EARLY RENDERING FOR FAST CHANNEL SWITCHING

• US 20090016445A1
• Filed: 07/10/2007
• Published: 01/15/2009
• Est. Priority Date: 07/10/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Chen, Peisong, Gao, Qiang
• Granted Patent: US 9,426,522 B2
• Time in Patent Office: Days
• US Class Current: 375/240.250
• CPC Class Codes: H04N 19/895 in combination with error concealment
• 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 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/43072 of multiple content streams on the same device
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/4384 involving operations to reduce the access time, e.g. fast-tuning for reducing channel switching latency
• CPC Class Codes: H04N 21/44004 involving video buffer management, e.g. video decoder buffer or video display buffer
• CPC Class Codes: H04N 21/44016 involving splicing one content stream with another content stream, e.g. for substituting a video clip

Abstract

The disclosure relates to techniques for switching between channels of digital multimedia content. In particular, a decoding device decodes and renders to a display at least one frame of a segment of data prior to receiving the entire segment. In certain aspects, the decoding device may render one of the frames of the segment and freeze the rendered frame until the decoding device receives all of the frames of the segment. In other aspects, the decoding device may render frames of one or more segments at a reduced rendering rate until the receiving and rendering operations of decoding device are synchronized such that the rendering of the current segment occurs at substantially the same time as the receiving of the next segment. By rendering at least frame prior to receiving the entire segment the decoding device more quickly displays content to a user during a channel switching event.

Claims

1. A method for processing video data, the method comprising:

decoding at least one coded frame of a plurality of coded frames of at least a portion of a segment of the video data; and

rendering the at least one decoded frame to a display before a playback time associated with the at least one decoded frame in response to an event.

2. The method of claim 1, further comprising freezing the at least one rendered frame until the playback time associated with the at least one decoded frame.

3. The method of claim 2, wherein freezing the at least one rendered frame comprises maintaining decoded data of the frame in a frame memory until the playback time associated with the at least one decoded frame.

4. The method of claim 1, wherein rendering the at least one decoded frame to the display comprises rendering the at least one decoded frame to the display at a reduced rendering rate until the playback time associated with a last one of the at least one decoded frame.

5. The method of claim 4, wherein rendering the at least one decoded frame to the display at the reduced rendering rate comprises refreshing decoded data of a frame memory with decoded data of a subsequent one of the frames at a refresh rate that is less than a normal rendering rate.

6. The method of claim 4, further comprising rendering frames to the display at an original rendering rate after the playback time associated with the last one of the at least one decoded frame.

7. The method of claim 6, wherein the reduced rendering rate is one half of the original rendering rate.

8. The method of claim 4, further comprising incrementally increasing the reduced rendering rate at which the frames are rendered to the display.

9. The method of claim 1, further comprising:

receiving the segment of video data, wherein the received segment includes a data block that includes the plurality of coded frames of video data and an associated error correction unit, and

decoding the at least one coded frame comprises decoding the at least one coded frame prior to receiving the associated error correction unit.

10. The method of claim 1, further comprising:

detecting an error within a second frame; and

freezing the decoded data of the first frame on the display upon detecting the error within the second frame.

11. The method of claim 1, wherein rendering the at least one decoded frame to a display before a playback time associated with the at least one decoded frame comprises rendering decoded data of a first one of the at least one decoded frame to the display and rendering decoded data of a second one of the at least one decoded frame to the display when no error is detected in the second one of the at least one of the decoded frame.

12. The method of claim 1, wherein rendering the at least one decoded frame to the display comprises rendering the at least one decoded frame to the display before the playback time associated with the at least one decoded frame in response to a channel switch request.

13. The method of claim 1, wherein rendering the at least one decoded frame to the display comprises:

storing the decoded data of the at least one decoded frame in a frame memory; and

driving the display with the data in the frame memory.

14. An apparatus for processing video data, the apparatus comprising:

a decoding module that decodes at least one coded frame of a plurality of coded frames of at least a portion of a segment of the video data; and

a rendering module that renders the at least one decoded frame to a display before a playback time associated with the at least one decoded frame in response to an event.

15. The apparatus of claim 14, wherein the rendering module freezes the at least one rendered frame until the playback time associated with the at least one decoded frame.

16. The apparatus of claim 15, wherein the rendering module maintains decoded data of the frame in a frame memory until the playback time associated with the at least one decoded frame.

17. The apparatus of claim 14, wherein the rendering module renders the at least one decoded frame to the display at a reduced rendering rate until the playback time associated with a last one of the at least one decoded frame.

18. The apparatus of claim 17, wherein the rendering module refreshes decoded data of a frame memory with decoded data of a subsequent one of the frames at a refresh rate that is less than a normal rendering rate.

19. The apparatus of claim 17, wherein the rendering module renders frames to the display at an original rendering rate after the playback time associated with the last one of the at least one decoded frame.

20. The apparatus of claim 19, wherein the reduced rendering rate is one half of the original rendering rate.

21. The apparatus of claim 17, wherein the rendering module incrementally increases the reduced rendering rate at which the frames are rendered to the display.

22. The apparatus of claim 14, further comprising a receiver that receives the segment of video data, wherein the received segment includes a data block that includes the plurality of coded frames of video data and an associated error correction unit, and wherein the decoding module decodes the at least one coded frame prior to the receiver receiving the associated error correction unit.

23. The apparatus of claim 22, wherein:

the receiver detects an error within the data block; and

the rendering module freezes the decoded data of the first frame on the display upon detecting the error within the data block.

