JP2017069862A - Dynamic image encoding device, dynamic image encoding method, and dynamic image encoding computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dynamic image encoding device capable of suppressing reduction of encoding efficiency even without sharing information about a motion vector between encoders when performing encoding while using a different encoder for each of regions obtained by dividing a picture.SOLUTION: Regarding a restriction object block that refers to a referenced block within a second region of the other picture encoded by the other encoder in the case of prediction vector generation, an encoder (11-1) which is included in the dynamic image encoding device and encodes a first region within a picture assumed that a motion vector is defined in the referenced block, uses a dummy vector in place of the motion vector in the referenced block to generate a first temporary list including candidates of a prediction vector, assumes that the motion vector is not defined in the referenced block, generates a second temporary list including candidates of the prediction vector and, if the candidates of the prediction vector at the same position between the two temporary lists become identical, enables the candidates of the prediction vector to be used.SELECTED DRAWING: Figure 19

Description

  The present invention relates to, for example, a moving picture coding apparatus, a moving picture coding method, and a moving picture coding computer program that divide a picture into a plurality of areas and code each area.

  The moving image data generally has a very large amount of data. For this reason, a device that handles moving image data encodes moving image data with high efficiency when moving image data is to be transmitted to another device or when moving image data is to be stored in a storage device. “High-efficiency encoding” refers to an encoding process for converting a data string into another data string and compressing the data amount.

  As a high-efficiency encoding method for moving image data, an intra-picture prediction (intra prediction) encoding method is known. This encoding method uses the fact that moving image data is highly correlated in the spatial direction, and does not use encoded images of other pictures. A picture encoded by the intra-picture predictive encoding method can be restored only with information in the picture.

  Further, as another encoding method employed in the high efficiency encoding method, an inter-picture prediction (inter prediction) encoding method is known. This encoding method uses the fact that moving image data is highly correlated in the time direction. In moving image data, in general, there is often a high degree of similarity between a picture at a certain timing and a picture that follows that picture. Therefore, the inter prediction encoding method uses the property of moving image data. In general, a moving image encoding apparatus divides an original picture to be encoded into a plurality of encoded blocks. For each block, the moving image encoding apparatus selects, as a reference block, an area similar to the encoded block from the reference pictures among the locally decoded pictures obtained by decoding the encoded pictures. Then, the moving picture coding apparatus removes temporal redundancy by calculating a prediction error signal representing a difference between the reference block and the coding block. Then, the moving image encoding apparatus realizes a high compression rate by encoding the motion vector information indicating the amount of movement between the encoded block and the reference block and the prediction error signal. In general, the inter prediction encoding method has higher compression efficiency than the intra prediction encoding method.

  Typical picture coding methods that employ these predictive coding methods are Moving Picture Experts Group phase 2 (MPEG-2), MPEG-, developed by the International Standardization Organization / International Electrotechnical Commission (ISO / IEC). 4 or H.264 MPEG-4 Advanced Video Coding (H.264 MPEG-4 AVC) is widely used. In these encoding schemes, for example, whether an intra prediction encoding method or an inter prediction encoding method is selected for a picture is explicitly described in a video stream including encoded moving image data. The selected predictive coding method is called a coding mode.

  In these moving picture coding systems, I picture, P picture, and B picture are defined. An I picture is a picture that is encoded using only the information of the picture itself. If the picture to be coded is an I picture, the moving picture coding apparatus can select only the intra prediction coding method as the prediction method to be actually used.

  On the other hand, a P picture is a picture that can be inter-predictively encoded using information of one already encoded picture. A B picture is a picture that can be bi-predictively encoded using information of two pictures that have already been encoded. If the picture to be coded is a P picture or a B picture, the moving picture coding apparatus can select not only an intra prediction coding method but also an inter prediction coding method as a prediction method to be actually used.

  In general, as the number of pixels included in a picture increases, the amount of calculation of the moving image encoding process also increases. Therefore, it has been studied to reduce the time required for encoding by dividing each picture included in a moving image into a plurality of regions and encoding each region with an individual encoder. .

  As a method for dividing a picture into a plurality of regions, it is known to divide a picture in units of slices. In this case, each encoder regards the input slice as one picture and independently encodes the slice, and the encoded data output from each encoder is multiplexed and output. In this way, by using different encoders for each slice, it is possible to use arithmetic devices with low processing capabilities as encoders. For example, the manufacturing cost of the encoders as a whole can be suppressed. is there.

  Also, in a method in which a plurality of encoders encode different regions, encoded data of the entire picture encoded in the past is stored as shared information accessible from each encoder. At that time, in order to reduce the necessary hardware resources, it is considered to reduce the temporary storage memory of the shared information by suppressing the data amount of the shared information (see, for example, Patent Documents 1 to 3). ).

JP 7-135654 A JP-A-10-276437 JP 2000-165883 A

  In the latest video coding scheme (High Efficiency Video Coding, HEVC), a picture is divided in units of Coding Tree Unit (CTU), and each CTU is encoded in the order of raster scanning in each slice. A plurality of CTUs included in one slice are handled as one group, and when encoding a CTU included in a certain slice, it is prohibited to predict the CTU from other slices of the same picture.

  In HEVC, tiles (Tile) are newly introduced together with slices as a unit for dividing a picture. Unlike a slice, a tile can be set to divide a picture in the vertical direction. For example, the tile is set to a rectangular shape.

  FIG. 1 is a diagram illustrating an example of tiles set in a picture. In this example, the picture 100 is divided into a lattice shape by four rectangular tiles 101 by the tile boundaries 103 in the horizontal direction and the vertical direction. The CTUs 102 are grouped for each rectangular tile 101. Each tile 101 in the picture 100 is encoded in raster scan order. Each CTU 102 in the tile 101 is also encoded in raster scan order.

  When a CTU included in a tile is encoded, it is prohibited to predict the CTU from another tile across the boundary between tiles of the same picture. On the other hand, when encoding a CTU included in a certain tile, the moving image encoding apparatus may predict the CTU from another tile of another already encoded picture.

On the other hand, in HEVC, a prediction vector is obtained in order to predictively encode a motion vector. In HEVC, two modes are defined as vector modes that define a method for setting a prediction vector. One is Adaptive Motion Vector Prediction (AMVP) mode that encodes the difference vector using the prediction vector, and the other is Merge mode that copies the motion vector of the encoded PU as the motion vector of the encoding target PU. is there. In these modes, the following are defined as modes for defining a method for creating a prediction vector.
Spatial mode using motion vectors of spatial surrounding blocks of the encoding target block. Hereinafter, prediction vector candidates selected from the spatial motion vectors of spatial surrounding blocks of the encoding target block in the Spatial mode are referred to as spatial prediction vectors.
Temporal mode using motion vectors of surrounding blocks in the same area as the encoding target block in the previously encoded picture temporally before the encoding target picture including the encoding target block. In the following, a prediction vector candidate selected from motion vectors of blocks on another encoded picture in the Temporal mode is referred to as a temporal prediction vector.
-Combined bi-predictive mode using a combination of spatial prediction vector and temporal prediction vector-Combined bi-predictive mode-Zero, that is, the value of the element representing the horizontal movement amount and the vertical movement amount Zero mode using a zero vector whose elements are both zero

  In the AMVP mode and the Merge mode, when obtaining the temporal prediction vector, there is a possibility that reference across the boundary between tiles is performed. When encoding a moving image using different encoders for each tile, in order to be able to refer to the motion vector across the boundary between the tiles, a motion vector is used between a plurality of encoders. Such information is required to be shared. On the other hand, in order to reduce information shared among multiple encoders, if the encoder prohibits motion vector references across tile boundaries, the number of available prediction vector candidates is insufficient. It may become. In some cases, there are no usable prediction vector candidates, and the intra-prediction coding mode must be applied. As a result, there is a possibility that the coding efficiency is lowered.

  In one aspect, the present invention can suppress a decrease in encoding efficiency without sharing information on motion vectors between encoders when encoding is performed with different encoders for each divided region of a picture. It is an object of the present invention to provide a moving image encoding apparatus.

According to one embodiment, a moving picture coding apparatus for coding a picture included in a moving picture is provided. The moving image encoding apparatus includes: a division unit that divides a picture into a plurality of regions; a plurality of encoders that encode different regions of the plurality of regions to generate encoded data; and a plurality of encodings And a multiplexing unit that generates encoded data of a picture by arranging the encoded data output from each of the units in a predetermined order.
The first encoder of the plurality of encoders is a prediction vector for a motion vector among a plurality of blocks obtained by dividing the first region encoded by the first encoder of the plurality of regions. In a predetermined vector mode that defines the generation method of the second encoded by the second encoder of the plurality of encoders of the plurality of regions obtained by dividing another encoded picture. It is assumed that a restriction block specifying unit that specifies a restriction target block that refers to a reference block included in the area of the block, a motion vector is defined in the reference block for the restriction target block, and the motion of the reference block A first temporary list generating unit that generates a first temporary list including a plurality of prediction vector candidates according to a predetermined vector mode using a dummy vector instead of a vector; Assuming that no motion vector is defined in the referenced block for the target block, a second temporary list generation unit that generates a second temporary list including a plurality of prediction vector candidates according to a predetermined vector mode; When prediction vector candidates at the same position between the first temporary list and the second temporary list are the same, a common candidate specifying unit that can use the prediction vector candidates, and inter prediction of the restriction target block When encoding in the encoding mode, a prediction encoding unit that generates prediction encoded data of the first region by using any of the usable prediction vector candidates as a prediction vector, and prediction encoded data And an entropy encoding unit that generates encoded data by entropy encoding.

  When encoding is performed with different encoders for each divided region of the picture, it is possible to suppress a decrease in encoding efficiency without sharing information regarding motion vectors between the encoders.

