JP2016140092A - Moving picture encoding device, moving picture encoding method and moving picture encoding program, and transmission device, transmission method and transmission program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moving picture encoding technology for reducing the amount of code of coding information by improving the encoding efficiency.SOLUTION: In inter prediction that is performed by partitioning a first block, which is obtained by partitioning each picture, into one or more second blocks, a spatial merge candidate generating unit 130 derives a spatial merge candidate without referring to a block included in the first block that includes the second blocks. In the case of a mode where a coding block is divided by a horizontal border into upper and lower prediction blocks, a reference index derivation unit 131 of a time merge candidate sets reference index information of the time merge candidate to a value of reference index information of an encoded prediction block adjacent to a left edge of a prediction block subject to encoding. In the case of a mode where a coding block is divided by a vertical border into left and right prediction blocks, the reference index derivation unit sets reference index information of the time merge candidate to a value of reference index information of an encoded prediction block adjacent to an upper edge of a prediction block subject to encoding.SELECTED DRAWING: Figure 13

Description

  The present invention relates to a moving picture coding technique, and more particularly to a moving picture coding technique using motion compensated prediction.

  As a typical moving image compression encoding method, MPEG-4 AVC / H. There are H.264 standards. MPEG-4 AVC / H. In H.264, motion compensation is used in which a picture is divided into a plurality of rectangular blocks, a picture that has already been encoded / decoded is used as a reference picture, and motion from the reference picture is predicted. This method of predicting motion by motion compensation is called inter prediction or motion compensated prediction. MPEG-4 AVC / H. In the inter prediction in H.264, a plurality of pictures can be used as reference pictures, and the most suitable reference picture is selected for each block from the plurality of reference pictures to perform motion compensation. Therefore, a reference index is assigned to each reference picture, and the reference picture is specified by this reference index. For B pictures, a maximum of two pictures can be selected from decoded reference pictures and used for inter prediction. The predictions from these two reference pictures are distinguished as L0 prediction (list 0 prediction) mainly used as forward prediction and L1 prediction (list 1 prediction) mainly used as backward prediction.

  Furthermore, bi-prediction using two inter predictions of L0 prediction and L1 prediction at the same time is also defined. In the case of bi-prediction, bi-directional prediction is performed, the inter-predicted signals of L0 prediction and L1 prediction are multiplied by a weighting coefficient, an offset value is added and superimposed, and a final inter-predicted image signal is obtained. Generate. As weighting coefficients and offset values used for weighted prediction, representative values are set for each reference picture in each list and encoded. The encoding information related to inter prediction includes, for each block, a prediction mode for distinguishing between L0 prediction and L1 prediction and bi-prediction, a reference index for specifying a reference picture for each reference list for each block, and a moving direction and a moving amount of the block. There is a motion vector that expresses and encodes and decodes the encoded information.

  Furthermore, MPEG-4 AVC / H. H.264 defines a direct mode for generating inter prediction information of a block to be encoded or decoded from inter prediction information of a decoded block. In the direct mode, encoding of inter prediction information is not necessary, so that encoding efficiency is improved.

  The temporal direct mode using the correlation of inter prediction information in the time direction will be described with reference to FIG. A picture in which the reference index of L1 is registered as 0 is defined as a reference picture colPic. A block in the same position as the block to be encoded or decoded in the reference picture colPic is set as a reference block.

  If the reference block is encoded using the L0 prediction, the L0 motion vector of the reference block is set as the reference motion vector mvCol, and the reference block is not encoded using the L0 prediction and is encoded using the L1 prediction. If this is the case, the L1 motion vector of the reference block is set as the reference motion vector mvCol. The picture referred to by the reference motion vector mvCol is the L0 reference picture in the temporal direct mode, and the reference picture colPic is the L1 reference picture in the temporal direct mode.

  From the reference motion vector mvCol, the L0 motion vector mvL0 and the L1 motion vector mvL1 in the temporal direct mode are derived by scaling calculation processing.

The inter-picture distance td is derived by subtracting the POC of the L0 reference picture in the temporal direct mode from the POC of the base picture colPic. Note that POC is a variable associated with the picture to be encoded, and is set to a value that increases by 1 in the picture output order. The difference in POC between two pictures indicates the inter-picture distance in the time axis direction.
td = POC of base picture colPic-POC of L0 reference picture in temporal direct mode

The inter-picture distance tb is derived by subtracting the POC of the L0 reference picture in the temporal direct mode from the POC of the picture to be encoded or decoded.
tb = POC of picture to be encoded or decoded-POC of reference picture of L0 in temporal direct mode

The motion vector mvL0 of L0 in the temporal direct mode is derived from the reference motion vector mvCol by scaling calculation processing.
mvL0 = tb / td * mvCol

The motion vector mvL1 of L1 is derived by subtracting the reference motion vector mvCol from the motion vector mvL0 of L0 in the temporal direct mode.
mvL1 = mvL0-mvCol

JP 2004-129191 A

  However, in the conventional method, for the block to be encoded and decoded, the prediction accuracy is reduced and the encoding efficiency may not be improved in the time direct.

  Under such circumstances, the present inventors have come to recognize the necessity of further compressing the encoded information and reducing the overall code amount in the moving image encoding method using motion compensation prediction.

  The present invention has been made in view of such a situation, and an object of the present invention is to calculate a moving picture coding that reduces coding amount of coding information and improves coding efficiency by calculating coding information candidates. To provide technology.

A moving picture coding apparatus that divides a first block obtained by dividing each picture into one or a plurality of second blocks and codes a moving picture using inter prediction, in a picture to be coded A first prediction information deriving unit for deriving one or more first inter prediction information candidates from inter prediction information of one or more third blocks adjacent to the second block to be encoded, Derivation of second inter prediction information candidates from inter prediction information of a fourth block existing at the same position or in the vicinity of the second block to be encoded in a picture different from the picture to be encoded A second prediction information deriving unit that performs processing, and when the first inter prediction information candidate is derived, the derived first inter prediction information candidate is represented by the second inter prediction. When a report candidate is derived, a candidate list construction unit that constructs a prediction information candidate list including predetermined prediction information candidates obtained by adding the derived second inter prediction information candidates, and the prediction information candidates A selection unit that selects an inter prediction information candidate used for the inter prediction of the second block to be encoded from the prediction information candidates in a list, and determines an index indicating the inter prediction information; and the encoding An encoding unit that encodes an index indicating inter prediction information used for inter prediction of the second block to be processed, and the first prediction information deriving unit includes the first block as an upper block; The second block to be encoded in the division mode in which the lower block is vertically divided into 1: 1, 1: 3, or 3: 1. In the case of the lower block, the first inter prediction information candidate derivation process is performed without referring to the encoding information of the fifth block adjacent to the upper side of the second block, and the second prediction information The derivation unit is a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by the upper block and the lower block, and the second block that is the encoding target. Without referring to the encoding information of the fifth block included in the same first block as the first block including the first block, the reference index value of the second inter prediction information candidate as a default value, There is provided a moving picture coding apparatus characterized in that the second inter prediction information candidate derivation process is performed based on a reference index.
A moving picture coding method for dividing a first block obtained by dividing each picture into one or a plurality of second blocks and coding a moving picture using inter prediction, in a picture to be coded A first prediction information derivation step of performing derivation processing of one or more first inter prediction information candidates from inter prediction information of one or more third blocks adjacent to the second block to be encoded; Derivation of second inter prediction information candidates from inter prediction information of a fourth block existing at the same position or in the vicinity of the second block to be encoded in a picture different from the picture to be encoded A second prediction information deriving step for performing processing, and when the first inter prediction information candidate is derived, the derived first inter prediction information candidate is defined as the second inter prediction information candidate. A candidate list construction step of constructing a prediction information candidate list composed of predetermined prediction information candidates obtained by adding the derived second inter prediction information candidates, respectively, A selection step of selecting a candidate of inter prediction information used for the inter prediction of the second block to be encoded from the prediction information candidates in the information candidate list, and determining an index indicating the inter prediction information; An encoding step for encoding an index indicating inter prediction information used for inter prediction of the second block to be encoded, and the first prediction information deriving step includes the first block as an upper block. And the lower block in a split mode that divides up and down 1: 1, 1: 3, or 3: 1. When the second block to be encoded is a lower block, the first inter prediction information candidate is not referenced without referring to the encoding information of the fifth block adjacent to the upper side of the second block. In addition to performing a derivation process, the second prediction information derivation step includes a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by an upper block and a lower block. The second inter prediction information candidate without referring to the encoding information of the fifth block included in the same first block as the first block including the second block to be encoded The video encoding method is characterized in that the second inter prediction information candidate derivation process is performed based on the reference index using the reference index value as a default value.
A moving picture encoding program that divides a first block obtained by dividing each picture into one or a plurality of second blocks and encodes a moving picture using inter prediction, in a picture to be encoded A first prediction information derivation step of performing derivation processing of one or more first inter prediction information candidates from inter prediction information of one or more third blocks adjacent to the second block to be encoded; Derivation of second inter prediction information candidates from inter prediction information of a fourth block existing at the same position or in the vicinity of the second block to be encoded in a picture different from the picture to be encoded A second prediction information deriving step for performing processing, and when the first inter prediction information candidate is derived, the derived first inter prediction information candidate is When a second inter prediction information candidate is derived, a candidate list construction step of constructing a prediction information candidate list composed of predetermined prediction information candidates obtained by adding the derived second inter prediction information candidates, A selection step of selecting an inter prediction information candidate used for the inter prediction of the second block to be encoded from the prediction information candidates in the prediction information candidate list, and determining an index indicating the inter prediction information; , Causing the computer to execute an encoding step for encoding an index indicating inter prediction information used for inter prediction of the second block to be encoded, and the first prediction information derivation step includes the first prediction information derivation step. Blocks are 1: 1, 1: 3 or 3: 1 up and down with the upper and lower blocks When the second block to be encoded is a lower block in the division mode to be divided, the encoding information of the fifth block adjacent to the upper side of the second block is referred to without referring to the encoding information. The first inter prediction information candidate derivation process is performed, and the second prediction information derivation step includes 1: 1, 1: 3, or 3 up and down of the first block in the upper block and the lower block. Without dividing the encoding information of the fifth block included in the same first block as the first block including the second block to be encoded in the division mode of dividing into 1: The second inter prediction information candidate reference index value is set as a default value, and the second inter prediction information candidate derivation process is performed based on the reference index. Serve grams.
A first block obtained by dividing each picture is divided into one or a plurality of second blocks, and an encoded stream encoded by a moving image encoding method that encodes a moving image using inter prediction is packetized. A packet processing unit for obtaining encoded data and a transmission unit for transmitting the packetized encoded data. The moving image encoding method is an encoding target in a picture to be encoded. A first prediction information derivation step for deriving one or more first inter prediction information candidates from inter prediction information of one or more third blocks adjacent to the second block; and a picture to be encoded; Are inter-prediction information based on inter-prediction information of a fourth block existing at the same position or in the vicinity of the second block to be encoded in a different picture. A second prediction information derivation step for performing an information candidate derivation process; and when the first inter prediction information candidate is derived, the derived first inter prediction information candidate is designated as the second inter prediction information candidate. Is derived, a candidate list construction step of constructing a prediction information candidate list composed of predetermined prediction information candidates, each of the derived second inter prediction information candidates added, and in the prediction information candidate list A selection step of selecting a candidate of inter prediction information used for the inter prediction of the second block to be encoded from the prediction information candidates, and determining an index indicating inter prediction information; An encoding step for encoding an index indicating inter prediction information used for inter prediction of the second block. The first prediction information derivation step is a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by an upper block and a lower block; When the second block to be encoded is a lower block, the first inter prediction information candidate without referring to the encoding information of the fifth block adjacent to the upper side of the second block In the second prediction information derivation step, the first block is divided into 1: 1, 1: 3, or 3: 1 in the vertical direction by the upper block and the lower block. In the mode, the second inter prediction information without referring to the encoding information of the fifth block included in the same first block as the first block including the second block to be encoded Candidate reference index As a default value, the second inter prediction information candidate derivation process is performed based on the reference index.
A first block obtained by dividing each picture is divided into one or a plurality of second blocks, and an encoded stream encoded by a moving image encoding method that encodes a moving image using inter prediction is packetized. A packet processing step for obtaining encoded data and a transmission step for transmitting the packetized encoded data, wherein the moving image encoding method is an encoding target in a picture to be encoded A first prediction information derivation step for deriving one or more first inter prediction information candidates from inter prediction information of one or more third blocks adjacent to the second block; and a picture to be encoded; Is obtained from the inter prediction information of the fourth block existing at the same position or in the vicinity of the second block to be encoded in a different picture. A second prediction information derivation step for deriving an inter prediction information candidate; and when the first inter prediction information candidate is derived, the derived first inter prediction information candidate is converted into the second inter prediction information candidate. When an information candidate is derived, a candidate list construction step of constructing a prediction information candidate list composed of predetermined prediction information candidates obtained by adding the derived second inter prediction information candidates, and the prediction information candidates A selection step of selecting a candidate of inter prediction information used for the inter prediction of the second block to be encoded from the prediction information candidates in a list, and determining an index indicating the inter prediction information; and the encoding An index indicating inter prediction information used for inter prediction of the second block as a target is encoded. An encoding step, wherein the first prediction information deriving step divides the first block into a 1: 1, 1: 3, or 3: 1 vertically by an upper block and a lower block. In the mode, when the second block to be encoded is a lower block, the first interface is referred to without referring to the encoding information of the fifth block adjacent to the upper side of the second block. In addition to performing a prediction information candidate derivation process, the second prediction information derivation step is configured such that the first block is 1: 1, 1: 3, or 3: 1 up and down between the upper block and the lower block. In the division mode to divide, the second block without referring to the encoding information of the fifth block included in the same first block as the first block including the second block to be encoded Inter prediction information candidate reference Provided is a transmission method characterized in that the second inter prediction information candidate derivation process is performed based on the reference index using an index value as a default value.
A first block obtained by dividing each picture is divided into one or a plurality of second blocks, and an encoded stream encoded by a moving image encoding method that encodes a moving image using inter prediction is packetized. The computer executes a packet processing step for obtaining encoded data and a transmission step for transmitting the packetized encoded data, and the moving picture encoding method includes encoding in a picture to be encoded. A first prediction information derivation step for deriving one or more first inter prediction information candidates from inter prediction information of one or more third blocks adjacent to the target second block; In the fourth block existing in the same position as or near the second block to be encoded in a picture different from the picture to be encoded A second prediction information derivation step for deriving a second inter prediction information candidate from the prediction information; and when the first inter prediction information candidate is derived, the derived first inter prediction information candidate is When the second inter prediction information candidate is derived, a candidate list construction step of constructing a prediction information candidate list made up of predetermined prediction information candidates obtained by adding the derived second inter prediction information candidates, respectively. Selecting an inter prediction information candidate to be used for the inter prediction of the second block to be encoded from the prediction information candidates in the prediction information candidate list, and determining an index indicating the inter prediction information And an index indicating inter prediction information used for inter prediction of the second block to be encoded And the first prediction information derivation step includes 1: 1, 1: 3, or 3: up and down of the first block in an upper block and a lower block. When the second block to be encoded is a lower block in the division mode of dividing into 1, the encoding information of the fifth block adjacent to the upper side of the second block is not referred to. The first inter prediction information candidate derivation process is performed, and in the second prediction information derivation step, the first block is vertically divided into 1: 1 and 1: 3 by an upper block and a lower block. Alternatively, in the division mode dividing into 3: 1, the encoding information of the fifth block included in the same first block as the first block including the second block to be encoded is not referred to. And the second interface Provided is a transmission program characterized in that the second inter prediction information candidate derivation process is performed based on the reference index with the value of the reference index of the prediction information candidate as a default value.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  According to the present invention, it is possible to reduce the amount of generated code of encoded information to be transmitted and improve the encoding efficiency.

It is a block diagram which shows the structure of the moving image encoder which performs the motion vector prediction method which concerns on embodiment. It is a block diagram which shows the structure of the moving image decoding apparatus which performs the motion vector prediction method which concerns on embodiment. It is a figure explaining a tree block and an encoding block. It is a figure explaining the division mode of a prediction block. It is a figure explaining the prediction block which adjoins to the prediction block of the process target by the spatial merge candidate in merge mode. It is a figure explaining the prediction block which adjoins to the prediction block of the process target by the spatial merge candidate in merge mode. It is a figure explaining the prediction block which adjoins to the prediction block of the process target by the spatial merge candidate in merge mode. It is a figure explaining the prediction block which adjoins to the prediction block of the process target by the spatial merge candidate in merge mode. It is a figure explaining the prediction block referred in the time of derivation | leading-out of the time merge candidate in merge mode. It is a figure explaining the syntax of the bit stream in the slice level regarding merge mode. It is a figure explaining the syntax of the bit stream in the prediction block level regarding merge mode. It is a figure explaining an example of the entropy code | symbol of the syntax element of a merge index. It is a block diagram which shows the detailed structure of the inter prediction information derivation | leading-out part of the moving image encoder of FIG. It is a block diagram which shows the detailed structure of the inter prediction information derivation | leading-out part of the moving image decoding apparatus of FIG. It is a figure explaining the prediction block adjacent to the prediction block of the process target in merge mode. It is a flowchart explaining the process sequence of the sequential process of merge candidate derivation | leading-out and the merge candidate list construction process. It is a flowchart explaining the processing procedure of the parallel processing of merge candidate derivation | leading-out and the merge candidate list construction processing. It is a flowchart explaining a merge candidate derivation process in merge mode and a merge candidate list construction process. It is a flowchart explaining the space merge candidate derivation | leading-out process of merge mode. It is a figure explaining the adjacent block referred in the derivation | leading-out process of the reference index of the time merge candidate in Example 1 of this Embodiment. 10 is a flowchart for explaining a reference index derivation processing procedure for temporal merge candidates in the merge mode according to the method of the first embodiment. It is a figure explaining the adjacent block referred in the derivation | leading-out process of the reference index of the time merge candidate in Example 2 of this Embodiment. 12 is a flowchart for explaining a reference index derivation processing procedure of a temporal merge candidate in a merge mode according to the method of the second embodiment. It is a figure explaining the adjacent block referred in the derivation | leading-out process of the reference index of the time merge candidate in Example 3 of this Embodiment. 10 is a flowchart for explaining a reference index derivation processing procedure for temporal merge candidates in a merge mode according to the method of the third embodiment. It is a figure explaining the adjacent block referred in the derivation | leading-out process of the reference index of the time merge candidate in Example 4 of this Embodiment. 15 is a flowchart for describing a reference index derivation processing procedure for temporal merge candidates in the merge mode according to the method of the fourth embodiment. It is a figure explaining the adjacent block referred in the derivation | leading-out process of the reference index of the time merge candidate in Example 5 of this Embodiment. FIG. 10 is a flowchart for describing a reference index derivation processing procedure for a merged time temporal merge candidate according to the method of the fifth embodiment. 22 is a flowchart for describing a reference index derivation processing procedure for temporal merge candidates in the merge mode according to the method of the sixth embodiment. It is a figure explaining the adjacent block referred in the derivation | leading-out process of the reference index of the time merge candidate in Example 7 of this Embodiment. FIG. 25 is a flowchart for describing a procedure for deriving a reference index of a merge mode temporal merge candidate according to the method of the seventh embodiment. It is a figure explaining the adjacent block referred in the derivation | leading-out process of the reference index of the encoding block of a NxN division | segmentation. It is a flowchart explaining the time merge candidate derivation | leading-out process procedure of merge mode. It is a flowchart explaining the derivation | leading-out process procedure of the picture of the time from which merge mode differs. It is a flowchart explaining the derivation | leading-out process procedure of the prediction block of the picture of the time from which merge mode differs. It is a flowchart explaining the time merge candidate derivation | leading-out process procedure of merge mode. It is a flowchart explaining the time merge candidate derivation | leading-out process procedure of merge mode. It is a flowchart explaining the scaling calculation processing procedure of a motion vector. It is a flowchart explaining the scaling calculation processing procedure of a motion vector. It is a flowchart explaining the construction process procedure of the merge candidate list | wrist of merge mode. Conventional MPEG-4 AVC / H. It is a figure explaining the H.264 time direct mode. It is a figure explaining the adjacent block referred in the derivation | leading-out process of the reference index of the time merge candidate in Example 8 of this Embodiment. FIG. 30 is a flowchart for describing a reference index derivation process procedure for a temporal merge candidate in the merge mode according to the method of the eighth embodiment.

