1 2 /* pngwrite.c - general routines to write a PNG file 3 * 4 * Copyright (c) 2018-2022 Cosmin Truta 5 * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson 6 * Copyright (c) 1996-1997 Andreas Dilger 7 * 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_<chunk> flag, and check info_ptr->valid before 79 * writing the chunk, as that will keep the code from breaking if you want 80 * to just write a plain PNG file. If you have long comments, I suggest 81 * writing 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, 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 if (tbuf == NULL) 493 { 494 /* TODO: add a safe function which takes a png_ptr argument and raises 495 * a png_error if the ttime argument is invalid and the call to gmtime 496 * fails as a consequence. 497 */ 498 memset(ptime, 0, sizeof(*ptime)); 499 return; 500 } 501 502 png_convert_from_struct_tm(ptime, tbuf); 503 } 504 #endif 505 506 /* Initialize png_ptr structure, and allocate any memory needed */ 507 PNG_FUNCTION(png_structp,PNGAPI 508 png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr, 509 png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED) 510 { 511 #ifndef PNG_USER_MEM_SUPPORTED 512 png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr, 513 error_fn, warn_fn, NULL, NULL, NULL); 514 #else 515 return png_create_write_struct_2(user_png_ver, error_ptr, error_fn, 516 warn_fn, NULL, NULL, NULL); 517 } 518 519 /* Alternate initialize png_ptr structure, and allocate any memory needed */ 520 PNG_FUNCTION(png_structp,PNGAPI 521 png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, 522 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, 523 png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED) 524 { 525 png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr, 526 error_fn, warn_fn, mem_ptr, malloc_fn, free_fn); 527 #endif /* USER_MEM */ 528 if (png_ptr != NULL) 529 { 530 /* Set the zlib control values to defaults; they can be overridden by the 531 * application after the struct has been created. 532 */ 533 png_ptr->zbuffer_size = PNG_ZBUF_SIZE; 534 535 /* The 'zlib_strategy' setting is irrelevant because png_default_claim in 536 * pngwutil.c defaults it according to whether or not filters will be 537 * used, and ignores this setting. 538 */ 539 png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY; 540 png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION; 541 png_ptr->zlib_mem_level = 8; 542 png_ptr->zlib_window_bits = 15; 543 png_ptr->zlib_method = 8; 544 545 #ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED 546 png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY; 547 png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION; 548 png_ptr->zlib_text_mem_level = 8; 549 png_ptr->zlib_text_window_bits = 15; 550 png_ptr->zlib_text_method = 8; 551 #endif /* WRITE_COMPRESSED_TEXT */ 552 553 /* This is a highly dubious configuration option; by default it is off, 554 * but it may be appropriate for private builds that are testing 555 * extensions not conformant to the current specification, or of 556 * applications that must not fail to write at all costs! 557 */ 558 #ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED 559 /* In stable builds only warn if an application error can be completely 560 * handled. 561 */ 562 png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN; 563 #endif 564 565 /* App warnings are warnings in release (or release candidate) builds but 566 * are errors during development. 567 */ 568 #if PNG_RELEASE_BUILD 569 png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN; 570 #endif 571 572 /* TODO: delay this, it can be done in png_init_io() (if the app doesn't 573 * do it itself) avoiding setting the default function if it is not 574 * required. 575 */ 576 png_set_write_fn(png_ptr, NULL, NULL, NULL); 577 } 578 579 return png_ptr; 580 } 581 582 583 /* Write a few rows of image data. If the image is interlaced, 584 * either you will have to write the 7 sub images, or, if you 585 * have called png_set_interlace_handling(), you will have to 586 * "write" the image seven times. 587 */ 588 void PNGAPI 589 png_write_rows(png_structrp png_ptr, png_bytepp row, 590 png_uint_32 num_rows) 591 { 592 png_uint_32 i; /* row counter */ 593 png_bytepp rp; /* row pointer */ 594 595 png_debug(1, "in png_write_rows"); 596 597 if (png_ptr == NULL) 598 return; 599 600 /* Loop through the rows */ 601 for (i = 0, rp = row; i < num_rows; i++, rp++) 602 { 603 png_write_row(png_ptr, *rp); 604 } 605 } 606 607 /* Write the image. You only need to call this function once, even 608 * if you are writing an interlaced image. 609 */ 610 void PNGAPI 611 png_write_image(png_structrp png_ptr, png_bytepp image) 612 { 613 png_uint_32 i; /* row index */ 614 int pass, num_pass; /* pass variables */ 615 png_bytepp rp; /* points to current row */ 616 617 if (png_ptr == NULL) 618 return; 619 620 png_debug(1, "in png_write_image"); 621 622 #ifdef PNG_WRITE_INTERLACING_SUPPORTED 623 /* Initialize interlace handling. If image is not interlaced, 624 * this will set pass to 1 625 */ 626 num_pass = png_set_interlace_handling(png_ptr); 627 #else 628 num_pass = 1; 629 #endif 630 /* Loop through passes */ 631 for (pass = 0; pass < num_pass; pass++) 632 { 633 /* Loop through image */ 634 for (i = 0, rp = image; i < png_ptr->height; i++, rp++) 635 { 636 png_write_row(png_ptr, *rp); 637 } 638 } 639 } 640 641 #ifdef PNG_MNG_FEATURES_SUPPORTED 642 /* Performs intrapixel differencing */ 643 static void 644 png_do_write_intrapixel(png_row_infop row_info, png_bytep row) 645 { 646 png_debug(1, "in png_do_write_intrapixel"); 647 648 if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) 649 { 650 int bytes_per_pixel; 651 png_uint_32 row_width = row_info->width; 652 if (row_info->bit_depth == 8) 653 { 654 png_bytep rp; 655 png_uint_32 i; 656 657 if (row_info->color_type == PNG_COLOR_TYPE_RGB) 658 bytes_per_pixel = 3; 659 660 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) 661 bytes_per_pixel = 4; 662 663 else 664 return; 665 666 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) 667 { 668 *(rp) = (png_byte)(*rp - *(rp + 1)); 669 *(rp + 2) = (png_byte)(*(rp + 2) - *(rp + 1)); 670 } 671 } 672 673 #ifdef PNG_WRITE_16BIT_SUPPORTED 674 else if (row_info->bit_depth == 16) 675 { 676 png_bytep rp; 677 png_uint_32 i; 678 679 if (row_info->color_type == PNG_COLOR_TYPE_RGB) 680 bytes_per_pixel = 6; 681 682 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) 683 bytes_per_pixel = 8; 684 685 else 686 return; 687 688 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) 689 { 690 png_uint_32 s0 = (png_uint_32)(*(rp ) << 8) | *(rp + 1); 691 png_uint_32 s1 = (png_uint_32)(*(rp + 2) << 8) | *(rp + 3); 692 png_uint_32 s2 = (png_uint_32)(*(rp + 4) << 8) | *(rp + 5); 693 png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL); 694 png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL); 695 *(rp ) = (png_byte)(red >> 8); 696 *(rp + 1) = (png_byte)red; 697 *(rp + 4) = (png_byte)(blue >> 8); 698 *(rp + 5) = (png_byte)blue; 699 } 700 } 701 #endif /* WRITE_16BIT */ 702 } 703 } 704 #endif /* MNG_FEATURES */ 705 706 /* Called by user to write a row of image data */ 707 void PNGAPI 708 png_write_row(png_structrp png_ptr, png_const_bytep row) 709 { 710 /* 1.5.6: moved from png_struct to be a local structure: */ 711 png_row_info row_info; 712 713 if (png_ptr == NULL) 714 return; 715 716 png_debug2(1, "in