && td->td_bitspersample != 16
69 			    && td->td_bitspersample != 32) {
70 				TIFFErrorExt(tif->tif_clientdata, module,
71 				    "Horizontal differencing \"Predictor\" not supported with %d-bit samples",
72 				    td->td_bitspersample);
73 				return 0;
74 			}
75 			break;
76 		case PREDICTOR_FLOATINGPOINT:
77 			if (td->td_sampleformat != SAMPLEFORMAT_IEEEFP) {
78 				TIFFErrorExt(tif->tif_clientdata, module,
79 				    "Floating point \"Predictor\" not supported with %d data format",
80 				    td->td_sampleformat);
81 				return 0;
82 			}
83                         if (td->td_bitspersample != 16
84                             && td->td_bitspersample != 24
85                             && td->td_bitspersample != 32
86                             && td->td_bitspersample != 64) { /* Should 64 be allowed? */
87                                 TIFFErrorExt(tif->tif_clientdata, module,
88                                              "Floating point \"Predictor\" not supported with %d-bit samples",
89                                              td->td_bitspersample);
90 				return 0;
91                             }
92 			break;
93 		default:
94 			TIFFErrorExt(tif->tif_clientdata, module,
95 			    "\"Predictor\" value %d not supported",
96 			    sp->predictor);
97 			return 0;
98 	}
99 	sp->stride = (td->td_planarconfig == PLANARCONFIG_CONTIG ?
100 	    td->td_samplesperpixel : 1);
101 	/*
102 	 * Calculate the scanline/tile-width size in bytes.
103 	 */
104 	if (isTiled(tif))
105 		sp->rowsize = TIFFTileRowSize(tif);
106 	else
107 		sp->rowsize = TIFFScanlineSize(tif);
108 	if (sp->rowsize == 0)
109 		return 0;
110 
111 	return 1;
112 }
113 
114 static int
PredictorSetupDecode(TIFF * tif)115 PredictorSetupDecode(TIFF* tif)
116 {
117 	TIFFPredictorState* sp = PredictorState(tif);
118 	TIFFDirectory* td = &tif->tif_dir;
119 
120 	/* Note: when PredictorSetup() fails, the effets of setupdecode() */
121 	/* will not be "cancelled" so setupdecode() might be robust to */
122 	/* be called several times. */
123 	if (!(*sp->setupdecode)(tif) || !PredictorSetup(tif))
124 		return 0;
125 
126 	if (sp->predictor == 2) {
127 		switch (td->td_bitspersample) {
128 			case 8:  sp->decodepfunc = horAcc8; break;
129 			case 16: sp->decodepfunc = horAcc16; break;
130 			case 32: sp->decodepfunc = horAcc32; break;
131 		}
132 		/*
133 		 * Override default decoding method with one that does the
134 		 * predictor stuff.
135 		 */
136                 if( tif->tif_decoderow != PredictorDecodeRow )
137                 {
138                     sp->decoderow = tif->tif_decoderow;
139                     tif->tif_decoderow = PredictorDecodeRow;
140                     sp->decodestrip = tif->tif_decodestrip;
141                     tif->tif_decodestrip = PredictorDecodeTile;
142                     sp->decodetile = tif->tif_decodetile;
143                     tif->tif_decodetile = PredictorDecodeTile;
144                 }
145 
146 		/*
147 		 * If the data is horizontally differenced 16-bit data that
148 		 * requires byte-swapping, then it must be byte swapped before
149 		 * the accumulation step.  We do this with a special-purpose
150 		 * routine and override the normal post decoding logic that
151 		 * the library setup when the directory was read.
152 		 */
153 		if (tif->tif_flags & TIFF_SWAB) {
154 			if (sp->decodepfunc == horAcc16) {
155 				sp->decodepfunc = swabHorAcc16;
156 				tif->tif_postdecode = _TIFFNoPostDecode;
157             } else if (sp->decodepfunc == horAcc32) {
158 				sp->decodepfunc = swabHorAcc32;
159 				tif->tif_postdecode = _TIFFNoPostDecode;
160             }
161 		}
162 	}
163 
164 	else if (sp->predictor == 3) {
165 		sp->decodepfunc = fpAcc;
166 		/*
167 		 * Override default decoding method with one that does the
168 		 * predictor stuff.
