Use of messages in program signal streams by set-top terminals

1. A method of operating a receiving device coupled to a display device at a user location, the method comprising:

programming the receiving device to record a selected one of at least one program to be received in an MPEG encoded program signal stream, starting at a first program start clock time;

receiving the MPEG encoded program signal stream comprising at least the selected program and at least one message containing a second program start time for the selected program, the second program start time being in units of time with respect to progression of the MPEG encoded program signal stream, from receipt of the message to a start of the selected program in the program stream, the program signal stream and the at least one message being received from a same originator;

identifying the at least one message in the received program stream;

comparing the first program start clock time of the selected program with the second program start time, in units of time, contained in the at least one message; and

starting to record the selected program based, at least in part, on the second program start time in units of time, contained in the at least one message, if the second program start time is different from the first program start clock time.

2. The method of claim 1 , comprising:

programming the receiving device to record the selected program by selecting the program from a program listing.

3. The method of claim 2 , wherein the program listing defines the first program start clock time of the selected program, the method further comprising:

setting a recording start clock time for the selected program based on the first program start time defined by the program listing;

comparing the second program start time of the selected program contained in the at least one message to the first program start clock time; and

adjusting the recording start time of the selected program to the second program start time, if the second program start time is different than the first program start time.

4. The method of claim 3 , further comprising:

setting a recording end clock time for the selected program based on a first program end clock time defined by the program listing;

wherein the at least one message contains a second program end time of the selected program, the second program end time being in units of time with respect to progression of the MPEG encoded program signal stream, from receipt of the message to an end of the selected program in the program stream, the method further comprising:

comparing the second program end time, in units of time, contained in the at least one message to the recording end time;

adjusting the recording end time of the selected program to the second program end time, if the recording end time is different than the second program end time; and

ending recording of the selected program at the second program end time, if the recording end time has been adjusted.

5. The method of claim 4 , wherein the at least one message comprises a single message defining the second program start time and the second program end time, the method comprising:

receiving the program signal stream including the single message.

6. The method of claim 4 , further comprising,

after starting to record the selected program:

receiving at least one second message defining a start time for unscheduled content of the selected program, the at least one second message being received prior to the scheduled end time, in the MPEG encoded program signal stream;

continuing to record the selected program after the scheduled end time;

while recording the selected program, receiving at least one third message defining an end time for the unscheduled content of the selected program, the end time for the unscheduled content being after the scheduled end time of the selected program, the at least one third message being received prior to the end time of the unscheduled content MPEG encoded program signal stream; and

ending recording of the selected program at the end time of the unscheduled content defined by at least one of the at least one third message.

7. The method of claim 6 , wherein the selected program is a sporting event and the unscheduled content comprises overtime of the sporting event.

8. The method of claim 6 , wherein the at least one third message comprises at least one fourth message defining at least one respective expected end time of the unscheduled content and at least one fifth message defining an actual end time of the unscheduled content, the method comprising:

receiving the at least one fourth message prior to receiving the at least one fifth message; and

ending recording of the selected program at the actual end time defined by the at least one fifth message.

9. The method of claim 6 , wherein the at least one second message defines the start time of the unscheduled content by indicating an amount of time to the start of the unscheduled content in units of time with respect to progression of the MPEG encoded program signal stream, from receipt of a respective second message to a start of the selected program in the program stream, and the at least one third message defines the end time of the unscheduled content by indicating an amount of time to the end of the unscheduled content in units of time with respect to progression of the MPEG encoded program signal stream, from receipt of a respective third message to an end of the selected program in the program stream.

10. The method of claim 6 , wherein the at least one first, second and third messages and the at least one program are received from a same originator.

11. The method of claim 6 , wherein at least one of the at least one second message and at least one of the at least one third message are a single message.

12. The method of claim 6 , wherein the unscheduled content starts at the scheduled end of the selected program.

13. The method of claim 1 , wherein the at least one message is encrypted, the method comprising:

receiving the program signal stream and the at least one encrypted message.

14. The method of claim 1 , wherein the at least one message defines a start time for unscheduled content, the method further comprising:

recording the selected program based, at least in part, on the start time for the unscheduled content.

15. The method of claim 14 , wherein the at least one message defines an end time for the unscheduled content, the method further comprising:

recording the selected program based, at least in part, on the end time for the unscheduled content.

16. The method of claim 1 , wherein the at least one message contains an end time for the unscheduled content, the method further comprising:

recording the selected program based, at least in part, on the end time for the unscheduled content.

17. The method of claim 1 , comprising setting the first program start clock time and a first program end clock time based, at least in part, on user input of the first program start clock time and the first program end clock time.

