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[xy_vsfilter.git] / src / libpng / pngpread.c
blob5c73923fefb590a8df72544c000923450ea3b719
1
2 /* pngpread.c - read a png file in push mode
3 *
4 * Last changed in libpng 1.2.37 [June 4, 2009]
5 * For conditions of distribution and use, see copyright notice in png.h
6 * Copyright (c) 1998-2009 Glenn Randers-Pehrson
7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
9 */
10
11 #define PNG_INTERNAL
12 #include "png.h"
13 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
14
15 /* Push model modes */
16 #define PNG_READ_SIG_MODE 0
17 #define PNG_READ_CHUNK_MODE 1
18 #define PNG_READ_IDAT_MODE 2
19 #define PNG_SKIP_MODE 3
20 #define PNG_READ_tEXt_MODE 4
21 #define PNG_READ_zTXt_MODE 5
22 #define PNG_READ_DONE_MODE 6
23 #define PNG_READ_iTXt_MODE 7
24 #define PNG_ERROR_MODE 8
25
26 void PNGAPI
27 png_process_data(png_structp png_ptr, png_infop info_ptr,
28 png_bytep buffer, png_size_t buffer_size)
29 {
30 if (png_ptr == NULL || info_ptr == NULL)
31 return;
32
33 png_push_restore_buffer(png_ptr, buffer, buffer_size);
34
35 while (png_ptr->buffer_size)
36 {
37 png_process_some_data(png_ptr, info_ptr);
38 }
39 }
40
41 /* What we do with the incoming data depends on what we were previously
42 * doing before we ran out of data...
43 */
44 void /* PRIVATE */
45 png_process_some_data(png_structp png_ptr, png_infop info_ptr)
46 {
47 if (png_ptr == NULL)
48 return;
49
50 switch (png_ptr->process_mode)
51 {
52 case PNG_READ_SIG_MODE:
53 {
54 png_push_read_sig(png_ptr, info_ptr);
55 break;
56 }
57
58 case PNG_READ_CHUNK_MODE:
59 {
60 png_push_read_chunk(png_ptr, info_ptr);
61 break;
62 }
63
64 case PNG_READ_IDAT_MODE:
65 {
66 png_push_read_IDAT(png_ptr);
67 break;
68 }
69
70 #if defined(PNG_READ_tEXt_SUPPORTED)
71 case PNG_READ_tEXt_MODE:
72 {
73 png_push_read_tEXt(png_ptr, info_ptr);
74 break;
75 }
76
77 #endif
78 #if defined(PNG_READ_zTXt_SUPPORTED)
79 case PNG_READ_zTXt_MODE:
80 {
81 png_push_read_zTXt(png_ptr, info_ptr);
82 break;
83 }
84
85 #endif
86 #if defined(PNG_READ_iTXt_SUPPORTED)
87 case PNG_READ_iTXt_MODE:
88 {
89 png_push_read_iTXt(png_ptr, info_ptr);
90 break;
91 }
92
93 #endif
94 case PNG_SKIP_MODE:
95 {
96 png_push_crc_finish(png_ptr);
97 break;
98 }
99
100 default:
101 {
102 png_ptr->buffer_size = 0;
103 break;
104 }
105 }
106 }
107
108 /* Read any remaining signature bytes from the stream and compare them with
109 * the correct PNG signature. It is possible that this routine is called
110 * with bytes already read from the signature, either because they have been
111 * checked by the calling application, or because of multiple calls to this
112 * routine.
113 */
114 void /* PRIVATE */
115 png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
116 {
117 png_size_t num_checked = png_ptr->sig_bytes,
118 num_to_check = 8 - num_checked;
119
120 if (png_ptr->buffer_size < num_to_check)
121 {
122 num_to_check = png_ptr->buffer_size;
123 }
124
125 png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
126 num_to_check);
127 png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
128
129 if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
130 {
131 if (num_checked < 4 &&
132 png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
133 png_error(png_ptr, "Not a PNG file");
134 else
135 png_error(png_ptr, "PNG file corrupted by ASCII conversion");
136 }
137 else
138 {
139 if (png_ptr->sig_bytes >= 8)
140 {
141 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
142 }
143 }
144 }
145
146 void /* PRIVATE */
147 png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
148 {
149 #ifdef PNG_USE_LOCAL_ARRAYS
150 PNG_CONST PNG_IHDR;
151 PNG_CONST PNG_IDAT;
152 PNG_CONST PNG_IEND;
153 PNG_CONST PNG_PLTE;
154 #if defined(PNG_READ_bKGD_SUPPORTED)
155 PNG_CONST PNG_bKGD;
156 #endif
157 #if defined(PNG_READ_cHRM_SUPPORTED)
158 PNG_CONST PNG_cHRM;
159 #endif
160 #if defined(PNG_READ_gAMA_SUPPORTED)
161 PNG_CONST PNG_gAMA;
162 #endif
163 #if defined(PNG_READ_hIST_SUPPORTED)
164 PNG_CONST PNG_hIST;
165 #endif
166 #if defined(PNG_READ_iCCP_SUPPORTED)
167 PNG_CONST PNG_iCCP;
168 #endif
169 #if defined(PNG_READ_iTXt_SUPPORTED)
170 PNG_CONST PNG_iTXt;
171 #endif
172 #if defined(PNG_READ_oFFs_SUPPORTED)
173 PNG_CONST PNG_oFFs;
174 #endif
175 #if defined(PNG_READ_pCAL_SUPPORTED)
176 PNG_CONST PNG_pCAL;
177 #endif
178 #if defined(PNG_READ_pHYs_SUPPORTED)
179 PNG_CONST PNG_pHYs;
180 #endif
181 #if defined(PNG_READ_sBIT_SUPPORTED)
182 PNG_CONST PNG_sBIT;
183 #endif
184 #if defined(PNG_READ_sCAL_SUPPORTED)
185 PNG_CONST PNG_sCAL;
186 #endif
187 #if defined(PNG_READ_sRGB_SUPPORTED)
188 PNG_CONST PNG_sRGB;
189 #endif
190 #if defined(PNG_READ_sPLT_SUPPORTED)
191 PNG_CONST PNG_sPLT;
192 #endif
193 #if defined(PNG_READ_tEXt_SUPPORTED)
194 PNG_CONST PNG_tEXt;
195 #endif
196 #if defined(PNG_READ_tIME_SUPPORTED)
197 PNG_CONST PNG_tIME;
198 #endif
199 #if defined(PNG_READ_tRNS_SUPPORTED)
200 PNG_CONST PNG_tRNS;
201 #endif
202 #if defined(PNG_READ_zTXt_SUPPORTED)
203 PNG_CONST PNG_zTXt;
204 #endif
205 #endif /* PNG_USE_LOCAL_ARRAYS */
206 /* First we make sure we have enough data for the 4 byte chunk name
207 * and the 4 byte chunk length before proceeding with decoding the
208 * chunk data. To fully decode each of these chunks, we also make
209 * sure we have enough data in the buffer for the 4 byte CRC at the
210 * end of every chunk (except IDAT, which is handled separately).
