WO2018097079A1

WO2018097079A1 - Encoding device, decoding device, encoding method, and decoding method

Info

Publication number: WO2018097079A1
Application number: PCT/JP2017/041597
Authority: WO
Inventors: 安倍　清史; 西　孝啓; 遠間　正真; 橋本　隆
Original assignee: パナソニックインテレクチュアルプロパティコーポレーションオブアメリカ
Priority date: 2016-11-22
Filing date: 2017-11-20
Publication date: 2018-05-31
Also published as: TW201826793A

Abstract

An encoding device (100) is equipped with circuitry (160) and memory (162). The circuitry (160) uses the memory (162) to: derive, from a motion vector used in the motion compensation of a processed block, a plurality of candidate motion vectors for a block to be processed included in a picture to be processed (S101); select, without using the image region of the block to be processed, a final motion vector from among the plurality of candidate motion vectors by referring to two processed reference pictures that are both positioned either before or after the picture to be processed in terms of display time (S104, S106, or S108); and perform motion compensation for the block to be processed using the final motion vector (S105 or S107).

Description

Encoding device, decoding device, encoding method, and decoding method

The present disclosure relates to an encoding device, a decoding device, an encoding method, and a decoding method.

In the HEVC (High Efficiency Video Coding) standard, which is the latest video coding standard, various studies have been made to improve the coding efficiency (for example, see Non-Patent Document 1). This method is described in H.264. ITU-T (International Telecommunication Union Telecommunication Standardization Sector) standard represented by 26x and ISO / IEC standard represented by MPEG-x. H.264 / AVC or MPEG-4 AVC was studied as the next video coding standard after the standard.

In such an encoding method and decoding method, it is desired that the encoding efficiency can be improved.

This disclosure is intended to provide a decoding device, an encoding device, a decoding method, or an encoding method that can improve encoding efficiency.

An encoding apparatus according to an aspect of the present disclosure includes a circuit and a memory, and the circuit uses the memory to process a plurality of candidate motion vectors for a processing target block included in a processing target picture. Two processes that are derived from the motion vector used for motion compensation of the processed block, do not use the image area of the processing target block, and whose display time is located in the same direction between the front and rear of the processing target picture A final motion vector is selected from the plurality of candidate motion vectors with reference to a completed reference picture, and motion compensation of the processing target block is performed using the final motion vector.

A decoding device according to an aspect of the present disclosure includes a circuit and a memory, and the circuit has processed a plurality of candidate motion vectors for a processing target block included in a processing target picture using the memory. Derived from the motion vector used for block motion compensation, does not use the image area of the processing target block, and two processed images whose display time is located in the same direction between the front and rear of the processing target picture Referring to the reference picture, a final motion vector is selected from the plurality of candidate motion vectors, and motion compensation of the processing target block is performed using the final motion vector.

Note that these comprehensive or specific aspects may be realized by a system, apparatus, method, integrated circuit, computer program, or non-transitory recording medium such as a computer-readable CD-ROM. The present invention may be realized by any combination of an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

The present disclosure can provide a decoding device, an encoding device, a decoding method, or an encoding method that can improve the encoding efficiency.

FIG. 1 is a block diagram showing a functional configuration of the encoding apparatus according to Embodiment 1. FIG. 2 is a diagram illustrating an example of block division in the first embodiment. FIG. 3 is a table showing conversion basis functions corresponding to each conversion type. FIG. 4A is a diagram illustrating an example of the shape of a filter used in ALF. FIG. 4B is a diagram illustrating another example of the shape of a filter used in ALF. FIG. 4C is a diagram illustrating another example of the shape of a filter used in ALF. FIG. 5 is a diagram illustrating 67 intra prediction modes in intra prediction. FIG. 6 is a diagram for explaining pattern matching (bilateral matching) between two blocks along the motion trajectory. FIG. 7 is a diagram for explaining pattern matching (template matching) between a template in the current picture and a block in the reference picture. FIG. 8 is a diagram for explaining a model assuming constant velocity linear motion. FIG. 9 is a diagram for explaining the derivation of motion vectors in units of sub-blocks based on the motion vectors of a plurality of adjacent blocks. FIG. 10 is a block diagram showing a functional configuration of the decoding apparatus according to the first embodiment. FIG. 11 is a flowchart of the inter-screen prediction process according to the first embodiment. FIG. 12 is a diagram for explaining an example of an evaluation value calculation process according to the first embodiment. FIG. 13 is a diagram for explaining an example of an evaluation value calculation process according to the first embodiment. FIG. 14 is a diagram for explaining an example of an evaluation value calculation process according to the first embodiment. FIG. 15 is a diagram for explaining an example of an evaluation value calculation process according to the first embodiment. FIG. 16 is a flowchart of inter-screen prediction processing in the encoding apparatus according to Embodiment 2. FIG. 17 is a flowchart of selected reference picture list determination processing in the encoding apparatus according to Embodiment 2. FIG. 18 is a flowchart of inter-screen prediction processing in the decoding apparatus according to Embodiment 2. FIG. 19 is a flowchart of selected reference picture list determination processing in the decoding apparatus according to Embodiment 2. FIG. 20 is a block diagram illustrating an implementation example of an encoding device. FIG. 21 is a block diagram illustrating an implementation example of a decoding device. FIG. 22 is an overall configuration diagram of a content supply system that implements a content distribution service. FIG. 23 is a diagram illustrating an example of a coding structure at the time of scalable coding. FIG. 24 is a diagram illustrating an example of a coding structure at the time of scalable coding. FIG. 25 shows an example of a web page display screen. FIG. 26 is a diagram illustrating a display screen example of a web page. FIG. 27 is a diagram illustrating an example of a smartphone. FIG. 28 is a block diagram illustrating a configuration example of a smartphone.

(Knowledge that became the basis of this disclosure)
For example, the encoding device encodes an image for each block. The encoding apparatus may use inter-screen prediction or intra-screen prediction when encoding an image for each block. When the inter-frame prediction is used for encoding the processing target block (current block), the encoding device detects a motion vector of the processing target block and generates a predicted image of the processing target block using the detected motion vector. . Then, the encoding device reduces the code amount by encoding a difference image between the predicted image of the processing target block and the original image of the processing target block.

Also, the encoding device encodes motion vector information indicating a motion vector, and the decoding device decodes the motion vector information. Further, the decoding device decodes the difference image. Then, the decoding device generates a predicted image of the processing target block using the motion vector indicated by the decoded motion vector information, and reconstructs the original image by adding the predicted image and the difference image. Thereby, the decoding apparatus can decode an image.

When the encoding device encodes the motion vector information and the decoding device decodes the motion vector information, the decoding device appropriately generates a predicted image of the processing target block using the motion vector used in the encoding device. can do. On the other hand, since the motion vector information is encoded, the amount of codes may increase.

The encoding device and the decoding device may use a technique called FRUC (Frame Rate Up-Conversion) in order to reduce such a code amount. In FRUC, the encoding device and the decoding device derive motion vectors by the same method in the encoding device and the decoding device without encoding and decoding motion vector information.

For example, in the bilateral FRUC scheme, the encoding device and the decoding device refer to the motion vector of the encoded block spatially or temporally adjacent to the processing target block, and each of the candidates has a motion vector predictor. A motion vector is derived. Next, the encoding device and the decoding device calculate the evaluation values of each of the plurality of candidate motion vectors, and select one final motion vector based on the evaluation values. Next, the encoding device and the decoding device perform motion compensation using the final motion vector.

Also, the evaluation value is calculated by pattern matching between a region in the reference picture indicated by the candidate motion vector and a region in a predetermined picture different from the reference picture. For example, two reference pictures that sandwich the processing target picture in display order are used. That is, there is a problem that this method cannot be used when there are no two pictures that sandwich the processing target block in the display order as referenceable pictures.

Furthermore, in the P picture, there may be a case where only one reference picture is registered in the reference picture list. In this case, there is a possibility that two reference pictures cannot be used. Thereby, there exists a subject that a bilateral FRUC system cannot be used.

According to this, bilateral FRUC can be used, for example, even when there are no two pictures that sandwich the processing target block in the display order in the referable pictures. Therefore, the bilateral FRUC method can be used in more cases, so that the coding efficiency can be improved.

For example, the processing target picture may be a P picture.

According to this, since the bilateral FRUC can be used for the P picture, the bilateral FRUC method can be used in more cases. Therefore, encoding efficiency can be improved.

For example, when two reference pictures are indicated in the reference picture list for the processing target picture, the two processed reference pictures are the two reference pictures indicated in the reference picture list. Also good.

For example, when one reference picture is indicated in the reference picture list for the processing target picture, one of the two processed reference pictures is the one reference picture indicated in the reference picture list. Yes, the other of the two processed reference pictures may be another processed reference picture not shown in the reference picture list.

According to this, even when only one reference picture is shown in the reference picture list of the P picture, the bilateral FRUC can be used. Therefore, the bilateral FRUC method can be used in more cases, so that the coding efficiency can be improved.

For example, the circuit may further store the one reference picture shown in the reference picture list and the other processed reference pictures in a picture memory.

For example, in the selection of the final motion vector, the evaluation values of each of the plurality of candidate motion vectors are calculated with reference to the two processed reference pictures, and the final motion vector is calculated based on the calculated evaluation values. And the one of the two processed reference pictures is a reference picture indicated by a candidate motion vector to be processed among the plurality of candidate motion vectors, and the other of the two processed reference pictures May be a picture whose display time is closest to the processing target picture among the referable pictures.

For example, the processing target picture may be a B picture.

According to this, in the B picture, bilateral FRUC can be used even if there are no two pictures that sandwich the processing target block in the display order in the referenceable picture. Therefore, the bilateral FRUC method can be used in more cases, so that the coding efficiency can be improved.

For example, in the selection of the final motion vector, the evaluation values of each of the plurality of candidate motion vectors are calculated with reference to the two processed reference pictures, and the final motion vector is calculated based on the calculated evaluation values. And the processing target picture has a first reference picture list and a second reference picture list, and one of the two processed reference pictures is a candidate motion to be processed among the plurality of candidate motion vectors. A reference picture indicated by a vector, which is a reference picture belonging to the first reference picture list, and the other of the two processed reference pictures is the reference picture belonging to the second reference picture list. It may be a picture whose display time is closest to the target picture.

For example, the processing target picture may be a P picture.

For example, in the selection of the final motion vector, the evaluation values of each of the plurality of candidate motion vectors are calculated with reference to the two processed reference pictures, and the final motion vector is calculated based on the calculated evaluation values. And one of the two processed reference pictures is a reference picture indicated by a candidate motion vector to be processed among the plurality of candidate motion vectors, and the other of the two processed reference pictures is Of the pictures that can be referred to, the picture that is closest in display time to the processing target picture may be used.

For example, the processing target picture may be a B picture.

The encoding method according to an aspect of the present disclosure derives a plurality of candidate motion vectors for a processing target block included in a processing target picture from motion vectors used for motion compensation of the processed block, and the processing target The final motion is determined from the plurality of candidate motion vectors by referring to two processed reference pictures that do not use an image area of a block and that are displayed in the same direction between the forward and backward display times of the processing target picture. A vector may be selected, and motion compensation of the processing target block may be performed using the final motion vector.

The decoding method according to an aspect of the present disclosure derives a plurality of candidate motion vectors for a processing target block included in a processing target picture from motion vectors used for motion compensation of the processed block, and the processing target block The final motion vector is determined from the plurality of candidate motion vectors by referring to two processed reference pictures whose display times are located in the same direction of the front and rear of the processing target picture without using the image area And the motion compensation of the processing target block may be performed using the final motion vector.

Furthermore, these comprehensive or specific aspects may be realized by a system, an apparatus, a method, an integrated circuit, a computer program, or a non-transitory recording medium such as a computer-readable CD-ROM. The present invention may be realized by any combination of an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

Also, in the bilateral FRUC method, it is necessary to calculate the evaluation values of each of a plurality of candidate motion vectors. Therefore, there is a problem that the processing amount increases as the number of candidate motion vectors increases.

An encoding apparatus according to an aspect of the present disclosure includes a circuit and a memory, and the circuit uses the memory to include a processing target block included in a processing target picture that is a B picture having two reference picture lists. Are derived from the motion vectors used for motion compensation of the processed block, and the image regions of the processing target block are not used, and the two candidate motion vectors of the plurality of candidate motion vectors are An evaluation value of a candidate motion vector indicating a reference picture indicated by a selected reference picture list that is one of the reference picture lists is calculated, and the candidate indicating a reference picture indicated by the selected reference picture list is calculated based on the calculated evaluation value A final motion vector is selected from the motion vectors, and the motion compensation of the processing target block is performed using the final motion vector. It is carried out.

According to this, since the candidate motion vector for calculating the evaluation value can be reduced, the processing amount can be reduced.

For example, the circuit further uses the memory to select the reference picture list in which the display time of the reference picture registered at the top is closer to the display time of the processing target picture from the two reference picture lists. The reference picture list may be determined.

According to this, more useful candidate motion vectors can be extracted.

For example, the circuit uses the memory to generate a reference picture list that is set such that a reference picture registered at the top of the two reference picture lists is decoded with higher priority. The selected reference picture list may be determined.

According to this, more useful candidate motion vectors can be extracted.

For example, the circuit further determines, as the selected reference picture list, a reference picture list having a smaller quantization width of a reference picture registered at the top of the two reference picture lists, using the memory. May be.

