1 2 /* pngread.c - read a PNG file 3 * 4 * Last changed in libpng 1.2.44 [June 26, 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 * 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 23 /* Create a PNG structure for reading, and allocate any memory needed. */ 24 png_structp PNGAPI 25 png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr, 26 png_error_ptr error_fn, png_error_ptr warn_fn) 27 { 28 29 #ifdef PNG_USER_MEM_SUPPORTED 30 return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn, 31 warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL)); 32 } 33 34 /* Alternate create PNG structure for reading, and allocate any memory 35 * needed. 36 */ 37 png_structp PNGAPI 38 png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr, 39 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, 40 png_malloc_ptr malloc_fn, png_free_ptr free_fn) 41 { 42 #endif /* PNG_USER_MEM_SUPPORTED */ 43 44 #ifdef PNG_SETJMP_SUPPORTED 45 volatile 46 #endif 47 png_structp png_ptr; 48 49 #ifdef PNG_SETJMP_SUPPORTED 50 #ifdef USE_FAR_KEYWORD 51 jmp_buf jmpbuf; 52 #endif 53 #endif 54 55 int i; 56 57 png_debug(1, "in png_create_read_struct"); 58 59 #ifdef PNG_USER_MEM_SUPPORTED 60 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG, 61 (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr); 62 #else 63 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG); 64 #endif 65 if (png_ptr == NULL) 66 return (NULL); 67 68 /* Added at libpng-1.2.6 */ 69 #ifdef PNG_USER_LIMITS_SUPPORTED 70 png_ptr->user_width_max = PNG_USER_WIDTH_MAX; 71 png_ptr->user_height_max = PNG_USER_HEIGHT_MAX; 72 # ifdef PNG_USER_CHUNK_CACHE_MAX 73 /* Added at libpng-1.2.43 and 1.4.0 */ 74 png_ptr->user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX; 75 # endif 76 # ifdef PNG_SET_USER_CHUNK_MALLOC_MAX 77 /* Added at libpng-1.2.43 and 1.4.1 */ 78 png_ptr->user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX; 79 # endif 80 #endif 81 82 #ifdef PNG_SETJMP_SUPPORTED 83 #ifdef USE_FAR_KEYWORD 84 if (setjmp(jmpbuf)) 85 #else 86 if (setjmp(png_ptr->jmpbuf)) 87 #endif 88 { 89 png_free(png_ptr, png_ptr->zbuf); 90 png_ptr->zbuf = NULL; 91 #ifdef PNG_USER_MEM_SUPPORTED 92 png_destroy_struct_2((png_voidp)png_ptr, 93 (png_free_ptr)free_fn, (png_voidp)mem_ptr); 94 #else 95 png_destroy_struct((png_voidp)png_ptr); 96 #endif 97 return (NULL); 98 } 99 #ifdef USE_FAR_KEYWORD 100 png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf)); 101 #endif 102 #endif /* PNG_SETJMP_SUPPORTED */ 103 104 #ifdef PNG_USER_MEM_SUPPORTED 105 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn); 106 #endif 107 108 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn); 109 110 if (user_png_ver) 111 { 112 i = 0; 113 do 114 { 115 if (user_png_ver[i] != png_libpng_ver[i]) 116 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; 117 } while (png_libpng_ver[i++]); 118 } 119 else 120 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; 121 122 123 if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) 124 { 125 /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so 126 * we must recompile any applications that use any older library version. 127 * For versions after libpng 1.0, we will be compatible, so we need 128 * only check the first digit. 129 */ 130 if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] || 131 (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) || 132 (user_png_ver[0] == '0' && user_png_ver[2] < '9')) 133 { 134 #if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE) 135 char msg[80]; 136 if (user_png_ver) 137 { 138 png_snprintf(msg, 80, 139 "Application was compiled with png.h from libpng-%.20s", 140 user_png_ver); 141 png_warning(png_ptr, msg); 142 } 143 png_snprintf(msg, 80, 144 "Application is running with png.c from libpng-%.20s", 145 png_libpng_ver); 146 png_warning(png_ptr, msg); 147 #endif 148 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 149 png_ptr->flags = 0; 150 #endif 151 png_error(png_ptr, 152 "Incompatible libpng version in application and library"); 153 } 154 } 155 156 /* Initialize zbuf - compression buffer */ 157 png_ptr->zbuf_size = PNG_ZBUF_SIZE; 158 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, 159 (png_uint_32)png_ptr->zbuf_size); 160 png_ptr->zstream.zalloc = png_zalloc; 161 png_ptr->zstream.zfree = png_zfree; 162 png_ptr->zstream.opaque = (voidpf)png_ptr; 163 164 switch (inflateInit(&png_ptr->zstream)) 165 { 166 case Z_OK: /* Do nothing */ break; 167 case Z_MEM_ERROR: 168 case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory error"); 169 break; 170 case Z_VERSION_ERROR: png_error(png_ptr, "zlib version error"); 171 break; 172 default: png_error(png_ptr, "Unknown zlib error"); 173 } 174 175 176 png_ptr->zstream.next_out = png_ptr->zbuf; 177 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; 178 179 png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL); 180 181 #ifdef PNG_SETJMP_SUPPORTED 182 /* Applications that neglect to set up their own setjmp() and then 183 encounter a png_error() will longjmp here. Since the jmpbuf is 184 then meaningless we abort instead of returning. */ 185 #ifdef USE_FAR_KEYWORD 186 if (setjmp(jmpbuf)) 187 PNG_ABORT(); 188 png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf)); 189 #else 190 if (setjmp(png_ptr->jmpbuf)) 191 PNG_ABORT(); 192 #endif 193 #endif /* PNG_SETJMP_SUPPORTED */ 194 195 return (png_ptr); 196 } 197 198 #if defined(PNG_1_0_X) || defined(PNG_1_2_X) 199 /* Initialize PNG structure for reading, and allocate any memory needed. 200 * This interface is deprecated in favour of the png_create_read_struct(), 201 * and it will disappear as of libpng-1.3.0. 