  In the present embodiment, with regard to moving picture coding, in particular, to improve coding efficiency in moving picture coding in which a picture is divided into rectangular blocks of an arbitrary size and shape and motion compensation is performed in units of blocks between pictures. In addition, a plurality of predicted motion vectors are derived from the motion vectors of a block adjacent to the encoding target block or a block of an encoded picture, and a difference vector between the motion vector of the encoding target block and the selected prediction motion vector The amount of code is reduced by calculating and encoding. Alternatively, the coding amount is reduced by deriving the coding information of the coding target block by using the coding information of the block adjacent to the coding target block or the block of the coded picture. Also, in the case of decoding a moving image, a plurality of predicted motion vectors are calculated from the motion vectors of a block adjacent to the decoding target block or a block of a decoded picture, and selected from the difference vector decoded from the encoded stream The motion vector of the decoding target block is calculated from the predicted motion vector and decoded. Alternatively, the encoding information of the decoding target block is derived by using the encoding information of the block adjacent to the decoding target block or the block of the decoded picture.

  First, techniques used in the present embodiment and technical terms are defined.

(About tree blocks and coding blocks)
In the embodiment, as shown in FIG. 3, the picture is equally divided into square units of any same size. This unit is defined as a tree block, and is a block to be encoded or decoded in a picture (a block to be encoded in the encoding process and a block to be decoded in the decoding process. Hereinafter, unless otherwise noted, It is used as a basic unit of address management for specifying. Except for monochrome, the tree block is composed of one luminance signal and two color difference signals. The size of the tree block can be freely set to a power of 2 depending on the picture size and the texture in the picture. In order to optimize the encoding process according to the texture in the picture, the tree block divides the luminance signal and chrominance signal in the tree block hierarchically into four parts (two parts vertically and horizontally) as necessary, The block can be made smaller in block size. Each block is defined as a coding block, and is a basic unit of processing when performing coding and decoding. Except for monochrome, the coding block is also composed of one luminance signal and two color difference signals. The maximum size of the coding block is the same as the size of the tree block. An encoded block having the minimum size of the encoded block is called a minimum encoded block, and can be freely set to a power of 2.

  In FIG. 3, the encoding block A is a single encoding block without dividing the tree block. The encoding block B is an encoding block formed by dividing a tree block into four. The coding block C is a coding block obtained by further dividing the block obtained by dividing the tree block into four. The coding block D is a coding block obtained by further dividing the block obtained by dividing the tree block into four parts and further dividing the block into four twice hierarchically, and is a coding block of the minimum size.

(About prediction mode)
Encoded or decoded within the picture to be encoded or decoded in units of coding blocks (in the encoding process, the encoded signal is used for a decoded picture, a prediction block, an image signal, etc., and the decoded picture in the decoding process) This is used for prediction blocks, image signals, etc. Hereinafter, unless otherwise noted, it is used in this sense.) From intra-prediction (MODE_INTRA) in which prediction is performed from surrounding image signals, and from encoded or decoded picture image signals Switch inter prediction (MODE_INTER) to perform prediction. A mode for identifying the intra prediction (MODE_INTRA) and the inter prediction (MODE_INTER) is defined as a prediction mode (PredMode). The prediction mode (PredMode) has intra prediction (MODE_INTRA) or inter prediction (MODE_INTER) as a value, and can be selected and encoded.

(About split mode, prediction block, prediction unit)
When performing intra prediction (MODE_INTRA) and inter prediction (MODE_INTER) by dividing the picture into blocks, the coded block is divided as necessary to reduce the unit for switching the intra prediction and inter prediction methods. Make predictions. A mode for identifying the division method of the luminance signal and the color difference signal of the coding block is defined as a division mode (PartMode). Furthermore, this divided block is defined as a prediction block. As shown in FIG. 4, eight types of partition modes (PartMode) are defined according to the method of dividing the luminance signal of the coding block.

  A division mode (PartMode) that is regarded as one prediction block without dividing the luminance signal of the encoded block shown in FIG. 4A is defined as 2N × 2N division (PART_2Nx2N). The division modes (PartMode) for dividing the luminance signal of the coding block shown in FIGS. 4B, 4C, and 4D into two prediction blocks arranged vertically are 2N × N division (PART_2NxN) and 2N × nU, respectively. It is defined as division (PART_2NxnU) and 2N × nD division (PART_2NxnD). However, 2N × N division (PART_2NxN) is a division mode divided up and down at a ratio of 1: 1, and 2N × nU division (PART_2NxnU) is a division mode divided up and down at a ratio of 1: 3 and 2N × The nD division (PART_2NxnD) is a division mode in which division is performed at a ratio of 3: 1 up and down. The division modes (PartMode) for dividing the luminance signals of the coding blocks shown in FIGS. 4 (e), (f), and (g) into two prediction blocks arranged on the left and right are divided into N × 2N divisions (PART_Nx2N) and nL × 2N, respectively. It is defined as division (PART_nLx2N) and nR × 2N division (PART_nRx2N). However, N × 2N division (PART_Nx2N) is a division mode in which left and right are divided at a ratio of 1: 1, and nL × 2N division (PART_nLx2N) is a division mode in which division is performed at a ratio of 1: 3 in the left and right, and nR × 2N division (PART_nRx2N) is a division mode in which the image is divided in the ratio of 3: 1 to the left and right. The division mode (PartMode) in which the luminance signal of the coding block shown in FIG. 4 (h) is divided into four parts in the vertical and horizontal directions and defined as four prediction blocks is defined as N × N division (PART_NxN).

  Note that the color difference signal is also divided in the same manner as the vertical and horizontal division ratios of the luminance signal for each division mode (PartMode).

  In order to specify each prediction block within the coding block, a number starting from 0 is assigned to the prediction block existing inside the coding block in the coding order. This number is defined as a split index PartIdx. A number described in each prediction block of the encoded block in FIG. 4 represents a partition index PartIdx of the prediction block. In the 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), and 2N × nD partition (PART_2NxnD) shown in FIGS. 4B, 4C, and 4D, the partition index PartIdx of the upper prediction block is set to 0. The partition index PartIdx of the lower prediction block is set to 1. In the N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), and nR × 2N partition (PART_nRx2N) shown in FIGS. 4E, 4F, and 4G, the partition index PartIdx of the left prediction block is set to 0. The division index PartIdx of the right prediction block is set to 1. In the N × N partition (PART_NxN) shown in FIG. 4H, the partition index PartIdx of the upper left prediction block is 0, the partition index PartIdx of the upper right prediction block is 1, and the partition index PartIdx of the lower left prediction block is 2. And the division index PartIdx of the prediction block at the lower right is set to 3.

  When the prediction mode (PredMode) is inter prediction (MODE_INTER), the partition mode (PartMode) is 2N × 2N partition (PART_2Nx2N), 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), 2N × nD partition (PART_2NxnD) , N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), and nR × 2N partition (PART_nRx2N). Only coding block D, which is the smallest coding block, has a partition mode (PartMode) of 2N × 2N partition (PART_2Nx2N), 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), 2N × nD partition (PART_2NxnD) In addition to N × 2N division (PART_Nx2N), nL × 2N division (PART_nLx2N), and nR × 2N division (PART_nRx2N), N × N division (PART_NxN) can be defined. It is assumed that the partition mode (PartMode) does not define N × N partition (PART_NxN).

  When the prediction mode (PredMode) is intra prediction (MODE_INTRA), only the 2N × 2N partition (PART_2Nx2N) is defined as the partition mode (PartMode) except for the encoding block D which is the minimum encoding block, and the minimum encoding block For only the coding block D, the partition mode (PartMode) defines N × N partition (PART_NxN) in addition to 2N × 2N partition (PART_2Nx2N). The reason why N × N division (PART_NxN) is not defined other than the smallest coding block is that, except for the smallest coding block, the coding block can be divided into four to represent a small coding block.

(Position of tree block, coding block, prediction block, transform block)
The position of each block including the tree block, the encoding block, the prediction block, and the transform block according to the present embodiment has the position of the pixel of the luminance signal at the upper left of the luminance signal screen as the origin (0, 0). The pixel position of the upper left luminance signal included in each block area is represented by two-dimensional coordinates (x, y). The direction of the coordinate axis is a right direction in the horizontal direction and a downward direction in the vertical direction, respectively, and the unit is one pixel unit of the luminance signal. Of course, the luminance signal and the color difference signal have the same image size (number of pixels) and the color difference format is 4: 4: 4. Of course, the luminance signal and the color difference signal have a different color size format of 4: 4. Even in the case of 2: 0, 4: 2: 2, the position of each block of the color difference signal is represented by the coordinates of the pixel of the luminance signal included in the block area, and the unit is one pixel of the luminance signal. In this way, not only can the position of each block of the color difference signal be specified, but also the relationship between the positions of the luminance signal block and the color difference signal block can be clarified only by comparing the coordinate values.

(Inter prediction mode, reference list)
In the embodiment of the present invention, in inter prediction in which prediction is performed from an image signal of a decoded picture, a plurality of decoded pictures can be used as reference pictures. In order to identify a reference picture selected from a plurality of reference pictures, a reference index is attached to each prediction block. In the B slice, any two reference pictures can be selected for each prediction block, and inter prediction can be performed. As inter prediction modes, there are L0 prediction (Pred_L0), L1 prediction (Pred_L1), and bi-prediction (Pred_BI). The reference picture is managed by L0 (reference list 0) and L1 (reference list 1) of the list structure, and the reference picture can be specified by specifying the reference index of L0 or L1. L0 prediction (Pred_L0) is inter prediction that refers to a reference picture managed in L0, L1 prediction (Pred_L1) is inter prediction that refers to a reference picture managed in L1, and bi-prediction (Pred_BI) is This is inter prediction in which both L0 prediction and L1 prediction are performed and one reference picture managed by each of L0 and L1 is referred to. Only L0 prediction can be used in inter prediction of P slice, and L0 prediction, L1 prediction, and bi-prediction (Pred_BI) that averages or weights and adds L0 prediction and L1 prediction can be used in inter prediction of B slice. In the subsequent processing, it is assumed that the constants and variables with the subscript LX in the output are processed for each of L0 and L1.

(Merge mode, merge candidate)
In the merge mode, the prediction mode of the prediction block to be encoded or decoded, the inter prediction information such as the reference index and the motion vector is not encoded or decoded, but within the same picture as the prediction block to be encoded or decoded. Prediction block close to the prediction block to be encoded or decoded, or the same position as or near the prediction block to be encoded or decoded of a decoded picture that is temporally different from the prediction block to be encoded or decoded (neighboring In this mode, the inter prediction is performed by deriving the inter prediction information of the prediction block to be encoded or decoded from the inter prediction information of the prediction block existing at the position. A prediction block close to the prediction block to be encoded or decoded in the same picture as the prediction block to be encoded or decoded and inter prediction information of the prediction block are spatial merge candidates, a prediction block to be encoded or decoded, and time Prediction information derived from a prediction block existing at the same position as or near (previously near) a prediction block to be encoded or decoded of a differently encoded or decoded picture and inter prediction information of the prediction block Are time merge candidates. Each merge candidate is registered in the merge candidate list, and the merge candidate used in the inter prediction is specified by the merge index.

(About adjacent prediction blocks)
5, 6, 7, and 8 illustrate the encoding or decoding within the same picture as the prediction block to be encoded or decoded that is referenced when the spatial merge candidate is derived and the reference index of the temporal merge candidate is derived. It is a figure explaining the prediction block adjacent to the prediction block of object. FIG. 9 illustrates the same position as the prediction block to be encoded or decoded in a picture that has been encoded or decoded that is temporally different from the prediction block to be encoded or decoded that is referred to when the reference index of the temporal merge candidate is derived. It is a figure explaining the prediction block already encoded or decoded which exists in the vicinity. A prediction block that is close in the spatial direction of a prediction block to be encoded or decoded and a prediction block at the same position at different times will be described with reference to FIGS. 5, 6, 7, 8, and 9. FIG.

  As shown in FIG. 5, a prediction block A close to the left side of the prediction block to be encoded or decoded in the same picture as the prediction block to be encoded or decoded, a prediction block B close to the upper side, A prediction block C that is close to the upper right vertex, a prediction block D that is close to the lower left vertex, and a prediction block E that is close to the upper left vertex are defined as prediction blocks close to the spatial direction.

  As shown in FIG. 6, when the size of the prediction block adjacent to the left side of the prediction block to be encoded or decoded is smaller than the prediction block to be encoded or decoded and there are a plurality of prediction blocks, this embodiment In the embodiment, the lowest prediction block A10 among the prediction blocks close to the left side is assumed to be the prediction block A close to the left side.

  Similarly, when the size of the prediction block adjacent to the upper side of the prediction block to be encoded or decoded is smaller than the prediction block to be encoded or decoded and there are a plurality of prediction blocks, the left side in the present embodiment The rightmost prediction block B10 among the prediction blocks adjacent to is assumed to be the prediction block B1 adjacent to the upper side.

  In addition, as shown in FIG. 7, even when the size of the prediction block F adjacent to the left side of the prediction block to be encoded or decoded is larger than the prediction block to be encoded or decoded, it is close to the left side according to the above condition. If the prediction block A is close to the left side of the prediction block to be encoded or decoded, the prediction block A is determined. If the prediction block A is close to the lower left vertex of the prediction block to be encoded or decoded, the prediction block D is determined. If it is close to the top left vertex of the prediction block to be encoded or decoded, the prediction block E is determined. In the example of FIG. 6, the prediction block A, the prediction block E, and the prediction block E are the same prediction block.

  In addition, as shown in FIG. 8, even when the size of the prediction block G adjacent to the upper side of the prediction block to be encoded or decoded is larger than the prediction block to be encoded or decoded, the size is close to the upper side according to the above condition. When the prediction block G is close to the upper side of the prediction block to be encoded or decoded, the prediction block B is used. When the prediction block G is close to the upper right vertex of the prediction block to be encoded or decoded, the prediction block C is set. If it is close to the top left vertex of the prediction block to be encoded or decoded, the prediction block E is determined. In the example of FIG. 8, the prediction block B, the prediction block C, and the prediction block E are the same prediction block.

  As shown in FIG. 9, in a decoded picture that is temporally different from a prediction block to be encoded or decoded, an already encoded or decoded image that exists at or near the same position as the prediction block to be encoded or decoded Prediction blocks T0 and T1 are defined as prediction blocks at the same position at different times.

(About POC)
POC is a variable associated with the picture to be encoded, and is set to a value that increases by 1 in the picture output order. Based on the POC value, it is possible to determine whether they are the same picture, to determine the anteroposterior relationship between pictures in the output order, or to derive the distance between pictures. For example, if the POCs of two pictures have the same value, it can be determined that they are the same picture. When the POCs of two pictures have different values, it can be determined that the picture with the smaller POC value is the picture output first, and the difference between the POCs of the two pictures indicates the inter-picture distance in the time axis direction. Show.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a moving picture coding apparatus according to an embodiment of the present invention. The moving image encoding apparatus according to the embodiment includes an image memory 101, a motion vector detection unit 102, a difference motion vector calculation unit 103, an inter prediction information derivation unit 104, a motion compensation prediction unit 105, an intra prediction unit 106, and a prediction method determination unit. 107, residual signal generation section 108, orthogonal transform / quantization section 109, first encoded bit string generation section 110, second encoded bit string generation section 111, multiplexing section 112, inverse quantization / inverse orthogonal transform section 113, a decoded image signal superimposing unit 114, an encoded information storage memory 115, and a decoded image memory 116.

  The image memory 101 temporarily stores the image signal of the encoding target picture supplied in the order of shooting / display time. The image memory 101 supplies the stored image signal of the picture to be encoded to the motion vector detection unit 102, the prediction method determination unit 107, and the residual signal generation unit 108 in units of predetermined pixel blocks. At this time, the image signals of the pictures stored in the order of shooting / display time are rearranged in the encoding order and output from the image memory 101 in units of pixel blocks.

  The motion vector detection unit 102 uses the motion vector for each prediction block size and each prediction mode by block matching between the image signal supplied from the image memory 101 and the reference picture supplied from the decoded image memory 116 for each prediction block. Detection is performed in units, and the detected motion vector is supplied to the motion compensation prediction unit 105, the difference motion vector calculation unit 103, and the prediction method determination unit 107.

  The difference motion vector calculation unit 103 calculates a plurality of motion vector predictor candidates by using the encoded information of the already encoded image signal stored in the encoded information storage memory 115, and generates a prediction motion vector list. The optimum motion vector predictor is selected from a plurality of motion vector predictor candidates registered and registered in the motion vector predictor list, and a motion vector difference is calculated from the motion vector detected by the motion vector detector 102 and the motion vector predictor. Then, the calculated difference motion vector is supplied to the prediction method determination unit 107. Furthermore, a prediction motion vector index that identifies a prediction motion vector selected from prediction motion vector candidates registered in the prediction motion vector list is supplied to the prediction method determination unit 107.

  The inter prediction information deriving unit 104 derives merge candidates in the merge mode. A plurality of merge candidates are derived using the encoding information of the already encoded prediction block stored in the encoding information storage memory 115 and registered in a merge candidate list described later, and registered in the merge candidate list Flags predFlagL0 [xP] [yP], predFlagL1 [xP indicating whether or not to use the L0 prediction and L1 prediction of each prediction block of the selected merge candidate from among a plurality of merge candidates ] [yP], reference index refIdxL0 [xP] [yP], refIdxL1 [xP] [yP], motion vector mvL0 [xP] [yP], mvL1 [xP] [yP] etc. And a merge index for specifying the selected merge candidate is supplied to the prediction method determination unit 107. Here, xP and yP are indexes indicating the position of the upper left pixel of the prediction block in the picture. The detailed configuration and operation of the inter prediction information deriving unit 104 will be described later.

  The motion compensated prediction unit 105 generates a predicted image signal by inter prediction (motion compensated prediction) from the reference picture using the motion vectors detected by the motion vector detection unit 102 and the inter prediction information deriving unit 104, and generates the predicted image signal. This is supplied to the prediction method determination unit 107. In L0 prediction and L1 prediction, one-way prediction is performed. In the case of bi-prediction (Pred_BI), bi-directional prediction is performed, the inter-predicted signals of L0 prediction and L1 prediction are adaptively multiplied by weighting factors, offset values are added and superimposed, and finally A predicted image signal is generated.

  The intra prediction unit 106 performs intra prediction for each intra prediction mode. A prediction image signal is generated by intra prediction from the decoded image signal stored in the decoded image memory 211, a suitable intra prediction mode is selected from a plurality of intra prediction modes, the selected intra prediction mode, and A prediction image signal corresponding to the selected intra prediction mode is supplied to the prediction method determination unit 107.

  The prediction method determination unit 107 evaluates the encoding information and the code amount of the residual signal for each prediction method, the distortion amount between the prediction image signal and the image signal, and the like from among a plurality of prediction methods. The prediction mode PredMode and split mode PartMode are determined to determine whether inter prediction (PRED_INTER) or intra prediction (PRED_INTRA) is optimal for each coding block. In inter prediction (PRED_INTER), it is determined whether or not the mode is merge mode. When the merge mode is selected, the merge index is determined. When the merge mode is not selected, the inter prediction mode, the prediction motion vector index, the L0 and L1 reference indexes, the difference motion vector, and the like are determined. To the encoded bit string generation unit 110.

  Furthermore, the prediction method determination unit 107 stores information indicating the determined prediction method and encoded information including a motion vector corresponding to the determined prediction method in the encoded information storage memory 115. The encoded information stored here is a flag predFlagL0 [xP] [yP], predFlagL1 [indicating whether to use the prediction mode PredMode, the partition mode PartMode, the L0 prediction of each prediction block, and the L1 prediction of each prediction block. xP] [yP], L0, L1 reference indices refIdxL0 [xP] [yP], refIdxL1 [xP] [yP], L0, L1 motion vectors mvL0 [xP] [yP], mvL1 [xP] [yP], etc. It is. Here, xP and yP are indexes indicating the position of the upper left pixel of the prediction block in the picture. When the prediction mode PredMode is intra prediction (MODE_INTRA), a flag predFlagL0 [xP] [yP] indicating whether to use L0 prediction and a flag predFlagL1 [xP] [yP] indicating whether to use L1 prediction are Both are zero. On the other hand, when the prediction mode PredMode is inter prediction (MODE_INTER) and the inter prediction mode is L0 prediction (Pred_L0), the flag predFlagL0 [xP] [yP] indicating whether to use L0 prediction is 1, L1 prediction is used. The flag predFlagL1 [xP] [yP] indicating whether or not is zero. When the inter prediction mode is L1 prediction (Pred_L1), the flag predFlagL0 [xP] [yP] indicating whether to use L0 prediction is 0, and the flag predFlagL1 [xP] [yP] indicating whether to use L1 prediction is 1. When the inter prediction mode is bi-prediction (Pred_BI), a flag predFlagL0 [xP] [yP] indicating whether to use L0 prediction and a flag predFlagL1 [xP] [yP] indicating whether to use L1 prediction are both 1. It is. The prediction method determination unit 107 supplies a prediction image signal corresponding to the determined prediction mode to the residual signal generation unit 108 and the decoded image signal superimposition unit 114.

