Video encoding method, video decoding method, video encoding device, video decoding device, and program

1. A video encoding method, implemented by a processor, including an entropy encoding step of entropy-encoding a quadtree split flag, a skip flag, a binary tree split flag, and a binary tree split direction flag, the video encoding method comprising:

an entropy encoding control step of, in the case where the skip flag of a block of an end node in a quadtree structure indicates that the binary tree split flag succeeds, causing the entropy encoding step to entropy-encode the binary tree split flag and the binary tree split direction flag, and in the case where the skip flag of the block of the end node in the quadtree structure indicates that the binary tree split flag does not succeed, causing the entropy encoding step not to entropy-encode the binary tree split flag and the binary tree split direction flag.

2. A video decoding method, implemented by a processor, including an entropy decoding step of entropy-decoding a quadtree split flag, a skip flag, a binary tree split flag, and a binary tree split direction flag, the video decoding method comprising:

an entropy decoding control step of, in the case where the skip flag of a block of an end node in a quadtree structure indicates that the binary tree split flag succeeds, causing the entropy decoding step to entropy-decode the binary tree split flag and the binary tree split direction flag, and in the case where the skip flag of the block of the end node in the quadtree structure indicates that the binary tree split flag does not succeed, causing the entropy decoding step not to entropy-decode the binary tree split flag and the binary tree split direction flag.

3. The video decoding method according to claim 2 ,

wherein in the entropy decoding control step, in the case where the skip flag of the block of the end node in the quadtree structure indicates that the binary tree split flag does not succeed, the binary tree split flag that is not entropy-decoded is interpreted as indicating that partitioning based on a binary tree structure is not performed.

4. A video encoding device comprising:

a hardware including at least a processor,

the hardware implements,

an entropy encoding unit which entropy-encodes at least a quadtree split flag, a skip flag, a binary tree split flag, and a binary tree split direction flag; and

an entropy encoding control unit which controls the entropy encoding unit,

wherein the entropy encoding control unit, in the case where the skip flag of a block of an end node in a quadtree structure indicates that the binary tree split flag succeeds, causes the entropy encoding unit to entropy-encode the binary tree split flag and the binary tree split direction flag, and in the case where the skip flag of the block oft the end node in the quadtree structure indicates that the binary tree split flag does not succeed, causes the entropy encoding unit not to entropy-encode the binary tree split flag and the binary tree split direction flag.

5. A video decoding device comprising:

an entropy decoding unit which entropy-decodes at least a quadtree split flag, a skip flag, a binary tree split flag, and a binary tree split direction flag; and

an entropy decoding control unit which controls the entropy decoding unit,

wherein the entropy decoding control unit, in the case where the skip flag of a block of an end node in a quadtree structure indicates that the binary tree split flag succeeds, causes the entropy decoding unit to entropy-decode the binary tree split flag and the binary tree split direction flag, and in the case where the skip flag of the block of the end node in the quadtree structure indicates that the binary tree split flag does not succeed, causes the entropy decoding unit not to entropy-decode the binary tree split flag and the binary tree split direction flag.

6. The video decoding device according to claim 5 ,

wherein in the case where the skip flag of the block of the end node in the quadtree structure indicates that the binary tree split flag does not succeed, the entropy decoding control unit interprets the binary tree split flag that is not entropy-decoded, as indicating that partitioning based on a binary tree structure is not performed.

7. A non-transitory computer readable information recording medium storing a video encoding program for causing a computer to execute a process including an entropy encoding process of entropy-encoding a quadtree split flag, a skip flag, a binary tree split flag, and a binary tree split direction flag,

the video encoding program further causing the computer to execute, in the case where the skip flag of a block of an end node in a quadtree structure indicates that the binary tree split flag succeeds, entropy-encoding the binary tree split flag and the binary tree split direction flag, and in the case where the skip flag of the block of the end node in the quadtree structure indicates that the binary tree split flag does not succeed, not entropy-encoding the binary tree split flag and the binary tree split direction flag.

8. A non-transitory computer readable information recording medium storing a video decoding program for causing a computer to execute a process including an entropy decoding process of entropy-decoding a quadtree split flag, a skip flag, a binary tree split flag, and a binary tree split direction flag,

the video decoding program further causing the computer to execute, in the case where the skip flag of a block of an end node in a quadtree structure indicates that the binary tree split flag succeeds, entropy decoding the binary tree split flag and the binary tree split direction flag, and in the case where the skip flag of the block of the end node in the quadtree structure indicates that the binary tree split flag does not succeed, not entropy decoding the binary tree split flag and the binary tree split direction flag.

9. The information recording medium according to claim 8 ,

wherein the video decoding program further causing the computer to, in the case where the skip flag of the block of the end node in the quadtree structure indicates that the binary tree split flag does not succeed, interpret the binary tree split flag that is not entropy-decoded, as indicating that partitioning based on a binary tree structure is not performed.