source: trunk/src/3rdparty/libpng/png.c@ 1034

Last change on this file since 1034 was 846, checked in by Dmitry A. Kuminov, 14 years ago

trunk: Merged in qt 4.7.2 sources from branches/vendor/nokia/qt.
File size: 26.0 KB
Line 
1
2/* png.c - location for general purpose libpng functions
3 *
4 * Last changed in libpng 1.4.0 [January 3, 2010]
5 * Copyright (c) 1998-2010 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
8 *
9 * This code is released under the libpng license.
10 * For conditions of distribution and use, see the disclaimer
11 * and license in png.h
12 */
13
14#define PNG_NO_EXTERN
15#define PNG_NO_PEDANTIC_WARNINGS
16#include "png.h"
17#include "pngpriv.h"
18
19/* Generate a compiler error if there is an old png.h in the search path. */
20typedef version_1_4_0 Your_png_h_is_not_version_1_4_0;
21
22/* Version information for C files. This had better match the version
23 * string defined in png.h.
24 */
25
26/* Tells libpng that we have already handled the first "num_bytes" bytes
27 * of the PNG file signature. If the PNG data is embedded into another
28 * stream we can set num_bytes = 8 so that libpng will not attempt to read
29 * or write any of the magic bytes before it starts on the IHDR.
30 */
31
32#ifdef PNG_READ_SUPPORTED
33void PNGAPI
34png_set_sig_bytes(png_structp png_ptr, int num_bytes)
35{
36 png_debug(1, "in png_set_sig_bytes");
37
38 if (png_ptr == NULL)
39 return;
40
41 if (num_bytes > 8)
42 png_error(png_ptr, "Too many bytes for PNG signature");
43
44 png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
45}
46
47/* Checks whether the supplied bytes match the PNG signature. We allow
48 * checking less than the full 8-byte signature so that those apps that
49 * already read the first few bytes of a file to determine the file type
50 * can simply check the remaining bytes for extra assurance. Returns
51 * an integer less than, equal to, or greater than zero if sig is found,
52 * respectively, to be less than, to match, or be greater than the correct
53 * PNG signature (this is the same behaviour as strcmp, memcmp, etc).
54 */
55int PNGAPI
56png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
57{
58 png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
59 if (num_to_check > 8)
60 num_to_check = 8;
61 else if (num_to_check < 1)
62 return (-1);
63
64 if (start > 7)
65 return (-1);
66
67 if (start + num_to_check > 8)
68 num_to_check = 8 - start;
69
70 return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
71}
72
73#endif /* PNG_READ_SUPPORTED */
74
75#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
76/* Function to allocate memory for zlib and clear it to 0. */
77voidpf /* PRIVATE */
78png_zalloc(voidpf png_ptr, uInt items, uInt size)
79{
80 png_voidp ptr;
81 png_structp p=(png_structp)png_ptr;
82 png_uint_32 save_flags=p->flags;
83 png_alloc_size_t num_bytes;
84
85 if (png_ptr == NULL)
86 return (NULL);
87 if (items > PNG_UINT_32_MAX/size)
88 {
89 png_warning (p, "Potential overflow in png_zalloc()");
90 return (NULL);
91 }
92 num_bytes = (png_alloc_size_t)items * size;
93
94 p->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
95 ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
96 p->flags=save_flags;
97
98 return ((voidpf)ptr);
99}
100
101/* Function to free memory for zlib */
102void /* PRIVATE */
103png_zfree(voidpf png_ptr, voidpf ptr)
104{
105 png_free((png_structp)png_ptr, (png_voidp)ptr);
106}
107
108/* Reset the CRC variable to 32 bits of 1's. Care must be taken
109 * in case CRC is > 32 bits to leave the top bits 0.
110 */
111void /* PRIVATE */
112png_reset_crc(png_structp png_ptr)
113{
114 png_ptr->crc = crc32(0, Z_NULL, 0);
115}
116
117/* Calculate the CRC over a section of data. We can only pass as
118 * much data to this routine as the largest single buffer size. We
119 * also check that this data will actually be used before going to the
120 * trouble of calculating it.
