PageRenderTime 129ms CodeModel.GetById 20ms app.highlight 98ms RepoModel.GetById 1ms app.codeStats 0ms

/src/FreeImage/Source/LibPNG/pngwrite.c

https://bitbucket.org/cabalistic/ogredeps/
C | 1655 lines | 1198 code | 246 blank | 211 comment | 284 complexity | afcc7da336ac5d4166ab7aed311ab8df MD5 | raw file

Large files files are truncated, but you can click here to view the full file

   1
   2/* pngwrite.c - general routines to write a PNG file
   3 *
   4 * Last changed in libpng 1.5.7 [December 15, 2011]
   5 * Copyright (c) 1998-2011 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
  16#ifdef PNG_WRITE_SUPPORTED
  17
  18/* Writes all the PNG information.  This is the suggested way to use the
  19 * library.  If you have a new chunk to add, make a function to write it,
  20 * and put it in the correct location here.  If you want the chunk written
  21 * after the image data, put it in png_write_end().  I strongly encourage
  22 * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
  23 * the chunk, as that will keep the code from breaking if you want to just
  24 * write a plain PNG file.  If you have long comments, I suggest writing
  25 * them in png_write_end(), and compressing them.
  26 */
  27void PNGAPI
  28png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
  29{
  30   png_debug(1, "in png_write_info_before_PLTE");
  31
  32   if (png_ptr == NULL || info_ptr == NULL)
  33      return;
  34
  35   if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
  36   {
  37   /* Write PNG signature */
  38   png_write_sig(png_ptr);
  39
  40#ifdef PNG_MNG_FEATURES_SUPPORTED
  41   if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) && \
  42       (png_ptr->mng_features_permitted))
  43   {
  44      png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
  45      png_ptr->mng_features_permitted = 0;
  46   }
  47#endif
  48
  49   /* Write IHDR information. */
  50   png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
  51       info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
  52       info_ptr->filter_type,
  53#ifdef PNG_WRITE_INTERLACING_SUPPORTED
  54       info_ptr->interlace_type);
  55#else
  56       0);
  57#endif
  58   /* The rest of these check to see if the valid field has the appropriate
  59    * flag set, and if it does, writes the chunk.
  60    */
  61#ifdef PNG_WRITE_gAMA_SUPPORTED
  62   if (info_ptr->valid & PNG_INFO_gAMA)
  63      png_write_gAMA_fixed(png_ptr, info_ptr->gamma);
  64#endif
  65#ifdef PNG_WRITE_sRGB_SUPPORTED
  66   if (info_ptr->valid & PNG_INFO_sRGB)
  67      png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
  68#endif
  69
  70#ifdef PNG_WRITE_iCCP_SUPPORTED
  71   if (info_ptr->valid & PNG_INFO_iCCP)
  72      png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
  73          (png_charp)info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
  74#endif
  75#ifdef PNG_WRITE_sBIT_SUPPORTED
  76   if (info_ptr->valid & PNG_INFO_sBIT)
  77      png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
  78#endif
  79#ifdef PNG_WRITE_cHRM_SUPPORTED
  80   if (info_ptr->valid & PNG_INFO_cHRM)
  81      png_write_cHRM_fixed(png_ptr,
  82          info_ptr->x_white, info_ptr->y_white,
  83          info_ptr->x_red, info_ptr->y_red,
  84          info_ptr->x_green, info_ptr->y_green,
  85          info_ptr->x_blue, info_ptr->y_blue);
  86#endif
  87
  88#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
  89   if (info_ptr->unknown_chunks_num)
  90   {
  91      png_unknown_chunk *up;
  92
  93      png_debug(5, "writing extra chunks");
  94
  95      for (up = info_ptr->unknown_chunks;
  96           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
  97           up++)
  98      {
  99         int keep = png_handle_as_unknown(png_ptr, up->name);
 100
 101         if (keep != PNG_HANDLE_CHUNK_NEVER &&
 102             up->location &&
 103             !(up->location & PNG_HAVE_PLTE) &&
 104             !(up->location & PNG_HAVE_IDAT) &&
 105             !(up->location & PNG_AFTER_IDAT) &&
 106             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
 107             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
 108         {
 109            if (up->size == 0)
 110               png_warning(png_ptr, "Writing zero-length unknown chunk");
 111
 112            png_write_chunk(png_ptr, up->name, up->data, up->size);
 113         }
 114      }
 115   }
 116#endif
 117      png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
 118   }
 119}
 120
 121void PNGAPI
 122png_write_info(png_structp png_ptr, png_infop info_ptr)
 123{
 124#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
 125   int i;
 126#endif
 127
 128   png_debug(1, "in png_write_info");
 129
 130   if (png_ptr == NULL || info_ptr == NULL)
 131      return;
 132
 133   png_write_info_before_PLTE(png_ptr, info_ptr);
 134
 135   if (info_ptr->valid & PNG_INFO_PLTE)
 136      png_write_PLTE(png_ptr, info_ptr->palette,
 137          (png_uint_32)info_ptr->num_palette);
 138
 139   else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
 140      png_error(png_ptr, "Valid palette required for paletted images");
 141
 142#ifdef PNG_WRITE_tRNS_SUPPORTED
 143   if (info_ptr->valid & PNG_INFO_tRNS)
 144   {
 145#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
 146      /* Invert the alpha channel (in tRNS) */
 147      if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
 148          info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
 149      {
 150         int j;
 151         for (j = 0; j<(int)info_ptr->num_trans; j++)
 152            info_ptr->trans_alpha[j] =
 153               (png_byte)(255 - info_ptr->trans_alpha[j]);
 154      }
 155#endif
 156      png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color),
 157          info_ptr->num_trans, info_ptr->color_type);
 158   }
 159#endif
 160#ifdef PNG_WRITE_bKGD_SUPPORTED
 161   if (info_ptr->valid & PNG_INFO_bKGD)
 162      png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
 163#endif
 164
 165#ifdef PNG_WRITE_hIST_SUPPORTED
 166   if (info_ptr->valid & PNG_INFO_hIST)
 167      png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
 168#endif
 169
 170#ifdef PNG_WRITE_oFFs_SUPPORTED
 171   if (info_ptr->valid & PNG_INFO_oFFs)
 172      png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
 173          info_ptr->offset_unit_type);
 174#endif
 175
 176#ifdef PNG_WRITE_pCAL_SUPPORTED
 177   if (info_ptr->valid & PNG_INFO_pCAL)
 178      png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
 179          info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
 180          info_ptr->pcal_units, info_ptr->pcal_params);
 181#endif
 182
 183#ifdef PNG_WRITE_sCAL_SUPPORTED
 184   if (info_ptr->valid & PNG_INFO_sCAL)
 185      png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
 186          info_ptr->scal_s_width, info_ptr->scal_s_height);
 187#endif /* sCAL */
 188
 189#ifdef PNG_WRITE_pHYs_SUPPORTED
 190   if (info_ptr->valid & PNG_INFO_pHYs)
 191      png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
 192          info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
 193#endif /* pHYs */
 194
 195#ifdef PNG_WRITE_tIME_SUPPORTED
 196   if (info_ptr->valid & PNG_INFO_tIME)
 197   {
 198      png_write_tIME(png_ptr, &(info_ptr->mod_time));
 199      png_ptr->mode |= PNG_WROTE_tIME;
 200   }
 201#endif /* tIME */
 202
 203#ifdef PNG_WRITE_sPLT_SUPPORTED
 204   if (info_ptr->valid & PNG_INFO_sPLT)
 205      for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
