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source: vbox/trunk/src/libs/libpng-1.2.8/pngread.c@ 48765

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export libpng and zlib so Windows and OS/2 builds cleanly.
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1
2/* pngread.c - read a PNG file
3 *
4 * libpng 1.2.8 - December 3, 2004
5 * For conditions of distribution and use, see copyright notice in png.h
6 * Copyright (c) 1998-2004 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/* Create a PNG structure for reading, and allocate any memory needed. */
18png_structp PNGAPI
19png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr,
20 png_error_ptr error_fn, png_error_ptr warn_fn)
21{
22
23#ifdef PNG_USER_MEM_SUPPORTED
24 return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
25 warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
26}
27
28/* Alternate create PNG structure for reading, and allocate any memory needed. */
29png_structp PNGAPI
30png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
31 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
32 png_malloc_ptr malloc_fn, png_free_ptr free_fn)
33{
34#endif /* PNG_USER_MEM_SUPPORTED */
35
36 png_structp png_ptr;
37
38#ifdef PNG_SETJMP_SUPPORTED
39#ifdef USE_FAR_KEYWORD
40 jmp_buf jmpbuf;
41#endif
42#endif
43
44 int i;
45
46 png_debug(1, "in png_create_read_struct\n");
47#ifdef PNG_USER_MEM_SUPPORTED
48 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
49 (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
50#else
51 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
52#endif
53 if (png_ptr == NULL)
54 return (NULL);
55
56#if !defined(PNG_1_0_X)
57#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
58 png_init_mmx_flags(png_ptr); /* 1.2.0 addition */
59#endif
60#endif /* PNG_1_0_X */
61
62 /* added at libpng-1.2.6 */
63#ifdef PNG_SET_USER_LIMITS_SUPPORTED
64 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
65 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
66#endif
67
68#ifdef PNG_SETJMP_SUPPORTED
69#ifdef USE_FAR_KEYWORD
70 if (setjmp(jmpbuf))
71#else
72 if (setjmp(png_ptr->jmpbuf))
73#endif
74 {
75 png_free(png_ptr, png_ptr->zbuf);
76 png_ptr->zbuf=NULL;
77#ifdef PNG_USER_MEM_SUPPORTED
78 png_destroy_struct_2((png_voidp)png_ptr,
79 (png_free_ptr)free_fn, (png_voidp)mem_ptr);
80#else
81 png_destroy_struct((png_voidp)png_ptr);
82#endif
83 return (NULL);
84 }
85#ifdef USE_FAR_KEYWORD
86 png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
87#endif
88#endif
89
90#ifdef PNG_USER_MEM_SUPPORTED
91 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
92#endif
93
94 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
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 if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
104 {
105 /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
106 * we must recompile any applications that use any older library version.
107 * For versions after libpng 1.0, we will be compatible, so we need
108 * only check the first digit.
109 */
110 if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
111 (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
112 (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
113 {
114#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
115 char msg[80];
116 if (user_png_ver)
117 {
118 sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
119 user_png_ver);
120 png_warning(png_ptr, msg);
121 }
122 sprintf(msg, "Application is running with png.c from libpng-%.20s",
123 png_libpng_ver);
124 png_warning(png_ptr, msg);
125#endif
126#ifdef PNG_ERROR_NUMBERS_SUPPORTED
127 png_ptr->flags=0;
128#endif
129 png_error(png_ptr,
130 "Incompatible libpng version in application and library");
131 }
132 }
133
134 /* initialize zbuf - compression buffer */
135 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
136 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
137 (png_uint_32)png_ptr->zbuf_size);
138 png_ptr->zstream.zalloc = png_zalloc;
139 png_ptr->zstream.zfree = png_zfree;
140 png_ptr->zstream.opaque = (voidpf)png_ptr;
141
142 switch (inflateInit(&png_ptr->zstream))
143 {
144 case Z_OK: /* Do nothing */ break;
145 case Z_MEM_ERROR:
146 case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory error"); break;
147 case Z_VERSION_ERROR: png_error(png_ptr, "zlib version error"); break;
148 default: png_error(png_ptr, "Unknown zlib error");
149 }
150
151 png_ptr->zstream.next_out = png_ptr->zbuf;
152 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
153
154 png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
155
156#ifdef PNG_SETJMP_SUPPORTED
157/* Applications that neglect to set up their own setjmp() and then encounter
158 a png_error() will longjmp here. Since the jmpbuf is then meaningless we
159 abort instead of returning. */
160#ifdef USE_FAR_KEYWORD
161 if (setjmp(jmpbuf))
162 PNG_ABORT();
163 png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
164#else
165 if (setjmp(png_ptr->jmpbuf))
166 PNG_ABORT();
167#endif
168#endif
169 return (png_ptr);
170}
171
172/* Initialize PNG structure for reading, and allocate any memory needed.
