INTRA PREDICTION FROM A PREDICTIVE BLOCK

• US 20150195559A1
• Filed: 01/08/2015
• Published: 07/09/2015
• Est. Priority Date: 01/09/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Chen, Ying, Pang, Chao, Zhang, Li, Sole Rojals, Joel, Karczewicz, Marta
• Granted Patent: US 9,883,197 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04N 19/11 among a plurality of spatial predictive coding modes
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/513 Processing of motion vectors
• CPC Class Codes: H04N 19/52 by predictive encoding
• CPC Class Codes: H04N 19/593 involving spatial prediction techniques

Abstract

A device for coding video data, the device comprising a memory configured to store video data and a video coder comprising one or more processors configured to: determine a coding unit of a picture of the video data is coded using an intra block copy mode; determine a vector for a first chroma block of the coding unit; locate a first chroma reference block using the vector, wherein the first chroma reference block is in the picture; predict the first chroma block based on the first chroma reference block; locate a second chroma reference block using the vector, wherein the second chroma reference block is in the picture; and predict a second chroma block of the coding unit based on the second chroma reference block.

Claims

1. A method of decoding video data, the method comprising:

determining a coding unit of a picture of the video data is coded using an intra block copy mode;

determining from a plurality of vectors associated with the coding unit a vector for a first chroma block of the coding unit;

locating a first chroma reference block using the vector, wherein the first chroma reference block is in the picture;

predicting the first chroma block based on the first chroma reference block;

using the same vector that was used to locate the first chroma reference block, locating a second chroma reference block for a second chroma block of the same coding unit, wherein the second chroma reference block is in the picture, and different from the first chroma reference block; and

predicting the second chroma block of the coding unit based on the second chroma reference block.

2. The method of claim 1, wherein the coding unit comprises two or more prediction units, wherein the first chroma block corresponds to a first prediction unit of the coding unit and the second chroma block corresponds to a second prediction unit of the coding unit, and wherein determining the vector for the first chroma block of the coding unit comprises obtaining a vector for the first prediction unit.

3. The method of claim 1, wherein the coding unit comprises two or more prediction units, wherein each prediction unit has an associated vector, the method further comprising:

locating a first luma reference block using the vector associated with a first prediction unit of the coding unit;

locating a second luma reference block using the vector associated with the second prediction unit of the coding unit;

locating the first chroma reference block using the vector associated with the first prediction unit; and

;

locating the second chroma reference block using the vector associated with the first prediction unit.

4. The method of claim 1, wherein a chroma sampling format for the coding unit is 4:

2;

0, and wherein the vector determined from the plurality of vectors is associated with a bottom-right block of the coding unit.

5. The method of claim 4, wherein the second chroma block is a top-right block of the coding unit, the method further comprising:

locating a third reference block using the vector, wherein the third reference block is in the picture;

predicting a third chroma block based on the first reference block, wherein the third chroma block is a top-left block of the coding unit;

locating a fourth reference block using the vector, wherein the fourth reference block is in the picture;

predicting a fourth chroma block of the coding unit based on the second reference block, wherein the fourth chroma block is a bottom-left block of the coding unit.

6. The method of claim 1, wherein a chroma sampling format for the coding unit is 4:

2;

2, and wherein the first chroma block is a top-right block and the second chroma block is a top-left block of the coding unit.

7. The method of claim 6, further comprising:

determining a second vector for a third chroma block of the coding unit;

locating a third reference block using the second vector, wherein the third reference block is in the picture;

using the third reference block as a predictor for the third chroma block;

locating a fourth reference block using the vector, wherein the fourth reference block is in the picture;

using the fourth reference block as a predictor for a fourth chroma block of the coding unit.

8. The method of claim 1, wherein the coding unit comprises residual data.

9. A method of encoding video data, the method comprising:

determining from a plurality of vectors associated with the coding unit a vector for a first chroma block of a coding unit of a picture;

locating a first chroma reference block using the vector, wherein the first chroma reference block is in the picture;

predicting the first chroma block based on the first chroma reference block;

using the same vector that was used to locate the first chroma reference block, locating a second chroma reference block for a second chroma block of the same coding unit, wherein the second chroma reference block is in the picture, and different from the first chroma reference block;

predicting a second chroma block of the coding unit based on the second chroma reference block; and

generating, for inclusion in the encoded video data, an indication that the coding unit of the picture is coded using an intra block copy mode and an indication of a vector for each luma block of the coding unit.

10. The method of claim 9, wherein the coding unit comprises two or more prediction units and wherein the first chroma block corresponds to a first prediction unit and the second chroma block corresponds to a second prediction unit, and wherein determining the vector for the second chroma block of the coding unit comprises obtaining a vector for the first prediction unit.

11. The method of claim 9, wherein the coding unit comprises two or more prediction units, wherein each prediction unit has an associated vector, the method further comprising:

locating a first luma reference block using the vector associated with the first prediction unit;

locating a second luma reference block using the vector associated with the second prediction unit;

locating the first chroma reference block using the vector associated with the first prediction unit; and

locating the second chroma reference block using the vector associated with the first prediction unit.

