Exemplo n.º 1
0
void PNGAPI
png_set_IHDR(png_const_structrp png_ptr, png_inforp info_ptr,
    png_uint_32 width, png_uint_32 height, int bit_depth,
    int color_type, int interlace_type, int compression_type,
    int filter_type)
{
   png_debug1(1, "in %s storage function", "IHDR");

   if (png_ptr == NULL || info_ptr == NULL)
      return;

   info_ptr->width = width;
   info_ptr->height = height;
   info_ptr->bit_depth = (png_byte)bit_depth;
   info_ptr->color_type = (png_byte)color_type;
   info_ptr->compression_type = (png_byte)compression_type;
   info_ptr->filter_type = (png_byte)filter_type;
   info_ptr->interlace_type = (png_byte)interlace_type;

   png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
       info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
       info_ptr->compression_type, info_ptr->filter_type);

   if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
      info_ptr->channels = 1;

   else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
      info_ptr->channels = 3;

   else
      info_ptr->channels = 1;

   if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
      info_ptr->channels++;

   info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);

   info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
}
void PNGAPI
png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
{
   PNG_IDAT;
   PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
      0xff};
   PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
   int ret;

   if (png_ptr == NULL)
      return;

   png_debug2(1, "in png_read_row (row %lu, pass %d)",
      (unsigned long) png_ptr->row_number, png_ptr->pass);

   if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
      png_read_start_row(png_ptr);
   if (png_ptr->row_number == 0 && png_ptr->pass == 0)
   {
   /* Check for transforms that have been set but were defined out */
#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
   if (png_ptr->transformations & PNG_INVERT_MONO)
      png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined");
#endif
#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
   if (png_ptr->transformations & PNG_FILLER)
      png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined");
#endif
#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
    !defined(PNG_READ_PACKSWAP_SUPPORTED)
   if (png_ptr->transformations & PNG_PACKSWAP)
      png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined");
#endif
#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
   if (png_ptr->transformations & PNG_PACK)
      png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined");
#endif
#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
   if (png_ptr->transformations & PNG_SHIFT)
      png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined");
#endif
#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
   if (png_ptr->transformations & PNG_BGR)
      png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined");
#endif
#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
   if (png_ptr->transformations & PNG_SWAP_BYTES)
      png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined");
#endif
   }

#ifdef PNG_READ_INTERLACING_SUPPORTED
   /* If interlaced and we do not need a new row, combine row and return */
   if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
   {
      switch (png_ptr->pass)
      {
         case 0:
            if (png_ptr->row_number & 0x07)
            {
               if (dsp_row != NULL)
                  png_combine_row(png_ptr, dsp_row,
                     png_pass_dsp_mask[png_ptr->pass]);
               png_read_finish_row(png_ptr);
               return;
            }
            break;

         case 1:
            if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
            {
               if (dsp_row != NULL)
                  png_combine_row(png_ptr, dsp_row,
                     png_pass_dsp_mask[png_ptr->pass]);
               png_read_finish_row(png_ptr);
               return;
            }
            break;

         case 2:
            if ((png_ptr->row_number & 0x07) != 4)
            {
               if (dsp_row != NULL && (png_ptr->row_number & 4))
                  png_combine_row(png_ptr, dsp_row,
                     png_pass_dsp_mask[png_ptr->pass]);
               png_read_finish_row(png_ptr);
               return;
            }
            break;

         case 3:
            if ((png_ptr->row_number & 3) || png_ptr->width < 3)
            {
               if (dsp_row != NULL)
                  png_combine_row(png_ptr, dsp_row,
                     png_pass_dsp_mask[png_ptr->pass]);
               png_read_finish_row(png_ptr);
               return;
            }
            break;

         case 4:
            if ((png_ptr->row_number & 3) != 2)
            {
               if (dsp_row != NULL && (png_ptr->row_number & 2))
                  png_combine_row(png_ptr, dsp_row,
                     png_pass_dsp_mask[png_ptr->pass]);
               png_read_finish_row(png_ptr);
               return;
            }
            break;

         case 5:
            if ((png_ptr->row_number & 1) || png_ptr->width < 2)
            {
               if (dsp_row != NULL)
                  png_combine_row(png_ptr, dsp_row,
                     png_pass_dsp_mask[png_ptr->pass]);
               png_read_finish_row(png_ptr);
               return;
            }
            break;

         default:
         case 6:
            if (!(png_ptr->row_number & 1))
            {
               png_read_finish_row(png_ptr);
               return;
            }
            break;
      }
   }
#endif

   if (!(png_ptr->mode & PNG_HAVE_IDAT))
      png_error(png_ptr, "Invalid attempt to read row data");

   png_ptr->zstream.next_out = png_ptr->row_buf;
   png_ptr->zstream.avail_out =
       (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
       png_ptr->iwidth) + 1);
   do
   {
      if (!(png_ptr->zstream.avail_in))
      {
         while (!png_ptr->idat_size)
         {
            png_crc_finish(png_ptr, 0);

            png_ptr->idat_size = png_read_chunk_header(png_ptr);
            if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
               png_error(png_ptr, "Not enough image data");
         }
         png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
         png_ptr->zstream.next_in = png_ptr->zbuf;
         if (png_ptr->zbuf_size > png_ptr->idat_size)
            png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
         png_crc_read(png_ptr, png_ptr->zbuf,
            (png_size_t)png_ptr->zstream.avail_in);
         png_ptr->idat_size -= png_ptr->zstream.avail_in;
      }
      ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
      if (ret == Z_STREAM_END)
      {
         if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
            png_ptr->idat_size)
            png_benign_error(png_ptr, "Extra compressed data");
         png_ptr->mode |= PNG_AFTER_IDAT;
         png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
         break;
      }
      if (ret != Z_OK)
         png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
                   "Decompression error");

