Method and apparatus for video decoding, and method and apparatus for video encoding
Provided are a method and apparatus for performing intra prediction, in a video encoding and decoding procedure, by configuring an additional mode set based on most probable mode (MPM) modes of a current block, and determining an intra prediction mode of the current block, based on the MPM modes and the additional mode set. To solve the technical problems, a video decoding method provided in the present disclosure includes configuring an additional mode set based on MPM modes of a current block; determining an intra prediction mode of the current block, based on the MPM modes and the additional mode set; and performing intra prediction on the current block, based on the intra prediction mode.
1. A video decoding method comprising:
configuring an additional mode set based on most probable mode (MPM) modes of a current block;
if a flag, obtained from a bitstream, indicates that the additional mode set is used in determining an intra prediction mode of the current block, determining an additional mode among a plurality of additional modes included in the additional mode set as the intra prediction mode of the current; and performing intra prediction on the current block, based on the intra prediction mode of the current block,
performing intra prediction on the current block, based on the intra prediction mode of the current block,
wherein types of the MPM modes are all angular modes, the additional mode set comprises at least one of a DC mode, an intra prediction mode having an index increased by 1 from an index of one of the MPM modes, an intra prediction mode having an index decreased by 1 from the index of the one of the MPM modes, and an intra prediction mode having an index decreased by 2 from the index of the one of the MPM modes.
2. A video decoding apparatus comprising:
a memory; and
at least one processor connected with the memory,
wherein the at least one processor is configured to
configure an additional mode set based on most probable mode (MPM) modes of a current block,
if a flag, obtained from a bitstream, indicates that the additional mode set is used in determining an intra prediction mode of the current block, determine an additional mode among a plurality of additional modes included in the additional mode set as the intra prediction mode of the current block, and
perform intra prediction on the current block, based on the intra prediction mode of the current block,
wherein, when the types of the MPM modes are all angular modes, the additional mode set comprises at least one of a DC mode, an intra prediction modes having an index increased by 1 from index of the one of the MPM modes, intra prediction modes having an index decreased by 1 from the index of the one of the MPM modes, and intra prediction modes having an index decreased by 2 from the index of the one of the MPM modes.