- /* check for width and height valid values */
- if (width == 0 || height == 0)
- png_error(png_ptr, "Image width or height is zero in IHDR");
-#ifdef PNG_SET_USER_LIMITS_SUPPORTED
- if (width > png_ptr->user_width_max || height > png_ptr->user_height_max)
- png_error(png_ptr, "image size exceeds user limits in IHDR");
-#else
- if (width > PNG_USER_WIDTH_MAX || height > PNG_USER_HEIGHT_MAX)
- png_error(png_ptr, "image size exceeds user limits in IHDR");
-#endif
- if (width > PNG_UINT_31_MAX || height > PNG_UINT_31_MAX)
- png_error(png_ptr, "Invalid image size in IHDR");
- if ( width > (PNG_UINT_32_MAX
- >> 3) /* 8-byte RGBA pixels */
- - 64 /* bigrowbuf hack */
- - 1 /* filter byte */
- - 7*8 /* rounding of width to multiple of 8 pixels */
- - 8) /* extra max_pixel_depth pad */
- png_warning(png_ptr, "Width is too large for libpng to process pixels");
-
- /* check other values */
- if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
- bit_depth != 8 && bit_depth != 16)
- png_error(png_ptr, "Invalid bit depth in IHDR");
-
- if (color_type < 0 || color_type == 1 ||
- color_type == 5 || color_type > 6)
- png_error(png_ptr, "Invalid color type in IHDR");
-
- if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) ||
- ((color_type == PNG_COLOR_TYPE_RGB ||
- color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
- color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
- png_error(png_ptr, "Invalid color type/bit depth combination in IHDR");
-
- if (interlace_type >= PNG_INTERLACE_LAST)
- png_error(png_ptr, "Unknown interlace method in IHDR");
-
- if (compression_type != PNG_COMPRESSION_TYPE_BASE)
- png_error(png_ptr, "Unknown compression method in IHDR");
-
-#if defined(PNG_MNG_FEATURES_SUPPORTED)
- /* Accept filter_method 64 (intrapixel differencing) only if
- * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
- * 2. Libpng did not read a PNG signature (this filter_method is only
- * used in PNG datastreams that are embedded in MNG datastreams) and
- * 3. The application called png_permit_mng_features with a mask that
- * included PNG_FLAG_MNG_FILTER_64 and
- * 4. The filter_method is 64 and
- * 5. The color_type is RGB or RGBA
- */
- if((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&png_ptr->mng_features_permitted)
- png_warning(png_ptr,"MNG features are not allowed in a PNG datastream");
- if(filter_type != PNG_FILTER_TYPE_BASE)
- {
- if(!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
- (filter_type == PNG_INTRAPIXEL_DIFFERENCING) &&
- ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
- (color_type == PNG_COLOR_TYPE_RGB ||
- color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
- png_error(png_ptr, "Unknown filter method in IHDR");
- if(png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)
- png_warning(png_ptr, "Invalid filter method in IHDR");
- }
-#else
- if(filter_type != PNG_FILTER_TYPE_BASE)
- png_error(png_ptr, "Unknown filter method in IHDR");
-#endif
-