The residual signal generation unit 108 generates a residual signal by performing subtraction between the image signal to be encoded and the predicted image signal, and supplies the residual signal to the orthogonal transform / quantization unit 109.
The orthogonal transform / quantization unit 109 performs orthogonal transform and quantization on the residual signal in accordance with the quantization parameter to generate an orthogonal transform / quantized residual signal, and a second encoded bit string generation unit 111 and the inverse quantization / inverse orthogonal transform unit 113. Further, the orthogonal transform / quantization unit 109 stores the quantization parameter in the encoded information storage memory 115.

  The first encoded bit string generation unit 110, in addition to information in units of sequences, pictures, slices, and encoded blocks, codes corresponding to the prediction method determined by the prediction method determination unit 107 for each encoded block and predicted block Encoding information is encoded. Specifically, in the prediction mode PredMode, partition mode PartMode, and inter prediction (PRED_INTER) for each coding block, a flag that determines whether or not the mode is merge mode, merge index in the case of merge mode, and inter prediction in the case of not in merge mode Encoding information such as information on the mode, the predicted motion vector index, and the difference motion vector is encoded according to a prescribed syntax rule to be described later to generate a first encoded bit string, which is supplied to the multiplexing unit 112.

  The second encoded bit string generation unit 111 generates a second encoded bit string by entropy-encoding the orthogonally transformed and quantized residual signal according to a specified syntax rule, and supplies the second encoded bit string to the multiplexing unit 112. The multiplexing unit 112 multiplexes the first encoded bit string and the second encoded bit string in accordance with a prescribed syntax rule, and outputs a bit stream.

  The inverse quantization / inverse orthogonal transform unit 113 performs inverse quantization and inverse orthogonal transform on the orthogonal transform / quantized residual signal supplied from the orthogonal transform / quantization unit 109 to calculate a residual signal, and performs decoding. This is supplied to the image signal superimposing unit 114. The decoded image signal superimposing unit 114 superimposes the predicted image signal according to the determination by the prediction method determining unit 107 and the residual signal subjected to inverse quantization and inverse orthogonal transform by the inverse quantization / inverse orthogonal transform unit 113 to decode the decoded image. Is generated and stored in the decoded image memory 116. Note that the decoded image may be stored in the decoded image memory 116 after filtering processing for reducing distortion such as block distortion due to encoding.

  FIG. 2 is a block diagram showing the configuration of the moving picture decoding apparatus according to the embodiment of the present invention corresponding to the moving picture encoding apparatus of FIG. The moving picture decoding apparatus according to the embodiment includes a separation unit 201, a first encoded bit string decoding unit 202, a second encoded bit string decoding unit 203, a motion vector calculation unit 204, an inter prediction information derivation unit 205, and a motion compensation prediction unit 206. , An intra prediction unit 207, an inverse quantization / inverse orthogonal transform unit 208, a decoded image signal superimposing unit 209, an encoded information storage memory 210, and a decoded image memory 211.

  The decoding process of the moving picture decoding apparatus in FIG. 2 corresponds to the decoding process provided in the moving picture encoding apparatus in FIG. 1, so the motion compensation prediction unit 206 in FIG. The configuration of the inverse orthogonal transform unit 208, the decoded image signal superimposing unit 209, the encoded information storage memory 210, and the decoded image memory 211 is the same as that of the motion compensation prediction unit 105, the inverse quantization / inverse of the moving image encoding device in FIG. The orthogonal transform unit 113, the decoded image signal superimposing unit 114, the encoded information storage memory 115, and the decoded image memory 116 have functions corresponding to the respective configurations.

  The bit stream supplied to the separation unit 201 is separated according to a rule of a prescribed syntax, the separated first encoded bit string is supplied to the first encoded bit string decoding unit 202, and the second encoded bit string is the first encoded bit string. This is supplied to the 2-encoded bit string decoding unit 203.

  The first encoded bit string decoding unit 202 decodes the supplied encoded bit string to obtain sequence, picture, slice, encoded block unit information, and predicted block unit encoded information. Specifically, in the prediction mode PredMode for determining whether the prediction is inter prediction (PRED_INTER) or intra prediction (PRED_INTRA) for each coding block, split mode PartMode, and inter prediction (PRED_INTER), a flag for determining whether the mode is merge mode, When the merge mode is selected, the merge index is decoded. When the merge mode is not selected, the encoded information related to the inter prediction mode, the predicted motion vector index, the difference motion vector, and the like is decoded according to a predetermined syntax rule to be described later, and the encoded information is a motion vector calculation unit. 204, supplied to the inter prediction information deriving unit 205 or the intra prediction unit 207.

  The second encoded bit string decoding unit 203 calculates a residual signal that has been orthogonally transformed / quantized by decoding the supplied encoded bit string, and dequantized / inverted the residual signal that has been orthogonally transformed / quantized. This is supplied to the orthogonal transform unit 208.

  When the prediction mode PredMode of the prediction block to be decoded is inter prediction (PRED_INTER) and not the merge mode, the motion vector calculation unit 204 stores the encoded information of the already decoded image signal stored in the encoded information storage memory 210. A plurality of motion vector predictor candidates that are derived and registered in a motion vector predictor list to be described later, and a first encoded bit string decoding unit is selected from the motion vector predictor candidates registered in the motion vector predictor list A prediction motion vector corresponding to the prediction motion vector index decoded and supplied in 202 is selected, a motion vector is calculated from the difference vector decoded in the first encoded bit string decoding unit 202 and the selected prediction motion vector, The encoded information is supplied to the motion compensation prediction unit 206 and stored in the encoded information storage memory 210. To. The encoding information of the prediction block supplied / stored here is a flag predFlagL0 [xP] [yP], predFlagL1 [xP] [yP indicating whether to use the prediction mode PredMode, the partition mode PartMode, the L0 prediction, and the L1 prediction. ], L0, L1 reference indices refIdxL0 [xP] [yP], refIdxL1 [xP] [yP], L0, L1 motion vectors mvL0 [xP] [yP], mvL1 [xP] [yP], and the like. Here, xP and yP are indexes indicating the position of the upper left pixel of the prediction block in the picture. When the prediction mode PredMode is inter prediction (MODE_INTER) and the inter prediction mode is L0 prediction (Pred_L0), the flag predFlagL0 indicating whether to use the L0 prediction is 1, and the flag predFlagL1 indicating whether to use the L1 prediction is 0. It is. When the inter prediction mode is L1 prediction (Pred_L1), the flag predFlagL0 indicating whether to use L0 prediction is 0, and the flag predFlagL1 indicating whether to use L1 prediction is 1. When the inter prediction mode is bi-prediction (Pred_BI), a flag predFlagL0 indicating whether to use L0 prediction and a flag predFlagL1 indicating whether to use L1 prediction are both 1.

  The inter prediction information deriving unit 205 derives merge candidates when the prediction mode PredMode of the prediction block to be decoded is inter prediction (PRED_INTER) and in the merge mode. A plurality of merge candidates are derived and registered in a merge candidate list, which will be described later, using the encoded information of already decoded prediction blocks stored in the encoded information storage memory 115, and registered in the merge candidate list Whether a merge candidate corresponding to the merge index decoded and supplied by the first encoded bit string decoding unit 202 is selected from among a plurality of merge candidates, and whether to use the L0 prediction and the L1 prediction of the selected merge candidate PredFlagL0 [xP] [yP], predFlagL1 [xP] [yP], L0, L1 reference indices refIdxL0 [xP] [yP], refIdxL1 [xP] [yP], L0, L1 motion vectors mvL0 [xP] Inter prediction information such as [yP] and mvL1 [xP] [yP] is supplied to the motion compensation prediction unit 206 and stored in the encoded information storage memory 210. Here, xP and yP are indexes indicating the position of the upper left pixel of the prediction block in the picture. The detailed configuration and operation of the inter prediction information deriving unit 205 will be described later.

  The motion compensation prediction unit 206 performs prediction by inter prediction (motion compensation prediction) from the reference picture stored in the decoded image memory 211 using the inter prediction information calculated by the motion vector calculation unit 204 or the inter prediction information deriving unit 205. An image signal is generated, and the predicted image signal is supplied to the decoded image signal superimposing unit 209. In the case of bi-prediction (Pred_BI), a weighted coefficient is adaptively multiplied and superimposed on the two motion-compensated predicted image signals of L0 prediction and L1 prediction to generate a final predicted image signal.

  The intra prediction unit 207 performs intra prediction when the prediction mode PredMode of the prediction block to be decoded is intra prediction (PRED_INTRA). The encoded information decoded by the first encoded bit string decoding unit includes an intra prediction mode, and by intra prediction from a decoded image signal stored in the decoded image memory 211 according to the intra prediction mode. A predicted image signal is generated, and the predicted image signal is supplied to the decoded image signal superimposing unit 209. Flags predFlagL0 [xP] [yP] and predFlagL1 [xP] [yP] indicating whether to use L0 prediction and L1 prediction are both set to 0 and stored in the encoded information storage memory 210. Here, xP and yP are indexes indicating the position of the upper left pixel of the prediction block in the picture.

  The inverse quantization / inverse orthogonal transform unit 208 performs inverse orthogonal transform and inverse quantization on the orthogonal transform / quantized residual signal decoded by the first encoded bit string decoding unit 202, and performs inverse orthogonal transform / An inverse quantized residual signal is obtained.

  The decoded image signal superimposing unit 209 performs the prediction image signal inter-predicted by the motion compensation prediction unit 206 or the prediction image signal intra-predicted by the intra prediction unit 207 and the inverse orthogonal transform by the inverse quantization / inverse orthogonal transform unit 208. The decoded image signal is decoded by superimposing the dequantized residual signal, and stored in the decoded image memory 211. When stored in the decoded image memory 211, the decoded image may be stored in the decoded image memory 211 after filtering processing that reduces block distortion or the like due to encoding is performed on the decoded image.

(About syntax)
Next, a syntax that is a common rule for encoding and decoding a bit stream of a moving image that is encoded by a moving image encoding device including the motion vector prediction method according to the present embodiment and decoded by the decoding device explain.

  FIG. 10 shows a first syntax structure described in the slice header in units of slices of the bitstream generated according to the present embodiment. However, only syntax elements relevant to the present embodiment are shown. When the slice type is a B slice, a picture colPic at a different time used in deriving a temporal motion vector predictor candidate or merge candidate is a L0 reference list of pictures including a prediction block to be processed or an L1 reference picture A flag collocated_from_l0_flag indicating which reference picture registered in the reference list is used is set. Details of the flag collocated_from_l0_flag will be described later.

  Note that the above syntax elements may be placed in a picture parameter set describing syntax elements set in units of pictures.

  FIG. 11 shows a syntax pattern described in units of prediction blocks. When the value of the prediction mode PredMode of the prediction block is inter prediction (MODE_INTER), merge_flag [x0] [y0] indicating whether the mode is the merge mode is set. Here, x0 and y0 are indices indicating the position of the upper left pixel of the prediction block in the picture of the luminance signal, and merge_flag [x0] [y0] is the prediction block located at (x0, y0) in the picture It is a flag indicating whether or not merge mode.

  Next, when merge_flag [x0] [y0] is 1, it indicates merge mode, and a merge list index syntax element merge_idx [x0] [y0] is set, which is a list of merge candidates to be referred to. . Here, x0 and y0 are indices indicating the position of the upper left pixel of the prediction block in the picture, and merge_idx [x0] [y0] is the merge index of the prediction block located at (x0, y0) in the picture. is there. FIG. 12 shows an example of the entropy code of the merge index syntax element merge_idx [x0] [y0]. In the present embodiment of the present invention, the number of merge candidates is set to five. When the merge index is 0, 1, 2, 3, 4, the signs of the merge index syntax elements merge_idx [x0] [y0] are “0”, “10”, “110”, “1110”, and “1111”, respectively. 'Become.

  On the other hand, when merge_flag [x0] [y0] is 0, it indicates that the mode is not merge mode. When the slice type is B slice, a syntax element inter_pred_flag [x0] [y0] for identifying the inter prediction mode is installed. The syntax element identifies L0 prediction (Pred_L0), L1 prediction (Pred_L1), and bi-prediction (Pred_BI). For each of L0 and L1, syntax elements ref_idx_l0 [x0] [y0] and ref_idx_l1 [x0] [y0] of the reference index for specifying the reference picture, the motion vector and prediction of the prediction block obtained by motion vector detection The differential motion vector syntax elements mvd_l0 [x0] [y0] [j] and mvd_l1 [x0] [y0] [j], which are the differences from the motion vector, are provided. Here, x0 and y0 are indexes indicating the position of the upper left pixel of the prediction block in the picture, and ref_idx_l0 [x0] [y0] and mvd_l0 [x0] [y0] [j] are respectively (x0 , y0) is the reference index of L0 of the prediction block and the differential motion vector, and ref_idx_l1 [x0] [y0] and mvd_l1 [x0] [y0] [j] are respectively (x0, y0) in the picture It is the reference index of L1 of the prediction block located, and a difference motion vector. Further, j represents a differential motion vector component, j represents 0 as an x component, and j represents 1 as a y component. Next, syntax elements mvp_idx_l0 [x0] [y0] and mvp_idx_l1 [x0] [y0] of an index of a predicted motion vector list that is a list of predicted motion vector candidates to be referred to are set. Here, x0 and y0 are indices indicating the position of the upper left pixel of the prediction block in the picture, and mvp_idx_l0 [x0] [y0] and mvp_idx_l1 [x0] [y0] are in (x0, y0) in the picture It is the prediction motion vector index of L0 and L1 of the prediction block located. In the present embodiment of the present invention, the value of the number of candidates is set to 2.

  The inter prediction information deriving method according to the embodiment is implemented in the inter prediction information deriving unit 104 of the video encoding device in FIG. 1 and the inter prediction information deriving unit 205 of the video decoding device in FIG.

  Next, the inter prediction information derivation method according to the embodiment will be described with reference to the drawings. The inter prediction information derivation method is performed in any of encoding and decoding processes for each prediction block constituting the encoding block. When the prediction mode PredMode of the prediction block is inter prediction (MODE_INTER) and in the merge mode, in the case of encoding, the prediction block to be encoded using the prediction mode, reference index, and motion vector of the encoded prediction block When the prediction mode, the reference index, and the motion vector are derived, in the case of decoding, the prediction mode, the reference index, and the motion vector of the prediction block to be decoded using the prediction mode, the reference index, and the motion vector of the decoded prediction block It is carried out when deriving.

  The merge mode is the prediction block A that is close to the left, the prediction block B that is close to the top, the prediction block C that is close to the top right, and the prediction block D that is close to the bottom left described with reference to FIGS. 5, 6, 7, and 8. In addition to the five prediction blocks of the prediction block E adjacent to the upper left, from the prediction block Col (either T0 or T1) existing at or near the same position at different times described with reference to FIG. Derive merge candidates. The inter prediction information deriving unit 104 of the moving image encoding device and the inter prediction information deriving unit 205 of the moving image decoding device register these merge candidates in the merge candidate list in a common order on the encoding side and the decoding side. The inter prediction information deriving unit 104 of the video encoding device determines a merge index for specifying an element of the merge candidate list, encodes it via the first encoded bit string generation unit, and performs inter prediction of the video decoding device. The information deriving unit 205 is supplied with the merge index decoded by the first encoded bit string decoding unit 202, selects a prediction block corresponding to the merge index from the merge candidate list, and selects the prediction mode of the selected merge candidate, Motion compensation prediction is performed using inter prediction information such as a reference index and a motion vector.

  FIG. 13 is a diagram illustrating a detailed configuration of the inter prediction information deriving unit 104 of the video encoding device in FIG. FIG. 14 is a diagram illustrating a detailed configuration of the inter prediction information deriving unit 205 of the video decoding device in FIG.

  13 and FIG. 14 indicate the inter prediction information deriving unit 104 of the moving picture coding apparatus and the inter prediction information deriving unit 205 of the moving picture decoding apparatus, respectively.

  Furthermore, the portions surrounded by the thick dotted lines inside them are the merge candidate list construction unit 120 of the moving picture coding apparatus that derives the respective merge candidates and constructs the merge candidate list, and the merge candidate list of the moving picture decoding apparatus. A construction unit 220 is shown, which is similarly installed in a moving picture decoding apparatus corresponding to the moving picture encoding apparatus of the embodiment, so that the same derivation result consistent with encoding and decoding can be obtained.

  In the inter prediction information derivation method according to the embodiment, merge candidate derivation and merge candidate list construction processing in the merge candidate list construction unit 120 of the video encoding device and the merge candidate list construction unit 220 of the video decoding device , Merging candidate derivation and merge candidate list construction processing of the prediction block to be processed are performed without referring to a prediction block included in the same encoding block as the encoding block including the prediction block to be processed. In this way, when the coding block division mode (PartMode) is not 2N × 2N division (PART_2Nx2N), that is, when there are a plurality of prediction blocks in the coding block, the coding side performs coding. The merge candidate derivation of each prediction block and the merge candidate list construction process can be performed in parallel in the conversion block.

  The parallel processing for constructing the merge candidate list of each prediction block in the coding block will be described for each partition mode (PartMode) with reference to FIG. FIG. 15 is a diagram illustrating a prediction block that is close to a processing target prediction block for each division mode (PartMode) of the processing target coding block. In FIG. 15, A0, B0, C0, D0, and E0 are a prediction block A that is close to the left side of the prediction block to be processed whose partition index PartIdx is 0, a prediction block B that is close to the upper side, and a vertex at the upper right. A prediction block C that is close to, a prediction block D that is close to the lower left vertex, and a prediction block E that is close to the upper left vertex are shown, and A1, B1, C1, D1, and E1 are predictions of processing targets with a partition index PartIdx of 1 Prediction block A near the left side of each block, prediction block B near the top side, prediction block C near the top right vertex, prediction block D near the bottom left vertex, and top left vertex Indicates the prediction block E, and A2, B2, C2, D2, and E2 are the left sides of the prediction blocks to be processed whose partition index PartIdx is 2, respectively. A prediction block A that is close, a prediction block B that is close to the upper side, a prediction block C that is close to the top right vertex, a prediction block D that is close to the bottom left vertex, and a prediction block E that is close to the top left vertex are shown as A3 , B3, C3, D3, and E3 are a prediction block A that is close to the left side of the prediction block to be processed whose partition index PartIdx is 3, a prediction block B that is close to the upper side, and a prediction block that is close to the top right vertex. C, a prediction block D close to the lower left vertex, and a prediction block E close to the upper left vertex.

  FIGS. 15B, 15C, and 15D show that the partition mode (PartMode) for dividing the encoded block to be processed into two prediction blocks arranged vertically is 2N × N partition (PART_2NxN), 2N × nU partition ( It is a figure which shows the prediction block which adjoins in PART_2NxnU) and 2NxnD division | segmentation (PART_2NxnD). A prediction block B1 close to a processing target prediction block with PartIdx of 1 is a prediction block with PartIdx of 0. Therefore, with reference to the prediction block B1, in order to perform merge candidate derivation and merge candidate list construction processing for a prediction block with PartIdx of 1, merging prediction blocks with a PartIdx of 0 belonging to the same coding block as the prediction block B1 The processing cannot be performed unless the candidate derivation and merge candidate list construction processing is completed and the merge candidates to be used are specified. Therefore, in the inter prediction information derivation method according to the embodiment, the partition mode (PartMode) is 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), 2N × nD partition (PART_2NxnD), and the prediction of the processing target When the block's PartIdx is 1, the encoding of the prediction block B1 that is close to the upper side of the processing target prediction block and included in the same coding block as the coding block including the processing target prediction block is a prediction block having a PartIdx of 0 Without referring to the information, with reference to the encoding information of the prediction block A1, C1, D1, or E1 that is not included in the same encoding block as the encoding block including the prediction block to be processed, the prediction block of PartIdx = 1 By performing merge candidate derivation and merge candidate list construction processing, merge candidate derivation and merge candidate of two prediction blocks in the encoded block Complementary list construction processing can be processed in parallel.