 206         png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
 207#endif /* sPLT */
 208
 209#ifdef PNG_WRITE_TEXT_SUPPORTED
 210   /* Check to see if we need to write text chunks */
 211   for (i = 0; i < info_ptr->num_text; i++)
 212   {
 213      png_debug2(2, "Writing header text chunk %d, type %d", i,
 214          info_ptr->text[i].compression);
 215      /* An internationalized chunk? */
 216      if (info_ptr->text[i].compression > 0)
 217      {
 218#ifdef PNG_WRITE_iTXt_SUPPORTED
 219         /* Write international chunk */
 220         png_write_iTXt(png_ptr,
 221             info_ptr->text[i].compression,
 222             info_ptr->text[i].key,
 223             info_ptr->text[i].lang,
 224             info_ptr->text[i].lang_key,
 225             info_ptr->text[i].text);
 226#else
 227          png_warning(png_ptr, "Unable to write international text");
 228#endif
 229          /* Mark this chunk as written */
 230          info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
 231      }
 232
 233      /* If we want a compressed text chunk */
 234      else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
 235      {
 236#ifdef PNG_WRITE_zTXt_SUPPORTED
 237         /* Write compressed chunk */
 238         png_write_zTXt(png_ptr, info_ptr->text[i].key,
 239             info_ptr->text[i].text, 0,
 240             info_ptr->text[i].compression);
 241#else
 242         png_warning(png_ptr, "Unable to write compressed text");
 243#endif
 244         /* Mark this chunk as written */
 245         info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
 246      }
 247
 248      else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
 249      {
 250#ifdef PNG_WRITE_tEXt_SUPPORTED
 251         /* Write uncompressed chunk */
 252         png_write_tEXt(png_ptr, info_ptr->text[i].key,
 253             info_ptr->text[i].text,
 254             0);
 255         /* Mark this chunk as written */
 256         info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
 257#else
 258         /* Can't get here */
 259         png_warning(png_ptr, "Unable to write uncompressed text");
 260#endif
 261      }
 262   }
 263#endif /* tEXt */
 264
 265#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
 266   if (info_ptr->unknown_chunks_num)
 267   {
 268      png_unknown_chunk *up;
 269
 270      png_debug(5, "writing extra chunks");
 271
 272      for (up = info_ptr->unknown_chunks;
 273           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
 274           up++)
 275      {
 276         int keep = png_handle_as_unknown(png_ptr, up->name);
 277         if (keep != PNG_HANDLE_CHUNK_NEVER &&
 278             up->location &&
 279             (up->location & PNG_HAVE_PLTE) &&
 280             !(up->location & PNG_HAVE_IDAT) &&
 281             !(up->location & PNG_AFTER_IDAT) &&
 282             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
 283             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
 284         {
 285            png_write_chunk(png_ptr, up->name, up->data, up->size);
 286         }
 287      }
 288   }
 289#endif
 290}
 291
 292/* Writes the end of the PNG file.  If you don't want to write comments or
 293 * time information, you can pass NULL for info.  If you already wrote these
 294 * in png_write_info(), do not write them again here.  If you have long
 295 * comments, I suggest writing them here, and compressing them.
 296 */
 297void PNGAPI
 298png_write_end(png_structp png_ptr, png_infop info_ptr)
 299{
 300   png_debug(1, "in png_write_end");
 301
 302   if (png_ptr == NULL)
 303      return;
 304
 305   if (!(png_ptr->mode & PNG_HAVE_IDAT))
 306      png_error(png_ptr, "No IDATs written into file");
 307
 308   /* See if user wants us to write information chunks */
 309   if (info_ptr != NULL)
 310   {
 311#ifdef PNG_WRITE_TEXT_SUPPORTED
 312      int i; /* local index variable */
 313#endif
 314#ifdef PNG_WRITE_tIME_SUPPORTED
 315      /* Check to see if user has supplied a time chunk */
 316      if ((info_ptr->valid & PNG_INFO_tIME) &&
 317          !(png_ptr->mode & PNG_WROTE_tIME))
 318         png_write_tIME(png_ptr, &(info_ptr->mod_time));
 319
 320#endif
 321#ifdef PNG_WRITE_TEXT_SUPPORTED
 322      /* Loop through comment chunks */
 323      for (i = 0; i < info_ptr->num_text; i++)
 324      {
 325         png_debug2(2, "Writing trailer text chunk %d, type %d", i,
 326            info_ptr->text[i].compression);
 327         /* An internationalized chunk? */
 328         if (info_ptr->text[i].compression > 0)
 329         {
 330#ifdef PNG_WRITE_iTXt_SUPPORTED
 331            /* Write international chunk */
 332            png_write_iTXt(png_ptr,
 333                info_ptr->text[i].compression,
 334                info_ptr->text[i].key,
 335                info_ptr->text[i].lang,
 336                info_ptr->text[i].lang_key,
 337                info_ptr->text[i].text);
 338#else
 339            png_warning(png_ptr, "Unable to write international text");
 340#endif
 341            /* Mark this chunk as written */
 342            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
 343         }
 344
 345         else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
 346         {
 347#ifdef PNG_WRITE_zTXt_SUPPORTED
 348            /* Write compressed chunk */
 349            png_write_zTXt(png_ptr, info_ptr->text[i].key,
 350                info_ptr->text[i].text, 0,
 351                info_ptr->text[i].compression);
 352#else
 353            png_warning(png_ptr, "Unable to write compressed text");
 354#endif
 355            /* Mark this chunk as written */
 356            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
 357         }
 358
 359         else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
 360         {
 361#ifdef PNG_WRITE_tEXt_SUPPORTED
 362            /* Write uncompressed chunk */
 363            png_write_tEXt(png_ptr, info_ptr->text[i].key,
 364                info_ptr->text[i].text, 0);
 365#else
 366            png_warning(png_ptr, "Unable to write uncompressed text");
 367#endif
 368
 369            /* Mark this chunk as written */
 370            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
 371         }
 372      }
 373#endif
 374#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
 375   if (info_ptr->unknown_chunks_num)
 376   {
 377      png_unknown_chunk *up;
 378
 379      png_debug(5, "writing extra chunks");
 380
 381      for (up = info_ptr->unknown_chunks;
 382           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
 383           up++)
 384      {
 385         int keep = png_handle_as_unknown(png_ptr, up->name);
 386         if (keep != PNG_HANDLE_CHUNK_NEVER &&
 387             up->location &&
 388             (up->location & PNG_AFTER_IDAT) &&
 389             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
 390             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
 391         {
 392            png_write_chunk(png_ptr, up->name, up->data, up->size);
 393         }
 394      }
 395   }
 396#endif
 397   }
 398
 399   png_ptr->mode |= PNG_AFTER_IDAT;
 400
 401   /* Write end of PNG file */
 402   png_write_IEND(png_ptr);
 403   /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
 404    * and restored again in libpng-1.2.30, may cause some applications that
 405    * do not set png_ptr->output_flush_fn to crash.  If your application
 406    * experiences a problem, please try building libpng with
 407    * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
 408    * png-mng-implement at lists.sf.net .
