release/src/router/libpng/pngread.c

   1
   2 /* pngread.c - read a PNG file
   3  *
   4  * Last changed in libpng 1.2.51 [February 6, 2014]
   5  * Copyright (c) 1998-2014 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  * This file contains routines that an application calls directly to
  14  * read a PNG file or stream.
  15  */
  16
  17 #define PNG_INTERNAL
  18 #define PNG_NO_PEDANTIC_WARNINGS
  19 #include "png.h"
  20 #ifdef PNG_READ_SUPPORTED
  21
  22 /* Create a PNG structure for reading, and allocate any memory needed. */
  23 png_structp PNGAPI
  24 png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr,
  25    png_error_ptr error_fn, png_error_ptr warn_fn)
  26 {
  27
  28 #ifdef PNG_USER_MEM_SUPPORTED
  29    return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
  30       warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
  31 }
  32
  33 /* Alternate create PNG structure for reading, and allocate any memory
  34  * needed.
  35  */
  36 png_structp PNGAPI
  37 png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
  38    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
  39    png_malloc_ptr malloc_fn, png_free_ptr free_fn)
  40 {
  41 #endif /* PNG_USER_MEM_SUPPORTED */
  42
  43 #ifdef PNG_SETJMP_SUPPORTED
  44    volatile
  45 #endif
  46    png_structp png_ptr;
  47
  48 #ifdef PNG_SETJMP_SUPPORTED
  49 #ifdef USE_FAR_KEYWORD
  50    jmp_buf jmpbuf;
  51 #endif
  52 #endif
  53
  54    int i;
  55
  56    png_debug(1, "in png_create_read_struct");
  57
  58 #ifdef PNG_USER_MEM_SUPPORTED
  59    png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
  60       (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
  61 #else
  62    png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
  63 #endif
  64    if (png_ptr == NULL)
  65       return (NULL);
  66
  67    /* Added at libpng-1.2.6 */
  68 #ifdef PNG_USER_LIMITS_SUPPORTED
  69    png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
  70    png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
  71    /* Added at libpng-1.2.43 and 1.4.0 */
  72    png_ptr->user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX;
  73 #endif
  74
  75 #ifdef PNG_SETJMP_SUPPORTED
  76 #ifdef USE_FAR_KEYWORD
  77    if (setjmp(jmpbuf))
  78 #else
  79    if (setjmp(png_ptr->jmpbuf))
  80 #endif
  81    {
  82       png_free(png_ptr, png_ptr->zbuf);
  83       png_ptr->zbuf = NULL;
  84 #ifdef PNG_USER_MEM_SUPPORTED
  85       png_destroy_struct_2((png_voidp)png_ptr,
  86          (png_free_ptr)free_fn, (png_voidp)mem_ptr);
  87 #else
  88       png_destroy_struct((png_voidp)png_ptr);
  89 #endif
  90       return (NULL);
  91    }
  92 #ifdef USE_FAR_KEYWORD
  93    png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
  94 #endif
  95 #endif /* PNG_SETJMP_SUPPORTED */
  96
  97 #ifdef PNG_USER_MEM_SUPPORTED
  98    png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
  99 #endif
 100
 101    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 102
 103    if (user_png_ver)
 104    {
 105       i = 0;
 106       do
 107       {
 108          if (user_png_ver[i] != png_libpng_ver[i])
 109             png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
 110       } while (png_libpng_ver[i++]);
 111     }
 112     else
 113          png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
 114
 115
 116     if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
 117     {
 118        /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
 119        * we must recompile any applications that use any older library version.
 120        * For versions after libpng 1.0, we will be compatible, so we need
 121        * only check the first digit.
 122        */
 123       if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
 124           (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
 125           (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
 126       {
 127 #if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
 128          char msg[80];
 129          if (user_png_ver)
 130          {
 131            png_snprintf(msg, 80,
 132               "Application was compiled with png.h from libpng-%.20s",
 133               user_png_ver);
 134            png_warning(png_ptr, msg);
 135          }
 136          png_snprintf(msg, 80,
 137              "Application  is  running with png.c from libpng-%.20s",
 138              png_libpng_ver);
 139          png_warning(png_ptr, msg);
 140 #endif
 141 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 142          png_ptr->flags = 0;
 143 #endif
 144          png_error(png_ptr,
 145             "Incompatible libpng version in application and library");
 146       }
 147    }
 148
 149    /* Initialize zbuf - compression buffer */
 150    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
 151    png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
 152      (png_uint_32)png_ptr->zbuf_size);
 153    png_ptr->zstream.zalloc = png_zalloc;
 154    png_ptr->zstream.zfree = png_zfree;
 155    png_ptr->zstream.opaque = (voidpf)png_ptr;
 156
 157       switch (inflateInit(&png_ptr->zstream))
 158       {
 159          case Z_OK: /* Do nothing */ break;
 160          case Z_MEM_ERROR:
 161          case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory error");
 162             break;
 163          case Z_VERSION_ERROR: png_error(png_ptr, "zlib version error");
 164             break;
 165          default: png_error(png_ptr, "Unknown zlib error");
 166       }
 167
 168
 169    png_ptr->zstream.next_out = png_ptr->zbuf;
 170    png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
 171
 172    png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
 173
 174 #ifdef PNG_SETJMP_SUPPORTED
 175 /* Applications that neglect to set up their own setjmp() and then
 176    encounter a png_error() will longjmp here.  Since the jmpbuf is
 177    then meaningless we abort instead of returning. */
 178 #ifdef USE_FAR_KEYWORD
 179    if (setjmp(jmpbuf))
 180        PNG_ABORT();
 181    png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
 182 #else
 183    if (setjmp(png_ptr->jmpbuf))
 184        PNG_ABORT();
 185 #endif
 186 #endif /* PNG_SETJMP_SUPPORTED */
 187
 188    return (png_ptr);
 189 }
 190
 191 #if defined(PNG_1_0_X) || defined(PNG_1_2_X)
 192 /* Initialize PNG structure for reading, and allocate any memory needed.
 193  * This interface is deprecated in favour of the png_create_read_struct(),
 194  * and it will disappear as of libpng-1.3.0.
