1
2 /* pngread.c - read a PNG file
3 *
4 * Last changed in libpng 1.2.19 August 18, 2007
5 * For conditions of distribution and use, see copyright notice in png.h
6 * Copyright (c) 1998-2007 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 * This file contains routines that an application calls directly to
11 * read a PNG file or stream.
12 */
13
14 #define PNG_INTERNAL
15 #include "png.h"
16
17 #if defined(PNG_READ_SUPPORTED)
18
19 /* Create a PNG structure for reading, and allocate any memory needed. */
20 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)21 png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr,
22 png_error_ptr error_fn, png_error_ptr warn_fn)
23 {
24
25 #ifdef PNG_USER_MEM_SUPPORTED
26 return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
27 warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
28 }
29
30 /* Alternate create PNG structure for reading, and allocate any memory needed. */
31 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)32 png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
33 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
34 png_malloc_ptr malloc_fn, png_free_ptr free_fn)
35 {
36 #endif /* PNG_USER_MEM_SUPPORTED */
37
38 png_structp png_ptr;
39
40 #ifdef PNG_SETJMP_SUPPORTED
41 #ifdef USE_FAR_KEYWORD
42 jmp_buf jmpbuf;
43 #endif
44 #endif
45
46 int i;
47
48 png_debug(1, "in png_create_read_struct\n");
49 #ifdef PNG_USER_MEM_SUPPORTED
50 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
51 (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
52 #else
53 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
54 #endif
55 if (png_ptr == NULL)
56 return (NULL);
57
58 #if !defined(PNG_1_0_X)
59 #ifdef PNG_MMX_CODE_SUPPORTED
60 png_init_mmx_flags(png_ptr); /* 1.2.0 addition */
61 #endif
62 #endif /* PNG_1_0_X */
63
64 /* added at libpng-1.2.6 */
65 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
66 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
67 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
68 #endif
69
70 #ifdef PNG_SETJMP_SUPPORTED
71 #ifdef USE_FAR_KEYWORD
72 if (setjmp(jmpbuf))
73 #else
74 if (setjmp(png_ptr->jmpbuf))
75 #endif
76 {
77 png_free(png_ptr, png_ptr->zbuf);
78 png_ptr->zbuf=NULL;
79 #ifdef PNG_USER_MEM_SUPPORTED
80 png_destroy_struct_2((png_voidp)png_ptr,
81 (png_free_ptr)free_fn, (png_voidp)mem_ptr);
82 #else
83 png_destroy_struct((png_voidp)png_ptr);
84 #endif
85 return (NULL);
86 }
87 #ifdef USE_FAR_KEYWORD
88 png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
89 #endif
90 #endif
91
92 #ifdef PNG_USER_MEM_SUPPORTED
93 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
94 #endif
95
96 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
97
98 i=0;
99 do
100 {
101 if(user_png_ver[i] != png_libpng_ver[i])
102 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
103 } while (png_libpng_ver[i++]);
104
105 if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
106 {
107 /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
108 * we must recompile any applications that use any older library version.
109 * For versions after libpng 1.0, we will be compatible, so we need
110 * only check the first digit.
111 */
112 if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
113 (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
114 (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
115 {
116 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
117 char msg[80];
118 if (user_png_ver)
119 {
120 png_snprintf(msg, 80,
121 "Application was compiled with png.h from libpng-%.20s",
122 user_png_ver);
123 png_warning(png_ptr, msg);
124 }
125 png_snprintf(msg, 80,
126 "Application is running with png.c from libpng-%.20s",
127 png_libpng_ver);
128 png_warning(png_ptr, msg);
129 #endif
130 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
131 png_ptr->flags=0;
132 #endif
133 png_error(png_ptr,
134 "Incompatible libpng version in application and library");
135 }
136 }
137
138 /* initialize zbuf - compression buffer */
139 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
140 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
141 (png_uint_32)png_ptr->zbuf_size);
142 png_ptr->zstream.zalloc = png_zalloc;
143 png_ptr->zstream.zfree = png_zfree;
144 png_ptr->zstream.opaque = (voidpf)png_ptr;
145
146 switch (inflateInit(&png_ptr->zstream))
147 {
148 case Z_OK: /* Do nothing */ break;
149 case Z_MEM_ERROR:
150 case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory error"); break;
151 case Z_VERSION_ERROR: png_error(png_ptr, "zlib version error"); break;
152 default: png_error(png_ptr, "Unknown zlib error");
153 }
154
155 png_ptr->zstream.next_out = png_ptr->zbuf;
156 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
157
158 png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
159
160 #ifdef PNG_SETJMP_SUPPORTED
161 /* Applications that neglect to set up their own setjmp() and then encounter
162 a png_error() will longjmp here. Since the jmpbuf is then meaningless we
163 abort instead of returning. */
164 #ifdef USE_FAR_KEYWORD
165 if (setjmp(jmpbuf))
166 PNG_ABORT();
167 png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
168 #else
169 if (setjmp(png_ptr->jmpbuf))
170 PNG_ABORT();
171 #endif
172 #endif
173 return (png_ptr);
174 }
175
176 #if defined(PNG_1_0_X) || defined(PNG_1_2_X)
177 /* Initialize PNG structure for reading, and allocate any memory needed.