   } while (png_ptr->zstream.avail_out);

   png_ptr->row_info.color_type = png_ptr->color_type;
   png_ptr->row_info.width = png_ptr->iwidth;
   png_ptr->row_info.channels = png_ptr->channels;
   png_ptr->row_info.bit_depth = png_ptr->bit_depth;
   png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
   png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
       png_ptr->row_info.width);

   if (png_ptr->row_buf[0])
   png_read_filter_row(png_ptr, &(png_ptr->row_info),
      png_ptr->row_buf + 1, png_ptr->prev_row + 1,
      (int)(png_ptr->row_buf[0]));

   png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1);

#ifdef PNG_MNG_FEATURES_SUPPORTED
   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
      (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
   {
      /* Intrapixel differencing */
      png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
   }
#endif


   if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
      png_do_read_transformations(png_ptr);

#ifdef PNG_READ_INTERLACING_SUPPORTED
   /* Blow up interlaced rows to full size */
   if (png_ptr->interlaced &&
      (png_ptr->transformations & PNG_INTERLACE))
   {
      if (png_ptr->pass < 6)
         /* Old interface (pre-1.0.9):
          * png_do_read_interlace(&(png_ptr->row_info),
          *    png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
          */
         png_do_read_interlace(png_ptr);

      if (dsp_row != NULL)
         png_combine_row(png_ptr, dsp_row,
            png_pass_dsp_mask[png_ptr->pass]);
      if (row != NULL)
         png_combine_row(png_ptr, row,
            png_pass_mask[png_ptr->pass]);
   }
   else
#endif
   {
      if (row != NULL)
         png_combine_row(png_ptr, row, 0xff);
      if (dsp_row != NULL)
         png_combine_row(png_ptr, dsp_row, 0xff);
   }
   png_read_finish_row(png_ptr);

   if (png_ptr->read_row_fn != NULL)
      (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
}
Exemplo n.º 3
0
void /* PRIVATE */
png_read_push_finish_row(png_structp png_ptr)
{
#ifdef PNG_USE_LOCAL_ARRAYS
   /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */

   /* start of interlace block */
   PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};

   /* offset to next interlace block */
   PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};

   /* start of interlace block in the y direction */
   PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};

   /* offset to next interlace block in the y direction */
   PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};

   /* Height of interlace block.  This is not currently used - if you need
    * it, uncomment it here and in png.h
   PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
   */
#endif

   png_ptr->row_number++;
   if (png_ptr->row_number < png_ptr->num_rows)
      return;

   if (png_ptr->interlaced)
   {
      png_ptr->row_number = 0;
      png_memset_check(png_ptr, png_ptr->prev_row, 0,
         png_ptr->rowbytes + 1);
      do
      {
         png_ptr->pass++;
         if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
             (png_ptr->pass == 3 && png_ptr->width < 3) ||
             (png_ptr->pass == 5 && png_ptr->width < 2))
           png_ptr->pass++;

         if (png_ptr->pass > 7)
            png_ptr->pass--;
         if (png_ptr->pass >= 7)
            break;

         png_ptr->iwidth = (png_ptr->width +
            png_pass_inc[png_ptr->pass] - 1 -
            png_pass_start[png_ptr->pass]) /
            png_pass_inc[png_ptr->pass];

         png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
            png_ptr->iwidth) + 1;

         if (png_ptr->transformations & PNG_INTERLACE)
            break;

         png_ptr->num_rows = (png_ptr->height +
            png_pass_yinc[png_ptr->pass] - 1 -
            png_pass_ystart[png_ptr->pass]) /
            png_pass_yinc[png_ptr->pass];

      } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
   }
}
Exemplo n.º 4
0
void /* PRIVATE */
png_push_process_row(png_structp png_ptr)
{
   png_ptr->row_info.color_type = png_ptr->color_type;
   png_ptr->row_info.width = png_ptr->iwidth;
   png_ptr->row_info.channels = png_ptr->channels;
   png_ptr->row_info.bit_depth = png_ptr->bit_depth;
   png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;

   png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
       png_ptr->row_info.width);

   png_read_filter_row(png_ptr, &(png_ptr->row_info),
      png_ptr->row_buf + 1, png_ptr->prev_row + 1,
      (int)(png_ptr->row_buf[0]));

   png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
      png_ptr->rowbytes + 1);

   if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
      png_do_read_transformations(png_ptr);

#if defined(PNG_READ_INTERLACING_SUPPORTED)
   /* blow up interlaced rows to full size */
   if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
   {
      if (png_ptr->pass < 6)
/*       old interface (pre-1.0.9):
         png_do_read_interlace(&(png_ptr->row_info),
            png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
 */
         png_do_read_interlace(png_ptr);