It is a figure which shows an example of the tile set to the picture. It is a figure which shows an example of the division | segmentation of the picture by HEVC. It is an operation | movement flowchart which shows the determination procedure of the prediction vector in AMVP mode. It is a figure which shows the registration order of the spatial prediction vector in AMVP mode. (A)-(c) is a figure which shows an example of the positional relationship of an encoding object block and ColPU, respectively. 12 is an operation flowchart showing a procedure for creating a prediction vector candidate list mergeCandList in Merge mode. It is a figure which shows the registration order of a spatial prediction vector in Merge mode. It is a figure which shows the table showing the relationship between the prediction vector candidate of L0 direction, the prediction vector candidate of L1 direction, and combined prediction vector candidate mvLXcombCand. It is a figure which shows the relationship between a tile and a time prediction vector. It is a schematic block diagram of the moving image encoder by one Embodiment. It is explanatory drawing of the position of the boundary between tiles. It is a schematic block diagram of an encoder. It is a figure which shows the allocation method of the index of the horizontal direction of CTU. (A)-(d) is a figure which shows the index allocated to each CU contained in one CTU for every hierarchical structure of CU. (A)-(d) is a map which shows inter prediction restriction | limiting object CU about CU whose size is 64x64 pixel, 32x32 pixel, 16x16 pixel, and 8x8 pixel, respectively. (A)-(h) is a figure which shows the index each allocated to each PU contained in one CU. (A)-(h) is an example of the map which shows inter prediction restriction | limiting object PU in case PU division mode PartMode is 2Nx2N, NxN, 2NxN, Nx2N, 2NxU, 2NxnD, nRx2N, nLx2N, respectively. (A)-(h) is another example of the map which shows inter prediction restriction | limiting object PU in case PU division mode PartMode is 2Nx2N, NxN, 2NxN, Nx2N, 2NxU, 2NxnD, nRx2N, nLx2N, respectively. It is a schematic block diagram of a prediction vector candidate list production | generation part. It is a figure which shows an example of the motion vector of PU around the prediction prediction object PU, and the 1st temporary list and 2nd temporary list which are produced | generated by Merge mode. It is a figure which shows another example of the motion vector of PU around the inter prediction restriction | limiting target PU, and the 1st temporary list produced | generated in Merge mode, and a 2nd temporary list. It is a figure which shows an example of the motion vector of PU around the inter prediction restriction target PU, and the first temporary list and the second temporary list generated in the AMVP mode. It is an operation | movement flowchart of a prediction vector candidate list production | generation process. It is explanatory drawing of the procedure of encoding mode determination. It is an operation | movement flowchart of a moving image encoding process. It is a block diagram of the computer which operate | moves as a moving image encoder by the computer program which implement | achieves the function of each part of the moving image encoder by embodiment or its modification.

  Hereinafter, a moving picture coding apparatus according to an embodiment will be described with reference to the drawings. This moving image encoding apparatus divides a picture into a plurality of regions, and each of the plurality of encoders encodes a different region. At this time, each encoder of the moving image encoding apparatus predictively encodes a motion vector without referring to information on a motion vector in a region encoded by another encoder. First, the details of the CTU and the motion vector predictive coding method in HEVC will be described.

  FIG. 2 is a diagram illustrating an example of picture division by HEVC. As shown in FIG. 2, the picture 200 is divided in units of CTUs, and each CTU 201 is encoded in the raster scan order. The size of the CTU 201 can be selected from 64 × 64 to 16 × 16 pixels. However, the size of the CTU 201 is constant for each sequence.

  The CTU 201 is further divided into a plurality of Coding Units (CU) 202 in a quadtree structure. Each CU 202 in one CTU 201 is encoded in the Z scan order. The size of the CU 202 is variable, and the size is selected from 8 × 8 to 64 × 64 pixels in the CU division mode. The CU 202 is a unit for selecting an intra prediction encoding mode and an inter prediction encoding mode that are encoding modes. The CU 202 is individually processed in units of Prediction Unit (PU) 203 or Transform Unit (TU) 204. The PU 203 is a unit for performing prediction according to the encoding mode. For example, the PU 203 is a unit to which the prediction mode is applied in the intra prediction coding mode, and is a unit for performing motion compensation in the inter prediction coding mode. The size of the PU 203 can be selected, for example, from PU partition modes PartMode = 2Nx2N, NxN, 2NxN, Nx2N, 2NxU, 2NxnD, nRx2N, and nLx2N in inter prediction coding. On the other hand, the TU 204 is a unit of orthogonal transformation, and the size of the TU 204 is selected from 4 × 4 pixels to 32 × 32 pixels. The TU 204 is divided by a quadtree structure and processed in the Z scan order.

  Next, a motion vector predictive coding method in HEVC will be described. First, the AMVP mode will be described.

  In the AMVP mode, a prediction vector candidate list mvpListLX including a maximum of two vector candidates that can be used as prediction vectors is created for each prediction direction.

FIG. 3 is an operation flowchart showing a procedure for determining a prediction vector in the AMVP mode.
The video encoding apparatus first selects a prediction vector candidate from motion vectors of an already encoded block adjacent to the encoding target block.

  Specifically, the video encoding apparatus selects a motion vector of a block adjacent to the left side of the encoding target block as a spatial prediction vector mvLXA according to a predetermined order (step S101).

  Details of selection of the spatial prediction vector will be described with reference to FIG. FIG. 4 is a diagram showing the registration order of spatial prediction vectors in the AMVP mode. The moving image encoding apparatus, as indicated by the arrow 401, for the encoding target block 400, the motion vector of each block in the order of the block A0 adjacent to the lower left and the block A1 adjacent to the upper side of the block A0 are spatially predicted vectors. It is determined whether or not to register as.

  The moving picture coding apparatus determines whether or not the block A0 has been coded. When the block A0 has been encoded, the video encoding apparatus determines whether the block A0 has been subjected to inter prediction encoding in the same direction as the encoding target block 400. When the block A0 is inter-predictively encoded in the same direction as the encoding target block 400, the video encoding device determines whether or not the reference picture refIdxLXA0 of the block A0 matches the reference picture refIdxLX of the encoding target block 400 To determine. When the reference picture refIdxLXA0 matches the reference picture refIdxLX, the video encoding device selects the motion vector of the block A0 as the first spatial prediction vector mvLXA.

  On the other hand, when the block A0 is not encoded or the reference picture refIdxLXA0 does not match the reference picture refIdxLX, the video encoding apparatus performs the same determination process for the block A1. Then, when the block A1 has been encoded and the reference picture refIdxLXA1 referenced by the block A1 matches the reference picture refIdxLX, the moving picture coding apparatus selects the motion vector of the block A1 as the spatial prediction vector mvLXA .

  When neither of the reference pictures refIdxLXA0 and refIdxLXA1 matches the reference picture refIdxLX, and the block A0 is inter-predictively encoded in the same direction as the coding target block 400, the moving picture coding apparatus Select a vector. Then, the moving picture encoding apparatus sets the ratio of the time between the encoding target picture and the reference picture refIdxLX to the time between the encoding target picture including the encoding target block 400 and the reference picture refIdxLXA0 as the motion vector of the block A0. Multiply. The video encoding apparatus uses the vector obtained as a result as the spatial prediction vector mvLXA.

When the spatial prediction vector mvLXA is not obtained even by the above processing, and the block A1 is inter-predictively encoded in the same direction as the encoding target block 400, the moving image encoding apparatus calculates the motion vector of the block A1. select. Then, the moving image encoding apparatus multiplies the motion vector of the block A1 by the ratio of the time between the encoding target picture and the reference picture refIdxLX to the time between the encoding target picture and the reference picture refIdxLXA1. The video encoding apparatus uses the vector obtained as a result as the spatial prediction vector mvLXA.
Note that the spatial prediction vector mvLXA is not selected unless both the blocks A0 and A1 are inter-predictively encoded in the same direction as the encoding target block 400.

  Next, the moving image encoding apparatus selects a motion vector of a block adjacent to the upper side of the encoding target block as a spatial prediction vector mvLXB according to a predetermined order (step S102).

  Referring to FIG. 4 again, the moving image encoding apparatus performs the same processing as the selection processing for blocks A0 and A1 with respect to blocks B0, B1, and B2 adjacent to the upper side of the encoding target block 400 in the order indicated by the arrow 402. Perform the process. Then, the moving image encoding apparatus determines whether or not to select the motion vector of those blocks as the spatial prediction vector mvLXB. The block B0 is adjacent to the upper right of the encoding target block 400, and the block B1 is adjacent to the left of the block B0. The block B2 is adjacent to the upper left of the encoding target block 400.

  That is, the moving picture coding apparatus selects, as the spatial prediction vector mvLXB, the motion vector of the block in which the reference picture and the reference picture refIdxLX of the coding target block 400 first match in the order of the blocks B0 to B2. On the other hand, if none of the reference pictures of the blocks B0 to B2 match the reference picture refIdxLX, the video encoding device specifies the first block for which the motion vector is obtained in the order of the blocks B0 to B2. To do. A vector obtained by multiplying the motion vector of the identified block by the ratio of the time between the encoding target picture and the reference picture refIdxLX to the time between the reference picture referenced by the identified block and the encoding target picture is a space. The prediction vector is mvLXB.

  Note that if none of the blocks B0 to B2 is inter-predictively encoded in the same direction as the encoding target block 400, the video encoding apparatus substitutes the spatial prediction vector mvLXA for the spatial prediction vector mvLXB. In this case, if the spatial prediction vector mvLXA is not selected, the spatial prediction vector mvLXB is not selected.

  The video encoding apparatus registers the spatial prediction vectors mvLXA and mvLXB in the prediction vector candidate list mvpListLX (step S103). However, when the spatial prediction vector mvLXA and the spatial prediction vector mvLXB are equal, the video encoding device deletes the spatial prediction vector mvLXB from the candidate list mvpListLX.

  The moving picture coding apparatus determines whether or not there are two or more prediction vector candidates registered in the candidate list mvpListLX (step S104). If there are two or more prediction vector candidates registered in the candidate list mvpListLX (step S104—Yes), the video encoding device ends the creation of the prediction vector candidate list. On the other hand, when the number of spatial prediction vectors registered in the candidate list mvpListLX is less than 2 (No in step S104), the moving picture encoding apparatus executes Temporal mode processing.

  In the Temporal mode process, the moving image encoding apparatus selects a block ColPU at a predetermined position on an encoded picture. Then, the moving picture coding apparatus determines whether or not to use the motion vector mvCol of the block ColPU as a prediction vector candidate (step S105).

  The moving image encoding apparatus selects a candidate picture from encoded pictures that may be referred to by the encoding target block. Then, the moving picture encoding device specifies a block ColPU adjacent to the block at the same position as the encoding target block on the selected picture ColPic.

  Here, the syntax collocatedFromL0Flag specifies whether the picture ColPic including ColPU is selected from the L0 direction or the L1 direction. Also, the picture selected as ColPic is indicated by the syntax collocatedRefIdx.