169 		 */
170                 if( tif->tif_decoderow != PredictorDecodeRow )
171                 {
172                     sp->decoderow = tif->tif_decoderow;
173                     tif->tif_decoderow = PredictorDecodeRow;
174                     sp->decodestrip = tif->tif_decodestrip;
175                     tif->tif_decodestrip = PredictorDecodeTile;
176                     sp->decodetile = tif->tif_decodetile;
177                     tif->tif_decodetile = PredictorDecodeTile;
178                 }
179 		/*
180 		 * The data should not be swapped outside of the floating
181 		 * point predictor, the accumulation routine should return
182 		 * byres in the native order.
183 		 */
184 		if (tif->tif_flags & TIFF_SWAB) {
185 			tif->tif_postdecode = _TIFFNoPostDecode;
186 		}
187 		/*
188 		 * Allocate buffer to keep the decoded bytes before
189 		 * rearranging in the right order
190 		 */
191 	}
192 
193 	return 1;
194 }
195 
196 static int
PredictorSetupEncode(TIFF * tif)197 PredictorSetupEncode(TIFF* tif)
198 {
199 	TIFFPredictorState* sp = PredictorState(tif);
200 	TIFFDirectory* td = &tif->tif_dir;
201 
202 	if (!(*sp->setupencode)(tif) || !PredictorSetup(tif))
203 		return 0;
204 
205 	if (sp->predictor == 2) {
206 		switch (td->td_bitspersample) {
207 			case 8:  sp->encodepfunc = horDiff8; break;
208 			case 16: sp->encodepfunc = horDiff16; break;
209 			case 32: sp->encodepfunc = horDiff32; break;
210 		}
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                  * If the data is horizontally differenced 16-bit data that
227                  * requires byte-swapping, then it must be byte swapped after
228                  * the differentiation step.  We do this with a special-purpose
229                  * routine and override the normal post decoding logic that
230                  * the library setup when the directory was read.
231                  */
232                 if (tif->tif_flags & TIFF_SWAB) {
233                     if (sp->encodepfunc == horDiff16) {
234                             sp->encodepfunc = swabHorDiff16;
235                             tif->tif_postdecode = _TIFFNoPostDecode;
236                     } else if (sp->encodepfunc == horDiff32) {
237                             sp->encodepfunc = swabHorDiff32;
238                             tif->tif_postdecode = _TIFFNoPostDecode;
239                     }
240                 }
241         }
242 
243 	else if (sp->predictor == 3) {
244 		sp->encodepfunc = fpDiff;
245 		/*
246 		 * Override default encoding method with one that does the
247 		 * predictor stuff.
248 		 */
249                 if( tif->tif_encoderow != PredictorEncodeRow )
250                 {
251                     sp->encoderow = tif->tif_encoderow;
252                     tif->tif_encoderow = PredictorEncodeRow;
253                     sp->encodestrip = tif->tif_encodestrip;
254                     tif->tif_encodestrip = PredictorEncodeTile;
255                     sp->encodetile = tif->tif_encodetile;
256                     tif->tif_encodetile = PredictorEncodeTile;
257                 }
258 	}
259 
260 	return 1;
261 }
262 
263 #define REPEAT4(n, op)		\
264     switch (n) {		\
265     default: { \
266         tmsize_t i; for (i = n-4; i > 0; i--) { op; } }  /*-fallthrough*/  \
267     case 4:  op; /*-fallthrough*/ \
268     case 3:  op; /*-fallthrough*/ \
269     case 2:  op; /*-fallthrough*/ \
270     case 1:  op; /*-fallthrough*/ \
271     case 0:  ;			\
272     }
273 
274 /* Remarks related to C standard compliance in all below functions : */
275 /* - to avoid any undefined behaviour, we only operate on unsigned types */
276 /*   since the behaviour of "overflows" is defined (wrap over) */
277 /* - when storing into the byte stream, we explicitly mask with 0xff so */
278 /*   as to make icc -check=conversions happy (not necessary by the standard) */
279 
280 static int
horAcc8(TIFF * tif,uint8 * cp0,tmsize_t cc)281 horAcc8(TIFF* tif, uint8* cp0, tmsize_t cc)
282 {
283 	tmsize_t stride = PredictorState(tif)->stride;
284 
285 	unsigned char* cp = (unsigned char*) cp0;
286     if((cc%stride)!=0)
287     {
288         TIFFErrorExt(tif->tif_clientdata, "horAcc8",
289                      "%s", "(cc%stride)!=0");
290         return 0;
291     }
292 
293 	if (cc > stride) {
294 		/*
295 		 * Pipeline the most common cases.
