source: trunk/third/libpng/pngread.c @ 20647

Revision 20647, 44.2 KB checked in by zacheiss, 20 years ago (diff)
Assorted security patches.
Line 
1
2/* pngread.c - read a PNG file
3 *
4 * libpng 1.2.5 - October 3, 2002
5 * For conditions of distribution and use, see copyright notice in png.h
6 * Copyright (c) 1998-2002 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#ifdef PNG_SETJMP_SUPPORTED
63#ifdef USE_FAR_KEYWORD
64   if (setjmp(jmpbuf))
65#else
66   if (setjmp(png_ptr->jmpbuf))
67#endif
68   {
69      png_free(png_ptr, png_ptr->zbuf);
70      png_ptr->zbuf=NULL;
71#ifdef PNG_USER_MEM_SUPPORTED
72      png_destroy_struct_2((png_voidp)png_ptr,
73         (png_free_ptr)free_fn, (png_voidp)mem_ptr);
74#else
75      png_destroy_struct((png_voidp)png_ptr);
76#endif
77      return (NULL);
78   }
79#ifdef USE_FAR_KEYWORD
80   png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
81#endif
82#endif
83
84#ifdef PNG_USER_MEM_SUPPORTED
85   png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
86#endif
87
88   png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
89
90   i=0;
91   do
92   {
93     if(user_png_ver[i] != png_libpng_ver[i])
94        png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
95   } while (png_libpng_ver[i++]);
96
97   if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
98   {
99     /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
100      * we must recompile any applications that use any older library version.
101      * For versions after libpng 1.0, we will be compatible, so we need
102      * only check the first digit.
103      */
104     if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
105         (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
106         (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
107     {
108#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
109        char msg[80];
110        if (user_png_ver)
111        {
112          sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
113             user_png_ver);
114          png_warning(png_ptr, msg);
115        }
116        sprintf(msg, "Application  is  running with png.c from libpng-%.20s",
117           png_libpng_ver);
118        png_warning(png_ptr, msg);
119#endif
120#ifdef PNG_ERROR_NUMBERS_SUPPORTED
121        png_ptr->flags=0;
122#endif
123        png_error(png_ptr,
124           "Incompatible libpng version in application and library");
125     }
126   }
127
128   /* initialize zbuf - compression buffer */
129   png_ptr->zbuf_size = PNG_ZBUF_SIZE;
130   png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
131     (png_uint_32)png_ptr->zbuf_size);
132   png_ptr->zstream.zalloc = png_zalloc;
133   png_ptr->zstream.zfree = png_zfree;
134   png_ptr->zstream.opaque = (voidpf)png_ptr;
135
136   switch (inflateInit(&png_ptr->zstream))
137   {
138     case Z_OK: /* Do nothing */ break;
139     case Z_MEM_ERROR:
140     case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory error"); break;
141     case Z_VERSION_ERROR: png_error(png_ptr, "zlib version error"); break;
142     default: png_error(png_ptr, "Unknown zlib error");
143   }
144
145   png_ptr->zstream.next_out = png_ptr->zbuf;
146   png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
147
148   png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
149
150#ifdef PNG_SETJMP_SUPPORTED
151/* Applications that neglect to set up their own setjmp() and then encounter
152   a png_error() will longjmp here.  Since the jmpbuf is then meaningless we
153   abort instead of returning. */
154#ifdef USE_FAR_KEYWORD
155   if (setjmp(jmpbuf))
156      PNG_ABORT();
157   png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
158#else
159   if (setjmp(png_ptr->jmpbuf))
160      PNG_ABORT();
161#endif
162#endif
163   return (png_ptr);
164}
165
166/* Initialize PNG structure for reading, and allocate any memory needed.
167   This interface is deprecated in favour of the png_create_read_struct(),
168   and it will eventually disappear. */
169#undef png_read_init
170void PNGAPI
171png_read_init(png_structp png_ptr)
172{
173   /* We only come here via pre-1.0.7-compiled applications */
174   png_read_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
175}
176
177void PNGAPI
178png_read_init_2(png_structp png_ptr, png_const_charp user_png_ver,
179   png_size_t png_struct_size, png_size_t png_info_size)
180{
181   /* We only come here via pre-1.0.12-compiled applications */
182#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
183   if(sizeof(png_struct) > png_struct_size || sizeof(png_info) > png_info_size)
184   {
185      char msg[80];
186      png_ptr->warning_fn=NULL;
187      if (user_png_ver)
188      {
189        sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
190           user_png_ver);
191        png_warning(png_ptr, msg);
192      }
193      sprintf(msg, "Application  is  running with png.c from libpng-%.20s",
194         png_libpng_ver);
195      png_warning(png_ptr, msg);
196   }
197#endif
198   if(sizeof(png_struct) > png_struct_size)
199     {
200       png_ptr->error_fn=NULL;
201#ifdef PNG_ERROR_NUMBERS_SUPPORTED
202       png_ptr->flags=0;
203#endif
204       png_error(png_ptr,
205       "The png struct allocated by the application for reading is too small.");
206     }
207   if(sizeof(png_info) > png_info_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 info struct allocated by application for reading is too small.");
215     }
216   png_read_init_3(&png_ptr, user_png_ver, png_struct_size);
