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/src/compiler/android/jni/ftk/png.c

http://ftk.googlecode.com/
C | 1100 lines | 827 code | 129 blank | 144 comment | 185 complexity | 752b6dd749f29f9e64d27a004cd35bc2 MD5 | raw file
   1
   2/* png.c - location for general purpose libpng functions
   3 *
   4 * Last changed in libpng 1.2.43 [February 25, 2010]
   5 * Copyright (c) 1998-2010 Glenn Randers-Pehrson
   6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
   7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
   8 *
   9 * This code is released under the libpng license.
  10 * For conditions of distribution and use, see the disclaimer
  11 * and license in png.h
  12 */
  13
  14#define PNG_INTERNAL
  15#define PNG_NO_EXTERN
  16#define PNG_NO_PEDANTIC_WARNINGS
  17#include "png.h"
  18
  19/* Generate a compiler error if there is an old png.h in the search path. */
  20typedef version_1_2_44 Your_png_h_is_not_version_1_2_44;
  21
  22/* Version information for C files.  This had better match the version
  23 * string defined in png.h.
  24 */
  25
  26#ifdef PNG_USE_GLOBAL_ARRAYS
  27/* png_libpng_ver was changed to a function in version 1.0.5c */
  28PNG_CONST char png_libpng_ver[18] = PNG_LIBPNG_VER_STRING;
  29
  30#ifdef PNG_READ_SUPPORTED
  31
  32/* png_sig was changed to a function in version 1.0.5c */
  33/* Place to hold the signature string for a PNG file. */
  34PNG_CONST png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
  35#endif /* PNG_READ_SUPPORTED */
  36
  37/* Invoke global declarations for constant strings for known chunk types */
  38PNG_IHDR;
  39PNG_IDAT;
  40PNG_IEND;
  41PNG_PLTE;
  42PNG_bKGD;
  43PNG_cHRM;
  44PNG_gAMA;
  45PNG_hIST;
  46PNG_iCCP;
  47PNG_iTXt;
  48PNG_oFFs;
  49PNG_pCAL;
  50PNG_sCAL;
  51PNG_pHYs;
  52PNG_sBIT;
  53PNG_sPLT;
  54PNG_sRGB;
  55PNG_tEXt;
  56PNG_tIME;
  57PNG_tRNS;
  58PNG_zTXt;
  59
  60#ifdef PNG_READ_SUPPORTED
  61/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
  62
  63/* Start of interlace block */
  64PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
  65
  66/* Offset to next interlace block */
  67PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
  68
  69/* Start of interlace block in the y direction */
  70PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
  71
  72/* Offset to next interlace block in the y direction */
  73PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
  74
  75/* Height of interlace block.  This is not currently used - if you need
  76 * it, uncomment it here and in png.h
  77PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
  78*/
  79
  80/* Mask to determine which pixels are valid in a pass */
  81PNG_CONST int FARDATA png_pass_mask[] =
  82    {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
  83
  84/* Mask to determine which pixels to overwrite while displaying */
  85PNG_CONST int FARDATA png_pass_dsp_mask[]
  86   = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
  87
  88#endif /* PNG_READ_SUPPORTED */
  89#endif /* PNG_USE_GLOBAL_ARRAYS */
  90
  91/* Tells libpng that we have already handled the first "num_bytes" bytes
  92 * of the PNG file signature.  If the PNG data is embedded into another
  93 * stream we can set num_bytes = 8 so that libpng will not attempt to read
  94 * or write any of the magic bytes before it starts on the IHDR.
  95 */
  96
  97#ifdef PNG_READ_SUPPORTED
  98void PNGAPI
  99png_set_sig_bytes(png_structp png_ptr, int num_bytes)
 100{
 101   png_debug(1, "in png_set_sig_bytes");
 102
 103   if (png_ptr == NULL)
 104      return;
 105
 106   if (num_bytes > 8)
 107      png_error(png_ptr, "Too many bytes for PNG signature.");
 108
 109   png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
 110}
 111
 112/* Checks whether the supplied bytes match the PNG signature.  We allow
 113 * checking less than the full 8-byte signature so that those apps that
 114 * already read the first few bytes of a file to determine the file type
 115 * can simply check the remaining bytes for extra assurance.  Returns
 116 * an integer less than, equal to, or greater than zero if sig is found,
 117 * respectively, to be less than, to match, or be greater than the correct
 118 * PNG signature (this is the same behaviour as strcmp, memcmp, etc).
 119 */
 120int PNGAPI
 121png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
 122{
 123   png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
 124   if (num_to_check > 8)
 125      num_to_check = 8;
 126   else if (num_to_check < 1)
 127      return (-1);
 128
 129   if (start > 7)
 130      return (-1);
 131
 132   if (start + num_to_check > 8)
 133      num_to_check = 8 - start;
 134
 135   return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
 136}
 137
 138#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
 139/* (Obsolete) function to check signature bytes.  It does not allow one
 140 * to check a partial signature.  This function might be removed in the
 141 * future - use png_sig_cmp().  Returns true (nonzero) if the file is PNG.