173 This interface is deprecated in favour of the png_create_read_struct(),
174 and it will eventually disappear. */
175#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
176#undef png_read_init
177void PNGAPI
178png_read_init(png_structp png_ptr)
179{
180 /* We only come here via pre-1.0.7-compiled applications */
181 png_read_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
182}
183#endif
184
185void PNGAPI
186png_read_init_2(png_structp png_ptr, png_const_charp user_png_ver,
187 png_size_t png_struct_size, png_size_t png_info_size)
188{
189 /* We only come here via pre-1.0.12-compiled applications */
190#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
191 if(png_sizeof(png_struct) > png_struct_size ||
192 png_sizeof(png_info) > png_info_size)
193 {
194 char msg[80];
195 png_ptr->warning_fn=NULL;
196 if (user_png_ver)
197 {
198 sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
199 user_png_ver);
200 png_warning(png_ptr, msg);
201 }
202 sprintf(msg, "Application is running with png.c from libpng-%.20s",
203 png_libpng_ver);
204 png_warning(png_ptr, msg);
205 }
206#endif
207 if(png_sizeof(png_struct) > png_struct_size)
208 {
209 png_ptr->error_fn=NULL;
210#ifdef PNG_ERROR_NUMBERS_SUPPORTED
211 png_ptr->flags=0;
212#endif
213 png_error(png_ptr,
214 "The png struct allocated by the application for reading is too small.");
215 }
216 if(png_sizeof(png_info) > png_info_size)
217 {
218 png_ptr->error_fn=NULL;
219#ifdef PNG_ERROR_NUMBERS_SUPPORTED
220 png_ptr->flags=0;
221#endif
222 png_error(png_ptr,
223 "The info struct allocated by application for reading is too small.");
224 }
225 png_read_init_3(&png_ptr, user_png_ver, png_struct_size);
226}
227
228void PNGAPI
229png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
230 png_size_t png_struct_size)
231{
232#ifdef PNG_SETJMP_SUPPORTED
233 jmp_buf tmp_jmp; /* to save current jump buffer */
234#endif
235
236 int i=0;
237
238 png_structp png_ptr=*ptr_ptr;
239
240 do
241 {
242 if(user_png_ver[i] != png_libpng_ver[i])
243 {
244#ifdef PNG_LEGACY_SUPPORTED
245 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
246#else
247 png_ptr->warning_fn=NULL;
248 png_warning(png_ptr,
249 "Application uses deprecated png_read_init() and should be recompiled.");
250 break;
251#endif
252 }
253 } while (png_libpng_ver[i++]);
254
255 png_debug(1, "in png_read_init_3\n");
256
257#ifdef PNG_SETJMP_SUPPORTED
258 /* save jump buffer and error functions */
259 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
260#endif
261
262 if(png_sizeof(png_struct) > png_struct_size)
263 {
264 png_destroy_struct(png_ptr);
265 *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
266 png_ptr = *ptr_ptr;
267 }
268
269 /* reset all variables to 0 */
270 png_memset(png_ptr, 0, png_sizeof (png_struct));
271
272#ifdef PNG_SETJMP_SUPPORTED
273 /* restore jump buffer */
274 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
275#endif
276
277 /* added at libpng-1.2.6 */
278#ifdef PNG_SET_USER_LIMITS_SUPPORTED
279 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
280 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
281#endif
282
283 /* initialize zbuf - compression buffer */
284 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
285 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
286 (png_uint_32)png_ptr->zbuf_size);
287 png_ptr->zstream.zalloc = png_zalloc;
288 png_ptr->zstream.zfree = png_zfree;
289 png_ptr->zstream.opaque = (voidpf)png_ptr;
290
291 switch (inflateInit(&png_ptr->zstream))
292 {
293 case Z_OK: /* Do nothing */ break;
294 case Z_MEM_ERROR:
295 case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory"); break;
296 case Z_VERSION_ERROR: png_error(png_ptr, "zlib version"); break;
297 default: png_error(png_ptr, "Unknown zlib error");
298 }
299
300 png_ptr->zstream.next_out = png_ptr->zbuf;
301 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
302
303 png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
304}
305
306#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
307/* Read the information before the actual image data. This has been
308 * changed in v0.90 to allow reading a file that already has the magic
309 * bytes read from the stream. You can tell libpng how many bytes have
310 * been read from the beginning of the stream (up to the maximum of 8)
311 * via png_set_sig_bytes(), and we will only check the remaining bytes
312 * here. The application can then have access to the signature bytes we
313 * read if it is determined that this isn't a valid PNG file.
314 */
315void PNGAPI
316png_read_info(png_structp png_ptr, png_infop info_ptr)
317{
318 png_debug(1, "in png_read_info\n");
319 /* If we haven't checked all of the PNG signature bytes, do so now. */
320 if (png_ptr->sig_bytes < 8)
321 {
322 png_size_t num_checked = png_ptr->sig_bytes,
323 num_to_check = 8 - num_checked;
324
325 png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
326 png_ptr->sig_bytes = 8;
327
328 if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
329 {
330 if (num_checked < 4 &&
331 png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
332 png_error(png_ptr, "Not a PNG file");
333 else
334 png_error(png_ptr, "PNG file corrupted by ASCII conversion");
335 }
336 if (num_checked < 3)
337 png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
338 }
339
340 for(;;)
341 {
342#ifdef PNG_USE_LOCAL_ARRAYS
343 PNG_IHDR;
344 PNG_IDAT;
345 PNG_IEND;
346 PNG_PLTE;
347#if defined(PNG_READ_bKGD_SUPPORTED)
348 PNG_bKGD;
349#endif
350#if defined(PNG_READ_cHRM_SUPPORTED)
351 PNG_cHRM;
352#endif
353#if defined(PNG_READ_gAMA_SUPPORTED)
354 PNG_gAMA;
355#endif
356#if defined(PNG_READ_hIST_SUPPORTED)
357 PNG_hIST;
358#endif
359#if defined(PNG_READ_iCCP_SUPPORTED)
360 PNG_iCCP;
361#endif
362#if defined(PNG_READ_iTXt_SUPPORTED)
363 PNG_iTXt;
364#endif
365#if defined(PNG_READ_oFFs_SUPPORTED)
366 PNG_oFFs;
367#endif
368#if defined(PNG_READ_pCAL_SUPPORTED)
369 PNG_pCAL;
370#endif
371#if defined(PNG_READ_pHYs_SUPPORTED)
372 PNG_pHYs;
373#endif
374#if defined(PNG_READ_sBIT_SUPPORTED)
375 PNG_sBIT;
376#endif
377#if defined(PNG_READ_sCAL_SUPPORTED)
378 PNG_sCAL;
379#endif
380#if defined(PNG_READ_sPLT_SUPPORTED)
381 PNG_sPLT;
382#endif
383#if defined(PNG_READ_sRGB_SUPPORTED)
384 PNG_sRGB;
385#endif
386#if defined(PNG_READ_tEXt_SUPPORTED)
387 PNG_tEXt;
388#endif
389#if defined(PNG_READ_tIME_SUPPORTED)
390 PNG_tIME;
391#endif
392#if defined(PNG_READ_tRNS_SUPPORTED)
393 PNG_tRNS;
394#endif
395#if defined(PNG_READ_zTXt_SUPPORTED)
396 PNG_zTXt;
397#endif
398#endif /* PNG_USE_LOCAL_ARRAYS */
399 png_byte chunk_length[4];
400 png_uint_32 length;
401
402 png_read_data(png_ptr, chunk_length, 4);
403 length = png_get_uint_31(png_ptr,chunk_length);
404
405 png_reset_crc(png_ptr);
406 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
407
408 png_debug2(0, "Reading %s chunk, length=%lu.\n", png_ptr->chunk_name,
409 length);
410
411 /* This should be a binary subdivision search or a hash for
412 * matching the chunk name rather than a linear search.