296 		 */
297 		if (stride == 3)  {
298 			unsigned int cr = cp[0];
299 			unsigned int cg = cp[1];
300 			unsigned int cb = cp[2];
301 			cc -= 3;
302 			cp += 3;
303 			while (cc>0) {
304 				cp[0] = (unsigned char) ((cr += cp[0]) & 0xff);
305 				cp[1] = (unsigned char) ((cg += cp[1]) & 0xff);
306 				cp[2] = (unsigned char) ((cb += cp[2]) & 0xff);
307 				cc -= 3;
308 				cp += 3;
309 			}
310 		} else if (stride == 4)  {
311 			unsigned int cr = cp[0];
312 			unsigned int cg = cp[1];
313 			unsigned int cb = cp[2];
314 			unsigned int ca = cp[3];
315 			cc -= 4;
316 			cp += 4;
317 			while (cc>0) {
318 				cp[0] = (unsigned char) ((cr += cp[0]) & 0xff);
319 				cp[1] = (unsigned char) ((cg += cp[1]) & 0xff);
320 				cp[2] = (unsigned char) ((cb += cp[2]) & 0xff);
321 				cp[3] = (unsigned char) ((ca += cp[3]) & 0xff);
322 				cc -= 4;
323 				cp += 4;
324 			}
325 		} else  {
326 			cc -= stride;
327 			do {
328 				REPEAT4(stride, cp[stride] =
329 					(unsigned char) ((cp[stride] + *cp) & 0xff); cp++)
330 				cc -= stride;
331 			} while (cc>0);
332 		}
333 	}
334 	return 1;
335 }
336 
337 static int
swabHorAcc16(TIFF * tif,uint8 * cp0,tmsize_t cc)338 swabHorAcc16(TIFF* tif, uint8* cp0, tmsize_t cc)
339 {
340 	uint16* wp = (uint16*) cp0;
341 	tmsize_t wc = cc / 2;
342 
343         TIFFSwabArrayOfShort(wp, wc);
344         return horAcc16(tif, cp0, cc);
345 }
346 
347 static int
horAcc16(TIFF * tif,uint8 * cp0,tmsize_t cc)348 horAcc16(TIFF* tif, uint8* cp0, tmsize_t cc)
349 {
350 	tmsize_t stride = PredictorState(tif)->stride;
351 	uint16* wp = (uint16*) cp0;
352 	tmsize_t wc = cc / 2;
353 
354     if((cc%(2*stride))!=0)
355     {
356         TIFFErrorExt(tif->tif_clientdata, "horAcc16",
357                      "%s", "cc%(2*stride))!=0");
358         return 0;
359     }
360 
361 	if (wc > stride) {
362 		wc -= stride;
363 		do {
364 			REPEAT4(stride, wp[stride] = (uint16)(((unsigned int)wp[stride] + (unsigned int)wp[0]) & 0xffff); wp++)
365 			wc -= stride;
366 		} while (wc > 0);
367 	}
368 	return 1;
369 }
370 
371 static int
swabHorAcc32(TIFF * tif,uint8 * cp0,tmsize_t cc)372 swabHorAcc32(TIFF* tif, uint8* cp0, tmsize_t cc)
373 {
374 	uint32* wp = (uint32*) cp0;
375 	tmsize_t wc = cc / 4;
376 
377         TIFFSwabArrayOfLong(wp, wc);
378 	return horAcc32(tif, cp0, cc);
379 }
380 
381 static int
horAcc32(TIFF * tif,uint8 * cp0,tmsize_t cc)382 horAcc32(TIFF* tif, uint8* cp0, tmsize_t cc)
383 {
384 	tmsize_t stride = PredictorState(tif)->stride;
385 	uint32* wp = (uint32*) cp0;
386 	tmsize_t wc = cc / 4;
387 
388     if((cc%(4*stride))!=0)
389     {
390         TIFFErrorExt(tif->tif_clientdata, "horAcc32",
391                      "%s", "cc%(4*stride))!=0");
392         return 0;
393     }
394 
395 	if (wc > stride) {
396 		wc -= stride;
397 		do {
398 			REPEAT4(stride, wp[stride] += wp[0]; wp++)
399 			wc -= stride;
400 		} while (wc > 0);
401 	}
402 	return 1;
403 }
404 
405 /*
406  * Floating point predictor accumulation routine.