202 */ 203 #undef png_read_init 204 void PNGAPI 205 png_read_init(png_structp png_ptr) 206 { 207 /* We only come here via pre-1.0.7-compiled applications */ 208 png_read_init_2(png_ptr, "1.0.6 or earlier", 0, 0); 209 } 210 211 void PNGAPI 212 png_read_init_2(png_structp png_ptr, png_const_charp user_png_ver, 213 png_size_t png_struct_size, png_size_t png_info_size) 214 { 215 /* We only come here via pre-1.0.12-compiled applications */ 216 if (png_ptr == NULL) 217 return; 218 #if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE) 219 if (png_sizeof(png_struct) > png_struct_size || 220 png_sizeof(png_info) > png_info_size) 221 { 222 char msg[80]; 223 png_ptr->warning_fn = NULL; 224 if (user_png_ver) 225 { 226 png_snprintf(msg, 80, 227 "Application was compiled with png.h from libpng-%.20s", 228 user_png_ver); 229 png_warning(png_ptr, msg); 230 } 231 png_snprintf(msg, 80, 232 "Application is running with png.c from libpng-%.20s", 233 png_libpng_ver); 234 png_warning(png_ptr, msg); 235 } 236 #endif 237 if (png_sizeof(png_struct) > png_struct_size) 238 { 239 png_ptr->error_fn = NULL; 240 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 241 png_ptr->flags = 0; 242 #endif 243 png_error(png_ptr, 244 "The png struct allocated by the application for reading is" 245 " too small."); 246 } 247 if (png_sizeof(png_info) > png_info_size) 248 { 249 png_ptr->error_fn = NULL; 250 #ifdef PNG_ERROR_NUMBERS_SUPPORTED 251 png_ptr->flags = 0; 252 #endif 253 png_error(png_ptr, 254 "The info struct allocated by application for reading is" 255 " too small."); 256 } 257 png_read_init_3(&png_ptr, user_png_ver, png_struct_size); 258 } 259 #endif /* PNG_1_0_X || PNG_1_2_X */ 260 261 void PNGAPI 262 png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver, 263 png_size_t png_struct_size) 264 { 265 #ifdef PNG_SETJMP_SUPPORTED 266 jmp_buf tmp_jmp; /* to save current jump buffer */ 267 #endif 268 269 int i = 0; 270 271 png_structp png_ptr=*ptr_ptr; 272 273 if (png_ptr == NULL) 274 return; 275 276 do 277 { 278 if (user_png_ver[i] != png_libpng_ver[i]) 279 { 280 #ifdef PNG_LEGACY_SUPPORTED 281 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; 282 #else 283 png_ptr->warning_fn = NULL; 284 png_warning(png_ptr, 285 "Application uses deprecated png_read_init() and should be" 286 " recompiled."); 287 break; 288 #endif 289 } 290 } while (png_libpng_ver[i++]); 291 292 png_debug(1, "in png_read_init_3"); 293 294 #ifdef PNG_SETJMP_SUPPORTED 295 /* Save jump buffer and error functions */ 296 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf)); 297 #endif 298 299 if (png_sizeof(png_struct) > png_struct_size) 300 { 301 png_destroy_struct(png_ptr); 302 *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG); 303 png_ptr = *ptr_ptr; 304 } 305 306 /* Reset all variables to 0 */ 307 png_memset(png_ptr, 0, png_sizeof(png_struct)); 308 309 #ifdef PNG_SETJMP_SUPPORTED 310 /* Restore jump buffer */ 311 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf)); 312 #endif 313 314 /* Added at libpng-1.2.6 */ 315 #ifdef PNG_SET_USER_LIMITS_SUPPORTED 316 png_ptr->user_width_max = PNG_USER_WIDTH_MAX; 317 png_ptr->user_height_max = PNG_USER_HEIGHT_MAX; 318 #endif 319 320 /* Initialize zbuf - compression buffer */ 321 png_ptr->zbuf_size = PNG_ZBUF_SIZE; 322 png_ptr->zstream.zalloc = png_zalloc; 323 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, 324 (png_uint_32)png_ptr->zbuf_size); 325 png_ptr->zstream.zalloc = png_zalloc; 326 png_ptr->zstream.zfree = png_zfree; 327 png_ptr->zstream.opaque = (voidpf)png_ptr; 328 329 switch (inflateInit(&png_ptr->zstream)) 330 { 331 case Z_OK: /* Do nothing */ break; 332 case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory error"); break; 333 case Z_VERSION_ERROR: png_error(png_ptr, "zlib version error"); 334 break; 335 default: png_error(png_ptr, "Unknown zlib error"); 336 } 337 338 png_ptr->zstream.next_out = png_ptr->zbuf; 339 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; 340 341 png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL); 342 } 343 344 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 345 /* Read the information before the actual image data. This has been 346 * changed in v0.90 to allow reading a file that already has the magic 347 * bytes read from the stream. You can tell libpng how many bytes have 348 * been read from the beginning of the stream (up to the maximum of 8) 349 * via png_set_sig_bytes(), and we will only check the remaining bytes 350 * here. The application can then have access to the signature bytes we 351 * read if it is determined that this isn't a valid PNG file. 352 */ 353 void PNGAPI 354 png_read_info(png_structp png_ptr, png_infop info_ptr) 355 { 356 png_debug(1, "in png_read_info"); 357 358 if (png_ptr == NULL || info_ptr == NULL) 359 return; 360 361 /* If we haven't checked all of the PNG signature bytes, do so now. */ 362 if (png_ptr->sig_bytes < 8) 363 { 364 png_size_t num_checked = png_ptr->sig_bytes, 365 num_to_check = 8 - num_checked; 366 367 png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); 368 png_ptr->sig_bytes = 8; 369 370 if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) 371 { 372 if (num_checked < 4 && 373 png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) 374 png_error(png_ptr, "Not a PNG file"); 375 else 376 png_error(png_ptr, "PNG file corrupted by ASCII conversion"); 377 } 378 if (num_checked < 3) 379 png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; 380 } 381 382 for (;;) 383 { 384 #ifdef PNG_USE_LOCAL_ARRAYS 385 PNG_CONST PNG_IHDR; 386 PNG_CONST PNG_IDAT; 387 PNG_CONST PNG_IEND; 388 PNG_CONST PNG_PLTE; 389 #ifdef PNG_READ_bKGD_SUPPORTED 390 PNG_CONST PNG_bKGD; 391 #endif 392 #ifdef PNG_READ_cHRM_SUPPORTED 393 PNG_CONST PNG_cHRM; 394 #endif 395 #ifdef PNG_READ_gAMA_SUPPORTED 396 PNG_CONST PNG_gAMA; 397 #endif 398 #ifdef PNG_READ_hIST_SUPPORTED 399 PNG_CONST PNG_hIST; 400 #endif 401 #ifdef PNG_READ_iCCP_SUPPORTED 402 PNG_CONST PNG_iCCP; 403 #endif 404 #ifdef PNG_READ_iTXt_SUPPORTED 405 PNG_CONST PNG_iTXt; 406 #endif 407 #ifdef PNG_READ_oFFs_SUPPORTED 408 PNG_CONST PNG_oFFs; 409 #endif 410 #ifdef PNG_READ_pCAL_SUPPORTED 411 PNG_CONST PNG_pCAL; 412 #endif 413 #ifdef PNG_READ_pHYs_SUPPORTED 414 PNG_CONST PNG_pHYs; 415 #endif 416 #ifdef PNG_READ_sBIT_SUPPORTED 417 PNG_CONST PNG_sBIT; 418 #endif 419 #ifdef PNG_READ_sCAL_SUPPORTED 420 PNG_CONST PNG_sCAL; 421 #endif 422 #ifdef PNG_READ_sPLT_SUPPORTED 423 PNG_CONST PNG_sPLT; 424 #endif 425 #ifdef PNG_READ_sRGB_SUPPORTED 426 PNG_CONST PNG_sRGB; 427 #endif 428 #ifdef PNG_READ_tEXt_SUPPORTED 429 PNG_CONST PNG_tEXt; 430 #endif 431 #ifdef PNG_READ_tIME_SUPPORTED 432 PNG_CONST PNG_tIME; 433 #endif 434 #ifdef PNG_READ_tRNS_SUPPORTED 435 PNG_CONST PNG_tRNS; 436 #endif 437 #ifdef PNG_READ_zTXt_SUPPORTED 438 PNG_CONST PNG_zTXt; 439 #endif 440 #endif /* PNG_USE_LOCAL_ARRAYS */ 441 png_uint_32 length = png_read_chunk_header(png_ptr); 442 PNG_CONST png_bytep chunk_name = png_ptr->chunk_name; 443 444 /* This should be a binary subdivision search or a hash for 445 * matching the chunk name rather than a linear search. 