 142 */
 143int PNGAPI
 144png_check_sig(png_bytep sig, int num)
 145{
 146  return ((int)!png_sig_cmp(sig, (png_size_t)0, (png_size_t)num));
 147}
 148#endif
 149#endif /* PNG_READ_SUPPORTED */
 150
 151#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 152/* Function to allocate memory for zlib and clear it to 0. */
 153#ifdef PNG_1_0_X
 154voidpf PNGAPI
 155#else
 156voidpf /* PRIVATE */
 157#endif
 158png_zalloc(voidpf png_ptr, uInt items, uInt size)
 159{
 160   png_voidp ptr;
 161   png_structp p=(png_structp)png_ptr;
 162   png_uint_32 save_flags=p->flags;
 163   png_uint_32 num_bytes;
 164
 165   if (png_ptr == NULL)
 166      return (NULL);
 167   if (items > PNG_UINT_32_MAX/size)
 168   {
 169     png_warning (p, "Potential overflow in png_zalloc()");
 170     return (NULL);
 171   }
 172   num_bytes = (png_uint_32)items * size;
 173
 174   p->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
 175   ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
 176   p->flags=save_flags;
 177
 178#if defined(PNG_1_0_X) && !defined(PNG_NO_ZALLOC_ZERO)
 179   if (ptr == NULL)
 180       return ((voidpf)ptr);
 181
 182   if (num_bytes > (png_uint_32)0x8000L)
 183   {
 184      png_memset(ptr, 0, (png_size_t)0x8000L);
 185      png_memset((png_bytep)ptr + (png_size_t)0x8000L, 0,
 186         (png_size_t)(num_bytes - (png_uint_32)0x8000L));
 187   }
 188   else
 189   {
 190      png_memset(ptr, 0, (png_size_t)num_bytes);
 191   }
 192#endif
 193   return ((voidpf)ptr);
 194}
 195
 196/* Function to free memory for zlib */
 197#ifdef PNG_1_0_X
 198void PNGAPI
 199#else
 200void /* PRIVATE */
 201#endif
 202png_zfree(voidpf png_ptr, voidpf ptr)
 203{
 204   png_free((png_structp)png_ptr, (png_voidp)ptr);
 205}
 206
 207/* Reset the CRC variable to 32 bits of 1's.  Care must be taken
 208 * in case CRC is > 32 bits to leave the top bits 0.
 209 */
 210void /* PRIVATE */
 211png_reset_crc(png_structp png_ptr)
 212{
 213   png_ptr->crc = crc32(0, Z_NULL, 0);
 214}
 215
 216/* Calculate the CRC over a section of data.  We can only pass as
 217 * much data to this routine as the largest single buffer size.  We
 218 * also check that this data will actually be used before going to the
 219 * trouble of calculating it.
 220 */
 221void /* PRIVATE */
 222png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length)
 223{
 224   int need_crc = 1;
 225
 226   if (png_ptr->chunk_name[0] & 0x20)                     /* ancillary */
 227   {
 228      if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
 229          (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
 230         need_crc = 0;
 231   }
 232   else                                                    /* critical */
 233   {
 234      if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
 235         need_crc = 0;
 236   }
 237
 238   if (need_crc)
 239      png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length);
 240}
 241
 242/* Allocate the memory for an info_struct for the application.  We don't
 243 * really need the png_ptr, but it could potentially be useful in the
 244 * future.  This should be used in favour of malloc(png_sizeof(png_info))
 245 * and png_info_init() so that applications that want to use a shared
 246 * libpng don't have to be recompiled if png_info changes size.
 247 */
 248png_infop PNGAPI
 249png_create_info_struct(png_structp png_ptr)
 250{
 251   png_infop info_ptr;
 252
 253   png_debug(1, "in png_create_info_struct");
 254
 255   if (png_ptr == NULL)
 256      return (NULL);
 257
 258#ifdef PNG_USER_MEM_SUPPORTED
 259   info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
 260      png_ptr->malloc_fn, png_ptr->mem_ptr);
 261#else
 262   info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
 263#endif
 264   if (info_ptr != NULL)
 265      png_info_init_3(&info_ptr, png_sizeof(png_info));
 266
 267   return (info_ptr);
 268}
 269
 270/* This function frees the memory associated with a single info struct.
 271 * Normally, one would use either png_destroy_read_struct() or
 272 * png_destroy_write_struct() to free an info struct, but this may be
 273 * useful for some applications.