178 This interface is deprecated in favour of the png_create_read_struct(),
179 and it will disappear as of libpng-1.3.0. */
180 #undef png_read_init
181 void PNGAPI
png_read_init(png_structp png_ptr)182 png_read_init(png_structp png_ptr)
183 {
184 /* We only come here via pre-1.0.7-compiled applications */
185 png_read_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
186 }
187
188 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)189 png_read_init_2(png_structp png_ptr, png_const_charp user_png_ver,
190 png_size_t png_struct_size, png_size_t png_info_size)
191 {
192 /* We only come here via pre-1.0.12-compiled applications */
193 if(png_ptr == NULL) return;
194 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
195 if(png_sizeof(png_struct) > png_struct_size ||
196 png_sizeof(png_info) > png_info_size)
197 {
198 char msg[80];
199 png_ptr->warning_fn=NULL;
200 if (user_png_ver)
201 {
202 png_snprintf(msg, 80,
203 "Application was compiled with png.h from libpng-%.20s",
204 user_png_ver);
205 png_warning(png_ptr, msg);
206 }
207 png_snprintf(msg, 80,
208 "Application is running with png.c from libpng-%.20s",
209 png_libpng_ver);
210 png_warning(png_ptr, msg);
211 }
212 #endif
213 if(png_sizeof(png_struct) > png_struct_size)
214 {
215 png_ptr->error_fn=NULL;
216 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
217 png_ptr->flags=0;
218 #endif
219 png_error(png_ptr,
220 "The png struct allocated by the application for reading is too small.");
221 }
222 if(png_sizeof(png_info) > png_info_size)
223 {
224 png_ptr->error_fn=NULL;
225 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
226 png_ptr->flags=0;
227 #endif
228 png_error(png_ptr,
229 "The info struct allocated by application for reading is too small.");
230 }
231 png_read_init_3(&png_ptr, user_png_ver, png_struct_size);
232 }
233 #endif /* PNG_1_0_X || PNG_1_2_X */
234
235 void PNGAPI
png_read_init_3(png_structpp ptr_ptr,png_const_charp user_png_ver,png_size_t png_struct_size)236 png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
237 png_size_t png_struct_size)
238 {
239 #ifdef PNG_SETJMP_SUPPORTED
240 jmp_buf tmp_jmp; /* to save current jump buffer */
241 #endif
242
243 int i=0;
244
245 png_structp png_ptr=*ptr_ptr;
246
247 if(png_ptr == NULL) return;
248
249 do
250 {
251 if(user_png_ver[i] != png_libpng_ver[i])
252 {
253 #ifdef PNG_LEGACY_SUPPORTED
254 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
255 #else
256 png_ptr->warning_fn=NULL;
257 png_warning(png_ptr,
258 "Application uses deprecated png_read_init() and should be recompiled.");
259 break;
260 #endif
261 }
262 } while (png_libpng_ver[i++]);
263
264 png_debug(1, "in png_read_init_3\n");
265
266 #ifdef PNG_SETJMP_SUPPORTED
267 /* save jump buffer and error functions */
268 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
269 #endif
270
271 if(png_sizeof(png_struct) > png_struct_size)
272 {
273 png_destroy_struct(png_ptr);
274 *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
275 png_ptr = *ptr_ptr;
276 }
277
278 /* reset all variables to 0 */
279 png_memset(png_ptr, 0, png_sizeof (png_struct));
280
281 #ifdef PNG_SETJMP_SUPPORTED
282 /* restore jump buffer */
283 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
284 #endif
285
286 /* added at libpng-1.2.6 */
287 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
288 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
289 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
290 #endif
291
292 /* initialize zbuf - compression buffer */
293 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
294 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
295 (png_uint_32)png_ptr->zbuf_size);
296 png_ptr->zstream.zalloc = png_zalloc;
297 png_ptr->zstream.zfree = png_zfree;
298 png_ptr->zstream.opaque = (voidpf)png_ptr;
299
300 switch (inflateInit(&png_ptr->zstream))
301 {
302 case Z_OK: /* Do nothing */ break;
303 case Z_MEM_ERROR:
304 case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory"); break;
305 case Z_VERSION_ERROR: png_error(png_ptr, "zlib version"); break;
306 default: png_error(png_ptr, "Unknown zlib error");
307 }
308
309 png_ptr->zstream.next_out = png_ptr->zbuf;
310 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
311
312 png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
313 }
314
315 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
316 /* Read the information before the actual image data. This has been
317 * changed in v0.90 to allow reading a file that already has the magic
318 * bytes read from the stream. You can tell libpng how many bytes have
319 * been read from the beginning of the stream (up to the maximum of 8)
320 * via png_set_sig_bytes(), and we will only check the remaining bytes
321 * here. The application can then have access to the signature bytes we
322 * read if it is determined that this isn't a valid PNG file.
323 */
324 void PNGAPI
png_read_info(png_structp png_ptr,png_infop info_ptr)325 png_read_info(png_structp png_ptr, png_infop info_ptr)
326 {
327 if(png_ptr == NULL) return;
328 png_debug(1, "in png_read_info\n");
329 /* If we haven't checked all of the PNG signature bytes, do so now. */
330 if (png_ptr->sig_bytes < 8)
331 {
332 png_size_t num_checked = png_ptr->sig_bytes,
333 num_to_check = 8 - num_checked;
334
335 png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
336 png_ptr->sig_bytes = 8;
337
338 if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
339 {
340 if (num_checked < 4 &&
341 png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
342 png_error(png_ptr, "Not a PNG file");
343 else
344 png_error(png_ptr, "PNG file corrupted by ASCII conversion");
345 }
346 if (num_checked < 3)
347 png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
348 }
349
350 for(;;)
351 {
352 #ifdef PNG_USE_LOCAL_ARRAYS
353 PNG_CONST PNG_IHDR;
354 PNG_CONST PNG_IDAT;
355 PNG_CONST PNG_IEND;
356 PNG_CONST PNG_PLTE;
357 #if defined(PNG_READ_bKGD_SUPPORTED)
358 PNG_CONST PNG_bKGD;
359 #endif
360 #if defined(PNG_READ_cHRM_SUPPORTED)
361 PNG_CONST PNG_cHRM;
362 #endif
363 #if defined(PNG_READ_gAMA_SUPPORTED)
364 PNG_CONST PNG_gAMA;
365 #endif
366 #if defined(PNG_READ_hIST_SUPPORTED)
367 PNG_CONST PNG_hIST;
368 #endif
369 #if defined(PNG_READ_iCCP_SUPPORTED)
370 PNG_CONST PNG_iCCP;
371 #endif
372 #if defined(PNG_READ_iTXt_SUPPORTED)
373 PNG_CONST PNG_iTXt;
374 #endif
375 #if defined(PNG_READ_oFFs_SUPPORTED)
376 PNG_CONST PNG_oFFs;
377 #endif
378 #if defined(PNG_READ_pCAL_SUPPORTED)
379 PNG_CONST PNG_pCAL;
380 #endif
381 #if defined(PNG_READ_pHYs_SUPPORTED)
382 PNG_CONST PNG_pHYs;
383 #endif
384 #if defined(PNG_READ_sBIT_SUPPORTED)
385 PNG_CONST PNG_sBIT;
386 #endif
387 #if defined(PNG_READ_sCAL_SUPPORTED)
388 PNG_CONST PNG_sCAL;
389 #endif
390 #if defined(PNG_READ_sPLT_SUPPORTED)
391 PNG_CONST PNG_sPLT;
392 #endif
393 #if defined(PNG_READ_sRGB_SUPPORTED)
394 PNG_CONST PNG_sRGB;
395 #endif
396 #if defined(PNG_READ_tEXt_SUPPORTED)
397 PNG_CONST PNG_tEXt;
398 #endif
399 #if defined(PNG_READ_tIME_SUPPORTED)
400 PNG_CONST PNG_tIME;
401 #endif
402 #if defined(PNG_READ_tRNS_SUPPORTED)
403 PNG_CONST PNG_tRNS;
404 #endif
405 #if defined(PNG_READ_zTXt_SUPPORTED)
406 PNG_CONST PNG_zTXt;
407 #endif
408 #endif /* PNG_USE_LOCAL_ARRAYS */
409 png_byte chunk_length[4];
410 png_uint_32 length;
411
412 png_read_data(png_ptr, chunk_length, 4);
413 length = png_get_uint_31(png_ptr,chunk_length);
414
415 png_reset_crc(png_ptr);
416 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
417
418 png_debug2(0, "Reading %s chunk, length=%lu.\n", png_ptr->chunk_name,
419 length);
420
421 /* This should be a binary subdivision search or a hash for
422 * matching the chunk name rather than a linear search.