446 */ 447 if (!png_memcmp(chunk_name, png_IDAT, 4)) 448 if (png_ptr->mode & PNG_AFTER_IDAT) 449 png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; 450 451 if (!png_memcmp(chunk_name, png_IHDR, 4)) 452 png_handle_IHDR(png_ptr, info_ptr, length); 453 else if (!png_memcmp(chunk_name, png_IEND, 4)) 454 png_handle_IEND(png_ptr, info_ptr, length); 455 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED 456 else if (png_handle_as_unknown(png_ptr, chunk_name)) 457 { 458 if (!png_memcmp(chunk_name, png_IDAT, 4)) 459 png_ptr->mode |= PNG_HAVE_IDAT; 460 png_handle_unknown(png_ptr, info_ptr, length); 461 if (!png_memcmp(chunk_name, png_PLTE, 4)) 462 png_ptr->mode |= PNG_HAVE_PLTE; 463 else if (!png_memcmp(chunk_name, png_IDAT, 4)) 464 { 465 if (!(png_ptr->mode & PNG_HAVE_IHDR)) 466 png_error(png_ptr, "Missing IHDR before IDAT"); 467 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && 468 !(png_ptr->mode & PNG_HAVE_PLTE)) 469 png_error(png_ptr, "Missing PLTE before IDAT"); 470 break; 471 } 472 } 473 #endif 474 else if (!png_memcmp(chunk_name, png_PLTE, 4)) 475 png_handle_PLTE(png_ptr, info_ptr, length); 476 else if (!png_memcmp(chunk_name, png_IDAT, 4)) 477 { 478 if (!(png_ptr->mode & PNG_HAVE_IHDR)) 479 png_error(png_ptr, "Missing IHDR before IDAT"); 480 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && 481 !(png_ptr->mode & PNG_HAVE_PLTE)) 482 png_error(png_ptr, "Missing PLTE before IDAT"); 483 484 png_ptr->idat_size = length; 485 png_ptr->mode |= PNG_HAVE_IDAT; 486 break; 487 } 488 #ifdef PNG_READ_bKGD_SUPPORTED 489 else if (!png_memcmp(chunk_name, png_bKGD, 4)) 490 png_handle_bKGD(png_ptr, info_ptr, length); 491 #endif 492 #ifdef PNG_READ_cHRM_SUPPORTED 493 else if (!png_memcmp(chunk_name, png_cHRM, 4)) 494 png_handle_cHRM(png_ptr, info_ptr, length); 495 #endif 496 #ifdef PNG_READ_gAMA_SUPPORTED 497 else if (!png_memcmp(chunk_name, png_gAMA, 4)) 498 png_handle_gAMA(png_ptr, info_ptr, length); 499 #endif 500 #ifdef PNG_READ_hIST_SUPPORTED 501 else if (!png_memcmp(chunk_name, png_hIST, 4)) 502 png_handle_hIST(png_ptr, info_ptr, length); 503 #endif 504 #ifdef PNG_READ_oFFs_SUPPORTED 505 else if (!png_memcmp(chunk_name, png_oFFs, 4)) 506 png_handle_oFFs(png_ptr, info_ptr, length); 507 #endif 508 #ifdef PNG_READ_pCAL_SUPPORTED 509 else if (!png_memcmp(chunk_name, png_pCAL, 4)) 510 png_handle_pCAL(png_ptr, info_ptr, length); 511 #endif 512 #ifdef PNG_READ_sCAL_SUPPORTED 513 else if (!png_memcmp(chunk_name, png_sCAL, 4)) 514 png_handle_sCAL(png_ptr, info_ptr, length); 515 #endif 516 #ifdef PNG_READ_pHYs_SUPPORTED 517 else if (!png_memcmp(chunk_name, png_pHYs, 4)) 518 png_handle_pHYs(png_ptr, info_ptr, length); 519 #endif 520 #ifdef PNG_READ_sBIT_SUPPORTED 521 else if (!png_memcmp(chunk_name, png_sBIT, 4)) 522 png_handle_sBIT(png_ptr, info_ptr, length); 523 #endif 524 #ifdef PNG_READ_sRGB_SUPPORTED 525 else if (!png_memcmp(chunk_name, png_sRGB, 4)) 526 png_handle_sRGB(png_ptr, info_ptr, length); 527 #endif 528 #ifdef PNG_READ_iCCP_SUPPORTED 529 else if (!png_memcmp(chunk_name, png_iCCP, 4)) 530 png_handle_iCCP(png_ptr, info_ptr, length); 531 #endif 532 #ifdef PNG_READ_sPLT_SUPPORTED 533 else if (!png_memcmp(chunk_name, png_sPLT, 4)) 534 png_handle_sPLT(png_ptr, info_ptr, length); 535 #endif 536 #ifdef PNG_READ_tEXt_SUPPORTED 537 else if (!png_memcmp(chunk_name, png_tEXt, 4)) 538 png_handle_tEXt(png_ptr, info_ptr, length); 539 #endif 540 #ifdef PNG_READ_tIME_SUPPORTED 541 else if (!png_memcmp(chunk_name, png_tIME, 4)) 542 png_handle_tIME(png_ptr, info_ptr, length); 543 #endif 544 #ifdef PNG_READ_tRNS_SUPPORTED 545 else if (!png_memcmp(chunk_name, png_tRNS, 4)) 546 png_handle_tRNS(png_ptr, info_ptr, length); 547 #endif 548 #ifdef PNG_READ_zTXt_SUPPORTED 549 else if (!png_memcmp(chunk_name, png_zTXt, 4)) 550 png_handle_zTXt(png_ptr, info_ptr, length); 551 #endif 552 #ifdef PNG_READ_iTXt_SUPPORTED 553 else if (!png_memcmp(chunk_name, png_iTXt, 4)) 554 png_handle_iTXt(png_ptr, info_ptr, length); 555 #endif 556 else 557 png_handle_unknown(png_ptr, info_ptr, length); 558 } 559 } 560 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ 561 562 /* Optional call to update the users info_ptr structure */ 563 void PNGAPI 564 png_read_update_info(png_structp png_ptr, png_infop info_ptr) 565 { 566 png_debug(1, "in png_read_update_info"); 567 568 if (png_ptr == NULL) 569 return; 570 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) 571 png_read_start_row(png_ptr); 572 else 573 png_warning(png_ptr, 574 "Ignoring extra png_read_update_info() call; row buffer not reallocated"); 575 576 png_read_transform_info(png_ptr, info_ptr); 577 } 578 579 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 580 /* Initialize palette, background, etc, after transformations 581 * are set, but before any reading takes place. This allows 582 * the user to obtain a gamma-corrected palette, for example. 583 * If the user doesn't call this, we will do it ourselves. 