    switch (png_ptr->pass)
    {
         case 0:
         {
            int i;
            for (i = 0; i < 8 && png_ptr->pass == 0; i++)
            {
               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
               png_read_push_finish_row(png_ptr); /* updates png_ptr->pass */
            }
            if (png_ptr->pass == 2) /* pass 1 might be empty */
            {
               for (i = 0; i < 4 && png_ptr->pass == 2; i++)
               {
                  png_push_have_row(png_ptr, png_bytep_NULL);
                  png_read_push_finish_row(png_ptr);
               }
            }
            if (png_ptr->pass == 4 && png_ptr->height <= 4)
            {
               for (i = 0; i < 2 && png_ptr->pass == 4; i++)
               {
                  png_push_have_row(png_ptr, png_bytep_NULL);
                  png_read_push_finish_row(png_ptr);
               }
            }
            if (png_ptr->pass == 6 && png_ptr->height <= 4)
            {
                png_push_have_row(png_ptr, png_bytep_NULL);
                png_read_push_finish_row(png_ptr);
            }
            break;
         }
         case 1:
         {
            int i;
            for (i = 0; i < 8 && png_ptr->pass == 1; i++)
            {
               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
               png_read_push_finish_row(png_ptr);
            }
            if (png_ptr->pass == 2) /* skip top 4 generated rows */
            {
               for (i = 0; i < 4 && png_ptr->pass == 2; i++)
               {
                  png_push_have_row(png_ptr, png_bytep_NULL);
                  png_read_push_finish_row(png_ptr);
               }
            }
            break;
         }
         case 2:
         {
            int i;
            for (i = 0; i < 4 && png_ptr->pass == 2; i++)
            {
               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
               png_read_push_finish_row(png_ptr);
            }
            for (i = 0; i < 4 && png_ptr->pass == 2; i++)
            {
               png_push_have_row(png_ptr, png_bytep_NULL);
               png_read_push_finish_row(png_ptr);
            }
            if (png_ptr->pass == 4) /* pass 3 might be empty */
            {
               for (i = 0; i < 2 && png_ptr->pass == 4; i++)
               {
                  png_push_have_row(png_ptr, png_bytep_NULL);
                  png_read_push_finish_row(png_ptr);
               }
            }
            break;
         }
         case 3:
         {
            int i;
            for (i = 0; i < 4 && png_ptr->pass == 3; i++)
            {
               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
               png_read_push_finish_row(png_ptr);
            }
            if (png_ptr->pass == 4) /* skip top two generated rows */
            {
               for (i = 0; i < 2 && png_ptr->pass == 4; i++)
               {
                  png_push_have_row(png_ptr, png_bytep_NULL);
                  png_read_push_finish_row(png_ptr);
               }
            }
            break;
         }
         case 4:
         {
            int i;
            for (i = 0; i < 2 && png_ptr->pass == 4; i++)
            {
               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
               png_read_push_finish_row(png_ptr);
            }
            for (i = 0; i < 2 && png_ptr->pass == 4; i++)
            {
               png_push_have_row(png_ptr, png_bytep_NULL);
               png_read_push_finish_row(png_ptr);
            }
            if (png_ptr->pass == 6) /* pass 5 might be empty */
            {
               png_push_have_row(png_ptr, png_bytep_NULL);
               png_read_push_finish_row(png_ptr);
            }
            break;
         }
         case 5:
         {
            int i;
            for (i = 0; i < 2 && png_ptr->pass == 5; i++)
            {
               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
               png_read_push_finish_row(png_ptr);
            }
            if (png_ptr->pass == 6) /* skip top generated row */
            {
               png_push_have_row(png_ptr, png_bytep_NULL);
               png_read_push_finish_row(png_ptr);
            }
            break;
         }
         case 6:
         {
            png_push_have_row(png_ptr, png_ptr->row_buf + 1);
            png_read_push_finish_row(png_ptr);
            if (png_ptr->pass != 6)
               break;
            png_push_have_row(png_ptr, png_bytep_NULL);
            png_read_push_finish_row(png_ptr);
         }
      }
   }
   else
#endif
   {
      png_push_have_row(png_ptr, png_ptr->row_buf + 1);
      png_read_push_finish_row(png_ptr);
   }
}
Exemplo n.º 5
0
void /* PRIVATE */
png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
{
#ifdef PNG_USE_LOCAL_ARRAYS
      PNG_CONST PNG_IHDR;
      PNG_CONST PNG_IDAT;
      PNG_CONST PNG_IEND;
      PNG_CONST PNG_PLTE;
#ifdef PNG_READ_bKGD_SUPPORTED
      PNG_CONST PNG_bKGD;
#endif
#ifdef PNG_READ_cHRM_SUPPORTED
      PNG_CONST PNG_cHRM;
#endif
#ifdef PNG_READ_gAMA_SUPPORTED
      PNG_CONST PNG_gAMA;
#endif
#ifdef PNG_READ_hIST_SUPPORTED
      PNG_CONST PNG_hIST;
#endif
#ifdef PNG_READ_iCCP_SUPPORTED
      PNG_CONST PNG_iCCP;
#endif
#ifdef PNG_READ_iTXt_SUPPORTED
      PNG_CONST PNG_iTXt;
#endif
#ifdef PNG_READ_oFFs_SUPPORTED
      PNG_CONST PNG_oFFs;
#endif
#ifdef PNG_READ_pCAL_SUPPORTED
      PNG_CONST PNG_pCAL;
#endif
#ifdef PNG_READ_pHYs_SUPPORTED
      PNG_CONST PNG_pHYs;
#endif
#ifdef PNG_READ_sBIT_SUPPORTED
      PNG_CONST PNG_sBIT;
#endif
#ifdef PNG_READ_sCAL_SUPPORTED
      PNG_CONST PNG_sCAL;
#endif
#ifdef PNG_READ_sRGB_SUPPORTED
      PNG_CONST PNG_sRGB;
#endif
#ifdef PNG_READ_sPLT_SUPPORTED
      PNG_CONST PNG_sPLT;
#endif
#ifdef PNG_READ_tEXt_SUPPORTED
      PNG_CONST PNG_tEXt;
#endif
#ifdef PNG_READ_tIME_SUPPORTED
      PNG_CONST PNG_tIME;
#endif
#ifdef PNG_READ_tRNS_SUPPORTED
      PNG_CONST PNG_tRNS;
#endif
#ifdef PNG_READ_zTXt_SUPPORTED
      PNG_CONST PNG_zTXt;
#endif
#endif /* PNG_USE_LOCAL_ARRAYS */

