WO2020004879A1

WO2020004879A1 - Method and device for image decoding according to inter-prediction using plurality of neighboring blocks in image coding system

Info

Publication number: WO2020004879A1
Application number: PCT/KR2019/007595
Authority: WO
Inventors: 유선미; 남정학; 박내리; 이재호; 임재현; 장형문
Original assignee: 엘지전자 주식회사
Priority date: 2018-06-25
Filing date: 2019-06-24
Publication date: 2020-01-02

Abstract

An image decoding method performed by a decoding device according to the present invention comprises the steps of: deriving neighboring blocks of a current block; configuring a motion information candidate list on the basis of the derived neighboring blocks; deriving motion information of the current block on the basis of the motion information candidate list; and generating a predicted block of the current block on the basis of the motion information, wherein the neighboring blocks include a non-adjacent block that is not adjacent to the current block, and the non-adjacent block is derived on the basis of a motion vector of a block adjacent to the current block, a maximum coding unit including the current block, or a current picture including the current block.

Description

An image decoding method and apparatus according to inter prediction using a plurality of neighboring blocks in an image coding system

The present invention relates to an image coding technique, and more particularly, to an image decoding method and apparatus according to inter prediction using a plurality of neighboring blocks in an image coding system.

Recently, the demand for high resolution and high quality images such as high definition (HD) images and ultra high definition (UHD) images is increasing in various fields. The higher the resolution and the higher quality of the image data, the more information or bit rate is transmitted than the existing image data. Therefore, the image data can be transmitted by using a medium such as a conventional wired / wireless broadband line or by using a conventional storage medium. In the case of storage, the transmission cost and the storage cost are increased.

Accordingly, a high efficiency image compression technique is required to effectively transmit, store, and reproduce high resolution, high quality image information.

An object of the present invention is to provide a method and apparatus for improving image coding efficiency.

Another object of the present invention is to provide an image decoding method and apparatus for deriving a motion information candidate list based on a plurality of neighboring blocks.

Another object of the present invention is to provide an image decoding method and apparatus for deriving a motion information candidate list based on neighboring blocks that are not adjacent to a current block and performing prediction based on the derived motion information candidate list.

Another object of the present invention is to provide an image decoding method and apparatus for performing prediction by selecting neighboring blocks according to a specific condition among neighboring blocks in the current block and deriving a motion information candidate list based on the selected neighboring blocks. .

According to an embodiment of the present invention, there is provided an image decoding method performed by a decoding apparatus. The method includes deriving neighboring blocks for the motion information candidate list of the current block among neighboring blocks of the current block, constructing the motion information candidate list based on the derived neighboring blocks, and the motion information candidate list. Deriving motion information of the current block based on the step of performing the prediction of the current block based on the motion information, wherein the neighboring blocks include non-adjacent blocks that are not adjacent to the current block. The non-adjacent block is characterized in that a block adjacent to the current block is derived based on a motion vector, a maximum coding unit including the current block, or a current picture including the current block.

According to another embodiment of the present invention, a decoding apparatus for performing image decoding is provided. The decoding apparatus derives neighboring blocks for the motion information candidate list of the current block among neighboring blocks of the current block, constructs the motion information candidate list based on the derived neighboring blocks, and extracts the motion information candidate list. A prediction unit configured to derive motion information of the current block based on the motion information, and to predict the current block based on the motion information, wherein the neighboring blocks include non-adjacent blocks that are not adjacent to the current block; The non-adjacent block is characterized in that a block adjacent to the current block is derived based on a motion vector, a maximum coding unit including the current block, or a current picture including the current block.

According to another embodiment of the present invention, a video encoding method performed by an encoding apparatus is provided. The method includes deriving neighboring blocks for the motion information candidate list of the current block among neighboring blocks of the current block, constructing the motion information candidate list based on the derived neighboring blocks, and the motion information candidate list. Deriving motion information of the current block based on the step of performing prediction of the current block based on the motion information, and encoding image information including information on the prediction of the current block. The neighboring blocks may include non-adjacent blocks that are not adjacent to the current block, and the non-adjacent blocks include a motion vector, a maximum coding unit including the current block, or the current block, in which a block adjacent to the current block is located. Characterized in that it is derived based on the current picture.

According to another embodiment of the present invention, a video encoding apparatus is provided. The encoding apparatus derives neighboring blocks for the motion information candidate list of the current block among neighboring blocks of the current block, constructs the motion information candidate list based on the derived neighboring blocks, and constructs the motion information candidate list. A motion estimation unit for deriving motion information of the current block based on the motion information, and a prediction unit for performing prediction of the current block based on the motion information, and an entropy encoding unit for encoding image information including information about prediction of the current block. The neighboring blocks may include non-adjacent blocks that are not adjacent to the current block, and the non-adjacent blocks include a motion vector, a maximum coding unit including the current block, or the current block, in which a block adjacent to the current block is located. Characterized in that it is derived based on the current picture.

According to the present invention, in order to derive the motion information of the current block, the motion information can be searched in a wider area which is already decoded, and not limited to adjacent neighboring blocks. Can be used as a candidate for improving the prediction accuracy.

According to the present invention, the neighboring blocks suitable for the current block among the neighboring blocks can be derived based on a specific condition, and the motion information candidate list can be derived based on the derived neighboring blocks. bandwidth can be saved, and coding efficiency can be improved by improving prediction performance.