18. The method of claim 1 , wherein the originator comprises a program origination system.

19. The method of claim 1 , comprising receiving the program signal stream, including the at least one message, via a cable television network.

20. The method of claim 1 , comprising starting to record the selected program based, at least in part, on the second program start time contained in the at least one message, if a difference between the second program start time and the first program start time is greater than a threshold.

21. A receiving device to receive a program signal stream, the receiving device to be coupled to a display device, the receiving device comprising:

an interface to receive an MPEG encoded program signal stream comprising at least one program and to provide the program signal stream to the display device, the program signal stream comprising at least one message containing a first program start time for a selected one of the at least one programs, the first program start time being in units of time with respect to progression of the MPEG encoded program signal stream, from receipt of the message to a start time of the selected program in the program stream, wherein the program signal stream including the at least one message is received from a same originator; a processor coupled to the interface, wherein:

the processor is programmable by a user to record the selected program starting at a second program start clock time;

the processor being programmed to:

receive the MPEG encoded program signal stream;

identify the at least one message in the received program signal stream;

compare the first program start time of the selected program in units of time, contained in the at least one message to the second program start clock time; and

start to record the selected program starting at the first start time, in units of time, contained in the at least one message, if the second start time is different from the first start clock time;

the receiving device further comprising memory coupled to the processor to store the selected recorded program.

22. The receiving device of claim 2 , wherein the processor is programmable to record the selected program by selecting the program from a program listing.

23. The receiving device of claim 22 , wherein the program listing defines the second program start time of the selected program and the processor is programmed to:

set a recording start time for the selected program based on the second program start clock time defined by the program listing;

compare the recording start time of the selected program to the second program start time, in units of time, contained in the at least one message; and

adjust the recording start time of the selected program to the second program start time if the second start time is different than the recording start time.

24. The receiving device of claim 23 , wherein the processor is programmed to:

set a recording end time for the selected program based on a second end clock time defined by the program listing; and

the at least one message defines a second program end time of the selected program, the second program end time being in units of time with respect to progression of the MPEG encoded program signal stream, from receipt of the message to an end of the selected program in the program stream;

the processor being further programmed to:

compare the recording program end time of the selected program to the second program end time in units of time, contained in the at least one message; and

adjust the recording end time of the selected program to the second program end time if the second program end time is different than the recording program end time.

25. The receiving device of claim 24 , wherein the at least one message comprises a single message defining the first program start time and the first program end time, the processor being programmed to:

receive the program signal stream including the single message.

26. The receiving device of claim 24 , wherein:

the MPEG encoded program signal stream comprises at least one second message defining a start time for unscheduled content of the selected program and at least one third message defining an end time for the unscheduled content of the selected program, the end time for the unscheduled content of the selected program being after the scheduled end time of the selected program; and

the processor is further programmed to:

receive the at least one second message defining a start time for the unscheduled content of the selected program after starting to record the selected program;

continue to record the selected program after the scheduled end time for the selected program;

receive the at least one third message defining an end time for the unscheduled content, while recording the selected program; and

end recording of the program at the end time of the unscheduled content defined by the at least one third message.

27. The receiving device of claim 21 , wherein the at least one message is encrypted and the processor is further programmed to:

decrypt the encrypted message.

28. The system of claim 21 , wherein the processor is programmed to start to record the selected program at the first program start time contained in the at least one message, if a difference between the first program start time and the second program start clock time is greater than a threshold.

29. A method of operating a receiving device coupled to a display device at a user location, the receiving device receiving a program signal stream comprising at least one program, the method comprising:

programming the receiving device to record a selected program to be received, starting at a first start clock time and to end recording at a first end clock time;

receiving a program signal stream including the selected program from an originator;

receiving at least one first message in the form of at least one first respective transport packet in the same program signal stream from the same originator, the at least one message containing a second program start time indicating an amount of time to the start of the program, in units of time with respect to progression of the program stream, from receipt of the message to a start time of the selected program in the program stream;

comparing the first program start clock time of the selected program with the second program start time, in units of time, contained in the at least one message; and

starting to record the selected program based on the second program start time defined by the at least one message, in units of time, if the first program start clock time is different than the second program start time;

after starting to record the selected program, receiving at least one second message in the form of at least one respective second transport packet in the program signal stream, the at least one second message defining a second program end time by indicating an amount of time until the end of the program, in units of time with respect to progression of the program signal stream, from receipt of the message to an end of the selected program in the program stream;

comparing the programmed first program end clock time of the program with the second program end time, in units of time, contained in the at least one second message; and

ending recording of the program at the second program end time, in units of time, contained in the at least one second message, if the first program end clock time is different from the second program end time.

30. The method of claim 29 , comprising receiving the selected program and receiving the at least one first, second and third messages from the same originator.