584 */ 585 void PNGAPI 586 png_start_read_image(png_structp png_ptr) 587 { 588 png_debug(1, "in png_start_read_image"); 589 590 if (png_ptr == NULL) 591 return; 592 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) 593 png_read_start_row(png_ptr); 594 } 595 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ 596 597 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 598 void PNGAPI 599 png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) 600 { 601 PNG_CONST PNG_IDAT; 602 PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 603 0xff}; 604 PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff}; 605 int ret; 606 607 if (png_ptr == NULL) 608 return; 609 610 png_debug2(1, "in png_read_row (row %lu, pass %d)", 611 png_ptr->row_number, png_ptr->pass); 612 613 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) 614 png_read_start_row(png_ptr); 615 if (png_ptr->row_number == 0 && png_ptr->pass == 0) 616 { 617 /* Check for transforms that have been set but were defined out */ 618 #if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED) 619 if (png_ptr->transformations & PNG_INVERT_MONO) 620 png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined."); 621 #endif 622 #if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED) 623 if (png_ptr->transformations & PNG_FILLER) 624 png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined."); 625 #endif 626 #if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \ 627 !defined(PNG_READ_PACKSWAP_SUPPORTED) 628 if (png_ptr->transformations & PNG_PACKSWAP) 629 png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined."); 630 #endif 631 #if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED) 632 if (png_ptr->transformations & PNG_PACK) 633 png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined."); 634 #endif 635 #if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) 636 if (png_ptr->transformations & PNG_SHIFT) 637 png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined."); 638 #endif 639 #if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED) 640 if (png_ptr->transformations & PNG_BGR) 641 png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined."); 642 #endif 643 #if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED) 644 if (png_ptr->transformations & PNG_SWAP_BYTES) 645 png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined."); 646 #endif 647 } 648 649 #ifdef PNG_READ_INTERLACING_SUPPORTED 650 /* If interlaced and we do not need a new row, combine row and return */ 651 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) 652 { 653 switch (png_ptr->pass) 654 { 655 case 0: 656 if (png_ptr->row_number & 0x07) 657 { 658 if (dsp_row != NULL) 659 png_combine_row(png_ptr, dsp_row, 660 png_pass_dsp_mask[png_ptr->pass]); 661 png_read_finish_row(png_ptr); 662 return; 663 } 664 break; 665 case 1: 666 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5) 667 { 668 if (dsp_row != NULL) 669 png_combine_row(png_ptr, dsp_row, 670 png_pass_dsp_mask[png_ptr->pass]); 671 png_read_finish_row(png_ptr); 672 return; 673 } 674 break; 675 case 2: 676 if ((png_ptr->row_number & 0x07) != 4) 677 { 678 if (dsp_row != NULL && (png_ptr->row_number & 4)) 679 png_combine_row(png_ptr, dsp_row, 680 png_pass_dsp_mask[png_ptr->pass]); 681 png_read_finish_row(png_ptr); 682 return; 683 } 684 break; 685 case 3: 686 if ((png_ptr->row_number & 3) || png_ptr->width < 3) 687 { 688 if (dsp_row != NULL) 689 png_combine_row(png_ptr, dsp_row, 690 png_pass_dsp_mask[png_ptr->pass]); 691 png_read_finish_row(png_ptr); 692 return; 693 } 694 break; 695 case 4: 696 if ((png_ptr->row_number & 3) != 2) 697 { 698 if (dsp_row != NULL && (png_ptr->row_number & 2)) 699 png_combine_row(png_ptr, dsp_row, 700 png_pass_dsp_mask[png_ptr->pass]); 701 png_read_finish_row(png_ptr); 702 return; 703 } 704 break; 705 case 5: 706 if ((png_ptr->row_number & 1) || png_ptr->width < 2) 707 { 708 if (dsp_row != NULL) 709 png_combine_row(png_ptr, dsp_row, 710 png_pass_dsp_mask[png_ptr->pass]); 711 png_read_finish_row(png_ptr); 712 return; 713 } 714 break; 715 case 6: 716 if (!(png_ptr->row_number & 1)) 717 { 718 png_read_finish_row(png_ptr); 719 return; 720 } 721 break; 722 } 723 } 724 #endif 725 726 if (!(png_ptr->mode & PNG_HAVE_IDAT)) 727 png_error(png_ptr, "Invalid attempt to read row data"); 728 729 png_ptr->zstream.next_out = png_ptr->row_buf; 730 png_ptr->zstream.avail_out = 731 (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth, 732 png_ptr->iwidth) + 1); 733 do 734 { 735 if (!(png_ptr->zstream.avail_in)) 736 { 737 while (!png_ptr->idat_size) 738 { 739 png_crc_finish(png_ptr, 0); 740 741 png_ptr->idat_size = png_read_chunk_header(png_ptr); 742 if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) 743 png_error(png_ptr, "Not enough image data"); 744 } 745 png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size; 746 png_ptr->zstream.next_in = png_ptr->zbuf; 747 if (png_ptr->zbuf_size > png_ptr->idat_size) 748 png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size; 749 png_crc_read(png_ptr, png_ptr->zbuf, 750 (png_size_t)png_ptr->zstream.avail_in); 751 png_ptr->idat_size -= png_ptr->zstream.avail_in; 752 } 753 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); 754 if (ret == Z_STREAM_END) 755 { 756 if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in || 757 png_ptr->idat_size) 758 png_error(png_ptr, "Extra compressed data"); 759 png_ptr->mode |= PNG_AFTER_IDAT; 760 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; 761 break; 762 } 763 if (ret != Z_OK) 764 png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg : 765 "Decompression error"); 766 767 } while (png_ptr->zstream.avail_out); 768 769 png_ptr->row_info.color_type = png_ptr->color_type; 770 png_ptr->row_info.width = png_ptr->iwidth; 771 png_ptr->row_info.channels = png_ptr->channels; 772 png_ptr->row_info.bit_depth = png_ptr->bit_depth; 773 png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; 774 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, 775 png_ptr->row_info.width); 776 777 if (png_ptr->row_buf[0]) 778 png_read_filter_row(png_ptr, &(png_ptr->row_info), 779 png_ptr->row_buf + 