 409    */
 410#ifdef PNG_WRITE_FLUSH_SUPPORTED
 411#  ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
 412   png_flush(png_ptr);
 413#  endif
 414#endif
 415}
 416
 417#ifdef PNG_CONVERT_tIME_SUPPORTED
 418/* "tm" structure is not supported on WindowsCE */
 419void PNGAPI
 420png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm FAR * ttime)
 421{
 422   png_debug(1, "in png_convert_from_struct_tm");
 423
 424   ptime->year = (png_uint_16)(1900 + ttime->tm_year);
 425   ptime->month = (png_byte)(ttime->tm_mon + 1);
 426   ptime->day = (png_byte)ttime->tm_mday;
 427   ptime->hour = (png_byte)ttime->tm_hour;
 428   ptime->minute = (png_byte)ttime->tm_min;
 429   ptime->second = (png_byte)ttime->tm_sec;
 430}
 431
 432void PNGAPI
 433png_convert_from_time_t(png_timep ptime, time_t ttime)
 434{
 435   struct tm *tbuf;
 436
 437   png_debug(1, "in png_convert_from_time_t");
 438
 439   tbuf = gmtime(&ttime);
 440   png_convert_from_struct_tm(ptime, tbuf);
 441}
 442#endif
 443
 444/* Initialize png_ptr structure, and allocate any memory needed */
 445PNG_FUNCTION(png_structp,PNGAPI
 446png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
 447    png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
 448{
 449#ifdef PNG_USER_MEM_SUPPORTED
 450   return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
 451       warn_fn, NULL, NULL, NULL));
 452}
 453
 454/* Alternate initialize png_ptr structure, and allocate any memory needed */
 455static void png_reset_filter_heuristics(png_structp png_ptr); /* forward decl */
 456
 457PNG_FUNCTION(png_structp,PNGAPI
 458png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
 459    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
 460    png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
 461{
 462#endif /* PNG_USER_MEM_SUPPORTED */
 463   volatile int png_cleanup_needed = 0;
 464#ifdef PNG_SETJMP_SUPPORTED
 465   volatile
 466#endif
 467   png_structp png_ptr;
 468#ifdef PNG_SETJMP_SUPPORTED
 469#ifdef USE_FAR_KEYWORD
 470   jmp_buf tmp_jmpbuf;
 471#endif
 472#endif
 473
 474   png_debug(1, "in png_create_write_struct");
 475
 476#ifdef PNG_USER_MEM_SUPPORTED
 477   png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
 478       (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
 479#else
 480   png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
 481#endif /* PNG_USER_MEM_SUPPORTED */
 482   if (png_ptr == NULL)
 483      return (NULL);
 484
 485   /* Added at libpng-1.2.6 */
 486#ifdef PNG_SET_USER_LIMITS_SUPPORTED
 487   png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
 488   png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
 489#endif
 490
 491#ifdef PNG_SETJMP_SUPPORTED
 492/* Applications that neglect to set up their own setjmp() and then
 493 * encounter a png_error() will longjmp here.  Since the jmpbuf is
 494 * then meaningless we abort instead of returning.
 495 */
 496#ifdef USE_FAR_KEYWORD
 497   if (setjmp(tmp_jmpbuf))
 498#else
 499   if (setjmp(png_jmpbuf(png_ptr))) /* sets longjmp to match setjmp */
 500#endif
 501#ifdef USE_FAR_KEYWORD
 502   png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
 503#endif
 504      PNG_ABORT();
 505#endif
 506
 507#ifdef PNG_USER_MEM_SUPPORTED
 508   png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
 509#endif /* PNG_USER_MEM_SUPPORTED */
 510   png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 511
 512   if (!png_user_version_check(png_ptr, user_png_ver))
 513      png_cleanup_needed = 1;
 514
 515   /* Initialize zbuf - compression buffer */
 516   png_ptr->zbuf_size = PNG_ZBUF_SIZE;
 517
 518   if (!png_cleanup_needed)
 519   {
 520      png_ptr->zbuf = (png_bytep)png_malloc_warn(png_ptr,
 521          png_ptr->zbuf_size);
 522      if (png_ptr->zbuf == NULL)
 523         png_cleanup_needed = 1;
 524   }
 525
 526   if (png_cleanup_needed)
 527   {
 528       /* Clean up PNG structure and deallocate any memory. */
 529       png_free(png_ptr, png_ptr->zbuf);
 530       png_ptr->zbuf = NULL;
 531#ifdef PNG_USER_MEM_SUPPORTED
 532       png_destroy_struct_2((png_voidp)png_ptr,
 533           (png_free_ptr)free_fn, (png_voidp)mem_ptr);
 534#else
 535       png_destroy_struct((png_voidp)png_ptr);
 536#endif
 537       return (NULL);
 538   }
 539
 540   png_set_write_fn(png_ptr, NULL, NULL, NULL);
 541
 542#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
 543   png_reset_filter_heuristics(png_ptr);
 544#endif
 545
 546   return (png_ptr);
 547}
 548
 549
 550/* Write a few rows of image data.  If the image is interlaced,
 551 * either you will have to write the 7 sub images, or, if you
 552 * have called png_set_interlace_handling(), you will have to
 553 * "write" the image seven times.
