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view libs/libpng/pngread.c @ 35:643f4ab609a4
added readme and license
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Sat, 31 Oct 2015 05:45:35 +0200 |
| parents | |
| children |
line source
2 /* pngread.c - read a PNG file
3 *
4 * Last changed in libpng 1.2.30 [August 15, 2008]
5 * For conditions of distribution and use, see copyright notice in png.h
6 * Copyright (c) 1998-2008 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 */
14 #define PNG_INTERNAL
15 #include "png.h"
16 #if defined(PNG_READ_SUPPORTED)
18 /* Create a PNG structure for reading, and allocate any memory needed. */
19 png_structp PNGAPI
20 png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr,
21 png_error_ptr error_fn, png_error_ptr warn_fn)
22 {
24 #ifdef PNG_USER_MEM_SUPPORTED
25 return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
26 warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
27 }
29 /* Alternate create PNG structure for reading, and allocate any memory needed. */
30 png_structp PNGAPI
31 png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
32 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
33 png_malloc_ptr malloc_fn, png_free_ptr free_fn)
34 {
35 #endif /* PNG_USER_MEM_SUPPORTED */
37 #ifdef PNG_SETJMP_SUPPORTED
38 volatile
39 #endif
40 png_structp png_ptr;
42 #ifdef PNG_SETJMP_SUPPORTED
43 #ifdef USE_FAR_KEYWORD
44 jmp_buf jmpbuf;
45 #endif
46 #endif
48 int i;
50 png_debug(1, "in png_create_read_struct\n");
51 #ifdef PNG_USER_MEM_SUPPORTED
52 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
53 (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
54 #else
55 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
56 #endif
57 if (png_ptr == NULL)
58 return (NULL);
60 /* added at libpng-1.2.6 */
61 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
62 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
63 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
64 #endif
66 #ifdef PNG_SETJMP_SUPPORTED
67 #ifdef USE_FAR_KEYWORD
68 if (setjmp(jmpbuf))
69 #else
70 if (setjmp(png_ptr->jmpbuf))
71 #endif
72 {
73 png_free(png_ptr, png_ptr->zbuf);
74 png_ptr->zbuf = NULL;
75 #ifdef PNG_USER_MEM_SUPPORTED
76 png_destroy_struct_2((png_voidp)png_ptr,
77 (png_free_ptr)free_fn, (png_voidp)mem_ptr);
78 #else
79 png_destroy_struct((png_voidp)png_ptr);
80 #endif
81 return (NULL);
82 }
83 #ifdef USE_FAR_KEYWORD
84 png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
85 #endif
86 #endif
88 #ifdef PNG_USER_MEM_SUPPORTED
89 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
90 #endif
92 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
94 if (user_png_ver)
95 {
96 i = 0;
97 do
98 {
99 if (user_png_ver[i] != png_libpng_ver[i])
100 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
101 } while (png_libpng_ver[i++]);
102 }
103 else
104 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
107 if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
108 {
109 /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
110 * we must recompile any applications that use any older library version.
111 * For versions after libpng 1.0, we will be compatible, so we need
112 * only check the first digit.
113 */
114 if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
115 (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
116 (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
117 {
118 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
119 char msg[80];
120 if (user_png_ver)
121 {
122 png_snprintf(msg, 80,
123 "Application was compiled with png.h from libpng-%.20s",
124 user_png_ver);
125 png_warning(png_ptr, msg);
126 }
127 png_snprintf(msg, 80,
128 "Application is running with png.c from libpng-%.20s",
129 png_libpng_ver);
130 png_warning(png_ptr, msg);
131 #endif
132 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
133 png_ptr->flags = 0;
134 #endif
135 png_error(png_ptr,
136 "Incompatible libpng version in application and library");
137 }
138 }
140 /* initialize zbuf - compression buffer */
141 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
142 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
143 (png_uint_32)png_ptr->zbuf_size);
144 png_ptr->zstream.zalloc = png_zalloc;
145 png_ptr->zstream.zfree = png_zfree;
146 png_ptr->zstream.opaque = (voidpf)png_ptr;
148 switch (inflateInit(&png_ptr->zstream))
149 {
150 case Z_OK: /* Do nothing */ break;
151 case Z_MEM_ERROR:
152 case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory error"); break;
153 case Z_VERSION_ERROR: png_error(png_ptr, "zlib version error"); break;
154 default: png_error(png_ptr, "Unknown zlib error");
155 }
157 png_ptr->zstream.next_out = png_ptr->zbuf;
158 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
160 png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
162 #ifdef PNG_SETJMP_SUPPORTED
163 /* Applications that neglect to set up their own setjmp() and then encounter
164 a png_error() will longjmp here. Since the jmpbuf is then meaningless we
165 abort instead of returning. */
166 #ifdef USE_FAR_KEYWORD
167 if (setjmp(jmpbuf))
168 PNG_ABORT();
169 png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
170 #else
171 if (setjmp(png_ptr->jmpbuf))
172 PNG_ABORT();
173 #endif
174 #endif
175 return (png_ptr);
176 }
178 #if defined(PNG_1_0_X) || defined(PNG_1_2_X)
179 /* Initialize PNG structure for reading, and allocate any memory needed.