1, png_ptr->prev_row + 1, 780 (int)(png_ptr->row_buf[0])); 781 782 png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf, 783 png_ptr->rowbytes + 1); 784 785 #ifdef PNG_MNG_FEATURES_SUPPORTED 786 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && 787 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) 788 { 789 /* Intrapixel differencing */ 790 png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1); 791 } 792 #endif 793 794 795 if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA)) 796 png_do_read_transformations(png_ptr); 797 798 #ifdef PNG_READ_INTERLACING_SUPPORTED 799 /* Blow up interlaced rows to full size */ 800 if (png_ptr->interlaced && 801 (png_ptr->transformations & PNG_INTERLACE)) 802 { 803 if (png_ptr->pass < 6) 804 /* Old interface (pre-1.0.9): 805 * png_do_read_interlace(&(png_ptr->row_info), 806 * png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); 807 */ 808 png_do_read_interlace(png_ptr); 809 810 if (dsp_row != NULL) 811 png_combine_row(png_ptr, dsp_row, 812 png_pass_dsp_mask[png_ptr->pass]); 813 if (row != NULL) 814 png_combine_row(png_ptr, row, 815 png_pass_mask[png_ptr->pass]); 816 } 817 else 818 #endif 819 { 820 if (row != NULL) 821 png_combine_row(png_ptr, row, 0xff); 822 if (dsp_row != NULL) 823 png_combine_row(png_ptr, dsp_row, 0xff); 824 } 825 png_read_finish_row(png_ptr); 826 827 if (png_ptr->read_row_fn != NULL) 828 (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); 829 } 830 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ 831 832 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 833 /* Read one or more rows of image data. If the image is interlaced, 834 * and png_set_interlace_handling() has been called, the rows need to 835 * contain the contents of the rows from the previous pass. If the 836 * image has alpha or transparency, and png_handle_alpha()[*] has been 837 * called, the rows contents must be initialized to the contents of the 838 * screen. 839 * 840 * "row" holds the actual image, and pixels are placed in it 841 * as they arrive. If the image is displayed after each pass, it will 842 * appear to "sparkle" in. "display_row" can be used to display a 843 * "chunky" progressive image, with finer detail added as it becomes 844 * available. If you do not want this "chunky" display, you may pass 845 * NULL for display_row. If you do not want the sparkle display, and 846 * you have not called png_handle_alpha(), you may pass NULL for rows. 847 * If you have called png_handle_alpha(), and the image has either an 848 * alpha channel or a transparency chunk, you must provide a buffer for 849 * rows. In this case, you do not have to provide a display_row buffer 850 * also, but you may. If the image is not interlaced, or if you have 851 * not called png_set_interlace_handling(), the display_row buffer will 852 * be ignored, so pass NULL to it. 853 * 854 * [*] png_handle_alpha() does not exist yet, as of this version of libpng 855 */ 856 857 void PNGAPI 858 png_read_rows(png_structp png_ptr, png_bytepp row, 859 png_bytepp display_row, png_uint_32 num_rows) 860 { 861 png_uint_32 i; 862 png_bytepp rp; 863 png_bytepp dp; 864 865 png_debug(1, "in png_read_rows"); 866 867 if (png_ptr == NULL) 868 return; 869 rp = row; 870 dp = display_row; 871 if (rp != NULL && dp != NULL) 872 for (i = 0; i < num_rows; i++) 873 { 874 png_bytep rptr = *rp++; 875 png_bytep dptr = *dp++; 876 877 png_read_row(png_ptr, rptr, dptr); 878 } 879 else if (rp != NULL) 880 for (i = 0; i < num_rows; i++) 881 { 882 png_bytep rptr = *rp; 883 png_read_row(png_ptr, rptr, png_bytep_NULL); 884 rp++; 885 } 886 else if (dp != NULL) 887 for (i = 0; i < num_rows; i++) 888 { 889 png_bytep dptr = *dp; 890 png_read_row(png_ptr, png_bytep_NULL, dptr); 891 dp++; 892 } 893 } 894 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ 895 896 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 897 /* Read the entire image. If the image has an alpha channel or a tRNS 898 * chunk, and you have called png_handle_alpha()[*], you will need to 899 * initialize the image to the current image that PNG will be overlaying. 900 * We set the num_rows again here, in case it was incorrectly set in 901 * png_read_start_row() by a call to png_read_update_info() or 902 * png_start_read_image() if png_set_interlace_handling() wasn't called 903 * prior to either of these functions like it should have been. You can 904 * only call this function once. If you desire to have an image for 905 * each pass of a interlaced image, use png_read_rows() instead. 906 * 907 * [*] png_handle_alpha() does not exist yet, as of this version of libpng 908 */ 909 void PNGAPI 910 png_read_image(png_structp png_ptr, png_bytepp image) 911 { 912 png_uint_32 i, image_height; 913 int pass, j; 914 png_bytepp rp; 915 916 png_debug(1, "in png_read_image"); 917 918 if (png_ptr == NULL) 919 return; 920 921 #ifdef PNG_READ_INTERLACING_SUPPORTED 922 pass = png_set_interlace_handling(png_ptr); 923 #else 924 if (png_ptr->interlaced) 925 png_error(png_ptr, 926 "Cannot read interlaced image -- interlace handler disabled."); 927 pass = 1; 928 #endif 929 930 931 image_height=png_ptr->height; 932 png_ptr->num_rows = image_height; /* Make sure this is set correctly */ 933 934 for (j = 0; j < pass; j++) 935 { 936 rp = image; 937 for (i = 0; i < image_height; i++) 938 { 939 png_read_row(png_ptr, *rp, png_bytep_NULL); 940 rp++; 941 } 942 } 943 } 944 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ 945 946 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 947 /* Read the end of the PNG file. Will not read past the end of the 948 * file, will verify the end is accurate, and will read any comments 949 * or time information at the end of the file, if info is not NULL. 950 */ 951 void PNGAPI 952 png_read_end(png_structp png_ptr, png_infop info_ptr) 953 { 954 png_debug(1, "in png_read_end"); 955 956 if (png_ptr == NULL) 957 return; 958 png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */ 