VIDEO DECODER ERROR HANDLING

• US 20090213938A1
• Filed: 07/10/2008
• Published: 08/27/2009
• Est. Priority Date: 02/26/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Lee, Yen-Chi, Teng, Chia-Yuan, Dai, Min
• Granted Patent: US 9,357,233 B2
• Time in Patent Office: Days
• US Class Current: 375/240.240
• CPC Class Codes: H04N 19/105 Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
• CPC Class Codes: H04N 19/134 characterised by the element, parameter or criterion affecting or controlling the adaptive coding
• CPC Class Codes: H04N 19/174 the region being a slice, e.g. a line of blocks or a group of blocks
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/573 Motion compensation with multiple frame prediction using two or more reference frames in a given prediction direction
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/68 involving the insertion of resynchronisation markers into the bitstream
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 19/895 in combination with error concealment

Abstract

A video decoder performs a sequential error handling process to detect and conceal errors within a corrupted data segment of video data units. The decoder sequentially decodes a current data unit. Upon detecting an error, the decoder sets an error flag and resynchronizes decoding at the start of the next unit. If the error flag is set, the video decoder identifies the end of the corrupted data segment based on the start of the later unit. The decoder conceals data between the start of the current unit and the end of the corrupted data segment. If the error flag is not set, the decoder may decode the remainder of the current unit and proceed to decode the next available unit without performing error handling and concealment for the current unit. The decoder also may address reference unit mismatches caused by lost video data units.

Claims

1. A video decoding method comprising:

determining a start of a current unit of encoded video data;

decoding at least a portion of the current unit;

detecting a decoding error in the current unit;

determining a start of a next available unit of the encoded video data;

if the decoding error is detected, determining an end of a corrupted data segment based on the start of the next available unit; and

concealing the corrupted data segment based on the start of the current unit and the end of the corrupted data segment.

2. The method of claim 1, wherein each of the current unit and the next available unit includes a video data slice.

3. The method of claim 1, wherein the corrupted data segment includes the current unit and at least one additional unit of encoded video data.

4. The method of claim 1, wherein the current unit is a current slice of a first frame, and the corrupted data segment includes the current slice and at least one additional slice of encoded video data from a second frame.

5. The method of claim 1, further comprising:

if the decoding error is detected, setting an error flag to indicate the detection of the decoding error; and

determining the end of the corrupted data segment based on the start of the next available unit when the error flag is set.

6. The method of claim 5, wherein the next available unit comprises at least one slice, the method further comprising seeking a slice header associated with the slice when the decoding error is detected.

7. The method of claim 5, further comprising, if the decoding error is detected, stopping decoding of the current unit, and proceeding to decode the next available unit.

8. The method of claim 1, further comprising, if the decoding error is not detected, decoding the entire first unit.

9. The method of claim 1, wherein the decoding error comprises at least one of a syntax error, semantic error, or entropy coding error.

10. The method of claim 1, wherein determining a start of the current unit comprises determining a first macroblock (MB) number associated with the start of the current unit, determining an end of the corrupted data segment comprises determining a second MB number prior to a start of the second unit, and concealing comprises concealing the corrupted data segment from the first MB number to the second MB number.

11. The method of claim 10, wherein determining a start of the second unit comprises determining a third MB number associated with the start of the second unit, and wherein determining the second MB number comprises subtracting one from the third MB number to produce the second MB number.

12. The method of claim 10, wherein determining a start of the first unit comprises determining a first macroblock (MB) number and a first frame number associated with the start of the first unit, determining an end of the corrupted data segment comprises determining a second MB number and a second frame number associated with the end of the corrupted data segment, and concealing comprises concealing at least a portion of the corrupted data segment based on the first and second MB numbers and the first and second frame numbers, wherein the first and second frame numbers may be the same or different.

13. The method of claim 1, further comprising:

detecting a loss of one or more frames; and

replacing the one or more lost frames to conceal a reference frame mismatch for another frame.