180 This interface is deprecated in favour of the png_create_read_struct(),
181 and it will disappear as of libpng-1.3.0. */
182 #undef png_read_init
183 void PNGAPI
184 png_read_init(png_structp png_ptr)
185 {
186 /* We only come here via pre-1.0.7-compiled applications */
187 png_read_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
188 }
190 void PNGAPI
191 png_read_init_2(png_structp png_ptr, png_const_charp user_png_ver,
192 png_size_t png_struct_size, png_size_t png_info_size)
193 {
194 /* We only come here via pre-1.0.12-compiled applications */
195 if (png_ptr == NULL) return;
196 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
197 if (png_sizeof(png_struct) > png_struct_size ||
198 png_sizeof(png_info) > png_info_size)
199 {
200 char msg[80];
201 png_ptr->warning_fn = NULL;
202 if (user_png_ver)
203 {
204 png_snprintf(msg, 80,
205 "Application was compiled with png.h from libpng-%.20s",
206 user_png_ver);
207 png_warning(png_ptr, msg);
208 }
209 png_snprintf(msg, 80,
210 "Application is running with png.c from libpng-%.20s",
211 png_libpng_ver);
212 png_warning(png_ptr, msg);
213 }
214 #endif
215 if (png_sizeof(png_struct) > png_struct_size)
216 {
217 png_ptr->error_fn = NULL;
218 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
219 png_ptr->flags = 0;
220 #endif
221 png_error(png_ptr,
222 "The png struct allocated by the application for reading is too small.");
223 }
224 if (png_sizeof(png_info) > png_info_size)
225 {
226 png_ptr->error_fn = NULL;
227 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
228 png_ptr->flags = 0;
229 #endif
230 png_error(png_ptr,
231 "The info struct allocated by application for reading is too small.");
232 }
233 png_read_init_3(&png_ptr, user_png_ver, png_struct_size);
234 }
235 #endif /* PNG_1_0_X || PNG_1_2_X */
237 void PNGAPI
238 png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
239 png_size_t png_struct_size)
240 {
241 #ifdef PNG_SETJMP_SUPPORTED
242 jmp_buf tmp_jmp; /* to save current jump buffer */
243 #endif
245 int i = 0;
247 png_structp png_ptr=*ptr_ptr;
249 if (png_ptr == NULL) return;
251 do
252 {
253 if (user_png_ver[i] != png_libpng_ver[i])
254 {
255 #ifdef PNG_LEGACY_SUPPORTED
256 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
257 #else
258 png_ptr->warning_fn = NULL;
259 png_warning(png_ptr,
260 "Application uses deprecated png_read_init() and should be recompiled.");
261 break;
262 #endif
263 }
264 } while (png_libpng_ver[i++]);
266 png_debug(1, "in png_read_init_3\n");
268 #ifdef PNG_SETJMP_SUPPORTED
269 /* save jump buffer and error functions */
270 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
271 #endif
273 if (png_sizeof(png_struct) > png_struct_size)
274 {
275 png_destroy_struct(png_ptr);
276 *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
277 png_ptr = *ptr_ptr;
278 }
280 /* reset all variables to 0 */
281 png_memset(png_ptr, 0, png_sizeof(png_struct));
283 #ifdef PNG_SETJMP_SUPPORTED
284 /* restore jump buffer */
285 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
286 #endif
288 /* added at libpng-1.2.6 */
289 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
290 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
291 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
292 #endif
294 /* initialize zbuf - compression buffer */
295 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
296 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
297 (png_uint_32)png_ptr->zbuf_size);
298 png_ptr->zstream.zalloc = png_zalloc;
299 png_ptr->zstream.zfree = png_zfree;
300 png_ptr->zstream.opaque = (voidpf)png_ptr;
302 switch (inflateInit(&png_ptr->zstream))
303 {
304 case Z_OK: /* Do nothing */ break;
305 case Z_MEM_ERROR:
306 case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory"); break;
307 case Z_VERSION_ERROR: png_error(png_ptr, "zlib version"); break;
308 default: png_error(png_ptr, "Unknown zlib error");
309 }
311 png_ptr->zstream.next_out = png_ptr->zbuf;
312 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
314 png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
315 }
317 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
318 /* Read the information before the actual image data. This has been
319 * changed in v0.90 to allow reading a file that already has the magic
320 * bytes read from the stream. You can tell libpng how many bytes have
321 * been read from the beginning of the stream (up to the maximum of 8)
322 * via png_set_sig_bytes(), and we will only check the remaining bytes
323 * here. The application can then have access to the signature bytes we
324 * read if it is determined that this isn't a valid PNG file.
325 */
326 void PNGAPI
327 png_read_info(png_structp png_ptr, png_infop info_ptr)
328 {
329 if (png_ptr == NULL || info_ptr == NULL) return;
330 png_debug(1, "in png_read_info\n");
331 /* If we haven't checked all of the PNG signature bytes, do so now. */
332 if (png_ptr->sig_bytes < 8)
333 {
334 png_size_t num_checked = png_ptr->sig_bytes,
335 num_to_check = 8 - num_checked;
337 png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
338 png_ptr->sig_bytes = 8;
340 if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
341 {
342 if (num_checked < 4 &&
343 png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
344 png_error(png_ptr, "Not a PNG file");
345 else
346 png_error(png_ptr, "PNG file corrupted by ASCII conversion");
347 }
348 if (num_checked < 3)
349 png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
350 }
352 for (;;)
353 {
354 #ifdef PNG_USE_LOCAL_ARRAYS
355 PNG_CONST PNG_IHDR;
356 PNG_CONST PNG_IDAT;
357 PNG_CONST PNG_IEND;
358 PNG_CONST PNG_PLTE;
359 #if defined(PNG_READ_bKGD_SUPPORTED)
360 PNG_CONST PNG_bKGD;
361 #endif
362 #if defined(PNG_READ_cHRM_SUPPORTED)
363 PNG_CONST PNG_cHRM;
364 #endif
365 #if defined(PNG_READ_gAMA_SUPPORTED)
366 PNG_CONST PNG_gAMA;
367 #endif
368 #if defined(PNG_READ_hIST_SUPPORTED)
369 PNG_CONST PNG_hIST;
370 #endif
371 #if defined(PNG_READ_iCCP_SUPPORTED)
372 PNG_CONST PNG_iCCP;
373 #endif
374 #if defined(PNG_READ_iTXt_SUPPORTED)
375 PNG_CONST PNG_iTXt;
376 #endif
377 #if defined(PNG_READ_oFFs_SUPPORTED)
378 PNG_CONST PNG_oFFs;
379 #endif
380 #if defined(PNG_READ_pCAL_SUPPORTED)
381 PNG_CONST PNG_pCAL;
382 #endif
383 #if defined(PNG_READ_pHYs_SUPPORTED)
384 PNG_CONST PNG_pHYs;
385 #endif
386 #if defined(PNG_READ_sBIT_SUPPORTED)
387 PNG_CONST PNG_sBIT;
388 #endif
389 #if defined(PNG_READ_sCAL_SUPPORTED)
390 PNG_CONST PNG_sCAL;
391 #endif
392 #if defined(PNG_READ_sPLT_SUPPORTED)
393 PNG_CONST PNG_sPLT;
394 #endif
395 #if defined(PNG_READ_sRGB_SUPPORTED)
396 PNG_CONST PNG_sRGB;
397 #endif
398 #if defined(PNG_READ_tEXt_SUPPORTED)
399 PNG_CONST PNG_tEXt;
400 #endif
401 #if defined(PNG_READ_tIME_SUPPORTED)
402 PNG_CONST PNG_tIME;
403 #endif
404 #if defined(PNG_READ_tRNS_SUPPORTED)
405 PNG_CONST PNG_tRNS;
406 #endif
407 #if defined(PNG_READ_zTXt_SUPPORTED)
408 PNG_CONST PNG_zTXt;
409 #endif
410 #endif /* PNG_USE_LOCAL_ARRAYS */
411 png_uint_32 length = png_read_chunk_header(png_ptr);
412 PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
414 /* This should be a binary subdivision search or a hash for
415 * matching the chunk name rather than a linear search.