217}
218
219void PNGAPI
220png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
221   png_size_t png_struct_size)
222{
223#ifdef PNG_SETJMP_SUPPORTED
224   jmp_buf tmp_jmp;  /* to save current jump buffer */
225#endif
226
227   int i=0;
228
229   png_structp png_ptr=*ptr_ptr;
230
231   do
232   {
233     if(user_png_ver[i] != png_libpng_ver[i])
234     {
235#ifdef PNG_LEGACY_SUPPORTED
236       png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
237#else
238       png_ptr->warning_fn=NULL;
239       png_warning(png_ptr,
240        "Application uses deprecated png_read_init() and should be recompiled.");
241       break;
242#endif
243     }
244   } while (png_libpng_ver[i++]);
245
246   png_debug(1, "in png_read_init_3\n");
247
248#ifdef PNG_SETJMP_SUPPORTED
249   /* save jump buffer and error functions */
250   png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
251#endif
252
253   if(sizeof(png_struct) > png_struct_size)
254     {
255       png_destroy_struct(png_ptr);
256       *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
257       png_ptr = *ptr_ptr;
258     }
259
260   /* reset all variables to 0 */
261   png_memset(png_ptr, 0, sizeof (png_struct));
262
263#ifdef PNG_SETJMP_SUPPORTED
264   /* restore jump buffer */
265   png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
266#endif
267
268   /* initialize zbuf - compression buffer */
269   png_ptr->zbuf_size = PNG_ZBUF_SIZE;
270   png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
271     (png_uint_32)png_ptr->zbuf_size);
272   png_ptr->zstream.zalloc = png_zalloc;
273   png_ptr->zstream.zfree = png_zfree;
274   png_ptr->zstream.opaque = (voidpf)png_ptr;
275
276   switch (inflateInit(&png_ptr->zstream))
277   {
278     case Z_OK: /* Do nothing */ break;
279     case Z_MEM_ERROR:
280     case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory"); break;
281     case Z_VERSION_ERROR: png_error(png_ptr, "zlib version"); break;
282     default: png_error(png_ptr, "Unknown zlib error");
283   }
284
285   png_ptr->zstream.next_out = png_ptr->zbuf;
286   png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
287
288   png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
289}
290
291/* Read the information before the actual image data.  This has been
292 * changed in v0.90 to allow reading a file that already has the magic
293 * bytes read from the stream.  You can tell libpng how many bytes have
294 * been read from the beginning of the stream (up to the maximum of 8)
295 * via png_set_sig_bytes(), and we will only check the remaining bytes
296 * here.  The application can then have access to the signature bytes we
297 * read if it is determined that this isn't a valid PNG file.
298 */
299void PNGAPI
300png_read_info(png_structp png_ptr, png_infop info_ptr)
301{
302   png_debug(1, "in png_read_info\n");
303   /* If we haven't checked all of the PNG signature bytes, do so now. */
304   if (png_ptr->sig_bytes < 8)
305   {
306      png_size_t num_checked = png_ptr->sig_bytes,
307                 num_to_check = 8 - num_checked;
308
309      png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
310      png_ptr->sig_bytes = 8;
311
312      if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
313      {
314         if (num_checked < 4 &&
315             png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
316            png_error(png_ptr, "Not a PNG file");
317         else
318            png_error(png_ptr, "PNG file corrupted by ASCII conversion");
319      }
320      if (num_checked < 3)
321         png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
322   }
323
324   for(;;)
325   {
326#ifdef PNG_USE_LOCAL_ARRAYS
327      PNG_IHDR;
328      PNG_IDAT;
329      PNG_IEND;
330      PNG_PLTE;
331#if defined(PNG_READ_bKGD_SUPPORTED)
332      PNG_bKGD;
333#endif
334#if defined(PNG_READ_cHRM_SUPPORTED)
335      PNG_cHRM;
336#endif
337#if defined(PNG_READ_gAMA_SUPPORTED)
338      PNG_gAMA;
339#endif
340#if defined(PNG_READ_hIST_SUPPORTED)
341      PNG_hIST;
342#endif
343#if defined(PNG_READ_iCCP_SUPPORTED)
344      PNG_iCCP;
345#endif
346#if defined(PNG_READ_iTXt_SUPPORTED)
347      PNG_iTXt;
348#endif
349#if defined(PNG_READ_oFFs_SUPPORTED)
350      PNG_oFFs;
351#endif
352#if defined(PNG_READ_pCAL_SUPPORTED)
353      PNG_pCAL;
354#endif
355#if defined(PNG_READ_pHYs_SUPPORTED)
356      PNG_pHYs;
357#endif
358#if defined(PNG_READ_sBIT_SUPPORTED)
359      PNG_sBIT;
360#endif
361#if defined(PNG_READ_sCAL_SUPPORTED)
362      PNG_sCAL;
363#endif
364#if defined(PNG_READ_sPLT_SUPPORTED)
365      PNG_sPLT;
366#endif
367#if defined(PNG_READ_sRGB_SUPPORTED)
368      PNG_sRGB;
369#endif
370#if defined(PNG_READ_tEXt_SUPPORTED)
371      PNG_tEXt;
372#endif
373#if defined(PNG_READ_tIME_SUPPORTED)
374      PNG_tIME;
375#endif
376#if defined(PNG_READ_tRNS_SUPPORTED)
377      PNG_tRNS;
378#endif
379#if defined(PNG_READ_zTXt_SUPPORTED)
380      PNG_zTXt;
381#endif
382#endif /* PNG_GLOBAL_ARRAYS */
383      png_byte chunk_length[4];
384      png_uint_32 length;
385
386      png_read_data(png_ptr, chunk_length, 4);
387      length = png_get_uint_31(png_ptr,chunk_length);
388
389      png_reset_crc(png_ptr);
390      png_crc_read(png_ptr, png_ptr->chunk_name, 4);
391
392      png_debug2(0, "Reading %s chunk, length=%lu.\n", png_ptr->chunk_name,
393         length);
394
395      /* This should be a binary subdivision search or a hash for
396       * matching the chunk name rather than a linear search.