 554 */
 555void PNGAPI
 556png_write_rows(png_structp png_ptr, png_bytepp row,
 557    png_uint_32 num_rows)
 558{
 559   png_uint_32 i; /* row counter */
 560   png_bytepp rp; /* row pointer */
 561
 562   png_debug(1, "in png_write_rows");
 563
 564   if (png_ptr == NULL)
 565      return;
 566
 567   /* Loop through the rows */
 568   for (i = 0, rp = row; i < num_rows; i++, rp++)
 569   {
 570      png_write_row(png_ptr, *rp);
 571   }
 572}
 573
 574/* Write the image.  You only need to call this function once, even
 575 * if you are writing an interlaced image.
 576 */
 577void PNGAPI
 578png_write_image(png_structp png_ptr, png_bytepp image)
 579{
 580   png_uint_32 i; /* row index */
 581   int pass, num_pass; /* pass variables */
 582   png_bytepp rp; /* points to current row */
 583
 584   if (png_ptr == NULL)
 585      return;
 586
 587   png_debug(1, "in png_write_image");
 588
 589#ifdef PNG_WRITE_INTERLACING_SUPPORTED
 590   /* Initialize interlace handling.  If image is not interlaced,
 591    * this will set pass to 1
 592    */
 593   num_pass = png_set_interlace_handling(png_ptr);
 594#else
 595   num_pass = 1;
 596#endif
 597   /* Loop through passes */
 598   for (pass = 0; pass < num_pass; pass++)
 599   {
 600      /* Loop through image */
 601      for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
 602      {
 603         png_write_row(png_ptr, *rp);
 604      }
 605   }
 606}
 607
 608/* Called by user to write a row of image data */
 609void PNGAPI
 610png_write_row(png_structp png_ptr, png_const_bytep row)
 611{
 612   /* 1.5.6: moved from png_struct to be a local structure: */
 613   png_row_info row_info;
 614
 615   if (png_ptr == NULL)
 616      return;
 617
 618   png_debug2(1, "in png_write_row (row %u, pass %d)",
 619      png_ptr->row_number, png_ptr->pass);
 620
 621   /* Initialize transformations and other stuff if first time */
 622   if (png_ptr->row_number == 0 && png_ptr->pass == 0)
 623   {
 624      /* Make sure we wrote the header info */
 625      if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
 626         png_error(png_ptr,
 627             "png_write_info was never called before png_write_row");
 628
 629      /* Check for transforms that have been set but were defined out */
 630#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
 631      if (png_ptr->transformations & PNG_INVERT_MONO)
 632         png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined");
 633#endif
 634
 635#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
 636      if (png_ptr->transformations & PNG_FILLER)
 637         png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined");
 638#endif
 639#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
 640    defined(PNG_READ_PACKSWAP_SUPPORTED)
 641      if (png_ptr->transformations & PNG_PACKSWAP)
 642         png_warning(png_ptr,
 643             "PNG_WRITE_PACKSWAP_SUPPORTED is not defined");
 644#endif
 645
 646#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
 647      if (png_ptr->transformations & PNG_PACK)
 648         png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined");
 649#endif
 650
 651#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
 652      if (png_ptr->transformations & PNG_SHIFT)
 653         png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined");
 654#endif
 655
 656#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
 657      if (png_ptr->transformations & PNG_BGR)
 658         png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined");
 659#endif
 660
 661#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
 662      if (png_ptr->transformations & PNG_SWAP_BYTES)
 663         png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined");
 664#endif
 665
 666      png_write_start_row(png_ptr);
 667   }
 668
 669#ifdef PNG_WRITE_INTERLACING_SUPPORTED
 670   /* If interlaced and not interested in row, return */
 671   if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
 672   {
 673      switch (png_ptr->pass)
 674      {
 675         case 0:
 676            if (png_ptr->row_number & 0x07)
 677            {
 678               png_write_finish_row(png_ptr);
 679               return;
 680            }
 681            break;
 682
 683         case 1:
 684            if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
 685            {
 686               png_write_finish_row(png_ptr);
 687               return;
 688            }
 689            break;
 690
 691         case 2:
 692            if ((png_ptr->row_number & 0x07) != 4)
 693            {
 694               png_write_finish_row(png_ptr);
 695               return;
 696            }
 697            break;
 698
 699         case 3:
 700            if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
 701            {
 702               png_write_finish_row(png_ptr);
 703               return;
 704            }
 705            break;
 706
 707         case 4:
 708            if ((png_ptr->row_number & 0x03) != 2)
 709            {
 710               png_write_finish_row(png_ptr);
 711               return;
 712            }
 713            break;
 714
 715         case 5:
 716            if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
 717            {
 718               png_write_finish_row(png_ptr);
 719               return;
 720            }
 721            break;
 722
 723         case 6:
 724            if (!(png_ptr->row_number & 0x01))
 725            {
 726               png_write_finish_row(png_ptr);
 727               return;
 728            }
 729            break;
 730
 731         default: /* error: ignore it */
 732            break;
 733      }
 734   }
 735#endif
 736
 737   /* Set up row info for transformations */
 738   row_info.color_type = png_ptr->color_type;
 739   row_info.width = png_ptr->usr_width;
 740   row_info.channels = png_ptr->usr_channels;
 741   row_info.bit_depth = png_ptr->usr_bit_depth;
 742   row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels);
 743   row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
 744
 745   png_debug1(3, "row_info->color_type = %d", row_info.color_type);
 746   png_debug1(3, "row_info->width = %u", row_info.width);
 747   png_debug1(3, "row_info->channels = %d", row_info.channels);
 748   png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth);
 749   png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth);
 750   png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes);
 751
 752   /* Copy user's row into buffer, leaving room for filter byte. */
 753   png_memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
 754
 755#ifdef PNG_WRITE_INTERLACING_SUPPORTED
 756   /* Handle interlacing */
 757   if (png_ptr->interlaced && png_ptr->pass < 6 &&
 758       (png_ptr->transformations & PNG_INTERLACE))
 759   {
 760      png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass);
 761      /* This should always get caught above, but still ... */
 762      if (!(row_info.width))
 763      {
 764         png_write_finish_row(png_ptr);
 765         return;
 766      }
 767   }
 768#endif
 769
 770#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
 771   /* Handle other transformations */
 772   if (png_ptr->transformations)
 773      png_do_write_transformations(png_ptr, &row_info);
 774#endif
 775
 776   /* At this point the row_info pixel depth must match the 'transformed' depth,
 777    * which is also the output depth.
