JP6065088B2 - Moving picture coding apparatus, moving picture coding method, moving picture coding program, transmission apparatus, transmission method, and transmission program - Google Patents

Description

  The present invention relates to a moving picture coding technique using motion compensated prediction, and in particular, a moving picture coding apparatus, a moving picture coding method, a moving picture coding program, and a moving picture coding program for coding motion information used in motion compensated prediction, and The present invention relates to a transmission device, a transmission method, and a transmission program.

  In general video compression coding, motion compensation prediction is used. The motion compensated prediction is performed by dividing the target image into fine blocks, using the decoded image as a reference image, and moving from the processing target block of the target image to the reference block of the reference image based on the amount of motion indicated by the motion vector. This is a technique for generating a signal as a prediction signal. There are two types of motion compensated prediction, one for single prediction using one motion vector and the other for bi-prediction using two motion vectors.

  For a motion vector, a motion vector of an encoded block adjacent to the processing target block is set as a prediction motion vector (also simply referred to as “prediction vector”), and a difference between the motion vector of the processing target block and the prediction vector is obtained. The compression efficiency is improved by transmitting the vector as an encoded vector.

  MPEG-4 AVC / H. In moving picture compression coding such as H.264 (hereinafter referred to as MPEG-4 AVC), motion compensation prediction with high accuracy is made possible by making the block size for motion compensation prediction fine and diverse. On the other hand, there is a problem that the code amount of the encoded vector is increased by reducing the block size.

  Therefore, in MPEG-4 AVC, focusing on the continuity of movement in the time direction, a block on a reference image which is a processed image different from a processing target image having a processing target block at the same position as the processing target block has. Motion compensated prediction in the temporal direct mode is used in which a motion vector is scaled by a distance between frames and used as a motion vector of a processing target block to realize motion compensated prediction without transmitting an encoded vector. As a result, the code amount of the motion vector is reduced, and the encoding efficiency is improved.

  Also, in Patent Document 1, paying attention to the continuity of motion in the spatial direction, the encoded vector is transmitted using the motion vector of the processed block adjacent to the processing target block as the motion vector of the processing target block. A method for realizing motion compensated prediction without the need is disclosed.

JP-A-10-276439

  In the derivation of the motion vector in the temporal direct mode as defined in the above-described MPEG-4 AVC, since the derivation requires scaling, a complicated calculation is required. In the method described in Patent Document 1, a motion vector included in a processed block adjacent to a processing target prediction block is used as a motion vector of the processing target prediction block, and a plurality of adjacent prediction blocks are collected. When motion compensation prediction is performed, parallel motion compensation prediction processing may not be performed.

  The present invention has been made in view of such a situation, and an object of the present invention is to use a plurality of adjacent motion vectors while generating a motion vector of a processed block adjacent to a processing target prediction block for generating a motion vector of the processing target prediction block. It is an object of the present invention to provide a moving picture coding and moving picture decoding technique capable of realizing high-efficiency parallel processing of motion compensated prediction in which motion compensation prediction is performed for all the prediction blocks.

In order to solve the above-described problem, a video encoding device according to an aspect of the present invention is a video encoding device that encodes a coding block including one or more prediction blocks, and includes a coding block in the coding block. Information indicating whether or not joint motion information candidates to be commonly used for all of the prediction blocks is derived derives joint motion information candidates to be commonly used for all of the prediction blocks in the coding block. The combined motion information candidate generating unit (140) for deriving a plurality of combined motion information candidates to be used in common for all of the prediction blocks in the encoded block, and the plurality of combined motions A combined motion information selection unit (141) that selects one combined motion information candidate from the information candidates and uses the selected combined motion information candidate in a prediction block to be encoded; The a coding unit (104) for encoding as a candidate specifying index index for identifying the one coupling motion information candidates, the coupling motion information candidate generating unit, the prediction block of the coded block Information indicating whether or not joint motion information candidates to be used in common for all of the coding blocks are to be derived indicates that joint motion information candidates to be used in common for all of the prediction blocks in the coding block are not derived. If it is information, the plurality of combined motion information candidates are derived based on the size and position of the prediction block to be encoded .

Yet another aspect of the present invention is a video encoding method. This method is a moving image coding method for coding a coding block composed of one or more prediction blocks, and derives joint motion information candidates to be used in common for all the prediction blocks in the coding block. If the information indicating whether or not to perform is information indicating that joint motion information candidates to be commonly used for all of the prediction blocks in the encoded block are derived, the prediction block of the encoded block A combined motion information candidate generating step for deriving a plurality of combined motion information candidates to be used in common for all, selecting one combined motion information candidate from the plurality of combined motion information candidates, and selecting the one combined Combined motion information selection step for using motion information candidates in a prediction block to be encoded, and an index for identifying the selected combined motion information candidate And a coding step of coding a candidate particular index, the combined motion information candidate generating step, whether or not to derive the binding motion information candidates to use in common for all the prediction blocks of the coded block Is information indicating that joint motion information candidates to be used in common for all prediction blocks in the encoded block are not derived, based on the size and position of the prediction block to be encoded The plurality of combined motion information candidates are derived .

Yet another embodiment of the present invention is a transmission device. This apparatus is a transmitting apparatus that transmits an encoded stream encoded by a moving image encoding method for encoding an encoded block composed of one or more prediction blocks, wherein the encoded stream is packetized and encoded. A packet processing unit for obtaining data; and a transmission unit for transmitting the packetized encoded data. In the moving image encoding method, information indicating whether or not joint motion information candidates to be commonly used for all prediction blocks in the encoding block are derived is included in all prediction blocks in the encoding block. In the case of information indicating that a joint motion information candidate to be used in common is derived, joint motion for deriving a plurality of joint motion information candidates to be used in common for all the prediction blocks in the coding block An information candidate generation step; a combined motion information selection step of selecting one combined motion information candidate from the plurality of combined motion information candidates and using the selected combined motion information candidate in a prediction block to be encoded; , and a coding step of coding the index for identifying the one coupling motion information candidates selected as candidates particular index, the formation In the motion information candidate generation step, information indicating whether to derive joint motion information candidates to be commonly used for all of the prediction blocks in the encoded block includes information for all of the prediction blocks in the encoded block. If the information indicates that joint motion information candidates to be commonly used are not derived, the plurality of joint motion information candidates are derived based on the size and position of the prediction block to be encoded .
Yet another embodiment of the present invention is a transmission method. This method is a transmission method for transmitting an encoded stream encoded by a moving image encoding method for encoding an encoded block composed of one or more prediction blocks, wherein the encoded stream is packetized and encoded. A packet processing step of obtaining data; and a transmission step of transmitting the packetized encoded data. In the moving image encoding method, information indicating whether or not joint motion information candidates to be commonly used for all prediction blocks in the encoding block are derived is included in all prediction blocks in the encoding block. In the case of information indicating that a joint motion information candidate to be used in common is derived, joint motion for deriving a plurality of joint motion information candidates to be used in common for all the prediction blocks in the coding block An information candidate generation step; a combined motion information selection step of selecting one combined motion information candidate from the plurality of combined motion information candidates and using the selected combined motion information candidate in a prediction block to be encoded; , and a coding step of coding the index for identifying the one coupling motion information candidates selected as candidates particular index, the formation In the motion information candidate generation step, information indicating whether to derive joint motion information candidates to be commonly used for all of the prediction blocks in the encoded block includes information for all of the prediction blocks in the encoded block. If the information indicates that joint motion information candidates to be commonly used are not derived, the plurality of joint motion information candidates are derived based on the size and position of the prediction block to be encoded .

  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, motion compensation for performing motion compensation prediction on a plurality of adjacent prediction blocks collectively while using a motion vector of a processed block adjacent to the processing target prediction block for generating a motion vector of the processing target prediction block. Predictive parallel processing can be realized with high efficiency.

FIGS. 1A and 1B are diagrams for explaining an encoded block. FIGS. 2A to 2D are diagrams for explaining the prediction block size type. It is a figure explaining a prediction block size type. It is a figure explaining prediction coding mode. It is a figure explaining the relationship between a merge index and a code sequence. It is a figure explaining an example of the syntax of a prediction block. 1 is a diagram illustrating a configuration of a moving image encoding device according to Embodiment 1. FIG. It is a figure which shows the structure of the motion information generation part of FIG. It is a figure explaining the structure of the merge mode determination part of FIG. It is a figure explaining the structure of the joint motion information candidate list production | generation part of FIG. 10 is a flowchart illustrating an operation of a combined motion information candidate list generation unit in FIG. 9. It is a figure explaining the candidate block group of the prediction block whose prediction block size type is 2Nx2N. The figure which shows a candidate block group at the time of applying the same positional relationship as the prediction block of the encoding block whose prediction block size type is 2Nx2N about the prediction block in the encoding block whose prediction block size type is not 2Nx2N. is there. 6 is a diagram for explaining an example of a positional relationship between a prediction block whose prediction block size type is other than 2N × 2N and a spatial candidate block group in Embodiment 1. FIG. It is a flowchart explaining operation | movement of the space joint motion information candidate production | generation part of FIG. It is a flowchart explaining operation | movement of the time combination motion information candidate production | generation part of FIG. It is a flowchart explaining the operation | movement of the 1st joint motion information candidate supplement part of FIG. It is a figure explaining the relationship between the frequency | count of combination inspection, combined motion information candidate M, and combined motion information candidate N. It is a flowchart explaining the operation | movement of the 2nd joint motion information candidate supplement part of FIG. 1 is a diagram illustrating a configuration of a video decoding device according to Embodiment 1. FIG. It is a figure which shows the structure of the motion information reproduction | regeneration part of FIG. It is a figure which shows the structure of the joint motion information reproduction | regeneration part of FIG. It is a figure explaining the positional relationship of a prediction block other than the prediction block size type in Embodiment 2 and a space candidate block group except 2Nx2N. It is a figure explaining the positional relationship of the prediction block and the spatial candidate block group whose prediction block size type is other than 2N × 2N in an example in which the prediction block size type in the coding block is common without depending on the prediction block size type. is there. It is a figure explaining the positional relationship of a prediction block other than the prediction block size type in Embodiment 3, and a space candidate block group except 2Nx2N. 10 is a flowchart illustrating an operation of a combined motion information candidate list generation unit according to the third embodiment. It is a figure explaining the largest encoding block lower limit line and a time candidate block group. It is a figure explaining the positional relationship of the prediction block and prediction candidate block size other than 2Nx2N in Embodiment 4 and a space candidate block group. FIG. 10 is a diagram for describing a configuration of a combined motion information candidate list generation unit according to a fourth embodiment. 18 is a flowchart for explaining the operation of the combined motion information candidate list generation unit according to the fourth embodiment. FIG. 25 is a diagram for describing a configuration of a combined motion information candidate list generation unit according to the fifth embodiment. 29 is a flowchart for explaining the operation of the combined motion information candidate list generation unit of the fifth embodiment. The structure of a prediction vector mode determination part is shown. It is a figure explaining the structure of a prediction vector candidate list production | generation part. It is a flowchart explaining operation | movement of a prediction vector candidate list production | generation part. It is a figure explaining the structure of a motion vector reproduction | regeneration part.

  First, a technique that is a premise of the embodiment of the present invention will be described.

  Currently, apparatuses and systems that comply with an encoding method such as MPEG (Moving Picture Experts Group) are widely used. In such an encoding method, a plurality of images that are continuous on the time axis are handled as digital signal information. At that time, for the purpose of broadcasting, transmitting or storing information with high efficiency, motion compensated prediction using the temporal redundancy by dividing the image into a plurality of blocks and the discrete cosine using the redundancy in the spatial direction Compression encoding is performed using orthogonal transformation such as transformation.

  In 2003, a joint effort between the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) Joint Technical Committee (ISO / IEC) and the International Telecommunication Union Telecommunication Standardization Sector (ITU-T) AVC / H. An encoding method called H.264 (the ISO / IEC has a standard number of 14496-10 and ITU-T has an H.264 standard number, hereinafter referred to as MPEG-4AVC) has been established as an international standard. In MPEG-4 AVC, basically, a median value of motion vectors of a plurality of adjacent blocks of a processing target block is used as a prediction vector. When the prediction block size is not square and the reference index of a specific adjacent block of the processing target block matches the reference index of the processing target block, the motion vector of the specific adjacent block is set as a prediction vector.

  Coding currently called HEVC by the joint work of the International Technical Organization (ISO) and the International Electrotechnical Commission (IEC) Joint Technical Committee (ISO / IEC) and the International Telecommunication Union Telecommunication Standardization Sector (ITU-T) Standardization of the method is being studied.

  In the HEVC standardization, a plurality of adjacent blocks and another decoded image block are used as candidate blocks, and one candidate block is selected from a candidate block group composed of these candidate blocks, and information on the selected candidate block is obtained. A merge mode in which is encoded and decoded is under consideration.

[Embodiment 1]
(Encoding block)
In the present embodiment, the input image signal is divided into units of maximum encoding blocks, and the divided maximum encoding blocks are processed in a raster scan order. The encoding block has a hierarchical structure, and can be made into a smaller encoding block by sequentially dividing into four in consideration of encoding efficiency and the like. Note that the encoded blocks divided into four are encoded in the zigzag scan order. An encoded block that cannot be further reduced is called a minimum encoded block. The encoded block is a unit of encoding, and the maximum encoded block is also an encoded block when the number of divisions is zero. In this embodiment, the maximum coding block is 64 pixels × 64 pixels, and the minimum coding block is 8 pixels × 8 pixels.

  FIGS. 1A and 1B are diagrams for explaining an encoded block. In the example of FIG. 1A, the encoded block is divided into ten. CU0, CU1 and CU9 are 32 × 32 coding blocks, CU2, CU3 and CU8 are 16 × 16 coding blocks, and CU4, CU5, CU6 and CU7 are 8 × 8 coding blocks. It has become. In the example of FIG. 1B, the encoded block is divided into one.

(Prediction block)
In the present embodiment, the encoded block is further divided into prediction blocks (also referred to as partitions). The encoded block is divided into one or more prediction blocks according to a prediction block size type (also referred to as “partition type” or partition type). FIGS. 2A to 2D are diagrams for explaining the prediction block size type. 2 (a) is 2N × 2N that does not divide the encoded block, FIG. 2 (b) is 2N × N that is horizontally divided, FIG. 2 (c) is N × 2N that is vertically divided, and FIG. d) shows N × N which is divided into 4 parts horizontally and vertically. 2N × 2N is one prediction block 0, 2N × N and N × 2N are two prediction blocks 0 and 1, and N × N is four prediction blocks 0, prediction block 1, prediction block 2, and prediction It consists of block 3. The prediction block 0, the prediction block 1, the prediction block 2, and the prediction block 3 are encoded in this order.

