Encoding and decoding methods and apparatus

1 . A method for decoding comprising:

determining, from a video, if a group of blocks level weighted prediction mode is enabled for a current block, the group of blocks level weighted prediction mode being such that, for a current block of a group of blocks of a current picture on which is applied the group of blocks level weighted prediction mode, a residual block is based on a difference between the current block and either a weighted version of a reference block or a weighted average of a plurality of reference blocks calculated using weighting information, each reference block being extracted from a reference picture different from the current picture, the weighting information being identical for each block of the group of blocks on which is applied the group of blocks level weighted prediction mode; and

responsive to the group of blocks level weighted prediction mode being enabled, modifying a part of a reconstruction process of the current block related to at least another prediction tool of a set of tools comprising a Combined Intra and Inter Prediction, or a tool in which motion information used for motion compensation is refined based on an optical flow model;

wherein the group of blocks level weighted prediction mode is enabled when a reference image providing a reference block for inter prediction of the current block is associated to a weight different from a default weight.

2 . The method of claim 1 , wherein the reconstruction process of the current block is modified by preventing an application of the at least another prediction tool even though syntax elements related to the at least another prediction tool indicate that the at least another prediction tool needs to be applied to the current block.

3 . The method of claim 1 , wherein the reconstruction process of the current block is modified by replacing an application of the at least another prediction tool to the current block specified in a video stream representative of the video by an application of an alternative inter prediction tool.

4 . The method of claim 3 , wherein the reconstruction process of the current block is modified by changing an interpretation of a syntax element related to the at least another prediction tool by changing a semantic of the syntax element.

5 . The method of claim 1 , wherein the reconstruction process of the current block is modified by changing an order of execution of the group of blocks level weighted prediction mode and of the at least another prediction tool.

6 . A method for encoding comprising:

determining if a group of blocks level weighted prediction mode is enabled for a current block, the group of blocks level weighted prediction mode being such that, for a current block of a group of blocks of a current picture on which is applied the group of blocks level weighted prediction mode, a residual block is based on a difference between the current block and either a weighted version of a reference block or a weighted average of a plurality of reference blocks calculated using weighting information, each reference block being extracted from a reference picture different from the current picture, the weighting information being identical for each block of the group of blocks on which is applied the group of blocks level weighted prediction mode; and

responsive to the group of blocks level weighted prediction mode being enabled, modifying a part of an encoding process of the current block related to at least another prediction tool of a set of tools comprising a Combined Intra and Inter Prediction, or a tool in which motion information used for motion compensation is refined based on an optical flow model;

wherein the group of blocks level weighted prediction mode is enabled when a reference image providing a reference block for inter prediction of the current block is associated to a weight different from a default weight.

7 . A non-transitory information storage medium storing program code instructions for execution by a processor, which, when implemented, cause the processor to perform the decoding method according to claim 1 .

8 . A device for decoding comprising:

electronic circuitry configured to:

determine, from a video, if a group of blocks level weighted prediction mode is enabled for a current block, the group of blocks level weighted prediction mode being such that, for a current block of a group of blocks of a current picture on which is applied the group of blocks level weighted prediction mode, a residual block is based on a difference between the current block and either a weighted version of a reference block or a weighted average of a plurality of reference blocks calculated using weighting information, each reference block being extracted from a reference picture different from the current picture, the weighting information being identical for each block of the group of blocks on which is applied the group of blocks level weighted prediction mode; and

modify, responsive to the group of blocks level weighted prediction mode being enabled, a part of a reconstruction process of the current block related to at least another prediction tool of a set of tools comprising a Combined Intra and Inter Prediction, or a tool in which motion information used for motion compensation is refined based on an optical flow model;

wherein the group of blocks level weighted prediction mode is enabled when a reference image providing a reference block for inter prediction of the current block is associated to a weight different from a default weight.

9 . The device of claim 8 , wherein the reconstruction process of the current block is modified by preventing an application of the at least another prediction tool even though syntax elements related to the at least another prediction tool indicates that the at least another prediction tool needs to be applied to the current block.

10 . The device of claim 8 , wherein the reconstruction process of the current block is modified by replacing an application of the at least another prediction tool to the current block specified in a video stream representative of the video by an application of an alternative inter prediction tool.

11 . The device of claim 10 , wherein the reconstruction process of the current block is modified by changing an interpretation of a syntax element related to the at least another prediction tool by changing a semantic of the syntax element.

12 . The device of claim 8 , wherein the reconstruction process of the current block is modified by changing an order of execution of the group of blocks level weighted prediction mode and of the at least another prediction tool.

13 . A device for encoding comprising:

electronic circuitry configured to:

determine if a group of blocks level weighted prediction mode is enabled for a current block, the group of blocks level weighted prediction mode being such that, for a current block of a group of blocks of a current picture on which is applied the group of blocks level weighted prediction mode, a residual block is based on a difference between the current block and either a weighted version of a reference block or a weighted average of a plurality of reference blocks calculated using weighting information, each reference block being extracted from a reference picture different from the current picture, the weighting information being identical for each block of the group of blocks on which is applied the group of blocks level weighted prediction mode; and

modify, responsive to the group of blocks level weighted prediction mode being enabled, a part of an encoding process of the current block related to at least another prediction tool of a set of tools comprising a Combined Intra and Inter Prediction, or a tool in which motion information used for motion compensation is refined based on an optical flow model;

wherein the group of blocks level weighted prediction mode is enabled when a reference image providing a reference block for inter prediction of the current block is associated to a weight different from a default weight.

14 . A non-transitory information storage medium storing program code instructions for execution by a processor, which, when implemented, cause the processor to perform the encoding method according to claim 6 .