Encoding method based on encoding order change and device therefor, and decoding method based on encoding order change and device thprefor

Abstract

Provided is a video decoding method including obtaining split information indicating whether a current block is to be split; and when the split information indicates that the current block is to be split, splitting the current block into at least two lower blocks, obtaining encoding order information indicating an encoding order of the at least two lower blocks of the current block from the bitstream, determining a decoding order of the at least two lower blocks based on the encoding order information, and decoding the at least two lower blocks according to the decoding order.

1 . A video decoding method comprising:
 obtaining, from a bitstream, encoding order information indicating a decoding order of at least two coding units split from a current coding unit, the at least two coding units including horizontally neighboring coding units;   determining whether the decoding order of the at least two coding units is a first order from a left coding unit to a right coding unit, among the horizontally neighboring coding units, or a second order from the right coding unit to the left coding unit, based on the encoding order information; and   decoding the horizontally neighboring coding units according to the first order or the second order,   wherein the decoding of the horizontally neighboring coding units comprises:   when the right coding unit is decoded prior to the left coding unit, among the horizontally neighboring coding units, determining a context model for the left coding unit based on whether a width or a height of the right coding unit is greater than a width or a height of the left coding unit;   obtaining, from the bitstream, split information of the left coding unit, by performing entropy decoding using the context model; and   when the split information indicates a split of the left coding unit, splitting the left coding unit into two or three coding units, vertically or horizontally; and   when the split information indicates a non-split of the left coding unit, decoding the left coding unit.   
     
     
         2 . A video decoding device comprising:
 an encoding order determiner configured to obtain, from a bitstream, encoding order information indicating a decoding order of at least two coding units split from a current coding unit, the at least two coding units including horizontally neighboring coding units, and determine whether the decoding order of the at least two coding units is a first order from a left coding unit to a right coding unit, among the horizontally neighboring coding units, or a second order from the right coding unit to the left coding unit, based on the encoding order information; and   a decoder configured to decode the horizontally neighboring coding units according to the first order or the second order,   characterized in that:   when the right coding unit is decoded prior to the left coding unit, among the horizontally neighboring coding units, according to the second order, the decoder determines a context model for the left coding unit based on whether a width or a height of the right coding unit is greater than a width or a height of the left coding unit, and obtains, from the bitstream, split information of the left coding unit, by performing entropy decoding using the context model,   when the split information indicates a split of the left coding unit, the decoder splits the left coding unit into two or three coding units, vertically or horizontally, and   when the split information indicates a non-split of the left coding unit, the decoder decodes the left coding unit.   
     
     
         3 . A video encoding method comprising:
 determining an encoding order of horizontally neighboring lower coding units, among at least two coding units split from a current coding unit, the at least two coding units including horizontally neighboring coding units;   generating encoding order information indicating whether the encoding order of the horizontally neighboring coding units is a first order from a left coding unit to a right coding unit, among the horizontally neighboring coding units, or a second order from the right coding unit to the left coding unit;   when the right coding unit is coded prior to the left coding unit, among the horizontally neighboring coding units, according to the second order, determining a context model for the left coding unit based on whether a width or a height of the right coding unit is greater than a width or a height of the left coding unit;   performing entropy coding on split information of the left coding unit by using the context model, the split information indicating whether the left coding unit is split into two or three coding units vertically or horizontally, or not split into smaller coding units; and   
       outputting a bitstream comprising the encoding order information and the split information of the left coding unit.