416 */
417 if (!png_memcmp(chunk_name, png_IDAT, 4))
418 if (png_ptr->mode & PNG_AFTER_IDAT)
419 png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
421 if (!png_memcmp(chunk_name, png_IHDR, 4))
422 png_handle_IHDR(png_ptr, info_ptr, length);
423 else if (!png_memcmp(chunk_name, png_IEND, 4))
424 png_handle_IEND(png_ptr, info_ptr, length);
425 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
426 else if (png_handle_as_unknown(png_ptr, chunk_name))
427 {
428 if (!png_memcmp(chunk_name, png_IDAT, 4))
429 png_ptr->mode |= PNG_HAVE_IDAT;
430 png_handle_unknown(png_ptr, info_ptr, length);
431 if (!png_memcmp(chunk_name, png_PLTE, 4))
432 png_ptr->mode |= PNG_HAVE_PLTE;
433 else if (!png_memcmp(chunk_name, png_IDAT, 4))
434 {
435 if (!(png_ptr->mode & PNG_HAVE_IHDR))
436 png_error(png_ptr, "Missing IHDR before IDAT");
437 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
438 !(png_ptr->mode & PNG_HAVE_PLTE))
439 png_error(png_ptr, "Missing PLTE before IDAT");
440 break;
441 }
442 }
443 #endif
444 else if (!png_memcmp(chunk_name, png_PLTE, 4))
445 png_handle_PLTE(png_ptr, info_ptr, length);
446 else if (!png_memcmp(chunk_name, png_IDAT, 4))
447 {
448 if (!(png_ptr->mode & PNG_HAVE_IHDR))
449 png_error(png_ptr, "Missing IHDR before IDAT");
450 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
451 !(png_ptr->mode & PNG_HAVE_PLTE))
452 png_error(png_ptr, "Missing PLTE before IDAT");
454 png_ptr->idat_size = length;
455 png_ptr->mode |= PNG_HAVE_IDAT;
456 break;
457 }
458 #if defined(PNG_READ_bKGD_SUPPORTED)
459 else if (!png_memcmp(chunk_name, png_bKGD, 4))
460 png_handle_bKGD(png_ptr, info_ptr, length);
461 #endif
462 #if defined(PNG_READ_cHRM_SUPPORTED)
463 else if (!png_memcmp(chunk_name, png_cHRM, 4))
464 png_handle_cHRM(png_ptr, info_ptr, length);
465 #endif
466 #if defined(PNG_READ_gAMA_SUPPORTED)
467 else if (!png_memcmp(chunk_name, png_gAMA, 4))
468 png_handle_gAMA(png_ptr, info_ptr, length);
469 #endif
470 #if defined(PNG_READ_hIST_SUPPORTED)
471 else if (!png_memcmp(chunk_name, png_hIST, 4))
472 png_handle_hIST(png_ptr, info_ptr, length);
473 #endif
474 #if defined(PNG_READ_oFFs_SUPPORTED)
475 else if (!png_memcmp(chunk_name, png_oFFs, 4))
476 png_handle_oFFs(png_ptr, info_ptr, length);
477 #endif
478 #if defined(PNG_READ_pCAL_SUPPORTED)
479 else if (!png_memcmp(chunk_name, png_pCAL, 4))
480 png_handle_pCAL(png_ptr, info_ptr, length);
481 #endif
482 #if defined(PNG_READ_sCAL_SUPPORTED)
483 else if (!png_memcmp(chunk_name, png_sCAL, 4))
484 png_handle_sCAL(png_ptr, info_ptr, length);
485 #endif
486 #if defined(PNG_READ_pHYs_SUPPORTED)
487 else if (!png_memcmp(chunk_name, png_pHYs, 4))
488 png_handle_pHYs(png_ptr, info_ptr, length);
489 #endif
490 #if defined(PNG_READ_sBIT_SUPPORTED)
491 else if (!png_memcmp(chunk_name, png_sBIT, 4))
492 png_handle_sBIT(png_ptr, info_ptr, length);
493 #endif
494 #if defined(PNG_READ_sRGB_SUPPORTED)
495 else if (!png_memcmp(chunk_name, png_sRGB, 4))
496 png_handle_sRGB(png_ptr, info_ptr, length);
497 #endif
498 #if defined(PNG_READ_iCCP_SUPPORTED)
499 else if (!png_memcmp(chunk_name, png_iCCP, 4))
500 png_handle_iCCP(png_ptr, info_ptr, length);
501 #endif
502 #if defined(PNG_READ_sPLT_SUPPORTED)
503 else if (!png_memcmp(chunk_name, png_sPLT, 4))
504 png_handle_sPLT(png_ptr, info_ptr, length);
505 #endif
506 #if defined(PNG_READ_tEXt_SUPPORTED)
507 else if (!png_memcmp(chunk_name, png_tEXt, 4))
508 png_handle_tEXt(png_ptr, info_ptr, length);
509 #endif
510 #if defined(PNG_READ_tIME_SUPPORTED)
511 else if (!png_memcmp(chunk_name, png_tIME, 4))
512 png_handle_tIME(png_ptr, info_ptr, length);
513 #endif
514 #if defined(PNG_READ_tRNS_SUPPORTED)
515 else if (!png_memcmp(chunk_name, png_tRNS, 4))
516 png_handle_tRNS(png_ptr, info_ptr, length);
517 #endif
518 #if defined(PNG_READ_zTXt_SUPPORTED)
519 else if (!png_memcmp(chunk_name, png_zTXt, 4))
520 png_handle_zTXt(png_ptr, info_ptr, length);
521 #endif
522 #if defined(PNG_READ_iTXt_SUPPORTED)
523 else if (!png_memcmp(chunk_name, png_iTXt, 4))
524 png_handle_iTXt(png_ptr, info_ptr, length);
525 #endif
526 else
527 png_handle_unknown(png_ptr, info_ptr, length);
528 }
529 }
530 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
532 /* optional call to update the users info_ptr structure */
533 void PNGAPI
534 png_read_update_info(png_structp png_ptr, png_infop info_ptr)
535 {
536 png_debug(1, "in png_read_update_info\n");
537 if (png_ptr == NULL) return;
538 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
539 png_read_start_row(png_ptr);
540 else
541 png_warning(png_ptr,
542 "Ignoring extra png_read_update_info() call; row buffer not reallocated");
543 png_read_transform_info(png_ptr, info_ptr);
544 }
546 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
547 /* Initialize palette, background, etc, after transformations
548 * are set, but before any reading takes place. This allows
549 * the user to obtain a gamma-corrected palette, for example.
550 * If the user doesn't call this, we will do it ourselves.