397       */
398      if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
399         png_handle_IHDR(png_ptr, info_ptr, length);
400      else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
401         png_handle_IEND(png_ptr, info_ptr, length);
402#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
403      else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
404      {
405         if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
406            png_ptr->mode |= PNG_HAVE_IDAT;
407         png_handle_unknown(png_ptr, info_ptr, length);
408         if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
409            png_ptr->mode |= PNG_HAVE_PLTE;
410         else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
411         {
412            if (!(png_ptr->mode & PNG_HAVE_IHDR))
413               png_error(png_ptr, "Missing IHDR before IDAT");
414            else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
415                     !(png_ptr->mode & PNG_HAVE_PLTE))
416               png_error(png_ptr, "Missing PLTE before IDAT");
417            break;
418         }
419      }
420#endif
421      else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
422         png_handle_PLTE(png_ptr, info_ptr, length);
423      else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
424      {
425         if (!(png_ptr->mode & PNG_HAVE_IHDR))
426            png_error(png_ptr, "Missing IHDR before IDAT");
427         else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
428                  !(png_ptr->mode & PNG_HAVE_PLTE))
429            png_error(png_ptr, "Missing PLTE before IDAT");
430
431         png_ptr->idat_size = length;
432         png_ptr->mode |= PNG_HAVE_IDAT;
433         break;
434      }
435#if defined(PNG_READ_bKGD_SUPPORTED)
436      else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
437         png_handle_bKGD(png_ptr, info_ptr, length);
438#endif
439#if defined(PNG_READ_cHRM_SUPPORTED)
440      else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
441         png_handle_cHRM(png_ptr, info_ptr, length);
442#endif
443#if defined(PNG_READ_gAMA_SUPPORTED)
444      else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
445         png_handle_gAMA(png_ptr, info_ptr, length);
446#endif
447#if defined(PNG_READ_hIST_SUPPORTED)
448      else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
449         png_handle_hIST(png_ptr, info_ptr, length);
450#endif
451#if defined(PNG_READ_oFFs_SUPPORTED)
452      else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
453         png_handle_oFFs(png_ptr, info_ptr, length);
454#endif
455#if defined(PNG_READ_pCAL_SUPPORTED)
456      else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
457         png_handle_pCAL(png_ptr, info_ptr, length);
458#endif
459#if defined(PNG_READ_sCAL_SUPPORTED)
460      else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
461         png_handle_sCAL(png_ptr, info_ptr, length);
462#endif
463#if defined(PNG_READ_pHYs_SUPPORTED)
464      else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
465         png_handle_pHYs(png_ptr, info_ptr, length);
466#endif
467#if defined(PNG_READ_sBIT_SUPPORTED)
468      else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
469         png_handle_sBIT(png_ptr, info_ptr, length);
470#endif
471#if defined(PNG_READ_sRGB_SUPPORTED)
472      else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
473         png_handle_sRGB(png_ptr, info_ptr, length);
474#endif
475#if defined(PNG_READ_iCCP_SUPPORTED)
476      else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
477         png_handle_iCCP(png_ptr, info_ptr, length);
478#endif
479#if defined(PNG_READ_sPLT_SUPPORTED)
480      else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
481         png_handle_sPLT(png_ptr, info_ptr, length);
482#endif
483#if defined(PNG_READ_tEXt_SUPPORTED)
484      else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
485         png_handle_tEXt(png_ptr, info_ptr, length);
486#endif
487#if defined(PNG_READ_tIME_SUPPORTED)
488      else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
489         png_handle_tIME(png_ptr, info_ptr, length);
490#endif
491#if defined(PNG_READ_tRNS_SUPPORTED)
492      else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
493         png_handle_tRNS(png_ptr, info_ptr, length);
494#endif
495#if defined(PNG_READ_zTXt_SUPPORTED)
496      else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
497         png_handle_zTXt(png_ptr, info_ptr, length);
498#endif
499#if defined(PNG_READ_iTXt_SUPPORTED)
500      else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
501         png_handle_iTXt(png_ptr, info_ptr, length);
502#endif
503      else
504         png_handle_unknown(png_ptr, info_ptr, length);
505   }
506}
507
508/* optional call to update the users info_ptr structure */
509void PNGAPI
510png_read_update_info(png_structp png_ptr, png_infop info_ptr)
511{
512   png_debug(1, "in png_read_update_info\n");
513   if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
514      png_read_start_row(png_ptr);
515   else
516      png_warning(png_ptr,
517      "Ignoring extra png_read_update_info() call; row buffer not reallocated");
518   png_read_transform_info(png_ptr, info_ptr);
519}
520
521/* Initialize palette, background, etc, after transformations
522 * are set, but before any reading takes place.  This allows
523 * the user to obtain a gamma-corrected palette, for example.
524 * If the user doesn't call this, we will do it ourselves.