413 */
414 if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
415 png_handle_IHDR(png_ptr, info_ptr, length);
416 else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
417 png_handle_IEND(png_ptr, info_ptr, length);
418#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
419 else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
420 {
421 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
422 png_ptr->mode |= PNG_HAVE_IDAT;
423 png_handle_unknown(png_ptr, info_ptr, length);
424 if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
425 png_ptr->mode |= PNG_HAVE_PLTE;
426 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
427 {
428 if (!(png_ptr->mode & PNG_HAVE_IHDR))
429 png_error(png_ptr, "Missing IHDR before IDAT");
430 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
431 !(png_ptr->mode & PNG_HAVE_PLTE))
432 png_error(png_ptr, "Missing PLTE before IDAT");
433 break;
434 }
435 }
436#endif
437 else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
438 png_handle_PLTE(png_ptr, info_ptr, length);
439 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
440 {
441 if (!(png_ptr->mode & PNG_HAVE_IHDR))
442 png_error(png_ptr, "Missing IHDR before IDAT");
443 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
444 !(png_ptr->mode & PNG_HAVE_PLTE))
445 png_error(png_ptr, "Missing PLTE before IDAT");
446
447 png_ptr->idat_size = length;
448 png_ptr->mode |= PNG_HAVE_IDAT;
449 break;
450 }
451#if defined(PNG_READ_bKGD_SUPPORTED)
452 else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
453 png_handle_bKGD(png_ptr, info_ptr, length);
454#endif
455#if defined(PNG_READ_cHRM_SUPPORTED)
456 else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
457 png_handle_cHRM(png_ptr, info_ptr, length);
458#endif
459#if defined(PNG_READ_gAMA_SUPPORTED)
460 else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
461 png_handle_gAMA(png_ptr, info_ptr, length);
462#endif
463#if defined(PNG_READ_hIST_SUPPORTED)
464 else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
465 png_handle_hIST(png_ptr, info_ptr, length);
466#endif
467#if defined(PNG_READ_oFFs_SUPPORTED)
468 else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
469 png_handle_oFFs(png_ptr, info_ptr, length);
470#endif
471#if defined(PNG_READ_pCAL_SUPPORTED)
472 else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
473 png_handle_pCAL(png_ptr, info_ptr, length);
474#endif
475#if defined(PNG_READ_sCAL_SUPPORTED)
476 else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
477 png_handle_sCAL(png_ptr, info_ptr, length);
478#endif
479#if defined(PNG_READ_pHYs_SUPPORTED)
480 else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
481 png_handle_pHYs(png_ptr, info_ptr, length);
482#endif
483#if defined(PNG_READ_sBIT_SUPPORTED)
484 else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
485 png_handle_sBIT(png_ptr, info_ptr, length);
486#endif
487#if defined(PNG_READ_sRGB_SUPPORTED)
488 else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
489 png_handle_sRGB(png_ptr, info_ptr, length);
490#endif
491#if defined(PNG_READ_iCCP_SUPPORTED)
492 else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
493 png_handle_iCCP(png_ptr, info_ptr, length);
494#endif
495#if defined(PNG_READ_sPLT_SUPPORTED)
496 else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
497 png_handle_sPLT(png_ptr, info_ptr, length);
498#endif
499#if defined(PNG_READ_tEXt_SUPPORTED)
500 else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
501 png_handle_tEXt(png_ptr, info_ptr, length);
502#endif
503#if defined(PNG_READ_tIME_SUPPORTED)
504 else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
505 png_handle_tIME(png_ptr, info_ptr, length);
506#endif
507#if defined(PNG_READ_tRNS_SUPPORTED)
508 else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
509 png_handle_tRNS(png_ptr, info_ptr, length);
510#endif
511#if defined(PNG_READ_zTXt_SUPPORTED)
512 else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
513 png_handle_zTXt(png_ptr, info_ptr, length);
514#endif
515#if defined(PNG_READ_iTXt_SUPPORTED)
516 else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
517 png_handle_iTXt(png_ptr, info_ptr, length);
518#endif
519 else
520 png_handle_unknown(png_ptr, info_ptr, length);
521 }
522}
523#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
524
525/* optional call to update the users info_ptr structure */
526void PNGAPI
527png_read_update_info(png_structp png_ptr, png_infop info_ptr)
528{
529 png_debug(1, "in png_read_update_info\n");
530 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
531 png_read_start_row(png_ptr);
532 else
533 png_warning(png_ptr,
534 "Ignoring extra png_read_update_info() call; row buffer not reallocated");
535 png_read_transform_info(png_ptr, info_ptr);
536}
537
538#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
539/* Initialize palette, background, etc, after transformations
540 * are set, but before any reading takes place. This allows
541 * the user to obtain a gamma-corrected palette, for example.