According to this, more useful candidate motion vectors can be extracted.

For example, the circuit may further generate an encoded bitstream including information for specifying the selected reference picture list using the memory.

According to this, since it is not necessary to perform the process of determining the selected motion vector in the decoding device, the processing amount of the decoding device can be reduced.

A decoding device according to an aspect of the present disclosure includes a circuit and a memory, and the circuit uses the memory to process a processing target block included in a processing target picture that is a B picture having two reference picture lists. A plurality of candidate motion vectors for the processing are derived from the motion vectors used for motion compensation of the processed blocks, and the two reference motions of the plurality of candidate motion vectors are used without using the image area of the processing target block. An evaluation value of a candidate motion vector indicating a reference picture indicated by a selected reference picture list that is one of the picture lists is calculated, and the candidate motion indicating a reference picture indicated by the selected reference picture list is calculated based on the calculated evaluation value A final motion vector is selected from the vectors, and the motion compensation of the processing target block is performed using the final motion vector Do.

According to this, more useful candidate motion vectors can be extracted.

For example, the circuit further acquires information for specifying the selected reference picture list included in the encoded bitstream using the memory, and specifies the selected reference picture list using the information. May be.

An encoding method according to an aspect of the present disclosure uses a plurality of candidate motion vectors for a processing target block included in a processing target picture that is a B picture having two reference picture lists, for motion compensation of the processed block. A reference picture that is derived from the obtained motion vector, does not use the image area of the processing target block, and is indicated by a selected reference picture list that is one of the two reference picture lists, among the plurality of candidate motion vectors. An evaluation value of the candidate motion vector is calculated, and based on the calculated evaluation value, a final motion vector is selected from the candidate motion vectors indicating the reference pictures indicated in the selected reference picture list, and the final motion vector is used. Motion compensation of the processing target block is performed.

In the decoding method according to an aspect of the present disclosure, a plurality of candidate motion vectors for a processing target block included in a processing target picture that is a B picture having two reference picture lists are used for motion compensation of the processed block. A candidate indicating a reference picture indicated by a selected reference picture list that is one of the two reference picture lists, out of the plurality of candidate motion vectors, without using an image area of the processing target block. A motion vector evaluation value is calculated, and based on the calculated evaluation value, a final motion vector is selected from the candidate motion vectors indicating a reference picture indicated in the selected reference picture list, and the final motion vector is used to select the motion vector. Performs motion compensation for the processing target block.

Hereinafter, embodiments will be specifically described with reference to the drawings.

It should be noted that each of the embodiments described below shows a comprehensive or specific example. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the scope of the claims. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

(Embodiment 1)
First, an outline of the first embodiment will be described as an example of an encoding device and a decoding device to which the processing and / or configuration described in each aspect of the present disclosure to be described later can be applied. However, the first embodiment is merely an example of an encoding device and a decoding device to which the processing and / or configuration described in each aspect of the present disclosure can be applied, and the processing and / or processing described in each aspect of the present disclosure. The configuration can also be implemented in an encoding device and a decoding device different from those in the first embodiment.

When applying the processing and / or configuration described in each aspect of the present disclosure to Embodiment 1, for example, one of the following may be performed.

(1) The encoding apparatus or decoding apparatus according to the first embodiment corresponds to the constituent elements described in each aspect of the present disclosure among a plurality of constituent elements constituting the encoding apparatus or decoding apparatus. Replacing the constituent elements with constituent elements described in each aspect of the present disclosure (2) A plurality of constituent elements constituting the encoding apparatus or decoding apparatus with respect to the encoding apparatus or decoding apparatus of the first embodiment The constituent elements corresponding to the constituent elements described in each aspect of the present disclosure are added to the present disclosure after arbitrary changes such as addition, replacement, and deletion of functions or processes to be performed on some constituent elements among the constituent elements. (3) Addition of processes and / or a plurality of processes included in the method to the method performed by the encoding apparatus or decoding apparatus of the first embodiment home Replace any processing corresponding to the processing described in each aspect of the present disclosure with the processing described in each aspect of the present disclosure after performing arbitrary changes such as replacement and deletion of a part of the processing (4) Implementation The constituent elements described in each aspect of the present disclosure, the constituent elements described in the respective aspects of the present disclosure are part of the plurality of constituent elements constituting the encoding device or the decoding device of the first embodiment (5) Encoding device according to Embodiment 1 that is implemented in combination with a component that includes a part of the functions provided, or a component that performs a part of processing performed by a component described in each aspect of the present disclosure Alternatively, a component provided with a part of the functions provided by some of the components included in the decoding device, or a plurality of components included in the encoding device or the decoding device according to the first embodiment. Some of A component that performs a part of processing performed by a component is a component that is described in each aspect of the present disclosure, a component that includes a part of a function included in the component described in each aspect of the present disclosure, (6) A method performed by the encoding device or the decoding device according to Embodiment 1 is performed in combination with a component that performs a part of processing performed by the component described in each aspect of the disclosure. Of the plurality of processes included in the method, the process corresponding to the process described in each aspect of the present disclosure is replaced with the process described in each aspect of the present disclosure. (7) The encoding apparatus according to the first embodiment or A part of the plurality of processes included in the method performed by the decoding device is performed in combination with the processes described in each aspect of the present disclosure

Note that the processes and / or configurations described in each aspect of the present disclosure are not limited to the above examples. For example, the present invention may be implemented in an apparatus used for a different purpose from the moving picture / picture encoding apparatus or moving picture / picture decoding apparatus disclosed in the first embodiment, and the processing and / or described in each aspect. The configuration may be implemented alone. Moreover, you may implement combining the process and / or structure which were demonstrated in the different aspect.

[Outline of encoding device]
First, the outline | summary of the encoding apparatus which concerns on Embodiment 1 is demonstrated. FIG. 1 is a block diagram showing a functional configuration of encoding apparatus 100 according to Embodiment 1. The encoding device 100 is a moving image / image encoding device that encodes moving images / images in units of blocks.

As shown in FIG. 1, an encoding apparatus 100 is an apparatus that encodes an image in units of blocks, and includes a dividing unit 102, a subtracting unit 104, a transforming unit 106, a quantizing unit 108, and entropy encoding. Unit 110, inverse quantization unit 112, inverse transform unit 114, addition unit 116, block memory 118, loop filter unit 120, frame memory 122, intra prediction unit 124, inter prediction unit 126, A prediction control unit 128.

The encoding device 100 is realized by, for example, a general-purpose processor and a memory. In this case, when the software program stored in the memory is executed by the processor, the processor performs the division unit 102, the subtraction unit 104, the conversion unit 106, the quantization unit 108, the entropy encoding unit 110, and the inverse quantization unit 112. , An inverse transform unit 114, an addition unit 116, a loop filter unit 120, an intra prediction unit 124, an inter prediction unit 126, and a prediction control unit 128. The encoding apparatus 100 includes a dividing unit 102, a subtracting unit 104, a transforming unit 106, a quantizing unit 108, an entropy coding unit 110, an inverse quantizing unit 112, an inverse transforming unit 114, an adding unit 116, and a loop filter unit 120. The intra prediction unit 124, the inter prediction unit 126, and the prediction control unit 128 may be implemented as one or more dedicated electronic circuits.

Hereinafter, each component included in the encoding device 100 will be described.

[Division part]
The dividing unit 102 divides each picture included in the input moving image into a plurality of blocks, and outputs each block to the subtracting unit 104. For example, the dividing unit 102 first divides a picture into blocks of a fixed size (for example, 128 × 128). This fixed size block may be referred to as a coding tree unit (CTU). Then, the dividing unit 102 divides each of the fixed size blocks into blocks of a variable size (for example, 64 × 64 or less) based on recursive quadtree and / or binary tree block division. . This variable size block may be referred to as a coding unit (CU), a prediction unit (PU) or a transform unit (TU). In the present embodiment, CU, PU, and TU do not need to be distinguished, and some or all blocks in a picture may be processing units of CU, PU, and TU.

FIG. 2 is a diagram showing an example of block division in the first embodiment. In FIG. 2, a solid line represents a block boundary by quadtree block division, and a broken line represents a block boundary by binary tree block division.

Here, the block 10 is a 128 × 128 pixel square block (128 × 128 block). The 128 × 128 block 10 is first divided into four square 64 × 64 blocks (quadtree block division).

The upper left 64 × 64 block is further divided vertically into two rectangular 32 × 64 blocks, and the left 32 × 64 block is further divided vertically into two rectangular 16 × 64 blocks (binary tree block division). As a result, the upper left 64 × 64 block is divided into two 16 × 64

blocks

11 and 12 and a 32 × 64 block 13.

The upper right 64 × 64 block is horizontally divided into two rectangular 64 × 32 blocks 14 and 15 (binary tree block division).

The lower left 64x64 block is divided into four square 32x32 blocks (quadrant block division). Of the four 32 × 32 blocks, the upper left block and the lower right block are further divided. The upper left 32 × 32 block is vertically divided into two rectangular 16 × 32 blocks, and the right 16 × 32 block is further divided horizontally into two 16 × 16 blocks (binary tree block division). The lower right 32 × 32 block is horizontally divided into two 32 × 16 blocks (binary tree block division). As a result, the lower left 64 × 64 block is divided into a 16 × 32 block 16, two 16 × 16

blocks

17 and 18, two 32 × 32

blocks

19 and 20, and two 32 × 16

blocks

21 and 22.

The lower right 64x64 block 23 is not divided.

As described above, in FIG. 2, the block 10 is divided into 13 variable-size blocks 11 to 23 based on the recursive quadtree and binary tree block division. Such division may be called QTBT (quad-tree plus binary tree) division.

In FIG. 2, one block is divided into four or two blocks (quadrature tree or binary tree block division), but the division is not limited to this. For example, one block may be divided into three blocks (triple tree block division). Such a division including a tri-tree block division may be called an MBT (multi type tree) division.

[Subtraction section]
The subtraction unit 104 subtracts the prediction signal (prediction sample) from the original signal (original sample) in units of blocks divided by the division unit 102. That is, the subtraction unit 104 calculates a prediction error (also referred to as a residual) of a coding target block (hereinafter referred to as a current block). Then, the subtraction unit 104 outputs the calculated prediction error to the conversion unit 106.

The original signal is an input signal of the encoding device 100, and is a signal (for example, a luminance (luma) signal and two color difference (chroma) signals) representing an image of each picture constituting the moving image. Hereinafter, a signal representing an image may be referred to as a sample.

[Conversion section]
The transform unit 106 transforms the prediction error in the spatial domain into a transform factor in the frequency domain, and outputs the transform coefficient to the quantization unit 108. Specifically, the transform unit 106 performs, for example, a predetermined discrete cosine transform (DCT) or discrete sine transform (DST) on a prediction error in the spatial domain.

Note that the conversion unit 106 adaptively selects a conversion type from a plurality of conversion types, and converts a prediction error into a conversion coefficient using a conversion basis function corresponding to the selected conversion type. May be. Such a conversion may be referred to as EMT (explicit multiple core transform) or AMT (adaptive multiple transform).

The plurality of conversion types include, for example, DCT-II, DCT-V, DCT-VIII, DST-I and DST-VII. FIG. 3 is a table showing conversion basis functions corresponding to each conversion type. In FIG. 3, N indicates the number of input pixels. Selection of a conversion type from among these multiple conversion types may depend on, for example, the type of prediction (intra prediction and inter prediction), or may depend on an intra prediction mode.

Information indicating whether or not to apply such EMT or AMT (for example, called an AMT flag) and information indicating the selected conversion type are signaled at the CU level. Note that the signalization of these pieces of information need not be limited to the CU level, but may be other levels (for example, a sequence level, a picture level, a slice level, a tile level, or a CTU level).

Further, the conversion unit 106 may reconvert the conversion coefficient (conversion result). Such reconversion is sometimes referred to as AST (adaptive secondary transform) or NSST (non-separable secondary transform). For example, the conversion unit 106 performs re-conversion for each sub-block (for example, 4 × 4 sub-block) included in the block of the conversion coefficient corresponding to the intra prediction error. Information indicating whether or not NSST is applied and information related to the transformation matrix used for NSST are signaled at the CU level. Note that the signalization of these pieces of information need not be limited to the CU level, but may be other levels (for example, a sequence level, a picture level, a slice level, a tile level, or a CTU level).

Here, the separable conversion is a method of performing the conversion a plurality of times by separating the number of dimensions of the input for each direction, and the non-separable conversion is two or more when the input is multidimensional. In this method, the dimensions are collectively regarded as one dimension, and conversion is performed collectively.

For example, as an example of non-separable conversion, if an input is a 4 × 4 block, it is regarded as one array having 16 elements, and 16 × 16 conversion is performed on the array. The thing which performs the conversion process with a matrix is mentioned.

Similarly, a 4 × 4 input block is regarded as a single array having 16 elements, and then the Givens rotation is performed multiple times on the array (Hypercube Givens Transform) is also a non-separable. It is an example of conversion.

[Quantization unit]
The quantization unit 108 quantizes the transform coefficient output from the transform unit 106. Specifically, the quantization unit 108 scans the transform coefficients of the current block in a predetermined scanning order, and quantizes the transform coefficients based on the quantization parameter (QP) corresponding to the scanned transform coefficients. Then, the quantization unit 108 outputs the quantized transform coefficient (hereinafter referred to as a quantization coefficient) of the current block to the entropy encoding unit 110 and the inverse quantization unit 112.