525 */
526void PNGAPI
527png_start_read_image(png_structp png_ptr)
528{
529   png_debug(1, "in png_start_read_image\n");
530   if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
531      png_read_start_row(png_ptr);
532}
533
534void PNGAPI
535png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
536{
537#ifdef PNG_USE_LOCAL_ARRAYS
538   PNG_IDAT;
539   const int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
540   const int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
541#endif
542   int ret;
543   png_debug2(1, "in png_read_row (row %lu, pass %d)\n",
544      png_ptr->row_number, png_ptr->pass);
545   if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
546      png_read_start_row(png_ptr);
547   if (png_ptr->row_number == 0 && png_ptr->pass == 0)
548   {
549   /* check for transforms that have been set but were defined out */
550#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
551   if (png_ptr->transformations & PNG_INVERT_MONO)
552      png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined.");
553#endif
554#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
555   if (png_ptr->transformations & PNG_FILLER)
556      png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined.");
557#endif
558#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && !defined(PNG_READ_PACKSWAP_SUPPORTED)
559   if (png_ptr->transformations & PNG_PACKSWAP)
560      png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined.");
561#endif
562#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
563   if (png_ptr->transformations & PNG_PACK)
564      png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined.");
565#endif
566#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
567   if (png_ptr->transformations & PNG_SHIFT)
568      png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined.");
569#endif
570#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
571   if (png_ptr->transformations & PNG_BGR)
572      png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined.");
573#endif
574#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
575   if (png_ptr->transformations & PNG_SWAP_BYTES)
576      png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined.");
577#endif
578   }
579
580#if defined(PNG_READ_INTERLACING_SUPPORTED)
581   /* if interlaced and we do not need a new row, combine row and return */
582   if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
583   {
584      switch (png_ptr->pass)
585      {
586         case 0:
587            if (png_ptr->row_number & 0x07)
588            {
589               if (dsp_row != NULL)
590                  png_combine_row(png_ptr, dsp_row,
591                     png_pass_dsp_mask[png_ptr->pass]);
592               png_read_finish_row(png_ptr);
593               return;
594            }
595            break;
596         case 1:
597            if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
598            {
599               if (dsp_row != NULL)
600                  png_combine_row(png_ptr, dsp_row,
601                     png_pass_dsp_mask[png_ptr->pass]);
602               png_read_finish_row(png_ptr);
603               return;
604            }
605            break;
606         case 2:
607            if ((png_ptr->row_number & 0x07) != 4)
608            {
609               if (dsp_row != NULL && (png_ptr->row_number & 4))
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 3:
617            if ((png_ptr->row_number & 3) || png_ptr->width < 3)
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 4:
627            if ((png_ptr->row_number & 3) != 2)
628            {
629               if (dsp_row != NULL && (png_ptr->row_number & 2))
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 5:
637            if ((png_ptr->row_number & 1) || png_ptr->width < 2)
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 6:
647            if (!(png_ptr->row_number & 1))
648            {
649               png_read_finish_row(png_ptr);
650               return;
651            }
652            break;
653      }
654   }
655#endif
656
657   if (!(png_ptr->mode & PNG_HAVE_IDAT))
658      png_error(png_ptr, "Invalid attempt to read row data");
659
660   png_ptr->zstream.next_out = png_ptr->row_buf;
661   png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
662   do
663   {
664      if (!(png_ptr->zstream.avail_in))
665      {
666         while (!png_ptr->idat_size)
667         {
668            png_byte chunk_length[4];
669
670            png_crc_finish(png_ptr, 0);
671
672            png_read_data(png_ptr, chunk_length, 4);
673            png_ptr->idat_size = png_get_uint_31(png_ptr,chunk_length);
674
675            png_reset_crc(png_ptr);
676            png_crc_read(png_ptr, png_ptr->chunk_name, 4);
677            if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
678               png_error(png_ptr, "Not enough image data");
679         }
680         png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
681         png_ptr->zstream.next_in = png_ptr->zbuf;
682         if (png_ptr->zbuf_size > png_ptr->idat_size)
683            png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
684         png_crc_read(png_ptr, png_ptr->zbuf,
685            (png_size_t)png_ptr->zstream.avail_in);
686         png_ptr->idat_size -= png_ptr->zstream.avail_in;
687      }
688      ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
689      if (ret == Z_STREAM_END)
690      {
691         if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
692            png_ptr->idat_size)
693            png_error(png_ptr, "Extra compressed data");
694         png_ptr->mode |= PNG_AFTER_IDAT;
695         png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
696         break;
697      }
698      if (ret != Z_OK)
699         png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
700                   "Decompression error");
701
702   } while (png_ptr->zstream.avail_out);
703
704   png_ptr->row_info.color_type = png_ptr->color_type;
705   png_ptr->row_info.width = png_ptr->iwidth;
706   png_ptr->row_info.channels = png_ptr->channels;
707   png_ptr->row_info.bit_depth = png_ptr->bit_depth;
708   png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
709   png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *
710      (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);
711
712   if(png_ptr->row_buf[0])
713   png_read_filter_row(png_ptr, &(png_ptr->row_info),
714      png_ptr->row_buf + 1, png_ptr->prev_row + 1,
715      (int)(png_ptr->row_buf[0]));
716
717   png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
718      png_ptr->rowbytes + 1);
719   
720#if defined(PNG_MNG_FEATURES_SUPPORTED)
721   if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
722      (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
723   {
724      /* Intrapixel differencing */
725      png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
726   }
727#endif
728
729   if (png_ptr->transformations)
730      png_do_read_transformations(png_ptr);
731
732#if defined(PNG_READ_INTERLACING_SUPPORTED)
733   /* blow up interlaced rows to full size */
734   if (png_ptr->interlaced &&
735      (png_ptr->transformations & PNG_INTERLACE))
736   {
737      if (png_ptr->pass < 6)
738/*       old interface (pre-1.0.9):
739         png_do_read_interlace(&(png_ptr->row_info),
740            png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
741 */
742         png_do_read_interlace(png_ptr);
743
744      if (dsp_row != NULL)
745         png_combine_row(png_ptr, dsp_row,
746            png_pass_dsp_mask[png_ptr->pass]);
747      if (row != NULL)
748         png_combine_row(png_ptr, row,
749            png_pass_mask[png_ptr->pass]);
750   }
751   else
752#endif
753   {
754      if (row != NULL)
755         png_combine_row(png_ptr, row, 0xff);
756      if (dsp_row != NULL)
757         png_combine_row(png_ptr, dsp_row, 0xff);
758   }
759   png_read_finish_row(png_ptr);
760
761   if (png_ptr->read_row_fn != NULL)
762      (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
763}
764
765/* Read one or more rows of image data.  If the image is interlaced,
766 * and png_set_interlace_handling() has been called, the rows need to
767 * contain the contents of the rows from the previous pass.  If the
768 * image has alpha or transparency, and png_handle_alpha()[*] has been
769 * called, the rows contents must be initialized to the contents of the
770 * screen.
771 *
772 * "row" holds the actual image, and pixels are placed in it
773 * as they arrive.  If the image is displayed after each pass, it will
774 * appear to "sparkle" in.  "display_row" can be used to display a
775 * "chunky" progressive image, with finer detail added as it becomes
776 * available.  If you do not want this "chunky" display, you may pass
777 * NULL for display_row.  If you do not want the sparkle display, and
778 * you have not called png_handle_alpha(), you may pass NULL for rows.