211 */
212 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
213 {
214 png_byte chunk_length[4];
215
216 if (png_ptr->buffer_size < 8)
217 {
218 png_push_save_buffer(png_ptr);
219 return;
220 }
221
222 png_push_fill_buffer(png_ptr, chunk_length, 4);
223 png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
224 png_reset_crc(png_ptr);
225 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
226 png_check_chunk_name(png_ptr, png_ptr->chunk_name);
227 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
228 }
229
230 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
231 if (png_ptr->mode & PNG_AFTER_IDAT)
232 png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
233
234 if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
235 {
236 if (png_ptr->push_length != 13)
237 png_error(png_ptr, "Invalid IHDR length");
238
239 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
240 {
241 png_push_save_buffer(png_ptr);
242 return;
243 }
244
245 png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
246 }
247
248 else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
249 {
250 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
251 {
252 png_push_save_buffer(png_ptr);
253 return;
254 }
255
256 png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
257
258 png_ptr->process_mode = PNG_READ_DONE_MODE;
259 png_push_have_end(png_ptr, info_ptr);
260 }
261
262 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
263 else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
264 {
265 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
266 {
267 png_push_save_buffer(png_ptr);
268 return;
269 }
270
271 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
272 png_ptr->mode |= PNG_HAVE_IDAT;
273
274 png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
275
276 if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
277 png_ptr->mode |= PNG_HAVE_PLTE;
278
279 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
280 {
281 if (!(png_ptr->mode & PNG_HAVE_IHDR))
282 png_error(png_ptr, "Missing IHDR before IDAT");
283
284 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
285 !(png_ptr->mode & PNG_HAVE_PLTE))
286 png_error(png_ptr, "Missing PLTE before IDAT");
287 }
288 }
289
290 #endif
291 else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
292 {
293 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
294 {
295 png_push_save_buffer(png_ptr);
296 return;
297 }
298 png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
299 }
300
301 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
302 {
303 /* If we reach an IDAT chunk, this means we have read all of the
304 * header chunks, and we can start reading the image (or if this
305 * is called after the image has been read - we have an error).
306 */
307
308 if (!(png_ptr->mode & PNG_HAVE_IHDR))
309 png_error(png_ptr, "Missing IHDR before IDAT");
310
311 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
312 !(png_ptr->mode & PNG_HAVE_PLTE))
313 png_error(png_ptr, "Missing PLTE before IDAT");
314
315 if (png_ptr->mode & PNG_HAVE_IDAT)
316 {
317 if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
318 if (png_ptr->push_length == 0)
319 return;
320
321 if (png_ptr->mode & PNG_AFTER_IDAT)
322 png_error(png_ptr, "Too many IDAT's found");
323 }
324
325 png_ptr->idat_size = png_ptr->push_length;
326 png_ptr->mode |= PNG_HAVE_IDAT;
327 png_ptr->process_mode = PNG_READ_IDAT_MODE;
328 png_push_have_info(png_ptr, info_ptr);
329 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
330 png_ptr->zstream.next_out = png_ptr->row_buf;
331 return;
332 }
333
334 #if defined(PNG_READ_gAMA_SUPPORTED)
335 else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
336 {
337 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
338 {
339 png_push_save_buffer(png_ptr);
340 return;
341 }
342
343 png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
344 }
345
346 #endif
347 #if defined(PNG_READ_sBIT_SUPPORTED)
348 else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
349 {
350 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
351 {
352 png_push_save_buffer(png_ptr);
353 return;
354 }
355
356 png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
357 }
358
359 #endif
360 #if defined(PNG_READ_cHRM_SUPPORTED)
361 else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
362 {
363 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
364 {
365 png_push_save_buffer(png_ptr);
366 return;
367 }
368
369 png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
370 }
371
372 #endif
373 #if defined(PNG_READ_sRGB_SUPPORTED)
374 else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
375 {
376 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
377 {
378 png_push_save_buffer(png_ptr);
379 return;
380 }
381
382 png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
383 }
384
385 #endif
386 #if defined(PNG_READ_iCCP_SUPPORTED)
387 else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
388 {
389 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
390 {
391 png_push_save_buffer(png_ptr);
392 return;
393 }
394
395 png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
396 }
397
398 #endif
399 #if defined(PNG_READ_sPLT_SUPPORTED)
400 else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
401 {
402 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
403 {
404 png_push_save_buffer(png_ptr);
405 return;
406 }
407
408 png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
409 }
410
411 #endif
412 #if defined(PNG_READ_tRNS_SUPPORTED)
413 else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
414 {
415 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
416 {
417 png_push_save_buffer(png_ptr);
418 return;
419 }
420
421 png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
422 }
423
424 #endif
425 #if defined(PNG_READ_bKGD_SUPPORTED)
426 else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
427 {
428 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
429 {
430 png_push_save_buffer(png_ptr);
431 return;
432 }
433