121 */
122void /* PRIVATE */
123png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length)
124{
125 int need_crc = 1;
126
127 if (png_ptr->chunk_name[0] & 0x20) /* ancillary */
128 {
129 if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
130 (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
131 need_crc = 0;
132 }
133 else /* critical */
134 {
135 if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
136 need_crc = 0;
137 }
138
139 if (need_crc)
140 png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length);
141}
142
143/* Allocate the memory for an info_struct for the application. We don't
144 * really need the png_ptr, but it could potentially be useful in the
145 * future. This should be used in favour of malloc(png_sizeof(png_info))
146 * and png_info_init() so that applications that want to use a shared
147 * libpng don't have to be recompiled if png_info changes size.
148 */
149png_infop PNGAPI
150png_create_info_struct(png_structp png_ptr)
151{
152 png_infop info_ptr;
153
154 png_debug(1, "in png_create_info_struct");
155
156 if (png_ptr == NULL)
157 return (NULL);
158
159#ifdef PNG_USER_MEM_SUPPORTED
160 info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
161 png_ptr->malloc_fn, png_ptr->mem_ptr);
162#else
163 info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
164#endif
165 if (info_ptr != NULL)
166 png_info_init_3(&info_ptr, png_sizeof(png_info));
167
168 return (info_ptr);
169}
170
171/* This function frees the memory associated with a single info struct.
172 * Normally, one would use either png_destroy_read_struct() or
173 * png_destroy_write_struct() to free an info struct, but this may be
174 * useful for some applications.
175 */
176void PNGAPI
177png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
178{
179 png_infop info_ptr = NULL;
180
181 png_debug(1, "in png_destroy_info_struct");
182
183 if (png_ptr == NULL)
184 return;
185
186 if (info_ptr_ptr != NULL)
187 info_ptr = *info_ptr_ptr;
188
189 if (info_ptr != NULL)
190 {
191 png_info_destroy(png_ptr, info_ptr);
192
193#ifdef PNG_USER_MEM_SUPPORTED
194 png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn,
195 png_ptr->mem_ptr);
196#else
197 png_destroy_struct((png_voidp)info_ptr);
198#endif
199 *info_ptr_ptr = NULL;
200 }
201}
202
203/* Initialize the info structure. This is now an internal function (0.89)
204 * and applications using it are urged to use png_create_info_struct()
205 * instead.
206 */
207
208void PNGAPI
209png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size)
210{
211 png_infop info_ptr = *ptr_ptr;
212
213 png_debug(1, "in png_info_init_3");
214
215 if (info_ptr == NULL)
216 return;
217
218 if (png_sizeof(png_info) > png_info_struct_size)
219 {
220 png_destroy_struct(info_ptr);
221 info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
222 *ptr_ptr = info_ptr;
223 }
224
225 /* Set everything to 0 */
226 png_memset(info_ptr, 0, png_sizeof(png_info));
227}
228
229void PNGAPI
230png_data_freer(png_structp png_ptr, png_infop info_ptr,
231 int freer, png_uint_32 mask)
232{
233 png_debug(1, "in png_data_freer");
234
235 if (png_ptr == NULL || info_ptr == NULL)
236 return;
237
238 if (freer == PNG_DESTROY_WILL_FREE_DATA)
239 info_ptr->free_me |= mask;
240 else if (freer == PNG_USER_WILL_FREE_DATA)
241 info_ptr->free_me &= ~mask;
242 else
243 png_warning(png_ptr,
244 "Unknown freer parameter in png_data_freer");
245}
246
247void PNGAPI
248png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
249 int num)
250{
251 png_debug(1, "in png_free_data");
252
253 if (png_ptr == NULL || info_ptr == NULL)
254 return;
255
256#ifdef PNG_TEXT_SUPPORTED
257 /* Free text item num or (if num == -1) all text items */
258 if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
259 {
260 if (num != -1)
261 {
262 if (info_ptr->text && info_ptr->text[num].key)
263 {
264 png_free(png_ptr, info_ptr->text[num].key);
265 info_ptr->text[num].key = NULL;
266 }
267 }
268 else
269 {
270 int i;
271 for (i = 0; i < info_ptr->num_text; i++)
272 png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
273 png_free(png_ptr, info_ptr->text);
274 info_ptr->text = NULL;
275 info_ptr->num_text=0;
276 }
277 }
278#endif
279
280#ifdef PNG_tRNS_SUPPORTED
281 /* Free any tRNS entry */
282 if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