779 * If you have called png_handle_alpha(), and the image has either an
780 * alpha channel or a transparency chunk, you must provide a buffer for
781 * rows.  In this case, you do not have to provide a display_row buffer
782 * also, but you may.  If the image is not interlaced, or if you have
783 * not called png_set_interlace_handling(), the display_row buffer will
784 * be ignored, so pass NULL to it.
785 *
786 * [*] png_handle_alpha() does not exist yet, as of libpng version 1.2.5
787 */
788
789void PNGAPI
790png_read_rows(png_structp png_ptr, png_bytepp row,
791   png_bytepp display_row, png_uint_32 num_rows)
792{
793   png_uint_32 i;
794   png_bytepp rp;
795   png_bytepp dp;
796
797   png_debug(1, "in png_read_rows\n");
798   rp = row;
799   dp = display_row;
800   if (rp != NULL && dp != NULL)
801      for (i = 0; i < num_rows; i++)
802      {
803         png_bytep rptr = *rp++;
804         png_bytep dptr = *dp++;
805
806         png_read_row(png_ptr, rptr, dptr);
807      }
808   else if(rp != NULL)
809      for (i = 0; i < num_rows; i++)
810      {
811         png_bytep rptr = *rp;
812         png_read_row(png_ptr, rptr, png_bytep_NULL);
813         rp++;
814      }
815   else if(dp != NULL)
816      for (i = 0; i < num_rows; i++)
817      {
818         png_bytep dptr = *dp;
819         png_read_row(png_ptr, png_bytep_NULL, dptr);
820         dp++;
821      }
822}
823
824/* Read the entire image.  If the image has an alpha channel or a tRNS
825 * chunk, and you have called png_handle_alpha()[*], you will need to
826 * initialize the image to the current image that PNG will be overlaying.
827 * We set the num_rows again here, in case it was incorrectly set in
828 * png_read_start_row() by a call to png_read_update_info() or
829 * png_start_read_image() if png_set_interlace_handling() wasn't called
830 * prior to either of these functions like it should have been.  You can
831 * only call this function once.  If you desire to have an image for
832 * each pass of a interlaced image, use png_read_rows() instead.
833 *
834 * [*] png_handle_alpha() does not exist yet, as of libpng version 1.2.5
835 */
836void PNGAPI
837png_read_image(png_structp png_ptr, png_bytepp image)
838{
839   png_uint_32 i,image_height;
840   int pass, j;
841   png_bytepp rp;
842
843   png_debug(1, "in png_read_image\n");
844
845#ifdef PNG_READ_INTERLACING_SUPPORTED
846   pass = png_set_interlace_handling(png_ptr);
847#else
848   if (png_ptr->interlaced)
849      png_error(png_ptr,
850        "Cannot read interlaced image -- interlace handler disabled.");
851   pass = 1;
852#endif
853
854
855   image_height=png_ptr->height;
856   png_ptr->num_rows = image_height; /* Make sure this is set correctly */
857
858   for (j = 0; j < pass; j++)
859   {
860      rp = image;
861      for (i = 0; i < image_height; i++)
862      {
863         png_read_row(png_ptr, *rp, png_bytep_NULL);
864         rp++;
865      }
866   }
867}
868
869/* Read the end of the PNG file.  Will not read past the end of the
870 * file, will verify the end is accurate, and will read any comments
871 * or time information at the end of the file, if info is not NULL.
872 */
873void PNGAPI
874png_read_end(png_structp png_ptr, png_infop info_ptr)
875{
876   png_byte chunk_length[4];
877   png_uint_32 length;
878
879   png_debug(1, "in png_read_end\n");
880   png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
881
882   do
883   {
884#ifdef PNG_USE_LOCAL_ARRAYS
885      PNG_IHDR;
886      PNG_IDAT;
887      PNG_IEND;
888      PNG_PLTE;
889#if defined(PNG_READ_bKGD_SUPPORTED)
890      PNG_bKGD;
891#endif
892#if defined(PNG_READ_cHRM_SUPPORTED)
893      PNG_cHRM;
894#endif
895#if defined(PNG_READ_gAMA_SUPPORTED)
896      PNG_gAMA;
897#endif
898#if defined(PNG_READ_hIST_SUPPORTED)
899      PNG_hIST;
900#endif
901#if defined(PNG_READ_iCCP_SUPPORTED)
902      PNG_iCCP;
903#endif
904#if defined(PNG_READ_iTXt_SUPPORTED)
905      PNG_iTXt;
906#endif
907#if defined(PNG_READ_oFFs_SUPPORTED)
908      PNG_oFFs;
909#endif
910#if defined(PNG_READ_pCAL_SUPPORTED)
911      PNG_pCAL;
912#endif
913#if defined(PNG_READ_pHYs_SUPPORTED)
914      PNG_pHYs;
915#endif
916#if defined(PNG_READ_sBIT_SUPPORTED)
917      PNG_sBIT;
918#endif
919#if defined(PNG_READ_sCAL_SUPPORTED)
920      PNG_sCAL;
921#endif
922#if defined(PNG_READ_sPLT_SUPPORTED)
923      PNG_sPLT;
924#endif
925#if defined(PNG_READ_sRGB_SUPPORTED)
926      PNG_sRGB;
927#endif
928#if defined(PNG_READ_tEXt_SUPPORTED)
929      PNG_tEXt;
930#endif
931#if defined(PNG_READ_tIME_SUPPORTED)
932      PNG_tIME;
933#endif
934#if defined(PNG_READ_tRNS_SUPPORTED)
935      PNG_tRNS;
936#endif
937#if defined(PNG_READ_zTXt_SUPPORTED)
938      PNG_zTXt;
939#endif
940#endif /* PNG_GLOBAL_ARRAYS */
941
942      png_read_data(png_ptr, chunk_length, 4);
943      length = png_get_uint_31(png_ptr,chunk_length);
944
945      png_reset_crc(png_ptr);
946      png_crc_read(png_ptr, png_ptr->chunk_name, 4);
947
948      png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name);
949
950      if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
951         png_handle_IHDR(png_ptr, info_ptr, length);
952      else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
953         png_handle_IEND(png_ptr, info_ptr, length);
954#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
955      else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
956      {
957         if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
958         {
959            if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT)
960               png_error(png_ptr, "Too many IDAT's found");
961         }
962         else
963            png_ptr->mode |= PNG_AFTER_IDAT;
964         png_handle_unknown(png_ptr, info_ptr, length);
965         if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
966            png_ptr->mode |= PNG_HAVE_PLTE;
967      }
968#endif
969      else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
970      {
971         /* Zero length IDATs are legal after the last IDAT has been
972          * read, but not after other chunks have been read.
