An encoding apparatus adds delay time information DTI indicating initial delay time i_d and delay time d of each group data to a position to be read prior to frame data by a decoding apparatus in the group data of encoding stream data DBI and transmits the same to the decoding apparatus 3. Namely, the encoding apparatus does not transmit initial offset delay time i_of to the decoding apparatus 3. The encoding apparatus starts to read and transmit the encoding stream data DBI from a transmission buffer at a predetermined bit rate R at timing designated by the initial offset delay time i_of.