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[wxWidgets.git] / src / png / pngpread.c
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1
2/* pngpread.c - read a png file in push mode
3 *
4 * libpng 1.2.5rc3 - September 18, 2002
5 * For conditions of distribution and use, see copyright notice in png.h
6 * Copyright (c) 1998-2002 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
14#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
15
16/* push model modes */
17#define PNG_READ_SIG_MODE 0
18#define PNG_READ_CHUNK_MODE 1
19#define PNG_READ_IDAT_MODE 2
20#define PNG_SKIP_MODE 3
21#define PNG_READ_tEXt_MODE 4
22#define PNG_READ_zTXt_MODE 5
23#define PNG_READ_DONE_MODE 6
24#define PNG_READ_iTXt_MODE 7
25#define PNG_ERROR_MODE 8
26
27void PNGAPI
28png_process_data(png_structp png_ptr, png_infop info_ptr,
29 png_bytep buffer, png_size_t buffer_size)
30{
31 png_push_restore_buffer(png_ptr, buffer, buffer_size);
32
33 while (png_ptr->buffer_size)
34 {
35 png_process_some_data(png_ptr, info_ptr);
36 }
37}
38
39/* What we do with the incoming data depends on what we were previously
40 * doing before we ran out of data...
41 */
42void /* PRIVATE */
43png_process_some_data(png_structp png_ptr, png_infop info_ptr)
44{
45 switch (png_ptr->process_mode)
46 {
47 case PNG_READ_SIG_MODE:
48 {
49 png_push_read_sig(png_ptr, info_ptr);
50 break;
51 }
52 case PNG_READ_CHUNK_MODE:
53 {
54 png_push_read_chunk(png_ptr, info_ptr);
55 break;
56 }
57 case PNG_READ_IDAT_MODE:
58 {
59 png_push_read_IDAT(png_ptr);
60 break;
61 }
62#if defined(PNG_READ_tEXt_SUPPORTED)
63 case PNG_READ_tEXt_MODE:
64 {
65 png_push_read_tEXt(png_ptr, info_ptr);
66 break;
67 }
68#endif
69#if defined(PNG_READ_zTXt_SUPPORTED)
70 case PNG_READ_zTXt_MODE:
71 {
72 png_push_read_zTXt(png_ptr, info_ptr);
73 break;
74 }
75#endif
76#if defined(PNG_READ_iTXt_SUPPORTED)
77 case PNG_READ_iTXt_MODE:
78 {
79 png_push_read_iTXt(png_ptr, info_ptr);
80 break;
81 }
82#endif
83 case PNG_SKIP_MODE:
84 {
85 png_push_crc_finish(png_ptr);
86 break;
87 }
88 default:
89 {
90 png_ptr->buffer_size = 0;
91 break;
92 }
93 }
94}
95
96/* Read any remaining signature bytes from the stream and compare them with
97 * the correct PNG signature. It is possible that this routine is called
98 * with bytes already read from the signature, either because they have been
99 * checked by the calling application, or because of multiple calls to this
100 * routine.
101 */
102void /* PRIVATE */
103png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
104{
105 png_size_t num_checked = png_ptr->sig_bytes,
106 num_to_check = 8 - num_checked;
107
108 if (png_ptr->buffer_size < num_to_check)
109 {
110 num_to_check = png_ptr->buffer_size;
111 }
112
113 png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
114 num_to_check);
115 png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes+num_to_check);
116
117 if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
118 {
119 if (num_checked < 4 &&
120 png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
121 png_error(png_ptr, "Not a PNG file");
122 else
123 png_error(png_ptr, "PNG file corrupted by ASCII conversion");
124 }
125 else
126 {
127 if (png_ptr->sig_bytes >= 8)
128 {
129 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
130 }
131 }
132}
133
134void /* PRIVATE */
135png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
136{
137#ifdef PNG_USE_LOCAL_ARRAYS
138 PNG_IHDR;
139 PNG_IDAT;
140 PNG_IEND;
141 PNG_PLTE;
142#if defined(PNG_READ_bKGD_SUPPORTED)
143 PNG_bKGD;
144#endif
145#if defined(PNG_READ_cHRM_SUPPORTED)
146 PNG_cHRM;
147#endif
148#if defined(PNG_READ_gAMA_SUPPORTED)
149 PNG_gAMA;
150#endif
151#if defined(PNG_READ_hIST_SUPPORTED)
152 PNG_hIST;
153#endif
154#if defined(PNG_READ_iCCP_SUPPORTED)
155 PNG_iCCP;
156#endif
157#if defined(PNG_READ_iTXt_SUPPORTED)
158 PNG_iTXt;
159#endif
160#if defined(PNG_READ_oFFs_SUPPORTED)
161 PNG_oFFs;
162#endif
163#if defined(PNG_READ_pCAL_SUPPORTED)
164 PNG_pCAL;
165#endif
166#if defined(PNG_READ_pHYs_SUPPORTED)
167 PNG_pHYs;
168#endif
169#if defined(PNG_READ_sBIT_SUPPORTED)
170 PNG_sBIT;
171#endif
172#if defined(PNG_READ_sCAL_SUPPORTED)
173 PNG_sCAL;
174#endif
175#if defined(PNG_READ_sRGB_SUPPORTED)
176 PNG_sRGB;
177#endif
178#if defined(PNG_READ_sPLT_SUPPORTED)
179 PNG_sPLT;
180#endif
181#if defined(PNG_READ_tEXt_SUPPORTED)
182 PNG_tEXt;
183#endif
184#if defined(PNG_READ_tIME_SUPPORTED)
185 PNG_tIME;
186#endif
187#if defined(PNG_READ_tRNS_SUPPORTED)
188 PNG_tRNS;
189#endif
190#if defined(PNG_READ_zTXt_SUPPORTED)
191 PNG_zTXt;
192#endif
193#endif /* PNG_USE_LOCAL_ARRAYS */
194 /* First we make sure we have enough data for the 4 byte chunk name
195 * and the 4 byte chunk length before proceeding with decoding the
196 * chunk data. To fully decode each of these chunks, we also make
197 * sure we have enough data in the buffer for the 4 byte CRC at the
198 * end of every chunk (except IDAT, which is handled separately).