407  */
408 static int
fpAcc(TIFF * tif,uint8 * cp0,tmsize_t cc)409 fpAcc(TIFF* tif, uint8* cp0, tmsize_t cc)
410 {
411 	tmsize_t stride = PredictorState(tif)->stride;
412 	uint32 bps = tif->tif_dir.td_bitspersample / 8;
413 	tmsize_t wc = cc / bps;
414 	tmsize_t count = cc;
415 	uint8 *cp = (uint8 *) cp0;
416 	uint8 *tmp;
417 
418     if(cc%(bps*stride)!=0)
419     {
420         TIFFErrorExt(tif->tif_clientdata, "fpAcc",
421                      "%s", "cc%(bps*stride))!=0");
422         return 0;
423     }
424 
425     tmp = (uint8 *)_TIFFmalloc(cc);
426 	if (!tmp)
427 		return 0;
428 
429 	while (count > stride) {
430 		REPEAT4(stride, cp[stride] =
431                         (unsigned char) ((cp[stride] + cp[0]) & 0xff); cp++)
432 		count -= stride;
433 	}
434 
435 	_TIFFmemcpy(tmp, cp0, cc);
436 	cp = (uint8 *) cp0;
437 	for (count = 0; count < wc; count++) {
438 		uint32 byte;
439 		for (byte = 0; byte < bps; byte++) {
440 			#if WORDS_BIGENDIAN
441 			cp[bps * count + byte] = tmp[byte * wc + count];
442 			#else
443 			cp[bps * count + byte] =
444 				tmp[(bps - byte - 1) * wc + count];
445 			#endif
446 		}
447 	}
448 	_TIFFfree(tmp);
449     return 1;
450 }
451 
452 /*
453  * Decode a scanline and apply the predictor routine.
454  */
455 static int
PredictorDecodeRow(TIFF * tif,uint8 * op0,tmsize_t occ0,uint16 s)456 PredictorDecodeRow(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s)
457 {
458 	TIFFPredictorState *sp = PredictorState(tif);
459 
460 	assert(sp != NULL);
461 	assert(sp->decoderow != NULL);
462 	assert(sp->decodepfunc != NULL);
463 
464 	if ((*sp->decoderow)(tif, op0, occ0, s)) {
465 		return (*sp->decodepfunc)(tif, op0, occ0);
466 	} else
467 		return 0;
468 }
469 
470 /*
471  * Decode a tile/strip and apply the predictor routine.
472  * Note that horizontal differencing must be done on a
473  * row-by-row basis.  The width of a "row" has already
474  * been calculated at pre-decode time according to the
475  * strip/tile dimensions.