283 {
284 png_free(png_ptr, info_ptr->trans_alpha);
285 info_ptr->trans_alpha = NULL;
286 info_ptr->valid &= ~PNG_INFO_tRNS;
287 }
288#endif
289
290#ifdef PNG_sCAL_SUPPORTED
291 /* Free any sCAL entry */
292 if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
293 {
294#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
295 png_free(png_ptr, info_ptr->scal_s_width);
296 png_free(png_ptr, info_ptr->scal_s_height);
297 info_ptr->scal_s_width = NULL;
298 info_ptr->scal_s_height = NULL;
299#endif
300 info_ptr->valid &= ~PNG_INFO_sCAL;
301 }
302#endif
303
304#ifdef PNG_pCAL_SUPPORTED
305 /* Free any pCAL entry */
306 if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
307 {
308 png_free(png_ptr, info_ptr->pcal_purpose);
309 png_free(png_ptr, info_ptr->pcal_units);
310 info_ptr->pcal_purpose = NULL;
311 info_ptr->pcal_units = NULL;
312 if (info_ptr->pcal_params != NULL)
313 {
314 int i;
315 for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
316 {
317 png_free(png_ptr, info_ptr->pcal_params[i]);
318 info_ptr->pcal_params[i] = NULL;
319 }
320 png_free(png_ptr, info_ptr->pcal_params);
321 info_ptr->pcal_params = NULL;
322 }
323 info_ptr->valid &= ~PNG_INFO_pCAL;
324 }
325#endif
326
327#ifdef PNG_iCCP_SUPPORTED
328 /* Free any iCCP entry */
329 if ((mask & PNG_FREE_ICCP) & info_ptr->free_me)
330 {
331 png_free(png_ptr, info_ptr->iccp_name);
332 png_free(png_ptr, info_ptr->iccp_profile);
333 info_ptr->iccp_name = NULL;
334 info_ptr->iccp_profile = NULL;
335 info_ptr->valid &= ~PNG_INFO_iCCP;
336 }
337#endif
338
339#ifdef PNG_sPLT_SUPPORTED
340 /* Free a given sPLT entry, or (if num == -1) all sPLT entries */
341 if ((mask & PNG_FREE_SPLT) & info_ptr->free_me)
342 {
343 if (num != -1)
344 {
345 if (info_ptr->splt_palettes)
346 {
347 png_free(png_ptr, info_ptr->splt_palettes[num].name);
348 png_free(png_ptr, info_ptr->splt_palettes[num].entries);
349 info_ptr->splt_palettes[num].name = NULL;
350 info_ptr->splt_palettes[num].entries = NULL;
351 }
352 }
353 else
354 {
355 if (info_ptr->splt_palettes_num)
356 {
357 int i;
358 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
359 png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i);
360
361 png_free(png_ptr, info_ptr->splt_palettes);
362 info_ptr->splt_palettes = NULL;
363 info_ptr->splt_palettes_num = 0;
364 }
365 info_ptr->valid &= ~PNG_INFO_sPLT;
366 }
367 }
368#endif
369
370#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
371 if (png_ptr->unknown_chunk.data)
372 {
373 png_free(png_ptr, png_ptr->unknown_chunk.data);
374 png_ptr->unknown_chunk.data = NULL;
375 }
376
377 if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
378 {
379 if (num != -1)
380 {
381 if (info_ptr->unknown_chunks)
382 {
383 png_free(png_ptr, info_ptr->unknown_chunks[num].data);
384 info_ptr->unknown_chunks[num].data = NULL;
385 }
386 }
387 else
388 {
389 int i;
390
391 if (info_ptr->unknown_chunks_num)
392 {
393 for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++)
394 png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
395
396 png_free(png_ptr, info_ptr->unknown_chunks);
397 info_ptr->unknown_chunks = NULL;
398 info_ptr->unknown_chunks_num = 0;
399 }
400 }
401 }
402#endif
403
404#ifdef PNG_hIST_SUPPORTED
405 /* Free any hIST entry */
406 if ((mask & PNG_FREE_HIST) & info_ptr->free_me)
407 {
408 png_free(png_ptr, info_ptr->hist);
409 info_ptr->hist = NULL;
410 info_ptr->valid &= ~PNG_INFO_hIST;
411 }
412#endif
413
414 /* Free any PLTE entry that was internally allocated */
415 if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
416 {
417 png_zfree(png_ptr, info_ptr->palette);
418 info_ptr->palette = NULL;
419 info_ptr->valid &= ~PNG_INFO_PLTE;
420 info_ptr->num_palette = 0;
421 }
422
423#ifdef PNG_INFO_IMAGE_SUPPORTED
424 /* Free any image bits attached to the info structure */
425 if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
426 {
427 if (info_ptr->row_pointers)
428 {
429 int row;
430 for (row = 0; row < (int)info_ptr->height; row++)
431 {
432 png_free(png_ptr, info_ptr->row_pointers[row]);
433 info_ptr->row_pointers[row] = NULL;
434 }
435 png_free(png_ptr, info_ptr->row_pointers);
436 info_ptr->row_pointers = NULL;
437 }
438 info_ptr->valid &= ~PNG_INFO_IDAT;
439 }
440#endif
441
442 if (num == -1)
443 info_ptr->free_me &= ~mask;