The predetermined order is an order for quantization / inverse quantization of transform coefficients. For example, the predetermined scanning order is defined in ascending order of frequency (order from low frequency to high frequency) or descending order (order from high frequency to low frequency).

The quantization parameter is a parameter that defines a quantization step (quantization width). For example, if the value of the quantization parameter increases, the quantization step also increases. That is, if the value of the quantization parameter increases, the quantization error increases.

[Entropy encoding unit]
The entropy encoding unit 110 generates an encoded signal (encoded bit stream) by performing variable length encoding on the quantization coefficient that is input from the quantization unit 108. Specifically, the entropy encoding unit 110 binarizes the quantization coefficient, for example, and arithmetically encodes the binary signal.

[Inverse quantization unit]
The inverse quantization unit 112 inversely quantizes the quantization coefficient that is an input from the quantization unit 108. Specifically, the inverse quantization unit 112 inversely quantizes the quantization coefficient of the current block in a predetermined scanning order. Then, the inverse quantization unit 112 outputs the inverse-quantized transform coefficient of the current block to the inverse transform unit 114.

[Inverse conversion part]
The inverse transform unit 114 restores the prediction error by inverse transforming the transform coefficient that is an input from the inverse quantization unit 112. Specifically, the inverse transform unit 114 restores the prediction error of the current block by performing an inverse transform corresponding to the transform by the transform unit 106 on the transform coefficient. Then, the inverse transformation unit 114 outputs the restored prediction error to the addition unit 116.

Note that the restored prediction error does not match the prediction error calculated by the subtraction unit 104 because information is lost due to quantization. That is, the restored prediction error includes a quantization error.

[Addition part]
The adder 116 reconstructs the current block by adding the prediction error input from the inverse transform unit 114 and the prediction sample input from the prediction control unit 128. Then, the adding unit 116 outputs the reconfigured block to the block memory 118 and the loop filter unit 120. The reconstructed block is sometimes referred to as a local decoding block.

[Block memory]
The block memory 118 is a storage unit for storing blocks in an encoding target picture (hereinafter referred to as current picture) that are referred to in intra prediction. Specifically, the block memory 118 stores the reconstructed block output from the adding unit 116.

[Loop filter section]
The loop filter unit 120 applies a loop filter to the block reconstructed by the adding unit 116 and outputs the filtered reconstructed block to the frame memory 122. The loop filter is a filter (in-loop filter) used in the encoding loop, and includes, for example, a deblocking filter (DF), a sample adaptive offset (SAO), an adaptive loop filter (ALF), and the like.

In ALF, a least square error filter is applied to remove coding distortion. For example, for each 2 × 2 sub-block in the current block, a plurality of multiples based on the direction of the local gradient and the activity are provided. One filter selected from the filters is applied.

Specifically, first, sub-blocks (for example, 2 × 2 sub-blocks) are classified into a plurality of classes (for example, 15 or 25 classes). Sub-block classification is performed based on gradient direction and activity. For example, the classification value C (for example, C = 5D + A) is calculated using the gradient direction value D (for example, 0 to 2 or 0 to 4) and the gradient activity value A (for example, 0 to 4). Then, based on the classification value C, the sub-blocks are classified into a plurality of classes (for example, 15 or 25 classes).

The direction value D of the gradient is derived, for example, by comparing gradients in a plurality of directions (for example, horizontal, vertical, and two diagonal directions). The gradient activation value A is derived, for example, by adding gradients in a plurality of directions and quantizing the addition result.

-Based on the result of such classification, a filter for a sub-block is determined from among a plurality of filters.

As the shape of the filter used in ALF, for example, a circularly symmetric shape is used. 4A to 4C are diagrams showing a plurality of examples of filter shapes used in ALF. 4A shows a 5 × 5 diamond shape filter, FIG. 4B shows a 7 × 7 diamond shape filter, and FIG. 4C shows a 9 × 9 diamond shape filter. Information indicating the shape of the filter is signalized at the picture level. It should be noted that the signalization of the information indicating the filter shape need not be limited to the picture level, but may be another level (for example, a sequence level, a slice level, a tile level, a CTU level, or a CU level).

ON / OFF of ALF is determined at the picture level or the CU level, for example. For example, for luminance, it is determined whether to apply ALF at the CU level, and for color difference, it is determined whether to apply ALF at the picture level. Information indicating ALF on / off is signaled at the picture level or the CU level. Signaling of information indicating ALF on / off need not be limited to the picture level or the CU level, and may be performed at other levels (for example, a sequence level, a slice level, a tile level, or a CTU level). Good.

A coefficient set of a plurality of selectable filters (for example, up to 15 or 25 filters) is signalized at the picture level. The signalization of the coefficient set need not be limited to the picture level, but may be another level (for example, sequence level, slice level, tile level, CTU level, CU level, or sub-block level).

[Frame memory]
The frame memory 122 is a storage unit for storing a reference picture used for inter prediction, and is sometimes called a frame buffer. Specifically, the frame memory 122 stores the reconstructed block filtered by the loop filter unit 120.

[Intra prediction section]
The intra prediction unit 124 generates a prediction signal (intra prediction signal) by referring to the block in the current picture stored in the block memory 118 and performing intra prediction (also referred to as intra-screen prediction) of the current block. Specifically, the intra prediction unit 124 generates an intra prediction signal by performing intra prediction with reference to a sample (for example, luminance value and color difference value) of a block adjacent to the current block, and performs prediction control on the intra prediction signal. To the unit 128.

For example, the intra prediction unit 124 performs intra prediction using one of a plurality of predefined intra prediction modes. The plurality of intra prediction modes include one or more non-directional prediction modes and a plurality of directional prediction modes.

One or more non-directional prediction modes are for example H.264. It includes Planar prediction mode and DC prediction mode defined by H.265 / HEVC (High-Efficiency Video Coding) standard (Non-patent Document 1).

The multiple directionality prediction modes are for example H.264. It includes 33-direction prediction modes defined in the H.265 / HEVC standard. In addition to the 33 directions, the plurality of directionality prediction modes may further include 32 direction prediction modes (a total of 65 directionality prediction modes). FIG. 5 is a diagram illustrating 67 intra prediction modes (two non-directional prediction modes and 65 directional prediction modes) in intra prediction. The solid line arrows The 33 directions defined in the H.265 / HEVC standard are represented, and the dashed arrow represents the added 32 directions.

Note that the luminance block may be referred to in the intra prediction of the color difference block. That is, the color difference component of the current block may be predicted based on the luminance component of the current block. Such intra prediction is sometimes called CCLM (cross-component linear model) prediction. The intra prediction mode (for example, called CCLM mode) of the color difference block which refers to such a luminance block may be added as one of the intra prediction modes of the color difference block.

The intra prediction unit 124 may correct the pixel value after intra prediction based on the gradient of the reference pixel in the horizontal / vertical direction. Intra prediction with such correction may be called PDPC (position dependent intra prediction combination). Information indicating whether or not PDPC is applied (for example, referred to as a PDPC flag) is signaled, for example, at the CU level. The signalization of this information need not be limited to the CU level, but may be another level (for example, a sequence level, a picture level, a slice level, a tile level, or a CTU level).

[Inter prediction section]
The inter prediction unit 126 refers to a reference picture stored in the frame memory 122 and is different from the current picture, and performs inter prediction (also referred to as inter-screen prediction) of the current block, thereby generating a prediction signal (inter prediction signal). Prediction signal). Inter prediction is performed in units of a current block or a sub-block (for example, 4 × 4 block) in the current block. For example, the inter prediction unit 126 performs motion estimation in the reference picture for the current block or sub-block. Then, the inter prediction unit 126 generates an inter prediction signal of the current block or sub-block by performing motion compensation using motion information (for example, a motion vector) obtained by motion search. Then, the inter prediction unit 126 outputs the generated inter prediction signal to the prediction control unit 128.

The motion information used for motion compensation is signaled. A motion vector predictor may be used for signalizing the motion vector. That is, the difference between the motion vector and the predicted motion vector may be signaled.

Note that an inter prediction signal may be generated using not only the motion information of the current block obtained by motion search but also the motion information of adjacent blocks. Specifically, the inter prediction signal is generated in units of sub-blocks in the current block by weighted addition of the prediction signal based on the motion information obtained by motion search and the prediction signal based on the motion information of adjacent blocks. May be. Such inter prediction (motion compensation) is sometimes called OBMC (overlapped block motion compensation).

In such an OBMC mode, information indicating the size of a sub-block for OBMC (for example, called OBMC block size) is signaled at the sequence level. Also, information indicating whether or not to apply the OBMC mode (for example, referred to as an OBMC flag) is signaled at the CU level. Note that the level of signalization of these information does not need to be limited to the sequence level and the CU level, and may be other levels (for example, a picture level, a slice level, a tile level, a CTU level, or a sub-block level). Good.

Note that the motion information may be derived on the decoding device side without being converted into a signal. For example, H.M. A merge mode defined in the H.265 / HEVC standard may be used. Further, for example, the motion information may be derived by performing motion search on the decoding device side. In this case, motion search is performed without using the pixel value of the current block.

Here, a mode in which motion search is performed on the decoding device side will be described. The mode in which motion search is performed on the decoding device side is sometimes called a PMMVD (patterned motion vector derivation) mode or an FRUC (frame rate up-conversion) mode.

First, by referring to the motion vector of an encoded block spatially or temporally adjacent to the current block, a list of a plurality of candidates each having a predicted motion vector (may be common with the merge list) is generated Is done. Then, the evaluation value of each candidate included in the candidate list is calculated, and one candidate is selected based on the evaluation value.

Then, a motion vector for the current block is derived based on the selected candidate motion vector. Specifically, for example, the selected candidate motion vector is directly derived as a motion vector for the current block. Further, for example, the motion vector for the current block may be derived by performing pattern matching in the peripheral region at the position in the reference picture corresponding to the selected candidate motion vector.

Note that the evaluation value is calculated by pattern matching between an area in the reference picture corresponding to the motion vector and a predetermined area.

As the pattern matching, the first pattern matching or the second pattern matching is used. The first pattern matching and the second pattern matching may be referred to as bilateral matching and template matching, respectively.

In the first pattern matching, pattern matching is performed between two blocks in two different reference pictures that follow the motion trajectory of the current block. Therefore, in the first pattern matching, a region in another reference picture along the motion trajectory of the current block is used as the predetermined region for calculating the candidate evaluation value described above.

FIG. 6 is a diagram for explaining pattern matching (bilateral matching) between two blocks along a motion trajectory. As shown in FIG. 6, in the first pattern matching, two blocks along the motion trajectory of the current block (Cur block) and two blocks in two different reference pictures (Ref0, Ref1) are used. By searching for the best matching pair, two motion vectors (MV0, MV1) are derived.

Under the assumption of continuous motion trajectory, the motion vectors (MV0, MV1) pointing to the two reference blocks are temporal distances between the current picture (Cur Pic) and the two reference pictures (Ref0, Ref1). It is proportional to (TD0, TD1). For example, when the current picture is temporally located between two reference pictures and the temporal distances from the current picture to the two reference pictures are equal, the first pattern matching uses a mirror-symmetric bi-directional motion vector Is derived.

In the second pattern matching, pattern matching is performed between a template in the current picture (a block adjacent to the current block in the current picture (for example, an upper and / or left adjacent block)) and a block in the reference picture. Therefore, in the second pattern matching, a block adjacent to the current block in the current picture is used as the predetermined region for calculating the candidate evaluation value described above.

FIG. 7 is a diagram for explaining pattern matching (template matching) between a template in the current picture and a block in the reference picture. As shown in FIG. 7, in the second pattern matching, the current block is searched by searching the reference picture (Ref0) for the block that most closely matches the block adjacent to the current block (Cur block) in the current picture (Cur Pic). Of motion vectors are derived.

Information indicating whether or not to apply such FRUC mode (for example, called FRUC flag) is signaled at the CU level. In addition, when the FRUC mode is applied (for example, when the FRUC flag is true), information indicating the pattern matching method (first pattern matching or second pattern matching) (for example, called the FRUC mode flag) is signaled at the CU level. It becomes. Note that the signalization of these pieces of information need not be limited to the CU level, but may be other levels (for example, sequence level, picture level, slice level, tile level, CTU level, or sub-block level). .

Note that motion information may be derived on the decoding device side by a method different from motion search. For example, the motion vector correction amount may be calculated using a peripheral pixel value for each pixel based on a model assuming constant velocity linear motion.

Here, a mode for deriving a motion vector based on a model assuming constant velocity linear motion will be described. This mode may be referred to as a BIO (bi-directional optical flow) mode.

FIG. 8 is a diagram for explaining a model assuming constant velocity linear motion. In FIG. 8, (v _x , v _y ) indicates a velocity vector, and τ ₀ and τ ₁ are the time between the current picture (Cur Pic) and two reference pictures (Ref ₀ , Ref ₁ ), respectively. The distance. (MVx ₀ , MVy ₀ ) indicates a motion vector corresponding to the reference picture Ref ₀ , and (MVx ₁ , MVy ₁ ) indicates a motion vector corresponding to the reference picture Ref ₁ .

At this time, under the assumption of constant velocity linear motion of the velocity vector (v _x , v _y ), (MVx ₀ , MVy ₀ ) and (MVx ₁ , MVy ₁ ) are (v _x τ ₀ , v _y τ), respectively. ₀ ) and (−v _x τ ₁ , −v _y τ ₁ ), and the following optical flow equation (1) holds.

