Merge candidate derivation device, image decoding device, and image coding device
Since complexity is high in derivation of an enhancement merge candidate which is a scalable merge candidate, a problem may arise in that a processing amount is large when the enhancement merge candidate is used in a case where a prediction unit in which it is necessary to derive many merge candidates is small. In a merge candidate derivation section including an enhancement merge candidate section that derives a merge candidate referring to an inter-layer picture and a base merge candidate derivation section that derives a merge candidate not referring to an inter-layer picture (referring to the temporary picture or the adjacent block of the same layer), the merge candidate derived from the base merge candidate and the merge candidate derived from the enhancement merge candidate are added to a merge candidate list in a case where the size of a prediction unit is greater than a predetermined size. The merge candidate derived from the base merge candidate is added to the merge candidate list in a case where the size of the prediction unit is equal to or less than the predetermined size.
1. A video decoding device decoding coded data formed by a plurality of layers, the video decoding device comprising:
a prediction device that includes at least one circuitry, wherein
the circuitry
derives a base merge candidate list and an enhancement merge candidate list including at least one enhancement merge candidates, wherein the enhancement merge candidates include at least an interview merge candidate, a disparity merge candidate, a motion shift merge candidate, and a disparity shift merge candidate;
derives a prediction parameter by using the base merge candidate list in a case where a sum of a width and a height of a prediction block is equal to 12;
derives the prediction parameter by using the enhancement merge candidate list in a case where the sum of the width and the height of the prediction block is not equal to 12,
determines whether or not each of the enhancement merge candidates is stored in the enhancement merge candidate list by using at least one of following flags which are different from each other,
(i) a flag indicating whether the interview merge candidate is included in the enhancement merge candidate list, (ii) a flag indicating whether the disparity merge candidate is included in the enhancement merge candidate list, (iii) a flag indicating whether the motion shift merge candidate is included in the enhancement merge candidate list, and (iv) a flag indicating whether the disparity shift merge candidate is included in the enhancement merge candidate list; and
uses the prediction parameter to generate a predicted image.
2. A video coding device coding coded data formed by a plurality of layers, the video coding device comprising:
a prediction device that includes at least one circuitry, wherein the circuitry
derives a base merge candidate list and an enhancement merge candidate list including at least one enhancement merge candidates, wherein the enhancement merge candidates include at least an interview merge candidate, a disparity merge candidate, a motion shift merge candidate, and a disparity shift merge candidate;
derives a prediction parameter by using the base merge candidate list in a case where a sum of a width and a height of a prediction block is equal to 12;
derives the prediction parameter by using the enhancement merge candidate list, in a case where the sum of the width and the height of the prediction block is not equal to 12;
determines whether or not each of the enhancement merge candidates is stored in the enhancement merge candidate list by using at least one of following flags which are different from each other,
(i) a flag indicating whether the interview merge candidate is included in the enhancement merge candidate list, (ii) a flag indicating whether the disparity merge candidate is included in the enhancement merge candidate list, (iii) a flag indicating whether the motion shift merge candidate is included in the enhancement merge candidate list, and (iv) a flag indicating whether the disparity shift merge candidate is included in the enhancement merge candidate list; and
uses the prediction parameter to generate a predicted image.