  The positional relationship between the encoding target block and the ColPU will be described with reference to FIGS. In FIGS. 5A to 5C, one CTU 500 in the picture is shown. Basically, a PU adjacent to the lower right of the PU that is the encoding target block is selected as the ColPU. For example, when the PU adjacent to the lower right of the encoding target block is inter prediction encoded, the upper left pixel of the 16 × 16 pixel grid including the pixel adjacent to the lower right of the encoding target block PU including is selected as ColPU. In addition, when there is no PU including the adjacent pixel at the lower right of the encoding target block or when intra prediction encoding is performed, the PU including the pixel at the lower right of the encoding target block is selected as the ColPU. The

  For example, as shown in FIG. 5A, when the PU 510 that is the encoding target block is larger than the upper left 16 × 16 pixels in the CTU 500, the pixel 511 adjacent to the lower right of the PU 510 is 16 × 16 pixel grid unit is in the same position. Therefore, in ColPic 501, PU 512 adjacent to the lower right of PU 510 is the first ColPU candidate. The PU 514 including the pixel at the same position as the pixel 513 at the lower right corner of the PU 510 is a second ColPU candidate.

  On the other hand, as shown in FIG. 5B, when the PU 520 that is the encoding target block is the upper left block of the 16 × 16 pixel block divided into four, the pixel 521 adjacent to the lower right is , Located in the vicinity of the center of the grid 522 of 16 × 16 pixels. Therefore, in the ColPic 501, the PU 524 including the pixel 523 at the upper left corner of the grid 522 is the ColPU.

  In addition, when a horizontal CTU boundary is sandwiched between the encoding target block and the PU adjacent to the lower right, the position of the upper left pixel at the center of the encoding target block is obtained, and the pixel is included. A 16 × 16 pixel grid is specified. Then, the PU on ColPic including the pixel at the upper left corner of the identified grid is ColPU.

  For example, as illustrated in FIG. 5C, when the PU 530 that is the encoding target block is located at the lower right of the CTU 500, a CTU boundary is located between the PU 530 and the lower right pixel 531. Therefore, the central pixel 532 in the PU 530 is obtained, and a 16 × 16 pixel grid 533 including the pixel 532 is specified. In the ColPic 501, the PU 535 including the pixel 534 at the upper left end of the grid 533 is the ColPU.

  Here, if the ColPU is a block on which intra prediction encoding has been performed, since no motion vector is defined in the ColPU, the moving image encoding device cannot use the motion vector of the ColPU as a prediction vector. Also, when there is no motion vector in the L0 direction for ColPU, the video encoding apparatus uses the motion vector in the L1 direction. On the other hand, when there is no motion vector in the L1 direction for ColPU, the video encoding apparatus uses the motion vector in the L0 direction. Also, for ColPU, if motion vectors in both directions of L0 and L1 exist and the reference pictures of the current block are all past pictures or the current picture, the video encoding device specifies with the syntax collocatedFromL0Flag The motion vector in the specified direction is used. On the other hand, if there are motion vectors in both the L0 direction and the L1 direction for the ColPU, and the future picture is included in the reference picture of the current block, the video encoding device uses the syntax collocatedFromL0Flag. Use a motion vector in the direction opposite to the specified direction.

  When the motion vector mvCol is available (step S105—Yes), the moving image encoding apparatus registers the vector obtained by time-scaling the motion vector mvCol as a temporal prediction vector mvLXB in the candidate list mvpListLX (step S106). . Specifically, the moving picture encoding apparatus performs the encoding target picture including the encoding target block and the picture referred to by the encoding target block with respect to the time between the picture including the Col block and the picture referred to by the Col block. Multiply the motion vector mvCol by the time ratio between. Note that, when the two vectors mvLXA registered in the candidate list mvpListLX are equal to the temporal prediction vector mvLXB, the video encoding device deletes the temporal prediction vector mvLXB from the candidate list mvpListLX.

  After step S106 or when the motion vector mvCol cannot be used in step S105 (step S105-No), it is determined whether or not there are two or more prediction vector candidates registered in the candidate list mvpListLX (step S107). When the number of prediction vector candidates registered in the candidate list mvpListLX is less than two (step S107—No), the video encoding apparatus registers a zero vector as a prediction vector candidate in the candidate list mvpListLX (step S108). ).

After step S108, the moving image encoding apparatus selects a candidate having a smaller error with respect to the motion vector of the encoding target block as the prediction vector mvpLX from the two candidates (step S109). Also, when the number of prediction vector candidates registered in the candidate list mvpListLX in step S107 is two or more (step S107—Yes), the video encoding apparatus executes the process of step S109. Then, the video encoding apparatus ends the prediction vector determination procedure.
The vector selected as the prediction vector mvpLX is represented by the syntax mvpLxFlag that represents the position of the selected vector in the candidate list mvpListLX. The syntax mvpLxFlag and the difference vector between the motion vector and the prediction vector of the encoding target block are entropy encoded.

  If the current picture to be coded is a P picture, the moving picture coding apparatus performs the above process only for the motion vector in the L0 direction. On the other hand, if the encoding target picture is a B picture, the moving image encoding apparatus performs the above-described processing on motion vectors in both the L0 direction and the L1 direction.

  Next, the Merge mode will be described.

  FIG. 6 is an operation flowchart showing a procedure for creating a prediction vector candidate list mergeCandList in the Merge mode. In the Merge mode, the moving image encoding apparatus selects one vector as the Merge vector mvLXN from the number of available Merge vector candidates indicated by the syntax MaxNumMergeCand (maximum 5). The selected vector is represented by a syntax mergeIdx indicating the position of the candidate list mergeCandList.

  The moving image encoding apparatus selects a motion vector of a block adjacent to the left side or the upper side of the encoding target block as a spatial prediction vector candidate according to a predetermined order (step S201).

  Details of selection of the spatial prediction vector will be described with reference to FIG. FIG. 7 is a diagram showing the registration order of spatial prediction vectors in the Merge mode. As shown by arrows 701 to 704, the moving image encoding apparatus uses the motion vectors of the blocks as spatial prediction vector candidates in the order of blocks A1 → B1 → B0 → A0 → B2, as indicated by arrows 701 to 704. Determine whether to register.

  Moreover, if a plurality of spatial prediction vector candidates are the same value, one other than the plurality of spatial prediction vector candidates is deleted. For example, when a certain block is divided and the block is a candidate for a vector of another block, the block is deleted because it is not necessary to be divided. For block B2, if four spatial prediction vector candidates have already been selected, the motion vector of block B2 is excluded from the spatial prediction vector candidates. The respective spatial prediction vector candidates are mvLXA0, mvLXA1, mvLXB0, mvLXB1, and mvLXB2.

  Next, the moving picture encoding apparatus performs temporal mode processing and selects a temporal prediction vector candidate mvLXCol (step S202). Note that the Temporal mode process in the Merge mode is the same as the Temporal mode process in the AMVP mode, and thus a detailed description of the Temporal mode process is omitted.

  The video encoding apparatus registers the selected prediction vector candidate in the candidate list mergeCandList (step S203). Then, the moving image encoding apparatus calculates the number of prediction vector candidates numOrigMergeCand registered in the candidate list mergeCandList (step S204).

  Next, the moving picture encoding apparatus determines whether the encoding target picture including the encoding target block is a B picture and numOrigMergeCand is 2 or more and less than MaxNumMergeCand (step S205). When the determination condition in step S205 is satisfied, the video encoding apparatus combines prediction vector candidates registered in the candidate list mergeCandList to derive a combined bi-predictive vector. Then, the video encoding apparatus adds the derived vector as a prediction vector candidate (step S206). The moving picture encoding apparatus repeatedly executes the process of step S206 until numOrigMergeCand * (numOrigMergeCand-1) times or the number of prediction vector candidates reaches MaxNumMergeCand. The calculated vector candidate is expressed as mvLXcombCand.

  FIG. 8 shows a table representing the relationship between the prediction vector candidate in the L0 direction and the prediction vector candidate in the L1 direction and the combined bi-prediction vector candidate mvLXcombCand when MaxNumMergeCand is 4. In the table 800, l0CandIdx indicates the registration order of prediction vector candidates in the L0 direction in the candidate list mergeCandList, and l1CandIdx indicates the registration order of prediction vector candidates in the L1 direction in the candidate list mergeCandList. CombIdx indicates mvLXcombCand derived from a combination of a prediction vector candidate in the L0 direction and a prediction vector candidate in the L1 direction.

  After step S206 or when the determination condition in step S205 is not satisfied, the video encoding device determines whether the number of prediction vector candidates is less than MaxNumMergeCand (step S207). If the number of prediction vector candidates numOrigMergeCand is less than MaxNumMergeCand (step S207—Yes), there is still an empty space in the candidate list mergeCandList. Therefore, the video encoding apparatus registers the zero vector as a candidate for the prediction vector in the candidate list mergeCandList until the number of prediction vector candidates reaches MaxNumMergeCand (step S208).

  After step S208, the video encoding apparatus selects a candidate having the smallest difference from the motion vector of the current block from among the prediction vector candidates as a merge vector mvLXN (step S209). Also, in the case where the number of prediction vector candidates numOrigMergeCand is greater than or equal to MaxNumMergeCand in Step S207 (No in Step S207), the video encoding apparatus executes the process of Step S209. Thereafter, the moving image encoding device ends the creation of the candidate list mergeCandList.

Here, it is considered that the AMVP mode or the Merge mode is applied when a picture is encoded using a different encoder for each tile.
FIG. 9 is a diagram illustrating the relationship between tiles and temporal prediction vectors. In FIG. 9, the picture 900 is divided into a left tile 901 and a right tile 902 for simplicity. The CTU 904 included in the tile 901 and the CTU 905 included in the tile 902 each have a size of 64 pixels × 64 pixels and are adjacent to the boundary 903 between the tiles. The CTUs 904 and 905 are divided in units of PUs, which are motion vector generation units.

  When obtaining a temporal prediction vector for the PU 906 on the upper right side of the CTU 904, the moving image encoding apparatus refers to the motion vector of the ColPU 911 that is the same as the PU 907 on the lower right side of the PU 906 in the encoded ColPic 910. At this time, the ColPU 911 belongs to the tile 902 at a position beyond the tile boundary 903 from the PU 906. Here, when the tiles 901 and 902 are encoded by separate encoders, the data necessary for calculating the temporal prediction vector of the PU 906 is an encoder that encodes the tile 902 and a code that encodes the tile 901. Need to be shared with the generator.

