1 2 /* pngwrite.c - general routines to write a PNG file 3 * 4 * Last changed in libpng 1.6.32 [August 24, 2017] 5 * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson 6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) 7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) 8 * 9 * This code is released under the libpng license. 10 * For conditions of distribution and use, see the disclaimer 11 * and license in png.h 12 */ 13 14 #include "pngpriv.h" 15 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED 16 # include <errno.h> 17 #endif /* SIMPLIFIED_WRITE_STDIO */ 18 19 #ifdef PNG_WRITE_SUPPORTED 20 21 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED 22 /* Write out all the unknown chunks for the current given location */ 23 static void 24 write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr, 25 unsigned int where) 26 { 27 if (info_ptr->unknown_chunks_num != 0) 28 { 29 png_const_unknown_chunkp up; 30 31 png_debug(5, "writing extra chunks"); 32 33 for (up = info_ptr->unknown_chunks; 34 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num; 35 ++up) 36 if ((up->location & where) != 0) 37 { 38 /* If per-chunk unknown chunk handling is enabled use it, otherwise 39 * just write the chunks the application has set. 40 */ 41 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED 42 int keep = png_handle_as_unknown(png_ptr, up->name); 43 44 /* NOTE: this code is radically different from the read side in the 45 * matter of handling an ancillary unknown chunk. In the read side 46 * the default behavior is to discard it, in the code below the default 47 * behavior is to write it. Critical chunks are, however, only 48 * written if explicitly listed or if the default is set to write all 49 * unknown chunks. 50 * 51 * The default handling is also slightly weird - it is not possible to 52 * stop the writing of all unsafe-to-copy chunks! 53 * 54 * TODO: REVIEW: this would seem to be a bug. 55 */ 56 if (keep != PNG_HANDLE_CHUNK_NEVER && 57 ((up->name[3] & 0x20) /* safe-to-copy overrides everything */ || 58 keep == PNG_HANDLE_CHUNK_ALWAYS || 59 (keep == PNG_HANDLE_CHUNK_AS_DEFAULT && 60 png_ptr->unknown_default == PNG_HANDLE_CHUNK_ALWAYS))) 61 #endif 62 { 63 /* TODO: review, what is wrong with a zero length unknown chunk? */ 64 if (up->size == 0) 65 png_warning(png_ptr, "Writing zero-length unknown chunk"); 66 67 png_write_chunk(png_ptr, up->name, up->data, up->size); 68 } 69 } 70 } 71 } 72 #endif /* WRITE_UNKNOWN_CHUNKS */ 73 74 /* Writes all the PNG information. This is the suggested way to use the 75 * library. If you have a new chunk to add, make a function to write it, 76 * and put it in the correct location here. If you want the chunk written 77 * after the image data, put it in png_write_end(). I strongly encourage 78 * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing 79 * the chunk, as that will keep the code from breaking if you want to just 80 * write a plain PNG file. If you have long comments, I suggest writing 81 * them in png_write_end(), and compressing them. 82 */ 83 void PNGAPI 84 png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr) 85 { 86 png_debug(1, "in png_write_info_before_PLTE"); 87 88 if (png_ptr == NULL || info_ptr == NULL) 89 return; 90 91 if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0) 92 { 93 /* Write PNG signature */ 94 png_write_sig(png_ptr); 95 96 #ifdef PNG_MNG_FEATURES_SUPPORTED 97 if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 && \ 98 png_ptr->mng_features_permitted != 0) 99 { 100 png_warning(png_ptr, 101 "MNG features are not allowed in a PNG datastream"); 102 png_ptr->mng_features_permitted = 0; 103 } 104 #endif 105 106 /* Write IHDR information. */ 107 png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height, 108 info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type, 109 info_ptr->filter_type, 110 #ifdef PNG_WRITE_INTERLACING_SUPPORTED 111 info_ptr->interlace_type 112 #else 113 0 114 #endif 115 ); 116 117 /* The rest of these check to see if the valid field has the appropriate 118 * flag set, and if it does, writes the chunk. 119 * 120 * 1.6.0: COLORSPACE support controls the writing of these chunks too, and 121 * the chunks will be written if the WRITE routine is there and 122 * information * is available in the COLORSPACE. (See 123 * png_colorspace_sync_info in png.c for where the valid flags get set.) 124 * 125 * Under certain circumstances the colorspace can be invalidated without 126 * syncing the info_struct 'valid' flags; this happens if libpng detects 127 * an error and calls png_error while the color space is being set, yet 128 * the application continues writing the PNG. So check the 'invalid' 129 * flag here too. 130 */ 131 #ifdef PNG_GAMMA_SUPPORTED 132 # ifdef PNG_WRITE_gAMA_SUPPORTED 133 if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && 134 (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) != 0 && 135 (info_ptr->valid & PNG_INFO_gAMA) != 0) 136 png_write_gAMA_fixed(png_ptr, info_ptr->colorspace.gamma); 137 # endif 138 #endif 139 140 #ifdef PNG_COLORSPACE_SUPPORTED 141 /* Write only one of sRGB or an ICC profile. If a profile was supplied 142 * and it matches one of the known sRGB ones issue a warning. 143 */ 144 # ifdef PNG_WRITE_iCCP_SUPPORTED 145 if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && 146 (info_ptr->valid & PNG_INFO_iCCP) != 0) 147 { 148 # ifdef PNG_WRITE_sRGB_SUPPORTED 149 if ((info_ptr->valid & PNG_INFO_sRGB) != 0) 150 png_app_warning(png_ptr, 151 "profile matches sRGB but writing iCCP instead"); 152 # endif 153 154 png_write_iCCP(png_ptr, info_ptr->iccp_name, 155 info_ptr->iccp_profile); 156 } 157 # ifdef PNG_WRITE_sRGB_SUPPORTED 158 else 159 # endif 160 # endif 161 162 # ifdef PNG_WRITE_sRGB_SUPPORTED 163 if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && 164 (info_ptr->valid & PNG_INFO_sRGB) != 0) 165 png_write_sRGB(png_ptr, info_ptr->colorspace.rendering_intent); 166 # endif /* WRITE_sRGB */ 167 #endif /* COLORSPACE */ 168 169 #ifdef PNG_WRITE_sBIT_SUPPORTED 170 if ((info_ptr->valid & PNG_INFO_sBIT) != 0) 171 png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type); 172 #endif 173 174 #ifdef PNG_COLORSPACE_SUPPORTED 175 # ifdef PNG_WRITE_cHRM_SUPPORTED 176 if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && 177 (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0 && 178 (info_ptr->valid & PNG_INFO_cHRM) != 0) 179 png_write_cHRM_fixed(png_ptr, &info_ptr->colorspace.end_points_xy); 180 # endif 181 #endif 182 183 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED 184 write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_IHDR); 185 #endif 186 187 png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE; 188 } 189 } 190 191 void PNGAPI 192 png_write_info(png_structrp png_ptr, png_const_inforp info_ptr) 193 { 194 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) 195 int i; 196 #endif 197 198 png_debug(1, "in png_write_info"); 199 200 if (png_ptr == NULL || info_ptr == NULL) 201 return; 202 203 png_write_info_before_PLTE(png_ptr, info_ptr); 204 205 if ((info_ptr->valid & PNG_INFO_PLTE) != 0) 206 png_write_PLTE(png_ptr, info_ptr->palette, 207 (png_uint_32)info_ptr->num_palette); 208 209 else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) 210 png_error(png_ptr, "Valid palette required for paletted images"); 211 212 #ifdef PNG_WRITE_tRNS_SUPPORTED 213 if ((info_ptr->valid & PNG_INFO_tRNS) !=0) 214 { 215 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED 216 /* Invert the alpha channel (in tRNS) */ 217 if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0 && 218 info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) 219 { 220 int j, jend; 221 222 jend = info_ptr->num_trans; 223 if (jend > PNG_MAX_PALETTE_LENGTH) 224 jend = PNG_MAX_PALETTE_LENGTH; 225 226 for (j = 0; j<jend; ++j) 227 info_ptr->trans_alpha[j] = 228 (png_byte)(255 - info_ptr->trans_alpha[j]); 229 } 230 #endif 231 png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color), 232 info_ptr->num_trans, info_ptr->color_type); 233 } 234 #endif 235 #ifdef PNG_WRITE_bKGD_SUPPORTED 236 if ((info_ptr->valid & PNG_INFO_bKGD) != 0) 237 png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type); 238 #endif 239 240 #ifdef PNG_WRITE_eXIf_SUPPORTED 241 if ((info_ptr->valid & PNG_INFO_eXIf) != 0) 242 png_write_eXIf(png_ptr, info_ptr->exif, info_ptr->num_exif); 243 #endif 244 245 #ifdef PNG_WRITE_hIST_SUPPORTED 246 if ((info_ptr->valid & PNG_INFO_hIST) != 0) 247 png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette); 248 #endif 249 250 #ifdef PNG_WRITE_oFFs_SUPPORTED 251 if ((info_ptr->valid & PNG_INFO_oFFs) != 0) 252 png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset, 253 info_ptr->offset_unit_type); 254 #endif 255 256 #ifdef PNG_WRITE_pCAL_SUPPORTED 257 if ((info_ptr->valid & PNG_INFO_pCAL) != 0) 258 png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0, 259 info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams, 260 info_ptr->pcal_units, info_ptr->pcal_params); 261 #endif 262 263 #ifdef PNG_WRITE_sCAL_SUPPORTED 264 if ((info_ptr->valid & PNG_INFO_sCAL) != 0) 265 png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit, 266 info_ptr->scal_s_width, info_ptr->scal_s_height); 267 #endif /* sCAL */ 268 269 #ifdef PNG_WRITE_pHYs_SUPPORTED 270 if ((info_ptr->valid & PNG_INFO_pHYs) != 0) 271 png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit, 