   /* First we make sure we have enough data for the 4 byte chunk name
    * and the 4 byte chunk length before proceeding with decoding the
    * chunk data.  To fully decode each of these chunks, we also make
    * sure we have enough data in the buffer for the 4 byte CRC at the
    * end of every chunk (except IDAT, which is handled separately).
    */
   if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
   {
      png_byte chunk_length[4];

      if (png_ptr->buffer_size < 8)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_push_fill_buffer(png_ptr, chunk_length, 4);
      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
      png_reset_crc(png_ptr);
      png_crc_read(png_ptr, png_ptr->chunk_name, 4);
      png_check_chunk_name(png_ptr, png_ptr->chunk_name);
      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
   }

   if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
     if (png_ptr->mode & PNG_AFTER_IDAT)
        png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;

   if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
   {
      if (png_ptr->push_length != 13)
         png_error(png_ptr, "Invalid IHDR length");

      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
   }

   else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);

      png_ptr->process_mode = PNG_READ_DONE_MODE;
      png_push_have_end(png_ptr, info_ptr);
   }

#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
   else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
         png_ptr->mode |= PNG_HAVE_IDAT;

      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);

      if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
         png_ptr->mode |= PNG_HAVE_PLTE;

      else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
      {
         if (!(png_ptr->mode & PNG_HAVE_IHDR))
            png_error(png_ptr, "Missing IHDR before IDAT");

         else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
                  !(png_ptr->mode & PNG_HAVE_PLTE))
            png_error(png_ptr, "Missing PLTE before IDAT");
      }
   }

#endif
   else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }
      png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
   }

   else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
   {
      /* If we reach an IDAT chunk, this means we have read all of the
       * header chunks, and we can start reading the image (or if this
       * is called after the image has been read - we have an error).
       */

      if (!(png_ptr->mode & PNG_HAVE_IHDR))
         png_error(png_ptr, "Missing IHDR before IDAT");

      else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
          !(png_ptr->mode & PNG_HAVE_PLTE))
         png_error(png_ptr, "Missing PLTE before IDAT");

      if (png_ptr->mode & PNG_HAVE_IDAT)
      {
         if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
            if (png_ptr->push_length == 0)
               return;

         if (png_ptr->mode & PNG_AFTER_IDAT)
            png_error(png_ptr, "Too many IDAT's found");
      }

      png_ptr->idat_size = png_ptr->push_length;
      png_ptr->mode |= PNG_HAVE_IDAT;
      png_ptr->process_mode = PNG_READ_IDAT_MODE;
      png_push_have_info(png_ptr, info_ptr);
      png_ptr->zstream.avail_out =
          (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
          png_ptr->iwidth) + 1;
      png_ptr->zstream.next_out = png_ptr->row_buf;
      return;
   }

#ifdef PNG_READ_gAMA_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_sBIT_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_cHRM_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_sRGB_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_iCCP_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_sPLT_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_tRNS_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_bKGD_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_hIST_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_pHYs_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_oFFs_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
   }
#endif

#ifdef PNG_READ_pCAL_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_sCAL_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_tIME_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_tEXt_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_zTXt_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_iTXt_SUPPORTED
   else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
   else
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }
      png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
   }

   png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
}
Exemplo n.º 6
0
void /* PRIVATE */
png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
   png_size_t buffer_length)
{
   /* The caller checks for a non-zero buffer length. */
   if (!(buffer_length > 0) || buffer == NULL)
      png_error(png_ptr, "No IDAT data (internal error)");

   /* This routine must process all the data it has been given
    * before returning, calling the row callback as required to
    * handle the uncompressed results.
    */
   png_ptr->zstream.next_in = buffer;
   png_ptr->zstream.avail_in = (uInt)buffer_length;

   /* Keep going until the decompressed data is all processed
    * or the stream marked as finished.
    */
   while (png_ptr->zstream.avail_in > 0 &&
	  !(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
   {
      int ret;

      /* We have data for zlib, but we must check that zlib
       * has somewhere to put the results.  It doesn't matter
       * if we don't expect any results -- it may be the input
       * data is just the LZ end code.
       */
      if (!(png_ptr->zstream.avail_out > 0))
      {
         png_ptr->zstream.avail_out =
             (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
             png_ptr->iwidth) + 1;
         png_ptr->zstream.next_out = png_ptr->row_buf;
      }

      /* Using Z_SYNC_FLUSH here means that an unterminated
       * LZ stream can still be handled (a stream with a missing
       * end code), otherwise (Z_NO_FLUSH) a future zlib
       * implementation might defer output and, therefore,
       * change the current behavior.  (See comments in inflate.c
       * for why this doesn't happen at present with zlib 1.2.5.)
       */
      ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH);

      /* Check for any failure before proceeding. */
      if (ret != Z_OK && ret != Z_STREAM_END)
      {
	 /* Terminate the decompression. */
	 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;

         /* This may be a truncated stream (missing or
	  * damaged end code).  Treat that as a warning.
	  */
         if (png_ptr->row_number >= png_ptr->num_rows ||
	     png_ptr->pass > 6)
	    png_warning(png_ptr, "Truncated compressed data in IDAT");
	 else
	    png_error(png_ptr, "Decompression error in IDAT");

	 /* Skip the check on unprocessed input */
         return;
      }

      /* Did inflate output any data? */
      if (png_ptr->zstream.next_out != png_ptr->row_buf)
      {
	 /* Is this unexpected data after the last row?
	  * If it is, artificially terminate the LZ output
	  * here.
	  */
         if (png_ptr->row_number >= png_ptr->num_rows ||
	     png_ptr->pass > 6)
         {
	    /* Extra data. */
	    png_warning(png_ptr, "Extra compressed data in IDAT");
            png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
	    /* Do no more processing; skip the unprocessed
	     * input check below.
	     */
            return;
	 }