  FIG. 3 is a diagram for explaining the prediction block size according to the number of times of coding block division and the prediction block size type. The prediction block size in the present embodiment is from 64 pixels × 64 pixels in which the number of CU divisions is 0 and the prediction block size type is 2N × 2N, and the number of CU divisions is 3, and the prediction block size type is N × N. There are 13 predicted block sizes up to 4 pixels x 4 pixels. For example, the coding block can be asymmetrically divided into two horizontally and vertically.

  In the present embodiment, the maximum encoding block is 64 pixels × 64 pixels and the minimum encoding block is 8 pixels × 8 pixels, but the present invention is not limited to this combination. In addition, although the prediction block division pattern is shown in FIGS. 2A to 2D, the combination is not limited to this as long as the combination is divided into one or more.

(Predictive coding mode)
In the present embodiment, the motion compensation prediction and the number of encoded vectors can be switched for each prediction block. Here, an example of a predictive coding mode in which motion compensation prediction is associated with the number of coding vectors will be briefly described with reference to FIG. FIG. 4 is a diagram for explaining the predictive coding mode.

  In the predictive coding mode shown in FIG. 4, the prediction direction of motion compensation prediction is single prediction (L0 prediction) and the number of coding vectors is PredL0, and the prediction direction of motion compensation prediction is single prediction (L1 prediction). PredL1 in which the number of encoding vectors is 1, PredBI in which the prediction direction of motion compensation prediction is bi-prediction (BI prediction) and the number of encoding vectors is 2, and the prediction direction in motion compensation prediction is single prediction ( There is a merge mode (MERGE) which is L0 prediction / L1 prediction) or bi-prediction (BI prediction) and the number of encoding vectors is zero. There is also an intra mode (Intra) which is a predictive coding mode in which motion compensation prediction is not performed. Here, PredL0, PredL1, and PredBI are prediction vector modes.

  In the merge mode, the prediction direction is any of L0 prediction / L1 prediction / BI prediction. This is because the prediction direction of the merge mode takes over the prediction direction of the candidate block selected from the candidate block group as it is, or is decoded information. This is because it is derived from In the merge mode, the encoded vector is not encoded. This is because the merge mode encoding vector inherits the motion vector of the candidate block selected from the candidate block group as it is or is derived by a predetermined rule.

(Reference index)
In this embodiment, in order to improve the accuracy of motion compensation prediction, it is possible to select an optimal reference image from a plurality of reference images in motion compensation prediction. For this reason, the reference image used in the motion compensation prediction is encoded as a reference image index together with the encoded vector. The reference image index used in motion compensation prediction is a numerical value of 0 or more. If the motion compensation prediction is uni-prediction, one reference index is used, and if the motion compensation prediction is bi-prediction, two reference indexes are used (FIG. 4).

  In merge mode, the reference index is not encoded. This is because the merge mode reference index is derived from the reference index of the candidate block selected from the candidate block group as it is or according to a predetermined rule.

(Reference index list)
In the present embodiment, one or more reference images that can be used in motion compensation prediction are registered in the reference index list, and the reference image is confirmed by indicating the reference image registered in the reference index list with the reference index. Used in motion compensated prediction. The reference index list includes a reference index list L0 (also referred to as a reference index list for L0 prediction) and a reference index list L1 (also referred to as a reference index list for L1 prediction). When the motion compensation prediction is simple prediction, either L0 prediction using a reference image in the reference index list L0 or L1 prediction using a reference image in the reference index list L1 is used. In the case of bi-prediction, BI prediction using the reference index list L0 and the reference index list L1 is used. The maximum number of reference images that can be registered in each reference index list is 16.

(Merge index)
In the present embodiment, in the merge mode, the same position in the same position prediction block that is at the same position as the plurality of adjacent blocks in the processing target image and the processing target prediction block in another encoded image A merge index for selecting a candidate block having an optimal predictive coding mode, motion vector, and reference index from the candidate block group using blocks around the prediction block as a candidate block group, and indicating the selected candidate block Is encoded and decoded. Only one merge index is used in the merge mode (FIG. 4). The maximum number of merge indexes (also called the maximum number of merge candidates) is 5, and the merge index is an integer from 0 to 4. Here, the maximum number of merge indexes is set to 5, but it may be 2 or more, and is not limited to this.

  Hereinafter, the motion information of the candidate block that is the target of the merge index is referred to as a combined motion information candidate, and the aggregate of combined motion information candidates is referred to as a combined motion information candidate list. Hereinafter, the motion information includes a prediction direction, a motion vector, and a reference index.

  Next, the relationship between the merge index and the code string will be described. FIG. 5 is a diagram for explaining the relationship between the merge index and the code string. The code string when the merge index is 0 is '0', the code string when the merge index is 1 is '10', the code string when the merge index is 2 is '110', and the code string when the merge index is 3 When the column is “1110” and the merge index is 4, the code string is “1111”, and the code string is set to be longer as the merge index is larger. Therefore, it is possible to improve the encoding efficiency by assigning a small merge index to a candidate block with a high selection rate.

  Next, the relationship between the combined motion information candidate list and the merge index will be described. The merge index 0 indicates the first (0th) combined motion information candidate in the combined motion information candidate list. Hereinafter, the merge index m indicates the m-th combined motion information candidate in the combined motion information candidate list. Here, m is an integer from 0 to (maximum number of merge candidates−1).

(Predicted vector index)
In the present embodiment, in order to improve the accuracy of the prediction vector, the same position in the same position prediction block that is in the same position as the plurality of adjacent blocks in the processing target image and the processing target block of another encoded image A candidate block having an optimal motion vector as a prediction vector is selected from the candidate block group using blocks around the prediction block as a candidate block group, and a prediction vector index for indicating the selected candidate block is encoded and decoded. If the motion compensation prediction is uni-prediction, one prediction vector index is used, and if the motion compensation prediction is bi-prediction, two prediction vector indexes are used (FIG. 4). The maximum number of prediction vector indexes (also referred to as the maximum number of prediction vector candidates) is 2, and the prediction vector index is an integer of 0 or 1. Although the maximum number of prediction vector candidates is 2 here, it may be 2 or more, and is not limited to this.

  Next, the relationship between the prediction vector index and the code string will be described. The code string of the prediction vector index is “0” when the prediction vector index is 0, and is “1” when the prediction vector index is 1. When the maximum number of prediction vector candidates is 3 or more, a code string can be assigned according to the same rule as the merge index (the code string becomes longer as the index becomes larger).

  Hereinafter, a motion vector of a candidate block that is a target of a prediction vector index is referred to as a prediction vector candidate, and a set of prediction vector candidates is referred to as a prediction vector candidate list.

(Syntax)
An example of the syntax of the prediction block according to the present embodiment will be described. FIG. 6 is a diagram for explaining the syntax according to the present embodiment. FIG. 6 shows an example of a syntax configuration of a coding tree, a coding block, and a prediction block. In the coding tree, the division information of the coding block is managed. A split_coding_unit_flag is set in the coding tree. If split_coding_unit_flag is 1, the coding tree is divided into four coding trees. If split_coding_unit_flag is 0, the coding tree is a coding block (Coding Unit). The encoded block is provided with a skip mode flag (skip_flag), a prediction mode (pred_mode), and a prediction block size type (part_mode), and one, two, or four according to the skip mode flag and the prediction block size type. Divided into prediction blocks. The prediction mode indicates whether it is a coding block that performs intra prediction (intra-screen prediction) or an encoding block that performs inter prediction (motion compensation prediction). When the skip mode flag is 1, the skip mode is set. The skip mode has one prediction block. The number of divisions of the coding block (coding tree) is also referred to as the depth of the coding block (coding tree).

  The prediction block includes a merge flag (merge_flag), a merge index (merge_idx), an inter prediction type (inter_pred_type), an L0 prediction reference index (ref_idx_l0), an L0 prediction difference vector (mvd_l0 [0], mvd_l0 [1]), A prediction vector index for L0 prediction (mvp_idx_l0), a reference index for L1 prediction (ref_idx_l1), a difference vector for L1 prediction (mvd_l1 [0], mvd_l1 [1]), and a prediction vector index for L1 prediction (mvp_idx_l1) are installed. Yes. [0] of the difference vector indicates a horizontal component and [1] indicates a vertical component.

  Here, inter_pred_type indicates a prediction direction (also referred to as inter prediction type) of motion compensation prediction, and three types of Pred_L0 (uni prediction of L0 prediction), Pred_L1 (uni prediction of L1 prediction) and Pred_BI (bi prediction of BI prediction). There is. When inter_pred_type is Pred_L0 or Pred_BI, information about L0 prediction is installed, and when inter_pred_type is Pred_L1 or Pred_BI, information about L1 prediction is installed. In the P picture (P slice), inter_pred_type is uniquely Pred_L0, and therefore inter_pred_type is omitted.

  In the skip mode, the prediction block is an encoding block that performs inter prediction, and the prediction encoding mode is the merge mode. Therefore, a merge index is set in the skip mode.

  Although the syntax according to the present embodiment is set as shown in FIG. 6, the encoding block and the prediction block have a plurality of block sizes, and the merge mode and the prediction vector mode may be used, and the present invention is not limited to this. .

  Hereinafter, with reference to the drawings, details of a moving image encoding apparatus, a moving image encoding method, a moving image encoding program, a moving image decoding apparatus, a moving image decoding method, and a moving image decoding program according to a preferred embodiment of the present invention will be described. explain. In the description of the drawings, the same elements are denoted by the same reference numerals and redundant description is omitted.

(Configuration of moving picture coding apparatus 100)
FIG. 7 shows the configuration of moving picture coding apparatus 100 according to the first embodiment. The moving image encoding apparatus 100 is an apparatus that encodes a moving image signal in units of prediction blocks for performing motion compensated prediction. Encoding block division, skip mode determination, prediction block size type determination, prediction block size and prediction block position (also referred to as prediction block position information and prediction block number), prediction coding Whether the mode is intra is determined by a higher-level encoding control unit (not shown). In the first embodiment, a case where the predictive encoding mode is not intra will be described. Further, in the first embodiment, a B picture (B slice) corresponding to bi-prediction will be described, but L1 prediction may be omitted for a P picture (P slice) not corresponding to bi-prediction.

  The moving image encoding apparatus 100 is realized by hardware such as an information processing apparatus including a CPU (Central Processing Unit), a frame memory, and a hard disk. The moving image encoding apparatus 100 realizes functional components described below by operating the above components. Note that the position information of the prediction block to be processed, the prediction block size, and the prediction direction of motion compensated prediction are assumed to be shared in the video encoding device 100 and are not shown.

  The moving image encoding apparatus 100 according to Embodiment 1 includes a prediction block image acquisition unit 101, a subtraction unit 102, a prediction error encoding unit 103, a code string generation unit 104, a prediction error decoding unit 105, a motion compensation unit 106, and an addition unit. 107, a motion vector detection unit 108, a motion information generation unit 109, a frame memory 110, and a motion information memory 111.

(Function and operation of moving picture coding apparatus 100)
Hereinafter, the function and operation of each unit will be described. The prediction block image acquisition unit 101 acquires the image signal of the prediction block to be processed from the image signal supplied from the terminal 10 based on the position information and the prediction block size of the prediction block, and subtracts the image signal of the prediction block 102, and supplied to the motion vector detection unit 108 and the motion information generation unit 109.

  The motion vector detection unit 108 obtains motion vectors and reference images of the L0 prediction and the L1 prediction from the image signal supplied from the prediction block image acquisition unit 101 and image signals corresponding to a plurality of reference images stored therein. Detect the reference index indicated. The motion vector of the L0 prediction and the L1 prediction and the reference index of the L0 prediction and the L1 prediction are supplied to the motion information generation unit 109. Here, the motion vector detection unit 108 uses image signals corresponding to a plurality of reference images stored therein as reference images, but a reference image stored in the frame memory 110 can also be used.

  A general motion vector detection method calculates an error evaluation value for an image signal of a target image and a prediction signal of a reference image moved by a predetermined movement amount from the same position, and a movement amount that minimizes the error evaluation value. Is a motion vector. When there are a plurality of reference images, a motion vector is detected for each reference image, and a reference image having a minimum error evaluation value is selected. As the error evaluation value, SAD (Sum of Absolute Difference) indicating the sum of absolute differences, MSE (Mean Square Error) indicating the mean square error, or the like can be used. It is also possible to evaluate by adding the motion vector code amount to the error evaluation value.

  The motion information generation unit 109 indicates L0 prediction and L1 prediction motion vectors supplied from the motion vector detection unit 108, reference indexes for L0 prediction and L1 prediction, candidate block groups supplied from the motion information memory 111, and reference indexes. The prediction encoding mode is determined from the reference image in the frame memory 110 and the image signal supplied from the prediction block image acquisition unit 101.

  Based on the determined predictive coding mode, the merge flag, the merge index, the prediction direction of motion compensation prediction, the reference index of L0 prediction and L1 prediction, the difference vector of L0 prediction and L1 prediction, and the prediction vector of L0 prediction and L1 prediction The index is supplied to the code string generation unit 104 as necessary. The motion compensation prediction direction, the reference index of L0 prediction and L1 prediction, and the motion vector of L0 prediction and L1 prediction are supplied to the motion compensation unit 106 and the motion information memory 111. Details of the motion information generation unit 109 will be described later.

  If the prediction direction of the motion compensation prediction supplied from the motion information generation unit 109 is LN prediction, the motion compensation unit 106 stores the frame compensation information in the frame memory 110 indicated by the LN prediction reference index supplied from the motion information generation unit 109. The reference image is motion-compensated based on the LN prediction motion vector supplied from the motion information generation unit 109 to generate a prediction signal for LN prediction. N is 0 or 1. Here, if the prediction direction of motion compensation prediction is bi-prediction, the average value of the prediction signals of L0 prediction and L1 prediction is the prediction signal. Note that the prediction signals of the L0 prediction and the L1 prediction may be weighted. The motion compensation unit 106 supplies the prediction signal to the subtraction unit 102.

  The subtraction unit 102 subtracts the image signal supplied from the prediction block image acquisition unit 101 and the prediction signal supplied from the motion compensation unit 106 to calculate a prediction error signal, and calculates the prediction error signal to the prediction error encoding unit 103. To supply.

  The prediction error encoding unit 103 performs processing such as orthogonal transformation and quantization on the prediction error signal supplied from the subtraction unit 102 to generate prediction error encoded data, and encodes the prediction error encoded data. The data is supplied to the column generation unit 104 and the prediction error decoding unit 105.

  The code string generation unit 104 includes prediction error encoded data supplied from the prediction error encoding unit 103, a merge flag, a merge index, and a motion compensation prediction prediction direction (inter prediction type) supplied from the motion information generation unit 109. , The reference index of L0 prediction and L1 prediction, the difference vector of L0 prediction and L1 prediction, and the prediction vector index of L0 prediction and L1 prediction are entropy-coded according to the syntax sequence shown in FIG. The sequence is supplied to the terminal 11 as an encoded stream. Entropy coding is performed by a method including variable length coding such as arithmetic coding or Huffman coding.