199 */
200 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
201 {
202 png_byte chunk_length[4];
203
204 if (png_ptr->buffer_size < 8)
205 {
206 png_push_save_buffer(png_ptr);
207 return;
208 }
209
210 png_push_fill_buffer(png_ptr, chunk_length, 4);
211 png_ptr->push_length = png_get_uint_32(chunk_length);
212 png_reset_crc(png_ptr);
213 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
214 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
215 }
216
217 if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
218 {
219 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
220 {
221 png_push_save_buffer(png_ptr);
222 return;
223 }
224 png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
225 }
226 else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
227 {
228 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
229 {
230 png_push_save_buffer(png_ptr);
231 return;
232 }
233 png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
234 }
235 else if (!png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
236 {
237 /* If we reach an IDAT chunk, this means we have read all of the
238 * header chunks, and we can start reading the image (or if this
239 * is called after the image has been read - we have an error).
240 */
241 if (!(png_ptr->mode & PNG_HAVE_IHDR))
242 png_error(png_ptr, "Missing IHDR before IDAT");
243 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
244 !(png_ptr->mode & PNG_HAVE_PLTE))
245 png_error(png_ptr, "Missing PLTE before IDAT");
246
247 if (png_ptr->mode & PNG_HAVE_IDAT)
248 {
249 if (png_ptr->push_length == 0)
250 return;
251
252 if (png_ptr->mode & PNG_AFTER_IDAT)
253 png_error(png_ptr, "Too many IDAT's found");
254 }
255
256 png_ptr->idat_size = png_ptr->push_length;
257 png_ptr->mode |= PNG_HAVE_IDAT;
258 png_ptr->process_mode = PNG_READ_IDAT_MODE;
259 png_push_have_info(png_ptr, info_ptr);
260 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
261 png_ptr->zstream.next_out = png_ptr->row_buf;
262 return;
263 }
264 else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
265 {
266 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
267 {
268 png_push_save_buffer(png_ptr);
269 return;
270 }
271 png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
272
273 png_ptr->process_mode = PNG_READ_DONE_MODE;
274 png_push_have_end(png_ptr, info_ptr);
275 }
276#if defined(PNG_READ_gAMA_SUPPORTED)
277 else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
278 {
279 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
280 {
281 png_push_save_buffer(png_ptr);
282 return;
283 }
284 png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
285 }
286#endif
287#if defined(PNG_READ_sBIT_SUPPORTED)
288 else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
289 {
290 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
291 {
292 png_push_save_buffer(png_ptr);
293 return;
294 }
295 png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
296 }
297#endif
298#if defined(PNG_READ_cHRM_SUPPORTED)
299 else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
300 {
301 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
302 {
303 png_push_save_buffer(png_ptr);
304 return;
305 }
306 png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
307 }
308#endif
309#if defined(PNG_READ_sRGB_SUPPORTED)
310 else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
311 {
312 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
313 {
314 png_push_save_buffer(png_ptr);
315 return;
316 }
317 png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
318 }
319#endif
320#if defined(PNG_READ_iCCP_SUPPORTED)
321 else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
322 {
323 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
324 {
325 png_push_save_buffer(png_ptr);
326 return;
327 }
328 png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
329 }
330#endif
331#if defined(PNG_READ_sPLT_SUPPORTED)
332 else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
333 {
334 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
335 {
336 png_push_save_buffer(png_ptr);
337 return;
338 }
339 png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
340 }
341#endif
342#if defined(PNG_READ_tRNS_SUPPORTED)
343 else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
344 {
345 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
346 {
347 png_push_save_buffer(png_ptr);
348 return;
349 }
350 png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
351 }
352#endif
353#if defined(PNG_READ_bKGD_SUPPORTED)
354 else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
355 {
356 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
357 {
358 png_push_save_buffer(png_ptr);
359 return;
360 }
361 png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
362 }
363#endif
364#if defined(PNG_READ_hIST_SUPPORTED)
365 else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
366 {
367 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
368 {
369 png_push_save_buffer(png_ptr);
370 return;
371 }
372 png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
373 }
374#endif
375#if defined(PNG_READ_pHYs_SUPPORTED)
376 else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
377 {
378 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
379 {
380 png_push_save_buffer(png_ptr);
381 return;
382 }
383 png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
384 }
385#endif