423 */
424 if (!png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
425 if(png_ptr->mode & PNG_AFTER_IDAT)
426 png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
427
428 if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
429 png_handle_IHDR(png_ptr, info_ptr, length);
430 else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
431 png_handle_IEND(png_ptr, info_ptr, length);
432 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
433 else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
434 {
435 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
436 png_ptr->mode |= PNG_HAVE_IDAT;
437 png_handle_unknown(png_ptr, info_ptr, length);
438 if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
439 png_ptr->mode |= PNG_HAVE_PLTE;
440 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
441 {
442 if (!(png_ptr->mode & PNG_HAVE_IHDR))
443 png_error(png_ptr, "Missing IHDR before IDAT");
444 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
445 !(png_ptr->mode & PNG_HAVE_PLTE))
446 png_error(png_ptr, "Missing PLTE before IDAT");
447 break;
448 }
449 }
450 #endif
451 else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
452 png_handle_PLTE(png_ptr, info_ptr, length);
453 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
454 {
455 if (!(png_ptr->mode & PNG_HAVE_IHDR))
456 png_error(png_ptr, "Missing IHDR before IDAT");
457 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
458 !(png_ptr->mode & PNG_HAVE_PLTE))
459 png_error(png_ptr, "Missing PLTE before IDAT");
460
461 png_ptr->idat_size = length;
462 png_ptr->mode |= PNG_HAVE_IDAT;
463 break;
464 }
465 #if defined(PNG_READ_bKGD_SUPPORTED)
466 else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
467 png_handle_bKGD(png_ptr, info_ptr, length);
468 #endif
469 #if defined(PNG_READ_cHRM_SUPPORTED)
470 else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
471 png_handle_cHRM(png_ptr, info_ptr, length);
472 #endif
473 #if defined(PNG_READ_gAMA_SUPPORTED)
474 else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
475 png_handle_gAMA(png_ptr, info_ptr, length);
476 #endif
477 #if defined(PNG_READ_hIST_SUPPORTED)
478 else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
479 png_handle_hIST(png_ptr, info_ptr, length);
480 #endif
481 #if defined(PNG_READ_oFFs_SUPPORTED)
482 else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
483 png_handle_oFFs(png_ptr, info_ptr, length);
484 #endif
485 #if defined(PNG_READ_pCAL_SUPPORTED)
486 else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
487 png_handle_pCAL(png_ptr, info_ptr, length);
488 #endif
489 #if defined(PNG_READ_sCAL_SUPPORTED)
490 else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
491 png_handle_sCAL(png_ptr, info_ptr, length);
492 #endif
493 #if defined(PNG_READ_pHYs_SUPPORTED)
494 else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
495 png_handle_pHYs(png_ptr, info_ptr, length);
496 #endif
497 #if defined(PNG_READ_sBIT_SUPPORTED)
498 else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
499 png_handle_sBIT(png_ptr, info_ptr, length);
500 #endif
501 #if defined(PNG_READ_sRGB_SUPPORTED)
502 else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
503 png_handle_sRGB(png_ptr, info_ptr, length);
504 #endif
505 #if defined(PNG_READ_iCCP_SUPPORTED)
506 else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
507 png_handle_iCCP(png_ptr, info_ptr, length);
508 #endif
509 #if defined(PNG_READ_sPLT_SUPPORTED)
510 else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
511 png_handle_sPLT(png_ptr, info_ptr, length);
512 #endif
513 #if defined(PNG_READ_tEXt_SUPPORTED)
514 else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
515 png_handle_tEXt(png_ptr, info_ptr, length);
516 #endif
517 #if defined(PNG_READ_tIME_SUPPORTED)
518 else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
519 png_handle_tIME(png_ptr, info_ptr, length);
520 #endif
521 #if defined(PNG_READ_tRNS_SUPPORTED)
522 else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
523 png_handle_tRNS(png_ptr, info_ptr, length);
524 #endif
525 #if defined(PNG_READ_zTXt_SUPPORTED)
526 else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
527 png_handle_zTXt(png_ptr, info_ptr, length);
528 #endif
529 #if defined(PNG_READ_iTXt_SUPPORTED)
530 else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
531 png_handle_iTXt(png_ptr, info_ptr, length);
532 #endif
533 else
534 png_handle_unknown(png_ptr, info_ptr, length);
535 }
536 }
537 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
538
539 /* optional call to update the users info_ptr structure */
540 void PNGAPI
png_read_update_info(png_structp png_ptr,png_infop info_ptr)541 png_read_update_info(png_structp png_ptr, png_infop info_ptr)
542 {
543 png_debug(1, "in png_read_update_info\n");
544 if(png_ptr == NULL) return;
545 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
546 png_read_start_row(png_ptr);
547 else
548 png_warning(png_ptr,
549 "Ignoring extra png_read_update_info() call; row buffer not reallocated");
550 png_read_transform_info(png_ptr, info_ptr);
551 }
552
553 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
554 /* Initialize palette, background, etc, after transformations
555 * are set, but before any reading takes place. This allows
556 * the user to obtain a gamma-corrected palette, for example.
557 * If the user doesn't call this, we will do it ourselves.