png_write_row (row %u, pass %d)", 717 png_ptr->row_number, png_ptr->pass); 718 719 /* Initialize transformations and other stuff if first time */ 720 if (png_ptr->row_number == 0 && png_ptr->pass == 0) 721 { 722 /* Make sure we wrote the header info */ 723 if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0) 724 png_error(png_ptr, 725 "png_write_info was never called before png_write_row"); 726 727 /* Check for transforms that have been set but were defined out */ 728 #if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED) 729 if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) 730 png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined"); 731 #endif 732 733 #if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED) 734 if ((png_ptr->transformations & PNG_FILLER) != 0) 735 png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined"); 736 #endif 737 #if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \ 738 defined(PNG_READ_PACKSWAP_SUPPORTED) 739 if ((png_ptr->transformations & PNG_PACKSWAP) != 0) 740 png_warning(png_ptr, 741 "PNG_WRITE_PACKSWAP_SUPPORTED is not defined"); 742 #endif 743 744 #if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED) 745 if ((png_ptr->transformations & PNG_PACK) != 0) 746 png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined"); 747 #endif 748 749 #if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED) 750 if ((png_ptr->transformations & PNG_SHIFT) != 0) 751 png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined"); 752 #endif 753 754 #if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED) 755 if ((png_ptr->transformations & PNG_BGR) != 0) 756 png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined"); 757 #endif 758 759 #if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED) 760 if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) 761 png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined"); 762 #endif 763 764 png_write_start_row(png_ptr); 765 } 766 767 #ifdef PNG_WRITE_INTERLACING_SUPPORTED 768 /* If interlaced and not interested in row, return */ 769 if (png_ptr->interlaced != 0 && 770 (png_ptr->transformations & PNG_INTERLACE) != 0) 771 { 772 switch (png_ptr->pass) 773 { 774 case 0: 775 if ((png_ptr->row_number & 0x07) != 0) 776 { 777 png_write_finish_row(png_ptr); 778 return; 779 } 780 break; 781 782 case 1: 783 if ((png_ptr->row_number & 0x07) != 0 || png_ptr->width < 5) 784 { 785 png_write_finish_row(png_ptr); 786 return; 787 } 788 break; 789 790 case 2: 791 if ((png_ptr->row_number & 0x07) != 4) 792 { 793 png_write_finish_row(png_ptr); 794 return; 795 } 796 break; 797 798 case 3: 799 if ((png_ptr->row_number & 0x03) != 0 || png_ptr->width < 3) 800 { 801 png_write_finish_row(png_ptr); 802 return; 803 } 804 break; 805 806 case 4: 807 if ((png_ptr->row_number & 0x03) != 2) 808 { 809 png_write_finish_row(png_ptr); 810 return; 811 } 812 break; 813 814 case 5: 815 if ((png_ptr->row_number & 0x01) != 0 || png_ptr->width < 2) 816 { 817 png_write_finish_row(png_ptr); 818 return; 819 } 820 break; 821 822 case 6: 823 if ((png_ptr->row_number & 0x01) == 0) 824 { 825 png_write_finish_row(png_ptr); 826 return; 827 } 828 break; 829 830 default: /* error: ignore it */ 831 break; 832 } 833 } 834 #endif 835 836 /* Set up row info for transformations */ 837 row_info.color_type = png_ptr->color_type; 838 row_info.width = png_ptr->usr_width; 839 row_info.channels = png_ptr->usr_channels; 840 row_info.bit_depth = png_ptr->usr_bit_depth; 841 row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels); 842 row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); 843 844 png_debug1(3, "row_info->color_type = %d", row_info.color_type); 845 png_debug1(3, "row_info->width = %u", row_info.width); 846 png_debug1(3, "row_info->channels = %d", row_info.channels); 847 png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth); 848 png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth); 849 png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes); 850 851 /* Copy user's row into buffer, leaving room for filter byte. */ 852 memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes); 853 854 #ifdef PNG_WRITE_INTERLACING_SUPPORTED 855 /* Handle interlacing */ 856 if (png_ptr->interlaced && png_ptr->pass < 6 && 857 (png_ptr->transformations & PNG_INTERLACE) != 0) 858 { 859 png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass); 860 /* This should always get caught above, but still ... */ 861 if (row_info.width == 0) 862 { 863 png_write_finish_row(png_ptr); 864 return; 865 } 866 } 867 #endif 868 869 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED 870 /* Handle other transformations */ 871 if (png_ptr->transformations != 0) 872 png_do_write_transformations(png_ptr, &row_info); 873 #endif 874 875 /* At this point the row_info pixel depth must match the 'transformed' depth, 876 * which is also the output depth. 877 */ 878 if (row_info.pixel_depth != png_ptr->pixel_depth || 879 row_info.pixel_depth != png_ptr->transformed_pixel_depth) 880 png_error(png_ptr, "internal write transform logic error"); 881 882 #ifdef PNG_MNG_FEATURES_SUPPORTED 883 /* Write filter_method 64 (intrapixel differencing) only if 884 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and 885 * 2. Libpng did not write a PNG signature (this filter_method is only 886 * used in PNG datastreams that are embedded in MNG datastreams) and 887 * 3. The application called png_permit_mng_features with a mask that 888 * included PNG_FLAG_MNG_FILTER_64 and 889 * 4. The filter_method is 64 and 890 * 5. The color_type is RGB or RGBA 891 */ 892 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && 893 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) 894 { 895 /* Intrapixel differencing */ 896 png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1); 897 } 898 #endif 899 900 /* Added at libpng-1.5.10 */ 901 #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED 902 /* Check for out-of-range palette index */ 903 if (row_info.color_type == PNG_COLOR_TYPE_PALETTE && 904 png_ptr->num_palette_max >= 0) 905 png_do_check_palette_indexes(png_ptr, &row_info); 906 #endif 907 908 /* Find a filter if necessary, filter the row and write it out. */ 909 png_write_find_filter(png_ptr, &row_info); 910 911 if (png_ptr->write_row_fn != NULL) 912 (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); 913 } 914 915 #ifdef PNG_WRITE_FLUSH_SUPPORTED 916 /* Set the automatic flush interval or 0 to turn flushing off */ 917 void PNGAPI 918 png_set_flush(png_structrp png_ptr, int nrows) 919 { 920 png_debug(1, "in png_set_flush"); 921 922 if (png_ptr == NULL) 923 return; 924 925 png_ptr->flush_dist = (nrows < 0 ? 