12. The method of claim 9, wherein a chroma sampling format for the coding unit is 4:

2;

0, and wherein the vector determined from the plurality of vectors is associated with a bottom-right block of the coding unit.

13. The method of claim 12, wherein the second chroma block is a top-right block of the coding unit, the method further comprising:

locating a third reference block using the vector, wherein the third reference block is in the picture;

predicting a third chroma block based on the first reference block, wherein the third chroma block is a top-left block of the coding unit;

locating a fourth reference block using the vector, wherein the fourth reference block is in the picture; and

predicting a fourth chroma block of the coding unit based on the second reference block, wherein the fourth chroma block is a bottom-left block of the coding unit.

14. The method of claim 9, wherein a chroma sampling format for the coding unit is 4:

2;

2, and wherein the first chroma block is a top-right block and the second chroma block is a top-left block of the coding unit.

15. The method of claim 14, further comprising:

determining a second vector for a third chroma block of the coding unit;

locating a third reference block using the second vector, wherein the third reference block is in the picture;

using the third reference block as a predictor for the third chroma block;

locating a fourth reference block using the vector, wherein the fourth reference block is in the picture; and

using the fourth reference block as a predictor for a fourth chroma block of the coding unit.

16. The method of claim 9, wherein the coding unit comprises residual data.

17. A device for coding video data, the device comprising:

a memory configured to store video data;

a video coder comprising one or more processors configured to;

determine from a plurality of vectors associated with the coding unit a coding unit of a picture of the video data is coded using an intra block copy mode;

determine a vector for a first chroma block of the coding unit;

locate a first chroma reference block using the vector, wherein the first chroma reference block is in the picture;

predict the first chroma block based on the first chroma reference block;

using the same vector that was used to locate the first chroma reference block, locate a second chroma reference block for a second chroma block of the same coding unit, wherein the second chroma reference block is in the picture, and different from the first chroma reference block; and

predict a second chroma block of the coding unit based on the second chroma reference block.

18. The device of claim 17, wherein the coding unit comprises two or more prediction units and wherein the first chroma block corresponds to a first prediction unit and the second chroma block corresponds to a second prediction unit, and wherein determining the vector for the second chroma block of the coding unit comprises obtaining a vector for the first prediction unit.

19. The device of claim 17, wherein the coding unit comprises two or more prediction units, wherein each prediction unit has an associated vector, and wherein the one or more processors are further configured to:

locate a first luma reference block using the vector associated with the first prediction unit;

locate a second luma reference block using the vector associated with the second prediction unit;

locate the first chroma reference block using the vector associated with the first prediction unit; and

locate the second chroma reference block using the vector associated with the first prediction unit.

20. The device of claim 17, wherein a chroma sampling format for the coding unit is 4:

2;

0, and wherein the vector determined from the plurality of vectors is associated with a bottom-right block of the coding unit.

21. The device of claim 20, wherein the second chroma block is a top-right block of the coding unit, and wherein the one or more processors are further configured to:

locate a third reference block using the vector, wherein the third reference block is in the picture;

predict a third chroma block based on the first reference block, wherein the third chroma block is a top-left block of the coding unit;

locate a fourth reference block using the vector, wherein the fourth reference block is in the picture; and

predict a fourth chroma block of the coding unit based on the second reference block, wherein the fourth chroma block is a bottom-left block of the coding unit.

22. The device of claim 17, wherein a chroma sampling format for the coding unit is 4:

2;

2, and wherein the first chroma block is a top-right block and the second chroma block is a top-left block of the coding unit.

23. The device of claim 22, and wherein the one or more processors are further configured to:

determine a second vector for a third chroma block of the coding unit;

locate a third reference block using the second vector, wherein the third reference block is in the picture;

use the third reference block as a predictor for the third chroma block;

locate a fourth reference block using the vector, wherein the fourth reference block is in the picture; and

use the fourth reference block as a predictor for a fourth chroma block of the coding unit.

24. The device of claim 17, wherein the coding unit comprises residual data.

25. The device of claim 17, wherein the device comprises one of:

a microprocessor;

an integrated circuit (IC); and

a wireless communication device comprising the video encoder.

26. The device of claim 17, wherein the video coder comprises a video encoder.

27. The device of claim 17, wherein the video coder comprises a video decoder.

28. An apparatus for coding video data, the apparatus comprising:

means for determining from a plurality of vectors associated with the coding unit a coding unit of a picture of the video data is coded using an intra block copy mode;

means for determining a vector for a first chroma block of the coding unit;

means for using the same vector that was used to locate the first chroma reference block to locate a second chroma reference block for a second chroma block of the same coding unit, wherein the second chroma reference block is in the picture, and different from the first chroma reference block;

means for predicting the first chroma block based on the first chroma reference block;

means for locating a second chroma reference block using the vector, wherein the second chroma reference block is in the picture; and

means for predicting a second chroma block of the coding unit based on the second chroma reference block.