Here, I ^(k) represents the luminance value of the reference image k (k = 0, 1) after motion compensation. This optical flow equation consists of (i) the product of the time derivative of the luminance value, (ii) the horizontal component of the horizontal velocity and the spatial gradient of the reference image, and (iii) the vertical velocity and the spatial gradient of the reference image. Indicates that the sum of the products of the vertical components of is equal to zero. Based on a combination of this optical flow equation and Hermite interpolation, a block-based motion vector obtained from a merge list or the like is corrected in pixel units.

Note that the motion vector may be derived on the decoding device side by a method different from the derivation of the motion vector based on the model assuming constant velocity linear motion. For example, a motion vector may be derived for each subblock based on the motion vectors of a plurality of adjacent blocks.

Here, a mode for deriving a motion vector for each sub-block based on the motion vectors of a plurality of adjacent blocks will be described. This mode may be referred to as an affine motion compensation prediction mode.

FIG. 9 is a diagram for explaining the derivation of motion vectors in units of sub-blocks based on the motion vectors of a plurality of adjacent blocks. In FIG. 9, the current block includes 16 4 × 4 sub-blocks. Here, the motion vector v ₀ of the upper left corner control point of the current block is derived based on the motion vector of the adjacent block, and the motion vector v ₁ of the upper right corner control point of the current block is derived based on the motion vector of the adjacent sub block. Is done. Then, using the two motion vectors v ₀ and v ₁ , the motion vector (v _x , v _y ) of each sub-block in the current block is derived by the following equation (2).

Here, x and y indicate the horizontal position and vertical position of the sub-block, respectively, and w indicates a predetermined weight coefficient.

Such an affine motion compensation prediction mode may include several modes in which the motion vector derivation methods of the upper left and upper right corner control points are different. Information indicating such an affine motion compensation prediction mode (for example, called an affine flag) is signaled at the CU level. Note that the information indicating the affine motion compensation prediction mode need not be limited to the CU level, but other levels (for example, sequence level, picture level, slice level, tile level, CTU level, or sub-block level). ).

[Prediction control unit]
The prediction control unit 128 selects either the intra prediction signal or the inter prediction signal, and outputs the selected signal to the subtraction unit 104 and the addition unit 116 as a prediction signal.

[Outline of Decoding Device]
Next, an outline of a decoding apparatus capable of decoding the encoded signal (encoded bit stream) output from the encoding apparatus 100 will be described. FIG. 10 is a block diagram showing a functional configuration of decoding apparatus 200 according to Embodiment 1. The decoding device 200 is a moving image / image decoding device that decodes moving images / images in units of blocks.

As illustrated in FIG. 10, the decoding device 200 includes an entropy decoding unit 202, an inverse quantization unit 204, an inverse transformation unit 206, an addition unit 208, a block memory 210, a loop filter unit 212, and a frame memory 214. And an intra prediction unit 216, an inter prediction unit 218, and a prediction control unit 220.

The decoding device 200 is realized by, for example, a general-purpose processor and a memory. In this case, when the software program stored in the memory is executed by the processor, the processor executes the entropy decoding unit 202, the inverse quantization unit 204, the inverse transformation unit 206, the addition unit 208, the loop filter unit 212, and the intra prediction unit. 216, the inter prediction unit 218, and the prediction control unit 220. Also, the decoding apparatus 200 is dedicated to the entropy decoding unit 202, the inverse quantization unit 204, the inverse transformation unit 206, the addition unit 208, the loop filter unit 212, the intra prediction unit 216, the inter prediction unit 218, and the prediction control unit 220. It may be realized as one or more electronic circuits.

Hereinafter, each component included in the decoding device 200 will be described.

[Entropy decoding unit]
The entropy decoding unit 202 performs entropy decoding on the encoded bit stream. Specifically, the entropy decoding unit 202 performs arithmetic decoding from a coded bit stream to a binary signal, for example. Then, the entropy decoding unit 202 debinarizes the binary signal. As a result, the entropy decoding unit 202 outputs the quantized coefficient to the inverse quantization unit 204 in units of blocks.

[Inverse quantization unit]
The inverse quantization unit 204 inversely quantizes the quantization coefficient of a decoding target block (hereinafter referred to as a current block) that is an input from the entropy decoding unit 202. Specifically, the inverse quantization unit 204 inversely quantizes each quantization coefficient of the current block based on the quantization parameter corresponding to the quantization coefficient. Then, the inverse quantization unit 204 outputs the quantization coefficient (that is, the transform coefficient) obtained by inverse quantization of the current block to the inverse transform unit 206.

[Inverse conversion part]
The inverse transform unit 206 restores the prediction error by inverse transforming the transform coefficient that is an input from the inverse quantization unit 204.

For example, when the information read from the encoded bit stream indicates that EMT or AMT is applied (for example, the AMT flag is true), the inverse conversion unit 206 determines the current block based on the information indicating the read conversion type. Inversely transform the conversion coefficient of.

Also, for example, when the information read from the encoded bitstream indicates that NSST is applied, the inverse transform unit 206 applies inverse retransformation to the transform coefficient.

[Addition part]
The adder 208 reconstructs the current block by adding the prediction error input from the inverse converter 206 and the prediction sample input from the prediction controller 220. Then, the adding unit 208 outputs the reconfigured block to the block memory 210 and the loop filter unit 212.

[Block memory]
The block memory 210 is a storage unit for storing a block that is referred to in intra prediction and that is within a decoding target picture (hereinafter referred to as a current picture). Specifically, the block memory 210 stores the reconstructed block output from the adding unit 208.

[Loop filter section]
The loop filter unit 212 applies a loop filter to the block reconstructed by the adding unit 208, and outputs the filtered reconstructed block to the frame memory 214, the display device, and the like.

If the ALF on / off information read from the encoded bitstream indicates ALF on, one filter is selected from the plurality of filters based on the local gradient direction and activity, The selected filter is applied to the reconstruction block.

[Frame memory]
The frame memory 214 is a storage unit for storing a reference picture used for inter prediction, and is sometimes called a frame buffer. Specifically, the frame memory 214 stores the reconstructed block filtered by the loop filter unit 212.

[Intra prediction section]
The intra prediction unit 216 performs intra prediction with reference to the block in the current picture stored in the block memory 210 based on the intra prediction mode read from the encoded bitstream, so that a prediction signal (intra prediction Signal). Specifically, the intra prediction unit 216 generates an intra prediction signal by performing intra prediction with reference to a sample (for example, luminance value and color difference value) of a block adjacent to the current block, and performs prediction control on the intra prediction signal. Output to the unit 220.

In addition, when the intra prediction mode that refers to the luminance block is selected in the intra prediction of the color difference block, the intra prediction unit 216 may predict the color difference component of the current block based on the luminance component of the current block. .

In addition, when the information read from the encoded bitstream indicates application of PDPC, the intra prediction unit 216 corrects the pixel value after intra prediction based on the gradient of the reference pixel in the horizontal / vertical direction.

[Inter prediction section]
The inter prediction unit 218 refers to the reference picture stored in the frame memory 214 and predicts the current block. Prediction is performed in units of a current block or a sub-block (for example, 4 × 4 block) in the current block. For example, the inter prediction unit 218 generates an inter prediction signal of the current block or sub-block by performing motion compensation using motion information (for example, a motion vector) read from the encoded bitstream, and generates the inter prediction signal. The result is output to the prediction control unit 220.

When the information read from the encoded bitstream indicates that the OBMC mode is to be applied, the inter prediction unit 218 includes not only the motion information of the current block obtained by motion search but also the motion information of adjacent blocks. To generate an inter prediction signal.

Also, when the information read from the encoded bitstream indicates that the FRUC mode is applied, the inter prediction unit 218 follows the pattern matching method (bilateral matching or template matching) read from the encoded stream. Motion information is derived by performing motion search. Then, the inter prediction unit 218 performs motion compensation using the derived motion information.

In addition, when the BIO mode is applied, the inter prediction unit 218 derives a motion vector based on a model assuming constant velocity linear motion. Also, when the information read from the encoded bitstream indicates that the affine motion compensated prediction mode is applied, the inter prediction unit 218 determines the motion vector in units of subblocks based on the motion vectors of a plurality of adjacent blocks. Is derived.

[Prediction control unit]
The prediction control unit 220 selects either the intra prediction signal or the inter prediction signal, and outputs the selected signal to the adding unit 208 as a prediction signal.

[Inter-screen prediction processing]
FIG. 11 is a flowchart of inter-screen prediction processing in the encoding method according to the present embodiment. When the encoding apparatus 100 illustrated in FIG. 1 encodes a moving image including a plurality of pictures, the inter prediction unit 126 and the like of the encoding apparatus 100 execute the processing illustrated in FIG.

The inter prediction unit 126 repeatedly performs the processing of steps S101 to S108 for each of a plurality of blocks included in the processing target picture. Here, the block is a processing unit obtained by dividing the target picture, and is, for example, an image area called a coding unit, a prediction block, or a prediction unit. The block may be a sub-block obtained by dividing these processing units.

First, the inter prediction unit 126 derives a plurality of candidate motion vectors from the motion vectors of the processed blocks (S101). Specifically, the inter prediction unit 126 derives a candidate motion vector of the processing target block from the motion vector used for motion compensation of the processed block.

More specifically, the inter prediction unit 126 may derive a motion vector used for motion compensation of the processed block as a candidate motion vector of the processing target block. Further, the inter prediction unit 126 may scale the motion vector used for motion compensation of the processed block at a predetermined ratio, and derive the scaled motion vector as a candidate motion vector of the processing target block.

Here, the processed block is a sub-block processed before the processing target block is processed, and can also be expressed as a preceding block. For example, the processed sub-block may be a block on which motion compensation has been performed, or may be an encoded or decoded block.

Also, for example, the processed block for deriving the candidate motion vector of the processing target block is specified by the position of the processing target block. Specifically, the processed block for deriving the candidate motion vector of the processing target block may be a processed block that is spatially or temporally adjacent to the processing target block.

Also, the inter prediction unit 126 may derive candidate motion vectors of the processing target block from a plurality of motion vectors of a plurality of processed blocks. That is, the inter prediction unit 126 may derive a candidate motion vector of a processing target block by combining a plurality of motion vectors of a plurality of processed blocks. Further, the inter prediction unit 126 may derive a plurality of candidate motion vectors of the processing target block from a plurality of motion vectors of the plurality of processed blocks.

Next, the inter prediction unit 126 selects a final motion vector from a plurality of candidate motion vectors. Here, the inter prediction unit 126 refers to only the processed region of the processing target region and the processed region. That is, the inter prediction unit 126 selects the final motion vector of the processing target block by referring to the reconstructed image of the processed area in the plurality of processed blocks without referring to the image of the processing target area in the processing target block. To do.

Specifically, the inter prediction unit 126 refers to a reconstructed image or the like of a plurality of candidate areas indicated by a plurality of candidate motion vectors using the bilateral FRUC method, and calculates an evaluation value for each candidate motion vector. calculate. Then, the inter prediction unit 126 selects a candidate motion vector having the highest evaluation value among a plurality of candidate motion vectors as a final motion vector.

First, the operation when the processing target picture is a B picture (B picture in S102) will be described. FIG. 12 is a diagram for explaining a method for calculating an evaluation value in this case.

In this example, the processing target picture is a B picture, and has two reference picture lists, a first reference picture list and a second reference picture list. Two processed pictures are registered in each of the first reference picture list and the second reference picture list. Further, the candidate motion vector to be evaluated indicates the 0th reference picture (first reference picture) in the first reference picture list.

The inter prediction unit 126 calculates an evaluation value using the first reference picture and the second reference picture. Here, the second reference picture is registered in a picture list (second reference picture list) different from the first reference picture, which is included in a picture that can be referred to in the picture memory (for example, the frame memory 122 or 214). Of the pictures, the display time is closest to the processing target picture. Further, both the first reference picture and the second reference picture are pictures whose display time is earlier than the processing target picture.

The inter prediction unit 126, with respect to the processing target block, a candidate region that is a reconstructed image at the same position of the first reference picture specified by the candidate motion vector to be evaluated, and the second reference specified by the symmetric motion vector A difference value with respect to a symmetric region which is a reconstructed image at an equivalent position of a picture is derived. For example, the shape and size of the processing target block are the same as the shape and size of the candidate region and the symmetric region.

Also, the inter prediction unit 126 derives a symmetric motion vector by scaling the candidate motion vector by a predetermined ratio. Here, the predetermined ratio refers to the display order of the second reference picture from the display order of the processing target picture with respect to the value obtained by subtracting the display order of the first reference picture from the display order (display time) of the processing target picture. It may be a ratio of values obtained by subtracting. The display order can be expressed by POC (Picture Order Count).

Also, the inter prediction unit 126 derives a difference value between the reconstructed image of the candidate area and the reconstructed image of the symmetric area by using a sum of absolute differences (SAD), a sum of squared differences (SSD), or the like.

The inter prediction unit 126 calculates an evaluation value using the obtained difference value. For example, the inter prediction unit 126 calculates a higher evaluation value as the difference value is smaller. Note that the inter prediction unit 126 may calculate an evaluation value using information other than the difference value.