0 : (png_uint_32)nrows); 926 } 927 928 /* Flush the current output buffers now */ 929 void PNGAPI 930 png_write_flush(png_structrp png_ptr) 931 { 932 png_debug(1, "in png_write_flush"); 933 934 if (png_ptr == NULL) 935 return; 936 937 /* We have already written out all of the data */ 938 if (png_ptr->row_number >= png_ptr->num_rows) 939 return; 940 941 png_compress_IDAT(png_ptr, NULL, 0, Z_SYNC_FLUSH); 942 png_ptr->flush_rows = 0; 943 png_flush(png_ptr); 944 } 945 #endif /* WRITE_FLUSH */ 946 947 /* Free any memory used in png_ptr struct without freeing the struct itself. */ 948 static void 949 png_write_destroy(png_structrp png_ptr) 950 { 951 png_debug(1, "in png_write_destroy"); 952 953 /* Free any memory zlib uses */ 954 if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0) 955 deflateEnd(&png_ptr->zstream); 956 957 /* Free our memory. png_free checks NULL for us. */ 958 png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list); 959 png_free(png_ptr, png_ptr->row_buf); 960 png_ptr->row_buf = NULL; 961 #ifdef PNG_WRITE_FILTER_SUPPORTED 962 png_free(png_ptr, png_ptr->prev_row); 963 png_free(png_ptr, png_ptr->try_row); 964 png_free(png_ptr, png_ptr->tst_row); 965 png_ptr->prev_row = NULL; 966 png_ptr->try_row = NULL; 967 png_ptr->tst_row = NULL; 968 #endif 969 970 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED 971 png_free(png_ptr, png_ptr->chunk_list); 972 png_ptr->chunk_list = NULL; 973 #endif 974 975 /* The error handling and memory handling information is left intact at this 976 * point: the jmp_buf may still have to be freed. See png_destroy_png_struct 977 * for how this happens. 978 */ 979 } 980 981 /* Free all memory used by the write. 982 * In libpng 1.6.0 this API changed quietly to no longer accept a NULL value for 983 * *png_ptr_ptr. Prior to 1.6.0 it would accept such a value and it would free 984 * the passed in info_structs but it would quietly fail to free any of the data 985 * inside them. In 1.6.0 it quietly does nothing (it has to be quiet because it 986 * has no png_ptr.) 987 */ 988 void PNGAPI 989 png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr) 990 { 991 png_debug(1, "in png_destroy_write_struct"); 992 993 if (png_ptr_ptr != NULL) 994 { 995 png_structrp png_ptr = *png_ptr_ptr; 996 997 if (png_ptr != NULL) /* added in libpng 1.6.0 */ 998 { 999 png_destroy_info_struct(png_ptr, info_ptr_ptr); 1000 1001 *png_ptr_ptr = NULL; 1002 png_write_destroy(png_ptr); 1003 png_destroy_png_struct(png_ptr); 1004 } 1005 } 1006 } 1007 1008 /* Allow the application to select one or more row filters to use. */ 1009 void PNGAPI 1010 png_set_filter(png_structrp png_ptr, int method, int filters) 1011 { 1012 png_debug(1, "in png_set_filter"); 1013 1014 if (png_ptr == NULL) 1015 return; 1016 1017 #ifdef PNG_MNG_FEATURES_SUPPORTED 1018 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && 1019 (method == PNG_INTRAPIXEL_DIFFERENCING)) 1020 method = PNG_FILTER_TYPE_BASE; 1021 1022 #endif 1023 if (method == PNG_FILTER_TYPE_BASE) 1024 { 1025 switch (filters & (PNG_ALL_FILTERS | 0x07)) 1026 { 1027 #ifdef PNG_WRITE_FILTER_SUPPORTED 1028 case 5: 1029 case 6: 1030 case 7: png_app_error(png_ptr, "Unknown row filter for method 0"); 1031 #endif /* WRITE_FILTER */ 1032 /* FALLTHROUGH */ 1033 case PNG_FILTER_VALUE_NONE: 1034 png_ptr->do_filter = PNG_FILTER_NONE; break; 1035 1036 #ifdef PNG_WRITE_FILTER_SUPPORTED 1037 case PNG_FILTER_VALUE_SUB: 1038 png_ptr->do_filter = PNG_FILTER_SUB; break; 1039 1040 case PNG_FILTER_VALUE_UP: 1041 png_ptr->do_filter = PNG_FILTER_UP; break; 1042 1043 case PNG_FILTER_VALUE_AVG: 1044 png_ptr->do_filter = PNG_FILTER_AVG; break; 1045 1046 case PNG_FILTER_VALUE_PAETH: 1047 png_ptr->do_filter = PNG_FILTER_PAETH; break; 1048 1049 default: 1050 png_ptr->do_filter = (png_byte)filters; break; 1051 #else 1052 default: 1053 png_app_error(png_ptr, "Unknown row filter for method 0"); 1054 #endif /* WRITE_FILTER */ 1055 } 1056 1057 #ifdef PNG_WRITE_FILTER_SUPPORTED 1058 /* If we have allocated the row_buf, this means we have already started 1059 * with the image and we should have allocated all of the filter buffers 1060 * that have been selected. If prev_row isn't already allocated, then 1061 * it is too late to start using the filters that need it, since we 1062 * will be missing the data in the previous row. If an application 1063 * wants to start and stop using particular filters during compression, 1064 * it should start out with all of the filters, and then remove them 1065 * or add them back after the start of compression. 1066 * 1067 * NOTE: this is a nasty constraint on the code, because it means that the 1068 * prev_row buffer must be maintained even if there are currently no 1069 * 'prev_row' requiring filters active. 1070 */ 1071 if (png_ptr->row_buf != NULL) 1072 { 1073 int num_filters; 1074 png_alloc_size_t buf_size; 1075 1076 /* Repeat the checks in png_write_start_row; 1 pixel high or wide 1077 * images cannot benefit from certain filters. If this isn't done here 1078 * the check below will fire on 1 pixel high images. 1079 */ 1080 if (png_ptr->height == 1) 1081 filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); 1082 1083 if (png_ptr->width == 1) 1084 filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH); 1085 1086 if ((filters & (PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH)) != 0 1087 && png_ptr->prev_row == NULL) 1088 { 1089 /* This is the error case, however it is benign - the previous row 1090 * is not available so the filter can't be used. Just warn here. 1091 */ 1092 png_app_warning(png_ptr, 1093 "png_set_filter: UP/AVG/PAETH cannot be added after start"); 1094 filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); 1095 } 1096 1097 num_filters = 0; 1098 1099 if (filters & PNG_FILTER_SUB) 1100 num_filters++; 1101 1102 if (filters & PNG_FILTER_UP) 1103 num_filters++; 1104 1105 if (filters & PNG_FILTER_AVG) 1106 num_filters++; 1107 1108 if (filters & PNG_FILTER_PAETH) 1109 num_filters++; 1110 1111 /* Allocate needed row buffers if they have not already been 1112 * allocated. 1113 */ 1114 buf_size = PNG_ROWBYTES(png_ptr->usr_channels * png_ptr->usr_bit_depth, 1115 png_ptr->width) + 1; 1116 1117 if (png_ptr->try_row == NULL) 1118 png_ptr->try_row = png_voidcast(png_bytep, 1119 png_malloc(png_ptr, buf_size)); 1120 1121 if (num_filters > 1) 1122 { 1123 if (png_ptr->tst_row == NULL) 1124 png_ptr->tst_row = png_voidcast(png_bytep, 1125 png_malloc(png_ptr, buf_size)); 1126 } 1127 } 1128 png_ptr->do_filter = (png_byte)filters; 1129 #endif 1130 } 1131 else 1132 png_error(png_ptr, "Unknown custom filter method"); 1133 } 1134 1135 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ 1136 /* Provide floating and fixed point APIs */ 1137 #ifdef PNG_FLOATING_POINT_SUPPORTED 1138 void PNGAPI 1139 png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method, 1140 int num_weights, png_const_doublep filter_weights, 1141 png_const_doublep filter_costs) 1142 { 1143 PNG_UNUSED(png_ptr) 1144 PNG_UNUSED(heuristic_method) 1145 PNG_UNUSED(num_weights) 1146 PNG_UNUSED(filter_weights) 1147 PNG_UNUSED(filter_costs) 1148 } 1149 #endif /* FLOATING_POINT */ 1150 1151 #ifdef PNG_FIXED_POINT_SUPPORTED 1152 void PNGAPI 1153 png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method, 1154 int num_weights, png_const_fixed_point_p filter_weights, 1155 png_const_fixed_point_p filter_costs) 1156 { 1157 PNG_UNUSED(png_ptr) 1158 PNG_UNUSED(heuristic_method) 1159 PNG_UNUSED(num_weights) 1160 PNG_UNUSED(filter_weights) 1161 PNG_UNUSED(filter_costs) 1162 } 1163 #endif /* FIXED_POINT */ 1164 #endif /* WRITE_WEIGHTED_FILTER */ 1165 1166 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED 1167 void PNGAPI 1168 png_set_compression_level(png_structrp png_ptr, int level) 1169 { 1170 png_debug(1, "in png_set_compression_level"); 1171 1172 if (png_ptr == NULL) 1173 return; 1174 1175 png_ptr->zlib_level = level; 1176 } 1177 1178 void PNGAPI 1179 png_set_compression_mem_level(png_structrp png_ptr, int mem_level) 1180 { 1181 png_debug(1, "in png_set_compression_mem_level"); 1182 1183 if (png_ptr == NULL) 1184 return; 1185 1186 png_ptr->zlib_mem_level = mem_level; 1187 } 1188 1189 void PNGAPI 1190 png_set_compression_strategy(png_structrp png_ptr, int strategy) 1191 { 1192 png_debug(1, "in png_set_compression_strategy"); 1193 1194 if (png_ptr == NULL) 1195 return; 1196 1197 /* The flag setting here prevents the libpng dynamic selection of strategy. 