Macroblock level bit allocation

• US 7,848,409 B2
• Filed: 05/02/2005
• Issued: 12/07/2010
• Est. Priority Date: 05/02/2005
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Malayath, Narendranath, Wang, Haohong
• Primary Examiner(s): WONG, ALLEN C
• Application Number:
  US11/120,389
• Publication Number:
  US 20060245493A1
• Time in Patent Office: 2,045 Days
• Field of Search: 375/240, 375/240.01, 375/240.02, 375/240.03, 375/240.12, 375/240.14, 375/240.23
• US Class Current: 375/240.03
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/149 by estimating the code amount by means of a model, e.g. mathematical model or statistical model
• CPC Class Codes: H04N 19/152 by measuring the fullness of the transmission buffer
• 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 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/194 involving only two passes
• CPC Class Codes: H04N 19/196 being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters processing of motion vectors H04N19/513
• CPC Class Codes: H04N 19/198 including smoothing of a sequence of encoding parameters, e.g. by averaging, by choice of the maximum, minimum or median value

Abstract

The disclosure is directed to video processing. The various video processing techniques include generating blocks of information for a frame of video, allocating bits from a bit budget to each of the blocks, the number of bits being allocated to each of the blocks being a function of the information contained therein, and using the bits allocated to each of the blocks to represent the information contained therein.

Claims

1. A video system, comprising:

a video processor configured to generate blocks of information for a first frame of video and to partition blocks of the first frame into a slice, wherein the blocks are partitioned based on a function of the residual information contained therein; and

a controller configured to compute a budget for the percentage of non-zero data (ρ

) in the slice from the residual information of the blocks in the first frame and to allocate bits from a bit budget to each of the blocks of the slice, the number of bits being allocated to each of the blocks of the slice being a function of the budget for the percentage of non-zero data in the slice;

wherein the video processor is further configured to use the bits allocated to each of the blocks to represent the information contained therein.

2. The video system of claim 1 wherein the video processor further comprises a motion estimator configured to convert the information in each of the blocks to motion information, the number of bits allocated by the controller to each of the blocks being a function of the motion information contained therein.

3. The video system of claim 2 wherein the motion information in each of the blocks comprises a Sum of Absolute Difference (SAD) value.

4. The video system of claim 1 wherein the controller is further configured to derive a parameter for each of the blocks relating to the bits allocated to the controller, and wherein the video processor is further configured to use the parameters to represent the information in each of the blocks with the allocated number of bits.

5. The video system of claim 4 wherein the video processor comprises a texture engine configured to convert the information in each of the blocks to residual information, and wherein the video processor is further configured to use the bits allocated to each of the blocks to represent the residual information contained therein.

6. The video system of claim 5 wherein the texture engine comprises a quantizer configured to quantize the residual information in the blocks based on the parameters.

7. The video system of claim 6 wherein the controller is further configured to derive the parameters based on the percentage of non-zero data (ρ

) among quantized transform coefficients in the first frame.

8. The video system of claim 7 wherein the controller is further configured to derive the parameters by generating a ρ

-QP table from the information in the blocks, and using the ρ

-QP table to derive the parameters.

9. The video system of claim 8 wherein the controller is further configured to pass the blocks of information through the texture engine to generate the ρ

-QP table, and pass the blocks of information through the texture engine a second time to allocate the bits to the individual blocks using the ρ

-QP table.

10. The video system of claim 9 wherein the controller is further configured to enable and disable the second pass of the blocks of information through the texture engine.

11. The video system of claim 7 wherein the video processor further comprises a motion estimator configured to convert the information in each of the blocks to motion information, each of the parameters derived by the controller being based on the motion information contained in each respective block.

12. The video system of claim 11 wherein the motion information for each of the blocks comprises a Sum of Absolute Difference (SAD) value.

13. The video system of claim 12 wherein the controller is further configured to derive the parameters by computing ρ

for each of the blocks, each of the ρ

computations using the SAD for each respective block.

14. A video system configured to generate blocks of information for a frame of video, comprising:

means for partitioning blocks of a first frame into a slice from the first frame, wherein the blocks are partitioned based on a function of the residual information contained therein;

means for computing a budget for the percentage of non-zero data (ρ

) in the slice from the residual information of the blocks in the first frame;

means for allocating bits from a bit budget to the blocks of the slice, the number of bits being allocated to each of the blocks of the slice being a function of the budget for the percentage of non-zero data in the slice; and

means for representing the information in each of the blocks using the bits allocated to each block.

15. The video system of claim 14 further comprising means for converting the information in each of the blocks to motion information, the number of bits allocated to each of the blocks being a function of the motion information contained therein.

16. The video system of claim 15 wherein the motion information in each of the blocks comprises a Sum of Absolute Difference (SAD) value.

17. The video system of claim 14 wherein the means for allocating bits from a bit budget is configured to derive a parameter for each of the blocks relating to the bits allocated to the blocks, and wherein the means for representing the information comprises a quantizer responsive to the parameters.

18. The video system of claim 17 further comprising means for converting the information in each of the blocks to residual information, and wherein the quantizer is further configured to use the bits allocated to each of the blocks to represent the residual information contained therein.

