1 /* PDFlib GmbH cvsid: $Id: pngread.c,v 1.9.6.1 2009/06/03 08:53:24 rjs Exp $ */
2
3 /* pngread.c - read a PNG file
4 *
5 * Last changed in libpng 1.2.35 [February 14, 2009]
6 * For conditions of distribution and use, see copyright notice in png.h
7 * Copyright (c) 1998-2009 Glenn Randers-Pehrson
8 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
9 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
10 *
11 * This file contains routines that an application calls directly to
12 * read a PNG file or stream.
13 */
14
15 #define PNG_INTERNAL
16 #include "png.h"
17 #if defined(PNG_READ_SUPPORTED)
18
19 /* PDFlib GmbH */
20 #if defined(__ia64__) && defined (__linux__)
21 #define PDFLIB_ALIGN16
22 #endif
23
24 /* Create a PNG structure for reading, and allocate any memory needed. */
25 png_structp PNGAPI
png_create_read_struct(png_const_charp user_png_ver,png_voidp error_ptr,png_error_ptr error_fn,png_error_ptr warn_fn)26 png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr,
27 png_error_ptr error_fn, png_error_ptr warn_fn)
28 {
29
30 #ifdef PNG_USER_MEM_SUPPORTED
31 return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
32 warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
33 }
34
35 /* Alternate create PNG structure for reading, and allocate any memory needed.
36 */
37 png_structp PNGAPI
png_create_read_struct_2(png_const_charp user_png_ver,png_voidp error_ptr,png_error_ptr error_fn,png_error_ptr warn_fn,png_voidp mem_ptr,png_malloc_ptr malloc_fn,png_free_ptr free_fn)38 png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
39 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
40 png_malloc_ptr malloc_fn, png_free_ptr free_fn)
41 {
42 #endif /* PNG_USER_MEM_SUPPORTED */
43
44 #ifdef PNG_SETJMP_SUPPORTED
45 volatile
46 #endif
47 png_structp png_ptr;
48
49 #ifdef PNG_SETJMP_SUPPORTED
50 #if defined(USE_FAR_KEYWORD) || defined (PDFLIB_ALIGN16)
51 jmp_buf jmpbuf;
52 #endif
53 #endif
54
55 int i;
56
57 png_debug(1, "in png_create_read_struct");
58 #ifdef PNG_USER_MEM_SUPPORTED
59 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
60 (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
61 #else
62 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
63 #endif
64 if (png_ptr == NULL)
65 return (NULL);
66
67 /* added at libpng-1.2.6 */
68 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
69 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
70 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
71 #endif
72
73 #ifdef PNG_SETJMP_SUPPORTED
74 #if defined (USE_FAR_KEYWORD) || defined (PDFLIB_ALIGN16)
75 if (setjmp(jmpbuf))
76 #else
77 if (setjmp(png_ptr->jmpbuf))
78 #endif
79 {
80 png_free(png_ptr, png_ptr->zbuf);
81 png_ptr->zbuf = NULL;
82 #ifdef PNG_USER_MEM_SUPPORTED
83 png_destroy_struct_2((png_voidp)png_ptr,
84 (png_free_ptr)free_fn, (png_voidp)mem_ptr);
85 #else
86 png_destroy_struct((png_voidp)png_ptr);
87 #endif
88 return (NULL);
89 }
90 #if defined (USE_FAR_KEYWORD) || defined (PDFLIB_ALIGN16)
91 png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
92 #endif
93 #endif
94
95 #ifdef PNG_USER_MEM_SUPPORTED
96 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
97 #endif
98
99 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
100
101 if (user_png_ver)
102 {
103 i = 0;
104 do
105 {
106 if (user_png_ver[i] != png_libpng_ver[i])
107 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
108 } while (png_libpng_ver[i++]);
109 }
110 else
111 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
112
113
114 if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
115 {
116 /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
117 * we must recompile any applications that use any older library version.
118 * For versions after libpng 1.0, we will be compatible, so we need
119 * only check the first digit.
120 */
121 if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
122 (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
123 (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
124 {
125 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
126 char msg[80];
127 if (user_png_ver)
128 {
129 png_snprintf(msg, 80,
130 "Application was compiled with png.h from libpng-%.20s",
131 user_png_ver);
132 png_warning(png_ptr, msg);
133 }
134 png_snprintf(msg, 80,
135 "Application is running with png.c from libpng-%.20s",
136 png_libpng_ver);
137 png_warning(png_ptr, msg);
138 #endif
139 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
140 png_ptr->flags = 0;
141 #endif
142 png_error(png_ptr,
143 "Incompatible libpng version in application and library");
144 }
145 }
146
147 /* initialize zbuf - compression buffer */
148 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
149 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
150 (png_uint_32)png_ptr->zbuf_size);
151 png_ptr->zstream.zalloc = png_zalloc;
152 png_ptr->zstream.zfree = png_zfree;
153 png_ptr->zstream.opaque = (voidpf)png_ptr;
154
155 switch (inflateInit(&png_ptr->zstream))
156 {
157 case Z_OK: /* Do nothing */ break;
158 case Z_MEM_ERROR:
159 case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory error"); break;
160 case Z_VERSION_ERROR: png_error(png_ptr, "zlib version error"); break;
161 default: png_error(png_ptr, "Unknown zlib error");
162 }
163
164 png_ptr->zstream.next_out = png_ptr->zbuf;
165 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
166
167 png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
168
169 #ifdef PNG_SETJMP_SUPPORTED
170 /* Applications that neglect to set up their own setjmp() and then encounter
171 a png_error() will longjmp here. Since the jmpbuf is then meaningless we
172 abort instead of returning. */
173 #if defined (USE_FAR_KEYWORD) || defined (PDFLIB_ALIGN16)
174 if (setjmp(jmpbuf))
175 PNG_ABORT();
176 png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
177 #else
178 if (setjmp(png_ptr->jmpbuf))
179 PNG_ABORT();
180 #endif
181 #endif
182 return (png_ptr);
183 }
184
185 #if defined(PNG_1_0_X) || defined(PNG_1_2_X)
186 /* Initialize PNG structure for reading, and allocate any memory needed.