1198 */ 1199 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY; 1200 png_ptr->zlib_strategy = strategy; 1201 } 1202 1203 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1204 * smaller value of window_bits if it can do so safely. 1205 */ 1206 void PNGAPI 1207 png_set_compression_window_bits(png_structrp png_ptr, int window_bits) 1208 { 1209 if (png_ptr == NULL) 1210 return; 1211 1212 /* Prior to 1.6.0 this would warn but then set the window_bits value. This 1213 * meant that negative window bits values could be selected that would cause 1214 * libpng to write a non-standard PNG file with raw deflate or gzip 1215 * compressed IDAT or ancillary chunks. Such files can be read and there is 1216 * no warning on read, so this seems like a very bad idea. 1217 */ 1218 if (window_bits > 15) 1219 { 1220 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); 1221 window_bits = 15; 1222 } 1223 1224 else if (window_bits < 8) 1225 { 1226 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG"); 1227 window_bits = 8; 1228 } 1229 1230 png_ptr->zlib_window_bits = window_bits; 1231 } 1232 1233 void PNGAPI 1234 png_set_compression_method(png_structrp png_ptr, int method) 1235 { 1236 png_debug(1, "in png_set_compression_method"); 1237 1238 if (png_ptr == NULL) 1239 return; 1240 1241 /* This would produce an invalid PNG file if it worked, but it doesn't and 1242 * deflate will fault it, so it is harmless to just warn here. 1243 */ 1244 if (method != 8) 1245 png_warning(png_ptr, "Only compression method 8 is supported by PNG"); 1246 1247 png_ptr->zlib_method = method; 1248 } 1249 #endif /* WRITE_CUSTOMIZE_COMPRESSION */ 1250 1251 /* The following were added to libpng-1.5.4 */ 1252 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED 1253 void PNGAPI 1254 png_set_text_compression_level(png_structrp png_ptr, int level) 1255 { 1256 png_debug(1, "in png_set_text_compression_level"); 1257 1258 if (png_ptr == NULL) 1259 return; 1260 1261 png_ptr->zlib_text_level = level; 1262 } 1263 1264 void PNGAPI 1265 png_set_text_compression_mem_level(png_structrp png_ptr, int mem_level) 1266 { 1267 png_debug(1, "in png_set_text_compression_mem_level"); 1268 1269 if (png_ptr == NULL) 1270 return; 1271 1272 png_ptr->zlib_text_mem_level = mem_level; 1273 } 1274 1275 void PNGAPI 1276 png_set_text_compression_strategy(png_structrp png_ptr, int strategy) 1277 { 1278 png_debug(1, "in png_set_text_compression_strategy"); 1279 1280 if (png_ptr == NULL) 1281 return; 1282 1283 png_ptr->zlib_text_strategy = strategy; 1284 } 1285 1286 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a 1287 * smaller value of window_bits if it can do so safely. 1288 */ 1289 void PNGAPI 1290 png_set_text_compression_window_bits(png_structrp png_ptr, int window_bits) 1291 { 1292 if (png_ptr == NULL) 1293 return; 1294 1295 if (window_bits > 15) 1296 { 1297 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); 1298 window_bits = 15; 1299 } 1300 1301 else if (window_bits < 8) 1302 { 1303 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG"); 1304 window_bits = 8; 1305 } 1306 1307 png_ptr->zlib_text_window_bits = window_bits; 1308 } 1309 1310 void PNGAPI 1311 png_set_text_compression_method(png_structrp png_ptr, int method) 1312 { 1313 png_debug(1, "in png_set_text_compression_method"); 1314 1315 if (png_ptr == NULL) 1316 return; 1317 1318 if (method != 8) 1319 png_warning(png_ptr, "Only compression method 8 is supported by PNG"); 1320 1321 png_ptr->zlib_text_method = method; 1322 } 1323 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ 1324 /* end of API added to libpng-1.5.4 */ 1325 1326 void PNGAPI 1327 png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn) 1328 { 1329 if (png_ptr == NULL) 1330 return; 1331 1332 png_ptr->write_row_fn = write_row_fn; 1333 } 1334 1335 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED 1336 void PNGAPI 1337 png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr 1338 write_user_transform_fn) 1339 { 1340 png_debug(1, "in png_set_write_user_transform_fn"); 1341 1342 if (png_ptr == NULL) 1343 return; 1344 1345 png_ptr->transformations |= PNG_USER_TRANSFORM; 1346 png_ptr->write_user_transform_fn = write_user_transform_fn; 1347 } 1348 #endif 1349 1350 1351 #ifdef PNG_INFO_IMAGE_SUPPORTED 1352 void PNGAPI 1353 png_write_png(png_structrp png_ptr, png_inforp info_ptr, 1354 int transforms, voidp params) 1355 { 1356 if (png_ptr == NULL || info_ptr == NULL) 1357 return; 1358 1359 if ((info_ptr->valid & PNG_INFO_IDAT) == 0) 1360 { 1361 png_app_error(png_ptr, "no rows for png_write_image to write"); 1362 return; 1363 } 1364 1365 /* Write the file header information. */ 1366 png_write_info(png_ptr, info_ptr); 1367 1368 /* ------ these transformations don't touch the info structure ------- */ 1369 1370 /* Invert monochrome pixels */ 1371 if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0) 1372 #ifdef PNG_WRITE_INVERT_SUPPORTED 1373 png_set_invert_mono(png_ptr); 1374 #else 1375 png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported"); 1376 #endif 1377 1378 /* Shift the pixels up to a legal bit depth and fill in 1379 * as appropriate to correctly scale the image. 1380 */ 1381 if ((transforms & PNG_TRANSFORM_SHIFT) != 0) 1382 #ifdef PNG_WRITE_SHIFT_SUPPORTED 1383 if ((info_ptr->valid & PNG_INFO_sBIT) != 0) 1384 png_set_shift(png_ptr, &info_ptr->sig_bit); 1385 #else 1386 png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported"); 1387 #endif 1388 1389 /* Pack pixels into bytes */ 1390 if ((transforms & PNG_TRANSFORM_PACKING) != 0) 1391 #ifdef PNG_WRITE_PACK_SUPPORTED 1392 png_set_packing(png_ptr); 1393 #else 1394 png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported"); 1395 #endif 1396 1397 /* Swap location of alpha bytes from ARGB to RGBA */ 1398 if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0) 1399 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED 1400 png_set_swap_alpha(png_ptr); 1401 #else 1402 png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported"); 1403 #endif 1404 1405 /* Remove a filler (X) from XRGB/RGBX/AG/GA into to convert it into 1406 * RGB, note that the code expects the input color type to be G or RGB; no 1407 * alpha channel. 