444 else
445 info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
446}
447
448/* This is an internal routine to free any memory that the info struct is
449 * pointing to before re-using it or freeing the struct itself. Recall
450 * that png_free() checks for NULL pointers for us.
451 */
452void /* PRIVATE */
453png_info_destroy(png_structp png_ptr, png_infop info_ptr)
454{
455 png_debug(1, "in png_info_destroy");
456
457 png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
458
459#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
460 if (png_ptr->num_chunk_list)
461 {
462 png_free(png_ptr, png_ptr->chunk_list);
463 png_ptr->chunk_list = NULL;
464 png_ptr->num_chunk_list = 0;
465 }
466#endif
467
468 png_info_init_3(&info_ptr, png_sizeof(png_info));
469}
470#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
471
472/* This function returns a pointer to the io_ptr associated with the user
473 * functions. The application should free any memory associated with this
474 * pointer before png_write_destroy() or png_read_destroy() are called.
475 */
476png_voidp PNGAPI
477png_get_io_ptr(png_structp png_ptr)
478{
479 if (png_ptr == NULL)
480 return (NULL);
481 return (png_ptr->io_ptr);
482}
483
484#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
485#ifdef PNG_STDIO_SUPPORTED
486/* Initialize the default input/output functions for the PNG file. If you
487 * use your own read or write routines, you can call either png_set_read_fn()
488 * or png_set_write_fn() instead of png_init_io(). If you have defined
489 * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't
490 * necessarily available.
491 */
492void PNGAPI
493png_init_io(png_structp png_ptr, png_FILE_p fp)
494{
495 png_debug(1, "in png_init_io");
496
497 if (png_ptr == NULL)
498 return;
499
500 png_ptr->io_ptr = (png_voidp)fp;
501}
502#endif
503
504#ifdef PNG_TIME_RFC1123_SUPPORTED
505/* Convert the supplied time into an RFC 1123 string suitable for use in
506 * a "Creation Time" or other text-based time string.
507 */
508png_charp PNGAPI
509png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
510{
511 static PNG_CONST char short_months[12][4] =
512 {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
513 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
514
515 if (png_ptr == NULL)
516 return (NULL);
517 if (png_ptr->time_buffer == NULL)
518 {
519 png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
520 png_sizeof(char)));
521 }
522
523#ifdef USE_FAR_KEYWORD
524 {
525 char near_time_buf[29];
526 png_snprintf6(near_time_buf, 29, "%d %s %d %02d:%02d:%02d +0000",
527 ptime->day % 32, short_months[(ptime->month - 1) % 12],
528 ptime->year, ptime->hour % 24, ptime->minute % 60,
529 ptime->second % 61);
530 png_memcpy(png_ptr->time_buffer, near_time_buf,
531 29*png_sizeof(char));
532 }
533#else
534 png_snprintf6(png_ptr->time_buffer, 29, "%d %s %d %02d:%02d:%02d +0000",
535 ptime->day % 32, short_months[(ptime->month - 1) % 12],
536 ptime->year, ptime->hour % 24, ptime->minute % 60,
537 ptime->second % 61);
538#endif
539 return ((png_charp)png_ptr->time_buffer);
540}
541#endif /* PNG_TIME_RFC1123_SUPPORTED */
542
543#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
544
545png_charp PNGAPI
546png_get_copyright(png_structp png_ptr)
547{
548 png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */
549#ifdef PNG_STRING_COPYRIGHT
550 return PNG_STRING_COPYRIGHT
551#else
552#ifdef __STDC__
553 return ((png_charp) PNG_STRING_NEWLINE \
554 "libpng version 1.4.0 - January 3, 2010" PNG_STRING_NEWLINE \
555 "Copyright (c) 1998-2010 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
556 "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
557 "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
558 PNG_STRING_NEWLINE);
559#else
560 return ((png_charp) "libpng version 1.4.0 - January 3, 2010\
561 Copyright (c) 1998-2010 Glenn Randers-Pehrson\
562 Copyright (c) 1996-1997 Andreas Dilger\
563 Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.");
564#endif
565#endif
566}
567
568/* The following return the library version as a short string in the
569 * format 1.0.0 through 99.99.99zz. To get the version of *.h files
570 * used with your application, print out PNG_LIBPNG_VER_STRING, which
571 * is defined in png.h.