  As described above, in order to calculate the temporal prediction vector for the motion vector of the PU adjacent to the tile boundary, information regarding the motion vector of the region encoded by another encoder is necessary. On the other hand, in order to reduce hardware resources, it is not preferable to refer to information on a motion vector of a region encoded by another encoder. Therefore, each encoder has a list of prediction vector candidates when it is assumed that there is a motion vector in ColPU, and a prediction vector when it is assumed that there is no motion vector in ColPU. And a list of candidates for each. Each encoder uses a candidate common to the two lists for motion vector predictive encoding. Thus, the moving picture encoding apparatus suppresses the number of prediction vector candidates from becoming insufficient without sharing information such as motion vectors among a plurality of encoders, thereby improving the encoding efficiency. Suppresses the decline.

  FIG. 10 is a schematic configuration diagram of a moving image encoding apparatus according to an embodiment. The moving image encoding device 1 includes a dividing unit 10, a plurality of encoders 11-1 to 11-n (where n is an integer equal to or greater than 2), and a multiplexing unit 12.

  Each of these units included in the moving image encoding apparatus 1 is formed as a separate circuit. Alternatively, these units included in the video encoding device 1 may be mounted on the video encoding device 1 as one integrated circuit in which circuits corresponding to the respective units are integrated. Furthermore, each of these units included in the moving image encoding device 1 may be a functional module realized by a computer program executed on a processor included in the moving image encoding device 1.

  Pictures are sequentially input to the dividing unit 10 in accordance with the order of pictures set by a control unit (not shown) that controls the entire moving image encoding apparatus 1. Then, every time a picture is input, the dividing unit 10 divides the picture into n areas according to the picture division information given by the control unit. In the present embodiment, each region includes one tile. Then, the dividing unit 10 divides the picture so that the boundary between the regions becomes the boundary between the tiles. Note that the position of the boundary between tiles is constant throughout the sequence. Each region of the picture divided by the dividing unit 10 is input to the encoders 11-1 to 11-n, respectively.

  The position of the boundary between tiles will be described with reference to FIG. In the picture 1100, the horizontal and vertical sizes of individual CTUs are set to CTUSIZE (for example, 64 pixels). Further, the number of vertical pixels of the picture 1100 is set to PictureSizeV, and the number of horizontal pixels is set to PictureSizeH. The picture division information includes, for example, a vertical division number DivNumV and a horizontal division number DivNumH. In this example, DivNumV = DivNumH = 2. That is, the picture 1100 is divided into two parts in the horizontal direction and the vertical direction.

  The number of CTUs in the vertical direction of the picture 1100 is CTUNumV (= PictureSizeV / CTUSIZE), and the number of CTUs in the horizontal direction is PicCTUNumH (= PictureSizeH / CTUSIZE). In this case, the vertical CTU number TileCTUNumV per region when the picture is equally divided in the vertical direction is PicCTUNumV / DivNumV. However, when PicCTUNumV is not an integral multiple of DivNumV, the lowest tile may include an extra number of CTUs less than TileCTUNumV. Similarly, the number of CTUs TileCTUNumH in the vertical direction per region when the picture is equally divided in the horizontal direction is PicCTUNumH / DivNumH. However, if PicCTUNumH is not an integer multiple of DivNumH, the rightmost tile may include an extra number of CTUs less than TileCTUNumH. Here, for simplification, PicCTUNumV is an integer multiple of DivNumV, and PicCTUNumH is an integer multiple of DivNumH.

  In this example, the picture 1100 is divided into four tiles 1103 to 1106 by a vertical tile boundary 1101 and a horizontal tile boundary 1102. For example, the upper left tile 1103 is input to the encoder 11-1, and the upper right tile 1104 is input to the encoder 11-2. The lower left tile 1105 is input to the encoder 11-3, and the lower right tile 1106 is input to the encoder 11-4.

  Each of the encoders 11-1 to 11-n encodes the input region independently of each other to generate encoded data. The encoders 11-1 to 11-n output the encoded data to the multiplexing unit 12. Details of the encoders 11-1 to 11-n will be described later.

  The multiplexing unit 12 arranges the encoded data of each region received from the encoders 11-1 to 11-n in the raster scan order and adds predetermined header information based on HEVC, thereby Generate encoded data of a picture. Then, the multiplexing unit 12 outputs the encoded data of each picture according to the order of the pictures.

  Details of the encoders 11-1 to 11-n will be described below. In addition, since the encoders 11-1 to 11-n have the same configuration and the same function, the encoder 11-1 will be described below.

  The encoder 11-1 encodes a plurality of CTUs included in the input area for each CTU in the raster scan order.

  FIG. 12 is a schematic configuration diagram of the encoder 11-1. The encoder 11-1 includes a motion search unit 20, a restricted block identification unit 21, a prediction vector candidate list generation unit 25, an encoding mode determination unit 26, a prediction encoding unit 27, and an entropy encoding unit 28. And have.

  When the picture to be coded is a picture to which the inter prediction coding mode can be applied, the motion search unit 20 is applicable to each CTU included in the area to be coded by the encoder 11-1. A motion vector is calculated for each PU.

  The motion search unit 20 performs block matching with respect to an area that can be referred to for a locally decoded picture for the PU of interest of the encoding target CTU, and identifies the reference block that most closely matches the PU of interest. Then, the motion search unit 20 calculates a vector representing the amount of movement between the focused PU and the reference block as a motion vector. The motion search unit 20 notifies the coding mode determination unit 26 of the motion vector of each PU.

  The restricted block specifying unit 21 uses the motion vector of the PU included in the region encoded by another encoder of the encoded picture as the temporal prediction vector of the motion vector used when the PU is inter-predictively encoded. Identify PUs that may be referenced. For this purpose, the restricted block specifying unit 21 includes an inter prediction restriction target CTU determination unit 22, an inter prediction restriction target CU determination unit 23, and an inter prediction restriction target PU determination unit 24. In the following, for convenience of explanation, a PU that may refer to a motion vector of a PU included in an area encoded by another encoder of a coded picture is used as a temporal prediction vector. Call it.

  The inter prediction restriction target CTU determination unit 22 determines a CTU including an inter prediction restriction target PU based on a boundary position between two regions (that is, a boundary position between tiles) input to different encoders. . A CTU including an inter prediction restriction target PU is hereinafter referred to as an inter prediction restriction target CTU for convenience of explanation.

  Referring to FIG. 11 again, for example, for the tile 1103, the tile boundary is the right end and the lower end of the tile 1103. For the tile 1104, the tile boundary is the left end and the bottom end of the tile 1104. Similarly, for the tile 1105, the tile boundary is the right end and the top end of the tile 1105. For the tile 1106, the tile boundary is the left end and the top end of the tile 1106.

  Here, as a feature of the Temporal mode, a PU adjacent to the lower right of the focused PU in the encoded picture referred to in the inter prediction encoding mode is referred to. Furthermore, PUs located beyond the boundary between horizontal CTUs are not referred to by the focused PU. In view of this, in the tile for which each encoder is responsible for the encoding process, only the tile having a tile boundary on the right side includes the inter prediction restriction target CTU. That is, in this example, the tile 1103 and the tile 1105 include the inter prediction restriction target CTU. Hereinafter, the tile 1103 will be described as an example.

  In order to facilitate understanding of the method for specifying the inter prediction restriction target CTU, an index for specifying the CTU assigned to each CTU will be described with reference to FIG. In FIG. 13, the tile 1300 is divided into a plurality of CTUs 1301. Here, the CTU size CTUSIZE is 64 pixels. As described above, a plurality of CTUs included in a picture are encoded in raster scan order. Therefore, the index CTUIDX for specifying each CTU is set in the encoding order. Further, the horizontal index CTUHIDX of each CTU shown in each CTU 1301 is assigned in order from the leftmost CTU. That is, CTUHIDX for the leftmost CTU is 0, and CTUHIDX for the (N + 1) th CTU from the left end is N. The CTUHIDX for the rightmost CTU is (TileCTUNumH-1).

  From the operation definition of the Temporal mode, as described above, there is a possibility that the right end is a CTU that is in contact with the vertical boundary between tiles that may be referred to across the boundary between tiles. Therefore, the inter prediction restriction target CTU determination unit 22 determines a CTU whose horizontal index CTUHIDX is (TileCTUNumH-1) as the inter prediction restriction target CTU.

  In the inter prediction restriction target CTU, the inter prediction restriction target CU determination unit 23 refers to a motion vector included in a tile that is not at the same position as the encoding target tile on the encoded picture from the operation definition of Temporal mode. Identify PUs that can Note that a PU that can refer to a motion vector included in a tile that is not at the same position as the encoding target tile is an inter prediction restriction target PU. Then, the inter prediction restriction target CU determination unit 23 specifies a CU including the specified inter prediction restriction target PU. Hereinafter, for convenience of explanation, a CU including an inter prediction restriction target PU is referred to as an inter prediction restriction target CU.

  As shown in FIG. 2, in HEVC, the selectable CU sizes are 32 × 32 pixels, 16 × 16 pixels, and 8 × 8 pixels in a quadtree structure from a maximum of 64 × 64 pixels. This represents the hierarchical structure of the CU. In order to determine the CU size in the encoding mode determination unit 26, the inter prediction restriction target CU is determined for each hierarchical structure of the CU.

  A CU index CUIDX for identifying a CU, which is assigned to each CU included in one CTU 1400 for each hierarchical structure of the CU, will be described with reference to FIGS. 14 (a) to 14 (d). 14A to 14D, each block 1401 represents one CU, and the numerical value shown in the block represents the CU index CUIDX. The numerical value shown above the CTU 1400 represents the horizontal CU index CUHIDX. FIG. 14A shows an index CUIDX when the CU size is 64 × 64 pixels. Similarly, FIGS. 14B to 14D show the CU index CUIDX when the CU size is 32 × 32 pixels, 16 × 16 pixels, and 8 × 8 pixels, respectively.

  The CU index CUIDX is assigned according to an encoding order, for example, a raster scan order. In the present embodiment, the CU horizontal index CUHIDX, which is the index of the CU in the horizontal direction, is assigned to each CU in order from left to right in the horizontal direction.

  For convenience, coordinates for the inter prediction restriction target CTU are defined with reference to the left end of the CTU. In this coordinate system, tb = (TileCTUNumH * CTUSIZE-1), where tb is the tile boundary coordinate (pixel accuracy) at the right end of the tile. However, the coordinate of the pixel at the left end of the tile is 0.

  The inter prediction restriction target CU determination unit 23 sets a CU that meets CUHIDX = tb / CUSIZE in contact with the tile boundary at the right end of the tile as an inter prediction restriction target CU. However, as shown in FIG. 5C, the CU corresponding to the encoding target PU in which the CTU boundary is located between the encoding target PU and the lower right PU, that is, CUIDX = {(CTUSIZE / For CU of (CUSIZE) * (CTUSIZE / CUSIZE) -1}, the position of ColPU is modified. Therefore, the inter prediction restriction target CU determination unit 23 does not have to exceptionally set the CU as the inter prediction restriction target CU.