1408 */ 1409 if ((transforms & (PNG_TRANSFORM_STRIP_FILLER_AFTER| 1410 PNG_TRANSFORM_STRIP_FILLER_BEFORE)) != 0) 1411 { 1412 #ifdef PNG_WRITE_FILLER_SUPPORTED 1413 if ((transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) != 0) 1414 { 1415 if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0) 1416 png_app_error(png_ptr, 1417 "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported"); 1418 1419 /* Continue if ignored - this is the pre-1.6.10 behavior */ 1420 png_set_filler(png_ptr, 0, PNG_FILLER_AFTER); 1421 } 1422 1423 else if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0) 1424 png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); 1425 #else 1426 png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_FILLER not supported"); 1427 #endif 1428 } 1429 1430 /* Flip BGR pixels to RGB */ 1431 if ((transforms & PNG_TRANSFORM_BGR) != 0) 1432 #ifdef PNG_WRITE_BGR_SUPPORTED 1433 png_set_bgr(png_ptr); 1434 #else 1435 png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported"); 1436 #endif 1437 1438 /* Swap bytes of 16-bit files to most significant byte first */ 1439 if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0) 1440 #ifdef PNG_WRITE_SWAP_SUPPORTED 1441 png_set_swap(png_ptr); 1442 #else 1443 png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported"); 1444 #endif 1445 1446 /* Swap bits of 1-bit, 2-bit, 4-bit packed pixel formats */ 1447 if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0) 1448 #ifdef PNG_WRITE_PACKSWAP_SUPPORTED 1449 png_set_packswap(png_ptr); 1450 #else 1451 png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported"); 1452 #endif 1453 1454 /* Invert the alpha channel from opacity to transparency */ 1455 if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0) 1456 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED 1457 png_set_invert_alpha(png_ptr); 1458 #else 1459 png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported"); 1460 #endif 1461 1462 /* ----------------------- end of transformations ------------------- */ 1463 1464 /* Write the bits */ 1465 png_write_image(png_ptr, info_ptr->row_pointers); 1466 1467 /* It is REQUIRED to call this to finish writing the rest of the file */ 1468 png_write_end(png_ptr, info_ptr); 1469 1470 PNG_UNUSED(params) 1471 } 1472 #endif 1473 1474 1475 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED 1476 /* Initialize the write structure - general purpose utility. */ 1477 static int 1478 png_image_write_init(png_imagep image) 1479 { 1480 png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image, 1481 png_safe_error, png_safe_warning); 1482 1483 if (png_ptr != NULL) 1484 { 1485 png_infop info_ptr = png_create_info_struct(png_ptr); 1486 1487 if (info_ptr != NULL) 1488 { 1489 png_controlp control = png_voidcast(png_controlp, 1490 png_malloc_warn(png_ptr, (sizeof *control))); 1491 1492 if (control != NULL) 1493 { 1494 memset(control, 0, (sizeof *control)); 1495 1496 control->png_ptr = png_ptr; 1497 control->info_ptr = info_ptr; 1498 control->for_write = 1; 1499 1500 image->opaque = control; 1501 return 1; 1502 } 1503 1504 /* Error clean up */ 1505 png_destroy_info_struct(png_ptr, &info_ptr); 1506 } 1507 1508 png_destroy_write_struct(&png_ptr, NULL); 1509 } 1510 1511 return png_image_error(image, "png_image_write_: out of memory"); 1512 } 1513 1514 /* Arguments to png_image_write_main: */ 1515 typedef struct 1516 { 1517 /* Arguments: */ 1518 png_imagep image; 1519 png_const_voidp buffer; 1520 png_int_32 row_stride; 1521 png_const_voidp colormap; 1522 int convert_to_8bit; 1523 /* Local variables: */ 1524 png_const_voidp first_row; 1525 ptrdiff_t row_bytes; 1526 png_voidp local_row; 1527 /* Byte count for memory writing */ 1528 png_bytep memory; 1529 png_alloc_size_t memory_bytes; /* not used for STDIO */ 1530 png_alloc_size_t output_bytes; /* running total */ 1531 } png_image_write_control; 1532 1533 /* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to 1534 * do any necessary byte swapping. The component order is defined by the 1535 * png_image format value. 1536 */ 1537 static int 1538 png_write_image_16bit(png_voidp argument) 1539 { 1540 png_image_write_control *display = png_voidcast(png_image_write_control*, 1541 argument); 1542 png_imagep image = display->image; 1543 png_structrp png_ptr = image->opaque->png_ptr; 1544 1545 png_const_uint_16p input_row = png_voidcast(png_const_uint_16p, 1546 display->first_row); 1547 png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row); 1548 png_uint_16p row_end; 1549 unsigned int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 1550 3 : 1; 1551 int aindex = 0; 1552 png_uint_32 y = image->height; 1553 1554 if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0) 1555 { 1556 # ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED 1557 if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0) 1558 { 1559 aindex = -1; 1560 ++input_row; /* To point to the first component */ 1561 ++output_row; 1562 } 1563 else 1564 aindex = (int)channels; 1565 # else 1566 aindex = (int)channels; 1567 # endif 1568 } 1569 1570 else 1571 png_error(png_ptr, "png_write_image: internal call error"); 1572 1573 /* Work out the output row end and count over this, note that the increment 1574 * above to 'row' means that row_end can actually be beyond the end of the 1575 * row; this is correct. 1576 */ 1577 row_end = output_row + image->width * (channels+1); 1578 1579 for (; y > 0; --y) 1580 { 1581 png_const_uint_16p in_ptr = input_row; 1582 png_uint_16p out_ptr = output_row; 1583 1584 while (out_ptr < row_end) 1585 { 1586 png_uint_16 alpha = in_ptr[aindex]; 1587 png_uint_32 reciprocal = 0; 1588 int c; 1589 1590 out_ptr[aindex] = alpha; 1591 1592 /* Calculate a reciprocal. The correct calculation is simply 1593 * component/alpha*65535 << 15. (I.e. 15 bits of precision); this 1594 * allows correct rounding by adding .5 before the shift. 'reciprocal' 1595 * is only initialized when required. 1596 */ 1597 if (alpha > 0 && alpha < 65535) 1598 reciprocal = ((0xffff<<15)+(alpha>>1))/alpha; 1599 1600 c = (int)channels; 1601 do /* always at least one channel */ 1602 { 1603 png_uint_16 component = *in_ptr++; 1604 1605 /* The following gives 65535 for an alpha of 0, which is fine, 1606 * otherwise if 0/0 is represented as some other value there is more 1607 * likely to be a discontinuity which will probably damage 1608 * compression when moving from a fully transparent area to a 1609 * nearly transparent one. (The assumption here is that opaque 1610 * areas tend not to be 0 intensity.) 1611 */ 1612 if (component >= alpha) 1613 component = 65535; 1614 1615 /* component<alpha, so component/alpha is less than one and 1616 * component*reciprocal is less than 2^31. 1617 */ 1618 else if (component > 0 && alpha < 65535) 1619 { 1620 png_uint_32 calc = component * reciprocal; 1621 calc += 16384; /* round to nearest */ 1622 component = (png_uint_16)(calc >> 15); 1623 } 1624 1625 *out_ptr++ = component; 1626 } 1627 while (--c > 0); 1628 1629 /* Skip to next component (skip the intervening alpha channel) */ 1630 ++in_ptr; 1631 ++out_ptr; 1632 } 1633 1634 png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row)); 1635 input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16)); 1636 } 1637 1638 return 1; 1639 } 1640 1641 /* Given 16-bit input (1 to 4 channels) write 8-bit output. If an alpha channel 1642 * is present it must be removed from the components, the components are then 1643 * written in sRGB encoding. No components are added or removed. 1644 * 1645 * Calculate an alpha reciprocal to reverse pre-multiplication. As above the 1646 * calculation can be done to 15 bits of accuracy; however, the output needs to 1647 * be scaled in the range 0..255*65535, so include that scaling here. 1648 */ 1649 # define UNP_RECIPROCAL(alpha) ((((0xffff*0xff)<<7)+((alpha)>>1))/(alpha)) 1650 1651 static png_byte 1652 png_unpremultiply(png_uint_32 component, png_uint_32 alpha, 1653 png_uint_32 reciprocal/*from the above macro*/) 1654 { 1655 /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0 1656 * is represented as some other value there is more likely to be a 1657 * discontinuity which will probably damage compression when moving from a 1658 * fully transparent area to a nearly transparent one. (The assumption here 1659 * is that opaque areas tend not to be 0 intensity.) 