272 info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type); 273 #endif /* pHYs */ 274 275 #ifdef PNG_WRITE_tIME_SUPPORTED 276 if ((info_ptr->valid & PNG_INFO_tIME) != 0) 277 { 278 png_write_tIME(png_ptr, &(info_ptr->mod_time)); 279 png_ptr->mode |= PNG_WROTE_tIME; 280 } 281 #endif /* tIME */ 282 283 #ifdef PNG_WRITE_sPLT_SUPPORTED 284 if ((info_ptr->valid & PNG_INFO_sPLT) != 0) 285 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++) 286 png_write_sPLT(png_ptr, info_ptr->splt_palettes + i); 287 #endif /* sPLT */ 288 289 #ifdef PNG_WRITE_TEXT_SUPPORTED 290 /* Check to see if we need to write text chunks */ 291 for (i = 0; i < info_ptr->num_text; i++) 292 { 293 png_debug2(2, "Writing header text chunk %d, type %d", i, 294 info_ptr->text[i].compression); 295 /* An internationalized chunk? */ 296 if (info_ptr->text[i].compression > 0) 297 { 298 #ifdef PNG_WRITE_iTXt_SUPPORTED 299 /* Write international chunk */ 300 png_write_iTXt(png_ptr, 301 info_ptr->text[i].compression, 302 info_ptr->text[i].key, 303 info_ptr->text[i].lang, 304 info_ptr->text[i].lang_key, 305 info_ptr->text[i].text); 306 /* Mark this chunk as written */ 307 if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) 308 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; 309 else 310 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; 311 #else 312 png_warning(png_ptr, "Unable to write international text"); 313 #endif 314 } 315 316 /* If we want a compressed text chunk */ 317 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt) 318 { 319 #ifdef PNG_WRITE_zTXt_SUPPORTED 320 /* Write compressed chunk */ 321 png_write_zTXt(png_ptr, info_ptr->text[i].key, 322 info_ptr->text[i].text, info_ptr->text[i].compression); 323 /* Mark this chunk as written */ 324 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; 325 #else 326 png_warning(png_ptr, "Unable to write compressed text"); 327 #endif 328 } 329 330 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) 331 { 332 #ifdef PNG_WRITE_tEXt_SUPPORTED 333 /* Write uncompressed chunk */ 334 png_write_tEXt(png_ptr, info_ptr->text[i].key, 335 info_ptr->text[i].text, 336 0); 337 /* Mark this chunk as written */ 338 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; 339 #else 340 /* Can't get here */ 341 png_warning(png_ptr, "Unable to write uncompressed text"); 342 #endif 343 } 344 } 345 #endif /* tEXt */ 346 347 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED 348 write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE); 349 #endif 350 } 351 352 /* Writes the end of the PNG file. If you don't want to write comments or 353 * time information, you can pass NULL for info. If you already wrote these 354 * in png_write_info(), do not write them again here. If you have long 355 * comments, I suggest writing them here, and compressing them. 356 */ 357 void PNGAPI 358 png_write_end(png_structrp png_ptr, png_inforp info_ptr) 359 { 360 png_debug(1, "in png_write_end"); 361 362 if (png_ptr == NULL) 363 return; 364 365 if ((png_ptr->mode & PNG_HAVE_IDAT) == 0) 366 png_error(png_ptr, "No IDATs written into file"); 367 368 #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED 369 if (png_ptr->num_palette_max > png_ptr->num_palette) 370 png_benign_error(png_ptr, "Wrote palette index exceeding num_palette"); 371 #endif 372 373 /* See if user wants us to write information chunks */ 374 if (info_ptr != NULL) 375 { 376 #ifdef PNG_WRITE_TEXT_SUPPORTED 377 int i; /* local index variable */ 378 #endif 379 #ifdef PNG_WRITE_tIME_SUPPORTED 380 /* Check to see if user has supplied a time chunk */ 381 if ((info_ptr->valid & PNG_INFO_tIME) != 0 && 382 (png_ptr->mode & PNG_WROTE_tIME) == 0) 383 png_write_tIME(png_ptr, &(info_ptr->mod_time)); 384 385 #endif 386 #ifdef PNG_WRITE_TEXT_SUPPORTED 387 /* Loop through comment chunks */ 388 for (i = 0; i < info_ptr->num_text; i++) 389 { 390 png_debug2(2, "Writing trailer text chunk %d, type %d", i, 391 info_ptr->text[i].compression); 392 /* An internationalized chunk? */ 393 if (info_ptr->text[i].compression > 0) 394 { 395 #ifdef PNG_WRITE_iTXt_SUPPORTED 396 /* Write international chunk */ 397 png_write_iTXt(png_ptr, 398 info_ptr->text[i].compression, 399 info_ptr->text[i].key, 400 info_ptr->text[i].lang, 401 info_ptr->text[i].lang_key, 402 info_ptr->text[i].text); 403 /* Mark this chunk as written */ 404 if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) 405 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; 406 else 407 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; 408 #else 409 png_warning(png_ptr, "Unable to write international text"); 410 #endif 411 } 412 413 else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt) 414 { 415 #ifdef PNG_WRITE_zTXt_SUPPORTED 416 /* Write compressed chunk */ 417 png_write_zTXt(png_ptr, info_ptr->text[i].key, 418 info_ptr->text[i].text, info_ptr->text[i].compression); 419 /* Mark this chunk as written */ 420 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; 421 #else 422 png_warning(png_ptr, "Unable to write compressed text"); 423 #endif 424 } 425 426 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) 427 { 428 #ifdef PNG_WRITE_tEXt_SUPPORTED 429 /* Write uncompressed chunk */ 430 png_write_tEXt(png_ptr, info_ptr->text[i].key, 431 info_ptr->text[i].text, 0); 432 /* Mark this chunk as written */ 433 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; 434 #else 435 png_warning(png_ptr, "Unable to write uncompressed text"); 436 #endif 437 } 438 } 439 #endif 440 441 #ifdef PNG_WRITE_eXIf_SUPPORTED 442 if ((info_ptr->valid & PNG_INFO_eXIf) != 0) 443 png_write_eXIf(png_ptr, info_ptr->exif, info_ptr->num_exif); 444 #endif 445 446 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED 447 write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT); 448 #endif 449 } 450 451 png_ptr->mode |= PNG_AFTER_IDAT; 452 453 /* Write end of PNG file */ 454 png_write_IEND(png_ptr); 455 456 /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03, 457 * and restored again in libpng-1.2.30, may cause some applications that 458 * do not set png_ptr->output_flush_fn to crash. If your application 459 * experiences a problem, please try building libpng with 460 * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to 461 * png-mng-implement at lists.sf.net . 462 */ 463 #ifdef PNG_WRITE_FLUSH_SUPPORTED 464 # ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED 465 png_flush(png_ptr); 466 # endif 467 #endif 468 } 469 470 #ifdef PNG_CONVERT_tIME_SUPPORTED 471 void PNGAPI 472 png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm * ttime) 473 { 474 png_debug(1, "in png_convert_from_struct_tm"); 475 476 ptime->year = (png_uint_16)(1900 + ttime->tm_year); 477 ptime->month = (png_byte)(ttime->tm_mon + 1); 478 ptime->day = (png_byte)ttime->tm_mday; 479 ptime->hour = (png_byte)ttime->tm_hour; 480 ptime->minute = (png_byte)ttime->tm_min; 481 ptime->second = (png_byte)ttime->tm_sec; 482 } 483 484 void PNGAPI 485 png_convert_from_time_t(png_timep ptime, time_t ttime) 486 { 487 struct tm *tbuf; 488 489 png_debug(1, "in png_convert_from_time_t"); 490 491 tbuf = gmtime(&ttime); 492 png_convert_from_struct_tm(ptime, tbuf); 493 } 494 #endif 495 496 /* Initialize png_ptr structure, and allocate any memory needed */ 497 PNG_FUNCTION(png_structp,PNGAPI 498 png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr, 499 png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED) 500 { 501 #ifndef PNG_USER_MEM_SUPPORTED 502 png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr, 503 error_fn, warn_fn, NULL, NULL, NULL); 504 #else 505 return png_create_write_struct_2(user_png_ver, error_ptr, error_fn, 506 warn_fn, NULL, NULL, NULL); 507 } 508 509 /* Alternate initialize png_ptr structure, and allocate any memory needed */ 510 PNG_FUNCTION(png_structp,PNGAPI 511 png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, 512 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, 513 png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED) 514 { 515 png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr, 516 error_fn, warn_fn, mem_ptr, malloc_fn, free_fn); 517 #endif /* USER_MEM */ 518 if (png_ptr != NULL) 519 { 520 /* Set the zlib control values to defaults; they can be overridden by the 521 * application after the struct has been created. 522 */ 523 png_ptr->zbuffer_size = PNG_ZBUF_SIZE; 524 525 /* The 'zlib_strategy' setting is irrelevant because png_default_claim in 526 * pngwutil.c defaults it according to whether or not filters will be 527 * used, and ignores this setting. 528 */ 529 png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY; 530 png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION; 531 png_ptr->zlib_mem_level = 8; 532 png_ptr->zlib_window_bits = 15; 533 png_ptr->zlib_method = 8; 534 535 #ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED 536 png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY; 537 png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION; 538 png_ptr->zlib_text_mem_level = 8; 539 png_ptr->zlib_text_window_bits = 15; 540 png_ptr->zlib_text_method = 8; 541 #endif /* WRITE_COMPRESSED_TEXT */ 542 543 /* This is a highly dubious configuration option; by default it is off, 544 * but it may be appropriate for private builds that are testing 545 * extensions not conformant to the current specification, or of 546 * applications that must not fail to write at all costs! 