386#if defined(PNG_READ_oFFs_SUPPORTED)
387 else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 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 png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
395 }
396#endif
397#if defined(PNG_READ_pCAL_SUPPORTED)
398 else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
399 {
400 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
401 {
402 png_push_save_buffer(png_ptr);
403 return;
404 }
405 png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
406 }
407#endif
408#if defined(PNG_READ_sCAL_SUPPORTED)
409 else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
410 {
411 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
412 {
413 png_push_save_buffer(png_ptr);
414 return;
415 }
416 png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
417 }
418#endif
419#if defined(PNG_READ_tIME_SUPPORTED)
420 else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
421 {
422 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
423 {
424 png_push_save_buffer(png_ptr);
425 return;
426 }
427 png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
428 }
429#endif
430#if defined(PNG_READ_tEXt_SUPPORTED)
431 else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
432 {
433 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
434 {
435 png_push_save_buffer(png_ptr);
436 return;
437 }
438 png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
439 }
440#endif
441#if defined(PNG_READ_zTXt_SUPPORTED)
442 else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
443 {
444 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
445 {
446 png_push_save_buffer(png_ptr);
447 return;
448 }
449 png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
450 }
451#endif
452#if defined(PNG_READ_iTXt_SUPPORTED)
453 else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
454 {
455 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
456 {
457 png_push_save_buffer(png_ptr);
458 return;
459 }
460 png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
461 }
462#endif
463 else
464 {
465 if (png_ptr->push_length + 4 > png_ptr->buffer_size)
466 {
467 png_push_save_buffer(png_ptr);
468 return;
469 }
470 png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
471 }
472
473 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
474}
475
476void /* PRIVATE */
477png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
478{
479 png_ptr->process_mode = PNG_SKIP_MODE;
480 png_ptr->skip_length = skip;
481}
482
483void /* PRIVATE */
484png_push_crc_finish(png_structp png_ptr)
485{
486 if (png_ptr->skip_length && png_ptr->save_buffer_size)
487 {
488 png_size_t save_size;
489
490 if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)
491 save_size = (png_size_t)png_ptr->skip_length;
492 else
493 save_size = png_ptr->save_buffer_size;
494
495 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
496
497 png_ptr->skip_length -= save_size;
498 png_ptr->buffer_size -= save_size;
499 png_ptr->save_buffer_size -= save_size;
500 png_ptr->save_buffer_ptr += save_size;
501 }
502 if (png_ptr->skip_length && png_ptr->current_buffer_size)
503 {
504 png_size_t save_size;
505
506 if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)
507 save_size = (png_size_t)png_ptr->skip_length;
508 else
509 save_size = png_ptr->current_buffer_size;
510
511 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
512
513 png_ptr->skip_length -= save_size;
514 png_ptr->buffer_size -= save_size;
515 png_ptr->current_buffer_size -= save_size;
516 png_ptr->current_buffer_ptr += save_size;
517 }
518 if (!png_ptr->skip_length)
519 {
520 if (png_ptr->buffer_size < 4)
521 {
522 png_push_save_buffer(png_ptr);
523 return;
524 }
525
526 png_crc_finish(png_ptr, 0);
527 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
528 }
529}
530
531void PNGAPI
532png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
533{
534 png_bytep ptr;
535
536 ptr = buffer;
537 if (png_ptr->save_buffer_size)
538 {
539 png_size_t save_size;
540
541 if (length < png_ptr->save_buffer_size)
542 save_size = length;
543 else
544 save_size = png_ptr->save_buffer_size;
545
546 png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
547 length -= save_size;
548 ptr += save_size;
549 png_ptr->buffer_size -= save_size;
550 png_ptr->save_buffer_size -= save_size;
551 png_ptr->save_buffer_ptr += save_size;
552 }
553 if (length && png_ptr->current_buffer_size)
554 {
555 png_size_t save_size;
556
557 if (length < png_ptr->current_buffer_size)
558 save_size = length;
559 else
560 save_size = png_ptr->current_buffer_size;
561
562 png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
563 png_ptr->buffer_size -= save_size;
564 png_ptr->current_buffer_size -= save_size;
565 png_ptr->current_buffer_ptr += save_size;
566 }
567}
568
569void /* PRIVATE */
570png_push_save_buffer(png_structp png_ptr)
571{
572 if (png_ptr->save_buffer_size)
573 {
574 if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
575 {
576 png_size_t i,istop;
577 png_bytep sp;
578 png_bytep dp;
579
580 istop = png_ptr->save_buffer_size;
581 for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
582 i < istop; i++, sp++, dp++)
583 {
584 *dp = *sp;
585 }
586 }
587 }
588 if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
589 png_ptr->save_buffer_max)
590 {
591 png_size_t new_max;
592 png_bytep old_buffer;
593