  15 (e), (f), and (g) show that the division mode (PartMode) indicating the mode for dividing the coding block to be processed into two prediction blocks arranged side by side is N × 2N division (PART_Nx2N), nL × It is a figure which shows the prediction block which adjoins by 2N division | segmentation (PART_nLx2N) and nRx2N division | segmentation (PART_nRx2N). A prediction block A1 adjacent to a processing target prediction block with PartIdx of 1 is a prediction block with PartIdx of 0. Therefore, with reference to the prediction block A1, in order to perform merge candidate derivation and merge candidate list construction processing for a prediction block with PartIdx of 1, the merge of prediction blocks with PartIdx of 0 belonging to the same coding block that is the prediction block A1 The processing cannot be performed unless the candidate derivation and merge candidate list construction processing is completed and the merge candidates to be used are specified. Therefore, in the inter prediction information derivation method according to the embodiment, the partition mode (PartMode) is N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), and nR × 2N partition (PART_nRx2N), When the block's PartIdx is 1, the encoding of the prediction block A1 is a prediction block that is close to the left side of the processing target prediction block and is included in the same encoding block as the encoding block including the processing target prediction block. Without referring to the information, the encoding information of the prediction block B1, C1, D1, or E1 that is not included in the same encoding block as the encoding block including the prediction block to be processed is referred to and the prediction block of PartIdx is 1 By performing merge candidate derivation and merge candidate list construction processing, merge candidate derivation and marching of each prediction block in the encoded block are performed. The candidate list construction process can be processed in parallel.

  Here, parallel processing of merge candidate derivation and merge candidate list construction processing will be described. FIG. 16 is a flowchart for explaining merge candidate derivation and merge candidate list construction processing by sequential processing, and FIG. 17 is a flowchart for explaining merge candidate derivation and merge candidate list construction processing by parallel processing.

  In the sequential processing of merge candidate derivation and merge candidate list construction processing shown in FIG. 16, derivation of merge candidates of a prediction block whose partition index PartIdx of a coding block to be processed is 0 and construction of a merge candidate list (steps) S101). Subsequently, when the division mode (PartMode) is 2N × 2N division (PART_2Nx2N) (NO in step S102), the merge candidate derivation and merge candidate list construction processing are terminated. When the partition mode (PartMode) is not 2N × 2N partition (PART_2Nx2N) (NO in step S102), that is, the partition mode (PartMode) is 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), 2N × nD partition (PART_2NxnD), N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), nR × 2N partition (PART_nRx2N) The derivation and merge candidate list is constructed (step S103), and the merge candidate derivation and merge candidate list construction process ends.

  In the parallel processing of merge candidate derivation and merge candidate list construction processing shown in FIG. 17, the merge candidate derivation of the prediction block whose partition index PartIdx of the coding block to be processed is 0 and the merge candidate list are constructed (step) S101). In parallel with step S101, when the partition mode (PartMode) is not 2N × 2N partition (PART_2Nx2N) (NO in step S102), that is, the partition mode (PartMode) is 2N × N partition (PART_2NxN), 2N × nU partition ( In the case of PART_2NxnU), 2N × nD partition (PART_2NxnD), N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), nR × 2N partition (PART_nRx2N), the partition index PartIdx of the processing target coding block is 1 Derivation of merge candidates for the prediction block and a merge candidate list are constructed (step S103).

  In the parallel processing of merge candidate derivation and merge candidate list construction processing shown in FIG. 17, the partition mode (PartMode) is 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), 2N × nD partition (PART_2NxnD), For N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), or nR × 2N partition (PART_nRx2N), a prediction block with PartIdx equal to 1 without referring to a prediction block with PartIdx of 0 in the same encoded block By performing the merge candidate derivation and merge candidate list construction processing, it is possible to simultaneously start merge candidate derivation and merge candidate list construction processing of two prediction blocks whose partition indexes PartIdx are 0 and 1.

  In the sequential processing of merge candidate derivation and merge candidate list construction processing shown in FIG. 16, merge candidate derivation and merge candidate list construction processing for a prediction block with PartIdx of 1 are performed without referring to a prediction block with PartIdx of 0. Is possible.

  In this embodiment, the division mode (PartMode) does not define N × N division (PART_NxN), but N × N division (PART_NxN) can also be defined. FIG. 15 (h) shows adjacent prediction blocks in which the division mode (PartMode) is divided into four prediction blocks by dividing the luminance signal of the coding block to be processed into four prediction blocks in the vertical and horizontal directions, and in N × N division (PART_NxN). FIG. A prediction block A1 adjacent to a processing target prediction block with PartIdx of 1 is a prediction block with PartIdx of 0. Therefore, in order to perform merge candidate derivation and merge candidate list construction processing for a prediction block with PartIdx of 1 with reference to the prediction block A1, merge candidates of prediction blocks with PartIdx of 0 belonging to the same coding block that is the prediction block A1. The process cannot be performed unless the derivation and merge candidate list construction process is completed and the merge candidates to be used are specified. Therefore, in the inter prediction information derivation method according to the embodiment, the prediction mode is a prediction block in which the partition mode (PartMode) is N × N partition (PART_NxN), the processing target prediction block PartIdx is 1, and PartIdx is 0 The merge candidate derivation and merge candidate list construction processing for each prediction block in the encoded block by performing merge candidate derivation and merge candidate list construction processing for a prediction block whose PartIdx is 1 without referring to the block A1 Can be processed in parallel. A prediction block B2 adjacent to a processing target prediction block with PartIdx of 2 is a prediction block with PartIdx of 0, and a prediction block C2 is a prediction block of PartIdx with 1. Therefore, in order to perform merge candidate derivation and merge candidate list construction processing for a prediction block whose PartIdx is 2 with reference to the prediction blocks B2 and C2, the PartIdx belonging to the same coding block that is the prediction blocks B2 and C2 is 0 and 1 After the prediction block merge candidate derivation and merge candidate list construction processing are completed and the merge candidates to be used are specified, the processing cannot be performed. Therefore, in the inter prediction information deriving method according to the embodiment, the partition mode (PartMode) is N × N partition (PART_NxN), the prediction block to be processed is PartIdx of 2, and the partIdx is 0 and 1 prediction blocks. By performing merge candidate derivation of a prediction block with PartIdx of 2 and construction of a merge candidate list without referring to certain prediction blocks B2 and C2, merge candidate derivation and merge candidate of each prediction block in the encoded block are performed. The list construction process can be processed in parallel. The prediction block E3 that is close to the processing target prediction block whose PartIdx is 3 is a prediction block whose PartIdx is 0, the prediction block B3 is a prediction block whose PartIdx is 1, and the prediction block A3 is a prediction block whose PartIdx is 2. . Accordingly, in order to perform merge candidate derivation and merge candidate list construction processing for a prediction block with PartIdx of 3 with reference to the prediction blocks E3, B3, and A3, PartIdx belonging to the same encoded block that is the prediction blocks E3, B3, and A3 If the merge candidate derivation and merge candidate list construction process for the prediction blocks of 0, 1, and 2 are completed and the merge candidates to be used are specified, the process cannot be performed. Therefore, in the inter prediction information derivation method according to the embodiment, when the partition mode (PartMode) is N × N partition (PART_NxN), and the PartIdx of the prediction block to be processed is 3, the prediction of PartIdx is 0, 1 and 2 By performing the merge candidate derivation of the prediction block with PartIdx of 3 and the construction of the merge candidate list without referring to the prediction blocks E3, B3, and A3 that are blocks, the merge candidate of each prediction block in the encoded block The derivation and merge candidate list construction processes can be processed in parallel.

  The inter prediction information deriving unit 104 of the video encoding device in FIG. 13 includes a spatial merge candidate generation unit 130, a temporal merge candidate reference index deriving unit 131, a temporal merge candidate generation unit 132, a merge candidate registration unit 133, and the same merge candidate. A determination unit 134, a merge candidate supplement unit 135, and an encoding information selection unit 136 are included.

  The inter prediction information deriving unit 205 of the video decoding device in FIG. 14 includes a spatial merge candidate generation unit 230, a temporal merge candidate reference index deriving unit 231, a temporal merge candidate generation unit 232, a merge candidate registration unit 233, and a merge candidate identical determination. Section 234, merge candidate supplement section 235, and encoding information selection section 236.

  FIG. 18 is a merge candidate derivation process and a merge candidate list having functions common to the inter prediction information deriving unit 104 of the video encoding device and the inter prediction information deriving unit 205 of the video decoding device according to the embodiment of the present invention. It is a flowchart explaining the procedure of this construction process. Hereinafter, the processes will be described in order. In the following description, a case where the slice type slice_type is a B slice will be described unless otherwise specified, but the present invention can also be applied to a P slice. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  In the spatial merge candidate generation unit 130 of the inter prediction information deriving unit 104 of the moving image encoding device and the spatial merge candidate generation unit 230 of the inter prediction information deriving unit 205 of the moving image decoding device, each of them close to the encoding or decoding target block. Spatial merge candidates A, B, C, D, E from the prediction blocks A, B, C, D, E are derived and output. Here, N indicating any one of A, B, C, D, E and the temporal merge candidate Col is defined. A flag availableFlagN indicating whether or not the inter prediction information of the prediction block N can be used as the spatial merge candidate N, the L0 reference index refIdxL0N and the L1 reference index refIdxL1N of the spatial merge candidate N, and the L0 prediction indicating whether or not L0 prediction is performed. The flag predFlagL0N and the L1 prediction flag predFlagL1N indicating whether or not the L1 prediction is performed, the L0 motion vector mvL0N, and the L1 motion vector mvL1N are output (step S201). However, in the present embodiment, the merge candidate is derived without referring to the prediction block included in the same encoding block as the encoding block including the prediction block to be processed, so that the code including the prediction block to be processed Spatial merge candidates included in the same coding block as the coding block are not derived. The detailed processing procedure of step S201 will be described later in detail using the flowchart of FIG.

  Subsequently, the temporal merge candidate reference index deriving unit 131 of the inter prediction information deriving unit 104 of the video encoding device and the temporal merge candidate reference index deriving unit 231 of the inter prediction information deriving unit 205 of the video decoding device A reference index of a temporal merge candidate is derived and output from a prediction block adjacent to a block to be converted or decoded (step S202). However, in the present embodiment, the reference index of the temporal merge candidate is derived without referring to the prediction block included in the same encoded block as the encoded block including the prediction block to be processed. When the inter prediction is performed using the inter prediction information of the temporal merge candidate when the slice type slice_type is P slice, only the L0 reference index is derived in order to perform the L0 prediction (Pred_L0), and the slice type slice_type is the B slice. When performing inter prediction using inter prediction information of temporal merge candidates, in order to perform bi-prediction (Pred_BI), respective reference indexes of L0 and L1 are derived. The detailed processing procedure of step S202 will be described later in detail using the flowcharts of FIGS. 21, 23, 25, 27, 29, 30, and 32.

  Subsequently, in the temporal merge candidate generating unit 132 of the inter prediction information deriving unit 104 of the video encoding device and the temporal merge candidate generating unit 232 of the inter prediction information deriving unit 205 of the video decoding device, time from pictures at different times A merge candidate is derived and a time merge candidate is output. A flag availableFlagCol indicating whether a temporal merge candidate is available, an L0 prediction flag predFlagL0Col indicating whether L0 prediction of the temporal merge candidate is performed, an L1 prediction flag predFlagL1Col indicating whether L1 prediction is performed, and a motion vector of L0 The motion vector mvL1N of mvL0N and L1 is output (step S203). The detailed processing procedure of step S203 will be described later in detail using the flowchart of FIG.

  Subsequently, the merge candidate registration unit 133 of the inter prediction information deriving unit 104 of the video encoding device and the merge candidate registration unit 233 of the inter prediction information deriving unit 205 of the video decoding device create a merge candidate list mergeCandList and merge The merge candidate list mergeCandList is constructed by adding the spatial merge candidates A, B, C, D, E and the temporal merge candidate Col to the candidate list mergeCandList, and the merge candidate list mergeCandList is output (step S204). The detailed processing procedure of step S204 will be described later in detail using the flowchart of FIG.

  Subsequently, in the merge candidate identity determination unit 134 of the inter prediction information deriving unit 104 of the video encoding device and the merge candidate identity determination unit 234 of the inter prediction information deriving unit 205 of the video decoding device, in the merge candidate list mergeCandList, When the motion vectors of the same reference index have the same value as the merge candidate, the merge candidate is removed except for the merge candidate in the smallest order, and the merge candidate list mergeCandList is output (step S205).

  Subsequently, the merge candidate supplementing unit 135 of the inter prediction information deriving unit 104 of the video encoding device and the merge candidate supplementing unit 235 of the inter prediction information deriving unit 205 of the video decoding device are registered in the merge candidate list mergeCandList. The merge candidates are supplemented so that the number of merge candidates that are present becomes the specified number, and the merge candidate list mergeCandList is output (step S206). In the present embodiment, the number of merge candidates is defined as five. The merge candidate list mergeCandList has a maximum number of merge candidates up to five, and the prediction mode in which the combination of L0 prediction and L1 prediction between already registered merge candidates is changed is a bi-prediction (Pred_BI) merge candidate or A merge candidate having a prediction mode having a value of (0, 0) at a different reference index and biprediction (Pred_BI) is added.

Next, a method for deriving the merge candidate N from the prediction block N adjacent to the encoding or decoding target block, which is the processing procedure of step S201 in FIG. 18, will be described in detail. FIG. 19 is a flowchart for describing the spatial merge candidate derivation processing procedure in step S201 of FIG.
In N, A (left side), B (upper side), C (upper right), D (lower left), or E (upper left) representing the region of the adjacent prediction block is entered. In this embodiment, a maximum of four spatial merge candidates are derived from five adjacent prediction blocks.

  In FIG. 18, the encoding information of the prediction block A adjacent to the left side of the prediction block to be encoded or decoded is determined with the variable N as A to derive the merge candidate A, and the prediction block adjacent to the upper side with the variable N as B The encoding information of B is examined to derive the merge candidate B, the encoding information of the prediction block C adjacent to the upper right side is determined with the variable N as C, the merge candidate C is derived, and the variable N is set as D to the lower left side. The encoding information of the adjacent prediction block D is checked to derive the merge candidate D, and the variable N is set as E to check the encoding information of the prediction block E adjacent to the upper left side to derive the merge candidate E (step S1101 to step S1101). S1114).

  First, when the variable N is E and the values of the flags availableFlagA, availableFlagB, availableFlagC, and availableFlagD are added and the total is 4 (YES in step S1102), that is, when four spatial merge candidates are derived, the merge candidate E The flag availableFlagE is set to 0 (step S1107), the values of the motion vectors mvL0E and mvL1E of the merge candidate E are both set to (0, 0) (step S1108), and the values of the flags predFlagL0E and predFlagL1E of the merge candidate E are both set. It is set to 0 (step S1109), and the space merge candidate derivation process is terminated. In the present embodiment, four merge candidates are derived from adjacent prediction blocks. Therefore, when four spatial merge candidates are already derived, it is not necessary to perform further spatial merge candidate derivation processing.

  On the other hand, if the variable N is not E or the values of the flags availableFlagA, availableFlagB, availableFlagC, and availableFlagD are added and the total is not 4 (NO in step S1102), the process proceeds to step S1103. When the adjacent prediction block N is included in the same encoding block as the encoding block including the prediction block to be derived (YES in step S1103), the value of the flag availableFlagN of the merge candidate N is set to 0 (step S1107). The values of the motion vectors mvL0N and mvL1N of the merge candidate N are both set to (0, 0) (step S1108), and the values of the flags predFlagL0N and predFlagL1N of the merge candidate N are both set to 0 (step S1109). When the adjacent prediction block N is included in the same encoding block as the encoding block including the prediction block to be derived (YES in step S1103), the encoding information of the adjacent prediction block N is not referred to, and the merge candidate N By setting the value of the flag availableFlagN to 0 and not making it a spatial merge candidate, parallel processing of merge candidate derivation and merge candidate list construction processing for each prediction block in the same coding block is enabled.

  Specifically, the partition mode (PartMode) is 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU) or 2N × nD partition (PART_2NxnD), and the processing target prediction block PartIdx is 1, The case of the prediction block B adjacent to the upper side of the prediction block is a case where the adjacent prediction block N is included in the same encoded block as the encoded block including the prediction block to be derived. In this case, since the prediction block B adjacent to the upper side of the prediction block to be derived is a prediction block in which the PartIdx included in the same encoding block as the encoding block including the prediction block to be derived is 0, the adjacent prediction block B By not setting the value of the flag availableFlagB of the merge candidate B to 0 and setting it as a spatial merge candidate, the merge candidate derivation and merge candidate list of each prediction block in the same encoded block are not referred to. Enables parallel processing of construction processing.

  Furthermore, the partition mode (PartMode) is N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N) or nR × 2N partition (PART_nRx2N), and the processing target prediction block PartIdx is 1, and the derivation target prediction block The case of the prediction block A adjacent to the left side is also a case where the adjacent prediction block N is included in the same encoding block as the encoding block including the prediction block to be derived. Also in this case, since the prediction block A adjacent to the left side of the prediction block to be derived is a prediction block in which the PartIdx included in the same encoding block as the encoding block including the prediction block to be derived is 0, the adjacent prediction block By not referring to the encoding information of A and setting the value of the flag availableFlagA of the merge candidate A to 0 to make it not a spatial merge candidate, merge candidate derivation and merge candidate list of each prediction block in the same encoded block Enables parallel processing of the building process.

  Further, although not defined in the present embodiment, the adjacent prediction block N is derived even when the partition mode (PartMode) is N × N partition (PART_NxN) and the PartIdx of the prediction block to be processed is 1, 2 or 3. It may be included in the same encoded block as the encoded block including the target prediction block.

  On the other hand, when the adjacent prediction block N is not included in the same encoding block as the encoding block including the processing target prediction block (NO in step S1103), the prediction block N adjacent to the prediction block to be encoded or decoded is determined. If each prediction block N is specified, the encoding information of the prediction block N is acquired from the encoding information storage memory 115 or 210 (step S1104).

  If the adjacent prediction block N cannot be used (NO in step S1105), or the prediction mode PredMode of the prediction block N is intra prediction (MODE_INTRA) (NO in step S1106), the value of the flag availableFlagN of the merge candidate N is set to 0. (Step S1107), the values of the motion vectors mvL0N and mvL1N of the merge candidate N are both set to (0, 0) (Step S1108), and the values of the flags predFlagL0N and predFlagL1N of the merge candidate N are both set to 0 ( Step S1109). Here, when the adjacent prediction block N cannot be used, specifically, when the adjacent prediction block N is located outside the slice to be encoded or decoded, or still in the encoding or decoding processing order. This corresponds to the case where the encoding or decoding process has not been completed.

  On the other hand, whether the adjacent prediction block N is outside the same encoding block as the encoding block of the prediction block to be derived (YES in step S1104), or the adjacent prediction block N can be used (YES in step S1105). When the prediction mode PredMode is not intra prediction (MODE_INTRA) (YES in step S1106), the inter prediction information of the prediction block N is set as the inter prediction information of the merge candidate N. The value of the flag availableFlagN of the merge candidate N is set to 1 (step S1110), and the motion vectors mvL0N and mvL1N of the merge candidate N are respectively used as the motion vectors mvL0N [xN] [yN] and mvL1N [xN] [yN] of the prediction block N. (Step S1111), the reference indexes refIdxL0N and refIdxL1N of the merge candidate N are set to the same values as the reference indexes refIdxL0 [xN] [yN] and refIdxL1 [xN] [yN] of the prediction block N, respectively ( In step S1112, the flags predFlagL0N and predFlagL1N of the merge candidate N are set to the flags predFlagL0 [xN] [yN] and predFlagL1 [xN] [yN] of the prediction block N, respectively (step S1113). Here, xN and yN are indexes indicating the position of the upper left pixel of the prediction block N in the picture.

  The processes in steps S1102 to S1113 are repeated for N = A, B, C, D, and E (steps S1101 to S1114).

  Next, a method for deriving the reference index of the time merge candidate in S202 of FIG. 18 will be described in detail. The reference indices of L0 and L1 as temporal merge candidates are derived.

  In the present embodiment, the reference index of the temporal merge candidate is derived using the reference index of the spatial merge candidate, that is, the reference index used in the prediction block adjacent to the encoding or decoding target block. This is because when the temporal merge candidate is selected, the reference index of the prediction block to be encoded or decoded has a high correlation with the reference index of the prediction block adjacent to the encoding or decoding target block to be the spatial merge candidate. It is. In particular, in the present embodiment, except for Example 6 and Example 7 described later, reference is made to the prediction block A that is close to the left side of the prediction block to be derived or the prediction block B that is close to the upper side. Use only the index. This is because the prediction blocks A and B that are in contact with the sides of the prediction block to be encoded or decoded among the adjacent prediction blocks A, B, C, D, and E that are also spatial merge candidates are predicted to be encoded or decoded. This is because the correlation is higher than prediction blocks C, D, and E that are in contact with only the vertices of the block. By limiting the prediction blocks to be used to the prediction blocks A and B without using the prediction blocks C, D, and E having relatively low correlation, the effect of improving the coding efficiency by deriving the reference index of the temporal merge candidate In addition, the amount of computation and the amount of memory access related to the reference index derivation process of the temporal merge candidate are reduced.