551 */
552 void PNGAPI
553 png_start_read_image(png_structp png_ptr)
554 {
555 png_debug(1, "in png_start_read_image\n");
556 if (png_ptr == NULL) return;
557 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
558 png_read_start_row(png_ptr);
559 }
560 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
562 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
563 void PNGAPI
564 png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
565 {
566 #ifdef PNG_USE_LOCAL_ARRAYS
567 PNG_CONST PNG_IDAT;
568 PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
569 0xff};
570 PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
571 #endif
572 int ret;
573 if (png_ptr == NULL) return;
574 png_debug2(1, "in png_read_row (row %lu, pass %d)\n",
575 png_ptr->row_number, png_ptr->pass);
576 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
577 png_read_start_row(png_ptr);
578 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
579 {
580 /* check for transforms that have been set but were defined out */
581 #if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
582 if (png_ptr->transformations & PNG_INVERT_MONO)
583 png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined.");
584 #endif
585 #if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
586 if (png_ptr->transformations & PNG_FILLER)
587 png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined.");
588 #endif
589 #if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && !defined(PNG_READ_PACKSWAP_SUPPORTED)
590 if (png_ptr->transformations & PNG_PACKSWAP)
591 png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined.");
592 #endif
593 #if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
594 if (png_ptr->transformations & PNG_PACK)
595 png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined.");
596 #endif
597 #if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
598 if (png_ptr->transformations & PNG_SHIFT)
599 png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined.");
600 #endif
601 #if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
602 if (png_ptr->transformations & PNG_BGR)
603 png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined.");
604 #endif
605 #if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
606 if (png_ptr->transformations & PNG_SWAP_BYTES)
607 png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined.");
608 #endif
609 }
611 #if defined(PNG_READ_INTERLACING_SUPPORTED)
612 /* if interlaced and we do not need a new row, combine row and return */
613 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
614 {
615 switch (png_ptr->pass)
616 {
617 case 0:
618 if (png_ptr->row_number & 0x07)
619 {
620 if (dsp_row != NULL)
621 png_combine_row(png_ptr, dsp_row,
622 png_pass_dsp_mask[png_ptr->pass]);
623 png_read_finish_row(png_ptr);
624 return;
625 }
626 break;
627 case 1:
628 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
629 {
630 if (dsp_row != NULL)
631 png_combine_row(png_ptr, dsp_row,
632 png_pass_dsp_mask[png_ptr->pass]);
633 png_read_finish_row(png_ptr);
634 return;
635 }
636 break;
637 case 2:
638 if ((png_ptr->row_number & 0x07) != 4)
639 {
640 if (dsp_row != NULL && (png_ptr->row_number & 4))
641 png_combine_row(png_ptr, dsp_row,
642 png_pass_dsp_mask[png_ptr->pass]);
643 png_read_finish_row(png_ptr);
644 return;
645 }
646 break;
647 case 3:
648 if ((png_ptr->row_number & 3) || png_ptr->width < 3)
649 {
650 if (dsp_row != NULL)
651 png_combine_row(png_ptr, dsp_row,
652 png_pass_dsp_mask[png_ptr->pass]);
653 png_read_finish_row(png_ptr);
654 return;
655 }
656 break;
657 case 4:
658 if ((png_ptr->row_number & 3) != 2)
659 {
660 if (dsp_row != NULL && (png_ptr->row_number & 2))
661 png_combine_row(png_ptr, dsp_row,
662 png_pass_dsp_mask[png_ptr->pass]);
663 png_read_finish_row(png_ptr);
664 return;
665 }
666 break;
667 case 5:
668 if ((png_ptr->row_number & 1) || png_ptr->width < 2)
669 {
670 if (dsp_row != NULL)
671 png_combine_row(png_ptr, dsp_row,
672 png_pass_dsp_mask[png_ptr->pass]);
673 png_read_finish_row(png_ptr);
674 return;
675 }
676 break;
677 case 6:
678 if (!(png_ptr->row_number & 1))
679 {
680 png_read_finish_row(png_ptr);
681 return;
682 }
683 break;
684 }
685 }
686 #endif
688 if (!(png_ptr->mode & PNG_HAVE_IDAT))
689 png_error(png_ptr, "Invalid attempt to read row data");
691 png_ptr->zstream.next_out = png_ptr->row_buf;
692 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
693 do
694 {
695 if (!(png_ptr->zstream.avail_in))
696 {
697 while (!png_ptr->idat_size)
698 {
699 png_crc_finish(png_ptr, 0);
701 png_ptr->idat_size = png_read_chunk_header(png_ptr);
702 if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
703 png_error(png_ptr, "Not enough image data");
704 }
705 png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
706 png_ptr->zstream.next_in = png_ptr->zbuf;
707 if (png_ptr->zbuf_size > png_ptr->idat_size)
708 png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
709 png_crc_read(png_ptr, png_ptr->zbuf,
710 (png_size_t)png_ptr->zstream.avail_in);
711 png_ptr->idat_size -= png_ptr->zstream.avail_in;
712 }
713 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
714 if (ret == Z_STREAM_END)
715 {
716 if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
717 png_ptr->idat_size)
718 png_error(png_ptr, "Extra compressed data");
719 png_ptr->mode |= PNG_AFTER_IDAT;
720 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
721 break;
722 }
723 if (ret != Z_OK)
724 png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
725 "Decompression error");
727 } while (png_ptr->zstream.avail_out);
729 png_ptr->row_info.color_type = png_ptr->color_type;
730 png_ptr->row_info.width = png_ptr->iwidth;
731 png_ptr->row_info.channels = png_ptr->channels;
732 png_ptr->row_info.bit_depth = png_ptr->bit_depth;
733 png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
734 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
735 png_ptr->row_info.width);
737 if (png_ptr->row_buf[0])
738 png_read_filter_row(png_ptr, &(png_ptr->row_info),
739 png_ptr->row_buf + 1, png_ptr->prev_row + 1,
740 (int)(png_ptr->row_buf[0]));
742 png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
743 png_ptr->rowbytes + 1);
745 #if defined(PNG_MNG_FEATURES_SUPPORTED)
746 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
747 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
748 {
749 /* Intrapixel differencing */
750 png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
751 }
752 #endif
755 if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
756 png_do_read_transformations(png_ptr);
758 #if defined(PNG_READ_INTERLACING_SUPPORTED)
759 /* blow up interlaced rows to full size */
760 if (png_ptr->interlaced &&
761 (png_ptr->transformations & PNG_INTERLACE))
762 {
763 if (png_ptr->pass < 6)
764 /* old interface (pre-1.0.9):
765 png_do_read_interlace(&(png_ptr->row_info),
766 png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
767 */
768 png_do_read_interlace(png_ptr);
770 if (dsp_row != NULL)
771 png_combine_row(png_ptr, dsp_row,
772 png_pass_dsp_mask[png_ptr->pass]);
773 if (row != NULL)
774 png_combine_row(png_ptr, row,
775 png_pass_mask[png_ptr->pass]);
776 }
777 else
778 #endif
779 {
780 if (row != NULL)
781 png_combine_row(png_ptr, row, 0xff);
782 if (dsp_row != NULL)
783 png_combine_row(png_ptr, dsp_row, 0xff);
784 }
785 png_read_finish_row(png_ptr);
787 if (png_ptr->read_row_fn != NULL)
788 (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
789 }
790 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
792 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
793 /* Read one or more rows of image data. If the image is interlaced,
794 * and png_set_interlace_handling() has been called, the rows need to
795 * contain the contents of the rows from the previous pass. If the
796 * image has alpha or transparency, and png_handle_alpha()[*] has been
797 * called, the rows contents must be initialized to the contents of the
798 * screen.