FIG. 13 is a diagram showing another example of operation. The configuration of the reference picture list is the same as that shown in FIG. In the example illustrated in FIG. 13, the candidate motion vector to be evaluated indicates the 0th reference picture (first reference picture) in the second reference picture list.

Similarly to the above, the inter prediction unit 126 performs the most processing among the pictures registered in a picture list (first reference picture list) different from the first reference picture included in the referable pictures in the picture memory. A picture whose display time is close to the target picture is selected as the second reference picture. Therefore, in this case, the 0th reference picture in the first reference picture list located between the processing target picture and the first reference picture in the display time order is selected as the second reference picture. Similarly to the above, both the first reference picture and the second reference picture are pictures whose display time is earlier than the processing target picture.

In addition, the inter prediction unit 126 identifies a candidate area, a symmetric motion vector, and a symmetric area by the same method as described above, and calculates an evaluation value based on a difference value between the candidate area and the symmetric area. In the example illustrated in FIG. 13, the second reference picture is located after the first reference picture in display time order, and thus the symmetric motion vector indicates the reverse direction of the candidate motion vector.

Through such processing, the inter prediction unit 126 calculates the evaluation value of each of the plurality of candidate motion vectors.

Next, the inter prediction unit 126 selects the candidate motion vector having the best evaluation value (for example, the highest evaluation value) among the plurality of candidate motion vectors as the final motion vector.

Thus, the inter prediction unit 126 selects a final motion vector using the two reference pictures indicated by the first reference picture list and the second reference picture list (S104). In the examples shown in FIGS. 12 and 13, the reference picture number 0 in the reference picture list is used as the first reference picture and the second reference picture, but reference pictures other than the number 0 may be used. .

Next, the inter prediction unit 126 performs motion compensation using both the candidate region of the first reference picture pointed to by the final motion vector and the symmetric region of the second reference picture pointed to by the symmetric motion vector, thereby predicting the predicted image. Is generated (S105).

Next, the operation when the processing target picture is a P picture will be described. FIG. 14 shows an operation example when the processing target picture is a P picture (P picture in S102), and two processed pictures are registered in the first reference picture list of the processing target picture (Yes in S103). FIG. The candidate motion vector to be evaluated indicates the first reference picture (first reference picture) in the first reference picture list.

Also in this case, the inter prediction unit 126 selects, as a second reference picture, a picture that is the closest to the processing target picture among the pictures different from the first reference picture included in the referenceable pictures in the picture memory. To do. Therefore, in this case, the 0th reference picture in the first reference picture list is selected as the second reference picture. Similarly to the above, both the first reference picture and the second reference picture are pictures whose display time is earlier than the processing target picture.

In FIG. 14, referenceable pictures in the picture memory include pictures other than those included in the first reference picture list, but these pictures may not be included in the referenceable pictures. Further, when the referenceable picture in the picture memory includes a picture other than the picture included in the first reference picture list, the inter prediction unit 126 refers to the first reference picture included in the first reference picture list. Of the different pictures, a picture having a display time closest to the processing target picture may be selected as the second reference picture. That is, the inter prediction unit 126 may select the second reference picture from the pictures included in the first reference picture list among the referenceable pictures in the picture memory.

In addition, the inter prediction unit 126 identifies a candidate area, a symmetric motion vector, and a symmetric area by the same method as described above, and calculates an evaluation value based on a difference value between the candidate area and the symmetric area.

Through such processing, the inter prediction unit 126 calculates the evaluation value of each of the plurality of candidate motion vectors. Next, the inter prediction unit 126 selects a candidate motion vector having the best evaluation value (for example, the highest evaluation value) among the plurality of candidate motion vectors as the final motion vector.

Thus, the inter prediction unit 126 selects the final motion vector using the two reference pictures indicated by the first reference picture list (S106). In the example illustrated in FIG. 14, the first reference picture in the first reference picture list is used as the first reference picture, but a reference picture other than the first reference picture may be used.

Next, the inter prediction unit 126 generates a prediction image by performing motion compensation using the candidate region of the first reference picture indicated by the final motion vector (S107). That is, the inter prediction unit 126 performs motion compensation without using a symmetric region. Note that the inter prediction unit 126 may generate a prediction image by performing motion compensation using both the candidate region and the symmetric region, similarly to the B picture.

Next, the operation when the processing target picture is a P picture (P picture in S102) and only one processed picture is registered in the first reference picture list of the processing target picture (No in S103) will be described. To do. FIG. 15 is a diagram illustrating an operation example in this case. In this example, the candidate motion vector to be evaluated indicates the 0th reference picture (first reference picture) in the first reference picture list.

Also in this case, the inter prediction unit 126 selects, as a second reference picture, a picture that is the closest to the processing target picture among the pictures different from the first reference picture included in the referenceable pictures in the picture memory. To do. Similarly to the above, both the first reference picture and the second reference picture are pictures whose display time is earlier than the processing target picture.

However, in this case, the second reference picture is a picture that is not registered in the first reference picture list. Therefore, the encoding device 100 and the decoding device 200 store the second reference picture as a picture that can be referred to in the picture memory. For example, the encoding apparatus 100 generates an encoded bit stream including information specifying the second reference picture. The decoding device 200 stores the second reference picture as a picture that can be referred to in the picture memory by referring to the information. For example, the information is stored in the header area of the encoded bitstream as information different from the reference picture list. For example, this information is stored in one of the header areas of the sequence layer, the picture layer, and the slice layer.

In FIG. 15, the referenceable picture in the picture memory includes a plurality of pictures other than the pictures included in the first reference picture list. However, one or more pictures other than the pictures included in the first reference picture list are included. May be included. For example, the one or more pictures include a picture that is different from the first reference picture and has a display time closest to the processing target picture among picture pictures having a display time earlier than the processing target picture.

As described above, the inter prediction unit 126 selects a final motion vector using one reference picture indicated by the first reference picture list and another picture not indicated by the first reference picture list (S108).

Next, the inter prediction unit 126 generates a prediction image by performing motion compensation using the candidate region of the first reference picture indicated by the final motion vector (S107). That is, the inter prediction unit 126 performs motion compensation without using a symmetric region. Note that the inter prediction unit 126 may generate a measured image by performing motion compensation using both the candidate region and the symmetric region, similarly to the B picture.

In addition, after selecting the final motion vector described above, the inter prediction unit 126 further searches for a region around the region indicated by the final motion vector using the same method, and the evaluation value is further increased. The final motion vector may be corrected so as to indicate a region having a good value, and motion compensation may be performed using the corrected final motion vector.

Further, the processing shown in FIG. 11 may be performed not in units of blocks but in units of sub-blocks obtained by further dividing the block. Further, the inter prediction unit 126 may perform processing in two stages by combining block-unit processing and sub-block-unit processing.

In the above description, an example is shown in which the display times of the first reference picture and the second reference picture are both before the display time of the processing target picture, but both the display times of the first reference picture and the second reference picture are processed. It may be after the display time of the target picture.

Further, the process shown in FIG. 11 is performed in both the encoding device 100 and the decoding device 200.

As described above, encoding apparatus 100 or decoding apparatus 200 according to the present embodiment uses a plurality of candidate motion vectors for a processing target block included in a processing target picture for motion compensation of the processed block. Derived from the motion vector (S101), without using the image area of the processing target block, with reference to two processed reference pictures whose display times are located in the same direction between the front and rear of the processing target picture Then, a final motion vector is selected from a plurality of candidate motion vectors (S104, S106, or S108), and motion compensation of the processing target block is performed using the final motion vector (S105 or S107).

Also, the processing target picture is a P picture (P picture in S102). According to this, since the bilateral FRUC can be used for the P picture, the bilateral FRUC method can be used in more cases. Therefore, encoding efficiency can be improved.

When two reference pictures are indicated in the reference picture list for the processing target picture (Yes in S103), the two processed reference pictures are the two reference pictures indicated in the reference picture list. .

When one reference picture is indicated in the reference picture list for the processing target picture (No in S103), one of the two processed reference pictures is one reference picture indicated in the reference picture list. The other of the two processed reference pictures is another processed reference picture not shown in the reference picture list.

Also, the encoding device 100 or the decoding device 200 stores one reference picture shown in the reference picture list and another processed reference picture in the picture memory.

Further, in the selection of the final motion vector (S108), the evaluation values of each of the plurality of candidate motion vectors are calculated with reference to the two processed reference pictures, and the final motion vector is determined based on the calculated evaluation values. One of the two processed reference pictures is a reference picture indicated by the candidate motion vector to be processed among the plurality of candidate motion vectors, and the other of the two processed reference pictures can be referred to Of the pictures, the display time is the closest to the processing target picture.

Further, the processing target picture is a B picture (B picture in S102). According to this, bilateral FRUC can be used even in the case where B pictures do not have two pictures that sandwich the processing target block in the display order. Therefore, the bilateral FRUC method can be used in more cases, so that the coding efficiency can be improved.

Further, in the selection of the final motion vector (S104), the evaluation values of each of the plurality of candidate motion vectors are calculated with reference to the two processed reference pictures, and the final motion vector is determined based on the calculated evaluation values. select. The processing target picture (B picture) has a first reference picture list and a second reference picture list. One of the two processed reference pictures is a reference picture indicated by a candidate motion vector to be processed among a plurality of candidate motion vectors, and is a reference picture belonging to the first reference picture list. The other of the two processed reference pictures is a picture having a display time closest to the processing target picture among the reference pictures belonging to the second reference picture list.

(Embodiment 2)
In the present embodiment, another form of inter-screen prediction processing will be described. In this embodiment, candidate motion vectors for calculating evaluation values are narrowed down. Thereby, a processing amount can be reduced.

FIG. 16 is a flowchart of inter-screen prediction processing in the encoding method according to the present embodiment. When the encoding device 100 illustrated in FIG. 1 encodes a moving image including a plurality of pictures, the inter prediction unit 126 and the like of the encoding device 100 execute the processing illustrated in FIG.

Further, the processing target picture is a B picture, and has a first reference picture list and a second reference picture list.

First, the inter prediction unit 126 selects one of the first reference picture list and the second reference picture list as a selected reference picture list (S201). Details of this process will be described later.

Next, the encoding device 100 (for example, the entropy encoding unit 110) encodes the selected reference picture list information for specifying the selected reference picture list (S202). That is, the encoding apparatus 100 generates an encoded bitstream including selected reference picture list information. For example, the selected reference picture list information is stored in one of the header areas of the sequence layer, the picture layer, and the slice layer. For example, the selected reference picture list information is a 1-bit flag, the first value indicates that the first reference picture list is the selected reference picture list, and the second value is the second reference picture list. Indicates a selected reference picture list.

Next, the inter prediction unit 126 performs the following processing in units of blocks. First, the inter prediction unit 126 derives a plurality of candidate motion vectors from the motion vectors of the processed blocks (S203). The details of this process are the same as in step S101 of the first embodiment.

Next, the inter prediction unit 126 determines one or more evaluation target motion vectors by narrowing down a plurality of candidate motion vectors (S204). Next, the inter prediction unit 126 calculates each evaluation value of the evaluation target motion vector, and selects an evaluation target motion vector having the best evaluation value as a final motion vector (S205). As a method for calculating the evaluation value, for example, a method similar to that of the first embodiment can be used. However, in the present embodiment, the inter prediction unit 126 may calculate the evaluation value using two processed pictures, a picture with a display time before and a picture after the processing target picture.

Finally, the inter prediction unit 126 generates a prediction image by performing motion compensation using the selected final motion vector (S206).

In narrowing down a plurality of candidate motion vectors (S204), the inter prediction unit 126 selects, for each of the plurality of candidate motion vectors, a reference picture list that includes a reference picture indicated by the candidate motion vector, determined in step S201. It is determined whether it matches the reference picture list (S204A). That is, the inter prediction unit 126 determines whether the reference picture indicated by the candidate motion vector to be determined is included in the selected reference picture list. When they do not match (No in S204A), the inter prediction unit 126 excludes the candidate motion vector to be determined from the evaluation target motion vector (S204B). Further, when they match (Yes in S204A), the inter prediction unit 126 determines the candidate motion vector to be determined as the evaluation target motion vector. That is, the inter prediction unit 126 determines one or more candidate motion vectors indicating the reference pictures included in the selected reference picture list among the plurality of candidate motion vectors as the evaluation target motion vectors.

As described above, the number of candidate motion vectors that need to be evaluated to select the final motion vector can be suppressed, so that the processing amount can be reduced.

Next, a method for determining the selected reference picture list (S201) will be described. FIG. 17 is a flowchart of the selection reference picture list determination process (S201).

First, the inter prediction unit 126 represents the picture Pic1 registered at the top (0th) of the first reference picture list and the picture Pic2 registered at the top (0th) of the second reference picture list. (S211).

Next, the inter prediction unit 126 compares the display time difference between the processing target picture and the first representative picture (Pic1) with the display time difference between the processing target picture and the second representative picture (Pic2), A reference picture list including a representative picture with a small display time difference from the processing target picture is determined as a selected reference picture list (S212, S213, and S214).

If the difference in display time is the same, the inter prediction unit 126 compares the priorities at the time of decoding the first representative picture and the second representative picture, and selects a reference picture list including a representative picture with a higher priority. The reference picture list is determined (S215, S216, and S217). Here, the priority at the time of decoding is, for example, a temporal scalability number. The case where the display time difference is the same is, for example, a case where the first representative picture and the second representative picture exist before and after the processing target picture and the display time difference is the same.