  In addition, the code string generation unit 104 determines the encoding stream division information, the prediction block size type, and the prediction encoding mode used by the video encoding apparatus 100, and parameters for determining the characteristics of the encoded stream. Coding with SPS (Sequence Parameter Set) that defines picture characteristics, PPS (Picture Parameter Set) that defines parameter groups for determining picture characteristics, and a slice header that defines parameter groups for determining slice characteristics Multiplex in the stream.

  The prediction error decoding unit 105 performs a process such as inverse quantization or inverse orthogonal transform on the prediction error encoded data supplied from the prediction error encoding unit 103 to generate a prediction error signal, and the prediction error signal Is supplied to the adder 107. The addition unit 107 adds the prediction error signal supplied from the prediction error decoding unit 105 and the prediction signal supplied from the motion compensation unit 106 to generate a decoded image signal, and supplies the decoded image signal to the frame memory 110. To do.

  The frame memory 110 stores the decoded image signal supplied from the adding unit 107. In addition, for a decoded image in which decoding of the entire image is completed, a predetermined number of images of 1 or more is stored as a reference image. The frame memory 110 supplies the stored reference image signal to the motion compensation unit 106 and the motion information generation unit 109. A storage area for storing the reference image is controlled by a FIFO (First In First Out) method.

  The motion information memory 111 stores the motion information supplied from the motion information generation unit 109 for a predetermined number of images in units of the minimum predicted block size. The motion information of the adjacent block of the prediction block to be processed is set as a space candidate block group.

  In addition, the motion information memory 111 uses the motion information of the same position prediction block on the ColPic at the same position as the processing target prediction block and its neighboring blocks as a time candidate block group. The motion information memory 111 supplies the spatial candidate block group and the temporal candidate block group to the motion information generation unit 109 as candidate block groups. The motion information memory 111 is synchronized with the frame memory 110 and is controlled by a FIFO (First In First Out) method.

  Here, ColPic is a decoded image different from an image having a prediction block to be processed, and is stored in the frame memory 110 as a reference image. In Embodiment 1, ColPic is a reference image decoded immediately before the processing target image. In Embodiment 1, ColPic is a reference image decoded immediately before the processing target image. However, it may be a decoded image, for example, the reference image immediately before in the display order or the reference image immediately after in the display order. Alternatively, it can be specified in the encoded stream.

  Here, a method for managing motion information in the motion information memory 111 will be described. The motion information is stored in each memory area in units of the smallest prediction block. Each memory area stores at least a prediction direction, a motion vector for L0 prediction, a reference index for L0 prediction, a motion vector for L1 prediction, and a reference index for L1 prediction.

  When the predictive coding mode is the intra mode, (0, 0) is stored as a motion vector for L0 prediction and L1 prediction, and “−1” is stored as a reference index for L0 prediction and L prediction. Hereinafter, in the motion vector (H, V), H represents a horizontal component and V represents a vertical component. The reference index “−1” may be any value as long as it can be determined that the mode in which motion compensation prediction is not performed. From this point onward, unless expressed otherwise, the term “block” refers to the smallest predicted block unit when expressed simply as a block. Also, in the case of a block outside the area, (0, 0) is stored as a motion vector for L0 prediction and L1 prediction, and “−1” is stored as a reference index for L0 prediction and L1 prediction, as in the intra mode. The When the LX direction (X is 0 or 1) is valid, the reference index in the LX direction is 0 or more, and when the LX direction is invalid (not valid), the reference index in the LX direction is “−1”. That is.

(Configuration of the motion information generation unit 109)
Next, a detailed configuration of the motion information generation unit 109 will be described. FIG. 8 shows a configuration of the motion information generation unit 109. The motion information generation unit 109 includes a prediction vector mode determination unit 120, a merge mode determination unit 121, and a prediction encoding mode determination unit 122. The terminal 12 is in the motion information memory 111, the terminal 13 is in the motion vector detection unit 108, the terminal 14 is in the frame memory 110, the terminal 15 is in the prediction block image acquisition unit 101, the terminal 16 is in the code string generation unit 104, and the terminal 50 Are connected to the motion compensation unit 106, and the terminal 51 is connected to the motion information memory 111, respectively.

(Function and operation of motion information generation unit 109)
Hereinafter, the function and operation of each unit will be described. The prediction vector mode determination unit 120 includes a candidate block group supplied from the terminal 12, a motion vector for L0 prediction and L1 prediction supplied from the terminal 13, a reference index for L0 prediction and L1 prediction, and a reference index supplied from the terminal 14. The inter-prediction type is determined from the reference image shown in FIG. 5 and the image signal supplied from the terminal 15, and the prediction vector index of the L0 prediction and the L1 prediction is selected according to the inter prediction type, and the difference vector between the L0 prediction and the L1 prediction is selected. , A prediction error is calculated, and a rate distortion evaluation value is calculated. Then, motion information, a difference vector, a prediction vector index, and a rate distortion evaluation value based on the inter prediction type are supplied to the prediction coding mode determination unit 122.

  The merge mode determination unit 121 generates a combined motion information candidate list from the candidate block group supplied from the terminal 12, the reference image supplied from the terminal 14, and the image signal supplied from the terminal 15, and the combined motion information One merged motion information candidate is selected from the candidate list, a merge index is determined, and a rate distortion evaluation value is calculated. Then, the motion information of the combined motion information candidate, the merge index, and the rate distortion evaluation value are supplied to the predictive coding mode determination unit 122. Details of the merge mode determination unit 121 will be described later.

  The prediction coding mode determination unit 122 compares the rate distortion evaluation value supplied from the prediction vector mode determination unit 120 and the rate distortion evaluation value supplied from the merge mode determination unit 121 to determine a merge flag.

  If the predicted vector mode rate distortion evaluation value is less than the merge mode rate distortion evaluation value, the merge flag is set to “0”. The prediction encoding mode determination unit 122 supplies the merge flag, the inter prediction type, the reference index, the difference vector, and the prediction vector index supplied from the prediction vector mode determination unit 120 to the terminal 16, and the prediction vector mode determination unit 120 The supplied motion information is supplied to the terminal 50 and the terminal 51.

  If the merge mode rate distortion evaluation value is less than or equal to the predicted vector mode rate distortion evaluation value, the merge flag is set to “1”. The predictive coding mode determination unit 122 supplies the merge flag and the merge index supplied from the merge mode determination unit 121 to the terminal 16, and supplies the motion information supplied from the merge mode determination unit 121 to the terminal 50 and the terminal 51. To do. Although a specific calculation method of the rate distortion evaluation value is not the main point of the present invention, detailed description is omitted, but the prediction error amount per code amount is calculated from the prediction error and the code amount, and the rate distortion evaluation value is calculated. The evaluation value has a characteristic that the encoding efficiency increases as the value decreases. Therefore, encoding efficiency can be improved by selecting a predictive encoding mode with a small rate distortion evaluation value.

(Configuration of merge mode determination unit 121)
Next, a detailed configuration of the merge mode determination unit 121 will be described. FIG. 9 is a diagram for explaining the configuration of the merge mode determination unit 121. The merge mode determination unit 121 includes a combined motion information candidate list generation unit 140 and a combined motion information selection unit 141. The combined motion information candidate list generation unit 140 is also installed in the video decoding device 200 that decodes the code sequence generated by the video encoding device 100 according to Embodiment 1 in the same manner. The moving image decoding apparatus 200 generates the same combined motion information list.

(Function and operation of merge mode determination unit 121)
Hereinafter, the function and operation of each unit will be described. The combined motion information candidate list generation unit 140 generates a combined motion information candidate list including the maximum number of merge candidate motion candidates from the candidate block group supplied from the terminal 12, and uses the combined motion information candidate list as the combined motion information. This is supplied to the selection unit 141. A detailed configuration of the combined motion information candidate list generation unit 140 will be described later.

  The combined motion information selection unit 141 selects the optimum combined motion information candidate from the combined motion information candidate list supplied from the combined motion information candidate list generation unit 140, and is information indicating the selected combined motion information candidate. A certain merge index is determined and the merge index is supplied to the terminal 17.

  Here, a method for selecting an optimal combined motion information candidate will be described. A prediction error amount is calculated from the reference image supplied from the terminal 14 obtained by motion compensation prediction based on the prediction direction, motion vector, and reference index of the combined motion information candidate, and the image signal supplied from the terminal 15. . A rate distortion evaluation value is calculated from the code amount of the merge index and the prediction error amount, and a combined motion information candidate that minimizes the rate distortion evaluation value is selected as an optimal combined motion information candidate.

(Configuration of combined motion information candidate list generation unit 140)
Next, a detailed configuration of the combined motion information candidate list generation unit 140 will be described. FIG. 10 is a diagram for explaining the configuration of the combined motion information candidate list generation unit 140. The terminal 19 is connected to the combined motion information selection unit 141. The combined motion information candidate list generating unit 140 includes a spatially combined motion information candidate generating unit 160, a temporally combined motion information candidate generating unit 161, a redundant combined motion information candidate deleting unit 162, a first combined motion information candidate supplementing unit 163, and a second A combined motion information candidate supplementing unit 164 is included. Hereinafter, it is described that a combined motion information candidate is generated, but it may be paraphrased to be derived.

(Function and operation of combined motion information candidate list generation unit 140)
Hereinafter, the function and operation of each unit will be described. FIG. 11 is a flowchart for explaining the operation of the combined motion information candidate list generation unit 140. First, the combined motion information candidate list generation unit 140 initializes a combined motion information candidate list (S100). There are no combined motion information candidates in the initialized combined motion information candidate list.

  Next, the spatially coupled motion information candidate generation unit 160 generates the maximum number of spatially coupled motion information candidates from 0 candidate block groups supplied from the terminal 12 and adds them to the combined motion information candidate list. In step S101, the combined motion information candidate list and the candidate block group are supplied to the temporally combined motion information candidate generation unit 161. The detailed operation of the spatially coupled motion information candidate generation unit 160 will be described later. The maximum number of spatially coupled motion information candidates will be described later.

  Next, the temporally combined motion information candidate generating unit 161 generates the maximum number of temporally combined motion information candidates from the 0 candidate block group supplied from the spatially combined motion information candidate generating unit 160 to generate the spatially combined motion information candidate. This is added to the combined motion information candidate list supplied from the combined motion information candidate generation unit 160 (S102), and the combined motion information candidate list is supplied to the redundant combined motion information candidate deletion unit 162. The detailed operation of the time combination motion information candidate generation unit 161 will be described later. Further, the maximum number of temporally combined motion information candidates will be described later.

  Next, the redundant combined motion information candidate deletion unit 162 examines the combined motion information candidates registered in the combined motion information candidate list supplied from the temporal combined motion information candidate generation unit 161, and combines the same motion information. When there are a plurality of motion information candidates, one combined motion information candidate is left and other combined motion information candidates are deleted (S103), and the combined motion information candidate list is supplied to the first combined motion information candidate supplementing unit 163. To do. Here, the combined motion information candidates registered in the combined motion information candidate list are all different combined motion information candidates.

  Next, the first combined motion information candidate supplementing unit 163 includes 0 to 2 first supplemental combining from the combined motion information candidates registered in the combined motion information candidate list supplied from the redundant combined motion information candidate deleting unit 162. A motion information candidate is generated and added to the combined motion information candidate list (S104), and the combined motion information candidate list is supplied to the second combined motion information candidate supplement unit 164. The detailed operation of the first combined motion information candidate supplement unit 163 will be described later.

  Next, the second combined motion information candidate supplementing unit 164 until the number of combined motion information candidates registered in the combined motion information candidate list supplied from the first combined motion information candidate supplementing unit 163 reaches the maximum number of merge candidates. A second supplementary combined motion information candidate is generated and added to the combined motion information candidate list (S105), and the combined motion information candidate list is supplied to the terminal 19. The detailed operation of the second combined motion information candidate supplement unit 164 will be described later.

  Here, the spatial combination motion information candidate generation unit 160 and the temporal combination motion information candidate generation unit 161 generate the spatial combination motion information candidate and the temporal combination motion information candidate and add them to the combined motion information candidate list. The motion information candidate generation unit 160 and the temporally combined motion information candidate generator 161 only generate a spatially combined motion information candidate and a temporally combined motion information candidate, respectively, and combine them from candidates generated immediately before the redundantly combined motion information candidate deletion unit 162. A motion information candidate list may be generated.

(About 2N × 2N candidate block group)
Hereinafter, candidate block groups of prediction blocks will be described. First, a prediction block whose prediction block size type is 2N × 2N will be described. FIG. 12 is a diagram for explaining a candidate block group of prediction blocks whose prediction block size type is 2N × 2N. FIG. 12 shows an example in which the predicted block size is 16 pixels × 16 pixels. Note that temporal candidate blocks H and I, which will be described later, exist in pictures different from decoded pictures that are different from pictures in which spatial candidate blocks A to E, which will also be described later, exist, but for ease of understanding and explanation. In FIG. 12, it is shown together with the space candidate blocks A to E.

  The spatial candidate block group includes a block A positioned to the left of the lower left pixel of the prediction block, a block B positioned above the upper right pixel of the prediction block, a block C positioned diagonally to the upper right of the upper right pixel of the prediction block, It is assumed that a block E is located at the lower left corner of the lower left pixel of the prediction block, and a block D is located at the upper left corner of the upper left pixel of the prediction block. Thus, the space candidate block group is determined based on the position and size of the prediction block. There are two time candidate block groups, block H and block I, which are representative blocks of a predetermined area of ColPic. If the position of the upper left pixel of the prediction block to be processed is (x, y) and the width and height of the prediction block to be processed are PUW and PUH, respectively, ((((x + PUW) >> 4) << 4) , ((Y + PUH) >> 4) << 4)) is a block on ColPic including the position of the pixel on the upper left of the block as a time candidate block H. Here, >> is a bit shift in the right direction, and << is a bit shift in the left direction.

  Similarly, a block on ColPic including the position of the pixel at (x + (PUW >> 1), y + (PUH >> 1)) as the position of the upper left pixel of the block is set as a time candidate block I. Thus, the time candidate block group is determined based on the position and size of the prediction block. In this way, by setting the time candidate block as a representative block of a predetermined area of ColPic (16 pixels × 16 pixels in this case), it is possible to reduce motion vectors and reference indexes to be stored by ColPic. By reducing the motion vector and reference index stored in one image, a plurality of decoded images can be targeted for ColPic, which has the effect of improving prediction efficiency.

  Here, since the coding block whose prediction block size type is 2N × 2N is configured by one prediction block, the position of the candidate block with respect to the prediction block whose prediction block size type is 2N × 2N is the coding block. Is equal to the position of the candidate block, and the position of the candidate block is outside the encoded block.

