Moving picture decoding device, moving picture decoding method, moving picture decoding program, and receiving device
A prediction information derivation unit derives inter prediction information candidates from inter prediction information of coded prediction blocks neighboring a prediction block subject to coding within the same picture as the prediction block subject to coding and inter prediction information of a prediction block in a coded picture that is different from the prediction block subject to coding. The prediction information derivation unit determines an inter prediction information candidate to be used for inter prediction of the prediction block subject to coding from the inter prediction information candidates that have been derived. A second bitstream generation unit codes an index that indicates the inter prediction information candidate based on the number of the inter prediction information candidates.
1. A moving picture decoding device adapted to decode a bitstream in which moving pictures are coded in units of blocks obtained by partitioning each picture of the moving pictures, comprising:
a first bitstream decoding unit configured to set the number of merge candidates;
a second bitstream decoding unit configured to decode information indicating indices of the merge candidates;
a spatial merge candidate generation unit configured to derive spatial merge candidates from a first predefined number of blocks neighboring a prediction block subject to decoding;
a temporal merge candidate generation unit configured to derive a temporal merge candidate from a block that exists at the same position as or near a prediction block subject to decoding in a decoded picture that is different from the prediction block subject to decoding;
a merge candidate addition unit configured to add the spatial merge candidates and the temporal merge candidates to a merge candidate list;
a coding information selection unit configured to select a merge candidate from the merge candidates added to the merge list; and
a motion compensation prediction unit configured to perform inter prediction of the prediction block subject to decoding by the merge candidate thus selected,
wherein the second bitstream decoding unit derives the indices of the merge candidates based on the number of the merge candidates; and
the spatial merge candidate generation unit stops deriving the spatial merge candidates when the number of the derived spatial merge candidates reaches a second predefined number smaller than the first predefined number.
2. A moving picture decoding method adapted to decode a bitstream in which moving pictures are coded in units of blocks obtained by partitioning each picture of the moving pictures, comprising:
a first bitstream decoding step of setting the number of merge candidates;
a second bitstream decoding step of decoding information indicating indices of the merge candidates;
a spatial merge candidate generation step of deriving spatial merge candidates from a first predefined number of blocks neighboring a prediction block subject to decoding;
a temporal merge candidate generation step of deriving a temporal merge candidate from a block that exists at the same position as or near a prediction block subject to decoding in a decoded picture that is different from the prediction block subject to decoding;
a merge candidate addition step of adding the spatial merge candidates and the temporal merge candidates to a merge candidate list;
a coding information selection step of selecting a merge candidate from the merge candidates added to the merge list; and
a motion compensation prediction step of performing inter prediction of the prediction block subject to decoding by the merge candidate thus selected,
wherein the second bitstream decoding step derives the indices of the merge candidates based on the number of the merge candidates; and
the spatial merge candidate generation step stops deriving spatial merge candidates when the number of the derived spatial merge candidates reaches a second predefined number smaller than the first predefined number.
3. A non-transitory computer-readable recording medium having embedded thereon a moving picture decoding program adapted to decode a bitstream in which moving pictures are coded in units of blocks obtained by partitioning each picture of the moving pictures,
the moving picture decoding program comprising:
a first bitstream decoding step of setting the number of merge candidates;
a second bitstream decoding step of decoding information indicating indices of the merge candidates;
a spatial merge candidate generation step of deriving spatial merge candidates from a first predefined number of blocks neighboring a prediction block subject to decoding;
a temporal merge candidate generation step of deriving a temporal merge candidate from a block that exists at the same position as or near a prediction block subject to decoding in a decoded picture that is different from the prediction block subject to decoding;
a merge candidate addition step of adding the spatial merge candidates and the temporal merge candidates to a merge candidate list;
a coding information selection step of selecting a merge candidate from the merge candidates added to the merge list; and
a motion compensation prediction step of performing inter prediction of the prediction block subject to decoding by the merge candidate thus selected,
wherein the second bitstream decoding step derives the indices of the merge candidates based on the number of the merge candidates; and
the spatial merge candidate generation step stops deriving the spatial merge candidates when the number of the derived spatial merge candidates reaches a second predefined number smaller than the first predefined number.