pngread.c (46934B)
1 2 /* pngread.c - read a PNG file 3 * 4 * Last changed in libpng 1.2.48 [March 8, 2012] 5 * Copyright (c) 1998-2012 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 (png_get_valid(png_ptr, info_ptr, 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) 1428 && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT)) 1429 { 1430 png_color_8p sig_bit; 1431 1432 png_get_sBIT(png_ptr, info_ptr, &sig_bit); 1433 png_set_shift(png_ptr, sig_bit); 1434 } 1435 #endif 1436 1437 #ifdef PNG_READ_BGR_SUPPORTED 1438 /* Flip the RGB pixels to BGR (or RGBA to BGRA) 1439 */ 1440 if (transforms & PNG_TRANSFORM_BGR) 1441 png_set_bgr(png_ptr); 1442 #endif 1443 1444 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED 1445 /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) 1446 */ 1447 if (transforms & PNG_TRANSFORM_SWAP_ALPHA) 1448 png_set_swap_alpha(png_ptr); 1449 #endif 1450 1451 #ifdef PNG_READ_SWAP_SUPPORTED 1452 /* Swap bytes of 16 bit files to least significant byte first 1453 */ 1454 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN) 1455 png_set_swap(png_ptr); 1456 #endif 1457 1458 /* Added at libpng-1.2.41 */ 1459 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED 1460 /* Invert the alpha channel from opacity to transparency 1461 */ 1462 if (transforms & PNG_TRANSFORM_INVERT_ALPHA) 1463 png_set_invert_alpha(png_ptr); 1464 #endif 1465 1466 /* Added at libpng-1.2.41 */ 1467 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED 1468 /* Expand grayscale image to RGB 1469 */ 1470 if (transforms & PNG_TRANSFORM_GRAY_TO_RGB) 1471 png_set_gray_to_rgb(png_ptr); 1472 #endif 1473 1474 /* We don't handle adding filler bytes */ 1475 1476 /* Optional call to gamma correct and add the background to the palette 1477 * and update info structure. REQUIRED if you are expecting libpng to 1478 * update the palette for you (i.e., you selected such a transform above). 1479 */ 1480 png_read_update_info(png_ptr, info_ptr); 1481 1482 /* -------------- image transformations end here ------------------- */ 1483 1484 #ifdef PNG_FREE_ME_SUPPORTED 1485 png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0); 1486 #endif 1487 if (info_ptr->row_pointers == NULL) 1488 { 1489 info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr, 1490 info_ptr->height * png_sizeof(png_bytep)); 1491 png_memset(info_ptr->row_pointers, 0, info_ptr->height 1492 * png_sizeof(png_bytep)); 1493 1494 #ifdef PNG_FREE_ME_SUPPORTED 1495 info_ptr->free_me |= PNG_FREE_ROWS; 1496 #endif 1497 1498 for (row = 0; row < (int)info_ptr->height; row++) 1499 info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr, 1500 png_get_rowbytes(png_ptr, info_ptr)); 1501 } 1502 1503 png_read_image(png_ptr, info_ptr->row_pointers); 1504 info_ptr->valid |= PNG_INFO_IDAT; 1505 1506 /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */ 1507 png_read_end(png_ptr, info_ptr); 1508 1509 transforms = transforms; /* Quiet compiler warnings */ 1510 params = params; 1511 1512 } 1513 #endif /* PNG_INFO_IMAGE_SUPPORTED */ 1514 #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ 1515 #endif /* PNG_READ_SUPPORTED */