434 png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
435 }
436
437 #endif
438 #if defined(PNG_READ_hIST_SUPPORTED)
439 else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
440 {
441 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
442 {
443 png_push_save_buffer(png_ptr);
444 return;
445 }
446
447 png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
448 }
449
450 #endif
451 #if defined(PNG_READ_pHYs_SUPPORTED)
452 else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
453 {
454 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
455 {
456 png_push_save_buffer(png_ptr);
457 return;
458 }
459
460 png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
461 }
462
463 #endif
464 #if defined(PNG_READ_oFFs_SUPPORTED)
465 else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
466 {
467 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
468 {
469 png_push_save_buffer(png_ptr);
470 return;
471 }
472
473 png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
474 }
475 #endif
476
477 #if defined(PNG_READ_pCAL_SUPPORTED)
478 else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
479 {
480 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
481 {
482 png_push_save_buffer(png_ptr);
483 return;
484 }
485
486 png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
487 }
488
489 #endif
490 #if defined(PNG_READ_sCAL_SUPPORTED)
491 else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
492 {
493 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
494 {
495 png_push_save_buffer(png_ptr);
496 return;
497 }
498
499 png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
500 }
501
502 #endif
503 #if defined(PNG_READ_tIME_SUPPORTED)
504 else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
505 {
506 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
507 {
508 png_push_save_buffer(png_ptr);
509 return;
510 }
511
512 png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
513 }
514
515 #endif
516 #if defined(PNG_READ_tEXt_SUPPORTED)
517 else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
518 {
519 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
520 {
521 png_push_save_buffer(png_ptr);
522 return;
523 }
524
525 png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
526 }
527
528 #endif
529 #if defined(PNG_READ_zTXt_SUPPORTED)
530 else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
531 {
532 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
533 {
534 png_push_save_buffer(png_ptr);
535 return;
536 }
537
538 png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
539 }
540
541 #endif
542 #if defined(PNG_READ_iTXt_SUPPORTED)
543 else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
544 {
545 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
546 {
547 png_push_save_buffer(png_ptr);
548 return;
549 }
550
551 png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
552 }
553
554 #endif
555 else
556 {
557 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
558 {
559 png_push_save_buffer(png_ptr);
560 return;
561 }
562 png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
563 }
564
565 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
566 }
567
568 void /* PRIVATE */
569 png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
570 {
571 png_ptr->process_mode = PNG_SKIP_MODE;
572 png_ptr->skip_length = skip;
573 }
574
575 void /* PRIVATE */
576 png_push_crc_finish(png_structp png_ptr)
577 {
578 if (png_ptr->skip_length && png_ptr->save_buffer_size)
579 {
580 png_size_t save_size;
581
582 if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)
583 save_size = (png_size_t)png_ptr->skip_length;
584 else
585 save_size = png_ptr->save_buffer_size;
586
587 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
588
589 png_ptr->skip_length -= save_size;
590 png_ptr->buffer_size -= save_size;
591 png_ptr->save_buffer_size -= save_size;
592 png_ptr->save_buffer_ptr += save_size;
593 }
594 if (png_ptr->skip_length && png_ptr->current_buffer_size)
595 {
596 png_size_t save_size;
597
598 if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)
599 save_size = (png_size_t)png_ptr->skip_length;
600 else
601 save_size = png_ptr->current_buffer_size;
602
603 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
604
605 png_ptr->skip_length -= save_size;
606 png_ptr->buffer_size -= save_size;
607 png_ptr->current_buffer_size -= save_size;
608 png_ptr->current_buffer_ptr += save_size;
609 }
610 if (!png_ptr->skip_length)
611 {
612 if (png_ptr->buffer_size < 4)
613 {
614 png_push_save_buffer(png_ptr);
615 return;
616 }
617
618 png_crc_finish(png_ptr, 0);
619 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
620 }
621 }
622
623 void PNGAPI
624 png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
625 {
626 png_bytep ptr;
627
628 if (png_ptr == NULL)
629 return;
630
631 ptr = buffer;
632 if (png_ptr->save_buffer_size)
633 {
634 png_size_t save_size;
635
636 if (length < png_ptr->save_buffer_size)
637 save_size = length;
638 else
639 save_size = png_ptr->save_buffer_size;
640
641 png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
642 length -= save_size;
643 ptr += save_size;
644 png_ptr->buffer_size -= save_size;
645 png_ptr->save_buffer_size -= save_size;
646 png_ptr->save_buffer_ptr += save_size;
647 }
648 if (length && png_ptr->current_buffer_size)
649 {
650 png_size_t save_size;
651
652 if (length < png_ptr->current_buffer_size)
653 save_size = length;
654
655 else
656 save_size = png_ptr->current_buffer_size;
657
658 png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
659 png_ptr->buffer_size -= save_size;
660 png_ptr->current_buffer_size -= save_size;
661 png_ptr->current_buffer_ptr += save_size;
662 }
663 }
664
665 void /* PRIVATE */
666 png_push_save_buffer(png_structp png_ptr)
667 {
668 if (png_ptr->save_buffer_size)
669 {
670 if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
671 {
672 png_size_t i, istop;
673 png_bytep sp;
674 png_bytep dp;
675
676 istop = png_ptr->save_buffer_size;
677 for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
678 i < istop; i++, sp++, dp++)