  Here, the block A is set to the lower left of the prediction block, but it is sufficient that the block A is in contact with the left side of the prediction block, and the present invention is not limited to this. Moreover, although the block B was made into the upper right of the prediction block, it should just touch the upper side of a prediction block, and is not limited to this. In addition, although the time candidate block group includes two blocks H and I, the present invention is not limited to this.

(Application example of the same positional relationship as 2N × 2N to a candidate block group other than 2N × 2N)
Next, an example will be described in which the same positional relationship is applied to a prediction block in a coding block whose prediction block size type is not 2N × 2N as a prediction block of a coding block whose prediction block size type is 2N × 2N. FIG. 13 shows a candidate block group in the case where the same positional relationship as that of a prediction block of a coding block whose prediction block size type is 2N × 2N is applied to a prediction block in a coding block whose prediction block size type is not 2N × 2N. FIG. In FIG. 13, as in FIG. 12, the temporal candidate blocks H and I exist in a different picture from the decoded picture different from the picture in which the spatial candidate blocks A to E exist. Therefore, it is shown together with the space candidate blocks A to E. FIGS. 13A to 13H show a prediction block 0 with a prediction block size type of N × 2N, a prediction block 1 with a prediction block size type of N × 2N, a prediction block 0 with a prediction block size type of 2N × N, Prediction block 1 with a prediction block size type of 2N × N, prediction block 0 with a prediction block size type of N × N, prediction block 1 with a prediction block size type of N × N, and prediction block with a prediction block size type of N × N 2 shows a candidate block group when the prediction block size type is a prediction block 3 of N × N. FIG. 13 shows an example in which the predicted block size is 16 pixels × 16 pixels. Note that the temporal candidate block group is derived in the same manner as when the predicted block size type is 2N × 2N, and FIG. In this way, in a prediction block included in an encoded block whose prediction block size type is not 2N × 2N, a candidate block group is determined for each prediction block based on the position and size of the prediction block.

  Here, in the case of the prediction block 1 of which the prediction block size type is N × 2N (FIG. 13B), the block A is inside the prediction block 0 of the same coding block, and the motion information of the block A is obtained. Since the motion information of the prediction block 0 needs to be determined before the prediction block 1 is processed, when the block A is used as the candidate block of the prediction block 1, the prediction block 0 and the prediction block 1 are processed simultaneously. I can't do it. Further, since the largest encoded block is performed in the raster scan order and the encoded block is performed in the zigzag scan order, the block E is always an unprocessed block. Similarly, in the case of the prediction block 1 of which the prediction block size type is 2N × N (FIG. 13D), the block B is inside the prediction block 0 of the same encoded block, and the block C is always an unprocessed block. Become. For the prediction block 1 (FIG. 13 (f)), the prediction block 2 (FIG. 13 (g)), and the prediction block 3 (FIG. 13 (h)) of which the prediction block size type is N × N, FIG. 13 shows an internal block and an unprocessed block.

  Prediction block 1 with a prediction block size type of N × 2N, prediction block 1 with a prediction block size type of 2N × N, prediction block 1 with a prediction block size type of N × N, and prediction block with a prediction block size type of N × N For 2, the number of candidate blocks that are not in the same coding block and are not necessarily processed is 3, and the prediction block 3 whose prediction block size type is N × N is not in the same coding block and is always unprocessed. The number of candidate blocks that are not processed is zero. Decreasing the number of candidate blocks leads to a decrease in prediction efficiency.

(Positional block position relationship)
FIG. 14 is a diagram for explaining an example of a positional relationship between a prediction block and a spatial candidate block group whose prediction block size type is other than 2N × 2N in the first embodiment. The time candidate block group is the same as in FIG. 14 (a) to 14 (h) respectively show a prediction block 0 whose prediction block size type is N × 2N, a prediction block 1 whose prediction block size type is N × 2N, and a prediction block 0 whose prediction block size type is 2N × N. Prediction block 1 with a prediction block size type of 2N × N, prediction block 0 with a prediction block size type of N × N, prediction block 1 with a prediction block size type of N × N, and prediction block with a prediction block size type of N × N 2 shows a spatial candidate block group when the prediction block size type is a prediction block 3 of N × N. FIG. 14 shows an example in which the predicted block size is 16 pixels × 16 pixels.

  Here, a block inside another prediction block of the same encoded block is replaced with a prediction block candidate block having a prediction block size type of 2N × 2N. That is, in the case of the prediction block 1 with the prediction block size type of N × 2N (FIG. 14B), the block A is the block A of the prediction block candidate block with the prediction block size type of 2N × 2N. When the prediction block size type is prediction block 1 of 2N × N (FIG. 14 (d)), block B is set as a block B of a prediction block candidate block having a prediction block size type of 2N × 2N. When the prediction block size type is N × N prediction block 1 (FIG. 14 (f)), block A and block E are prediction block candidate blocks of block A and block E whose prediction block size type is 2N × 2N. To do. When the prediction block size type is N × N prediction block 2 (FIG. 14G), block B and block C are prediction block candidate blocks B and C that are prediction block size types 2N × 2N. To do. When the prediction block size type is N × N prediction block 3 (FIG. 14 (h)), block A, block B, and block D are predicted blocks A, which are prediction block candidate types having a prediction block size type of 2N × 2N, Let it be block B and block D.

  Prediction block 1 with a prediction block size type of N × 2N, prediction block 1 with a prediction block size type of 2N × N, prediction block 1 with a prediction block size type of N × N, and prediction block with a prediction block size type of N × N 2. The number of effective candidate blocks for the prediction block 3 whose prediction block size type is N × N is 5.

  As described above, a candidate block included in another prediction block of the same encoded block has a prediction block size type of 2N × 2N that maximizes the prediction block size among the prediction block sizes of the encoded block. By making a prediction block candidate block, there is no dependency relationship of motion information between prediction blocks included in the encoded block, and a plurality of predicted blocks included in the encoded block can be processed simultaneously.

(Detailed operation of spatially coupled motion information candidate generation unit 160)
Next, a detailed operation of the spatially coupled motion information candidate generation unit 160 will be described. FIG. 15 is a flowchart for explaining the operation of the spatially coupled motion information candidate generation unit 160. The spatially coupled motion information candidate generating unit 160 repeatedly performs the following processing in the order of block A, block B, block C, block E, and block D, which are candidate blocks included in the spatial candidate block group of the candidate block group (from S110) S114).

  First, it is checked whether the candidate block is valid (S111). That the candidate block is valid means that at least one of the reference indexes of the L0 prediction and the L1 prediction of the candidate block is 0 or more. If the candidate block is valid (Y in S111), the motion information of the candidate block is added to the combined motion information candidate list as a spatially combined motion information candidate (S112). If the candidate block is not valid (N in S111), the next candidate block is inspected (S114). Following step S112, it is checked whether the number of spatially combined motion information candidates added to the combined motion information candidate list is the maximum number of spatially combined motion information candidates (S113). Here, the maximum number of spatially coupled motion information candidates is 4. If the number of spatially combined motion information candidates added to the combined motion information candidate list is not the maximum number of spatially combined motion information candidates (N in S113), the next candidate block is examined (S114). If the number of spatially combined motion information candidates added to the combined motion information candidate list is the maximum number of spatially combined motion information candidates (Y in S113), the process ends.

  Here, the processing information is processed so that the motion information of block A and block B, which are generally considered to have a long tangent to the processing target block and generally have a high correlation with the processing target block, can be preferentially registered in the combined motion information candidate list. Although the order is block A, block B, block C, block E, and block D, the combined motion information candidates are added to the combined motion information candidate list in the order of high correlation with the processing target block or as the candidate block. It only needs to be registered, and is not limited to this. For example, when the prediction block size type is N × 2N prediction block 1, the prediction block size type is 2N × N prediction block 1 in the order of block B, block C, block E, block D, and block A. , Block A, block C, block E, block D, block B, in the order of prediction block size type N × N, block B, block C, block D, block A, block E When the prediction block size type is N × N prediction block 2, the prediction block size type is N × N prediction block 3 in the order of block A, block E, block D, block B, and block C. Block C, block E, block A, block B, and block D can be arranged in this order. In this way, by adding to the combined motion information candidate list in order from the closest to the prediction block to be processed, it is possible to prevent a large merge index from being assigned to a block close to the prediction block to be processed, and to improve the encoding efficiency. Can be improved. Although the maximum number of spatially coupled motion information candidates is four, the maximum number of spatially coupled motion information candidates may be 1 or more and less than the maximum number of merge candidates, and is not limited thereto.

(Detailed operation of time combination motion information candidate generation unit 161)
Subsequently, a detailed operation of the time combination motion information candidate generation unit 161 will be described. FIG. 16 is a flowchart for explaining the operation of the time combination motion information candidate generation unit 161. The following processing is repeated for each prediction direction LX of L0 prediction and L1 prediction (S120 to S127). Here, X is 0 or 1. Further, the following processing is repeated in the order of block H and block I, which are candidate blocks included in the time candidate block group of the candidate block group (S121 to S126).

  The temporal combination motion information candidate generation unit 161 checks whether the LN prediction of the candidate block is valid (S122). Here, N is 0 or 1. Here, N is the same as X. That the LN prediction of the candidate block is valid means that the reference index of the LN prediction of the candidate block is 0 or more. If the LN prediction of the candidate block is valid (Y in S122), the LN prediction motion vector of the candidate block is set as the reference motion vector (S123). If the LN prediction of the candidate block is not valid (N in S122), step 123 to step 126 are skipped and the next candidate block is examined (S126).

  Subsequent to step S123, a reference image for LX prediction of a temporally combined motion information candidate is determined (S124). Here, the LX prediction reference image of the temporally combined motion information candidate is a reference image with a reference index 0 of LX prediction. Here, the LX prediction reference image of the temporally combined motion information candidate is the reference image of the LX prediction reference index 0, but the reference image does not depend on the values of other prediction blocks in the encoded block, and is not limited thereto. . Next, the base motion vector is scaled to match the distance between the processing target image and the LX prediction reference image of the temporally combined motion information candidate to calculate the temporally combined motion information candidate LX prediction motion vector (S125). The prediction direction is processed (S127). A specific calculation formula for the motion vector of the LX prediction of the temporally combined motion information candidate will be described later. Subsequent to step S127 in which the processing for the L0 prediction and the L1 prediction is completed, it is checked whether at least one of the L0 prediction and the L1 prediction of the temporally coupled motion information candidate is valid (S128). If at least one of the L0 prediction and the L1 prediction of the temporally combined motion information candidate is valid (Y in S128), the inter prediction type of the temporally combined motion information candidate is determined, and the temporally combined motion information candidate is combined with the motion. The information is added to the information candidate list (S129). Here, in the determination of the inter prediction type, if only the L0 prediction is valid, the inter prediction type of the temporally combined motion information candidate is Pred_L0, and if only the L1 prediction is valid, the inter prediction type of the temporally combined motion information candidate is Is Pred_L1, and if both the L0 prediction and the L1 prediction are valid, the inter prediction type of the temporally combined motion information candidate is Pred_BI.

Next, a formula for calculating a motion vector for LX prediction of temporally combined motion information candidates will be described. The distance between images of ColPic having a temporal candidate block and ColRefLXPic which is a picture to which the temporal candidate block refers in motion compensated prediction of LX prediction is td, the reference image RefLXPic of the LX prediction of the temporal combined motion information candidate and the image of the processing target image CurPic When the inter-distance is tb and the reference motion vector for LX prediction is mvLX, the LX prediction motion vector mvLXCol of the temporally combined motion information candidate is calculated from Equation 1. It can be seen from Equation 1 that subtraction, division, and multiplication for calculating tb and td are required to calculate a motion vector for LX prediction of temporally combined motion information candidates.
mvLXCol = tb / td * mvLX; Equation 1

In the case where the expression 1 is an integer operation for simplifying the floating point operation, for example, the expression 1 may be expanded and used as the expression 2 to 4. Abs (v) is a function that calculates the absolute value of the value v, Clip3 (uv, lv, v) is a function that limits the value v from the lower limit lv to the upper limit uv, and Sign (v) For example, the function returns 1 when the value v is smaller than 0.
tx = (16384 + Abs (td / 2)) / td; Equation 2
DistScaleFactor = Clip3 (-1024, 1023, (tb * tx + 32) >>6); Equation 3
mvLXCol = Sign (DistScaleFactor * mvLX) * ((Abs (DistScaleFactor * mvLX) +127) >>8); Equation 4

  Here, the maximum number of temporally combined motion information candidates that is the maximum number of temporally combined motion information candidates that can be registered in the combined motion information candidate list is 1. Therefore, FIG. 16 omits the processing corresponding to step S115 shown in FIG. 14 which is a flowchart for explaining the operation of the spatially coupled motion information candidate generating unit 160, but the maximum number of temporally coupled motion information candidate candidates is 2 or more. In this case, a process corresponding to step S115 can be added after step S129.

  Here, N is the same as X, but N may be different from X and is not limited to this.

(Detailed operation of first combined motion information candidate supplementing unit 163)
Next, the detailed operation of the first combined motion information candidate supplement unit 163 will be described. FIG. 17 is a flowchart for explaining the operation of the first combined motion information candidate supplementing unit 163. First, MaxNumGenCand, which is the maximum number for generating the first supplemental combined motion information candidate from the number of combined motion information candidates (NumCandList) and the maximum number of merge candidates (MaxNumMergeCand) registered in the combined motion information candidate list to be supplied. Is calculated from Equation 5 (S170).
MaxNumGenCand = MaxNumMergeCand-NumCandList; (NumCandList> 1)
MaxNumGenCand = 0; (NumCandList <= 1) Equation 5

  Next, it is checked whether MaxNumGenCand is greater than 0 (S171). If MaxNumGenCand is not greater than 0 (N in S171), the process ends. If MaxNumGenCand is greater than 0 (Y in S171), the following processing is performed. First, loopTimes that is the number of combination inspections is determined. loopTimes is set to NumCandList × NumCandList. However, if loopTimes exceeds 8, loopTimes is limited to 8 (S172). Here, loopTimes is an integer from 0 to 7. The following processing is repeated for loopTimes (S172 to S180). A combination of the combined motion information candidate M and the combined motion information candidate N is determined (S173). Here, the relationship between the number of combination inspections, the combined motion information candidate M, and the combined motion information candidate N will be described. FIG. 18 is a diagram for explaining the relationship between the number of combination inspections, the combined motion information candidate M, and the combined motion information candidate N. As shown in FIG. 18, M and N are different values, and are set in order of decreasing total value of M and N. It is checked whether the L0 prediction of the combined motion information candidate M is valid and the L1 prediction of the combined motion information candidate N is valid (S174). If the L0 prediction of the combined motion information candidate M is valid and the L1 prediction of the combined motion information candidate N is valid (Y in S174), the L0 prediction reference image of the combined motion information candidate M and the motion vector are combined motion information candidates. It is checked whether or not the reference image of the N L1 prediction is different from the motion vector (S175). If the L0 prediction of the combined motion information candidate M is not valid and the L1 prediction of the combined motion information candidate N is not valid (N in S174), the next combination is processed. If the reference image for L0 prediction of the combined motion information candidate M and the reference image for L1 prediction of the combined motion information candidate N are different (Y in S175), the motion vector of the combined motion information candidate M and the reference image for the L0 prediction are combined motion information. By combining the motion vector of L1 prediction of candidate N and the reference image, a bi-join motion information candidate having an inter prediction type of Pred_BI is generated (S176). Here, as the first supplemental combined motion information candidate, bi-coupled motion information is generated by combining the L0 prediction of a certain combined motion information candidate and the L1 prediction motion information of a different combined motion information candidate. If the reference image for L0 prediction of the combined motion information candidate M and the reference image for L1 prediction of the combined motion information candidate N are the same (N in S175), the next combination is processed. Subsequent to step S176, the bi-join motion information candidate is added to the joint motion information candidate list (S178). Subsequent to step S178, it is checked whether the number of generated double-coupled motion information is MaxNumGenCand (S179). If the number of generated double coupled motion information is MaxNumGenCand (Y in S179), the process ends. If the number of generated double coupled motion information is not MaxNumGenCand (N in S179), the next combination is processed.