558 */
559 void PNGAPI
png_start_read_image(png_structp png_ptr)560 png_start_read_image(png_structp png_ptr)
561 {
562 png_debug(1, "in png_start_read_image\n");
563 if(png_ptr == NULL) return;
564 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
565 png_read_start_row(png_ptr);
566 }
567 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
568
569 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
570 void PNGAPI
png_read_row(png_structp png_ptr,png_bytep row,png_bytep dsp_row)571 png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
572 {
573 #ifdef PNG_USE_LOCAL_ARRAYS
574 PNG_CONST PNG_IDAT;
575 PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
576 0xff};
577 PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
578 #endif
579 int ret;
580 if(png_ptr == NULL) return;
581 png_debug2(1, "in png_read_row (row %lu, pass %d)\n",
582 png_ptr->row_number, png_ptr->pass);
583 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
584 png_read_start_row(png_ptr);
585 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
586 {
587 /* check for transforms that have been set but were defined out */
588 #if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
589 if (png_ptr->transformations & PNG_INVERT_MONO)
590 png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined.");
591 #endif
592 #if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
593 if (png_ptr->transformations & PNG_FILLER)
594 png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined.");
595 #endif
596 #if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && !defined(PNG_READ_PACKSWAP_SUPPORTED)
597 if (png_ptr->transformations & PNG_PACKSWAP)
598 png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined.");
599 #endif
600 #if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
601 if (png_ptr->transformations & PNG_PACK)
602 png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined.");
603 #endif
604 #if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
605 if (png_ptr->transformations & PNG_SHIFT)
606 png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined.");
607 #endif
608 #if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
609 if (png_ptr->transformations & PNG_BGR)
610 png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined.");
611 #endif
612 #if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
613 if (png_ptr->transformations & PNG_SWAP_BYTES)
614 png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined.");
615 #endif
616 }
617
618 #if defined(PNG_READ_INTERLACING_SUPPORTED)
619 /* if interlaced and we do not need a new row, combine row and return */
620 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
621 {
622 switch (png_ptr->pass)
623 {
624 case 0:
625 if (png_ptr->row_number & 0x07)
626 {
627 if (dsp_row != NULL)
628 png_combine_row(png_ptr, dsp_row,
629 png_pass_dsp_mask[png_ptr->pass]);
630 png_read_finish_row(png_ptr);
631 return;
632 }
633 break;
634 case 1:
635 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
636 {
637 if (dsp_row != NULL)
638 png_combine_row(png_ptr, dsp_row,
639 png_pass_dsp_mask[png_ptr->pass]);
640 png_read_finish_row(png_ptr);
641 return;
642 }
643 break;
644 case 2:
645 if ((png_ptr->row_number & 0x07) != 4)
646 {
647 if (dsp_row != NULL && (png_ptr->row_number & 4))
648 png_combine_row(png_ptr, dsp_row,
649 png_pass_dsp_mask[png_ptr->pass]);
650 png_read_finish_row(png_ptr);
651 return;
652 }
653 break;
654 case 3:
655 if ((png_ptr->row_number & 3) || png_ptr->width < 3)
656 {
657 if (dsp_row != NULL)
658 png_combine_row(png_ptr, dsp_row,
659 png_pass_dsp_mask[png_ptr->pass]);
660 png_read_finish_row(png_ptr);
661 return;
662 }
663 break;
664 case 4:
665 if ((png_ptr->row_number & 3) != 2)
666 {
667 if (dsp_row != NULL && (png_ptr->row_number & 2))
668 png_combine_row(png_ptr, dsp_row,
669 png_pass_dsp_mask[png_ptr->pass]);
670 png_read_finish_row(png_ptr);
671 return;
672 }
673 break;
674 case 5:
675 if ((png_ptr->row_number & 1) || png_ptr->width < 2)
676 {
677 if (dsp_row != NULL)
678 png_combine_row(png_ptr, dsp_row,
679 png_pass_dsp_mask[png_ptr->pass]);
680 png_read_finish_row(png_ptr);
681 return;
682 }
683 break;
684 case 6:
685 if (!(png_ptr->row_number & 1))
686 {
687 png_read_finish_row(png_ptr);
688 return;
689 }
690 break;
691 }
692 }
693 #endif
694
695 if (!(png_ptr->mode & PNG_HAVE_IDAT))
696 png_error(png_ptr, "Invalid attempt to read row data");
697
698 png_ptr->zstream.next_out = png_ptr->row_buf;
699 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
700 do
701 {
702 if (!(png_ptr->zstream.avail_in))
703 {
704 while (!png_ptr->idat_size)
705 {
706 png_byte chunk_length[4];
707
708 png_crc_finish(png_ptr, 0);
709
710 png_read_data(png_ptr, chunk_length, 4);
711 png_ptr->idat_size = png_get_uint_31(png_ptr,chunk_length);
712
713 png_reset_crc(png_ptr);
714 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
715 if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
716 png_error(png_ptr, "Not enough image data");
717 }
718 png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
719 png_ptr->zstream.next_in = png_ptr->zbuf;
720 if (png_ptr->zbuf_size > png_ptr->idat_size)
721 png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
722 png_crc_read(png_ptr, png_ptr->zbuf,
723 (png_size_t)png_ptr->zstream.avail_in);
724 png_ptr->idat_size -= png_ptr->zstream.avail_in;
725 }
726 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
727 if (ret == Z_STREAM_END)
728 {
729 if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
730 png_ptr->idat_size)
731 png_error(png_ptr, "Extra compressed data");
732 png_ptr->mode |= PNG_AFTER_IDAT;
733 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
734 break;
735 }
736 if (ret != Z_OK)
737 png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
738 "Decompression error");
739
740 } while (png_ptr->zstream.avail_out);
741
742 png_ptr->row_info.color_type = png_ptr->color_type;
743 png_ptr->row_info.width = png_ptr->iwidth;
744 png_ptr->row_info.channels = png_ptr->channels;
745 png_ptr->row_info.bit_depth = png_ptr->bit_depth;
746 png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
747 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
748 png_ptr->row_info.width);
749
750 if(png_ptr->row_buf[0])
751 png_read_filter_row(png_ptr, &(png_ptr->row_info),
752 png_ptr->row_buf + 1, png_ptr->prev_row + 1,
753 (int)(png_ptr->row_buf[0]));
754
755 png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
756 png_ptr->rowbytes + 1);
757
758 #if defined(PNG_MNG_FEATURES_SUPPORTED)
759 if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
760 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
761 {
762 /* Intrapixel differencing */
763 png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
764 }
765 #endif
766
767
768 if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
769 png_do_read_transformations(png_ptr);
770
771 #if defined(PNG_READ_INTERLACING_SUPPORTED)
772 /* blow up interlaced rows to full size */
773 if (png_ptr->interlaced &&
774 (png_ptr->transformations & PNG_INTERLACE))
775 {
776 if (png_ptr->pass < 6)
777 /* old interface (pre-1.0.9):
778 png_do_read_interlace(&(png_ptr->row_info),
779 png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
780 */
781 png_do_read_interlace(png_ptr);
782
783 if (dsp_row != NULL)
784 png_combine_row(png_ptr, dsp_row,
785 png_pass_dsp_mask[png_ptr->pass]);
786 if (row != NULL)
787 png_combine_row(png_ptr, row,
788 png_pass_mask[png_ptr->pass]);
789 }
790 else
791 #endif
792 {
793 if (row != NULL)
794 png_combine_row(png_ptr, row, 0xff);
795 if (dsp_row != NULL)
796 png_combine_row(png_ptr, dsp_row, 0xff);
797 }
798 png_read_finish_row(png_ptr);
799
800 if (png_ptr->read_row_fn != NULL)
801 (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
802 }
803 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
804
805 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
806 /* Read one or more rows of image data. If the image is interlaced,
807 * and png_set_interlace_handling() has been called, the rows need to
808 * contain the contents of the rows from the previous pass. If the
809 * image has alpha or transparency, and png_handle_alpha()[*] has been
810 * called, the rows contents must be initialized to the contents of the
811 * screen.