679 {
680 *dp = *sp;
681 }
682 }
683 }
684 if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
685 png_ptr->save_buffer_max)
686 {
687 png_size_t new_max;
688 png_bytep old_buffer;
689
690 if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
691 (png_ptr->current_buffer_size + 256))
692 {
693 png_error(png_ptr, "Potential overflow of save_buffer");
694 }
695
696 new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
697 old_buffer = png_ptr->save_buffer;
698 png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr,
699 (png_uint_32)new_max);
700 png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
701 png_free(png_ptr, old_buffer);
702 png_ptr->save_buffer_max = new_max;
703 }
704 if (png_ptr->current_buffer_size)
705 {
706 png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
707 png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
708 png_ptr->save_buffer_size += png_ptr->current_buffer_size;
709 png_ptr->current_buffer_size = 0;
710 }
711 png_ptr->save_buffer_ptr = png_ptr->save_buffer;
712 png_ptr->buffer_size = 0;
713 }
714
715 void /* PRIVATE */
716 png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
717 png_size_t buffer_length)
718 {
719 png_ptr->current_buffer = buffer;
720 png_ptr->current_buffer_size = buffer_length;
721 png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
722 png_ptr->current_buffer_ptr = png_ptr->current_buffer;
723 }
724
725 void /* PRIVATE */
726 png_push_read_IDAT(png_structp png_ptr)
727 {
728 #ifdef PNG_USE_LOCAL_ARRAYS
729 PNG_CONST PNG_IDAT;
730 #endif
731 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
732 {
733 png_byte chunk_length[4];
734
735 if (png_ptr->buffer_size < 8)
736 {
737 png_push_save_buffer(png_ptr);
738 return;
739 }
740
741 png_push_fill_buffer(png_ptr, chunk_length, 4);
742 png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
743 png_reset_crc(png_ptr);
744 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
745 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
746
747 if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
748 {
749 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
750 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
751 png_error(png_ptr, "Not enough compressed data");
752 return;
753 }
754
755 png_ptr->idat_size = png_ptr->push_length;
756 }
757 if (png_ptr->idat_size && png_ptr->save_buffer_size)
758 {
759 png_size_t save_size;
760
761 if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
762 {
763 save_size = (png_size_t)png_ptr->idat_size;
764
765 /* Check for overflow */
766 if ((png_uint_32)save_size != png_ptr->idat_size)
767 png_error(png_ptr, "save_size overflowed in pngpread");
768 }
769 else
770 save_size = png_ptr->save_buffer_size;
771
772 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
773
774 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
775 png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
776
777 png_ptr->idat_size -= save_size;
778 png_ptr->buffer_size -= save_size;
779 png_ptr->save_buffer_size -= save_size;
780 png_ptr->save_buffer_ptr += save_size;
781 }
782 if (png_ptr->idat_size && png_ptr->current_buffer_size)
783 {
784 png_size_t save_size;
785
786 if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
787 {
788 save_size = (png_size_t)png_ptr->idat_size;
789
790 /* Check for overflow */
791 if ((png_uint_32)save_size != png_ptr->idat_size)
792 png_error(png_ptr, "save_size overflowed in pngpread");
793 }
794 else
795 save_size = png_ptr->current_buffer_size;
796
797 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
798 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
799 png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
800
801 png_ptr->idat_size -= save_size;
802 png_ptr->buffer_size -= save_size;
803 png_ptr->current_buffer_size -= save_size;
804 png_ptr->current_buffer_ptr += save_size;
805 }
806 if (!png_ptr->idat_size)
807 {
808 if (png_ptr->buffer_size < 4)
809 {
810 png_push_save_buffer(png_ptr);
811 return;
812 }
813
814 png_crc_finish(png_ptr, 0);
815 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
816 png_ptr->mode |= PNG_AFTER_IDAT;
817 }
818 }
819
820 void /* PRIVATE */
821 png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
822 png_size_t buffer_length)
823 {
824 int ret;
825
826 if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)
827 png_error(png_ptr, "Extra compression data");
828
829 png_ptr->zstream.next_in = buffer;
830 png_ptr->zstream.avail_in = (uInt)buffer_length;
831 for (;;)
832 {
833 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
834 if (ret != Z_OK)
835 {
836 if (ret == Z_STREAM_END)
837 {
838 if (png_ptr->zstream.avail_in)
839 png_error(png_ptr, "Extra compressed data");
840
841 if (!(png_ptr->zstream.avail_out))
842 {
843 png_push_process_row(png_ptr);
844 }
845
846 png_ptr->mode |= PNG_AFTER_IDAT;
847 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
848 break;
849 }
850 else if (ret == Z_BUF_ERROR)
851 break;
852
853 else
854 png_error(png_ptr, "Decompression Error");
855 }
856 if (!(png_ptr->zstream.avail_out))
857 {
858 if ((
859 #if defined(PNG_READ_INTERLACING_SUPPORTED)
860 png_ptr->interlaced && png_ptr->pass > 6) ||
861 (!png_ptr->interlaced &&
862 #endif
863 png_ptr->row_number == png_ptr->num_rows))
864 {
865 if (png_ptr->zstream.avail_in)
866 png_warning(png_ptr, "Too much data in IDAT chunks");
867 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
868 break;
869 }
870 png_push_process_row(png_ptr);
871 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
872 png_ptr->zstream.next_out = png_ptr->row_buf;
873 }
874
875 else
876 break;
877 }
878 }
879
880 void /* PRIVATE */
881 png_push_process_row(png_structp png_ptr)
882 {
883 png_ptr->row_info.color_type = png_ptr->color_type;
884 png_ptr->row_info.width = png_ptr->iwidth;
885 png_ptr->row_info.channels = png_ptr->channels;
886 png_ptr->row_info.bit_depth = png_ptr->bit_depth;
887 png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
888
889 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
