Patent ID: 7280475

Claim:
A data transfer apparatus that receives from an upper station a data stream that includes a plurality of types of repeat data, each type of repeat data being repeatedly transmitted according to a carousel transmission method by the upper station and repeat data of a same type being identical in content, and transfers the repeat data to a lower station, comprising: storage means having a storage area; extraction means for extracting the types of repeat data from the received data stream; writing means for writing the extracted repeat data to the storage area; data structure ratio determination means for determining a ratio between the types of repeat data to be output in a data stream per fixed length of time; and data output means for outputting the repeat data at the determined ratio by reading and outputting each type of repeat data a number of times that corresponds to the determined ratio, wherein each type of repeat data is composed of a plurality of data packets that are transmitted according to a carousel transmission method, the data stream is a transport stream, each of the types of repeat data has a PID that specifies the type of repeat data, the storage means stores at least one set of a first PID and a second PID, the first PID identifying a PID that is to be re-written, and the second PID specifying a PID with which the PID identified by the first PID is to be rewritten, and the data output means includes: a judgement unit for judging whether a PID of repeat data to be read by the data output means matches the first PID in the set stored by the storage means; and a PID re-writing unit for, when the PID of the repeat data to be read matches the first PID, re-writing the PID of the repeat data with the PID specified by the second PID in the set.