 195  */
 196 #undef png_read_init
 197 void PNGAPI
 198 png_read_init(png_structp png_ptr)
 199 {
 200    /* We only come here via pre-1.0.7-compiled applications */
 201    png_read_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
 202 }
 203
 204 void PNGAPI
 205 png_read_init_2(png_structp png_ptr, png_const_charp user_png_ver,
 206    png_size_t png_struct_size, png_size_t png_info_size)
 207 {
 208    /* We only come here via pre-1.0.12-compiled applications */
 209    if (png_ptr == NULL)
 210       return;
 211 #if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
 212    if (png_sizeof(png_struct) > png_struct_size ||
 213       png_sizeof(png_info) > png_info_size)
 214    {
 215       char msg[80];
 216       png_ptr->warning_fn = NULL;
 217       if (user_png_ver)
 218       {
 219         png_snprintf(msg, 80,
 220            "Application was compiled with png.h from libpng-%.20s",
 221            user_png_ver);
 222         png_warning(png_ptr, msg);
 223       }
 224       png_snprintf(msg, 80,
 225          "Application  is  running with png.c from libpng-%.20s",
 226          png_libpng_ver);
 227       png_warning(png_ptr, msg);
 228    }
 229 #endif
 230    if (png_sizeof(png_struct) > png_struct_size)
 231    {
 232       png_ptr->error_fn = NULL;
 233 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 234       png_ptr->flags = 0;
 235 #endif
 236       png_error(png_ptr,
 237       "The png struct allocated by the application for reading is"
 238       " too small.");
 239    }
 240    if (png_sizeof(png_info) > png_info_size)
 241    {
 242       png_ptr->error_fn = NULL;
 243 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 244       png_ptr->flags = 0;
 245 #endif
 246       png_error(png_ptr,
 247         "The info struct allocated by application for reading is"
 248         " too small.");
 249    }
 250    png_read_init_3(&png_ptr, user_png_ver, png_struct_size);
 251 }
 252 #endif /* PNG_1_0_X || PNG_1_2_X */
 253
 254 void PNGAPI
 255 png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
 256    png_size_t png_struct_size)
 257 {
 258 #ifdef PNG_SETJMP_SUPPORTED
 259    jmp_buf tmp_jmp;  /* to save current jump buffer */
 260 #endif
 261
 262    int i = 0;
 263
 264    png_structp png_ptr=*ptr_ptr;
 265
 266    if (png_ptr == NULL)
 267       return;
 268
 269    do
 270    {
 271       if (user_png_ver[i] != png_libpng_ver[i])
 272       {
 273 #ifdef PNG_LEGACY_SUPPORTED
 274         png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
 275 #else
 276         png_ptr->warning_fn = NULL;
 277         png_warning(png_ptr,
 278          "Application uses deprecated png_read_init() and should be"
 279          " recompiled.");
 280         break;
 281 #endif
 282       }
 283    } while (png_libpng_ver[i++]);
 284
 285    png_debug(1, "in png_read_init_3");
 286
 287 #ifdef PNG_SETJMP_SUPPORTED
 288    /* Save jump buffer and error functions */
 289    png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
 290 #endif
 291
 292    if (png_sizeof(png_struct) > png_struct_size)
 293    {
 294       png_destroy_struct(png_ptr);
 295       *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
 296       png_ptr = *ptr_ptr;
 297    }
 298
 299    /* Reset all variables to 0 */
 300    png_memset(png_ptr, 0, png_sizeof(png_struct));
 301
 302 #ifdef PNG_SETJMP_SUPPORTED
 303    /* Restore jump buffer */
 304    png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
 305 #endif
 306
 307    /* Added at libpng-1.2.6 */
 308 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
 309    png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
 310    png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
 311 #endif
 312
 313    /* Initialize zbuf - compression buffer */
 314    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
 315    png_ptr->zstream.zalloc = png_zalloc;
 316    png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
 317      (png_uint_32)png_ptr->zbuf_size);
 318    png_ptr->zstream.zalloc = png_zalloc;
 319    png_ptr->zstream.zfree = png_zfree;
 320    png_ptr->zstream.opaque = (voidpf)png_ptr;
 321
 322    switch (inflateInit(&png_ptr->zstream))
 323    {
 324       case Z_OK: /* Do nothing */ break;
 325       case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory error"); break;
 326       case Z_VERSION_ERROR: png_error(png_ptr, "zlib version error");
 327           break;
 328       default: png_error(png_ptr, "Unknown zlib error");
 329    }
 330
 331    png_ptr->zstream.next_out = png_ptr->zbuf;
 332    png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
 333
 334    png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
 335 }
 336
 337 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 338 /* Read the information before the actual image data.  This has been
 339  * changed in v0.90 to allow reading a file that already has the magic
 340  * bytes read from the stream.  You can tell libpng how many bytes have
 341  * been read from the beginning of the stream (up to the maximum of 8)
 342  * via png_set_sig_bytes(), and we will only check the remaining bytes
 343  * here.  The application can then have access to the signature bytes we
 344  * read if it is determined that this isn't a valid PNG file.
 345  */
 346 void PNGAPI
 347 png_read_info(png_structp png_ptr, png_infop info_ptr)
 348 {
 349    png_debug(1, "in png_read_info");
 350
 351    if (png_ptr == NULL || info_ptr == NULL)
 352       return;
 353
 354    /* If we haven't checked all of the PNG signature bytes, do so now. */
 355    if (png_ptr->sig_bytes < 8)
 356    {
 357       png_size_t num_checked = png_ptr->sig_bytes,
 358                  num_to_check = 8 - num_checked;
 359
 360       png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
 361       png_ptr->sig_bytes = 8;
 362
 363       if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
 364       {
 365          if (num_checked < 4 &&
 366              png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
 367             png_error(png_ptr, "Not a PNG file");
 368          else
 369             png_error(png_ptr, "PNG file corrupted by ASCII conversion");
 370       }
 371       if (num_checked < 3)
 372          png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
 373    }
 374
 375    for (;;)
 376    {
 377 #ifdef PNG_USE_LOCAL_ARRAYS
 378       PNG_CONST PNG_IHDR;
 379       PNG_CONST PNG_IDAT;
 380       PNG_CONST PNG_IEND;
 381       PNG_CONST PNG_PLTE;
 382 #ifdef PNG_READ_bKGD_SUPPORTED
 383       PNG_CONST PNG_bKGD;
 384 #endif
 385 #ifdef PNG_READ_cHRM_SUPPORTED
 386       PNG_CONST PNG_cHRM;
 387 #endif
 388 #ifdef PNG_READ_gAMA_SUPPORTED
 389       PNG_CONST PNG_gAMA;
 390 #endif
 391 #ifdef PNG_READ_hIST_SUPPORTED
 392       PNG_CONST PNG_hIST;
 393 #endif
 394 #ifdef PNG_READ_iCCP_SUPPORTED
 395       PNG_CONST PNG_iCCP;
 396 #endif
 397 #ifdef PNG_READ_iTXt_SUPPORTED
 398       PNG_CONST PNG_iTXt;
 399 #endif
 400 #ifdef PNG_READ_oFFs_SUPPORTED
 401       PNG_CONST PNG_oFFs;
 402 #endif
 403 #ifdef PNG_READ_pCAL_SUPPORTED
 404       PNG_CONST PNG_pCAL;
 405 #endif
 406 #ifdef PNG_READ_pHYs_SUPPORTED
 407       PNG_CONST PNG_pHYs;
 408 #endif
 409 #ifdef PNG_READ_sBIT_SUPPORTED
 410       PNG_CONST PNG_sBIT;
 411 #endif
 412 #ifdef PNG_READ_sCAL_SUPPORTED
 413       PNG_CONST PNG_sCAL;
 414 #endif
 415 #ifdef PNG_READ_sPLT_SUPPORTED
 416       PNG_CONST PNG_sPLT;
 417 #endif
 418 #ifdef PNG_READ_sRGB_SUPPORTED
 419       PNG_CONST PNG_sRGB;
 420 #endif
 421 #ifdef PNG_READ_tEXt_SUPPORTED
 422       PNG_CONST PNG_tEXt;
 423 #endif
 424 #ifdef PNG_READ_tIME_SUPPORTED
 425       PNG_CONST PNG_tIME;
 426 #endif
 427 #ifdef PNG_READ_tRNS_SUPPORTED
 428       PNG_CONST PNG_tRNS;
 429 #endif
 430 #ifdef PNG_READ_zTXt_SUPPORTED
 431       PNG_CONST PNG_zTXt;
 432 #endif
 433 #endif /* PNG_USE_LOCAL_ARRAYS */
 434       png_uint_32 length = png_read_chunk_header(png_ptr);
 435       PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
 436
 437       /* This should be a binary subdivision search or a hash for
 438        * matching the chunk name rather than a linear search.
