JP2013232775A - Moving image decoding device and moving image coding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve coding efficiency of coded data in which each layer is coded by a different coding system.SOLUTION: A moving image decoding device comprises: a variable-length decoding unit 13 that decodes a motion vector used in decoding a first layer; a motion information normalization unit 22 that derives an intermediate motion vector on the basis of the decoded motion vector; and a motion information conversion processing unit 20 that derives a motion vector used in decoding a second layer with reference to the derived intermediate motion vector.

Description

  The present invention relates to a moving picture decoding apparatus that decodes hierarchically encoded data and a moving picture encoding apparatus that generates encoded data by hierarchically encoding an image.

  In order to efficiently transmit or record a moving image, a moving image encoding device (encoding device) that generates encoded data by encoding the moving image, and decoding by decoding the encoded data A video decoding device (decoding device) that generates an image is used.

  As a specific moving image encoding method, hierarchical encoding is used in which moving images are encoded hierarchically according to a required data rate. Hierarchical coding methods include ISO / IEC and ITU-T standards as H.264 standards. H.264 / AVC Annex G Scalable Video Coding (SVC) (Non-Patent Document 1).

  In SVC, encoded data can be made into two layers (hierarchies) of a base layer (lower layer) and an enhancement layer (upper layer). Thereby, for example, in the decoding device, it is possible to realize low-quality reproduction referring only to the base layer and high-quality reproduction referring to the base layer and the enhancement layer.

  In addition, SVC supports spatial scalability, temporal scalability, and SNR scalability. For example, in the case of spatial scalability, an image obtained by down-sampling an original image to a desired resolution is used as a lower layer. It is encoded with H.264 / AVC. In the upper layer, inter-layer prediction is performed in order to remove redundancy between layers. As inter-layer prediction, there is motion information prediction in which information related to motion prediction is predicted from information in lower layers at the same time, or intra-layer prediction in which prediction is performed from an image obtained by up-sampling a decoded image of a lower layer at the same time (non- Patent Document 2).

  Non-Patent Document 3 describes a method employed in HM (HEVC TestModel) software as an encoding method.

  Also, with the development of network networks such as the Internet, there is also a transmission method called hybrid delivery that distributes content data using multiple routes, especially heterogeneous networks, such as broadcast and communication, unicast communication and multicast communication. Proposed. A receiving terminal that has received data distributed by hybrid transmission can display data received from a plurality of routes on the screen as one data by synchronizing, superimposing, synthesizing, or the like. By using the hybrid transmission, it is possible to broadcast the base layer data and the hybrid transmission of the extension layer data via the communication network for the scalable encoded (SVC) moving image.

ISO / IEC 14496-2: 2004 (June 1, 2004) ITU-T H.264 Advanced video coding for generic audiovisual services (March 2010) Draft ISO / IEC 23008-HEVC: 201x (E): High efficiency video coding (HEVC) text specification draft 6

  However, in the conventional scalable coding (SVC), when different coding methods are used for each layer, a configuration in which encoding and decoding of each layer is performed independently or an encoding method of an enhancement layer is changed to that of the base layer. Encoding can be performed only with a configuration depending on the encoding method. In other words, when the encoding method differs between the base layer and the enhancement layer, the encoding information used for the encoding of the base layer cannot be used for the encoding of the enhancement layer.

  For example, in an existing broadcasting system, MPEG-2 or H.264 is used as an encoding method. H.264 / AVC is adopted, but the basic layer is MPEG-2 or H.264. When encoded by H.264 / AVC, MPEG-2 or H.264 is used in the enhancement layer. When encoding by an encoding method different from H.264 / AVC, for example, HEVC, it is necessary to perform encoding / decoding with a configuration independent of the base layer.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to perform enhancement layer coding even when the base layer coding scheme and the enhancement layer coding scheme are different in scalable coding. It is to realize a moving picture decoding apparatus and the like that can use encoded information used for encoding a base layer.

  In order to solve the above problem, a video decoding device according to the present invention is a video decoding device that decodes encoded data composed of a plurality of layers having different encoding methods, and includes a plurality of layers. With reference to the motion vector information included in the first layer, the first layer motion vector decoding means for decoding the motion vector used for decoding the first layer and the first layer motion vector decoding means An intermediate motion vector deriving unit for deriving an intermediate motion vector based on the motion vector, and an intermediate motion vector derived by the intermediate motion vector deriving unit with reference to the second of the plurality of layers And second layer motion vector deriving means for deriving a motion vector used for layer decoding.

  According to said structure, since a 2nd layer motion vector is derived | led-out based on the motion vector contained in a 1st layer, code amount can be reduced and encoding efficiency can be improved. In addition, since the intermediate motion vector deriving unit is provided, it is possible to cope with a case where various encoding methods are used as the first layer and the second ear.

  In the moving picture decoding apparatus according to the present invention, the intermediate motion vector deriving means converts the motion vector decoded by the first layer motion vector decoding means into a value separated by a predetermined frame to obtain an intermediate motion vector. It may be a thing.

  According to the above configuration, since the motion vector of the first layer is converted into a format that does not depend on the encoding method of the first layer, even if the encoding method of the second layer does not depend on the first layer. Second, the motion vector of the first layer can be used for layer decoding. Thereby, encoding efficiency can be improved.

  Here, converting to a value separated by a predetermined frame means that the length of the decoded motion vector is a predetermined number of frames (for example, one frame) or a time distance corresponding to a predetermined field (for example, one field). To convert to a value.

  In the video decoding device according to the present invention, the first layer includes a motion vector derived using a plurality of fields for one frame, and the intermediate motion vector deriving means includes the second layer. Based on the motion vector derived using the field corresponding to the processing target frame among the plurality of fields in the first layer frame corresponding to the processing target frame. The intermediate motion vector may be derived.

  According to the above configuration, even if the first layer includes motion vectors derived using a plurality of fields for one frame, the motion vectors can be derived from the corresponding fields. Thereby, a motion vector can be appropriately derived.

  In the moving picture decoding apparatus according to the present invention, the intermediate motion vector deriving means converts the motion vector used for the second layer decoding target frame into a motion vector in the first layer frame corresponding to the processing target frame. Based on this, the intermediate motion vector may be derived.

  According to the above configuration, a motion vector can be derived from a frame corresponding to a processing target frame. Thereby, a motion vector can be appropriately derived.

  In the moving picture decoding apparatus according to the present invention, the intermediate motion vector deriving means includes a motion in a prediction direction required in the second layer in the first layer frame corresponding to the decoding target frame in the second layer. When the vector is not included, the intermediate motion vector may be derived based on the motion vector included in the reference frame closest to the frame of the first layer in the encoding order.

  According to said structure, even if it is a case where a motion vector is not contained in the flame | frame corresponding to the process target frame, a motion vector can be derived | led-out appropriately.

  In order to solve the above problem, a video decoding device according to the present invention is a video decoding device that decodes encoded data composed of a plurality of layers having different encoding methods, and includes a plurality of layers. With reference to the motion vector information included in the first layer, the first layer motion vector decoding means for decoding the motion vector used for decoding the first layer and the first layer motion vector decoding means Second layer motion vector deriving means for deriving a motion vector used for decoding the second layer of the plurality of layers based on the reference relationship between the motion vector and the reference frame of the second layer. It is a feature.

  According to said structure, since a 2nd layer motion vector is derived | led-out based on the motion vector contained in a 1st layer, code amount can be reduced and encoding efficiency can be improved.

  In the video decoding device according to the present invention, the first layer includes motion vectors derived using a plurality of fields for one frame, and the second layer motion vector deriving means includes the second layer A motion vector used for a decoding target frame of the layer is based on a motion vector derived using a field corresponding to the processing target frame among a plurality of fields in the first layer frame corresponding to the processing target frame. The second layer motion vector may be derived.

  According to the above configuration, even if the first layer includes motion vectors derived using a plurality of fields for one frame, the motion vectors can be derived from the corresponding fields. Thereby, a motion vector can be appropriately derived.

  In the moving image decoding apparatus according to the present invention, the second layer motion vector deriving means uses the motion vector used for the second layer decoding target frame as the motion vector in the first layer frame corresponding to the processing target frame. Based on the above, the second layer motion vector may be derived.

  According to the above configuration, a motion vector can be derived from a frame corresponding to a processing target frame. Thereby, a motion vector can be appropriately derived.

  In order to solve the above-described problem, a video encoding apparatus according to the present invention is encoded data including a plurality of layers having different encoding methods, and each layer includes an original image and a predicted image. In a video encoding device that generates encoded data including a prediction residual that is a difference, an intermediate motion vector deriving unit that derives an intermediate motion vector based on a motion vector used for decoding of the first layer, and Referring to the intermediate motion vector derived by the intermediate motion vector deriving means, second layer motion vector derivation for deriving the motion vector used for generating the predicted image for generating the second layer encoded data And means.

  According to said structure, since the motion vector of a 2nd layer is derived | led-out based on the motion vector used for the decoding of a 1st layer, code amount can be reduced and encoding efficiency can be improved. Further, by deriving the intermediate motion vector, it is possible to cope with cases where various encoding methods are used as the first layer and the second layer.

  In order to solve the above-described problem, a video encoding apparatus according to the present invention is encoded data including a plurality of layers having different encoding methods, and each layer includes an original image and a predicted image. In the video encoding device that generates encoded data including a prediction residual that is a difference, the second layer code is based on the reference relationship between the motion vector used for decoding the first layer and the reference frame of the second layer. It is characterized by comprising second layer motion vector deriving means for deriving a motion vector used for generating the predicted image for generating the quantized data.

  According to said structure, since a 2nd layer motion vector is derived | led-out based on the motion vector contained in a 1st layer, code amount can be reduced and encoding efficiency can be improved.

  As described above, the moving picture decoding apparatus according to the present invention is a moving picture decoding apparatus that decodes encoded data including a plurality of layers having different encoding schemes, and is the first of the plurality of layers. By referring to the motion vector information included in one layer, the first layer motion vector decoding means for decoding the motion vector used for decoding the first layer, and the motion vector decoded by the first layer motion vector decoding means Based on the intermediate motion vector deriving means for deriving the intermediate motion vector, and decoding the second layer of the plurality of layers with reference to the intermediate motion vector derived by the intermediate motion vector deriving means And a second layer motion vector deriving unit for deriving a motion vector used for.

  According to said structure, since a 2nd layer motion vector is derived | led-out based on the motion vector contained in a 1st layer, there exists an effect that code amount can be reduced and encoding efficiency can be improved. In addition, since the intermediate motion vector deriving unit is provided, there is an effect that it is possible to cope with cases where various encoding methods are used as the first layer and the second layer.