799 *
800 * "row" holds the actual image, and pixels are placed in it
801 * as they arrive. If the image is displayed after each pass, it will
802 * appear to "sparkle" in. "display_row" can be used to display a
803 * "chunky" progressive image, with finer detail added as it becomes
804 * available. If you do not want this "chunky" display, you may pass
805 * NULL for display_row. If you do not want the sparkle display, and
806 * you have not called png_handle_alpha(), you may pass NULL for rows.
807 * If you have called png_handle_alpha(), and the image has either an
808 * alpha channel or a transparency chunk, you must provide a buffer for
809 * rows. In this case, you do not have to provide a display_row buffer
810 * also, but you may. If the image is not interlaced, or if you have
811 * not called png_set_interlace_handling(), the display_row buffer will
812 * be ignored, so pass NULL to it.
813 *
814 * [*] png_handle_alpha() does not exist yet, as of this version of libpng
815 */
817 void PNGAPI
818 png_read_rows(png_structp png_ptr, png_bytepp row,
819 png_bytepp display_row, png_uint_32 num_rows)
820 {
821 png_uint_32 i;
822 png_bytepp rp;
823 png_bytepp dp;
825 png_debug(1, "in png_read_rows\n");
826 if (png_ptr == NULL) return;
827 rp = row;
828 dp = display_row;
829 if (rp != NULL && dp != NULL)
830 for (i = 0; i < num_rows; i++)
831 {
832 png_bytep rptr = *rp++;
833 png_bytep dptr = *dp++;
835 png_read_row(png_ptr, rptr, dptr);
836 }
837 else if (rp != NULL)
838 for (i = 0; i < num_rows; i++)
839 {
840 png_bytep rptr = *rp;
841 png_read_row(png_ptr, rptr, png_bytep_NULL);
842 rp++;
843 }
844 else if (dp != NULL)
845 for (i = 0; i < num_rows; i++)
846 {
847 png_bytep dptr = *dp;
848 png_read_row(png_ptr, png_bytep_NULL, dptr);
849 dp++;
850 }
851 }
852 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
854 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
855 /* Read the entire image. If the image has an alpha channel or a tRNS
856 * chunk, and you have called png_handle_alpha()[*], you will need to
857 * initialize the image to the current image that PNG will be overlaying.
858 * We set the num_rows again here, in case it was incorrectly set in
859 * png_read_start_row() by a call to png_read_update_info() or
860 * png_start_read_image() if png_set_interlace_handling() wasn't called
861 * prior to either of these functions like it should have been. You can
862 * only call this function once. If you desire to have an image for
863 * each pass of a interlaced image, use png_read_rows() instead.
864 *
865 * [*] png_handle_alpha() does not exist yet, as of this version of libpng
866 */
867 void PNGAPI
868 png_read_image(png_structp png_ptr, png_bytepp image)
869 {
870 png_uint_32 i, image_height;
871 int pass, j;
872 png_bytepp rp;
874 png_debug(1, "in png_read_image\n");
875 if (png_ptr == NULL) return;
877 #ifdef PNG_READ_INTERLACING_SUPPORTED
878 pass = png_set_interlace_handling(png_ptr);
879 #else
880 if (png_ptr->interlaced)
881 png_error(png_ptr,
882 "Cannot read interlaced image -- interlace handler disabled.");
883 pass = 1;
884 #endif
887 image_height=png_ptr->height;
888 png_ptr->num_rows = image_height; /* Make sure this is set correctly */
890 for (j = 0; j < pass; j++)
891 {
892 rp = image;
893 for (i = 0; i < image_height; i++)
894 {
895 png_read_row(png_ptr, *rp, png_bytep_NULL);
896 rp++;
897 }
898 }
899 }
900 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
902 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
903 /* Read the end of the PNG file. Will not read past the end of the
904 * file, will verify the end is accurate, and will read any comments
905 * or time information at the end of the file, if info is not NULL.