594 new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
595 old_buffer = png_ptr->save_buffer;
596 png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr,
597 (png_uint_32)new_max);
598 png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
599 png_free(png_ptr, old_buffer);
600 png_ptr->save_buffer_max = new_max;
601 }
602 if (png_ptr->current_buffer_size)
603 {
604 png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
605 png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
606 png_ptr->save_buffer_size += png_ptr->current_buffer_size;
607 png_ptr->current_buffer_size = 0;
608 }
609 png_ptr->save_buffer_ptr = png_ptr->save_buffer;
610 png_ptr->buffer_size = 0;
611}
612
613void /* PRIVATE */
614png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
615 png_size_t buffer_length)
616{
617 png_ptr->current_buffer = buffer;
618 png_ptr->current_buffer_size = buffer_length;
619 png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
620 png_ptr->current_buffer_ptr = png_ptr->current_buffer;
621}
622
623void /* PRIVATE */
624png_push_read_IDAT(png_structp png_ptr)
625{
626#ifdef PNG_USE_LOCAL_ARRAYS
627 PNG_IDAT;
628#endif
629 if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
630 {
631 png_byte chunk_length[4];
632
633 if (png_ptr->buffer_size < 8)
634 {
635 png_push_save_buffer(png_ptr);
636 return;
637 }
638
639 png_push_fill_buffer(png_ptr, chunk_length, 4);
640 png_ptr->push_length = png_get_uint_32(chunk_length);
641
642 png_reset_crc(png_ptr);
643 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
644 png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
645
646 if (png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
647 {
648 png_ptr->process_mode = PNG_READ_CHUNK_MODE;
649 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
650 png_error(png_ptr, "Not enough compressed data");
651 return;
652 }
653
654 png_ptr->idat_size = png_ptr->push_length;
655 }
656 if (png_ptr->idat_size && png_ptr->save_buffer_size)
657 {
658 png_size_t save_size;
659
660 if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
661 {
662 save_size = (png_size_t)png_ptr->idat_size;
663 /* check for overflow */
664 if((png_uint_32)save_size != png_ptr->idat_size)
665 png_error(png_ptr, "save_size overflowed in pngpread");
666 }
667 else
668 save_size = png_ptr->save_buffer_size;
669
670 png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
671 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
672 png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
673 png_ptr->idat_size -= save_size;
674 png_ptr->buffer_size -= save_size;
675 png_ptr->save_buffer_size -= save_size;
676 png_ptr->save_buffer_ptr += save_size;
677 }
678 if (png_ptr->idat_size && png_ptr->current_buffer_size)
679 {
680 png_size_t save_size;
681
682 if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
683 {
684 save_size = (png_size_t)png_ptr->idat_size;
685 /* check for overflow */
686 if((png_uint_32)save_size != png_ptr->idat_size)
687 png_error(png_ptr, "save_size overflowed in pngpread");
688 }
689 else
690 save_size = png_ptr->current_buffer_size;
691
692 png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
693 if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
694 png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
695
696 png_ptr->idat_size -= save_size;
697 png_ptr->buffer_size -= save_size;
698 png_ptr->current_buffer_size -= save_size;
699 png_ptr->current_buffer_ptr += save_size;
700 }
701 if (!png_ptr->idat_size)
702 {
703 if (png_ptr->buffer_size < 4)
704 {
705 png_push_save_buffer(png_ptr);
706 return;
707 }
708
709 png_crc_finish(png_ptr, 0);
710 png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
711 png_ptr->mode |= PNG_AFTER_IDAT;
712 }
713}
714
715void /* PRIVATE */
716png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
717 png_size_t buffer_length)
718{
719 int ret;
720
721 if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)
722 png_error(png_ptr, "Extra compression data");
723
724 png_ptr->zstream.next_in = buffer;
725 png_ptr->zstream.avail_in = (uInt)buffer_length;
726 for(;;)
727 {
728 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
729 if (ret != Z_OK)
730 {
731 if (ret == Z_STREAM_END)
732 {
733 if (png_ptr->zstream.avail_in)
734 png_error(png_ptr, "Extra compressed data");
735 if (!(png_ptr->zstream.avail_out))
736 {
737 png_push_process_row(png_ptr);
738 }
739
740 png_ptr->mode |= PNG_AFTER_IDAT;
741 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
742 break;
743 }
744 else if (ret == Z_BUF_ERROR)
745 break;
746 else
747 png_error(png_ptr, "Decompression Error");
748 }
749 if (!(png_ptr->zstream.avail_out))
750 {
751 if ((
752#if defined(PNG_READ_INTERLACING_SUPPORTED)
753 png_ptr->interlaced && png_ptr->pass > 6) ||
754 (!png_ptr->interlaced &&
755#endif
756 png_ptr->row_number == png_ptr->num_rows-1))
757 {
758 if (png_ptr->zstream.avail_in)
759 png_warning(png_ptr, "Too much data in IDAT chunks");
760 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
761 break;
762 }
763 png_push_process_row(png_ptr);
764 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
765 png_ptr->zstream.next_out = png_ptr->row_buf;
766 }
767 else
768 break;
769 }
770}
771
772void /* PRIVATE */
773png_push_process_row(png_structp png_ptr)
774{
775 png_ptr->row_info.color_type = png_ptr->color_type;
776 png_ptr->row_info.width = png_ptr->iwidth;