 778    */
 779   if (row_info.pixel_depth != png_ptr->pixel_depth ||
 780      row_info.pixel_depth != png_ptr->transformed_pixel_depth)
 781      png_error(png_ptr, "internal write transform logic error");
 782
 783#ifdef PNG_MNG_FEATURES_SUPPORTED
 784   /* Write filter_method 64 (intrapixel differencing) only if
 785    * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
 786    * 2. Libpng did not write a PNG signature (this filter_method is only
 787    *    used in PNG datastreams that are embedded in MNG datastreams) and
 788    * 3. The application called png_permit_mng_features with a mask that
 789    *    included PNG_FLAG_MNG_FILTER_64 and
 790    * 4. The filter_method is 64 and
 791    * 5. The color_type is RGB or RGBA
 792    */
 793   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
 794       (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
 795   {
 796      /* Intrapixel differencing */
 797      png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1);
 798   }
 799#endif
 800
 801   /* Find a filter if necessary, filter the row and write it out. */
 802   png_write_find_filter(png_ptr, &row_info);
 803
 804   if (png_ptr->write_row_fn != NULL)
 805      (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
 806}
 807
 808#ifdef PNG_WRITE_FLUSH_SUPPORTED
 809/* Set the automatic flush interval or 0 to turn flushing off */
 810void PNGAPI
 811png_set_flush(png_structp png_ptr, int nrows)
 812{
 813   png_debug(1, "in png_set_flush");
 814
 815   if (png_ptr == NULL)
 816      return;
 817
 818   png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
 819}
 820
 821/* Flush the current output buffers now */
 822void PNGAPI
 823png_write_flush(png_structp png_ptr)
 824{
 825   int wrote_IDAT;
 826
 827   png_debug(1, "in png_write_flush");
 828
 829   if (png_ptr == NULL)
 830      return;
 831
 832   /* We have already written out all of the data */
 833   if (png_ptr->row_number >= png_ptr->num_rows)
 834      return;
 835
 836   do
 837   {
 838      int ret;
 839
 840      /* Compress the data */
 841      ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
 842      wrote_IDAT = 0;
 843
 844      /* Check for compression errors */
 845      if (ret != Z_OK)
 846      {
 847         if (png_ptr->zstream.msg != NULL)
 848            png_error(png_ptr, png_ptr->zstream.msg);
 849
 850         else
 851            png_error(png_ptr, "zlib error");
 852      }
 853
 854      if (!(png_ptr->zstream.avail_out))
 855      {
 856         /* Write the IDAT and reset the zlib output buffer */
 857         png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
 858         wrote_IDAT = 1;
 859      }
 860   } while (wrote_IDAT == 1);
 861
 862   /* If there is any data left to be output, write it into a new IDAT */
 863   if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
 864   {
 865      /* Write the IDAT and reset the zlib output buffer */
 866      png_write_IDAT(png_ptr, png_ptr->zbuf,
 867          png_ptr->zbuf_size - png_ptr->zstream.avail_out);
 868   }
 869   png_ptr->flush_rows = 0;
 870   png_flush(png_ptr);
 871}
 872#endif /* PNG_WRITE_FLUSH_SUPPORTED */
 873
 874/* Free all memory used by the write */
 875void PNGAPI
 876png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
 877{
 878   png_structp png_ptr = NULL;
 879   png_infop info_ptr = NULL;
 880#ifdef PNG_USER_MEM_SUPPORTED
 881   png_free_ptr free_fn = NULL;
 882   png_voidp mem_ptr = NULL;
 883#endif
 884
 885   png_debug(1, "in png_destroy_write_struct");
 886
 887   if (png_ptr_ptr != NULL)
 888      png_ptr = *png_ptr_ptr;
 889
 890#ifdef PNG_USER_MEM_SUPPORTED
 891   if (png_ptr != NULL)
 892   {
 893      free_fn = png_ptr->free_fn;
 894      mem_ptr = png_ptr->mem_ptr;
 895   }
 896#endif
 897
 898   if (info_ptr_ptr != NULL)
 899      info_ptr = *info_ptr_ptr;
 900
 901   if (info_ptr != NULL)
 902   {
 903      if (png_ptr != NULL)
 904      {
 905         png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
 906
 907#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
 908         if (png_ptr->num_chunk_list)
 909         {
 910            png_free(png_ptr, png_ptr->chunk_list);
 911            png_ptr->num_chunk_list = 0;
 912         }
 913#endif
 914      }
 915
 916#ifdef PNG_USER_MEM_SUPPORTED
 917      png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
 918          (png_voidp)mem_ptr);
 919#else
 920      png_destroy_struct((png_voidp)info_ptr);
 921#endif
 922      *info_ptr_ptr = NULL;
 923   }
 924
 925   if (png_ptr != NULL)
 926   {
 927      png_write_destroy(png_ptr);
 928#ifdef PNG_USER_MEM_SUPPORTED
 929      png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
 930          (png_voidp)mem_ptr);
 931#else
 932      png_destroy_struct((png_voidp)png_ptr);
 933#endif
 934      *png_ptr_ptr = NULL;
 935   }
 936}
 937
 938
 939/* Free any memory used in png_ptr struct (old method) */
 940void /* PRIVATE */
 941png_write_destroy(png_structp png_ptr)
 942{
 943#ifdef PNG_SETJMP_SUPPORTED
 944   jmp_buf tmp_jmp; /* Save jump buffer */
 945#endif
 946   png_error_ptr error_fn;
 947#ifdef PNG_WARNINGS_SUPPORTED
 948   png_error_ptr warning_fn;
 949#endif
 950   png_voidp error_ptr;
 951#ifdef PNG_USER_MEM_SUPPORTED
 952   png_free_ptr free_fn;
 953#endif
 954
 955   png_debug(1, "in png_write_destroy");
 956
 957   /* Free any memory zlib uses */
 958   if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED)
 959      deflateEnd(&png_ptr->zstream);
 960
 961   /* Free our memory.  png_free checks NULL for us. */
 962   png_free(png_ptr, png_ptr->zbuf);
 963   png_free(png_ptr, png_ptr->row_buf);
 964#ifdef PNG_WRITE_FILTER_SUPPORTED
 965   png_free(png_ptr, png_ptr->prev_row);
 966   png_free(png_ptr, png_ptr->sub_row);
 967   png_free(png_ptr, png_ptr->up_row);
 968   png_free(png_ptr, png_ptr->avg_row);
 969   png_free(png_ptr, png_ptr->paeth_row);
 970#endif
 971
 972#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
 973   /* Use this to save a little code space, it doesn't free the filter_costs */
 974   png_reset_filter_heuristics(png_ptr);
 975   png_free(png_ptr, png_ptr->filter_costs);
 976   png_free(png_ptr, png_ptr->inv_filter_costs);
 977#endif
 978
 979#ifdef PNG_SETJMP_SUPPORTED
 980   /* Reset structure */
 981   png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
 982#endif
 983
 984   error_fn = png_ptr->error_fn;
 985#ifdef PNG_WARNINGS_SUPPORTED
 986   warning_fn = png_ptr->warning_fn;
 987#endif
 988   error_ptr = png_ptr->error_ptr;
 989#ifdef PNG_USER_MEM_SUPPORTED
 990   free_fn = png_ptr->free_fn;
 991#endif
 992
 993   png_memset(png_ptr, 0, png_sizeof(png_struct));
 994
 995   png_ptr->error_fn = error_fn;
 996#ifdef PNG_WARNINGS_SUPPORTED
 997   png_ptr->warning_fn = warning_fn;
 998#endif
 999   png_ptr->error_ptr = error_ptr;
1000#ifdef PNG_USER_MEM_SUPPORTED
1001   png_ptr->free_fn = free_fn;
1002#endif
1003
1004#ifdef PNG_SETJMP_SUPPORTED
1005   png_memcpy(png_ptr->longjmp_buffer, tmp_jmp, png_sizeof(jmp_buf));
1006#endif
1007}
1008
1009/* Allow the application to select one or more row filters to use. */
1010void PNGAPI
1011png_set_filter(png_structp png_ptr, int method, int filters)
1012{
1013   png_debug(1, "in png_set_filter");
1014
