Video signal processing method and apparatus using multi-assumption prediction

1. A non-transitory computer-readable medium storing a bitstream, the bitstream being decoded by a decoding method,

wherein the decoding method, comprising:

determining whether a merge mode is applied to a current block;

if the merge mode is applied to the current block, obtaining a first syntax element indicating whether combined prediction is applied to the current block, the combined prediction is a prediction mode that combines inter-prediction and intra-prediction, and a mode for the intra-prediction is a planar mode;

if the first syntax element indicates that the combined prediction is not applied to the current block, obtaining a second syntax element indicating whether sub-block transform is applied to the current block, and the sub-block transform indicates a transform mode that applies transform to one of sub-blocks of the current block divided in a horizontal direction or in a vertical direction;

if the first syntax element indicates that the combined prediction is applied to the current block, reconstructing the current block based on the combined prediction; and

if the first syntax element indicates that the combined prediction is not applied to the current block and the second syntax element indicates that the sub-block transform is applied to the current block, reconstructing the current block based on the sub-block transform.

2. The non-transitory computer-readable medium storing a bitstream of claim 1 ,

wherein, if the first syntax element indicates that the combined prediction is applied to the current block, the current block is reconstructed based on a combined prediction block of the current block,

wherein the combined prediction block of the current block is obtained by performing a weighted-sum of an inter-prediction block and an intra-prediction block,

wherein the inter-prediction block is obtained by using the inter prediction for the current block, and the intra-prediction block is obtained by using the intra prediction for the current block.

3. The non-transitory computer-readable medium storing a bitstream of claim 1 ,

wherein, if the second syntax element is not present, a value of the second syntax element is inferred to be 0.

4. The non-transitory computer-readable medium storing a bitstream of claim 1 ,

wherein locations of a neighboring block referenced for the combined prediction are identical to locations of a neighboring block referenced for the intra-prediction.

5. The non-transitory computer-readable medium storing a bitstream of claim 1 ,

wherein locations of a neighboring block referenced for the combined prediction are determined based on a color component index value of the current block.

6. A video signal decoding device, the device comprising:

a processor,

wherein the processor is configured to:

determine whether a merge mode is applied to a current block;

if the merge mode is applied to the current block, obtain a first syntax element indicating whether combined prediction is applied to the current block, the combined prediction is a prediction mode that combines inter-prediction and intra-prediction, and a mode for the intra-prediction is a planar mode;

if the first syntax element indicates that the combined prediction is not applied to the current block, obtain a second syntax element indicating whether sub-block transform is applied to the current block, and the sub-block transform indicates a transform mode that applies transform to one of sub-blocks of the current block divided in a horizontal direction or in a vertical direction;

if the first syntax element indicates that the combined prediction is applied to the current block, reconstruct the current block based on the combined prediction; and

if the first syntax element indicates that the combined prediction is not applied to the current block and the second syntax element indicates that the sub-block transform is applied to the current block, reconstruct the current block based on the sub-block transform.

7. The video signal decoding device of claim 6 ,

wherein, if the first syntax element indicates that the combined prediction is applied to the current block, the current block is reconstructed based on a combined prediction block of the current block,

wherein the combined prediction block of the current block is obtained by performing a weighted-sum of an inter-prediction block and an intra-prediction block,

wherein the inter-prediction block is obtained by using the inter prediction for the current block, and the intra-prediction block is obtained by using the intra prediction for the current block.

8. The video signal decoding device of claim 6 ,

wherein, if the second syntax element is not present, a value of the second syntax element is inferred to be 0.

9. The video signal decoding device of claim 6 ,

wherein locations of a neighboring block referenced for the combined prediction are identical to locations of a neighboring block referenced for the intra-prediction.

10. The video signal decoding device of claim 6 ,

wherein locations of a neighboring block referenced for the combined prediction are determined based on a color component index value of the current block.

11. A video signal encoding device comprising:

a processor,

wherein the processor is configured to

obtain a bitstream to be decoded by a decoder using a decoding method,

wherein the decoding method comprising:

determining whether a merge mode is applied to a current block;

if the merge mode is applied to the current block, obtaining a first syntax element indicating whether combined prediction is applied to the current block, the combined prediction is a prediction mode that combines inter-prediction and intra-prediction, and a mode for the intra-prediction is a planar mode;

if the first syntax element indicates that the combined prediction is not applied to the current block, obtaining a second syntax element indicating whether sub-block transform is applied to the current block, and the sub-block transform indicates a transform mode that applies transform to one of sub-blocks of the current block divided in a horizontal direction or in a vertical direction;

if the first syntax element indicates that the combined prediction is applied to the current block, reconstructing the current block based on the combined prediction; and

if the first syntax element indicates that the combined prediction is not applied to the current block and the second syntax element indicates that the sub-block transform is applied to the current block, reconstructing the current block based on the sub-block transform.

12. The video signal encoding device of claim 11 ,

wherein, if the first syntax element indicates that the combined prediction is applied to the current block, the current block is reconstructed based on a combined prediction block of the current block,

wherein the combined prediction block of the current block is obtained by performing a weighted-sum of an inter-prediction block and an intra-prediction block,

wherein the inter-prediction block is obtained by using the inter prediction for the current block, and the intra-prediction block is obtained by using the intra prediction for the current block.

13. The video signal encoding device of claim 11 ,

wherein, if the second syntax element is not present, a value of the second syntax element is inferred to be 0.

14. The video signal encoding device of claim 11 ,

wherein locations of a neighboring block referenced for the combined prediction are identical to locations of a neighboring block referenced for the intra-prediction.

15. The video signal encoding device of claim 11 ,

wherein locations of a neighboring block referenced for the combined prediction are determined based on a color component index value of the current block.