  Here, the first supplemental combined motion information candidate is set as an L0 prediction motion vector of a certain combined motion information candidate registered in the combined motion information candidate list and the reference image, and the L1 prediction motion vector of another combined motion information candidate. In combination with the reference image, a bi-coupled motion information candidate in which the direction of motion compensation prediction is bidirectional is used, but the present invention is not limited to this. For example, combined motion information in which the direction of motion compensated prediction in which an offset value such as +1 is added to the motion vector of L0 prediction and the motion vector of L1 prediction of a certain combined motion information candidate registered in the combined motion information candidate list is bidirectional. Combined motion information in which the direction of motion compensated prediction obtained by adding an offset value such as +1 to the motion vector of L0 prediction or the motion vector of L1 prediction of a certain combined motion information candidate registered in the candidate, combined motion information candidate list is unidirectional Can also be a candidate. As another example of the first supplemental combined motion information candidate, a motion vector of L1 prediction is obtained by scaling based on a motion vector of L0 prediction of a combined motion information candidate registered in the combined motion information candidate list, and these are combined. A new combined motion information candidate in which the direction of motion compensation prediction is bidirectional may be generated. Moreover, you may combine them arbitrarily.

  Here, the first supplemental combined motion information candidate is a combined motion information candidate when there is a slight difference between the motion information of the combined motion information candidate registered in the combined motion information candidate list and the motion information candidate to be processed. By correcting the motion information of the combined motion information candidate registered in the list and generating a new effective combined motion information candidate, the encoding efficiency can be improved.

(Detailed operation of second combined motion information candidate supplementing unit 164)
Next, the detailed operation of the second combined motion information candidate supplement unit 164 will be described. FIG. 19 is a flowchart for explaining the operation of the second combined motion information candidate supplementing unit 164. First, from the number of combined motion information candidates (NumCandList) registered in the combined motion information candidate list supplied from the first combined motion information candidate supplementing unit 163 and the maximum number of merge candidates (MaxNumMergeCand), the first supplemental combined motion information is obtained. MaxNumGenCand, which is the maximum number for generating candidates, is calculated from Equation 6 (S190).
MaxNumGenCand = MaxNumMergeCand-NumCandList; Formula 6

  Next, the following process is repeated MaxNumCand times for i (S191 to S195). Here, i is an integer from 0 to MaxNumGenCand-1. The second supplemental combined motion in which the motion vector for L0 prediction is (0,0), the reference index is i, the motion vector for L1 prediction is (0,0), and the inter prediction type for which the reference index is i is Pred_BI. Information candidates are generated (S192). The second supplementary combined motion information candidate is added to the combined motion information candidate list (S194). The next i is processed (S195).

  Here, the second supplementary combined motion information candidate has a motion vector for L0 prediction of (0, 0), a reference index of i, a motion vector of L1 prediction of (0, 0), and a reference index of i. The combined motion information candidate whose inter prediction type is Pred_BI is used. This is because, in a general moving image, the frequency of occurrence of combined motion information candidates in which the motion vector for L0 prediction and the motion vector for L1 prediction are (0, 0) is statistically high. The present invention is not limited to this as long as it is a combined motion information candidate that is statistically frequently used without depending on the motion information of the combined motion information candidate registered in the combined motion information candidate list. For example, the motion vectors of L0 prediction and L1 prediction may be vector values other than (0, 0), respectively, and may be set so that the reference indexes of L0 prediction and L1 prediction are different. Alternatively, the second supplementary combined motion information candidate can be set as an encoded image or motion information with a high occurrence frequency of a part of the encoded image, encoded in an encoded stream, and transmitted. Although the B picture has been described here, in the case of the P picture, a second supplementary combined motion information candidate having an L0 prediction motion vector of (0, 0) and an inter prediction type of Pred_L0 is generated.

  Here, by setting a combined motion information candidate that does not depend on the combined motion information candidate registered in the combined motion information candidate list as the second supplemental combined motion information candidate, the combined motion information candidate registered in the combined motion information candidate list When the number is zero, it is possible to use the merge mode and improve the encoding efficiency. In addition, when the motion information of the combined motion information candidate registered in the combined motion information candidate list and the motion information candidate motion to be processed are different, by generating a new combined motion information candidate and expanding the range of options, Encoding efficiency can be improved.

(Configuration of moving picture decoding apparatus 200)
Next, the moving picture decoding apparatus according to the first embodiment will be described. FIG. 20 is a diagram showing a configuration of the video decoding device 200 according to Embodiment 1. The video decoding device 200 is a device that generates a playback image by decoding the code string encoded by the video encoding device 100.

  The moving picture decoding apparatus 200 is realized by hardware such as an information processing apparatus including a CPU (Central Processing Unit), a frame memory, and a hard disk. The moving picture decoding apparatus 200 realizes functional components described below by operating the above components. Encoding block division, skip mode determination, prediction block size type determination, prediction block size and position of prediction block in encoding block (prediction block position information), whether prediction encoding mode is intra Is determined by a higher-level control unit (not shown), and a case where the predictive coding mode is not intra will be described here. Note that the position information and the prediction block size of the prediction block to be decoded are shared in the video decoding device 200 and are not shown.

  The moving picture decoding apparatus 200 according to Embodiment 1 includes a code string analysis unit 201, a prediction error decoding unit 202, an addition unit 203, a motion information reproduction unit 204, a motion compensation unit 205, a frame memory 206, and a motion information memory 207.

(Operation of the video decoding device 200)
Hereinafter, the function and operation of each unit will be described. The code string analysis unit 201 analyzes the code string supplied from the terminal 30 to generate prediction error encoded data, a merge flag, a merge index, a motion compensation prediction direction (inter prediction type), a reference index, a difference vector, and Entropy decodes the prediction vector index according to the syntax. Entropy decoding is performed by a method including variable length coding such as arithmetic coding or Huffman coding. Then, the prediction error encoded data is supplied to the prediction error decoding unit 202, and the merge flag, the merge index, the inter prediction type, the reference index, the difference vector, and the prediction vector index are supplied to the motion information reproduction unit 204. To do.

  In addition, the code stream analysis unit 201 sets the parameter group for determining the characteristics of the encoded stream, the division information of the encoded block used in the video decoding device 200, the predicted block size type, and the predicted encoding mode. An encoded stream together with a defined SPS (Sequence Parameter Set), a PPS (Picture Parameter Set) that defines a parameter group for determining picture characteristics, a slice header that defines a parameter group for determining slice characteristics, and the like Decrypt from.

  The motion information reproduction unit 204 includes a merge flag, a merge index, an inter prediction type, a reference index, a difference vector, and a prediction vector index supplied from the code string analysis unit 201 and a candidate block group supplied from the motion information memory 207. The motion information is reproduced, and the motion information is supplied to the motion compensation unit 205 and the motion information memory 207. A detailed configuration of the motion information reproducing unit 204 will be described later.

  Based on the motion information supplied from the motion information reproducing unit 204, the motion compensation unit 205 performs motion compensation on the reference image indicated by the reference index in the frame memory 206 based on the motion vector to generate a prediction signal. If the prediction direction is bi-prediction, an average of the prediction signals of the L0 prediction and the L1 prediction is generated as a prediction signal, and the prediction signal is supplied to the adding unit 203.

  The prediction error decoding unit 202 performs a process such as inverse quantization or inverse orthogonal transform on the prediction error encoded data supplied from the code string analysis unit 201 to generate a prediction error signal, and the prediction error signal is It supplies to the addition part 203.

  The adding unit 203 adds the prediction error signal supplied from the prediction error decoding unit 202 and the prediction signal supplied from the motion compensation unit 205 to generate a decoded image signal, and the decoded image signal is stored in the frame memory 206 and Supply to terminal 31.

  The frame memory 206 and the motion information memory 207 have the same functions as the frame memory 110 and the motion information memory 111 of the video encoding device 100. The frame memory 206 stores the decoded image signal supplied from the adding unit 203. The motion information memory 207 stores the motion information supplied from the motion information reproducing unit 204 in units of the minimum predicted block size.

(Detailed configuration of the motion information playback unit 204)
Next, a detailed configuration of the motion information reproducing unit 204 will be described. FIG. 21 shows the configuration of the motion information playback unit 204. The motion information playback unit 204 includes an encoding mode determination unit 210, a motion vector playback unit 211, and a combined motion information playback unit 212. The terminal 32 is connected to the code string analysis unit 201, the terminal 33 is connected to the motion information memory 207, the terminal 34 is connected to the motion compensation unit 205, and the terminal 36 is connected to the motion information memory 207.

(Detailed operation of the motion information playback unit 204)
Hereinafter, the function and operation of each unit will be described. The encoding mode determination unit 210 determines whether the merge flag supplied from the code string analysis unit 201 is “0” or “1”. If the merge flag is “0”, the inter prediction type, reference index, difference vector, and prediction vector index supplied from the code string analysis unit 201 are supplied to the motion vector reproduction unit 211. If the merge flag is “1”, the merge index supplied from the code string analysis unit 201 is supplied to the combined motion information reproduction unit 212.

  The motion vector reproduction unit 211 reproduces a motion vector from the inter prediction type, the reference index, the difference vector, and the prediction vector index supplied from the encoding mode determination unit 210 and the candidate block group supplied from the terminal 33. Motion information is generated and supplied to the terminals 34 and 36.

  The combined motion information reproduction unit 212 generates a combined motion information candidate list from the candidate block group supplied from the terminal 33, and combines the index indicated by the merge index supplied from the encoding mode determination unit 210 from the combined motion information candidate list. The motion information candidate motion information is selected and supplied to the terminals 34 and 36.

(Detailed Configuration of Combined Motion Information Reproducing Unit 212)
Next, a detailed configuration of the combined motion information reproduction unit 212 will be described. FIG. 22 shows the configuration of the combined motion information playback unit 212. The combined motion information reproduction unit 212 includes a combined motion information candidate list generation unit 230 and a combined motion information selection unit 231. The terminal 35 is connected to the encoding mode determination unit 210.

(Detailed operation of the combined motion information reproduction unit 212)
Hereinafter, the function and operation of each unit will be described. The combined motion information candidate list generation unit 230 has the same function as the combined motion information candidate list generation unit 140 of the video encoding device 100, and is the same as the combined motion information candidate list generation unit 140 of the video encoding device 100. The combined motion information candidate list is generated by the operation, and the combined motion information candidate list is supplied to the combined motion information selection unit 231.

  The combined motion information selection unit 231 selects a combined motion information candidate indicated by the merge index supplied from the terminal 35 from the combined motion information candidate list supplied from the combined motion information candidate list generation unit 230 and combines motion The information is determined, and the motion information of the combined motion information is supplied to the terminal 34 and the terminal 36.

  As described above, the moving picture decoding apparatus 200 can generate a reproduction image by decoding the code string encoded by the moving picture encoding apparatus 100.

[Embodiment 2]
The second embodiment will be described below. The spatial candidate block group used in the spatially coupled motion information candidate generation unit 160 is different from that of the first embodiment for a prediction block whose prediction block size type is other than 2N × 2N. Hereinafter, spatial candidate block groups of prediction blocks whose prediction block size type according to Embodiment 2 is other than 2N × 2N will be described.

  FIG. 23 is a diagram for explaining the positional relationship between a prediction block other than the prediction block size type of 2N × 2N and a spatial candidate block group in the second embodiment. 23 (a) to (h) respectively show a prediction block 0 with a prediction block size type of N × 2N, a prediction block 1 with a prediction block size type of N × 2N, a prediction block 0 with a prediction block size type of 2N × N, Prediction block 1 with a prediction block size type of 2N × N, prediction block 0 with a prediction block size type of N × N, prediction block 1 with a prediction block size type of N × N, and prediction block with a prediction block size type of N × N 2 shows a spatial candidate block group when the prediction block size type is a prediction block 3 of N × N. FIG. 23 shows an example in which the prediction block size is 16 pixels × 16 pixels. In this way, in a prediction block included in an encoded block whose prediction block size type is not 2N × 2N, a candidate block group is determined for each prediction block based on the position and size of the prediction block.

  Here, in addition to the first example described above, blocks that are always unprocessed are also replaced with prediction block candidate blocks whose prediction block size type is 2N × 2N. That is, when the prediction block size type is the prediction block 1 of N × 2N (FIG. 23B), the block E is the block E of the prediction block candidate block having the prediction block size type of 2N × 2N. In the case of the prediction block 1 having a prediction block size type of 2N × N (FIG. 23D), the block C is a block C that is a candidate block of a prediction block having a prediction block size type of 2N × 2N. In the case of the prediction block 3 of which the prediction block size type is N × N (FIG. 23 (h)), the block C and the block E are the block C and the block E which are candidate blocks of the prediction block whose prediction block size type is 2N × 2N. To do.

  As described above, a candidate block that is necessarily unprocessed may be enabled by making a candidate block that is always unprocessed a candidate block of a prediction block whose prediction block size type is 2N × 2N. By increasing the merge mode options, the merge mode selection rate can be increased and the encoding efficiency can be improved. The motion information of the replaced candidate block is combined with the motion information of the other combined motion information candidates to generate new motion information, or the motion information of the replaced candidate block is corrected so that the second supplementary combined motion information candidate By adding the first supplementary combined motion information candidate having a relatively high selection rate to the combined motion information candidate list, the encoding efficiency can be increased. In particular, since at least two combined motion information candidates are required when using a dual combined motion information candidate, only one combined motion information candidate other than the candidate block replaced with the combined motion information candidate list is registered. In this case, the motion information of the replaced candidate block works effectively.

  In addition, in the operation of the spatially coupled motion information candidate generation unit 160, the registration order in the combined motion information candidate list is set to block A, block B, block C, block E, and block D, but may be modified as follows. it can.