959 960 do 961 { 962 #ifdef PNG_USE_LOCAL_ARRAYS 963 PNG_CONST PNG_IHDR; 964 PNG_CONST PNG_IDAT; 965 PNG_CONST PNG_IEND; 966 PNG_CONST PNG_PLTE; 967 #ifdef PNG_READ_bKGD_SUPPORTED 968 PNG_CONST PNG_bKGD; 969 #endif 970 #ifdef PNG_READ_cHRM_SUPPORTED 971 PNG_CONST PNG_cHRM; 972 #endif 973 #ifdef PNG_READ_gAMA_SUPPORTED 974 PNG_CONST PNG_gAMA; 975 #endif 976 #ifdef PNG_READ_hIST_SUPPORTED 977 PNG_CONST PNG_hIST; 978 #endif 979 #ifdef PNG_READ_iCCP_SUPPORTED 980 PNG_CONST PNG_iCCP; 981 #endif 982 #ifdef PNG_READ_iTXt_SUPPORTED 983 PNG_CONST PNG_iTXt; 984 #endif 985 #ifdef PNG_READ_oFFs_SUPPORTED 986 PNG_CONST PNG_oFFs; 987 #endif 988 #ifdef PNG_READ_pCAL_SUPPORTED 989 PNG_CONST PNG_pCAL; 990 #endif 991 #ifdef PNG_READ_pHYs_SUPPORTED 992 PNG_CONST PNG_pHYs; 993 #endif 994 #ifdef PNG_READ_sBIT_SUPPORTED 995 PNG_CONST PNG_sBIT; 996 #endif 997 #ifdef PNG_READ_sCAL_SUPPORTED 998 PNG_CONST PNG_sCAL; 999 #endif 1000 #ifdef PNG_READ_sPLT_SUPPORTED 1001 PNG_CONST PNG_sPLT; 1002 #endif 1003 #ifdef PNG_READ_sRGB_SUPPORTED 1004 PNG_CONST PNG_sRGB; 1005 #endif 1006 #ifdef PNG_READ_tEXt_SUPPORTED 1007 PNG_CONST PNG_tEXt; 1008 #endif 1009 #ifdef PNG_READ_tIME_SUPPORTED 1010 PNG_CONST PNG_tIME; 1011 #endif 1012 #ifdef PNG_READ_tRNS_SUPPORTED 1013 PNG_CONST PNG_tRNS; 1014 #endif 1015 #ifdef PNG_READ_zTXt_SUPPORTED 1016 PNG_CONST PNG_zTXt; 1017 #endif 1018 #endif /* PNG_USE_LOCAL_ARRAYS */ 1019 png_uint_32 length = png_read_chunk_header(png_ptr); 1020 PNG_CONST png_bytep chunk_name = png_ptr->chunk_name; 1021 1022 if (!png_memcmp(chunk_name, png_IHDR, 4)) 1023 png_handle_IHDR(png_ptr, info_ptr, length); 1024 else if (!png_memcmp(chunk_name, png_IEND, 4)) 1025 png_handle_IEND(png_ptr, info_ptr, length); 1026 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED 1027 else if (png_handle_as_unknown(png_ptr, chunk_name)) 1028 { 1029 if (!png_memcmp(chunk_name, png_IDAT, 4)) 1030 { 1031 if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) 1032 png_error(png_ptr, "Too many IDAT's found"); 1033 } 1034 png_handle_unknown(png_ptr, info_ptr, length); 1035 if (!png_memcmp(chunk_name, png_PLTE, 4)) 1036 png_ptr->mode |= PNG_HAVE_PLTE; 1037 } 1038 #endif 1039 else if (!png_memcmp(chunk_name, png_IDAT, 4)) 1040 { 1041 /* Zero length IDATs are legal after the last IDAT has been 1042 * read, but not after other chunks have been read. 1043 */ 1044 if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) 1045 png_error(png_ptr, "Too many IDAT's found"); 1046 png_crc_finish(png_ptr, length); 1047 } 1048 else if (!png_memcmp(chunk_name, png_PLTE, 4)) 1049 png_handle_PLTE(png_ptr, info_ptr, length); 1050 #ifdef PNG_READ_bKGD_SUPPORTED 1051 else if (!png_memcmp(chunk_name, png_bKGD, 4)) 1052 png_handle_bKGD(png_ptr, info_ptr, length); 1053 #endif 1054 #ifdef PNG_READ_cHRM_SUPPORTED 1055 else if (!png_memcmp(chunk_name, png_cHRM, 4)) 1056 png_handle_cHRM(png_ptr, info_ptr, length); 1057 #endif 1058 #ifdef PNG_READ_gAMA_SUPPORTED 1059 else if (!png_memcmp(chunk_name, png_gAMA, 4)) 1060 png_handle_gAMA(png_ptr, info_ptr, length); 1061 #endif 1062 #ifdef PNG_READ_hIST_SUPPORTED 1063 else if (!png_memcmp(chunk_name, png_hIST, 4)) 1064 png_handle_hIST(png_ptr, info_ptr, length); 1065 #endif 1066 #ifdef PNG_READ_oFFs_SUPPORTED 1067 else if (!png_memcmp(chunk_name, png_oFFs, 4)) 1068 png_handle_oFFs(png_ptr, info_ptr, length); 1069 #endif 1070 #ifdef PNG_READ_pCAL_SUPPORTED 1071 else if (!png_memcmp(chunk_name, png_pCAL, 4)) 1072 png_handle_pCAL(png_ptr, info_ptr, length); 1073 #endif 1074 #ifdef PNG_READ_sCAL_SUPPORTED 1075 else if (!png_memcmp(chunk_name, png_sCAL, 4)) 1076 png_handle_sCAL(png_ptr, info_ptr, length); 1077 #endif 1078 #ifdef PNG_READ_pHYs_SUPPORTED 1079 else if (!png_memcmp(chunk_name, png_pHYs, 4)) 1080 png_handle_pHYs(png_ptr, info_ptr, length); 1081 #endif 1082 #ifdef PNG_READ_sBIT_SUPPORTED 1083 else if (!png_memcmp(chunk_name, png_sBIT, 4)) 1084 png_handle_sBIT(png_ptr, info_ptr, length); 1085 #endif 1086 #ifdef PNG_READ_sRGB_SUPPORTED 1087 else if (!png_memcmp(chunk_name, png_sRGB, 4)) 1088 png_handle_sRGB(png_ptr, info_ptr, length); 1089 #endif 1090 #ifdef PNG_READ_iCCP_SUPPORTED 1091 else if (!png_memcmp(chunk_name, png_iCCP, 4)) 1092 png_handle_iCCP(png_ptr, info_ptr, length); 1093 #endif 1094 #ifdef PNG_READ_sPLT_SUPPORTED 1095 else if (!png_memcmp(chunk_name, png_sPLT, 4)) 1096 png_handle_sPLT(png_ptr, info_ptr, length); 1097 #endif 1098 #ifdef PNG_READ_tEXt_SUPPORTED 1099 else if (!png_memcmp(chunk_name, png_tEXt, 4)) 1100 png_handle_tEXt(png_ptr, info_ptr, length); 1101 #endif 1102 #ifdef PNG_READ_tIME_SUPPORTED 1103 else if (!png_memcmp(chunk_name, png_tIME, 4)) 1104 png_handle_tIME(png_ptr, info_ptr, length); 1105 #endif 1106 #ifdef PNG_READ_tRNS_SUPPORTED 1107 else if (!png_memcmp(chunk_name, png_tRNS, 4)) 1108 png_handle_tRNS(png_ptr, info_ptr, length); 1109 #endif 1110 #ifdef PNG_READ_zTXt_SUPPORTED 1111 else if (!png_memcmp(chunk_name, png_zTXt, 4)) 1112 png_handle_zTXt(png_ptr, info_ptr, length); 1113 #endif 1114 #ifdef PNG_READ_iTXt_SUPPORTED 1115 else if (!png_memcmp(chunk_name, png_iTXt, 4)) 1116 png_handle_iTXt(png_ptr, info_ptr, length); 1117 #endif 1118 else 1119 png_handle_unknown(png_ptr, info_ptr, length); 1120 } while (!