890 png_ptr->row_info.width);
891
892 png_read_filter_row(png_ptr, &(png_ptr->row_info),
893 png_ptr->row_buf + 1, png_ptr->prev_row + 1,
894 (int)(png_ptr->row_buf[0]));
895
896 png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
897 png_ptr->rowbytes + 1);
898
899 if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
900 png_do_read_transformations(png_ptr);
901
902 #if defined(PNG_READ_INTERLACING_SUPPORTED)
903 /* Blow up interlaced rows to full size */
904 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
905 {
906 if (png_ptr->pass < 6)
907 /* old interface (pre-1.0.9):
908 png_do_read_interlace(&(png_ptr->row_info),
909 png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
910 */
911 png_do_read_interlace(png_ptr);
912
913 switch (png_ptr->pass)
914 {
915 case 0:
916 {
917 int i;
918 for (i = 0; i < 8 && png_ptr->pass == 0; i++)
919 {
920 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
921 png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */
922 }
923
924 if (png_ptr->pass == 2) /* Pass 1 might be empty */
925 {
926 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
927 {
928 png_push_have_row(png_ptr, png_bytep_NULL);
929 png_read_push_finish_row(png_ptr);
930 }
931 }
932
933 if (png_ptr->pass == 4 && png_ptr->height <= 4)
934 {
935 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
936 {
937 png_push_have_row(png_ptr, png_bytep_NULL);
938 png_read_push_finish_row(png_ptr);
939 }
940 }
941
942 if (png_ptr->pass == 6 && png_ptr->height <= 4)
943 {
944 png_push_have_row(png_ptr, png_bytep_NULL);
945 png_read_push_finish_row(png_ptr);
946 }
947
948 break;
949 }
950
951 case 1:
952 {
953 int i;
954 for (i = 0; i < 8 && png_ptr->pass == 1; i++)
955 {
956 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
957 png_read_push_finish_row(png_ptr);
958 }
959
960 if (png_ptr->pass == 2) /* Skip top 4 generated rows */
961 {
962 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
963 {
964 png_push_have_row(png_ptr, png_bytep_NULL);
965 png_read_push_finish_row(png_ptr);
966 }
967 }
968
969 break;
970 }
971
972 case 2:
973 {
974 int i;
975
976 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
977 {
978 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
979 png_read_push_finish_row(png_ptr);
980 }
981
982 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
983 {
984 png_push_have_row(png_ptr, png_bytep_NULL);
985 png_read_push_finish_row(png_ptr);
986 }
987
988 if (png_ptr->pass == 4) /* Pass 3 might be empty */
989 {
990 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
991 {
992 png_push_have_row(png_ptr, png_bytep_NULL);
993 png_read_push_finish_row(png_ptr);
994 }
995 }
996
997 break;
998 }
999
1000 case 3:
1001 {
1002 int i;
1003
1004 for (i = 0; i < 4 && png_ptr->pass == 3; i++)
1005 {
1006 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1007 png_read_push_finish_row(png_ptr);
1008 }
1009
1010 if (png_ptr->pass == 4) /* Skip top two generated rows */
1011 {
1012 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1013 {
1014 png_push_have_row(png_ptr, png_bytep_NULL);
1015 png_read_push_finish_row(png_ptr);
1016 }
1017 }
1018
1019 break;
1020 }
1021
1022 case 4:
1023 {
1024 int i;
1025
1026 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1027 {
1028 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1029 png_read_push_finish_row(png_ptr);
1030 }
1031
1032 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
1033 {
1034 png_push_have_row(png_ptr, png_bytep_NULL);
1035 png_read_push_finish_row(png_ptr);
1036 }
1037
1038 if (png_ptr->pass == 6) /* Pass 5 might be empty */
1039 {
1040 png_push_have_row(png_ptr, png_bytep_NULL);
1041 png_read_push_finish_row(png_ptr);
1042 }
1043
1044 break;
1045 }
1046
1047 case 5:
1048 {
1049 int i;
1050
1051 for (i = 0; i < 2 && png_ptr->pass == 5; i++)
1052 {
1053 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1054 png_read_push_finish_row(png_ptr);
1055 }
1056
1057 if (png_ptr->pass == 6) /* Skip top generated row */
1058 {
1059 png_push_have_row(png_ptr, png_bytep_NULL);
1060 png_read_push_finish_row(png_ptr);
1061 }
1062
1063 break;
1064 }
1065 case 6:
1066 {
1067 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1068 png_read_push_finish_row(png_ptr);
1069
1070 if (png_ptr->pass != 6)
1071 break;
1072
1073 png_push_have_row(png_ptr, png_bytep_NULL);
1074 png_read_push_finish_row(png_ptr);
1075 }
1076 }
1077 }
1078 else
1079 #endif
1080 {
1081 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
1082 png_read_push_finish_row(png_ptr);
1083 }
1084 }
1085
1086 void /* PRIVATE */
1087 png_read_push_finish_row(png_structp png_ptr)
1088 {
1089 #ifdef PNG_USE_LOCAL_ARRAYS
1090 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1091
1092 /* Start of interlace block */
1093 PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
1094
1095 /* Offset to next interlace block */
1096 PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
1097
1098 /* Start of interlace block in the y direction */
1099 PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
1100
1101 /* Offset to next interlace block in the y direction */
1102 PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
1103
1104 /* Height of interlace block. This is not currently used - if you need
1105 * it, uncomment it here and in png.h
1106 PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
1107 */
1108 #endif
1109
1110 png_ptr->row_number++;
1111 if (png_ptr->row_number < png_ptr->num_rows)
1112 return;
1113
1114 #if defined(PNG_READ_INTERLACING_SUPPORTED)
1115 if (png_ptr->interlaced)
1116 {
1117 png_ptr->row_number = 0;
1118 png_memset_check(png_ptr, png_ptr->prev_row, 0,
1119 png_ptr->rowbytes + 1);
1120 do
1121 {
1122 png_ptr->pass++;
1123 if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
1124 (png_ptr->pass == 3 && png_ptr->width < 3) ||
1125 (png_ptr->pass == 5 && png_ptr->width < 2))
1126 png_ptr->pass++;
1127
1128 if (png_ptr->pass > 7)
1129 png_ptr->pass--;
1130
1131 if (png_ptr->pass >= 7)
1132 break;
