US-12621432-B2 - Motion candidate lists that use local illumination compensation

Abstract

A video processing method is provided to include: maintaining, for a conversion between blocks of a video and a coded representation of the video, a table of motion information used during the conversion of previous blocks that are processed prior to a current block; and updating the table selectively based on a use of a local illumination coding (LIC) tool for the conversion of the current block, wherein the LIC tool uses a linear model of illumination changes in the current block during the conversion.

Inventors

• Hongbin Liu
• Li Zhang
• Kai Zhang
• Yue Wang

Assignees

• BEIJING BYTEDANCE NETWORK TECHNOLOGY CO., LTD.
• BYTEDANCE INC.

Dates

Publication Date

20260505

Application Date

20210715

Priority Date

20190115

Claims (17)

1. 1 . A method of processing video data, comprising: maintaining a history-based motion vector prediction (HMVP) table that includes entries that represent a past history of motion information used for a conversion between a current block of a video comprising video blocks and a bitstream of the video, wherein a local illumination compensation (LIC) flag is stored for each entry of the motion information and is stored together with the motion information in the HMVP table; and performing the conversion of the current block based on the entries in the HMVP table, wherein the LIC flag indicates a use of an LIC coding tool that uses a linear model of illumination changes for the conversion, wherein the method further comprises: comparing two candidate motion information using the LIC flag, and wherein the performing of the conversion is based on the comparing, wherein the HMVP table is updated using the LIC flag, and wherein in case that the current block is coded with an LIC coding mode, an updating of the HMVP table is skipped.
2. 2 . The method of claim 1 , further comprising: comparing two candidate motion information without using the LIC flag, and wherein the performing of the conversion is based on the comparing.
3. 3 . The method of claim 1 , wherein a merge candidate from an entry in the HMVP table includes data associated with the LIC flag that is copied to the merge candidate.
4. 4 . The method of claim 1 , wherein a default LIC flag value is set for each entry of the motion information.
5. 5 . The method of claim 1 , wherein the current block coded with an LIC coding mode is used to update the HMVP table.
6. 6 . The method of claim 1 , wherein entries with an enabled LIC coding mode are put in a motion candidate list to be before all or a part of entries with a disabled LIC coding mode.
7. 7 . The method of claim 1 , wherein entries with a disabled LIC coding mode are put in a motion candidate list to be before all or a part of entries with an enabled LIC coding mode.
8. 8 . The method of claim 1 , wherein different processes for maintaining the HMVP table are performed for a video block coded with a LIC coding mode and for a video block not coded with the LIC coding mode.
9. 9 . The method of claim 1 , wherein the HMVP table is constructed in an order according to the local illumination compensation (LIC) flag associated with entry of the motion information and/or a type of the entry of the motion information.
10. 10 . The method of claim 9 , wherein the type of the entry of the motion information is a merge candidate or an advanced motion vector prediction (AMVP) candidate.
11. 11 . The method of claim 1 , wherein a motion candidate list for a video block coded with a LIC coding mode does not include an entry of the motion information derived from spatial or temporal neighboring or non-adjacent blocks that are not coded with the LIC coding mode or from HMVP candidates with an LIC flag equal to false.
12. 12 . The method of claim 1 , wherein a motion candidate list for a video block not coded with a LIC coding mode does not include an entry of the motion information derived from spatial or temporal neighboring or non-adjacent blocks that are coded with the LIC coding mode or from HMVP candidates with an LIC flag equal to true.
13. 13 . The method of claim 1 , wherein the conversion includes encoding the current block into the bitstream.
14. 14 . The method of claim 1 , wherein the conversion includes decoding the current block from the bitstream.
15. 15 . 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: maintain a history-based motion vector prediction (HMVP) table that includes entries that represent a past history of motion information used for a conversion between a current block of a video comprising video blocks and a bitstream of the video, wherein a local illumination compensation (LIC) flag is stored for each entry of the motion information and is stored together with the motion information in the HMVP table; and perform the conversion of the current block based on the entries in the HMVP table, wherein the LIC flag indicates a use of an LIC coding tool that uses a linear model of illumination changes for the conversion, wherein the instructions upon execution by the processor further cause the processor to: compare two candidate motion information using the LIC flag, and wherein the performing of the conversion is based on the comparing, wherein the HMVP table is updated using the LIC flag, and wherein in case that the current block is coded with an LIC coding mode, an updating of the HMVP table is skipped.
16. 16 . A non-transitory computer-readable storage medium storing instructions that cause a processor to: maintain a history-based motion vector prediction (HMVP) table that includes entries that represent a past history of motion information used for a conversion between a current block of a video comprising video blocks and a bitstream of the video, wherein a local illumination compensation (LIC) flag is stored for each entry of the motion information and is stored together with the motion information in the HMVP table; and perform the conversion of the current block based on the entries in the HMVP table, wherein the LIC flag indicates a use of an LIC coding tool that uses a linear model of illumination changes for the conversion, wherein the instructions further cause the processor to: compare two candidate motion information using the LIC flag, and wherein the performing of the conversion is based on the comparing, wherein the HMVP table is updated using the LIC flag; wherein in case that the current block is coded with an LIC coding mode, an updating of the HMVP table is skipped.