547 */ 548 #ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED 549 /* In stable builds only warn if an application error can be completely 550 * handled. 551 */ 552 png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN; 553 #endif 554 555 /* App warnings are warnings in release (or release candidate) builds but 556 * are errors during development. 557 */ 558 #if PNG_RELEASE_BUILD 559 png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN; 560 #endif 561 562 /* TODO: delay this, it can be done in png_init_io() (if the app doesn't 563 * do it itself) avoiding setting the default function if it is not 564 * required. 565 */ 566 png_set_write_fn(png_ptr, NULL, NULL, NULL); 567 } 568 569 return png_ptr; 570 } 571 572 573 /* Write a few rows of image data. If the image is interlaced, 574 * either you will have to write the 7 sub images, or, if you 575 * have called png_set_interlace_handling(), you will have to 576 * "write" the image seven times. 577 */ 578 void PNGAPI 579 png_write_rows(png_structrp png_ptr, png_bytepp row, 580 png_uint_32 num_rows) 581 { 582 png_uint_32 i; /* row counter */ 583 png_bytepp rp; /* row pointer */ 584 585 png_debug(1, "in png_write_rows"); 586 587 if (png_ptr == NULL) 588 return; 589 590 /* Loop through the rows */ 591 for (i = 0, rp = row; i < num_rows; i++, rp++) 592 { 593 png_write_row(png_ptr, *rp); 594 } 595 } 596 597 /* Write the image. You only need to call this function once, even 598 * if you are writing an interlaced image. 599 */ 600 void PNGAPI 601 png_write_image(png_structrp png_ptr, png_bytepp image) 602 { 603 png_uint_32 i; /* row index */ 604 int pass, num_pass; /* pass variables */ 605 png_bytepp rp; /* points to current row */ 606 607 if (png_ptr == NULL) 608 return; 609 610 png_debug(1, "in png_write_image"); 611 612 #ifdef PNG_WRITE_INTERLACING_SUPPORTED 613 /* Initialize interlace handling. If image is not interlaced, 614 * this will set pass to 1 615 */ 616 num_pass = png_set_interlace_handling(png_ptr); 617 #else 618 num_pass = 1; 619 #endif 620 /* Loop through passes */ 621 for (pass = 0; pass < num_pass; pass++) 622 { 623 /* Loop through image */ 624 for (i = 0, rp = image; i < png_ptr->height; i++, rp++) 625 { 626 png_write_row(png_ptr, *rp); 627 } 628 } 629 } 630 631 #ifdef PNG_MNG_FEATURES_SUPPORTED 632 /* Performs intrapixel differencing */ 633 static void 634 png_do_write_intrapixel(png_row_infop row_info, png_bytep row) 635 { 636 png_debug(1, "in png_do_write_intrapixel"); 637 638 if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) 639 { 640 int bytes_per_pixel; 641 png_uint_32 row_width = row_info->width; 642 if (row_info->bit_depth == 8) 643 { 644 png_bytep rp; 645 png_uint_32 i; 646 647 if (row_info->color_type == PNG_COLOR_TYPE_RGB) 648 bytes_per_pixel = 3; 649 650 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) 651 bytes_per_pixel = 4; 652 653 else 654 return; 655 656 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) 657 { 658 *(rp) = (png_byte)(*rp - *(rp + 1)); 659 *(rp + 2) = (png_byte)(*(rp + 2) - *(rp + 1)); 660 } 661 } 662 663 #ifdef PNG_WRITE_16BIT_SUPPORTED 664 else if (row_info->bit_depth == 16) 665 { 666 png_bytep rp; 667 png_uint_32 i; 668 669 if (row_info->color_type == PNG_COLOR_TYPE_RGB) 670 bytes_per_pixel = 6; 671 672 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) 673 bytes_per_pixel = 8; 674 675 else 676 return; 677 678 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) 679 { 680 png_uint_32 s0 = (png_uint_32)(*(rp ) << 8) | *(rp + 1); 681 png_uint_32 s1 = (png_uint_32)(*(rp + 2) << 8) | *(rp + 3); 682 png_uint_32 s2 = (png_uint_32)(*(rp + 4) << 8) | *(rp + 5); 683 png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL); 684 png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL); 685 *(rp ) = (png_byte)(red >> 8); 686 *(rp + 1) = (png_byte)red; 687 *(rp + 4) = (png_byte)(blue >> 8); 688 *(rp + 5) = (png_byte)blue; 689 } 690 } 691 #endif /* WRITE_16BIT */ 692 } 693 } 694 #endif /* MNG_FEATURES */ 695 696 /* Called by user to write a row of image data */ 697 void PNGAPI 698 png_write_row(png_structrp png_ptr, png_const_bytep row) 699 { 700 /* 1.5.6: moved from png_struct to be a local structure: */ 701 png_row_info row_info; 702 703 if (png_ptr == NULL) 704 return; 705 706 png_debug2(1, "in png_write_row (row %u, pass %d)", 707 png_ptr->row_number, png_ptr->pass); 708 709 /* Initialize transformations and other stuff if first time */ 710 if (png_ptr->row_number == 0 && png_ptr->pass == 0) 711 { 712 /* Make sure we wrote the header info */ 713 if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0) 714 png_error(png_ptr, 715 "png_write_info was never called before png_write_row"); 716 717 /* Check for transforms that have been set but were defined out */ 718 #if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED) 719 if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) 720 png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined"); 721 #endif 722 723 #if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED) 724 if ((png_ptr->transformations & PNG_FILLER) != 0) 725 png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined"); 726 #endif 727 #if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \ 728 defined(PNG_READ_PACKSWAP_SUPPORTED) 729 if ((png_ptr->transformations & PNG_PACKSWAP) != 0) 730 png_warning(png_ptr, 731 "PNG_WRITE_PACKSWAP_SUPPORTED is not defined"); 732 #endif 733 734 #if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED) 735 if ((png_ptr->transformations & PNG_PACK) != 0) 736 png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined"); 737 #endif 738 739 #if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED) 740 if ((png_ptr->transformations & PNG_SHIFT) != 0) 741 png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined"); 742 #endif 743 744 #if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED) 745 if ((png_ptr->transformations & PNG_BGR) != 0) 746 png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined"); 747 #endif 748 749 #if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED) 750 if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) 751 png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined"); 752 #endif 753 754 png_write_start_row(png_ptr); 755 } 756 757 #ifdef PNG_WRITE_INTERLACING_SUPPORTED 758 /* If interlaced and not interested in row, return */ 759 if (png_ptr->interlaced != 0 && 760 (png_ptr->transformations & PNG_INTERLACE) != 0) 761 { 762 switch (png_ptr->pass) 763 { 764 case 0: 765 if ((png_ptr->row_number & 0x07) != 0) 766 { 767 png_write_finish_row(png_ptr); 768 return; 769 } 770 break; 771 772 case 1: 773 if ((png_ptr->row_number & 0x07) != 0 || png_ptr->width < 5) 774 { 775 png_write_finish_row(png_ptr); 776 return; 777 } 778 break; 779 780 case 2: 781 if ((png_ptr->row_number & 0x07) != 4) 782 { 783 png_write_finish_row(png_ptr); 784 return; 785 } 786 break; 787 788 case 3: 789 if ((png_ptr->row_number & 0x03) != 0 || png_ptr->width < 3) 790 { 791 png_write_finish_row(png_ptr); 792 return; 793 } 794 break; 795 796 case 4: 797 if ((png_ptr->row_number & 0x03) != 2) 798 { 799 png_write_finish_row(png_ptr); 800 return; 801 } 802 break; 803 804 case 5: 805 if ((png_ptr->row_number & 0x01) != 0 || png_ptr->width < 2) 806 { 807 png_write_finish_row(png_ptr); 808 return; 809 } 810 break; 811 812 case 6: 813 if ((png_ptr->row_number & 0x01) == 0) 814 { 815 png_write_finish_row(png_ptr); 816 return; 817 } 818 break; 819 820 default: /* error: ignore it */ 821 break; 822 } 823 } 824 #endif 825 826 /* Set up row info for transformations */ 827 row_info.color_type = png_ptr->color_type; 828 row_info.width = png_ptr->usr_width; 829 row_info.channels = png_ptr->usr_channels; 830 row_info.bit_depth = png_ptr->usr_bit_depth; 831 row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels); 832 row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); 833 834 png_debug1(3, "row_info->color_type = %d", row_info.color_type); 835 png_debug1(3, "row_info->width = %u", row_info.width); 836 png_debug1(3, "row_info->channels = %d", row_info.channels); 837 png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth); 838 png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth); 839 png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes); 840 841 /* Copy user's row into buffer, leaving room for filter byte. */ 842 memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes); 843 844 #ifdef PNG_WRITE_INTERLACING_SUPPORTED 845 /* Handle interlacing */ 846 if (png_ptr->interlaced && png_ptr->pass < 6 && 847 (png_ptr->transformations & PNG_INTERLACE) != 0) 848 { 849 png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass); 850 /* This should always get caught above, but still ... */ 851 if (row_info.width == 0) 852 { 853 png_write_finish_row(png_ptr); 854 return; 855 } 856 } 857 #endif 858 859 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED 860 /* Handle other transformations */ 861 if (png_ptr->transformations != 0) 862 png_do_write_transformations(png_ptr, &row_info); 863 #endif 864 865 /* At this point the row_info pixel depth must match the 'transformed' depth, 866 * which is also the output depth. 