 274 */
 275void PNGAPI
 276png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
 277{
 278   png_infop info_ptr = NULL;
 279
 280   png_debug(1, "in png_destroy_info_struct");
 281
 282   if (png_ptr == NULL)
 283      return;
 284
 285   if (info_ptr_ptr != NULL)
 286      info_ptr = *info_ptr_ptr;
 287
 288   if (info_ptr != NULL)
 289   {
 290      png_info_destroy(png_ptr, info_ptr);
 291
 292#ifdef PNG_USER_MEM_SUPPORTED
 293      png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn,
 294          png_ptr->mem_ptr);
 295#else
 296      png_destroy_struct((png_voidp)info_ptr);
 297#endif
 298      *info_ptr_ptr = NULL;
 299   }
 300}
 301
 302/* Initialize the info structure.  This is now an internal function (0.89)
 303 * and applications using it are urged to use png_create_info_struct()
 304 * instead.
 305 */
 306#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
 307#undef png_info_init
 308void PNGAPI
 309png_info_init(png_infop info_ptr)
 310{
 311   /* We only come here via pre-1.0.12-compiled applications */
 312   png_info_init_3(&info_ptr, 0);
 313}
 314#endif
 315
 316void PNGAPI
 317png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size)
 318{
 319   png_infop info_ptr = *ptr_ptr;
 320
 321   png_debug(1, "in png_info_init_3");
 322
 323   if (info_ptr == NULL)
 324      return;
 325
 326   if (png_sizeof(png_info) > png_info_struct_size)
 327   {
 328      png_destroy_struct(info_ptr);
 329      info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
 330      *ptr_ptr = info_ptr;
 331   }
 332
 333   /* Set everything to 0 */
 334   png_memset(info_ptr, 0, png_sizeof(png_info));
 335}
 336
 337#ifdef PNG_FREE_ME_SUPPORTED
 338void PNGAPI
 339png_data_freer(png_structp png_ptr, png_infop info_ptr,
 340   int freer, png_uint_32 mask)
 341{
 342   png_debug(1, "in png_data_freer");
 343
 344   if (png_ptr == NULL || info_ptr == NULL)
 345      return;
 346
 347   if (freer == PNG_DESTROY_WILL_FREE_DATA)
 348      info_ptr->free_me |= mask;
 349   else if (freer == PNG_USER_WILL_FREE_DATA)
 350      info_ptr->free_me &= ~mask;
 351   else
 352      png_warning(png_ptr,
 353         "Unknown freer parameter in png_data_freer.");
 354}
 355#endif
 356
 357void PNGAPI
 358png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
 359   int num)
 360{
 361   png_debug(1, "in png_free_data");
 362
 363   if (png_ptr == NULL || info_ptr == NULL)
 364      return;
 365
 366#ifdef PNG_TEXT_SUPPORTED
 367   /* Free text item num or (if num == -1) all text items */
 368#ifdef PNG_FREE_ME_SUPPORTED
 369   if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
 370#else
 371   if (mask & PNG_FREE_TEXT)
 372#endif
 373   {
 374      if (num != -1)
 375      {
 376         if (info_ptr->text && info_ptr->text[num].key)
 377         {
 378            png_free(png_ptr, info_ptr->text[num].key);
 379            info_ptr->text[num].key = NULL;
 380         }
 381      }
 382      else
 383      {
 384         int i;
 385         for (i = 0; i < info_ptr->num_text; i++)
 386             png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
 387         png_free(png_ptr, info_ptr->text);
 388         info_ptr->text = NULL;
 389         info_ptr->num_text=0;
 390      }
 391   }
 392#endif
 393
 394#ifdef PNG_tRNS_SUPPORTED
 395   /* Free any tRNS entry */
 396#ifdef PNG_FREE_ME_SUPPORTED
 397   if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
 398#else
 399   if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS))
 400#endif
 401   {
 402      png_free(png_ptr, info_ptr->trans);
 403      info_ptr->trans = NULL;
 404      info_ptr->valid &= ~PNG_INFO_tRNS;
 405#ifndef PNG_FREE_ME_SUPPORTED
 406      png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
 407#endif
 408   }
 409#endif
 410
 411#ifdef PNG_sCAL_SUPPORTED
 412   /* Free any sCAL entry */
 413#ifdef PNG_FREE_ME_SUPPORTED
 414   if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
 415#else
 416   if (mask & PNG_FREE_SCAL)
 417#endif
 418   {
 419#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
 420      png_free(png_ptr, info_ptr->scal_s_width);
 421      png_free(png_ptr, info_ptr->scal_s_height);
 422      info_ptr->scal_s_width = NULL;
 423      info_ptr->scal_s_height = NULL;
 424#endif
 425      info_ptr->valid &= ~PNG_INFO_sCAL;
 426   }
 427#endif
 428
 429#ifdef PNG_pCAL_SUPPORTED
 430   /* Free any pCAL entry */
 431#ifdef PNG_FREE_ME_SUPPORTED
 432   if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
 433#else
 434   if (mask & PNG_FREE_PCAL)
 435#endif
 436   {
 437      png_free(png_ptr, info_ptr->pcal_purpose);
 438      png_free(png_ptr, info_ptr->pcal_units);
 439      info_ptr->pcal_purpose = NULL;
 440      info_ptr->pcal_units = NULL;
 441      if (info_ptr->pcal_params != NULL)
 442         {
 443            int i;
 444            for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
 445            {
 446               png_free(png_ptr, info_ptr->pcal_params[i]);
 447               info_ptr->pcal_params[i] = NULL;
 448            }
 449            png_free(png_ptr, info_ptr->pcal_params);
