Methods and apparatus for constructing a program association table when reducing multiplexed data streams
First Claim
1. A method for constructing a program association table (PAT) when reducing a multiplexed data stream, comprising the steps of:
- receiving at a transcoder an inbound multiplexed data stream having an all-inclusive PAT, a plurality of predefined multiplexed data stream subgroups, and a plurality of hidden PATs, each hidden PAT identified by a unique packet identifier (PID) and associated with an allowable predefined combination of said multiplexed data stream subgroups;
selecting one hidden PAT corresponding to a desired combination of multiplexed data stream subgroups;
determining the PID makeup of the desired multiplexed data stream subgroup combination from the selected hidden PAT;
discarding one or more of the all-inclusive PAT, unused hidden PATs, and any subgroups not contained in the desired multiplexed data stream subgroup combination;
re-mapping the selected hidden PAT to a predetermined PID; and
outputting the re-mapped PAT from the transcoder with the desired multiplexed data stream subgroup combination.
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Accused Products
Abstract
The present invention provides methods and apparatus for creating a Program Association Table (PAT) for a reduced portion of a multiplexed data stream, when the multiplexed data stream has been reduced, for example, to carry fewer services over a cable television plant. More particularly, the present invention provides methods and apparatus for creating a PAT for a desired combination of multiplexed data stream subgroups contained within an incoming data stream, when the incoming multiplexed data stream is reduced. The invention enables a new PAT to be output which correctly corresponds to the services in a reduced data stream (e.g., for cable-side transmissions). The present invention is particularly useful when reducing high data rate satellite television data streams for cable-side transmission.
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Citations
34 Claims
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1. A method for constructing a program association table (PAT) when reducing a multiplexed data stream, comprising the steps of:
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receiving at a transcoder an inbound multiplexed data stream having an all-inclusive PAT, a plurality of predefined multiplexed data stream subgroups, and a plurality of hidden PATs, each hidden PAT identified by a unique packet identifier (PID) and associated with an allowable predefined combination of said multiplexed data stream subgroups;
selecting one hidden PAT corresponding to a desired combination of multiplexed data stream subgroups;
determining the PID makeup of the desired multiplexed data stream subgroup combination from the selected hidden PAT;
discarding one or more of the all-inclusive PAT, unused hidden PATs, and any subgroups not contained in the desired multiplexed data stream subgroup combination;
re-mapping the selected hidden PAT to a predetermined PID; and
outputting the re-mapped PAT from the transcoder with the desired multiplexed data stream subgroup combination. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. Apparatus for constructing a program association table (PAT) when reducing a multiplexed data stream, comprising:
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a transcoder for receiving an inbound multiplexed data stream having an all-inclusive PAT, a plurality of predefined multiplexed data stream subgroups, and a plurality of hidden PATs, each hidden PAT identified by a unique packet identifier (PID) and associated with an allowable predefined combination of said multiplexed data stream subgroups; and
a processor associated with said transcoder;
wherein;
said processor is coupled to receive from the transcoder said all-inclusive PAT and said hidden PATs for each multiplexed data stream subgroup combination;
the processor is configured to select one hidden PAT corresponding to a desired multiplexed data stream subgroup combination;
the processor determines the PID makeup of the desired multiplexed data stream subgroup combination from the selected hidden PAT;
the processor discards one or more of the all-inclusive PAT, unused hidden PATs, and any subgroups not contained in the desired multiplexed data stream subgroup combination;
the processor causes the transcoder to re-map the selected hidden PAT to a predetermined PID; and
the transcoder outputs the re-mapped PAT with the selected multiplexed data stream subgroup combination. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. A method for creating a multiplexed data stream which is to be reduced, comprising:
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receiving a plurality of multiplexed data stream subgroups;
creating an all-inclusive PAT describing all the services contained in the plurality of data stream subgroups;
defining a plurality of data stream subgroup combinations;
creating for each defined combination of data stream subgroups a hidden PAT identified by a unique PID, each hidden PAT describing the services contained in said defined combination of data stream subgroups;
combining said all-inclusive PAT, said hidden PATs, and said data stream subgroups to create a multiplexed data stream.
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34. Apparatus for creating a multiplexed data stream which is to be reduced, comprising:
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an encoder; and
a processor associated with the encoder;
wherein;
the encoder receives a plurality of multiplexed data stream subgroups;
the processor generates an all-inclusive PAT describing all the services contained in the plurality of data stream subgroups;
the processor defines a plurality of data stream subgroup combinations;
the processor creates for each defined combination of data stream subgroups a hidden PAT identified by a unique PID, each hidden PAT describing the services contained in said defined combination of data stream subgroups; and
the encoder combines said all-inclusive PAT, said hidden PATs, and said data stream subgroups to create a multiplexed data stream.
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Specification