187 This interface is deprecated in favour of the png_create_read_struct(),
188 and it will disappear as of libpng-1.3.0. */
189 /* PDFlib GmbH: the messy hack below would fool our pdf_ prefixes. */
190 #if 0
191 #undef png_read_init
192 void PNGAPI
193 png_read_init(png_structp png_ptr)
194 {
195 /* We only come here via pre-1.0.7-compiled applications */
196 png_read_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
197 }
198 #endif
199
200 void PNGAPI
png_read_init_2(png_structp png_ptr,png_const_charp user_png_ver,png_size_t png_struct_size,png_size_t png_info_size)201 png_read_init_2(png_structp png_ptr, png_const_charp user_png_ver,
202 png_size_t png_struct_size, png_size_t png_info_size)
203 {
204 /* We only come here via pre-1.0.12-compiled applications */
205 if (png_ptr == NULL) return;
206 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
207 if (png_sizeof(png_struct) > png_struct_size ||
208 png_sizeof(png_info) > png_info_size)
209 {
210 char msg[80];
211 png_ptr->warning_fn = NULL;
212 if (user_png_ver)
213 {
214 png_snprintf(msg, 80,
215 "Application was compiled with png.h from libpng-%.20s",
216 user_png_ver);
217 png_warning(png_ptr, msg);
218 }
219 png_snprintf(msg, 80,
220 "Application is running with png.c from libpng-%.20s",
221 png_libpng_ver);
222 png_warning(png_ptr, msg);
223 }
224 #endif
225 if (png_sizeof(png_struct) > png_struct_size)
226 {
227 png_ptr->error_fn = NULL;
228 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
229 png_ptr->flags = 0;
230 #endif
231 png_error(png_ptr,
232 "The png struct allocated by the application for reading is too small.");
233 }
234 if (png_sizeof(png_info) > png_info_size)
235 {
236 png_ptr->error_fn = NULL;
237 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
238 png_ptr->flags = 0;
239 #endif
240 png_error(png_ptr,
241 "The info struct allocated by application for reading is too small.");
242 }
243 png_read_init_3(&png_ptr, user_png_ver, png_struct_size);
244 }
245 #endif /* PNG_1_0_X || PNG_1_2_X */
246
247 void PNGAPI
png_read_init_3(png_structpp ptr_ptr,png_const_charp user_png_ver,png_size_t png_struct_size)248 png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
249 png_size_t png_struct_size)
250 {
251 #ifdef PNG_SETJMP_SUPPORTED
252 jmp_buf tmp_jmp; /* to save current jump buffer */
253 #endif
254
255 int i = 0;
256
257 png_structp png_ptr=*ptr_ptr;
258
259 if (png_ptr == NULL) return;
260
261 do
262 {
263 if (user_png_ver[i] != png_libpng_ver[i])
264 {
265 #ifdef PNG_LEGACY_SUPPORTED
266 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
267 #else
268 png_ptr->warning_fn = NULL;
269 png_warning(png_ptr,
270 "Application uses deprecated png_read_init() and should be recompiled.");
271 break;
272 #endif
273 }
274 } while (png_libpng_ver[i++]);
275
276 png_debug(1, "in png_read_init_3");
277
278 #ifdef PNG_SETJMP_SUPPORTED
279 /* save jump buffer and error functions */
280 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
281 #endif
282
283 if (png_sizeof(png_struct) > png_struct_size)
284 {
285 png_destroy_struct(png_ptr);
286 *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
287 png_ptr = *ptr_ptr;
288 }
289
290 /* reset all variables to 0 */
291 png_memset(png_ptr, 0, png_sizeof(png_struct));
292
293 #ifdef PNG_SETJMP_SUPPORTED
294 /* restore jump buffer */
295 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
296 #endif
297
298 /* added at libpng-1.2.6 */
299 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
300 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
301 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
302 #endif
303
304 /* initialize zbuf - compression buffer */
305 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
306 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
307 (png_uint_32)png_ptr->zbuf_size);
308 png_ptr->zstream.zalloc = png_zalloc;
309 png_ptr->zstream.zfree = png_zfree;
310 png_ptr->zstream.opaque = (voidpf)png_ptr;
311
312 switch (inflateInit(&png_ptr->zstream))
313 {
314 case Z_OK: /* Do nothing */ break;
315 case Z_MEM_ERROR:
316 case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory"); break;
317 case Z_VERSION_ERROR: png_error(png_ptr, "zlib version"); break;
318 default: png_error(png_ptr, "Unknown zlib error");
319 }
320
321 png_ptr->zstream.next_out = png_ptr->zbuf;
322 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
323
324 png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
325 }
326
327 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
328 /* Read the information before the actual image data. This has been
329 * changed in v0.90 to allow reading a file that already has the magic
330 * bytes read from the stream. You can tell libpng how many bytes have
331 * been read from the beginning of the stream (up to the maximum of 8)
332 * via png_set_sig_bytes(), and we will only check the remaining bytes
333 * here. The application can then have access to the signature bytes we
334 * read if it is determined that this isn't a valid PNG file.
335 */
336 void PNGAPI
png_read_info(png_structp png_ptr,png_infop info_ptr)337 png_read_info(png_structp png_ptr, png_infop info_ptr)
338 {
339 if (png_ptr == NULL || info_ptr == NULL) return;
340 png_debug(1, "in png_read_info");
341 /* If we haven't checked all of the PNG signature bytes, do so now. */
342 if (png_ptr->sig_bytes < 8)
343 {
344 png_size_t num_checked = png_ptr->sig_bytes,
345 num_to_check = 8 - num_checked;
346
347 png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
348 png_ptr->sig_bytes = 8;
349
350 if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
351 {
352 if (num_checked < 4 &&
353 png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
354 png_error(png_ptr, "Not a PNG file");
355 else
356 png_error(png_ptr, "PNG file corrupted by ASCII conversion");
357 }
358 if (num_checked < 3)
359 png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
360 }
361
362 for (;;)
363 {
364 #ifdef PNG_USE_LOCAL_ARRAYS
365 PNG_CONST PNG_IHDR;
366 PNG_CONST PNG_IDAT;
367 PNG_CONST PNG_IEND;
368 PNG_CONST PNG_PLTE;
369 #if defined(PNG_READ_bKGD_SUPPORTED)
370 PNG_CONST PNG_bKGD;
371 #endif
372 #if defined(PNG_READ_cHRM_SUPPORTED)
373 PNG_CONST PNG_cHRM;
374 #endif
375 #if defined(PNG_READ_gAMA_SUPPORTED)
376 PNG_CONST PNG_gAMA;
377 #endif
378 #if defined(PNG_READ_hIST_SUPPORTED)
379 PNG_CONST PNG_hIST;
380 #endif
381 #if defined(PNG_READ_iCCP_SUPPORTED)
382 PNG_CONST PNG_iCCP;
383 #endif
384 #if defined(PNG_READ_iTXt_SUPPORTED)
385 PNG_CONST PNG_iTXt;
386 #endif
387 #if defined(PNG_READ_oFFs_SUPPORTED)
388 PNG_CONST PNG_oFFs;
389 #endif
390 #if defined(PNG_READ_pCAL_SUPPORTED)
391 PNG_CONST PNG_pCAL;
392 #endif
393 #if defined(PNG_READ_pHYs_SUPPORTED)
394 PNG_CONST PNG_pHYs;
395 #endif
396 #if defined(PNG_READ_sBIT_SUPPORTED)
397 PNG_CONST PNG_sBIT;
398 #endif
399 #if defined(PNG_READ_sCAL_SUPPORTED)
400 PNG_CONST PNG_sCAL;
401 #endif
402 #if defined(PNG_READ_sPLT_SUPPORTED)
403 PNG_CONST PNG_sPLT;
404 #endif
405 #if defined(PNG_READ_sRGB_SUPPORTED)
406 PNG_CONST PNG_sRGB;
407 #endif
408 #if defined(PNG_READ_tEXt_SUPPORTED)
409 PNG_CONST PNG_tEXt;
410 #endif
411 #if defined(PNG_READ_tIME_SUPPORTED)
412 PNG_CONST PNG_tIME;
413 #endif
414 #if defined(PNG_READ_tRNS_SUPPORTED)
415 PNG_CONST PNG_tRNS;
416 #endif
417 #if defined(PNG_READ_zTXt_SUPPORTED)
418 PNG_CONST PNG_zTXt;
419 #endif
420 #endif /* PNG_USE_LOCAL_ARRAYS */
421 png_uint_32 length = png_read_chunk_header(png_ptr);
422 PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
423
424 /* This should be a binary subdivision search or a hash for
425 * matching the chunk name rather than a linear search.