812 *
813 * "row" holds the actual image, and pixels are placed in it
814 * as they arrive. If the image is displayed after each pass, it will
815 * appear to "sparkle" in. "display_row" can be used to display a
816 * "chunky" progressive image, with finer detail added as it becomes
817 * available. If you do not want this "chunky" display, you may pass
818 * NULL for display_row. If you do not want the sparkle display, and
819 * you have not called png_handle_alpha(), you may pass NULL for rows.
820 * If you have called png_handle_alpha(), and the image has either an
821 * alpha channel or a transparency chunk, you must provide a buffer for
822 * rows. In this case, you do not have to provide a display_row buffer
823 * also, but you may. If the image is not interlaced, or if you have
824 * not called png_set_interlace_handling(), the display_row buffer will
825 * be ignored, so pass NULL to it.
826 *
827 * [*] png_handle_alpha() does not exist yet, as of this version of libpng
828 */
829
830 void PNGAPI
png_read_rows(png_structp png_ptr,png_bytepp row,png_bytepp display_row,png_uint_32 num_rows)831 png_read_rows(png_structp png_ptr, png_bytepp row,
832 png_bytepp display_row, png_uint_32 num_rows)
833 {
834 png_uint_32 i;
835 png_bytepp rp;
836 png_bytepp dp;
837
838 png_debug(1, "in png_read_rows\n");
839 if(png_ptr == NULL) return;
840 rp = row;
841 dp = display_row;
842 if (rp != NULL && dp != NULL)
843 for (i = 0; i < num_rows; i++)
844 {
845 png_bytep rptr = *rp++;
846 png_bytep dptr = *dp++;
847
848 png_read_row(png_ptr, rptr, dptr);
849 }
850 else if(rp != NULL)
851 for (i = 0; i < num_rows; i++)
852 {
853 png_bytep rptr = *rp;
854 png_read_row(png_ptr, rptr, png_bytep_NULL);
855 rp++;
856 }
857 else if(dp != NULL)
858 for (i = 0; i < num_rows; i++)
859 {
860 png_bytep dptr = *dp;
861 png_read_row(png_ptr, png_bytep_NULL, dptr);
862 dp++;
863 }
864 }
865 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
866
867 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
868 /* Read the entire image. If the image has an alpha channel or a tRNS
869 * chunk, and you have called png_handle_alpha()[*], you will need to
870 * initialize the image to the current image that PNG will be overlaying.
871 * We set the num_rows again here, in case it was incorrectly set in
872 * png_read_start_row() by a call to png_read_update_info() or
873 * png_start_read_image() if png_set_interlace_handling() wasn't called
874 * prior to either of these functions like it should have been. You can
875 * only call this function once. If you desire to have an image for
876 * each pass of a interlaced image, use png_read_rows() instead.
877 *
878 * [*] png_handle_alpha() does not exist yet, as of this version of libpng
879 */
880 void PNGAPI
png_read_image(png_structp png_ptr,png_bytepp image)881 png_read_image(png_structp png_ptr, png_bytepp image)
882 {
883 png_uint_32 i,image_height;
884 int pass, j;
885 png_bytepp rp;
886
887 png_debug(1, "in png_read_image\n");
888 if(png_ptr == NULL) return;
889
890 #ifdef PNG_READ_INTERLACING_SUPPORTED
891 pass = png_set_interlace_handling(png_ptr);
892 #else
893 if (png_ptr->interlaced)
894 png_error(png_ptr,
895 "Cannot read interlaced image -- interlace handler disabled.");
896 pass = 1;
897 #endif
898
899
900 image_height=png_ptr->height;
901 png_ptr->num_rows = image_height; /* Make sure this is set correctly */
902
903 for (j = 0; j < pass; j++)
904 {
905 rp = image;
906 for (i = 0; i < image_height; i++)
907 {
908 png_read_row(png_ptr, *rp, png_bytep_NULL);
909 rp++;
910 }
911 }
912 }
913 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
914
915 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
916 /* Read the end of the PNG file. Will not read past the end of the
917 * file, will verify the end is accurate, and will read any comments
918 * or time information at the end of the file, if info is not NULL.