1133
1134 png_ptr->iwidth = (png_ptr->width +
1135 png_pass_inc[png_ptr->pass] - 1 -
1136 png_pass_start[png_ptr->pass]) /
1137 png_pass_inc[png_ptr->pass];
1138
1139 png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
1140 png_ptr->iwidth) + 1;
1141
1142 if (png_ptr->transformations & PNG_INTERLACE)
1143 break;
1144
1145 png_ptr->num_rows = (png_ptr->height +
1146 png_pass_yinc[png_ptr->pass] - 1 -
1147 png_pass_ystart[png_ptr->pass]) /
1148 png_pass_yinc[png_ptr->pass];
1149
1150 } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
1151 }
1152 #endif /* PNG_READ_INTERLACING_SUPPORTED */
1153 }
1154
1155 #if defined(PNG_READ_tEXt_SUPPORTED)
1156 void /* PRIVATE */
1157 png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1158 length)
1159 {
1160 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1161 {
1162 png_error(png_ptr, "Out of place tEXt");
1163 info_ptr = info_ptr; /* To quiet some compiler warnings */
1164 }
1165
1166 #ifdef PNG_MAX_MALLOC_64K
1167 png_ptr->skip_length = 0; /* This may not be necessary */
1168
1169 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1170 {
1171 png_warning(png_ptr, "tEXt chunk too large to fit in memory");
1172 png_ptr->skip_length = length - (png_uint_32)65535L;
1173 length = (png_uint_32)65535L;
1174 }
1175 #endif
1176
1177 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1178 (png_uint_32)(length + 1));
1179 png_ptr->current_text[length] = '\0';
1180 png_ptr->current_text_ptr = png_ptr->current_text;
1181 png_ptr->current_text_size = (png_size_t)length;
1182 png_ptr->current_text_left = (png_size_t)length;
1183 png_ptr->process_mode = PNG_READ_tEXt_MODE;
1184 }
1185
1186 void /* PRIVATE */
1187 png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
1188 {
1189 if (png_ptr->buffer_size && png_ptr->current_text_left)
1190 {
1191 png_size_t text_size;
1192
1193 if (png_ptr->buffer_size < png_ptr->current_text_left)
1194 text_size = png_ptr->buffer_size;
1195
1196 else
1197 text_size = png_ptr->current_text_left;
1198
1199 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1200 png_ptr->current_text_left -= text_size;
1201 png_ptr->current_text_ptr += text_size;
1202 }
1203 if (!(png_ptr->current_text_left))
1204 {
1205 png_textp text_ptr;
1206 png_charp text;
1207 png_charp key;
1208 int ret;
1209
1210 if (png_ptr->buffer_size < 4)
1211 {
1212 png_push_save_buffer(png_ptr);
1213 return;
1214 }
1215
1216 png_push_crc_finish(png_ptr);
1217
1218 #if defined(PNG_MAX_MALLOC_64K)
1219 if (png_ptr->skip_length)
1220 return;
1221 #endif
1222
1223 key = png_ptr->current_text;
1224
1225 for (text = key; *text; text++)
1226 /* Empty loop */ ;
1227
1228 if (text < key + png_ptr->current_text_size)
1229 text++;
1230
1231 text_ptr = (png_textp)png_malloc(png_ptr,
1232 (png_uint_32)png_sizeof(png_text));
1233 text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
1234 text_ptr->key = key;
1235 #ifdef PNG_iTXt_SUPPORTED
1236 text_ptr->lang = NULL;
1237 text_ptr->lang_key = NULL;
1238 #endif
1239 text_ptr->text = text;
1240
1241 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1242
1243 png_free(png_ptr, key);
1244 png_free(png_ptr, text_ptr);
1245 png_ptr->current_text = NULL;
1246
1247 if (ret)
1248 png_warning(png_ptr, "Insufficient memory to store text chunk.");
1249 }
1250 }
1251 #endif
1252
1253 #if defined(PNG_READ_zTXt_SUPPORTED)
1254 void /* PRIVATE */
1255 png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1256 length)
1257 {
1258 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1259 {
1260 png_error(png_ptr, "Out of place zTXt");
1261 info_ptr = info_ptr; /* To quiet some compiler warnings */
1262 }
1263
1264 #ifdef PNG_MAX_MALLOC_64K
1265 /* We can't handle zTXt chunks > 64K, since we don't have enough space
1266 * to be able to store the uncompressed data. Actually, the threshold
1267 * is probably around 32K, but it isn't as definite as 64K is.
1268 */
1269 if (length > (png_uint_32)65535L)
1270 {
1271 png_warning(png_ptr, "zTXt chunk too large to fit in memory");
1272 png_push_crc_skip(png_ptr, length);
1273 return;
1274 }
1275 #endif
1276
1277 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1278 (png_uint_32)(length + 1));
1279 png_ptr->current_text[length] = '\0';
1280 png_ptr->current_text_ptr = png_ptr->current_text;
1281 png_ptr->current_text_size = (png_size_t)length;
1282 png_ptr->current_text_left = (png_size_t)length;
1283 png_ptr->process_mode = PNG_READ_zTXt_MODE;
1284 }
1285
1286 void /* PRIVATE */
1287 png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
1288 {
1289 if (png_ptr->buffer_size && png_ptr->current_text_left)
1290 {
1291 png_size_t text_size;
1292
1293 if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
1294 text_size = png_ptr->buffer_size;
1295
1296 else
1297 text_size = png_ptr->current_text_left;
1298
1299 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1300 png_ptr->current_text_left -= text_size;
1301 png_ptr->current_text_ptr += text_size;
1302 }
1303 if (!(png_ptr->current_text_left))
1304 {
1305 png_textp text_ptr;
1306 png_charp text;
1307 png_charp key;
1308 int ret;
1309 png_size_t text_size, key_size;
1310
1311 if (png_ptr->buffer_size < 4)
1312 {
1313 png_push_save_buffer(png_ptr);
1314 return;
1315 }
1316
1317 png_push_crc_finish(png_ptr);
1318
1319 key = png_ptr->current_text;
1320
1321 for (text = key; *text; text++)
1322 /* Empty loop */ ;
1323
1324 /* zTXt can't have zero text */
1325 if (text >= key + png_ptr->current_text_size)
1326 {
1327 png_ptr->current_text = NULL;
1328 png_free(png_ptr, key);
1329 return;
1330 }
1331
1332 text++;
1333
1334 if (*text != PNG_TEXT_COMPRESSION_zTXt) /* Check compression byte */
1335 {
1336 png_ptr->current_text = NULL;
1337 png_free(png_ptr, key);
1338 return;
1339 }
1340
1341 text++;
1342
1343 png_ptr->zstream.next_in = (png_bytep )text;
1344 png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
1345 (text - key));
1346 png_ptr->zstream.next_out = png_ptr->zbuf;
1347 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1348