24. The apparatus of claim 22, wherein the rendering module renders decoded data of a first one of the at least one decoded frame to the display and renders decoded data of a second one of the at least one decoded frame to the display when no error is detected in the data block.

25. The apparatus of claim 14, wherein the rendering module renders the at least one decoded frame to the display before the playback time associated with the at least one decoded frame in response to a channel switch request.

26. The apparatus of claim 14, wherein the rendering module stores the decoded data of the at least one decoded frame in a frame memory and drives the display with the data in the frame memory.

27. An apparatus for processing video data, the apparatus comprising:

means for decoding at least one coded frame of a plurality of coded frames of at least a portion of a segment of the video data; and

means for rendering the at least one decoded frame to a display before a playback time associated with the at least one decoded frame in response to an event.

28. The apparatus of claim 27, wherein the rendering means freezes the at least one rendered frame until the playback time associated with the at least one decoded frame.

29. The apparatus of claim 28, wherein the rendering means maintains decoded data of the frame in a frame memory until the playback time associated with the at least one decoded frame.

30. The apparatus of claim 27, wherein the rendering means renders the at least one decoded frame to the display at a reduced rendering rate until the playback time associated with a last one of the at least one decoded frame.

31. The apparatus of claim 30, wherein the rendering means refreshes decoded data of a frame memory with decoded data of a subsequent one of the frames at a refresh rate that is less than a normal rendering rate.

32. The apparatus of claim 30, the rendering means renders frames to the display at an original rendering rate after the playback time associated with the last one of the at least one decoded frame.

33. The apparatus of claim 32, wherein the reduced rendering rate is one half of the original rendering rate.

34. The apparatus of claim 30, the rendering means incrementally increases the reduced rendering rate at which the frames are rendered to the display.

35. The apparatus of claim 27, further comprising:

means for receiving the segment of video data, wherein the received segment includes a data block that includes the plurality of coded frames of video data and an associated error correction unit, wherein

the decoding means decodes the at least one coded frame prior to receiving the associated error correction unit.

36. The apparatus of claim 27, further comprising:

means for detecting an error within a second frame, wherein

the rendering means freezes the decoded data of the first frame on the display upon detecting the error within the second frame.

37. The apparatus of claim 27, wherein the rendering means renders decoded data of a first one of the at least one decoded frame to the display and renders decoded data of a second one of the at least one decoded frame to the display when no error is detected in the second one of the at least one of the decoded frame.

38. The apparatus of claim 27, wherein the rendering means renders the at least one decoded frame to the display before the playback time associated with the at least one decoded frame in response to a channel switch request.

39. The apparatus of claim 27, wherein the rendering means stores the decoded data of the at least one decoded frame in a frame memory and drives the display with the data in the frame memory.

40. A computer-program product for processing multimedia data comprising a computer readable medium having instructions thereon, the instructions comprising:

code for decoding at least one coded frame of a plurality of coded frames of at least a portion of a segment of the video data; and

code for rendering the at least one decoded frame to a display before a playback time associated with the at least one decoded frame in response to an event.

41. The computer-program product of claim 40, further comprising code for freezing the at least one rendered frame until the playback time associated with the at least one decoded frame.

42. The computer-program product of claim 41, wherein the code for freezing the at least one rendered frame comprises code for maintaining decoded data of the frame in a frame memory until the playback time associated with the at least one decoded frame.

43. The computer-program product of claim 40, wherein the code for rendering the at least one decoded frame to the display comprises code for rendering the at least one decoded frame to the display at a reduced rendering rate until the playback time associated with a last one of the at least one decoded frame.

44. The computer-program product of claim 43, wherein the code for rendering the at least one decoded frame to the display at the reduced rendering rate comprises code for refreshing decoded data of a frame memory with decoded data of a subsequent one of the frames at a refresh rate that is less than a normal rendering rate.

45. The computer-program product of claim 43, further comprising code for rendering frames to the display at an original rendering rate after the playback time associated with the last one of the at least one decoded frame.

46. The computer-program product of claim 45, wherein the reduced rendering rate is one half of the original rendering rate.

47. The computer-program product of claim 43, further comprising code for incrementally increasing the reduced rendering rate at which the frames are rendered to the display.

48. The computer-program product of claim 40, further comprising:

code for receiving the segment of video data, wherein the received segment includes a data block that includes the plurality of coded frames of video data and an associated error correction unit, and

code for decoding the at least one coded frame comprises decoding the at least one coded frame prior to receiving the associated error correction unit.

49. The computer-program product of claim 40, further comprising:

code for detecting an error within a second frame; and

code for freezing the decoded data of the first frame on the display upon detecting the error within the second frame.

50. The computer-program product of claim 40, wherein the code for rendering the at least one decoded frame to a display before a playback time associated with the at least one decoded frame comprises:

code for rendering decoded data of a first one of the at least one decoded frame to the display; and

code for rendering decoded data of a second one of the at least one decoded frame to the display when no error is detected in the second one of the at least one of the decoded frame.

51. The computer-program product of claim 40, wherein the code for rendering the at least one decoded frame to the display comprises code for rendering the at least one decoded frame to the display before the playback time associated with the at least one decoded frame in response to a channel switch request.

52. The computer-program product of claim 40, wherein the code for rendering the at least one decoded frame to the display comprises:

code for storing the decoded data of the at least one decoded frame in a frame memory; and

code for driving the display with the data in the frame memory.