Abstract: When short MPEG2 data transfer streams, such as those used for commercials, are sequentially distributed within a short period of time, a decoder method synchronizes the transfer and prevents accumulation of data in a buffer and data losses. The synchronization method extracts sync data originating at the transmission source from a received data stream; acquires sync data for a decoder based on a reference clock; compares the sync data originating at the transmission source with the sync data for the decoder in order to sequentially obtain control values, sequentially updates the frequency of the reference clock for transfer synchronization for the received data stream; determines whether or not a data stream that differs from the received data stream has been received; and employs, when a different data stream has been received, the reference clock obtained when the received data stream has been received, to initiate transfer synchronization for the different data stream.