Simplification of hash-based motion searching

1. A method of processing video data, comprising:

determining, for a conversion between a current block of a video and a bitstream of the video, motion information associated with the current block using a hash-based motion search that includes performing a K-pel integer motion vector (MV) precision check for the hash-based motion search, wherein K is a positive integer;

applying, based on the motion information and a video picture comprising the current block, a prediction for the current block; and

performing, based on the prediction, the conversion,

wherein the method further comprises:

determining the hash-based motion search resulted in a hash match,

determining a quantization parameter (QP) of a reference frame is larger than a QP of a video block, and

determining a rate-distortion cost of the prediction based on (a) the hash-based motion search resulting in the hash match and (b) the QP of the reference frame being larger than the QP of the video block,

wherein further processing of the current block is based on the rate-distortion cost, and

wherein determining the rate-distortion cost (a) is based on a dimension of the current block and (b) includes skipping advanced motion vector prediction (AMVP) or stopping finer-grained block partition checking.

2. The method of claim 1 , wherein K=4.

3. The method of claim 1 , wherein a size of the current block is N×N, wherein N is a positive integer less than or equal to a threshold.

4. The method of claim 1 , wherein a size of the current block is M×N, wherein M and N are positive integers and M is not equal to N, and wherein M or N are less than or equal to a threshold.

5. The method of claim 3 , wherein the threshold is 64.

6. The method of claim 4 , wherein the threshold is 64.

7. The method of claim 1 , wherein a size of the current block is 8×4 or 4×8.

8. The method of claim 1 , wherein the hash-based motion search is applied to a luma component of the video.

9. The method of claim 1 , wherein the hash-based motion search is applied to a base color component of the video.

10. The method of claim 1 , wherein the conversion includes encoding the current block into the bitstream.

11. The method of claim 1 , wherein the conversion includes decoding generates the current block from the bitstream.

12. An apparatus for processing video data comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to:

determine, for a conversion between a current block of a video and a bitstream of the video, motion information associated with the current block using a hash-based motion search that includes performing a K-pel integer motion vector (MV) precision check for the hash-based motion search, wherein K is a positive integer;

apply, based on the motion information and a video picture comprising the current block, a prediction for the current block; and

perform, based on the prediction, the conversion,

wherein the instructions upon execution by the processor, further cause the processor to:

determine the hash-based motion search resulted in a hash match,

determine a quantization parameter (QP) of a reference frame is larger than a QP of a video block, and

determine a rate-distortion cost of the prediction based on (a) the hash-based motion search resulting in the hash match and (b) the QP of the reference frame being larger than the QP of the video block,

wherein further processing of the current block is based on the rate-distortion cost, and

wherein determining the rate-distortion cost (a) is based on a dimension of the current block and (b) includes skipping advanced motion vector prediction (AMVP) or stopping finer-grained block partition checking.

13. The apparatus of claim 12 , wherein K=4.

14. The apparatus of claim 12 , wherein a size of the current block is N×N, wherein N is a positive integer less than or equal to a threshold.

15. The apparatus of claim 12 , wherein a size of the current block is M×N, wherein M and N are positive integers and M is not equal to N, and wherein M or N are less than or equal to a threshold.

16. The apparatus of claim 14 , wherein the threshold is 64.

17. The apparatus of claim 15 , wherein the threshold is 64.

18. The apparatus of claim 12 , wherein a size of the current block is 8×4 or 4×8.

19. The apparatus of claim 12 , wherein the hash-based motion search is applied to a luma component of the video.

20. A non-transitory computer-readable recording medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises:

determining, motion information associated with a current block of the video using a hash-based motion search that includes performing a K-pel integer motion vector (MV) precision check for the hash-based motion search, wherein K is a positive integer;

applying, based on the motion information and a video picture comprising the current block, a prediction for the current block; and

generating, based on the prediction, the bitstream,

wherein the method further comprises:

determining the hash-based motion search resulted in a hash match,

determining a quantization parameter (QP) of a reference frame is larger than a QP of a video block, and

determining a rate-distortion cost of the prediction based on (a) the hash-based motion search resulting in the hash match and (b) the QP of the reference frame being larger than the QP of the video block,

wherein further processing of the current block is based on the rate-distortion cost, and

wherein determining the rate-distortion cost (a) is based on a dimension of the current block and (b) includes skipping advanced motion vector prediction (AMVP) or stopping finer-grained block partition checking.