Temporal slice persistence method and apparatus for delivery of interactive program guide
View Patent ↗Techniques to efficiently deliver interactive program guide (IPG) to a number of terminals. Each IPG page can be decomposed into a guide portion that is specific to each IPG page and a background portion that is common for all IPG pages. The background portion can be further decomposed into a time-varying video portion and other static portions. One method includes receiving a viewer selection for imagery, where the imagery includes at least one intracoded slice and at least one predictively coded slice, and each of the intracoded and predictively codes slices are associated with respective bitstreams. Packets from the at least one bitstream corresponding to the at least one intracoded slice of the selected imagery are extracted, and packets from the at least one bitstream corresponding to the at least one predictively coded slice of the selected imagery are also extracted. The payload portions of the extracted packets are then arranged to form the selected imagery.
1. A method, comprising:
receiving a viewer selection for imagery, said imagery including at least one intracoded slice and at least one predictively coded slice, each of said intracoded and predictively codes slices being associated with respective bitstreams;
extracting packets from the at least one bitstream corresponding to the at least one intracoded slice of the selected imagery;
extracting packets from the at least one bitstream corresponding to the at least one predictively coded slice of the selected imagery; and
arranging payload portions of the extracted packets to form said selected imagery.
2. The method of claim 1 , wherein:
said selected imagery comprises a sequence of image frames forming a group of pictures (GOP), said GOP comprising a first image frame primarily formed using intracoded slices and a plurality of subsequent image frames primarily formed using predictively codes slices.
3. The method of claim 1 , wherein:
said imagery comprises an interactive program guide (IPG) page including a guide portion and a video portion.
4. The method of claim 1 , wherein:
each bitstream has associated with it a respective packet identifier (PID), said PIDs being used by said steps of extracting to identify bitstreams corresponding to the at least one intracoded slice and the at least one predictively coded slice forming the selected imagery.
5. The method of claim 4 , further comprising:
sending said extracted packets to a decoder for processing.
6. The method of claim 4 , further comprising:
modifying packet identifiers (PIDs) associated with said selected imagery to a predetermined PID value prior to said extracting steps.
7. The method of claim 6 , wherein said modified PIDs are changed to a PID value equal to a lowest PID value associated with said selected imagery.
8. The method of claim 6 , wherein said extracting steps comprise extracting said packets having said predetermined PID value.
9. The method of claim 8 , further comprising:
setting a discontinuity indicator in an adaptation field of a header of a packet that immediately follows a merge point.
10. The method of claim 4 , wherein said extracting packets from the at least one bitstream corresponding to the at least one intracoded slice of the selected imagery, further comprises:
identifying a splice countdown value in an adaptation field of a packet header for packets having PIDs associated with intracoded slices (I-PIDs).
extracting packets having I-PIDs from said bitstream that have a countdown value approaching and including a countdown value of zero; and
sending payloads of said extracted packets having I-PIDs to a decoder for processing.
11. The method of claim 10 , further comprising:
identifying a splice countdown value in an adaptation field of a packet header for packets having PIDs associated with predictively coded slices (P-PIDs),
extracting packets having P-PIDs from said bitstream that have a countdown value approaching and including a countdown value of zero; and
sending payloads of said extracted packets having P-PIDs to a decoder for processing.
12. Apparatus, comprising:
means for receiving a viewer selection for imagery, said imagery including at least one intracoded slice and at least one predictively coded slice, each of said intracoded and predictively codes slices being associated with respective bitstreams;
means for extracting packets from the at least one bitstream corresponding to the at least one intracoded slice of the selected imagery;
means for extracting packets from the at least one bitstream corresponding to the at least one predictively coded slice of the selected imagery; and
means for arranging payload portions of the extracted packets to form said selected imagery.
13. The apparatus of claim 12 , wherein:
said selected imagery comprises a sequence of image frames forming a group of pictures (GOP), said GOP comprising a first image frame primarily formed using intracoded slices and a plurality of subsequent image frames primarily formed using predictively codes slices.
14. The apparatus of claim 12 , wherein:
said imagery comprises an interactive program guide (IPG) page including a guide portion and a video portion.
15. The apparatus of claim 12 , wherein:
each bitstream has associated with it a respective packet identifier (PID), said PIDs being used by said steps of extracting to identify bitstreams corresponding to the at least one intracoded slice and the at least one predictively coded slice forming the selected imagery.
16. The apparatus of claim 15 , further comprising:
sending said extracted packets to a decoder for processing.
17. The apparatus of claim 15 , further comprising:
modifying packet identifiers (PIDs) associated with said selected imagery to a predetermined PID value prior to said extracting steps.
18. The apparatus of claim 17 , wherein said modified PIDs are changed to a PID value equal to a lowest PID value associated with said selected imagery.
19. The apparatus of claim 17 , wherein said extracting steps comprise extracting said packets having said predetermined PID value.
20. The apparatus of claim 19 , further comprising:
means for setting a discontinuity indicator in an adaptation field of a header of a packet that immediately follows a merge point.
21. The method of claim 15 , wherein said extracting packets from the at least one bitstream corresponding to the at least one intracoded slice of the selected imagery, further comprises:
means for identifying a splice countdown value in an adaptation field of a packet header for packets having PIDs associated with intracoded slices (I-PIDs).
means for extracting packets having I-PIDs from said bitstream that have a countdown value approaching and including a countdown value of zero; and
means for sending payloads of said extracted packets having I-PIDs to a decoder for processing.
22. The apparatus of claim 21 , further comprising:
means for identifying a splice countdown value in an adaptation field of a packet header for packets having PIDs associated with predictively coded slices (P-PIDs),
extracting packets having P-PIDs from said bitstream that have a countdown value approaching and including a countdown value of zero; and
sending payloads of said extracted packets having P-PIDs to a decoder for processing.