777 png_ptr->row_info.channels = png_ptr->channels;
778 png_ptr->row_info.bit_depth = png_ptr->bit_depth;
779 png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
780
781 png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *
782 (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);
783
784 png_read_filter_row(png_ptr, &(png_ptr->row_info),
785 png_ptr->row_buf + 1, png_ptr->prev_row + 1,
786 (int)(png_ptr->row_buf[0]));
787
788 png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
789 png_ptr->rowbytes + 1);
790
791 if (png_ptr->transformations)
792 png_do_read_transformations(png_ptr);
793
794#if defined(PNG_READ_INTERLACING_SUPPORTED)
795 /* blow up interlaced rows to full size */
796 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
797 {
798 if (png_ptr->pass < 6)
799/* old interface (pre-1.0.9):
800 png_do_read_interlace(&(png_ptr->row_info),
801 png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
802 */
803 png_do_read_interlace(png_ptr);
804
805 switch (png_ptr->pass)
806 {
807 case 0:
808 {
809 int i;
810 for (i = 0; i < 8 && png_ptr->pass == 0; i++)
811 {
812 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
813 png_read_push_finish_row(png_ptr); /* updates png_ptr->pass */
814 }
815 if (png_ptr->pass == 2) /* pass 1 might be empty */
816 {
817 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
818 {
819 png_push_have_row(png_ptr, png_bytep_NULL);
820 png_read_push_finish_row(png_ptr);
821 }
822 }
823 if (png_ptr->pass == 4 && png_ptr->height <= 4)
824 {
825 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
826 {
827 png_push_have_row(png_ptr, png_bytep_NULL);
828 png_read_push_finish_row(png_ptr);
829 }
830 }
831 if (png_ptr->pass == 6 && png_ptr->height <= 4)
832 {
833 png_push_have_row(png_ptr, png_bytep_NULL);
834 png_read_push_finish_row(png_ptr);
835 }
836 break;
837 }
838 case 1:
839 {
840 int i;
841 for (i = 0; i < 8 && png_ptr->pass == 1; i++)
842 {
843 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
844 png_read_push_finish_row(png_ptr);
845 }
846 if (png_ptr->pass == 2) /* skip top 4 generated rows */
847 {
848 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
849 {
850 png_push_have_row(png_ptr, png_bytep_NULL);
851 png_read_push_finish_row(png_ptr);
852 }
853 }
854 break;
855 }
856 case 2:
857 {
858 int i;
859 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
860 {
861 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
862 png_read_push_finish_row(png_ptr);
863 }
864 for (i = 0; i < 4 && png_ptr->pass == 2; i++)
865 {
866 png_push_have_row(png_ptr, png_bytep_NULL);
867 png_read_push_finish_row(png_ptr);
868 }
869 if (png_ptr->pass == 4) /* pass 3 might be empty */
870 {
871 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
872 {
873 png_push_have_row(png_ptr, png_bytep_NULL);
874 png_read_push_finish_row(png_ptr);
875 }
876 }
877 break;
878 }
879 case 3:
880 {
881 int i;
882 for (i = 0; i < 4 && png_ptr->pass == 3; i++)
883 {
884 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
885 png_read_push_finish_row(png_ptr);
886 }
887 if (png_ptr->pass == 4) /* skip top two generated rows */
888 {
889 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
890 {
891 png_push_have_row(png_ptr, png_bytep_NULL);
892 png_read_push_finish_row(png_ptr);
893 }
894 }
895 break;
896 }
897 case 4:
898 {
899 int i;
900 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
901 {
902 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
903 png_read_push_finish_row(png_ptr);
904 }
905 for (i = 0; i < 2 && png_ptr->pass == 4; i++)
906 {
907 png_push_have_row(png_ptr, png_bytep_NULL);
908 png_read_push_finish_row(png_ptr);
909 }
910 if (png_ptr->pass == 6) /* pass 5 might be empty */
911 {
912 png_push_have_row(png_ptr, png_bytep_NULL);
913 png_read_push_finish_row(png_ptr);
914 }
915 break;
916 }
917 case 5:
918 {
919 int i;
920 for (i = 0; i < 2 && png_ptr->pass == 5; i++)
921 {
922 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
923 png_read_push_finish_row(png_ptr);
924 }
925 if (png_ptr->pass == 6) /* skip top generated row */
926 {
927 png_push_have_row(png_ptr, png_bytep_NULL);
928 png_read_push_finish_row(png_ptr);
929 }
930 break;
931 }
932 case 6:
933 {
934 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
935 png_read_push_finish_row(png_ptr);
936 if (png_ptr->pass != 6)
937 break;
938 png_push_have_row(png_ptr, png_bytep_NULL);
939 png_read_push_finish_row(png_ptr);
940 }
941 }
942 }
943 else
944#endif
945 {
946 png_push_have_row(png_ptr, png_ptr->row_buf + 1);
947 png_read_push_finish_row(png_ptr);
948 }
949}
950
951void /* PRIVATE */
952png_read_push_finish_row(png_structp png_ptr)
953{
954#ifdef PNG_USE_LOCAL_ARRAYS
955 /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
956
957 /* start of interlace block */
958 const int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
959
960 /* offset to next interlace block */
961 const int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
962
963 /* start of interlace block in the y direction */
964 const int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
965
966 /* offset to next interlace block in the y direction */
967 const int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
968
969 /* Width of interlace block. This is not currently used - if you need
970 * it, uncomment it here and in png.h
