PNG_INFO_sPLT     447 3rdparty/libpng/png.c          info_ptr->valid &= ~PNG_INFO_sPLT;
PNG_INFO_sPLT    1020 3rdparty/libpng/pngset.c    info_ptr->valid |= PNG_INFO_sPLT;
PNG_INFO_sPLT     204 3rdparty/libpng/pngwrite.c    if (info_ptr->valid & PNG_INFO_sPLT)