 439        */
 440       if (!png_memcmp(chunk_name, png_IDAT, 4))
 441         if (png_ptr->mode & PNG_AFTER_IDAT)
 442           png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
 443
 444       if (!png_memcmp(chunk_name, png_IHDR, 4))
 445          png_handle_IHDR(png_ptr, info_ptr, length);
 446       else if (!png_memcmp(chunk_name, png_IEND, 4))
 447          png_handle_IEND(png_ptr, info_ptr, length);
 448 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
 449       else if (png_handle_as_unknown(png_ptr, chunk_name))
 450       {
 451          if (!png_memcmp(chunk_name, png_IDAT, 4))
 452             png_ptr->mode |= PNG_HAVE_IDAT;
 453          png_handle_unknown(png_ptr, info_ptr, length);
 454          if (!png_memcmp(chunk_name, png_PLTE, 4))
 455             png_ptr->mode |= PNG_HAVE_PLTE;
 456          else if (!png_memcmp(chunk_name, png_IDAT, 4))
 457          {
 458             if (!(png_ptr->mode & PNG_HAVE_IHDR))
 459                png_error(png_ptr, "Missing IHDR before IDAT");
 460             else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
 461                      !(png_ptr->mode & PNG_HAVE_PLTE))
 462                png_error(png_ptr, "Missing PLTE before IDAT");
 463             break;
 464          }
 465       }
 466 #endif
 467       else if (!png_memcmp(chunk_name, png_PLTE, 4))
 468          png_handle_PLTE(png_ptr, info_ptr, length);
 469       else if (!png_memcmp(chunk_name, png_IDAT, 4))
 470       {
 471          if (!(png_ptr->mode & PNG_HAVE_IHDR))
 472             png_error(png_ptr, "Missing IHDR before IDAT");
 473          else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
 474                   !(png_ptr->mode & PNG_HAVE_PLTE))
 475             png_error(png_ptr, "Missing PLTE before IDAT");
 476
 477          png_ptr->idat_size = length;
 478          png_ptr->mode |= PNG_HAVE_IDAT;
 479          break;
 480       }
 481 #ifdef PNG_READ_bKGD_SUPPORTED
 482       else if (!png_memcmp(chunk_name, png_bKGD, 4))
 483          png_handle_bKGD(png_ptr, info_ptr, length);
 484 #endif
 485 #ifdef PNG_READ_cHRM_SUPPORTED
 486       else if (!png_memcmp(chunk_name, png_cHRM, 4))
 487          png_handle_cHRM(png_ptr, info_ptr, length);
 488 #endif
 489 #ifdef PNG_READ_gAMA_SUPPORTED
 490       else if (!png_memcmp(chunk_name, png_gAMA, 4))
 491          png_handle_gAMA(png_ptr, info_ptr, length);
 492 #endif
 493 #ifdef PNG_READ_hIST_SUPPORTED
 494       else if (!png_memcmp(chunk_name, png_hIST, 4))
 495          png_handle_hIST(png_ptr, info_ptr, length);
 496 #endif
 497 #ifdef PNG_READ_oFFs_SUPPORTED
 498       else if (!png_memcmp(chunk_name, png_oFFs, 4))
 499          png_handle_oFFs(png_ptr, info_ptr, length);
 500 #endif
 501 #ifdef PNG_READ_pCAL_SUPPORTED
 502       else if (!png_memcmp(chunk_name, png_pCAL, 4))
 503          png_handle_pCAL(png_ptr, info_ptr, length);
 504 #endif
 505 #ifdef PNG_READ_sCAL_SUPPORTED
 506       else if (!png_memcmp(chunk_name, png_sCAL, 4))
 507          png_handle_sCAL(png_ptr, info_ptr, length);
 508 #endif
 509 #ifdef PNG_READ_pHYs_SUPPORTED
 510       else if (!png_memcmp(chunk_name, png_pHYs, 4))
 511          png_handle_pHYs(png_ptr, info_ptr, length);
 512 #endif
 513 #ifdef PNG_READ_sBIT_SUPPORTED
 514       else if (!png_memcmp(chunk_name, png_sBIT, 4))
 515          png_handle_sBIT(png_ptr, info_ptr, length);
 516 #endif
 517 #ifdef PNG_READ_sRGB_SUPPORTED
 518       else if (!png_memcmp(chunk_name, png_sRGB, 4))
 519          png_handle_sRGB(png_ptr, info_ptr, length);
 520 #endif
 521 #ifdef PNG_READ_iCCP_SUPPORTED
 522       else if (!png_memcmp(chunk_name, png_iCCP, 4))
 523          png_handle_iCCP(png_ptr, info_ptr, length);
 524 #endif
 525 #ifdef PNG_READ_sPLT_SUPPORTED
 526       else if (!png_memcmp(chunk_name, png_sPLT, 4))
 527          png_handle_sPLT(png_ptr, info_ptr, length);
 528 #endif
 529 #ifdef PNG_READ_tEXt_SUPPORTED
 530       else if (!png_memcmp(chunk_name, png_tEXt, 4))
 531          png_handle_tEXt(png_ptr, info_ptr, length);
 532 #endif
 533 #ifdef PNG_READ_tIME_SUPPORTED
 534       else if (!png_memcmp(chunk_name, png_tIME, 4))
 535          png_handle_tIME(png_ptr, info_ptr, length);
 536 #endif
 537 #ifdef PNG_READ_tRNS_SUPPORTED
 538       else if (!png_memcmp(chunk_name, png_tRNS, 4))
 539          png_handle_tRNS(png_ptr, info_ptr, length);
 540 #endif
 541 #ifdef PNG_READ_zTXt_SUPPORTED
 542       else if (!png_memcmp(chunk_name, png_zTXt, 4))
 543          png_handle_zTXt(png_ptr, info_ptr, length);
 544 #endif
 545 #ifdef PNG_READ_iTXt_SUPPORTED
 546       else if (!png_memcmp(chunk_name, png_iTXt, 4))
 547          png_handle_iTXt(png_ptr, info_ptr, length);
 548 #endif
 549       else
 550          png_handle_unknown(png_ptr, info_ptr, length);
 551    }
 552 }
 553 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
 554
 555 /* Optional call to update the users info_ptr structure */
 556 void PNGAPI
 557 png_read_update_info(png_structp png_ptr, png_infop info_ptr)
 558 {
 559    png_debug(1, "in png_read_update_info");
 560
 561    if (png_ptr == NULL)
 562       return;
 563    if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
 564       png_read_start_row(png_ptr);
 565    else
 566       png_warning(png_ptr,
 567       "Ignoring extra png_read_update_info() call; row buffer not reallocated");
 568
 569    png_read_transform_info(png_ptr, info_ptr);
 570 }
 571
 572 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 573 /* Initialize palette, background, etc, after transformations
 574  * are set, but before any reading takes place.  This allows
 575  * the user to obtain a gamma-corrected palette, for example.