  The moving picture decoding apparatus according to the present invention is a moving picture decoding apparatus that decodes encoded data composed of a plurality of layers having different encoding schemes, and is applied to a first layer of the plurality of layers. With reference to the included motion vector information, based on the first layer motion vector decoding means for decoding the motion vector used for decoding the first layer, and the motion vector decoded by the first layer motion vector decoding means, A second layer motion vector deriving unit for deriving a motion vector used for decoding the second layer of the plurality of layers.

  According to said structure, since a 2nd layer motion vector is derived | led-out based on the motion vector contained in a 1st layer, there exists an effect that code amount can be reduced and encoding efficiency can be improved.

  In order to solve the above-described problem, a moving image encoding apparatus according to the present invention is encoded data including a plurality of layers having different encoding methods, and an original image and a predicted image are included in each layer. An intermediate motion vector deriving unit for deriving an intermediate motion vector based on a motion vector used for decoding of the first layer in a video encoding device that generates encoded data including a prediction residual that is a difference between A second layer motion for deriving a motion vector used for generating the predicted image for generating the second layer encoded data with reference to the intermediate motion vector derived by the intermediate motion vector deriving means Vector derivation means.

  According to said structure, since the motion vector of a 2nd layer is derived | led-out based on the motion vector used for the decoding of a 1st layer, there exists an effect that a code amount can be reduced and encoding efficiency can be improved. . Further, by deriving the intermediate motion vector, there is an effect that it is possible to cope with cases where various encoding methods are used as the first layer and the second layer.

  The video encoding apparatus according to the present invention is encoded data composed of a plurality of layers having different encoding methods, and each layer has a prediction residual that is a difference between an original image and a predicted image. A motion vector used for generating the predicted image for generating the second layer encoded data based on a motion vector used for decoding the first layer in a video encoding device that generates encoded data including Is provided with second layer motion vector deriving means for deriving.

  According to said structure, since a 2nd layer motion vector is derived | led-out based on the motion vector contained in a 1st layer, there exists an effect that a code amount can be reduced and encoding efficiency can be improved.

It is a block diagram which shows the principal part structure of the moving image decoding apparatus which concerns on embodiment of this invention. It is a figure for demonstrating the outline | summary of this invention. It is a figure for demonstrating the structure of the coding data which concern on embodiment of this invention, Comprising: (a) has shown the sequence layer which prescribes | regulates sequence SEQ, (b) is the picture which prescribes | regulates picture PICT (C) shows a slice layer that defines a slice S, (d) shows a tree block layer that defines a tree block TBLK, and (e) shows 2 shows a CU layer that defines a coding unit (CU) included in the tree block TBLK. FIG. 3 is a diagram illustrating a configuration of encoded data according to an embodiment of the present invention, where (a) is a diagram illustrating a configuration of a picture layer of encoded data, and (b) is a slice layer included in the picture layer. (C) is a figure which shows the structure of the macroblock layer contained in a slice layer, (d) is a figure which shows the structure of the block layer contained in a macroblock layer. It is a figure for demonstrating the field prediction and frame prediction in a frame structure, (a) is a figure which shows field prediction, (b) is a figure which shows frame prediction. It is a block diagram which shows the principal part structure of the inter estimation part of a moving image decoding apparatus. It is a figure for demonstrating the method of deriving a motion vector. It is a figure for demonstrating the method of deriving a motion vector. It is a figure for demonstrating the method of deriving a motion vector. It is a figure for demonstrating the method of deriving a motion vector. It is a figure which shows the motion information accumulate | stored in a motion information storage part. It is a flowchart which shows the flow of a decoding process of an enhancement layer. It is a flowchart which shows the flow of an inter prediction process. It is a figure which shows the table for deriving a motion compensation parameter. It is a flowchart which shows the flow of intermediate | middle motion information derivation processing. It is a flowchart which shows the flow of the motion estimation process between layers. It is a block diagram which shows the principal part structure of the moving image decoding apparatus which concerns on another embodiment of this invention. It is a figure for demonstrating the method of deriving a motion vector. It is a figure for demonstrating the method of deriving a motion vector. It is a figure which shows the motion information accumulate | stored in a motion information storage part. It is a block diagram which shows the principal part structure of the moving image encoder which concerns on embodiment of this invention. It is a block diagram which shows the principal part structure of the motion estimation / compensation part of a moving image encoder. It is a block diagram which shows the principal part structure of the moving image encoder which concerns on another embodiment of this invention. It is the figure shown about the structure of the transmitter which mounts the said moving image encoder, and the receiver which mounts the said moving image decoder. (A) shows a transmitting apparatus equipped with a moving picture coding apparatus, and (b) shows a receiving apparatus equipped with a moving picture decoding apparatus. It is the figure shown about the structure of the recording device which mounts the said moving image encoder, and the reproducing | regenerating apparatus which mounts the said moving image decoder. (A) shows a recording apparatus equipped with a moving picture coding apparatus, and (b) shows a reproduction apparatus equipped with a moving picture decoding apparatus.

Embodiment 1
The moving picture decoding apparatus 1 according to the present embodiment, when decoding encoded data that has been subjected to scalable coding (SVC), uses a coding method in the base layer (first layer) and an enhancement layer (second layer). Even if the encoding method is different, the encoding information used when decoding the base layer can be used when decoding the enhancement layer.

  More specifically, the base layer motion prediction information and prediction mode information are converted into a format that does not depend on the base layer encoding method, thereby performing processing dependent on the base layer encoding method in the enhancement layer. Rather, it can be referred to as an enhancement layer motion vector.

  As a result, it is possible to employ unique encoding methods for the base layer and the enhancement layer, respectively, and to improve the encoding efficiency. In this embodiment, when transmitting ultra-high-definition video (moving image, 4k video data), the ultra-high-definition video is scalable-coded, and the base layer downscales 4k video data for interlacing. Recorded video data is MPEG-2 or H.264. The following describes a case where the H.264 / AVC encoding is performed and transmitted on the television broadcasting network, and the enhancement layer is a case where 4k video is encoded by HEVC (progressive) and transmitted over the Internet. The encoding method is not limited to this.

(Encoded data # 1 (a, b))
Prior to detailed description of the video encoding device 2 and the video decoding device 1 according to the present embodiment, encoded data # 1 (generated by the video encoding device 2 and decoded by the video decoding device 1). The data structure of a and b) will be described. The encoded data # 1 includes a base layer (encoded data # 1b) and an enhancement layer (encoded data # 1a). The base layer and the enhancement layer may be supplied to the video decoding device 1 via different transmission paths, or may be supplied to the video decoding device 1 via the same transmission path. There may be.

  As an example, as shown in FIG. 2, a bit stream (encoded data # 1b) including a base layer is transmitted by a broadcast wave, and a bit stream (encoded data # 1a) including an enhancement layer is transmitted by an Internet communication network. Can be mentioned.

  Further, as described above, the base layer is, for example, MPEG-2 or H.264. H.264 / AVC, and the enhancement layer is, for example, H.264. It is encoded by the HEVC (High Efficiency Video Coding) method, which is a successor to H.264 / MPEG-4 AVC. As described above, in the following description, a case where the base layer and the enhancement layer are encoded by different encoding methods will be described as an example, but this does not limit the present embodiment.

(Encoded data of enhancement layer # 1a)
FIG. 3 is a diagram showing a data structure (encoded data # 1a) of the enhancement layer of encoded data # 1. The encoded data # 1a illustratively includes a sequence and a plurality of pictures constituting the sequence.

  A hierarchical structure of data in the encoded data # 1a is shown in FIG. 3A to 3E respectively show a sequence layer that defines a sequence SEQ, a picture layer that defines a picture PICT, a slice layer that defines a slice S, and a tree block that defines a tree block TBLK. It is a figure which shows the CU layer which prescribes | regulates the coding unit (Coding Unit; CU) contained in a layer and tree block TBLK.

(Sequence layer)
In the sequence layer, a set of data referred to by the video decoding device 1 for decoding a sequence SEQ to be processed (hereinafter also referred to as a target sequence) is defined. As shown in FIG. 3A, the sequence SEQ includes a sequence parameter set SPS (Sequence Parameter Set), a picture parameter set PPS (Picture Parameter Set), an adaptive parameter set APS (Adaptation Parameter Set), and pictures PICT1 to PICTNP ( The NP includes the total number of pictures included in the sequence SEQ) and supplemental enhancement information (SEI).

  In the sequence parameter set SPS, a set of encoding parameters referred to by the video decoding device 1 in order to decode the target sequence is defined.

  In the picture parameter set PPS, a set of encoding parameters referred to by the video decoding device 1 for decoding each picture in the target sequence is defined. A plurality of PPS may exist. In that case, one of a plurality of PPSs is selected from each picture in the target sequence.

  The adaptive parameter set APS defines a set of coding parameters that the video decoding device 1 refers to in order to decode each slice in the target sequence. There may be a plurality of APSs. In that case, one of a plurality of APSs is selected from each slice in the target sequence.

(Picture layer)
In the picture layer, a set of data referred to by the video decoding device 1 for decoding a picture PICT to be processed (hereinafter also referred to as a target picture) is defined. As shown in FIG. 3B, the picture PICT includes a picture header PH and slices S1 to SNS (NS is the total number of slices included in the picture PICT).

  Hereinafter, when it is not necessary to distinguish each of the slices S1 to SNS, the subscripts may be omitted. The same applies to other data with subscripts included in encoded data # 1 described below.

  The picture header PH includes a coding parameter group that is referred to by the video decoding device 1 in order to determine a decoding method of the target picture. Note that the encoding parameter group is not necessarily included directly in the picture header PH, and may be included indirectly, for example, by including a reference to the picture parameter set PPS.

(Slice layer)
In the slice layer, a set of data referred to by the video decoding device 1 for decoding the slice S to be processed (also referred to as a target slice) is defined. As shown in FIG. 3C, the slice S includes a slice header SH and a sequence of tree blocks TBLK1 to TBLKNC (NC is the total number of tree blocks included in the slice S).

  The slice header SH includes an encoding parameter group that is referred to by the video decoding device 1 in order to determine a decoding method of the target slice. Slice type designation information (slice_type) for designating a slice type is an example of an encoding parameter included in the slice header SH.

  As slice types that can be specified by the slice type specification information, (1) I slice that uses only intra prediction at the time of encoding, (2) P slice that uses unidirectional prediction or intra prediction at the time of encoding, (3) B-slice using unidirectional prediction, bidirectional prediction, or intra prediction at the time of encoding may be used.

  Note that the slice header SH may include a reference to the picture parameter set PPS (pic_parameter_set_id) and a reference to the adaptive parameter set APS (aps_id) included in the sequence layer.

  Further, the slice header SH includes an ALF parameter FP that is referred to by an adaptive filter included in the video decoding device 1. Details of the ALF parameter FP will be described later.

(Tree block layer)
In the tree block layer, a set of data referred to by the video decoding device 1 for decoding a processing target tree block TBLK (hereinafter also referred to as a target tree block) is defined. Note that the tree block may be referred to as a coding tree block (CTB) or a maximum coding unit (LCU).