476  */
477 static int
PredictorDecodeTile(TIFF * tif,uint8 * op0,tmsize_t occ0,uint16 s)478 PredictorDecodeTile(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s)
479 {
480 	TIFFPredictorState *sp = PredictorState(tif);
481 
482 	assert(sp != NULL);
483 	assert(sp->decodetile != NULL);
484 
485 	if ((*sp->decodetile)(tif, op0, occ0, s)) {
486 		tmsize_t rowsize = sp->rowsize;
487 		assert(rowsize > 0);
488 		if((occ0%rowsize) !=0)
489         {
490             TIFFErrorExt(tif->tif_clientdata, "PredictorDecodeTile",
491                          "%s", "occ0%rowsize != 0");
492             return 0;
493         }
494 		assert(sp->decodepfunc != NULL);
495 		while (occ0 > 0) {
496 			if( !(*sp->decodepfunc)(tif, op0, rowsize) )
497                 return 0;
498 			occ0 -= rowsize;
499 			op0 += rowsize;
500 		}
501 		return 1;
502 	} else
503 		return 0;
504 }
505 
506 static int
horDiff8(TIFF * tif,uint8 * cp0,tmsize_t cc)507 horDiff8(TIFF* tif, uint8* cp0, tmsize_t cc)
508 {
509 	TIFFPredictorState* sp = PredictorState(tif);
510 	tmsize_t stride = sp->stride;
511 	unsigned char* cp = (unsigned char*) cp0;
512 
513     if((cc%stride)!=0)
514     {
515         TIFFErrorExt(tif->tif_clientdata, "horDiff8",
516                      "%s", "(cc%stride)!=0");
517         return 0;
518     }
519 
520 	if (cc > stride) {
521 		cc -= stride;
522 		/*
523 		 * Pipeline the most common cases.
524 		 */
525 		if (stride == 3) {
526 			unsigned int r1, g1, b1;
527 			unsigned int r2 = cp[0];
528 			unsigned int g2 = cp[1];
529 			unsigned  int b2 = cp[2];
530 			do {
531 				r1 = cp[3]; cp[3] = (unsigned char)((r1-r2)&0xff); r2 = r1;
532 				g1 = cp[4]; cp[4] = (unsigned char)((g1-g2)&0xff); g2 = g1;
533 				b1 = cp[5]; cp[5] = (unsigned char)((b1-b2)&0xff); b2 = b1;
534 				cp += 3;
535 			} while ((cc -= 3) > 0);
536 		} else if (stride == 4) {
537 			unsigned int r1, g1, b1, a1;
538 			unsigned int r2 = cp[0];
539 			unsigned int g2 = cp[1];
540 			unsigned int b2 = cp[2];
541 			unsigned int a2 = cp[3];
542 			do {
543 				r1 = cp[4]; cp[4] = (unsigned char)((r1-r2)&0xff); r2 = r1;
544 				g1 = cp[5]; cp[5] = (unsigned char)((g1-g2)&0xff); g2 = g1;
545 				b1 = cp[6]; cp[6] = (unsigned char)((b1-b2)&0xff); b2 = b1;
546 				a1 = cp[7]; cp[7] = (unsigned char)((a1-a2)&0xff); a2 = a1;
547 				cp += 4;
548 			} while ((cc -= 4) > 0);
549 		} else {
550 			cp += cc - 1;
551 			do {
552 				REPEAT4(stride, cp[stride] = (unsigned char)((cp[stride] - cp[0])&0xff); cp--)
553 			} while ((cc -= stride) > 0);
554 		}
555 	}
556 	return 1;
557 }
558 
559 static int
horDiff16(TIFF * tif,uint8 * cp0,tmsize_t cc)560 horDiff16(TIFF* tif, uint8* cp0, tmsize_t cc)
561 {
562 	TIFFPredictorState* sp = PredictorState(tif);
563 	tmsize_t stride = sp->stride;
564 	uint16 *wp = (uint16*) cp0;
565 	tmsize_t wc = cc/2;
566 
567     if((cc%(2*stride))!=0)
568     {
569         TIFFErrorExt(tif->tif_clientdata, "horDiff8",
570                      "%s", "(cc%(2*stride))!=0");