14. A video decoding device comprising:

means for determining a start of a current unit of encoded video data;

means for decoding at least a portion of the current unit;

means for detecting a decoding error in the current unit;

means for determining a start of a next available unit of the encoded video data;

means for determining, if the decoding error is detected, an end of a corrupted data segment based on the start of the next available unit; and

means for concealing the corrupted data segment based on the start of the current unit and the end of the corrupted data segment.

15. The device of claim 14, wherein each of the current unit and the next available unit includes a video data slice.

16. The device of claim 14, wherein the corrupted data segment includes the current unit and at least one additional unit of encoded video data.

17. The device of claim 14, wherein the current unit is a current slice of a first frame, and the corrupted data segment includes the current slice and at least one additional slice of encoded video data from a second frame.

18. The device of claim 14, further comprising:

means for setting, if the decoding error is detected, an error flag to indicate the detection of the decoding error; and

means for determining the end of the corrupted data segment based on the start of the next available unit when the error flag is set.

19. The device of claim 18, wherein the next available unit comprises at least one slice, the device further comprising means for seeking a slice header associated with the slice when the decoding error is detected.

20. The device of claim 18, further comprising means for, if the decoding error is detected, stopping decoding of the current unit, and proceeding to decode the next available unit.

21. The device of claim 14, further comprising means for decoding, if the decoding error is not detected, the entire first unit.

22. The device of claim 14, wherein the decoding error comprises at least one of a syntax error, semantic error, or entropy coding error.

23. The device of claim 14, wherein the means for determining a start of the current unit comprises means for determining a first macroblock (MB) number associated with the start of the current unit, the means for determining an end of the corrupted data segment comprises means for determining a second MB number prior to a start of the second unit, and the means for concealing comprises means for concealing the corrupted data segment from the first MB number to the second MB number.

24. The device of claim 23, wherein the means for determining a start of the second unit comprises means for determining a third MB number associated with the start of the second unit, and wherein the means for determining the second MB number comprises means for subtracting one from the third MB number to produce the second MB number.

25. The device of claim 23, wherein the means for determining a start of the first unit comprises means for determining a first macroblock (MB) number and a first frame number associated with the start of the first unit, the means for determining an end of the corrupted data segment comprises means for determining a second MB number and a second frame number associated with the end of the corrupted data segment, and the means for concealing comprises means for concealing at least a portion of the corrupted data segment based on the first and second MB numbers and the first and second frame numbers, wherein the first and second frame numbers may be the same or different.

26. The device of claim 14, further comprising:

means for detecting a loss of one or more frames; and

means for replacing the one or more lost frames to conceal a reference frame mismatch for another frame.

27. A video decoding device comprising:

a decoding engine that decodes at least a portion of a current unit of encoded video data;

an error detection module that detects a decoding error in the current unit;

an error mapping module that determines a start of the current unit, determines a start of a next available unit of the encoded video data and, if the decoding error is detected, determines an end of a corrupted data segment based on the start of the next available unit; and

an error concealment module that conceals the corrupted data segment based on the start of the current unit and the end of the corrupted data segment.

28. The device of claim 27, wherein each of the current unit and the next available unit includes a video data slice.

29. The device of claim 27, wherein the corrupted data segment includes the current unit and at least one additional unit of encoded video data.

30. The device of claim 27, wherein the current unit is a current slice of a first frame, and the corrupted data segment includes the current slice and at least one additional slice of encoded video data from a second frame.

31. The device of claim 27, wherein the error detection module sets an error flag to indicate the detection of the decoding error, and the error mapping module determines the end of the corrupted data segment based on the start of the next available unit when the error flag is set.

32. The device of claim 31, wherein the next available unit comprises at least one slice, and the decoding engine seeks a slice header associated with the slice when the decoding error is detected.

33. The device of claim 31, wherein, if the decoding error is detected, the decoding engine stops decoding of the current unit, and proceeds to decode the next available unit.