542 * If the user doesn't call this, we will do it ourselves.
543 */
544void PNGAPI
545png_start_read_image(png_structp png_ptr)
546{
547 png_debug(1, "in png_start_read_image\n");
548 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
549 png_read_start_row(png_ptr);
550}
551#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
552
553#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
554void PNGAPI
555png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
556{
557#ifdef PNG_USE_LOCAL_ARRAYS
558 PNG_IDAT;
559 const int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
560 const int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
561#endif
562 int ret;
563 png_debug2(1, "in png_read_row (row %lu, pass %d)\n",
564 png_ptr->row_number, png_ptr->pass);
565 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
566 png_read_start_row(png_ptr);
567 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
568 {
569 /* check for transforms that have been set but were defined out */
570#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
571 if (png_ptr->transformations & PNG_INVERT_MONO)
572 png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined.");
573#endif
574#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
575 if (png_ptr->transformations & PNG_FILLER)
576 png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined.");
577#endif
578#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && !defined(PNG_READ_PACKSWAP_SUPPORTED)
579 if (png_ptr->transformations & PNG_PACKSWAP)
580 png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined.");
581#endif
582#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
583 if (png_ptr->transformations & PNG_PACK)
584 png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined.");
585#endif
586#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
587 if (png_ptr->transformations & PNG_SHIFT)
588 png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined.");
589#endif
590#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
591 if (png_ptr->transformations & PNG_BGR)
592 png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined.");
593#endif
594#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
595 if (png_ptr->transformations & PNG_SWAP_BYTES)
596 png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined.");
597#endif
598 }
599
600#if defined(PNG_READ_INTERLACING_SUPPORTED)
601 /* if interlaced and we do not need a new row, combine row and return */
602 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
603 {
604 switch (png_ptr->pass)
605 {
606 case 0:
607 if (png_ptr->row_number & 0x07)
608 {
609 if (dsp_row != NULL)
610 png_combine_row(png_ptr, dsp_row,
611 png_pass_dsp_mask[png_ptr->pass]);
612 png_read_finish_row(png_ptr);
613 return;
614 }
615 break;
616 case 1:
617 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
618 {
619 if (dsp_row != NULL)
620 png_combine_row(png_ptr, dsp_row,
621 png_pass_dsp_mask[png_ptr->pass]);
622 png_read_finish_row(png_ptr);
623 return;
624 }
625 break;
626 case 2:
627 if ((png_ptr->row_number & 0x07) != 4)
628 {
629 if (dsp_row != NULL && (png_ptr->row_number & 4))
630 png_combine_row(png_ptr, dsp_row,
631 png_pass_dsp_mask[png_ptr->pass]);
632 png_read_finish_row(png_ptr);
633 return;
634 }
635 break;
636 case 3:
637 if ((png_ptr->row_number & 3) || png_ptr->width < 3)
638 {
639 if (dsp_row != NULL)
640 png_combine_row(png_ptr, dsp_row,
641 png_pass_dsp_mask[png_ptr->pass]);
642 png_read_finish_row(png_ptr);
643 return;
644 }
645 break;
646 case 4:
647 if ((png_ptr->row_number & 3) != 2)
648 {
649 if (dsp_row != NULL && (png_ptr->row_number & 2))
650 png_combine_row(png_ptr, dsp_row,
651 png_pass_dsp_mask[png_ptr->pass]);
652 png_read_finish_row(png_ptr);
653 return;
654 }
655 break;
656 case 5:
657 if ((png_ptr->row_number & 1) || png_ptr->width < 2)
658 {
659 if (dsp_row != NULL)
660 png_combine_row(png_ptr, dsp_row,
661 png_pass_dsp_mask[png_ptr->pass]);
662 png_read_finish_row(png_ptr);
663 return;
664 }
665 break;
666 case 6:
667 if (!(png_ptr->row_number & 1))
668 {
669 png_read_finish_row(png_ptr);
670 return;
671 }
672 break;
673 }
674 }
675#endif
676
677 if (!(png_ptr->mode & PNG_HAVE_IDAT))
678 png_error(png_ptr, "Invalid attempt to read row data");
679
680 png_ptr->zstream.next_out = png_ptr->row_buf;
681 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
682 do
683 {
684 if (!(png_ptr->zstream.avail_in))
685 {
686 while (!png_ptr->idat_size)
687 {
688 png_byte chunk_length[4];
689
690 png_crc_finish(png_ptr, 0);
691
692 png_read_data(png_ptr, chunk_length, 4);
693 png_ptr->idat_size = png_get_uint_31(png_ptr,chunk_length);
694
695 png_reset_crc(png_ptr);
696 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
697 if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
698 png_error(png_ptr, "Not enough image data");
699 }
700 png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
701 png_ptr->zstream.next_in = png_ptr->zbuf;
702 if (png_ptr->zbuf_size > png_ptr->idat_size)
703 png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
704 png_crc_read(png_ptr, png_ptr->zbuf,
705 (png_size_t)png_ptr->zstream.avail_in);
706 png_ptr->idat_size -= png_ptr->zstream.avail_in;
707 }
708 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
709 if (ret == Z_STREAM_END)
710 {