(png_ptr->mode & PNG_HAVE_IEND)); 1121 } 1122 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ 1123 1124 /* Free all memory used by the read */ 1125 void PNGAPI 1126 png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr, 1127 png_infopp end_info_ptr_ptr) 1128 { 1129 png_structp png_ptr = NULL; 1130 png_infop info_ptr = NULL, end_info_ptr = NULL; 1131 #ifdef PNG_USER_MEM_SUPPORTED 1132 png_free_ptr free_fn = NULL; 1133 png_voidp mem_ptr = NULL; 1134 #endif 1135 1136 png_debug(1, "in png_destroy_read_struct"); 1137 1138 if (png_ptr_ptr != NULL) 1139 png_ptr = *png_ptr_ptr; 1140 if (png_ptr == NULL) 1141 return; 1142 1143 #ifdef PNG_USER_MEM_SUPPORTED 1144 free_fn = png_ptr->free_fn; 1145 mem_ptr = png_ptr->mem_ptr; 1146 #endif 1147 1148 if (info_ptr_ptr != NULL) 1149 info_ptr = *info_ptr_ptr; 1150 1151 if (end_info_ptr_ptr != NULL) 1152 end_info_ptr = *end_info_ptr_ptr; 1153 1154 png_read_destroy(png_ptr, info_ptr, end_info_ptr); 1155 1156 if (info_ptr != NULL) 1157 { 1158 #ifdef PNG_TEXT_SUPPORTED 1159 png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1); 1160 #endif 1161 1162 #ifdef PNG_USER_MEM_SUPPORTED 1163 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn, 1164 (png_voidp)mem_ptr); 1165 #else 1166 png_destroy_struct((png_voidp)info_ptr); 1167 #endif 1168 *info_ptr_ptr = NULL; 1169 } 1170 1171 if (end_info_ptr != NULL) 1172 { 1173 #ifdef PNG_READ_TEXT_SUPPORTED 1174 png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1); 1175 #endif 1176 #ifdef PNG_USER_MEM_SUPPORTED 1177 png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn, 1178 (png_voidp)mem_ptr); 1179 #else 1180 png_destroy_struct((png_voidp)end_info_ptr); 1181 #endif 1182 *end_info_ptr_ptr = NULL; 1183 } 1184 1185 if (png_ptr != NULL) 1186 { 1187 #ifdef PNG_USER_MEM_SUPPORTED 1188 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn, 1189 (png_voidp)mem_ptr); 1190 #else 1191 png_destroy_struct((png_voidp)png_ptr); 1192 #endif 1193 *png_ptr_ptr = NULL; 1194 } 1195 } 1196 1197 /* Free all memory used by the read (old method) */ 1198 void /* PRIVATE */ 1199 png_read_destroy(png_structp png_ptr, png_infop info_ptr, 1200 png_infop end_info_ptr) 1201 { 1202 #ifdef PNG_SETJMP_SUPPORTED 1203 jmp_buf tmp_jmp; 1204 #endif 1205 png_error_ptr error_fn; 1206 png_error_ptr warning_fn; 1207 png_voidp error_ptr; 1208 #ifdef PNG_USER_MEM_SUPPORTED 1209 png_free_ptr free_fn; 1210 #endif 1211 1212 png_debug(1, "in png_read_destroy"); 1213 1214 if (info_ptr != NULL) 1215 png_info_destroy(png_ptr, info_ptr); 1216 1217 if (end_info_ptr != NULL) 1218 png_info_destroy(png_ptr, end_info_ptr); 1219 1220 png_free(png_ptr, png_ptr->zbuf); 1221 png_free(png_ptr, png_ptr->big_row_buf); 1222 png_free(png_ptr, png_ptr->prev_row); 1223 png_free(png_ptr, png_ptr->chunkdata); 1224 #ifdef PNG_READ_DITHER_SUPPORTED 1225 png_free(png_ptr, png_ptr->palette_lookup); 1226 png_free(png_ptr, png_ptr->dither_index); 1227 #endif 1228 #ifdef PNG_READ_GAMMA_SUPPORTED 1229 png_free(png_ptr, png_ptr->gamma_table); 1230 #endif 1231 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1232 png_free(png_ptr, png_ptr->gamma_from_1); 1233 png_free(png_ptr, png_ptr->gamma_to_1); 1234 #endif 1235 #ifdef PNG_FREE_ME_SUPPORTED 1236 if (png_ptr->free_me & PNG_FREE_PLTE) 1237 png_zfree(png_ptr, png_ptr->palette); 1238 png_ptr->free_me &= ~PNG_FREE_PLTE; 1239 #else 1240 if (png_ptr->flags & PNG_FLAG_FREE_PLTE) 1241 png_zfree(png_ptr, png_ptr->palette); 1242 png_ptr->flags &= ~PNG_FLAG_FREE_PLTE; 1243 #endif 1244 #if defined(PNG_tRNS_SUPPORTED) || \ 1245 defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) 1246 #ifdef PNG_FREE_ME_SUPPORTED 1247 if (png_ptr->free_me & PNG_FREE_TRNS) 1248 png_free(png_ptr, png_ptr->trans); 1249 png_ptr->free_me &= ~PNG_FREE_TRNS; 1250 #else 1251 if (png_ptr->flags & PNG_FLAG_FREE_TRNS) 1252 png_free(png_ptr, png_ptr->trans); 1253 png_ptr->flags &= ~PNG_FLAG_FREE_TRNS; 1254 #endif 1255 #endif 1256 #ifdef PNG_READ_hIST_SUPPORTED 1257 #ifdef PNG_FREE_ME_SUPPORTED 1258 if (png_ptr->free_me & PNG_FREE_HIST) 1259 png_free(png_ptr, png_ptr->hist); 1260 png_ptr->free_me &= ~PNG_FREE_HIST; 1261 #else 1262 if (png_ptr->flags & PNG_FLAG_FREE_HIST) 1263 png_free(png_ptr, png_ptr->hist); 1264 png_ptr->flags &= ~PNG_FLAG_FREE_HIST; 1265 #endif 1266 #endif 1267 #ifdef PNG_READ_GAMMA_SUPPORTED 1268 if (png_ptr->gamma_16_table != NULL) 1269 { 1270 int i; 1271 int istop = (1 << (8 - png_ptr->gamma_shift)); 1272 for (i = 0; i < istop; i++) 1273 { 1274 png_free(png_ptr, png_ptr->gamma_16_table[i]); 1275 } 1276 png_free(png_ptr, png_ptr->gamma_16_table); 1277 } 1278 #ifdef PNG_READ_BACKGROUND_SUPPORTED 1279 if (png_ptr->gamma_16_from_1 != NULL) 1280 { 1281 int i; 1282 int istop = (1 << (8 - png_ptr->gamma_shift)); 1283 for (i = 0; i < istop; i++) 1284 { 1285 png_free(png_ptr, png_ptr->gamma_16_from_1[i]); 1286 } 1287 png_free(png_ptr, png_ptr->gamma_16_from_1); 1288 } 1289 if (png_ptr->gamma_16_to_1 != NULL) 1290 { 1291 int i; 1292 int istop = (1 << (8 - png_ptr->gamma_shift)); 1293 for (i = 0; i < istop; i++) 1294 { 1295 png_free(png_ptr, png_ptr->gamma_16_to_1[i]); 1296 } 1297 png_free(png_ptr, png_ptr->gamma_16_to_1); 1298 } 1299 #endif 1300 #endif 1301 #ifdef PNG_TIME_RFC1123_SUPPORTED 1302 png_free(png_ptr, png_ptr->time_buffer); 1303 #endif 1304 1305 inflateEnd(&png_ptr->zstream); 1306 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 1307 png_free(png_ptr, png_ptr->save_buffer); 1308 #endif 1309 1310 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED 1311 #ifdef PNG_TEXT_SUPPORTED 1312 png_free(png_ptr, png_ptr->current_text); 1313 #endif /* PNG_TEXT_SUPPORTED */ 1314 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ 1315 1316 /* Save the important info out of the png_struct, in case it is 1317 * being used again. 1318 */ 1319 #ifdef PNG_SETJMP_SUPPORTED 1320 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf)); 1321 #endif 1322 1323 error_fn = png_ptr->error_fn; 1324 warning_fn = png_ptr->warning_fn; 1325 error_ptr = png_ptr->error_ptr; 1326 #ifdef PNG_USER_MEM_SUPPORTED 1327 free_fn = png_ptr->free_fn; 1328 #endif 1329 1330 png_memset(png_ptr, 0, png_sizeof(png_struct)); 1331 1332 png_ptr->error_fn = error_fn; 1333 png_ptr->warning_fn = warning_fn; 1334 png_ptr->error_ptr = error_ptr; 1335 #ifdef PNG_USER_MEM_SUPPORTED 1336 png_ptr->free_fn = free_fn; 1337 #endif 1338 1339 #ifdef PNG_SETJMP_SUPPORTED 1340 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf)); 1341 #endif 1342 1343 } 1344 1345 void PNGAPI 1346 png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn) 1347 { 1348 if (png_ptr == NULL) 1349 return; 1350 png_ptr->read_row_fn = read_row_fn; 1351 } 1352 1353 1354 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED 1355 #ifdef PNG_INFO_IMAGE_SUPPORTED 1356 void PNGAPI 1357 png_read_png(png_structp png_ptr, png_infop info_ptr, 1358 int transforms, 1359 voidp params) 1360 { 1361 int row; 1362 1363 if (png_ptr == NULL) 1364 return; 1365 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED 1366 /* Invert the alpha channel from opacity to transparency 1367 */ 1368 if (transforms & PNG_TRANSFORM_INVERT_ALPHA) 1369 png_set_invert_alpha(png_ptr); 1370 #endif 1371 1372 /* png_read_info() gives us all of the information from the 1373 * PNG file before the first IDAT (image data chunk). 