1660 * 1661 * There is a rounding problem here; if alpha is less than 128 it will end up 1662 * as 0 when scaled to 8 bits. To avoid introducing spurious colors into the 1663 * output change for this too. 1664 */ 1665 if (component >= alpha || alpha < 128) 1666 return 255; 1667 1668 /* component<alpha, so component/alpha is less than one and 1669 * component*reciprocal is less than 2^31. 1670 */ 1671 else if (component > 0) 1672 { 1673 /* The test is that alpha/257 (rounded) is less than 255, the first value 1674 * that becomes 255 is 65407. 1675 * NOTE: this must agree with the PNG_DIV257 macro (which must, therefore, 1676 * be exact!) [Could also test reciprocal != 0] 1677 */ 1678 if (alpha < 65407) 1679 { 1680 component *= reciprocal; 1681 component += 64; /* round to nearest */ 1682 component >>= 7; 1683 } 1684 1685 else 1686 component *= 255; 1687 1688 /* Convert the component to sRGB. */ 1689 return (png_byte)PNG_sRGB_FROM_LINEAR(component); 1690 } 1691 1692 else 1693 return 0; 1694 } 1695 1696 static int 1697 png_write_image_8bit(png_voidp argument) 1698 { 1699 png_image_write_control *display = png_voidcast(png_image_write_control*, 1700 argument); 1701 png_imagep image = display->image; 1702 png_structrp png_ptr = image->opaque->png_ptr; 1703 1704 png_const_uint_16p input_row = png_voidcast(png_const_uint_16p, 1705 display->first_row); 1706 png_bytep output_row = png_voidcast(png_bytep, display->local_row); 1707 png_uint_32 y = image->height; 1708 unsigned int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 1709 3 : 1; 1710 1711 if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0) 1712 { 1713 png_bytep row_end; 1714 int aindex; 1715 1716 # ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED 1717 if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0) 1718 { 1719 aindex = -1; 1720 ++input_row; /* To point to the first component */ 1721 ++output_row; 1722 } 1723 1724 else 1725 # endif 1726 aindex = (int)channels; 1727 1728 /* Use row_end in place of a loop counter: */ 1729 row_end = output_row + image->width * (channels+1); 1730 1731 for (; y > 0; --y) 1732 { 1733 png_const_uint_16p in_ptr = input_row; 1734 png_bytep out_ptr = output_row; 1735 1736 while (out_ptr < row_end) 1737 { 1738 png_uint_16 alpha = in_ptr[aindex]; 1739 png_byte alphabyte = (png_byte)PNG_DIV257(alpha); 1740 png_uint_32 reciprocal = 0; 1741 int c; 1742 1743 /* Scale and write the alpha channel. */ 1744 out_ptr[aindex] = alphabyte; 1745 1746 if (alphabyte > 0 && alphabyte < 255) 1747 reciprocal = UNP_RECIPROCAL(alpha); 1748 1749 c = (int)channels; 1750 do /* always at least one channel */ 1751 *out_ptr++ = png_unpremultiply(*in_ptr++, alpha, reciprocal); 1752 while (--c > 0); 1753 1754 /* Skip to next component (skip the intervening alpha channel) */ 1755 ++in_ptr; 1756 ++out_ptr; 1757 } /* while out_ptr < row_end */ 1758 1759 png_write_row(png_ptr, png_voidcast(png_const_bytep, 1760 display->local_row)); 1761 input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16)); 1762 } /* while y */ 1763 } 1764 1765 else 1766 { 1767 /* No alpha channel, so the row_end really is the end of the row and it 1768 * is sufficient to loop over the components one by one. 1769 */ 1770 png_bytep row_end = output_row + image->width * channels; 1771 1772 for (; y > 0; --y) 1773 { 1774 png_const_uint_16p in_ptr = input_row; 1775 png_bytep out_ptr = output_row; 1776 1777 while (out_ptr < row_end) 1778 { 1779 png_uint_32 component = *in_ptr++; 1780 1781 component *= 255; 1782 *out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component); 1783 } 1784 1785 png_write_row(png_ptr, output_row); 1786 input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16)); 1787 } 1788 } 1789 1790 return 1; 1791 } 1792 1793 static void 1794 png_image_set_PLTE(png_image_write_control *display) 1795 { 1796 png_imagep image = display->image; 1797 const void *cmap = display->colormap; 1798 int entries = image->colormap_entries > 256 ? 256 : 1799 (int)image->colormap_entries; 1800 1801 /* NOTE: the caller must check for cmap != NULL and entries != 0 */ 1802 png_uint_32 format = image->format; 1803 unsigned int channels = PNG_IMAGE_SAMPLE_CHANNELS(format); 1804 1805 # if defined(PNG_FORMAT_BGR_SUPPORTED) &&\ 1806 defined(PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED) 1807 int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 && 1808 (format & PNG_FORMAT_FLAG_ALPHA) != 0; 1809 # else 1810 # define afirst 0 1811 # endif 1812 1813 # ifdef PNG_FORMAT_BGR_SUPPORTED 1814 int bgr = (format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0; 1815 # else 1816 # define bgr 0 1817 # endif 1818 1819 int i, num_trans; 1820 png_color palette[256]; 1821 png_byte tRNS[256]; 1822 1823 memset(tRNS, 255, (sizeof tRNS)); 1824 memset(palette, 0, (sizeof palette)); 1825 1826 for (i=num_trans=0; i<entries; ++i) 1827 { 1828 /* This gets automatically converted to sRGB with reversal of the 1829 * pre-multiplication if the color-map has an alpha channel. 1830 */ 1831 if ((format & PNG_FORMAT_FLAG_LINEAR) != 0) 1832 { 1833 png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap); 1834 1835 entry += (unsigned int)i * channels; 1836 1837 if ((channels & 1) != 0) /* no alpha */ 1838 { 1839 if (channels >= 3) /* RGB */ 1840 { 1841 palette[i].blue = (png_byte)PNG_sRGB_FROM_LINEAR(255 * 1842 entry[(2 ^ bgr)]); 1843 palette[i].green = (png_byte)PNG_sRGB_FROM_LINEAR(255 * 1844 entry[1]); 1845 palette[i].red = (png_byte)PNG_sRGB_FROM_LINEAR(255 * 1846 entry[bgr]); 1847 } 1848 1849 else /* Gray */ 1850 palette[i].blue = palette[i].red = palette[i].green = 1851 (png_byte)PNG_sRGB_FROM_LINEAR(255 * *entry); 1852 } 1853 1854 else /* alpha */ 1855 { 1856 png_uint_16 alpha = entry[afirst ? 0 : channels-1]; 1857 png_byte alphabyte = (png_byte)PNG_DIV257(alpha); 1858 png_uint_32 reciprocal = 0; 1859 1860 /* Calculate a reciprocal, as in the png_write_image_8bit code above 1861 * this is designed to produce a value scaled to 255*65535 when 1862 * divided by 128 (i.e. asr 7). 1863 */ 1864 if (alphabyte > 0 && alphabyte < 255) 1865 reciprocal = (((0xffff*0xff)<<7)+(alpha>>1))/alpha; 1866 1867 tRNS[i] = alphabyte; 1868 if (alphabyte < 255) 1869 num_trans = i+1; 1870 1871 if (channels >= 3) /* RGB */ 1872 { 1873 palette[i].blue = png_unpremultiply(entry[afirst + (2 ^ bgr)], 1874 alpha, reciprocal); 1875 palette[i].green = png_unpremultiply(entry[afirst + 1], alpha, 1876 reciprocal); 1877 palette[i].red = png_unpremultiply(entry[afirst + bgr], alpha, 1878 reciprocal); 1879 } 1880 1881 else /* gray */ 1882 palette[i].blue = palette[i].red = palette[i].green = 1883 png_unpremultiply(entry[afirst], alpha, reciprocal); 1884 } 1885 } 1886 1887 else /* Color-map has sRGB values */ 1888 { 1889 png_const_bytep entry = png_voidcast(png_const_bytep, cmap); 1890 1891 entry += (unsigned int)i * channels; 1892 1893 switch (channels) 1894 { 1895 case 4: 1896 tRNS[i] = entry[afirst ? 