711 if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
712 png_ptr->idat_size)
713 png_error(png_ptr, "Extra compressed data");
714 png_ptr->mode |= PNG_AFTER_IDAT;
715 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
716 break;
717 }
718 if (ret != Z_OK)
719 png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
720 "Decompression error");
721
722 } while (png_ptr->zstream.avail_out);
723
724 png_ptr->row_info.color_type = png_ptr->color_type;
725 png_ptr->row_info.width = png_ptr->iwidth;
726 png_ptr->row_info.channels = png_ptr->channels;
727 png_ptr->row_info.bit_depth = png_ptr->bit_depth;
728 png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
729 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
730 png_ptr->row_info.width);
731
732 if(png_ptr->row_buf[0])
733 png_read_filter_row(png_ptr, &(png_ptr->row_info),
734 png_ptr->row_buf + 1, png_ptr->prev_row + 1,
735 (int)(png_ptr->row_buf[0]));
736
737 png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
738 png_ptr->rowbytes + 1);
739
740#if defined(PNG_MNG_FEATURES_SUPPORTED)
741 if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
742 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
743 {
744 /* Intrapixel differencing */
745 png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
746 }
747#endif
748
749
750 if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
751 png_do_read_transformations(png_ptr);
752
753#if defined(PNG_READ_INTERLACING_SUPPORTED)
754 /* blow up interlaced rows to full size */
755 if (png_ptr->interlaced &&
756 (png_ptr->transformations & PNG_INTERLACE))
757 {
758 if (png_ptr->pass < 6)
759/* old interface (pre-1.0.9):
760 png_do_read_interlace(&(png_ptr->row_info),
761 png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
762 */
763 png_do_read_interlace(png_ptr);
764
765 if (dsp_row != NULL)
766 png_combine_row(png_ptr, dsp_row,
767 png_pass_dsp_mask[png_ptr->pass]);
768 if (row != NULL)
769 png_combine_row(png_ptr, row,
770 png_pass_mask[png_ptr->pass]);
771 }
772 else
773#endif
774 {
775 if (row != NULL)
776 png_combine_row(png_ptr, row, 0xff);
777 if (dsp_row != NULL)
778 png_combine_row(png_ptr, dsp_row, 0xff);
779 }
780 png_read_finish_row(png_ptr);
781
782 if (png_ptr->read_row_fn != NULL)
783 (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
784}
785#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
786
787#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
788/* Read one or more rows of image data. If the image is interlaced,
789 * and png_set_interlace_handling() has been called, the rows need to
790 * contain the contents of the rows from the previous pass. If the
791 * image has alpha or transparency, and png_handle_alpha()[*] has been
792 * called, the rows contents must be initialized to the contents of the
793 * screen.
794 *
795 * "row" holds the actual image, and pixels are placed in it
796 * as they arrive. If the image is displayed after each pass, it will
797 * appear to "sparkle" in. "display_row" can be used to display a
798 * "chunky" progressive image, with finer detail added as it becomes
799 * available. If you do not want this "chunky" display, you may pass
800 * NULL for display_row. If you do not want the sparkle display, and
801 * you have not called png_handle_alpha(), you may pass NULL for rows.
802 * If you have called png_handle_alpha(), and the image has either an
803 * alpha channel or a transparency chunk, you must provide a buffer for
804 * rows. In this case, you do not have to provide a display_row buffer
805 * also, but you may. If the image is not interlaced, or if you have
806 * not called png_set_interlace_handling(), the display_row buffer will
807 * be ignored, so pass NULL to it.
808 *
809 * [*] png_handle_alpha() does not exist yet, as of libpng version 1.2.8
810 */
811
812void PNGAPI
813png_read_rows(png_structp png_ptr, png_bytepp row,
814 png_bytepp display_row, png_uint_32 num_rows)
815{
816 png_uint_32 i;
817 png_bytepp rp;
818 png_bytepp dp;
819
820 png_debug(1, "in png_read_rows\n");
821 rp = row;
822 dp = display_row;
823 if (rp != NULL && dp != NULL)
824 for (i = 0; i < num_rows; i++)
825 {
826 png_bytep rptr = *rp++;
827 png_bytep dptr = *dp++;
828
829 png_read_row(png_ptr, rptr, dptr);
830 }
831 else if(rp != NULL)
832 for (i = 0; i < num_rows; i++)
833 {
834 png_bytep rptr = *rp;
835 png_read_row(png_ptr, rptr, png_bytep_NULL);
836 rp++;
837 }
838 else if(dp != NULL)
839 for (i = 0; i < num_rows; i++)
840 {
841 png_bytep dptr = *dp;
842 png_read_row(png_ptr, png_bytep_NULL, dptr);
843 dp++;
844 }
845}
846#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
847
848#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
849/* Read the entire image. If the image has an alpha channel or a tRNS
850 * chunk, and you have called png_handle_alpha()[*], you will need to
851 * initialize the image to the current image that PNG will be overlaying.
852 * We set the num_rows again here, in case it was incorrectly set in
853 * png_read_start_row() by a call to png_read_update_info() or
854 * png_start_read_image() if png_set_interlace_handling() wasn't called
855 * prior to either of these functions like it should have been. You can
856 * only call this function once. If you desire to have an image for
857 * each pass of a interlaced image, use png_read_rows() instead.
