Apparatus and method for video encoding or decoding

A method for decoding video data, the method comprising:

• decoding, from a bitstream, position information which indicates one reference line selected among a plurality of reference lines neighboring with a current block of the video data;
• decoding, from the bitstream, intra mode data which specifies an intra mode of the current block for predicting the current block;
• predicting the current block using the reference line indicated by the position information based on the intra mode of the current block to generate a predicted block of the current block;
• decoding, from the bitstream, a residual block of the current block;
• and
• reconstructing the current block based on the predicted block and the residual block,
• wherein the decoding of intra mode data comprises, when the intra mode of the current block is an MPM, decoding one or more syntax elements which specify the intra mode of the current block among a plurality of MPMs,
• and wherein the one or more syntax elements include at least one of:
• a first syntax element indicating which MPM group of the two MPM groups the intra mode of the current block belongs to, wherein one of the two MPM groups includes at least Planar mode and the other of two MPM groups includes intra modes derived from reconstructed blocks neighboring with the current block;
• and
• a second syntax element indicating one of the MPMs belonging to the MPM group indicated by the first syntax element.

A non-transitory computer readable medium storing a bitstream generated by encoding video data, the bitstream generated by processes of:

• encoding position information which indicates one reference line selected among a plurality of reference lines neighboring with a current block of the video data,
• encoding intra mode data which specifies an intra mode of the current block for predicting the current block;
• predicting the current block using the reference line indicated by the position information based on the intra mode of the current block to generate a predicted block of the current block;
• generating a residual block of the current block based on the predicted block;
• and
• encoding the residual block of the current block,
• wherein the encoding of intra mode data comprises, when the intra mode of the current block is an MPM, encoding one or more syntax elements which specify the intra mode of the current block among a plurality of MPMs,
• and wherein the one or more syntax elements include at least one of:
• a first syntax element indicating which MPM group of the two MPM groups the intra mode of the current block belongs to, wherein one of the two MPM groups includes at least Planar mode and the other of two MPM groups includes intra modes derived from reconstructed blocks neighboring with the current block;
• and
• a second syntax element indicating one of the MPMs belonging to the MPM group indicated by the first syntax element.