Alternative interpolation filters in video coding

1. A method of processing video data, comprising:

determining, for a first conversion between a first video block of a video and a bitstream of the video, a coding mode of the first video block; and

performing the first conversion at least based on the coding mode of the first video block;

wherein in response to the coding mode of the first video block being a first specific coding mode, a first half-pel precision interpolation filter other than a second half-pel precision interpolation filter is used for the first video block,

wherein in the first specific coding mode, a first motion information for a first geometric partition of the first video block and a second motion information for a second geometric partition of the first video block is determined and a weighting process for generating a final prediction for samples within a weighted area of the first video block is applied based on a weighted sum of prediction samples derived based on the first motion information and the second motion information, and

wherein the first half-pel precision interpolation filter is an 8-tap filter, and the second half- pel precision interpolation filter is a 6-tap filter.

2. The method of claim 1 , wherein the first half-pel precision interpolation filter is a default half-pel precision interpolation filter.

3. The method of claim 1 , wherein the first specific coding mode is a triangle prediction mode.

4. The method of claim 1 , wherein an indication indicating which one of the first half-pel precision interpolation filter and the second half-pel precision interpolation filter to be used is not present in the bitstream.

5. The method of claim 1 , wherein a half-pel precision interpolation filter index (hpellfldx) of the first half-pel precision interpolation filter is equal to 0, and a half-pel precision interpolation filter index of the second half-pel precision interpolation filter is equal to 1.

6. The method of claim 1 , wherein the method further comprises:

determining, for a second conversion between a second video block of the video and the bitstream, a coding mode of the second video block; and

performing the second conversion at least based on the coding mode of the second video block;

wherein in response to the coding mode of the second video block being a second specific coding mode, a half-pel motion vector precision is disabled for the second video block.

7. The method of claim 6 , wherein in the second specific coding mode, prediction sample of the second video block is generated by using at least a block vector pointing to another video block in a same picture containing the second video block.

8. The method of claim 6 , wherein the second specific coding mode is an intra block copy mode.

9. The method of claim 6 , wherein in the second specific coding mode, an indication of the use of half-pel motion vector precision is not present in the bitstream.

10. The method of claim 9 , wherein the first conversion comprises encoding the first video block into the bitstream, and the second conversion comprises encoding the second video block into the bitstream.

11. The method of claim 9 , wherein the first conversion comprises decoding the first video block from the bitstream, and the second conversion comprises decoding the second video block from the bitstream.

12. An apparatus for coding 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 first conversion between a first video block of a video and a bitstream of the video, a coding mode of the first video block; and

perform the first conversion at least based on the coding mode of the first video block;

wherein in response to the coding mode of the first video block being a first specific coding mode, a first half-pel precision interpolation filter other than a second half-pel precision interpolation filter is used for the first video block,

wherein in the first specific coding mode, a first motion information for a first geometric partition of the first video block and a second motion information for a second geometric partition of the first video block is determined and a weighting process for generating a final prediction for samples within a weighted area of the first video block is applied based on a weighted sum of prediction samples derived based on the first motion information and the second motion information, and

wherein the first half-pel precision interpolation filter is an 8-tap filter, and the second half-pel precision interpolation filter is a 6-tap filter.

13. The apparatus of claim 12 , wherein the first half-pel precision interpolation filter is a default half-pel precision interpolation filter.

14. The apparatus of claim 12 , wherein the first specific coding mode is a triangle prediction mode.

15. The apparatus of claim 12 , wherein an indication indicating which one of the first half-pel precision interpolation filter and the second half-pel precision interpolation filter to be used is not present in the bitstream.

16. The apparatus of claim 12 , wherein the instructions upon execution by the processor, cause the processor further to:

determine, for a second conversion between a second video block of the video and the bitstream, a coding mode of the second video block; and

perform the second conversion at least based on the coding mode of the second video block;

wherein in response to the coding mode of the second video block being a second specific coding mode, a half-pel motion vector precision is disabled for the second video block.

17. The apparatus of claim 16 , wherein in the second specific coding mode, prediction sample of the second video block is generated by using at least a block vector pointing to another video block in a same picture containing the second video block.

18. A non-transitory computer-readable storage medium storing instructions that cause a processor to:

determine, for a first conversion between a first video block of a video and a bitstream of the video, a coding mode of the first video block; and

perform the first conversion at least based on the coding mode of the first video block;

wherein in response to the coding mode of the first video block is a first specific coding mode, a first half-pel precision interpolation filter other than a second half-pel precision interpolation filter is used for the first video block,

wherein in the first specific coding mode, a first motion information for a first geometric partition of the first video block and a second motion information for a second geometric partition of the first video block is determined and a weighting process for generating a final prediction for samples within a weighted area of the first video block is applied based on a weighted sum of prediction samples derived based on the first motion information and the second motion information, and

wherein the first half-pel precision interpolation filter is an 8-tap filter, and the second half- pel precision interpolation filter is a 6-tap filter.

19. The medium of claim 18 , wherein the first half-pel precision interpolation filter is a default half-pel precision interpolation filter.

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

determining a coding mode of a first video block of a video; and

generating the bitstream at least based on the coding mode of the first video block;

wherein in response to the coding mode of the first video block is a first specific coding mode, a first half-pel precision interpolation filter other than a second half-pel precision interpolation filter is used for the first video block,

wherein in the first specific coding mode, a first motion information for a first geometric partition of the first video block and a second motion information for a second geometric partition of the first video block is determined and a weighting process for generating a final prediction for samples within a weighted area of the first video block is applied based on a weighted sum of prediction samples derived based on the first motion information and the second motion information, and

wherein the first half-pel precision interpolation filter is an 8-tap filter, and the second half-pel precision interpolation filter is a 6-tap filter.