PNG_FILTER_HEURISTIC_UNWEIGHTED 1167 3rdparty/libpng/pngwrite.c    png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
PNG_FILTER_HEURISTIC_UNWEIGHTED 1261 3rdparty/libpng/pngwrite.c       heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)