571         return 0;
572     }
573 
574 	if (wc > stride) {
575 		wc -= stride;
576 		wp += wc - 1;
577 		do {
578 			REPEAT4(stride, wp[stride] = (uint16)(((unsigned int)wp[stride] - (unsigned int)wp[0]) & 0xffff); wp--)
579 			wc -= stride;
580 		} while (wc > 0);
581 	}
582 	return 1;
583 }
584 
585 static int
swabHorDiff16(TIFF * tif,uint8 * cp0,tmsize_t cc)586 swabHorDiff16(TIFF* tif, uint8* cp0, tmsize_t cc)
587 {
588     uint16* wp = (uint16*) cp0;
589     tmsize_t wc = cc / 2;
590 
591     if( !horDiff16(tif, cp0, cc) )
592         return 0;
593 
594     TIFFSwabArrayOfShort(wp, wc);
595     return 1;
596 }
597 
598 static int
horDiff32(TIFF * tif,uint8 * cp0,tmsize_t cc)599 horDiff32(TIFF* tif, uint8* cp0, tmsize_t cc)
600 {
601 	TIFFPredictorState* sp = PredictorState(tif);
602 	tmsize_t stride = sp->stride;
603 	uint32 *wp = (uint32*) cp0;
604 	tmsize_t wc = cc/4;
605 
606     if((cc%(4*stride))!=0)
607     {
608         TIFFErrorExt(tif->tif_clientdata, "horDiff32",
609                      "%s", "(cc%(4*stride))!=0");
610         return 0;
611     }
612 
613 	if (wc > stride) {
614 		wc -= stride;
615 		wp += wc - 1;
616 		do {
617 			REPEAT4(stride, wp[stride] -= wp[0]; wp--)
618 			wc -= stride;
619 		} while (wc > 0);
620 	}
621 	return 1;
622 }
623 
624 static int
swabHorDiff32(TIFF * tif,uint8 * cp0,tmsize_t cc)625 swabHorDiff32(TIFF* tif, uint8* cp0, tmsize_t cc)
626 {
627     uint32* wp = (uint32*) cp0;
628     tmsize_t wc = cc / 4;
629 
630     if( !horDiff32(tif, cp0, cc) )
631         return 0;
632 
633     TIFFSwabArrayOfLong(wp, wc);
634     return 1;
635 }
636 
637 /*
638  * Floating point predictor differencing routine.
639  */
640 static int
fpDiff(TIFF * tif,uint8 * cp0,tmsize_t cc)641 fpDiff(TIFF* tif, uint8* cp0, tmsize_t cc)
642 {
643 	tmsize_t stride = PredictorState(tif)->stride;
644 	uint32 bps = tif->tif_dir.td_bitspersample / 8;
645 	tmsize_t wc = cc / bps;
646 	tmsize_t count;
647 	uint8 *cp = (uint8 *) cp0;
648 	uint8 *tmp;
649 
650     if((cc%(bps*stride))!=0)
651     {
652         TIFFErrorExt(tif->tif_clientdata, "fpDiff",
653                      "%s", "(cc%(bps*stride))!=0");
654         return 0;
655     }
656 
657     tmp = (uint8 *)_TIFFmalloc(cc);
658 	if (!tmp)
659 		return 0;
660 
661 	_TIFFmemcpy(tmp, cp0, cc);
662 	for (count = 0; count < wc; count++) {
663 		uint32 byte;
664 		for (byte = 0; byte < bps; byte++) {
665 			#if WORDS_BIGENDIAN
666 			cp[byte * wc + count] = tmp[bps * count + byte];
667 			#else
668 			cp[(bps - byte - 1) * wc + count] =
669 				tmp[bps * count + byte];
670 			#endif
671 		}
672 	}
673 	_TIFFfree(tmp);
674 
675 	cp = (uint8 *) cp0;
676 	cp += cc - stride - 1;
677 	for (count = cc; count > stride; count -= stride)
678 		REPEAT4(stride, cp[stride] = (unsigned char)((cp[stride] - cp[0])&0xff); cp--)
679     return 1;
680 }
681 
682 static int
PredictorEncodeRow(TIFF * tif,uint8 * bp,tmsize_t cc,uint16 s)683 PredictorEncodeRow(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s)