Example 1
Hereinafter, this embodiment will be described by dividing it into several examples. First, Example 1 of the present embodiment will be described. FIG. 20 is a diagram illustrating adjacent blocks referred to in the time merge candidate reference index derivation process according to the first embodiment of the present embodiment. In Example 1 of the present embodiment, either the prediction block adjacent to the left side of the prediction block to be derived or the prediction block adjacent to the upper side is switched according to the division mode (PartMode). Reference is made to a prediction block close to a side outside the coding block. When the partition mode (PartMode) is 2N × 2N partition (PART_2Nx2N), as shown in FIG. 20A, the prediction block A0 adjacent to the left of the prediction block to be derived is referred to, and the LX reference index of the temporal merge candidate Is set to the value of the reference index of the LX of the prediction block A0.

  When the partition mode (PartMode) for dividing the processing target coding block into two prediction blocks arranged vertically is 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), and 2N × nD partition (PART_2NxnD), FIG. As shown in (b), (c), and (d), the prediction block adjacent to the left side of the prediction block to be derived is referred to, and the LX reference index of each temporal merge candidate is used as the prediction block to be derived. Is set to the value of the reference index of the LX of the prediction block adjacent to the left side of. In a prediction block whose partition index PartIdx to be derived is 0, the prediction block A0 adjacent to the left is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction block A0. In a prediction block whose division index PartIdx to be derived is 1, the prediction block A1 that is adjacent to the left is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction block A1. Since the prediction blocks A0 and A1 to be referred to are both outside the coding block, the reference indexes of the temporal merge candidates of the two prediction blocks whose division indexes PartIdx are 0 and 1 can be derived in parallel.

  When the division mode (PartMode) for dividing the coding block to be processed into two prediction blocks arranged side by side is N × 2N division (PART_Nx2N), nL × 2N division (PART_nLx2N), and nR × 2N division (PART_nRx2N), FIG. As shown in (e), (f), and (g), the prediction block adjacent to the upper side of the prediction block to be derived is referred to, and the LX reference index of each temporal merge candidate is used as the prediction block of each derivation target. Is set to the value of the reference index of the LX of the prediction block adjacent to the upper side. In the prediction block whose partition index PartIdx to be derived is 0, the prediction block B0 that is close to the top is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction blocks B0 and B1. In a prediction block whose partition index PartIdx to be derived is 1, the prediction block B1 that is close to the top is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction block B1. Since the prediction blocks B0 and B1 to be referred to are both outside the coding block, the reference indexes of the temporal merge candidates of the two prediction blocks whose division indexes PartIdx are 0 and 1 can be derived in parallel.

  However, when the adjacent prediction block A and prediction block B do not perform LX prediction, the reference index value of the LX that is a temporal merge candidate is set to 0 as the default value. When the adjacent prediction block A and prediction block B do not perform LX prediction, the default value of the reference index of the temporal merge candidate LX is set to 0 because the reference picture corresponding to the reference index value of 0 in inter prediction This is because the probability of being most selected is high. However, the present invention is not limited to this, and the default value of the reference index may be a value other than 0 (1, 2, etc.), and the default value of the reference index may be set in the encoded stream at the sequence level, picture level, or slice level. The syntax element shown may be installed and transmitted so that it can be selected on the encoding side.

  FIG. 21 is a flow chart for explaining the procedure for deriving the reference index of the time merge candidate in step S202 of FIG. 18 by the method of Example 1 of the present embodiment. First, when the partition mode (PartMode) is not N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), or nR × 2N partition (PART_nRx2N) (NO in step S2101), that is, 2N × 2N partition (PART_2Nx2N), 2N In the case of × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), and 2N × nD partition (PART_2NxnD), the encoded information of the prediction block A adjacent to the left is acquired from the encoded information storage memory 115 or 210 ( Step S2111).

  The subsequent processing from step S2113 to step S2115 is performed in each of L0 and L1 (steps S2112 to S2116). Note that LX is set to L0 when deriving the L0 reference index of the temporal merge candidate, and LX is set to L1 when deriving the L1 reference index. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  When the flag predFlagLX [xA] [yA] indicating whether to perform LX prediction of the prediction block A is not 0 (YES in step S2113), the LX reference index refIdxLXCol of the temporal merge candidate is used as the LX reference index refIdxLX of the prediction block A. The same value as [xA] [yA] is set (step S2114). Here, xA and yA are indexes indicating the position of the upper left pixel of the prediction block A in the picture.

  In the present embodiment, in the prediction block N (N = A, B), when the prediction block N cannot be used outside the slice to be encoded or decoded, the prediction block N is encoded or encoded in the decoding order. Alternatively, a flag indicating whether or not to use L0 prediction when the encoding block is not encoded or decoded after the decoding target prediction block and cannot be used, or when the prediction mode PredMode of the prediction block N is intra prediction (MODE_INTRA). Both predFlagL0 [xN] [yN] and the flag predFlagL1 [xN] [yN] indicating whether to use the L1 prediction of the prediction block N are 0. Here, xN and yN are indexes indicating the position of the upper left pixel of the prediction block N in the picture. When the prediction mode PredMode of the prediction block N is inter prediction (MODE_INTER) and the inter prediction mode is L0 prediction (Pred_L0), the flag predFlagL0 [xN] [yN] indicating whether to use the L0 prediction of the prediction block N is 1 , Flag predFlagL1 [xN] [yN] indicating whether to use L1 prediction is zero. When the inter prediction mode of the prediction block N is L1 prediction (Pred_L1), a flag predFlagL0 [xN] [yN] indicating whether or not to use the L0 prediction of the prediction block N is 0 and a flag indicating whether or not to use the L1 prediction predFlagL1 [xN] [yN] is 1. When the inter prediction mode of the prediction block N is bi-prediction (Pred_BI), a flag predFlagL0 [xN] [yN] indicating whether to use the L0 prediction of the prediction block N, and a flag predFlagL1 [indicating whether to use the L1 prediction xN] [yN] are both 1.

  When the flag predFlagLX [xA] [yA] indicating whether or not to perform LX prediction of the prediction block A is 0 (NO in step S2113), the reference index refIdxLXCol of the LX that is a temporal merge candidate is set to a default value of 0 ( Step S2115).

  The processing from step S2113 to step S2115 is performed in each of L0 and L1 (steps S2112 to S2116), and this reference index derivation processing is terminated.

  On the other hand, when the partition mode (PartMode) is N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), nR × 2N partition (PART_nRx2N) (YES in step S2101), derived from the encoded information storage memory 115 or 210 The encoding information of the prediction block B adjacent on the target prediction block is acquired (step S2117).

  The subsequent processing from step S2119 to step S2121 is performed in each of L0 and L1 (steps S2118 to S2122). Note that LX is set to L0 when deriving the L0 reference index of the temporal merge candidate, and LX is set to L1 when deriving the L1 reference index. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  When the flag predFlagLX [xB] [yB] indicating whether to perform LX prediction of the prediction block B is not 0 (YES in step S2119), the LX reference index refIdxLXCol of the temporal merge candidate is used as the LX reference index refIdxLX of the prediction block B. It is set to the same value as [xB] [yB] (step S2120). Here, xB and yB are indexes indicating the position of the upper left pixel of the prediction block B in the picture.

  When the flag predFlagLX [xB] [yB] indicating whether or not to perform LX prediction of the prediction block B is 0 (NO in step S2119), the reference index refIdxLXCol of the time merge candidate LX is set to a default value of 0 ( Step S2121).

  The processing from step S2119 to step S2121 is performed in each of L0 and L1 (steps S2118 to S2122), and this reference index derivation processing is terminated.

Example 2
Next, Example 2 of the present embodiment will be described. FIG. 22 is a diagram illustrating neighboring blocks referred to in the time merge candidate reference index derivation process according to the second example of the present embodiment. In Example 2 of the present embodiment, the prediction block close to the left side of the prediction block to be derived or the prediction block close to the upper side is determined according to the partition mode (PartMode) of the encoded block and the partition index PartIdx of the prediction block. Switch which one to reference. Reference is made to a prediction block close to a side outside the coding block. When the partition mode (PartMode) is 2N × 2N partition (PART_2Nx2N), as shown in FIG. 22A, the prediction block A0 adjacent to the left of the prediction block to be derived is referred to, and the LX reference index of the temporal merge candidate Is set to the value of the reference index of the LX of the prediction block A0.

  When the partition mode (PartMode) for dividing the processing target coding block into two prediction blocks arranged vertically is 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), and 2N × nD partition (PART_2NxnD), FIG. As shown in (b), (c), and (d), the prediction block adjacent to the left side of the prediction block to be derived is referred to, and the LX reference index of each temporal merge candidate is used as the prediction block to be derived. Is set to the value of the reference index of the LX of the prediction block adjacent to the left side of. In a prediction block whose partition index PartIdx to be derived is 0, the prediction block A0 adjacent to the left is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction block A0. In a prediction block whose division index PartIdx to be derived is 1, the prediction block A1 that is adjacent to the left is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction block A1. Since the prediction blocks A0 and A1 to be referred to are both outside the coding block, the reference indexes of the temporal merge candidates of the two prediction blocks whose division indexes PartIdx are 0 and 1 can be derived in parallel.

  When the division mode (PartMode) for dividing the processing target coding block into two prediction blocks arranged side by side is N × 2N division (PART_Nx2N), nL × 2N division (PART_nLx2N), and nR × 2N division (PART_nRx2N), FIG. As shown in (e), (f), and (g), in the prediction block whose partition index PartIdx to be derived is 0, the prediction block A0 that is adjacent to the left is referred to, and the LX reference index that is the temporal merge candidate is the prediction block Set to the value of the LX reference index of A0. In a prediction block whose partition index PartIdx to be derived is 1, the prediction block B1 that is close to the top is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction block B1. Since the prediction blocks A0 and B1 to be referred to are both outside the coding block, the reference indexes of the temporal merge candidates of the two prediction blocks having the division indexes PartIdx of 0 and 1 can be derived in parallel.

  However, when the adjacent prediction block A and prediction block B do not perform LX prediction, the reference index value of the LX that is a temporal merge candidate is set to 0 as the default value. When the adjacent prediction block A and prediction block B do not perform LX prediction, the default value of the reference index of the temporal merge candidate LX is set to 0 because the reference picture corresponding to the reference index value of 0 in inter prediction This is because the probability of being most selected is high. However, the present invention is not limited to this, and the default value of the reference index may be a value other than 0 (1, 2, etc.), and the default value of the reference index may be set in the encoded stream at the sequence level, picture level, or slice level. The syntax element shown may be installed and transmitted so that it can be selected on the encoding side.

  FIG. 23 is a flow chart for explaining the procedure for deriving the reference index of the time merge candidate in step S202 of FIG. 18 by the method of Example 2 of the present embodiment. First, when the partition mode (PartMode) is N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), nR × 2N partition (PART_nRx2N) and the partition index PartIdx is not 1 (NO in step S2102), that is, 2N × 2N Partition (PART_2Nx2N), 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), 2N × nD partition (PART_2NxnD), or N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), nR × When 2N division (PART_nRx2N) and the division index PartIdx is 0, the encoding information of the prediction block A adjacent to the left of the prediction block to be derived is acquired from the encoding information storage memory 115 or 210 (step S2111).

  The subsequent processing from step S2113 to step S2115 is performed in each of L0 and L1 (steps S2112 to S2116). Note that LX is set to L0 when deriving the L0 reference index of the temporal merge candidate, and LX is set to L1 when deriving the L1 reference index. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  When the flag predFlagLX [xA] [yA] indicating whether to perform LX prediction of the prediction block A is not 0 (YES in step S2113), the LX reference index refIdxLXCol of the temporal merge candidate is used as the LX reference index refIdxLX of the prediction block A. The same value as [xA] [yA] is set (step S2114). Here, xA and yA are indexes indicating the position of the upper left pixel of the prediction block A in the picture.

  In the present embodiment, in the prediction block N (N = A, B), when the prediction block N cannot be used outside the slice to be encoded or decoded, the prediction block N is encoded or encoded in the decoding order. Alternatively, a flag indicating whether or not to use L0 prediction when the encoding block is not encoded or decoded after the decoding target prediction block and cannot be used, or when the prediction mode PredMode of the prediction block N is intra prediction (MODE_INTRA). Both predFlagL0 [xN] [yN] and the flag predFlagL1 [xN] [yN] indicating whether to use the L1 prediction of the prediction block N are 0. Here, xN and yN are indexes indicating the position of the upper left pixel of the prediction block N in the picture. When the prediction mode PredMode of the prediction block N is inter prediction (MODE_INTER) and the inter prediction mode is L0 prediction (Pred_L0), the flag predFlagL0 [xN] [yN] indicating whether to use the L0 prediction of the prediction block N is 1 , Flag predFlagL1 [xN] [yN] indicating whether to use L1 prediction is zero. When the inter prediction mode of the prediction block N is L1 prediction (Pred_L1), a flag predFlagL0 [xN] [yN] indicating whether or not to use the L0 prediction of the prediction block N is 0 and a flag indicating whether or not to use the L1 prediction predFlagL1 [xN] [yN] is 1. When the inter prediction mode of the prediction block N is bi-prediction (Pred_BI), a flag predFlagL0 [xN] [yN] indicating whether to use the L0 prediction of the prediction block N, and a flag predFlagL1 [indicating whether to use the L1 prediction xN] [yN] are both 1.

  When the flag predFlagLX [xA] [yA] indicating whether or not to perform LX prediction of the prediction block A is 0 (NO in step S2113), the reference index refIdxLXCol of the LX that is a temporal merge candidate is set to a default value of 0 ( Step S2115).

  The processing from step S2113 to step S2115 is performed in each of L0 and L1 (steps S2112 to S2116), and this reference index derivation processing is terminated.

  On the other hand, when the partition mode (PartMode) is N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), and nR × 2N partition (PART_nRx2N) and the partition index PartIdx is 1 (YES in step S2102), encoding information The encoding information of the prediction block B adjacent to the prediction block to be derived is acquired from the storage memory 115 or 210 (step S2117).

  The subsequent processing from step S2119 to step S2121 is performed in each of L0 and L1 (steps S2118 to S2122). Note that LX is set to L0 when deriving the L0 reference index of the temporal merge candidate, and LX is set to L1 when deriving the L1 reference index. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  When the flag predFlagLX [xB] [yB] indicating whether to perform LX prediction of the prediction block B is not 0 (YES in step S2119), the LX reference index refIdxLXCol of the temporal merge candidate is used as the LX reference index refIdxLX of the prediction block B. It is set to the same value as [xB] [yB] (step S2120). Here, xB and yB are indexes indicating the position of the upper left pixel of the prediction block B in the picture.

  When the flag predFlagLX [xB] [yB] indicating whether or not to perform LX prediction of the prediction block B is 0 (NO in step S2119), the reference index refIdxLXCol of the time merge candidate LX is set to a default value of 0 ( Step S2121).

  The processing from step S2119 to step S2121 is performed in each of L0 and L1 (steps S2118 to S2122), and this reference index derivation processing is terminated.

Example 3
Next, Example 3 of the present embodiment will be described. FIG. 24 is a diagram illustrating neighboring blocks referred to in the time merge candidate reference index derivation process according to the third example of the present embodiment. In Example 3 of the present embodiment, the prediction block close to the left side of the prediction block to be derived or the prediction block close to the upper side is determined according to the partition mode (PartMode) of the encoded block and the partition index PartIdx of the prediction block. Switch which one to reference. For a prediction block with a partition index PartIdx of 0, refer to a prediction block close to a long side having higher correlation, and for a prediction block with a partition index PartIdx of 1, refer to a prediction block close to a side outside the coding block To do. When the partition mode (PartMode) is 2N × 2N partition (PART_2Nx2N), as shown in FIG. 24A, the prediction block A0 adjacent to the left of the prediction block to be derived is referred to, and the LX reference index of the temporal merge candidate Is set to the value of the reference index of the LX of the prediction block A0.

  When the division mode (PartMode) for dividing the coding block to be processed into two prediction blocks arranged vertically is 2N × N division (PART_2NxN), 2N × nU division (PART_2NxnU), 2N × nD division (PART_2NxnD), FIG. As shown in (b), (c), and (d), the prediction block B0 that is close to the upper side, which is a long side in the prediction block whose partition index PartIdx to be derived is 0, is referenced, and the LX reference of the temporal merge candidate The index is set to the value of the LX reference index of the prediction block B0. In the prediction block whose partition index PartIdx is 1 to be derived, the prediction block A1 close to the left side outside the coding block is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction block A1. To do. Since the prediction blocks B0 and A1 to be referred to are both outside the encoded block, the reference indexes of the temporal merge candidates of the two prediction blocks whose division indexes PartIdx are 0 and 1 can be derived in parallel.

  When the division mode (PartMode) for dividing the coding block to be processed into two prediction blocks arranged side by side is N × 2N division (PART_Nx2N), nL × 2N division (PART_nLx2N), and nR × 2N division (PART_nRx2N), FIG. As shown in (e), (f), and (g), a prediction block A0 that is close to the left side, which is a long side in a prediction block whose partition index PartIdx to be derived is 0, is referenced, and a reference to LX that is a temporal merge candidate The index is set to the value of the LX reference index of the prediction block A0. In the prediction block whose partition index PartIdx is 1 to be derived, the prediction block B1 close to the upper side outside the coding block is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction block B1. To do. Since the prediction blocks A0 and B1 to be referred to are both outside the coding block, the reference indexes of the temporal merge candidates of the two prediction blocks having the division indexes PartIdx of 0 and 1 can be derived in parallel.

  However, when the adjacent prediction block A and prediction block B do not perform LX prediction, the reference index value of the LX that is a temporal merge candidate is set to 0 as the default value. When the adjacent prediction block A and prediction block B do not perform LX prediction, the default value of the reference index of the temporal merge candidate LX is set to 0 because the reference picture corresponding to the reference index value of 0 in inter prediction This is because the probability of being most selected is high. However, the present invention is not limited to this, and the default value of the reference index may be a value other than 0 (1, 2, etc.), and the default value of the reference index may be set in the encoded stream at the sequence level, picture level, or slice level. The syntax element shown may be installed and transmitted so that it can be selected on the encoding side.

  FIG. 25 is a flow chart for explaining the procedure for deriving the reference index of the time merge candidate in step S202 of FIG. 18 according to the method of Example 3 of the present embodiment. First, the partition mode (PartMode) is 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), 2N × nD partition (PART_2NxnD), and the partition index PartIdx is not 0, N × 2N partition (PART_Nx2N), nL × When 2N partition (PART_nLx2N), nR × 2N partition (PART_nRx2N) and partition index PartIdx is not 1 (NO in step S2103), that is, 2N × 2N partition (PART_2Nx2N) or 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), 2N × nD partition (PART_2NxnD) and partition index PartIdx is 0, or N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), nR × 2N partition (PART_nRx2N) partition index PartIdx Is 0, the encoding information of the prediction block A adjacent to the left of the prediction block to be derived is acquired from the encoding information storage memory 115 or 210 (step S21). 1).

  The subsequent processing from step S2113 to step S2115 is performed in each of L0 and L1 (steps S2112 to S2116). Note that LX is set to L0 when deriving the L0 reference index of the temporal merge candidate, and LX is set to L1 when deriving the L1 reference index. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  When the flag predFlagLX [xA] [yA] indicating whether to perform LX prediction of the prediction block A is not 0 (YES in step S2113), the LX reference index refIdxLXCol of the temporal merge candidate is used as the LX reference index refIdxLX of the prediction block A. The same value as [xA] [yA] is set (step S2114). Here, xA and yA are indexes indicating the position of the upper left pixel of the prediction block A in the picture.