29. The apparatus of claim 28, wherein the coding unit comprises two or more prediction units and wherein the first chroma block corresponds to a first prediction unit and the second chroma block corresponds to a second prediction unit, and wherein the means for determining the vector for the second chroma block of the coding unit comprises means for obtaining a vector for the first prediction unit.

30. The apparatus of claim 28, wherein the coding unit comprises two or more prediction units, wherein each prediction unit has an associated vector, the apparatus further comprising:

means for locating a first luma reference block using the vector associated with the first prediction unit;

means for locating a second luma reference block using the vector associated with the second prediction unit;

means for locating the first chroma reference block using the vector associated with the first prediction unit; and

means for locating the second chroma reference block using the vector associated with the first prediction unit.

31. The apparatus of claim 28, wherein a chroma sampling format for the coding unit is 4:

2;

0, and wherein the vector determined from the plurality of vectors is associated with a bottom-right block of the coding unit.

32. The apparatus of claim 31, wherein the second chroma block is a top-right block of the coding unit, the apparatus further comprising:

means for locating a third reference block using the vector, wherein the third reference block is in the picture;

means for predicting a third chroma block based on the first reference block, wherein the third chroma block is a top-left block of the coding unit;

means for locating a fourth reference block using the vector, wherein the fourth reference block is in the picture; and

means for predicting a fourth chroma block of the coding unit based on the second reference block, wherein the fourth chroma block is a bottom-left block of the coding unit.

33. The apparatus of claim 28, wherein a chroma sampling format for the coding unit is 4:

2;

2, and wherein the first chroma block is a top-right block and the second chroma block is a top-left block of the coding unit.

34. The apparatus of claim 33, further comprising:

means for determining a second vector for a third chroma block of the coding unit;

means for locating a third reference block using the second vector, wherein the third reference block is in the picture;

means for using the third reference block as a predictor for the third chroma block;

means for locating a fourth reference block using the vector, wherein the fourth reference block is in the picture; and

means for using the fourth reference block as a predictor for a fourth chroma block of the coding unit.

35. The apparatus of claim 28, wherein the coding unit comprises residual data.

36. A computer readable storage medium storing instructions that when executed by one or more processors cause the one or more processors to:

determine from a plurality of vectors associated with the coding unit a coding unit of a picture of the video data is coded using an intra block copy mode;

determine a vector for a first chroma block of the coding unit;

use the same vector that was used to locate the first chroma reference block to locate a second chroma reference block for a second chroma block of the same coding unit, wherein the second chroma reference block is in the picture, and different from the first chroma reference block;

predict the first chroma block based on the first chroma reference block;

locate a second chroma reference block using the vector, wherein the second chroma reference block is in the picture; and

predict a second chroma block of the coding unit based on the second chroma reference block.

37. The computer-readable storage medium of claim 36, wherein the coding unit comprises two or more prediction units and wherein the first chroma block corresponds to a first prediction unit and the second chroma block corresponds to a second prediction unit, and wherein determining the vector for the second chroma block of the coding unit comprises obtaining a vector for the first prediction unit.

38. The computer-readable storage medium of claim 36, wherein the coding unit comprises two or more prediction units, wherein each prediction unit has an associated vector, and wherein the computer-readable storage medium stores further instructions that when executed by the one or more processors cause the one or more processors to:

locate a first luma reference block using the vector associated with the first prediction unit;

locate a second luma reference block using the vector associated with the second prediction unit;

locate the first chroma reference block using the vector associated with the first prediction unit; and

locate the second chroma reference block using the vector associated with the first prediction unit.

39. The computer-readable storage medium of claim 36, wherein a chroma sampling format for the coding unit is 4:

2;

0, and wherein the vector determined from the plurality of vectors is associated with a bottom-right block of the coding unit.

40. The computer-readable storage medium of claim 39, wherein the second chroma block is a top-right block of the coding unit, and wherein the computer-readable storage medium stores further instructions that when executed by the one or more processors cause the one or more processors to:

locate a third reference block using the vector, wherein the third reference block is in the picture;

predict a third chroma block based on the first reference block, wherein the third chroma block is a top-left block of the coding unit;

locate a fourth reference block using the vector, wherein the fourth reference block is in the picture; and

predict a fourth chroma block of the coding unit based on the second reference block, wherein the fourth chroma block is a bottom-left block of the coding unit.

41. The computer-readable storage medium of claim 36, wherein a chroma sampling format for the coding unit is 4:

2;

2, and wherein the first chroma block is a top-right block and the second chroma block is a top-left block of the coding unit.

42. The computer-readable storage medium of claim 41, storing further instructions that when executed by the one or more processors cause the one or more processors to:

determine a second vector for a third chroma block of the coding unit;

locate a third reference block using the second vector, wherein the third reference block is in the picture;

use the third reference block as a predictor for the third chroma block;

locate a fourth reference block using the vector, wherein the fourth reference block is in the picture; and

use the fourth reference block as a predictor for a fourth chroma block of the coding unit.

43. The computer-readable storage medium of claim 36, wherein the coding unit comprises residual data.