 450            info_ptr->pcal_params = NULL;
 451         }
 452      info_ptr->valid &= ~PNG_INFO_pCAL;
 453   }
 454#endif
 455
 456#ifdef PNG_iCCP_SUPPORTED
 457   /* Free any iCCP entry */
 458#ifdef PNG_FREE_ME_SUPPORTED
 459   if ((mask & PNG_FREE_ICCP) & info_ptr->free_me)
 460#else
 461   if (mask & PNG_FREE_ICCP)
 462#endif
 463   {
 464      png_free(png_ptr, info_ptr->iccp_name);
 465      png_free(png_ptr, info_ptr->iccp_profile);
 466      info_ptr->iccp_name = NULL;
 467      info_ptr->iccp_profile = NULL;
 468      info_ptr->valid &= ~PNG_INFO_iCCP;
 469   }
 470#endif
 471
 472#ifdef PNG_sPLT_SUPPORTED
 473   /* Free a given sPLT entry, or (if num == -1) all sPLT entries */
 474#ifdef PNG_FREE_ME_SUPPORTED
 475   if ((mask & PNG_FREE_SPLT) & info_ptr->free_me)
 476#else
 477   if (mask & PNG_FREE_SPLT)
 478#endif
 479   {
 480      if (num != -1)
 481      {
 482         if (info_ptr->splt_palettes)
 483         {
 484            png_free(png_ptr, info_ptr->splt_palettes[num].name);
 485            png_free(png_ptr, info_ptr->splt_palettes[num].entries);
 486            info_ptr->splt_palettes[num].name = NULL;
 487            info_ptr->splt_palettes[num].entries = NULL;
 488         }
 489      }
 490      else
 491      {
 492         if (info_ptr->splt_palettes_num)
 493         {
 494            int i;
 495            for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
 496               png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i);
 497
 498            png_free(png_ptr, info_ptr->splt_palettes);
 499            info_ptr->splt_palettes = NULL;
 500            info_ptr->splt_palettes_num = 0;
 501         }
 502         info_ptr->valid &= ~PNG_INFO_sPLT;
 503      }
 504   }
 505#endif
 506
 507#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
 508   if (png_ptr->unknown_chunk.data)
 509   {
 510      png_free(png_ptr, png_ptr->unknown_chunk.data);
 511      png_ptr->unknown_chunk.data = NULL;
 512   }
 513
 514#ifdef PNG_FREE_ME_SUPPORTED
 515   if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
 516#else
 517   if (mask & PNG_FREE_UNKN)
 518#endif
 519   {
 520      if (num != -1)
 521      {
 522          if (info_ptr->unknown_chunks)
 523          {
 524             png_free(png_ptr, info_ptr->unknown_chunks[num].data);
 525             info_ptr->unknown_chunks[num].data = NULL;
 526          }
 527      }
 528      else
 529      {
 530         int i;
 531
 532         if (info_ptr->unknown_chunks_num)
 533         {
 534            for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++)
 535               png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
 536
 537            png_free(png_ptr, info_ptr->unknown_chunks);
 538            info_ptr->unknown_chunks = NULL;
 539            info_ptr->unknown_chunks_num = 0;
 540         }
 541      }
 542   }
 543#endif
 544
 545#ifdef PNG_hIST_SUPPORTED
 546   /* Free any hIST entry */
 547#ifdef PNG_FREE_ME_SUPPORTED
 548   if ((mask & PNG_FREE_HIST)  & info_ptr->free_me)
 549#else
 550   if ((mask & PNG_FREE_HIST) && (png_ptr->flags & PNG_FLAG_FREE_HIST))
 551#endif
 552   {
 553      png_free(png_ptr, info_ptr->hist);
 554      info_ptr->hist = NULL;
 555      info_ptr->valid &= ~PNG_INFO_hIST;
 556#ifndef PNG_FREE_ME_SUPPORTED
 557      png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
 558#endif
 559   }
 560#endif
 561
 562   /* Free any PLTE entry that was internally allocated */
 563#ifdef PNG_FREE_ME_SUPPORTED
 564   if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
 565#else
 566   if ((mask & PNG_FREE_PLTE) && (png_ptr->flags & PNG_FLAG_FREE_PLTE))
 567#endif
 568   {
 569      png_zfree(png_ptr, info_ptr->palette);
 570      info_ptr->palette = NULL;
 571      info_ptr->valid &= ~PNG_INFO_PLTE;
 572#ifndef PNG_FREE_ME_SUPPORTED
 573      png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
 574#endif
 575      info_ptr->num_palette = 0;
 576   }
 577
 578#ifdef PNG_INFO_IMAGE_SUPPORTED
 579   /* Free any image bits attached to the info structure */
 580#ifdef PNG_FREE_ME_SUPPORTED
 581   if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
 582#else
 583   if (mask & PNG_FREE_ROWS)
 584#endif
 585   {
 586      if (info_ptr->row_pointers)
 587      {
 588         int row;
 589         for (row = 0; row < (int)info_ptr->height; row++)
 590         {
 591            png_free(png_ptr, info_ptr->row_pointers[row]);
 592            info_ptr->row_pointers[row] = NULL;
 593         }
 594         png_free(png_ptr, info_ptr->row_pointers);
 595         info_ptr->row_pointers = NULL;
 596      }
 597      info_ptr->valid &= ~PNG_INFO_IDAT;
 598   }
 599#endif
 600
 601#ifdef PNG_FREE_ME_SUPPORTED
 602   if (num == -1)
 603      info_ptr->free_me &= ~mask;
 604   else
 605      info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
 606#endif
 607}
 608
 609/* This is an internal routine to free any memory that the info struct is
 610 * pointing to before re-using it or freeing the struct itself.  Recall
 611 * that png_free() checks for NULL pointers for us.