1015   if (png_ptr == NULL)
1016      return;
1017
1018#ifdef PNG_MNG_FEATURES_SUPPORTED
1019   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1020       (method == PNG_INTRAPIXEL_DIFFERENCING))
1021      method = PNG_FILTER_TYPE_BASE;
1022
1023#endif
1024   if (method == PNG_FILTER_TYPE_BASE)
1025   {
1026      switch (filters & (PNG_ALL_FILTERS | 0x07))
1027      {
1028#ifdef PNG_WRITE_FILTER_SUPPORTED
1029         case 5:
1030         case 6:
1031         case 7: png_warning(png_ptr, "Unknown row filter for method 0");
1032#endif /* PNG_WRITE_FILTER_SUPPORTED */
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_warning(png_ptr, "Unknown row filter for method 0");
1054#endif /* PNG_WRITE_FILTER_SUPPORTED */
1055      }
1056
1057      /* If we have allocated the row_buf, this means we have already started
1058       * with the image and we should have allocated all of the filter buffers
1059       * that have been selected.  If prev_row isn't already allocated, then
1060       * it is too late to start using the filters that need it, since we
1061       * will be missing the data in the previous row.  If an application
1062       * wants to start and stop using particular filters during compression,
1063       * it should start out with all of the filters, and then add and
1064       * remove them after the start of compression.
1065       */
1066      if (png_ptr->row_buf != NULL)
1067      {
1068#ifdef PNG_WRITE_FILTER_SUPPORTED
1069         if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
1070         {
1071            png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1072                (png_ptr->rowbytes + 1));
1073            png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1074         }
1075
1076         if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
1077         {
1078            if (png_ptr->prev_row == NULL)
1079            {
1080               png_warning(png_ptr, "Can't add Up filter after starting");
1081               png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
1082                   ~PNG_FILTER_UP);
1083            }
1084
1085            else
1086            {
1087               png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1088                   (png_ptr->rowbytes + 1));
1089               png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1090            }
1091         }
1092
1093         if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
1094         {
1095            if (png_ptr->prev_row == NULL)
1096            {
1097               png_warning(png_ptr, "Can't add Average filter after starting");
1098               png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
1099                   ~PNG_FILTER_AVG);
1100            }
1101
1102            else
1103            {
1104               png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1105                   (png_ptr->rowbytes + 1));
1106               png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1107            }
1108         }
1109
1110         if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
1111             png_ptr->paeth_row == NULL)
1112         {
1113            if (png_ptr->prev_row == NULL)
1114            {
1115               png_warning(png_ptr, "Can't add Paeth filter after starting");
1116               png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
1117            }
1118
1119            else
1120            {
1121               png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1122                   (png_ptr->rowbytes + 1));
1123               png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1124            }
1125         }
1126
1127         if (png_ptr->do_filter == PNG_NO_FILTERS)
1128#endif /* PNG_WRITE_FILTER_SUPPORTED */
1129            png_ptr->do_filter = PNG_FILTER_NONE;
1130      }
1131   }
1132   else
1133      png_error(png_ptr, "Unknown custom filter method");
1134}
1135
1136/* This allows us to influence the way in which libpng chooses the "best"
1137 * filter for the current scanline.  While the "minimum-sum-of-absolute-
1138 * differences metric is relatively fast and effective, there is some
1139 * question as to whether it can be improved upon by trying to keep the
1140 * filtered data going to zlib more consistent, hopefully resulting in
1141 * better compression.
1142 */
1143#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED      /* GRR 970116 */
1144/* Convenience reset API. */
1145static void
1146png_reset_filter_heuristics(png_structp png_ptr)
1147{
1148   /* Clear out any old values in the 'weights' - this must be done because if
1149    * the app calls set_filter_heuristics multiple times with different
1150    * 'num_weights' values we would otherwise potentially have wrong sized
1151    * arrays.
1152    */
1153   png_ptr->num_prev_filters = 0;
1154   png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
1155   if (png_ptr->prev_filters != NULL)
1156   {
1157      png_bytep old = png_ptr->prev_filters;
1158      png_ptr->prev_filters = NULL;
1159      png_free(png_ptr, old);
1160   }
1161   if (png_ptr->filter_weights != NULL)
1162   {
1163      png_uint_16p old = png_ptr->filter_weights;
1164      png_ptr->filter_weights = NULL;
1165      png_free(png_ptr, old);
1166   }
1167
1168   if (png_ptr->inv_filter_weights != NULL)
1169   {
1170      png_uint_16p old = png_ptr->inv_filter_weights;
1171      png_ptr->inv_filter_weights = NULL;
1172      png_free(png_ptr, old);
1173   }
1174
1175   /* Leave the filter_costs - this array is fixed size. */
1176}
1177
1178static int
1179png_init_filter_heuristics(png_structp png_ptr, int heuristic_method,
1180   int num_weights)
1181{
1182   if (png_ptr == NULL)
1183      return 0;
1184
1185   /* Clear out the arrays */
1186   png_reset_filter_heuristics(png_ptr);
1187
1188   /* Check arguments; the 'reset' function makes the correct settings for the
1189    * unweighted case, but we must handle the weight case by initializing the
1190    * arrays for the caller.
1191    */
1192   if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
1193   {
1194      int i;
1195
1196      if (num_weights > 0)
1197      {
1198         png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
1199             (png_uint_32)(png_sizeof(png_byte) * num_weights));
1200
1201         /* To make sure that the weighting starts out fairly */
1202         for (i = 0; i < num_weights; i++)
1203         {
1204            png_ptr->prev_filters[i] = 255;
1205         }
1206
1207         png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
1208             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1209
1210         png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
1211             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1212
1213         for (i = 0; i < num_weights; i++)
1214         {
1215            png_ptr->inv_filter_weights[i] =
1216            png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1217         }
1218
1219         /* Safe to set this now */
1220         png_ptr->num_prev_filters = (png_byte)num_weights;
1221      }
1222
1223      /* If, in the future, there are other filter methods, this would
1224       * need to be based on png_ptr->filter.
