Concept of using one or multiple look up tables to store motion information of previously coded in order and use them to code following blocks

1. A method of processing video data, comprising:

deriving motion information for a first video block, wherein one or more candidates of one of a plurality of tables are selectively checked in an order and whether to add the one or more candidates or at least one motion vector of the one or more candidates to a motion candidate list or not is based on a result of the checking during a motion candidate list construction process which is used to derive the motion information for the first video block, wherein each table of the plurality of tables includes candidates derived from previously coded video blocks that are coded prior to the first video block; and

performing a conversion between the first video block and a bitstream of a video including the first video block based on the motion information,

wherein an arrangement of the one or more candidates in a table is based on a sequence of addition of the one or more candidates into the table,

wherein the method further comprises:

determining whether to use the motion information for the first video block to update the one of the plurality of tables; and

deriving, based on the one of the plurality of updated tables, motion information for a subsequent video block to perform the conversion for the subsequent video block,

wherein a first table of the plurality of tables is updated with motion information only from blocks coded with an inter mode.

2. The method of claim 1 , wherein the first video block is coded using an inter-coding mode which uses reference samples from at least one different picture.

3. The method of claim 1 , wherein the determining comprises:

determining, based on properties of the first video block, whether using the motion information of the first video block to update the one of the plurality of tables.

4. The method of claim 1 , wherein checking the one or more candidates of the one of the plurality of tables is determined at least based on a number of candidates in the motion candidate list not reaching a maximally allowed number.

5. The method of claim 1 , wherein the motion candidate list is one of a merge candidate list and an Advanced Motion Vector Prediction (AMVP) candidate list.

6. The method of claim 1 , wherein the motion information includes at least one of: a prediction direction, a reference picture index, motion vector values, intensity compensation flag, affine flag, motion vector difference precision, filter parameters, motion vector difference value, or indications of blocks where the motion information is coming from.

7. The method of claim 1 , wherein a second table of the plurality of tables is updated with motion information from blocks coded with intra block copy mode.

8. The method of claim 1 , wherein the conversion includes encoding the first video block into the bitstream.

9. The method of claim 1 , wherein the conversion includes decoding the first video block from the bitstream.

10. 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:

derive motion information for a first video block, wherein one or more candidates of a plurality of tables are selectively checked in an order and whether to add the one or more candidates or at least one motion vector of the one or more candidates to a motion candidate list or not is based on a result of the checking during a motion candidate list construction process which is used to derive the motion information for the first video block, wherein each table of the plurality of tables includes candidates derived from previously coded video blocks that are coded prior to the first video block; and

perform a conversion between the first video block and a bitstream of a video including the first video block based on the motion information,

wherein an arrangement of the candidates in a table is based on a sequence of addition of the candidates into the table,

wherein the instructions upon execution by the processor, further cause the processor to:

determine whether to use the motion information for the first video block to update the one of the plurality of tables; and

derive, based on the one of the plurality of updated tables, motion information for a subsequent video block to perform the conversion for the subsequent video block,

wherein a first table of the plurality of tables is updated with motion information only from blocks coded with an inter mode.

11. The apparatus of claim 10 , wherein the first video block is encoded using an inter-coding mode which uses reference samples from at least one different picture.

12. The apparatus of claim 10 , wherein the motion candidate list is one of a merge candidate list and an Advanced Motion Vector Prediction (AMVP) candidate list.

13. The apparatus of claim 10 , wherein the motion information includes at least one of: a prediction direction, a reference picture index, motion vector values, intensity compensation flag, affine flag, motion vector difference precision, filter parameters, or motion vector difference value or indications of blocks where the motion information is coming from.

14. A non-transitory computer-readable storage medium storing instructions that cause a processor to:

derive motion information for a first video block, wherein one or more candidates of a plurality of tables are selectively checked in an order and whether to add the one or more candidates or at least one motion vector of the one or more candidates to a motion candidate list or not is based on a result of the checking during a motion candidate list construction process which is used to derive the motion information for the first video block, wherein each table of the plurality of tables includes candidates derived from previously coded video blocks that are coded prior to the first video block; and

perform a conversion between the first video block and a bitstream of a video including the first video block based on the motion information,

wherein an arrangement of the candidates in a table is based on a sequence of addition of the candidates into the table,

wherein the instructions upon execution by the processor, further cause the processor to:

determine whether to use the motion information for the first video block to update the one of the plurality of tables; and

derive, based on the one of the plurality of updated tables, motion information for a subsequent video block to perform the conversion for the subsequent video block,

wherein a first table of the plurality of tables is updated with motion information only from blocks coded with an inter mode.

15. 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:

deriving motion information for a first video block, wherein one or more candidates of a plurality of tables are selectively checked in an order and whether to add the one or more candidates or at least one motion vector of the one or more candidates to a motion candidate list or not is based on a result of the checking during a motion candidate list construction process which is used to derive the motion information for the first video block, wherein each table of the plurality of tables includes candidates derived from previously coded video blocks that are coded prior to the first video block; and

generating the bitstream from the first video block based on the motion information,

wherein an arrangement of the candidates in a table is based on a sequence of addition of the motion candidates into the table,

wherein the method further comprises:

determining whether to use the motion information for the first video block to update the one of the plurality of tables; and

deriving, based on the one of the plurality of updated tables, motion information for a subsequent video block to generate a bitstream perform a conversion for the subsequent video block,

wherein a first table of the plurality of tables is updated with motion information only from blocks coded with an inter mode.

16. The non-transitory computer-readable storage medium of claim 14 , wherein the first video block is coded using an inter-coding mode which uses reference samples from at least one different picture.

17. The non-transitory computer-readable storage medium of claim 14 , wherein the motion candidate list is one of a merge candidate list and an Advanced Motion Vector Prediction (AMVP) candidate list.

18. The non-transitory computer-readable recording medium of claim 15 , wherein the first video block is coded using an inter-coding mode which uses reference samples from at least one different picture.

19. The non-transitory computer-readable recording medium of claim 15 , wherein the motion candidate list is one of a merge candidate list and an Advanced Motion Vector Prediction (AMVP) candidate list.

20. The non-transitory computer-readable storage medium of claim 14 , wherein checking the one or more candidates of the one of the plurality of tables is determined at least based on a number of candidates in the motion candidate list not reaching a maximally allowed number.