867 */ 868 if (row_info.pixel_depth != png_ptr->pixel_depth || 869 row_info.pixel_depth != png_ptr->transformed_pixel_depth) 870 png_error(png_ptr, "internal write transform logic error"); 871 872 #ifdef PNG_MNG_FEATURES_SUPPORTED 873 /* Write filter_method 64 (intrapixel differencing) only if 874 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and 875 * 2. Libpng did not write a PNG signature (this filter_method is only 876 * used in PNG datastreams that are embedded in MNG datastreams) and 877 * 3. The application called png_permit_mng_features with a mask that 878 * included PNG_FLAG_MNG_FILTER_64 and 879 * 4. The filter_method is 64 and 880 * 5. The color_type is RGB or RGBA 881 */ 882 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && 883 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) 884 { 885 /* Intrapixel differencing */ 886 png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1); 887 } 888 #endif 889 890 /* Added at libpng-1.5.10 */ 891 #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED 892 /* Check for out-of-range palette index */ 893 if (row_info.color_type == PNG_COLOR_TYPE_PALETTE && 894 png_ptr->num_palette_max >= 0) 895 png_do_check_palette_indexes(png_ptr, &row_info); 896 #endif 897 898 /* Find a filter if necessary, filter the row and write it out. */ 899 png_write_find_filter(png_ptr, &row_info); 900 901 if (png_ptr->write_row_fn != NULL) 902 (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); 903 } 904 905 #ifdef PNG_WRITE_FLUSH_SUPPORTED 906 /* Set the automatic flush interval or 0 to turn flushing off */ 907 void PNGAPI 908 png_set_flush(png_structrp png_ptr, int nrows) 909 { 910 png_debug(1, "in png_set_flush"); 911 912 if (png_ptr == NULL) 913 return; 914 915 png_ptr->flush_dist = (nrows < 0 ? 0 : (png_uint_32)nrows); 916 } 917 918 /* Flush the current output buffers now */ 919 void PNGAPI 920 png_write_flush(png_structrp png_ptr) 921 { 922 png_debug(1, "in png_write_flush"); 923 924 if (png_ptr == NULL) 925 return; 926 927 /* We have already written out all of the data */ 928 if (png_ptr->row_number >= png_ptr->num_rows) 929 return; 930 931 png_compress_IDAT(png_ptr, NULL, 0, Z_SYNC_FLUSH); 932 png_ptr->flush_rows = 0; 933 png_flush(png_ptr); 934 } 935 #endif /* WRITE_FLUSH */ 936 937 /* Free any memory used in png_ptr struct without freeing the struct itself. */ 938 static void 939 png_write_destroy(png_structrp png_ptr) 940 { 941 png_debug(1, "in png_write_destroy"); 942 943 /* Free any memory zlib uses */ 944 if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0) 945 deflateEnd(&png_ptr->zstream); 946 947 /* Free our memory. png_free checks NULL for us. */ 948 png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list); 949 png_free(png_ptr, png_ptr->row_buf); 950 png_ptr->row_buf = NULL; 951 #ifdef PNG_WRITE_FILTER_SUPPORTED 952 png_free(png_ptr, png_ptr->prev_row); 953 png_free(png_ptr, png_ptr->try_row); 954 png_free(png_ptr, png_ptr->tst_row); 955 png_ptr->prev_row = NULL; 956 png_ptr->try_row = NULL; 957 png_ptr->tst_row = NULL; 958 #endif 959 960 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED 961 png_free(png_ptr, png_ptr->chunk_list); 962 png_ptr->chunk_list = NULL; 963 #endif 964 965 /* The error handling and memory handling information is left intact at this 966 * point: the jmp_buf may still have to be freed. See png_destroy_png_struct 967 * for how this happens. 968 */ 969 } 970 971 /* Free all memory used by the write. 972 * In libpng 1.6.0 this API changed quietly to no longer accept a NULL value for 973 * *png_ptr_ptr. Prior to 1.6.0 it would accept such a value and it would free 974 * the passed in info_structs but it would quietly fail to free any of the data 975 * inside them. In 1.6.0 it quietly does nothing (it has to be quiet because it 976 * has no png_ptr.) 977 */ 978 void PNGAPI 979 png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr) 980 { 981 png_debug(1, "in png_destroy_write_struct"); 982 983 if (png_ptr_ptr != NULL) 984 { 985 png_structrp png_ptr = *png_ptr_ptr; 986 987 if (png_ptr != NULL) /* added in libpng 1.6.0 */ 988 { 989 png_destroy_info_struct(png_ptr, info_ptr_ptr); 990 991 *png_ptr_ptr = NULL; 992 png_write_destroy(png_ptr); 993 png_destroy_png_struct(png_ptr); 994 } 995 } 996 } 997 998 /* Allow the application to select one or more row filters to use. */ 999 void PNGAPI 1000 png_set_filter(png_structrp png_ptr, int method, int filters) 1001 { 1002 png_debug(1, "in png_set_filter"); 1003 1004 if (png_ptr == NULL) 1005 return; 1006 1007 #ifdef PNG_MNG_FEATURES_SUPPORTED 1008 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && 1009 (method == PNG_INTRAPIXEL_DIFFERENCING)) 1010 method = PNG_FILTER_TYPE_BASE; 1011 1012 #endif 1013 if (method == PNG_FILTER_TYPE_BASE) 1014 { 1015 switch (filters & (PNG_ALL_FILTERS | 0x07)) 1016 { 1017 #ifdef PNG_WRITE_FILTER_SUPPORTED 1018 case 5: 1019 case 6: 1020 case 7: png_app_error(png_ptr, "Unknown row filter for method 0"); 1021 #endif /* WRITE_FILTER */ 1022 /* FALLTHROUGH */ 1023 case PNG_FILTER_VALUE_NONE: 1024 png_ptr->do_filter = PNG_FILTER_NONE; break; 1025 1026 #ifdef PNG_WRITE_FILTER_SUPPORTED 1027 case PNG_FILTER_VALUE_SUB: 1028 png_ptr->do_filter = PNG_FILTER_SUB; break; 1029 1030 case PNG_FILTER_VALUE_UP: 1031 png_ptr->do_filter = PNG_FILTER_UP; break; 1032 1033 case PNG_FILTER_VALUE_AVG: 1034 png_ptr->do_filter = PNG_FILTER_AVG; break; 1035 1036 case PNG_FILTER_VALUE_PAETH: 1037 png_ptr->do_filter = PNG_FILTER_PAETH; break; 1038 1039 default: 1040 png_ptr->do_filter = (png_byte)filters; break; 1041 #else 1042 default: 1043 png_app_error(png_ptr, "Unknown row filter for method 0"); 1044 #endif /* WRITE_FILTER */ 1045 } 1046 1047 #ifdef PNG_WRITE_FILTER_SUPPORTED 1048 /* If we have allocated the row_buf, this means we have already started 1049 * with the image and we should have allocated all of the filter buffers 1050 * that have been selected. If prev_row isn't already allocated, then 1051 * it is too late to start using the filters that need it, since we 1052 * will be missing the data in the previous row. If an application 1053 * wants to start and stop using particular filters during compression, 1054 * it should start out with all of the filters, and then remove them 1055 * or add them back after the start of compression. 1056 * 1057 * NOTE: this is a nasty constraint on the code, because it means that the 1058 * prev_row buffer must be maintained even if there are currently no 1059 * 'prev_row' requiring filters active. 1060 */ 1061 if (png_ptr->row_buf != NULL) 1062 { 1063 int num_filters; 1064 png_alloc_size_t buf_size; 1065 1066 /* Repeat the checks in png_write_start_row; 1 pixel high or wide 1067 * images cannot benefit from certain filters. If this isn't done here 1068 * the check below will fire on 1 pixel high images. 1069 */ 1070 if (png_ptr->height == 1) 1071 filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); 1072 1073 if (png_ptr->width == 1) 1074 filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH); 1075 1076 if ((filters & (PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH)) != 0 1077 && png_ptr->prev_row == NULL) 1078 { 1079 /* This is the error case, however it is benign - the previous row 1080 * is not available so the filter can't be used. Just warn here. 1081 */ 1082 png_app_warning(png_ptr, 1083 "png_set_filter: UP/AVG/PAETH cannot be added after start"); 1084 filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); 1085 } 1086 1087 num_filters = 0; 1088 1089 if (filters & PNG_FILTER_SUB) 1090 num_filters++; 1091 1092 if (filters & PNG_FILTER_UP) 1093 num_filters++; 1094 1095 if (filters & PNG_FILTER_AVG) 1096 num_filters++; 1097 1098 if (filters & PNG_FILTER_PAETH) 1099 num_filters++; 1100 1101 /* Allocate needed row buffers if they have not already been 1102 * allocated. 1103 */ 1104 buf_size = PNG_ROWBYTES(png_ptr->usr_channels * png_ptr->usr_bit_depth, 1105 png_ptr->width) + 1; 1106 1107 if (png_ptr->try_row == NULL) 1108 png_ptr->try_row = png_voidcast(png_bytep, 1109 png_malloc(png_ptr, buf_size)); 1110 1111 if (num_filters > 1) 1112 { 1113 if (png_ptr->tst_row == NULL) 1114 png_ptr->tst_row = png_voidcast(png_bytep, 1115 png_malloc(png_ptr, buf_size)); 1116 } 1117 } 1118 png_ptr->do_filter = (png_byte)filters; 1119 #endif 1120 } 1121 else 1122 png_error(png_ptr, "Unknown custom filter method"); 1123 } 1124 1125 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ 1126 /* Provide floating and fixed point APIs */ 1127 #ifdef PNG_FLOATING_POINT_SUPPORTED 1128 void PNGAPI 1129 png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method, 1130 int num_weights, png_const_doublep filter_weights, 1131 png_const_doublep filter_costs) 1132 { 1133 PNG_UNUSED(png_ptr) 1134 PNG_UNUSED(heuristic_method) 1135 PNG_UNUSED(num_weights) 1136 PNG_UNUSED(filter_weights) 1137 PNG_UNUSED(filter_costs) 1138 } 1139 #endif /* FLOATING_POINT */ 1140 1141 #ifdef PNG_FIXED_POINT_SUPPORTED 1142 void PNGAPI 1143 png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method, 1144 int num_weights, png_const_fixed_point_p filter_weights, 1145 png_const_fixed_point_p filter_costs) 1146 { 1147 PNG_UNUSED(png_ptr) 1148 PNG_UNUSED(heuristic_method) 1149 PNG_UNUSED(num_weights) 1150 PNG_UNUSED(filter_weights) 1151 PNG_UNUSED(filter_costs) 1152 } 1153 #endif /* FIXED_POINT */ 1154 #endif /* WRITE_WEIGHTED_FILTER */ 1155 1156 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED 1157 void PNGAPI 1158 png_set_compression_level(png_structrp png_ptr, int level) 1159 { 1160 png_debug(1, "in png_set_compression_level"); 1161 1162 if (png_ptr == NULL) 1163 return; 1164 1165 png_ptr->zlib_level = level; 1166 } 1167 1168 void PNGAPI 1169 png_set_compression_mem_level(png_structrp png_ptr, int mem_level) 1170 { 1171 png_debug(1, "in png_set_compression_mem_level"); 1172 1173 if (png_ptr == NULL) 1174 return; 1175 1176 png_ptr->zlib_mem_level = mem_level; 1177 } 1178 1179 void PNGAPI 1180 png_set_compression_strategy(png_structrp png_ptr, int strategy) 1181 { 1182 png_debug(1, "in png_set_compression_strategy"); 1183 1184 if (png_ptr == NULL) 1185 return; 1186 1187 /* The flag setting here prevents the libpng dynamic selection of strategy. 