  When the prediction block size type is prediction block 1 of N × 2N, block B, block C, block D, block A, block E, and in the order of prediction block size type 2N × N prediction block 1, In the order of A, block E, block D, block B, and block C, when the prediction block size type is N × N prediction block 1, prediction is performed in the order of block B, block C, block D, block A, and block E. In the case of the prediction block 2 having a block size type of N × N, the block A, the block E, the block D, the block B, and the block C can be arranged in this order. In this way, by adding to the combined motion information candidate list in order from the closest to the prediction block to be processed, it is possible to prevent a large merge index from being assigned to a block close to the prediction block to be processed, and to improve the encoding efficiency. Can be improved.

[Embodiment 3]
First, an example in which the prediction block candidate blocks in the encoded block are made common without depending on the prediction block size type will be described. The prediction block size type is different from that of the first embodiment in the prediction block, the spatial candidate block group, and the temporal candidate block group other than 2N × 2N. Hereinafter, a spatial candidate block group and a temporal candidate block group of a prediction block whose prediction block size type is an example other than 2N × 2N, in which the prediction block size type in the encoded block is common without depending on the prediction block size type. explain. In this example, the prediction block candidate block in the encoded block is determined as a prediction block candidate block having a prediction block size type of 2N × 2N without depending on the prediction block size type.

  FIG. 24 illustrates the positional relationship between a prediction block and a candidate block group whose prediction block size type is other than 2N × 2N in an example in which the prediction block size type in the coding block is common without depending on the prediction block size type. FIG. In FIG. 24, the temporal candidate blocks H and I exist in a picture different from the decoded picture different from the picture in which the spatial candidate blocks A to E exist, but for the sake of easy understanding and explanation, the spatial candidate blocks H and I exist. It is shown together with blocks A to E. 24 (a) to 24 (h) respectively show a prediction block 0 whose prediction block size type is N × 2N, a prediction block 1 whose prediction block size type is N × 2N, and a prediction block 0 whose prediction block size type is 2N × N. Prediction block 1 with a prediction block size type of 2N × N, prediction block 0 with a prediction block size type of N × N, prediction block 1 with a prediction block size type of N × N, and prediction block with a prediction block size type of N × N 2 shows a spatial candidate block group when the prediction block size type is a prediction block 3 of N × N. FIG. 24 shows an example in which the predicted block size is 16 pixels × 16 pixels. As the time candidate block group of the prediction block other than the prediction block size type of 2N × 2N, the time candidate block group derived as the prediction block of the prediction block size type of 2N × 2N as shown in FIG. 24 is used.

  As described above, regardless of the prediction block size type, the candidate block is a prediction block candidate block having a prediction size type of 2N × 2N. In other words, the candidate block when the prediction block size type is 2N × 2N does not depend on the prediction block size type, and is commonly used in all prediction blocks of the encoded block. That is, according to the combined motion information candidate list generation units 140 and 230, if the candidate blocks are the same, the same combined motion information candidate list is generated, so the prediction block size type is not dependent on the prediction block size type. The combined motion information candidate list derived in the case of 2N × 2N can be used in common for all prediction blocks of the encoded block. Thereby, a candidate block can be decided before a prediction block type size is decided, and a combined motion information candidate list can be decided. Further, when the encoded block is divided into a plurality of prediction blocks, it is not necessary to derive a candidate block for each prediction block. Therefore, the number of times of generating the combined motion information candidate list shown in FIG. (In the case of division) or 1/4 (in the case of 4 division). Moreover, the prediction block of an encoding block can be processed in parallel.

  Hereinafter, another example of the third embodiment will be described. The operation of the spatial candidate block group, the temporal candidate block group, and the combined motion information candidate list generation unit 140 used in the spatial combination motion information candidate generation unit 160 for prediction blocks other than the prediction block size type of 2N × 2N in the first embodiment Is different. Hereinafter, the spatial candidate block group and the temporal candidate block group of the prediction block whose prediction block size type is other than 2N × 2N according to the third embodiment will be described.

  Here, when the prediction block is divided into a plurality of blocks, the candidate block of the prediction block 0 is used as a candidate block of all the prediction blocks in the encoded block.

  FIG. 25 is a diagram for explaining the positional relationship between a prediction block and a candidate block group whose prediction block size type is other than 2N × 2N in the third embodiment. In FIG. 25, the temporal candidate blocks H and I exist in a picture different from the decoded picture different from the picture in which the spatial candidate blocks A to E exist, but for the sake of easy understanding and explanation, the spatial candidate blocks H and I exist. It is shown together with blocks A to E. 25 (a) to 25 (h) respectively show a prediction block 0 whose prediction block size type is N × 2N, a prediction block 1 whose prediction block size type is N × 2N, and a prediction block 0 whose prediction block size type is 2N × N. Prediction block 1 with a prediction block size type of 2N × N, prediction block 0 with a prediction block size type of N × N, prediction block 1 with a prediction block size type of N × N, and prediction block with a prediction block size type of N × N 2 shows a spatial candidate block group and a temporal candidate block group when the prediction block size type is a prediction block 3 of N × N. FIG. 25 shows an example in which the prediction block size is 16 pixels × 16 pixels. As the time candidate block group of the prediction block whose prediction block size type is other than 2N × 2N, the time candidate block group derived as the prediction block 0 as shown in FIG. 25 is used.

  Next, the operation of the combined motion information candidate list generation unit 140 will be described. FIG. 26 is a flowchart for explaining the operation of the combined motion information candidate list generation unit 140 according to the third embodiment. It differs from FIG. 11 which is operation | movement of the joint motion information candidate list production | generation part 140 of Embodiment 1 in that step S106 and step S107 are added. Steps S106 and S107 different from the first embodiment will be described. Whether the prediction block is 0 is checked (S106). If it is the prediction block 0 (Y of S106), the process of step S100 to S105 will be performed and a process will be complete | finished. If the prediction block is not 0 (N in S106), the combined motion information candidate list of the prediction block 0 is used as the combined motion information candidate list of the prediction block to be processed (S107), and the process is terminated.

  As described above, when the coding block is divided into a plurality of blocks, the prediction block 0 candidate block is used as a candidate block for all prediction blocks in the coding block, so that the coding block has a plurality of prediction blocks. 11, since it is not necessary to generate a combined motion information candidate list for a prediction block other than the prediction block 0, the number of times of generating the combined motion information candidate list shown in FIG. ) Or 1/4 (in the case of 4 divisions). That is, the combined motion information candidate list derived in the prediction block 0 can be commonly used in any prediction block of the encoded block. In addition, if the prediction block size type is determined for the combined motion information candidate list, it can be generated before the position of the predicted block is determined, so the circuit design and software design are flexible, and the circuit scale and software scale are reduced. It becomes possible. Moreover, the prediction block of an encoding block can be processed in parallel.

  Furthermore, the prediction block size type is set to 2N by setting the position of the prediction block candidate block other than the prediction block size type of 2N × 2N to a position of a candidate block different from the prediction block having the prediction block size type of 2N × 2N. The selection probability to be a prediction block other than × 2N can be increased, and the coding efficiency is improved compared to the example in which the prediction block candidate block in the coding block is shared without depending on the prediction block size type. be able to. Furthermore, since the prediction block 0 does not include candidate blocks included in other prediction blocks of the same encoded block and candidate blocks that are necessarily unprocessed, the prediction efficiency is improved by increasing the probability that the combined motion information candidate is valid. Can be improved. Note that the skip mode with the highest coding efficiency is not affected by the present embodiment because the prediction block size type is equivalent to 2N × 2N.

  In Embodiment 3, the prediction block 0 which is the first prediction block in the coding block is used as the representative block of the coding block, but the present invention is not limited to this. For example, a prediction block that uses a merge mode first in an encoded block may be used. In this case, S106 and S107 are as follows. It is checked whether a combined motion information candidate list has already been generated in the encoded block (S106). If the combined motion information candidate list has not already been generated in the encoded block (Y in S106), the process from step S100 to S105 is performed and the process is terminated. If the combined motion information candidate list has already been generated in the encoded block (N in S106), the combined motion information candidate list in which the combined motion information candidate list has already been generated in the encoded block is used (S107), End the process.

  As described above, by using the combined motion information candidate list of the prediction block that first uses the merge mode in the coding block also in other prediction blocks in the coding block, at least the prediction using the merge mode first. The prediction efficiency of blocks can be improved. Further, the last prediction block in the encoding block (prediction block 1 in the case of two divisions, prediction block 3 in the case of four divisions) can be used as a representative block of the encoding block. In this case, the selection probability that the prediction block size type becomes a prediction block other than 2N × 2N is obtained by setting the position of the temporal candidate block group to a position of a candidate block different from the prediction block having the prediction block size type of 2N × 2N. The prediction efficiency can be improved.

  Further, as in the second embodiment, the order of addition to the combined motion information candidate list may be the order close to the prediction block to be processed.

[Modification 1 of Embodiment 3]
Hereinafter, Modification 1 of Embodiment 3 will be described. The difference from Embodiment 3 is that the time candidate block group is limited by the maximum coding block lower limit line. The limitation of the time candidate block group in the maximum encoding block lower limit line will be described. FIG. 27 is a diagram for explaining the maximum encoding block lower limit line and the time candidate block group. As shown in FIG. 27, the maximum encoding block lower limit line is a line including the lowermost pixel of the maximum encoding block. By restricting the blocks below the maximum encoding block lower limit line from being used, the moving image encoding device 100 and the moving image decoding device 200 reduce the capacity of the temporary storage area for the time candidate block group. be able to.

  When the same positional relationship as that of a prediction block of a coding block having a prediction block size type of 2N × 2N is applied to a prediction block in a coding block whose prediction block size type is not 2N × 2N, a maximum coding block lower limit line is provided. In this case, the position of the temporal candidate block (H1) of the prediction block 1 whose prediction block size type is 2N × N that touches the maximum coding block lower limit line in FIG. 27 cannot be used.

  However, when the prediction block is divided into a plurality of blocks as in the third embodiment, the candidate block of the prediction block 0 is used as the candidate block of all the prediction blocks in the encoded block, and as a temporal candidate block group. Since the time candidate block (H0) is used, the time candidate block can be validated and the prediction efficiency can be improved. The same applies to the prediction block 2 and the prediction block 3 whose prediction block size type is N × N.

[Embodiment 4]
Hereinafter, the fourth embodiment will be described. The configuration and operation of the spatial candidate block group, the temporal candidate block group, and the combined motion information candidate list generation unit 140 of the prediction block whose prediction block size type is other than 2N × 2N are different from those of the first embodiment. Hereinafter, a prediction block, a spatial candidate block group, and a temporal candidate block group whose prediction block size type is other than 2N × 2N according to Embodiment 4 will be described.

  Here, it is assumed that the same positional relationship is applied to the spatial candidate block group as the prediction block of the encoded block whose prediction block size type is 2N × 2N. The time candidate block group derived as the prediction block 0 is used as the time candidate block group.

  FIG. 28 is a diagram for explaining the positional relationship between a prediction block and a candidate block group whose prediction block size type is other than 2N × 2N in the fourth embodiment. In FIG. 28, the temporal candidate blocks H and I exist in a picture different from the decoded picture different from the picture in which the spatial candidate blocks A to E exist, but for the sake of easy understanding and explanation, the spatial candidate blocks H and I exist. It is shown together with blocks A to E. 28 (a) to 28 (h) respectively show a prediction block 0 whose prediction block size type is N × 2N, a prediction block 1 whose prediction block size type is N × 2N, and a prediction block 0 whose prediction block size type is 2N × N. Prediction block 1 with a prediction block size type of 2N × N, prediction block 0 with a prediction block size type of N × N, prediction block 1 with a prediction block size type of N × N, and prediction block with a prediction block size type of N × N 2 shows a spatial candidate block group when the prediction block size type is a prediction block 3 of N × N. FIG. 28 shows an example in which the prediction block size is 16 pixels × 16 pixels. As the time candidate block group of the prediction block whose prediction block size type is other than 2N × 2N, the time candidate block group derived as the prediction block 0 as shown in FIG. 28 is used. Of course, a temporal candidate block group derived as a predictive block having a predictive block size type of 2N × 2N may be used as a predictive block size group of predictive blocks other than the predictive block size type of 2N × 2N.

  Next, the configuration and operation of the combined motion information candidate list generation unit 140 will be described. FIG. 29 is a diagram illustrating the configuration of the combined motion information candidate list generation unit 140 according to the fourth embodiment. The difference from Embodiment 1 is that the position of the temporally combined motion information candidate generating unit 161 is installed at the subsequent stage of the first combined motion information candidate supplementing unit 163. FIG. 30 is a flowchart for explaining the operation of the combined motion information candidate list generation unit 140 according to the fourth embodiment. The operation of the combined motion information candidate list generation unit 140 of the first embodiment is different from FIG. 11 in that step S106 and step S108 are added, and the position of step S102 is different. Differences from the first embodiment will be described.

  The spatially coupled motion information candidate generating unit 160 generates the maximum number of spatially coupled motion information candidates from 0 candidate block groups supplied from the terminal 12 and adds them to the coupled motion information candidate list (S101). ), The combined motion information candidate list and the candidate block group are supplied to the redundant combined motion information candidate deletion unit 162.

  Next, the redundant combined motion information candidate deletion unit 162 examines the combined motion information candidates registered in the combined motion information candidate list supplied from the spatially combined motion information candidate generation unit 160, and combines the same motion information. When there are a plurality of motion information candidates, one combined motion information candidate is left and other combined motion information candidates are deleted (S103), and the combined motion information candidate list is supplied to the first combined motion information candidate supplementing unit 163. To do.

  Next, the first combined motion information candidate supplementing unit 163 includes 0 to 2 first supplemental combining from the combined motion information candidates registered in the combined motion information candidate list supplied from the redundant combined motion information candidate deleting unit 162. A motion information candidate is generated and added to the combined motion information candidate list (S104), and the combined motion information candidate list and the candidate block group are supplied to the time combined motion information candidate generating unit 161.

  Next, the time combination motion information candidate generation unit 161 checks whether the prediction block to be processed is the prediction block 0 (S106). If the prediction block to be processed is the prediction block 0 (Y in S106), the time combination motion information candidates from 0 to the maximum number of time combination motion information candidates from the candidate block group supplied from the redundant combination motion information candidate deletion unit 162 are used. Is added to the combined motion information candidate list supplied from the redundant combined motion information candidate deleting unit 162 (S102), and the combined motion information candidate list is supplied to the second combined motion information candidate supplementing unit 164. If the prediction block to be processed is not the prediction block 0 (N in S106), the temporally combined motion information candidate of candidate block 0 is added to the combined motion information candidate list (S108), and the combined motion information candidate list is second combined. The motion information candidate supplement unit 164 is supplied.