919 */
920 void PNGAPI
png_read_end(png_structp png_ptr,png_infop info_ptr)921 png_read_end(png_structp png_ptr, png_infop info_ptr)
922 {
923 png_byte chunk_length[4];
924 png_uint_32 length;
925
926 png_debug(1, "in png_read_end\n");
927 if(png_ptr == NULL) return;
928 png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
929
930 do
931 {
932 #ifdef PNG_USE_LOCAL_ARRAYS
933 PNG_CONST PNG_IHDR;
934 PNG_CONST PNG_IDAT;
935 PNG_CONST PNG_IEND;
936 PNG_CONST PNG_PLTE;
937 #if defined(PNG_READ_bKGD_SUPPORTED)
938 PNG_CONST PNG_bKGD;
939 #endif
940 #if defined(PNG_READ_cHRM_SUPPORTED)
941 PNG_CONST PNG_cHRM;
942 #endif
943 #if defined(PNG_READ_gAMA_SUPPORTED)
944 PNG_CONST PNG_gAMA;
945 #endif
946 #if defined(PNG_READ_hIST_SUPPORTED)
947 PNG_CONST PNG_hIST;
948 #endif
949 #if defined(PNG_READ_iCCP_SUPPORTED)
950 PNG_CONST PNG_iCCP;
951 #endif
952 #if defined(PNG_READ_iTXt_SUPPORTED)
953 PNG_CONST PNG_iTXt;
954 #endif
955 #if defined(PNG_READ_oFFs_SUPPORTED)
956 PNG_CONST PNG_oFFs;
957 #endif
958 #if defined(PNG_READ_pCAL_SUPPORTED)
959 PNG_CONST PNG_pCAL;
960 #endif
961 #if defined(PNG_READ_pHYs_SUPPORTED)
962 PNG_CONST PNG_pHYs;
963 #endif
964 #if defined(PNG_READ_sBIT_SUPPORTED)
965 PNG_CONST PNG_sBIT;
966 #endif
967 #if defined(PNG_READ_sCAL_SUPPORTED)
968 PNG_CONST PNG_sCAL;
969 #endif
970 #if defined(PNG_READ_sPLT_SUPPORTED)
971 PNG_CONST PNG_sPLT;
972 #endif
973 #if defined(PNG_READ_sRGB_SUPPORTED)
974 PNG_CONST PNG_sRGB;
975 #endif
976 #if defined(PNG_READ_tEXt_SUPPORTED)
977 PNG_CONST PNG_tEXt;
978 #endif
979 #if defined(PNG_READ_tIME_SUPPORTED)
980 PNG_CONST PNG_tIME;
981 #endif
982 #if defined(PNG_READ_tRNS_SUPPORTED)
983 PNG_CONST PNG_tRNS;
984 #endif
985 #if defined(PNG_READ_zTXt_SUPPORTED)
986 PNG_CONST PNG_zTXt;
987 #endif
988 #endif /* PNG_USE_LOCAL_ARRAYS */
989
990 png_read_data(png_ptr, chunk_length, 4);
991 length = png_get_uint_31(png_ptr,chunk_length);
992
993 png_reset_crc(png_ptr);
994 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
995
996 png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name);
997
998 if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
999 png_handle_IHDR(png_ptr, info_ptr, length);
1000 else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
1001 png_handle_IEND(png_ptr, info_ptr, length);
1002 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1003 else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
1004 {
1005 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
1006 {
1007 if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
1008 png_error(png_ptr, "Too many IDAT's found");
1009 }
1010 png_handle_unknown(png_ptr, info_ptr, length);
1011 if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
1012 png_ptr->mode |= PNG_HAVE_PLTE;
1013 }
1014 #endif
1015 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
1016 {
1017 /* Zero length IDATs are legal after the last IDAT has been
1018 * read, but not after other chunks have been read.
1019 */
1020 if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
1021 png_error(png_ptr, "Too many IDAT's found");
1022 png_crc_finish(png_ptr, length);
1023 }
1024 else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
1025 png_handle_PLTE(png_ptr, info_ptr, length);
1026 #if defined(PNG_READ_bKGD_SUPPORTED)
1027 else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
1028 png_handle_bKGD(png_ptr, info_ptr, length);
1029 #endif
1030 #if defined(PNG_READ_cHRM_SUPPORTED)
1031 else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
1032 png_handle_cHRM(png_ptr, info_ptr, length);
1033 #endif
1034 #if defined(PNG_READ_gAMA_SUPPORTED)
1035 else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
1036 png_handle_gAMA(png_ptr, info_ptr, length);
1037 #endif
1038 #if defined(PNG_READ_hIST_SUPPORTED)
1039 else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
1040 png_handle_hIST(png_ptr, info_ptr, length);
1041 #endif
1042 #if defined(PNG_READ_oFFs_SUPPORTED)
1043 else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
1044 png_handle_oFFs(png_ptr, info_ptr, length);
1045 #endif
1046 #if defined(PNG_READ_pCAL_SUPPORTED)
1047 else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
1048 png_handle_pCAL(png_ptr, info_ptr, length);
1049 #endif
1050 #if defined(PNG_READ_sCAL_SUPPORTED)
1051 else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
1052 png_handle_sCAL(png_ptr, info_ptr, length);
1053 #endif
1054 #if defined(PNG_READ_pHYs_SUPPORTED)
1055 else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
1056 png_handle_pHYs(png_ptr, info_ptr, length);
1057 #endif
1058 #if defined(PNG_READ_sBIT_SUPPORTED)
1059 else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
1060 png_handle_sBIT(png_ptr, info_ptr, length);
1061 #endif
1062 #if defined(PNG_READ_sRGB_SUPPORTED)
1063 else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
1064 png_handle_sRGB(png_ptr, info_ptr, length);
1065 #endif
1066 #if defined(PNG_READ_iCCP_SUPPORTED)
1067 else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
1068 png_handle_iCCP(png_ptr, info_ptr, length);
1069 #endif
1070 #if defined(PNG_READ_sPLT_SUPPORTED)
1071 else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
1072 png_handle_sPLT(png_ptr, info_ptr, length);
1073 #endif
1074 #if defined(PNG_READ_tEXt_SUPPORTED)
1075 else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
1076 png_handle_tEXt(png_ptr, info_ptr, length);
1077 #endif
1078 #if defined(PNG_READ_tIME_SUPPORTED)
1079 else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
1080 png_handle_tIME(png_ptr, info_ptr, length);
1081 #endif
1082 #if defined(PNG_READ_tRNS_SUPPORTED)
1083 else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
1084 png_handle_tRNS(png_ptr, info_ptr, length);
1085 #endif
1086 #if defined(PNG_READ_zTXt_SUPPORTED)
1087 else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
1088 png_handle_zTXt(png_ptr, info_ptr, length);
1089 #endif
1090 #if defined(PNG_READ_iTXt_SUPPORTED)
1091 else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
1092 png_handle_iTXt(png_ptr, info_ptr, length);