971 const int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
972 */
973
974 /* Height of interlace block. This is not currently used - if you need
975 * it, uncomment it here and in png.h
976 const int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
977 */
978#endif
979
980 png_ptr->row_number++;
981 if (png_ptr->row_number < png_ptr->num_rows)
982 return;
983
984 if (png_ptr->interlaced)
985 {
986 png_ptr->row_number = 0;
987 png_memset_check(png_ptr, png_ptr->prev_row, 0,
988 png_ptr->rowbytes + 1);
989 do
990 {
991 png_ptr->pass++;
992 if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
993 (png_ptr->pass == 3 && png_ptr->width < 3) ||
994 (png_ptr->pass == 5 && png_ptr->width < 2))
995 png_ptr->pass++;
996
997 if (png_ptr->pass > 7)
998 png_ptr->pass--;
999 if (png_ptr->pass >= 7)
1000 break;
1001
1002 png_ptr->iwidth = (png_ptr->width +
1003 png_pass_inc[png_ptr->pass] - 1 -
1004 png_pass_start[png_ptr->pass]) /
1005 png_pass_inc[png_ptr->pass];
1006
1007 png_ptr->irowbytes = ((png_ptr->iwidth *
1008 png_ptr->pixel_depth + 7) >> 3) + 1;
1009
1010 if (png_ptr->transformations & PNG_INTERLACE)
1011 break;
1012
1013 png_ptr->num_rows = (png_ptr->height +
1014 png_pass_yinc[png_ptr->pass] - 1 -
1015 png_pass_ystart[png_ptr->pass]) /
1016 png_pass_yinc[png_ptr->pass];
1017
1018 } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
1019 }
1020}
1021
1022#if defined(PNG_READ_tEXt_SUPPORTED)
1023void /* PRIVATE */
1024png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1025 length)
1026{
1027 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1028 {
1029 png_error(png_ptr, "Out of place tEXt");
1030 /* to quiet some compiler warnings */
1031 if(info_ptr == NULL) return;
1032 }
1033
1034#ifdef PNG_MAX_MALLOC_64K
1035 png_ptr->skip_length = 0; /* This may not be necessary */
1036
1037 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1038 {
1039 png_warning(png_ptr, "tEXt chunk too large to fit in memory");
1040 png_ptr->skip_length = length - (png_uint_32)65535L;
1041 length = (png_uint_32)65535L;
1042 }
1043#endif
1044
1045 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1046 (png_uint_32)(length+1));
1047 png_ptr->current_text[length] = '\0';
1048 png_ptr->current_text_ptr = png_ptr->current_text;
1049 png_ptr->current_text_size = (png_size_t)length;
1050 png_ptr->current_text_left = (png_size_t)length;
1051 png_ptr->process_mode = PNG_READ_tEXt_MODE;
1052}
1053
1054void /* PRIVATE */
1055png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
1056{
1057 if (png_ptr->buffer_size && png_ptr->current_text_left)
1058 {
1059 png_size_t text_size;
1060
1061 if (png_ptr->buffer_size < png_ptr->current_text_left)
1062 text_size = png_ptr->buffer_size;
1063 else
1064 text_size = png_ptr->current_text_left;
1065 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1066 png_ptr->current_text_left -= text_size;
1067 png_ptr->current_text_ptr += text_size;
1068 }
1069 if (!(png_ptr->current_text_left))
1070 {
1071 png_textp text_ptr;
1072 png_charp text;
1073 png_charp key;
1074 int ret;
1075
1076 if (png_ptr->buffer_size < 4)
1077 {
1078 png_push_save_buffer(png_ptr);
1079 return;
1080 }
1081
1082 png_push_crc_finish(png_ptr);
1083
1084#if defined(PNG_MAX_MALLOC_64K)
1085 if (png_ptr->skip_length)
1086 return;
1087#endif
1088
1089 key = png_ptr->current_text;
1090
1091 for (text = key; *text; text++)
1092 /* empty loop */ ;
1093
1094 if (text != key + png_ptr->current_text_size)
1095 text++;
1096
1097 text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
1098 text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
1099 text_ptr->key = key;
1100#ifdef PNG_iTXt_SUPPORTED
1101 text_ptr->lang = NULL;
1102 text_ptr->lang_key = NULL;
1103#endif
1104 text_ptr->text = text;
1105
1106 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1107
1108 png_free(png_ptr, key);
1109 png_free(png_ptr, text_ptr);
1110 png_ptr->current_text = NULL;
1111
1112 if (ret)
1113 png_warning(png_ptr, "Insufficient memory to store text chunk.");
1114 }
1115}
1116#endif
1117
1118#if defined(PNG_READ_zTXt_SUPPORTED)
1119void /* PRIVATE */
1120png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1121 length)
1122{
1123 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1124 {
1125 png_error(png_ptr, "Out of place zTXt");
1126 /* to quiet some compiler warnings */
1127 if(info_ptr == NULL) return;
1128 }
1129
1130#ifdef PNG_MAX_MALLOC_64K
1131 /* We can't handle zTXt chunks > 64K, since we don't have enough space
1132 * to be able to store the uncompressed data. Actually, the threshold
1133 * is probably around 32K, but it isn't as definite as 64K is.
1134 */
1135 if (length > (png_uint_32)65535L)
1136 {
1137 png_warning(png_ptr, "zTXt chunk too large to fit in memory");
1138 png_push_crc_skip(png_ptr, length);
1139 return;
1140 }
1141#endif
1142
1143 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1144 (png_uint_32)(length+1));
1145 png_ptr->current_text[length] = '\0';
1146 png_ptr->current_text_ptr = png_ptr->current_text;
1147 png_ptr->current_text_size = (png_size_t)length;
1148 png_ptr->current_text_left = (png_size_t)length;
1149 png_ptr->process_mode = PNG_READ_zTXt_MODE;
1150}
1151
1152void /* PRIVATE */
1153png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
1154{
1155 if (png_ptr->buffer_size && png_ptr->current_text_left)
1156 {
1157 png_size_t text_size;
1158