  In the present embodiment, in the prediction block N (N = A, B), when the prediction block N cannot be used outside the slice to be encoded or decoded, the prediction block N is encoded or encoded in the decoding order. Alternatively, a flag indicating whether or not to use L0 prediction when the encoding block is not encoded or decoded after the decoding target prediction block and cannot be used, or when the prediction mode PredMode of the prediction block N is intra prediction (MODE_INTRA). Both predFlagL0 [xN] [yN] and the flag predFlagL1 [xN] [yN] indicating whether to use the L1 prediction of the prediction block N are 0. Here, xN and yN are indexes indicating the position of the upper left pixel of the prediction block N in the picture. When the prediction mode PredMode of the prediction block N is inter prediction (MODE_INTER) and the inter prediction mode is L0 prediction (Pred_L0), the flag predFlagL0 [xN] [yN] indicating whether to use the L0 prediction of the prediction block N is 1 , Flag predFlagL1 [xN] [yN] indicating whether to use L1 prediction is zero. When the inter prediction mode of the prediction block N is L1 prediction (Pred_L1), a flag predFlagL0 [xN] [yN] indicating whether or not to use the L0 prediction of the prediction block N is 0 and a flag indicating whether or not to use the L1 prediction predFlagL1 [xN] [yN] is 1. When the inter prediction mode of the prediction block N is bi-prediction (Pred_BI), a flag predFlagL0 [xN] [yN] indicating whether to use the L0 prediction of the prediction block N, and a flag predFlagL1 [indicating whether to use the L1 prediction xN] [yN] are both 1.

  When the flag predFlagLX [xA] [yA] indicating whether or not to perform LX prediction of the prediction block A is 0 (NO in step S2113), the reference index refIdxLXCol of the LX that is a temporal merge candidate is set to a default value of 0 ( Step S2115).

  The processing from step S2113 to step S2115 is performed in each of L0 and L1 (steps S2112 to S2116), and this reference index derivation processing is terminated.

  On the other hand, when the partition mode (PartMode) is N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), and nR × 2N partition (PART_nRx2N) and the partition index PartIdx is 1 (YES in step S2102), encoding information The encoding information of the prediction block B adjacent to the prediction block to be derived is acquired from the storage memory 115 or 210 (step S2117).

  The subsequent processing from step S2119 to step S2121 is performed in each of L0 and L1 (steps S2118 to S2122). Note that LX is set to L0 when deriving the L0 reference index of the temporal merge candidate, and LX is set to L1 when deriving the L1 reference index. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  When the flag predFlagLX [xB] [yB] indicating whether to perform LX prediction of the prediction block B is not 0 (YES in step S2119), the LX reference index refIdxLXCol of the temporal merge candidate is used as the LX reference index refIdxLX of the prediction block B. It is set to the same value as [xB] [yB] (step S2120). Here, xB and yB are indexes indicating the position of the upper left pixel of the prediction block B in the picture.

  When the flag predFlagLX [xB] [yB] indicating whether or not to perform LX prediction of the prediction block B is 0 (NO in step S2119), the reference index refIdxLXCol of the time merge candidate LX is set to a default value of 0 ( Step S2121).

  The processing from step S2119 to step S2121 is performed in each of L0 and L1 (steps S2118 to S2122), and this reference index derivation processing is terminated.

Example 4
Next, Example 4 of the present embodiment will be described. FIG. 26 is a diagram illustrating adjacent blocks referred to in the time merge candidate reference index derivation process according to the fourth example of the present embodiment. In Example 4 of the present embodiment, whether to refer to the prediction block adjacent to the left side of the prediction block to be derived is switched according to the partition mode (PartMode) of the encoded block and the partition index PartIdx of the prediction block. This is referred to when the prediction block close to the left side is outside the coding block, and when it is inside the coding block, it is not referred to and is set as a default value. When the partition mode (PartMode) is 2N × 2N partition (PART_2Nx2N), as illustrated in FIG. 26A, the prediction block A0 adjacent to the left of the prediction block to be derived is referred to, and the LX reference index of the temporal merge candidate Is set to the value of the reference index of the LX of the prediction block A0.

  When the partition mode (PartMode) for dividing the processing target coding block into two prediction blocks arranged vertically is 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), and 2N × nD partition (PART_2NxnD), FIG. As shown in (b), (c), and (d), in the prediction block whose partitioning index PartIdx to be derived is 0, the prediction block A0 that is adjacent to the left is referred to, and the LX reference index that is the temporal merge candidate is the prediction block Set to the value of the LX reference index of A0. In a prediction block whose division index PartIdx to be derived is 1, the prediction block A1 that is adjacent to the left is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction block A1. Since the prediction blocks A0 and A1 to be referred to are both outside the coding block, the reference indexes of the temporal merge candidates of the two prediction blocks whose division indexes PartIdx are 0 and 1 can be derived in parallel.

  When the division mode (PartMode) for dividing the processing target coding block into two prediction blocks arranged side by side is N × 2N division (PART_Nx2N), nL × 2N division (PART_nLx2N), and nR × 2N division (PART_nRx2N), FIG. As shown in (e), (f), and (g), in the prediction block whose partition index PartIdx to be derived is 0, the prediction block A0 that is adjacent to the left is referred to, and the LX reference index that is the temporal merge candidate is the prediction block Set to the value of the LX reference index of A0. In the prediction block whose partition index PartIdx to be derived is 1, the adjacent prediction block is not referred to, and the LX reference index of the temporal merge candidate is set to the default value 0. Since the prediction block A0 to be referred to is outside the encoded block, the reference indexes of the temporal merge candidates of the two prediction blocks whose division indexes PartIdx are 0 and 1 can be derived in parallel.

  However, when the adjacent prediction block A does not perform LX prediction, the value of the reference index of the LX that is a temporal merge candidate is set to 0 as the default value. The reason why the default value of the LX reference index of the temporal merge candidate is 0 when the adjacent prediction block A does not perform LX prediction or when the partition index PartIdx of the prediction block to be derived is 1 is referred to in inter prediction This is because the reference picture corresponding to the index value 0 is most likely to be selected. However, the present invention is not limited to this, and the default value of the reference index may be a value other than 0 (1, 2, etc.), and the default value of the reference index may be set in the encoded stream at the sequence level, picture level, or slice level. The syntax element shown may be installed and transmitted so that it can be selected on the encoding side.

  FIG. 27 is a flowchart for explaining the reference process for deriving the reference index of the time merge candidate in step S202 of FIG. 18 according to the method of Example 4 of the present embodiment. First, when the partition mode (PartMode) is N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), nR × 2N partition (PART_nRx2N) and the partition index PartIdx is not 1 (NO in step S2102), that is, 2N × 2N Partition (PART_2Nx2N), 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), 2N × nD partition (PART_2NxnD), or N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), nR × When 2N division (PART_nRx2N) and the division index PartIdx is 0, the encoding information of the prediction block A adjacent to the left of the prediction block to be derived is acquired from the encoding information storage memory 115 or 210 (step S2111).

  The subsequent processing from step S2113 to step S2115 is performed in each of L0 and L1 (steps S2112 to S2116). Note that LX is set to L0 when deriving the L0 reference index of the temporal merge candidate, and LX is set to L1 when deriving the L1 reference index. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  When the flag predFlagLX [xA] [yA] indicating whether to perform LX prediction of the prediction block A is not 0 (YES in step S2113), the LX reference index refIdxLXCol of the temporal merge candidate is used as the LX reference index refIdxLX of the prediction block A. The same value as [xA] [yA] is set (step S2114). Here, xA and yA are indexes indicating the position of the upper left pixel of the prediction block A in the picture.

  In the present embodiment, in the prediction block N (N = A, B), when the prediction block N cannot be used outside the slice to be encoded or decoded, the prediction block N is encoded or encoded in the decoding order. Alternatively, a flag indicating whether or not to use L0 prediction when the encoding block is not encoded or decoded after the decoding target prediction block and cannot be used, or when the prediction mode PredMode of the prediction block N is intra prediction (MODE_INTRA). Both predFlagL0 [xN] [yN] and the flag predFlagL1 [xN] [yN] indicating whether to use the L1 prediction of the prediction block N are 0. Here, xN and yN are indexes indicating the position of the upper left pixel of the prediction block N in the picture. When the prediction mode PredMode of the prediction block N is inter prediction (MODE_INTER) and the inter prediction mode is L0 prediction (Pred_L0), the flag predFlagL0 [xN] [yN] indicating whether to use the L0 prediction of the prediction block N is 1 , Flag predFlagL1 [xN] [yN] indicating whether to use L1 prediction is zero. When the inter prediction mode of the prediction block N is L1 prediction (Pred_L1), a flag predFlagL0 [xN] [yN] indicating whether or not to use the L0 prediction of the prediction block N is 0 and a flag indicating whether or not to use the L1 prediction predFlagL1 [xN] [yN] is 1. When the inter prediction mode of the prediction block N is bi-prediction (Pred_BI), a flag predFlagL0 [xN] [yN] indicating whether to use the L0 prediction of the prediction block N, and a flag predFlagL1 [indicating whether to use the L1 prediction xN] [yN] are both 1.

  When the flag predFlagLX [xA] [yA] indicating whether or not to perform LX prediction of the prediction block A is 0 (NO in step S2113), the reference index refIdxLXCol of the LX that is a temporal merge candidate is set to a default value of 0 ( Step S2115).

  The processing from step S2113 to step S2115 is performed in each of L0 and L1 (steps S2112 to S2116), and this reference index derivation processing is terminated.

  On the other hand, when the partition mode (PartMode) is N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), and nR × 2N partition (PART_nRx2N) and the partition index PartIdx is 1 (YES in step S2102), the following step S2121 This process is performed in each of L0 and L1 (steps S2118 to S2122). Note that LX is set to L0 when deriving the L0 reference index of the temporal merge candidate, and LX is set to L1 when deriving the L1 reference index. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  The LX reference index refIdxLXCol of the time merge candidate is set to a default value of 0 (step S2121).

  The process up to step S2121 is performed in each of L0 and L1 (steps S2118 to S2122), and this reference index derivation process is terminated.

Example 5
Next, Example 5 of the present embodiment will be described. FIG. 28 is a diagram illustrating adjacent blocks that are referred to in the time merge candidate reference index derivation process according to the fifth example of the present embodiment. In Example 5 of the present embodiment, whether to refer to a prediction block adjacent to the left side of the prediction block to be derived is switched according to the division mode (PartMode). Reference is made to a prediction block close to a side outside the coding block. This is referred to when the prediction block close to the left side is outside the coding block, and when it is inside the coding block, it is not referred to and is set as a default value. When the partition mode (PartMode) is 2N × 2N partition (PART_2Nx2N), as shown in FIG. 28A, the prediction block A0 adjacent to the left of the prediction block to be derived is referred to, and the LX reference index of the temporal merge candidate Is set to the value of the reference index of the LX of the prediction block A0.

  When the division mode (PartMode) for dividing the coding block to be processed into two prediction blocks arranged vertically is 2N × N division (PART_2NxN), 2N × nU division (PART_2NxnU), and 2N × nD division (PART_2NxnD), FIG. As shown in (b), (c), and (d), in the prediction block whose partitioning index PartIdx to be derived is 0, the prediction block A0 that is adjacent to the left is referred to, and the LX reference index that is the temporal merge candidate is the prediction block Set to the value of the LX reference index of A0. In a prediction block whose division index PartIdx to be derived is 1, the prediction block A1 that is adjacent to the left is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction block A1. Since the prediction blocks A0 and A1 to be referred to are both outside the coding block, the reference indexes of the temporal merge candidates of the two prediction blocks whose division indexes PartIdx are 0 and 1 can be derived in parallel.

  When the division mode (PartMode) for dividing the processing target coding block into two prediction blocks arranged side by side is N × 2N division (PART_Nx2N), nL × 2N division (PART_nLx2N), and nR × 2N division (PART_nRx2N) In the prediction blocks having the partition index PartIdx of 0 and 1, both of the prediction blocks that are adjacent to each other are not referred to, and the LX reference index of the temporal merge candidate is set to a default value of 0. Since the prediction block adjacent to the prediction block to be processed is not referred to, the prediction block in the coding block is not referred to, and the reference indexes of the temporal merge candidates of the two prediction blocks whose division indexes PartIdx are 0 and 1, respectively. It can be derived in parallel.

  However, when the adjacent prediction block A does not perform LX prediction, the value of the reference index of the LX that is a temporal merge candidate is set to 0 as the default value. When the adjacent prediction block A does not perform LX prediction, or the partition mode (PartMode) of the encoding block including the prediction block to be derived is N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), nR × 2N partition In the case of (PART_nRx2N), the reason why the default value of the reference index of the LX as a temporal merge candidate is set to 0 is that there is a high probability that a reference picture corresponding to a reference index value of 0 is most selected in inter prediction. . However, the present invention is not limited to this, and the default value of the reference index may be a value other than 0 (1, 2, etc.), and the default value of the reference index may be set in the encoded stream at the sequence level, picture level, or slice level. The syntax element shown may be installed and transmitted so that it can be selected on the encoding side.

  FIG. 29 is a flow chart for explaining the procedure for deriving the reference index of the time merge candidate in step S202 of FIG. 18 according to the method of the fifth embodiment of the present embodiment. First, when the partition mode (PartMode) is not N × 2N partition (PART_Nx2N), nL × 2N partition (PART_nLx2N), or nR × 2N partition (PART_nRx2N) (NO in step S2101), that is, 2N × 2N partition (PART_2Nx2N), 2N In the case of × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), and 2N × nD partition (PART_2NxnD), the code of the prediction block A adjacent to the left of the prediction block to be derived from the encoded information storage memory 115 or 210 Information is acquired (step S2111).

  The subsequent processing from step S2113 to step S2115 is performed in each of L0 and L1 (steps S2112 to S2116). Note that LX is set to L0 when deriving the L0 reference index of the temporal merge candidate, and LX is set to L1 when deriving the L1 reference index. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  When the flag predFlagLX [xA] [yA] indicating whether to perform LX prediction of the prediction block A is not 0 (YES in step S2113), the LX reference index refIdxLXCol of the temporal merge candidate is used as the LX reference index refIdxLX of the prediction block A. The same value as [xA] [yA] is set (step S2114). Here, xA and yA are indexes indicating the position of the upper left pixel of the prediction block A in the picture.

  In the present embodiment, in the prediction block N (N = A, B), when the prediction block N cannot be used outside the slice to be encoded or decoded, the prediction block N is encoded or encoded in the decoding order. Alternatively, a flag indicating whether or not to use L0 prediction when the encoding block is not encoded or decoded after the decoding target prediction block and cannot be used, or when the prediction mode PredMode of the prediction block N is intra prediction (MODE_INTRA). Both predFlagL0 [xN] [yN] and the flag predFlagL1 [xN] [yN] indicating whether to use the L1 prediction of the prediction block N are 0. Here, xN and yN are indexes indicating the position of the upper left pixel of the prediction block N in the picture. When the prediction mode PredMode of the prediction block N is inter prediction (MODE_INTER) and the inter prediction mode is L0 prediction (Pred_L0), the flag predFlagL0 [xN] [yN] indicating whether to use the L0 prediction of the prediction block N is 1 , Flag predFlagL1 [xN] [yN] indicating whether to use L1 prediction is zero. When the inter prediction mode of the prediction block N is L1 prediction (Pred_L1), a flag predFlagL0 [xN] [yN] indicating whether or not to use the L0 prediction of the prediction block N is 0 and a flag indicating whether or not to use the L1 prediction predFlagL1 [xN] [yN] is 1. When the inter prediction mode of the prediction block N is bi-prediction (Pred_BI), a flag predFlagL0 [xN] [yN] indicating whether to use the L0 prediction of the prediction block N, and a flag predFlagL1 [indicating whether to use the L1 prediction xN] [yN] are both 1.

  When the flag predFlagLX [xA] [yA] indicating whether or not to perform LX prediction of the prediction block A is 0 (NO in step S2113), the reference index refIdxLXCol of the LX that is a temporal merge candidate is set to a default value of 0 ( Step S2115).

  The processing from step S2113 to step S2115 is performed in each of L0 and L1 (steps S2112 to S2116), and this reference index derivation processing is terminated.

  On the other hand, when the division mode (PartMode) is N × 2N division (PART_Nx2N), nL × 2N division (PART_nLx2N), or nR × 2N division (PART_nRx2N) (YES in step S2101), the processing in subsequent step S2121 is performed as L0 and L1. It performs in each (step S2118-S2122). Note that LX is set to L0 when deriving the L0 reference index of the temporal merge candidate, and LX is set to L1 when deriving the L1 reference index. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  The LX reference index refIdxLXCol of the time merge candidate is set to a default value of 0 (step S2121).

  The process up to step S2121 is performed in each of L0 and L1 (steps S2118 to S2122), and this reference index derivation process is terminated.

Example 6
Next, Example 6 of the present embodiment will be described. In Example 6 of the present embodiment, regardless of the value of the partition mode (PartMode) of the coding block including the prediction mode to be derived (the coding block to be processed) and the partition index PartIdx of the prediction mode to be derived, The reference index of LX as a temporal merge candidate is set to a default value of 0 without referring to adjacent prediction blocks. Since the prediction block adjacent to the prediction block to be processed is not referred to, the prediction block in the encoded block is not referred to, and the time of two prediction blocks whose division indexes PartIdx are 0 and 1 included in the same encoded block Merge candidates can be derived in parallel.

  The reason why the default value of the LX reference index of the temporal merge candidate is set to 0 is that there is a high probability that the reference picture corresponding to the reference index value of 0 is most selected in inter prediction. However, the present invention is not limited to this, and the default value of the reference index may be a value other than 0 (1, 2, etc.), and the default value of the reference index may be set in the encoded stream at the sequence level, picture level, or slice level. The syntax element shown may be installed and transmitted so that it can be selected on the encoding side.

  Further, in the sixth embodiment, the reference index refIdxLXCol of the time merge candidate LX is set to the default value of 0 without referring to the adjacent block, so the first, second, third, fourth, fifth, and later-described seventh embodiment. The derivation process can be simplified compared to.

  FIG. 30 is a flowchart for describing the reference process for deriving the reference index of the time merge candidate in step S202 of FIG. 18 according to the method of Example 6 of the present embodiment.

  The processing in step S2115 is performed in each of L0 and L1 (steps S21112 to S2116). Note that LX is set to L0 when deriving the L0 reference index of the temporal merge candidate, and LX is set to L1 when deriving the L1 reference index. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  The LX reference index refIdxLXCol of the time merge candidate is set to a default value of 0 (step S2115).

  The processing of step S2115 is performed in each of L0 and L1 (steps S2112 to S2116), and this reference index derivation processing is terminated.

Example 7
Next, Example 7 of the present embodiment will be described. FIG. 31 is a diagram illustrating adjacent blocks that are referred to in the time merge candidate reference index derivation process according to the seventh embodiment of the present embodiment. In Example 7 of the present embodiment, regardless of the value of the partition mode (PartMode) of the encoding block (the processing target encoding block) including the prediction mode to be derived and the value of the partition index PartIdx of the prediction mode to be derived, As illustrated in FIGS. 31A to 31G, the prediction block A adjacent to the left of the processing target encoding block is referred to, and the LX reference index of the prediction block A is used as the LX reference index of the prediction block A. Set to value. Since the prediction block A to be referred to is outside the encoded block, the reference indexes of the temporal merge candidates of the two prediction blocks whose division indexes PartIdx are 0 and 1 can be derived in parallel.

  However, when the adjacent prediction block A does not perform LX prediction, the value of the reference index of the LX that is a temporal merge candidate is set to 0 as the default value. When the adjacent prediction block A does not perform LX prediction, the reason why the default value of the reference index of the temporal merge candidate LX is set to 0 is that the reference picture corresponding to the reference index value of 0 is most selected in inter prediction. This is because the probability is high. However, the present invention is not limited to this, and the default value of the reference index may be a value other than 0 (1, 2, etc.), and the default value of the reference index may be set in the encoded stream at the sequence level, picture level, or slice level. The syntax element shown may be installed and transmitted so that it can be selected on the encoding side.

  In the seventh embodiment, since the reference index of the temporal merge candidate of each prediction block in the encoded block is set to a common value, the reference index of the temporal merge candidate is derived for each prediction block in the encoded block. There is no need, and the derivation process can be simplified.

  FIG. 32 is a flow chart for explaining the procedure for deriving the reference index of the time merge candidate in step S202 of FIG. 18 by the method of Example 7 of the present embodiment. First, the coding information of the prediction block A adjacent to the left of the coding block to be processed is acquired from the coding information storage memory 115 or 210 (step S2131).

  The subsequent processing from step S2133 to step S2135 is performed in each of L0 and L1 (steps S2132 to S2136). Note that LX is set to L0 when deriving the L0 reference index of the temporal merge candidate, and LX is set to L1 when deriving the L1 reference index. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  When the flag predFlagLX [xA] [yA] indicating whether or not to perform LX prediction of the prediction block A adjacent to the left of the processing target coding block is not 0 (YES in step S2133), the LX reference index of the temporal merge candidate refIdxLXCol is set to the same value as the value of the reference index refIdxLX [xA] [yA] of the LX of the prediction block A (step S2134). Here, xA and yA are indexes indicating the position of the upper left pixel of the prediction block A adjacent to the left of the coding block to be processed in the picture.