If the priorities are the same, the inter prediction unit 126 compares the quantization widths of the first representative picture and the second representative picture, and selects a reference picture list including a representative picture having a small quantization width. The list is determined (S218 to S220).

Note that the inter prediction unit 126 may perform only some of the three determinations described here, or may change the order of these determinations. In addition, the inter prediction unit 126 may perform the determination by adding a determination other than the above.

Next, the operation of the decoding apparatus 200 according to this embodiment will be described. FIG. 18 is a flowchart of inter-screen prediction processing in the decoding method according to the present embodiment. Note that the processing in steps S302 to S305 is the same as the processing in steps S203 to S206 shown in FIG.

The inter prediction unit 218 of the decoding device 200 selects one of the first reference picture list and the second reference picture list as the selected reference picture list (S301).

FIG. 19 is a flowchart of the selection reference picture list determination process (S301) in the decoding process.

First, the decoding device 200 (for example, the entropy decoding unit 202) acquires selected reference picture list information from the encoded bitstream (S311). For example, the decoding device 200 decodes the selected reference picture list information from the header area of any one of the sequence layer, the picture layer, and the slice layer of the encoded bitstream.

The inter prediction unit 218 determines one of the first reference picture list and the second reference picture list as the selected reference picture list according to the value of the selected reference picture list information. For example, when the selected reference picture list information indicates the first value (first value in S312), the inter prediction unit 218 determines the first reference picture list as the selected reference picture list (S313). When the selected reference picture list information indicates the second value (second value in S312), the inter prediction unit 218 determines the second reference picture list as the selected reference picture list (S314).

Note that the decoding device 200 may perform the same processing as the processing shown in FIG. 17 performed by the encoding device 100 in step S301 instead of the processing shown in FIG. In this case, the encoding apparatus 100 may not include the selected reference picture list information in the encoded bitstream. Thereby, the data amount of an encoding bit stream can be reduced.

As described above, encoding apparatus 100 or decoding apparatus 200 according to the present embodiment obtains a plurality of candidate motion vectors for a processing target block included in a processing target picture that is a B picture having two reference picture lists. Derived from the motion vector used for motion compensation of the processed block (S203 or S302), does not use the image area of the processing target block, and is one of two reference picture lists among a plurality of candidate motion vectors An evaluation value of a candidate motion vector indicating the reference picture indicated in the selected reference picture list is calculated, and a final motion vector is calculated from the candidate motion vector indicating the reference picture indicated in the selected reference picture list based on the calculated evaluation value. Select (S204 and S205, or S303 and S304), the final motion vector Performing motion compensation of the current block using (S206 or S305).

According to this, since the candidate motion vector for calculating the evaluation value can be reduced, the processing amount can be reduced. Also, the reference pictures shown in the two reference picture lists are often symmetric. Therefore, even when the evaluation target is limited to only the candidate motion vector indicating the reference picture shown in one reference picture list, the accuracy does not drop significantly. That is, the method of the present embodiment can reduce the processing amount while suppressing a decrease in accuracy.

In addition, the encoding apparatus 100 or the decoding apparatus 200 further selects a reference picture list in which the display time of the reference picture registered at the top is closer to the display time of the processing target picture from the two reference picture lists. (S212 to S214). According to this, more useful candidate motion vectors can be extracted.

In addition, the encoding apparatus 100 or the decoding apparatus 200 further selects a reference picture list that is set so that the reference picture registered at the head is decoded with higher priority from the two reference picture lists. The reference picture list is determined (S215 to S217). According to this, more useful candidate motion vectors can be extracted.

In addition, the encoding apparatus 100 or the decoding apparatus 200 further determines, as the selected reference picture list, a reference picture list having a smaller quantization width of the reference picture registered at the top of the two reference picture lists. (S218 to S220). According to this, more useful candidate motion vectors can be extracted.

Further, the encoding apparatus 100 further generates an encoded bitstream including information for specifying the selected reference picture list (S202). Further, the decoding apparatus 200 further acquires information for specifying the selected reference picture list included in the encoded bitstream (S311), and specifies the selected reference picture list using the information (S312 to S314). ). According to this, since it is not necessary to perform the process of determining the selected motion vector in the decoding apparatus 200, the processing amount of the decoding apparatus 200 can be reduced.

[Example of encoding device implementation]
FIG. 20 is a block diagram illustrating an implementation example of encoding apparatus 100 according to Embodiment 1 or Embodiment 2. The encoding device 100 includes a circuit 160 and a memory 162. For example, a plurality of components of the encoding device 100 shown in FIG. 1 are implemented by the circuit 160 and the memory 162 shown in FIG.

The circuit 160 is a circuit that performs information processing and is a circuit that can access the memory 162. For example, the circuit 160 is a dedicated or general-purpose electronic circuit that encodes image information. The circuit 160 may be a processor such as a CPU. The circuit 160 may be an aggregate of a plurality of electronic circuits. Further, for example, the circuit 160 may serve as a plurality of constituent elements excluding the constituent elements for storing information among the plurality of constituent elements of the encoding device 100 illustrated in FIG. 1.

The memory 162 is a general purpose or dedicated memory in which information for the circuit 160 to encode image information is stored. The memory 162 may be an electronic circuit or may be connected to the circuit 160. In addition, the memory 162 may be included in the circuit 160. The memory 162 may be an aggregate of a plurality of electronic circuits. Further, the memory 162 may be a magnetic disk or an optical disk, or may be expressed as a storage or a recording medium. The memory 162 may be a non-volatile memory or a volatile memory.

For example, the memory 162 may store image information to be encoded, or may store a bit string corresponding to the encoded image information. The memory 162 may store a program for the circuit 160 to encode image information.

For example, the circuit 160 may serve as a component for storing information among a plurality of components of the encoding device 100 illustrated in FIG. Specifically, the memory 162 may serve as the block memory 118 and the frame memory 122 shown in FIG.

Note that in the encoding device 100, not all of the plurality of components shown in FIG. 1 or the like may be mounted, or all of the plurality of processes described above may not be performed. Some of the plurality of components shown in FIG. 1 and the like may be included in another device, and some of the plurality of processes described above may be executed by another device. Then, in the encoding device 100, a part of the plurality of components shown in FIG. 1 and the like are mounted, and a part of the plurality of processes described above is performed, so that the processing delay can be suppressed. .

[Decoding device implementation example]
FIG. 21 is a block diagram illustrating an implementation example of the decoding device 200 according to Embodiment 1 or Embodiment 2. The decoding device 200 includes a circuit 260 and a memory 262. For example, a plurality of components of the decoding device 200 illustrated in FIG. 10 are implemented by the circuit 260 and the memory 262 illustrated in FIG.

The circuit 260 is a circuit that performs information processing and is a circuit that can access the memory 262. For example, the circuit 260 is a general-purpose or dedicated electronic circuit that decodes image information. The circuit 260 may be a processor such as a CPU. The circuit 260 may be an aggregate of a plurality of electronic circuits. Further, for example, the circuit 260 may serve as a plurality of constituent elements excluding the constituent elements for storing information among the plurality of constituent elements of the decoding device 200 illustrated in FIG. 10.

The memory 262 is a general purpose or dedicated memory in which information for the circuit 260 to decode the image information is stored. The memory 262 may be an electronic circuit or may be connected to the circuit 260. Further, the memory 262 may be included in the circuit 260. The memory 262 may be an aggregate of a plurality of electronic circuits. The memory 262 may be a magnetic disk or an optical disk, or may be expressed as a storage or a recording medium. Further, the memory 262 may be a nonvolatile memory or a volatile memory.

For example, the memory 262 may store a bit string corresponding to the encoded image information, or may store image information corresponding to the decoded bit string. The memory 262 may store a program for the circuit 260 to decode the image information.

For example, the circuit 260 may serve as a component for storing information among a plurality of components of the decoding device 200 illustrated in FIG. Specifically, the memory 262 may serve as the block memory 210 and the frame memory 214 shown in FIG.

Note that in the decoding device 200, not all of the plurality of components shown in FIG. 10 and the like may be implemented, or all of the plurality of processes described above may not be performed. Some of the plurality of components shown in FIG. 10 and the like may be included in another device, and some of the plurality of processes described above may be executed by another device. In the decoding device 200, a part of the plurality of components illustrated in FIG. 10 and the like are mounted, and a part of the plurality of processes described above is performed, so that processing delay can be suppressed.

As described above, the encoding device and the decoding device according to the present embodiment have been described, but the present disclosure is not limited to this embodiment.

Further, each processing unit included in the encoding device and the decoding device according to the above embodiment is typically realized as an LSI which is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them.

Further, the integration of circuits is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

In each of the above embodiments, each component may be configured by dedicated hardware or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or a processor reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory.

In other words, the encoding device and the decoding device include a processing circuit and a storage device (storage) electrically connected to the processing circuit (accessible from the processing circuit). The processing circuit includes at least one of dedicated hardware and a program execution unit. Further, when the processing circuit includes a program execution unit, the storage device stores a software program executed by the program execution unit. The processing circuit executes the encoding method or the decoding method in the above embodiment using a storage device.

Further, the present disclosure may be the above software program or a non-transitory computer readable recording medium on which the above program is recorded. Needless to say, the program can be distributed via a transmission medium such as the Internet.

Further, all the numbers used above are examples for specifically explaining the present disclosure, and the present disclosure is not limited to the illustrated numbers.

In addition, division of functional blocks in the block diagram is an example, and a plurality of functional blocks can be realized as one functional block, a single functional block can be divided into a plurality of functions, or some functions can be transferred to other functional blocks. May be. In addition, functions of a plurality of functional blocks having similar functions may be processed in parallel or time-division by a single hardware or software.

In addition, the order in which the steps included in the above encoding method or decoding method are executed is for illustrating the present disclosure specifically, and may be in an order other than the above. Also, some of the above steps may be executed simultaneously (in parallel) with other steps.

As described above, the encoding device, the decoding device, the encoding method, and the decoding method according to one or more aspects of the present disclosure have been described based on the embodiment, but the present disclosure is limited to the embodiment. It is not a thing. Unless it deviates from the gist of the present disclosure, one or more of the present disclosure may be applied to various modifications conceived by those skilled in the art in the present embodiment or a configuration constructed by combining components in different embodiments. It may be included within the scope of the embodiments.

(Embodiment 3)
In each of the above embodiments, each of the functional blocks can usually be realized by an MPU, a memory, and the like. Further, the processing by each functional block is usually realized by a program execution unit such as a processor reading and executing software (program) recorded on a recording medium such as a ROM. The software may be distributed by downloading or the like, or may be distributed by being recorded on a recording medium such as a semiconductor memory. Naturally, each functional block can be realized by hardware (dedicated circuit).

Further, the processing described in each embodiment may be realized by centralized processing using a single device (system), or may be realized by distributed processing using a plurality of devices. Good. The number of processors that execute the program may be one or more. That is, centralized processing may be performed, or distributed processing may be performed.

The present invention is not limited to the above embodiments, and various modifications are possible, and these are also included in the scope of the present invention.

Furthermore, application examples of the moving picture coding method (picture coding method) or the moving picture decoding method (picture decoding method) shown in the above embodiments and a system using the same will be described. The system includes an image encoding device using an image encoding method, an image decoding device using an image decoding method, and an image encoding / decoding device including both. Other configurations in the system can be appropriately changed according to circumstances.

[Example of use]
FIG. 22 is a diagram showing an overall configuration of a content supply system ex100 that implements a content distribution service. The communication service providing area is divided into desired sizes, and base stations ex106, ex107, ex108, ex109, and ex110, which are fixed wireless stations, are installed in each cell.

In the content supply system ex100, devices such as a computer ex111, a game machine ex112, a camera ex113, a home appliance ex114, and a smartphone ex115 via the Internet ex101, the Internet service provider ex102 or the communication network ex104, and the base stations ex106 to ex110. Is connected. The content supply system ex100 may be connected by combining any of the above elements. Each device may be directly or indirectly connected to each other via a telephone network or a short-range wireless communication without using the base stations ex106 to ex110 which are fixed wireless stations. The streaming server ex103 is connected to each device such as a computer ex111, a game machine ex112, a camera ex113, a home appliance ex114, and a smartphone ex115 via the Internet ex101. The streaming server ex103 is connected to a terminal in a hot spot in the airplane ex117 via the satellite ex116.

Note that a wireless access point or a hot spot may be used instead of the base stations ex106 to ex110. Further, the streaming server ex103 may be directly connected to the communication network ex104 without going through the Internet ex101 or the Internet service provider ex102, or may be directly connected to the airplane ex117 without going through the satellite ex116.

The camera ex113 is a device that can shoot still images and moving images such as a digital camera. The smartphone ex115 is a smartphone, a mobile phone, a PHS (Personal Handyphone System), or the like that corresponds to a mobile communication system generally called 2G, 3G, 3.9G, 4G, and 5G in the future.

The home appliance ex118 is a device included in a refrigerator or a household fuel cell cogeneration system.

In the content supply system ex100, a terminal having a photographing function is connected to the streaming server ex103 through the base station ex106 or the like, thereby enabling live distribution or the like. In live distribution, the terminal (computer ex111, game machine ex112, camera ex113, home appliance ex114, smartphone ex115, terminal in airplane ex117, etc.) is used for the still image or video content captured by the user using the terminal. The encoding process described in each embodiment is performed, and the video data obtained by the encoding and the sound data obtained by encoding the sound corresponding to the video are multiplexed, and the obtained data is transmitted to the streaming server ex103. That is, each terminal functions as an image encoding device according to an aspect of the present invention.