0 : 3]; 1897 if (tRNS[i] < 255) 1898 num_trans = i+1; 1899 /* FALLTHROUGH */ 1900 case 3: 1901 palette[i].blue = entry[afirst + (2 ^ bgr)]; 1902 palette[i].green = entry[afirst + 1]; 1903 palette[i].red = entry[afirst + bgr]; 1904 break; 1905 1906 case 2: 1907 tRNS[i] = entry[1 ^ afirst]; 1908 if (tRNS[i] < 255) 1909 num_trans = i+1; 1910 /* FALLTHROUGH */ 1911 case 1: 1912 palette[i].blue = palette[i].red = palette[i].green = 1913 entry[afirst]; 1914 break; 1915 1916 default: 1917 break; 1918 } 1919 } 1920 } 1921 1922 # ifdef afirst 1923 # undef afirst 1924 # endif 1925 # ifdef bgr 1926 # undef bgr 1927 # endif 1928 1929 png_set_PLTE(image->opaque->png_ptr, image->opaque->info_ptr, palette, 1930 entries); 1931 1932 if (num_trans > 0) 1933 png_set_tRNS(image->opaque->png_ptr, image->opaque->info_ptr, tRNS, 1934 num_trans, NULL); 1935 1936 image->colormap_entries = (png_uint_32)entries; 1937 } 1938 1939 static int 1940 png_image_write_main(png_voidp argument) 1941 { 1942 png_image_write_control *display = png_voidcast(png_image_write_control*, 1943 argument); 1944 png_imagep image = display->image; 1945 png_structrp png_ptr = image->opaque->png_ptr; 1946 png_inforp info_ptr = image->opaque->info_ptr; 1947 png_uint_32 format = image->format; 1948 1949 /* The following four ints are actually booleans */ 1950 int colormap = (format & PNG_FORMAT_FLAG_COLORMAP); 1951 int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR); /* input */ 1952 int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA); 1953 int write_16bit = linear && (display->convert_to_8bit == 0); 1954 1955 # ifdef PNG_BENIGN_ERRORS_SUPPORTED 1956 /* Make sure we error out on any bad situation */ 1957 png_set_benign_errors(png_ptr, 0/*error*/); 1958 # endif 1959 1960 /* Default the 'row_stride' parameter if required, also check the row stride 1961 * and total image size to ensure that they are within the system limits. 1962 */ 1963 { 1964 unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format); 1965 1966 if (image->width <= 0x7fffffffU/channels) /* no overflow */ 1967 { 1968 png_uint_32 check; 1969 png_uint_32 png_row_stride = image->width * channels; 1970 1971 if (display->row_stride == 0) 1972 display->row_stride = (png_int_32)/*SAFE*/png_row_stride; 1973 1974 if (display->row_stride < 0) 1975 check = (png_uint_32)(-display->row_stride); 1976 1977 else 1978 check = (png_uint_32)display->row_stride; 1979 1980 if (check >= png_row_stride) 1981 { 1982 /* Now check for overflow of the image buffer calculation; this 1983 * limits the whole image size to 32 bits for API compatibility with 1984 * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro. 1985 */ 1986 if (image->height > 0xffffffffU/png_row_stride) 1987 png_error(image->opaque->png_ptr, "memory image too large"); 1988 } 1989 1990 else 1991 png_error(image->opaque->png_ptr, "supplied row stride too small"); 1992 } 1993 1994 else 1995 png_error(image->opaque->png_ptr, "image row stride too large"); 1996 } 1997 1998 /* Set the required transforms then write the rows in the correct order. */ 1999 if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0) 2000 { 2001 if (display->colormap != NULL && image->colormap_entries > 0) 2002 { 2003 png_uint_32 entries = image->colormap_entries; 2004 2005 png_set_IHDR(png_ptr, info_ptr, image->width, image->height, 2006 entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)), 2007 PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE, 2008 PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); 2009 2010 png_image_set_PLTE(display); 2011 } 2012 2013 else 2014 png_error(image->opaque->png_ptr, 2015 "no color-map for color-mapped image"); 2016 } 2017 2018 else 2019 png_set_IHDR(png_ptr, info_ptr, image->width, image->height, 2020 write_16bit ? 16 : 8, 2021 ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) + 2022 ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0), 2023 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); 2024 2025 /* Counter-intuitively the data transformations must be called *after* 2026 * png_write_info, not before as in the read code, but the 'set' functions 2027 * must still be called before. Just set the color space information, never 2028 * write an interlaced image. 2029 */ 2030 2031 if (write_16bit != 0) 2032 { 2033 /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */ 2034 png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR); 2035 2036 if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0) 2037 png_set_cHRM_fixed(png_ptr, info_ptr, 2038 /* color x y */ 2039 /* white */ 31270, 32900, 2040 /* red */ 64000, 33000, 2041 /* green */ 30000, 60000, 2042 /* blue */ 15000, 6000 2043 ); 2044 } 2045 2046 else if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0) 2047 png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL); 2048 2049 /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit 2050 * space must still be gamma encoded. 2051 */ 2052 else 2053 png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE); 2054 2055 /* Write the file header. */ 2056 png_write_info(png_ptr, info_ptr); 2057 2058 /* Now set up the data transformations (*after* the header is written), 2059 * remove the handled transformations from the 'format' flags for checking. 2060 * 2061 * First check for a little endian system if writing 16-bit files. 2062 */ 2063 if (write_16bit != 0) 2064 { 2065 png_uint_16 le = 0x0001; 2066 2067 if ((*(png_const_bytep) & le) != 0) 2068 png_set_swap(png_ptr); 2069 } 2070 2071 # ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED 2072 if ((format & PNG_FORMAT_FLAG_BGR) != 0) 2073 { 2074 if (colormap == 0 && (format & PNG_FORMAT_FLAG_COLOR) != 0) 2075 png_set_bgr(png_ptr); 2076 format &= ~PNG_FORMAT_FLAG_BGR; 2077 } 2078 # endif 2079 2080 # ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED 2081 if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) 2082 { 2083 if (colormap == 0 && (format & PNG_FORMAT_FLAG_ALPHA) != 0) 2084 png_set_swap_alpha(png_ptr); 2085 format &= ~PNG_FORMAT_FLAG_AFIRST; 2086 } 2087 # endif 2088 2089 /* If there are 16 or fewer color-map entries we wrote a lower bit depth 2090 * above, but the application data is still byte packed. 2091 */ 2092 if (colormap != 0 && image->colormap_entries <= 16) 2093 png_set_packing(png_ptr); 2094 2095 /* That should have handled all (both) the transforms. */ 2096 if ((format & ~(png_uint_32)(PNG_FORMAT_FLAG_COLOR | PNG_FORMAT_FLAG_LINEAR | 2097 PNG_FORMAT_FLAG_ALPHA | PNG_FORMAT_FLAG_COLORMAP)) != 0) 2098 png_error(png_ptr, "png_write_image: unsupported transformation"); 2099 2100 { 2101 png_const_bytep row = png_voidcast(png_const_bytep, display->buffer); 2102 ptrdiff_t row_bytes = display->row_stride; 2103 2104 if (linear != 0) 2105 row_bytes *= (sizeof (png_uint_16)); 2106 2107 if (row_bytes < 0) 2108 row += (image->height-1) * (-row_bytes); 2109 2110 display->first_row = row; 2111 display->row_bytes = row_bytes; 2112 } 2113 2114 /* Apply 'fast' options if the flag is set. */ 2115 if ((image->flags & PNG_IMAGE_FLAG_FAST) != 0) 2116 { 2117 png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS); 2118 /* NOTE: determined by experiment using pngstest, this reflects some 2119 * balance between the time to write the image once and the time to read 2120 * it about 50 times. The speed-up in pngstest was about 10-20% of the 2121 * total (user) time on a heavily loaded system. 2122 */ 2123 # ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED 2124 png_set_compression_level(png_ptr, 3); 2125 # endif 2126 } 2127 2128 /* Check for the cases that currently require a pre-transform on the row 2129 * before it is written. This only applies when the input is 16-bit and 2130 * either there is an alpha channel or it is converted to 8-bit. 2131 */ 2132 if ((linear != 0 && alpha != 0 ) || 2133 (colormap == 0 && display->convert_to_8bit != 0)) 2134 { 2135 png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr, 2136 png_get_rowbytes(png_ptr, info_ptr))); 2137 int result; 2138 2139 display->local_row = row; 2140 if (write_16bit != 0) 2141 result = png_safe_execute(image, png_write_image_16bit, display); 2142 else 2143 result = png_safe_execute(image, png_write_image_8bit, display); 2144 display->local_row = NULL; 2145 2146 png_free(png_ptr, row); 2147 2148 /* Skip the 'write_end' on error: */ 2149 if (result == 0) 2150 return 0; 2151 } 2152 2153 /* Otherwise this is the case where the input is in a format currently 2154 * supported by the rest of the libpng write code; call it directly. 