684 {
685 	TIFFPredictorState *sp = PredictorState(tif);
686 
687 	assert(sp != NULL);
688 	assert(sp->encodepfunc != NULL);
689 	assert(sp->encoderow != NULL);
690 
691 	/* XXX horizontal differencing alters user's data XXX */
692 	if( !(*sp->encodepfunc)(tif, bp, cc) )
693         return 0;
694 	return (*sp->encoderow)(tif, bp, cc, s);
695 }
696 
697 static int
PredictorEncodeTile(TIFF * tif,uint8 * bp0,tmsize_t cc0,uint16 s)698 PredictorEncodeTile(TIFF* tif, uint8* bp0, tmsize_t cc0, uint16 s)
699 {
700 	static const char module[] = "PredictorEncodeTile";
701 	TIFFPredictorState *sp = PredictorState(tif);
702         uint8 *working_copy;
703 	tmsize_t cc = cc0, rowsize;
704 	unsigned char* bp;
705         int result_code;
706 
707 	assert(sp != NULL);
708 	assert(sp->encodepfunc != NULL);
709 	assert(sp->encodetile != NULL);
710 
711         /*
712          * Do predictor manipulation in a working buffer to avoid altering
713          * the callers buffer. http://trac.osgeo.org/gdal/ticket/1965
714          */
715         working_copy = (uint8*) _TIFFmalloc(cc0);
716         if( working_copy == NULL )
717         {
718             TIFFErrorExt(tif->tif_clientdata, module,
719                          "Out of memory allocating " TIFF_SSIZE_FORMAT " byte temp buffer.",
720                          cc0 );
721             return 0;
722         }
723         memcpy( working_copy, bp0, cc0 );
724         bp = working_copy;
725 
726 	rowsize = sp->rowsize;
727 	assert(rowsize > 0);
728 	if((cc0%rowsize)!=0)
729     {
730         TIFFErrorExt(tif->tif_clientdata, "PredictorEncodeTile",
731                      "%s", "(cc0%rowsize)!=0");
732         _TIFFfree( working_copy );
733         return 0;
734     }
735 	while (cc > 0) {
736 		(*sp->encodepfunc)(tif, bp, rowsize);
737 		cc -= rowsize;
738 		bp += rowsize;
739 	}
740 	result_code = (*sp->encodetile)(tif, working_copy, cc0, s);
741 
742         _TIFFfree( working_copy );
743 
744         return result_code;
745 }
746 
747 #define	FIELD_PREDICTOR	(FIELD_CODEC+0)		/* XXX */
748 
749 static const TIFFField predictFields[] = {
750     { TIFFTAG_PREDICTOR, 1, 1, TIFF_SHORT, 0, TIFF_SETGET_UINT16, TIFF_SETGET_UINT16, FIELD_PREDICTOR, FALSE, FALSE, "Predictor", NULL },
751 };
752 
753 static int
PredictorVSetField(TIFF * tif,uint32 tag,va_list ap)754 PredictorVSetField(TIFF* tif, uint32 tag, va_list ap)
755 {
756 	TIFFPredictorState *sp = PredictorState(tif);
757 
758 	assert(sp != NULL);
759 	assert(sp->vsetparent != NULL);
760 
761 	switch (tag) {
762 	case TIFFTAG_PREDICTOR:
763 		sp->predictor = (uint16) va_arg(ap, uint16_vap);
764 		TIFFSetFieldBit(tif, FIELD_PREDICTOR);
765 		break;
766 	default:
767 		return (*sp->vsetparent)(tif, tag, ap);
768 	}
769 	tif->tif_flags |= TIFF_DIRTYDIRECT;
770 	return 1;
771 }
772 
773 static int
PredictorVGetField(TIFF * tif,uint32 tag,va_list ap)774 PredictorVGetField(TIFF* tif, uint32 tag, va_list ap)