906 */
907 void PNGAPI
908 png_read_end(png_structp png_ptr, png_infop info_ptr)
909 {
910 png_debug(1, "in png_read_end\n");
911 if (png_ptr == NULL) return;
912 png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
914 do
915 {
916 #ifdef PNG_USE_LOCAL_ARRAYS
917 PNG_CONST PNG_IHDR;
918 PNG_CONST PNG_IDAT;
919 PNG_CONST PNG_IEND;
920 PNG_CONST PNG_PLTE;
921 #if defined(PNG_READ_bKGD_SUPPORTED)
922 PNG_CONST PNG_bKGD;
923 #endif
924 #if defined(PNG_READ_cHRM_SUPPORTED)
925 PNG_CONST PNG_cHRM;
926 #endif
927 #if defined(PNG_READ_gAMA_SUPPORTED)
928 PNG_CONST PNG_gAMA;
929 #endif
930 #if defined(PNG_READ_hIST_SUPPORTED)
931 PNG_CONST PNG_hIST;
932 #endif
933 #if defined(PNG_READ_iCCP_SUPPORTED)
934 PNG_CONST PNG_iCCP;
935 #endif
936 #if defined(PNG_READ_iTXt_SUPPORTED)
937 PNG_CONST PNG_iTXt;
938 #endif
939 #if defined(PNG_READ_oFFs_SUPPORTED)
940 PNG_CONST PNG_oFFs;
941 #endif
942 #if defined(PNG_READ_pCAL_SUPPORTED)
943 PNG_CONST PNG_pCAL;
944 #endif
945 #if defined(PNG_READ_pHYs_SUPPORTED)
946 PNG_CONST PNG_pHYs;
947 #endif
948 #if defined(PNG_READ_sBIT_SUPPORTED)
949 PNG_CONST PNG_sBIT;
950 #endif
951 #if defined(PNG_READ_sCAL_SUPPORTED)
952 PNG_CONST PNG_sCAL;
953 #endif
954 #if defined(PNG_READ_sPLT_SUPPORTED)
955 PNG_CONST PNG_sPLT;
956 #endif
957 #if defined(PNG_READ_sRGB_SUPPORTED)
958 PNG_CONST PNG_sRGB;
959 #endif
960 #if defined(PNG_READ_tEXt_SUPPORTED)
961 PNG_CONST PNG_tEXt;
962 #endif
963 #if defined(PNG_READ_tIME_SUPPORTED)
964 PNG_CONST PNG_tIME;
965 #endif
966 #if defined(PNG_READ_tRNS_SUPPORTED)
967 PNG_CONST PNG_tRNS;
968 #endif
969 #if defined(PNG_READ_zTXt_SUPPORTED)
970 PNG_CONST PNG_zTXt;
971 #endif
972 #endif /* PNG_USE_LOCAL_ARRAYS */
973 png_uint_32 length = png_read_chunk_header(png_ptr);
974 PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
976 if (!png_memcmp(chunk_name, png_IHDR, 4))
977 png_handle_IHDR(png_ptr, info_ptr, length);
978 else if (!png_memcmp(chunk_name, png_IEND, 4))
979 png_handle_IEND(png_ptr, info_ptr, length);
980 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
981 else if (png_handle_as_unknown(png_ptr, chunk_name))
982 {
983 if (!png_memcmp(chunk_name, png_IDAT, 4))
984 {
985 if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
986 png_error(png_ptr, "Too many IDAT's found");
987 }
988 png_handle_unknown(png_ptr, info_ptr, length);
989 if (!png_memcmp(chunk_name, png_PLTE, 4))
990 png_ptr->mode |= PNG_HAVE_PLTE;
991 }
992 #endif
993 else if (!png_memcmp(chunk_name, png_IDAT, 4))
994 {
995 /* Zero length IDATs are legal after the last IDAT has been
996 * read, but not after other chunks have been read.
997 */
998 if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
999 png_error(png_ptr, "Too many IDAT's found");
1000 png_crc_finish(png_ptr, length);
1001 }
1002 else if (!png_memcmp(chunk_name, png_PLTE, 4))
1003 png_handle_PLTE(png_ptr, info_ptr, length);
1004 #if defined(PNG_READ_bKGD_SUPPORTED)
1005 else if (!png_memcmp(chunk_name, png_bKGD, 4))
1006 png_handle_bKGD(png_ptr, info_ptr, length);
1007 #endif
1008 #if defined(PNG_READ_cHRM_SUPPORTED)
1009 else if (!png_memcmp(chunk_name, png_cHRM, 4))
1010 png_handle_cHRM(png_ptr, info_ptr, length);
1011 #endif
1012 #if defined(PNG_READ_gAMA_SUPPORTED)
1013 else if (!png_memcmp(chunk_name, png_gAMA, 4))
1014 png_handle_gAMA(png_ptr, info_ptr, length);
1015 #endif
1016 #if defined(PNG_READ_hIST_SUPPORTED)
1017 else if (!png_memcmp(chunk_name, png_hIST, 4))
1018 png_handle_hIST(png_ptr, info_ptr, length);
1019 #endif
1020 #if defined(PNG_READ_oFFs_SUPPORTED)
1021 else if (!png_memcmp(chunk_name, png_oFFs, 4))
1022 png_handle_oFFs(png_ptr, info_ptr, length);
1023 #endif
1024 #if defined(PNG_READ_pCAL_SUPPORTED)
1025 else if (!png_memcmp(chunk_name, png_pCAL, 4))
1026 png_handle_pCAL(png_ptr, info_ptr, length);
1027 #endif
1028 #if defined(PNG_READ_sCAL_SUPPORTED)
1029 else if (!png_memcmp(chunk_name, png_sCAL, 4))
1030 png_handle_sCAL(png_ptr, info_ptr, length);
1031 #endif
1032 #if defined(PNG_READ_pHYs_SUPPORTED)
1033 else if (!png_memcmp(chunk_name, png_pHYs, 4))
1034 png_handle_pHYs(png_ptr, info_ptr, length);
1035 #endif
1036 #if defined(PNG_READ_sBIT_SUPPORTED)
1037 else if (!png_memcmp(chunk_name, png_sBIT, 4))
1038 png_handle_sBIT(png_ptr, info_ptr, length);
1039 #endif
1040 #if defined(PNG_READ_sRGB_SUPPORTED)
1041 else if (!png_memcmp(chunk_name, png_sRGB, 4))
1042 png_handle_sRGB(png_ptr, info_ptr, length);
1043 #endif
1044 #if defined(PNG_READ_iCCP_SUPPORTED)
1045 else if (!png_memcmp(chunk_name, png_iCCP, 4))
1046 png_handle_iCCP(png_ptr, info_ptr, length);
1047 #endif
1048 #if defined(PNG_READ_sPLT_SUPPORTED)
1049 else if (!png_memcmp(chunk_name, png_sPLT, 4))
1050 png_handle_sPLT(png_ptr, info_ptr, length);
1051 #endif
1052 #if defined(PNG_READ_tEXt_SUPPORTED)
1053 else if (!png_memcmp(chunk_name, png_tEXt, 4))
1054 png_handle_tEXt(png_ptr, info_ptr, length);
1055 #endif
1056 #if defined(PNG_READ_tIME_SUPPORTED)
1057 else if (!png_memcmp(chunk_name, png_tIME, 4))
1058 png_handle_tIME(png_ptr, info_ptr, length);
1059 #endif
1060 #if defined(PNG_READ_tRNS_SUPPORTED)
1061 else if (!png_memcmp(chunk_name, png_tRNS, 4))
1062 png_handle_tRNS(png_ptr, info_ptr, length);
1063 #endif
1064 #if defined(PNG_READ_zTXt_SUPPORTED)
1065 else if (!png_memcmp(chunk_name, png_zTXt, 4))
1066 png_handle_zTXt(png_ptr, info_ptr, length);
1067 #endif
1068 #if defined(PNG_READ_iTXt_SUPPORTED)
1069 else if (!png_memcmp(chunk_name, png_iTXt, 4))
1070 png_handle_iTXt(png_ptr, info_ptr, length);
1071 #endif
1072 else
1073 png_handle_unknown(png_ptr, info_ptr, length);
1074 } while (!(png_ptr->mode & PNG_HAVE_IEND));
1075 }
1076 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