 576  * If the user doesn't call this, we will do it ourselves.
 577  */
 578 void PNGAPI
 579 png_start_read_image(png_structp png_ptr)
 580 {
 581    png_debug(1, "in png_start_read_image");
 582
 583    if (png_ptr == NULL)
 584       return;
 585    if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
 586       png_read_start_row(png_ptr);
 587 }
 588 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
 589
 590 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 591 void PNGAPI
 592 png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
 593 {
 594    PNG_CONST PNG_IDAT;
 595    PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
 596       0xff};
 597    PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
 598    int ret;
 599
 600    if (png_ptr == NULL)
 601       return;
 602
 603    png_debug2(1, "in png_read_row (row %lu, pass %d)",
 604       png_ptr->row_number, png_ptr->pass);
 605
 606    if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
 607       png_read_start_row(png_ptr);
 608    if (png_ptr->row_number == 0 && png_ptr->pass == 0)
 609    {
 610    /* Check for transforms that have been set but were defined out */
 611 #if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
 612    if (png_ptr->transformations & PNG_INVERT_MONO)
 613       png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined.");
 614 #endif
 615 #if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
 616    if (png_ptr->transformations & PNG_FILLER)
 617       png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined.");
 618 #endif
 619 #if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
 620     !defined(PNG_READ_PACKSWAP_SUPPORTED)
 621    if (png_ptr->transformations & PNG_PACKSWAP)
 622       png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined.");
 623 #endif
 624 #if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
 625    if (png_ptr->transformations & PNG_PACK)
 626       png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined.");
 627 #endif
 628 #if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
 629    if (png_ptr->transformations & PNG_SHIFT)
 630       png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined.");
 631 #endif
 632 #if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
 633    if (png_ptr->transformations & PNG_BGR)
 634       png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined.");
 635 #endif
 636 #if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
 637    if (png_ptr->transformations & PNG_SWAP_BYTES)
 638       png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined.");
 639 #endif
 640    }
 641
 642 #ifdef PNG_READ_INTERLACING_SUPPORTED
 643    /* If interlaced and we do not need a new row, combine row and return */
 644    if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
 645    {
 646       switch (png_ptr->pass)
 647       {
 648          case 0:
 649             if (png_ptr->row_number & 0x07)
 650             {
 651                if (dsp_row != NULL)
 652                   png_combine_row(png_ptr, dsp_row,
 653                      png_pass_dsp_mask[png_ptr->pass]);
 654                png_read_finish_row(png_ptr);
 655                return;
 656             }
 657             break;
 658          case 1:
 659             if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
 660             {
 661                if (dsp_row != NULL)
 662                   png_combine_row(png_ptr, dsp_row,
 663                      png_pass_dsp_mask[png_ptr->pass]);
 664                png_read_finish_row(png_ptr);
 665                return;
 666             }
 667             break;
 668          case 2:
 669             if ((png_ptr->row_number & 0x07) != 4)
 670             {
 671                if (dsp_row != NULL && (png_ptr->row_number & 4))
 672                   png_combine_row(png_ptr, dsp_row,
 673                      png_pass_dsp_mask[png_ptr->pass]);
 674                png_read_finish_row(png_ptr);
 675                return;
 676             }
 677             break;
 678          case 3:
 679             if ((png_ptr->row_number & 3) || png_ptr->width < 3)
 680             {
 681                if (dsp_row != NULL)
 682                   png_combine_row(png_ptr, dsp_row,
 683                      png_pass_dsp_mask[png_ptr->pass]);
 684                png_read_finish_row(png_ptr);
 685                return;
 686             }
 687             break;
 688          case 4:
 689             if ((png_ptr->row_number & 3) != 2)
 690             {
 691                if (dsp_row != NULL && (png_ptr->row_number & 2))
 692                   png_combine_row(png_ptr, dsp_row,
 693                      png_pass_dsp_mask[png_ptr->pass]);
 694                png_read_finish_row(png_ptr);
 695                return;
 696             }
 697             break;
 698          case 5:
 699             if ((png_ptr->row_number & 1) || png_ptr->width < 2)
 700             {
 701                if (dsp_row != NULL)
 702                   png_combine_row(png_ptr, dsp_row,
 703                      png_pass_dsp_mask[png_ptr->pass]);
 704                png_read_finish_row(png_ptr);
 705                return;
 706             }
 707             break;
 708          case 6:
 709             if (!(png_ptr->row_number & 1))
 710             {
 711                png_read_finish_row(png_ptr);
 712                return;
 713             }
 714             break;
 715       }
 716    }
 717 #endif
 718
 719    if (!(png_ptr->mode & PNG_HAVE_IDAT))
 720       png_error(png_ptr, "Invalid attempt to read row data");
 721
 722    png_ptr->zstream.next_out = png_ptr->row_buf;
 723    png_ptr->zstream.avail_out =
 724        (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
 725        png_ptr->iwidth) + 1);
 726    do
 727    {
 728       if (!(png_ptr->zstream.avail_in))
 729       {
 730          while (!png_ptr->idat_size)
 731          {
 732             png_crc_finish(png_ptr, 0);
 733
 734             png_ptr->idat_size = png_read_chunk_header(png_ptr);
 735             if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
 736                png_error(png_ptr, "Not enough image data");
 737          }
 738          png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
 739          png_ptr->zstream.next_in = png_ptr->zbuf;
 740          if (png_ptr->zbuf_size > png_ptr->idat_size)
 741             png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
 742          png_crc_read(png_ptr, png_ptr->zbuf,
 743             (png_size_t)png_ptr->zstream.avail_in);
 744          png_ptr->idat_size -= png_ptr->zstream.avail_in;
 745       }
 746       ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
 747       if (ret == Z_STREAM_END)
 748       {
 749          if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
 750             png_ptr->idat_size)
 751             png_error(png_ptr, "Extra compressed data");
 752          png_ptr->mode |= PNG_AFTER_IDAT;
 753          png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
 754          break;
 755       }
 756       if (ret != Z_OK)
 757          png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
 758                    "Decompression error");
 759
 760    } while (png_ptr->zstream.avail_out);
 761
 762    png_ptr->row_info.color_type = png_ptr->color_type;
 763    png_ptr->row_info.width = png_ptr->iwidth;
 764    png_ptr->row_info.channels = png_ptr->channels;
 765    png_ptr->row_info.bit_depth = png_ptr->bit_depth;
 766    png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
 767    png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
 768        png_ptr->row_info.width);
 769
 770    if (png_ptr->row_buf[0])
 771    png_read_filter_row(png_ptr, &(png_ptr->row_info),
 772       png_ptr->row_buf + 1, png_ptr->prev_row + 1,
 773       (int)(png_ptr->row_buf[0]));
 774
 775    png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
 776       png_ptr->rowbytes + 1);
 777
 778 #ifdef PNG_MNG_FEATURES_SUPPORTED
 779    if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
 780       (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
 781    {
 782       /* Intrapixel differencing */
 783       png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
 784    }
 785 #endif
 786
 787
 788    if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
 789       png_do_read_transformations(png_ptr);
 790
 791 #ifdef PNG_READ_INTERLACING_SUPPORTED
 792    /* Blow up interlaced rows to full size */
 793    if (png_ptr->interlaced &&
 794       (png_ptr->transformations & PNG_INTERLACE))
 795    {
 796       if (png_ptr->pass < 6)
 797          /* Old interface (pre-1.0.9):
 798           * png_do_read_interlace(&(png_ptr->row_info),
 799           *    png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
 800           */
 801          png_do_read_interlace(png_ptr);
 802
 803       if (dsp_row != NULL)
 804          png_combine_row(png_ptr, dsp_row,
 805             png_pass_dsp_mask[png_ptr->pass]);
 806       if (row != NULL)
 807          png_combine_row(png_ptr, row,
 808             png_pass_mask[png_ptr->pass]);
 809    }
 810    else
 811 #endif
 812    {
 813       if (row != NULL)
 814          png_combine_row(png_ptr, row, 0xff);
 815       if (dsp_row != NULL)
 816          png_combine_row(png_ptr, dsp_row, 0xff);
 817    }
 818    png_read_finish_row(png_ptr);
 819
 820    if (png_ptr->read_row_fn != NULL)
 821       (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
 822 }
 823 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
 824
 825 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 826 /* Read one or more rows of image data.  If the image is interlaced,
 827  * and png_set_interlace_handling() has been called, the rows need to
 828  * contain the contents of the rows from the previous pass.  If the
 829  * image has alpha or transparency, and png_handle_alpha()[*] has been
 830  * called, the rows contents must be initialized to the contents of the
 831  * screen.