	 /* Do we have a complete row? */
	 if (png_ptr->zstream.avail_out == 0)
	    png_push_process_row(png_ptr);
      }

      /* And check for the end of the stream. */
      if (ret == Z_STREAM_END)
	 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
   }

   /* All the data should have been processed, if anything
    * is left at this point we have bytes of IDAT data
    * after the zlib end code.
    */
   if (png_ptr->zstream.avail_in > 0)
      png_warning(png_ptr, "Extra compression data");
}
Exemplo n.º 7
0
void /* PRIVATE */
png_push_process_row(png_structrp png_ptr)
{
   /* 1.5.6: row_info moved out of png_struct to a local here. */
   png_row_info row_info;

   row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */
   row_info.color_type = png_ptr->color_type;
   row_info.bit_depth = png_ptr->bit_depth;
   row_info.channels = png_ptr->channels;
   row_info.pixel_depth = png_ptr->pixel_depth;
   row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);

   if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
   {
      if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST)
         png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1,
            png_ptr->prev_row + 1, png_ptr->row_buf[0]);
      else
         png_error(png_ptr, "bad adaptive filter value");
   }

   /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before
    * 1.5.6, while the buffer really is this big in current versions of libpng
    * it may not be in the future, so this was changed just to copy the
    * interlaced row count:
    */
   memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);

#ifdef PNG_READ_TRANSFORMS_SUPPORTED
   if (png_ptr->transformations != 0)
      png_do_read_transformations(png_ptr, &row_info);
#endif

   /* The transformed pixel depth should match the depth now in row_info. */
   if (png_ptr->transformed_pixel_depth == 0)
   {
      png_ptr->transformed_pixel_depth = row_info.pixel_depth;
      if (row_info.pixel_depth > png_ptr->maximum_pixel_depth)
         png_error(png_ptr, "progressive row overflow");
   }

   else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth)
      png_error(png_ptr, "internal progressive row size calculation error");


#ifdef PNG_READ_INTERLACING_SUPPORTED
   /* Expand interlaced rows to full size */
   if (png_ptr->interlaced != 0 &&
       (png_ptr->transformations & PNG_INTERLACE) != 0)
   {
      if (png_ptr->pass < 6)
         png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
            png_ptr->transformations);

      switch (png_ptr->pass)
      {
         case 0:
         {
            int i;
            for (i = 0; i < 8 && png_ptr->pass == 0; i++)
            {
               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
               png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */
            }

            if (png_ptr->pass == 2) /* Pass 1 might be empty */
            {
               for (i = 0; i < 4 && png_ptr->pass == 2; i++)
               {
                  png_push_have_row(png_ptr, NULL);
                  png_read_push_finish_row(png_ptr);
               }
            }

            if (png_ptr->pass == 4 && png_ptr->height <= 4)
            {
               for (i = 0; i < 2 && png_ptr->pass == 4; i++)
               {
                  png_push_have_row(png_ptr, NULL);
                  png_read_push_finish_row(png_ptr);
               }
            }

            if (png_ptr->pass == 6 && png_ptr->height <= 4)
            {
                png_push_have_row(png_ptr, NULL);
                png_read_push_finish_row(png_ptr);
            }

            break;
         }

         case 1:
         {
            int i;
            for (i = 0; i < 8 && png_ptr->pass == 1; i++)
            {
               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
               png_read_push_finish_row(png_ptr);
            }

            if (png_ptr->pass == 2) /* Skip top 4 generated rows */
            {
               for (i = 0; i < 4 && png_ptr->pass == 2; i++)
               {
                  png_push_have_row(png_ptr, NULL);
                  png_read_push_finish_row(png_ptr);
               }
            }

            break;
         }

         case 2:
         {
            int i;

            for (i = 0; i < 4 && png_ptr->pass == 2; i++)
            {
               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
               png_read_push_finish_row(png_ptr);
            }

            for (i = 0; i < 4 && png_ptr->pass == 2; i++)
            {
               png_push_have_row(png_ptr, NULL);
               png_read_push_finish_row(png_ptr);
            }

            if (png_ptr->pass == 4) /* Pass 3 might be empty */
            {
               for (i = 0; i < 2 && png_ptr->pass == 4; i++)
               {
                  png_push_have_row(png_ptr, NULL);
                  png_read_push_finish_row(png_ptr);
               }
            }

            break;
         }

         case 3:
         {
            int i;

            for (i = 0; i < 4 && png_ptr->pass == 3; i++)
            {
               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
               png_read_push_finish_row(png_ptr);
            }

            if (png_ptr->pass == 4) /* Skip top two generated rows */
            {
               for (i = 0; i < 2 && png_ptr->pass == 4; i++)
               {
                  png_push_have_row(png_ptr, NULL);
                  png_read_push_finish_row(png_ptr);
               }
            }

            break;
         }

         case 4:
         {
            int i;

            for (i = 0; i < 2 && png_ptr->pass == 4; i++)
            {
               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
               png_read_push_finish_row(png_ptr);
            }

            for (i = 0; i < 2 && png_ptr->pass == 4; i++)
            {
               png_push_have_row(png_ptr, NULL);
               png_read_push_finish_row(png_ptr);
            }

            if (png_ptr->pass == 6) /* Pass 5 might be empty */
            {
               png_push_have_row(png_ptr, NULL);
               png_read_push_finish_row(png_ptr);
            }

            break;
         }

         case 5:
         {
            int i;

            for (i = 0; i < 2 && png_ptr->pass == 5; i++)
            {
               png_push_have_row(png_ptr, png_ptr->row_buf + 1);
               png_read_push_finish_row(png_ptr);
            }

            if (png_ptr->pass == 6) /* Skip top generated row */
            {
               png_push_have_row(png_ptr, NULL);
               png_read_push_finish_row(png_ptr);
            }

            break;
         }

         default:
         case 6:
         {
            png_push_have_row(png_ptr, png_ptr->row_buf + 1);
            png_read_push_finish_row(png_ptr);

            if (png_ptr->pass != 6)
               break;

            png_push_have_row(png_ptr, NULL);
            png_read_push_finish_row(png_ptr);
         }
      }
   }
   else
#endif
   {
      png_push_have_row(png_ptr, png_ptr->row_buf + 1);
      png_read_push_finish_row(png_ptr);
   }
}
Exemplo n.º 8
0
void /* PRIVATE */
png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
{
   png_uint_32 chunk_name;
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
   int keep; /* unknown handling method */
#endif