1225       */
1226      if (png_ptr->filter_costs == NULL)
1227      {
1228         png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
1229             (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1230
1231         png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
1232             (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1233      }
1234
1235      for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1236      {
1237         png_ptr->inv_filter_costs[i] =
1238         png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1239      }
1240
1241      /* All the arrays are inited, safe to set this: */
1242      png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_WEIGHTED;
1243
1244      /* Return the 'ok' code. */
1245      return 1;
1246   }
1247   else if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT ||
1248      heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
1249   {
1250      return 1;
1251   }
1252   else
1253   {
1254      png_warning(png_ptr, "Unknown filter heuristic method");
1255      return 0;
1256   }
1257}
1258
1259/* Provide floating and fixed point APIs */
1260#ifdef PNG_FLOATING_POINT_SUPPORTED
1261void PNGAPI
1262png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
1263    int num_weights, png_const_doublep filter_weights,
1264    png_const_doublep filter_costs)
1265{
1266   png_debug(1, "in png_set_filter_heuristics");
1267
1268   /* The internal API allocates all the arrays and ensures that the elements of
1269    * those arrays are set to the default value.
1270    */
1271   if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
1272      return;
1273
1274   /* If using the weighted method copy in the weights. */
1275   if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
1276   {
1277      int i;
1278      for (i = 0; i < num_weights; i++)
1279      {
1280         if (filter_weights[i] <= 0.0)
1281         {
1282            png_ptr->inv_filter_weights[i] =
1283            png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1284         }
1285
1286         else
1287         {
1288            png_ptr->inv_filter_weights[i] =
1289                (png_uint_16)(PNG_WEIGHT_FACTOR*filter_weights[i]+.5);
1290
1291            png_ptr->filter_weights[i] =
1292                (png_uint_16)(PNG_WEIGHT_FACTOR/filter_weights[i]+.5);
1293         }
1294      }
1295
1296      /* Here is where we set the relative costs of the different filters.  We
1297       * should take the desired compression level into account when setting
1298       * the costs, so that Paeth, for instance, has a high relative cost at low
1299       * compression levels, while it has a lower relative cost at higher
1300       * compression settings.  The filter types are in order of increasing
1301       * relative cost, so it would be possible to do this with an algorithm.
1302       */
1303      for (i = 0; i < PNG_FILTER_VALUE_LAST; i++) if (filter_costs[i] >= 1.0)
1304      {
1305         png_ptr->inv_filter_costs[i] =
1306             (png_uint_16)(PNG_COST_FACTOR / filter_costs[i] + .5);
1307
1308         png_ptr->filter_costs[i] =
1309             (png_uint_16)(PNG_COST_FACTOR * filter_costs[i] + .5);
1310      }
1311   }
1312}
1313#endif /* FLOATING_POINT */
1314
1315#ifdef PNG_FIXED_POINT_SUPPORTED
1316void PNGAPI
1317png_set_filter_heuristics_fixed(png_structp png_ptr, int heuristic_method,
1318    int num_weights, png_const_fixed_point_p filter_weights,
1319    png_const_fixed_point_p filter_costs)
1320{
1321   png_debug(1, "in png_set_filter_heuristics_fixed");
1322
1323   /* The internal API allocates all the arrays and ensures that the elements of
1324    * those arrays are set to the default value.
1325    */
1326   if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
1327      return;
1328
1329   /* If using the weighted method copy in the weights. */
1330   if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
1331   {
1332      int i;
1333      for (i = 0; i < num_weights; i++)
1334      {
1335         if (filter_weights[i] <= 0)
1336         {
1337            png_ptr->inv_filter_weights[i] =
1338            png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1339         }
1340
1341         else
1342         {
1343            png_ptr->inv_filter_weights[i] = (png_uint_16)
1344               ((PNG_WEIGHT_FACTOR*filter_weights[i]+PNG_FP_HALF)/PNG_FP_1);
1345
1346            png_ptr->filter_weights[i] = (png_uint_16)((PNG_WEIGHT_FACTOR*
1347               PNG_FP_1+(filter_weights[i]/2))/filter_weights[i]);
1348         }
1349      }
1350
1351      /* Here is where we set the relative costs of the different filters.  We
1352       * should take the desired compression level into account when setting
1353       * the costs, so that Paeth, for instance, has a high relative cost at low
1354       * compression levels, while it has a lower relative cost at higher
1355       * compression settings.  The filter types are in order of increasing
1356       * relative cost, so it would be possible to do this with an algorithm.
1357       */
1358      for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1359         if (filter_costs[i] >= PNG_FP_1)
1360      {
1361         png_uint_32 tmp;
1362
1363         /* Use a 32 bit unsigned temporary here because otherwise the
1364          * intermediate value will be a 32 bit *signed* integer (ANSI rules)
1365          * and this will get the wrong answer on division.
1366          */
1367         tmp = PNG_COST_FACTOR*PNG_FP_1 + (filter_costs[i]/2);
1368         tmp /= filter_costs[i];
1369
1370         png_ptr->inv_filter_costs[i] = (png_uint_16)tmp;
1371
1372         tmp = PNG_COST_FACTOR * filter_costs[i] + PNG_FP_HALF;
1373         tmp /= PNG_FP_1;
1374
1375         png_ptr->filter_costs[i] = (png_uint_16)tmp;
1376      }
1377   }
1378}
1379#endif /* FIXED_POINT */
1380#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1381
1382void PNGAPI
1383png_set_compression_level(png_structp png_ptr, int level)
1384{
1385   png_debug(1, "in png_set_compression_level");
1386
1387   if (png_ptr == NULL)
1388      return;
1389
1390   png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
1391   png_ptr->zlib_level = level;
1392}
1393
1394void PNGAPI
1395png_set_compression_mem_level(png_structp png_ptr, int mem_level)
1396{
1397   png_debug(1, "in png_set_compression_mem_level");
1398
1399   if (png_ptr == NULL)
1400      return;
1401
1402   png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
1403   png_ptr->zlib_mem_level = mem_level;
1404}
1405
1406void PNGAPI
1407png_set_compression_strategy(png_structp png_ptr, int strategy)
1408{
1409   png_debug(1, "in png_set_compression_strategy");
1410
1411   if (png_ptr == NULL)
1412      return;
1413
1414   png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1415   png_ptr->zlib_strategy = strategy;
1416}
1417
1418/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1419 * smaller value of window_bits if it can do so safely.
