Harmonization between local illumination compensation and inter prediction coding
A video processing method is provided to include: performing a determination, for a conversion between a current block of a video and a coded representation of the video, that a generalized bi prediction (GBI) tool or a multi-hypothesis inter prediction tool is enabled for the conversion or a local illumination compensation (LIC) tool being enabled for the conversion, and performing the conversion based on the determination. The LIC tool includes using a linear model of illumination changes in the current block during the conversion.
1. A method for video processing, comprising:
determining to use a local illumination compensation (LIC) tool with a multi-hypothesis prediction tool for a conversion between a current block of a video and a bitstream of the video; and
performing the conversion based on the determining,
wherein the LIC tool includes using a linear model of illumination changes in the current block during the conversion, and
wherein the current block is predicted with both additional motion information and an AMVP mode and wherein the LIC flag is applied to both the AMVP mode and the additional motion information.
2. The method of claim 1 , wherein an LIC flag is signaled for multi-hypothesis advanced motion vector prediction (AMVP) and merge mode.
3. The method of claim 2 , wherein the LIC flag is applied to both an AMVP mode and a merge mode or only to the AMVP mode.
4. The method of claim 1 , wherein an LIC flag is not signaled and the LIC is disabled for an AMVP mode.
5. The method of claim 1 , wherein an LIC flag is inherited from corresponding merge candidates for multi-hypothesis merge mode.
6. The method of claim 1 , wherein an LIC flag is signaled for multi-hypothesis inter prediction mode.
7. The method of claim 6 , wherein the current block is predicted with both additional motion information and either a merge mode or UMVE (Ultimate Motion Vector Expression) mode and wherein the LIC flag is applied to both the additional information and either the merge mode or the additional motion information or only to the additional motion information.
8. The method of claim 6 , wherein the current block is predicted with both additional motion information and either a merge mode or UMVE (Ultimate Motion Vector Expression) mode and wherein the LIC flag is not signaled and disabled for the additional motion information.
9. The method of claim 7 , wherein different LIC parameters are derived or inherited for the merge mode, the UMVE mode, the AMVP mode, and the additional motion information.
10. The method of claim 1 , wherein LIC is applied to certain prediction signals that are less than all prediction signals in case that a multi-hypothesis prediction is applied to the current block.
11. The method of claim 1 , wherein one or more flags are signaled or derived to indicate a usage of LIC in case that a multi-hypothesis prediction is applied to the current block.
12. An apparatus in a video system comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to:
determine to use a local illumination compensation (LIC) tool with a multi-hypothesis prediction tool for a conversion between a current block of a video and a bitstream of the video; and
perform the conversion based on the determining,
wherein the LIC tool includes using a linear model of illumination changes in the current block during the conversion, and
wherein the current block is predicted with both additional motion information and an AMVP mode and wherein the LIC flag is applied to both the AMVP mode and the additional motion information.
13. The apparatus of claim 12 , wherein an LIC flag is signaled for multi-hypothesis advanced motion vector prediction (AMVP) and merge mode.
14. The apparatus of claim 13 , wherein the LIC flag is applied to both an AMVP mode and a merge mode or only to the AMVP mode.
15. The apparatus of claim 12 , wherein an LIC flag is not signaled and the LIC is disabled for an AMVP mode.
16. The apparatus of claim 12 , wherein an LIC flag is inherited from corresponding merge candidates for multi-hypothesis merge mode.
17. The apparatus of claim 12 , wherein an LIC flag is signaled for multi-hypothesis inter prediction mode.
18. A non-transitory computer-readable storage medium storing instructions that cause a processor to:
determine to use a local illumination compensation (LIC) tool with a multi-hypothesis prediction tool for a conversion between a current block of a video and a bitstream of the video; and
perform the conversion based on the determining,
wherein the LIC tool includes using a linear model of illumination changes in the current block during the conversion, and
wherein the current block is predicted with both additional motion information and an AMVP mode and wherein the LIC flag is applied to both the AMVP mode and the additional motion information.
19. 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:
determining to use a local illumination compensation (LIC) tool with a multi-hypothesis prediction tool for a conversion between a current block of a video and a bitstream of the video; and
generating the bitstream based on the determining,
wherein the LIC tool includes using a linear model of illumination changes in the current block during the conversion, and
wherein the current block is predicted with both additional motion information and an AMVP mode and wherein the LIC flag is applied to both the AMVP mode and the additional motion information.
20. The apparatus of claim 17 , wherein the current block is predicted with both additional motion information and either a merge mode or UMVE (Ultimate Motion Vector Expression) mode and wherein the LIC flag is applied to both the additional information and either the merge mode or the additional motion information or only to the additional motion information.