 832  *
 833  * "row" holds the actual image, and pixels are placed in it
 834  * as they arrive.  If the image is displayed after each pass, it will
 835  * appear to "sparkle" in.  "display_row" can be used to display a
 836  * "chunky" progressive image, with finer detail added as it becomes
 837  * available.  If you do not want this "chunky" display, you may pass
 838  * NULL for display_row.  If you do not want the sparkle display, and
 839  * you have not called png_handle_alpha(), you may pass NULL for rows.
 840  * If you have called png_handle_alpha(), and the image has either an
 841  * alpha channel or a transparency chunk, you must provide a buffer for
 842  * rows.  In this case, you do not have to provide a display_row buffer
 843  * also, but you may.  If the image is not interlaced, or if you have
 844  * not called png_set_interlace_handling(), the display_row buffer will
 845  * be ignored, so pass NULL to it.
 846  *
 847  * [*] png_handle_alpha() does not exist yet, as of this version of libpng
 848  */
 849
 850 void PNGAPI
 851 png_read_rows(png_structp png_ptr, png_bytepp row,
 852    png_bytepp display_row, png_uint_32 num_rows)
 853 {
 854    png_uint_32 i;
 855    png_bytepp rp;
 856    png_bytepp dp;
 857
 858    png_debug(1, "in png_read_rows");
 859
 860    if (png_ptr == NULL)
 861       return;
 862    rp = row;
 863    dp = display_row;
 864    if (rp != NULL && dp != NULL)
 865       for (i = 0; i < num_rows; i++)
 866       {
 867          png_bytep rptr = *rp++;
 868          png_bytep dptr = *dp++;
 869
 870          png_read_row(png_ptr, rptr, dptr);
 871       }
 872    else if (rp != NULL)
 873       for (i = 0; i < num_rows; i++)
 874       {
 875          png_bytep rptr = *rp;
 876          png_read_row(png_ptr, rptr, png_bytep_NULL);
 877          rp++;
 878       }
 879    else if (dp != NULL)
 880       for (i = 0; i < num_rows; i++)
 881       {
 882          png_bytep dptr = *dp;
 883          png_read_row(png_ptr, png_bytep_NULL, dptr);
 884          dp++;
 885       }
 886 }
 887 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
 888
 889 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 890 /* Read the entire image.  If the image has an alpha channel or a tRNS
 891  * chunk, and you have called png_handle_alpha()[*], you will need to
 892  * initialize the image to the current image that PNG will be overlaying.
 893  * We set the num_rows again here, in case it was incorrectly set in
 894  * png_read_start_row() by a call to png_read_update_info() or
 895  * png_start_read_image() if png_set_interlace_handling() wasn't called
 896  * prior to either of these functions like it should have been.  You can
 897  * only call this function once.  If you desire to have an image for
 898  * each pass of a interlaced image, use png_read_rows() instead.
 899  *
 900  * [*] png_handle_alpha() does not exist yet, as of this version of libpng
 901  */
 902 void PNGAPI
 903 png_read_image(png_structp png_ptr, png_bytepp image)
 904 {
 905    png_uint_32 i, image_height;
 906    int pass, j;
 907    png_bytepp rp;
 908
 909    png_debug(1, "in png_read_image");
 910
 911    if (png_ptr == NULL)
 912       return;
 913
 914 #ifdef PNG_READ_INTERLACING_SUPPORTED
 915    pass = png_set_interlace_handling(png_ptr);
 916 #else
 917    if (png_ptr->interlaced)
 918       png_error(png_ptr,
 919         "Cannot read interlaced image -- interlace handler disabled.");
 920    pass = 1;
 921 #endif
 922
 923
 924    image_height=png_ptr->height;
 925    png_ptr->num_rows = image_height; /* Make sure this is set correctly */
 926
 927    for (j = 0; j < pass; j++)
 928    {
 929       rp = image;
 930       for (i = 0; i < image_height; i++)
 931       {
 932          png_read_row(png_ptr, *rp, png_bytep_NULL);
 933          rp++;
 934       }
 935    }
 936 }
 937 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
 938
 939 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 940 /* Read the end of the PNG file.  Will not read past the end of the
 941  * file, will verify the end is accurate, and will read any comments
 942  * or time information at the end of the file, if info is not NULL.