1188 */ 1189 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY; 1190 png_ptr->zlib_strategy = strategy; 1191 } 1192 1193 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1194 * smaller value of window_bits if it can do so safely. 1195 */ 1196 void PNGAPI 1197 png_set_compression_window_bits(png_structrp png_ptr, int window_bits) 1198 { 1199 if (png_ptr == NULL) 1200 return; 1201 1202 /* Prior to 1.6.0 this would warn but then set the window_bits value. This 1203 * meant that negative window bits values could be selected that would cause 1204 * libpng to write a non-standard PNG file with raw deflate or gzip 1205 * compressed IDAT or ancillary chunks. Such files can be read and there is 1206 * no warning on read, so this seems like a very bad idea. 1207 */ 1208 if (window_bits > 15) 1209 { 1210 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); 1211 window_bits = 15; 1212 } 1213 1214 else if (window_bits < 8) 1215 { 1216 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG"); 1217 window_bits = 8; 1218 } 1219 1220 png_ptr->zlib_window_bits = window_bits; 1221 } 1222 1223 void PNGAPI 1224 png_set_compression_method(png_structrp png_ptr, int method) 1225 { 1226 png_debug(1, "in png_set_compression_method"); 1227 1228 if (png_ptr == NULL) 1229 return; 1230 1231 /* This would produce an invalid PNG file if it worked, but it doesn't and 1232 * deflate will fault it, so it is harmless to just warn here. 1233 */ 1234 if (method != 8) 1235 png_warning(png_ptr, "Only compression method 8 is supported by PNG"); 1236 1237 png_ptr->zlib_method = method; 1238 } 1239 #endif /* WRITE_CUSTOMIZE_COMPRESSION */ 1240 1241 /* The following were added to libpng-1.5.4 */ 1242 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED 1243 void PNGAPI 1244 png_set_text_compression_level(png_structrp png_ptr, int level) 1245 { 1246 png_debug(1, "in png_set_text_compression_level"); 1247 1248 if (png_ptr == NULL) 1249 return; 1250 1251 png_ptr->zlib_text_level = level; 1252 } 1253 1254 void PNGAPI 1255 png_set_text_compression_mem_level(png_structrp png_ptr, int mem_level) 1256 { 1257 png_debug(1, "in png_set_text_compression_mem_level"); 1258 1259 if (png_ptr == NULL) 1260 return; 1261 1262 png_ptr->zlib_text_mem_level = mem_level; 1263 } 1264 1265 void PNGAPI 1266 png_set_text_compression_strategy(png_structrp png_ptr, int strategy) 1267 { 1268 png_debug(1, "in png_set_text_compression_strategy"); 1269 1270 if (png_ptr == NULL) 1271 return; 1272 1273 png_ptr->zlib_text_strategy = strategy; 1274 } 1275 1276 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1277 * smaller value of window_bits if it can do so safely. 1278 */ 1279 void PNGAPI 1280 png_set_text_compression_window_bits(png_structrp png_ptr, int window_bits) 1281 { 1282 if (png_ptr == NULL) 1283 return; 1284 1285 if (window_bits > 15) 1286 { 1287 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); 1288 window_bits = 15; 1289 } 1290 1291 else if (window_bits < 8) 1292 { 1293 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG"); 1294 window_bits = 8; 1295 } 1296 1297 png_ptr->zlib_text_window_bits = window_bits; 1298 } 1299 1300 void PNGAPI 1301 png_set_text_compression_method(png_structrp png_ptr, int method) 1302 { 1303 png_debug(1, "in png_set_text_compression_method"); 1304 1305 if (png_ptr == NULL) 1306 return; 1307 1308 if (method != 8) 1309 png_warning(png_ptr, "Only compression method 8 is supported by PNG"); 1310 1311 png_ptr->zlib_text_method = method; 1312 } 1313 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ 1314 /* end of API added to libpng-1.5.4 */ 1315 1316 void PNGAPI 1317 png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn) 1318 { 1319 if (png_ptr == NULL) 1320 return; 1321 1322 png_ptr->write_row_fn = write_row_fn; 1323 } 1324 1325 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 1326 void PNGAPI 1327 png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr 1328 write_user_transform_fn) 1329 { 1330 png_debug(1, "in png_set_write_user_transform_fn"); 1331 1332 if (png_ptr == NULL) 1333 return; 1334 1335 png_ptr->transformations |= PNG_USER_TRANSFORM; 1336 png_ptr->write_user_transform_fn = write_user_transform_fn; 1337 } 1338 #endif 1339 1340 1341 #ifdef PNG_INFO_IMAGE_SUPPORTED 1342 void PNGAPI 1343 png_write_png(png_structrp png_ptr, png_inforp info_ptr, 1344 int transforms, voidp params) 1345 { 1346 if (png_ptr == NULL || info_ptr == NULL) 1347 return; 1348 1349 if ((info_ptr->valid & PNG_INFO_IDAT) == 0) 1350 { 1351 png_app_error(png_ptr, "no rows for png_write_image to write"); 1352 return; 1353 } 1354 1355 /* Write the file header information. */ 1356 png_write_info(png_ptr, info_ptr); 1357 1358 /* ------ these transformations don't touch the info structure ------- */ 1359 1360 /* Invert monochrome pixels */ 1361 if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0) 1362 #ifdef PNG_WRITE_INVERT_SUPPORTED 1363 png_set_invert_mono(png_ptr); 1364 #else 1365 png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported"); 1366 #endif 1367 1368 /* Shift the pixels up to a legal bit depth and fill in 1369 * as appropriate to correctly scale the image. 1370 */ 1371 if ((transforms & PNG_TRANSFORM_SHIFT) != 0) 1372 #ifdef PNG_WRITE_SHIFT_SUPPORTED 1373 if ((info_ptr->valid & PNG_INFO_sBIT) != 0) 1374 png_set_shift(png_ptr, &info_ptr->sig_bit); 1375 #else 1376 png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported"); 1377 #endif 1378 1379 /* Pack pixels into bytes */ 1380 if ((transforms & PNG_TRANSFORM_PACKING) != 0) 1381 #ifdef PNG_WRITE_PACK_SUPPORTED 1382 png_set_packing(png_ptr); 1383 #else 1384 png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported"); 1385 #endif 1386 1387 /* Swap location of alpha bytes from ARGB to RGBA */ 1388 if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0) 1389 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED 1390 png_set_swap_alpha(png_ptr); 1391 #else 1392 png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported"); 1393 #endif 1394 1395 /* Remove a filler (X) from XRGB/RGBX/AG/GA into to convert it into 1396 * RGB, note that the code expects the input color type to be G or RGB; no 1397 * alpha channel. 1398 */ 1399 if ((transforms & (PNG_TRANSFORM_STRIP_FILLER_AFTER| 1400 PNG_TRANSFORM_STRIP_FILLER_BEFORE)) != 0) 1401 { 1402 #ifdef PNG_WRITE_FILLER_SUPPORTED 1403 if ((transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) != 0) 1404 { 1405 if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0) 1406 png_app_error(png_ptr, 1407 "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported"); 1408 1409 /* Continue if ignored - this is the pre-1.6.10 behavior */ 1410 png_set_filler(png_ptr, 0, PNG_FILLER_AFTER); 1411 } 1412 1413 else if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0) 1414 png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); 1415 #else 1416 png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_FILLER not supported"); 1417 #endif 1418 } 1419 1420 /* Flip BGR pixels to RGB */ 1421 if ((transforms & PNG_TRANSFORM_BGR) != 0) 1422 #ifdef PNG_WRITE_BGR_SUPPORTED 1423 png_set_bgr(png_ptr); 1424 #else 1425 png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported"); 1426 #endif 1427 1428 /* Swap bytes of 16-bit files to most significant byte first */ 1429 if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0) 1430 #ifdef PNG_WRITE_SWAP_SUPPORTED 1431 png_set_swap(png_ptr); 1432 #else 1433 png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported"); 1434 #endif 1435 1436 /* Swap bits of 1-bit, 2-bit, 4-bit packed pixel formats */ 1437 if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0) 1438 #ifdef PNG_WRITE_PACKSWAP_SUPPORTED 1439 png_set_packswap(png_ptr); 1440 #else 1441 png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported"); 1442 #endif 1443 1444 /* Invert the alpha channel from opacity to transparency */ 1445 if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0) 1446 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED 1447 png_set_invert_alpha(png_ptr); 1448 #else 1449 png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported"); 1450 #endif 1451 1452 /* ----------------------- end of transformations ------------------- */ 1453 1454 /* Write the bits */ 1455 png_write_image(png_ptr, info_ptr->row_pointers); 1456 1457 /* It is REQUIRED to call this to finish writing the rest of the file */ 1458 png_write_end(png_ptr, info_ptr); 1459 1460 PNG_UNUSED(params) 1461 } 1462 #endif 1463 1464 1465 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED 1466 /* Initialize the write structure - general purpose utility. */ 1467 static int 1468 png_image_write_init(png_imagep image) 1469 { 1470 png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image, 1471 png_safe_error, png_safe_warning); 