426 */
427 if (!png_memcmp(chunk_name, png_IDAT, 4))
428 if (png_ptr->mode & PNG_AFTER_IDAT)
429 png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
430
431 if (!png_memcmp(chunk_name, png_IHDR, 4))
432 png_handle_IHDR(png_ptr, info_ptr, length);
433 else if (!png_memcmp(chunk_name, png_IEND, 4))
434 png_handle_IEND(png_ptr, info_ptr, length);
435 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
436 else if (png_handle_as_unknown(png_ptr, chunk_name))
437 {
438 if (!png_memcmp(chunk_name, png_IDAT, 4))
439 png_ptr->mode |= PNG_HAVE_IDAT;
440 png_handle_unknown(png_ptr, info_ptr, length);
441 if (!png_memcmp(chunk_name, png_PLTE, 4))
442 png_ptr->mode |= PNG_HAVE_PLTE;
443 else if (!png_memcmp(chunk_name, png_IDAT, 4))
444 {
445 if (!(png_ptr->mode & PNG_HAVE_IHDR))
446 png_error(png_ptr, "Missing IHDR before IDAT");
447 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
448 !(png_ptr->mode & PNG_HAVE_PLTE))
449 png_error(png_ptr, "Missing PLTE before IDAT");
450 break;
451 }
452 }
453 #endif
454 else if (!png_memcmp(chunk_name, png_PLTE, 4))
455 png_handle_PLTE(png_ptr, info_ptr, length);
456 else if (!png_memcmp(chunk_name, png_IDAT, 4))
457 {
458 if (!(png_ptr->mode & PNG_HAVE_IHDR))
459 png_error(png_ptr, "Missing IHDR before IDAT");
460 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
461 !(png_ptr->mode & PNG_HAVE_PLTE))
462 png_error(png_ptr, "Missing PLTE before IDAT");
463
464 png_ptr->idat_size = length;
465 png_ptr->mode |= PNG_HAVE_IDAT;
466 break;
467 }
468 #if defined(PNG_READ_bKGD_SUPPORTED)
469 else if (!png_memcmp(chunk_name, png_bKGD, 4))
470 png_handle_bKGD(png_ptr, info_ptr, length);
471 #endif
472 #if defined(PNG_READ_cHRM_SUPPORTED)
473 else if (!png_memcmp(chunk_name, png_cHRM, 4))
474 png_handle_cHRM(png_ptr, info_ptr, length);
475 #endif
476 #if defined(PNG_READ_gAMA_SUPPORTED)
477 else if (!png_memcmp(chunk_name, png_gAMA, 4))
478 png_handle_gAMA(png_ptr, info_ptr, length);
479 #endif
480 #if defined(PNG_READ_hIST_SUPPORTED)
481 else if (!png_memcmp(chunk_name, png_hIST, 4))
482 png_handle_hIST(png_ptr, info_ptr, length);
483 #endif
484 #if defined(PNG_READ_oFFs_SUPPORTED)
485 else if (!png_memcmp(chunk_name, png_oFFs, 4))
486 png_handle_oFFs(png_ptr, info_ptr, length);
487 #endif
488 #if defined(PNG_READ_pCAL_SUPPORTED)
489 else if (!png_memcmp(chunk_name, png_pCAL, 4))
490 png_handle_pCAL(png_ptr, info_ptr, length);
491 #endif
492 #if defined(PNG_READ_sCAL_SUPPORTED)
493 else if (!png_memcmp(chunk_name, png_sCAL, 4))
494 png_handle_sCAL(png_ptr, info_ptr, length);
495 #endif
496 #if defined(PNG_READ_pHYs_SUPPORTED)
497 else if (!png_memcmp(chunk_name, png_pHYs, 4))
498 png_handle_pHYs(png_ptr, info_ptr, length);
499 #endif
500 #if defined(PNG_READ_sBIT_SUPPORTED)
501 else if (!png_memcmp(chunk_name, png_sBIT, 4))
502 png_handle_sBIT(png_ptr, info_ptr, length);
503 #endif
504 #if defined(PNG_READ_sRGB_SUPPORTED)
505 else if (!png_memcmp(chunk_name, png_sRGB, 4))
506 png_handle_sRGB(png_ptr, info_ptr, length);
507 #endif
508 #if defined(PNG_READ_iCCP_SUPPORTED)
509 else if (!png_memcmp(chunk_name, png_iCCP, 4))
510 png_handle_iCCP(png_ptr, info_ptr, length);
511 #endif
512 #if defined(PNG_READ_sPLT_SUPPORTED)
513 else if (!png_memcmp(chunk_name, png_sPLT, 4))
514 png_handle_sPLT(png_ptr, info_ptr, length);
515 #endif
516 #if defined(PNG_READ_tEXt_SUPPORTED)
517 else if (!png_memcmp(chunk_name, png_tEXt, 4))
518 png_handle_tEXt(png_ptr, info_ptr, length);
519 #endif
520 #if defined(PNG_READ_tIME_SUPPORTED)
521 else if (!png_memcmp(chunk_name, png_tIME, 4))
522 png_handle_tIME(png_ptr, info_ptr, length);
523 #endif
524 #if defined(PNG_READ_tRNS_SUPPORTED)
525 else if (!png_memcmp(chunk_name, png_tRNS, 4))
526 png_handle_tRNS(png_ptr, info_ptr, length);
527 #endif
528 #if defined(PNG_READ_zTXt_SUPPORTED)
529 else if (!png_memcmp(chunk_name, png_zTXt, 4))
530 png_handle_zTXt(png_ptr, info_ptr, length);
531 #endif
532 #if defined(PNG_READ_iTXt_SUPPORTED)
533 else if (!png_memcmp(chunk_name, png_iTXt, 4))
534 png_handle_iTXt(png_ptr, info_ptr, length);
535 #endif
536 else
537 png_handle_unknown(png_ptr, info_ptr, length);
538 }
539 }
540 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
541
542 /* optional call to update the users info_ptr structure */
543 void PNGAPI
png_read_update_info(png_structp png_ptr,png_infop info_ptr)544 png_read_update_info(png_structp png_ptr, png_infop info_ptr)
545 {
546 png_debug(1, "in png_read_update_info");
547 if (png_ptr == NULL) return;
548 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
549 png_read_start_row(png_ptr);
550 else
551 png_warning(png_ptr,
552 "Ignoring extra png_read_update_info() call; row buffer not reallocated");
553 png_read_transform_info(png_ptr, info_ptr);
554 }
555
556 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
557 /* Initialize palette, background, etc, after transformations
558 * are set, but before any reading takes place. This allows
559 * the user to obtain a gamma-corrected palette, for example.