2155 */ 2156 else 2157 { 2158 png_const_bytep row = png_voidcast(png_const_bytep, display->first_row); 2159 ptrdiff_t row_bytes = display->row_bytes; 2160 png_uint_32 y = image->height; 2161 2162 for (; y > 0; --y) 2163 { 2164 png_write_row(png_ptr, row); 2165 row += row_bytes; 2166 } 2167 } 2168 2169 png_write_end(png_ptr, info_ptr); 2170 return 1; 2171 } 2172 2173 2174 static void (PNGCBAPI 2175 image_memory_write)(png_structp png_ptr, png_bytep/*const*/ data, size_t size) 2176 { 2177 png_image_write_control *display = png_voidcast(png_image_write_control*, 2178 png_ptr->io_ptr/*backdoor: png_get_io_ptr(png_ptr)*/); 2179 png_alloc_size_t ob = display->output_bytes; 2180 2181 /* Check for overflow; this should never happen: */ 2182 if (size <= ((png_alloc_size_t)-1) - ob) 2183 { 2184 /* I don't think libpng ever does this, but just in case: */ 2185 if (size > 0) 2186 { 2187 if (display->memory_bytes >= ob+size) /* writing */ 2188 memcpy(display->memory+ob, data, size); 2189 2190 /* Always update the size: */ 2191 display->output_bytes = ob+size; 2192 } 2193 } 2194 2195 else 2196 png_error(png_ptr, "png_image_write_to_memory: PNG too big"); 2197 } 2198 2199 static void (PNGCBAPI 2200 image_memory_flush)(png_structp png_ptr) 2201 { 2202 PNG_UNUSED(png_ptr) 2203 } 2204 2205 static int 2206 png_image_write_memory(png_voidp argument) 2207 { 2208 png_image_write_control *display = png_voidcast(png_image_write_control*, 2209 argument); 2210 2211 /* The rest of the memory-specific init and write_main in an error protected 2212 * environment. This case needs to use callbacks for the write operations 2213 * since libpng has no built in support for writing to memory. 2214 */ 2215 png_set_write_fn(display->image->opaque->png_ptr, display/*io_ptr*/, 2216 image_memory_write, image_memory_flush); 2217 2218 return png_image_write_main(display); 2219 } 2220 2221 int PNGAPI 2222 png_image_write_to_memory(png_imagep image, void *memory, 2223 png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8bit, 2224 const void *buffer, png_int_32 row_stride, const void *colormap) 2225 { 2226 /* Write the image to the given buffer, or count the bytes if it is NULL */ 2227 if (image != NULL && image->version == PNG_IMAGE_VERSION) 2228 { 2229 if (memory_bytes != NULL && buffer != NULL) 2230 { 2231 /* This is to give the caller an easier error detection in the NULL 2232 * case and guard against uninitialized variable problems: 2233 */ 2234 if (memory == NULL) 2235 *memory_bytes = 0; 2236 2237 if (png_image_write_init(image) != 0) 2238 { 2239 png_image_write_control display; 2240 int result; 2241 2242 memset(&display, 0, (sizeof display)); 2243 display.image = image; 2244 display.buffer = buffer; 2245 display.row_stride = row_stride; 2246 display.colormap = colormap; 2247 display.convert_to_8bit = convert_to_8bit; 2248 display.memory = png_voidcast(png_bytep, memory); 2249 display.memory_bytes = *memory_bytes; 2250 display.output_bytes = 0; 2251 2252 result = png_safe_execute(image, png_image_write_memory, &display); 2253 png_image_free(image); 2254 2255 /* write_memory returns true even if we ran out of buffer. */ 2256 if (result) 2257 { 2258 /* On out-of-buffer this function returns '0' but still updates 2259 * memory_bytes: 2260 */ 2261 if (memory != NULL && display.output_bytes > *memory_bytes) 2262 result = 0; 2263 2264 *memory_bytes = display.output_bytes; 2265 } 2266 2267 return result; 2268 } 2269 2270 else 2271 return 0; 2272 } 2273 2274 else 2275 return png_image_error(image, 2276 "png_image_write_to_memory: invalid argument"); 2277 } 2278 2279 else if (image != NULL) 2280 return png_image_error(image, 2281 "png_image_write_to_memory: incorrect PNG_IMAGE_VERSION"); 2282 2283 else 2284 return 0; 2285 } 2286 2287 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED 2288 int PNGAPI 2289 png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit, 2290 const void *buffer, png_int_32 row_stride, const void *colormap) 2291 { 2292 /* Write the image to the given (FILE*). */ 2293 if (image != NULL && image->version == PNG_IMAGE_VERSION) 2294 { 2295 if (file != NULL && buffer != NULL) 2296 { 2297 if (png_image_write_init(image) != 0) 2298 { 2299 png_image_write_control display; 2300 int result; 2301 2302 /* This is slightly evil, but png_init_io doesn't do anything other 2303 * than this and we haven't changed the standard IO functions so 2304 * this saves a 'safe' function. 2305 */ 2306 image->opaque->png_ptr->io_ptr = file; 2307 2308 memset(&display, 0, (sizeof display)); 2309 display.image = image; 2310 display.buffer = buffer; 2311 display.row_stride = row_stride; 2312 display.colormap = colormap; 2313 display.convert_to_8bit = convert_to_8bit; 2314 2315 result = png_safe_execute(image, png_image_write_main, &display); 2316 png_image_free(image); 2317 return result; 2318 } 2319 2320 else 2321 return 0; 2322 } 2323 2324 else 2325 return png_image_error(image, 2326 "png_image_write_to_stdio: invalid argument"); 2327 } 2328 2329 else if (image != NULL) 2330 return png_image_error(image, 2331 "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION"); 2332 2333 else 2334 return 0; 2335 } 2336 2337 int PNGAPI 2338 png_image_write_to_file(png_imagep image, const char *file_name, 2339 int convert_to_8bit, const void *buffer, png_int_32 row_stride, 2340 const void *colormap) 2341 { 2342 /* Write the image to the named file. */ 2343 if (image != NULL && image->version == PNG_IMAGE_VERSION) 2344 { 2345 if (file_name != NULL && buffer != NULL) 2346 { 2347 FILE *fp = fopen(file_name, "wb"); 2348 2349 if (fp != NULL) 2350 { 2351 if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer, 2352 row_stride, colormap) != 0) 2353 { 2354 int error; /* from fflush/fclose */ 2355 2356 /* Make sure the file is flushed correctly. */ 2357 if (fflush(fp) == 0 && ferror(fp) == 0) 2358 { 2359 if (fclose(fp) == 0) 2360 return 1; 2361 2362 error = errno; /* from fclose */ 2363 } 2364 2365 else 2366 { 2367 error = errno; /* from fflush or ferror */ 2368 (void)fclose(fp); 2369 } 2370 2371 (void)remove(file_name); 2372 /* The image has already been cleaned up; this is just used to 2373 * set the error (because the original write succeeded). 2374 */ 2375 return png_image_error(image, strerror(error)); 2376 } 2377 2378 else 2379 { 2380 /* Clean up: just the opened file. */ 2381 (void)fclose(fp); 2382 (void)remove(file_name); 2383 return 0; 2384 } 2385 } 2386 2387 else 2388 return png_image_error(image, strerror(errno)); 2389 } 2390 2391 else 2392 return png_image_error(image, 2393 "png_image_write_to_file: invalid argument"); 2394 } 2395 2396 else if (image != NULL) 2397 return png_image_error(image, 2398 "png_image_write_to_file: incorrect PNG_IMAGE_VERSION"); 2399 2400 else 2401 return 0; 2402 } 2403 #endif /* SIMPLIFIED_WRITE_STDIO */ 2404 #endif /* SIMPLIFIED_WRITE */ 2405 #endif /* WRITE */ 2406