1159 if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
1160 text_size = png_ptr->buffer_size;
1161 else
1162 text_size = png_ptr->current_text_left;
1163 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1164 png_ptr->current_text_left -= text_size;
1165 png_ptr->current_text_ptr += text_size;
1166 }
1167 if (!(png_ptr->current_text_left))
1168 {
1169 png_textp text_ptr;
1170 png_charp text;
1171 png_charp key;
1172 int ret;
1173 png_size_t text_size, key_size;
1174
1175 if (png_ptr->buffer_size < 4)
1176 {
1177 png_push_save_buffer(png_ptr);
1178 return;
1179 }
1180
1181 png_push_crc_finish(png_ptr);
1182
1183 key = png_ptr->current_text;
1184
1185 for (text = key; *text; text++)
1186 /* empty loop */ ;
1187
1188 /* zTXt can't have zero text */
1189 if (text == key + png_ptr->current_text_size)
1190 {
1191 png_ptr->current_text = NULL;
1192 png_free(png_ptr, key);
1193 return;
1194 }
1195
1196 text++;
1197
1198 if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */
1199 {
1200 png_ptr->current_text = NULL;
1201 png_free(png_ptr, key);
1202 return;
1203 }
1204
1205 text++;
1206
1207 png_ptr->zstream.next_in = (png_bytep )text;
1208 png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -
1209 (text - key));
1210 png_ptr->zstream.next_out = png_ptr->zbuf;
1211 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1212
1213 key_size = text - key;
1214 text_size = 0;
1215 text = NULL;
1216 ret = Z_STREAM_END;
1217
1218 while (png_ptr->zstream.avail_in)
1219 {
1220 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
1221 if (ret != Z_OK && ret != Z_STREAM_END)
1222 {
1223 inflateReset(&png_ptr->zstream);
1224 png_ptr->zstream.avail_in = 0;
1225 png_ptr->current_text = NULL;
1226 png_free(png_ptr, key);
1227 png_free(png_ptr, text);
1228 return;
1229 }
1230 if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
1231 {
1232 if (text == NULL)
1233 {
1234 text = (png_charp)png_malloc(png_ptr,
1235 (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
1236 + key_size + 1));
1237 png_memcpy(text + key_size, png_ptr->zbuf,
1238 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1239 png_memcpy(text, key, key_size);
1240 text_size = key_size + png_ptr->zbuf_size -
1241 png_ptr->zstream.avail_out;
1242 *(text + text_size) = '\0';
1243 }
1244 else
1245 {
1246 png_charp tmp;
1247
1248 tmp = text;
1249 text = (png_charp)png_malloc(png_ptr, text_size +
1250 (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
1251 + 1));
1252 png_memcpy(text, tmp, text_size);
1253 png_free(png_ptr, tmp);
1254 png_memcpy(text + text_size, png_ptr->zbuf,
1255 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
1256 text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
1257 *(text + text_size) = '\0';
1258 }
1259 if (ret != Z_STREAM_END)
1260 {
1261 png_ptr->zstream.next_out = png_ptr->zbuf;
1262 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1263 }
1264 }
1265 else
1266 {
1267 break;
1268 }
1269
1270 if (ret == Z_STREAM_END)
1271 break;
1272 }
1273
1274 inflateReset(&png_ptr->zstream);
1275 png_ptr->zstream.avail_in = 0;
1276
1277 if (ret != Z_STREAM_END)
1278 {
1279 png_ptr->current_text = NULL;
1280 png_free(png_ptr, key);
1281 png_free(png_ptr, text);
1282 return;
1283 }
1284
1285 png_ptr->current_text = NULL;
1286 png_free(png_ptr, key);
1287 key = text;
1288 text += key_size;
1289
1290 text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
1291 text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
1292 text_ptr->key = key;
1293#ifdef PNG_iTXt_SUPPORTED
1294 text_ptr->lang = NULL;
1295 text_ptr->lang_key = NULL;
1296#endif
1297 text_ptr->text = text;
1298
1299 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1300
1301 png_free(png_ptr, key);
1302 png_free(png_ptr, text_ptr);
1303
1304 if (ret)
1305 png_warning(png_ptr, "Insufficient memory to store text chunk.");
1306 }
1307}
1308#endif
1309
1310#if defined(PNG_READ_iTXt_SUPPORTED)
1311void /* PRIVATE */
1312png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
1313 length)
1314{
1315 if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
1316 {
1317 png_error(png_ptr, "Out of place iTXt");
1318 /* to quiet some compiler warnings */
1319 if(info_ptr == NULL) return;
1320 }
1321
1322#ifdef PNG_MAX_MALLOC_64K
1323 png_ptr->skip_length = 0; /* This may not be necessary */
1324
1325 if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
1326 {
1327 png_warning(png_ptr, "iTXt chunk too large to fit in memory");
1328 png_ptr->skip_length = length - (png_uint_32)65535L;
1329 length = (png_uint_32)65535L;
1330 }
1331#endif
1332
1333 png_ptr->current_text = (png_charp)png_malloc(png_ptr,
1334 (png_uint_32)(length+1));
1335 png_ptr->current_text[length] = '\0';
1336 png_ptr->current_text_ptr = png_ptr->current_text;
1337 png_ptr->current_text_size = (png_size_t)length;
1338 png_ptr->current_text_left = (png_size_t)length;
1339 png_ptr->process_mode = PNG_READ_iTXt_MODE;
1340}
1341
1342void /* PRIVATE */
1343png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
1344{
1345
1346 if (png_ptr->buffer_size && png_ptr->current_text_left)
1347 {
1348 png_size_t text_size;
1349
1350 if (png_ptr->buffer_size < png_ptr->current_text_left)
1351 text_size = png_ptr->buffer_size;
1352 else
1353 text_size = png_ptr->current_text_left;
1354 png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
1355 png_ptr->current_text_left -= text_size;