FIGS. 15A to 15D are maps showing inter prediction restriction target CUs in the inter prediction restriction target CTU 1500 for CUs having sizes of 64 × 64 pixels, 32 × 32 pixels, 16 × 16 pixels, and 8 × 8 pixels, respectively. Each block 1501 represents one CU. Of the “0” to “2” shown in the CU, “0” represents that the CU is not an inter prediction restriction target CU. Further, “1” represents an inter prediction restriction target CU. And “2” indicates that among the inter prediction restriction target CUs, the CU includes a PU that is exceptionally not restricted to use of the Temporal mode. As shown in FIGS. 15A to 15D, the rightmost CU of the inter prediction restriction target CTU is the inter prediction restriction target CU. However, CUs located at the right end and bottom end of the inter prediction restriction target CTU are treated as exceptions.
For simplification of setting, the inter prediction restriction target CU determination unit 23 may set all the CUs included in the inter prediction restriction target CTU as the inter prediction restriction target CU.

  Note that the inter prediction restriction target CU determination unit 23 may restrict the selectable CU sizes. For example, the inter prediction restriction target CU determination unit 23 can restrict division of CUs selected in the CTU by defining a value indicating invalidity as a CU restriction index. As described above, the CU is a unit for determining the coding mode, and the moving image coding apparatus 1 selects either the intra prediction coding mode or the inter prediction coding mode as the coding mode for each CU. it can. Although detailed description will be given later, there is a possibility that the CU including the PU referred to in the Temporal mode may be intra prediction encoded. Since the intra prediction coding mode generally has a lower compression efficiency than the inter prediction coding mode, the size of the CU to which the intra prediction coding mode is applied may be the smallest of the selectable CU sizes. preferable. For example, the inter prediction restriction target CU determination unit 23 selects an inter prediction restriction target CU at the CU minimum size CUSIZE = 8. Therefore, when the CU size is larger than 8, the inter prediction restriction target CU determination unit 23 sets the value of the CU restriction index of the CU including the same position as the CU of the minimum size whose CU restriction index is non-zero to a value indicating invalidity. For example, set to '3'.

  The inter prediction restriction target PU determination unit 24 uses, as PUs that can be referred to in the temporal mode, a region encoded by another encoder among PUs included in the inter prediction restriction target CU. .

  As shown in FIG. 2, in HEVC, the selectable CU sizes are 32 × 32 pixels, 16 × 16 pixels, and 8 × 8 pixels in a quadtree structure from a maximum of 64 × 64 pixels. Each size of CU is divided into a plurality of PUs according to the PU partition mode PartMode = 2Nx2N, NxN, 2NxN, Nx2N, 2NxU, 2NxnD, nRx2N, and nLx2N shown in FIG. That is, the PU also has a hierarchical structure with respect to the CU. Therefore, the inter prediction restriction target PU is determined for each hierarchical structure of the CU.

  A PU index PUIDX for identifying a PU, which is assigned to each PU included in one CU 1600, will be described with reference to FIGS. FIGS. 16A to 16H show indexes PUIDX when the PU partitioning mode PartMode is 2Nx2N, NxN, 2NxN, Nx2N, 2NxU, 2NxnD, nRx2N, and nLx2N, respectively. In FIG. 16A to FIG. 16H, each block 1601 represents one PU, and the numerical value shown in the block represents the PU index PUIDX. The numerical value shown on the upper side of the CU 1600 represents the horizontal PU index PUHIDX.

  The index PUIDX is assigned according to the encoding order of the PU. Also, the horizontal PU index PUHIDX is assigned to each PU in order from left to right in the horizontal direction.

  The inter prediction restriction target PU determination unit 24 refers to a CU restriction map that is a map of restriction indexes of each CU indicating the inter prediction restriction target CU, and sets a CU focusing on the CU with the CU restriction index “1”. Then, the inter prediction restriction target PU determination unit 24 determines, for each PU included in the focused CU, whether or not to refer to a PU in an area encoded by another encoder in the Temporal mode.

  Specifically, the inter prediction restriction target PU determination unit 24 sets a PU with PUHIDX = tb / PUHSIZE among PUs included in a CU having a restriction index of “1” as an inter prediction restriction target PU. Here, PUHSIZE represents the size of the PU in the horizontal direction.

  FIG. 17A to FIG. 17H are maps showing prediction restriction target PUs when the PU partition modes PartMode are 2Nx2N, NxN, 2NxN, Nx2N, 2NxU, 2NxnD, nRx2N, and nLx2N, respectively. In FIG. 17A to FIG. 17H, each block 1701 represents one PU. The numerical value shown in the PU is the value of the PU restriction flag set for the PU. The PU restriction flag value “0” indicates that the corresponding PU is not an inter prediction restriction target PU. On the other hand, the value “1” of the PU restriction flag indicates that the corresponding PU is an inter prediction restriction target PU. As shown in FIG. 17A to FIG. 17H, a tile boundary, that is, a PU adjacent to the left side of a boundary between regions encoded by different encoders is set as an inter prediction restriction target PU. The

  In addition, the inter prediction restriction target PU determination unit 24 makes an exception for PUs whose CTU boundary is located between the PU and the lower right PU among the PUs included in the CU whose CU restriction index is “2”. As such, it may be excluded from the inter prediction restriction target PU. That is, the value of the PU restriction flag of the PU is set to “0”. For PUs where the CTU boundary is located between the PU and the lower right PU, ColPU is set so that it overlaps with the PU, and prediction vector candidates selected in Temporal mode are encoded by another encoder This is because the area to be used is not referred to.

  In this case, the maps indicating the inter prediction restriction target PUs when the PU partition mode PartMode is 2Nx2N, NxN, 2NxN, Nx2N, 2NxU, 2NxnD, nRx2N, nLx2N are shown in FIG. 18 (a) to FIG. 18 (h). It will be. In FIG. 18A to FIG. 18H, each block 1801 represents one PU. The numerical value shown in the PU is the value of the PU restriction flag set for the PU.

  The inter prediction restriction target PU determination unit 24 passes the PU restriction flag of each PU to the prediction vector candidate list generation unit 25 for each PU.

  The prediction vector candidate list generation unit 25 generates a prediction vector candidate list for the motion vector of the target PU. FIG. 19 is a schematic configuration diagram of the prediction vector candidate list generation unit 25. The prediction vector candidate list generation unit 25 includes a determination unit 30, an unrestricted list generation unit 31, a first temporary list generation unit 32, a second temporary list generation unit 33, and a common candidate specification unit 34.

  The determination unit 30 refers to the PU restriction flag and determines whether each of the PUs applicable to the encoding target CTU is an inter prediction restriction target PU. Then, if the focused PU is not the inter prediction restriction target PU, the determination unit 30 notifies the unrestricted list generation unit 31 of the PU. On the other hand, if the focused PU is an inter prediction restriction target PU, the determination unit 30 notifies the first temporary list generation unit 32 and the second temporary list generation unit 33 of the PU.

  The unrestricted list generation unit 31 generates prediction vector candidate lists according to the normal AMVP mode and the Merge mode for PUs that are not applicable to the inter prediction restriction target PU among the PUs applicable to the encoding target CTU. . That is, the non-restricted list generation unit 31 generates a list of prediction vector candidates in the AMVP mode according to the operation flowchart shown in FIG. 3 for PUs that are not inter prediction restriction target PUs. Further, the unrestricted list generation unit 31 generates a list of prediction vector candidates in the merge mode for PUs that are not inter prediction restriction target PUs according to the operation flowchart shown in FIG. Then, the non-restricted list generation unit 31 outputs the generated prediction vector candidate list to the encoding mode determination unit 26.

  For the inter prediction restriction target PU, the first candidate PU of ColPU is encoded by another encoder, so it is unknown whether a motion vector is set for the first candidate PU. is there. Therefore, it is assumed that the first temporary list generation unit 32 has an available temporal prediction vector for the inter prediction restriction target PU among the PUs applicable to the encoding target CTU. Then, the first temporary list generation unit 32 generates a list of prediction vector candidates according to each of the AMVP mode and the Merge mode on the assumption. Hereinafter, the list of prediction vector candidates generated by the first temporary list generation unit 32 is referred to as a first temporary list.

  When a CTU boundary exists between the inter prediction restriction target PU and the ColPU, the first temporary list generation unit 32 cannot refer to the ColPU motion vector. Therefore, the first temporary list generation unit 32 uses a dummy vector as a temporal prediction vector. This dummy vector can be, for example, a vector having an element value that cannot be taken by a motion vector, for example, a vector in which the value of each element cannot be expressed in 16 bits. Or the 1st temporary list production | generation part 32 may match the flag showing that it is a dummy vector with the candidate of the prediction vector derived from the dummy vector among the 1st temporary lists.

  That is, the first temporary list generation unit 32 generates the first temporary list regarding the AMVP mode, assuming that the determination in step S105 in the operation flowchart of FIG. 3 is always Yes. At that time, the first temporary list generation unit 32 may register a dummy vector in the first temporary list in the process of step S106 in the operation flowchart of FIG.

  In addition, regarding the Merge mode, the first temporary list generation unit 32 may set the dummy vector as the temporal prediction vector in step S202 in the operation flowchart of FIG. Moreover, the 1st temporary list production | generation part 32 should just use a dummy vector as a time prediction vector in the case of the production | generation of a Combined bi-predictive vector in step S206. Then, the first temporary list generating unit 32 outputs the generated first temporary list to the common candidate specifying unit 34.

  On the other hand, the second temporary list generation unit 33 assumes that there is no temporal prediction vector that can be used for the inter prediction restriction target PU among the PUs applicable to the encoding target CTU, and the AMVP mode and the Merge mode. A list of prediction vector candidates is generated according to each of. Hereinafter, the list of prediction vector candidates generated by the second temporary list generation unit 33 is referred to as a second temporary list.

  That is, regarding the AMVP mode, the second temporary list generation unit 33 generates the first temporary list assuming that the determination in step S105 in the operation flowchart of FIG. 3 is always No. Further, the second temporary list generation unit 33 skips the process of step S202 in the operation flowchart of FIG. 6 for the Merge mode and does not use the Combined bi-predictive vector based on the temporal prediction vector. Is generated. Then, the second temporary list generating unit 33 outputs the generated second temporary list to the common candidate specifying unit 34.

