Moving picture decoding device, moving picture decoding method, and moving picture decoding program

A moving picture coding method adapted to encode a bitstream using motion compensation prediction in units of blocks obtained by partitioning each picture of moving pictures, comprising:

• deriving a first direction motion vector and a second direction motion vector of a block subject to coding on a basis of a first direction motion vector and a second direction motion vector of a selected neighboring block selected from spatial neighboring blocks of the block subject to coding;
• generating a predicted value of the block subject to coding by motion compensation prediction using the first direction motion vector and the second direction motion vector derived by the deriving;
• and
• storing the first direction motion vector and the second direction motion vector derived by the deriving,
• wherein the deriving is further configured to set a candidate block from the selected neighboring block based on whether:
• a first reference index indicating a first reference picture referred to by the first direction motion vector of the block subject to coding and a second reference index indicating a second reference picture referred to by the first direction motion vector of the selected neighboring block are identical with each other;
• and
• a third reference index indicating a third reference picture referred to by the second direction motion vector of the block subject to coding and a fourth reference index indicating a fourth reference picture referred to by the second direction motion vector of the selected neighboring block are identical with each other.

A non-transitory computer-readable recording medium having embodied thereon a moving picture coding program executable by a computer and adapted to encode a bitstream using motion compensation prediction in units of blocks obtained by partitioning each picture of moving pictures, the program comprising:

• a deriving module configured to derive a first direction motion vector and a second direction motion vector of a block subject to coding on a basis of a first direction motion vector and a second direction motion vector of a selected neighboring block selected from spatial neighboring blocks of the block subject to coding;
• a generating module configured to generate a predicted value of the block subject to coding by motion compensation prediction using the first direction motion vector and the second direction motion vector derived by the deriving module;
• and
• a storing module configured to store the first direction motion vector and the second direction motion vector derived by the deriving module,
• wherein the deriving module is further configured to set a candidate block from the selected neighboring block based on whether:
• a first reference index indicating a first reference picture referred to by the first direction motion vector of the block subject to coding and a second reference index indicating a second reference picture referred to by the first direction motion vector of the selected neighboring block are identical with each other;
• and
• a third reference index indicating a third reference picture referred to by the second direction motion vector of the block subject to coding and a fourth reference index indicating a fourth reference picture referred to by the second direction motion vector of the selected neighboring block are identical with each other.

A moving picture decoding device adapted to decode a bitstream encoded by using motion compensation prediction in units of blocks obtained by partitioning each picture of moving pictures, comprising:

• a motion information derivation unit configured to derive a first direction motion vector and a second direction motion vector of a block subject to decoding on a basis of a first direction motion vector and a second direction motion vector of a selected neighboring block selected from spatial neighboring blocks of the block subject to decoding;
• a motion compensation prediction unit configured to generate a predicted value of the block subject to decoding by motion compensation prediction using the first direction motion vector and the second direction motion vector derived by the motion information derivation unit;
• and
• a motion information storage unit configured to store the first direction motion vector and the second direction motion vector derived by the motion information derivation unit,
• wherein the motion information derivation unit is further configured to set a candidate block from the selected neighboring block based on whether:
• a first reference index indicating a first reference picture referred to by the first direction motion vector of the block subject to decoding and a second reference index indicating a second reference picture referred to by the first direction motion vector of the selected neighboring block are identical with each other, and
• a third reference index indicating a third reference picture referred to by the second direction motion vector of the block subject to decoding and a fourth reference index indicating a fourth reference picture referred to by the second direction motion vector of the selected neighboring block are identical with each other.

A moving picture decoding method adapted to decode a bitstream encoded by using motion compensation prediction in units of blocks obtained by partitioning each picture of moving pictures, comprising:

• deriving a first direction motion vector and a second direction motion vector of a block subject to decoding on a basis of a first direction motion vector and a second direction motion vector of a selected neighboring block selected from spatial neighboring blocks of the block subject to decoding;
• generating a predicted value of the block subject to decoding by motion compensation prediction using the first direction motion vector and the second direction motion vector derived by the deriving;
• and
• storing the first direction motion vector and the second direction motion vector derived by the deriving,
• wherein the deriving is further configured to set a candidate block from the selected neighboring block based on whether:
• a first reference index indicating a first reference picture referred to by the first direction motion vector of the block subject to decoding and a second reference index indicating a second reference picture referred to by the first direction motion vector of the selected neighboring block are identical with each other, and
• a third reference index indicating a third reference picture referred to by the second direction motion vector of the block subject to decoding and a fourth reference index indicating a fourth reference picture referred to by the second direction motion vector of the selected neighboring block are identical with each other.

A non-transitory computer-readable recording medium having embodied thereon a moving picture decoding program executable by a computer and adapted to decode a bitstream encoded by using motion compensation prediction in units of blocks obtained by partitioning each picture of moving pictures, the program comprising:

• a deriving module configured to derive a first direction motion vector and a second direction motion vector of a block subject to decoding on a basis of a first direction motion vector and a second direction motion vector of a selected neighboring block selected from spatial neighboring blocks of the block subject to decoding;
• a generating module configured to generate a predicted value of the block subject to decoding by motion compensation prediction using the first direction motion vector and the second direction motion vector derived by the deriving module;
• and
• a storing module configured to store the first direction motion vector and the second direction motion vector derived by the deriving module,
• wherein the deriving module is further configured to set a candidate block from the selected neighboring block based on whether:
• a first reference index indicating a first reference picture referred to by the first direction motion vector of the block subject to decoding and a second reference index indicating a second reference picture referred to by the first direction motion vector of the selected neighboring block are identical with each other, and
• a third reference index indicating a third reference picture referred to by the second direction motion vector of the block subject to decoding and a fourth reference index indicating a fourth reference picture referred to by the second direction motion vector of the selected neighboring block are identical with each other.