 612 */
 613void /* PRIVATE */
 614png_info_destroy(png_structp png_ptr, png_infop info_ptr)
 615{
 616   png_debug(1, "in png_info_destroy");
 617
 618   png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
 619
 620#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
 621   if (png_ptr->num_chunk_list)
 622   {
 623      png_free(png_ptr, png_ptr->chunk_list);
 624      png_ptr->chunk_list = NULL;
 625      png_ptr->num_chunk_list = 0;
 626   }
 627#endif
 628
 629   png_info_init_3(&info_ptr, png_sizeof(png_info));
 630}
 631#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
 632
 633/* This function returns a pointer to the io_ptr associated with the user
 634 * functions.  The application should free any memory associated with this
 635 * pointer before png_write_destroy() or png_read_destroy() are called.
 636 */
 637png_voidp PNGAPI
 638png_get_io_ptr(png_structp png_ptr)
 639{
 640   if (png_ptr == NULL)
 641      return (NULL);
 642   return (png_ptr->io_ptr);
 643}
 644
 645#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 646#ifdef PNG_STDIO_SUPPORTED
 647/* Initialize the default input/output functions for the PNG file.  If you
 648 * use your own read or write routines, you can call either png_set_read_fn()
 649 * or png_set_write_fn() instead of png_init_io().  If you have defined
 650 * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't
 651 * necessarily available.
 652 */
 653void PNGAPI
 654png_init_io(png_structp png_ptr, png_FILE_p fp)
 655{
 656   png_debug(1, "in png_init_io");
 657
 658   if (png_ptr == NULL)
 659      return;
 660
 661   png_ptr->io_ptr = (png_voidp)fp;
 662}
 663#endif
 664
 665#ifdef PNG_TIME_RFC1123_SUPPORTED
 666/* Convert the supplied time into an RFC 1123 string suitable for use in
 667 * a "Creation Time" or other text-based time string.
 668 */
 669png_charp PNGAPI
 670png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
 671{
 672   static PNG_CONST char short_months[12][4] =
 673        {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
 674         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
 675
 676   if (png_ptr == NULL)
 677      return (NULL);
 678   if (png_ptr->time_buffer == NULL)
 679   {
 680      png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
 681         png_sizeof(char)));
 682   }
 683
 684#ifdef _WIN32_WCE
 685   {
 686      wchar_t time_buf[29];
 687      wsprintf(time_buf, TEXT("%d %S %d %02d:%02d:%02d +0000"),
 688          ptime->day % 32, short_months[(ptime->month - 1) % 12],
 689        ptime->year, ptime->hour % 24, ptime->minute % 60,
 690          ptime->second % 61);
 691      WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer,
 692          29, NULL, NULL);
 693   }
 694#else
 695#ifdef USE_FAR_KEYWORD
 696   {
 697      char near_time_buf[29];
 698      png_snprintf6(near_time_buf, 29, "%d %s %d %02d:%02d:%02d +0000",
 699          ptime->day % 32, short_months[(ptime->month - 1) % 12],
 700          ptime->year, ptime->hour % 24, ptime->minute % 60,
 701          ptime->second % 61);
 702      png_memcpy(png_ptr->time_buffer, near_time_buf,
 703          29*png_sizeof(char));
 704   }
 705#else
 706   png_snprintf6(png_ptr->time_buffer, 29, "%d %s %d %02d:%02d:%02d +0000",
 707       ptime->day % 32, short_months[(ptime->month - 1) % 12],
 708       ptime->year, ptime->hour % 24, ptime->minute % 60,
 709       ptime->second % 61);
 710#endif
 711#endif /* _WIN32_WCE */
 712   return ((png_charp)png_ptr->time_buffer);
 713}
 714#endif /* PNG_TIME_RFC1123_SUPPORTED */
 715
 716#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
 717
 718png_charp PNGAPI
 719png_get_copyright(png_structp png_ptr)
 720{
 721   png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
 722#ifdef PNG_STRING_COPYRIGHT
 723      return PNG_STRING_COPYRIGHT
 724#else
 725#ifdef __STDC__
 726   return ((png_charp) PNG_STRING_NEWLINE \
 727     "libpng version 1.2.44 - June 26, 2010" PNG_STRING_NEWLINE \
 728     "Copyright (c) 1998-2010 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
 729     "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