560 * If the user doesn't call this, we will do it ourselves.
561 */
562 void PNGAPI
png_start_read_image(png_structp png_ptr)563 png_start_read_image(png_structp png_ptr)
564 {
565 png_debug(1, "in png_start_read_image");
566 if (png_ptr == NULL) return;
567 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
568 png_read_start_row(png_ptr);
569 }
570 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
571
572 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
573 void PNGAPI
png_read_row(png_structp png_ptr,png_bytep row,png_bytep dsp_row)574 png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
575 {
576 #ifdef PNG_USE_LOCAL_ARRAYS
577 PNG_CONST PNG_IDAT;
578 PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
579 0xff};
580 PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
581 #endif
582 int ret;
583 if (png_ptr == NULL) return;
584 png_debug2(1, "in png_read_row (row %lu, pass %d)",
585 png_ptr->row_number, png_ptr->pass);
586 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
587 png_read_start_row(png_ptr);
588 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
589 {
590 /* check for transforms that have been set but were defined out */
591 #if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
592 if (png_ptr->transformations & PNG_INVERT_MONO)
593 png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined.");
594 #endif
595 #if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
596 if (png_ptr->transformations & PNG_FILLER)
597 png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined.");
598 #endif
599 #if defined(PNG_WRITE_PACKSWAP_SUPPORTED) \
600 && !defined(PNG_READ_PACKSWAP_SUPPORTED)
601 if (png_ptr->transformations & PNG_PACKSWAP)
602 png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined.");
603 #endif
604 #if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
605 if (png_ptr->transformations & PNG_PACK)
606 png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined.");
607 #endif
608 #if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
609 if (png_ptr->transformations & PNG_SHIFT)
610 png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined.");
611 #endif
612 #if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
613 if (png_ptr->transformations & PNG_BGR)
614 png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined.");
615 #endif
616 #if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
617 if (png_ptr->transformations & PNG_SWAP_BYTES)
618 png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined.");
619 #endif
620 }
621
622 #if defined(PNG_READ_INTERLACING_SUPPORTED)
623 /* if interlaced and we do not need a new row, combine row and return */
624 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
625 {
626 switch (png_ptr->pass)
627 {
628 case 0:
629 if (png_ptr->row_number & 0x07)
630 {
631 if (dsp_row != NULL)
632 png_combine_row(png_ptr, dsp_row,
633 png_pass_dsp_mask[png_ptr->pass]);
634 png_read_finish_row(png_ptr);
635 return;
636 }
637 break;
638 case 1:
639 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
640 {
641 if (dsp_row != NULL)
642 png_combine_row(png_ptr, dsp_row,
643 png_pass_dsp_mask[png_ptr->pass]);
644 png_read_finish_row(png_ptr);
645 return;
646 }
647 break;
648 case 2:
649 if ((png_ptr->row_number & 0x07) != 4)
650 {
651 if (dsp_row != NULL && (png_ptr->row_number & 4))
652 png_combine_row(png_ptr, dsp_row,
653 png_pass_dsp_mask[png_ptr->pass]);
654 png_read_finish_row(png_ptr);
655 return;
656 }
657 break;
658 case 3:
659 if ((png_ptr->row_number & 3) || png_ptr->width < 3)
660 {
661 if (dsp_row != NULL)
662 png_combine_row(png_ptr, dsp_row,
663 png_pass_dsp_mask[png_ptr->pass]);
664 png_read_finish_row(png_ptr);
665 return;
666 }
667 break;
668 case 4:
669 if ((png_ptr->row_number & 3) != 2)
670 {
671 if (dsp_row != NULL && (png_ptr->row_number & 2))
672 png_combine_row(png_ptr, dsp_row,
673 png_pass_dsp_mask[png_ptr->pass]);
674 png_read_finish_row(png_ptr);
675 return;
676 }
677 break;
678 case 5:
679 if ((png_ptr->row_number & 1) || png_ptr->width < 2)
680 {
681 if (dsp_row != NULL)
682 png_combine_row(png_ptr, dsp_row,
683 png_pass_dsp_mask[png_ptr->pass]);
684 png_read_finish_row(png_ptr);
685 return;
686 }
687 break;
688 case 6:
689 if (!(png_ptr->row_number & 1))
690 {
691 png_read_finish_row(png_ptr);
692 return;
693 }
694 break;
695 }
696 }
697 #endif
698
699 if (!(png_ptr->mode & PNG_HAVE_IDAT))
700 png_error(png_ptr, "Invalid attempt to read row data");
701
702 png_ptr->zstream.next_out = png_ptr->row_buf;
703 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
704 do
705 {
706 if (!(png_ptr->zstream.avail_in))
707 {
708 while (!png_ptr->idat_size)
709 {
710 png_crc_finish(png_ptr, 0);
711
712 png_ptr->idat_size = png_read_chunk_header(png_ptr);
713 if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
714 png_error(png_ptr, "Not enough image data");
715 }
716 png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
717 png_ptr->zstream.next_in = png_ptr->zbuf;
718 if (png_ptr->zbuf_size > png_ptr->idat_size)
719 png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
720 png_crc_read(png_ptr, png_ptr->zbuf,
721 (png_size_t)png_ptr->zstream.avail_in);
722 png_ptr->idat_size -= png_ptr->zstream.avail_in;
723 }
724 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
725 if (ret == Z_STREAM_END)
726 {
727 if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
728 png_ptr->idat_size)
729 png_error(png_ptr, "Extra compressed data");
730 png_ptr->mode |= PNG_AFTER_IDAT;
731 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
732 break;
733 }
734 if (ret != Z_OK)
735 png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
736 "Decompression error");
737
738 } while (png_ptr->zstream.avail_out);
739
740 png_ptr->row_info.color_type = png_ptr->color_type;
741 png_ptr->row_info.width = png_ptr->iwidth;
742 png_ptr->row_info.channels = png_ptr->channels;
743 png_ptr->row_info.bit_depth = png_ptr->bit_depth;
744 png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
745 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
746 png_ptr->row_info.width);
747
748 if (png_ptr->row_buf[0])
749 png_read_filter_row(png_ptr, &(png_ptr->row_info),
750 png_ptr->row_buf + 1, png_ptr->prev_row + 1,
751 (int)(png_ptr->row_buf[0]));
752
753 png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
754 png_ptr->rowbytes + 1);
755
756 #if defined(PNG_MNG_FEATURES_SUPPORTED)
757 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
758 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
759 {
760 /* Intrapixel differencing */
761 png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
762 }
763 #endif
764
765
766 if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
767 png_do_read_transformations(png_ptr);
768
769 #if defined(PNG_READ_INTERLACING_SUPPORTED)
770 /* blow up interlaced rows to full size */
771 if (png_ptr->interlaced &&
772 (png_ptr->transformations & PNG_INTERLACE))
773 {
774 if (png_ptr->pass < 6)
775 /* old interface (pre-1.0.9):
776 png_do_read_interlace(&(png_ptr->row_info),
777 png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
778 */
779 png_do_read_interlace(png_ptr);
780
781 if (dsp_row != NULL)
782 png_combine_row(png_ptr, dsp_row,
783 png_pass_dsp_mask[png_ptr->pass]);
784 if (row != NULL)
785 png_combine_row(png_ptr, row,
786 png_pass_mask[png_ptr->pass]);
787 }
788 else
789 #endif
790 {
791 if (row != NULL)
792 png_combine_row(png_ptr, row, 0xff);
793 if (dsp_row != NULL)
794 png_combine_row(png_ptr, dsp_row, 0xff);
795 }
796 png_read_finish_row(png_ptr);
797
798 if (png_ptr->read_row_fn != NULL)
799 (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
800 }
801 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
802
803 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
804 /* Read one or more rows of image data. If the image is interlaced,
805 * and png_set_interlace_handling() has been called, the rows need to
806 * contain the contents of the rows from the previous pass. If the
807 * image has alpha or transparency, and png_handle_alpha()[*] has been
808 * called, the rows contents must be initialized to the contents of the
809 * screen.