   /* First we make sure we have enough data for the 4-byte chunk name
    * and the 4-byte chunk length before proceeding with decoding the
    * chunk data.  To fully decode each of these chunks, we also make
    * sure we have enough data in the buffer for the 4-byte CRC at the
    * end of every chunk (except IDAT, which is handled separately).
    */
   if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0)
   {
      png_byte chunk_length[4];
      png_byte chunk_tag[4];

      PNG_PUSH_SAVE_BUFFER_IF_LT(8)
      png_push_fill_buffer(png_ptr, chunk_length, 4);
      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
      png_reset_crc(png_ptr);
      png_crc_read(png_ptr, chunk_tag, 4);
      png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
      png_check_chunk_name(png_ptr, png_ptr->chunk_name);
      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
   }

   chunk_name = png_ptr->chunk_name;

   if (chunk_name == png_IDAT)
   {
      if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
         png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;

      /* If we reach an IDAT chunk, this means we have read all of the
       * header chunks, and we can start reading the image (or if this
       * is called after the image has been read - we have an error).
       */
      if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
         png_error(png_ptr, "Missing IHDR before IDAT");

      else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
          (png_ptr->mode & PNG_HAVE_PLTE) == 0)
         png_error(png_ptr, "Missing PLTE before IDAT");

      png_ptr->mode |= PNG_HAVE_IDAT;
      png_ptr->process_mode = PNG_READ_IDAT_MODE;

      if ((png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) == 0)
         if (png_ptr->push_length == 0)
            return;

      if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
         png_benign_error(png_ptr, "Too many IDATs found");
   }

   if (chunk_name == png_IHDR)
   {
      if (png_ptr->push_length != 13)
         png_error(png_ptr, "Invalid IHDR length");

      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
   }

   else if (chunk_name == png_IEND)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);

      png_ptr->process_mode = PNG_READ_DONE_MODE;
      png_push_have_end(png_ptr, info_ptr);
   }

#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
   else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep);

      if (chunk_name == png_PLTE)
         png_ptr->mode |= PNG_HAVE_PLTE;
   }
#endif

   else if (chunk_name == png_PLTE)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
   }

   else if (chunk_name == png_IDAT)
   {
      png_ptr->idat_size = png_ptr->push_length;
      png_ptr->process_mode = PNG_READ_IDAT_MODE;
      png_push_have_info(png_ptr, info_ptr);
      png_ptr->zstream.avail_out =
          (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
          png_ptr->iwidth) + 1;
      png_ptr->zstream.next_out = png_ptr->row_buf;
      return;
   }

#ifdef PNG_READ_gAMA_SUPPORTED
   else if (png_ptr->chunk_name == png_gAMA)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_sBIT_SUPPORTED
   else if (png_ptr->chunk_name == png_sBIT)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_cHRM_SUPPORTED
   else if (png_ptr->chunk_name == png_cHRM)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_sRGB_SUPPORTED
   else if (chunk_name == png_sRGB)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_iCCP_SUPPORTED
   else if (png_ptr->chunk_name == png_iCCP)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_sPLT_SUPPORTED
   else if (chunk_name == png_sPLT)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_tRNS_SUPPORTED
   else if (chunk_name == png_tRNS)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_bKGD_SUPPORTED
   else if (chunk_name == png_bKGD)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_hIST_SUPPORTED
   else if (chunk_name == png_hIST)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_pHYs_SUPPORTED
   else if (chunk_name == png_pHYs)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_oFFs_SUPPORTED
   else if (chunk_name == png_oFFs)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
   }
#endif

#ifdef PNG_READ_pCAL_SUPPORTED
   else if (chunk_name == png_pCAL)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_sCAL_SUPPORTED
   else if (chunk_name == png_sCAL)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_tIME_SUPPORTED
   else if (chunk_name == png_tIME)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_tEXt_SUPPORTED
   else if (chunk_name == png_tEXt)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_zTXt_SUPPORTED
   else if (chunk_name == png_zTXt)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_iTXt_SUPPORTED
   else if (chunk_name == png_iTXt)
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
   }
#endif

   else
   {
      PNG_PUSH_SAVE_BUFFER_IF_FULL
      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length,
         PNG_HANDLE_CHUNK_AS_DEFAULT);
   }

   png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
}
Exemplo n.º 9
0
void /* PRIVATE */
png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer,
                      png_size_t buffer_length)
{
    /* The caller checks for a non-zero buffer length. */
    if (!(buffer_length > 0) || buffer == NULL)
        png_error(png_ptr, "No IDAT data (internal error)");

#ifdef PNG_READ_APNG_SUPPORTED
    /* If the app is not APNG-aware, decode only the first frame */
    if ((png_ptr->apng_flags & PNG_APNG_APP) == 0 &&
            png_ptr->num_frames_read > 0)
    {
        png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
        return;
    }
#endif

    /* This routine must process all the data it has been given
     * before returning, calling the row callback as required to
     * handle the uncompressed results.
     */
    png_ptr->zstream.next_in = buffer;
    /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
    png_ptr->zstream.avail_in = (uInt)buffer_length;

