Method and apparatus for configuring content in a broadcast system

A method of transmitting media data, the method comprising:

• processing a media processing unit (MPU) including a data part and a control part, the MPU being processed independently, wherein the data part includes media data and the control part includes parameters related to the media data;
• and
• transmitting, by a transmitter, the MPU,
• wherein the MPU includes at least one fragmentation unit,
• wherein the parameters include a first parameter and a second parameter, based on the first parameter having a first value, the first parameter indicates that the at least one fragmentation unit comprises timed data including timeline information for decoding and/or presentation of content of the timed data, and based on the first parameter having a second value, the first parameter indicates that the at least one fragmentation unit comprises non-timed data, which does not include the timeline information for decoding and/or presentation of the content of the non-timed data,
• wherein the second parameter indicates a sequence number of the MPU,
• wherein the MPU is transmitted in at least one packet and the at least one packet includes information indicating if the at least one packet includes at least one random access point (RAP), and
• wherein the at least one fragmentation unit in the MPU is grouped into a first group including one or more fragmentation units of an I-picture type and one or more fragmentation units of a P-picture type and a second group including one or more fragmentation units of a B-picture type, according to a picture type for each of the fragmentation units, the first group is disposed ahead of the second group, and application-forward error control (AL-FEC) is applied only to the first group.