1349 key_size = text - key;
1350 text_size = 0;
1351 text = NULL;
1352 ret = Z_STREAM_END;
1353
1354 while (png_ptr->zstream.avail_in)
1355 {
1356 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
1357 if (ret != Z_OK && ret != Z_STREAM_END)
1358 {
1359 inflateReset(&png_ptr->zstream);
1360 png_ptr->zstream.avail_in = 0;
1361 png_ptr->current_text = NULL;
1362 png_free(png_ptr, key);
1363 png_free(png_ptr, text);
1364 return;
1365 }
1366 if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
1367 {
1368 if (text == NULL)
1369 {
1370 text = (png_charp)png_malloc(png_ptr,
1371 (png_uint_32)(png_ptr->zbuf_size
1372 - png_ptr->zstream.avail_out + key_size + 1));
1373
1374 png_memcpy(text + key_size, png_ptr->zbuf,
1375 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1376
1377 png_memcpy(text, key, key_size);
1378
1379 text_size = key_size + png_ptr->zbuf_size -
1380 png_ptr->zstream.avail_out;
1381
1382 *(text + text_size) = '\0';
1383 }
1384 else
1385 {
1386 png_charp tmp;
1387
1388 tmp = text;
1389 text = (png_charp)png_malloc(png_ptr, text_size +
1390 (png_uint_32)(png_ptr->zbuf_size
1391 - png_ptr->zstream.avail_out + 1));
1392
1393 png_memcpy(text, tmp, text_size);
1394 png_free(png_ptr, tmp);
1395
1396 png_memcpy(text + text_size, png_ptr->zbuf,
1397 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1398
1399 text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
1400 *(text + text_size) = '\0';
1401 }
1402 if (ret != Z_STREAM_END)
1403 {
1404 png_ptr->zstream.next_out = png_ptr->zbuf;
1405 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1406 }
1407 }
1408 else
1409 {
1410 break;
1411 }
1412
1413 if (ret == Z_STREAM_END)
1414 break;
1415 }
1416
1417 inflateReset(&png_ptr->zstream);
1418 png_ptr->zstream.avail_in = 0;
1419
1420 if (ret != Z_STREAM_END)
1421 {
1422 png_ptr->current_text = NULL;
1423 png_free(png_ptr, key);
1424 png_free(png_ptr, text);
1425 return;
1426 }
1427
1428 png_ptr->current_text = NULL;
1429 png_free(png_ptr, key);
1430 key = text;
1431 text += key_size;
1432
1433 text_ptr = (png_textp)png_malloc(png_ptr,
1434 (png_uint_32)png_sizeof(png_text));
1435 text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
1436 text_ptr->key = key;
1437 #ifdef PNG_iTXt_SUPPORTED
1438 text_ptr->lang = NULL;
1439 text_ptr->lang_key = NULL;
1440 #endif
1441 text_ptr->text = text;
1442
1443 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1444
1445 png_free(png_ptr, key);
1446 png_free(png_ptr, text_ptr);
1447
1448 if (ret)
1449 png_warning(png_ptr, "Insufficient memory to store text chunk.");
1450 }
1451 }
1452 #endif
1453
1454 #if defined(PNG_READ_iTXt_SUPPORTED)
1455 void /* PRIVATE */
1456 png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1457 length)
1458 {
1459 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1460 {
1461 png_error(png_ptr, "Out of place iTXt");
1462 info_ptr = info_ptr; /* To quiet some compiler warnings */
1463 }
1464
1465 #ifdef PNG_MAX_MALLOC_64K
1466 png_ptr->skip_length = 0; /* This may not be necessary */
1467
1468 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1469 {
1470 png_warning(png_ptr, "iTXt chunk too large to fit in memory");
1471 png_ptr->skip_length = length - (png_uint_32)65535L;
1472 length = (png_uint_32)65535L;
1473 }
1474 #endif
1475
1476 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1477 (png_uint_32)(length + 1));
1478 png_ptr->current_text[length] = '\0';
1479 png_ptr->current_text_ptr = png_ptr->current_text;
1480 png_ptr->current_text_size = (png_size_t)length;
1481 png_ptr->current_text_left = (png_size_t)length;
1482 png_ptr->process_mode = PNG_READ_iTXt_MODE;
1483 }
1484
1485 void /* PRIVATE */
1486 png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
1487 {
1488
1489 if (png_ptr->buffer_size && png_ptr->current_text_left)
1490 {
1491 png_size_t text_size;
1492
1493 if (png_ptr->buffer_size < png_ptr->current_text_left)
1494 text_size = png_ptr->buffer_size;
1495
1496 else
1497 text_size = png_ptr->current_text_left;
1498
1499 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1500 png_ptr->current_text_left -= text_size;
1501 png_ptr->current_text_ptr += text_size;
1502 }
1503 if (!(png_ptr->current_text_left))
1504 {
1505 png_textp text_ptr;
1506 png_charp key;
1507 int comp_flag;
1508 png_charp lang;
1509 png_charp lang_key;
1510 png_charp text;
1511 int ret;
1512
1513 if (png_ptr->buffer_size < 4)
1514 {
1515 png_push_save_buffer(png_ptr);
1516 return;
1517 }
1518
1519 png_push_crc_finish(png_ptr);
1520
1521 #if defined(PNG_MAX_MALLOC_64K)
1522 if (png_ptr->skip_length)
1523 return;
1524 #endif
1525
1526 key = png_ptr->current_text;
1527
1528 for (lang = key; *lang; lang++)
1529 /* Empty loop */ ;
1530
1531 if (lang < key + png_ptr->current_text_size - 3)
1532 lang++;
1533
1534 comp_flag = *lang++;
1535 lang++; /* Skip comp_type, always zero */
1536
1537 for (lang_key = lang; *lang_key; lang_key++)
1538 /* Empty loop */ ;
1539
1540 lang_key++; /* Skip NUL separator */
1541
1542 text=lang_key;
1543
1544 if (lang_key < key + png_ptr->current_text_size - 1)
1545 {
1546 for (; *text; text++)
1547 /* Empty loop */ ;
1548 }
1549
1550 if (text < key + png_ptr->current_text_size)
1551 text++;
1552
1553 text_ptr = (png_textp)png_malloc(png_ptr,
1554 (png_uint_32)png_sizeof(png_text));
1555
1556 text_ptr->compression = comp_flag + 2;
1557 text_ptr->key = key;
1558 text_ptr->lang = lang;
1559 text_ptr->lang_key = lang_key;
1560 text_ptr->text = text;
1561 text_ptr->text_length = 0;
1562 text_ptr->itxt_length = png_strlen(text);
1563
1564 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1565
1566 png_ptr->current_text = NULL;
1567
1568 png_free(png_ptr, text_ptr);
1569 if (ret)
1570 png_warning(png_ptr, "Insufficient memory to store iTXt chunk.");
1571 }
1572 }
1573 #endif
1574
1575 /* This function is called when we haven't found a handler for this
1576 * chunk. If there isn't a problem with the chunk itself (ie a bad chunk
1577 * name or a critical chunk), the chunk is (currently) silently ignored.