810 *
811 * "row" holds the actual image, and pixels are placed in it
812 * as they arrive. If the image is displayed after each pass, it will
813 * appear to "sparkle" in. "display_row" can be used to display a
814 * "chunky" progressive image, with finer detail added as it becomes
815 * available. If you do not want this "chunky" display, you may pass
816 * NULL for display_row. If you do not want the sparkle display, and
817 * you have not called png_handle_alpha(), you may pass NULL for rows.
818 * If you have called png_handle_alpha(), and the image has either an
819 * alpha channel or a transparency chunk, you must provide a buffer for
820 * rows. In this case, you do not have to provide a display_row buffer
821 * also, but you may. If the image is not interlaced, or if you have
822 * not called png_set_interlace_handling(), the display_row buffer will
823 * be ignored, so pass NULL to it.
824 *
825 * [*] png_handle_alpha() does not exist yet, as of this version of libpng
826 */
827
828 void PNGAPI
png_read_rows(png_structp png_ptr,png_bytepp row,png_bytepp display_row,png_uint_32 num_rows)829 png_read_rows(png_structp png_ptr, png_bytepp row,
830 png_bytepp display_row, png_uint_32 num_rows)
831 {
832 png_uint_32 i;
833 png_bytepp rp;
834 png_bytepp dp;
835
836 png_debug(1, "in png_read_rows");
837 if (png_ptr == NULL) return;
838 rp = row;
839 dp = display_row;
840 if (rp != NULL && dp != NULL)
841 for (i = 0; i < num_rows; i++)
842 {
843 png_bytep rptr = *rp++;
844 png_bytep dptr = *dp++;
845
846 png_read_row(png_ptr, rptr, dptr);
847 }
848 else if (rp != NULL)
849 for (i = 0; i < num_rows; i++)
850 {
851 png_bytep rptr = *rp;
852 png_read_row(png_ptr, rptr, png_bytep_NULL);
853 rp++;
854 }
855 else if (dp != NULL)
856 for (i = 0; i < num_rows; i++)
857 {
858 png_bytep dptr = *dp;
859 png_read_row(png_ptr, png_bytep_NULL, dptr);
860 dp++;
861 }
862 }
863 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
864
865 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
866 /* Read the entire image. If the image has an alpha channel or a tRNS
867 * chunk, and you have called png_handle_alpha()[*], you will need to
868 * initialize the image to the current image that PNG will be overlaying.
869 * We set the num_rows again here, in case it was incorrectly set in
870 * png_read_start_row() by a call to png_read_update_info() or
871 * png_start_read_image() if png_set_interlace_handling() wasn't called
872 * prior to either of these functions like it should have been. You can
873 * only call this function once. If you desire to have an image for
874 * each pass of a interlaced image, use png_read_rows() instead.
875 *
876 * [*] png_handle_alpha() does not exist yet, as of this version of libpng
877 */
878 void PNGAPI
png_read_image(png_structp png_ptr,png_bytepp image)879 png_read_image(png_structp png_ptr, png_bytepp image)
880 {
881 png_uint_32 i, image_height;
882 int pass, j;
883 png_bytepp rp;
884
885 png_debug(1, "in png_read_image");
886 if (png_ptr == NULL) return;
887
888 #ifdef PNG_READ_INTERLACING_SUPPORTED
889 pass = png_set_interlace_handling(png_ptr);
890 #else
891 if (png_ptr->interlaced)
892 png_error(png_ptr,
893 "Cannot read interlaced image -- interlace handler disabled.");
894 pass = 1;
895 #endif
896
897
898 image_height=png_ptr->height;
899 png_ptr->num_rows = image_height; /* Make sure this is set correctly */
900
901 for (j = 0; j < pass; j++)
902 {
903 rp = image;
904 for (i = 0; i < image_height; i++)
905 {
906 png_read_row(png_ptr, *rp, png_bytep_NULL);
907 rp++;
908 }
909 }
910 }
911 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
912
913 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
914 /* Read the end of the PNG file. Will not read past the end of the
915 * file, will verify the end is accurate, and will read any comments
916 * or time information at the end of the file, if info is not NULL.
