type mb_type = {quant : bool;forward : bool;backward : bool;pattern : bool;intra : bool;
}val address_increment : (string * int) listval mb_type_i : (string * mb_type) listval mb_type_p : (string * mb_type) listval mb_type_b : (string * mb_type) listval coded_block_pattern : (string * int) listval motion_code : (string * int) listval dc_size_luminance : (string * int) listval dc_size_chrominance : (string * int) listtype coefficient = | Coeff of int * int| Eob| Escape