  In the present embodiment, in the prediction block N (N = A, B), when the prediction block N cannot be used outside the slice to be encoded or decoded, the prediction block N is encoded or encoded in the decoding order. Alternatively, a flag indicating whether or not to use L0 prediction when the encoding block is not encoded or decoded after the decoding target prediction block and cannot be used, or when the prediction mode PredMode of the prediction block N is intra prediction (MODE_INTRA). Both predFlagL0 [xN] [yN] and the flag predFlagL1 [xN] [yN] indicating whether to use the L1 prediction of the prediction block N are 0. Here, xN and yN are indexes indicating the position of the upper left pixel of the prediction block N in the picture. When the prediction mode PredMode of the prediction block N is inter prediction (MODE_INTER) and the inter prediction mode is L0 prediction (Pred_L0), the flag predFlagL0 [xN] [yN] indicating whether to use the L0 prediction of the prediction block N is 1 , Flag predFlagL1 [xN] [yN] indicating whether to use L1 prediction is zero. When the inter prediction mode of the prediction block N is L1 prediction (Pred_L1), a flag predFlagL0 [xN] [yN] indicating whether or not to use the L0 prediction of the prediction block N is 0 and a flag indicating whether or not to use the L1 prediction predFlagL1 [xN] [yN] is 1. When the inter prediction mode of the prediction block N is bi-prediction (Pred_BI), a flag predFlagL0 [xN] [yN] indicating whether to use the L0 prediction of the prediction block N, and a flag predFlagL1 [indicating whether to use the L1 prediction xN] [yN] are both 1.

  When the flag predFlagLX [xA] [yA] indicating whether to perform LX prediction of the prediction block A is 0 (NO in step S2133), the reference index refIdxLXCol of the LX that is a temporal merge candidate is set to 0 as a default value ( Step S2135).

  The processing from step S2133 to step S2135 is performed in each of L0 and L1 (steps S2132 to S2136), and this reference index derivation processing is terminated.

  In the seventh embodiment, whether to refer to the prediction block adjacent to the left side of the encoded block including the prediction block to be derived is switched. However, instead of the prediction block adjacent to the left side, the prediction block close to the upper side is changed. You may switch whether to refer.

Example 8
Next, Example 8 of the present embodiment will be described. FIG. 43 is a diagram illustrating neighboring blocks referred to in the time merge candidate reference index derivation process according to the eighth embodiment of the present embodiment. In Example 8 of the present embodiment, whether to refer to a prediction block adjacent to the left side of the prediction block to be derived, according to the prediction index PartIdx of the prediction block, regardless of the encoding block partition mode (PartMode) Switch. When the partition index PartIdx of the prediction block is 0, the prediction block adjacent to the left side is referred to, and when the partition index PartIdx is other than 0, the adjacent prediction block is not referred to and is set as a default value. When the partition index PartIdx of the prediction block is 0, in any partition mode (PartMode), the prediction block close to the left side is always outside the encoded block, but when the partition index PartIdx of the prediction block is other than 0, the partition mode ( PartMode) depending on the coding block. As illustrated in FIG. 43A, the prediction block A0 adjacent to the left of the prediction block to be derived is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction block A0.

  The partition mode (PartMode) for dividing the processing target coding block into two prediction blocks arranged vertically is 2N × N partition (PART_2NxN), 2N × nU partition (PART_2NxnU), 2N × nD partition (PART_2NxnD), and processing target When the division mode (PartMode) for dividing the encoded block of 2 into two prediction blocks arranged side by side is N × 2N division (PART_Nx2N), nL × 2N division (PART_nLx2N), and nR × 2N division (PART_nRx2N), FIG. ), (C), (d), (e), (f), and (g), the prediction block A0 that is adjacent to the left is referred to in the prediction block with the division index PartIdx to be derived, and the time The LX reference index of the merge candidate is set to the value of the LX reference index of the prediction block A0. In the prediction block whose partition index PartIdx to be derived is 1, the adjacent prediction block is not referred to, and the LX reference index of the temporal merge candidate is set to the default value 0. Since the prediction block A0 to be referred to is outside the encoded block, the reference indexes of the temporal merge candidates of the two prediction blocks whose division indexes PartIdx are 0 and 1 can be derived in parallel.

  However, when the adjacent prediction block A does not perform LX prediction, the value of the reference index of the LX that is a temporal merge candidate is set to 0 as the default value. The reason why the default value of the LX reference index of the temporal merge candidate is 0 when the adjacent prediction block A does not perform LX prediction or when the partition index PartIdx of the prediction block to be derived is 1 is referred to in inter prediction This is because the reference picture corresponding to the index value 0 is most likely to be selected. However, the present invention is not limited to this, and the default value of the reference index may be a value other than 0 (1, 2, etc.), and the default value of the reference index may be set in the encoded stream at the sequence level, picture level, or slice level. The syntax element shown may be installed and transmitted so that it can be selected on the encoding side.

  FIG. 44 is a flowchart for describing the procedure for deriving the reference index of the time merge candidate in step S202 of FIG. 18 according to the method of Example 8 of the present embodiment. First, when the division index PartIdx is 0 (YES in step S2104), the encoding information of the prediction block A adjacent to the left of the prediction block to be derived is acquired from the encoding information storage memory 115 or 210 (step S2111). .

  The subsequent processing from step S2113 to step S2115 is performed in each of L0 and L1 (steps S2112 to S2116). Note that LX is set to L0 when deriving the L0 reference index of the temporal merge candidate, and LX is set to L1 when deriving the L1 reference index. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  When the flag predFlagLX [xA] [yA] indicating whether to perform LX prediction of the prediction block A is not 0 (YES in step S2113), the LX reference index refIdxLXCol of the temporal merge candidate is used as the LX reference index refIdxLX of the prediction block A. The same value as [xA] [yA] is set (step S2114). Here, xA and yA are indexes indicating the position of the upper left pixel of the prediction block A in the picture.

  In the present embodiment, in the prediction block N (N = A, B), when the prediction block N cannot be used outside the slice to be encoded or decoded, the prediction block N is encoded or encoded in the decoding order. Alternatively, a flag indicating whether or not to use L0 prediction when the encoding block is not encoded or decoded after the decoding target prediction block and cannot be used, or when the prediction mode PredMode of the prediction block N is intra prediction (MODE_INTRA). Both predFlagL0 [xN] [yN] and the flag predFlagL1 [xN] [yN] indicating whether to use the L1 prediction of the prediction block N are 0. Here, xN and yN are indexes indicating the position of the upper left pixel of the prediction block N in the picture. When the prediction mode PredMode of the prediction block N is inter prediction (MODE_INTER) and the inter prediction mode is L0 prediction (Pred_L0), the flag predFlagL0 [xN] [yN] indicating whether to use the L0 prediction of the prediction block N is 1 , Flag predFlagL1 [xN] [yN] indicating whether to use L1 prediction is zero. When the inter prediction mode of the prediction block N is L1 prediction (Pred_L1), a flag predFlagL0 [xN] [yN] indicating whether or not to use the L0 prediction of the prediction block N is 0 and a flag indicating whether or not to use the L1 prediction predFlagL1 [xN] [yN] is 1. When the inter prediction mode of the prediction block N is bi-prediction (Pred_BI), a flag predFlagL0 [xN] [yN] indicating whether to use the L0 prediction of the prediction block N, and a flag predFlagL1 [indicating whether to use the L1 prediction xN] [yN] are both 1.

  When the flag predFlagLX [xA] [yA] indicating whether or not to perform LX prediction of the prediction block A is 0 (NO in step S2113), the reference index refIdxLXCol of the LX that is a temporal merge candidate is set to a default value of 0 ( Step S2115).

  The processing from step S2113 to step S2115 is performed in each of L0 and L1 (steps S2112 to S2116), and this reference index derivation processing is terminated.

  On the other hand, when the division index PartIdx is not 0 (NO in step S2104), the subsequent processing in step S2121 is performed in each of L0 and L1 (steps S2118 to S2122). Note that LX is set to L0 when deriving the L0 reference index of the temporal merge candidate, and LX is set to L1 when deriving the L1 reference index. However, when the slice type slice_type is a P slice, only the L0 prediction (Pred_L0) is provided as the inter prediction mode, and there is no L1 prediction (Pred_L1) and bi-prediction (Pred_BI). Therefore, the processing related to L1 can be omitted.

  The LX reference index refIdxLXCol of the time merge candidate is set to a default value of 0 (step S2121).

  The process up to step S2121 is performed in each of L0 and L1 (steps S2118 to S2122), and this reference index derivation process is terminated.

  In the eighth embodiment, whether or not to refer to the prediction block close to the left side of the prediction block to be derived is switched, but whether or not to refer to the prediction block close to the upper side instead of the prediction block close to the left side is determined. You may switch.

  In the present embodiment, the partition mode (PartMode) of the encoded block does not define N × N partition (PART_NxN), but N × N partition (PART_NxN) can also be defined. Even when the coding block partition mode (PartMode) is N × N partition (PART_NxN), when deriving the reference index of the prediction block temporal merge candidate included in the processing target coding block, the processing target prediction block By deriving without referring to adjacent prediction blocks included in the same encoding block as the encoding block included in the reference block, reference to temporal merge candidates of four prediction blocks whose partition index PartIdx is 0, 1, 2, 3 Each index can be derived in parallel.

  For example, in N × N division (PART_NxN), adjacent reference blocks are not referenced, and the LX reference index of the temporal merge candidate is set to a default value of 0. Since the prediction block adjacent to the prediction block to be derived is not referred to, the reference indexes of the temporal merge candidates of the four prediction blocks whose division indexes PartIdx are 0, 1, 2, and 3 can be derived in parallel.

  Alternatively, the reference index of the temporal merge candidate can be derived by referring to the reference index of the neighboring block. FIG. 33 is a diagram for explaining adjacent blocks to be referred to in the process of deriving the reference index of the temporal merge candidate of the N × N division (PART_NxN) encoded block.

  As shown in FIG. 33 (a), in the prediction block whose partitioning index PartIdx to be derived is 0, the prediction block A0 adjacent to the left is referred to, and the LX reference index of the prediction block A0 is used as the LX reference index of the temporal merge candidate. Set to the value of. In a prediction block whose partition index PartIdx to be derived is 1, the prediction block B1 that is close to the top is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction block B1. In a prediction block with a partition index PartIdx of 2 to be derived, the prediction block A2 adjacent to the left is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction block A2. In a prediction block whose partitioning index PartIdx to be derived is 3, the adjacent prediction block is not referred to, and the LX reference index of the temporal merge candidate is set to a default value of 0. Since the prediction blocks A0 and A2 adjacent to the left of the prediction block to be processed and the prediction block B1 adjacent above are both outside the coding block, the four prediction blocks whose division index PartIdx is 0, 1, 2, 3 Reference indices for temporal merge candidates can be derived in parallel.

  Alternatively, as shown in FIG. 33 (b), in the prediction block whose partitioning index PartIdx to be derived is 0, the prediction block A0 adjacent to the left is referred to, and the LX reference index of the temporal merge candidate is set to the LX of the prediction block A0. Set to the value of the reference index. In a prediction block with a partition index PartIdx of 2 to be derived, the prediction block A2 adjacent to the left is referred to, and the LX reference index of the temporal merge candidate is set to the value of the LX reference index of the prediction block A2. In the prediction block whose partition index PartIdx to be derived is 1 or 3, the adjacent prediction block is not referred to, and the LX reference index of the temporal merge candidate is set to the default value 0. Since both the prediction blocks A0 and A2 adjacent to the left of the prediction block to be processed are outside the encoding block, the reference indexes of the temporal merge candidates of the four prediction blocks whose division indexes PartIdx are 0, 1, 2, and 3 are respectively set. It can be derived in parallel.

  Alternatively, as illustrated in FIG. 33C, the prediction block A adjacent to the left of the processing target coding block is referred to, and the LX reference index of the temporal merge candidate is changed to the value of the LX reference index of the prediction block A. Set. Since the prediction block A adjacent to the left of the coding block to be processed is outside the coding block, the reference indexes of the temporal merge candidates of the four prediction blocks whose division indexes PartIdx are 0, 1, 2, and 3 are respectively parallel. Can be derived.

  Alternatively, as shown in FIG. 33 (d), in the prediction block whose partitioning index PartIdx to be derived is 0, the prediction block A0 that is adjacent to the left is referred to, and the LX reference index of the temporal merge candidate is set to the LX of the prediction block A0. Set to the value of the reference index. In the prediction block whose partitioning index PartIdx to be derived is other than 0 (PartIdx is 1, 2 or 3), the adjacent prediction block is not referred to, and the reference index of the LX as a temporal merge candidate is set to the default value of 0. Since it is outside the prediction block A0 coding block adjacent to the left of the prediction block to be processed, the reference indexes of the temporal merge candidates of the four prediction blocks whose division indexes PartIdx are 0, 1, 2, and 3 are respectively derived in parallel. be able to.

  Next, the merge candidate derivation method using inter prediction information of pictures at different times in step S203 in FIG. 18 will be described in detail. FIG. 34 is a flowchart for explaining the time merge candidate derivation processing procedure in step S203 of FIG.

  First, a picture colPic at a different time is derived from the slice type slice_type and the above-described flag collocated_from_l0_flag (step S3101).

  FIG. 35 is a flowchart for explaining the procedure for deriving the picture colPic at different times in step S3101 of FIG. When the slice type slice_type is a B slice and the above-described flag collocated_from_l0_flag is 0 (YES in step S3201 and YES in step S3202), RefPicList1 [0], that is, a picture colPic at a time when the pictures with the reference index 0 in the reference list L1 are different (Step S3203). Otherwise, that is, when the slice type slice_type is B slice and the aforementioned flag collocated_from_l0_flag is 1 (YES in step S3201, NO in step S3202), or when the slice type slice_type is P slice (NO in step S3201 and YES in S3204) ), RefPicList0 [0], that is, the picture colPic of the reference list L0 with the reference index 0 is a different time (step S3205).

  Next, returning to the flowchart of FIG. 34, a prediction block colPU at a different time is derived, and encoded information is acquired (step S3102).

  FIG. 36 is a flowchart for explaining the procedure for deriving the prediction block colPU of the picture colPic at different times in step S3102 of FIG.

  First, a prediction block located at the lower right (outside) of the same position as a processing target prediction block in a picture colPic at a different time is set as a prediction block colPU at a different time (step S3301). This prediction block corresponds to the prediction block T0 in FIG.

  Next, encoding information of the prediction block colPU at different times is acquired (step S3302). When PredMode of a prediction block colPU at a different time cannot be used, or when the prediction mode PredMode of a prediction block colPU at a different time is intra prediction (MODE_INTRA) (YES in step S3303, YES in step S3304), the picture colPic in a different time The prediction block located in the upper left center of the same position as the processing target prediction block is set as a prediction block colPU at a different time (step S3305). This prediction block corresponds to the prediction block T1 in FIG.

  Next, returning to the flowchart of FIG. 34, a flag indicating whether the prediction motion vector mvL0Col of L0 derived from the prediction block of another picture at the same position as the prediction block to be encoded or decoded and the temporal merge candidate Col are valid. In addition to deriving availableFlagL0Col (step S3103), a flag availableFlagL1Col indicating whether the prediction motion vector mvL1Col of L1 and the temporal merge candidate Col are valid is derived. Further, when the flag availableFlagL0Col or the flag availableFlagL1Col is 1, a flag availableFlagCol indicating whether the time merge candidate Col is valid is set to 1.

  FIG. 37 is a flowchart for explaining the procedure for deriving inter prediction information of the temporal merge candidate in steps S3103 and S3104 in FIG. In L0 or L1, the list of time merge candidate derivation targets is LX, and the prediction using LX is LX prediction. Hereinafter, unless otherwise noted, this meaning is used. LX becomes L0 when called as step S3103, which is a time merge candidate L0 derivation process, and LX becomes L1, when called as step S3104, which is a time merge candidate L1 derivation process.

  When the prediction mode PredMode of the prediction block colPU at different time is intra prediction (MODE_INTRA) or cannot be used (NO in step S3401 and NO in step S3402), both the flag availableFlagLXCol and the flag predFlagLXCol are set to 0 (step S3403), and the motion vector mvLXCol Is set to (0, 0) (step S3404), and the process of deriving inter prediction information of the current time merge candidate ends.

  When the prediction block colPU is available and the prediction mode PredMode is not intra prediction (MODE_INTRA) (YES in step S3401 and YES in step S3402), mvCol, refIdxCol, and availableFlagCol are derived by the following procedure.

  When the flag PredFlagL0 [xPCol] [yPCol] indicating whether or not the L0 prediction of the prediction block colPU is used (YES in step S3405), the prediction mode of the prediction block colPU is Pred_L1, and therefore the motion vector mvCol is predicted. The same value as MvL1 [xPCol] [yPCol] that is the L1 motion vector of the block colPU is set (step S3406), and the reference index refIdxCol is set to the same value as the reference index RefIdxL1 [xPCol] [yPCol] of L1 (step S3406). In step S3407, the list ListCol is set to L1 (step S3408). Here, xPCol and yPCol are indexes indicating the position of the upper left pixel of the prediction block colPU in the picture colPic at different times.

  On the other hand, when the L0 prediction flag PredFlagL0 [xPCol] [yPCol] of the prediction block colPU is not 0 (NO in step S3405 in FIG. 37), it is determined whether the L1 prediction flag PredFlagL1 [xPCol] [yPCol] of the prediction block colPU is 0. To do. When the L1 prediction flag PredFlagL1 [xPCol] [yPCol] of the prediction block colPU is 0 (YES in step S3409), the motion vector mvCol becomes the same value as MvL0 [xPCol] [yPCol], which is the L0 motion vector of the prediction block colPU. It is set (step S3410), the reference index refIdxCol is set to the same value as the reference index RefIdxL0 [xPCol] [yPCol] of L0 (step S3411), and the list ListCol is set to L0 (step S3412).

  When the L0 prediction flag PredFlagL0 [xPCol] [yPCol] of the prediction block colPU and the L1 prediction flag PredFlagL1 [xPCol] [yPCol] of the prediction block colPU are not 0 (NO in step S3405, NO in step S3409), the prediction block colPU Since the inter prediction mode is bi-prediction (Pred_BI), one of the two motion vectors L0 and L1 is selected (step S3413).

  FIG. 38 is a flowchart illustrating a procedure for deriving inter prediction information of temporal merge candidates when the inter prediction mode of the prediction block colPU is bi-prediction (Pred_BI).

  First, it is determined whether the POCs of all the pictures registered in all the reference lists are smaller than the POC of the current encoding or decoding target picture (step S3501), and L0, which is all the reference lists of the prediction block colPU. When the POC of all the pictures registered in L1 is smaller than the POC of the current encoding or decoding target picture (YES in step S3501), LX is L0, that is, the motion vector of L0 of the encoding or decoding target picture When the prediction vector candidate is derived (YES in step S3502), the L0 inter prediction information of the prediction block colPU is selected, and LX is L1, that is, the prediction of the motion vector of the encoding or decoding target picture L1. When the vector candidate is derived (NO in step S3502), the prediction block The inter prediction information for L1 of the colPU is selected. On the other hand, when at least one of the POCs of pictures registered in all the reference lists L0 and L1 of the prediction block colPU is larger than the POC of the current encoding or decoding target picture (NO in step S3501), the flag collocated_from_l0_flag is 0. (YES in step S3503), the L0 inter prediction information of the prediction block colPU is selected. If the flag collocated_from_l0_flag is 1 (NO in step S3503), the L1 inter prediction information of the prediction block colPU is selected. To do.

  When the inter prediction information of L0 of the prediction block colPU is selected (YES in step, YES in step S3503), the motion vector mvCol is set to the same value as MvL0 [xPCol] [yPCol] (step S3504), and the reference index refIdxCol is set to the same value as RefIdxL0 [xPCol] [yPCol] (step S3505), and the list ListCol is set to L0 (step S3506).

  When the inter prediction information of L1 of the prediction block colPU is selected (NO in step S2502 and NO in step S3503), the motion vector mvCol is set to the same value as MvL1 [xPCol] [yPCol] (step S3507), see The index refIdxCol is set to the same value as RefIdxL1 [xPCol] [yPCol] (step S3508), and the list ListCol is set to L1 (step S3509).

  Returning to FIG. 37, when the inter prediction information can be acquired from the prediction block colPU, both the flag availableFlagLXCol and the flag predFlagLXCol are set to 1 (step S3414).

  Subsequently, the motion vector mvCol is scaled to obtain an LX motion vector mvLXCol as a temporal merge candidate (step S3415). The motion vector scaling calculation processing procedure will be described with reference to FIGS. 39 and 40. FIG.

  FIG. 39 is a flowchart showing the motion vector scaling calculation processing procedure in step S3105 of FIG.