  Note that only one of the AMVP mode and the Merge mode may be applied to the moving image data to be encoded. In this case, the non-restricted list generation unit 31, the first temporary list generation unit 32, and the second temporary list generation unit 33 may generate a list of prediction vector candidates only for one of these modes. Good.

  The common candidate specifying unit 34 determines whether or not each set of prediction vector candidates at the same position is common between the first temporary list and the second temporary list, that is, two sets included in the set. It is determined whether the prediction vector candidates are the same. Then, the common candidate specifying unit 34 sets prediction vector candidates common to the first temporary list and the second temporary list as vectors that can be used as prediction vector candidates.

  FIG. 20 is a diagram illustrating an example of motion vectors of PUs around the inter prediction restriction target PU, and the first temporary list and the second temporary list generated in the Merge mode. In this example, the PUs 2001 and 2002 at the positions of the blocks A0, A1, and B1 in FIG. There is a need for bidirectional motion vectors. L0 (a, b) represents a motion vector in the L0 direction, and L1 (a, b) represents a motion vector in the L1 direction.

  In this case, in the first temporary list 2010, the 0th and 1st candidates are spatial prediction vectors obtained from the motion vector of the PU 2003 and the motion vector of the PU 2004, respectively. The second candidate is a dummy temporal prediction vector. The third candidate is a combined bi-predictive vector generated from the L0 direction vector of the 0th spatial prediction vector and the L1 direction vector of the first spatial prediction vector. The fourth candidate is a combined bi-predictive vector generated from the L1 direction vector of the 0th spatial prediction vector and the L0 direction vector of the first spatial prediction vector. On the other hand, in the second temporary list 2011, the 0th and 1st candidates are spatial prediction vectors obtained from the motion vector of the PU 2003 and the motion vector of the PU 2004, respectively. The second candidate is a combined bi-predictive vector generated from the L0 direction vector of the 0th spatial prediction vector and the L1 direction vector of the first spatial prediction vector. Similarly, the third candidate is a combined bi-predictive vector generated from a vector in the L1 direction of the 0th spatial prediction vector and a vector in the L0 direction of the first spatial prediction vector. And the fourth candidate is a zero vector.

  Therefore, the 0th, 1st, and 4th candidates are common in the first temporary list and the second temporary list. Therefore, the common candidate specifying unit 34 determines that the 0th, 1st, and 4th candidates can be used as prediction vector candidates.

  On the other hand, in the prior art, since the second and subsequent candidates in the list of prediction vector candidates are not fixed, only the 0th and 1st spatial prediction vectors can be used as prediction vector candidates. As described above, the moving picture encoding apparatus 1 according to the present embodiment can increase the number of prediction vector candidates that can be used as compared with the conventional technique.

  FIG. 21 is a diagram illustrating another example of the motion vectors of the PUs around the inter prediction restriction target PU, and the first temporary list and the second temporary list generated in the Merge mode. In this example, for the inter prediction restriction target PU 2100, the PUs 2101 and 2102 at the positions of the blocks A1 and B1 in FIG. A unidirectional motion vector is desired. L0 (a, b) represents a motion vector in the L0 direction, and L1 (a, b) represents a motion vector in the L1 direction.

  In this case, in the first temporary list 2110, the 0th to 2nd candidates are spatial prediction vectors obtained from the motion vectors of the PU 2104, the PU 2103, and the PU 2105, respectively. The third candidate is a dummy temporal prediction vector. The fourth candidate is a combined bi-predictive vector generated from the L0 direction vector of the 0th spatial prediction vector and the L1 direction vector of the first spatial prediction vector. On the other hand, in the second temporary list 2111, the 0th to 2nd candidates are spatial prediction vectors obtained from the motion vectors of the PU 2104, PU 2103, and PU 2105, respectively. On the other hand, the third candidate is a combined bi-predictive vector generated from the L0 direction vector of the 0th spatial prediction vector and the L1 direction vector of the first spatial prediction vector. Similarly, the fourth candidate is a combined bi-predictive vector generated from the L0 direction vector of the 0th spatial prediction vector and the L1 direction vector of the second spatial prediction vector.

  Therefore, the 0-2nd and 4th candidates are common in the first temporary list and the second temporary list. Therefore, the common candidate specifying unit 34 determines that the 0th to second and fourth candidates can be used as prediction vector candidates.

  On the other hand, in the prior art, since the third and subsequent candidates in the list of prediction vector candidates are not fixed, only the 0th to second spatial prediction vectors can be used as prediction vector candidates. Therefore, also in this example, the moving picture encoding apparatus 1 according to the present embodiment can increase the number of usable prediction vector candidates as compared with the conventional technique.

  FIG. 22 is a diagram illustrating an example of motion vectors of PUs around the inter prediction restriction target PU, and a first temporary list and a second temporary list generated in the AMVP mode. In this example, with respect to the inter prediction restriction target PU 2200, all of the PUs 2201 to 2204 referred to when generating the spatial prediction vector are intra prediction encoded.

  In this case, in the first temporary list 2210, the 0th candidate is a dummy temporal prediction vector. The first candidate is a zero vector. On the other hand, in the second temporary list 2211, both the 0th and 1st candidates are zero vectors.

  Therefore, the first candidate is common to the first temporary list and the second temporary list. Therefore, the common candidate specifying unit 34 determines that the first candidate can be used as a prediction vector candidate.

  On the other hand, in the prior art, since the top candidate of the list of prediction vector candidates is not fixed, any candidate cannot be used as a prediction vector candidate. Therefore, the inter prediction restriction target PU 2200 is intra prediction encoded. Therefore, in this example, the moving image encoding apparatus 1 according to the present embodiment can apply the inter prediction encoding mode to the inter prediction restriction target PU 2200 to which the inter prediction encoding mode cannot be applied in the related art.

  The common candidate specifying unit 34 indicates a vector that can be used as a candidate for a prediction vector among vectors included in the first temporary list or the second temporary list and the first temporary list or the second temporary list. Information is notified to the encoding mode determination unit 26.

FIG. 23 is an operation flowchart of prediction vector candidate list generation processing. The prediction vector candidate list generation unit 25 generates a prediction vector candidate list according to the following operation flowchart for each PU.
The determination unit 30 determines whether or not the focused PU is an inter prediction restriction target PU (step S301). If the focused PU is not an inter prediction restriction target PU (No in step S301), the non-restricted list generation unit 31 generates a prediction vector candidate list according to each of the AMVP mode and the Merge mode (step S302).

  On the other hand, if the focused PU is an inter prediction restriction target PU (step S301-Yes), the first temporary list generation unit 32 assumes that a temporal prediction vector exists and sets the temporal prediction vector as a dummy vector. . Then, the first temporary list generating unit 32 generates a first temporary list according to each of the AMVP mode and the Merge mode (step S303). In addition, the second temporary list generation unit 33 generates a second temporary list according to each of the AMVP mode and the Merge mode, assuming that there is no temporal prediction vector (step S304).

The common candidate specifying unit 34 uses a vector that can be used as a candidate for a prediction vector from a set of prediction vector candidates at the same position between the first temporary list and the second temporary list. (Step S305).
After step S302 or step S305, the prediction vector candidate list generation unit 25 ends the prediction vector candidate list generation process.

When a motion vector exists for a PU that is a second ColPU candidate for an inter prediction restriction target PU, it is determined that a temporal prediction vector exists in the inter prediction restriction target PU. In this case, for the inter prediction restriction target PU, the prediction vector candidate list generated without restricting the reference to ColPU and the first temporary list other than prediction vector candidates derived from the temporal prediction vector Are the same.
Therefore, according to the modification, the common candidate specifying unit 34 selects candidates that are not derived from the dummy temporal prediction vector among the prediction vector candidates registered in the first temporary list as usable prediction vector candidates. May be added.

  For example, referring to FIG. 20 again, in the first provisional list 2010, the third vector is not derived from a dummy temporal prediction vector. Therefore, the common candidate specifying unit 34 can use the remaining candidates excluding the second candidate among the prediction vector candidates included in the first temporary list 2010 as the prediction vector candidates.

  According to this modified example, the number of prediction vector candidates that can be used for the inter prediction restriction target PU is increased, so that the video encoding device 1 can improve the coding efficiency for the CTU that includes the inter prediction restriction target PU. The decrease can be further suppressed.

  The encoding mode determination unit 26 determines a combination of a CU partition mode (CU size) and a PU partition mode (PU size) to be applied to the encoding target CTU of the encoding target picture. Furthermore, the encoding mode determination unit 26 determines the encoding mode for each CU included in the encoding target CTU. Further, the encoding mode determination unit 26 determines a prediction vector for each PU included in a CU to which the inter prediction encoding mode is applied with reference to a prediction vector candidate list of the PU.

The encoding mode determination unit 26 calculates an encoding cost that is an estimated value of the code amount for each combination of the CU partition mode and the PU partition mode in order to determine the CU partition mode and the PU partition mode. Select the combination that minimizes the cost. The encoding mode determination unit 26 calculates a prediction error, that is, a pixel difference absolute value sum SAD according to the following equation in order to calculate the encoding cost.
SAD = Σ | OrgPixel-PredPixel |
Here, OrgPixel is the value of the pixel of interest in the picture to be encoded, for example, the value of the pixel included in the PU of interest, and PredPixel is the value of the pixel contained in the prediction block corresponding to the block of interest, as determined by the HEVC standard It is.
However, the encoding mode determination unit 26 may calculate the absolute value sum SATD of each pixel after Hadamard transform of the difference image between the encoding target CTU and the prediction block, instead of SAD.

Further, regarding the AMVP mode, when the amount of information necessary for encoding the difference vector MVD = (predicted vector−motion vector) is MVDCost, the encoding cost Cost is expressed by the following equation.
Cost = SAD + λ * MVDCost
However, λ is a scaler that adjusts the balance between SAD and MVDCost.

  The processing of the encoding mode determination unit 26 will be described in more detail with reference to FIG. Note that the encoding mode determination unit 26 does not select an invalid CU, and therefore does not calculate the encoding cost of the combination including the CU. Here, for simplification, it is assumed that CUSIZE = 32 and CUSIZE = 16 are effective.