973          */
974         if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT)
975            png_error(png_ptr, "Too many IDAT's found");
976         png_crc_finish(png_ptr, length);
977      }
978      else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
979         png_handle_PLTE(png_ptr, info_ptr, length);
980#if defined(PNG_READ_bKGD_SUPPORTED)
981      else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
982         png_handle_bKGD(png_ptr, info_ptr, length);
983#endif
984#if defined(PNG_READ_cHRM_SUPPORTED)
985      else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
986         png_handle_cHRM(png_ptr, info_ptr, length);
987#endif
988#if defined(PNG_READ_gAMA_SUPPORTED)
989      else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
990         png_handle_gAMA(png_ptr, info_ptr, length);
991#endif
992#if defined(PNG_READ_hIST_SUPPORTED)
993      else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
994         png_handle_hIST(png_ptr, info_ptr, length);
995#endif
996#if defined(PNG_READ_oFFs_SUPPORTED)
997      else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
998         png_handle_oFFs(png_ptr, info_ptr, length);
999#endif
1000#if defined(PNG_READ_pCAL_SUPPORTED)
1001      else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
1002         png_handle_pCAL(png_ptr, info_ptr, length);
1003#endif
1004#if defined(PNG_READ_sCAL_SUPPORTED)
1005      else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
1006         png_handle_sCAL(png_ptr, info_ptr, length);
1007#endif
1008#if defined(PNG_READ_pHYs_SUPPORTED)
1009      else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
1010         png_handle_pHYs(png_ptr, info_ptr, length);
1011#endif
1012#if defined(PNG_READ_sBIT_SUPPORTED)
1013      else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
1014         png_handle_sBIT(png_ptr, info_ptr, length);
1015#endif
1016#if defined(PNG_READ_sRGB_SUPPORTED)
1017      else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
1018         png_handle_sRGB(png_ptr, info_ptr, length);
1019#endif
1020#if defined(PNG_READ_iCCP_SUPPORTED)
1021      else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
1022         png_handle_iCCP(png_ptr, info_ptr, length);
1023#endif
1024#if defined(PNG_READ_sPLT_SUPPORTED)
1025      else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
1026         png_handle_sPLT(png_ptr, info_ptr, length);
1027#endif
1028#if defined(PNG_READ_tEXt_SUPPORTED)
1029      else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
1030         png_handle_tEXt(png_ptr, info_ptr, length);
1031#endif
1032#if defined(PNG_READ_tIME_SUPPORTED)
1033      else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
1034         png_handle_tIME(png_ptr, info_ptr, length);
1035#endif
1036#if defined(PNG_READ_tRNS_SUPPORTED)
1037      else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
1038         png_handle_tRNS(png_ptr, info_ptr, length);
1039#endif
1040#if defined(PNG_READ_zTXt_SUPPORTED)
1041      else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
1042         png_handle_zTXt(png_ptr, info_ptr, length);
1043#endif
1044#if defined(PNG_READ_iTXt_SUPPORTED)
1045      else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
1046         png_handle_iTXt(png_ptr, info_ptr, length);
1047#endif
1048      else
1049         png_handle_unknown(png_ptr, info_ptr, length);
1050   } while (!(png_ptr->mode & PNG_HAVE_IEND));
1051}
1052
1053/* free all memory used by the read */
1054void PNGAPI
1055png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
1056   png_infopp end_info_ptr_ptr)
1057{
1058   png_structp png_ptr = NULL;
1059   png_infop info_ptr = NULL, end_info_ptr = NULL;
1060#ifdef PNG_USER_MEM_SUPPORTED
1061   png_free_ptr free_fn = NULL;
1062   png_voidp mem_ptr = NULL;
1063#endif
1064
1065   png_debug(1, "in png_destroy_read_struct\n");
1066   if (png_ptr_ptr != NULL)
1067      png_ptr = *png_ptr_ptr;
1068
1069   if (info_ptr_ptr != NULL)
1070      info_ptr = *info_ptr_ptr;
1071
1072   if (end_info_ptr_ptr != NULL)
1073      end_info_ptr = *end_info_ptr_ptr;
1074
1075#ifdef PNG_USER_MEM_SUPPORTED
1076   free_fn = png_ptr->free_fn;
1077   mem_ptr = png_ptr->mem_ptr;
1078#endif
1079
1080   png_read_destroy(png_ptr, info_ptr, end_info_ptr);
1081
1082   if (info_ptr != NULL)
1083   {
1084#if defined(PNG_TEXT_SUPPORTED)
1085      png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1);
1086#endif
1087
1088#ifdef PNG_USER_MEM_SUPPORTED
1089      png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1090          (png_voidp)mem_ptr);
1091#else
1092      png_destroy_struct((png_voidp)info_ptr);
1093#endif
1094      *info_ptr_ptr = NULL;
1095   }
1096