858 *
859 * [*] png_handle_alpha() does not exist yet, as of libpng version 1.2.8
860 */
861void PNGAPI
862png_read_image(png_structp png_ptr, png_bytepp image)
863{
864 png_uint_32 i,image_height;
865 int pass, j;
866 png_bytepp rp;
867
868 png_debug(1, "in png_read_image\n");
869
870#ifdef PNG_READ_INTERLACING_SUPPORTED
871 pass = png_set_interlace_handling(png_ptr);
872#else
873 if (png_ptr->interlaced)
874 png_error(png_ptr,
875 "Cannot read interlaced image -- interlace handler disabled.");
876 pass = 1;
877#endif
878
879
880 image_height=png_ptr->height;
881 png_ptr->num_rows = image_height; /* Make sure this is set correctly */
882
883 for (j = 0; j < pass; j++)
884 {
885 rp = image;
886 for (i = 0; i < image_height; i++)
887 {
888 png_read_row(png_ptr, *rp, png_bytep_NULL);
889 rp++;
890 }
891 }
892}
893#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
894
895#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
896/* Read the end of the PNG file. Will not read past the end of the
897 * file, will verify the end is accurate, and will read any comments
898 * or time information at the end of the file, if info is not NULL.
899 */
900void PNGAPI
901png_read_end(png_structp png_ptr, png_infop info_ptr)
902{
903 png_byte chunk_length[4];
904 png_uint_32 length;
905
906 png_debug(1, "in png_read_end\n");
907 png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
908
909 do
910 {
911#ifdef PNG_USE_LOCAL_ARRAYS
912 PNG_IHDR;
913 PNG_IDAT;
914 PNG_IEND;
915 PNG_PLTE;
916#if defined(PNG_READ_bKGD_SUPPORTED)
917 PNG_bKGD;
918#endif
919#if defined(PNG_READ_cHRM_SUPPORTED)
920 PNG_cHRM;
921#endif
922#if defined(PNG_READ_gAMA_SUPPORTED)
923 PNG_gAMA;
924#endif
925#if defined(PNG_READ_hIST_SUPPORTED)
926 PNG_hIST;
927#endif
928#if defined(PNG_READ_iCCP_SUPPORTED)
929 PNG_iCCP;
930#endif
931#if defined(PNG_READ_iTXt_SUPPORTED)
932 PNG_iTXt;
933#endif
934#if defined(PNG_READ_oFFs_SUPPORTED)
935 PNG_oFFs;
936#endif
937#if defined(PNG_READ_pCAL_SUPPORTED)
938 PNG_pCAL;
939#endif
940#if defined(PNG_READ_pHYs_SUPPORTED)
941 PNG_pHYs;
942#endif
943#if defined(PNG_READ_sBIT_SUPPORTED)
944 PNG_sBIT;
945#endif
946#if defined(PNG_READ_sCAL_SUPPORTED)
947 PNG_sCAL;
948#endif
949#if defined(PNG_READ_sPLT_SUPPORTED)
950 PNG_sPLT;
951#endif
952#if defined(PNG_READ_sRGB_SUPPORTED)
953 PNG_sRGB;
954#endif
955#if defined(PNG_READ_tEXt_SUPPORTED)
956 PNG_tEXt;
957#endif
958#if defined(PNG_READ_tIME_SUPPORTED)
959 PNG_tIME;
960#endif
961#if defined(PNG_READ_tRNS_SUPPORTED)
962 PNG_tRNS;
963#endif
964#if defined(PNG_READ_zTXt_SUPPORTED)
965 PNG_zTXt;
966#endif
967#endif /* PNG_USE_LOCAL_ARRAYS */
968
969 png_read_data(png_ptr, chunk_length, 4);
970 length = png_get_uint_31(png_ptr,chunk_length);
971
972 png_reset_crc(png_ptr);
973 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
974
975 png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name);
976
977 if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
978 png_handle_IHDR(png_ptr, info_ptr, length);
979 else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
980 png_handle_IEND(png_ptr, info_ptr, length);
981#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
982 else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
983 {
984 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
985 {
986 if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT)
987 png_error(png_ptr, "Too many IDAT's found");
988 }
989 else
990 png_ptr->mode |= PNG_AFTER_IDAT;
991 png_handle_unknown(png_ptr, info_ptr, length);
992 if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
993 png_ptr->mode |= PNG_HAVE_PLTE;
994 }
995#endif
996 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
997 {
998 /* Zero length IDATs are legal after the last IDAT has been
999 * read, but not after other chunks have been read.