1093 #endif
1094 else
1095 png_handle_unknown(png_ptr, info_ptr, length);
1096 } while (!(png_ptr->mode & PNG_HAVE_IEND));
1097 }
1098 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
1099
1100 /* free all memory used by the read */
1101 void PNGAPI
png_destroy_read_struct(png_structpp png_ptr_ptr,png_infopp info_ptr_ptr,png_infopp end_info_ptr_ptr)1102 png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
1103 png_infopp end_info_ptr_ptr)
1104 {
1105 png_structp png_ptr = NULL;
1106 png_infop info_ptr = NULL, end_info_ptr = NULL;
1107 #ifdef PNG_USER_MEM_SUPPORTED
1108 png_free_ptr free_fn;
1109 png_voidp mem_ptr;
1110 #endif
1111
1112 png_debug(1, "in png_destroy_read_struct\n");
1113 if (png_ptr_ptr != NULL)
1114 png_ptr = *png_ptr_ptr;
1115
1116 if (info_ptr_ptr != NULL)
1117 info_ptr = *info_ptr_ptr;
1118
1119 if (end_info_ptr_ptr != NULL)
1120 end_info_ptr = *end_info_ptr_ptr;
1121
1122 #ifdef PNG_USER_MEM_SUPPORTED
1123 free_fn = png_ptr->free_fn;
1124 mem_ptr = png_ptr->mem_ptr;
1125 #endif
1126
1127 png_read_destroy(png_ptr, info_ptr, end_info_ptr);
1128
1129 if (info_ptr != NULL)
1130 {
1131 #if defined(PNG_TEXT_SUPPORTED)
1132 png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1);
1133 #endif
1134
1135 #ifdef PNG_USER_MEM_SUPPORTED
1136 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1137 (png_voidp)mem_ptr);
1138 #else
1139 png_destroy_struct((png_voidp)info_ptr);
1140 #endif
1141 *info_ptr_ptr = NULL;
1142 }
1143
1144 if (end_info_ptr != NULL)
1145 {
1146 #if defined(PNG_READ_TEXT_SUPPORTED)
1147 png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1);
1148 #endif
1149 #ifdef PNG_USER_MEM_SUPPORTED
1150 png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn,
1151 (png_voidp)mem_ptr);
1152 #else
1153 png_destroy_struct((png_voidp)end_info_ptr);
1154 #endif
1155 *end_info_ptr_ptr = NULL;
1156 }
1157
1158 if (png_ptr != NULL)
1159 {
1160 #ifdef PNG_USER_MEM_SUPPORTED
1161 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1162 (png_voidp)mem_ptr);
1163 #else
1164 png_destroy_struct((png_voidp)png_ptr);
1165 #endif
1166 *png_ptr_ptr = NULL;
1167 }
1168 }
1169
1170 /* free all memory used by the read (old method) */
1171 void /* PRIVATE */
png_read_destroy(png_structp png_ptr,png_infop info_ptr,png_infop end_info_ptr)1172 png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr)
1173 {
1174 #ifdef PNG_SETJMP_SUPPORTED
1175 jmp_buf tmp_jmp;
1176 #endif
1177 png_error_ptr error_fn;
1178 png_error_ptr warning_fn;
1179 png_voidp error_ptr;
1180 #ifdef PNG_USER_MEM_SUPPORTED
1181 png_free_ptr free_fn;
1182 #endif
1183
1184 png_debug(1, "in png_read_destroy\n");
1185 if (info_ptr != NULL)
1186 png_info_destroy(png_ptr, info_ptr);
1187
1188 if (end_info_ptr != NULL)
1189 png_info_destroy(png_ptr, end_info_ptr);
1190
1191 png_free(png_ptr, png_ptr->zbuf);
1192 png_free(png_ptr, png_ptr->big_row_buf);
1193 png_free(png_ptr, png_ptr->prev_row);
1194 #if defined(PNG_READ_DITHER_SUPPORTED)
1195 png_free(png_ptr, png_ptr->palette_lookup);
1196 png_free(png_ptr, png_ptr->dither_index);
1197 #endif
1198 #if defined(PNG_READ_GAMMA_SUPPORTED)
1199 png_free(png_ptr, png_ptr->gamma_table);
1200 #endif
1201 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
1202 png_free(png_ptr, png_ptr->gamma_from_1);
1203 png_free(png_ptr, png_ptr->gamma_to_1);
1204 #endif
1205 #ifdef PNG_FREE_ME_SUPPORTED
1206 if (png_ptr->free_me & PNG_FREE_PLTE)
1207 png_zfree(png_ptr, png_ptr->palette);
1208 png_ptr->free_me &= ~PNG_FREE_PLTE;
1209 #else
1210 if (png_ptr->flags & PNG_FLAG_FREE_PLTE)
1211 png_zfree(png_ptr, png_ptr->palette);
1212 png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
1213 #endif
1214 #if defined(PNG_tRNS_SUPPORTED) || \
1215 defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1216 #ifdef PNG_FREE_ME_SUPPORTED
1217 if (png_ptr->free_me & PNG_FREE_TRNS)
1218 png_free(png_ptr, png_ptr->trans);
1219 png_ptr->free_me &= ~PNG_FREE_TRNS;
1220 #else
1221 if (png_ptr->flags & PNG_FLAG_FREE_TRNS)
1222 png_free(png_ptr, png_ptr->trans);
1223 png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
1224 #endif
1225 #endif
1226 #if defined(PNG_READ_hIST_SUPPORTED)
1227 #ifdef PNG_FREE_ME_SUPPORTED
1228 if (png_ptr->free_me & PNG_FREE_HIST)
1229 png_free(png_ptr, png_ptr->hist);
1230 png_ptr->free_me &= ~PNG_FREE_HIST;
1231 #else
1232 if (png_ptr->flags & PNG_FLAG_FREE_HIST)
1233 png_free(png_ptr, png_ptr->hist);
1234 png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
1235 #endif
1236 #endif
1237 #if defined(PNG_READ_GAMMA_SUPPORTED)
1238 if (png_ptr->gamma_16_table != NULL)
1239 {
1240 int i;
1241 int istop = (1 << (8 - png_ptr->gamma_shift));
1242 for (i = 0; i < istop; i++)
1243 {
1244 png_free(png_ptr, png_ptr->gamma_16_table[i]);
1245 }
1246 png_free(png_ptr, png_ptr->gamma_16_table);
1247 }
1248 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
1249 if (png_ptr->gamma_16_from_1 != NULL)
1250 {
1251 int i;
1252 int istop = (1 << (8 - png_ptr->gamma_shift));
1253 for (i = 0; i < istop; i++)
1254 {
1255 png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
1256 }
1257 png_free(png_ptr, png_ptr->gamma_16_from_1);
1258 }
1259 if (png_ptr->gamma_16_to_1 != NULL)
1260 {
1261 int i;
1262 int istop = (1 << (8 - png_ptr->gamma_shift));
1263 for (i = 0; i < istop; i++)
1264 {
1265 png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
1266 }
1267 png_free(png_ptr, png_ptr->gamma_16_to_1);
1268 }
1269 #endif
1270 #endif
1271 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1272 png_free(png_ptr, png_ptr->time_buffer);
1273 #endif
1274
1275 inflateEnd(&png_ptr->zstream);
1276 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1277 png_free(png_ptr, png_ptr->save_buffer);
1278 #endif
1279
1280 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1281 #ifdef PNG_TEXT_SUPPORTED
1282 png_free(png_ptr, png_ptr->current_text);
1283 #endif /* PNG_TEXT_SUPPORTED */
1284 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1285
1286 /* Save the important info out of the png_struct, in case it is
1287 * being used again.