  Next, the second combined motion information candidate supplementing unit 164 increases the number of combined motion information candidates registered in the combined motion information candidate list supplied from the temporal combined motion information candidate generating unit 161 until the maximum number of merge candidates is reached. Two supplementary combined motion information candidates are generated and added to the combined motion information candidate list (S105), and the combined motion information candidate list is supplied to the terminal 19.

  As described above, it is assumed that the same positional relationship as that of the prediction block of the encoded block having the prediction block size type of 2N × 2N is applied to the spatial candidate block group of the prediction block other than the prediction block size type of 2N × 2N, By setting the candidate block group as the time candidate block group of the prediction block 0, if the prediction block size type is determined, the time candidate block group can be determined. That is, the temporally combined motion information candidate derived from the prediction block 0 can be used in common in any prediction block of the encoded block. On the other hand, the space candidate block group is determined for each prediction block based on the position and size of the prediction block. Since the motion information of the candidate block is used as it is for the derivation of the spatially coupled motion information candidate, the calculation is unnecessary and the processing time is short. However, for the derivation of the temporally coupled motion information candidate, Formula 1 or Formula 2 to Formula 4 are used. Since processing for calculating such a vector is required and there is processing for determining the inter prediction type, the processing time becomes long.

  Therefore, the processing time when the prediction block is divided into a plurality of times by deriving the time combination motion information candidate that requires the most processing time in the process for generating the combined motion information candidate list once in the coding block. Can be shortened.

  Furthermore, by using a block adjacent to the prediction block to be processed as a spatially coupled motion information candidate, the selection probability that the prediction block size type becomes a prediction block other than 2N × 2N can be increased. Coding efficiency can be improved compared to an example in which the prediction block candidate blocks in the coding block are shared without depending on the type. Moreover, since the representative block of the predetermined area of ColPic is used as the time candidate block group, the accuracy of the time candidate block group is relatively lower than that of the space candidate block group. Decrease in prediction efficiency can be suppressed even if the value is dropped.

  Here, it is assumed that the time for deriving the temporally combined motion information candidate is sufficiently longer than the derivation of the spatially combined motion information candidate, the operation of the redundant combined motion information candidate deleting unit 162, and the operation of the first combined motion information candidate supplementing unit 163, The operation of the combined motion information candidate list generation unit 140 is shown in FIG. 30. For example, S106, S102, and S108 may be moved to the subsequent stage of S101 or S103 with priority on the prediction efficiency, and the processing efficiency is prioritized. S106, S102, and S108 can also be installed at the subsequent stage of S105. When S106, S102, and S108 are installed at the subsequent stage of S105, the number of merged motion information candidates registered in the combined motion information candidate list output from the second combined motion information candidate supplementing unit 164 is the maximum number of merge candidates. The number is smaller by one.

  In this example, the spatial relationship block group is applied with the same positional relationship as the prediction block of the encoded block whose prediction block size type is 2N × 2N, with emphasis on prediction efficiency. Candidate blocks included in other prediction blocks of the same coding block to realize parallel processing are not used as candidate blocks, or a spatial candidate block group is combined with other embodiments to generate temporal candidate blocks You may utilize the time candidate block group derived | led-out as the prediction block 0 as a group.

  In addition, here, it is assumed that the time candidate block group of the prediction block whose prediction block size type is other than 2N × 2N is the time candidate block group derived from the prediction block 0 which is the first prediction block in the encoded block. However, the present invention is not limited to this. For example, it may be a temporal candidate block group of a prediction block when the prediction block size type is 2N × 2N, and is the last prediction block in the encoded block (prediction block 1 in the case of 2 divisions, prediction in the case of 4 divisions). The time candidate block group of block 3) may be used. When the prediction block size type is a 2N × 2N prediction block temporal candidate block group, the temporal candidate block group can be generated before the prediction block size type and the prediction block position are determined. It is possible to make circuit design and software design flexible and reduce circuit scale and software scale.

[Embodiment 5]
The fifth embodiment will be described below. The configuration and operation of the combined motion information candidate list generation unit 140 are different from those of the first embodiment, and the operations of the code sequence generation unit 104 and the code sequence analysis unit 201 are different.

  First, the configuration of the combined motion information candidate list generation unit 140 will be described. FIG. 31 is a diagram illustrating the configuration of the combined motion information candidate list generation unit 140 according to the fifth embodiment. 10 differs from the combined motion information candidate list generation unit 140 of Embodiment 1 in that a candidate block setting unit 165 is added in the previous stage of the spatial combination motion information candidate generation unit 160. Here, a flag or the like is used to switch whether the candidate block arrangement gives priority to the prediction efficiency or the candidate block arrangement gives priority to the processing efficiency such as parallel processing and processing time reduction.

  Next, the operation of the combined motion information candidate list generation unit 140 will be described. FIG. 32 is a flowchart for explaining the operation of the combined motion information candidate list generation unit 140 according to the fifth embodiment. 11 differs from the operation of the combined motion information candidate list generation unit 140 of the first embodiment in FIG. 11 in that steps S106 to S108 are added before the step S100. Steps S106 to S108 will be described. First, it is determined whether cu_dependent_flag is 1 (S106). If cu_dependent_flag is 1 (Y in S106), the block arrangement is given priority on the prediction efficiency (S107). The block arrangement giving priority to the prediction efficiency is, for example, a candidate block group of a prediction block having a prediction block size type other than 2N × 2N and the same positional relationship as that of a prediction block having a prediction block size type of 2N × 2N in FIG. Such a block arrangement includes only candidate blocks adjacent to the prediction block to be processed. If cu_dependent_flag is 0 (N in S106), the block arrangement is given priority to the processing efficiency (S108). The block arrangement giving priority to processing efficiency is, for example, a block arrangement including candidate blocks that are not adjacent to the prediction block to be processed as shown in FIG. 14, FIG. 23, FIG. 24, FIG. Subsequent to Step S107 or Step S108, the processes after Step S100 are performed. Here, in this embodiment, for example, based on the block arrangement giving priority to prediction efficiency as shown in FIG. 12, for each prediction block of the encoded block, determination and combination of candidate block groups based on their positions and sizes The motion information candidate list is generated, or based on the block arrangement giving priority to the processing efficiency as shown in FIG. 24 or FIG. 25, for example, the combined motion information from candidate blocks that are commonly used in all the prediction blocks of the encoded block Whether to generate a candidate list is switched.

  In the video encoding device 100, it is assumed that whether enable_cu_parallel_flag is 0 or 1 is set higher than the video encoding device 100. Here, although the operation illustrated in FIG. 32 is performed by the combined motion information candidate list generation unit 140, the operation can be set higher than the moving image encoding apparatus 100.

  The code string generation unit 104 multiplexes cu_dependent_flag at a position other than the encoded block such as SPS, PPS, and slice header. The code string analysis unit 201 decodes cu_dependent_flag multiplexed at a position other than the encoded block, such as SPS, PPS, and slice header, and supplies the decoded cu_dependent_flag to the motion information reproduction unit 204.

  By multiplexing cu_dependent_flag in the encoded stream, it is possible to easily determine whether the encoded stream prioritizes prediction efficiency. Also, a common decoding apparatus can decode an encoded stream based on block arrangement giving priority to prediction efficiency and an encoded stream based on block arrangement giving priority to processing efficiency. For a decoding device that only decodes cu_dependent_flag of 0 or 1, for example, encoding is performed by fixing cu_dependent_flag to either 0 or 1 in accordance with operation regulations or profiles classified with encoding tools such as MPEG-4AVC. A coded stream can be correctly decoded by generating a stream and setting cu_dependent_flag ignored or implicitly. Also, the operation shown in FIG. 32 can be reduced by multiplexing the cu_dependent_flag into a higher-order header of the encoded block.

  Here, the block arrangement giving priority to the prediction efficiency and the block arrangement giving priority to the processing efficiency are switched by the cu_dependent_flag. For example, when the number of divisions of the encoded block is a predetermined number or more, the block arrangement giving priority to the processing efficiency is used. If the encoded block is not equal to or larger than the predetermined threshold size, the block arrangement is given priority to prediction efficiency. If the encoded block is smaller than the predetermined threshold size, the block arrangement is given priority to processing efficiency. If it is not smaller than the size, it is possible to make a block arrangement giving priority to prediction efficiency. In addition, by setting the predetermined threshold size to 8 × 8, which is the minimum coding block size, it can be applied only when the processing amount increases most, and the processing amount and the prediction efficiency can be optimally balanced. . In this case, in step S108, it is determined whether the encoded block has a predetermined threshold size. When the number of divisions of an encoded block is equal to or greater than a predetermined number (or less than a predetermined threshold size), the block arrangement is given priority to processing efficiency, and the number of divisions of the encoded block is equal to or greater than a predetermined number (or If it is not equal to or less than the predetermined threshold size, the prediction efficiency and the processing amount can be easily adjusted by setting the block arrangement with priority on the prediction efficiency. It should be noted that the predetermined threshold size or the predetermined number of times can be multiplexed at positions other than the encoded block such as SPS, PPS, and slice header. In addition, when enable_cu_parallel_flag is 1, a predetermined threshold size or a predetermined number of times is defined, and when enable_cu_parallel_flag is 0, the predetermined threshold size or the predetermined number of times is not defined, so that enable_cu_parallel_flag is used in an encoded stream. It is possible to adjust the processing amount and the prediction efficiency more flexibly by multiplexing. That is, by setting enable_cu_parallel_flag to 0, the block arrangement always gives priority to prediction efficiency regardless of the predetermined threshold size or the predetermined number of times, and by setting enable_cu_parallel_flag to 1, the prediction efficiency and processing are performed according to the predetermined threshold size or the predetermined number of times. By switching the efficiency, it is possible to optimally balance the processing amount and the prediction efficiency.

[Embodiment 6]
The sixth embodiment will be described below. The configuration of the prediction vector mode determination unit 120 and the operation of the motion vector reproduction unit 211 of the video encoding apparatus 100 according to Embodiment 3 will be described in detail. Hereinafter, a detailed configuration of the prediction vector mode determination unit 120 will be described.

(Configuration of Predictive Vector Mode Determination Unit 120)
Subsequently, a detailed configuration of the prediction vector mode determination unit 120 will be described. FIG. 33 shows the configuration of the prediction vector mode determination unit 120. The prediction vector mode determination unit 120 includes a prediction vector candidate list generation unit 130 and a prediction vector determination unit 131. The terminal 17 is connected to the predictive coding mode determination unit 122.

  The prediction vector candidate list generation unit 130 is also installed in the motion vector reproduction unit 211 in the video decoding device 200 that decodes the code sequence generated by the video encoding device 100 according to Embodiment 6. Thus, the same prediction vector candidate list is generated by the moving image encoding device 100 and the moving image decoding device 200.

(Operation of prediction vector mode determination unit 120)
Hereinafter, the operation of the prediction vector mode determination unit 120 will be described.

  First, the following processing is performed for L0 prediction. Hereinafter, X is assumed to be 0. The prediction vector candidate list generation unit 130 acquires a reference index for LX prediction supplied from the terminal 13. A prediction vector candidate list for LX prediction including the maximum number of prediction vector candidates is generated from the candidate block group supplied from the terminal 12 and the reference index for LX prediction. The prediction vector candidate list generation unit 130 supplies the prediction vector candidate list of the LX prediction to the prediction vector determination unit 131.

  The prediction vector determination unit 131 selects one prediction vector candidate as a prediction vector for LX prediction from the prediction vector candidate list for LX prediction supplied from the prediction vector candidate list generation unit 130, and sets a prediction vector index for the LX prediction. decide.

  The prediction vector determination unit 131 subtracts the LX prediction prediction vector from the LX prediction motion vector supplied from the terminal 13 to calculate the LX prediction difference vector, and the LX prediction difference vector and the LX prediction prediction vector. Output the index.

  The prediction vector determination unit 131 motion-predicted the image signal supplied from the terminal 15 and the reference image supplied from the terminal 14 based on the LX prediction motion vector and the LX prediction reference index supplied from the terminal 13. Pred_LX rate distortion evaluation value is calculated from the prediction error amount from the LX prediction prediction signal, and from the prediction error amount, the LX prediction difference vector, the LX prediction reference index, and the LX prediction vector index code amount. Is calculated.

  Next, X is set to 1 and the same processing as L0 prediction is performed for L1 prediction.

  Subsequently, the prediction vector determination unit 131 calculates a prediction error amount from the image signal supplied from the terminal 15 and the prediction signal of BI prediction obtained by averaging the prediction signal of L0 prediction and the prediction signal of L1 prediction, and the prediction The rate distortion evaluation value of Pred_BI is calculated from the error amount, the difference vector between the L0 prediction and the L1 prediction, the reference index of the L0 prediction and the L1 prediction, and the code amount of the prediction vector index of the L0 prediction and the L1 prediction.

  The prediction vector determination unit 131 compares the rate distortion evaluation value of Pred_L0, the rate distortion evaluation value of Pred_L1, and the rate distortion evaluation value of Pred_BI, and selects one prediction coding mode that is the minimum rate distortion evaluation value. . Then, motion information, a difference vector, a prediction vector index, and a rate distortion evaluation value based on the prediction coding mode are supplied to the prediction coding mode determination unit 122. If the predictive coding mode is Pred_L0, the motion vector for L1 prediction is (0, 0), the reference index for L1 prediction is “−1”, and if the predictive coding mode is Pred_L1, the motion for L0 prediction. The vector is (0,0), and the reference index for L0 prediction is “−1”.

(Configuration of Predictive Vector Candidate List Generation Unit 130)
Next, a detailed configuration of the prediction vector candidate list generation unit 130 will be described. FIG. 34 is a diagram for explaining the configuration of the prediction vector candidate list generation unit 130. The terminal 18 is connected to the prediction vector determination unit 131. The prediction vector candidate list generation unit 130 includes a spatial prediction vector candidate generation unit 150, a temporal prediction vector candidate generation unit 151, a redundant prediction vector candidate deletion unit 152, and a prediction vector candidate supplement unit 153.

(Operation of prediction vector candidate list generation unit 130)
Hereinafter, the function and operation of each unit will be described. The prediction vector candidate list generation unit 130 generates a prediction vector candidate list for L0 prediction and a prediction vector candidate list for L1 prediction as necessary. Hereinafter, this will be described as LX prediction. X is 0 or 1. FIG. 35 is a flowchart for explaining the operation of the prediction vector candidate list generation unit 130.

  First, the prediction vector candidate list generation unit 130 initializes a prediction vector information candidate list for LX prediction (S200). There is no prediction vector candidate in the initialized prediction vector candidate list of the LX prediction.

  Candidate blocks included in the space candidate block group supplied from the terminal 12 are divided into two groups, block E and block A as the first group, block C, block B, and block D as the second group, and the first group The following processing is repeated in the order of the second group (S201 to S203).