917 */
918 void PNGAPI
png_read_end(png_structp png_ptr,png_infop info_ptr)919 png_read_end(png_structp png_ptr, png_infop info_ptr)
920 {
921 png_debug(1, "in png_read_end");
922 if (png_ptr == NULL) return;
923 png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
924
925 do
926 {
927 #ifdef PNG_USE_LOCAL_ARRAYS
928 PNG_CONST PNG_IHDR;
929 PNG_CONST PNG_IDAT;
930 PNG_CONST PNG_IEND;
931 PNG_CONST PNG_PLTE;
932 #if defined(PNG_READ_bKGD_SUPPORTED)
933 PNG_CONST PNG_bKGD;
934 #endif
935 #if defined(PNG_READ_cHRM_SUPPORTED)
936 PNG_CONST PNG_cHRM;
937 #endif
938 #if defined(PNG_READ_gAMA_SUPPORTED)
939 PNG_CONST PNG_gAMA;
940 #endif
941 #if defined(PNG_READ_hIST_SUPPORTED)
942 PNG_CONST PNG_hIST;
943 #endif
944 #if defined(PNG_READ_iCCP_SUPPORTED)
945 PNG_CONST PNG_iCCP;
946 #endif
947 #if defined(PNG_READ_iTXt_SUPPORTED)
948 PNG_CONST PNG_iTXt;
949 #endif
950 #if defined(PNG_READ_oFFs_SUPPORTED)
951 PNG_CONST PNG_oFFs;
952 #endif
953 #if defined(PNG_READ_pCAL_SUPPORTED)
954 PNG_CONST PNG_pCAL;
955 #endif
956 #if defined(PNG_READ_pHYs_SUPPORTED)
957 PNG_CONST PNG_pHYs;
958 #endif
959 #if defined(PNG_READ_sBIT_SUPPORTED)
960 PNG_CONST PNG_sBIT;
961 #endif
962 #if defined(PNG_READ_sCAL_SUPPORTED)
963 PNG_CONST PNG_sCAL;
964 #endif
965 #if defined(PNG_READ_sPLT_SUPPORTED)
966 PNG_CONST PNG_sPLT;
967 #endif
968 #if defined(PNG_READ_sRGB_SUPPORTED)
969 PNG_CONST PNG_sRGB;
970 #endif
971 #if defined(PNG_READ_tEXt_SUPPORTED)
972 PNG_CONST PNG_tEXt;
973 #endif
974 #if defined(PNG_READ_tIME_SUPPORTED)
975 PNG_CONST PNG_tIME;
976 #endif
977 #if defined(PNG_READ_tRNS_SUPPORTED)
978 PNG_CONST PNG_tRNS;
979 #endif
980 #if defined(PNG_READ_zTXt_SUPPORTED)
981 PNG_CONST PNG_zTXt;
982 #endif
983 #endif /* PNG_USE_LOCAL_ARRAYS */
984 png_uint_32 length = png_read_chunk_header(png_ptr);
985 PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
986
987 if (!png_memcmp(chunk_name, png_IHDR, 4))
988 png_handle_IHDR(png_ptr, info_ptr, length);
989 else if (!png_memcmp(chunk_name, png_IEND, 4))
990 png_handle_IEND(png_ptr, info_ptr, length);
991 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
992 else if (png_handle_as_unknown(png_ptr, chunk_name))
993 {
994 if (!png_memcmp(chunk_name, png_IDAT, 4))
995 {
996 if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
997 png_error(png_ptr, "Too many IDAT's found");
998 }
999 png_handle_unknown(png_ptr, info_ptr, length);
1000 if (!png_memcmp(chunk_name, png_PLTE, 4))
1001 png_ptr->mode |= PNG_HAVE_PLTE;
1002 }
1003 #endif
1004 else if (!png_memcmp(chunk_name, png_IDAT, 4))
1005 {
1006 /* Zero length IDATs are legal after the last IDAT has been
1007 * read, but not after other chunks have been read.
1008 */
1009 if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
1010 png_error(png_ptr, "Too many IDAT's found");
1011 png_crc_finish(png_ptr, length);
1012 }
1013 else if (!png_memcmp(chunk_name, png_PLTE, 4))
1014 png_handle_PLTE(png_ptr, info_ptr, length);
1015 #if defined(PNG_READ_bKGD_SUPPORTED)
1016 else if (!png_memcmp(chunk_name, png_bKGD, 4))
1017 png_handle_bKGD(png_ptr, info_ptr, length);
1018 #endif
1019 #if defined(PNG_READ_cHRM_SUPPORTED)
1020 else if (!png_memcmp(chunk_name, png_cHRM, 4))
1021 png_handle_cHRM(png_ptr, info_ptr, length);
1022 #endif
1023 #if defined(PNG_READ_gAMA_SUPPORTED)
1024 else if (!png_memcmp(chunk_name, png_gAMA, 4))
1025 png_handle_gAMA(png_ptr, info_ptr, length);
1026 #endif
1027 #if defined(PNG_READ_hIST_SUPPORTED)
1028 else if (!png_memcmp(chunk_name, png_hIST, 4))
1029 png_handle_hIST(png_ptr, info_ptr, length);
1030 #endif
1031 #if defined(PNG_READ_oFFs_SUPPORTED)
1032 else if (!png_memcmp(chunk_name, png_oFFs, 4))
1033 png_handle_oFFs(png_ptr, info_ptr, length);
1034 #endif
1035 #if defined(PNG_READ_pCAL_SUPPORTED)
1036 else if (!png_memcmp(chunk_name, png_pCAL, 4))
1037 png_handle_pCAL(png_ptr, info_ptr, length);
1038 #endif
1039 #if defined(PNG_READ_sCAL_SUPPORTED)
1040 else if (!png_memcmp(chunk_name, png_sCAL, 4))
1041 png_handle_sCAL(png_ptr, info_ptr, length);
1042 #endif
1043 #if defined(PNG_READ_pHYs_SUPPORTED)
1044 else if (!png_memcmp(chunk_name, png_pHYs, 4))
1045 png_handle_pHYs(png_ptr, info_ptr, length);
1046 #endif
1047 #if defined(PNG_READ_sBIT_SUPPORTED)
1048 else if (!png_memcmp(chunk_name, png_sBIT, 4))
1049 png_handle_sBIT(png_ptr, info_ptr, length);
1050 #endif
1051 #if defined(PNG_READ_sRGB_SUPPORTED)
1052 else if (!png_memcmp(chunk_name, png_sRGB, 4))
1053 png_handle_sRGB(png_ptr, info_ptr, length);
1054 #endif
1055 #if defined(PNG_READ_iCCP_SUPPORTED)
1056 else if (!png_memcmp(chunk_name, png_iCCP, 4))
1057 png_handle_iCCP(png_ptr, info_ptr, length);
1058 #endif
1059 #if defined(PNG_READ_sPLT_SUPPORTED)
1060 else if (!png_memcmp(chunk_name, png_sPLT, 4))
1061 png_handle_sPLT(png_ptr, info_ptr, length);
1062 #endif
1063 #if defined(PNG_READ_tEXt_SUPPORTED)
1064 else if (!png_memcmp(chunk_name, png_tEXt, 4))
1065 png_handle_tEXt(png_ptr, info_ptr, length);
1066 #endif
1067 #if defined(PNG_READ_tIME_SUPPORTED)
1068 else if (!png_memcmp(chunk_name, png_tIME, 4))
1069 png_handle_tIME(png_ptr, info_ptr, length);
1070 #endif
1071 #if defined(PNG_READ_tRNS_SUPPORTED)
1072 else if (!png_memcmp(chunk_name, png_tRNS, 4))
1073 png_handle_tRNS(png_ptr, info_ptr, length);
1074 #endif
1075 #if defined(PNG_READ_zTXt_SUPPORTED)
1076 else if (!png_memcmp(chunk_name, png_zTXt, 4))
1077 png_handle_zTXt(png_ptr, info_ptr, length);
1078 #endif
1079 #if defined(PNG_READ_iTXt_SUPPORTED)
1080 else if (!png_memcmp(chunk_name, png_iTXt, 4))
1081 png_handle_iTXt(png_ptr, info_ptr, length);
1082 #endif
1083 else
1084 png_handle_unknown(png_ptr, info_ptr, length);
1085 } while (!(png_ptr->mode & PNG_HAVE_IEND));
1086 }
1087 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
1088
1089 /* free all memory used by the read */
1090 void PNGAPI