1356 png_ptr->current_text_ptr += text_size;
1357 }
1358 if (!(png_ptr->current_text_left))
1359 {
1360 png_textp text_ptr;
1361 png_charp key;
1362 int comp_flag;
1363 png_charp lang;
1364 png_charp lang_key;
1365 png_charp text;
1366 int ret;
1367
1368 if (png_ptr->buffer_size < 4)
1369 {
1370 png_push_save_buffer(png_ptr);
1371 return;
1372 }
1373
1374 png_push_crc_finish(png_ptr);
1375
1376#if defined(PNG_MAX_MALLOC_64K)
1377 if (png_ptr->skip_length)
1378 return;
1379#endif
1380
1381 key = png_ptr->current_text;
1382
1383 for (lang = key; *lang; lang++)
1384 /* empty loop */ ;
1385
1386 if (lang != key + png_ptr->current_text_size)
1387 lang++;
1388
1389 comp_flag = *lang++;
1390 lang++; /* skip comp_type, always zero */
1391
1392 for (lang_key = lang; *lang_key; lang_key++)
1393 /* empty loop */ ;
1394 lang_key++; /* skip NUL separator */
1395
1396 for (text = lang_key; *text; text++)
1397 /* empty loop */ ;
1398
1399 if (text != key + png_ptr->current_text_size)
1400 text++;
1401
1402 text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
1403 text_ptr->compression = comp_flag + 2;
1404 text_ptr->key = key;
1405 text_ptr->lang = lang;
1406 text_ptr->lang_key = lang_key;
1407 text_ptr->text = text;
1408 text_ptr->text_length = 0;
1409 text_ptr->itxt_length = png_strlen(text);
1410
1411 ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
1412
1413 png_ptr->current_text = NULL;
1414
1415 png_free(png_ptr, text_ptr);
1416 if (ret)
1417 png_warning(png_ptr, "Insufficient memory to store iTXt chunk.");
1418 }
1419}
1420#endif
1421
1422/* This function is called when we haven't found a handler for this
1423 * chunk. If there isn't a problem with the chunk itself (ie a bad chunk
1424 * name or a critical chunk), the chunk is (currently) silently ignored.
1425 */
1426void /* PRIVATE */
1427png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
1428 length)
1429{
1430 png_uint_32 skip=0;
1431 png_check_chunk_name(png_ptr, png_ptr->chunk_name);
1432
1433 if (!(png_ptr->chunk_name[0] & 0x20))
1434 {
1435#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
1436 if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1437 HANDLE_CHUNK_ALWAYS
1438#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1439 && png_ptr->read_user_chunk_fn == NULL
1440#endif
1441 )
1442#endif
1443 png_chunk_error(png_ptr, "unknown critical chunk");
1444
1445 /* to quiet compiler warnings about unused info_ptr */
1446 if (info_ptr == NULL)
1447 return;
1448 }
1449
1450#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
1451 if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
1452 {
1453 png_unknown_chunk chunk;
1454
1455#ifdef PNG_MAX_MALLOC_64K
1456 if (length > (png_uint_32)65535L)
1457 {
1458 png_warning(png_ptr, "unknown chunk too large to fit in memory");
1459 skip = length - (png_uint_32)65535L;
1460 length = (png_uint_32)65535L;
1461 }
1462#endif
1463
1464 png_strcpy((png_charp)chunk.name, (png_charp)png_ptr->chunk_name);
1465 chunk.data = (png_bytep)png_malloc(png_ptr, length);
1466 png_crc_read(png_ptr, chunk.data, length);
1467 chunk.size = length;
1468#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
1469 if(png_ptr->read_user_chunk_fn != NULL)
1470 {
1471 /* callback to user unknown chunk handler */
1472 if ((*(png_ptr->read_user_chunk_fn)) (png_ptr, &chunk) <= 0)
1473 {
1474 if (!(png_ptr->chunk_name[0] & 0x20))
1475 if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
1476 HANDLE_CHUNK_ALWAYS)
1477 png_chunk_error(png_ptr, "unknown critical chunk");
1478 }
1479 png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1);
1480 }
1481 else
1482#endif
1483 png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1);
1484 png_free(png_ptr, chunk.data);
1485 }
1486 else
1487#endif
1488 skip=length;
1489 png_push_crc_skip(png_ptr, skip);
1490}
1491
1492void /* PRIVATE */
1493png_push_have_info(png_structp png_ptr, png_infop info_ptr)
1494{
1495 if (png_ptr->info_fn != NULL)
1496 (*(png_ptr->info_fn))(png_ptr, info_ptr);
1497}
1498
1499void /* PRIVATE */
1500png_push_have_end(png_structp png_ptr, png_infop info_ptr)
1501{
1502 if (png_ptr->end_fn != NULL)
1503 (*(png_ptr->end_fn))(png_ptr, info_ptr);
1504}
1505
1506void /* PRIVATE */
1507png_push_have_row(png_structp png_ptr, png_bytep row)
1508{
1509 if (png_ptr->row_fn != NULL)
1510 (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
1511 (int)png_ptr->pass);
1512}
1513
1514void PNGAPI
1515png_progressive_combine_row (png_structp png_ptr,
1516 png_bytep old_row, png_bytep new_row)
1517{
1518#ifdef PNG_USE_LOCAL_ARRAYS
1519 const int FARDATA png_pass_dsp_mask[7] =
1520 {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
1521#endif
1522 if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */
1523 png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
1524}
1525
1526void PNGAPI
1527png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
1528 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1529 png_progressive_end_ptr end_fn)
1530{
1531 png_ptr->info_fn = info_fn;
1532 png_ptr->row_fn = row_fn;
1533 png_ptr->end_fn = end_fn;
1534
1535 png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
1536}
1537
1538png_voidp PNGAPI
1539png_get_progressive_ptr(png_structp png_ptr)
1540{
1541 return png_ptr->io_ptr;
1542}
1543#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
wxWidgets (Impactor)