Abstract: A program input stream reprocessing device and a data broadcasting system using the device. The program input stream reprocessing device receives and reprocesses program input streams provided by a program service provider and transmits results to the data broadcasting system. That is, additional data of a program included in the program input stream is extracted to control the packet identifier and bandwidth depending on the broadcasting service provider's condition. Also, ES (elementary stream) information to be linked with the PSI(program specific information)/PSIP(program and system information protocol) is extracted from the program input stream and is transmitted to the PSI/PSIP generator of the data broadcasting system.