1000 */
1001 if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT)
1002 png_error(png_ptr, "Too many IDAT's found");
1003 png_crc_finish(png_ptr, length);
1004 }
1005 else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
1006 png_handle_PLTE(png_ptr, info_ptr, length);
1007#if defined(PNG_READ_bKGD_SUPPORTED)
1008 else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
1009 png_handle_bKGD(png_ptr, info_ptr, length);
1010#endif
1011#if defined(PNG_READ_cHRM_SUPPORTED)
1012 else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
1013 png_handle_cHRM(png_ptr, info_ptr, length);
1014#endif
1015#if defined(PNG_READ_gAMA_SUPPORTED)
1016 else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
1017 png_handle_gAMA(png_ptr, info_ptr, length);
1018#endif
1019#if defined(PNG_READ_hIST_SUPPORTED)
1020 else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
1021 png_handle_hIST(png_ptr, info_ptr, length);
1022#endif
1023#if defined(PNG_READ_oFFs_SUPPORTED)
1024 else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
1025 png_handle_oFFs(png_ptr, info_ptr, length);
1026#endif
1027#if defined(PNG_READ_pCAL_SUPPORTED)
1028 else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
1029 png_handle_pCAL(png_ptr, info_ptr, length);
1030#endif
1031#if defined(PNG_READ_sCAL_SUPPORTED)
1032 else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
1033 png_handle_sCAL(png_ptr, info_ptr, length);
1034#endif
1035#if defined(PNG_READ_pHYs_SUPPORTED)
1036 else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
1037 png_handle_pHYs(png_ptr, info_ptr, length);
1038#endif
1039#if defined(PNG_READ_sBIT_SUPPORTED)
1040 else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
1041 png_handle_sBIT(png_ptr, info_ptr, length);
1042#endif
1043#if defined(PNG_READ_sRGB_SUPPORTED)
1044 else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
1045 png_handle_sRGB(png_ptr, info_ptr, length);
1046#endif
1047#if defined(PNG_READ_iCCP_SUPPORTED)
1048 else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
1049 png_handle_iCCP(png_ptr, info_ptr, length);
1050#endif
1051#if defined(PNG_READ_sPLT_SUPPORTED)
1052 else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
1053 png_handle_sPLT(png_ptr, info_ptr, length);
1054#endif
1055#if defined(PNG_READ_tEXt_SUPPORTED)
1056 else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
1057 png_handle_tEXt(png_ptr, info_ptr, length);
1058#endif
1059#if defined(PNG_READ_tIME_SUPPORTED)
1060 else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
1061 png_handle_tIME(png_ptr, info_ptr, length);
1062#endif
1063#if defined(PNG_READ_tRNS_SUPPORTED)
1064 else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
1065 png_handle_tRNS(png_ptr, info_ptr, length);
1066#endif
1067#if defined(PNG_READ_zTXt_SUPPORTED)
1068 else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
1069 png_handle_zTXt(png_ptr, info_ptr, length);
1070#endif
1071#if defined(PNG_READ_iTXt_SUPPORTED)
1072 else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
1073 png_handle_iTXt(png_ptr, info_ptr, length);
1074#endif
1075 else
1076 png_handle_unknown(png_ptr, info_ptr, length);
1077 } while (!(png_ptr->mode & PNG_HAVE_IEND));
1078}
1079#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
1080
1081/* free all memory used by the read */
1082void PNGAPI
1083png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
1084 png_infopp end_info_ptr_ptr)
1085{
1086 png_structp png_ptr = NULL;
1087 png_infop info_ptr = NULL, end_info_ptr = NULL;
1088#ifdef PNG_USER_MEM_SUPPORTED
1089 png_free_ptr free_fn;
1090 png_voidp mem_ptr;
1091#endif
1092
1093 png_debug(1, "in png_destroy_read_struct\n");
1094 if (png_ptr_ptr != NULL)
1095 png_ptr = *png_ptr_ptr;
1096
1097 if (info_ptr_ptr != NULL)
1098 info_ptr = *info_ptr_ptr;
1099
1100 if (end_info_ptr_ptr != NULL)
1101 end_info_ptr = *end_info_ptr_ptr;
1102
1103#ifdef PNG_USER_MEM_SUPPORTED
1104 free_fn = png_ptr->free_fn;
1105 mem_ptr = png_ptr->mem_ptr;
1106#endif
1107
1108 png_read_destroy(png_ptr, info_ptr, end_info_ptr);
1109
1110 if (info_ptr != NULL)
1111 {
1112#if defined(PNG_TEXT_SUPPORTED)
1113 png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1);
1114#endif
1115
1116#ifdef PNG_USER_MEM_SUPPORTED
1117 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1118 (png_voidp)mem_ptr);
1119#else
1120 png_destroy_struct((png_voidp)info_ptr);
1121#endif
1122 *info_ptr_ptr = NULL;
1123 }
1124
1125 if (end_info_ptr != NULL)
1126 {
1127#if defined(PNG_READ_TEXT_SUPPORTED)
1128 png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1);
1129#endif
1130#ifdef PNG_USER_MEM_SUPPORTED
1131 png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn,
1132 (png_voidp)mem_ptr);
1133#else
1134 png_destroy_struct((png_voidp)end_info_ptr);
1135#endif
1136 *end_info_ptr_ptr = NULL;
1137 }
1138
1139 if (png_ptr != NULL)
1140 {
1141#ifdef PNG_USER_MEM_SUPPORTED
1142 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1143 (png_voidp)mem_ptr);
1144#else
1145 png_destroy_struct((png_voidp)png_ptr);
1146#endif
1147 *png_ptr_ptr = NULL;
1148 }
1149}
1150
1151/* free all memory used by the read (old method) */
1152void /* PRIVATE */
1153png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr)
1154{
1155#ifdef PNG_SETJMP_SUPPORTED
1156 jmp_buf tmp_jmp;
1157#endif
1158 png_error_ptr error_fn;
1159 png_error_ptr warning_fn;
1160 png_voidp error_ptr;
1161#ifdef PNG_USER_MEM_SUPPORTED
1162 png_free_ptr free_fn;
1163#endif
1164
1165 png_debug(1, "in png_read_destroy\n");
1166 if (info_ptr != NULL)
1167 png_info_destroy(png_ptr, info_ptr);
1168
1169 if (end_info_ptr != NULL)
1170 png_info_destroy(png_ptr, end_info_ptr);
1171
1172 png_free(png_ptr, png_ptr->zbuf);
1173 png_free(png_ptr, png_ptr->big_row_buf);
1174 png_free(png_ptr, png_ptr->prev_row);
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
1255
1256 inflateEnd(&png_ptr->zstream);
1257#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1258 png_free(png_ptr, png_ptr->save_buffer);
1259#endif
1260
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 */
1266
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
1273
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
1280
1281 png_memset(png_ptr, 0, png_sizeof (png_struct));
1282
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
1289
1290#ifdef PNG_SETJMP_SUPPORTED
1291 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
1292#endif
1293
1294}
1295
1296void PNGAPI
1297png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
1298{
1299 png_ptr->read_row_fn = read_row_fn;
1300}
1301
1302
1303#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1304#if defined(PNG_INFO_IMAGE_SUPPORTED)
1305void PNGAPI
1306png_read_png(png_structp png_ptr, png_infop info_ptr,
1307 int transforms,
1308 voidp params)
1309{
1310 int row;
1311
1312#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
1313 /* invert the alpha channel from opacity to transparency
1314 */
1315 if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1316 png_set_invert_alpha(png_ptr);
1317#endif
1318
1319 /* png_read_info() gives us all of the information from the
1320 * PNG file before the first IDAT (image data chunk).