1472 1473 if (png_ptr != NULL) 1474 { 1475 png_infop info_ptr = png_create_info_struct(png_ptr); 1476 1477 if (info_ptr != NULL) 1478 { 1479 png_controlp control = png_voidcast(png_controlp, 1480 png_malloc_warn(png_ptr, (sizeof *control))); 1481 1482 if (control != NULL) 1483 { 1484 memset(control, 0, (sizeof *control)); 1485 1486 control->png_ptr = png_ptr; 1487 control->info_ptr = info_ptr; 1488 control->for_write = 1; 1489 1490 image->opaque = control; 1491 return 1; 1492 } 1493 1494 /* Error clean up */ 1495 png_destroy_info_struct(png_ptr, &info_ptr); 1496 } 1497 1498 png_destroy_write_struct(&png_ptr, NULL); 1499 } 1500 1501 return png_image_error(image, "png_image_write_: out of memory"); 1502 } 1503 1504 /* Arguments to png_image_write_main: */ 1505 typedef struct 1506 { 1507 /* Arguments: */ 1508 png_imagep image; 1509 png_const_voidp buffer; 1510 png_int_32 row_stride; 1511 png_const_voidp colormap; 1512 int convert_to_8bit; 1513 /* Local variables: */ 1514 png_const_voidp first_row; 1515 ptrdiff_t row_bytes; 1516 png_voidp local_row; 1517 /* Byte count for memory writing */ 1518 png_bytep memory; 1519 png_alloc_size_t memory_bytes; /* not used for STDIO */ 1520 png_alloc_size_t output_bytes; /* running total */ 1521 } png_image_write_control; 1522 1523 /* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to 1524 * do any necessary byte swapping. The component order is defined by the 1525 * png_image format value. 1526 */ 1527 static int 1528 png_write_image_16bit(png_voidp argument) 1529 { 1530 png_image_write_control *display = png_voidcast(png_image_write_control*, 1531 argument); 1532 png_imagep image = display->image; 1533 png_structrp png_ptr = image->opaque->png_ptr; 1534 1535 png_const_uint_16p input_row = png_voidcast(png_const_uint_16p, 1536 display->first_row); 1537 png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row); 1538 png_uint_16p row_end; 1539 const unsigned int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 1540 3 : 1; 1541 int aindex = 0; 1542 png_uint_32 y = image->height; 1543 1544 if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0) 1545 { 1546 # ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED 1547 if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0) 1548 { 1549 aindex = -1; 1550 ++input_row; /* To point to the first component */ 1551 ++output_row; 1552 } 1553 else 1554 aindex = (int)channels; 1555 # else 1556 aindex = (int)channels; 1557 # endif 1558 } 1559 1560 else 1561 png_error(png_ptr, "png_write_image: internal call error"); 1562 1563 /* Work out the output row end and count over this, note that the increment 1564 * above to 'row' means that row_end can actually be beyond the end of the 1565 * row; this is correct. 1566 */ 1567 row_end = output_row + image->width * (channels+1); 1568 1569 for (; y > 0; --y) 1570 { 1571 png_const_uint_16p in_ptr = input_row; 1572 png_uint_16p out_ptr = output_row; 1573 1574 while (out_ptr < row_end) 1575 { 1576 const png_uint_16 alpha = in_ptr[aindex]; 1577 png_uint_32 reciprocal = 0; 1578 int c; 1579 1580 out_ptr[aindex] = alpha; 1581 1582 /* Calculate a reciprocal. The correct calculation is simply 1583 * component/alpha*65535 << 15. (I.e. 15 bits of precision); this 1584 * allows correct rounding by adding .5 before the shift. 'reciprocal' 1585 * is only initialized when required. 1586 */ 1587 if (alpha > 0 && alpha < 65535) 1588 reciprocal = ((0xffff<<15)+(alpha>>1))/alpha; 1589 1590 c = (int)channels; 1591 do /* always at least one channel */ 1592 { 1593 png_uint_16 component = *in_ptr++; 1594 1595 /* The following gives 65535 for an alpha of 0, which is fine, 1596 * otherwise if 0/0 is represented as some other value there is more 1597 * likely to be a discontinuity which will probably damage 1598 * compression when moving from a fully transparent area to a 1599 * nearly transparent one. (The assumption here is that opaque 1600 * areas tend not to be 0 intensity.) 1601 */ 1602 if (component >= alpha) 1603 component = 65535; 1604 1605 /* component<alpha, so component/alpha is less than one and 1606 * component*reciprocal is less than 2^31. 1607 */ 1608 else if (component > 0 && alpha < 65535) 1609 { 1610 png_uint_32 calc = component * reciprocal; 1611 calc += 16384; /* round to nearest */ 1612 component = (png_uint_16)(calc >> 15); 1613 } 1614 1615 *out_ptr++ = component; 1616 } 1617 while (--c > 0); 1618 1619 /* Skip to next component (skip the intervening alpha channel) */ 1620 ++in_ptr; 1621 ++out_ptr; 1622 } 1623 1624 png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row)); 1625 input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16)); 1626 } 1627 1628 return 1; 1629 } 1630 1631 /* Given 16-bit input (1 to 4 channels) write 8-bit output. If an alpha channel 1632 * is present it must be removed from the components, the components are then 1633 * written in sRGB encoding. No components are added or removed. 1634 * 1635 * Calculate an alpha reciprocal to reverse pre-multiplication. As above the 1636 * calculation can be done to 15 bits of accuracy; however, the output needs to 1637 * be scaled in the range 0..255*65535, so include that scaling here. 1638 */ 1639 # define UNP_RECIPROCAL(alpha) ((((0xffff*0xff)<<7)+(alpha>>1))/alpha) 1640 1641 static png_byte 1642 png_unpremultiply(png_uint_32 component, png_uint_32 alpha, 1643 png_uint_32 reciprocal/*from the above macro*/) 1644 { 1645 /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0 1646 * is represented as some other value there is more likely to be a 1647 * discontinuity which will probably damage compression when moving from a 1648 * fully transparent area to a nearly transparent one. (The assumption here 1649 * is that opaque areas tend not to be 0 intensity.) 1650 * 1651 * There is a rounding problem here; if alpha is less than 128 it will end up 1652 * as 0 when scaled to 8 bits. To avoid introducing spurious colors into the 1653 * output change for this too. 1654 */ 1655 if (component >= alpha || alpha < 128) 1656 return 255; 1657 1658 /* component<alpha, so component/alpha is less than one and 1659 * component*reciprocal is less than 2^31. 1660 */ 1661 else if (component > 0) 1662 { 1663 /* The test is that alpha/257 (rounded) is less than 255, the first value 1664 * that becomes 255 is 65407. 1665 * NOTE: this must agree with the PNG_DIV257 macro (which must, therefore, 1666 * be exact!) [Could also test reciprocal != 0] 1667 */ 1668 if (alpha < 65407) 1669 { 1670 component *= reciprocal; 1671 component += 64; /* round to nearest */ 1672 component >>= 7; 1673 } 1674 1675 else 1676 component *= 255; 1677 1678 /* Convert the component to sRGB. */ 1679 return (png_byte)PNG_sRGB_FROM_LINEAR(component); 1680 } 1681 1682 else 1683 return 0; 1684 } 1685 1686 static int 1687 png_write_image_8bit(png_voidp argument) 1688 { 1689 png_image_write_control *display = png_voidcast(png_image_write_control*, 1690 argument); 1691 png_imagep image = display->image; 1692 png_structrp png_ptr = image->opaque->png_ptr; 1693 1694 png_const_uint_16p input_row = png_voidcast(png_const_uint_16p, 1695 display->first_row); 1696 png_bytep output_row = png_voidcast(png_bytep, display->local_row); 1697 png_uint_32 y = image->height; 1698 const unsigned int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 1699 3 : 1; 1700 1701 if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0) 1702 { 1703 png_bytep row_end; 1704 int aindex; 1705 1706 # ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED 1707 if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0) 1708 { 1709 aindex = -1; 1710 ++input_row; /* To point to the first component */ 1711 ++output_row; 1712 } 1713 1714 else 1715 # endif 1716 aindex = (int)channels; 1717 1718 /* Use row_end in place of a loop counter: */ 1719 row_end = output_row + image->width * (channels+1); 1720 1721 for (; y > 0; --y) 1722 { 1723 png_const_uint_16p in_ptr = input_row; 1724 png_bytep out_ptr = output_row; 1725 1726 while (out_ptr < row_end) 1727 { 1728 png_uint_16 alpha = in_ptr[aindex]; 1729 png_byte alphabyte = (png_byte)PNG_DIV257(alpha); 1730 png_uint_32 reciprocal = 0; 1731 int c; 1732 1733 /* Scale and write the alpha channel. */ 1734 out_ptr[aindex] = alphabyte; 1735 1736 if (alphabyte > 0 && alphabyte < 255) 1737 reciprocal = UNP_RECIPROCAL(alpha); 1738 1739 c = (int)channels; 1740 do /* always at least one channel */ 1741 *out_ptr++ = png_unpremultiply(*in_ptr++, alpha, reciprocal); 1742 while (--c > 0); 1743 1744 /* Skip to next component (skip the intervening alpha channel) */ 1745 ++in_ptr; 1746 ++out_ptr; 1747 } /* while out_ptr < row_end */ 1748 1749 png_write_row(png_ptr, png_voidcast(png_const_bytep, 1750 display->local_row)); 1751 input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16)); 1752 } /* while y */ 1753 } 1754 1755 else 1756 { 1757 /* No alpha channel, so the row_end really is the end of the row and it 1758 * is sufficient to loop over the components one by one. 1759 */ 1760 png_bytep row_end = output_row + image->width * channels; 1761 1762 for (; y > 0; --y) 1763 { 1764 png_const_uint_16p in_ptr = input_row; 1765 png_bytep out_ptr = output_row; 1766 1767 while (out_ptr < row_end) 1768 { 1769 png_uint_32 component = *in_ptr++; 1770 1771 component *= 255; 1772 *out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component); 1773 } 1774 1775 png_write_row(png_ptr, output_row); 1776 input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16)); 1777 } 1778 } 1779 1780 return 1; 1781 } 1782 1783 static void 1784 png_image_set_PLTE(png_image_write_control *display) 1785 { 1786 const png_imagep image = display->image; 1787 const void *cmap = display->colormap; 1788 const int entries = image->colormap_entries > 256 ? 