  First, the encoding mode determination unit 26 sets CUSIZE to 32 in the CTU 2400. The encoding mode determination unit 26 calculates the cost PuCost of each PU 2402 included in the CU 2401 in order to determine the cost PuSizeCost for each PU partition mode PartMode in the encoding target CU. The encoding mode determination unit 26 calculates the PU cost for each of the AMVP mode and the Merge mode. At that time, the encoding mode determination unit 26 uses the usable prediction vector selected by the prediction vector candidate list generation unit 25 as the prediction vector. As described above, for the inter prediction restriction target PU, a prediction vector is selected from vectors common to the first temporary list and the second temporary list. If the prediction vector is invalid in both the AMVP mode and the Merge mode, that is, if there is no usable prediction vector candidate, the encoding mode determination unit 26 invalidates the inter prediction mode and the PU cost PuCost is also set. Invalid value, that is, a very large value.

  If the AMVP mode is invalid and the Merge mode is valid, that is, there is no prediction vector candidate usable for the AMVP mode, and there is a prediction vector candidate usable for the Merge mode, the encoding mode determination unit 26 The vector mode to be applied is the merge mode. The encoding mode determination unit 26 sets the PU cost PuCost as the merge mode cost MergeCost. Conversely, if the AMVP mode is valid and the Merge mode is invalid, the encoding mode determination unit 26 sets the applied vector mode as the AMVP mode. Then, the encoding mode determination unit 26 sets the PU cost PuCost as the AMVP mode cost AMVPCost. If both the AMVP mode and the Merge mode are valid, the encoding mode determination unit 26 determines that the vector mode to be applied is a mode corresponding to the minimum value of the AMVP mode cost AMVPCost and the Merge mode cost MergeCost. To do. The encoding mode determination unit 26 sets the minimum value as the PU cost PuCost.

  When the PU cost PuCost is calculated for all the PUs included in the CU, the encoding mode determining unit 26 calculates the sum PuSizeCost = ΣPuCost of the PU costs PuCost of all the PUs included in the CU for each PU partition mode. Calculate as PU split mode cost. The encoding mode determination unit 26 selects a PU partition mode corresponding to the minimum value of the PU partition mode cost among all the PU partition modes that can be set. Further, the encoding mode determination unit 26 sets the minimum value of the PU partition mode cost as the cost InterCu32Cost of the inter prediction encoding mode for the focused CU size (32 in this example).

  Furthermore, the encoding mode determination unit 26 calculates the cost IntraCu32Cost of the intra prediction encoding mode when CU is intra prediction encoded at CUSIZE = 32. In this case, for example, the encoding mode determination unit 26 generates a prediction block according to a prediction block creation method that can be selected in the intra prediction encoding mode defined in the HEVC standard, and for each prediction block, The cost is calculated according to the above SAD calculation formula. And the encoding mode determination part 26 should just make the minimum value of the cost for every prediction block the cost IntraCu32Cost.

  The coding mode determination unit 26 sets the coding mode corresponding to the minimum value among the cost IntraCu32Cost of the intra prediction coding mode and the cost InterCu32Cost of the inter prediction coding mode as the coding mode selected for the CU size. . The selected coding mode is represented by a flag predModeFlag (= intra prediction coding mode or inter prediction coding mode). The encoding mode determination unit 26 sets the minimum value as the cost Cu32Cost of CUSIZE = 32. Note that if there is an invalid PU in one of the PUs included in the CU, InterCu32Cost becomes an invalid value. In this case, the encoding mode determination unit 26 selects an intra prediction encoding mode for a CU with CUSIZE = 32.

  Next, the encoding mode determination unit 26 sets CUSIZE to 16, and performs the same processing. Finally, the encoding mode determination unit 26 obtains the minimum value of the cost Cu16Cost which is the sum of the costs of the four CUs of CUSIZE = 32 and the cost Cu32Cost of CUSIZE = 32. Then, the encoding mode determination unit 26 determines a CU size, a PU partition mode, and an encoding mode corresponding to the minimum value.

  The encoding mode determination unit 26 notifies the prediction encoding unit 27 of the determined CU partition mode, PU partition mode, and encoding mode for each CTU.

  The prediction encoding unit 27 generates a prediction block for each PU according to the encoding mode applied to the CU in the CTU determined by the encoding mode determination unit 26 for each CTU, and between the prediction block and the PU. By encoding the prediction error, encoded data of each CTU is generated.

  When the target CU is subjected to inter prediction encoding, the predictive encoding unit 27 performs motion compensation on a local decoding region or a local decoded picture based on a motion vector for each PU included in the CU. Generate. The local decoding area is an area (in this embodiment, a tile) obtained by encoding and decoding once by the encoder 11-1. A local decoded picture is obtained by combining local decoding regions obtained by the respective encoders.

  Moreover, the prediction encoding part 27 produces | generates a prediction block from the block adjacent to the PU about each PU contained in the CU, when the attention CU is intra prediction encoded. At that time, the prediction encoding unit 27 generates a prediction block according to the prediction mode determined by the encoding mode determination unit 26 among various prediction modes defined in HEVC, for example.

  The prediction encoding unit 27 performs a difference operation between the encoding target PU and the prediction block. Then, the predictive encoding unit 27 uses the difference value corresponding to each pixel in the PU obtained by the difference calculation as a prediction error signal.

  The prediction encoding unit 27 obtains a frequency signal representing a horizontal frequency component and a vertical frequency component of the prediction error signal for each TU by orthogonally transforming the prediction error signal of the encoding target CTU in units of TUs. For example, the predictive coding unit 27 obtains a set of DCT coefficients for each TU as a frequency signal by performing a discrete cosine transform (DCT) on the prediction error signal as an orthogonal transform process.

  Next, the predictive coding unit 27 quantizes the frequency signal to calculate a quantization coefficient of the frequency signal. This quantization process is a process that represents a signal value included in a certain section as one signal value. The fixed interval is called a quantization width. For example, the prediction encoding unit 27 quantizes the frequency signal by truncating a predetermined number of lower bits corresponding to the quantization width from the frequency signal. The quantization width is determined by the quantization parameter. For example, the predictive coding unit 27 determines a quantization width to be used according to a function representing a quantization width value with respect to a quantization parameter value. The function can be a monotonically increasing function with respect to the value of the quantization parameter, and is set in advance.

  Alternatively, a plurality of quantization matrices that define quantization widths corresponding to the frequency components in the horizontal direction and the vertical direction are prepared in advance and stored in a memory included in the prediction encoding unit 27. Then, the predictive coding unit 27 selects a specific quantization matrix among the quantization matrices according to the quantization parameter. Then, the predictive encoding unit 27 may determine the quantization width for each frequency component of the frequency signal with reference to the selected quantization matrix.

The predictive encoding unit 27 may determine the quantization parameter according to any of various quantization parameter determination methods corresponding to a moving image encoding standard such as HEVC. The predictive encoding unit 27 can use, for example, a quantization parameter calculation method for the MPEG-2 standard test model 5. For the quantization parameter calculation method for the MPEG-2 standard test model 5, refer to the URL specified at http://www.mpeg.org/MPEG/MSSG/tm5/Ch10/Ch10.html, for example. I want to be.
Since the predictive encoding unit 27 can reduce the number of bits used to represent each frequency component of the frequency signal by executing the quantization process, the amount of information included in the encoding target TU can be reduced. The prediction encoding unit 27 outputs the quantized coefficient to the entropy encoding unit 28 as encoded data.

  Further, the predictive encoding unit 27 generates a local decoding block from the quantization coefficient of the encoding target CTU. For this purpose, the predictive coding unit 27 inversely quantizes the quantization coefficient by multiplying the quantization coefficient by a predetermined number corresponding to the quantization width determined by the quantization parameter. By this inverse quantization, the frequency signal of the encoding target CTU, for example, a set of DCT coefficients for each TU is restored. Thereafter, the predictive encoding unit 27 performs inverse orthogonal transform processing on the frequency signal for each TU. For example, when the predictive encoding unit 27 calculates a frequency signal using DCT, the predictive encoding unit 27 performs inverse DCT processing on the restored frequency signal. By performing the inverse quantization process and the inverse orthogonal transform process on the quantized signal, a prediction error signal having the same level of information as the prediction error signal before encoding is reproduced.

The prediction encoding unit 27 adds the reproduced prediction error signal corresponding to the pixel to each pixel value of the prediction block. By executing these processes for each block, the prediction encoding unit 27 generates a local decoding block.
Each time the prediction encoding unit 27 generates a local decoding block, the prediction encoding unit 27 stores the local decoding block in a memory (not shown) included in the prediction encoding unit 27.

  Further, the predictive coding unit 27 may perform an in-loop filter process on the local decoding block.

  The memory included in the predictive encoding unit 27 temporarily stores locally generated local decoding blocks. A local decoding region is obtained by combining all local decoding blocks included in a region encoded by one encoder according to the encoding order of each block. The memory included in the predictive encoding unit 27 stores a predetermined number of local decoding areas that may be referred to by the encoding target picture, and when the number of local decoding areas exceeds the predetermined number, The local decoding areas with the oldest coding order are discarded in order.

  Note that the encoder 11-1 may acquire a local decoding region obtained by another encoder from another encoder and store it in a memory included in the predictive encoder 27. As a result, the encoder 11-1 can obtain the locally decoded picture by combining the local decoding regions, and thus can widen the reference range in the motion search.

  Further, the memory included in the predictive encoding unit 27 stores the motion vector of each PU for each local decoding block including the inter prediction encoded PU.

  The entropy encoding unit 28 outputs a bit stream obtained by entropy encoding the quantized signal output from the predictive encoding unit 27, the prediction error signal of the motion vector, syntax, and the like. Then, the control unit (not shown) combines the output bit streams in a predetermined order, and adds header information defined by an encoding standard such as HEVC, so that the encoded moving image data is can get.

  FIG. 25 is an operation flowchart of a moving image encoding process performed by the moving image encoding device 1. The moving image encoding apparatus 1 encodes a picture according to the following operation flowchart for each picture.

  The dividing unit 10 divides the picture into a plurality of areas (step S401). Each region includes at least one tile, and a boundary between two adjacent regions is a boundary between tiles. Each region is input to one of the encoders 11-1 to 11-n. The motion search unit 20 of each encoder calculates a motion vector for each applicable PU (step S402). The inter prediction restriction target CTU determination unit 22 of each encoder identifies a CTU that restricts the application of the inter prediction encoding mode based on the boundary position between the regions (step S403).

  In addition, the inter prediction restriction target CU determination unit 23 of each encoder identifies a CU that restricts application of the inter prediction coding mode within the CTU that restricts application of the inter prediction coding mode (step S404). Note that, in a CTU where application of the inter prediction coding mode is not restricted, application of the inter prediction coding mode is not restricted for CUs and PUs in the CTU.