    /* Keep going until the decompressed data is all processed
     * or the stream marked as finished.
     */
    while (png_ptr->zstream.avail_in > 0 &&
            (png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
    {
        int ret;

        /* We have data for zlib, but we must check that zlib
         * has someplace to put the results.  It doesn't matter
         * if we don't expect any results -- it may be the input
         * data is just the LZ end code.
         */
        if (!(png_ptr->zstream.avail_out > 0))
        {
            /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
            png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
                                                png_ptr->iwidth) + 1);

            png_ptr->zstream.next_out = png_ptr->row_buf;
        }

        /* Using Z_SYNC_FLUSH here means that an unterminated
         * LZ stream (a stream with a missing end code) can still
         * be handled, otherwise (Z_NO_FLUSH) a future zlib
         * implementation might defer output and therefore
         * change the current behavior (see comments in inflate.c
         * for why this doesn't happen at present with zlib 1.2.5).
         */
        ret = PNG_INFLATE(png_ptr, Z_SYNC_FLUSH);

        /* Check for any failure before proceeding. */
        if (ret != Z_OK && ret != Z_STREAM_END)
        {
            /* Terminate the decompression. */
            png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
            png_ptr->zowner = 0;

            /* This may be a truncated stream (missing or
             * damaged end code).  Treat that as a warning.
             */
            if (png_ptr->row_number >= png_ptr->num_rows ||
                    png_ptr->pass > 6)
                png_warning(png_ptr, "Truncated compressed data in IDAT");

            else
            {
                if (ret == Z_DATA_ERROR)
                    png_benign_error(png_ptr, "IDAT: ADLER32 checksum mismatch");
                else
                    png_error(png_ptr, "Decompression error in IDAT");
            }

            /* Skip the check on unprocessed input */
            return;
        }

        /* Did inflate output any data? */
        if (png_ptr->zstream.next_out != png_ptr->row_buf)
        {
            /* Is this unexpected data after the last row?
             * If it is, artificially terminate the LZ output
             * here.
             */
            if (png_ptr->row_number >= png_ptr->num_rows ||
                    png_ptr->pass > 6)
            {
                /* Extra data. */
                png_warning(png_ptr, "Extra compressed data in IDAT");
                png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
                png_ptr->zowner = 0;

                /* Do no more processing; skip the unprocessed
                 * input check below.
                 */
                return;
            }

            /* Do we have a complete row? */
            if (png_ptr->zstream.avail_out == 0)
                png_push_process_row(png_ptr);
        }

        /* And check for the end of the stream. */
        if (ret == Z_STREAM_END)
            png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
    }

    /* All the data should have been processed, if anything
     * is left at this point we have bytes of IDAT data
     * after the zlib end code.
     */
    if (png_ptr->zstream.avail_in > 0)
        png_warning(png_ptr, "Extra compression data in IDAT");
}
Exemplo n.º 10
0
                    v = 0;
                } else {
                    shift -= 4;
                }

                sp++;
            }
            if (shift != 4) {
                *dp = (png_byte)v;
            }
            break;
        }
        }
        row_info->bit_depth = (png_byte)bit_depth;
        row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
        row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
                                          row_info->width);
    }
}
#endif

#if defined(PNG_WRITE_SHIFT_SUPPORTED)
/* Shift pixel values to take advantage of whole range.  Pass the
 * true number of bits in bit_depth.  The row should be packed
 * according to row_info->bit_depth.  Thus, if you had a row of
 * bit depth 4, but the pixels only had values from 0 to 7, you
 * would pass 3 as bit_depth, and this routine would translate the
 * data to 0 to 15.
 */
void /* PRIVATE */
png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth) {
    png_debug(1, "in png_do_shift\n");
Exemplo n.º 11
0
void /* PRIVATE */
png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
{
   png_uint_32 chunk_name;
#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
   int keep; /* unknown handling method */
#endif

   /* First we make sure we have enough data for the 4 byte chunk name
    * and the 4 byte chunk length before proceeding with decoding the
    * chunk data.  To fully decode each of these chunks, we also make
    * sure we have enough data in the buffer for the 4 byte CRC at the
    * end of every chunk (except IDAT, which is handled separately).
    */
   if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
   {
      png_byte chunk_length[4];
      png_byte chunk_tag[4];

      if (png_ptr->buffer_size < 8)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_push_fill_buffer(png_ptr, chunk_length, 4);
      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
      png_reset_crc(png_ptr);
      png_crc_read(png_ptr, chunk_tag, 4);
      png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
      png_check_chunk_name(png_ptr, png_ptr->chunk_name);
      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
   }

   chunk_name = png_ptr->chunk_name;

#ifdef PNG_READ_APNG_SUPPORTED
   if (png_ptr->num_frames_read > 0 &&
       png_ptr->num_frames_read < info_ptr->num_frames)
   {
      if (chunk_name == png_IDAT)
      {
         /* Discard trailing IDATs for the first frame */
         if (png_ptr->mode & PNG_HAVE_fcTL || png_ptr->num_frames_read > 1)
            png_error(png_ptr, "out of place IDAT");

         if (png_ptr->push_length + 4 > png_ptr->buffer_size)
         {
            png_push_save_buffer(png_ptr);
            return;
         }

         png_push_crc_skip(png_ptr, png_ptr->push_length);
         png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
         return;
      }
      else if (chunk_name == png_fdAT)
      {
         if (png_ptr->buffer_size < 4)
         {
            png_push_save_buffer(png_ptr);
            return;
         }

         png_ensure_sequence_number(png_ptr, 4);

         if (!(png_ptr->mode & PNG_HAVE_fcTL))
         {
            /* Discard trailing fdATs for frames other than the first */
            if (png_ptr->num_frames_read < 2)
               png_error(png_ptr, "out of place fdAT");

