pngrutil.c

It was built with libpng version 1.2.35, and is running with libpng version 1.2.35

#endif
#endif /* PNG_NO_CONSOLE_IO */
         }
         return;
      }
#endif /* PNG_READ_sRGB_SUPPORTED */

#ifdef PNG_FLOATING_POINT_SUPPORTED
   png_set_cHRM(png_ptr, info_ptr,
      white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y);
#endif
#ifdef PNG_FIXED_POINT_SUPPORTED
   png_set_cHRM_fixed(png_ptr, info_ptr,
      int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
      int_y_green, int_x_blue, int_y_blue);
#endif
}
#endif

#if defined(PNG_READ_sRGB_SUPPORTED)
void /* PRIVATE */
png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
   int intent;
   png_byte buf[1];

   png_debug(1, "in png_handle_sRGB");

   if (!(png_ptr->mode & PNG_HAVE_IHDR))
      png_error(png_ptr, "Missing IHDR before sRGB");
   else if (png_ptr->mode & PNG_HAVE_IDAT)
   {
      png_warning(png_ptr, "Invalid sRGB after IDAT");
      png_crc_finish(png_ptr, length);
      return;
   }
   else if (png_ptr->mode & PNG_HAVE_PLTE)
      /* Should be an error, but we can cope with it */
      png_warning(png_ptr, "Out of place sRGB chunk");

   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB))
   {
      png_warning(png_ptr, "Duplicate sRGB chunk");
      png_crc_finish(png_ptr, length);
      return;
   }

   if (length != 1)
   {
      png_warning(png_ptr, "Incorrect sRGB chunk length");
      png_crc_finish(png_ptr, length);
      return;
   }

   png_crc_read(png_ptr, buf, 1);
   if (png_crc_finish(png_ptr, 0))
      return;

   intent = buf[0];
   /* check for bad intent */
   if (intent >= PNG_sRGB_INTENT_LAST)
   {
      png_warning(png_ptr, "Unknown sRGB intent");
      return;
   }

#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA))
   {
   png_fixed_point igamma;
#ifdef PNG_FIXED_POINT_SUPPORTED
      igamma=info_ptr->int_gamma;
#else
#  ifdef PNG_FLOATING_POINT_SUPPORTED
      igamma=(png_fixed_point)(info_ptr->gamma * 100000.);
#  endif
#endif
      if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
      {
         png_warning(png_ptr,
           "Ignoring incorrect gAMA value when sRGB is also present");
#ifndef PNG_NO_CONSOLE_IO
#  ifdef PNG_FIXED_POINT_SUPPORTED
         fprintf(stderr, "incorrect gamma=(%d/100000)\n",
            (int)png_ptr->int_gamma);
#  else
#    ifdef PNG_FLOATING_POINT_SUPPORTED
         fprintf(stderr, "incorrect gamma=%f\n", png_ptr->gamma);
#    endif
#  endif
#endif
      }
   }
#endif /* PNG_READ_gAMA_SUPPORTED */

#ifdef PNG_READ_cHRM_SUPPORTED
#ifdef PNG_FIXED_POINT_SUPPORTED
   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
      if (PNG_OUT_OF_RANGE(info_ptr->int_x_white, 31270,  1000) ||
          PNG_OUT_OF_RANGE(info_ptr->int_y_white, 32900,  1000) ||
          PNG_OUT_OF_RANGE(info_ptr->int_x_red,   64000L, 1000) ||
          PNG_OUT_OF_RANGE(info_ptr->int_y_red,   33000,  1000) ||
          PNG_OUT_OF_RANGE(info_ptr->int_x_green, 30000,  1000) ||
          PNG_OUT_OF_RANGE(info_ptr->int_y_green, 60000L, 1000) ||
          PNG_OUT_OF_RANGE(info_ptr->int_x_blue,  15000,  1000) ||
          PNG_OUT_OF_RANGE(info_ptr->int_y_blue,   6000,  1000))
         {
            png_warning(png_ptr,
              "Ignoring incorrect cHRM value when sRGB is also present");
         }
#endif /* PNG_FIXED_POINT_SUPPORTED */
#endif /* PNG_READ_cHRM_SUPPORTED */

   png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent);
}
#endif /* PNG_READ_sRGB_SUPPORTED */