On the other hand, the streaming server ex103 streams the content data transmitted to the requested client. The client is a computer or the like in the computer ex111, the game machine ex112, the camera ex113, the home appliance ex114, the smart phone ex115, or the airplane ex117 that can decode the encoded data. Each device that has received the distributed data decrypts and reproduces the received data. That is, each device functions as an image decoding device according to an aspect of the present invention.

[Distributed processing]
The streaming server ex103 may be a plurality of servers or a plurality of computers, and may process, record, and distribute data in a distributed manner. For example, the streaming server ex103 may be realized by a CDN (Contents Delivery Network), and content distribution may be realized by a network connecting a large number of edge servers and edge servers distributed all over the world. In CDN, edge servers that are physically close to each other are dynamically allocated according to clients. Then, the content can be cached and distributed to the edge server, thereby reducing the delay. Also, if some error occurs or the communication status changes due to an increase in traffic, etc., the processing is distributed among multiple edge servers, the distribution subject is switched to another edge server, or the part of the network where the failure has occurred Since detouring can be continued, high-speed and stable distribution can be realized.

In addition to the distributed processing of the distribution itself, the captured data may be encoded at each terminal, may be performed on the server side, or may be shared with each other. As an example, in general, in an encoding process, a processing loop is performed twice. In the first loop, the complexity of the image or the code amount in units of frames or scenes is detected. In the second loop, processing for maintaining the image quality and improving the coding efficiency is performed. For example, the terminal performs the first encoding process, and the server receiving the content performs the second encoding process, thereby improving the quality and efficiency of the content while reducing the processing load on each terminal. it can. In this case, if there is a request to receive and decode in almost real time, the encoded data of the first time performed by the terminal can be received and reproduced by another terminal, enabling more flexible real-time distribution. Become.

As another example, the camera ex113 or the like extracts a feature amount from an image, compresses data relating to the feature amount as metadata, and transmits the metadata to the server. The server performs compression according to the meaning of the image, for example, by determining the importance of the object from the feature amount and switching the quantization accuracy. The feature data is particularly effective for improving the accuracy and efficiency of motion vector prediction at the time of re-compression on the server. Also, simple coding such as VLC (variable length coding) may be performed at the terminal, and coding with a large processing load such as CABAC (context adaptive binary arithmetic coding) may be performed at the server.

As yet another example, in a stadium, a shopping mall, a factory, or the like, there may be a plurality of video data in which almost the same scene is captured by a plurality of terminals. In this case, for example, a GOP (Group of Picture) unit, a picture unit, or a tile obtained by dividing a picture using a plurality of terminals that have performed shooting and other terminals and servers that have not performed shooting as necessary. Distributed processing is performed by assigning encoding processing in units or the like. Thereby, delay can be reduced and real-time property can be realized.

In addition, since the plurality of video data are almost the same scene, the server may manage and / or instruct the video data captured by each terminal to refer to each other. Alternatively, the encoded data from each terminal may be received by the server and the reference relationship may be changed among a plurality of data, or the picture itself may be corrected or replaced to be encoded again. This makes it possible to generate a stream with improved quality and efficiency of each piece of data.

Also, the server may distribute the video data after performing transcoding to change the encoding method of the video data. For example, the server may convert the MPEG encoding system to the VP encoding. H.264 in H.264. It may be converted into H.265.

Thus, the encoding process can be performed by a terminal or one or more servers. Therefore, in the following, description such as “server” or “terminal” is used as the subject performing processing, but part or all of processing performed by the server may be performed by the terminal, or processing performed by the terminal may be performed. Some or all may be performed at the server. The same applies to the decoding process.

[3D, multi-angle]
In recent years, different scenes photographed by terminals such as a plurality of cameras ex113 and / or smartphones ex115 that are substantially synchronized with each other, or images or videos obtained by photographing the same scene from different angles have been increasingly used. Yes. The video captured by each terminal is integrated based on the relative positional relationship between the terminals acquired separately or the region where the feature points included in the video match.

The server not only encodes a two-dimensional moving image, but also encodes a still image automatically based on a scene analysis of the moving image or at a time specified by the user and transmits it to the receiving terminal. Also good. In addition, when the server can acquire the relative positional relationship between the photographing terminals, the server obtains the three-dimensional shape of the scene based on not only the two-dimensional moving image but also the video obtained by photographing the same scene from different angles. Can be generated. The server may separately encode the three-dimensional data generated by the point cloud or the like, and the video to be transmitted to the receiving terminal based on the result of recognizing or tracking the person or the object using the three-dimensional data. Alternatively, the images may be selected or reconstructed from videos captured by a plurality of terminals.

In this way, the user can arbitrarily select each video corresponding to each photographing terminal and enjoy a scene, or can display a video of an arbitrary viewpoint from three-dimensional data reconstructed using a plurality of images or videos. You can also enjoy the clipped content. Furthermore, as with video, sound is collected from a plurality of different angles, and the server may multiplex and transmit sound from a specific angle or space according to the video.

Also, in recent years, content that associates the real world with the virtual world, such as Virtual Reality (VR) and Augmented Reality (AR), has become widespread. In the case of a VR image, the server may create viewpoint images for the right eye and the left eye, respectively, and perform encoding that allows reference between each viewpoint video by Multi-View Coding (MVC) or the like. You may encode as another stream, without referring. At the time of decoding another stream, it is preferable to reproduce in synchronization with each other so that a virtual three-dimensional space is reproduced according to the viewpoint of the user.

In the case of an AR image, the server superimposes virtual object information in the virtual space on the camera information in the real space based on the three-dimensional position or the movement of the user's viewpoint. The decoding device may acquire or hold virtual object information and three-dimensional data, generate a two-dimensional image according to the movement of the user's viewpoint, and create superimposition data by connecting them smoothly. Alternatively, the decoding device transmits the movement of the user's viewpoint to the server in addition to the request for the virtual object information, and the server creates superimposition data according to the movement of the viewpoint received from the three-dimensional data held in the server, The superimposed data may be encoded and distributed to the decoding device. Note that the superimposed data has an α value indicating transparency in addition to RGB, and the server sets the α value of a portion other than the object created from the three-dimensional data to 0 or the like, and the portion is transparent. May be encoded. Alternatively, the server may generate data in which a RGB value of a predetermined value is set as the background, such as a chroma key, and the portion other than the object is set to the background color.

Similarly, the decryption processing of the distributed data may be performed at each terminal as a client, may be performed on the server side, or may be performed in a shared manner. As an example, a terminal may once send a reception request to the server, receive content corresponding to the request at another terminal, perform a decoding process, and transmit a decoded signal to a device having a display. Regardless of the performance of the communicable terminal itself, it is possible to reproduce data with good image quality by distributing processing and selecting appropriate content. As another example, a part of a region such as a tile in which a picture is divided may be decoded and displayed on a viewer's personal terminal while receiving large-size image data on a TV or the like. Accordingly, it is possible to confirm at hand the area in which the person is responsible or the area to be confirmed in more detail while sharing the whole image.

In the future, in the situation where multiple short-distance, medium-distance, or long-distance wireless communications can be used regardless of whether indoors or outdoors, using a distribution system standard such as MPEG-DASH, It is expected that content is received seamlessly while switching appropriate data. Accordingly, the user can switch in real time while freely selecting a decoding device or a display device such as a display installed indoors or outdoors as well as his / her own terminal. Also, decoding can be performed while switching between a terminal to be decoded and a terminal to be displayed based on its own position information. This makes it possible to move while displaying map information on the wall surface of a neighboring building or a part of the ground in which a displayable device is embedded while moving to the destination. Also, access to encoded data on the network, such as when the encoded data is cached in a server that can be accessed from the receiving terminal in a short time, or copied to the edge server in the content delivery service. It is also possible to switch the bit rate of received data based on ease.

[Scalable coding]
The content switching will be described using a scalable stream that is compression-encoded by applying the moving image encoding method shown in each of the above embodiments shown in FIG. The server may have a plurality of streams of the same content and different quality as individual streams, but the temporal / spatial scalable implementation realized by dividing into layers as shown in the figure. The configuration may be such that the content is switched by utilizing the characteristics of the stream. In other words, the decoding side decides which layer to decode according to internal factors such as performance and external factors such as the state of communication bandwidth, so that the decoding side can combine low-resolution content and high-resolution content. You can switch freely and decrypt. For example, when the user wants to continue watching the video that was viewed on the smartphone ex115 while moving on a device such as an Internet TV after returning home, the device only has to decode the same stream to a different layer, so the load on the server side Can be reduced.

Further, as described above, the enhancement layer includes meta information based on image statistical information, etc., in addition to the configuration in which the picture is encoded for each layer and the enhancement layer exists above the base layer. The decoding side may generate content with high image quality by super-resolution of the base layer picture based on the meta information. Super-resolution may be either improvement of the SN ratio at the same resolution or enlargement of the resolution. The meta information includes information for specifying a linear or non-linear filter coefficient used for super-resolution processing, or information for specifying a parameter value in filter processing, machine learning, or least square calculation used for super-resolution processing. .

Alternatively, the picture may be divided into tiles or the like according to the meaning of the object in the image, and the decoding side may select only a part of the region by selecting the tile to be decoded. Also, by storing the object attributes (person, car, ball, etc.) and the position in the video (coordinate position in the same image, etc.) as meta information, the decoding side can determine the position of the desired object based on the meta information. Can be identified and the tile containing the object can be determined. For example, as shown in FIG. 24, the meta information is stored using a data storage structure different from the pixel data such as the SEI message in HEVC. This meta information indicates, for example, the position, size, or color of the main object.

Also, meta information may be stored in units composed of a plurality of pictures, such as streams, sequences, or random access units. Thereby, the decoding side can acquire the time when the specific person appears in the video, etc., and can match the picture in which the object exists and the position of the object in the picture by combining with the information in units of pictures.

[Web page optimization]
FIG. 25 is a diagram showing an example of a web page display screen on the computer ex111 or the like. FIG. 26 is a diagram illustrating a display screen example of a web page on the smartphone ex115 or the like. As shown in FIGS. 25 and 26, the web page may include a plurality of link images that are links to the image content, and the appearance differs depending on the browsing device. When a plurality of link images are visible on the screen, the display device until the user explicitly selects the link image, or until the link image approaches the center of the screen or the entire link image enters the screen. The (decoding device) displays a still image or an I picture included in each content as a link image, displays a video like a gif animation with a plurality of still images or I pictures, or receives only a base layer to receive a video. Are decoded and displayed.

When the link image is selected by the user, the display device decodes the base layer with the highest priority. If there is information indicating that the HTML constituting the web page is scalable content, the display device may decode up to the enhancement layer. Also, in order to ensure real-time properties, the display device only decodes forward reference pictures (I picture, P picture, forward reference only B picture) before being selected or when the communication band is very strict. In addition, the delay between the decoding time of the first picture and the display time (delay from the start of content decoding to the start of display) can be reduced by displaying. Further, the display device may intentionally ignore the reference relationship of pictures and roughly decode all B pictures and P pictures with forward reference, and perform normal decoding as the number of received pictures increases over time.

[Automatic driving]
In addition, when transmitting and receiving still image or video data such as two-dimensional or three-dimensional map information for automatic driving or driving support of a car, the receiving terminal adds meta data to image data belonging to one or more layers. Weather or construction information may also be received and decoded in association with each other. The meta information may belong to a layer or may be simply multiplexed with image data.

In this case, since the car, drone, airplane, or the like including the receiving terminal moves, the receiving terminal transmits the position information of the receiving terminal at the time of the reception request, thereby seamless reception and decoding while switching the base stations ex106 to ex110. Can be realized. In addition, the receiving terminal can dynamically switch how much meta-information is received or how much map information is updated according to the user's selection, the user's situation, or the communication band state. become.

As described above, in the content supply system ex100, the encoded information transmitted by the user can be received, decoded and reproduced in real time by the client.

[Distribution of personal contents]
Further, the content supply system ex100 can perform not only high-quality and long-time content by a video distributor but also unicast or multicast distribution of low-quality and short-time content by an individual. Moreover, such personal contents are expected to increase in the future. In order to make personal content superior, the server may perform the encoding process after performing the editing process. This can be realized, for example, with the following configuration.

After shooting, the server performs recognition processing such as shooting error, scene search, semantic analysis, and object detection from the original image or encoded data. Then, the server manually or automatically corrects out-of-focus or camera shake based on the recognition result, or selects a less important scene such as a scene whose brightness is lower than that of other pictures or is out of focus. Edit such as deleting, emphasizing the edge of an object, and changing the hue. The server encodes the edited data based on the editing result. It is also known that if the shooting time is too long, the audience rating will decrease, and the server will move not only in the less important scenes as described above, but also in motion according to the shooting time. A scene with few images may be automatically clipped based on the image processing result. Alternatively, the server may generate and encode a digest based on the result of the semantic analysis of the scene.