  Here, the candidate block group supplied from the terminal 12 is the same as the merge mode for the 2N × 2N candidate block group and the candidate block group other than 2N × 2N is applied with the same positional relationship as 2N × 2N. A group. In addition, it is assumed that the LX prediction reference index supplied from the terminal 13, the candidate block group supplied from the terminal 12, and the prediction vector information candidate list for LX prediction are shared in the prediction vector candidate list generation unit 130. To do.

  The spatial prediction vector candidate generation unit 150 generates 0 or 1 spatial prediction vector candidate for LX prediction from the i-th group (i is 1 or 2) candidate block group, and the spatial prediction vector candidate for the LX prediction is LX. The prediction vector candidate list for prediction is added to the prediction vector candidate list (S202), and the prediction vector candidate list and candidate block group for the LX prediction are supplied to the temporal prediction vector candidate generation unit 151.

  Here, a specific method for deriving spatial prediction vector candidates will be described. The following processing is repeated for the first group and the second group. The first group inspects block E and block A in order as candidate blocks, and the second group inspects block C, block B and block D in order of candidate blocks.

  For each candidate block, the following processing is performed in the order of L0 prediction and L1 prediction. Hereinafter, L0 prediction and L1 prediction of each candidate block will be described as LN prediction.

  It is checked whether the reference image indicated by the LN prediction reference index of the candidate block is the same as the reference image indicated by the LX prediction reference index supplied from the terminal 13.

  If the reference image indicated by the LN prediction reference index of the candidate block is the same as the reference image indicated by the LX prediction reference index supplied from the terminal 13, the LN prediction motion vector of the candidate block is processed as a spatial prediction vector candidate. finish.

  If the reference image indicated by the LN prediction reference index of the candidate block is not the same as the reference image indicated by the LX prediction reference index supplied from the terminal 13, the next LN prediction or the next candidate block is examined.

  If the inspection of all candidate blocks is completed, the process is terminated.

  As described above, 0 or 1 spatial prediction vector candidates are derived from each group, and 0 to 2 spatial prediction vector candidates are derived as LX prediction.

  Next, the temporal prediction vector candidate generation unit 151 generates zero or one temporal prediction vector candidate for LX prediction from the temporal candidate block group, and the temporal prediction vector candidate for the LX prediction is added to the prediction vector candidate list for LX prediction. Then, the prediction vector candidate list and candidate block group of the LX prediction are supplied to the prediction vector candidate supplementing unit 153 (S204).

Here, a specific method for deriving temporal prediction vector candidates will be described.
The time candidate block group is inspected in the order of block H and block I as candidate blocks.
For each candidate block, the following processing is performed in the order of L0 prediction and L1 prediction. Hereinafter, L0 prediction and L1 prediction of each candidate block will be described as LN prediction.
Check whether the candidate block's LN prediction is valid. The LN prediction of the candidate block is effective when the reference index is 0 or more.
If the LN prediction of the candidate block is valid, a temporal prediction vector candidate is derived using the motion vector of the LN prediction of the candidate block as a reference motion vector, and the process is terminated. A method for deriving temporal prediction vector candidates will be described later.
If the candidate block's LN prediction is not valid, the next candidate block is examined.
If the inspection of all candidate blocks is completed, the process is terminated.

  Here, a method for deriving temporal prediction vector candidates will be described. The inter-image distance between ColPic having a temporal candidate block and ColRefLXPic, which is a picture that the temporal candidate block refers to in motion compensated prediction of LN prediction, is td, and the inter-image distance between the reference image RefLXPPic indicated by the reference index of LX prediction and the processing target image CurPic Tb, and the reference motion vector for LX prediction is mvLX, and the temporal prediction vector candidate mvLXCol is calculated from Equation 1.

  The redundant prediction vector candidate deletion unit 152 checks the prediction vector candidates registered in the prediction vector candidate list of the LX prediction supplied from the temporal prediction vector candidate generation unit 151, and there are a plurality of prediction vector candidates having the same vector. If the number of prediction vector candidates registered in the prediction vector candidate list for LX prediction exceeds the maximum number of prediction vector candidates, one prediction vector candidate is left and other prediction vector candidates are deleted. The prediction vector candidates behind the prediction vector candidate list for LX prediction are deleted so that the number of prediction vector candidates registered in the prediction vector candidate list for prediction is equal to or less than the maximum number of prediction vector candidates (S205), and the LX prediction is performed. The predicted vector candidate list is supplied to the predicted vector candidate supplementing unit 153. Here, the combined motion information candidates registered in the prediction vector candidate list of the LX prediction are all different combined motion information candidates.

  The prediction vector candidate supplement unit 153 generates a prediction vector supplement candidate, and the number of prediction vector candidates registered in the prediction vector candidate list of the LX prediction supplied from the redundant prediction vector candidate deletion unit 152 becomes the maximum number of prediction vector candidates. Thus, the prediction vector supplement candidate is added to the prediction vector candidate list for LX prediction (S206) and supplied to the terminal 18. The prediction vector supplement candidate is a motion vector (0, 0). Here, the motion vector (0, 0) is used as the prediction vector supplement candidate, but a predetermined value such as (1, 1) may be used, and a motion vector in which the horizontal component and the vertical component of the spatial prediction vector candidate are +1 or −1. But you can.

  Here, the candidate blocks included in the spatial candidate block group supplied from the terminal 12 are divided into two groups so that one spatial prediction motion vector candidate can be selected from each group. The spatial prediction motion vector candidates may be selected.

  Hereinafter, a detailed configuration of the motion vector reproducing unit 211 will be described.

(Detailed Configuration of Motion Vector Reproducing Unit 211)
Next, a detailed configuration of the motion vector reproduction unit 211 will be described. FIG. 36 is a diagram for explaining the configuration of the motion vector reproducing unit 211. The motion vector reproduction unit 211 includes a prediction vector candidate list generation unit 220, a prediction vector selection unit 221, and an addition unit 222. The terminal 35 is connected to the encoding mode determination unit 210.

(Detailed operation of the motion vector reproduction unit 211)
Hereinafter, the function and operation of each unit will be described. The motion vector reproduction unit 211 calculates a motion vector for L0 prediction if the inter prediction type supplied from the terminal 35 is L0 prediction, and calculates a motion vector for L1 prediction if the inter prediction type is L1 prediction. If the inter prediction type is BI prediction, motion vectors are calculated for L0 prediction and L1 prediction. The motion vector for each LX prediction is calculated as follows.

  The motion vector reproduction unit 211 generates a prediction vector candidate list for LX prediction from the reference index for LX prediction supplied from the terminal 35 and the candidate block group supplied from the terminal 33. A prediction vector candidate indicated by the prediction vector index of LX prediction is selected as a prediction vector of LX prediction from the prediction vector list of LX prediction, and the LX prediction prediction vector and the difference vector of LX prediction are added to add an LX prediction motion vector. Is calculated.

  Motion information is generated by combining the motion vector of the LX prediction and the inter prediction type, and is supplied to the terminal 34 and the terminal 36.

  As described above, in the merge mode in which the maximum number of merge candidates is 5 and the number of candidates is relatively large, a candidate block group other than 2N × 2N is predicted as a candidate block of all prediction blocks in the encoded block. By using a candidate block of 0, the combined motion information candidate list can be shared in the coding block so that the processing required for candidate selection can be parallelized, the maximum number of prediction vector candidates is 2, and the number of candidates is relatively In the prediction vector mode with a small number of candidates, for candidate block groups other than 2N × 2N, the candidate block to which the same positional relationship as 2N × 2N is applied is used, and the prediction efficiency is optimized, so that the processing efficiency and the prediction efficiency are preferably improved. can do.

  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 100 moving image encoder, 101 prediction block image acquisition part, 102 subtraction part, 103 prediction error encoding part, 104 code stream production | generation part, 105 prediction error decoding part, 106 motion compensation part, 107 addition part, 108 motion vector detection , 109 motion information generation unit, 110 frame memory, 111 motion information memory, 120 prediction vector mode determination unit, 121 merge mode determination unit, 122 prediction coding mode determination unit, 130 prediction vector candidate list generation unit, 131 prediction vector determination 140 combined motion information candidate list generation unit, 141 combined motion information selection unit, 150 spatial prediction vector candidate generation unit, 151 temporal prediction vector candidate generation unit, 152 redundant prediction vector candidate deletion unit, 153 prediction vector candidate supplement unit, 1 0 spatial combination motion information candidate generation unit, 161 temporal combination motion information candidate generation unit, 162 redundant combination motion information candidate deletion unit, 163 first combination motion information candidate supplement unit, 164 second combination motion information candidate supplement unit, 165 candidate block Setting unit, 166 alternative combined motion information candidate supplementing unit, 200 moving image decoding apparatus, 201 code string analyzing unit, 202 prediction error decoding unit, 203 adding unit, 204 motion information reproducing unit, 205 motion compensating unit, 206 frame memory, 207 A motion information memory; 210 an encoding mode determination unit; 211 a motion vector playback unit; 212 a combined motion information playback unit; 230 a combined motion information candidate list generation unit; and 231 a combined motion information selection unit.

Claims (6)

A video encoding device that encodes a coding block composed of one or more prediction blocks,
Information indicating whether or not a joint motion information candidate to be used in common for all the prediction blocks in the coding block is derived is used in common for all the prediction blocks in the coding block. When it is information indicating that an information candidate is derived, a combined motion information candidate generation unit that derives a plurality of combined motion information candidates to be commonly used for all the prediction blocks in the encoded block;
A combined motion information selection unit that selects one combined motion information candidate from the plurality of combined motion information candidates and uses the selected combined motion information candidate in a prediction block to be encoded;
An encoding unit that encodes, as a candidate specifying index, an index for specifying the selected one combined motion information candidate ,
The combined motion information candidate generation unit includes information indicating whether to derive joint motion information candidates to be used in common for all the prediction blocks in the encoded block. The plurality of combined motion information candidates are derived based on the size and position of the prediction block to be encoded. A video encoding device. A moving picture coding method for coding a coding block including one or more prediction blocks,
Information indicating whether or not a joint motion information candidate to be used in common for all the prediction blocks in the coding block is derived is used in common for all the prediction blocks in the coding block. When it is information indicating that an information candidate is derived, a combined motion information candidate generation step for deriving a plurality of combined motion information candidates to be commonly used for all of the prediction blocks in the encoded block;
A combined motion information selection step of selecting one combined motion information candidate from the plurality of combined motion information candidates and using the selected combined motion information candidate in a prediction block to be encoded;
An encoding step of encoding, as a candidate specifying index, an index for specifying the selected one combined motion information candidate ,
In the combined motion information candidate generation step, information indicating whether or not joint motion information candidates to be commonly used for all of the prediction blocks in the encoded block are derived is all of the prediction blocks in the encoded block. The plurality of combined motion information candidates are derived based on the size and position of the prediction block to be encoded. A video encoding method. A moving picture coding program for coding a coding block composed of one or more prediction blocks,
Information indicating whether or not a joint motion information candidate to be used in common for all the prediction blocks in the coding block is derived is used in common for all the prediction blocks in the coding block. When it is information indicating that an information candidate is derived, a combined motion information candidate generation step for deriving a plurality of combined motion information candidates to be commonly used for all of the prediction blocks in the encoded block;
A combined motion information selection step of selecting one combined motion information candidate from the plurality of combined motion information candidates and using the selected combined motion information candidate in a prediction block to be encoded;
An encoding step of encoding an index for specifying the selected candidate combined motion information candidate as a candidate specifying index ;
In the combined motion information candidate generation step, information indicating whether or not joint motion information candidates to be commonly used for all of the prediction blocks in the encoded block are derived is all of the prediction blocks in the encoded block. The plurality of combined motion information candidates are derived based on the size and position of the prediction block to be encoded. A video encoding program. A transmission apparatus that transmits an encoded stream encoded by a moving image encoding method for encoding an encoded block including one or more prediction blocks,
A packet processing unit that packetizes the encoded stream to obtain encoded data;
A transmission unit for transmitting the packetized encoded data,
The moving image encoding method includes:
Information indicating whether or not a joint motion information candidate to be used in common for all the prediction blocks in the coding block is derived is used in common for all the prediction blocks in the coding block. When it is information indicating that an information candidate is derived, a combined motion information candidate generation step for deriving a plurality of combined motion information candidates to be commonly used for all of the prediction blocks in the encoded block;
A combined motion information selection step of selecting one combined motion information candidate from the plurality of combined motion information candidates and using the selected combined motion information candidate in a prediction block to be encoded;
An encoding step of encoding, as a candidate specifying index, an index for specifying the selected one combined motion information candidate ,
In the combined motion information candidate generation step, information indicating whether or not joint motion information candidates to be commonly used for all of the prediction blocks in the encoded block are derived is all of the prediction blocks in the encoded block. The plurality of combined motion information candidates are derived based on the size and position of the prediction block to be encoded. A transmitting device. A transmission method for transmitting an encoded stream encoded by a moving image encoding method for encoding an encoded block including one or more prediction blocks,
A packet processing step of packetizing the encoded stream to obtain encoded data;
Transmitting the packetized encoded data, and
The moving image encoding method includes:
Information indicating whether or not a joint motion information candidate to be used in common for all the prediction blocks in the coding block is derived is used in common for all the prediction blocks in the coding block. When it is information indicating that an information candidate is derived, a combined motion information candidate generation step for deriving a plurality of combined motion information candidates to be commonly used for all of the prediction blocks in the encoded block;
A combined motion information selection step of selecting one combined motion information candidate from the plurality of combined motion information candidates and using the selected combined motion information candidate in a prediction block to be encoded;
An encoding step of encoding, as a candidate specifying index, an index for specifying the selected one combined motion information candidate ,
In the combined motion information candidate generation step, information indicating whether or not joint motion information candidates to be commonly used for all of the prediction blocks in the encoded block are derived is all of the prediction blocks in the encoded block. The plurality of combined motion information candidates are derived based on the size and position of the prediction block to be encoded. And sending method. A transmission program for transmitting an encoded stream encoded by a moving image encoding method for encoding an encoded block composed of one or more prediction blocks,
A packet processing step of packetizing the encoded stream to obtain encoded data;
Transmitting the packetized encoded data to the computer, and
The moving image encoding method includes:
Information indicating whether or not a joint motion information candidate to be used in common for all the prediction blocks in the coding block is derived is used in common for all the prediction blocks in the coding block. When it is information indicating that an information candidate is derived, a combined motion information candidate generation step for deriving a plurality of combined motion information candidates to be commonly used for all of the prediction blocks in the encoded block;
A combined motion information selection step of selecting one combined motion information candidate from the plurality of combined motion information candidates and using the selected combined motion information candidate in a prediction block to be encoded;
An encoding step of encoding, as a candidate specifying index, an index for specifying the selected one combined motion information candidate ,
In the combined motion information candidate generation step, information indicating whether or not joint motion information candidates to be commonly used for all of the prediction blocks in the encoded block are derived is all of the prediction blocks in the encoded block. The plurality of combined motion information candidates are derived based on the size and position of the prediction block to be encoded. A sending program.

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