  The tree block TBLK includes a tree block header TBLKH and coding unit information CU1 to CUNL (NL is the total number of coding unit information included in the tree block TBLK). Here, first, a relationship between the tree block TBLK and the coding unit information CU will be described as follows.

  The tree block TBLK is divided into partitions for specifying a block size for each process of intra prediction or inter prediction and conversion.

  The partition of the tree block TBLK is divided by recursive quadtree partitioning. The tree structure obtained by this recursive quadtree partitioning is hereinafter referred to as a coding tree.

  Hereinafter, a partition corresponding to a leaf that is a node at the end of the coding tree is referred to as a coding node. In addition, since the encoding node is a basic unit of the encoding process, hereinafter, the encoding node is also referred to as an encoding unit (CU).

  That is, coding unit information (hereinafter referred to as CU information) CU1 to CUNL is information corresponding to each coding node (coding unit) obtained by recursively dividing the tree block TBLK into quadtrees.

  Also, the root of the coding tree is associated with the tree block TBLK. In other words, the tree block TBLK is associated with the highest node of the tree structure of the quadtree partition that recursively includes a plurality of encoding nodes.

  Note that the size of each coding node is half the size of the coding node to which the coding node directly belongs (that is, the partition of the node one layer higher than the coding node).

  Also, the size of the tree block TBLK and the size that each coding node can take are the size designation information of the minimum coding node and the maximum coding node and the minimum included in the sequence parameter set SPS of the coded data # 1. It depends on the difference in the hierarchical depth of the coding node. For example, when the size of the minimum coding node is 8 × 8 pixels and the difference in the layer depth between the maximum coding node and the minimum coding node is 3, the size of the tree block TBLK is 64 × 64 pixels. The size of the encoding node can take any of four sizes, namely, 64 × 64 pixels, 32 × 32 pixels, 16 × 16 pixels, and 8 × 8 pixels.

(Tree block header)
The tree block header TBLKH includes an encoding parameter referred to by the video decoding device 1 in order to determine a decoding method of the target tree block. Specifically, as shown in FIG. 3D, tree block division information SP_TBLK that specifies a division pattern of the target tree block into each CU, and a quantization parameter difference that specifies the size of the quantization step Δqp (qp_delta) is included.

  The tree block division information SP_TBLK is information representing a coding tree for dividing the tree block. Specifically, the shape and size of each CU included in the target tree block, and the position in the target tree block Is information to specify.

  Note that the tree block division information SP_TBLK may not explicitly include the shape or size of the CU. For example, the tree block division information SP_TBLK may be a set of flags indicating whether the entire target tree block or a partial region of the tree block is to be divided into four. In that case, the shape and size of each CU can be specified by using the shape and size of the tree block together.

  The quantization parameter difference Δqp is a difference qp−qp ′ between the quantization parameter qp in the target tree block and the quantization parameter qp ′ in the tree block encoded immediately before the target tree block.

(CU layer)
In the CU layer, a set of data referred to by the video decoding device 1 for decoding a CU to be processed (hereinafter also referred to as a target CU) is defined.

  Here, before describing specific contents of data included in the CU information CU, a tree structure of data included in the CU will be described. The encoding node is a node at the root of a prediction tree (PT) and a transform tree (TT). The prediction tree and the conversion tree are described as follows.

  In the prediction tree, the encoding node is divided into one or a plurality of prediction blocks, and the position and size of each prediction block are defined. In other words, the prediction block is one or a plurality of non-overlapping areas constituting the encoding node. The prediction tree includes one or a plurality of prediction blocks obtained by the above division.

  Prediction processing is performed for each prediction block. Hereinafter, a prediction block that is a unit of prediction is also referred to as a prediction unit (PU).

  Broadly speaking, there are two types of division in the prediction tree: intra prediction and inter prediction.

  In the case of intra prediction, there are 2N × 2N (the same size as the encoding node) and N × N division methods.

  In the case of inter prediction, the division method is 2N × 2N (the same size as the encoding node), 2N × N, 2N × nU, 2N × nD, N × 2N, nL × 2N, nR × 2N, and N XN etc. Note that 2N × nU indicates that a 2N × 2N encoding node is divided into two regions of 2N × 0.5N and 2N × 1.5N in order from the top. 2N × nD indicates that a 2N × 2N encoding node is divided into two regions of 2N × 1.5N and 2N × 0.5N in order from the top. nL × 2N indicates that a 2N × 2N coding node is divided into two regions of 0.5N × 2N and 1.5N × 2N in order from the left. nR × 2N indicates that a 2N × 2N coding node is divided into two regions of 1.5N × 2N and 0.5N × 1.5N in order from the left.

  In the transform tree, the encoding node is divided into one or a plurality of transform blocks, and the position and size of each transform block are defined. In other words, the transform block is one or a plurality of non-overlapping areas constituting the encoding node. The conversion tree includes one or a plurality of conversion blocks obtained by the above division.

  There are two types of division in the transformation tree: one in which an area having the same size as that of a coding node is assigned as a transformation block, and the other in division by recursive quadtree division as in the above-described division of a tree block.

  The conversion process is performed for each conversion block. Hereinafter, a transform block that is a unit of transform is also referred to as a transform unit (TU).

(Data structure of CU information)
Next, specific contents of data included in the CU information CU will be described with reference to FIG. As shown in FIG. 3E, the CU information CU specifically includes a skip flag SKIP, PT information PTI, and TT information TTI.

  The skip flag SKIP is a flag indicating whether or not the skip mode is applied to the target PU. When the value of the skip flag SKIP is 1, that is, when the skip mode is applied to the target CU, A part of the PT information PTI and the TT information TTI in the CU information CU are omitted. Note that the skip flag SKIP is omitted for the I slice.

  The PT information PTI is information related to the PT included in the CU. In other words, the PT information PTI is a set of information related to each of one or more PUs included in the PT, and is referred to when the moving image decoding apparatus 1 generates a predicted image. As shown in FIG. 3E, the PT information PTI includes prediction type information PType and prediction information PInfo.

  The prediction type information PType is information that specifies whether intra prediction or inter prediction is used as a predicted image generation method for the target PU.

  The prediction information PInfo is configured from intra prediction information or inter prediction information depending on which prediction method is specified by the prediction type information PType. Hereinafter, a PU to which intra prediction is applied is also referred to as an intra PU, and a PU to which inter prediction is applied is also referred to as an inter PU.

  Further, the prediction information PInfo includes information specifying the shape, size, and position of the target PU. As described above, the generation of the predicted image is performed in units of PU. Details of the prediction information PInfo will be described later.

  The TT information TTI is information regarding the TT included in the CU. In other words, the TT information TTI is a set of information regarding each of one or a plurality of TUs included in the TT, and is referred to when the moving image decoding apparatus 1 decodes residual data. Hereinafter, a TU may be referred to as a block.

  As shown in FIG. 3 (e), the TT information TTI includes TT division information SP_TT that specifies a division pattern of the target CU into each transform block, and quantized prediction residuals QD1 to QDNT (NT is the target CU). The total number of blocks contained in).

  Specifically, the TT division information SP_TT is information for determining the shape and size of each TU included in the target CU and the position within the target CU. For example, the TT division information SP_TT can be configured by a set of information (split_transform_unit_flag) indicating whether or not the target node is divided.

  For example, when the size of the CU is 64 × 64, each TU obtained by the division can take a size from 32 × 32 pixels to 4 × 4 pixels.

  Each quantized prediction residual QD is encoded data generated by the video encoding device 2 performing the following processes 1 to 3 on a target block that is a processing target block.

Process 1: DCT transform (Discrete Cosine Transform) of the prediction residual obtained by subtracting the prediction image from the encoding target image;
Process 2: Quantize the transform coefficient obtained in Process 1;
Process 3: Variable length coding is performed on the transform coefficient quantized in Process 2;
The quantization parameter qp described above represents the magnitude of the quantization step QP used when the moving image encoding apparatus 2 quantizes the transform coefficient (QP = 2qp / 6).

(Prediction information PInfo)
As described above, there are two types of prediction information PInfo: inter prediction information and intra prediction information.

  The inter prediction information includes a coding parameter that is referred to when the video decoding device 1 generates an inter prediction image by inter prediction. More specifically, the inter prediction information includes inter PU division information that specifies a division pattern of the target CU into each inter PU, and inter prediction parameters for each inter PU.

  The inter prediction parameters include a reference image index, an estimated motion vector index, and a motion vector residual.

  On the other hand, the intra prediction information includes an encoding parameter that is referred to when the video decoding device 1 generates an intra predicted image by intra prediction. More specifically, the intra prediction information includes intra PU division information that specifies a division pattern of the target CU into each intra PU, and intra prediction parameters for each intra PU. The intra prediction parameter is a parameter for designating an intra prediction method (prediction mode) for each intra PU.

(Base layer encoded data # 1b)
FIG. 4 is a diagram showing the data structure of the base layer of encoded data # 1 (encoded data # 1b). The encoded data # 1b includes, for example, a sequence and a GOP (Group of Pictures) composed of a plurality of picture groups constituting the sequence.

  The structure of the hierarchy below the picture layer is shown in FIG. 4A to 4D are diagrams showing the structures of the picture layer P, the slice layer S, the macroblock layer MB, and the block layer B, respectively.

  The picture layer P is a set of data referred to by the video decoding device 1 in order to decode the corresponding picture. As shown in FIG. 4A, the picture layer P includes a picture header PH and slice layers S1 to SNs (Ns is the total number of slice layers included in the picture layer P).

  The picture header PH includes a coding parameter group that is referred to by the video decoding device 1 in order to determine a decoding method of the corresponding picture. For example, a number (temporal reference) indicating the display order of images used in encoding by the moving image encoding device 2 and a code (picture type) indicating a difference between I picture, P picture, and B picture are pictures. It is an example of the encoding parameter contained in header PH.

  Each slice layer S included in the picture layer P is a set of data referred to by the video decoding device 1 in order to decode the corresponding slice. As shown in FIG. 4B, the slice layer S includes macroblock layers MB1 to MBNm (Nm is the total number of macroblocks included in the slice S).

  Each macroblock layer MB included in the slice layer S is a set of data that the video decoding device 1 refers to in order to decode the corresponding macroblock. As shown in FIG. 4C, the macroblock layer MB is a square pixel block of 16 pixels × 16 lines, and is composed of two 8-pixel × 8-line color difference blocks Cb and Cr corresponding to the luminance blocks Y1 to Y4. The block is further subdivided into 8 pixel × 8 pixel line blocks which are DCT processing units. This corresponds to two 8-pixel × 16-line color difference blocks when the color difference format of the encoded image is 4: 2: 0 and the color difference format of the encoded image is 4: 2: 2. The 4: 4: 4: color difference format corresponds to two 16 pixel × 16 line color difference blocks. Each block layer B included in the macroblock layer MB is usually composed of data that has been DCT transformed and quantized.