1078 /* free all memory used by the read */
1079 void PNGAPI
1080 png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
1081 png_infopp end_info_ptr_ptr)
1082 {
1083 png_structp png_ptr = NULL;
1084 png_infop info_ptr = NULL, end_info_ptr = NULL;
1085 #ifdef PNG_USER_MEM_SUPPORTED
1086 png_free_ptr free_fn = NULL;
1087 png_voidp mem_ptr = NULL;
1088 #endif
1090 png_debug(1, "in png_destroy_read_struct\n");
1091 if (png_ptr_ptr != NULL)
1092 png_ptr = *png_ptr_ptr;
1093 if (png_ptr == NULL)
1094 return;
1096 #ifdef PNG_USER_MEM_SUPPORTED
1097 free_fn = png_ptr->free_fn;
1098 mem_ptr = png_ptr->mem_ptr;
1099 #endif
1101 if (info_ptr_ptr != NULL)
1102 info_ptr = *info_ptr_ptr;
1104 if (end_info_ptr_ptr != NULL)
1105 end_info_ptr = *end_info_ptr_ptr;
1107 png_read_destroy(png_ptr, info_ptr, end_info_ptr);
1109 if (info_ptr != NULL)
1110 {
1111 #if defined(PNG_TEXT_SUPPORTED)
1112 png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1);
1113 #endif
1115 #ifdef PNG_USER_MEM_SUPPORTED
1116 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1117 (png_voidp)mem_ptr);
1118 #else
1119 png_destroy_struct((png_voidp)info_ptr);
1120 #endif
1121 *info_ptr_ptr = NULL;
1122 }
1124 if (end_info_ptr != NULL)
1125 {
1126 #if defined(PNG_READ_TEXT_SUPPORTED)
1127 png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1);
1128 #endif
1129 #ifdef PNG_USER_MEM_SUPPORTED
1130 png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn,
1131 (png_voidp)mem_ptr);
1132 #else
1133 png_destroy_struct((png_voidp)end_info_ptr);
1134 #endif
1135 *end_info_ptr_ptr = NULL;
1136 }
1138 if (png_ptr != NULL)
1139 {
1140 #ifdef PNG_USER_MEM_SUPPORTED
1141 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1142 (png_voidp)mem_ptr);
1143 #else
1144 png_destroy_struct((png_voidp)png_ptr);
1145 #endif
1146 *png_ptr_ptr = NULL;
1147 }
1148 }
1150 /* free all memory used by the read (old method) */
1151 void /* PRIVATE */
1152 png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr)
1153 {
1154 #ifdef PNG_SETJMP_SUPPORTED
1155 jmp_buf tmp_jmp;
1156 #endif
1157 png_error_ptr error_fn;
1158 png_error_ptr warning_fn;
1159 png_voidp error_ptr;
1160 #ifdef PNG_USER_MEM_SUPPORTED
1161 png_free_ptr free_fn;
1162 #endif
1164 png_debug(1, "in png_read_destroy\n");
1165 if (info_ptr != NULL)
1166 png_info_destroy(png_ptr, info_ptr);
1168 if (end_info_ptr != NULL)
1169 png_info_destroy(png_ptr, end_info_ptr);
1171 png_free(png_ptr, png_ptr->zbuf);
1172 png_free(png_ptr, png_ptr->big_row_buf);
1173 png_free(png_ptr, png_ptr->prev_row);
1174 png_free(png_ptr, png_ptr->chunkdata);
1175 #if defined(PNG_READ_DITHER_SUPPORTED)
1176 png_free(png_ptr, png_ptr->palette_lookup);
1177 png_free(png_ptr, png_ptr->dither_index);
1178 #endif
1179 #if defined(PNG_READ_GAMMA_SUPPORTED)
1180 png_free(png_ptr, png_ptr->gamma_table);
1181 #endif
1182 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
1183 png_free(png_ptr, png_ptr->gamma_from_1);
1184 png_free(png_ptr, png_ptr->gamma_to_1);
1185 #endif
1186 #ifdef PNG_FREE_ME_SUPPORTED
1187 if (png_ptr->free_me & PNG_FREE_PLTE)
1188 png_zfree(png_ptr, png_ptr->palette);
1189 png_ptr->free_me &= ~PNG_FREE_PLTE;
1190 #else
1191 if (png_ptr->flags & PNG_FLAG_FREE_PLTE)
1192 png_zfree(png_ptr, png_ptr->palette);
1193 png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
1194 #endif
1195 #if defined(PNG_tRNS_SUPPORTED) || \
1196 defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1197 #ifdef PNG_FREE_ME_SUPPORTED
1198 if (png_ptr->free_me & PNG_FREE_TRNS)
1199 png_free(png_ptr, png_ptr->trans);
1200 png_ptr->free_me &= ~PNG_FREE_TRNS;
1201 #else
1202 if (png_ptr->flags & PNG_FLAG_FREE_TRNS)
1203 png_free(png_ptr, png_ptr->trans);
1204 png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
1205 #endif
1206 #endif
1207 #if defined(PNG_READ_hIST_SUPPORTED)
1208 #ifdef PNG_FREE_ME_SUPPORTED
1209 if (png_ptr->free_me & PNG_FREE_HIST)
1210 png_free(png_ptr, png_ptr->hist);
1211 png_ptr->free_me &= ~PNG_FREE_HIST;
1212 #else
1213 if (png_ptr->flags & PNG_FLAG_FREE_HIST)
1214 png_free(png_ptr, png_ptr->hist);
1215 png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
1216 #endif
1217 #endif
1218 #if defined(PNG_READ_GAMMA_SUPPORTED)
1219 if (png_ptr->gamma_16_table != NULL)
1220 {
1221 int i;
1222 int istop = (1 << (8 - png_ptr->gamma_shift));
1223 for (i = 0; i < istop; i++)
1224 {
1225 png_free(png_ptr, png_ptr->gamma_16_table[i]);
1226 }
1227 png_free(png_ptr, png_ptr->gamma_16_table);
1228 }
1229 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
1230 if (png_ptr->gamma_16_from_1 != NULL)
1231 {
1232 int i;
1233 int istop = (1 << (8 - png_ptr->gamma_shift));
1234 for (i = 0; i < istop; i++)
1235 {
1236 png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
1237 }
1238 png_free(png_ptr, png_ptr->gamma_16_from_1);
1239 }
1240 if (png_ptr->gamma_16_to_1 != NULL)
1241 {
1242 int i;
1243 int istop = (1 << (8 - png_ptr->gamma_shift));
1244 for (i = 0; i < istop; i++)
1245 {
1246 png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
1247 }
1248 png_free(png_ptr, png_ptr->gamma_16_to_1);
1249 }
1250 #endif
1251 #endif
1252 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1253 png_free(png_ptr, png_ptr->time_buffer);
1254 #endif
1256 inflateEnd(&png_ptr->zstream);
1257 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1258 png_free(png_ptr, png_ptr->save_buffer);
1259 #endif
1261 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1262 #ifdef PNG_TEXT_SUPPORTED
1263 png_free(png_ptr, png_ptr->current_text);
1264 #endif /* PNG_TEXT_SUPPORTED */
1265 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1267 /* Save the important info out of the png_struct, in case it is
1268 * being used again.