1321 */
1322 png_read_info(png_ptr, info_ptr);
1323 if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
1324 png_error(png_ptr,"Image is too high to process with png_read_png()");
1325
1326 /* -------------- image transformations start here ------------------- */
1327
1328#if defined(PNG_READ_16_TO_8_SUPPORTED)
1329 /* tell libpng to strip 16 bit/color files down to 8 bits per color
1330 */
1331 if (transforms & PNG_TRANSFORM_STRIP_16)
1332 png_set_strip_16(png_ptr);
1333#endif
1334
1335#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1336 /* Strip alpha bytes from the input data without combining with
1337 * the background (not recommended).
1338 */
1339 if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
1340 png_set_strip_alpha(png_ptr);
1341#endif
1342
1343#if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
1344 /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
1345 * byte into separate bytes (useful for paletted and grayscale images).
1346 */
1347 if (transforms & PNG_TRANSFORM_PACKING)
1348 png_set_packing(png_ptr);
1349#endif
1350
1351#if defined(PNG_READ_PACKSWAP_SUPPORTED)
1352 /* Change the order of packed pixels to least significant bit first
1353 * (not useful if you are using png_set_packing).
1354 */
1355 if (transforms & PNG_TRANSFORM_PACKSWAP)
1356 png_set_packswap(png_ptr);
1357#endif
1358
1359#if defined(PNG_READ_EXPAND_SUPPORTED)
1360 /* Expand paletted colors into true RGB triplets
1361 * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
1362 * Expand paletted or RGB images with transparency to full alpha
1363 * channels so the data will be available as RGBA quartets.
1364 */
1365 if (transforms & PNG_TRANSFORM_EXPAND)
1366 if ((png_ptr->bit_depth < 8) ||
1367 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
1368 (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
1369 png_set_expand(png_ptr);
1370#endif
1371
1372 /* We don't handle background color or gamma transformation or dithering.
1373 */
1374
1375#if defined(PNG_READ_INVERT_SUPPORTED)
1376 /* invert monochrome files to have 0 as white and 1 as black
1377 */
1378 if (transforms & PNG_TRANSFORM_INVERT_MONO)
1379 png_set_invert_mono(png_ptr);
1380#endif
1381
1382#if defined(PNG_READ_SHIFT_SUPPORTED)
1383 /* If you want to shift the pixel values from the range [0,255] or
1384 * [0,65535] to the original [0,7] or [0,31], or whatever range the
1385 * colors were originally in:
1386 */
1387 if ((transforms & PNG_TRANSFORM_SHIFT)
1388 && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
1389 {
1390 png_color_8p sig_bit;
1391
1392 png_get_sBIT(png_ptr, info_ptr, &sig_bit);
1393 png_set_shift(png_ptr, sig_bit);
1394 }
1395#endif
1396
1397#if defined(PNG_READ_BGR_SUPPORTED)
1398 /* flip the RGB pixels to BGR (or RGBA to BGRA)
1399 */
1400 if (transforms & PNG_TRANSFORM_BGR)
1401 png_set_bgr(png_ptr);
1402#endif
1403
1404#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
1405 /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR)
1406 */
1407 if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1408 png_set_swap_alpha(png_ptr);
1409#endif
1410
1411#if defined(PNG_READ_SWAP_SUPPORTED)
1412 /* swap bytes of 16 bit files to least significant byte first
1413 */
1414 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1415 png_set_swap(png_ptr);
1416#endif
1417
1418 /* We don't handle adding filler bytes */
1419
1420 /* Optional call to gamma correct and add the background to the palette
1421 * and update info structure. REQUIRED if you are expecting libpng to
1422 * update the palette for you (i.e., you selected such a transform above).
1423 */
1424 png_read_update_info(png_ptr, info_ptr);
1425
1426 /* -------------- image transformations end here ------------------- */
1427
1428#ifdef PNG_FREE_ME_SUPPORTED
1429 png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
1430#endif
1431 if(info_ptr->row_pointers == NULL)
1432 {
1433 info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
1434 info_ptr->height * png_sizeof(png_bytep));
1435#ifdef PNG_FREE_ME_SUPPORTED
1436 info_ptr->free_me |= PNG_FREE_ROWS;
1437#endif
1438 for (row = 0; row < (int)info_ptr->height; row++)
1439 {
1440 info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,
1441 png_get_rowbytes(png_ptr, info_ptr));
1442 }
1443 }
1444
1445 png_read_image(png_ptr, info_ptr->row_pointers);
1446 info_ptr->valid |= PNG_INFO_IDAT;
1447
1448 /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
1449 png_read_end(png_ptr, info_ptr);
1450
1451 if(transforms == 0 || params == NULL)
1452 /* quiet compiler warnings */ return;
1453
1454}
1455#endif
1456#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
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