1374 */ 1375 png_read_info(png_ptr, info_ptr); 1376 if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep)) 1377 png_error(png_ptr, "Image is too high to process with png_read_png()"); 1378 1379 /* -------------- image transformations start here ------------------- */ 1380 1381 #ifdef PNG_READ_16_TO_8_SUPPORTED 1382 /* Tell libpng to strip 16 bit/color files down to 8 bits per color. 1383 */ 1384 if (transforms & PNG_TRANSFORM_STRIP_16) 1385 png_set_strip_16(png_ptr); 1386 #endif 1387 1388 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED 1389 /* Strip alpha bytes from the input data without combining with 1390 * the background (not recommended). 1391 */ 1392 if (transforms & PNG_TRANSFORM_STRIP_ALPHA) 1393 png_set_strip_alpha(png_ptr); 1394 #endif 1395 1396 #if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED) 1397 /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single 1398 * byte into separate bytes (useful for paletted and grayscale images). 1399 */ 1400 if (transforms & PNG_TRANSFORM_PACKING) 1401 png_set_packing(png_ptr); 1402 #endif 1403 1404 #ifdef PNG_READ_PACKSWAP_SUPPORTED 1405 /* Change the order of packed pixels to least significant bit first 1406 * (not useful if you are using png_set_packing). 1407 */ 1408 if (transforms & PNG_TRANSFORM_PACKSWAP) 1409 png_set_packswap(png_ptr); 1410 #endif 1411 1412 #ifdef PNG_READ_EXPAND_SUPPORTED 1413 /* Expand paletted colors into true RGB triplets 1414 * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel 1415 * Expand paletted or RGB images with transparency to full alpha 1416 * channels so the data will be available as RGBA quartets. 1417 */ 1418 if (transforms & PNG_TRANSFORM_EXPAND) 1419 if ((png_ptr->bit_depth < 8) || 1420 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) || 1421 (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))) 1422 png_set_expand(png_ptr); 1423 #endif 1424 1425 /* We don't handle background color or gamma transformation or dithering. 1426 */ 1427 1428 #ifdef PNG_READ_INVERT_SUPPORTED 1429 /* Invert monochrome files to have 0 as white and 1 as black 1430 */ 1431 if (transforms & PNG_TRANSFORM_INVERT_MONO) 1432 png_set_invert_mono(png_ptr); 1433 #endif 1434 1435 #ifdef PNG_READ_SHIFT_SUPPORTED 1436 /* If you want to shift the pixel values from the range [0,255] or 1437 * [0,65535] to the original [0,7] or [0,31], or whatever range the 1438 * colors were originally in: 1439 */ 1440 if ((transforms & PNG_TRANSFORM_SHIFT) 1441 && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT)) 1442 { 1443 png_color_8p sig_bit; 1444 1445 png_get_sBIT(png_ptr, info_ptr, &sig_bit); 1446 png_set_shift(png_ptr, sig_bit); 1447 } 1448 #endif 1449 1450 #ifdef PNG_READ_BGR_SUPPORTED 1451 /* Flip the RGB pixels to BGR (or RGBA to BGRA) 1452 */ 1453 if (transforms & PNG_TRANSFORM_BGR) 1454 png_set_bgr(png_ptr); 1455 #endif 1456 1457 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED 1458 /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) 1459 */ 1460 if (transforms & PNG_TRANSFORM_SWAP_ALPHA) 1461 png_set_swap_alpha(png_ptr); 1462 #endif 1463 1464 #ifdef PNG_READ_SWAP_SUPPORTED 1465 /* Swap bytes of 16 bit files to least significant byte first 1466 */ 1467 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN) 1468 png_set_swap(png_ptr); 1469 #endif 1470 1471 /* Added at libpng-1.2.41 */ 1472 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED 1473 /* Invert the alpha channel from opacity to transparency 1474 */ 1475 if (transforms & PNG_TRANSFORM_INVERT_ALPHA) 1476 png_set_invert_alpha(png_ptr); 1477 #endif 1478 1479 /* Added at libpng-1.2.41 */ 1480 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED 1481 /* Expand grayscale image to RGB 1482 */ 1483 if (transforms & PNG_TRANSFORM_GRAY_TO_RGB) 1484 png_set_gray_to_rgb(png_ptr); 1485 #endif 1486 1487 /* We don't handle adding filler bytes */ 1488 1489 /* Optional call to gamma correct and add the background to the palette 1490 * and update info structure. REQUIRED if you are expecting libpng to 1491 * update the palette for you (i.e., you selected such a transform above). 1492 */ 1493 png_read_update_info(png_ptr, info_ptr); 1494 1495 /* -------------- image transformations end here ------------------- */ 1496 1497 #ifdef PNG_FREE_ME_SUPPORTED 1498 png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0); 1499 #endif 1500 if (info_ptr->row_pointers == NULL) 1501 { 1502 info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr, 1503 info_ptr->height * png_sizeof(png_bytep)); 1504 png_memset(info_ptr->row_pointers, 0, info_ptr->height 1505 * png_sizeof(png_bytep)); 1506 1507 #ifdef PNG_FREE_ME_SUPPORTED 1508 info_ptr->free_me |= PNG_FREE_ROWS; 1509 #endif 1510 1511 for (row = 0; row < (int)info_ptr->height; row++) 1512 info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr, 1513 png_get_rowbytes(png_ptr, info_ptr)); 1514 } 1515 1516 png_read_image(png_ptr, info_ptr->row_pointers); 1517 info_ptr->valid |= PNG_INFO_IDAT; 1518 1519 /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */ 1520 png_read_end(png_ptr, info_ptr); 1521 1522 transforms = transforms; /* Quiet compiler warnings */ 1523 params = params; 1524 1525 } 1526 #endif /* PNG_INFO_IMAGE_SUPPORTED */ 1527 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ 1528 #endif /* PNG_READ_SUPPORTED */ 1529