572 * Note: now there is no difference between png_get_libpng_ver() and
573 * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard,
574 * it is guaranteed that png.c uses the correct version of png.h.
575 */
576png_charp PNGAPI
577png_get_libpng_ver(png_structp png_ptr)
578{
579 /* Version of *.c files used when building libpng */
580 png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */
581 return ((png_charp) PNG_LIBPNG_VER_STRING);
582}
583
584png_charp PNGAPI
585png_get_header_ver(png_structp png_ptr)
586{
587 /* Version of *.h files used when building libpng */
588 png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */
589 return ((png_charp) PNG_LIBPNG_VER_STRING);
590}
591
592png_charp PNGAPI
593png_get_header_version(png_structp png_ptr)
594{
595 /* Returns longer string containing both version and date */
596 png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */
597#ifdef __STDC__
598 return ((png_charp) PNG_HEADER_VERSION_STRING
599#ifndef PNG_READ_SUPPORTED
600 " (NO READ SUPPORT)"
601#endif
602 PNG_STRING_NEWLINE);
603#else
604 return ((png_charp) PNG_HEADER_VERSION_STRING);
605#endif
606}
607
608#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
609#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
610int PNGAPI
611png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
612{
613 /* Check chunk_name and return "keep" value if it's on the list, else 0 */
614 int i;
615 png_bytep p;
616 if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list<=0)
617 return 0;
618 p = png_ptr->chunk_list + png_ptr->num_chunk_list*5 - 5;
619 for (i = png_ptr->num_chunk_list; i; i--, p -= 5)
620 if (!png_memcmp(chunk_name, p, 4))
621 return ((int)*(p + 4));
622 return 0;
623}
624#endif
625
626/* This function, added to libpng-1.0.6g, is untested. */
627int PNGAPI
628png_reset_zstream(png_structp png_ptr)
629{
630 if (png_ptr == NULL)
631 return Z_STREAM_ERROR;
632 return (inflateReset(&png_ptr->zstream));
633}
634#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
635
636/* This function was added to libpng-1.0.7 */
637png_uint_32 PNGAPI
638png_access_version_number(void)
639{
640 /* Version of *.c files used when building libpng */
641 return((png_uint_32) PNG_LIBPNG_VER);
642}
643
644
645
646#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
647#ifdef PNG_SIZE_T
648/* Added at libpng version 1.2.6 */
649 PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
650png_size_t PNGAPI
651png_convert_size(size_t size)
652{
653 if (size > (png_size_t)-1)
654 PNG_ABORT(); /* We haven't got access to png_ptr, so no png_error() */
655 return ((png_size_t)size);
656}
657#endif /* PNG_SIZE_T */
658
659/* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */
660#ifdef PNG_cHRM_SUPPORTED
661#ifdef PNG_CHECK_cHRM_SUPPORTED
662
663/*
664 * Multiply two 32-bit numbers, V1 and V2, using 32-bit
665 * arithmetic, to produce a 64 bit result in the HI/LO words.
