Motion estimation in video compression systems

• US 20060002473A1
• Filed: 01/20/2005
• Published: 01/05/2006
• Est. Priority Date: 07/02/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Malayath, Narendranath, Mauro, Anthony Patrick II, Lai, King-Chung, Mohan, Sumit, Singh, Jatinder
• Granted Patent: US 8,462,850 B2
• Time in Patent Office: Days
• US Class Current: 375/240.160
• CPC Class Codes: H04N 19/43 Hardware specially adapted for motion estimation or compensation
• CPC Class Codes: H04N 19/533 Motion estimation using multistep search, e.g. 2D-log search or one-at-a-time search [OTS]
• CPC Class Codes: H04N 5/145 Movement estimation for video coding H04N19/51

Abstract

Motion estimation in video compressions systems. A programmable motion estimator may be used to estimate a motion vector for a macroblock in a current frame by searching for a matching macroblock in a previous frame. A controller may be used to program the motion estimator to perform a particular search.

Claims

1. A video processor, comprising:

a programmable motion estimator configured to estimate a motion vector for a macroblock in a current frame by searching for a matching macroblock in a previous frame, the motion estimator being capable of performing each of a plurality of searches including an exhaustive search and one or more limited searches; and

a controller configured to program the motion estimator to perform one of the searches.

2. The video processor of claim 1 wherein the motion estimator further comprises a SAD computation engine configured to estimate the motion vector.

3. The video processor of claim 2 wherein the SAD computation engine comprises a tree architecture.

4. The video processor of claim 1 wherein the motion estimator includes memory, and wherein the controller is configured to program the motion estimator by loading instructions into the memory.

5. The video processor of claim 4 wherein the motion estimator is further configured to estimate the motion vector by evaluating a plurality of macroblocks off an anchor point in the previous frame, the number of macroblocks evaluated being programmable by one or more of the instructions loaded into the memory by the controller.

6. The video processor of claim 5 wherein the distance between each of the macroblocks evaluated is also programmable with said one or more of the instructions.

7. The video processor of claim 5 wherein the location of one of the macroblocks evaluated relative to the anchor point is also programmable with said one or more of the instructions.

8. The video processor of claim 4 wherein the motion estimator is further configured to estimate the motion vector by evaluating a plurality of macroblocks off an anchor point in the previous frame, and selecting one of the macroblocks evaluated in response to one or more of the instructions loaded into the memory by the controller.

9. The video processor of claim 8 wherein the motion estimator is further configured to select said one of the macroblocks evaluated having the closest match to the macroblock in the current frame.

10. The video processor of claim 9 wherein the motion estimator further comprises a SAD computation engine configured to compute a SAD between the macroblock in the current frame and each of the macroblocks evaluated in the previous frame, and select said one of the macroblocks evaluated based on the SAD computations.

11. A video processor, comprising:

a programmable motion estimator having memory, the motion estimator being configured to estimate a motion vector for a macroblock in a current frame by searching for a matching macroblock in a previous frame, the search including an evaluation of a plurality of macroblocks off an anchor point in the previous frame; and

a controller configured to program the motion estimator by loading instructions into the memory, the number of macroblocks evaluated, the location of one of the macroblocks evaluated relative to the anchor point, and the distance between each of the macroblocks evaluated being programmed by one or more of the instructions loaded into the memory.

12. The video processor of claim 11 wherein the motion estimator further comprises a SAD computation engine configured to estimate the motion vector.

13. The video processor of claim 12 wherein the SAD computation engine comprises a tree architecture.

14. The video processor of claim 11 wherein the motion estimator is further configured to estimate the motion vector by selecting one of the evaluated macroblocks in response to one or more of the instructions loaded into the memory by the controller.

15. The video processor of claim 14 wherein the motion estimator is further configured to select said one of the evaluated macroblocks having the closest match to the macroblock in the current frame.

16. The video processor of claim 15 wherein the motion estimator further comprises a SAD computation engine configured to compute a SAD between the macroblock in the current frame and each of the evaluated macroblocks in the previous frame, and select said one of the evaluated macroblocks based on the SAD computations.

17. A method of video processing, comprising:

receiving instructions; and

estimating a motion vector for a macroblock in a current frame by searching for a matching macroblock in a previous frame, the search including evaluating a plurality of macroblocks off an anchor point in the previous frame;

wherein one or more of the received instructions includes the number of macroblocks evaluated, the location of one of the macroblocks evaluated relative to the anchor point, and the distance between each of the macroblocks evaluated.

18. The method of claim 17 wherein the estimation of the motion vector further comprises selecting one of the macroblocks evaluated in response to one or more of the received instructions.

19. The method of claim 18 wherein the selected one of the macroblocks evaluated is that which is the closest match to the macroblock in the current frame.

20. The method of claim 18 wherein the selection of said one of the macroblocks evaluated is based on a SAD computation between the macroblock in the current frame and each of the evaluated macroblocks in the previous frame.

21. The method of claim 18 wherein the estimation of the motion vector further comprises evaluating a plurality of macroblocks off a second anchor point in response to one or more of the received instructions, the second anchor point being the selected one of the macroblocks off the first anchor point.

22. The method of claim 21 wherein the one or more of the received instructions for the evaluation of the macroblocks off the second anchor point includes the distance between each of the evaluated macroblocks off the second anchor point, the distance between each of the evaluated macroblocks off the second anchor point being less than the distance between each of the evaluated macroblocks off the anchor point.

23. A video processor, comprising:

motion estimation means for estimating a motion vector for a macroblock in a current frame by searching for a matching macroblock in a previous frame, the motion estimation means being capable of performing each of a plurality of searches including an exhaustive search and one or more limited searches; and

control means for programming the motion estimation means to perform one of the searches.

24. The video processor of claim 23 wherein the motion estimation means is further configured to estimate the motion vector by evaluating a plurality of macroblocks off an anchor point in the previous frame, the number of macroblocks evaluated being programmable by the control means.

25. The video processor of claim 24 wherein the distance between each of the macroblocks evaluated is also programmable by the control means.

26. The video processor of claim 24 wherein the location of one of the macroblocks evaluated relative to the anchor point is also programmable by the control means.

27. Computer readable media embodying a program of instructions executable by a computer to perform a method of video processing, the method comprising:

receiving instructions; and

estimating a motion vector for a macroblock in a current frame by searching for a matching macroblock in a previous frame, the search including evaluating a plurality of macroblocks off an anchor point in the previous frame;

wherein one or more of the received instructions includes the number of macroblocks evaluated, the location of one of the macroblocks evaluated relative to the anchor point, and the distance between each of the macroblocks evaluated.

28. The computer readable media of claim 27 wherein the estimation of the motion vector further comprises selecting one of the macroblocks evaluated in response to one or more of the received instructions.

29. The computer readable media of claim 28 wherein the selected one of the macroblocks evaluated is that which is the closest match to the macroblock in the current frame.

30. The computer readable media of claim 28 wherein the selection of said one of the macroblocks evaluated is based on a SAD computation between the macroblock in the current frame and each of the evaluated macroblocks in the previous frame.

31. The computer readable media of claim 28 wherein the estimation of the motion vector further comprises evaluating a plurality of macroblocks off a second anchor point in response to one or more of the received instructions, the second anchor point being the selected one of the macroblocks off the first anchor point.

32. The computer readable media of claim 31 wherein the one or more of the received instructions for the evaluation of the macroblocks off the second anchor point includes the distance between each of the evaluated macroblocks off the second anchor point, the distance between each of the evaluated macroblocks off the second anchor point being less than the distance between each of the evaluated macroblocks off the anchor point.