Method for improving rate-distortion performance of a video compression system through parallel coefficient cancellation in the transform

• US 20040240556A1
• Filed: 06/02/2003
• Published: 12/02/2004
• Est. Priority Date: 06/02/2003
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: LSI Logic Corporation (Broadcom, Inc.)
• Inventors: Winger, Lowell L., Cote, Guy, Novotny, Pavel
• Granted Patent: US 7,327,786 B2
• Time in Patent Office: Days
• US Class Current: 375/240.18
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/136 Incoming video signal characteristics or properties
• CPC Class Codes: H04N 19/157 Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/18 the unit being a set of transform coefficients
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

A method for improving rate distortion performance of a compression system through parallel coefficient cancellation in a transform comprising the steps of (A) determining a block sum of absolute values for each of a plurality of blocks in a macroblock and (B) setting one or more coefficient values of a block to zero in response to a block sum value of said block being less than a first predetermined threshold value.

Claims

1. A method for improving rate distortion performance of a compression system through parallel coefficient cancellation in a transform comprising the steps of:

(A) determining a block sum of absolute values for each of a plurality of blocks in a macroblock; and

(B) setting one or more coefficient values of a block to zero in response to a block sum value of said block being less than a first predetermined threshold value.

2. The method according to claim 1, further comprising the steps of:

determining a group of blocks sum of absolute values for one or more groups of one or more of said plurality of blocks in said macroblock; and

setting coefficient values for said one or more groups of blocks to zero in response to a corresponding group of blocks sum value being less than a second predetermined threshold value.

3. The method according to claim 1, further comprising the steps of:

determining a block sum of absolute values for said macroblock; and

setting coefficient values of said macroblock to zero in response to said block sum of absolute values for said macroblock being less than a third predetermined threshold value.

4. The method according to claim 1, wherein said absolute values are calculated during quantization of said plurality of blocks.

5. The method according to claim 1, wherein said first threshold value is determined based on a class of said block and a type of said macroblock.

6. The method according to claim 2, wherein said second threshold value is determined based on a class of said group of blocks and a type of said macroblock.

7. The method according to claim 3, wherein said third threshold value is determined based on a type of said macroblock.

8. An apparatus comprising:

a first circuit configured to present quantized coefficients for a plurality of blocks in a macroblock; and

a second circuit configured to calculate a block sum of absolute values for each of said plurality of blocks in response to said quantized coefficients.

9. The apparatus according to claim 8, wherein said second block is further configured to set one or more of said coefficients of a block to zero in response to a corresponding block sum of absolute value of said block having a value less than a first predetermined threshold value.

10. The apparatus according to claim 9, wherein said second circuit is further configured to set the coefficients of a group of one or more of said plurality of blocks to zero in response to a block sum of absolute values of said group of blocks having a value less than a second predetermined threshold value.

11. The apparatus according to claim 10, wherein said second circuit is further configured to set all coefficients of a macroblock to zero in response to a block sum of absolute values for said macroblock having a value less than a third predetermined threshold value.

12. The apparatus according to claim 8, wherein said apparatus comprises an encoder.

13. The apparatus according to claim 8, wherein said apparatus comprises a transcoder.

14. The apparatus according to claim 8, wherein said apparatus comprises a transcoding statmux system of a video transmission system.

15. The apparatus according to claim 8, wherein said second circuit is further configured to:

(i) set one or more of said coefficients of a block to zero in response to a corresponding block sum of absolute value of said block having a value less than a first predetermined threshold value;

set the coefficients of a group of one or more of said plurality of blocks to zero in response to a block sum of absolute values of said group of blocks having a value less than a second predetermined threshold value; and

set all coefficients of a macroblock to zero in response to a block sum of absolute values for said macroblock having a value less than a third predetermined threshold value.

16. The apparatus according to claim 15, wherein said first threshold value is smaller than said second threshold value.

17. The apparatus according to claim 15, wherein said second threshold value is smaller than said third threshold value.

18. The apparatus according to claim 15, wherein said first threshold value is smaller than said second threshold value and said second threshold value is smaller than said third threshold value.

19. The apparatus according to claim 8, further comprising a zig-zag scan serialization circuit coupled to said second circuit.

20. An apparatus comprising:

means for presenting quantized coefficients for a plurality of blocks in a macroblock; and

means for determining a block sum of absolute values for each of said plurality of blocks in response to said quantized coefficients, wherein said quantized coefficients are set to zero in response to said block sum of absolute values and one or more predetermined threshold values.