(Moving picture decoding apparatus 1)
Next, the video decoding device 1 according to the present embodiment will be described with reference to FIGS. 1 and 6. The moving picture decoding apparatus 1 includes, as part thereof, a method adopted in MPEG-2, H.264, and H.264. H.264 / MPEG-4. A method adopted in AVC, a method adopted in KTA software, which is a codec for joint development in VCEG (Video Coding Expert Group), and a method adopted in TMuC (Test Model under Consideration) software, which is the successor codec And the technology employed in HM (HEVC TestModel) software.

  FIG. 1 is a block diagram showing a configuration of the moving picture decoding apparatus 1. As shown in FIG. 1, the moving picture decoding apparatus 1 includes an enhancement layer decoding unit (HEVC) 10 and a base layer decoding unit (MPEG-2) 11.

  The enhancement layer decoding unit 10 includes a variable length decoding unit 13, an inverse orthogonal transform / inverse quantization unit 14, an in-loop filter 15, an intra prediction unit 16, an expansion / IP conversion unit 17, a frame memory 18, an inter prediction unit 19, a motion An information conversion processing unit 20, a motion information storage unit 21, a motion information normalization unit 22, a selection unit 23, and an adder 24 are included.

  The enhancement layer decoding unit 10 performs a decoding process based on the decoded image and motion information decoded by the base layer decoding unit 11.

  The base layer decoding unit 11 includes a variable length decoding unit 31, an inverse orthogonal transform / inverse quantization unit 32, a frame memory 33, a motion compensation unit 34, and an adder 35.

  The base layer decoding unit 11 generates a decoded image based on motion information and intra prediction information decoded from the encoded data # 1b.

  The video decoding device 1 is a device for decoding the base layer of the encoded data # 1 by the base layer decoding unit 11 and the enhancement layer by the enhancement layer decoding unit 10, and the enhancement layer decoding unit 10 Decoding is performed using the encoded information (described later) decoded by the unit 11.

  The variable length decoding unit 13 decodes the quantized prediction residual QD for each block and the quantization parameter difference Δqp for the tree block including the block from the encoded data # 1a, and performs inverse orthogonal transform / inverse quantization To the unit 14. Further, the variable length decoding unit 13 decodes the prediction parameter PP related to each partition from the encoded data # 1a. That is, with respect to the inter prediction partition, the motion information and mode information such as the reference image index RI, the estimated motion vector index PMVI, and the motion vector residual MVD are decoded from the encoded data # 1, and these are transmitted to the inter prediction unit 19. Supply. On the other hand, with respect to the intra prediction partition, (1) decoding the intra prediction information including the size specifying information for specifying the size of the partition, and (2) the prediction index specifying information for specifying the prediction index, from the encoded data # 1, This is supplied to the intra prediction unit 16.

The inverse orthogonal transform / inverse quantization unit 14 (1) inversely quantizes the quantized prediction residual QD, (2) performs inverse DCT (Discrete Cosine Transform) conversion on the DCT coefficient obtained by the inverse quantization, and (3 ) The prediction residual D obtained by the inverse DCT transform is supplied to the adder 24. When the quantization prediction residual QD is inversely quantized, the inverse orthogonal transform / inverse quantization unit 14 derives a quantization step QP from the quantization parameter difference Δqp supplied from the variable length decoding unit 13. The quantization parameter qp can be derived by adding the quantization parameter difference Δqp to the quantization parameter qp ′ relating to the tree block that has just undergone inverse quantization / inverse DCT transformation, and the quantization step QP is performed from the quantization step qp to QP. = 2 ^{pq / 6} . The generation of the prediction residual D by the inverse orthogonal transform / inverse quantization unit 14 is performed in units of blocks (transform units).

  The in-loop filter 15 performs deblocking processing and filtering processing using adaptive filter parameters on the decoded image supplied from the adder 24.

  The intra prediction unit 16 generates a prediction image related to each intra prediction partition. Specifically, a prediction image is generated from the intra prediction information decoded from the encoded data # 1 and the decoded image of the base layer supplied from the expansion / IP conversion unit.

  The expansion / IP conversion unit 17 expands the base layer decoded image decoded by the base layer decoding unit 11 and supplies the image obtained by IP conversion to the intra prediction unit 16.

  The frame memory 18 stores a decoded image that has been filtered by the in-loop filter 15.

  The inter prediction part 19 produces | generates the motion compensation image regarding each inter prediction partition. Specifically, a motion compensated image is generated using motion information, mode information supplied from the variable length decoding unit 13, or motion information in the corresponding base layer supplied from the motion information conversion processing unit. The detailed configuration of the inter prediction unit 19 will be described later.

  The motion information normalization unit 22 converts the motion vector MV_BL in the corresponding macroblock of the base layer into an intermediate format MV_ITM (intermediate motion vector) that is aligned with the value when separated by one frame (field) in units of macroblocks. . Then, the converted intermediate format MV_ITM is supplied to the motion information storage unit.

  The motion information storage unit 21 stores the intermediate format MV_ITM converted by the motion information normalization unit 22 and supplies the intermediate format MV_ITM to the motion information conversion processing unit 20 in accordance with an instruction from the inter prediction unit 19. An example of information stored in the motion information storage unit 21 will be described with reference to FIG. As shown in FIG. 11, in the motion information storage unit 21, the field rate (v) in units of pictures is the direction of motion vectors (forward prediction motion vector, backward prediction motion vector) and horizontal components in units of macroblocks. Or information indicating whether the component is a vertical component is stored as motion information in association with the macroblock.

  The motion information conversion processing unit 20 scales the intermediate motion vector MV_ITM stored in the motion information storage unit 21 based on the picture reference relationship in the enhancement layer, and derives a motion vector MV_EL used by the inter prediction unit 19.

  The detailed contents of processing in the motion information normalization unit 22, the motion information storage unit 21, and the motion information conversion processing unit 20 will be described later.

  The selection unit 23 selects which one of the prediction image generated by the intra prediction unit 16 and the prediction image generated by the inter prediction unit 19 to use, and supplies the selected prediction image to the adder 24.

  The adder 24 generates a decoded image by adding the prediction image supplied from the selection unit 23 and the prediction residual D supplied from the inverse orthogonal transform / inverse quantization unit 14.

  The variable length decoding unit 31 is the variable length decoding unit 13, the inverse orthogonal transform / inverse quantization unit 32 is the inverse orthogonal transform / inverse quantization unit 14, the frame memory 33 is the frame memory 18, and the adder 35 is the adder 24. Since this has the same function, the description thereof is omitted.

  The motion compensation unit 34 restores the motion vector related to each inter prediction partition from the motion vector residual MVD related to that partition and the restored motion vector related to another partition, and generates an inter prediction image.

(Configuration of the inter prediction unit 19)
Next, the configuration of the inter prediction unit 19 will be described with reference to FIG. As illustrated in FIG. 6, the inter prediction unit 19 includes an enhancement layer motion vector buffer 901, a mode buffer 902, a motion compensation unit 903, and a base layer motion vector buffer 904.

  The enhancement layer motion vector buffer 901 stores the motion vector residual MVD supplied from the variable length decoding unit 13 and supplies it to the motion compensation unit 903 as enhancement layer motion vector information.

  The mode buffer 902 stores prediction mode information supplied from the variable length decoding unit 13.

  The base layer motion vector buffer 904 stores the base layer motion vector information supplied from the motion information conversion processing unit 20 and supplies the base layer motion vector information to the motion compensation unit 903.

  The motion compensation unit 903 generates an inter prediction image using either the enhancement layer motion vector information supplied from the enhancement layer motion vector buffer 901 or the base layer motion vector information supplied from the base layer motion vector buffer 904. , Supplied to the selector 23.

(Motion vector derivation method 1-1)
First, prior to the description of the motion vector derivation method, feed prediction and frame prediction will be described with reference to FIG. As shown in FIG. 5A, when performing field prediction, a motion vector is predicted from two fields for one picture. Prediction data is generated by two motion vectors from two identical or different fields.

  As shown in FIG. 5B, in the case of frame prediction, prediction data is generated from one frame by one motion vector.

  Next, the method of deriving the motion vector used by the inter prediction unit 19, in other words, the processing of the motion information normalization unit 22, the motion information storage unit 21, and the motion information conversion processing unit 20 will be described with reference to FIG. To do. Here, the motion vector derivation process used in the enhancement layer when field prediction in the frame structure is performed in the base layer will be described.

  FIG. 7 shows the arrangement of the frames in the display time order when the moving image decoding apparatus 1 decodes moving images. The base layer (BL) in FIG. 7 shows a field structure picture. For example, frame BB0 is a combination of fields B01 and B02 indicated by broken lines. The base layer frame BI2 is processed as an I picture, the frame BP5 is processed as a P picture, and the frames BB0, BB1, BB3, and BB4 are processed as B pictures. One frame can be handled as two fields. For example, the frame BB0 can be handled as fields B01 and B02, and the frame BB1 can be handled as fields B11 and B12. Here, it is assumed that each frame of the base layer is adaptively decoded in either a frame structure or a field structure.

  In the present embodiment, an example will be described in which a picture used for motion compensation in the base layer has a frame structure and field prediction is performed in units of fields.

  In the enhancement layer (EL) shown in FIG. 7, the picture of each frame corresponds to the picture of each field of the base layer. For example, the base layer field corresponding to the enhancement layer frame b0 is B01. Further, I4 of the enhancement layer is processed as an I picture, P10 is processed as a P picture, B1 and B7 are processed as reference B pictures, and b0, b2, b3, b6, b8, b9, and b11 are processed as non-reference B pictures.

  In this embodiment, the base layer and the enhancement layer are decoded in the order shown as “coding order” in FIG.

  Here, the current processing target is a frame B1, and the frame B1 uses an enhancement layer I4 as a backward reference picture and a base layer BB0 (fields B01 and B02) as an inter-layer reference picture. These reference pictures have already been decoded when the processing target frame B1 is decoded.

  Also, the frame (field) of the lower layer (base layer) corresponding to the current processing target frame of the enhancement layer is specified based on the time information included in the bit stream of each layer. The identification of the corresponding frame is not limited to the configuration based on the time information, and may be performed by a configuration in which a common picture number is assigned to the base layer and the enhancement layer, for example.

  Consider a case where the motion vector MV_EL (1) _a used in the prediction block PU of the frame B1 is derived from the base layer. In this case, the motion vector used when processing the macroblock a in the prediction block PU of the base layer frame BB0 corresponding to the frame B1 is used. In the present embodiment, the macroblock a is a macroblock a that is a base layer macroblock located at coordinates corresponding to the center point of the prediction block PU of the frame B1. Here, the macroblock of the base layer is specified based on the coordinates of the center point of the PU of the prediction block, but the macroblock of the base layer may be specified based on the coordinates of the upper left corner of the PU and other end points, However, the present invention is not limited to this.