666 *
667 * A B
668 * x C D
669 * ------
670 * AD || BD
671 * AC || CB || 0
672 *
673 * where A and B are the high and low 16-bit words of V1,
674 * C and D are the 16-bit words of V2, AD is the product of
675 * A and D, and X || Y is (X << 16) + Y.
676*/
677
678void /* PRIVATE */
679png_64bit_product (long v1, long v2, unsigned long *hi_product,
680 unsigned long *lo_product)
681{
682 int a, b, c, d;
683 long lo, hi, x, y;
684
685 a = (v1 >> 16) & 0xffff;
686 b = v1 & 0xffff;
687 c = (v2 >> 16) & 0xffff;
688 d = v2 & 0xffff;
689
690 lo = b * d; /* BD */
691 x = a * d + c * b; /* AD + CB */
692 y = ((lo >> 16) & 0xffff) + x;
693
694 lo = (lo & 0xffff) | ((y & 0xffff) << 16);
695 hi = (y >> 16) & 0xffff;
696
697 hi += a * c; /* AC */
698
699 *hi_product = (unsigned long)hi;
700 *lo_product = (unsigned long)lo;
701}
702
703int /* PRIVATE */
704png_check_cHRM_fixed(png_structp png_ptr,
705 png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
706 png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
707 png_fixed_point blue_x, png_fixed_point blue_y)
708{
709 int ret = 1;
710 unsigned long xy_hi,xy_lo,yx_hi,yx_lo;
711
712 png_debug(1, "in function png_check_cHRM_fixed");
713
714 if (png_ptr == NULL)
715 return 0;
716
717 if (white_x < 0 || white_y <= 0 ||
718 red_x < 0 || red_y < 0 ||
719 green_x < 0 || green_y < 0 ||
720 blue_x < 0 || blue_y < 0)
721 {
722 png_warning(png_ptr,
723 "Ignoring attempt to set negative chromaticity value");
724 ret = 0;
725 }
726 if (white_x > (png_fixed_point) PNG_UINT_31_MAX ||
727 white_y > (png_fixed_point) PNG_UINT_31_MAX ||
728 red_x > (png_fixed_point) PNG_UINT_31_MAX ||
729 red_y > (png_fixed_point) PNG_UINT_31_MAX ||
730 green_x > (png_fixed_point) PNG_UINT_31_MAX ||
731 green_y > (png_fixed_point) PNG_UINT_31_MAX ||
732 blue_x > (png_fixed_point) PNG_UINT_31_MAX ||
733 blue_y > (png_fixed_point) PNG_UINT_31_MAX )
734 {
735 png_warning(png_ptr,
736 "Ignoring attempt to set chromaticity value exceeding 21474.83");
737 ret = 0;
738 }
739 if (white_x > 100000L - white_y)
740 {
741 png_warning(png_ptr, "Invalid cHRM white point");
742 ret = 0;
743 }
744 if (red_x > 100000L - red_y)
745 {
746 png_warning(png_ptr, "Invalid cHRM red point");
747 ret = 0;
748 }
749 if (green_x > 100000L - green_y)
750 {
751 png_warning(png_ptr, "Invalid cHRM green point");
752 ret = 0;
753 }
754 if (blue_x > 100000L - blue_y)
755 {
756 png_warning(png_ptr, "Invalid cHRM blue point");
757 ret = 0;
758 }
759
760 png_64bit_product(green_x - red_x, blue_y - red_y, &xy_hi, &xy_lo);
761 png_64bit_product(green_y - red_y, blue_x - red_x, &yx_hi, &yx_lo);
762
763 if (xy_hi == yx_hi && xy_lo == yx_lo)
764 {
765 png_warning(png_ptr,
766 "Ignoring attempt to set cHRM RGB triangle with zero area");
767 ret = 0;
768 }
769
770 return ret;
771}
772#endif /* PNG_CHECK_cHRM_SUPPORTED */
773#endif /* PNG_cHRM_SUPPORTED */
774
775void /* PRIVATE */
776png_check_IHDR(png_structp png_ptr,
777 png_uint_32 width, png_uint_32 height, int bit_depth,
778 int color_type, int interlace_type, int compression_type,
779 int filter_type)
780{
781 int error = 0;
782
783 /* Check for width and height valid values */
784 if (width == 0)
785 {
786 png_warning(png_ptr, "Image width is zero in IHDR");
787 error = 1;
788 }
789
790 if (height == 0)
791 {
792 png_warning(png_ptr, "Image height is zero in IHDR");
793 error = 1;
794 }
795
796#ifdef PNG_SET_USER_LIMITS_SUPPORTED
797 if (width > png_ptr->user_width_max || width > PNG_USER_WIDTH_MAX)
798#else
799 if (width > PNG_USER_WIDTH_MAX)
