sqlite3 *mbtiles_open(char *dbname, char **argv);
void mbtiles_write_tile(sqlite3 *outdb, int z, int tx, int ty, const char *data, int size);
void mbtiles_write_metadata(sqlite3 *outdb, const char *fname, char **layername, int minzoom, int maxzoom, double minlat, double minlon, double maxlat, double maxlon, double midlat, double midlon, struct pool **file_keys, int nlayers);
void mbtiles_close(sqlite3 *outdb, char **argv);