17. 17 . 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: maintaining a history-based motion vector prediction (HMVP) table that includes entries that represent a past history of motion information used for a current block of the video comprising video blocks, wherein a local illumination compensation (LIC) flag is stored for each entry of the motion information and is stored together with the motion information in the HMVP table; and generating the bitstream based on the maintaining, wherein the LIC flag indicates a use of an LIC coding tool that uses a linear model of illumination changes for the generating, wherein the method further comprises: comparing two candidate motion information using the LIC flag, and wherein the generating of the bitstream is based on the comparing, wherein the HMVP table is updated using the LIC flag, and wherein in case that the current block is coded with an LIC coding mode, an updating of the HMVP table is skipped.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of International Application No. PCT/CN2020/072237, filed on Jan. 15, 2020, which claims the priority to and benefits of International Patent Application No. PCT/CN2019/071759, filed on Jan. 15, 2019, and International Patent Application No. PCT/CN2019/072154, filed on Jan. 17, 2019. All the aforementioned patent applications are hereby incorporated by reference in their entireties. TECHNICAL FIELD The present patent document relates to the field of video processing. BACKGROUND Currently, efforts are underway to improve the performance of current video codec technologies to provide better compression ratios or provide video coding and decoding schemes that allow for lower complexity or parallelized implementations. Industry experts have recently proposed several new video coding tools and tests are currently underway for determining their effectivity. SUMMARY The present document provides techniques for incorporating local illumination compensation in embodiments of video encoders or decoders. One example aspect, a video processing method is disclosed. The video processing method comprises: maintaining, for a conversion between blocks of a video and a coded representation of the video, a table of motion information used during the conversion of previous blocks that are processed prior to a current block; and updating the table selectively based on a use of a local illumination coding (LIC) tool for the conversion of the current block, wherein the LIC tool uses a linear model of illumination changes in the current block during the conversion. In another example aspect, a video processing method is disclosed. The video processing method comprises: determining, a procedure for deriving local illumination compensation parameters used for a conversion between a current video block of a video region or a video and a coded representation of the video based on a position rule of the current video block in the video region; and performing the conversion based on the determining. In another example aspect, a video processing method is disclosed. The video processing method comprises: constructing a motion candidate list in an order according to a local illumination compensation (LIC) flag associated with each motion candidate and/or a type of the motion candidate, wherein LIC flags indicate enablement statuses of an LIC coding mode for the motion candidates; and performing a conversion between a current block of a video and a coded representation of the video based on the motion candidate list, wherein the LIC coding mode uses a linear model of illumination changes in the current block during the conversion. In another example aspect, a video processing method is disclosed. The video processing method comprises: maintaining a table that includes entries that represent a past history of motion information used for a conversion between a current block of a video comprising video blocks and a coded representation of the video, wherein a combined inter-intra-prediction (CIIP) flag is stored for each entry of the motion information; and performing the conversion of the current block based on the entries in the table, wherein the CIIP flag indicates a use of a combined spatial and temporal redundancy coding tool for the conversion. In another example aspect, a video processing method is disclosed. The video processing method comprises: maintaining a table that includes entries that represent a past history of motion information used for a conversion between a current block of a video comprising video blocks and a coded representation of the video, wherein a local illumination compensation (LIC) flag is stored for each entry of the motion information; and performing the conversion of the current block based on the entries in the table, wherein the LIC flag indicates a use of an LIC coding tool that uses a linear model of illumination changes for the conversion. In another example aspect, a video processing method is disclosed. The video processing method comprises: In yet another representative aspect, the various techniques described herein may be embodied as a computer program product stored on a non-transitory computer readable media. The computer program product includes program code for carrying out the methods described herein. In yet another representative aspect, a video decoder apparatus may implement a method as described herein. The details of one or more implementations are set forth in the accompanying attachments, the drawings, and the description below. Other features will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an example of a derivation process for merge candidates list construction. FIG. 2 shows example positions of spatial merge candidates. FIG. 3 shows examples of candidate pairs considered for redundancy check of spatial merge candidates. FIG. 4 shows exam