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. For example, the processing circuitry decodes partition information from a coded video bitstream. The partition information is indicative of a minimum allowed quaternary tree (QT) leaf node size for an intra coded (I) slice. The minimum allowed QT leaf node size for the I slice is constrained by a threshold that is lower than a coding tree unit (CTU) size. Further, the processing circuitry partitions a coding tree block in the I slice into coding blocks based on the minimum allowed QT leaf node size, and reconstructs the coding blocks respectively from the coded video bitstream.
1. A method for video decoding in a decoder, comprising:
decoding, by processing circuitry, partition information from a coded video bitstream, the partition information being indicative of a minimum allowed quaternary tree (QT) leaf node size for an intra coded (I) slice, the minimum allowed QT leaf node size for the I slice being constrained by a threshold that is lower than a coding tree unit (CTU) size;
partitioning, by the processing circuitry, a coding tree block in the I slice into coding blocks based on the minimum allowed QT leaf node size indicated by the decoded partition information; and
reconstructing, by the processing circuitry, the coding blocks respectively from the coded video bitstream.
2. The method of claim 1 , wherein the decoded partition information is indicative of a minimum allowed QT leaf node size for a luma component.
3. The method of claim 2 , wherein the minimum allowed QT leaf node size for the I slice, as indicated by the decoded partition information, is constrained by the threshold in response to a dual tree partition being used for the I slice.
4. The method of claim 2 , further comprising determining the threshold based on an implicit QT split requirement.
5. The method of claim 1 , wherein the decoded partition information is indicative of a minimum allowed QT leaf node size for chroma components.
6. The method of claim 1 , further comprising decoding the partition information from a sequence parameter set (SPS).
7. The method of claim 1 , further comprising decoding the partition information is decoded from a picture header (PH).
8. The method of claim 1 , further comprising:
applying QT splits to partition the coding tree block into QT leaf nodes that satisfy a requirement of the minimum allowed QT leaf node size, before applying a binary tree (BT) split or a ternary tree (TT) split.
9. The method of claim 1 , wherein a base 2 logarithm of the minimum allowed QT leaf node size for the I slice, as indicated by the decoded partition information, is constrained to be smaller than a base 2 logarithm of the CTU size.
10. The method of claim 9 , wherein the base 2 logarithm of the minimum allowed QT leaf node size for the I slice, as indicated by the decoded partition information, is smaller than the base 2 logarithm of the CTU size by 1.
11. An apparatus for video decoding, comprising:
processing circuitry configured to:
decode partition information from a coded video bitstream, the partition information being indicative of a minimum allowed quaternary tree (QT) leaf node size for an intra coded (I) slice, the minimum allowed QT leaf node size for the I slice being constrained by a threshold that is lower than a coding tree unit (CTU) size;
partition a coding tree block in the I slice into coding blocks based on the minimum allowed QT leaf node size indicated by the decoded partition information; and
reconstruct the coding blocks respectively from the coded video bitstream.
12. The apparatus of claim 11 , wherein the partition information decoded by the processing circuitry is indicative of a minimum allowed QT leaf node size for a luma component.
13. The apparatus of claim 12 , wherein the minimum allowed QT leaf node size for the I slice, as indicated by the partition information decoded by the processing circuitry, is constrained by the threshold in response to a dual tree partition being used for the I slice.
14. The apparatus of claim 12 , wherein the processing circuitry is further configured to determine the threshold based on an implicit QT split requirement.
15. The apparatus of claim 11 , wherein the partition information decoded by the processing circuitry is indicative of a minimum allowed QT leaf node size for chroma components.
16. The apparatus of claim 11 , wherein the processing circuitry is further configured to decode the partition information from a sequence parameter set (SPS).
17. The apparatus of claim 11 , wherein the processing circuitry is further configured to decode the partition information from a picture header (PH).
18. The apparatus of claim 11 , wherein the processing circuitry is further configured to:
apply QT splits to partition the coding tree block into QT leaf nodes that satisfy a requirement of the minimum allowed QT leaf node size, before applying applying a binary tree (BT) split or a ternary tree (TT) split.
19. The apparatus of claim 11 , wherein a base 2 logarithm of the minimum allowed QT leaf node size for the I slice, as indicated by the partition information decoded by the processing circuitry, is constrained to be smaller than a base 2 logarithm of the CTU size.
20. The apparatus of claim 19 , wherein the base 2 logarithm of the minimum allowed QT leaf node size for the I slice, as indicated by the partition information decoded by the processing circuitry, is smaller than the base 2 logarithm of the CTU size by 1.