19. The video system of claim 17, wherein the controller is further configured to derive the parameters based on the percentage of non-zero data among quantized transform coefficients in the first frame.

20. A method of processing video, comprising:

generating blocks of information for a frame of video;

partitioning the blocks of the first frame into a slice, wherein the blocks are partitioned based on a function of the residual information contained therein;

computing a budget for the percentage of non-zero data (ρ

) in the slice from the residual information of the blocks in the first frame;

allocating bits from a bit budget to the blocks of the slice, the number of bits being allocated to each of the blocks of the slice being a function of the budget for the percentage of non-zero data in the slice; and

using the bits allocated to each of the blocks to represent the information contained therein, wherein the method of processing video is performed by a microprocessor.

21. The method of claim 20 further comprising converting the information in each of the blocks to motion information, the number of bits allocated by the controller to each of the blocks being a function of the motion information contained therein.

22. The method of claim 21 wherein the motion information in each of the blocks comprises a Sum of Absolute Difference (SAD) value.

23. The method of claim 20 wherein the allocation of bits from the bit budget comprises deriving a parameter for each of the blocks relating to the bits allocated to the blocks, the parameters being used to represent the information in each of the blocks with the allocated number of bits.

24. The method of claim 23 further comprising converting the information in each of the blocks to residual information, the bits allocated to each of the blocks being used to represent the residual information contained therein.

25. The method of claim 24 wherein the residual information in each of the blocks is represented with the allocated number of bits by quantizing the residual information using the parameters.

26. The method of claim 25, wherein the parameters are derived based on the percentage of non-zero data among quantized transform coefficients in the first frame.

27. The method of claim 26 wherein the parameters are derived by generating a ρ

-QP table from the information in the blocks, and using the ρ

-QP table to derive the parameters.

28. The method of claim 26 further comprising converting the information in each of the blocks to motion information, the derivation of each of the parameters being based on the motion information contained in its respective block.

29. The method of claim 28 wherein the motion information for each of the blocks comprises a Sum of Absolute Difference (SAD) value.

30. The method of claim 29 wherein the parameters are derived by computing ρ

for each of the blocks, each of the ρ

computations using the SAD for its respective block.

31. The method of processing video of claim 20, the method being performed by a video processor configured to generate blocks of information for a frame of video, wherein the video processor includes a texture engine, the method comprising:

passing the blocks of information in the first frame through the texture engine a first time to generate statistics for the first frame; and

passing the blocks of information in the first frame through the texture engine a second time to allocate bits from the bit budget to each of the blocks based on the statistics, and using the bits allocated to each of the blocks to represent the information contained therein.

32. The method of claim 31, wherein the statistics generated on the first pass through the texture engine comprises a ρ

-QP table.

33. The method of claim 32 wherein the first pass through the texture engine further comprises generating a Sum of Absolute Difference (SAD) value for each of the blocks, and wherein the second pass through the texture engine comprises computing ρ

for each of the blocks using each respective SAD, mapping the ρ

for each of the blocks to a QP, and for each of the blocks, using the QP for the block to quantize the information contained therein.

34. A non-transitory computer readable medium comprising instructions that when executed by a processor perform a method comprising:

generating blocks of information for a frame of video;

partitioning the blocks of the first frame into a slice, wherein the blocks are partitioned based on a function of the residual information contained therein;

computing a budget for the percentage of non-zero data (ρ

) in the slice from the residual information of the blocks in the first frame;

allocating bits from a bit budget to the blocks of the slice, the number of bits being allocated to each of the blocks of the slice being a function of the budget for the percentage of non-zero data in the slice; and

using the bits allocated to each of the blocks to represent the information contained therein.

35. The computer readable medium of claim 34 wherein the method further comprises converting the information in each of the blocks to motion information, the number of bits allocated by the controller to each of the blocks being a function of the motion information contained therein.

36. The computer readable medium of claim 35 wherein the motion information in each of the blocks comprises a Sum of Absolute Difference (SAD) value.

37. The computer readable medium of claim 34 wherein the allocation of bits from the bit budget comprises deriving a parameter for each of the blocks relating to the bits allocated to the blocks, the parameters being used to represent the information in each of the blocks with the allocated number of bits.

38. The computer readable medium of claim 37 wherein the method further comprises converting the information in each of the blocks to residual information, the bits allocated to each of the blocks being used to represent the residual information contained therein.

39. The computer readable medium of claim 38 wherein the residual information in each of the blocks is represented with the allocated number of bits by quantizing the residual information using the parameters.

40. The computer readable medium of claim 39, wherein the parameters are derived based on the percentage of non-zero data (ρ

) among quantized transform coefficients in the first frame.

41. The computer readable medium of claim 40 wherein the parameters are derived by generating a ρ

-QP table from the information in the blocks, and using the ρ

-QP table to derive the parameters.

42. The computer readable medium of claim 40 wherein the method further comprises converting the information in each of the blocks to motion information, the derivation of each of the parameters being based on the motion information contained in each respective block.

43. The computer readable medium of claim 42 wherein the motion information for each of the blocks comprises a Sum of Absolute Difference (SAD) value.

44. The computer readable medium of claim 43 wherein the parameters are derived by computing ρ

for each of the blocks, each of the ρ

computations using the SAD for each respective block.