256 : 1789 (int)image->colormap_entries; 1790 1791 /* NOTE: the caller must check for cmap != NULL and entries != 0 */ 1792 const png_uint_32 format = image->format; 1793 const unsigned int channels = PNG_IMAGE_SAMPLE_CHANNELS(format); 1794 1795 # if defined(PNG_FORMAT_BGR_SUPPORTED) &&\ 1796 defined(PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED) 1797 const int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 && 1798 (format & PNG_FORMAT_FLAG_ALPHA) != 0; 1799 # else 1800 # define afirst 0 1801 # endif 1802 1803 # ifdef PNG_FORMAT_BGR_SUPPORTED 1804 const int bgr = (format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0; 1805 # else 1806 # define bgr 0 1807 # endif 1808 1809 int i, num_trans; 1810 png_color palette[256]; 1811 png_byte tRNS[256]; 1812 1813 memset(tRNS, 255, (sizeof tRNS)); 1814 memset(palette, 0, (sizeof palette)); 1815 1816 for (i=num_trans=0; i<entries; ++i) 1817 { 1818 /* This gets automatically converted to sRGB with reversal of the 1819 * pre-multiplication if the color-map has an alpha channel. 1820 */ 1821 if ((format & PNG_FORMAT_FLAG_LINEAR) != 0) 1822 { 1823 png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap); 1824 1825 entry += (unsigned int)i * channels; 1826 1827 if ((channels & 1) != 0) /* no alpha */ 1828 { 1829 if (channels >= 3) /* RGB */ 1830 { 1831 palette[i].blue = (png_byte)PNG_sRGB_FROM_LINEAR(255 * 1832 entry[(2 ^ bgr)]); 1833 palette[i].green = (png_byte)PNG_sRGB_FROM_LINEAR(255 * 1834 entry[1]); 1835 palette[i].red = (png_byte)PNG_sRGB_FROM_LINEAR(255 * 1836 entry[bgr]); 1837 } 1838 1839 else /* Gray */ 1840 palette[i].blue = palette[i].red = palette[i].green = 1841 (png_byte)PNG_sRGB_FROM_LINEAR(255 * *entry); 1842 } 1843 1844 else /* alpha */ 1845 { 1846 png_uint_16 alpha = entry[afirst ? 0 : channels-1]; 1847 png_byte alphabyte = (png_byte)PNG_DIV257(alpha); 1848 png_uint_32 reciprocal = 0; 1849 1850 /* Calculate a reciprocal, as in the png_write_image_8bit code above 1851 * this is designed to produce a value scaled to 255*65535 when 1852 * divided by 128 (i.e. asr 7). 1853 */ 1854 if (alphabyte > 0 && alphabyte < 255) 1855 reciprocal = (((0xffff*0xff)<<7)+(alpha>>1))/alpha; 1856 1857 tRNS[i] = alphabyte; 1858 if (alphabyte < 255) 1859 num_trans = i+1; 1860 1861 if (channels >= 3) /* RGB */ 1862 { 1863 palette[i].blue = png_unpremultiply(entry[afirst + (2 ^ bgr)], 1864 alpha, reciprocal); 1865 palette[i].green = png_unpremultiply(entry[afirst + 1], alpha, 1866 reciprocal); 1867 palette[i].red = png_unpremultiply(entry[afirst + bgr], alpha, 1868 reciprocal); 1869 } 1870 1871 else /* gray */ 1872 palette[i].blue = palette[i].red = palette[i].green = 1873 png_unpremultiply(entry[afirst], alpha, reciprocal); 1874 } 1875 } 1876 1877 else /* Color-map has sRGB values */ 1878 { 1879 png_const_bytep entry = png_voidcast(png_const_bytep, cmap); 1880 1881 entry += (unsigned int)i * channels; 1882 1883 switch (channels) 1884 { 1885 case 4: 1886 tRNS[i] = entry[afirst ? 0 : 3]; 1887 if (tRNS[i] < 255) 1888 num_trans = i+1; 1889 /* FALLTHROUGH */ 1890 case 3: 1891 palette[i].blue = entry[afirst + (2 ^ bgr)]; 1892 palette[i].green = entry[afirst + 1]; 1893 palette[i].red = entry[afirst + bgr]; 1894 break; 1895 1896 case 2: 1897 tRNS[i] = entry[1 ^ afirst]; 1898 if (tRNS[i] < 255) 1899 num_trans = i+1; 1900 /* FALLTHROUGH */ 1901 case 1: 1902 palette[i].blue = palette[i].red = palette[i].green = 1903 entry[afirst]; 1904 break; 1905 1906 default: 1907 break; 1908 } 1909 } 1910 } 1911 1912 # ifdef afirst 1913 # undef afirst 1914 # endif 1915 # ifdef bgr 1916 # undef bgr 1917 # endif 1918 1919 png_set_PLTE(image->opaque->png_ptr, image->opaque->info_ptr, palette, 1920 entries); 1921 1922 if (num_trans > 0) 1923 png_set_tRNS(image->opaque->png_ptr, image->opaque->info_ptr, tRNS, 1924 num_trans, NULL); 1925 1926 image->colormap_entries = (png_uint_32)entries; 1927 } 1928 1929 static int 1930 png_image_write_main(png_voidp argument) 1931 { 1932 png_image_write_control *display = png_voidcast(png_image_write_control*, 1933 argument); 1934 png_imagep image = display->image; 1935 png_structrp png_ptr = image->opaque->png_ptr; 1936 png_inforp info_ptr = image->opaque->info_ptr; 1937 png_uint_32 format = image->format; 1938 1939 /* The following four ints are actually booleans */ 1940 int colormap = (format & PNG_FORMAT_FLAG_COLORMAP); 1941 int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR); /* input */ 1942 int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA); 1943 int write_16bit = linear && (display->convert_to_8bit == 0); 1944 1945 # ifdef PNG_BENIGN_ERRORS_SUPPORTED 1946 /* Make sure we error out on any bad situation */ 1947 png_set_benign_errors(png_ptr, 0/*error*/); 1948 # endif 1949 1950 /* Default the 'row_stride' parameter if required, also check the row stride 1951 * and total image size to ensure that they are within the system limits. 1952 */ 1953 { 1954 const unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format); 1955 1956 if (image->width <= 0x7fffffffU/channels) /* no overflow */ 1957 { 1958 png_uint_32 check; 1959 const png_uint_32 png_row_stride = image->width * channels; 1960 1961 if (display->row_stride == 0) 1962 display->row_stride = (png_int_32)/*SAFE*/png_row_stride; 1963 1964 if (display->row_stride < 0) 1965 check = (png_uint_32)(-display->row_stride); 1966 1967 else 1968 check = (png_uint_32)display->row_stride; 1969 1970 if (check >= png_row_stride) 1971 { 1972 /* Now check for overflow of the image buffer calculation; this 1973 * limits the whole image size to 32 bits for API compatibility with 1974 * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro. 1975 */ 1976 if (image->height > 0xffffffffU/png_row_stride) 1977 png_error(image->opaque->png_ptr, "memory image too large"); 1978 } 1979 1980 else 1981 png_error(image->opaque->png_ptr, "supplied row stride too small"); 1982 } 1983 1984 else 1985 png_error(image->opaque->png_ptr, "image row stride too large"); 1986 } 1987 1988 /* Set the required transforms then write the rows in the correct order. */ 1989 if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0) 1990 { 1991 if (display->colormap != NULL && image->colormap_entries > 0) 1992 { 1993 png_uint_32 entries = image->colormap_entries; 1994 1995 png_set_IHDR(png_ptr, info_ptr, image->width, image->height, 1996 entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)), 1997 PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE, 1998 PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); 1999 2000 png_image_set_PLTE(display); 2001 } 2002 2003 else 2004 png_error(image->opaque->png_ptr, 2005 "no color-map for color-mapped image"); 2006 } 2007 2008 else 2009 png_set_IHDR(png_ptr, info_ptr, image->width, image->height, 2010 write_16bit ? 16 : 8, 2011 ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) + 2012 ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0), 2013 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); 2014 2015 /* Counter-intuitively the data transformations must be called *after* 2016 * png_write_info, not before as in the read code, but the 'set' functions 2017 * must still be called before. Just set the color space information, never 2018 * write an interlaced image. 2019 */ 2020 2021 if (write_16bit != 0) 2022 { 2023 /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */ 2024 png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR); 2025 2026 if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0) 2027 png_set_cHRM_fixed(png_ptr, info_ptr, 2028 /* color x y */ 2029 /* white */ 31270, 32900, 2030 /* red */ 64000, 33000, 2031 /* green */ 30000, 60000, 2032 /* blue */ 15000, 6000 2033 ); 2034 } 2035 2036 else if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0) 2037 png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL); 2038 2039 /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit 2040 * space must still be gamma encoded. 2041 */ 2042 else 2043 png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE); 2044 2045 /* Write the file header. */ 2046 png_write_info(png_ptr, info_ptr); 2047 2048 /* Now set up the data transformations (*after* the header is written), 2049 * remove the handled transformations from the 'format' flags for checking. 2050 * 2051 * First check for a little endian system if writing 16-bit files. 2052 */ 2053 if (write_16bit != 0) 2054 { 2055 PNG_CONST png_uint_16 le = 0x0001; 2056 2057 if ((*(png_const_bytep) & le) != 0) 2058 png_set_swap(png_ptr); 2059 } 2060 2061 # ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED 2062 if ((format & PNG_FORMAT_FLAG_BGR) != 0) 2063 { 2064 if (colormap == 0 && (format & PNG_FORMAT_FLAG_COLOR) != 0) 2065 png_set_bgr(png_ptr); 2066 format &= ~PNG_FORMAT_FLAG_BGR; 2067 } 2068 # endif 2069 2070 # ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED 2071 if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) 2072 { 2073 if (colormap == 0 && (format & PNG_FORMAT_FLAG_ALPHA) != 0) 2074 png_set_swap_alpha(png_ptr); 2075 format &= ~PNG_FORMAT_FLAG_AFIRST; 2076 } 2077 # endif 2078 2079 /* If there are 16 or fewer color-map entries we wrote a lower bit depth 2080 * above, but the application data is still byte packed. 