  As described above, the frame BB0 is processed by field prediction as a frame structure. Here, the frame BB0 is referred to as the backward reference picture, referring to the fields I21 and I22, and the macroblock a refers to the respective reference pictures and is processed by the motion vectors MV_BL (1-1) _a and MV_BL (1-2) _a. It is assumed that

  Since the macro block a calculates a motion vector by field prediction, the reference source fields of MV_BL (1-1) _a and MV_BL (1-2) _a are B01 and B02, respectively. Since the base layer field corresponding to the processing target frame b1 is B02, the inter prediction unit 19 uses the intermediate motion vector MV_ITM (1) _a stored in the motion information storage unit 21 to convert it. Motion compensation is performed using the motion vector MV_EL (1) _a.

  Specifically, first, the inter prediction unit 19 specifies the frame BB0 of the base layer corresponding to B1 to be processed. Of the motion vector information (MV_BL (1-1) _a, MV_BL (1-2) _a) used when processing the corresponding macroblock of the frame BB0, the frame of the base layer corresponding to B1 to be processed An intermediate motion vector MV_ITM (1) _a obtained by normalizing the motion vector MV_BL (1-2) _a used when processing B02 is supplied from the motion information storage unit 21 to the motion information conversion processing unit 20.

  Here, it is assumed that the intermediate motion vector MV_ITM (1) _a stored in the motion information storage unit 21 is already normalized and stored by the motion information normalization unit 22 when the prediction block PU is decoded. The intermediate motion vector MV_ITM (1) _a is calculated by the motion information normalization unit 22 from the motion vector MV_BL (1-2) _a using Equation (1).

MV_ITM (1) _a = MV_BL (1-2) _a × tb_a / td_a Formula (1)
Here, tb is a time interval indicating a distance one frame away from the processing target frame, and td is a frame from which the motion vector MV_BL (1-2) _a used for decoding the target base layer is calculated. This is a time interval indicating the distance between B02 and the frame I22.

  Next, the motion information conversion processing unit 20 calculates a motion vector MV_EL (1) _a to be used according to Expression (2).

MV_EL (1) _a = MV_ITM (2) _a × tde_a / tb_a × scaling formula (2)
Here, the scaling processing is EL resolution / BL resolution, and tde is a time interval indicating a distance one frame away from the target frame B1.

  In this embodiment, the frame rate (field rate) is the same for the base layer and the enhancement layer. However, if the frame rate is different and multiplied, the enhancement layer frame rate / base layer The MV_EL may be obtained by multiplying the MV_ITM by the frame rate and adjusting the scale in the time direction. The base layer frame rate can be acquired from the sequence header in the case of MPEG-2.

  Moreover, although the decoding process was demonstrated above, the same process is performed also in the encoding process in the moving image encoding device 2. FIG.

(Motion vector deriving method 1-2)
Next, the motion vector derivation process used in the enhancement layer when frame prediction is performed in the frame structure in the base layer will be described with reference to FIG.

  Here, it is assumed that the decoding target is b2. First, the inter prediction unit 19 specifies the frame BB1 of the base layer corresponding to b2 to be processed. Then, an intermediate motion vector MV_ITM (1) _b obtained by normalizing the motion vector MV_BL (1) _b used when processing the corresponding macroblock of the frame BB1 is supplied from the motion information storage unit 21 to the motion information conversion processing unit 20. Let

  Here, it is assumed that the intermediate motion vector MV_ITM (1) _b stored in the motion information storage unit 21 is already normalized and stored by the motion information normalization unit 22 when the prediction block PU is decoded. The intermediate motion vector MV_ITM (1) _b is calculated by the motion information normalization unit 22 from the motion vector MV_BL (1) _b using equation (3).

MV_ITM (1) _b = MV_BL (1) _b × tb_b / td_b Formula (3)
Next, the motion information conversion processing unit 20 calculates a motion vector MV_EL (1) _b to be used according to Equation (4).

MV_EL (1) _b = MV_ITM (2) _b × tde_b / tb_b × scaling formula (4)
(Motion vector derivation method 1-3)
Next, another example of the motion vector derivation process used in the enhancement layer when field prediction in the frame structure is performed in the base layer will be described with reference to FIG.

  Here, it is assumed that the decoding target is b9. The inter prediction unit 19 specifies the frame BB4 of the base layer corresponding to b9. Since motion vector information in the same prediction direction is not stored in the motion information storage unit 21 in the corresponding macrobook of the frame BB4, it corresponds to P10 which is the nearest reference frame in the encoding order from b9 which is the decoding target frame. The motion vector information of the corresponding macroblock in the base layer frame BP5 is referred to. Among the motion vectors used when processing the anchor macroblock at the corresponding position in the frame BP5, that is, the fields P51 and P52, MV_BL (1-1) _c and MV_BL (1-2 ) _C. The intermediate motion vector MV_ITM (1-1) _c or MV_ITM (1-1) _c calculated from _c is supplied from the motion information storage unit 21 to the conversion unit 220. Here, the intermediate motion vector MV_ITM (1-1) _c is supplied. Note that both the intermediate motion vector MV_ITM (1-1) _c and MV_ITM (1-1) _c may be supplied.

  The motion information normalization unit 22 here assumes that the intermediate motion vector MV_ITM (1) _c is already normalized and accumulated when the prediction block PU is decoded. The intermediate motion vector MV_ITM (1) _c is calculated by the motion information normalization unit 22 using the equation (5) from the motion vector MV_BL (1-1) _b.

MV_ITM (1) _c = MV_BL (1-1) _c × tb_c / td_c Formula (5)
Next, the motion information conversion processing unit 20 calculates a motion vector MV_EL (1) _c to be used according to Equation (6).

MV_EL (1) _c = MV_ITM (2) _c × tde_c / tb_c × scaling formula (6)
(Motion vector deriving method 1-4)
Next, another example of motion vector derivation processing used in the enhancement layer when frame prediction is performed in the frame structure in the base layer will be described with reference to FIG.

  Here, it is assumed that the decoding target is b9. The inter prediction unit 19 specifies the frame B42 of the base layer corresponding to b9. Since motion vector information in the same prediction direction is not stored in the motion information storage unit 21 in the corresponding macrobook of the frame B42, it corresponds to P10 which is the nearest reference frame in the encoding order from b9 which is the decoding target frame. In the base layer frame BP5, that is, in the fields P51 and P52, the intermediate vector calculated from MV_BL (1) _d which is the motion vector in the same prediction direction among the motion vectors used when the anchor macroblock at the corresponding position is processed The motion vector MV_ITM (1) _d is supplied from the motion information storage unit 21 to the motion information conversion unit 20.

  Here, it is assumed that the intermediate motion vector MV_ITM (1) _d is already normalized and accumulated by the motion information normalization unit 22 when the prediction block PU is decoded. The intermediate motion vector MV_ITM (1) _d is calculated by the motion information normalization unit 22 from the motion vector MV_BL (1-1) _d using equation (7).

MV_ITM (1) _d = MV_BL (1-1) _d × tb_d / td_d Equation (7)
Next, the motion information conversion processing unit 20 calculates a motion vector MV_EL (1) _d to be used according to Expression (8).

MV_EL (1) _d = MV_ITM (2) _d × tde_d / tb_d × scaling formula (8)
Here, when the motion vector in the prediction direction required in the enhancement layer is not included in the base layer, the intermediate motion vector is based on the motion vector included in the reference frame nearest to the frame in the encoding order. However, if the base layer contains a motion vector with a prediction direction different from the prediction direction required by the enhancement layer, an intermediate motion vector is derived based on the motion vector. Also good.

(Processing flow in the video decoding device 1)
Next, the flow of processing in the video decoding device 1 will be described with reference to FIGS.

  First, an enhancement layer decoding process flow will be described with reference to FIG. The enhancement layer decoding unit 10 constructs a reference image list used for decoding the target frame (S101). The reference image list includes the position of the decoded image of each reference image in the frame buffer and the output order of each reference image.

  Next, the base layer decoding unit 11 decodes a picture (frame or field) of a base layer necessary for decoding the target frame of the enhancement layer (S102). Then, the motion information normalization unit 22 executes an intermediate motion information derivation process for calculating intermediate motion vector information from the motion vector used for decoding the corresponding base layer picture (intermediate motion derivation process: S103). .

  Next, the code unit CU to be processed is set (S104), and the variable length decoding unit 13 decodes the side information of the target CU. The side information includes a CU prediction type (intra prediction mode and inter prediction mode identification information), a skip flag, and PU partition information (S105).

  Furthermore, the variable length decoding unit 13 decodes the transform coefficient in each TU in the target CU, and the inverse orthogonal transform / inverse quantization unit 14 performs inverse orthogonal transform / inverse quantization to decode the prediction residual (S106). ).

  If the prediction unit PU in the target CU is an intra CU that generates a prediction image by intra prediction (YES in S107), the intra prediction unit 16 predicts each prediction unit PU in the target CU by intra prediction. Is generated (S108).

  On the other hand, if the prediction unit PU in the target CU is an inter CU that generates a prediction image by inter prediction (NO in S107), the inter prediction unit 19 uses the inter prediction to calculate the prediction image of each PU in the target CU. Generate (inter prediction process: S109).

  When a decoded image is generated for the target CU (S110) and decoded images are generated for all CUs (YES in S111), a deblocking filter, an adaptive offset filter (SAO: Sample Adaptive Offset), and an adaptive loop are added to the decoded image. A filter (ALF: Alternative Loop Filter) is applied (S112), and the process ends.

  Next, the flow of the inter prediction process will be described with reference to FIG.

  In the inter prediction process, the inter prediction unit 19 first sets a target PU (S201) and decodes PU side information (S202). The PU side information includes a base layer prediction flag (base_mode_flag), a merge flag (merge_flag), and a merge index (merge_idx).

  If the target PU is not a merge PU to be merged (NO in S203), the motion compensation parameter of the PU is decoded (S205). On the other hand, if the target PU is a merge PU (YES in S203) and the base mode refers to the motion vector of the base layer (YES in S203), the enhancement layer decoding unit 10 performs an inter-layer motion estimation process ( Inter-layer motion estimation processing: S207). If the target PU is not the base mode (NO in S204), the inter prediction unit 19 derives a merge candidate (S206).

  Thereafter, the inter prediction unit 19 performs motion compensation using the motion compensation parameter derived in step S205, step S206, or step S207 to generate a predicted image (S208). Then, when the process is completed for all PUs (YES in S209), the inter prediction process is terminated.

