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);
}
示例#2
0
文件: pngpread.c 项目: AGenews/GUI
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);
   }
}
示例#3
0
void
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_ptr->row_info.width *
      (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);

   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_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)
         png_do_read_interlace(&(png_ptr->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);
            }
            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)
            {
               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);
            }
            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)
            {
               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);
            }
            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)
            {
               png_push_have_row(png_ptr, 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, 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);
   }
}
示例#4
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);
   }
}
示例#5
0
void
png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
{
   int ret;
   png_debug2(1, "in png_read_row (row %d, pass %d)\n",
      png_ptr->row_number, png_ptr->pass);
   /* save jump buffer and error functions */
   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
   }

#if defined(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 & 7)
            {
               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 & 7) || 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 & 7) != 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;
         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_ptr->irowbytes;
   do
   {
      if (!(png_ptr->zstream.avail_in))
      {
         while (!png_ptr->idat_size)
         {
            png_byte chunk_length[4];

            png_crc_finish(png_ptr, 0);

            png_read_data(png_ptr, chunk_length, 4);
            png_ptr->idat_size = png_get_uint_32(chunk_length);

            png_reset_crc(png_ptr);
            png_crc_read(png_ptr, png_ptr->chunk_name, 4);
            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_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_ptr->row_info.width *
      (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);

   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_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)
         png_do_read_interlace(&(png_ptr->row_info),
            png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);

      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);
}