2081 */ 2082 if (colormap != 0 && image->colormap_entries <= 16) 2083 png_set_packing(png_ptr); 2084 2085 /* That should have handled all (both) the transforms. */ 2086 if ((format & ~(png_uint_32)(PNG_FORMAT_FLAG_COLOR | PNG_FORMAT_FLAG_LINEAR | 2087 PNG_FORMAT_FLAG_ALPHA | PNG_FORMAT_FLAG_COLORMAP)) != 0) 2088 png_error(png_ptr, "png_write_image: unsupported transformation"); 2089 2090 { 2091 png_const_bytep row = png_voidcast(png_const_bytep, display->buffer); 2092 ptrdiff_t row_bytes = display->row_stride; 2093 2094 if (linear != 0) 2095 row_bytes *= (sizeof (png_uint_16)); 2096 2097 if (row_bytes < 0) 2098 row += (image->height-1) * (-row_bytes); 2099 2100 display->first_row = row; 2101 display->row_bytes = row_bytes; 2102 } 2103 2104 /* Apply 'fast' options if the flag is set. */ 2105 if ((image->flags & PNG_IMAGE_FLAG_FAST) != 0) 2106 { 2107 png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS); 2108 /* NOTE: determined by experiment using pngstest, this reflects some 2109 * balance between the time to write the image once and the time to read 2110 * it about 50 times. The speed-up in pngstest was about 10-20% of the 2111 * total (user) time on a heavily loaded system. 2112 */ 2113 # ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED 2114 png_set_compression_level(png_ptr, 3); 2115 # endif 2116 } 2117 2118 /* Check for the cases that currently require a pre-transform on the row 2119 * before it is written. This only applies when the input is 16-bit and 2120 * either there is an alpha channel or it is converted to 8-bit. 2121 */ 2122 if ((linear != 0 && alpha != 0 ) || 2123 (colormap == 0 && display->convert_to_8bit != 0)) 2124 { 2125 png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr, 2126 png_get_rowbytes(png_ptr, info_ptr))); 2127 int result; 2128 2129 display->local_row = row; 2130 if (write_16bit != 0) 2131 result = png_safe_execute(image, png_write_image_16bit, display); 2132 else 2133 result = png_safe_execute(image, png_write_image_8bit, display); 2134 display->local_row = NULL; 2135 2136 png_free(png_ptr, row); 2137 2138 /* Skip the 'write_end' on error: */ 2139 if (result == 0) 2140 return 0; 2141 } 2142 2143 /* Otherwise this is the case where the input is in a format currently 2144 * supported by the rest of the libpng write code; call it directly. 2145 */ 2146 else 2147 { 2148 png_const_bytep row = png_voidcast(png_const_bytep, display->first_row); 2149 ptrdiff_t row_bytes = display->row_bytes; 2150 png_uint_32 y = image->height; 2151 2152 for (; y > 0; --y) 2153 { 2154 png_write_row(png_ptr, row); 2155 row += row_bytes; 2156 } 2157 } 2158 2159 png_write_end(png_ptr, info_ptr); 2160 return 1; 2161 } 2162 2163 2164 static void (PNGCBAPI 2165 image_memory_write)(png_structp png_ptr, png_bytep/*const*/ data, 2166 png_size_t size) 2167 { 2168 png_image_write_control *display = png_voidcast(png_image_write_control*, 2169 png_ptr->io_ptr/*backdoor: png_get_io_ptr(png_ptr)*/); 2170 const png_alloc_size_t ob = display->output_bytes; 2171 2172 /* Check for overflow; this should never happen: */ 2173 if (size <= ((png_alloc_size_t)-1) - ob) 2174 { 2175 /* I don't think libpng ever does this, but just in case: */ 2176 if (size > 0) 2177 { 2178 if (display->memory_bytes >= ob+size) /* writing */ 2179 memcpy(display->memory+ob, data, size); 2180 2181 /* Always update the size: */ 2182 display->output_bytes = ob+size; 2183 } 2184 } 2185 2186 else 2187 png_error(png_ptr, "png_image_write_to_memory: PNG too big"); 2188 } 2189 2190 static void (PNGCBAPI 2191 image_memory_flush)(png_structp png_ptr) 2192 { 2193 PNG_UNUSED(png_ptr) 2194 } 2195 2196 static int 2197 png_image_write_memory(png_voidp argument) 2198 { 2199 png_image_write_control *display = png_voidcast(png_image_write_control*, 2200 argument); 2201 2202 /* The rest of the memory-specific init and write_main in an error protected 2203 * environment. This case needs to use callbacks for the write operations 2204 * since libpng has no built in support for writing to memory. 2205 */ 2206 png_set_write_fn(display->image->opaque->png_ptr, display/*io_ptr*/, 2207 image_memory_write, image_memory_flush); 2208 2209 return png_image_write_main(display); 2210 } 2211 2212 int PNGAPI 2213 png_image_write_to_memory(png_imagep image, void *memory, 2214 png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8bit, 2215 const void *buffer, png_int_32 row_stride, const void *colormap) 2216 { 2217 /* Write the image to the given buffer, or count the bytes if it is NULL */ 2218 if (image != NULL && image->version == PNG_IMAGE_VERSION) 2219 { 2220 if (memory_bytes != NULL && buffer != NULL) 2221 { 2222 /* This is to give the caller an easier error detection in the NULL 2223 * case and guard against uninitialized variable problems: 2224 */ 2225 if (memory == NULL) 2226 *memory_bytes = 0; 2227 2228 if (png_image_write_init(image) != 0) 2229 { 2230 png_image_write_control display; 2231 int result; 2232 2233 memset(&display, 0, (sizeof display)); 2234 display.image = image; 2235 display.buffer = buffer; 2236 display.row_stride = row_stride; 2237 display.colormap = colormap; 2238 display.convert_to_8bit = convert_to_8bit; 2239 display.memory = png_voidcast(png_bytep, memory); 2240 display.memory_bytes = *memory_bytes; 2241 display.output_bytes = 0; 2242 2243 result = png_safe_execute(image, png_image_write_memory, &display); 2244 png_image_free(image); 2245 2246 /* write_memory returns true even if we ran out of buffer. */ 2247 if (result) 2248 { 2249 /* On out-of-buffer this function returns '0' but still updates 2250 * memory_bytes: 2251 */ 2252 if (memory != NULL && display.output_bytes > *memory_bytes) 2253 result = 0; 2254 2255 *memory_bytes = display.output_bytes; 2256 } 2257 2258 return result; 2259 } 2260 2261 else 2262 return 0; 2263 } 2264 2265 else 2266 return png_image_error(image, 2267 "png_image_write_to_memory: invalid argument"); 2268 } 2269 2270 else if (image != NULL) 2271 return png_image_error(image, 2272 "png_image_write_to_memory: incorrect PNG_IMAGE_VERSION"); 2273 2274 else 2275 return 0; 2276 } 2277 2278 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED 2279 int PNGAPI 2280 png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit, 2281 const void *buffer, png_int_32 row_stride, const void *colormap) 2282 { 2283 /* Write the image to the given (FILE*). */ 2284 if (image != NULL && image->version == PNG_IMAGE_VERSION) 2285 { 2286 if (file != NULL && buffer != NULL) 2287 { 2288 if (png_image_write_init(image) != 0) 2289 { 2290 png_image_write_control display; 2291 int result; 2292 2293 /* This is slightly evil, but png_init_io doesn't do anything other 2294 * than this and we haven't changed the standard IO functions so 2295 * this saves a 'safe' function. 2296 */ 2297 image->opaque->png_ptr->io_ptr = file; 2298 2299 memset(&display, 0, (sizeof display)); 2300 display.image = image; 2301 display.buffer = buffer; 2302 display.row_stride = row_stride; 2303 display.colormap = colormap; 2304 display.convert_to_8bit = convert_to_8bit; 2305 2306 result = png_safe_execute(image, png_image_write_main, &display); 2307 png_image_free(image); 2308 return result; 2309 } 2310 2311 else 2312 return 0; 2313 } 2314 2315 else 2316 return png_image_error(image, 2317 "png_image_write_to_stdio: invalid argument"); 2318 } 2319 2320 else if (image != NULL) 2321 return png_image_error(image, 2322 "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION"); 2323 2324 else 2325 return 0; 2326 } 2327 2328 int PNGAPI 2329 png_image_write_to_file(png_imagep image, const char *file_name, 2330 int convert_to_8bit, const void *buffer, png_int_32 row_stride, 2331 const void *colormap) 2332 { 2333 /* Write the image to the named file. */ 2334 if (image != NULL && image->version == PNG_IMAGE_VERSION) 2335 { 2336 if (file_name != NULL && buffer != NULL) 2337 { 2338 FILE *fp = fopen(file_name, "wb"); 2339 2340 if (fp != NULL) 2341 { 2342 if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer, 2343 row_stride, colormap) != 0) 2344 { 2345 int error; /* from fflush/fclose */ 2346 2347 /* Make sure the file is flushed correctly. */ 2348 if (fflush(fp) == 0 && ferror(fp) == 0) 2349 { 2350 if (fclose(fp) == 0) 2351 return 1; 2352 2353 error = errno; /* from fclose */ 2354 } 2355 2356 else 2357 { 2358 error = errno; /* from fflush or ferror */ 2359 (void)fclose(fp); 2360 } 2361 2362 (void)remove(file_name); 2363 /* The image has already been cleaned up; this is just used to 2364 * set the error (because the original write succeeded). 2365 */ 2366 return png_image_error(image, strerror(error)); 2367 } 2368 2369 else 2370 { 2371 /* Clean up: just the opened file. */ 2372 (void)fclose(fp); 2373 (void)remove(file_name); 2374 return 0; 2375 } 2376 } 2377 2378 else 2379 return png_image_error(image, strerror(errno)); 2380 } 2381 2382 else 2383 return png_image_error(image, 2384 "png_image_write_to_file: invalid argument"); 2385 } 2386 2387 else if (image != NULL) 2388 return png_image_error(image, 2389 "png_image_write_to_file: incorrect PNG_IMAGE_VERSION"); 2390 2391 else 2392 return 0; 2393 } 2394 #endif /* SIMPLIFIED_WRITE_STDIO */ 2395 #endif /* SIMPLIFIED_WRITE */ 2396 #endif /* WRITE */ 2397