1097   if (end_info_ptr != NULL)
1098   {
1099#if defined(PNG_READ_TEXT_SUPPORTED)
1100      png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1);
1101#endif
1102#ifdef PNG_USER_MEM_SUPPORTED
1103      png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn,
1104         (png_voidp)mem_ptr);
1105#else
1106      png_destroy_struct((png_voidp)end_info_ptr);
1107#endif
1108      *end_info_ptr_ptr = NULL;
1109   }
1110
1111   if (png_ptr != NULL)
1112   {
1113#ifdef PNG_USER_MEM_SUPPORTED
1114      png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1115          (png_voidp)mem_ptr);
1116#else
1117      png_destroy_struct((png_voidp)png_ptr);
1118#endif
1119      *png_ptr_ptr = NULL;
1120   }
1121}
1122
1123/* free all memory used by the read (old method) */
1124void /* PRIVATE */
1125png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr)
1126{
1127#ifdef PNG_SETJMP_SUPPORTED
1128   jmp_buf tmp_jmp;
1129#endif
1130   png_error_ptr error_fn;
1131   png_error_ptr warning_fn;
1132   png_voidp error_ptr;
1133#ifdef PNG_USER_MEM_SUPPORTED
1134   png_free_ptr free_fn;
1135#endif
1136
1137   png_debug(1, "in png_read_destroy\n");
1138   if (info_ptr != NULL)
1139      png_info_destroy(png_ptr, info_ptr);
1140
1141   if (end_info_ptr != NULL)
1142      png_info_destroy(png_ptr, end_info_ptr);
1143
1144   png_free(png_ptr, png_ptr->zbuf);
1145   png_free(png_ptr, png_ptr->big_row_buf);
1146   png_free(png_ptr, png_ptr->prev_row);
1147#if defined(PNG_READ_DITHER_SUPPORTED)
1148   png_free(png_ptr, png_ptr->palette_lookup);
1149   png_free(png_ptr, png_ptr->dither_index);
1150#endif
1151#if defined(PNG_READ_GAMMA_SUPPORTED)
1152   png_free(png_ptr, png_ptr->gamma_table);
1153#endif
1154#if defined(PNG_READ_BACKGROUND_SUPPORTED)
1155   png_free(png_ptr, png_ptr->gamma_from_1);
1156   png_free(png_ptr, png_ptr->gamma_to_1);
1157#endif
1158#ifdef PNG_FREE_ME_SUPPORTED
1159   if (png_ptr->free_me & PNG_FREE_PLTE)
1160      png_zfree(png_ptr, png_ptr->palette);
1161   png_ptr->free_me &= ~PNG_FREE_PLTE;
1162#else
1163   if (png_ptr->flags & PNG_FLAG_FREE_PLTE)
1164      png_zfree(png_ptr, png_ptr->palette);
1165   png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
1166#endif
1167#if defined(PNG_tRNS_SUPPORTED) || \
1168    defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1169#ifdef PNG_FREE_ME_SUPPORTED
1170   if (png_ptr->free_me & PNG_FREE_TRNS)
1171      png_free(png_ptr, png_ptr->trans);
1172   png_ptr->free_me &= ~PNG_FREE_TRNS;
1173#else
1174   if (png_ptr->flags & PNG_FLAG_FREE_TRNS)
1175      png_free(png_ptr, png_ptr->trans);
1176   png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
1177#endif
1178#endif
1179#if defined(PNG_READ_hIST_SUPPORTED)
1180#ifdef PNG_FREE_ME_SUPPORTED
1181   if (png_ptr->free_me & PNG_FREE_HIST)
1182      png_free(png_ptr, png_ptr->hist);
1183   png_ptr->free_me &= ~PNG_FREE_HIST;
1184#else
1185   if (png_ptr->flags & PNG_FLAG_FREE_HIST)
1186      png_free(png_ptr, png_ptr->hist);
1187   png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
1188#endif
1189#endif
1190#if defined(PNG_READ_GAMMA_SUPPORTED)
1191   if (png_ptr->gamma_16_table != NULL)
1192   {
1193      int i;
1194      int istop = (1 << (8 - png_ptr->gamma_shift));
1195      for (i = 0; i < istop; i++)
1196      {
1197         png_free(png_ptr, png_ptr->gamma_16_table[i]);
1198      }
1199   png_free(png_ptr, png_ptr->gamma_16_table);
1200   }
1201#if defined(PNG_READ_BACKGROUND_SUPPORTED)
1202   if (png_ptr->gamma_16_from_1 != NULL)
1203   {
1204      int i;
1205      int istop = (1 << (8 - png_ptr->gamma_shift));
1206      for (i = 0; i < istop; i++)
1207      {
1208         png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
1209      }
1210   png_free(png_ptr, png_ptr->gamma_16_from_1);
1211   }
1212   if (png_ptr->gamma_16_to_1 != NULL)
1213   {
1214      int i;
1215      int istop = (1 << (8 - png_ptr->gamma_shift));
1216      for (i = 0; i < istop; i++)
1217      {
1218         png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
1219      }
1220   png_free(png_ptr, png_ptr->gamma_16_to_1);
1221   }
1222#endif
1223#endif
1224#if defined(PNG_TIME_RFC1123_SUPPORTED)
1225   png_free(png_ptr, png_ptr->time_buffer);
1226#endif
1227
1228   inflateEnd(&png_ptr->zstream);
1229#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1230   png_free(png_ptr, png_ptr->save_buffer);
1231#endif
1232
1233#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1234#ifdef PNG_TEXT_SUPPORTED
1235   png_free(png_ptr, png_ptr->current_text);
1236#endif /* PNG_TEXT_SUPPORTED */
1237#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1238
1239   /* Save the important info out of the png_struct, in case it is
1240    * being used again.