  A table for deriving motion compensation parameters is shown in FIG. The motion compensation parameter derivation table shown in FIG. 14 associates CU side information and PU side information with a motion compensation parameter derivation method for the target PU. In FIG. 14, “0” and “1” indicate corresponding syntax values, and “−” indicates that decoding of the syntax elements is unnecessary.

  Next, the flow of the intermediate motion information derivation process will be described with reference to FIG.

  First, the motion information normalization unit 22 sets a base layer picture used for derivation as intermediate motion information (S301). Next, the motion information normalization unit 22 divides the target frame into basic processing units (in this embodiment, MPEG-2 macroblocks) (S302), and determines the position of the base layer picture corresponding to the target basic processing unit. The specified motion vector is read out (S303). Then, an intermediate motion vector MV_ITM is derived from the read motion vector (S304). When the processing is completed for all basic processing units (YES in S305), the intermediate motion information derivation processing ends.

  Next, the flow of the inter-layer motion estimation process will be described with reference to FIG. As illustrated in FIG. 16, first, the enhancement layer decoding unit 10 estimates the use flag of the reference image list. The use flag can be used for both L0 and L1 when there are two motion vectors in the intermediate motion information, and only L0 can be used when there is only one.

  Next, the enhancement layer decoding unit 10 sets a reference image list for referring to a motion vector used for decoding the target PU (S402). The reference image list is selected in the order of L0 → L1.

  The enhancement layer decoding unit 10 sets a reference image from the set reference image list (S403, refIdxLX = 0). Thereafter, the enhancement layer decoding unit 10 reads a motion vector from the intermediate motion information of the reference image, scales based on the display interval between the target frame and the reference image, and derives a motion vector (S404). When the processing is completed for all the reference image lists (S405), the inter-layer estimation processing is completed.

(Moving picture encoding device 2)
Next, the moving picture encoding apparatus 2 that generates encoded data # 1 (a, b) by encoding an encoding target image will be described with reference to FIGS. The moving image encoding apparatus 2 includes, in part, a method adopted in MPEG-2, H.264, and H.264. H.264 / MPEG-4. A method adopted in AVC, a method adopted in KTA software, which is a codec for joint development in VCEG (Video Coding Expert Group), and a method adopted in TMuC (Test Model under Consideration) software, which is the successor codec And the technology employed in HM (HEVC TestModel) software.

  FIG. 21 is a block diagram showing a configuration of the video encoding device 2 according to the present embodiment. As shown in FIG. 21, the moving picture coding apparatus 2 includes an enhancement layer coding unit (HEVC) 81, a base layer coding unit (MPEG-2) 82, and a reduction / interlacing processing unit 83. is there. Further, the enhancement layer encoding unit 81 includes an image rearrangement buffer 51, a motion information conversion processing unit 52, a motion information accumulation unit 53, a motion information normalization unit 54, a frame memory 55, a motion prediction / compensation unit 56, an enlargement / IP Transformer 57, intra-loop filter 58, intra prediction unit 59, selection unit 60, inverse orthogonal transform / inverse quantization unit 61, orthogonal transform / quantization unit 62, variable length coding unit 63, subtractor 64, adder 65 It is the structure containing.

  The base layer encoding unit 82 also includes an image rearrangement buffer 71, a motion estimation / motion compensation unit 72, a frame memory 73, an inverse orthogonal transform / inverse quantization unit 74, an orthogonal transform / quantization unit 75, and a variable length encoding. The unit 76 includes an adder 77 and a subtractor 78.

  The moving image encoding device 2 generates encoded data # 1 (a, b) including a base layer and an enhancement layer by performing scalable encoding (SVC) on moving image # 10 (encoding target image). It is.

  The image rearrangement buffer 51 and the image rearrangement buffer 71 are buffers for rearranging input images in the encoding order.

  The orthogonal transform / quantization unit 62 (1) performs DCT transform (Discrete Cosine Transform) on the prediction residual D obtained by subtracting the predicted image Pred from the encoding target image, and (2) DCT obtained by DCT transform. The coefficient is quantized, and (3) the quantized prediction residual QD obtained by the quantization is supplied to the variable length coding unit 63 and the inverse orthogonal transform / inverse quantization unit 61. The orthogonal transform / quantization unit 62 selects (1) a quantization step QP used for quantization for each tree block, and (2) a quantization parameter indicating the size of the selected quantization step QP. The difference Δqp is supplied to the variable length encoding unit 63, and (3) the selected quantization step QP is supplied to the inverse orthogonal transform / inverse quantization unit 61. Here, the quantization parameter difference Δqp is the quantization parameter qp for the tree block DCT transformed / quantized immediately before from the value of the quantization parameter qp (QP = 2pq / 6) for the tree block to be DCT transformed / quantized. The difference value obtained by subtracting the value of '.

  The variable length encoding unit 63 includes (1) a quantized prediction residual QD and Δqp supplied from the orthogonal transform / quantization unit 62, (2) intra prediction information supplied from the intra prediction unit 59, and (3) motion. The motion information supplied from the prediction / compensation unit 56 is variable-length encoded to generate encoded data # 1a.

  The motion prediction / compensation unit 56 detects the motion vector mv for each partition, and uses the detected motion vector mv and the reference image index RI that specifies the filtered decoded image used as the reference image, to compensate for the motion compensated image mc. Is generated. Details of the motion prediction / compensation unit 56 will be described later.

  The motion estimation / motion compensation unit 72 detects a motion vector mv related to each partition, and uses the detected motion vector mv and a reference image index RI that specifies a filtered decoded image used as a reference image, to compensate for a motion compensated image. Generate mc.

  The orthogonal transform / quantization unit 75 (1) performs DCT transform (Discrete Cosine Transform) on the prediction residual D obtained by subtracting the predicted image Pred from the encoding target image, and (2) DCT obtained by DCT transform. The coefficient is quantized, and (3) the quantized prediction residual QD obtained by the quantization is supplied to the variable length coding unit 76 and the inverse orthogonal transform / inverse quantization unit 74.

  The motion information conversion processing unit 52, the motion information storage unit 53, the motion information normalization unit 54, the frame memory 55, the expansion / IP conversion unit 57, the in-loop filter 58, the inverse orthogonal transform / inverse quantization unit 61, and the adder 65, the frame memory 73, and the inverse orthogonal transform / inverse quantization unit 74, the motion information conversion processing unit 20, the motion information storage unit 21, the motion information normalization unit 22, the frame memory 18, and the expansion / IP conversion unit 17 described above. The in-loop filter 15, the inverse orthogonal transform / inverse quantization unit 14, the adder 24, the frame memory 33, and the inverse orthogonal transform / inverse quantization unit 32 have the same functions, and thus description thereof is omitted.

(Motion prediction / compensation unit 56)
Next, the configuration of the motion prediction / compensation unit 56 will be described with reference to FIG. As shown in FIG. 22, the motion prediction / compensation unit 56 includes a motion search unit 911, a cost function calculation unit 912, a mode determination unit 913, and a motion compensation unit 914.

  The motion search unit 911 derives motion information from the input image information supplied from the image rearrangement buffer 51 and the reference image information supplied from the frame memory 55, and costs function calculation unit 912 as enhancement layer motion vector information. To supply.

  The cost function calculation unit 912 defines a cost function for motion vector information and mode determination.

  The mode determination unit 913 determines a prediction mode whether to perform merging using the cost function defined by the cost function calculation unit 912, to refer to the motion vector of the base layer, or to perform normal motion compensation processing.

  The motion compensation unit 914 selects an inter prediction process that minimizes the cost function as an optimum parameter, generates a prediction image, supplies the prediction image to the selection unit 60, and also supplies the motion compensation parameter and the motion vector information to the variable length coding unit 63. To supply.

  In the above-described embodiment, the calculated intermediate motion vector MV_ITM is converted and used as the enhancement layer motion vector MV_EL. However, the intermediate motion vector MV_ITM is expanded as one of motion vector candidates used in motion compensation. The motion compensation prediction processing of the layer may be performed, or may be used as a prediction vector in motion vector prediction. Further, in this embodiment, the picture used for motion compensation in the base layer has a frame structure, but processing may be performed in units of fields. In addition, although examples of frame prediction and field prediction will be described as prediction methods, even in the case of dual prime prediction in which an average of predictions from different fields is obtained for a macroblock, as described above, it is based on the reference relationship of pictures. Thus, it is possible to calculate an intermediate motion vector from the motion vector of the base layer.

  The reduction / interlacing processing unit 83 downscales the input image and interlaces it.

  In the above-described embodiment, the example using interlaced video data as the base layer has been described. However, even when progressive video data is used, an intermediate motion vector calculated from the motion vector of the base layer is used. Thus, the motion vector of the enhancement layer can be calculated. In this case, the reduction / interlacing processing unit 83 performs only the process of downscaling the input image.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIGS. For convenience of explanation, members having the same functions as those shown in the first embodiment are given the same reference numerals, and explanation thereof is omitted.

  The present embodiment is different from the first embodiment in that the enhancement layer is decoded based on the motion information of the base layer. In other words, in the first embodiment, the base layer motion information is converted into intermediate motion information and used for the enhancement layer decoding process. However, in the present embodiment, without converting into the intermediate motion information, Used for enhancement layer decoding.

(Moving picture decoding apparatus 1 ')
FIG. 17 shows the configuration of the video decoding device 1 ′ according to the present embodiment. The moving image decoding apparatus 1 ′ differs from the moving image decoding apparatus 1 in that it does not include the motion information normalization unit 22, and instead of the motion information conversion processing unit 20 and the motion information storage unit 21, motion information conversion processing is performed. It is a point provided with the part 20 'and the motion information storage part 21'.

  The motion information accumulating unit 21 ′ accumulates the base layer motion information MV_BL in units of macroblocks, and supplies the motion information MV_BL to the motion information conversion processing unit 20 ′ in accordance with an instruction from the inter prediction unit 19. An example of information stored in the motion information storage unit 21 ′ will be described with reference to FIG. As shown in FIG. 20, in the motion information storage unit 21 ′, the picture number difference value and the field rate in units of pictures, the direction of motion vectors (forward prediction motion vector, backward prediction motion vector) in units of macroblocks, Information indicating whether the component is a horizontal component or a vertical component is stored as motion information in association with the macroblock.

  For example, when the base layer is MPEG-2, the picture number difference value can be calculated by calculating the difference between the current picture number acquired from the picture header and the picture number of the reference picture. Further, when a common picture number is defined in the base layer and the enhancement layer, it can be calculated by taking a difference from the current picture number acquired from the slice header. That is, the picture number difference value only needs to indicate the time interval between the motion vector reference source and the reference destination picture.

  The frame rate is used when the display rates of the base layer and the enhancement layer are different. The frame rate can be obtained from the sequence header. In this embodiment, since the base layer is interlaced, it is converted to a field rate.