 730     "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
 731     PNG_STRING_NEWLINE);
 732#else
 733      return ((png_charp) "libpng version 1.2.44 - June 26, 2010\
 734      Copyright (c) 1998-2010 Glenn Randers-Pehrson\
 735      Copyright (c) 1996-1997 Andreas Dilger\
 736      Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.");
 737#endif
 738#endif
 739}
 740
 741/* The following return the library version as a short string in the
 742 * format 1.0.0 through 99.99.99zz.  To get the version of *.h files
 743 * used with your application, print out PNG_LIBPNG_VER_STRING, which
 744 * is defined in png.h.
 745 * Note: now there is no difference between png_get_libpng_ver() and
 746 * png_get_header_ver().  Due to the version_nn_nn_nn typedef guard,
 747 * it is guaranteed that png.c uses the correct version of png.h.
 748 */
 749png_charp PNGAPI
 750png_get_libpng_ver(png_structp png_ptr)
 751{
 752   /* Version of *.c files used when building libpng */
 753   png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
 754   return ((png_charp) PNG_LIBPNG_VER_STRING);
 755}
 756
 757png_charp PNGAPI
 758png_get_header_ver(png_structp png_ptr)
 759{
 760   /* Version of *.h files used when building libpng */
 761   png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
 762   return ((png_charp) PNG_LIBPNG_VER_STRING);
 763}
 764
 765png_charp PNGAPI
 766png_get_header_version(png_structp png_ptr)
 767{
 768   /* Returns longer string containing both version and date */
 769   png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
 770#ifdef __STDC__
 771   return ((png_charp) PNG_HEADER_VERSION_STRING
 772#ifndef PNG_READ_SUPPORTED
 773   "     (NO READ SUPPORT)"
 774#endif
 775   PNG_STRING_NEWLINE);
 776#else
 777   return ((png_charp) PNG_HEADER_VERSION_STRING);
 778#endif
 779}
 780
 781#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 782#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
 783int PNGAPI
 784png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
 785{
 786   /* Check chunk_name and return "keep" value if it's on the list, else 0 */
 787   int i;
 788   png_bytep p;
 789   if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list<=0)
 790      return 0;
 791   p = png_ptr->chunk_list + png_ptr->num_chunk_list*5 - 5;
 792   for (i = png_ptr->num_chunk_list; i; i--, p -= 5)
 793      if (!png_memcmp(chunk_name, p, 4))
 794        return ((int)*(p + 4));
 795   return 0;
 796}
 797#endif
 798
 799/* This function, added to libpng-1.0.6g, is untested. */
 800int PNGAPI
 801png_reset_zstream(png_structp png_ptr)
 802{
 803   if (png_ptr == NULL)
 804      return Z_STREAM_ERROR;
 805   return (inflateReset(&png_ptr->zstream));
 806}
 807#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
 808
 809/* This function was added to libpng-1.0.7 */
 810png_uint_32 PNGAPI
 811png_access_version_number(void)
 812{
 813   /* Version of *.c files used when building libpng */
 814   return((png_uint_32) PNG_LIBPNG_VER);
 815}
 816
 817
 818#if defined(PNG_READ_SUPPORTED) && defined(PNG_ASSEMBLER_CODE_SUPPORTED)
 819#ifndef PNG_1_0_X
 820/* This function was added to libpng 1.2.0 */
 821int PNGAPI
 822png_mmx_support(void)
 823{
 824   /* Obsolete, to be removed from libpng-1.4.0 */
 825    return -1;
 826}
 827#endif /* PNG_1_0_X */
 828#endif /* PNG_READ_SUPPORTED && PNG_ASSEMBLER_CODE_SUPPORTED */
 829
 830#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 831#ifdef PNG_SIZE_T
 832/* Added at libpng version 1.2.6 */
 833   PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
 834png_size_t PNGAPI
 835png_convert_size(size_t size)
 836{
 837   if (size > (png_size_t)-1)
 838      PNG_ABORT();  /* We haven't got access to png_ptr, so no png_error() */
 839   return ((png_size_t)size);
 840}
 841#endif /* PNG_SIZE_T */
 842
 843/* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */
 844#ifdef PNG_cHRM_SUPPORTED
 845#ifdef PNG_CHECK_cHRM_SUPPORTED
 846
 847/*
 848 *    Multiply two 32-bit numbers, V1 and V2, using 32-bit
 849 *    arithmetic, to produce a 64 bit result in the HI/LO words.
