Fractional motion estimation engine with parallel code unit pipelines

1. A system, comprising:

an integer level motion estimation hardware component configured to determine candidate integer level motion vectors for a video being encoded; and

a fractional motion estimation hardware component configured to:

receive the candidate integer level motion vectors from the integer level motion estimation hardware component;

divide the candidate integer level motion vectors from the integer level motion estimation hardware component into a plurality of groups, wherein each group of the plurality of groups corresponds to a different single row of coding units of the frame of the video; and

process a group of the plurality of groups by one of a plurality of parallel row pipelines, wherein a parallel row pipeline is configured to process in parallel with other parallel row pipelines a different single row of coding units of the frame of the video, and wherein the plurality of parallel pipelines refine the candidate integer level motion vectors into candidate sub-pixel level motion vectors.

2. The system of claim 1 , wherein the fractional motion estimation hardware component is further configured to compute a fractional motion vector and send the fractional motion vector to an inter prediction module of a mode decision module.

3. The system of claim 1 , wherein a coding unit of the frame of the video comprises a largest coding unit that may be divided into smaller prediction units.

4. The system of claim 1 , wherein in the event of data dependencies in processing the coding units across different rows of coding units of the frame of the video, the processing of a certain coding unit in a particular row and column is performed after the processing of another coding unit in a previous row and a particular column is finished by a different parallel pipeline.

5. The system of claim 1 , wherein a parallel pipeline comprises parallel partition unit pipelines, and wherein a partition unit pipeline is configured to process in parallel with the other partition unit pipelines different partition units, and wherein the partition unit pipeline is configured to process a different set of partition units.

6. The system of claim 5 , wherein a first parallel partition unit pipeline is configured to process partition units with the smallest partition unit shapes, and wherein a second parallel partition unit pipeline is configured to process partition units with the remaining larger partition unit shapes.

7. The system of claim 5 , wherein a parallel partition unit pipeline comprises pipelined half pixel interpolation, quarter pixel interpolation, and one-eighth pixel interpolation for refining the candidate integer level motion vectors into the candidate sub-pixel level motion vectors.

8. The system of claim 7 , wherein nine positions are searched in a half-pixel refinement, and wherein nine positions are searched in a quarter-pixel refinement, and wherein nine positions are searched in a one-eighth-pixel refinement.

9. The system of claim 8 , wherein the half-pixel refinement comprises searching one integer-pixel search center pointed to by an integer motion vector and eight half-pixel positions in half pixel interpolation, and wherein the quarter-pixel refinement comprises searching one half-pixel position and eight quarter-pixel positions in quarter pixel interpolation, and wherein the one-eighth-pixel refinement comprises searching one quarter-pixel position and eight one-eighth-pixel positions in one-eighth pixel interpolation.

10. A system, comprising:

a processor configured to:

determine candidate integer level motion vectors for a video being encoded;

divide the candidate integer level motion vectors into a plurality of groups, wherein each group of the plurality of groups corresponds to a different single row of coding units of the frame of the video; and

process a group of the plurality of groups by one of a plurality of parallel row pipelines, wherein a parallel row pipeline is configured to process in parallel with other parallel row pipelines a different single row of coding units of the frame of the video, and wherein the plurality of parallel pipelines refine the candidate integer level motion vectors into candidate sub-pixel level motion vectors; and

a memory coupled to the processor and configured to provide the processor with instructions.

11. A method of encoding a video, comprising:

determining candidate integer level motion vectors for the video being encoded; and

dividing the candidate integer level motion vectors into a plurality of groups, wherein each group of the plurality of groups corresponds to a different single row of coding units of the frame of the video; and

processing a group of the plurality of groups by one of a plurality of parallel row pipelines, wherein a parallel row pipeline is configured to process in parallel with other parallel row pipelines a different single row of coding units of the frame of the video, and wherein the plurality of parallel pipelines refine the candidate integer level motion vectors into candidate sub-pixel level motion vectors.

12. The method of claim 11 , further comprising computing a fractional motion vector and sending the fractional motion vector to an inter prediction module of a mode decision module.

13. The method of claim 11 , wherein a coding unit of the frame of the video comprises a largest coding unit that may be divided into smaller prediction units.

14. The method of claim 11 , wherein in the event of data dependencies in processing the coding units across different rows of coding units of the frame of the video, processing a certain coding unit in a particular row and column after the processing of another coding unit in a previous row and a particular column is finished by a different parallel pipeline.

15. The method of claim 11 , wherein a parallel pipeline comprises parallel partition unit pipelines, and wherein a partition unit pipeline is configured to process in parallel with the other partition unit pipelines different partition units, and wherein the partition unit pipeline is configured to process a different set of partition units.

16. The method of claim 15 , wherein a first parallel partition unit pipeline is configured to process partition units with the smallest partition unit shapes, and wherein a second parallel partition unit pipeline is configured to process partition units with the remaining larger partition unit shapes.

17. The method of claim 15 , wherein a parallel partition unit pipeline comprises pipelined half pixel interpolation, quarter pixel interpolation, and one-eighth pixel interpolation for refining the candidate integer level motion vectors into the candidate sub-pixel level motion vectors.

18. The method of claim 17 , wherein nine positions are searched in a half-pixel refinement, and wherein nine positions are searched in a quarter-pixel refinement, and wherein nine positions are searched in a one-eighth-pixel refinement.

19. The method of claim 18 , wherein the half-pixel refinement comprises searching one integer-pixel search center pointed to by an integer motion vector and eight half-pixel positions in half pixel interpolation, and wherein the quarter-pixel refinement comprises searching one half-pixel position and eight quarter-pixel positions in quarter pixel interpolation, and wherein the one-eighth-pixel refinement comprises searching one quarter-pixel position and eight one-eighth-pixel positions in one-eighth pixel interpolation.

20. The system of claim 10 , wherein in the event of data dependencies in processing the coding units across different rows of coding units of the frame of the video, the processing of a certain coding unit in a particular row and column is performed after the processing of another coding unit in a previous row and a particular column is finished by a different parallel pipeline.