34. The device of claim 27, wherein the decoding engine decodes the entire first unit if the decoding error is not detected.

35. The device of claim 27, wherein the decoding error comprises at least one of a syntax error, semantic error, or entropy coding error.

36. The device of claim 27, wherein the error mapping module determines a first macroblock (MB) number associated with the start of the current unit, and determines a second MB number prior to a start of the second unit, and the error concealment module conceals the corrupted data segment from the first MB number to the second MB number.

37. The device of claim 36, wherein the error mapping module determines a third MB number associated with the start of the second unit, and determining the second MB number by subtracting one from the third MB number to produce the second MB number.

38. The device of claim 36, wherein the error mapping module determines a first macroblock (MB) number and a first frame number associated with the start of the first unit, and determines a second MB number and a second frame number associated with the end of the corrupted data segment, and the error concealment module conceals at least a portion of the corrupted data segment based on the first and second MB numbers and the first and second frame numbers, wherein the first and second frame numbers may be the same or different.

39. The device of claim 27, wherein the error concealment module detects a loss of one or more frames, and replaces the one or more lost frames to conceal a reference frame mismatch for another frame.

40. The device of claim 27, wherein the device comprises a wireless communication device handset.

41. The device of claim 27, wherein the device comprises an integrated circuit device.

42. A computer-readable medium comprising instructions to cause one or more processors to:

determine a start of a current unit of encoded video data;

decode at least a portion of the current unit;

detect a decoding error in the current unit;

determine a start of a next available unit of the encoded video data;

if the decoding error is detected, determine an end of a corrupted data segment based on the start of the next available unit; and

conceal the corrupted data segment based on the start of the current unit and the end of the corrupted data segment.

43. The computer-readable medium of claim 42, wherein each of the current unit and the next available unit includes a video data slice.

44. The computer-readable medium of claim 42, wherein the corrupted data segment includes the current unit and at least one additional unit of encoded video data.

45. The computer-readable medium of claim 42, wherein the current unit is a current slice of a first frame, and the corrupted data segment includes the current slice and at least one additional slice of encoded video data from a second frame.

46. The computer-readable medium of claim 42, further comprising instructions to cause the one or more processors:

set an error flag to indicate the detection of the decoding error if the decoding error is detected; and

determine the end of the corrupted data segment based on the start of the next available unit when the error flag is set.

47. The computer-readable medium of claim 46, wherein the next available unit comprises at least one slice, and the instructions cause the one or more processors to seek a slice header associated with the slice when the decoding error is detected.

48. The computer-readable medium of claim 46, further comprising instructions to cause the one or more processors to, if the decoding error is detected, stop decoding of the current unit, and proceed to decode the next available unit.

49. The computer-readable medium of claim 42, wherein the instructions cause the one or more processors to decode the entire first unit if the decoding error is not detected.

50. The computer-readable medium of claim 42, wherein the decoding error comprises at least one of a syntax error, semantic error, or entropy coding error.

51. The computer-readable medium of claim 42, wherein the instructions cause the one or more processors to determine a first macroblock (MB) number associated with the start of the current unit, determine a second MB number prior to a start of the second unit, and conceal the corrupted data segment from the first MB number to the second MB number.

53. The computer-readable medium of claim 51, wherein the instructions cause the one or more processors to determine a first macroblock (MB) number and a first frame number associated with the start of the first unit, determine a second MB number and a second frame number associated with the end of the corrupted data segment, and conceal at least a portion of the corrupted data segment based on the first and second MB numbers and the first and second frame numbers, wherein the first and second frame numbers may be the same or different.

54. The computer-readable medium of claim 42, wherein the instructions cause the one or more processors to:

detect a loss of one or more frames; and

replace the one or more lost frames to conceal a reference frame mismatch for another frame.

52. The computer-readable medium of 51, wherein the instructions cause the one or more processors to determine a third MB number associated with the start of the second unit, and subtract one from the third MB number to produce the second MB number.