800#endif
801 {
802 png_warning(png_ptr, "Image width exceeds user limit in IHDR");
803 error = 1;
804 }
805
806#ifdef PNG_SET_USER_LIMITS_SUPPORTED
807 if (height > png_ptr->user_height_max || height > PNG_USER_HEIGHT_MAX)
808#else
809 if (height > PNG_USER_HEIGHT_MAX)
810#endif
811 {
812 png_warning(png_ptr, "Image height exceeds user limit in IHDR");
813 error = 1;
814 }
815
816 if (width > PNG_UINT_31_MAX)
817 {
818 png_warning(png_ptr, "Invalid image width in IHDR");
819 error = 1;
820 }
821
822 if ( height > PNG_UINT_31_MAX)
823 {
824 png_warning(png_ptr, "Invalid image height in IHDR");
825 error = 1;
826 }
827
828 if ( width > (PNG_UINT_32_MAX
829 >> 3) /* 8-byte RGBA pixels */
830 - 64 /* bigrowbuf hack */
831 - 1 /* filter byte */
832 - 7*8 /* rounding of width to multiple of 8 pixels */
833 - 8) /* extra max_pixel_depth pad */
834 png_warning(png_ptr, "Width is too large for libpng to process pixels");
835
836 /* Check other values */
837 if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
838 bit_depth != 8 && bit_depth != 16)
839 {
840 png_warning(png_ptr, "Invalid bit depth in IHDR");
841 error = 1;
842 }
843
844 if (color_type < 0 || color_type == 1 ||
845 color_type == 5 || color_type > 6)
846 {
847 png_warning(png_ptr, "Invalid color type in IHDR");
848 error = 1;
849 }
850
851 if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) ||
852 ((color_type == PNG_COLOR_TYPE_RGB ||
853 color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
854 color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
855 {
856 png_warning(png_ptr, "Invalid color type/bit depth combination in IHDR");
857 error = 1;
858 }
859
860 if (interlace_type >= PNG_INTERLACE_LAST)
861 {
862 png_warning(png_ptr, "Unknown interlace method in IHDR");
863 error = 1;
864 }
865
866 if (compression_type != PNG_COMPRESSION_TYPE_BASE)
867 {
868 png_warning(png_ptr, "Unknown compression method in IHDR");
869 error = 1;
870 }
871
872#ifdef PNG_MNG_FEATURES_SUPPORTED
873 /* Accept filter_method 64 (intrapixel differencing) only if
874 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
875 * 2. Libpng did not read a PNG signature (this filter_method is only
876 * used in PNG datastreams that are embedded in MNG datastreams) and
877 * 3. The application called png_permit_mng_features with a mask that
878 * included PNG_FLAG_MNG_FILTER_64 and
879 * 4. The filter_method is 64 and
880 * 5. The color_type is RGB or RGBA
881 */
882 if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) &&
883 png_ptr->mng_features_permitted)
884 png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
885
886 if (filter_type != PNG_FILTER_TYPE_BASE)
887 {
888 if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
889 (filter_type == PNG_INTRAPIXEL_DIFFERENCING) &&
890 ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) &&
891 (color_type == PNG_COLOR_TYPE_RGB ||
892 color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
893 {
894 png_warning(png_ptr, "Unknown filter method in IHDR");
895 error = 1;
896 }
897
898 if (png_ptr->mode & PNG_HAVE_PNG_SIGNATURE)
899 {
900 png_warning(png_ptr, "Invalid filter method in IHDR");
901 error = 1;
902 }
903 }
904
905#else
906 if (filter_type != PNG_FILTER_TYPE_BASE)
907 {
908 png_warning(png_ptr, "Unknown filter method in IHDR");
909 error = 1;
910 }
911#endif
912
913 if (error == 1)
914 png_error(png_ptr, "Invalid IHDR data");
915}
916#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
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