  Then, the inter prediction restriction target PU determination unit 24 of each encoder identifies a PU that restricts the application of the inter prediction coding mode within the CU that restricts the application of the inter prediction coding mode (step S405). Note that in a CU in which application of the inter prediction coding mode is not restricted, application of the inter prediction coding mode is not restricted for PUs in the CU.

  The prediction vector candidate list generation unit 25 of each encoder generates a list of prediction vector candidates according to whether or not the PU restricts application of the inter prediction encoding mode (step S406).

  The encoding mode determination unit 26 of each encoder determines, for each CTU, the combination of CU and PU that minimizes the encoding cost and the encoding mode to be applied (step S407).

  The predictive encoding unit 27 of each encoder predictively encodes each CTU according to the determined encoding mode (step S408). Then, the entropy encoding unit 28 of each encoder performs entropy encoding on the encoded data obtained by the predictive encoding (step S409). Entropy-encoded encoded data output from each encoder is input to the multiplexing unit 12.

The multiplexing unit 12 arranges the encoded data of each region received from the encoders 11-1 to 11-n in a predetermined order, for example, raster scan order, and adds predetermined header information based on HEVC. Thus, encoded data of one picture is generated (step S410). Then, the multiplexing unit 12 outputs the encoded data of each picture according to the order of the pictures.
After step S410, the moving image encoding apparatus 1 ends the moving image encoding process.

  As described above, this moving image encoding apparatus divides a picture into a plurality of regions such that the boundary between tiles is a boundary between regions, and encodes using a different encoder for each region. Turn into. Each encoder included in the moving image encoding apparatus, among PUs included in an area to be encoded by itself, is used as a prediction vector candidate of a block in an area encoded by another encoder. Inter prediction restriction target PUs that may select a motion vector are identified. This moving image encoding apparatus, for inter prediction restriction PU, between a prediction vector candidate list created assuming that a temporal prediction vector exists and a prediction vector candidate list created assuming that no temporal prediction vector exists The candidate of the prediction vector common in is identified. The moving picture encoding apparatus determines a prediction vector from the identified candidates. For this reason, this video encoding device suppresses a shortage of usable prediction vector candidates without sharing information on motion vectors between encoders, thereby reducing the encoding efficiency. Can be suppressed.

  FIG. 26 is a configuration diagram of a computer that operates as a moving image encoding apparatus when a computer program that realizes the functions of the respective units of the moving image encoding apparatus according to the above-described embodiment or its modification is operated.

  The computer 100 includes a user interface unit 101, a communication interface unit 102, a storage unit 103, a storage medium access device 104, and a processor 105. The processor 105 is connected to the user interface unit 101, the communication interface unit 102, the storage unit 103, and the storage medium access device 104 via, for example, a bus.

  The user interface unit 101 includes, for example, an input device such as a keyboard and a mouse, and a display device such as a liquid crystal display. Alternatively, the user interface unit 101 may include a device such as a touch panel display in which an input device and a display device are integrated. Then, the user interface unit 101 outputs, to the processor 105, an operation signal for selecting moving image data to be encoded or encoded moving image data to be decoded in accordance with a user operation, for example. The user interface unit 101 may display the decoded moving image data received from the processor 105.

  The communication interface unit 102 may include a communication interface for connecting the computer 100 to a device that generates moving image data, for example, a video camera, and a control circuit thereof. Such a communication interface can be, for example, Universal Serial Bus (Universal Serial Bus, USB).

  Furthermore, the communication interface unit 102 may include a communication interface for connecting to a communication network according to a communication standard such as Ethernet (registered trademark) and a control circuit thereof.

  In this case, the communication interface unit 102 acquires moving image data to be encoded from another device connected to the communication network, and passes the data to the processor 105. Further, the communication interface unit 102 may output the encoded moving image data received from the processor 105 to another device via a communication network.

  The storage unit 103 includes, for example, a readable / writable semiconductor memory and a read-only semiconductor memory. The storage unit 103 stores a computer program for executing a moving image encoding process executed on the processor 105, and data generated during or as a result of these processes.

  The storage medium access device 104 is a device that accesses a storage medium 106 such as a magnetic disk, a semiconductor memory card, and an optical storage medium. For example, the storage medium access device 104 reads a computer program for moving image encoding processing executed on the processor 105 stored in the storage medium 106 and passes the computer program to the processor 105.

  The processor 105 includes, for example, a plurality of arithmetic circuits, and each arithmetic circuit realizes the function of an encoder by executing the moving image encoding processing computer program according to the above-described embodiment or modification. Then, the processor 105 generates encoded moving image data. The processor 105 stores the generated encoded moving image data in the storage unit 103 or outputs it to other devices via the communication interface unit 102.

  Note that the computer program capable of executing the functions of the respective units of the moving image encoding device 1 on the processor may be provided in a form recorded on a computer-readable medium. However, such a recording medium does not include a carrier wave.

  All examples and specific terms listed herein are intended for instructional purposes to help the reader understand the concepts contributed by the inventor to the present invention and the promotion of the technology. It should be construed that it is not limited to the construction of any example herein, such specific examples and conditions, with respect to showing the superiority and inferiority of the present invention. Although embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions and modifications can be made thereto without departing from the spirit and scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Moving image encoder 10 Dividing part 11-1 to 11-n Encoder 12 Multiplexing part 13 Shared memory 21 Restriction block specific | specification part 22 Inter prediction restriction | limiting target CTU determination part 23 Inter prediction restriction | limiting target CU determination part 24 Inter prediction Restriction PU determination unit 25 Prediction vector candidate list generation unit 26 Coding mode determination unit 27 Prediction encoding unit 28 Entropy encoding unit 30 Determination unit 31 Unrestricted list generation unit 32 First temporary list generation unit 33 Second temporary list generation Unit 34 common candidate specifying unit 100 computer 101 user interface unit 102 communication interface unit 103 storage unit 104 storage medium access device 105 processor 106 storage medium

Claims (4)

A video encoding device that encodes a picture included in a video,
A dividing unit for dividing the picture into a plurality of regions;
A plurality of encoders that encode different regions of the plurality of regions to generate encoded data;
A multiplexing unit that generates encoded data of the picture by arranging the encoded data output from each of the plurality of encoders in a predetermined order;
A first encoder of the plurality of encoders is
Encoding in a predetermined vector mode that defines a prediction vector generation method for a motion vector among a plurality of blocks obtained by dividing the first region encoded by the first encoder of the plurality of regions. Of a plurality of regions obtained by dividing another completed picture, a restriction target that refers to a referenced block included in a second region encoded by a second encoder of the plurality of encoders A restriction block identification unit for identifying a block;
As for the restriction target block, it is assumed that a motion vector is defined in the referenced block, and a plurality of predictions are performed according to the predetermined vector mode using a dummy vector instead of the motion vector of the referenced block. A first temporary list generation unit for generating a first temporary list including vector candidates;
As for the restriction target block, a second temporary list that generates a second temporary list including a plurality of prediction vector candidates according to the predetermined vector mode on the assumption that no motion vector is defined in the referenced block. A generator,
A common candidate specifying unit that makes a prediction vector candidate usable as a prediction vector candidate when the prediction vector candidates at the same position are the same between the first temporary list and the second temporary list When,
When the restriction target block is encoded in the inter prediction encoding mode, the prediction encoded data of the first region is generated by using any of the usable prediction vector candidates as the prediction vector. A predictive coding unit;
An entropy encoding unit that generates the encoded data by entropy encoding the predictive encoded data;
A moving picture encoding apparatus having:   The common candidate specifying unit, when a motion vector is defined in a block including a predetermined position overlapping the restriction target block on the other picture, the prediction vector candidate registered in the first temporary list The video encoding apparatus according to claim 1, wherein a candidate not derived from the dummy vector is used as a candidate for the usable prediction vector. Divide a picture contained in a moving image into multiple areas,
The different regions of the plurality of regions are respectively encoded by different encoders of the plurality of encoders to generate encoded data,
Arranging the encoded data of each of the plurality of regions in a predetermined order to generate encoded data of the picture,
Generating the encoded data includes:
A predetermined encoder that defines a prediction vector generation method for a motion vector among a plurality of blocks obtained by dividing a first region of the plurality of regions by a first encoder of the plurality of encoders; In the vector mode, of the plurality of regions obtained by dividing another encoded picture, the referenced reference included in the second region encoded by the second encoder of the plurality of encoders Identify restricted blocks that reference the block,
Assuming that a motion vector is defined in the referenced block for the restriction target block by the first encoder, and using a dummy vector instead of the motion vector of the referenced block, Generating a first temporary list including a plurality of prediction vector candidates according to the predetermined vector mode;
Assuming that a motion vector is not defined in the referenced block for the restriction target block by the first encoder, a second temporary vector including a plurality of prediction vector candidates according to the predetermined vector mode. Generate a list
Prediction that can be used by the first encoder when the prediction vector candidates at the same position are the same between the first temporary list and the second temporary list. A vector candidate
When the first encoder encodes the restriction target block in the inter prediction encoding mode, any one of the usable prediction vector candidates is used as the prediction vector. Generate predictive encoded data for the region,
The encoded data is generated by entropy encoding the predictive encoded data by the first encoder.
A moving picture encoding method including the above. Divide a picture contained in a moving image into multiple areas,
Each of the different regions of the plurality of regions is individually encoded to generate encoded data,
A moving picture encoding computer program for causing a computer to generate the encoded data of the picture by arranging the encoded data of each of the plurality of regions in a predetermined order,
Generating the encoded data includes:
Among a plurality of blocks obtained by dividing the first region of the plurality of regions, a plurality of regions obtained by dividing another encoded picture in a predetermined vector mode that defines a prediction vector generation method for a motion vector Identifying a restriction target block that refers to a referenced block included in a second area different from the first area,
As for the restriction target block, it is assumed that a motion vector is defined in the referenced block, and a plurality of predictions are performed according to the predetermined vector mode using a dummy vector instead of the motion vector of the referenced block. Generate a first temporary list containing candidate vectors,
For the restriction target block, assuming that no motion vector is defined in the referenced block, generate a second temporary list including a plurality of prediction vector candidates according to the predetermined vector mode,
When the prediction vector candidates at the same position between the first temporary list and the second temporary list are the same, the prediction vector candidates are used as possible prediction vector candidates,
When encoding the restriction target block in the inter prediction encoding mode, by using any of the usable prediction vector candidates as the prediction vector, the prediction encoded data of the first region is generated. ,
Generating the encoded data by entropy encoding the predictive encoded data;
A computer program for encoding a moving image.

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