png_destroy_read_struct(png_structpp png_ptr_ptr,png_infopp info_ptr_ptr,png_infopp end_info_ptr_ptr)1091 png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
1092 png_infopp end_info_ptr_ptr)
1093 {
1094 png_structp png_ptr = NULL;
1095 png_infop info_ptr = NULL, end_info_ptr = NULL;
1096 #ifdef PNG_USER_MEM_SUPPORTED
1097 png_free_ptr free_fn = NULL;
1098 png_voidp mem_ptr = NULL;
1099 #endif
1100
1101 png_debug(1, "in png_destroy_read_struct");
1102 if (png_ptr_ptr != NULL)
1103 png_ptr = *png_ptr_ptr;
1104 if (png_ptr == NULL)
1105 return;
1106
1107 #ifdef PNG_USER_MEM_SUPPORTED
1108 free_fn = png_ptr->free_fn;
1109 mem_ptr = png_ptr->mem_ptr;
1110 #endif
1111
1112 if (info_ptr_ptr != NULL)
1113 info_ptr = *info_ptr_ptr;
1114
1115 if (end_info_ptr_ptr != NULL)
1116 end_info_ptr = *end_info_ptr_ptr;
1117
1118 png_read_destroy(png_ptr, info_ptr, end_info_ptr);
1119
1120 if (info_ptr != NULL)
1121 {
1122 #if defined(PNG_TEXT_SUPPORTED)
1123 png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1);
1124 #endif
1125
1126 #ifdef PNG_USER_MEM_SUPPORTED
1127 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1128 (png_voidp)mem_ptr);
1129 #else
1130 png_destroy_struct((png_voidp)info_ptr);
1131 #endif
1132 *info_ptr_ptr = NULL;
1133 }
1134
1135 if (end_info_ptr != NULL)
1136 {
1137 #if defined(PNG_READ_TEXT_SUPPORTED)
1138 png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1);
1139 #endif
1140 #ifdef PNG_USER_MEM_SUPPORTED
1141 png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn,
1142 (png_voidp)mem_ptr);
1143 #else
1144 png_destroy_struct((png_voidp)end_info_ptr);
1145 #endif
1146 *end_info_ptr_ptr = NULL;
1147 }
1148
1149 if (png_ptr != NULL)
1150 {
1151 #ifdef PNG_USER_MEM_SUPPORTED
1152 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1153 (png_voidp)mem_ptr);
1154 #else
1155 png_destroy_struct((png_voidp)png_ptr);
1156 #endif
1157 *png_ptr_ptr = NULL;
1158 }
1159 }
1160
1161 /* free all memory used by the read (old method) */
1162 void /* PRIVATE */
png_read_destroy(png_structp png_ptr,png_infop info_ptr,png_infop end_info_ptr)1163 png_read_destroy(png_structp png_ptr, png_infop info_ptr,
1164 png_infop end_info_ptr)
1165 {
1166 #ifdef PNG_SETJMP_SUPPORTED
1167 jmp_buf tmp_jmp;
1168 #endif
1169 png_error_ptr error_fn;
1170 png_error_ptr warning_fn;
1171 png_voidp error_ptr;
1172 #ifdef PNG_USER_MEM_SUPPORTED
1173 png_free_ptr free_fn;
1174 png_voidp mem_ptr; /* PDFlib GmbH: was missing */
1175 #endif
1176
1177 png_debug(1, "in png_read_destroy");
1178 if (info_ptr != NULL)
1179 png_info_destroy(png_ptr, info_ptr);
1180
1181 if (end_info_ptr != NULL)
1182 png_info_destroy(png_ptr, end_info_ptr);
1183
1184 png_free(png_ptr, png_ptr->zbuf);
1185 png_free(png_ptr, png_ptr->big_row_buf);
1186 png_free(png_ptr, png_ptr->prev_row);
1187 png_free(png_ptr, png_ptr->chunkdata);
1188 #if defined(PNG_READ_DITHER_SUPPORTED)
1189 png_free(png_ptr, png_ptr->palette_lookup);
1190 png_free(png_ptr, png_ptr->dither_index);
1191 #endif
1192 #if defined(PNG_READ_GAMMA_SUPPORTED)
1193 png_free(png_ptr, png_ptr->gamma_table);
1194 #endif
1195 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
1196 png_free(png_ptr, png_ptr->gamma_from_1);
1197 png_free(png_ptr, png_ptr->gamma_to_1);
1198 #endif
1199 #ifdef PNG_FREE_ME_SUPPORTED
1200 if (png_ptr->free_me & PNG_FREE_PLTE)
1201 png_zfree(png_ptr, png_ptr->palette);
1202 png_ptr->free_me &= ~PNG_FREE_PLTE;
1203 #else
1204 if (png_ptr->flags & PNG_FLAG_FREE_PLTE)
1205 png_zfree(png_ptr, png_ptr->palette);
1206 png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
1207 #endif
1208 #if defined(PNG_tRNS_SUPPORTED) || \
1209 defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1210 #ifdef PNG_FREE_ME_SUPPORTED
1211 if (png_ptr->free_me & PNG_FREE_TRNS)
1212 png_free(png_ptr, png_ptr->trans);
1213 png_ptr->free_me &= ~PNG_FREE_TRNS;
1214 #else
1215 if (png_ptr->flags & PNG_FLAG_FREE_TRNS)
1216 png_free(png_ptr, png_ptr->trans);
1217 png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
1218 #endif
1219 #endif
1220 #if defined(PNG_READ_hIST_SUPPORTED)
1221 #ifdef PNG_FREE_ME_SUPPORTED
1222 if (png_ptr->free_me & PNG_FREE_HIST)
1223 png_free(png_ptr, png_ptr->hist);
1224 png_ptr->free_me &= ~PNG_FREE_HIST;
1225 #else
1226 if (png_ptr->flags & PNG_FLAG_FREE_HIST)
1227 png_free(png_ptr, png_ptr->hist);
1228 png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
1229 #endif
1230 #endif
1231 #if defined(PNG_READ_GAMMA_SUPPORTED)
1232 if (png_ptr->gamma_16_table != NULL)
1233 {
1234 int i;
1235 int istop = (1 << (8 - png_ptr->gamma_shift));
1236 for (i = 0; i < istop; i++)
1237 {
1238 png_free(png_ptr, png_ptr->gamma_16_table[i]);
1239 }
1240 png_free(png_ptr, png_ptr->gamma_16_table);
1241 }
1242 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
1243 if (png_ptr->gamma_16_from_1 != NULL)
1244 {
1245 int i;
1246 int istop = (1 << (8 - png_ptr->gamma_shift));
1247 for (i = 0; i < istop; i++)
1248 {
1249 png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
1250 }
1251 png_free(png_ptr, png_ptr->gamma_16_from_1);
1252 }
1253 if (png_ptr->gamma_16_to_1 != NULL)
1254 {
1255 int i;
1256 int istop = (1 << (8 - png_ptr->gamma_shift));
1257 for (i = 0; i < istop; i++)
1258 {
1259 png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
1260 }
1261 png_free(png_ptr, png_ptr->gamma_16_to_1);
1262 }
1263 #endif
1264 #endif
1265 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1266 png_free(png_ptr, png_ptr->time_buffer);
1267 #endif
1268
1269 inflateEnd(&png_ptr->zstream);
1270 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1271 png_free(png_ptr, png_ptr->save_buffer);
1272 #endif
1273
1274 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1275 #ifdef PNG_TEXT_SUPPORTED
1276 png_free(png_ptr, png_ptr->current_text);
1277 #endif /* PNG_TEXT_SUPPORTED */
1278 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1279
1280 /* Save the important info out of the png_struct, in case it is
1281 * being used again.