 943  */
 944 void PNGAPI
 945 png_read_end(png_structp png_ptr, png_infop info_ptr)
 946 {
 947    png_debug(1, "in png_read_end");
 948
 949    if (png_ptr == NULL)
 950       return;
 951    png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
 952
 953    do
 954    {
 955 #ifdef PNG_USE_LOCAL_ARRAYS
 956       PNG_CONST PNG_IHDR;
 957       PNG_CONST PNG_IDAT;
 958       PNG_CONST PNG_IEND;
 959       PNG_CONST PNG_PLTE;
 960 #ifdef PNG_READ_bKGD_SUPPORTED
 961       PNG_CONST PNG_bKGD;
 962 #endif
 963 #ifdef PNG_READ_cHRM_SUPPORTED
 964       PNG_CONST PNG_cHRM;
 965 #endif
 966 #ifdef PNG_READ_gAMA_SUPPORTED
 967       PNG_CONST PNG_gAMA;
 968 #endif
 969 #ifdef PNG_READ_hIST_SUPPORTED
 970       PNG_CONST PNG_hIST;
 971 #endif
 972 #ifdef PNG_READ_iCCP_SUPPORTED
 973       PNG_CONST PNG_iCCP;
 974 #endif
 975 #ifdef PNG_READ_iTXt_SUPPORTED
 976       PNG_CONST PNG_iTXt;
 977 #endif
 978 #ifdef PNG_READ_oFFs_SUPPORTED
 979       PNG_CONST PNG_oFFs;
 980 #endif
 981 #ifdef PNG_READ_pCAL_SUPPORTED
 982       PNG_CONST PNG_pCAL;
 983 #endif
 984 #ifdef PNG_READ_pHYs_SUPPORTED
 985       PNG_CONST PNG_pHYs;
 986 #endif
 987 #ifdef PNG_READ_sBIT_SUPPORTED
 988       PNG_CONST PNG_sBIT;
 989 #endif
 990 #ifdef PNG_READ_sCAL_SUPPORTED
 991       PNG_CONST PNG_sCAL;
 992 #endif
 993 #ifdef PNG_READ_sPLT_SUPPORTED
 994       PNG_CONST PNG_sPLT;
 995 #endif
 996 #ifdef PNG_READ_sRGB_SUPPORTED
 997       PNG_CONST PNG_sRGB;
 998 #endif
 999 #ifdef PNG_READ_tEXt_SUPPORTED
1000       PNG_CONST PNG_tEXt;
1001 #endif
1002 #ifdef PNG_READ_tIME_SUPPORTED
1003       PNG_CONST PNG_tIME;
1004 #endif
1005 #ifdef PNG_READ_tRNS_SUPPORTED
1006       PNG_CONST PNG_tRNS;
1007 #endif
1008 #ifdef PNG_READ_zTXt_SUPPORTED
1009       PNG_CONST PNG_zTXt;
1010 #endif
1011 #endif /* PNG_USE_LOCAL_ARRAYS */
1012       png_uint_32 length = png_read_chunk_header(png_ptr);
1013       PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
1014
1015       if (!png_memcmp(chunk_name, png_IHDR, 4))
1016          png_handle_IHDR(png_ptr, info_ptr, length);
1017       else if (!png_memcmp(chunk_name, png_IEND, 4))
1018          png_handle_IEND(png_ptr, info_ptr, length);
1019 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1020       else if (png_handle_as_unknown(png_ptr, chunk_name))
1021       {
1022          if (!png_memcmp(chunk_name, png_IDAT, 4))
1023          {
1024             if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
1025                png_error(png_ptr, "Too many IDAT's found");
1026          }
1027          png_handle_unknown(png_ptr, info_ptr, length);
1028          if (!png_memcmp(chunk_name, png_PLTE, 4))
1029             png_ptr->mode |= PNG_HAVE_PLTE;
1030       }
1031 #endif
1032       else if (!png_memcmp(chunk_name, png_IDAT, 4))
1033       {
1034          /* Zero length IDATs are legal after the last IDAT has been
1035           * read, but not after other chunks have been read.
1036           */
1037          if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
1038             png_error(png_ptr, "Too many IDAT's found");
1039          png_crc_finish(png_ptr, length);
1040       }
1041       else if (!png_memcmp(chunk_name, png_PLTE, 4))
1042          png_handle_PLTE(png_ptr, info_ptr, length);
1043 #ifdef PNG_READ_bKGD_SUPPORTED
1044       else if (!png_memcmp(chunk_name, png_bKGD, 4))
1045          png_handle_bKGD(png_ptr, info_ptr, length);
1046 #endif
1047 #ifdef PNG_READ_cHRM_SUPPORTED
1048       else if (!png_memcmp(chunk_name, png_cHRM, 4))
1049          png_handle_cHRM(png_ptr, info_ptr, length);
1050 #endif
1051 #ifdef PNG_READ_gAMA_SUPPORTED
1052       else if (!png_memcmp(chunk_name, png_gAMA, 4))
1053          png_handle_gAMA(png_ptr, info_ptr, length);
1054 #endif
1055 #ifdef PNG_READ_hIST_SUPPORTED
1056       else if (!png_memcmp(chunk_name, png_hIST, 4))
1057          png_handle_hIST(png_ptr, info_ptr, length);
1058 #endif
1059 #ifdef PNG_READ_oFFs_SUPPORTED
1060       else if (!png_memcmp(chunk_name, png_oFFs, 4))
1061          png_handle_oFFs(png_ptr, info_ptr, length);
1062 #endif
1063 #ifdef PNG_READ_pCAL_SUPPORTED
1064       else if (!png_memcmp(chunk_name, png_pCAL, 4))
1065          png_handle_pCAL(png_ptr, info_ptr, length);
1066 #endif
1067 #ifdef PNG_READ_sCAL_SUPPORTED
1068       else if (!png_memcmp(chunk_name, png_sCAL, 4))
1069          png_handle_sCAL(png_ptr, info_ptr, length);
1070 #endif
1071 #ifdef PNG_READ_pHYs_SUPPORTED
1072       else if (!png_memcmp(chunk_name, png_pHYs, 4))
1073          png_handle_pHYs(png_ptr, info_ptr, length);
1074 #endif
1075 #ifdef PNG_READ_sBIT_SUPPORTED
1076       else if (!png_memcmp(chunk_name, png_sBIT, 4))
1077          png_handle_sBIT(png_ptr, info_ptr, length);
1078 #endif
1079 #ifdef PNG_READ_sRGB_SUPPORTED
1080       else if (!png_memcmp(chunk_name, png_sRGB, 4))
1081          png_handle_sRGB(png_ptr, info_ptr, length);
1082 #endif
1083 #ifdef PNG_READ_iCCP_SUPPORTED
1084       else if (!png_memcmp(chunk_name, png_iCCP, 4))
1085          png_handle_iCCP(png_ptr, info_ptr, length);
1086 #endif
1087 #ifdef PNG_READ_sPLT_SUPPORTED
1088       else if (!png_memcmp(chunk_name, png_sPLT, 4))
1089          png_handle_sPLT(png_ptr, info_ptr, length);
1090 #endif
1091 #ifdef PNG_READ_tEXt_SUPPORTED
1092       else if (!png_memcmp(chunk_name, png_tEXt, 4))
1093          png_handle_tEXt(png_ptr, info_ptr, length);
1094 #endif
1095 #ifdef PNG_READ_tIME_SUPPORTED
1096       else if (!png_memcmp(chunk_name, png_tIME, 4))
1097          png_handle_tIME(png_ptr, info_ptr, length);
1098 #endif
1099 #ifdef PNG_READ_tRNS_SUPPORTED
1100       else if (!png_memcmp(chunk_name, png_tRNS, 4))
1101          png_handle_tRNS(png_ptr, info_ptr, length);
1102 #endif
1103 #ifdef PNG_READ_zTXt_SUPPORTED
1104       else if (!png_memcmp(chunk_name, png_zTXt, 4))
1105          png_handle_zTXt(png_ptr, info_ptr, length);
1106 #endif
1107 #ifdef PNG_READ_iTXt_SUPPORTED
1108       else if (!png_memcmp(chunk_name, png_iTXt, 4))
1109          png_handle_iTXt(png_ptr, info_ptr, length);
1110 #endif
1111       else
1112          png_handle_unknown(png_ptr, info_ptr, length);
