EP-4736417-A1 - BI-PREDICTIVE MERGE LIST FOR INTRA BLOCK COPY CODING

Abstract

Systems, devices, and methods are described herein for using a bi-predictive merge list for bi-predictive merge list for intra block copy (IBC) coding. An example method (e.g., for video decoding) may involve constructing an intra block copy (IBC) merge list comprising a plurality of bi-predictive candidates and uni-predictive candidates. A merge index that indicates a candidate from the plurality of bi-predictive candidates and uni-predictive candidates may be received in video data. The candidate may be selected based on the merge index. A coding block may be decoded based on the selected candidate.

Inventors

• ROBERT, ANTOINE
• NASER, Karam
• CHEN, Ya
• RATH, Gagan Bihari

Assignees

• InterDigital CE Patent Holdings, SAS

Dates

Publication Date

20260506

Application Date

20240617

Claims (16)

1. 1 . A method for video decoding, the method comprising: constructing an intra block copy (IBC) merge list comprising a plurality of bi-predictive candidates and uni-predictive candidates; receiving, in video data, a merge index that indicates a candidate from the plurality of bi- predictive candidates and uni-predictive candidates; selecting the candidate based on the merge index; and decoding a coding block based on the selected candidate.
2. 2. The method of claim 1 , wherein constructing the IBC merge list comprising the plurality of bi- predictive candidates and uni-predictive candidates comprises: adding a first uni-predictive candidate and a second uni-predictive candidate to the IBC merge list; determining a bi-predictive candidate based on the first uni-predictive candidate and the second uni-predictive candidate; and adding the bi-predictive candidate to the IBC merge list, wherein the selected candidate comprises the first uni-predictive candidate, the second uni-predictive candidate, or the bi- predictive candidate.
3. 3. The method of claim 1 , wherein the coding block is a first coding block, and the method further comprises: determining that a block vector prediction merge mode is enabled for a second coding block; and for the second coding block, generating a block vector prediction merge candidate based on a block vector part and a merge part, wherein constructing the IBC merge list comprising the plurality of bi-predictive candidates and uni-predictive candidates comprises storing the block vector prediction merge candidate as a bi-predictive candidate in the IBC merge list.
4. 4. The method of claim 1 , wherein the coding block is a first coding block, the merge index is a first merge index, and the method further comprises: receiving a first indication of a first value, wherein the first value indicates that the candidate indicated by the first merge index is to be selected from the plurality of bi-predictive candidates and uni-predictive candidates; obtaining a second coding block; receiving a second merge index that indicates a first uni-predictive candidate, a third merge index that indicates a second uni-predictive candidate, and a second indication of a second value, wherein the second value indicates for the first uni-predictive candidate and the second uni-predictive candidate to be used to generate a bi-predictive candidate; generating the bi-predictive candidate based on the second merge index and the third merge index; and decoding the second coding block based on the bi-predictive candidate.
5. 5. The method of claim 1 , wherein the method further comprises generating the bi-predictive candidates using at least one of: an IBC block vector prediction (BVP) mode, a BVP-merge mode, an IBC template matching (IBC-TM) merge mode, an IBC combined inter-intra prediction (IBC-CIIP) mode, an IBC merge mode with block vector difference (IBC-MBVD) mode, or an IBC geometric partitioning mode (IBC-GPM).
6. 6. The method of claim 1 , wherein the method further comprises receiving an indication of whether the plurality of bi-predictive candidates are able to be used, and on a condition that the indication indicates that the plurality of bi-predictive candidates is not able to be used, selecting the candidate based on the merge index comprises selecting the candidate, from the uni-predictive candidates, based on the merge index.
7. 7. The method of any one of claims 1 , 2, 5, and 6, wherein the coding block is a first coding block, the merge index is a first merge index, and the method further comprises: storing the IBC merge list; receiving a second merge index that indicates a second candidate from the plurality of bi- predictive candidates and uni-predictive candidates; and decoding a second coding block based on the stored IBC merge list and the second merge index.
8. 8. A video decoding device comprising a processor, wherein the processor is configured to implement the steps of the method according to any one of claims 1 -7.
9. 9. A method for video encoding, the method comprising: constructing a bi-predictive intra block copy (IBC) merge list comprising a plurality of bi- predictive candidates and uni-predictive candidates; encoding a coding block based on a candidate from the plurality of bi-predictive candidates and uni-predictive candidates; and including, in video data, the encoded coding block and an indication of a merge index of the candidate.
10. 10. The method of claim 9, wherein constructing the IBC merge list comprising the plurality of bi- predictive candidates and uni-predictive candidates comprises: adding a first uni-predictive candidate and a second uni-predictive candidate to the IBC merge list; determining a bi-predictive candidate based on the first uni-predictive candidate and the second uni-predictive candidate; and adding the bi-predictive candidate to the IBC merge list, wherein the candidate comprises the first uni-predictive candidate, the second uni-predictive candidate, or the bi-predictive candidate.
11. 11 . The method of claim 9, wherein the coding block is a first coding block, and the method further comprises: determining that a block vector prediction merge mode is enabled for a second coding block; and for the second coding block, generating a block vector prediction merge candidate based on a block vector part and a merge part, wherein constructing the IBC merge list comprising the plurality of bi-predictive candidates and uni-predictive candidates comprises storing the block vector prediction merge candidate as a bi-predictive candidate in the IBC merge list.
12. 12. The method of claim 9, wherein the coding block is a first coding block, the merge index is a first merge index, the video data is first video data, and the method further comprises: including, in the first video data, a first indication of a first value, wherein the first value indicates that the candidate indicated by the first merge index is to be selected from the plurality of bi-predictive candidates and uni-predictive candidates; encoding a second coding block based on the candidate from the plurality of bi-predictive candidates and uni-predictive candidates; generating a bi-predictive candidate based on a first uni-predictive candidate and a second uni-predictive candidate; encoding the second coding block based on the bi-predictive candidate; and including, in second video data, a second merge index that indicates the first uni-predictive candidate, a third merge index that indicates the second uni-predictive candidate, and a second indication of a second value, wherein the second value indicates that the second coding block was encoded based on the bi-predictive candidate generated based on the first uni-predictive candidate and the second uni-predictive candidate.
13. 13. The method of claim 9, wherein the method further comprises generating the bi-predictive candidates using at least one of: an IBC block vector prediction (BVP) mode, a BVP-merge mode, an IBC template matching (IBC-TM) merge mode, an IBC combined inter-intra prediction (IBC-CIIP) mode, an IBC merge mode with block vector difference (IBC-MBVD) mode, or an IBC geometric partitioning mode (IBC-GPM).
14. 14. The method of claim 9, wherein the method further comprises including, in the video data, an indication of whether the plurality of bi-predictive candidates are able to be used.
15. 15. The method of any one of claims 9, 10, 13, and 14, wherein the coding block is a first coding block, the merge index is a first merge index, the candidate is a first candidate, the video data is first video data and the method further comprises: storing the IBC merge list; encoding a second coding block based on a second candidate in the stored IBC merge list; and including, in second video data, the encoded second coding block and a second merge index that indicates the second candidate.
16. 16. A video encoding device comprising a processor, wherein the processor is configured to implement the steps of the method according to any one of claims 9-15.

