1. A variable length coded data processing method, in which a first and second variable length coded data having end codes at rear ends thereof and each comprised of a plurality of compressed portion data are coupled and output to a buffer of a decoder, comprising the steps of: deleting the end code of the first variable length coded data; calculating an invalid data of an amount corresponding to a result of comparison of a value related to a buffer occupancy at a decoding timing of a last compressed portion data of the first variable length coded data with a buffer occupancy at a decoding timing of a first compressed portion data of the second variable length coded data; adding the calculated invalid data to the last compressed portion data of the first variable length coded data; and coupling the second variable length coded data thereto and outputting it to the decoder buffer.