1113    } while (!(png_ptr->mode & PNG_HAVE_IEND));
1114 }
1115 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
1116
1117 /* Free all memory used by the read */
1118 void PNGAPI
1119 png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
1120    png_infopp end_info_ptr_ptr)
1121 {
1122    png_structp png_ptr = NULL;
1123    png_infop info_ptr = NULL, end_info_ptr = NULL;
1124 #ifdef PNG_USER_MEM_SUPPORTED
1125    png_free_ptr free_fn = NULL;
1126    png_voidp mem_ptr = NULL;
1127 #endif
1128
1129    png_debug(1, "in png_destroy_read_struct");
1130
1131    if (png_ptr_ptr != NULL)
1132       png_ptr = *png_ptr_ptr;
1133    if (png_ptr == NULL)
1134       return;
1135
1136 #ifdef PNG_USER_MEM_SUPPORTED
1137    free_fn = png_ptr->free_fn;
1138    mem_ptr = png_ptr->mem_ptr;
1139 #endif
1140
1141    if (info_ptr_ptr != NULL)
1142       info_ptr = *info_ptr_ptr;
1143
1144    if (end_info_ptr_ptr != NULL)
1145       end_info_ptr = *end_info_ptr_ptr;
1146
1147    png_read_destroy(png_ptr, info_ptr, end_info_ptr);
1148
1149    if (info_ptr != NULL)
1150    {
1151 #ifdef PNG_TEXT_SUPPORTED
1152       png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1);
1153 #endif
1154
1155 #ifdef PNG_USER_MEM_SUPPORTED
1156       png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1157           (png_voidp)mem_ptr);
1158 #else
1159       png_destroy_struct((png_voidp)info_ptr);
1160 #endif
1161       *info_ptr_ptr = NULL;
1162    }
1163
1164    if (end_info_ptr != NULL)
1165    {
1166 #ifdef PNG_READ_TEXT_SUPPORTED
1167       png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1);
1168 #endif
1169 #ifdef PNG_USER_MEM_SUPPORTED
1170       png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn,
1171          (png_voidp)mem_ptr);
1172 #else
1173       png_destroy_struct((png_voidp)end_info_ptr);
1174 #endif
1175       *end_info_ptr_ptr = NULL;
1176    }
1177
1178    if (png_ptr != NULL)
1179    {
1180 #ifdef PNG_USER_MEM_SUPPORTED
1181       png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1182           (png_voidp)mem_ptr);
1183 #else
1184       png_destroy_struct((png_voidp)png_ptr);
1185 #endif
1186       *png_ptr_ptr = NULL;
1187    }
1188 }
1189
1190 /* Free all memory used by the read (old method) */
1191 void /* PRIVATE */
1192 png_read_destroy(png_structp png_ptr, png_infop info_ptr,
1193     png_infop end_info_ptr)
1194 {
1195 #ifdef PNG_SETJMP_SUPPORTED
1196    jmp_buf tmp_jmp;
1197 #endif
1198    png_error_ptr error_fn;
1199    png_error_ptr warning_fn;
1200    png_voidp error_ptr;
1201 #ifdef PNG_USER_MEM_SUPPORTED
1202    png_free_ptr free_fn;
1203 #endif
1204
1205    png_debug(1, "in png_read_destroy");
1206
1207    if (info_ptr != NULL)
1208       png_info_destroy(png_ptr, info_ptr);
1209
1210    if (end_info_ptr != NULL)
1211       png_info_destroy(png_ptr, end_info_ptr);
1212
1213    png_free(png_ptr, png_ptr->zbuf);
1214    png_free(png_ptr, png_ptr->big_row_buf);
1215    png_free(png_ptr, png_ptr->prev_row);
1216    png_free(png_ptr, png_ptr->chunkdata);
1217 #ifdef PNG_READ_DITHER_SUPPORTED
1218    png_free(png_ptr, png_ptr->palette_lookup);
1219    png_free(png_ptr, png_ptr->dither_index);
1220 #endif
1221 #ifdef PNG_READ_GAMMA_SUPPORTED
1222    png_free(png_ptr, png_ptr->gamma_table);
1223 #endif
1224 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1225    png_free(png_ptr, png_ptr->gamma_from_1);
1226    png_free(png_ptr, png_ptr->gamma_to_1);
1227 #endif
1228 #ifdef PNG_FREE_ME_SUPPORTED
1229    if (png_ptr->free_me & PNG_FREE_PLTE)
1230       png_zfree(png_ptr, png_ptr->palette);
1231    png_ptr->free_me &= ~PNG_FREE_PLTE;
1232 #else
1233    if (png_ptr->flags & PNG_FLAG_FREE_PLTE)
1234       png_zfree(png_ptr, png_ptr->palette);
1235    png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
1236 #endif
1237 #if defined(PNG_tRNS_SUPPORTED) || \
1238     defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1239 #ifdef PNG_FREE_ME_SUPPORTED
1240    if (png_ptr->free_me & PNG_FREE_TRNS)
1241       png_free(png_ptr, png_ptr->trans);
1242    png_ptr->free_me &= ~PNG_FREE_TRNS;
1243 #else
1244    if (png_ptr->flags & PNG_FLAG_FREE_TRNS)
1245       png_free(png_ptr, png_ptr->trans);
1246    png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
1247 #endif
1248 #endif
1249 #ifdef PNG_READ_hIST_SUPPORTED
1250 #ifdef PNG_FREE_ME_SUPPORTED
1251    if (png_ptr->free_me & PNG_FREE_HIST)
1252       png_free(png_ptr, png_ptr->hist);
1253    png_ptr->free_me &= ~PNG_FREE_HIST;
1254 #else
1255    if (png_ptr->flags & PNG_FLAG_FREE_HIST)
1256       png_free(png_ptr, png_ptr->hist);
1257    png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
1258 #endif
1259 #endif
1260 #ifdef PNG_READ_GAMMA_SUPPORTED
1261    if (png_ptr->gamma_16_table != NULL)
1262    {
1263       int i;
1264       int istop = (1 << (8 - png_ptr->gamma_shift));
1265       for (i = 0; i < istop; i++)
1266       {
1267          png_free(png_ptr, png_ptr->gamma_16_table[i]);
1268       }
1269    png_free(png_ptr, png_ptr->gamma_16_table);
1270    }
1271 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1272    if (png_ptr->gamma_16_from_1 != NULL)
1273    {
1274       int i;
1275       int istop = (1 << (8 - png_ptr->gamma_shift));
1276       for (i = 0; i < istop; i++)
1277       {
1278          png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
1279       }
1280    png_free(png_ptr, png_ptr->gamma_16_from_1);
1281    }
1282    if (png_ptr->gamma_16_to_1 != NULL)
1283    {
1284       int i;
1285       int istop = (1 << (8 - png_ptr->gamma_shift));
1286       for (i = 0; i < istop; i++)
1287       {
1288          png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
1289       }
1290    png_free(png_ptr, png_ptr->gamma_16_to_1);
1291    }
1292 #endif
1293 #endif
1294 #ifdef PNG_TIME_RFC1123_SUPPORTED
1295    png_free(png_ptr, png_ptr->time_buffer);
1296 #endif
1297
1298    inflateEnd(&png_ptr->zstream);
1299 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1300    png_free(png_ptr, png_ptr->save_buffer);
1301 #endif
1302
1303    /* Save the important info out of the png_struct, in case it is
1304     * being used again.