  In this embodiment, the frame rate (field rate) is the same for the base layer and the enhancement layer. However, if the frame rate is different and multiplied, the enhancement layer frame rate / base layer MV_EL may be obtained by multiplying MV_BL by “frame rate” and adjusting the scale in the time direction.

  The motion information conversion processing unit 20 ′ scales the motion vector MV_BL stored in the motion information storage unit 21 ′ based on the picture reference relationship in the enhancement layer, and derives a motion vector MV_EL used by the inter prediction unit 19. .

(Motion vector derivation method 2-1)
Next, a method for deriving a motion vector used by the inter prediction unit 19 will be described with reference to FIG. Here, the motion vector derivation process used in the enhancement layer when field prediction in the frame structure is performed in the base layer will be described.

  First, the processing target is a frame b3. Frame b3 uses B1 as the forward reference picture, I4 as the backward reference picture, and BB1 of the base layer as the inter-layer reference picture. These reference pictures have already been decoded when the processing target frame b3 is decoded.

  Consider a case where the motion vector MV_EL (1) _e used in the prediction block PU of the frame b3 is derived from the base layer. In this case, the motion vector used when processing the macroblock a corresponding to the prediction block PU of the base layer frame BB1 corresponding to the frame b3 is used. In this embodiment, the macroblock a is a macroblock a of the base layer located at the coordinates corresponding to the center point of the prediction block PU of the frame b3.

  As described above, the frame BB1 is processed by field prediction as a frame structure. Here, the frame BB1 refers to the fields I21 and I22 as backward reference pictures, and the macroblock a refers to the respective reference pictures and processes them with the motion vectors MV_BL (1-1) _e and MV_BL (1-2) _e. It is assumed that

  Since the macroblock a calculates a motion vector by field prediction, the reference source fields of MV_BL (1-1) _e and MV_BL (1-2) _e are B01 and B02, respectively. Since the base layer field corresponding to the frame b3 to be processed is B12, the inter prediction unit 19 performs motion compensation using the motion vector MV_BL (1-2) _e stored in the motion information storage unit 21.

  Specifically, first, the inter prediction unit 19 specifies the frame BB1 of the base layer corresponding to the processing target b3. Of the motion vector information (MV_BL (1-1) _e, MV_BL (1-2) _e) used when processing the corresponding macroblock of the frame BB1, the frame of the base layer corresponding to b3 to be processed The motion vector MV_BL (1-2) _e used when processing B12 is supplied from the motion information storage unit 21 ′ to the motion information conversion processing unit 20 ′.

  The motion information conversion processing unit 20 ′ calculates a motion vector MV_EL (1) _e from the motion vector MV_BL (1-2) _e according to the equation (9).

MV_EL (1) _e = MV_BL (1-2) _e × tb_e / td_e × scaling formula (9)
Here, the scaling processing is EL resolution / BL resolution, and tb / td is the ratio of the distances in the time direction of each picture.

(Motion vector derivation method 2-2)
Next, with reference to FIG. 19, a description will be given of a process for deriving a motion vector used in the enhancement layer when frame prediction is performed in the frame structure in the base layer.

  Here, it is assumed that the decoding target is b3. First, the inter prediction unit 19 specifies the frame B1 of the base layer corresponding to b3 to be processed. Then, the motion vector MV_BL (1) _f used when processing the corresponding macroblock of the frame B1 is supplied from the motion information storage unit 21 ′ to the motion information conversion processing unit 20 ′.

  The motion information conversion processing unit 20 ′ calculates a motion vector MV_EL (1) _f from the motion vector MV_BL (1) _f using the equation (10).

MV_EL (1) _f = MV_BL (1) _f × tb_f / td_f × scaling processing equation (10)
(Moving picture encoding device 2 ')
Next, the moving picture coding apparatus 2 ′ will be described with reference to FIG. The moving image encoding device 2 ′ differs from the moving image encoding device 2 in that the motion information normalization unit 54 is not provided, and the motion information conversion processing unit 52 and the motion information storage unit 53 are replaced with motion information. A conversion processing unit 52 ′ and a motion information storage unit 53 ′ are provided.

  The motion information conversion processing unit 52 ′ and the motion information storage unit 53 ′ have the same functions as the motion information conversion processing unit 20 ′ and the motion information storage unit 21 ′.

  In the present embodiment, the motion compensation prediction of the enhancement layer is performed using the motion vector calculated from the motion information of the base layer, but the motion vector candidate of the motion vector to be used for motion compensation is calculated. As one, the motion compensation prediction process of the enhancement layer may be performed, or may be used as a prediction vector in motion vector prediction. For example, a motion vector calculated from motion information of the base layer may be used as one of motion vector candidates used in merge mode or median prediction.

  Further, in this embodiment, the picture used for motion compensation in the base layer has a frame structure, but processing may be performed in units of fields. In addition, examples of frame prediction and field prediction will be described as prediction methods. However, even in the case of dual prime prediction in which an average of predictions from different fields is obtained for a macroblock, reference to pictures in each layer as described above. A motion vector from the base layer to the enhancement layer can be calculated based on the relationship.

  In the above-described embodiment, the example using interlaced video data as the base layer has been described. However, even when progressive video data is used, an intermediate motion vector calculated from the motion vector of the base layer is used. Thus, the motion vector of the enhancement layer can be calculated.

(Appendix 1)
The above-described moving image encoding device 2 and moving image decoding device 1 can be used by being mounted on various devices that perform transmission, reception, recording, and reproduction of moving images. The moving image may be a natural moving image captured by a camera or the like, or may be an artificial moving image (including CG and GUI) generated by a computer or the like.

  First, it will be described with reference to FIG. 20 that the moving picture encoding apparatus 2 and the moving picture decoding apparatus 1 described above can be used for transmission and reception of moving pictures.

  FIG. 20A is a block diagram illustrating a configuration of a transmission device PROD_A in which the moving image encoding device 2 is mounted. As illustrated in FIG. 20A, the transmission device PROD_A modulates a carrier wave with an encoding unit PROD_A1 that obtains encoded data by encoding a moving image, and the encoded data obtained by the encoding unit PROD_A1. Thus, a modulation unit PROD_A2 that obtains a modulation signal and a transmission unit PROD_A3 that transmits the modulation signal obtained by the modulation unit PROD_A2 are provided. The moving image encoding apparatus 2 described above is used as the encoding unit PROD_A1.

  The transmission device PROD_A is a camera PROD_A4 that captures a moving image, a recording medium PROD_A5 that records the moving image, an input terminal PROD_A6 that inputs the moving image from the outside, as a supply source of the moving image input to the encoding unit PROD_A1. An image processing unit A7 that generates or processes an image may be further provided. In FIG. 20A, a configuration in which all of these are provided in the transmission device PROD_A is illustrated, but a part may be omitted.

  The recording medium PROD_A5 may be a recording of a non-encoded moving image, or a recording of a moving image encoded by a recording encoding scheme different from the transmission encoding scheme. It may be a thing. In the latter case, a decoding unit (not shown) for decoding the encoded data read from the recording medium PROD_A5 according to the recording encoding method may be interposed between the recording medium PROD_A5 and the encoding unit PROD_A1.

  FIG. 20B is a block diagram illustrating a configuration of a receiving device PROD_B in which the video decoding device 1 is mounted. As illustrated in FIG. 20B, the receiving device PROD_B includes a receiving unit PROD_B1 that receives a modulated signal, a demodulating unit PROD_B2 that obtains encoded data by demodulating the modulated signal received by the receiving unit PROD_B1, and a demodulator. A decoding unit PROD_B3 that obtains a moving image by decoding the encoded data obtained by the unit PROD_B2. The moving picture decoding apparatus 1 described above is used as the decoding unit PROD_B3.

  The receiving device PROD_B has a display PROD_B4 for displaying a moving image, a recording medium PROD_B5 for recording the moving image, and an output terminal for outputting the moving image to the outside as a supply destination of the moving image output by the decoding unit PROD_B3. PROD_B6 may be further provided. FIG. 20B illustrates a configuration in which the reception apparatus PROD_B includes all of these, but a part may be omitted.

  The recording medium PROD_B5 may be used for recording a non-encoded moving image, or may be encoded using a recording encoding method different from the transmission encoding method. May be. In the latter case, an encoding unit (not shown) for encoding the moving image acquired from the decoding unit PROD_B3 according to the recording encoding method may be interposed between the decoding unit PROD_B3 and the recording medium PROD_B5.

  Note that the transmission medium for transmitting the modulation signal may be wireless or wired. Further, the transmission mode for transmitting the modulated signal may be broadcasting (here, a transmission mode in which the transmission destination is not specified in advance) or communication (here, transmission in which the transmission destination is specified in advance). Refers to the embodiment). That is, the transmission of the modulation signal may be realized by any of wireless broadcasting, wired broadcasting, wireless communication, and wired communication.

  For example, a terrestrial digital broadcast broadcasting station (such as broadcasting equipment) / receiving station (such as a television receiver) is an example of a transmitting device PROD_A / receiving device PROD_B that transmits and receives a modulated signal by wireless broadcasting. Further, a broadcasting station (such as broadcasting equipment) / receiving station (such as a television receiver) of cable television broadcasting is an example of a transmitting device PROD_A / receiving device PROD_B that transmits and receives a modulated signal by cable broadcasting.

  Also, a server (workstation or the like) / client (television receiver, personal computer, smartphone, etc.) such as a VOD (Video On Demand) service or a video sharing service using the Internet transmits and receives a modulated signal by communication. This is an example of PROD_A / reception device PROD_B (usually, either a wireless or wired transmission medium is used in a LAN, and a wired transmission medium is used in a WAN). Here, the personal computer includes a desktop PC, a laptop PC, and a tablet PC. The smartphone also includes a multi-function mobile phone terminal.

  Note that the client of the video sharing service has a function of encoding a moving image captured by a camera and uploading it to the server in addition to a function of decoding the encoded data downloaded from the server and displaying it on the display. That is, the client of the video sharing service functions as both the transmission device PROD_A and the reception device PROD_B.

  Next, the fact that the above-described moving image encoding device 2 and moving image decoding device 1 can be used for recording and reproduction of moving images will be described with reference to FIG.

  FIG. 21A is a block diagram showing a configuration of a recording apparatus PROD_C in which the above-described moving picture encoding apparatus 2 is mounted. As shown in FIG. 21 (a), the recording device PROD_C includes an encoding unit PROD_C1 that obtains encoded data by encoding a moving image, and the encoded data obtained by the encoding unit PROD_C1 on the recording medium PROD_M. A writing unit PROD_C2 for writing. The moving image encoding apparatus 2 described above is used as the encoding unit PROD_C1.

