Method and apparatus for processing video signal

1 . A method of decoding a video, the method comprising:

decoding a coded block flag indicating whether at least one non-zero transform coefficient exists in a current block;

decoding transform coefficients of the current block based on the coded block flag indicating that the at least one non-zero transform coefficient exists in the current block;

obtaining inverse-quantized transform coefficients by performing inverse-quantization on the transform coefficients of the current block;

determining, based on a transform skip flag indicating whether to skip inverse-transform, whether to skip the inverse-transform for the current block or not;

obtaining residual samples of the current block by skipping or performing the inverse-transform on the inverse-quantized transform coefficients in the current block; and

obtaining reconstruction sample by summing the residual samples and prediction samples,

wherein, in response to a case where the current block is one of two partitions generated by binary-partitioning a coding block in either a horizontal direction or a vertical direction, the transform skip flag is not parsed from a bitstream and it is determined not to skip the inverse-transform for the current block.

2 . The method of claim 1 , wherein the transform coefficients included in the current block are obtained based on a pre-defined scanning order, and

wherein the pre-defined scanning order is a diagonal scanning order.

3 . The method of claim 2 , wherein the transform coefficients included in the current block are obtained in units of sub-blocks,

wherein a shape of a sub-block is adaptively determined based on a shape of the current block when the current block is constituted with a pre-determined number of samples, and

wherein the pre-determined number is 16, 32 or 64.

4 . The method of claim 1 , wherein when it is determined not to skip the inverse-transform, the method further comprises determining a horizontal transform type and a vertical transform type of the current block, and

wherein the horizontal transform type and the vertical transform type are determined as a DCT (Discrete Cosine Transform) basis kernel or a DST (Discrete Sine Transform) basis kernel.

5 . A method of encoding a video, the method comprising:

obtaining residual samples of a current block by subtracting prediction samples from original samples;

obtaining transform coefficients by skipping or performing transform on the residual samples of the current block;

obtaining quantized transform coefficients by performing quantization on the transform coefficients;

encoding the quantized transform coefficients of the current block;

encoding a coded block flag indicating whether a non-zero quantized transform coefficient exists in the current block,

wherein it is determined whether to encode a transform skip flag indicating whether the transform is skipped or not, and

wherein, in response to a case where the current block is one of two partitions generated by binary-partitioning a coding block in either a horizontal direction or a vertical direction, it is determined not to skip the transform for the current block and the transform skip flag is not encoded into a bitstream.

6 . The method of claim 5 , wherein the quantized transform coefficients included in the current block are encoded based on a pre-defined scanning order, and

wherein the pre-defined scanning order is a diagonal scanning order.

7 . The method of claim 6 , wherein the quantized transform coefficients included in the current block are encoded in units of sub-blocks,

wherein a shape of a sub-block is adaptively determined based on a shape of the current block when the current block is constituted with a pre-determined number of samples, and

wherein the pre-determined number is 16, 32 or 64.

8 . The method of claim 5 , wherein the method further comprises determining a horizontal transform type and a vertical transform type of the current block, and

wherein the horizontal transform type and the vertical transform type are determined as a DCT (Discrete Cosine Transform) basis kernel or a DST (Discrete Sine Transform) basis kernel.

9 . 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 comprising:

obtaining residual samples of a current block by subtracting prediction samples from original samples;

obtaining transform coefficients by skipping or performing transform on the residual samples of the current block;

obtaining quantized transform coefficients by performing quantization on the transform coefficients;

encoding the quantized transform coefficients of the current block; and

encoding a coded block flag indicating whether a non-zero quantized transform coefficient exists in the current block,

wherein it is determined whether to encode a transform skip flag indicating whether the transform is skipped or not, and

wherein, in response to a case where the current block is one of two partitions generated by binary-partitioning a coding block in either a horizontal direction or a vertical direction, it is determined not to skip the transform for the current block and the transform skip flag is not encoded into the data stream.