Description

BI-PREDICTIVE MERGE LIST FOR INTRA BLOCK COPY CODING CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of European Provisional Patent Application No. EP23306086.2, filed June 30, 2023, the contents of which are hereby incorporated by reference herein. BACKGROUND [0002] Video coding systems may be used to compress digital video signals, e.g., to reduce the storage and/or transmission bandwidth needed for such signals. Video coding systems may include, for example, block-based, wavelet-based, and/or object-based systems. SUMMARY [0003] Systems, devices, and methods are described herein for using a bi-predictive merge list for intra block copy (IBC) coding. [0004] An example method (e.g., for video decoding) may involve constructing an intra block copy (IBC) merge list comprising a plurality of bi-predictive candidates and uni-predictive candidates. A merge index that indicates a candidate from the plurality of bi-predictive candidates and uni-predictive candidates may be received in video data. The candidate may be selected based on the merge index. A coding block may be decoded based on the selected candidate. [0005] The IBC merge list may be constructed by adding a first uni-predictive candidate and a second uni-predictive candidate to the IBC merge list; determining a bi-predictive candidate based on the first uni-predictive candidate and the second uni-predictive candidate; and adding the bi- predictive candidate to the IBC merge list. The selected candidate may be the first uni-predictive candidate, the second uni-predictive candidate, or the bi-predictive candidate. [0006] The coding block may be a first coding block. The method may determine that a block vector prediction merge mode is enabled for a second coding block. For the second coding block, a block vector prediction merge candidate may be generated based on a block vector part and a merge part. The IBC merge list may be generated by storing the block vector prediction merge candidate as a bi-predictive candidate in the IBC merge list. [0007] The method may involve receiving a first indication of a first value. The first value may indicate that the candidate indicated by the first merge index is to be selected from the plurality of bi-predictive candidates and uni-predictive candidates. A second coding block may be obtained. The method may involve receiving a second merge index that indicates a first uni-predictive candidate, a third merge index that indicates a second uni-predictive candidate, and a second indication of a second value. The second value may indicate for the first uni-predictive candidate and the second uni-predictive candidate to be used to generate a bi-predictive candidate. The method may involve generating the bi-predictive candidate based on the second merge index and the third merge index. The second coding block may be decoded based on the bi-predictive candidate. [0008] The bi-predictive candidates may be generated using at least one of: an IBC block vector prediction (BVP) mode, a BVP-merge mode, an IBC template matching (IBC-TM) merge mode, an IBC combined inter-intra prediction (IBC-CI IP) mode, an IBC merge mode with block vector difference (IBC-MBVD) mode, or an IBC geometric partitioning mode (IBC-GPM). [0009] The method may involve receiving an indication of whether the plurality of bi-predictive candidates are able to be used. On a condition that the indication indicates that the plurality of bi- predictive candidates is not able to be used, the candidate may be selected based on the merge index comprises selecting the candidate, from the uni-predictive candidates, based on the merge index. [0010] The merge index may be a first merge index. The IBC merge list may be stored. A second merge index that indicates a second candidate from the plurality of bi-predictive candidates and uni-predictive candidates may be received. A second coding block may be decoded based on the stored IBC merge list and the second merge index. [0011] A video decoding device may include a processor configured to implement the steps of the method(s) described herein. [0012] A method (e.g., for video encoding) may involve constructing bi-predictive intra block copy (IBC) merge list comprising a plurality of bi-predictive candidates and uni-predictive candidates. A coding block may be encoded based on a candidate from the plurality of bi- predictive candidates and uni-predictive candidates. The encoded coding block and an indication of a merge index of the candidate may be included in video data. [0013] Constructing the IBC merge list comprising the plurality of bi-predictive candidates and uni-predictive candidates may involve adding a first uni-predictive candidate and a second uni- predictive candidate to the IBC merge list; determining a bi-predictive candidate based on the first uni-predictive candidate and the second uni-predictive candidate; and adding the bi-predictive candidate to the IBC merge list.