 850 *
 851 *                  A B
 852 *                x C D
 853 *               ------
 854 *              AD || BD
 855 *        AC || CB || 0
 856 *
 857 *    where A and B are the high and low 16-bit words of V1,
 858 *    C and D are the 16-bit words of V2, AD is the product of
 859 *    A and D, and X || Y is (X << 16) + Y.
 860*/
 861
 862void /* PRIVATE */
 863png_64bit_product (long v1, long v2, unsigned long *hi_product,
 864   unsigned long *lo_product)
 865{
 866   int a, b, c, d;
 867   long lo, hi, x, y;
 868
 869   a = (v1 >> 16) & 0xffff;
 870   b = v1 & 0xffff;
 871   c = (v2 >> 16) & 0xffff;
 872   d = v2 & 0xffff;
 873
 874   lo = b * d;                   /* BD */
 875   x = a * d + c * b;            /* AD + CB */
 876   y = ((lo >> 16) & 0xffff) + x;
 877
 878   lo = (lo & 0xffff) | ((y & 0xffff) << 16);
 879   hi = (y >> 16) & 0xffff;
 880
 881   hi += a * c;                  /* AC */
 882
 883   *hi_product = (unsigned long)hi;
 884   *lo_product = (unsigned long)lo;
 885}
 886
 887int /* PRIVATE */
 888png_check_cHRM_fixed(png_structp png_ptr,
 889   png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
 890   png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
 891   png_fixed_point blue_x, png_fixed_point blue_y)
 892{
 893   int ret = 1;
 894   unsigned long xy_hi,xy_lo,yx_hi,yx_lo;
 895
 896   png_debug(1, "in function png_check_cHRM_fixed");
 897
 898   if (png_ptr == NULL)
 899      return 0;
 900
 901   if (white_x < 0 || white_y <= 0 ||
 902         red_x < 0 ||   red_y <  0 ||
 903       green_x < 0 || green_y <  0 ||
 904        blue_x < 0 ||  blue_y <  0)
 905   {
 906      png_warning(png_ptr,
 907        "Ignoring attempt to set negative chromaticity value");
 908      ret = 0;
 909   }
 910   if (white_x > (png_fixed_point) PNG_UINT_31_MAX ||
 911       white_y > (png_fixed_point) PNG_UINT_31_MAX ||
 912         red_x > (png_fixed_point) PNG_UINT_31_MAX ||
 913         red_y > (png_fixed_point) PNG_UINT_31_MAX ||
 914       green_x > (png_fixed_point) PNG_UINT_31_MAX ||
 915       green_y > (png_fixed_point) PNG_UINT_31_MAX ||
 916        blue_x > (png_fixed_point) PNG_UINT_31_MAX ||
 917        blue_y > (png_fixed_point) PNG_UINT_31_MAX )
 918   {
 919      png_warning(png_ptr,
 920        "Ignoring attempt to set chromaticity value exceeding 21474.83");
 921      ret = 0;
 922   }
 923   if (white_x > 100000L - white_y)
 924   {
 925      png_warning(png_ptr, "Invalid cHRM white point");
 926      ret = 0;
 927   }
 928   if (red_x > 100000L - red_y)
 929   {
 930      png_warning(png_ptr, "Invalid cHRM red point");
 931      ret = 0;
 932   }
 933   if (green_x > 100000L - green_y)
 934   {
 935      png_warning(png_ptr, "Invalid cHRM green point");
 936      ret = 0;
 937   }
 938   if (blue_x > 100000L - blue_y)
 939   {
 940      png_warning(png_ptr, "Invalid cHRM blue point");
 941      ret = 0;
 942   }
 943
 944   png_64bit_product(green_x - red_x, blue_y - red_y, &xy_hi, &xy_lo);
 945   png_64bit_product(green_y - red_y, blue_x - red_x, &yx_hi, &yx_lo);
 946
 947   if (xy_hi == yx_hi && xy_lo == yx_lo)
 948   {
 949      png_warning(png_ptr,
 950         "Ignoring attempt to set cHRM RGB triangle with zero area");
 951      ret = 0;
 952   }
 953
 954   return ret;
 955}
 956#endif /* PNG_CHECK_cHRM_SUPPORTED */
 957#endif /* PNG_cHRM_SUPPORTED */
 958
 959void /* PRIVATE */
 960png_check_IHDR(png_structp png_ptr,
 961   png_uint_32 width, png_uint_32 height, int bit_depth,
 962   int color_type, int interlace_type, int compression_type,
 963   int filter_type)
 964{
 965   int error = 0;
 966
 967   /* Check for width and height valid values */
 968   if (width == 0)
 969   {
 970      png_warning(png_ptr, "Image width is zero in IHDR");
 971      error = 1;
 972   }
 973
 974   if (height == 0)
 975   {
 976      png_warning(png_ptr, "Image height is zero in IHDR");
 977      error = 1;
 978   }
 979
 980#ifdef PNG_SET_USER_LIMITS_SUPPORTED
 981   if (width > png_ptr->user_width_max || width > PNG_USER_WIDTH_MAX)
 982#else