1578 */
1579 void /* PRIVATE */
1580 png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
1581 length)
1582 {
1583 png_uint_32 skip = 0;
1584
1585 if (!(png_ptr->chunk_name[0] & 0x20))
1586 {
1587 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
1588 if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1589 PNG_HANDLE_CHUNK_ALWAYS
1590 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1591 && png_ptr->read_user_chunk_fn == NULL
1592 #endif
1593 )
1594 #endif
1595 png_chunk_error(png_ptr, "unknown critical chunk");
1596
1597 info_ptr = info_ptr; /* To quiet some compiler warnings */
1598 }
1599
1600 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
1601 if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
1602 {
1603 #ifdef PNG_MAX_MALLOC_64K
1604 if (length > (png_uint_32)65535L)
1605 {
1606 png_warning(png_ptr, "unknown chunk too large to fit in memory");
1607 skip = length - (png_uint_32)65535L;
1608 length = (png_uint_32)65535L;
1609 }
1610 #endif
1611 png_memcpy((png_charp)png_ptr->unknown_chunk.name,
1612 (png_charp)png_ptr->chunk_name,
1613 png_sizeof(png_ptr->unknown_chunk.name));
1614 png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1]
1615 = '\0';
1616
1617 png_ptr->unknown_chunk.size = (png_size_t)length;
1618
1619 if (length == 0)
1620 png_ptr->unknown_chunk.data = NULL;
1621
1622 else
1623 {
1624 png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr,
1625 (png_uint_32)length);
1626 png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
1627 }
1628
1629 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1630 if (png_ptr->read_user_chunk_fn != NULL)
1631 {
1632 /* Callback to user unknown chunk handler */
1633 int ret;
1634 ret = (*(png_ptr->read_user_chunk_fn))
1635 (png_ptr, &png_ptr->unknown_chunk);
1636
1637 if (ret < 0)
1638 png_chunk_error(png_ptr, "error in user chunk");
1639
1640 if (ret == 0)
1641 {
1642 if (!(png_ptr->chunk_name[0] & 0x20))
1643 if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1644 PNG_HANDLE_CHUNK_ALWAYS)
1645 png_chunk_error(png_ptr, "unknown critical chunk");
1646 png_set_unknown_chunks(png_ptr, info_ptr,
1647 &png_ptr->unknown_chunk, 1);
1648 }
1649 }
1650
1651 else
1652 #endif
1653 png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
1654 png_free(png_ptr, png_ptr->unknown_chunk.data);
1655 png_ptr->unknown_chunk.data = NULL;
1656 }
1657
1658 else
1659 #endif
1660 skip=length;
1661 png_push_crc_skip(png_ptr, skip);
1662 }
1663
1664 void /* PRIVATE */
1665 png_push_have_info(png_structp png_ptr, png_infop info_ptr)
1666 {
1667 if (png_ptr->info_fn != NULL)
1668 (*(png_ptr->info_fn))(png_ptr, info_ptr);
1669 }
1670
1671 void /* PRIVATE */
1672 png_push_have_end(png_structp png_ptr, png_infop info_ptr)
1673 {
1674 if (png_ptr->end_fn != NULL)
1675 (*(png_ptr->end_fn))(png_ptr, info_ptr);
1676 }
1677
1678 void /* PRIVATE */
1679 png_push_have_row(png_structp png_ptr, png_bytep row)
1680 {
1681 if (png_ptr->row_fn != NULL)
1682 (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
1683 (int)png_ptr->pass);
1684 }
1685
1686 void PNGAPI
1687 png_progressive_combine_row (png_structp png_ptr,
1688 png_bytep old_row, png_bytep new_row)
1689 {
1690 #ifdef PNG_USE_LOCAL_ARRAYS
1691 PNG_CONST int FARDATA png_pass_dsp_mask[7] =
1692 {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
1693 #endif
1694 if (png_ptr == NULL)
1695 return;
1696
1697 if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */
1698 png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
1699 }
1700
1701 void PNGAPI
1702 png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
1703 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1704 png_progressive_end_ptr end_fn)
1705 {
1706 if (png_ptr == NULL)
1707 return;
1708
1709 png_ptr->info_fn = info_fn;
1710 png_ptr->row_fn = row_fn;
1711 png_ptr->end_fn = end_fn;
1712
1713 png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
1714 }
1715
1716 png_voidp PNGAPI
1717 png_get_progressive_ptr(png_structp png_ptr)
1718 {
1719 if (png_ptr == NULL)
1720 return (NULL);
1721
1722 return png_ptr->io_ptr;
1723 }
1724 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
vsfilter mod based on vsfilter 2.39