1288 */
1289 #ifdef PNG_SETJMP_SUPPORTED
1290 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
1291 #endif
1292
1293 error_fn = png_ptr->error_fn;
1294 warning_fn = png_ptr->warning_fn;
1295 error_ptr = png_ptr->error_ptr;
1296 #ifdef PNG_USER_MEM_SUPPORTED
1297 free_fn = png_ptr->free_fn;
1298 #endif
1299
1300 png_memset(png_ptr, 0, png_sizeof (png_struct));
1301
1302 png_ptr->error_fn = error_fn;
1303 png_ptr->warning_fn = warning_fn;
1304 png_ptr->error_ptr = error_ptr;
1305 #ifdef PNG_USER_MEM_SUPPORTED
1306 png_ptr->free_fn = free_fn;
1307 #endif
1308
1309 #ifdef PNG_SETJMP_SUPPORTED
1310 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
1311 #endif
1312
1313 }
1314
1315 void PNGAPI
png_set_read_status_fn(png_structp png_ptr,png_read_status_ptr read_row_fn)1316 png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
1317 {
1318 if(png_ptr == NULL) return;
1319 png_ptr->read_row_fn = read_row_fn;
1320 }
1321
1322
1323 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1324 #if defined(PNG_INFO_IMAGE_SUPPORTED)
1325 void PNGAPI
png_read_png(png_structp png_ptr,png_infop info_ptr,int transforms,voidp params)1326 png_read_png(png_structp png_ptr, png_infop info_ptr,
1327 int transforms,
1328 voidp params)
1329 {
1330 int row;
1331
1332 if(png_ptr == NULL) return;
1333 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
1334 /* invert the alpha channel from opacity to transparency
1335 */
1336 if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1337 png_set_invert_alpha(png_ptr);
1338 #endif
1339
1340 /* png_read_info() gives us all of the information from the
1341 * PNG file before the first IDAT (image data chunk).
1342 */
1343 png_read_info(png_ptr, info_ptr);
1344 if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
1345 png_error(png_ptr,"Image is too high to process with png_read_png()");
1346
1347 /* -------------- image transformations start here ------------------- */
1348
1349 #if defined(PNG_READ_16_TO_8_SUPPORTED)
1350 /* tell libpng to strip 16 bit/color files down to 8 bits per color
1351 */
1352 if (transforms & PNG_TRANSFORM_STRIP_16)
1353 png_set_strip_16(png_ptr);
1354 #endif
1355
1356 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1357 /* Strip alpha bytes from the input data without combining with
1358 * the background (not recommended).
1359 */
1360 if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
1361 png_set_strip_alpha(png_ptr);
1362 #endif
1363
1364 #if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
1365 /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
1366 * byte into separate bytes (useful for paletted and grayscale images).
1367 */
1368 if (transforms & PNG_TRANSFORM_PACKING)
1369 png_set_packing(png_ptr);
1370 #endif
1371
1372 #if defined(PNG_READ_PACKSWAP_SUPPORTED)
1373 /* Change the order of packed pixels to least significant bit first
1374 * (not useful if you are using png_set_packing).
1375 */
1376 if (transforms & PNG_TRANSFORM_PACKSWAP)
1377 png_set_packswap(png_ptr);
1378 #endif
1379
1380 #if defined(PNG_READ_EXPAND_SUPPORTED)
1381 /* Expand paletted colors into true RGB triplets
1382 * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
1383 * Expand paletted or RGB images with transparency to full alpha
1384 * channels so the data will be available as RGBA quartets.
1385 */
1386 if (transforms & PNG_TRANSFORM_EXPAND)
1387 if ((png_ptr->bit_depth < 8) ||
1388 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
1389 (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
1390 png_set_expand(png_ptr);
1391 #endif
1392
1393 /* We don't handle background color or gamma transformation or dithering.
1394 */
1395
1396 #if defined(PNG_READ_INVERT_SUPPORTED)
1397 /* invert monochrome files to have 0 as white and 1 as black
1398 */
1399 if (transforms & PNG_TRANSFORM_INVERT_MONO)
1400 png_set_invert_mono(png_ptr);
1401 #endif
1402
1403 #if defined(PNG_READ_SHIFT_SUPPORTED)
1404 /* If you want to shift the pixel values from the range [0,255] or
1405 * [0,65535] to the original [0,7] or [0,31], or whatever range the
1406 * colors were originally in:
1407 */
1408 if ((transforms & PNG_TRANSFORM_SHIFT)
1409 && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
1410 {
1411 png_color_8p sig_bit;
1412
1413 png_get_sBIT(png_ptr, info_ptr, &sig_bit);
1414 png_set_shift(png_ptr, sig_bit);
1415 }
1416 #endif
1417
1418 #if defined(PNG_READ_BGR_SUPPORTED)
1419 /* flip the RGB pixels to BGR (or RGBA to BGRA)
1420 */
1421 if (transforms & PNG_TRANSFORM_BGR)
1422 png_set_bgr(png_ptr);
1423 #endif
1424
1425 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
1426 /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR)
1427 */
1428 if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1429 png_set_swap_alpha(png_ptr);
1430 #endif
1431
1432 #if defined(PNG_READ_SWAP_SUPPORTED)
1433 /* swap bytes of 16 bit files to least significant byte first
1434 */
1435 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1436 png_set_swap(png_ptr);
1437 #endif
1438
1439 /* We don't handle adding filler bytes */
1440
1441 /* Optional call to gamma correct and add the background to the palette
1442 * and update info structure. REQUIRED if you are expecting libpng to
1443 * update the palette for you (i.e., you selected such a transform above).
1444 */
1445 png_read_update_info(png_ptr, info_ptr);
1446
1447 /* -------------- image transformations end here ------------------- */
1448
1449 #ifdef PNG_FREE_ME_SUPPORTED
1450 png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
1451 #endif
1452 if(info_ptr->row_pointers == NULL)
1453 {
1454 info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
1455 info_ptr->height * png_sizeof(png_bytep));
1456 #ifdef PNG_FREE_ME_SUPPORTED
1457 info_ptr->free_me |= PNG_FREE_ROWS;
1458 #endif
1459 for (row = 0; row < (int)info_ptr->height; row++)
1460 {
1461 info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,
1462 png_get_rowbytes(png_ptr, info_ptr));
1463 }
1464 }
1465
1466 png_read_image(png_ptr, info_ptr->row_pointers);
1467 info_ptr->valid |= PNG_INFO_IDAT;
1468
1469 /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
1470 png_read_end(png_ptr, info_ptr);
1471
1472 transforms = transforms; /* quiet compiler warnings */
1473 params = params;
1474
1475 }
1476 #endif /* PNG_INFO_IMAGE_SUPPORTED */
1477 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
1478 #endif /* PNG_READ_SUPPORTED */
1479