Interaction between pairwise average merging candidates and ibc

Abstract

A method of decoding visual information from a coded representation of the visual information includes determining that a block being decoded representing a portion of an encoded picture of visual information is coded using a motion candidate associated with a motion vector, wherein the motion vector is derived as a weighted average of a plurality of motion vectors, wherein all of the plurality of motion vectors refer to a same picture type, and wherein a first picture type represents a current picture and a second picture type represents a reference pictures different from the current picture and decoding the block being decoded by using the motion candidate.

What is claimed is: 
     
         1 . A method of coding video data, comprising:
 constructing, for a first conversion between a first video block of a video and a bitstream of the video, a motion vector candidate list comprising at least one motion vector candidate; and   performing the first conversion based on the motion vector candidate list,   wherein the motion vector candidate list is constructed by applying a pair-wise averaging operation, and a pair-wise average merge candidate associated with a motion vector derived from the pair-wise averaging operation is added to the motion vector candidate list,   wherein the motion vector is derived based on a weighted average of a plurality of motion vectors, wherein all the plurality of motion vectors refer to a reference picture not identical to a first picture which includes the first video block, and   wherein the plurality of motion vectors are derived based on the first two candidates in a merge candidate list of the first video block.   
     
     
         2 . The method of  claim 1 , further comprising:
 constructing, for a second conversion between a second video block of the video and a bitstream of the video, a block vector candidate list comprising at least one block vector candidate; and   performing the second conversion based on the block vector candidate list,   wherein the block vector candidate list is constructed by excluding the pair-wise averaging operation, and   wherein a prediction of the second video block is derived from blocks of sample values of the same picture which includes the second video block, wherein the same picture is not a picture type which is indicated as a long-term reference picture.   
     
     
         3 . The method of  claim 1 , further comprising applying equal weights to all the plurality of motion vectors. 
     
     
         4 . The method of  claim 1 , wherein the pair-wise average merge candidate is a motion vector of a pair-wise average merge candidate in inter prediction mode. 
     
     
         5 . The method of  claim 4 , wherein the pair-wise average merge candidate is derived based on a weighted average of a first motion vector of a first merge candidate and a second motion vector of a second merge candidate. 
     
     
         6 . The method of  claim 1 , wherein instead of plurality of motion vectors referring to a reference picture not identical to the first picture, all the plurality of motion vectors refer to the reference picture identical to the first picture. 
     
     
         7 . The method of  claim 1 , wherein the at least one motion vector candidate is a motion vector of a sub-block in a block coded with the spatial-temporal motion vector prediction (STMVP) mode. 
     
     
         8 . The method of  claim 1 , wherein the reference picture used in the first conversion is marked as a short-term reference picture or a long-term reference picture. 
     
     
         9 . The method of  claim 1 , further comprising:
 determining, for a third conversion between a third video block of a video and a bitstream of the video, that the third video block is coded with a subblock-based temporal motion vector prediction mode; and   performing the third conversion based on the determining,   in response to a spatial neighboring block of the third video block is coded with the IBC mode, determining that motion information of the spatial neighboring block is unavailable, and identifying at least one corresponding video region in a collocated picture of the third video block without using the motion information of the spatial neighboring block.   
     
     
         10 . The method of  claim 9 , wherein the reference picture of the third video block and a reference picture of the corresponding video region in the collocated picture are marked as a same picture type. 
     
     
         11 . The method of  claim 10 , wherein the same picture type is indicated as a short-term reference picture or a long-term reference picture. 
     
     
         12 . The method of  claim 1 , wherein the first conversion includes encoding the first video block into the bitstream. 
     
     
         13 . The method of  claim 1 , wherein the first conversion includes decoding the first video block from the bitstream. 
     
     
         14 . An apparatus for coding 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:
 construct, for a first conversion between a first video block of a video and a bitstream of the video, a motion vector candidate list comprising at least one motion vector candidate; and   perform the first conversion based on the motion vector candidate list,   wherein the motion vector candidate list is constructed by applying a pair-wise averaging operation, and a pair-wise average merge candidate associated with a motion vector derived from the pair-wise averaging operation is added to the motion vector candidate list,   wherein the motion vector is derived based on a weighted average of a plurality of motion vectors, wherein all the plurality of motion vectors refer to a reference picture not identical to a first picture which includes the first video block, and   wherein the plurality of motion vectors are derived based on the first two candidates in a merge candidate list of the first video block.   
     
     
         15 . The apparatus of  claim 14 , the instructions further cause the processor to:
 construct, fora second conversion between a second video block of the video and a bitstream of the video, a block vector candidate list comprising at least one block vector candidate; and   perform the second conversion based on the block vector candidate list,   wherein the block vector candidate list is constructed by excluding the pair-wise averaging operation, and   wherein a prediction of the second video block is derived from blocks of sample values of the same picture which includes the second video block, wherein the same picture is not a picture type which is indicated as a long-term reference picture.   
     
     
         16 . The apparatus of  claim 14 , the instructions further cause the processor to apply equal weights to all the plurality of motion vectors. 
     
     
         17 . The apparatus of  claim 14 , wherein the pair-wise average merge candidate is a motion vector of a pair-wise average merge candidate in inter prediction mode. 
     
     
         18 . The apparatus of  claim 17 , wherein the pair-wise average merge candidate is derived based on a weighted average of a first motion vector of a first merge candidate and a second motion vector of a second merge candidate. 
     
     
         19 . A non-transitory computer-readable storage medium storing instructions that cause a processor to:
 construct, for a first conversion between a first video block of a video and a bitstream of the video, a motion vector candidate list comprising at least one motion vector candidate; and   perform the first conversion based on the motion vector candidate list,   wherein the motion vector candidate list is constructed by applying a pair-wise averaging operation, and a pair-wise average merge candidate associated with a motion vector derived from the pair-wise averaging operation is added to the motion vector candidate list,   wherein the motion vector is derived based on a weighted average of a plurality of motion vectors, wherein all the plurality of motion vectors refer to a reference picture not identical to a first picture which includes the first video block, and   wherein the plurality of motion vectors are derived based on the first two candidates in a merge candidate list of the first video block.   
     
     
         20 . A non-transitory computer-readable recording medium storing a bitstream which is generated by a method performed by a video processing apparatus, wherein the method comprises:
 constructing, for a first video block of a video, a motion vector candidate list comprising at least one motion vector candidate; and   generating the bitstream based on the motion vector candidate list,   wherein the motion vector candidate list is constructed by applying a pair-wise averaging operation, and a pair-wise average merge candidate associated with a motion vector derived from the pair-wise averaging operation is added to the motion vector candidate list,   wherein the motion vector is derived based on a weighted average of a plurality of motion vectors, wherein all the plurality of motion vectors refer to a reference picture not identical to a first picture which includes the first video block, and   wherein the plurality of motion vectors are derived based on the first two candidates in a merge candidate list of the first video block.