  The recording medium PROD_M may be of a type built in the recording device PROD_C, such as (1) HDD (Hard Disk Drive) or SSD (Solid State Drive), or (2) SD memory. It may be of a type connected to the recording device PROD_C, such as a card or USB (Universal Serial Bus) flash memory, or (3) DVD (Digital Versatile Disc) or BD (Blu-ray Disc: registration) Or a drive device (not shown) built in the recording device PROD_C.

  In addition, the recording device PROD_C serves as a moving image supply source to be input to the encoding unit PROD_C1. The unit PROD_C5 and an image processing unit C6 that generates or processes an image may be further provided. FIG. 21A illustrates a configuration in which the recording apparatus PROD_C includes all of these, but a part of the configuration may be omitted.

  The receiving unit PROD_C5 may receive a non-encoded moving image, or may receive encoded data encoded by a transmission encoding scheme different from the recording encoding scheme. You may do. In the latter case, a transmission decoding unit (not shown) that decodes encoded data encoded by the transmission encoding method may be interposed between the reception unit PROD_C5 and the encoding unit PROD_C1.

  Examples of such a recording device PROD_C include a DVD recorder, a BD recorder, and an HDD (Hard Disk Drive) recorder (in this case, the input terminal PROD_C4 or the receiving unit PROD_C5 is a main supply source of moving images). . In addition, a camcorder (in this case, the camera PROD_C3 is a main source of moving images), a personal computer (in this case, the receiving unit PROD_C5 or the image processing unit C6 is a main source of moving images), a smartphone (in this case In this case, the camera PROD_C3 or the receiving unit PROD_C5 is a main supply source of moving images) is also an example of such a recording device PROD_C.

  FIG. 21B is a block diagram illustrating a configuration of a playback device PROD_D in which the above-described video decoding device 1 is mounted. As shown in (b) of FIG. 21, the playback device PROD_D reads a moving image by decoding a read unit PROD_D1 that reads encoded data written to the recording medium PROD_M and a coded data read by the read unit PROD_D1. And a decoding unit PROD_D2 to be obtained. The moving picture decoding apparatus 1 described above is used as the decoding unit PROD_D2.

  Note that the recording medium PROD_M may be of the type built into the playback device PROD_D, such as (1) HDD or SSD, or (2) such as an SD memory card or USB flash memory, It may be of a type connected to the playback device PROD_D, or (3) may be loaded into a drive device (not shown) built in the playback device PROD_D, such as DVD or BD. Good.

  In addition, the playback device PROD_D has a display PROD_D3 that displays a moving image, an output terminal PROD_D4 that outputs the moving image to the outside, and a transmission unit that transmits the moving image as a supply destination of the moving image output by the decoding unit PROD_D2. PROD_D5 may be further provided. FIG. 21B illustrates a configuration in which the playback apparatus PROD_D includes all of these, but a part may be omitted.

    The transmission unit PROD_D5 may transmit an unencoded moving image, or transmits encoded data encoded by a transmission encoding method different from the recording encoding method. You may do. In the latter case, it is preferable to interpose an encoding unit (not shown) that encodes a moving image with an encoding method for transmission between the decoding unit PROD_D2 and the transmission unit PROD_D5.

  Examples of such a playback device PROD_D include a DVD player, a BD player, and an HDD player (in this case, an output terminal PROD_D4 to which a television receiver or the like is connected is a main supply destination of moving images). . In addition, a television receiver (in this case, the display PROD_D3 is a main supply destination of moving images), a digital signage (also referred to as an electronic signboard or an electronic bulletin board), and the display PROD_D3 or the transmission unit PROD_D5 is the main supply of moving images. Desktop PC (in this case, the output terminal PROD_D4 or the transmission unit PROD_D5 is the main video image supply destination), laptop or tablet PC (in this case, the display PROD_D3 or the transmission unit PROD_D5 is a moving image) A smartphone (which is a main image supply destination), a smartphone (in this case, the display PROD_D3 or the transmission unit PROD_D5 is a main moving image supply destination), and the like are also examples of such a playback device PROD_D.

(Appendix 2)
Finally, each block of the moving picture decoding apparatus 1 (1 ′) and the moving picture encoding apparatus 2 (2 ′) is realized in hardware by a logic circuit formed on an integrated circuit (IC chip). Alternatively, it may be realized by software using a CPU (central processing unit).

  In the latter case, the moving picture decoding apparatus 1 (1 ′) and the moving picture encoding apparatus 2 (2 ′) include a CPU that executes instructions of a control program that implements each function, and a ROM (read only memory) that stores the program. ), A RAM (random access memory) for expanding the program, and a storage device (recording medium) such as a memory for storing the program and various data. An object of the present invention is to provide program codes (execution format program, intermediate code) of control programs of the video decoding device 1 (1 ′) and the video encoding device 2 (2 ′) which are software for realizing the functions described above. A recording medium in which a program and a source program are recorded so as to be readable by a computer is supplied to the moving picture decoding apparatus 1 (1 ′) and the moving picture encoding apparatus 2 (2 ′), and the computer (or CPU or MPU) (Micro processing unit)) can also be achieved by reading and executing the program code recorded on the recording medium.

  Examples of the recording medium include tapes such as a magnetic tape and a cassette tape, a magnetic disk such as a floppy (registered trademark) disk / hard disk, a CD-ROM (compact disc read-only memory) / MO (magneto-optical) / Disks including optical discs such as MD (Mini Disc) / DVD (digital versatile disk) / CD-R (CD Recordable), cards such as IC cards (including memory cards) / optical cards, mask ROM / EPROM (erasable) Uses semiconductor memory such as programmable read-only memory (EEPROM) / EEPROM (electrically erasable and programmable read-only memory) / flash ROM, or logic circuits such as PLD (Programmable logic device) and FPGA (Field Programmable Gate Array) be able to.

  Further, the moving picture decoding apparatus 1 (1 ′) and the moving picture encoding apparatus 2 (2 ′) may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited as long as it can transmit the program code. For example, the Internet, intranet, extranet, LAN (local area network), ISDN (integrated services digital network), VAN (value-added network), CATV (community antenna television) communication network, virtual private network (virtual private network), A telephone line network, a mobile communication network, a satellite communication network, etc. can be used. The transmission medium constituting the communication network may be any medium that can transmit the program code, and is not limited to a specific configuration or type. For example, infrared data such as IrDA (infrared data association) or remote control can be used for wired such as IEEE (institute of electrical and electronic engineers) 1394, USB, power line carrier, cable TV line, telephone line, ADSL (asynchronous digital subscriber loop) line, etc. , Bluetooth (registered trademark), IEEE 802.11 wireless, HDR (high data rate), NFC (Near Field Communication), DLNA (Digital Living Network Alliance), mobile phone network, satellite line, terrestrial digital network, etc. Is possible. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments can be obtained by appropriately combining technical means disclosed in different embodiments. The form is also included in the technical scope of the present invention.

  The present invention can be suitably used for an image encoding device and an image decoding device that perform encoding by scalable encoding.

1, 1 ′ moving picture decoding apparatus 31 variable length decoding unit (first layer motion vector decoding means)
20, 20 ′ motion information conversion processing unit (second layer motion vector deriving means)
22 Motion information normalization unit (intermediate motion vector deriving means)
2, 2 ′ moving image encoding device 52, 52 ′ motion information conversion processing unit (second layer motion vector deriving means)
54 Motion information normalization unit (intermediate motion vector deriving means)

Claims (10)

A video decoding device for decoding encoded data composed of a plurality of layers having different encoding methods,
A first layer motion vector decoding means for decoding a motion vector used for decoding the first layer with reference to motion vector information included in the first layer of the plurality of layers;
Intermediate motion vector deriving means for deriving an intermediate motion vector based on the motion vector decoded by the first layer motion vector decoding means;
Second layer motion vector deriving means for deriving a motion vector used for decoding the second layer of the plurality of layers with reference to the intermediate motion vector derived by the intermediate motion vector deriving means;
A moving picture decoding apparatus comprising:   2. The intermediate motion vector deriving unit converts the motion vector decoded by the first layer motion vector decoding unit into a value separated by a predetermined frame to obtain an intermediate motion vector. Video decoding device. The first layer includes motion vectors derived using a plurality of fields for one frame,
The intermediate motion vector deriving unit uses a motion vector used for the decoding target frame of the second layer as a field corresponding to the processing target frame among a plurality of fields in the first layer frame corresponding to the processing target frame. The moving image decoding apparatus according to claim 1, wherein the intermediate motion vector is derived based on a motion vector derived by using.   The intermediate motion vector deriving means derives the intermediate motion vector based on the motion vector used in the second layer decoding target frame based on the motion vector in the first layer frame corresponding to the processing target frame. The moving picture decoding apparatus according to claim 1, wherein the moving picture decoding apparatus is provided.   The intermediate motion vector deriving means, when the frame of the first layer corresponding to the decoding target frame of the second layer does not include a motion vector in the prediction direction required by the second layer, 3. The moving picture decoding apparatus according to claim 1, wherein the intermediate motion vector is derived based on a motion vector included in a reference frame nearest to the frame of the first layer in a conversion order. A video decoding device for decoding encoded data composed of a plurality of layers having different encoding methods,
A first layer motion vector decoding means for decoding a motion vector used for decoding the first layer with reference to motion vector information included in the first layer of the plurality of layers;
A second layer for deriving a motion vector used for decoding the second layer of the plurality of layers based on the reference relationship between the motion vector decoded by the first layer motion vector decoding means and the reference frame of the second layer; A motion vector deriving means;
A moving picture decoding apparatus comprising: The first layer includes motion vectors derived using a plurality of fields for one frame,
The second layer motion vector deriving means corresponds to a motion vector used for a decoding target frame of the second layer corresponding to the processing target frame among a plurality of fields in the first layer frame corresponding to the processing target frame. 7. The moving picture decoding apparatus according to claim 6, wherein the second layer motion vector is derived based on a motion vector derived using a field to be transmitted.   The second layer motion vector deriving means determines the motion vector used for the second layer decoding target frame based on the motion vector in the first layer frame corresponding to the processing target frame. The video decoding device according to claim 6, wherein a vector is derived. Video encoding apparatus that generates encoded data including a plurality of layers having different encoding methods and including a prediction residual that is a difference between an original image and a predicted image in each layer In
Intermediate motion vector deriving means for deriving an intermediate motion vector based on the motion vector used for decoding of the first layer;
A second layer motion vector for deriving a motion vector used for generating the predicted image for generating the second layer encoded data with reference to the intermediate motion vector derived by the intermediate motion vector deriving means A moving picture coding apparatus comprising: a derivation unit; Video encoding apparatus that generates encoded data including a plurality of layers having different encoding methods and including a prediction residual that is a difference between an original image and a predicted image in each layer In
A second vector for deriving a motion vector used for generating the predicted image for generating the encoded data of the second layer based on the reference relationship between the motion vector used for decoding the first layer and the reference frame of the second layer; A moving picture coding apparatus comprising layer motion vector deriving means.

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