Method and device for video signal processing

A method of decoding a video, the method comprising:

• determining a partition type of a current coding block, the current coding block being divided into a plurality of sub-blocks in response to the partition type representing horizontal partitioning or vertical partitioning;
• constructing an MPM (Most Probable Mode) list of the current coding block, the MPM list comprising MPM candidates derived based on an intra prediction mode of a neighboring block adjacent to the current coding block;
• determining an intra prediction mode of the current coding block, based on the MPM list;
• generating a prediction block for a sub-block based on the intra prediction mode of the current coding block;
• generating a residual block for the sub-block;
• and
• generating a reconstructed block based on the prediction block and the residual block,
• wherein a number of the sub-blocks generated by dividing the current coding block is adaptively determined as 2 or more depending on a size of the current coding block,
• wherein whether to perform an inverse-transform for the sub-block for generating the residual block is determined based on a transform skip flag,
• wherein, when the partition type of the current coding block is the horizontal partitioning or the vertical partitioning, the transform skip flag is not decoded from a bitstream regardless of a size of the sub-block, and
• wherein when decoding the transform skip flag is omitted, it is determined that the inverse-transform is not skipped for generating the residual block for the sub-block.

A method of encoding a video, the method comprising:

• determining a partition type of a current coding block, the current coding block being divided into a plurality of sub-blocks in response to the partition type representing horizontal partitioning or vertical partitioning;
• determining an intra prediction mode of the current coding block, the intra prediction mode being encoded based on an MPM (Most Probable Mode) list of the current coding block, the MPM list comprising MPM candidates derived based on an intra prediction mode of a neighboring block adjacent to the current coding block;
• generating a prediction block for a sub-block based on the intra prediction mode of the current coding block;
• and
• generating a residual block for the sub-block by subtracting the prediction block from an original block,
• wherein a number of the sub-blocks generated by dividing the current coding block is adaptively determined to 2 or more depending on a size of the current coding block,
• wherein when the partition type of the current coding block is the horizontal partitioning or the vertical partitioning, encoding of a transform skip flag specifying whether a transform has been skipped for the residual block or not is omitted regardless of a size of the sub-block, and
• wherein when encoding of the transform skip flag is omitted, it is determined that the transform is not skipped for the residual block.

A non-transitory computer-readable medium for storing data associated with a video signal, comprising:

• a data stream stored in the non-transitory computer-readable medium, the data stream being encoded by an encoding method which comprising:
• determining a partition type of a current coding block, the current coding block being divided into a plurality of sub-blocks in response to the partition type representing horizontal partitioning or vertical partitioning;
• determining an intra prediction mode of the current coding block, the intra prediction mode being encoded based on an MPM (Most Probable Mode) list of the current coding block, the MPM list comprising MPM candidates derived based on an intra prediction mode of a neighboring block adjacent to the current coding block;
• generating a prediction block for a sub-block based on the intra prediction mode of the current coding block;
• and
• generating a residual block for the sub-block by subtracting the prediction block from an original block,
• wherein a number of the sub-blocks generated by dividing the current coding block is adaptively determined to 2 or more depending on a size of the current coding block,
• wherein when the partition type of the current coding block is the horizontal partitioning or the vertical partitioning, encoding of a transform skip flag specifying whether a transform has been skipped for the residual block or not is omitted regardless of a size of the sub-block, and
• wherein when encoding of the transform skip flag is omitted, it is determined that the transform is not skipped for the residual block.