1420 */
1421void PNGAPI
1422png_set_compression_window_bits(png_structp png_ptr, int window_bits)
1423{
1424   if (png_ptr == NULL)
1425      return;
1426
1427   if (window_bits > 15)
1428      png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1429
1430   else if (window_bits < 8)
1431      png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1432
1433#ifndef WBITS_8_OK
1434   /* Avoid libpng bug with 256-byte windows */
1435   if (window_bits == 8)
1436      {
1437        png_warning(png_ptr, "Compression window is being reset to 512");
1438        window_bits = 9;
1439      }
1440
1441#endif
1442   png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
1443   png_ptr->zlib_window_bits = window_bits;
1444}
1445
1446void PNGAPI
1447png_set_compression_method(png_structp png_ptr, int method)
1448{
1449   png_debug(1, "in png_set_compression_method");
1450
1451   if (png_ptr == NULL)
1452      return;
1453
1454   if (method != 8)
1455      png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1456
1457   png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
1458   png_ptr->zlib_method = method;
1459}
1460
1461/* The following were added to libpng-1.5.4 */
1462#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1463void PNGAPI
1464png_set_text_compression_level(png_structp png_ptr, int level)
1465{
1466   png_debug(1, "in png_set_text_compression_level");
1467
1468   if (png_ptr == NULL)
1469      return;
1470
1471   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_LEVEL;
1472   png_ptr->zlib_text_level = level;
1473}
1474
1475void PNGAPI
1476png_set_text_compression_mem_level(png_structp png_ptr, int mem_level)
1477{
1478   png_debug(1, "in png_set_text_compression_mem_level");
1479
1480   if (png_ptr == NULL)
1481      return;
1482
1483   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL;
1484   png_ptr->zlib_text_mem_level = mem_level;
1485}
1486
1487void PNGAPI
1488png_set_text_compression_strategy(png_structp png_ptr, int strategy)
1489{
1490   png_debug(1, "in png_set_text_compression_strategy");
1491
1492   if (png_ptr == NULL)
1493      return;
1494
1495   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_STRATEGY;
1496   png_ptr->zlib_text_strategy = strategy;
1497}
1498
1499/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1500 * smaller value of window_bits if it can do so safely.
1501 */
1502void PNGAPI
1503png_set_text_compression_window_bits(png_structp png_ptr, int window_bits)
1504{
1505   if (png_ptr == NULL)
1506      return;
1507
1508   if (window_bits > 15)
1509      png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1510
1511   else if (window_bits < 8)
1512      png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1513
1514#ifndef WBITS_8_OK
1515   /* Avoid libpng bug with 256-byte windows */
1516   if (window_bits == 8)
1517      {
1518        png_warning(png_ptr, "Text compression window is being reset to 512");
1519        window_bits = 9;
1520      }
1521
1522#endif
1523   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS;
1524   png_ptr->zlib_text_window_bits = window_bits;
1525}
1526
1527void PNGAPI
1528png_set_text_compression_method(png_structp png_ptr, int method)
1529{
1530   png_debug(1, "in png_set_text_compression_method");
1531
1532   if (png_ptr == NULL)
1533      return;
1534
1535   if (method != 8)
1536      png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1537
1538   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_METHOD;
1539   png_ptr->zlib_text_method = method;
1540}
1541#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
1542/* end of API added to libpng-1.5.4 */
1543
1544void PNGAPI
1545png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
1546{
1547   if (png_ptr == NULL)
1548      return;
1549
1550   png_ptr->write_row_fn = write_row_fn;
1551}
1552
1553#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1554void PNGAPI
1555png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
1556    write_user_transform_fn)
1557{
1558   png_debug(1, "in png_set_write_user_transform_fn");
1559
1560   if (png_ptr == NULL)
1561      return;
1562
1563   png_ptr->transformations |= PNG_USER_TRANSFORM;
1564   png_ptr->write_user_transform_fn = write_user_transform_fn;
1565}
1566#endif
1567
1568
1569#ifdef PNG_INFO_IMAGE_SUPPORTED
1570void PNGAPI
1571png_write_png(png_structp png_ptr, png_infop info_ptr,
1572    int transforms, voidp params)
1573{
1574   if (png_ptr == NULL || info_ptr == NULL)
1575      return;
1576
1577   /* Write the file header information. */
1578   png_write_info(png_ptr, info_ptr);
1579
1580   /* ------ these transformations don't touch the info structure ------- */
1581
1582#ifdef PNG_WRITE_INVERT_SUPPORTED
1583   /* Invert monochrome pixels */
1584   if (transforms & PNG_TRANSFORM_INVERT_MONO)
1585      png_set_invert_mono(png_ptr);
1586#endif
1587
1588#ifdef PNG_WRITE_SHIFT_SUPPORTED
1589   /* Shift the pixels up to a legal bit depth and fill in
1590    * as appropriate to correctly scale the image.
1591    */
1592   if ((transforms & PNG_TRANSFORM_SHIFT)
1593       && (info_ptr->valid & PNG_INFO_sBIT))
1594      png_set_shift(png_ptr, &info_ptr->sig_bit);
1595#endif
1596
1597#ifdef PNG_WRITE_PACK_SUPPORTED
1598   /* Pack pixels into bytes */
1599   if (transforms & PNG_TRANSFORM_PACKING)
1600       png_set_packing(png_ptr);
1601#endif
1602
1603#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
1604   /* Swap location of alpha bytes from ARGB to RGBA */
1605   if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1606      png_set_swap_alpha(png_ptr);
1607#endif
1608
1609#ifdef PNG_WRITE_FILLER_SUPPORTED
1610   /* Pack XRGB/RGBX/ARGB/RGBA into RGB (4 channels -> 3 channels) */
1611   if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
1612      png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
1613
1614   else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
1615      png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1616#endif
1617
1618#ifdef PNG_WRITE_BGR_SUPPORTED
1619   /* Flip BGR pixels to RGB */
1620   if (transforms & PNG_TRANSFORM_BGR)
1621      png_set_bgr(png_ptr);
1622#endif
1623
1624#ifdef PNG_WRITE_SWAP_SUPPORTED
1625   /* Swap bytes of 16-bit files to most significant byte first */
1626   if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1627      png_set_swap(png_ptr);
1628#endif
1629
1630#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
1631   /* Swap bits of 1, 2, 4 bit packed pixel formats */
1632   if (transforms & PNG_TRANSFORM_PACKSWAP)
1633      png_set_packswap(png_ptr);
1634#endif
1635
1636#ifdef PNG_WRITE_INVERT_ALPHA_SUP…

Large files files are truncated, but you can click here to view the full file