Trick mode elementary stream and receiver system

• US 20050135783A1
• Filed: 11/15/2004
• Published: 06/23/2005
• Est. Priority Date: 09/07/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Crinon, Regis J.
• Granted Patent: US 8,213,779 B2
• Time in Patent Office: Days
• US Class Current: 386/344
• CPC Class Codes: H04N 19/44 Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 21/23424 involving splicing one content stream with another content stream, e.g. for inserting or substituting an advertisement
• CPC Class Codes: H04N 21/44016 involving splicing one content stream with another content stream, e.g. for substituting a video clip
• CPC Class Codes: H04N 21/8455 involving pointers to the content, e.g. pointers to the I-frames of the video stream

Abstract

A video receiver system comprises a video elementary stream decoder that decodes an elementary stream and one or more trick mode processing modules that modify the elementary stream to enable a trick mode effect. The trick mode processing module(s) produce a trick mode elementary stream for input to the video elementary stream decoder module. For example, the one or more trick mode processing modules can replace plural non-key frames of the elementary stream with one or more P-type skipped frames for a fast forward effect, where the trick mode elementary stream comprises one or more entry point key frames and the one or more P-type skipped frames. The video receiver system can selectively route the elementary stream to either the video elementary stream decoder module or the one or more trick mode processing modules.

Claims

1. A video receiver system comprising:

a video elementary stream decoder module operable to decode a video elementary stream; and

one or more trick mode processing modules operable to modify the video elementary stream to enable a trick mode effect, wherein the one or more trick mode processing modules produce a decoder-compliant trick mode elementary stream for input to the video elementary stream decoder module.

2. The video receiver system of claim 1 wherein the one or more trick mode processing modules replace plural non-key frames of the elementary stream with one or more P-type skipped frames for a fast forward effect, and wherein the trick mode elementary stream comprises one or more entry point key frames and the one or more P-type skipped frames.

3. The video receiver system of claim 2 wherein each of the replaced plural non-key frames of the elementary stream are selected from a group consisting of:

progressive B-frame, progressive P-frame, interlaced B-frame, interlaced P-frame, B/B-frame, P/P-frame, BI/B-frame, B/BI-frame, or BI/BI-frame.

4. The video receiver system of claim 1 further comprising:

a switch for engaging or disengaging a trick mode session, wherein the switch is designed for selectively routing the elementary stream to either the video elementary stream decoder module or the one or more trick mode processing modules, wherein the trick mode elementary stream is routed back to the video elementary stream decoder module after the one or more trick mode processing modules.

5. The video receiver system of claim 1 wherein the one or more trick mode processing modules comprise an entry point detector.

6. The video receiver system of claim 5 wherein the one or more trick mode processing modules further comprise a bitstream filter.

7. The video receiver system of claim 5 wherein the one or more trick mode processing modules further comprise a frame-dropping module and a P-type skipped frame insertion module.

8. The video receiver system of claim 1 wherein the one or more trick mode processing modules comprise a hypothetical reference decoder buffer adjustment module for producing buffer fullness values.

9. The video receiver system of claim 8 wherein the buffer adjustment module adjusts the buffer fullness values in entry point headers in the trick mode elementary stream so as to regulate a hypothetical reference decoder.

10. The video receiver system of claim 8 wherein the buffer adjustment module adjusts initial buffer fullness values signaled in the trick mode elementary stream.

11. A method comprising:

receiving an input video elementary stream in a video receiver system comprising at least a video elementary stream decoder and one or more trick mode processing modules;

receiving trick mode session information;

based at least in part on the received trick mode session information, processing the input video elementary stream in the one or more trick mode processing modules to enable a trick mode effect, wherein from the video elementary stream the one or more trick mode processing modules produce a trick mode elementary stream for input to the video elementary stream decoder.

12. The method of claim 11 wherein the processing the video elementary stream in the one or more trick mode processing modules includes replacing plural non-key frames of the video elementary stream with one or more P-type skipped frames for a fast forward effect, and wherein the trick mode elementary stream comprises one or more entry point key frames and the one or more P-type skipped frames.

13. The method of claim 12 wherein each of the one or more entry point key frames is of a type selected from a group consisting of progressive I-frame, interlaced I-frame, I/I-frame, I/P-frame, and P/I-frame.

14. The method of claim 11 wherein the processing the video elementary stream in the one or more trick mode processing modules includes dropping frames of the video elementary stream for a fast forward effect.

15. The method of claim 11 further comprising routing the trick mode elementary stream to the video elementary stream decoder for decoding.

16. The method of claim 11 further comprising:

switching from the trick mode elementary stream back to the video elementary stream, whereby the video elementary stream decoder stops decoding the trick mode elementary stream and starts decoding the video elementary stream.

17. The method of claim 11 wherein the trick mode effect is slow motion.

18. The method of claim 11 wherein the trick mode effect is fast reverse.

19. The method of claim 11 wherein the trick mode effect is slow reverse.

20. The method of claim 11 wherein the trick mode effect is freeze frame.

21. The method of claim 11 further comprising:

adjusting initial buffer fullness values signaled in entry point headers in the trick mode elementary stream so as to regulate a hypothetical reference decoder.

22. The method of claim 11 wherein the video elementary stream is contained within a transport stream.

23. The method of claim 11 wherein the video elementary stream decoder decodes the trick mode elementary stream without reference to the trick mode effect and without decoder logic adapted for implementing the trick mode effect.

24. The method of claim 11 wherein the trick mode elementary stream is input to the video elementary stream decoder in place of the video elementary stream.

25. One or more computer-readable media having stored thereon computer-executable instructions for performing the method of claim 11.

26. A method comprising:

receiving a video elementary stream in a video receiver system including an entry point detector, a bitstream filter, a P-type skipped frame insertion module and a video elementary stream decoder;

receiving trick mode session information for the video elementary stream;

in the entry point detector, detecting at least one entry point having a corresponding entry point key frame in the video elementary stream;

in the bitstream filter, removing at least one frame following the entry point key frame in the video elementary stream, the removing based at least in part on the received trick mode information;

in the skipped frame insertion module, inserting at least one P-type skipped frame in the video elementary stream to form a trick mode elementary stream with a fast forward effect, the inserting based at least in part on the received trick mode information; and

in the video elementary stream decoder, decoding the trick mode elementary stream.

27. The method of claim 26 wherein the entry point key frame is of a type selected from a group consisting of progressive I-frame, interlaced I-frame, I/I-frame, I/P-frame, and P/I-frame.

28. One or more computer-readable media having stored thereon computer-executable instructions for performing the method of claim 26.