#if defined(PNG_READ_iCCP_SUPPORTED)
void /* PRIVATE */
png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
/* Note: this does not properly handle chunks that are > 64K under DOS */
{
   png_byte compression_type;
   png_bytep pC;
   png_charp profile;
   png_uint_32 skip = 0;
   png_uint_32 profile_size, profile_length;
   png_size_t slength, prefix_length, data_length;

   png_debug(1, "in png_handle_iCCP");

   if (!(png_ptr->mode & PNG_HAVE_IHDR))
      png_error(png_ptr, "Missing IHDR before iCCP");
   else if (png_ptr->mode & PNG_HAVE_IDAT)
   {
      png_warning(png_ptr, "Invalid iCCP after IDAT");
      png_crc_finish(png_ptr, length);
      return;
   }
   else if (png_ptr->mode & PNG_HAVE_PLTE)
      /* Should be an error, but we can cope with it */
      png_warning(png_ptr, "Out of place iCCP chunk");

   if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP))
   {
      png_warning(png_ptr, "Duplicate iCCP chunk");
      png_crc_finish(png_ptr, length);
      return;
   }

#ifdef PNG_MAX_MALLOC_64K
   if (length > (png_uint_32)65535L)
   {
      png_warning(png_ptr, "iCCP chunk too large to fit in memory");
      skip = length - (png_uint_32)65535L;
      length = (png_uint_32)65535L;
   }
#endif

   png_free(png_ptr, png_ptr->chunkdata);
   png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
   slength = (png_size_t)length;
   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);

   if (png_crc_finish(png_ptr, skip))
   {
      png_free(png_ptr, png_ptr->chunkdata);
      png_ptr->chunkdata = NULL;
      return;
   }

   png_ptr->chunkdata[slength] = 0x00;

   for (profile = png_ptr->chunkdata; *profile; profile++)
      /* empty loop to find end of name */ ;

   ++profile;

   /* there should be at least one zero (the compression type byte)
      following the separator, and we should be on it  */
   if ( profile >= png_ptr->chunkdata + slength - 1)
   {
      png_free(png_ptr, png_ptr->chunkdata);
      png_ptr->chunkdata = NULL;
      png_warning(png_ptr, "Malformed iCCP chunk");
      return;
   }

   /* compression_type should always be zero */
   compression_type = *profile++;
   if (compression_type)
   {
      png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk");
      compression_type = 0x00;  /* Reset it to zero (libpng-1.0.6 through 1.0.8
                                 wrote nonzero) */
   }

   prefix_length = profile - png_ptr->chunkdata;
   png_decompress_chunk(png_ptr, compression_type,
     slength, prefix_length, &data_length);

   profile_length = data_length - prefix_length;

   if ( prefix_length > data_length || profile_length < 4)
   {
      png_free(png_ptr, png_ptr->chunkdata);
      png_ptr->chunkdata = NULL;
      png_warning(png_ptr, "Profile size field missing from iCCP chunk");
      return;
   }

   /* Check the profile_size recorded in the first 32 bits of the ICC profile */
   pC = (png_bytep)(png_ptr->chunkdata + prefix_length);
   profile_size = ((*(pC    ))<<24) |
                  ((*(pC + 1))<<16) |
                  ((*(pC + 2))<< 8) |
                  ((*(pC + 3))    );

   if (profile_size < profile_length)
      profile_length = profile_size;

   if (profile_size > profile_length)
   {
      png_free(png_ptr, png_ptr->chunkdata);
      png_ptr->chunkdata = NULL;
      png_warning(png_ptr, "Ignoring truncated iCCP profile.");
      return;
   }

   png_set_iCCP(png_ptr, info_ptr, png_ptr->chunkdata,
     compression_type, png_ptr->chunkdata + prefix_length, profile_length);
   png_free(png_ptr, png_ptr->chunkdata);
   png_ptr->chunkdata = NULL;
}
#endif /* PNG_READ_iCCP_SUPPORTED */

#if defined(PNG_READ_sPLT_SUPPORTED)
void /* PRIVATE */
png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
/* Note: this does not properly handle chunks that are > 64K under DOS */
{
   png_bytep entry_start;
   png_sPLT_t new_palette;
#ifdef PNG_NO_POINTER_INDEXING
   png_sPLT_entryp pp;
#endif
   int data_length, entry_size, i;
   png_uint_32 skip = 0;
   png_size_t slength;

   png_debug(1, "in png_handle_sPLT");


   if (!(png_ptr->mode & PNG_HAVE_IHDR))
      png_error(png_ptr, "Missing IHDR before sPLT");
   else if (png_ptr->mode & PNG_HAVE_IDAT)
   {
      png_warning(png_ptr, "Invalid sPLT after IDAT");
      png_crc_finish(png_ptr, length);
      return;
   }

#ifdef PNG_MAX_MALLOC_64K
   if (length > (png_uint_32)65535L)
   {
      png_warning(png_ptr, "sPLT chunk too large to fit in memory");
      skip = length - (png_uint_32)65535L;
      length = (png_uint_32)65535L;
   }
#endif

   png_free(png_ptr, png_ptr->chunkdata);
   png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
   slength = (png_size_t)length;
   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);

   if (png_crc_finish(png_ptr, skip))
   {
      png_free(png_ptr, png_ptr->chunkdata);
      png_ptr->chunkdata = NULL;
      return;
   }

   png_ptr->chunkdata[slength] = 0x00;

   for (entry_start = (png_bytep)png_ptr->chunkdata; *entry_start; entry_start++)
      /* empty loop to find end of name */ ;
   ++entry_start;

