APPARATUS FOR MULTIPLEXING AND DEMULTIPLEXING IN CABLE TV RECEIVER

摘要

A multiplexing/demultiplexing apparatus of a cable broadcasting receiver is provided to correct synchronization when a data stream descrambled through a cable card is demultiplexed. A TS(Transmission Stream) receiver changes broadcasting streams of channels selected by a subscriber into data blocks of TS packets. A PID(Packet Identifier) filter identifies PID field information in headers of the TS packets outputted from the TS receiver and then outputs only packets corresponding to a program selected by a viewer and discards the remaining packets. A pre-header generator attaches a pre-header of predetermined size to a TS packet which passes through the PID filter. An LTS(Local Time Stamp) generator generates a time stamp value necessary for an LTS field of the pre-header generator. An output unit stores packets of predetermined size outputted from the pre-header generator in an FIFO(First-In First-Out) manner. An output controller prevents the packets, which is outputted from the output unit, from colliding with each other.