Method and apparatus for video coding
Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes receiving circuitry and processing circuitry. In some embodiments, the processing circuitry decodes prediction information of a current block in a current coding from a coded video bitstream. The prediction information is indicative of an intra block copy mode. Then, the processing circuitry determines a block vector that points to a reference block in a same picture as the current block. The reference block is restricted within a coding region with reconstructed samples buffered in a reference sample memory. The coding region is one of multiple predefined regions of a coding tree unit (CTU). Then, the processing circuitry reconstructs at least a sample of the current block based on the reconstructed samples of the reference block that are retrieved from the reference sample memory.
1. A method for video decoding in a decoder, comprising:
decoding prediction information of a current block of a current coding region in a coded video bitstream, the prediction information being indicative of an intra block copy mode;
determining a block vector that points to a reference block in a same picture as the current block, the reference block being located within a search range, the search range including reconstructed samples of coding regions comprising a coding tree unit (CTU) of the current block and reconstructed samples of at least one coding region comprising a CTU adjacent to the CTU of the current block;
reconstructing at least a sample of the current block based on reconstructed samples of the reference block ; and
updating the search range for reconstruction of a next coding region such that reconstructed samples of the current block are included in the updated search range and the reconstructed samples of the at least one coding region comprising the CTU adjacent to the CTU of the current block are not available in the updated search range.
2. The method of claim 1 , wherein each coding region has a square shape.
3. The method of claim 1 , wherein each CTU is configured to have 128 samples by 128 samples of a luma component.
4. The method of claim 1 , wherein the search range is updated in a unit of one coding region.
5. The method of claim 1 , further comprising:
checking whether multiple corners of the reference block are within a coding region.
6. The method of claim 5 , wherein
each CTU contains 128×128 luma samples and each coding region is 64×64 luma samples in size.
7. The method of claim 5 , wherein
each CTU contains less than 128×128 luma samples and each coding region is the same as the CTU in size.
8. The method of claim 1 , further comprising:
moving the reference block into the search range when the reference block is partially in the search range before the moving.
9. The method of claim 8 , further comprising:
moving the reference block in a direction to reduce a distance between the reference block and the current block.
10. The method of claim 8 , further comprising:
moving the reference block in a direction that increases a percentage of reference samples in a coding region.
11. The method of claim 1 , further comprising:
using information of a first reference sample that is in the search range as information of a second reference sample that is out of the search range when the reference block is partially in the search range.
12. The method of claim 1 , wherein flexible block partition is prohibited as a partition of each CTU.
13. An apparatus of video decoding, comprising:
processing circuitry configured to:
decode prediction information of a current block of a current coding region in a coded video bitstream, the prediction information being indicative of an intra block copy mode;
determine a block vector that points to a reference block in a same picture as the current block, the reference block being located within a search range, the search range including reconstructed samples of coding regions comprising a coding tree unit (CTU) of the current block and reconstructed samples of at least one coding region comprising a CTU adjacent to the CTU of the current block;
reconstruct at least a sample of the current block based on reconstructed samples of the reference block; and
updating the search range for reconstruction of a next coding region such that reconstructed samples of the current block are included in the updated search range and the reconstructed samples of the at least one coding region comprising the CTU adjacent to the CTU of the current block are not available in the updated search range.
14. The apparatus of claim 13 , wherein each coding region has a square shape.
15. The apparatus of claim 13 , wherein each CTU is configured to have 128 samples by 128 samples of a luma component.
16. The apparatus of claim 13 , wherein the search range is updated in a unit of one coding region.
17. The apparatus of claim 13 , wherein the processing circuitry is further configured to:
check whether multiple corners of the reference block are within a coding region.
18. The apparatus of claim 17 , wherein
each CTU contains 128×128 luma samples and each coding region is 64×64 luma samples in size.
19. The apparatus of claim 17 , wherein
each CTU contains less than 128×128 luma samples and each coding region is the same as the CTU in size.
20. The apparatus of claim 13 , wherein the processing circuitry is further configured to:
move the reference block into the search range coding region when the reference block is partially in the search range before the moving.