The inter-picture distance td is derived by subtracting the POC of the reference picture corresponding to the reference index refIdxCol referenced in the list ListCol of the prediction block colPU from the POC of the picture colPic at different times (step S3601). Note that when the POC of the reference picture referenced in the list Col of the prediction block colPU is earlier in the display order than the picture colPic at a different time, the inter-picture distance td is a positive value, and the prediction is more accurate than the picture colPic at a different time. When the POC of the reference picture referenced in the list ListCol of the block colPU is later in the display order, the inter-picture distance td becomes a negative value.
td = POC of picture colPic at different time-POC of reference picture referenced by list ListCol of prediction block colPU

The inter-picture distance tb is derived by subtracting the POC of the reference picture corresponding to the reference index of the temporal merge candidate LX derived in step S202 of FIG. 18 from the POC of the current encoding or decoding target picture (step S3602). . If the reference picture referenced in the list LX of the current encoding or decoding target picture is earlier than the current encoding or decoding target picture in the display order, the inter-picture distance tb is a positive value. When the reference picture referred to in the encoding or decoding target picture list LX is later in the display order, the inter-picture distance tb is a negative value.
tb = POC of current encoding or decoding target picture—POC of reference picture corresponding to LX reference index of temporal merge candidate

Subsequently, the inter-picture distances td and tb are compared (step S3603). If the inter-picture distances td and tb are equal (YES in step S3603), the LX motion vector mvLXCol as a temporal merge candidate is set to the same value as the motion vector mvCol. After setting (step S3604), the scaling calculation process is terminated.
mvLXCol = mvCol

On the other hand, if the inter-picture distances td and tb are not equal (NO in step S3603), scaling calculation processing is performed by multiplying mvCol by the scale factor tb or td according to the following equation (step S3605), and the scaled temporal merge candidate Obtain the motion vector mvLXCol of LX.
mvLXCol = tb or td * mvCol

  FIG. 40 shows an example of the case where the scaling operation in step S3605 is performed with integer precision arithmetic. The processing in steps S3606 to S3608 in FIG. 40 corresponds to the processing in step S3605 in FIG.

  First, similarly to the flowchart of FIG. 39, the inter-picture distance td and the inter-picture distance tb are derived (steps S3601 and S3602).

Subsequently, the inter-picture distances td and tb are compared (step S3603). If the inter-picture distances td and tb are equal (YES in step S3603), the LX motion vector mvLXCol that is the temporal merge candidate is similar to the flowchart of FIG. Is set to the same value as the motion vector mvCol (step S3604), and this scaling calculation process is terminated.
mvLXCol = mvCol

On the other hand, if the inter-picture distances td and tb are not equal (NO in step S3603), a variable tx is derived from the following equation (step S3606).
tx = (16384 + Abs (td or 2)) or td

Subsequently, the scale coefficient DistScaleFactor is derived from the following equation (step S3607).
DistScaleFactor = (tb * tx + 32) >> 6

Subsequently, a scaled temporal merge candidate LX motion vector mvLXCol is obtained by the following equation (step S3608).
mvLXCol = ClipMv (Sign (DistScaleFactor * mvCol) * ((Abs (DistScaleFactor * mvCol) + 127) >> 8))

  Next, a method for registering the merge candidates in step S204 of FIG. 18 in the merge candidate list and constructing the merge candidate list will be described in detail. FIG. 41 is a flowchart showing a merge candidate list construction processing procedure. In this method, priorities are assigned, and merge candidates are registered in the merge candidate list mergeCandList in descending order of priority, thereby reducing the code amount of the merge index merge_idx [x0] [y0]. The amount of codes is reduced by placing elements with higher priorities in front of the merge candidate list. For example, when there are five elements in the merge candidate list mergeCandList, the index 0 of the merge candidate list is “0”, the index 1 is “10”, the index 2 is “110”, the index 3 is “1110”, and the index 4 is “ By setting “11110”, the code amount representing the index 0 becomes 1 bit, and the code amount is reduced by registering an element considered to have a high occurrence frequency in the index 0.

  The merge candidate list mergeCandList has a list structure, and is provided with a merge index indicating the location within the merge candidate list and a storage area for storing merge candidates corresponding to the index as elements. The number of the merge index starts from 0, and merge candidates are stored in the storage area of the merge candidate list mergeCandList. In the subsequent processing, a prediction block that is a merge candidate of the merge index i registered in the merge candidate list mergeCandList is represented by mergeCandList [i], and is distinguished from the merge candidate list mergeCandList by array notation. To do.

First, when availableFlagA is 1 (YES in step S4101), merge candidate A is registered at the head of the merge candidate list mergeCandList (step S4102).
Subsequently, when availableFlagB is 1 (YES in step S4103), merge candidate B is registered at the end of the merge candidate list mergeCandList (step S4104).
Subsequently, when availableFlagC is 1 (YES in step S4105), the merge candidate C is registered at the end of the merge candidate list mergeCandList (step S4106).
Subsequently, when availableFlagD is 1 (YES in step S4107), the merge candidate D is registered at the end of the merge candidate list mergeCandList (step S4108).
Subsequently, when availableFlagE is 1 (YES in step S4109), the merge candidate E is registered at the end of the merge candidate list mergeCandList (step S4110).
Subsequently, when availableFlagCol is 1 (YES in step S4109), the merge candidate Col is registered at the end of the merge candidate list mergeCandList (step S4110).

  In the merge mode, the prediction block A adjacent to the left and the prediction block B adjacent to the top often move together with the prediction block to be encoded or decoded, so inter prediction of the prediction blocks A and B is performed. When the information can be acquired, the merge candidates A and B are registered ahead of the merge candidate list in preference to the other merge candidates C, D, E, and Col.

  In FIG. 13, the encoding information selection unit 136 of the inter prediction information deriving unit 104 of the video encoding device selects a merge candidate from the merge candidates registered in the merge candidate list, and merge index and merge index are selected. The inter prediction information of the merge candidate corresponding to is supplied to the motion compensation prediction unit 105.

  In selecting a merge candidate, the same method as the prediction method determination unit 107 can be used. For each merge candidate, the coding information and the coding amount of the residual signal and the coding distortion between the predicted image signal and the image signal are derived, and the merge candidate that produces the least generated code amount and coding distortion is determined. The For each merge candidate, entropy coding is performed on the merge index syntax element merge_idx, which is coding information in the merge mode, and the code amount of the coding information is calculated. Further, for each merge candidate, a predicted image signal motion-compensated according to the inter prediction information of each merge candidate by the same method as the motion compensation prediction unit 105, and an encoding target image signal supplied from the image memory 101, The amount of code of the prediction residual signal obtained by encoding the prediction residual signal is calculated. Coding information, that is, the total generated code amount obtained by adding the code amount of the merge index and the code amount of the prediction residual signal is calculated as an evaluation value.

Further, after encoding such a prediction residual signal, it is decoded for distortion amount evaluation, and the encoding distortion is calculated as a ratio representing an error from the original image signal caused by the encoding. By comparing the total generated code amount and the encoding distortion for each merge candidate, encoding information with a small generated code amount and encoding distortion is determined. A merge index corresponding to the determined encoding information is encoded as a flag merge_idx represented by a second syntax pattern in units of prediction blocks.
The generated code amount calculated here is preferably a simulation of the encoding process, but can be approximated or approximated easily.

  On the other hand, in FIG. 14, the encoding information selection unit 236 of the inter prediction information deriving unit 205 of the moving image encoding device performs a merge corresponding to the supplied merge index from among the merge candidates registered in the merge candidate list. A candidate is selected, and the inter prediction information of the merge candidate is supplied to the motion compensation prediction unit 206 and stored in the encoded information storage memory 210.

  The moving image encoded stream output from the moving image encoding apparatus of the embodiment described above has a specific data format so that it can be decoded according to the encoding method used in the embodiment. Therefore, the moving picture decoding apparatus corresponding to the moving picture encoding apparatus can decode the encoded stream of this specific data format.

  When a wired or wireless network is used to exchange an encoded stream between a moving image encoding device and a moving image decoding device, the encoded stream is converted into a data format suitable for the transmission form of the communication path. It may be transmitted. In that case, a video transmission apparatus that converts the encoded stream output from the video encoding apparatus into encoded data in a data format suitable for the transmission form of the communication channel and transmits the encoded data to the network, and receives the encoded data from the network Then, a moving image receiving apparatus that restores the encoded stream and supplies the encoded stream to the moving image decoding apparatus is provided.

  The moving image transmitting apparatus is a memory that buffers the encoded stream output from the moving image encoding apparatus, a packet processing unit that packetizes the encoded stream, and transmission that transmits the packetized encoded data via the network. Part. The moving image receiving apparatus generates a coded stream by packetizing the received data, a receiving unit that receives the packetized coded data via a network, a memory that buffers the received coded data, and packet processing. And a packet processing unit provided to the video decoding device.

  The above processing relating to encoding and decoding can be realized as a transmission, storage, and reception device using hardware, and is stored in a ROM (Read Only Memory), a flash memory, or the like. It can also be realized by firmware or software such as a computer. The firmware program and software program can be recorded on a computer-readable recording medium, provided from a server through a wired or wireless network, or provided as a data broadcast of terrestrial or satellite digital broadcasting Is also possible.

  The present invention has been described based on the embodiments. The embodiments are exemplifications, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are within the scope of the present invention. .

  DESCRIPTION OF SYMBOLS 101 Image memory, 102 Motion vector detection part, 103 Difference motion vector calculation part, 104 Inter prediction information derivation part, 105 Motion compensation prediction part, 106 Intra prediction part, 107 Prediction method determination part, 108 Residual signal generation part, 109 Orthogonal Transform / quantization unit, 110 first encoded bit string generation unit, 111 second encoded bit string generation unit, 112 multiplexing unit, 130 spatial merge candidate generation unit, 131 time merge candidate reference index deriving unit, 132 time Merge candidate generation unit, 133 Merge candidate registration unit, 134 Merge candidate identity determination unit, 135 Merge candidate supplementation unit, 136 Encoding information selection unit, 201 Separation unit, 202 First encoded bit sequence decoding unit, 203 Second encoded bit sequence Decoding unit, 204 motion vector calculation unit 205 Inter prediction information derivation unit, 206 Motion compensation prediction unit, 207 Intra prediction unit, 208 Inverse quantization / inverse orthogonal transform unit, 209 Decoded image signal superimposing unit, 210 Encoded information storage memory, 211 Decoded image memory, 230 Spatial merge A candidate generation unit, a 231 time merge candidate reference index derivation unit, a 232 time merge candidate generation unit, a 233 merge candidate registration unit, a 234 merge candidate identity determination unit, a 235 merge candidate supplement unit, and a 236 encoding information selection unit.

Claims (6)

A moving picture coding apparatus that divides a first block obtained by dividing each picture into one or a plurality of second blocks and codes a moving picture using inter prediction,
A first process of deriving one or more first inter prediction information candidates from inter prediction information of one or more third blocks adjacent to the second block to be encoded in a picture to be encoded A prediction information deriving unit;
From the inter prediction information of the fourth block existing at the same position or in the vicinity of the second block to be encoded in a picture different from the picture to be encoded, the second inter prediction information candidate A second prediction information derivation unit that performs derivation processing;
When the first inter prediction information candidate is derived, the derived first inter prediction information candidate is obtained. When the second inter prediction information candidate is derived, the derived second inter prediction information candidate is derived. A candidate list construction unit for constructing a prediction information candidate list composed of predetermined prediction information candidates to which inter prediction information candidates are respectively added;
A selection unit that selects an inter prediction information candidate to be used for the inter prediction of the second block to be encoded from the prediction information candidates in the prediction information candidate list, and determines an index indicating inter prediction information; ,
An encoding unit that encodes an index indicating inter prediction information used for inter prediction of the second block to be encoded;
The first prediction information deriving unit is a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by an upper block and a lower block, and the encoding target When the second block is a lower block, the first inter prediction information candidate derivation process is performed without referring to the encoding information of the fifth block adjacent to the upper side of the second block. As well as
The second prediction information deriving unit is a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by an upper block and a lower block, and the encoding target Without referring to the coding information of the fifth block included in the same first block as the first block including the second block, the reference index value of the second inter prediction information candidate is A moving picture encoding apparatus, wherein the second inter prediction information candidate derivation process is performed as a default value based on the reference index. A moving picture coding method for dividing a first block obtained by dividing each picture into one or a plurality of second blocks and coding a moving picture using inter prediction,
A first process of deriving one or more first inter prediction information candidates from inter prediction information of one or more third blocks adjacent to the second block to be encoded in a picture to be encoded A prediction information deriving step;
From the inter prediction information of the fourth block existing at the same position or in the vicinity of the second block to be encoded in a picture different from the picture to be encoded, the second inter prediction information candidate A second prediction information derivation step for performing a derivation process;
When the first inter prediction information candidate is derived, the derived first inter prediction information candidate is obtained. When the second inter prediction information candidate is derived, the derived second inter prediction information candidate is derived. A candidate list construction step of constructing a prediction information candidate list composed of predetermined prediction information candidates to which inter prediction information candidates are added,
A selection step of selecting an inter prediction information candidate used for the inter prediction of the second block to be encoded from the prediction information candidates in the prediction information candidate list, and determining an index indicating the inter prediction information; ,
An encoding step of encoding an index indicating inter prediction information used for inter prediction of the second block to be encoded,
The first prediction information deriving step is a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by an upper block and a lower block, and the encoding target When the second block is a lower block, the first inter prediction information candidate derivation process is performed without referring to the encoding information of the fifth block adjacent to the upper side of the second block. As well as
The second prediction information derivation step is a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by an upper block and a lower block, and the encoding target Without referring to the coding information of the fifth block included in the same first block as the first block including the second block, the reference index value of the second inter prediction information candidate is A moving picture coding method, wherein the second inter prediction information candidate derivation process is performed as a default value based on the reference index. A moving picture encoding program that divides a first block obtained by dividing each picture into one or a plurality of second blocks and encodes a moving picture using inter prediction,
A first process of deriving one or more first inter prediction information candidates from inter prediction information of one or more third blocks adjacent to the second block to be encoded in a picture to be encoded A prediction information deriving step;
From the inter prediction information of the fourth block existing at the same position or in the vicinity of the second block to be encoded in a picture different from the picture to be encoded, the second inter prediction information candidate A second prediction information derivation step for performing a derivation process;
When the first inter prediction information candidate is derived, the derived first inter prediction information candidate is obtained. When the second inter prediction information candidate is derived, the derived second inter prediction information candidate is derived. A candidate list construction step of constructing a prediction information candidate list composed of predetermined prediction information candidates to which inter prediction information candidates are added,
A selection step of selecting an inter prediction information candidate used for the inter prediction of the second block to be encoded from the prediction information candidates in the prediction information candidate list, and determining an index indicating the inter prediction information; ,
Causing the computer to execute an encoding step of encoding an index indicating inter prediction information used for inter prediction of the second block to be encoded,
The first prediction information deriving step is a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by an upper block and a lower block, and the encoding target When the second block is a lower block, the first inter prediction information candidate derivation process is performed without referring to the encoding information of the fifth block adjacent to the upper side of the second block. As well as
The second prediction information derivation step is a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by an upper block and a lower block, and the encoding target Without referring to the coding information of the fifth block included in the same first block as the first block including the second block, the reference index value of the second inter prediction information candidate is A moving picture coding program that performs a derivation process of the second inter prediction information candidate based on the reference index as a default value. A first block obtained by dividing each picture is divided into one or a plurality of second blocks, and an encoded stream encoded by a moving image encoding method that encodes a moving image using inter prediction is packetized. A packet processing unit for obtaining encoded data by
A transmission unit for transmitting the packetized encoded data,
The moving image encoding method includes:
A first process of deriving one or more first inter prediction information candidates from inter prediction information of one or more third blocks adjacent to the second block to be encoded in a picture to be encoded A prediction information deriving step;
From the inter prediction information of the fourth block existing at the same position or in the vicinity of the second block to be encoded in a picture different from the picture to be encoded, the second inter prediction information candidate A second prediction information derivation step for performing a derivation process;
When the first inter prediction information candidate is derived, the derived first inter prediction information candidate is obtained. When the second inter prediction information candidate is derived, the derived second inter prediction information candidate is derived. A candidate list construction step of constructing a prediction information candidate list composed of predetermined prediction information candidates to which inter prediction information candidates are added,
A selection step of selecting an inter prediction information candidate used for the inter prediction of the second block to be encoded from the prediction information candidates in the prediction information candidate list, and determining an index indicating the inter prediction information; ,
An encoding step of encoding an index indicating inter prediction information used for inter prediction of the second block to be encoded,
The first prediction information deriving step is a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by an upper block and a lower block, and the encoding target When the second block is a lower block, the first inter prediction information candidate derivation process is performed without referring to the encoding information of the fifth block adjacent to the upper side of the second block. As well as
The second prediction information derivation step is a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by an upper block and a lower block, and the encoding target Without referring to the coding information of the fifth block included in the same first block as the first block including the second block, the reference index value of the second inter prediction information candidate is The transmission apparatus characterized in that the second inter prediction information candidate derivation process is performed based on the reference index as a default value. A first block obtained by dividing each picture is divided into one or a plurality of second blocks, and an encoded stream encoded by a moving image encoding method that encodes a moving image using inter prediction is packetized. Packet processing step for obtaining encoded data by
Transmitting the packetized encoded data, and
The moving image encoding method includes:
A first process of deriving one or more first inter prediction information candidates from inter prediction information of one or more third blocks adjacent to the second block to be encoded in a picture to be encoded A prediction information deriving step;
From the inter prediction information of the fourth block existing at the same position or in the vicinity of the second block to be encoded in a picture different from the picture to be encoded, the second inter prediction information candidate A second prediction information derivation step for performing a derivation process;
When the first inter prediction information candidate is derived, the derived first inter prediction information candidate is obtained. When the second inter prediction information candidate is derived, the derived second inter prediction information candidate is derived. A candidate list construction step of constructing a prediction information candidate list composed of predetermined prediction information candidates to which inter prediction information candidates are added,
A selection step of selecting an inter prediction information candidate used for the inter prediction of the second block to be encoded from the prediction information candidates in the prediction information candidate list, and determining an index indicating the inter prediction information; ,
An encoding step of encoding an index indicating inter prediction information used for inter prediction of the second block to be encoded,
The first prediction information deriving step is a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by an upper block and a lower block, and the encoding target When the second block is a lower block, the first inter prediction information candidate derivation process is performed without referring to the encoding information of the fifth block adjacent to the upper side of the second block. As well as
The second prediction information derivation step is a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by an upper block and a lower block, and the encoding target Without referring to the coding information of the fifth block included in the same first block as the first block including the second block, the reference index value of the second inter prediction information candidate is A transmission method, wherein the second inter prediction information candidate derivation process is performed as a default value based on the reference index. A first block obtained by dividing each picture is divided into one or a plurality of second blocks, and an encoded stream encoded by a moving image encoding method that encodes a moving image using inter prediction is packetized. Packet processing step for obtaining encoded data by
Transmitting the packetized encoded data to the computer, and
The moving image encoding method includes:
A first process of deriving one or more first inter prediction information candidates from inter prediction information of one or more third blocks adjacent to the second block to be encoded in a picture to be encoded A prediction information deriving step;
From the inter prediction information of the fourth block existing at the same position or in the vicinity of the second block to be encoded in a picture different from the picture to be encoded, the second inter prediction information candidate A second prediction information derivation step for performing a derivation process;
When the first inter prediction information candidate is derived, the derived first inter prediction information candidate is obtained. When the second inter prediction information candidate is derived, the derived second inter prediction information candidate is derived. A candidate list construction step of constructing a prediction information candidate list composed of predetermined prediction information candidates to which inter prediction information candidates are added,
A selection step of selecting an inter prediction information candidate used for the inter prediction of the second block to be encoded from the prediction information candidates in the prediction information candidate list, and determining an index indicating the inter prediction information; ,
An encoding step of encoding an index indicating inter prediction information used for inter prediction of the second block to be encoded,
The first prediction information deriving step is a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by an upper block and a lower block, and the encoding target When the second block is a lower block, the first inter prediction information candidate derivation process is performed without referring to the encoding information of the fifth block adjacent to the upper side of the second block. As well as
The second prediction information derivation step is a division mode in which the first block is vertically divided into 1: 1, 1: 3, or 3: 1 by an upper block and a lower block, and the encoding target Without referring to the coding information of the fifth block included in the same first block as the first block including the second block, the reference index value of the second inter prediction information candidate is A transmission program characterized in that, as a default value, the second inter prediction information candidate derivation process is performed based on the reference index.

Images