Apparatus and method for multi-service transport multiplexing

DETAILED DESCRIPTION It is desirable to be able to combine two or more transport streams into a single transport stream that contains all of the components of the source transport streams.
A problem encountered in combining transport streams is that the transport stream PIDs associated with one source stream typically conflict with the PIDs associated with one or more other source streams.
Other identifying information, such as the program_number, assigned to a service may also conflict with that assigned to a service in another transport stream.
Additionally, multiplexing two transport streams may cause embedded timing information, such as the Program Clock Reference (PCR), to be rendered inaccurate.
The above and other problems are solved by the multi-service transport multiplexing apparatus and method of the present invention.
The present invention defines a process for creating a transport stream by addition of services, one at a time, to a pre-existing transport stream multiplex.
The invention provides a capability for building a common set of service control information from the service control information tables of the individual streams being combined that avoids PID conflicts.
Accordingly, apparatus for multiplexing transport streams includes first and second transport demultiplexers for demultiplexing first and second input transport streams to their respective service components and service control information tables.
Each demultiplexer filters the respective service components and service control information tables according to a particular filter set that specifies PID processing actions.
A processor coupled to the first and second demultiplexers comprises means for examining the first and second service control information tables to determine whether any PID of one of the first and second transport streams overlaps or conflicts with any PID of the other of the first and second transport streams.
The processor further includes means for generating output service control information tables from the first and second service control information tables that have been modified to avoid any overlapping or conflicting PIDs