A method, computer program, and computer system is provided for coding video data. Video data including one or more blocks is received. A current block coded in intra block copy mode or string matching mode is predicted from among the one or more blocks based on a coded block vector or a string offset vector corresponding to one or more spatial neighboring or non-neighboring blocks from among the one or more blocks. The video data is decoded based on the predicted current block.

A method, computer program, and computer system is provided for coding video data. Video data including one or more blocks is received. A current block coded in intra block copy mode or string matching mode is predicted from among the one or more blocks based on a coded block vector or a string offset vector corresponding to one or more spatial neighboring or non-neighboring blocks from among the one or more blocks. The video data is decoded based on the predicted current block.

A method of video processing is described. The method includes: making a first determination about whether a collocated video block of a video block of a video is coded using an inter coding mode or a non-inter coding mode; making a second determination, based on the first determination, about availability of motion vectors of the collocated video block or a mode of derivation of motion vectors for the collocated video block; and performing a conversion between the video block and a coded representation of the video based on the second determination.

A method of video processing is described. The method includes: making a first determination about whether a collocated video block of a video block of a video is coded using an inter coding mode or a non-inter coding mode; making a second determination, based on the first determination, about availability of motion vectors of the collocated video block or a mode of derivation of motion vectors for the collocated video block; and performing a conversion between the video block and a coded representation of the video based on the second determination.

The present invention relates to an encoding method and decoding method, and a device using the same. The encoding method according to the present invention comprises the steps of: specifying an intra prediction mode for a current block; and scanning a residual signal by intra prediction of the current block, wherein the step of scanning the residual signal can determine a scanning type for a luminance signal and a chroma signal of the current block according to an intra prediction mode for a luminance sample of the current block.

The present invention relates to an encoding method and decoding method, and a device using the same. The encoding method according to the present invention comprises the steps of: specifying an intra prediction mode for a current block; and scanning a residual signal by intra prediction of the current block, wherein the step of scanning the residual signal can determine a scanning type for a luminance signal and a chroma signal of the current block according to an intra prediction mode for a luminance sample of the current block.

Technology for improving coding efficiency by performing a block split suitable for picture coding and decoding is provided. A picture decoding device includes a spatial candidate derivation unit configured to derive a spatial candidate from inter prediction information of a block neighboring a decoding target block and register the derived spatial candidate as a candidate in a first candidate list, a history-based candidate derivation unit configured to generate a second candidate list by adding a history-based candidate included in a history-based candidate list as a candidate to the first candidate list, a candidate selection unit configured to select a selection candidate from candidates included in the second candidate list; and an inter prediction unit configured to perform inter prediction using the selection candidate. The history-based candidate derivation unit switches between whether or not a history-based candidate overlapping a candidate included in the first candidate list is added in accordance with a prediction mode.

Technology for improving coding efficiency by performing a block split suitable for picture coding and decoding is provided. A picture decoding device includes a spatial candidate derivation unit configured to derive a spatial candidate from inter prediction information of a block neighboring a decoding target block and register the derived spatial candidate as a candidate in a first candidate list, a history-based candidate derivation unit configured to generate a second candidate list by adding a history-based candidate included in a history-based candidate list as a candidate to the first candidate list, a candidate selection unit configured to select a selection candidate from candidates included in the second candidate list; and an inter prediction unit configured to perform inter prediction using the selection candidate. The history-based candidate derivation unit switches between whether or not a history-based candidate overlapping a candidate included in the first candidate list is added in accordance with a prediction mode.

This application provides a chroma block prediction method and apparatus. The method includes: obtaining a maximum luma value and a minimum luma value based on luma samples corresponding to neighboring samples of a target chroma block, and calculating a first difference between the maximum luma value and the minimum luma value; if the first difference is not equal to 0, processing the first difference based on a quantity of significant bits of the first difference and a first preset bit depth to obtain a second difference; and determining, based on a first chroma value, a second chroma value, and the second difference, an intra prediction model parameter corresponding to the target chroma block, and determining prediction information of the target chroma block based on the intra prediction model parameter and luma reconstruction information corresponding to the target chroma block.

This application provides a chroma block prediction method and apparatus. The method includes: obtaining a maximum luma value and a minimum luma value based on luma samples corresponding to neighboring samples of a target chroma block, and calculating a first difference between the maximum luma value and the minimum luma value; if the first difference is not equal to 0, processing the first difference based on a quantity of significant bits of the first difference and a first preset bit depth to obtain a second difference; and determining, based on a first chroma value, a second chroma value, and the second difference, an intra prediction model parameter corresponding to the target chroma block, and determining prediction information of the target chroma block based on the intra prediction model parameter and luma reconstruction information corresponding to the target chroma block.