PNG_COST_FACTOR  1251 3rdparty/libpng/pngwrite.c          png_ptr->filter_costs[i] = PNG_COST_FACTOR;
PNG_COST_FACTOR  1319 3rdparty/libpng/pngwrite.c              (png_uint_16)(PNG_COST_FACTOR / filter_costs[i] + .5);
PNG_COST_FACTOR  1322 3rdparty/libpng/pngwrite.c              (png_uint_16)(PNG_COST_FACTOR * filter_costs[i] + .5);
PNG_COST_FACTOR  1380 3rdparty/libpng/pngwrite.c          tmp = PNG_COST_FACTOR*PNG_FP_1 + (filter_costs[i]/2);
PNG_COST_FACTOR  1385 3rdparty/libpng/pngwrite.c          tmp = PNG_COST_FACTOR * filter_costs[i] + PNG_FP_HALF;