 983   if (width > PNG_USER_WIDTH_MAX)
 984#endif
 985   {
 986      png_warning(png_ptr, "Image width exceeds user limit in IHDR");
 987      error = 1;
 988   }
 989
 990#ifdef PNG_SET_USER_LIMITS_SUPPORTED
 991   if (height > png_ptr->user_height_max || height > PNG_USER_HEIGHT_MAX)
 992#else
 993   if (height > PNG_USER_HEIGHT_MAX)
 994#endif
 995   {
 996      png_warning(png_ptr, "Image height exceeds user limit in IHDR");
 997      error = 1;
 998   }
 999
1000   if (width > PNG_UINT_31_MAX)
1001   {
1002      png_warning(png_ptr, "Invalid image width in IHDR");
1003      error = 1;
1004   }
1005
1006   if ( height > PNG_UINT_31_MAX)
1007   {
1008      png_warning(png_ptr, "Invalid image height in IHDR");
1009      error = 1;
1010   }
1011
1012   if ( width > (PNG_UINT_32_MAX
1013                 >> 3)      /* 8-byte RGBA pixels */
1014                 - 64       /* bigrowbuf hack */
1015                 - 1        /* filter byte */
1016                 - 7*8      /* rounding of width to multiple of 8 pixels */
1017                 - 8)       /* extra max_pixel_depth pad */
1018      png_warning(png_ptr, "Width is too large for libpng to process pixels");
1019
1020   /* Check other values */
1021   if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
1022       bit_depth != 8 && bit_depth != 16)
1023   {
1024      png_warning(png_ptr, "Invalid bit depth in IHDR");
1025      error = 1;
1026   }
1027
1028   if (color_type < 0 || color_type == 1 ||
1029       color_type == 5 || color_type > 6)
1030   {
1031      png_warning(png_ptr, "Invalid color type in IHDR");
1032      error = 1;
1033   }
1034
1035   if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) ||
1036       ((color_type == PNG_COLOR_TYPE_RGB ||
1037         color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
1038         color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
1039   {
1040      png_warning(png_ptr, "Invalid color type/bit depth combination in IHDR");
1041      error = 1;
1042   }
1043
1044   if (interlace_type >= PNG_INTERLACE_LAST)
1045   {
1046      png_warning(png_ptr, "Unknown interlace method in IHDR");
1047      error = 1;
1048   }
1049
1050   if (compression_type != PNG_COMPRESSION_TYPE_BASE)
1051   {
1052      png_warning(png_ptr, "Unknown compression method in IHDR");
1053      error = 1;
1054   }
1055
1056#ifdef PNG_MNG_FEATURES_SUPPORTED
1057   /* Accept filter_method 64 (intrapixel differencing) only if
1058    * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
1059    * 2. Libpng did not read a PNG signature (this filter_method is only
1060    *    used in PNG datastreams that are embedded in MNG datastreams) and
1061    * 3. The application called png_permit_mng_features with a mask that
1062    *    included PNG_FLAG_MNG_FILTER_64 and
1063    * 4. The filter_method is 64 and
1064    * 5. The color_type is RGB or RGBA
1065    */
1066   if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) &&
1067       png_ptr->mng_features_permitted)
1068      png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
1069
1070   if (filter_type != PNG_FILTER_TYPE_BASE)
1071   {
1072      if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1073         (filter_type == PNG_INTRAPIXEL_DIFFERENCING) &&
1074         ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) &&
1075         (color_type == PNG_COLOR_TYPE_RGB ||
1076         color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
1077      {
1078         png_warning(png_ptr, "Unknown filter method in IHDR");
1079         error = 1;
1080      }
1081
1082      if (png_ptr->mode & PNG_HAVE_PNG_SIGNATURE)
1083      {
1084         png_warning(png_ptr, "Invalid filter method in IHDR");
1085         error = 1;
1086      }
1087   }
1088
1089#else
1090   if (filter_type != PNG_FILTER_TYPE_BASE)
1091   {
1092      png_warning(png_ptr, "Unknown filter method in IHDR");
1093      error = 1;
1094   }
1095#endif
1096
1097   if (error == 1)
1098      png_error(png_ptr, "Invalid IHDR data");
1099}
1100#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */