Video signal processing method and device using motion compensation
Disclosed is a video signal processing method comprising the steps of: acquiring a merge index which indicates a candidate for prediction of a current block among a plurality of candidates for the prediction of the current block, which are included in a merge candidate list; acquiring motion information of the current block on the basis of motion information corresponding to the candidate indicated by the merge index; when the motion information of the current block includes a plurality of motion vectors corresponding to a list of different reference pictures, comparing picture order count (POC) differences between each of the reference pictures corresponding to the plurality of motion vectors and the current picture including the current block; correcting the plurality of motion vectors on the basis of a result of the comparison; and reconstructing the current block on the basis of the plurality of corrected motion vectors.
1. A video signal decoding device comprising:
a processor,
wherein the processor is configured to:
obtain a first motion vector of a current block corresponding to a first reference picture and a second motion vector of the current block corresponding to a second reference picture,
obtain a first picture order count (POC) difference representing a POC difference between the first reference picture and a current picture,
obtain a second POC difference representing a POC difference between the second reference picture and the current picture,
obtain at least one of a first correction value of the first motion vector and a second correction value of the second motion vector as a first value, based on a result of comparing the first POC difference and the second POC difference, wherein the first value is a specific offset,
obtain a first corrected motion vector by correcting the first motion vector based on the first correction value,
obtain a second corrected motion vector by correcting the second motion vector based on the second correction value, and
reconstruct the current block based on the first corrected motion vector and the second corrected motion vector,
wherein the first reference picture and the second reference picture are included in a first reference picture list and a second reference picture list, respectively, and
wherein the first reference picture list and the second reference picture are different from each other.
2. The video signal decoding device of claim 1 ,
wherein the first reference picture list is used in a first higher level region in which up to one motion vector is used for a specific sample and a second higher level region in which up to two motion vectors are used for the specific sample, and
wherein the second reference picture list is not used in the first higher level region.
3. The video signal decoding device of claim 1 ,
wherein when one of the first correction value and the second correction value is obtained as the first value,
a correction value obtained as the first value is obtained earlier than a correction value not obtained as the first value.
4. The video signal decoding device of claim 3 ,
wherein when an absolute value of the first POC difference is greater than or equal to an absolute value of the second POC difference, the first correction value is obtained as the first value, and
wherein when the absolute value of the first POC difference is less than the absolute value of the second POC difference, the second correction value is obtained as the first value.
5. The video signal decoding device of claim 4 ,
wherein when the absolute value of the first POC difference is greater than or equal to the absolute value of the second POC difference,
the first corrected motion vector is obtained by adding the first value to the first motion vector,
the second corrected motion vector is obtained by adding a second value to the second motion vector, and
the second value is obtained based on the first value.
6. The video signal decoding device of claim 1 ,
wherein a value representing the first reference picture list is 0 and a value representing the second reference picture list is 1.
7. 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:
obtaining a first motion vector of a current block corresponding to a first reference picture and a second motion vector of the current block corresponding to a second reference picture;
obtaining a first picture order count (POC) difference representing a POC difference between the first reference picture and a current picture;
obtaining a second POC difference representing a POC difference between the second reference picture and the current picture;
obtaining at least one of a first correction value of the first motion vector and a second correction value of the second motion vector as a first value, based on a result of comparing the first POC difference and the second POC difference, wherein the first value is equal to a specific offset;
obtaining a first corrected motion vector by correcting the first motion vector based on the first correction value;
obtaining a second corrected motion vector by correcting the second motion vector based on the second correction value; and
reconstructing the current block based on the first corrected motion vector and the second corrected motion vector,
wherein the first reference picture and the second reference picture are included in a first reference picture list and a second reference picture list, respectively, and
wherein the first reference picture list and the second reference picture are different from each other.
8. The video signal encoding device of claim 7 ,
wherein the first reference picture list is used in a first higher level region in which up to one motion vector is used for a specific sample and a second higher level region in which up to two motion vectors are used for the specific sample, and
wherein the second reference picture list is not used in the first higher level region.
9. The video signal encoding device of claim 7 ,
wherein when one of the first correction value and the second correction value is obtained as the first value,
a correction value obtained as the first value is obtained earlier than a correction value not obtained as the first value.
10. The video signal encoding device of claim 9 ,
wherein when an absolute value of the first POC difference is greater than or equal to an absolute value of the second POC difference, the first correction value is obtained as the first value, and
wherein when the absolute value of the first POC difference is less than the absolute value of the second POC difference, the second correction value is obtained as the first value.
11. The video signal encoding device of claim 10 ,
wherein when the absolute value of the first POC difference is greater than or equal to the absolute value of the second POC difference,
the first corrected motion vector is obtained by adding the first value to the first motion vector,
the second corrected motion vector is obtained by adding a second value to the second motion vector, and
the second value is obtained based on the first value.
12. The video signal encoding device of claim 7 ,
wherein a value representing the first reference picture list is 0 and a value representing the second reference picture list is 1.
13. A non-transitory computer-readable medium storing a bitstream, the bitstream being decoded by a decoding method,
wherein the decoding method, comprising:
obtaining a first motion vector of a current block corresponding to a first reference picture and a second motion vector of the current block corresponding to a second reference picture;
obtaining a first picture order count (POC) difference representing a POC difference between the first reference picture and a current picture;
obtaining a second POC difference representing a POC difference between the second reference picture and the current picture;
obtaining at least one of a first correction value of the first motion vector and a second correction value of the second motion vector as a first value, based on a result of comparing the first POC difference and the second POC difference, wherein the first value is a specific offset;
obtaining a first corrected motion vector by correcting the first motion vector based on the first correction value;
obtaining a second corrected motion vector by correcting the second motion vector based on the second correction value; and
reconstructing the current block based on the first corrected motion vector and the second corrected motion vector,
wherein the first reference picture and the second reference picture are included in a first reference picture list and a second reference picture list, respectively, and
wherein the first reference picture list and the second reference picture are different from each other.
14. The non-transitory computer-readable medium storing a bitstream of claim 13 ,
wherein the first reference picture list is used in a first higher level region in which up to one motion vector is used for a specific sample and a second higher level region in which up to two motion vectors are used for the specific sample, and
wherein the second reference picture list is not used in the first higher level region.
15. The non-transitory computer-readable medium storing a bitstream of claim 13 ,
wherein when one of the first correction value and the second correction value is obtained as the first value,
a correction value obtained as the first value is obtained earlier than a correction value not obtained as the first value.
16. The non-transitory computer-readable medium storing a bitstream of claim 15 ,
wherein when an absolute value of the first POC difference is greater than or equal to an absolute value of the second POC difference, the first correction value is obtained as the first value, and
wherein when the absolute value of the first POC difference is less than the absolute value of the second POC difference, the second correction value is obtained as the first value.
17. The non-transitory computer-readable medium storing a bitstream of claim 16 ,
wherein when the absolute value of the first POC difference is greater than or equal to the absolute value of the second POC difference,
the first corrected motion vector is obtained by adding the first value to the first motion vector,
the second corrected motion vector is obtained by adding a second value to the second motion vector, and
the second value is obtained based on the first value.
18. A video signal processing method, the method comprising:
obtaining a first motion vector of a current block corresponding to a first reference picture and a second motion vector of the current block corresponding to a second reference picture;
obtaining a first picture order count (POC) difference representing a POC difference between the first reference picture and a current picture;
obtaining a second POC difference representing a POC difference between the second reference picture and the current picture;
obtaining at least one of a first correction value of the first motion vector and a second correction value of the second motion vector as a first value, based on a result of comparing the first POC difference and the second POC difference, wherein the first value is a specific offset;
obtaining a first corrected motion vector by correcting the first motion vector based on the first correction value;
obtaining a second corrected motion vector by correcting the second motion vector based on the second correction value; and
reconstructing the current block based on the first corrected motion vector and the second corrected motion vector,
wherein the first reference picture and the second reference picture are included in a first reference picture list and a second reference picture list, respectively, and
wherein the first reference picture list and the second reference picture are different from each other.