1305     */
1306 #ifdef PNG_SETJMP_SUPPORTED
1307    png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
1308 #endif
1309
1310    error_fn = png_ptr->error_fn;
1311    warning_fn = png_ptr->warning_fn;
1312    error_ptr = png_ptr->error_ptr;
1313 #ifdef PNG_USER_MEM_SUPPORTED
1314    free_fn = png_ptr->free_fn;
1315 #endif
1316
1317    png_memset(png_ptr, 0, png_sizeof(png_struct));
1318
1319    png_ptr->error_fn = error_fn;
1320    png_ptr->warning_fn = warning_fn;
1321    png_ptr->error_ptr = error_ptr;
1322 #ifdef PNG_USER_MEM_SUPPORTED
1323    png_ptr->free_fn = free_fn;
1324 #endif
1325
1326 #ifdef PNG_SETJMP_SUPPORTED
1327    png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
1328 #endif
1329
1330 }
1331
1332 void PNGAPI
1333 png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
1334 {
1335    if (png_ptr == NULL)
1336       return;
1337    png_ptr->read_row_fn = read_row_fn;
1338 }
1339
1340
1341 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1342 #ifdef PNG_INFO_IMAGE_SUPPORTED
1343 void PNGAPI
1344 png_read_png(png_structp png_ptr, png_infop info_ptr,
1345                            int transforms,
1346                            voidp params)
1347 {
1348    int row;
1349
1350    if (png_ptr == NULL)
1351       return;
1352 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
1353    /* Invert the alpha channel from opacity to transparency
1354     */
1355    if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1356        png_set_invert_alpha(png_ptr);
1357 #endif
1358
1359    /* png_read_info() gives us all of the information from the
1360     * PNG file before the first IDAT (image data chunk).
1361     */
1362    png_read_info(png_ptr, info_ptr);
1363    if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
1364       png_error(png_ptr, "Image is too high to process with png_read_png()");
1365
1366    /* -------------- image transformations start here ------------------- */
1367
1368 #ifdef PNG_READ_16_TO_8_SUPPORTED
1369    /* Tell libpng to strip 16 bit/color files down to 8 bits per color.
1370     */
1371    if (transforms & PNG_TRANSFORM_STRIP_16)
1372       png_set_strip_16(png_ptr);
1373 #endif
1374
1375 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1376    /* Strip alpha bytes from the input data without combining with
1377     * the background (not recommended).
1378     */
1379    if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
1380       png_set_strip_alpha(png_ptr);
1381 #endif
1382
1383 #if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
1384    /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
1385     * byte into separate bytes (useful for paletted and grayscale images).
1386     */
1387    if (transforms & PNG_TRANSFORM_PACKING)
1388       png_set_packing(png_ptr);
1389 #endif
1390
1391 #ifdef PNG_READ_PACKSWAP_SUPPORTED
1392    /* Change the order of packed pixels to least significant bit first
1393     * (not useful if you are using png_set_packing).
1394     */
1395    if (transforms & PNG_TRANSFORM_PACKSWAP)
1396       png_set_packswap(png_ptr);
1397 #endif
1398
1399 #ifdef PNG_READ_EXPAND_SUPPORTED
1400    /* Expand paletted colors into true RGB triplets
1401     * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
1402     * Expand paletted or RGB images with transparency to full alpha
1403     * channels so the data will be available as RGBA quartets.
1404     */
1405    if (transforms & PNG_TRANSFORM_EXPAND)
1406       if ((png_ptr->bit_depth < 8) ||
1407           (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
1408           (info_ptr->valid & PNG_INFO_tRNS))
1409          png_set_expand(png_ptr);
1410 #endif
1411
1412    /* We don't handle background color or gamma transformation or dithering.
1413     */
1414
1415 #ifdef PNG_READ_INVERT_SUPPORTED
1416    /* Invert monochrome files to have 0 as white and 1 as black
1417     */
1418    if (transforms & PNG_TRANSFORM_INVERT_MONO)
1419       png_set_invert_mono(png_ptr);
1420 #endif
1421
1422 #ifdef PNG_READ_SHIFT_SUPPORTED
1423    /* If you want to shift the pixel values from the range [0,255] or
1424     * [0,65535] to the original [0,7] or [0,31], or whatever range the
1425     * colors were originally in:
1426     */
1427    if ((transforms & PNG_TRANSFORM_SHIFT) && (info_ptr->valid & PNG_INFO_sBIT))
1428       png_set_shift(png_ptr, &info_ptr->sig_bit);
1429 #endif
1430
1431 #ifdef PNG_READ_BGR_SUPPORTED
1432    /* Flip the RGB pixels to BGR (or RGBA to BGRA)
1433     */
1434    if (transforms & PNG_TRANSFORM_BGR)
1435       png_set_bgr(png_ptr);
1436 #endif
1437
1438 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
1439    /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR)
1440     */
1441    if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1442        png_set_swap_alpha(png_ptr);
1443 #endif
1444
1445 #ifdef PNG_READ_SWAP_SUPPORTED
1446    /* Swap bytes of 16 bit files to least significant byte first
1447     */
1448    if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1449       png_set_swap(png_ptr);
1450 #endif
1451
1452 /* Added at libpng-1.2.41 */
1453 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
1454    /* Invert the alpha channel from opacity to transparency
1455     */
1456    if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1457        png_set_invert_alpha(png_ptr);
1458 #endif
1459
1460 /* Added at libpng-1.2.41 */
1461 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1462    /* Expand grayscale image to RGB
1463     */
1464    if (transforms & PNG_TRANSFORM_GRAY_TO_RGB)
1465        png_set_gray_to_rgb(png_ptr);
1466 #endif
1467
1468    /* We don't handle adding filler bytes */
1469
1470    /* Optional call to gamma correct and add the background to the palette
1471     * and update info structure.  REQUIRED if you are expecting libpng to
1472     * update the palette for you (i.e., you selected such a transform above).
1473     */
1474    png_read_update_info(png_ptr, info_ptr);
1475
1476    /* -------------- image transformations end here ------------------- */
1477
1478 #ifdef PNG_FREE_ME_SUPPORTED
1479    png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
1480 #endif
1481    if (info_ptr->row_pointers == NULL)
1482    {
1483       info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
1484          info_ptr->height * png_sizeof(png_bytep));
1485       png_memset(info_ptr->row_pointers, 0, info_ptr->height
1486          * png_sizeof(png_bytep));
1487
1488 #ifdef PNG_FREE_ME_SUPPORTED
1489       info_ptr->free_me |= PNG_FREE_ROWS;
1490 #endif
1491
1492       for (row = 0; row < (int)info_ptr->height; row++)
1493          info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,
1494             png_get_rowbytes(png_ptr, info_ptr));
1495    }
1496
1497    png_read_image(png_ptr, info_ptr->row_pointers);
1498    info_ptr->valid |= PNG_INFO_IDAT;
1499
1500    /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */
1501    png_read_end(png_ptr, info_ptr);
1502
1503    PNG_UNUSED(transforms) /* Quiet compiler warnings */
1504    PNG_UNUSED(params)
1505
1506 }
1507 #endif /* PNG_INFO_IMAGE_SUPPORTED */
1508 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
1509 #endif /* PNG_READ_SUPPORTED */