            if (png_ptr->push_length + 4 > png_ptr->buffer_size)
            {
               png_push_save_buffer(png_ptr);
               return;
            }

            png_push_crc_skip(png_ptr, png_ptr->push_length);
            png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
            return;
         }

         else
         {
            /* frame data follows */
            png_ptr->idat_size = png_ptr->push_length - 4;
            png_ptr->mode |= PNG_HAVE_IDAT;
            png_ptr->process_mode = PNG_READ_IDAT_MODE;

            return;
         }
      }

      else if (chunk_name == png_fcTL)
      {
         if (png_ptr->push_length + 4 > png_ptr->buffer_size)
         {
            png_push_save_buffer(png_ptr);
            return;
         }

         png_read_reset(png_ptr);
         png_ptr->mode &= ~PNG_HAVE_fcTL;

         png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length);

         if (!(png_ptr->mode & PNG_HAVE_fcTL))
            png_error(png_ptr, "missing required fcTL chunk");

         png_read_reinit(png_ptr, info_ptr);
         png_progressive_read_reset(png_ptr);

         if (png_ptr->frame_info_fn != NULL)
            (*(png_ptr->frame_info_fn))(png_ptr, png_ptr->num_frames_read);

         png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;

         return;
      }

      else
      {
         if (png_ptr->push_length + 4 > png_ptr->buffer_size)
         {
            png_push_save_buffer(png_ptr);
            return;
         }
         png_warning(png_ptr, "Skipped (ignored) a chunk "
                              "between APNG chunks");
         png_push_crc_skip(png_ptr, png_ptr->push_length);
         png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
         return;
      }

      return;
   }
#endif /* PNG_READ_APNG_SUPPORTED */

   if (chunk_name == png_IDAT)
   {
      if (png_ptr->mode & PNG_AFTER_IDAT)
         png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;

      /* If we reach an IDAT chunk, this means we have read all of the
       * header chunks, and we can start reading the image (or if this
       * is called after the image has been read - we have an error).
       */
      if (!(png_ptr->mode & PNG_HAVE_IHDR))
         png_error(png_ptr, "Missing IHDR before IDAT");

      else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
          !(png_ptr->mode & PNG_HAVE_PLTE))
         png_error(png_ptr, "Missing PLTE before IDAT");

      png_ptr->mode |= PNG_HAVE_IDAT;

      if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
         if (png_ptr->push_length == 0)
            return;

      if (png_ptr->mode & PNG_AFTER_IDAT)
         png_benign_error(png_ptr, "Too many IDATs found");
   }

   if (chunk_name == png_IHDR)
   {
      if (png_ptr->push_length != 13)
         png_error(png_ptr, "Invalid IHDR length");

      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
   }

   else if (chunk_name == png_IEND)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);

      png_ptr->process_mode = PNG_READ_DONE_MODE;
      png_push_have_end(png_ptr, info_ptr);
   }

#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
   else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep);

      if (chunk_name == png_PLTE)
         png_ptr->mode |= PNG_HAVE_PLTE;
   }

#endif
   else if (chunk_name == png_PLTE)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }
      png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
   }

   else if (chunk_name == png_IDAT)
   {
#ifdef PNG_READ_APNG_SUPPORTED
      png_have_info(png_ptr, info_ptr);
#endif
      png_ptr->idat_size = png_ptr->push_length;
      png_ptr->process_mode = PNG_READ_IDAT_MODE;
      png_push_have_info(png_ptr, info_ptr);
      png_ptr->zstream.avail_out =
          (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
          png_ptr->iwidth) + 1;
      png_ptr->zstream.next_out = png_ptr->row_buf;
      return;
   }

#ifdef PNG_READ_gAMA_SUPPORTED
   else if (png_ptr->chunk_name == png_gAMA)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_sBIT_SUPPORTED
   else if (png_ptr->chunk_name == png_sBIT)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_cHRM_SUPPORTED
   else if (png_ptr->chunk_name == png_cHRM)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_sRGB_SUPPORTED
   else if (chunk_name == png_sRGB)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_iCCP_SUPPORTED
   else if (png_ptr->chunk_name == png_iCCP)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_sPLT_SUPPORTED
   else if (chunk_name == png_sPLT)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_tRNS_SUPPORTED
   else if (chunk_name == png_tRNS)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_bKGD_SUPPORTED
   else if (chunk_name == png_bKGD)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_hIST_SUPPORTED
   else if (chunk_name == png_hIST)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_pHYs_SUPPORTED
   else if (chunk_name == png_pHYs)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_oFFs_SUPPORTED
   else if (chunk_name == png_oFFs)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
   }
#endif

#ifdef PNG_READ_pCAL_SUPPORTED
   else if (chunk_name == png_pCAL)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_sCAL_SUPPORTED
   else if (chunk_name == png_sCAL)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_tIME_SUPPORTED
   else if (chunk_name == png_tIME)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_tEXt_SUPPORTED
   else if (chunk_name == png_tEXt)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_zTXt_SUPPORTED
   else if (chunk_name == png_zTXt)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_iTXt_SUPPORTED
   else if (chunk_name == png_iTXt)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
   }

#endif
#ifdef PNG_READ_APNG_SUPPORTED
   else if (chunk_name == png_acTL)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_acTL(png_ptr, info_ptr, png_ptr->push_length);
   }

   else if (chunk_name == png_fcTL)
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }

      png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length);
   }
#endif /* PNG_READ_APNG_SUPPORTED */

   else
   {
      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
      {
         png_push_save_buffer(png_ptr);
         return;
      }
      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length,
         PNG_HANDLE_CHUNK_AS_DEFAULT);
   }

   png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
}