1241    */
1242#ifdef PNG_SETJMP_SUPPORTED
1243   png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
1244#endif
1245
1246   error_fn = png_ptr->error_fn;
1247   warning_fn = png_ptr->warning_fn;
1248   error_ptr = png_ptr->error_ptr;
1249#ifdef PNG_USER_MEM_SUPPORTED
1250   free_fn = png_ptr->free_fn;
1251#endif
1252
1253   png_memset(png_ptr, 0, sizeof (png_struct));
1254
1255   png_ptr->error_fn = error_fn;
1256   png_ptr->warning_fn = warning_fn;
1257   png_ptr->error_ptr = error_ptr;
1258#ifdef PNG_USER_MEM_SUPPORTED
1259   png_ptr->free_fn = free_fn;
1260#endif
1261
1262#ifdef PNG_SETJMP_SUPPORTED
1263   png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
1264#endif
1265
1266}
1267
1268void PNGAPI
1269png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
1270{
1271   png_ptr->read_row_fn = read_row_fn;
1272}
1273
1274#if defined(PNG_INFO_IMAGE_SUPPORTED)
1275void PNGAPI
1276png_read_png(png_structp png_ptr, png_infop info_ptr,
1277                           int transforms,
1278                           voidp params)
1279{
1280   int row;
1281
1282#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
1283   /* invert the alpha channel from opacity to transparency */
1284   if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1285       png_set_invert_alpha(png_ptr);
1286#endif
1287
1288   /* The call to png_read_info() gives us all of the information from the
1289    * PNG file before the first IDAT (image data chunk).
1290    */
1291   png_read_info(png_ptr, info_ptr);
1292
1293   if (info_ptr->height > PNG_UINT_32_MAX/sizeof(png_bytep))
1294      png_error(png_ptr,"Image is too high to process with png_read_png()");
1295
1296   /* -------------- image transformations start here ------------------- */
1297
1298#if defined(PNG_READ_16_TO_8_SUPPORTED)
1299   /* tell libpng to strip 16 bit/color files down to 8 bits/color */
1300   if (transforms & PNG_TRANSFORM_STRIP_16)
1301       png_set_strip_16(png_ptr);
1302#endif
1303
1304#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1305   /* Strip alpha bytes from the input data without combining with the
1306    * background (not recommended).
1307    */
1308   if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
1309       png_set_strip_alpha(png_ptr);
1310#endif
1311
1312#if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
1313   /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single
1314    * byte into separate bytes (useful for paletted and grayscale images).
1315    */
1316   if (transforms & PNG_TRANSFORM_PACKING)
1317       png_set_packing(png_ptr);
1318#endif
1319
1320#if defined(PNG_READ_PACKSWAP_SUPPORTED)
1321   /* Change the order of packed pixels to least significant bit first
1322    * (not useful if you are using png_set_packing). */
1323   if (transforms & PNG_TRANSFORM_PACKSWAP)
1324       png_set_packswap(png_ptr);
1325#endif
1326
1327#if defined(PNG_READ_EXPAND_SUPPORTED)
1328   /* Expand paletted colors into true RGB triplets
1329    * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
1330    * Expand paletted or RGB images with transparency to full alpha
1331    * channels so the data will be available as RGBA quartets.
1332    */
1333   if (transforms & PNG_TRANSFORM_EXPAND)
1334       if ((png_ptr->bit_depth < 8) ||
1335           (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
1336           (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
1337         png_set_expand(png_ptr);
1338#endif
1339
1340   /* We don't handle background color or gamma transformation or dithering. */
1341
1342#if defined(PNG_READ_INVERT_SUPPORTED)
1343   /* invert monochrome files to have 0 as white and 1 as black */
1344   if (transforms & PNG_TRANSFORM_INVERT_MONO)
1345       png_set_invert_mono(png_ptr);
1346#endif
1347
1348#if defined(PNG_READ_SHIFT_SUPPORTED)
1349   /* If you want to shift the pixel values from the range [0,255] or
1350    * [0,65535] to the original [0,7] or [0,31], or whatever range the
1351    * colors were originally in:
1352    */
1353   if ((transforms & PNG_TRANSFORM_SHIFT)
1354       && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
1355   {
1356      png_color_8p sig_bit;
1357
1358      png_get_sBIT(png_ptr, info_ptr, &sig_bit);
1359      png_set_shift(png_ptr, sig_bit);
1360   }
1361#endif
1362
1363#if defined(PNG_READ_BGR_SUPPORTED)
1364   /* flip the RGB pixels to BGR (or RGBA to BGRA) */
1365   if (transforms & PNG_TRANSFORM_BGR)
1366       png_set_bgr(png_ptr);
1367#endif
1368
1369#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
1370   /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
1371   if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1372       png_set_swap_alpha(png_ptr);
1373#endif
1374
1375#if defined(PNG_READ_SWAP_SUPPORTED)
1376   /* swap bytes of 16 bit files to least significant byte first */
1377   if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1378       png_set_swap(png_ptr);
1379#endif
1380
1381   /* We don't handle adding filler bytes */
1382
1383   /* Optional call to gamma correct and add the background to the palette
1384    * and update info structure.  REQUIRED if you are expecting libpng to
1385    * update the palette for you (i.e., you selected such a transform above).
1386    */
1387   png_read_update_info(png_ptr, info_ptr);
1388
1389   /* -------------- image transformations end here ------------------- */
1390
1391#ifdef PNG_FREE_ME_SUPPORTED
1392   png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
1393#endif
1394   if(info_ptr->row_pointers == NULL)
1395   {
1396      info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
1397         info_ptr->height * sizeof(png_bytep));
1398#ifdef PNG_FREE_ME_SUPPORTED
1399      info_ptr->free_me |= PNG_FREE_ROWS;
1400#endif
1401      for (row = 0; row < (int)info_ptr->height; row++)
1402      {
1403         info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,
1404            png_get_rowbytes(png_ptr, info_ptr));
1405      }
1406   }
1407
1408   png_read_image(png_ptr, info_ptr->row_pointers);
1409   info_ptr->valid |= PNG_INFO_IDAT;
1410
1411   /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
1412   png_read_end(png_ptr, info_ptr);
1413
1414   if(transforms == 0 || params == NULL)
1415      /* quiet compiler warnings */ return;
1416
1417}
1418#endif
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