775 {
776 	TIFFPredictorState *sp = PredictorState(tif);
777 
778 	assert(sp != NULL);
779 	assert(sp->vgetparent != NULL);
780 
781 	switch (tag) {
782 	case TIFFTAG_PREDICTOR:
783 		*va_arg(ap, uint16*) = (uint16)sp->predictor;
784 		break;
785 	default:
786 		return (*sp->vgetparent)(tif, tag, ap);
787 	}
788 	return 1;
789 }
790 
791 static void
PredictorPrintDir(TIFF * tif,FILE * fd,long flags)792 PredictorPrintDir(TIFF* tif, FILE* fd, long flags)
793 {
794 	TIFFPredictorState* sp = PredictorState(tif);
795 
796 	(void) flags;
797 	if (TIFFFieldSet(tif,FIELD_PREDICTOR)) {
798 		fprintf(fd, "  Predictor: ");
799 		switch (sp->predictor) {
800 			case 1: fprintf(fd, "none "); break;
801 			case 2: fprintf(fd, "horizontal differencing "); break;
802 			case 3: fprintf(fd, "floating point predictor "); break;
803 		}
804 		fprintf(fd, "%d (0x%x)\n", sp->predictor, sp->predictor);
805 	}
806 	if (sp->printdir)
807 		(*sp->printdir)(tif, fd, flags);
808 }
809 
810 int
TIFFPredictorInit(TIFF * tif)811 TIFFPredictorInit(TIFF* tif)
812 {
813 	TIFFPredictorState* sp = PredictorState(tif);
814 
815 	assert(sp != 0);
816 
817 	/*
818 	 * Merge codec-specific tag information.
819 	 */
820 	if (!_TIFFMergeFields(tif, predictFields,
821 			      TIFFArrayCount(predictFields))) {
822 		TIFFErrorExt(tif->tif_clientdata, "TIFFPredictorInit",
823 		    "Merging Predictor codec-specific tags failed");
824 		return 0;
825 	}
826 
827 	/*
828 	 * Override parent get/set field methods.
829 	 */
830 	sp->vgetparent = tif->tif_tagmethods.vgetfield;
831 	tif->tif_tagmethods.vgetfield =
832             PredictorVGetField;/* hook for predictor tag */
833 	sp->vsetparent = tif->tif_tagmethods.vsetfield;
834 	tif->tif_tagmethods.vsetfield =
835 	    PredictorVSetField;/* hook for predictor tag */
836 	sp->printdir = tif->tif_tagmethods.printdir;
837 	tif->tif_tagmethods.printdir =
838             PredictorPrintDir;	/* hook for predictor tag */
839 
840 	sp->setupdecode = tif->tif_setupdecode;
841 	tif->tif_setupdecode = PredictorSetupDecode;
842 	sp->setupencode = tif->tif_setupencode;
843 	tif->tif_setupencode = PredictorSetupEncode;
844 
845 	sp->predictor = 1;			/* default value */
846 	sp->encodepfunc = NULL;			/* no predictor routine */
847 	sp->decodepfunc = NULL;			/* no predictor routine */
848 	return 1;
849 }
850 
851 int
TIFFPredictorCleanup(TIFF * tif)852 TIFFPredictorCleanup(TIFF* tif)
853 {
854 	TIFFPredictorState* sp = PredictorState(tif);
855 
856 	assert(sp != 0);
857 
858 	tif->tif_tagmethods.vgetfield = sp->vgetparent;
859 	tif->tif_tagmethods.vsetfield = sp->vsetparent;
860 	tif->tif_tagmethods.printdir = sp->printdir;
861 	tif->tif_setupdecode = sp->setupdecode;
862 	tif->tif_setupencode = sp->setupencode;
863 
864 	return 1;
865 }
866 
867 /* vim: set ts=8 sts=8 sw=8 noet: */
868 /*
869  * Local Variables:
870  * mode: c
871  * c-basic-offset: 8
872  * fill-column: 78
873  * End:
874  */
875