1282 */
1283 #ifdef PNG_SETJMP_SUPPORTED
1284 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
1285 #endif
1286
1287 error_fn = png_ptr->error_fn;
1288 warning_fn = png_ptr->warning_fn;
1289 error_ptr = png_ptr->error_ptr;
1290 #ifdef PNG_USER_MEM_SUPPORTED
1291 free_fn = png_ptr->free_fn;
1292 mem_ptr = png_ptr->mem_ptr; /* PDFlib GmbH: was missing */
1293 #endif
1294
1295 png_memset(png_ptr, 0, png_sizeof(png_struct));
1296
1297 png_ptr->error_fn = error_fn;
1298 png_ptr->warning_fn = warning_fn;
1299 png_ptr->error_ptr = error_ptr;
1300 #ifdef PNG_USER_MEM_SUPPORTED
1301 png_ptr->free_fn = free_fn;
1302 png_ptr->mem_ptr = mem_ptr; /* PDFlib GmbH: was missing */
1303 #endif
1304
1305 #ifdef PNG_SETJMP_SUPPORTED
1306 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
1307 #endif
1308
1309 }
1310
1311 void PNGAPI
png_set_read_status_fn(png_structp png_ptr,png_read_status_ptr read_row_fn)1312 png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
1313 {
1314 if (png_ptr == NULL) return;
1315 png_ptr->read_row_fn = read_row_fn;
1316 }
1317
1318
1319 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1320 #if defined(PNG_INFO_IMAGE_SUPPORTED)
1321 void PNGAPI
png_read_png(png_structp png_ptr,png_infop info_ptr,int transforms,voidp params)1322 png_read_png(png_structp png_ptr, png_infop info_ptr,
1323 int transforms,
1324 voidp params)
1325 {
1326 int row;
1327
1328 if (png_ptr == NULL) return;
1329 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
1330 /* invert the alpha channel from opacity to transparency
1331 */
1332 if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1333 png_set_invert_alpha(png_ptr);
1334 #endif
1335
1336 /* png_read_info() gives us all of the information from the
1337 * PNG file before the first IDAT (image data chunk).
1338 */
1339 png_read_info(png_ptr, info_ptr);
1340 if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
1341 png_error(png_ptr, "Image is too high to process with png_read_png()");
1342
1343 /* -------------- image transformations start here ------------------- */
1344
1345 #if defined(PNG_READ_16_TO_8_SUPPORTED)
1346 /* tell libpng to strip 16 bit/color files down to 8 bits per color
1347 */
1348 if (transforms & PNG_TRANSFORM_STRIP_16)
1349 png_set_strip_16(png_ptr);
1350 #endif
1351
1352 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1353 /* Strip alpha bytes from the input data without combining with
1354 * the background (not recommended).
1355 */
1356 if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
1357 png_set_strip_alpha(png_ptr);
1358 #endif
1359
1360 #if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
1361 /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
1362 * byte into separate bytes (useful for paletted and grayscale images).
1363 */
1364 if (transforms & PNG_TRANSFORM_PACKING)
1365 png_set_packing(png_ptr);
1366 #endif
1367
1368 #if defined(PNG_READ_PACKSWAP_SUPPORTED)
1369 /* Change the order of packed pixels to least significant bit first
1370 * (not useful if you are using png_set_packing).
1371 */
1372 if (transforms & PNG_TRANSFORM_PACKSWAP)
1373 png_set_packswap(png_ptr);
1374 #endif
1375
1376 #if defined(PNG_READ_EXPAND_SUPPORTED)
1377 /* Expand paletted colors into true RGB triplets
1378 * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
1379 * Expand paletted or RGB images with transparency to full alpha
1380 * channels so the data will be available as RGBA quartets.
1381 */
1382 if (transforms & PNG_TRANSFORM_EXPAND)
1383 if ((png_ptr->bit_depth < 8) ||
1384 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
1385 (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
1386 png_set_expand(png_ptr);
1387 #endif
1388
1389 /* We don't handle background color or gamma transformation or dithering.
1390 */
1391
1392 #if defined(PNG_READ_INVERT_SUPPORTED)
1393 /* invert monochrome files to have 0 as white and 1 as black
1394 */
1395 if (transforms & PNG_TRANSFORM_INVERT_MONO)
1396 png_set_invert_mono(png_ptr);
1397 #endif
1398
1399 #if defined(PNG_READ_SHIFT_SUPPORTED)
1400 /* If you want to shift the pixel values from the range [0,255] or
1401 * [0,65535] to the original [0,7] or [0,31], or whatever range the
1402 * colors were originally in:
1403 */
1404 if ((transforms & PNG_TRANSFORM_SHIFT)
1405 && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
1406 {
1407 png_color_8p sig_bit;
1408
1409 png_get_sBIT(png_ptr, info_ptr, &sig_bit);
1410 png_set_shift(png_ptr, sig_bit);
1411 }
1412 #endif
1413
1414 #if defined(PNG_READ_BGR_SUPPORTED)
1415 /* flip the RGB pixels to BGR (or RGBA to BGRA)
1416 */
1417 if (transforms & PNG_TRANSFORM_BGR)
1418 png_set_bgr(png_ptr);
1419 #endif
1420
1421 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
1422 /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR)
1423 */
1424 if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1425 png_set_swap_alpha(png_ptr);
1426 #endif
1427
1428 #if defined(PNG_READ_SWAP_SUPPORTED)
1429 /* swap bytes of 16 bit files to least significant byte first
1430 */
1431 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1432 png_set_swap(png_ptr);
1433 #endif
1434
1435 /* We don't handle adding filler bytes */
1436
1437 /* Optional call to gamma correct and add the background to the palette
1438 * and update info structure. REQUIRED if you are expecting libpng to
1439 * update the palette for you (i.e., you selected such a transform above).
1440 */
1441 png_read_update_info(png_ptr, info_ptr);
1442
1443 /* -------------- image transformations end here ------------------- */
1444
1445 #ifdef PNG_FREE_ME_SUPPORTED
1446 png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
1447 #endif
1448 if (info_ptr->row_pointers == NULL)
1449 {
1450 info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
1451 info_ptr->height * png_sizeof(png_bytep));
1452 png_memset(info_ptr->row_pointers, 0, info_ptr->height
1453 * png_sizeof(png_bytep));
1454 #ifdef PNG_FREE_ME_SUPPORTED
1455 info_ptr->free_me |= PNG_FREE_ROWS;
1456 #endif
1457 for (row = 0; row < (int)info_ptr->height; row++)
1458 info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,
1459 png_get_rowbytes(png_ptr, info_ptr));
1460 }
1461
1462 png_read_image(png_ptr, info_ptr->row_pointers);
1463 info_ptr->valid |= PNG_INFO_IDAT;
1464
1465 /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
1466 png_read_end(png_ptr, info_ptr);
1467
1468 transforms = transforms; /* quiet compiler warnings */
1469 params = params;
1470
1471 }
1472 #endif /* PNG_INFO_IMAGE_SUPPORTED */
1473 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
1474 #endif /* PNG_READ_SUPPORTED */
1475