   /* a sample depth should follow the separator, and we should be on it  */
   if (entry_start > (png_bytep)png_ptr->chunkdata + slength - 2)
   {
      png_free(png_ptr, png_ptr->chunkdata);
      png_ptr->chunkdata = NULL;
      png_warning(png_ptr, "malformed sPLT chunk");
      return;
   }

   new_palette.depth = *entry_start++;
   entry_size = (new_palette.depth == 8 ? 6 : 10);
   data_length = (slength - (entry_start - (png_bytep)png_ptr->chunkdata));

   /* integrity-check the data length */
   if (data_length % entry_size)
   {
      png_free(png_ptr, png_ptr->chunkdata);
      png_ptr->chunkdata = NULL;
      png_warning(png_ptr, "sPLT chunk has bad length");
      return;
   }

   new_palette.nentries = (png_int_32) ( data_length / entry_size);
   if ((png_uint_32) new_palette.nentries >
       (png_uint_32) (PNG_SIZE_MAX / png_sizeof(png_sPLT_entry)))
   {
       png_warning(png_ptr, "sPLT chunk too long");
       return;
   }
   new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
       png_ptr, new_palette.nentries * png_sizeof(png_sPLT_entry));
   if (new_palette.entries == NULL)
   {
       png_warning(png_ptr, "sPLT chunk requires too much memory");
       return;
   }

#ifndef PNG_NO_POINTER_INDEXING
   for (i = 0; i < new_palette.nentries; i++)
   {
      png_sPLT_entryp pp = new_palette.entries + i;

      if (new_palette.depth == 8)
      {
          pp->red = *entry_start++;
          pp->green = *entry_start++;
          pp->blue = *entry_start++;
          pp->alpha = *entry_start++;
      }
      else
      {
          pp->red   = png_get_uint_16(entry_start); entry_start += 2;
          pp->green = png_get_uint_16(entry_start); entry_start += 2;
          pp->blue  = png_get_uint_16(entry_start); entry_start += 2;
          pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
      }
      pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
   }
#else
   pp = new_palette.entries;
   for (i = 0; i < new_palette.nentries; i++)
   {

      if (new_palette.depth == 8)
      {
          pp[i].red   = *entry_start++;
          pp[i].green = *entry_start++;
          pp[i].blue  = *entry_start++;
          pp[i].alpha = *entry_start++;
      }
      else
      {
          pp[i].red   = png_get_uint_16(entry_start); entry_start += 2;
          pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
          pp[i].blue  = png_get_uint_16(entry_start); entry_start += 2;
          pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
      }
      pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
   }
#endif

   /* discard all chunk data except the name and stash that */
   new_palette.name = png_ptr->chunkdata;

   png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);

   png_free(png_ptr, png_ptr->chunkdata);
   png_ptr->chunkdata = NULL;
   png_free(png_ptr, new_palette.entries);
}
#endif /* PNG_READ_sPLT_SUPPORTED */

#if defined(PNG_READ_tRNS_SUPPORTED)
void /* PRIVATE */
png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{
   png_byte readbuf[PNG_MAX_PALETTE_LENGTH];

   png_debug(1, "in png_handle_tRNS");

   if (!(png_ptr->mode & PNG_HAVE_IHDR))
      png_error(png_ptr, "Missing IHDR before tRNS");
   else if (png_ptr->mode & PNG_HAVE_IDAT)
   {
      png_warning(png_ptr, "Invalid tRNS after IDAT");
      png_crc_finish(png_ptr, length);
      return;
   }
   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
   {
      png_warning(png_ptr, "Duplicate tRNS chunk");
      png_crc_finish(png_ptr, length);
      return;
   }

   if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
   {
      png_byte buf[2];

      if (length != 2)
      {
         png_warning(png_ptr, "Incorrect tRNS chunk length");
         png_crc_finish(png_ptr, length);
         return;
      }

      png_crc_read(png_ptr, buf, 2);
      png_ptr->num_trans = 1;
      png_ptr->trans_values.gray = png_get_uint_16(buf);
   }
   else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
   {
      png_byte buf[6];

      if (length != 6)
      {
         png_warning(png_ptr, "Incorrect tRNS chunk length");
         png_crc_finish(png_ptr, length);
         return;
      }
      png_crc_read(png_ptr, buf, (png_size_t)length);
      png_ptr->num_trans = 1;
      png_ptr->trans_values.red = png_get_uint_16(buf);
      png_ptr->trans_values.green = png_get_uint_16(buf + 2);
      png_ptr->trans_values.blue = png_get_uint_16(buf + 4);