1269 */
1270 #ifdef PNG_SETJMP_SUPPORTED
1271 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
1272 #endif
1274 error_fn = png_ptr->error_fn;
1275 warning_fn = png_ptr->warning_fn;
1276 error_ptr = png_ptr->error_ptr;
1277 #ifdef PNG_USER_MEM_SUPPORTED
1278 free_fn = png_ptr->free_fn;
1279 #endif
1281 png_memset(png_ptr, 0, png_sizeof(png_struct));
1283 png_ptr->error_fn = error_fn;
1284 png_ptr->warning_fn = warning_fn;
1285 png_ptr->error_ptr = error_ptr;
1286 #ifdef PNG_USER_MEM_SUPPORTED
1287 png_ptr->free_fn = free_fn;
1288 #endif
1290 #ifdef PNG_SETJMP_SUPPORTED
1291 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
1292 #endif
1294 }
1296 void PNGAPI
1297 png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
1298 {
1299 if (png_ptr == NULL) return;
1300 png_ptr->read_row_fn = read_row_fn;
1301 }
1304 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1305 #if defined(PNG_INFO_IMAGE_SUPPORTED)
1306 void PNGAPI
1307 png_read_png(png_structp png_ptr, png_infop info_ptr,
1308 int transforms,
1309 voidp params)
1310 {
1311 int row;
1313 if (png_ptr == NULL) return;
1314 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
1315 /* invert the alpha channel from opacity to transparency
1316 */
1317 if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1318 png_set_invert_alpha(png_ptr);
1319 #endif
1321 /* png_read_info() gives us all of the information from the
1322 * PNG file before the first IDAT (image data chunk).
1323 */
1324 png_read_info(png_ptr, info_ptr);
1325 if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
1326 png_error(png_ptr, "Image is too high to process with png_read_png()");
1328 /* -------------- image transformations start here ------------------- */
1330 #if defined(PNG_READ_16_TO_8_SUPPORTED)
1331 /* tell libpng to strip 16 bit/color files down to 8 bits per color
1332 */
1333 if (transforms & PNG_TRANSFORM_STRIP_16)
1334 png_set_strip_16(png_ptr);
1335 #endif
1337 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1338 /* Strip alpha bytes from the input data without combining with
1339 * the background (not recommended).
1340 */
1341 if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
1342 png_set_strip_alpha(png_ptr);
1343 #endif
1345 #if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
1346 /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
1347 * byte into separate bytes (useful for paletted and grayscale images).
1348 */
1349 if (transforms & PNG_TRANSFORM_PACKING)
1350 png_set_packing(png_ptr);
1351 #endif
1353 #if defined(PNG_READ_PACKSWAP_SUPPORTED)
1354 /* Change the order of packed pixels to least significant bit first
1355 * (not useful if you are using png_set_packing).
1356 */
1357 if (transforms & PNG_TRANSFORM_PACKSWAP)
1358 png_set_packswap(png_ptr);
1359 #endif
1361 #if defined(PNG_READ_EXPAND_SUPPORTED)
1362 /* Expand paletted colors into true RGB triplets
1363 * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
1364 * Expand paletted or RGB images with transparency to full alpha
1365 * channels so the data will be available as RGBA quartets.
1366 */
1367 if (transforms & PNG_TRANSFORM_EXPAND)
1368 if ((png_ptr->bit_depth < 8) ||
1369 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
1370 (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
1371 png_set_expand(png_ptr);
1372 #endif
1374 /* We don't handle background color or gamma transformation or dithering.
1375 */
1377 #if defined(PNG_READ_INVERT_SUPPORTED)
1378 /* invert monochrome files to have 0 as white and 1 as black
1379 */
1380 if (transforms & PNG_TRANSFORM_INVERT_MONO)
1381 png_set_invert_mono(png_ptr);
1382 #endif
1384 #if defined(PNG_READ_SHIFT_SUPPORTED)
1385 /* If you want to shift the pixel values from the range [0,255] or
1386 * [0,65535] to the original [0,7] or [0,31], or whatever range the
1387 * colors were originally in:
1388 */
1389 if ((transforms & PNG_TRANSFORM_SHIFT)
1390 && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
1391 {
1392 png_color_8p sig_bit;
1394 png_get_sBIT(png_ptr, info_ptr, &sig_bit);
1395 png_set_shift(png_ptr, sig_bit);
1396 }
1397 #endif
1399 #if defined(PNG_READ_BGR_SUPPORTED)
1400 /* flip the RGB pixels to BGR (or RGBA to BGRA)
1401 */
1402 if (transforms & PNG_TRANSFORM_BGR)
1403 png_set_bgr(png_ptr);
1404 #endif
1406 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
1407 /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR)
1408 */
1409 if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1410 png_set_swap_alpha(png_ptr);
1411 #endif
1413 #if defined(PNG_READ_SWAP_SUPPORTED)
1414 /* swap bytes of 16 bit files to least significant byte first
1415 */
1416 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1417 png_set_swap(png_ptr);
1418 #endif
1420 /* We don't handle adding filler bytes */
1422 /* Optional call to gamma correct and add the background to the palette
1423 * and update info structure. REQUIRED if you are expecting libpng to
1424 * update the palette for you (i.e., you selected such a transform above).
1425 */
1426 png_read_update_info(png_ptr, info_ptr);
1428 /* -------------- image transformations end here ------------------- */
1430 #ifdef PNG_FREE_ME_SUPPORTED
1431 png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
1432 #endif
1433 if (info_ptr->row_pointers == NULL)
1434 {
1435 info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
1436 info_ptr->height * png_sizeof(png_bytep));
1437 #ifdef PNG_FREE_ME_SUPPORTED
1438 info_ptr->free_me |= PNG_FREE_ROWS;
1439 #endif
1440 for (row = 0; row < (int)info_ptr->height; row++)
1441 {
1442 info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,
1443 png_get_rowbytes(png_ptr, info_ptr));
1444 }
1445 }
1447 png_read_image(png_ptr, info_ptr->row_pointers);
1448 info_ptr->valid |= PNG_INFO_IDAT;
1450 /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
1451 png_read_end(png_ptr, info_ptr);
1453 transforms = transforms; /* quiet compiler warnings */
1454 params = params;
1456 }
1457 #endif /* PNG_INFO_IMAGE_SUPPORTED */
1458 #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
1459 #endif /* PNG_READ_SUPPORTED */