In some cases, personal content may include infringements such as copyrights, author's personality rights, or portrait rights, which are inconvenient for individuals, such as exceeding the intended scope of sharing. In some cases. Therefore, for example, the server may change and encode the face of the person in the periphery of the screen or the inside of the house into an unfocused image. In addition, the server recognizes whether or not a face of a person different from the person registered in advance is shown in the encoding target image, and if so, performs processing such as applying a mosaic to the face part. May be. Alternatively, as a pre-processing or post-processing of encoding, the user designates a person or background area that the user wants to process an image from the viewpoint of copyright, etc., and the server replaces the designated area with another video or blurs the focus. It is also possible to perform such processing. If it is a person, the face image can be replaced while tracking the person in the moving image.

In addition, since viewing of personal content with a small amount of data is strongly demanded for real-time performance, the decoding device first receives the base layer with the highest priority and performs decoding and reproduction, depending on the bandwidth. The decoding device may receive the enhancement layer during this time, and may play back high-quality video including the enhancement layer when played back twice or more, such as when playback is looped. A stream that is scalable in this way can provide an experience in which the stream becomes smarter and the image is improved gradually, although it is a rough moving picture when it is not selected or at the beginning of viewing. In addition to scalable coding, the same experience can be provided even if the coarse stream played back the first time and the second stream coded with reference to the first video are configured as one stream. .

[Other usage examples]
In addition, these encoding or decoding processes are generally processed in the LSI ex500 included in each terminal. The LSI ex500 may be configured as a single chip or a plurality of chips. Note that moving image encoding or decoding software is incorporated into some recording medium (CD-ROM, flexible disk, hard disk, etc.) that can be read by the computer ex111 and the like, and encoding or decoding processing is performed using the software. Also good. Furthermore, when the smartphone ex115 has a camera, moving image data acquired by the camera may be transmitted. The moving image data at this time is data encoded by the LSI ex500 included in the smartphone ex115.

Note that the LSI ex500 may be configured to download and activate application software. In this case, the terminal first determines whether the terminal is compatible with the content encoding method or has a specific service execution capability. If the terminal does not support the content encoding method or does not have the capability to execute a specific service, the terminal downloads a codec or application software, and then acquires and reproduces the content.

Further, not only the content supply system ex100 via the Internet ex101, but also a digital broadcasting system, at least the moving image encoding device (image encoding device) or the moving image decoding device (image decoding device) of the above embodiments. Any of these can be incorporated. The difference is that the unicasting of the content supply system ex100 is suitable for multicasting because it uses a satellite or the like to transmit and receive multiplexed data in which video and sound are multiplexed on broadcasting radio waves. However, the same application is possible for the encoding process and the decoding process.

[Hardware configuration]
FIG. 27 is a diagram illustrating the smartphone ex115. FIG. 28 is a diagram illustrating a configuration example of the smartphone ex115. The smartphone ex115 receives the antenna ex450 for transmitting / receiving radio waves to / from the base station ex110, the camera unit ex465 capable of taking video and still images, the video captured by the camera unit ex465, and the antenna ex450. A display unit ex458 for displaying data obtained by decoding the video or the like. The smartphone ex115 further includes an operation unit ex466 that is a touch panel or the like, a voice output unit ex457 that is a speaker or the like for outputting voice or sound, a voice input unit ex456 that is a microphone or the like for inputting voice, and photographing. Memory unit ex467 that can store encoded video or still image, recorded audio, received video or still image, encoded data such as mail, or decoded data, and a user, and network A slot part ex464, which is an interface part with the SIMex 468 for authenticating access to various data. An external memory may be used instead of the memory unit ex467.

Also, a main control unit ex460 that comprehensively controls the display unit ex458, the operation unit ex466, and the like, a power supply circuit unit ex461, an operation input control unit ex462, a video signal processing unit ex455, a camera interface unit ex463, a display control unit ex459, a modulation / Demodulation unit ex452, multiplexing / demultiplexing unit ex453, audio signal processing unit ex454, slot unit ex464, and memory unit ex467 are connected via bus ex470.

When the power key is turned on by a user operation, the power supply circuit unit ex461 starts up the smartphone ex115 in an operable state by supplying power from the battery pack to each unit.

The smartphone ex115 performs processing such as calling and data communication based on the control of the main control unit ex460 having a CPU, a ROM, a RAM, and the like. During a call, the voice signal picked up by the voice input unit ex456 is converted into a digital voice signal by the voice signal processing unit ex454, spread spectrum processed by the modulation / demodulation unit ex452, and digital / analog converted by the transmission / reception unit ex451. After performing the processing and the frequency conversion processing, the data is transmitted via the antenna ex450. Further, the received data is amplified and subjected to frequency conversion processing and analog-digital conversion processing, spectrum despreading processing is performed by the modulation / demodulation unit ex452, and converted to analog audio signal by the audio signal processing unit ex454, and then this is output to the audio output unit ex457. Output from. In the data communication mode, text, still image, or video data is sent to the main control unit ex460 via the operation input control unit ex462 by the operation of the operation unit ex466 of the main body unit, and transmission / reception processing is performed similarly. When transmitting video, still image, or video and audio in the data communication mode, the video signal processing unit ex455 uses the video signal stored in the memory unit ex467 or the video signal input from the camera unit ex465 as described above. The video data is compressed and encoded by the moving image encoding method shown in the form, and the encoded video data is sent to the multiplexing / demultiplexing unit ex453. The audio signal processing unit ex454 encodes the audio signal picked up by the audio input unit ex456 while the camera unit ex465 captures a video or a still image, and sends the encoded audio data to the multiplexing / separating unit ex453. To do. The multiplexing / demultiplexing unit ex453 multiplexes the encoded video data and the encoded audio data by a predetermined method, and the modulation / demodulation unit (modulation / demodulation circuit unit) ex452 and the modulation / demodulation unit ex451 perform modulation processing and conversion. The data is processed and transmitted via the antenna ex450.

In order to decode the multiplexed data received via the antenna ex450 when the video attached to the e-mail or chat, or the video linked to the web page or the like is received, the multiplexing / demultiplexing unit ex453 performs multiplexing By separating the data, the multiplexed data is divided into a bit stream of video data and a bit stream of audio data, and the encoded video data is supplied to the video signal processing unit ex455 via the synchronization bus ex470. The converted audio data is supplied to the audio signal processing unit ex454. The video signal processing unit ex455 decodes the video signal by the video decoding method corresponding to the video encoding method shown in each of the above embodiments, and is linked from the display unit ex458 via the display control unit ex459. A video or still image included in the moving image file is displayed. The audio signal processing unit ex454 decodes the audio signal, and the audio is output from the audio output unit ex457. Since real-time streaming is widespread, depending on the user's situation, there may be occasions where audio playback is not socially appropriate. Therefore, it is desirable that the initial value is a configuration in which only the video data is reproduced without reproducing the audio signal. Audio may be synchronized and played back only when the user performs an operation such as clicking on video data.

In addition, although the smartphone ex115 has been described here as an example, in addition to a transmission / reception terminal having both an encoder and a decoder as a terminal, a transmission terminal having only an encoder and a reception having only a decoder There are three possible mounting formats: terminals. Furthermore, in the digital broadcasting system, it has been described as receiving or transmitting multiplexed data in which audio data or the like is multiplexed with video data. However, multiplexed data includes character data related to video in addition to audio data. Multiplexing may be performed, and video data itself may be received or transmitted instead of multiplexed data.

In addition, although it has been described that the main control unit ex460 including the CPU controls the encoding or decoding process, the terminal often includes a GPU. Therefore, a configuration may be adopted in which a wide area is processed in a lump by utilizing the performance of the GPU by using a memory shared by the CPU and the GPU or a memory whose addresses are managed so as to be used in common. As a result, the encoding time can be shortened, real-time performance can be ensured, and low delay can be realized. In particular, it is efficient to perform motion search, deblocking filter, SAO (Sample Adaptive Offset), and transformation / quantization processing in batches in units of pictures or the like instead of the CPU.

The present disclosure can be used for, for example, a television receiver, a digital video recorder, a car navigation, a mobile phone, a digital camera, a digital video camera, a video conference system, or an electronic mirror.

DESCRIPTION OF SYMBOLS 100 Coding apparatus 102 Division | segmentation part 104 Subtraction part 106 Conversion part 108 Quantization part 110 Entropy encoding part 112,204 Inverse quantization part 114,206 Inverse conversion part 116,208 Adder 118,210 Block memory 120,212

Loop filter Unit

122, 214

frame memory

124, 216

intra prediction unit

126, 218

inter prediction unit

128, 220

prediction control unit

160, 260

circuit

162, 262 memory 200 decoding device 202 entropy decoding unit

Claims

Circuit,
With memory,
The circuit uses the memory,
Deriving a plurality of candidate motion vectors for the processing target block included in the processing target picture from the motion vector used for motion compensation of the processed block;
The plurality of candidate motion vectors with reference to two processed reference pictures that do not use the image area of the processing target block and whose display times are located in the same direction between the front and rear of the processing target picture Select the final motion vector from
An encoding device that performs motion compensation of the processing target block using the final motion vector.
The encoding apparatus according to claim 1, wherein the processing target picture is a P picture.
3. When two reference pictures are indicated in the reference picture list for the processing target picture, the two processed reference pictures are the two reference pictures indicated in the reference picture list. The encoding device described.
When one reference picture is indicated in the reference picture list for the processing target picture, one of the two processed reference pictures is the one reference picture indicated in the reference picture list, The encoding apparatus according to claim 2, wherein the other of the two processed reference pictures is another processed reference picture not indicated in the reference picture list.
The circuit further comprises:
The encoding apparatus according to claim 4, wherein the one reference picture indicated in the reference picture list and the other processed reference picture are stored in a picture memory.
In the selection of the final motion vector, the evaluation values of each of the plurality of candidate motion vectors are calculated with reference to the two processed reference pictures, and the final motion vector is selected based on the calculated evaluation values And
The one of the two processed reference pictures is a reference picture indicated by a candidate motion vector to be processed among the plurality of candidate motion vectors, and the other of the two processed reference pictures can be referred to The encoding device according to claim 4, wherein the picture is a picture having a display time closest to the processing target picture.
The encoding apparatus according to claim 1, wherein the processing target picture is a B picture.
In the selection of the final motion vector, the evaluation values of each of the plurality of candidate motion vectors are calculated with reference to the two processed reference pictures, and the final motion vector is selected based on the calculated evaluation values And
The processing target picture has a first reference picture list and a second reference picture list,
One of the two processed reference pictures is a reference picture indicated by a candidate motion vector to be processed among the plurality of candidate motion vectors, and is a reference picture belonging to the first reference picture list,
The encoding apparatus according to claim 7, wherein the other of the two processed reference pictures is a picture having a display time closest to the processing target picture among reference pictures belonging to the second reference picture list.
Circuit,
With memory,
The circuit uses the memory,
Deriving a plurality of candidate motion vectors for the processing target block included in the processing target picture from the motion vector used for motion compensation of the processed block;
The plurality of candidate motion vectors with reference to two processed reference pictures that do not use the image area of the processing target block and whose display times are located in the same direction between the front and rear of the processing target picture Select the final motion vector from
A decoding device that performs motion compensation of the processing target block using the final motion vector.
The decoding device according to claim 9, wherein the processing target picture is a P picture.
11. When two reference pictures are indicated in a reference picture list for the processing target picture, the two processed reference pictures are the two reference pictures indicated in the reference picture list. The decoding device described.
When one reference picture is indicated in the reference picture list for the processing target picture, one of the two processed reference pictures is the one reference picture indicated in the reference picture list, The decoding device according to claim 10, wherein the other of the two processed reference pictures is another processed reference picture not indicated in the reference picture list.
The circuit further comprises:
The decoding device according to claim 12, wherein the one reference picture indicated in the reference picture list and the other processed reference picture are stored in a picture memory.
In the selection of the final motion vector, the evaluation values of each of the plurality of candidate motion vectors are calculated with reference to the two processed reference pictures, and the final motion vector is selected based on the calculated evaluation values And
One of the two processed reference pictures is a reference picture indicated by a candidate motion vector to be processed among the plurality of candidate motion vectors, and the other of the two processed reference pictures is a referenceable picture The decoding device according to claim 10, wherein the picture has a display time closest to the processing target picture.
The decoding device according to claim 9, wherein the processing target picture is a B picture.
In the selection of the final motion vector, the evaluation values of each of the plurality of candidate motion vectors are calculated with reference to the two processed reference pictures, and the final motion vector is selected based on the calculated evaluation values And
The processing target picture has a first reference picture list and a second reference picture list,
One of the two processed reference pictures is a reference picture indicated by a candidate motion vector to be processed among the plurality of candidate motion vectors, and is a reference picture belonging to the first reference picture list,
The decoding device according to claim 15, wherein the other of the two processed reference pictures is a picture having a display time closest to the processing target picture among reference pictures belonging to the second reference picture list.
Deriving a plurality of candidate motion vectors for the processing target block included in the processing target picture from the motion vector used for motion compensation of the processed block;
The plurality of candidate motion vectors with reference to two processed reference pictures that do not use the image area of the processing target block and whose display times are located in the same direction between the front and rear of the processing target picture Select the final motion vector from
An encoding method that performs motion compensation of the processing target block using the final motion vector.
Deriving a plurality of candidate motion vectors for the processing target block included in the processing target picture from the motion vector used for motion compensation of the processed block;
The plurality of candidate motion vectors with reference to two processed reference pictures that do not use the image area of the processing target block and whose display times are located in the same direction between the front and rear of the processing target picture Select the final motion vector from
A decoding method for performing motion compensation on the processing target block using the final motion vector.