1 is a diagram schematically illustrating a configuration of a video encoding apparatus to which the present invention may be applied.

2 is a diagram schematically illustrating a configuration of a video decoding apparatus to which the present invention may be applied.

3 exemplarily shows spatial neighboring blocks that can be used to derive a spatial candidate for the current block.

4 shows an example of spatial neighboring blocks that can be used to derive a spatial candidate for the current block.

5 shows another example of spatial neighboring blocks that can be used to derive a spatial candidate for the current block.

6 shows another example of spatial neighboring blocks that can be used to derive a spatial candidate for the current block.

7 illustrates an example of spatial neighboring blocks that may be used to derive a spatial candidate for the current block according to another scan order.

8 illustrates an example of spatial neighboring blocks located within one sample at the boundary of the current block that may be used to derive a spatial candidate for the current block according to another scan order.

9 shows an example of an available range of neighboring blocks for the current block.

10 illustrates an example of a specific area including a neighboring block that may be selected to form a motion information candidate list for the current block.

11 shows an example of a specific range determined based on a motion vector of a maximum absolute value of a block adjacent to the current block.

12 schematically illustrates a method of generating a motion prediction candidate list.

13 schematically illustrates an image encoding method by an encoding apparatus according to the present invention.

14 schematically illustrates an image decoding method by a decoding apparatus according to the present invention.

15 schematically shows the structure of a content streaming system.

As the present invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the invention to the specific embodiments. The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the spirit of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. The terms "comprise" or "having" in this specification are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features It is to be understood that the numbers, steps, operations, components, parts or figures do not exclude in advance the presence or possibility of adding them.

On the other hand, each configuration in the drawings described in the present invention are shown independently for the convenience of description of the different characteristic functions, it does not mean that each configuration is implemented by separate hardware or separate software. For example, two or more of each configuration may be combined to form one configuration, or one configuration may be divided into a plurality of configurations. Embodiments in which each configuration is integrated and / or separated are also included in the scope of the present invention without departing from the spirit of the present invention.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention. Hereinafter, the same reference numerals are used for the same components in the drawings, and redundant description of the same components is omitted.

On the other hand, the present invention relates to video / image coding. For example, the method / embodiment disclosed herein may be applied to the method disclosed in the versatile video coding (VVC) standard or the next generation video / image coding standard.

In the present specification, a picture generally refers to a unit representing one image of a specific time zone, and a slice is a unit constituting a part of a picture in coding. One picture may be composed of a plurality of slices, and if necessary, the picture and the slice may be mixed with each other.

A pixel or a pel may refer to a minimum unit constituting one picture (or image). Also, 'sample' may be used as a term corresponding to a pixel. A sample may generally represent a pixel or a value of a pixel, and may only represent pixel / pixel values of the luma component, or only pixel / pixel values of the chroma component.

A unit represents the basic unit of image processing. The unit may include at least one of a specific region of the picture and information related to the region. The unit may be used interchangeably with terms such as block or area in some cases. In a general case, an M × N block may represent a set of samples or transform coefficients composed of M columns and N rows.

Referring to FIG. 1, the video encoding apparatus 100 may include a picture splitter 105, a predictor 110, a residual processor 120, an entropy encoder 130, an adder 140, and a filter 150. ) And memory 160. The residual processing unit 120 may include a subtraction unit 121, a conversion unit 122, a quantization unit 123, a reordering unit 124, an inverse quantization unit 125, and an inverse conversion unit 126.

The picture divider 105 may divide the input picture into at least one processing unit.

As an example, the processing unit may be called a coding unit (CU). In this case, the coding unit may be recursively split from the largest coding unit (LCU) according to a quad-tree binary-tree (QTBT) structure. For example, one coding unit may be divided into a plurality of coding units of a deeper depth based on a quad tree structure and / or a binary tree structure. In this case, for example, the quad tree structure may be applied first and the binary tree structure may be applied later. Alternatively, the binary tree structure may be applied first. The coding procedure according to the present invention may be performed based on the final coding unit that is no longer split. In this case, the maximum coding unit may be used as the final coding unit immediately based on coding efficiency according to the image characteristic, or if necessary, the coding unit is recursively divided into coding units of lower depths and optimized. A coding unit of size may be used as the final coding unit. Here, the coding procedure may include a procedure of prediction, transform, and reconstruction, which will be described later.

As another example, the processing unit may include a coding unit (CU) prediction unit (PU) or a transform unit (TU). The coding unit may be split from the largest coding unit (LCU) into coding units of deeper depths along the quad tree structure. In this case, the maximum coding unit may be used as the final coding unit immediately based on coding efficiency according to the image characteristic, or if necessary, the coding unit is recursively divided into coding units of lower depths and optimized. A coding unit of size may be used as the final coding unit. If a smallest coding unit (SCU) is set, the coding unit may not be split into smaller coding units than the minimum coding unit. Here, the final coding unit refers to a coding unit that is the basis of partitioning or partitioning into a prediction unit or a transform unit. The prediction unit is a unit partitioning from the coding unit and may be a unit of sample prediction. In this case, the prediction unit may be divided into sub blocks. The transform unit may be divided along the quad tree structure from the coding unit, and may be a unit for deriving a transform coefficient and / or a unit for deriving a residual signal from the transform coefficient. Hereinafter, a coding unit may be called a coding block (CB), a prediction unit is a prediction block (PB), and a transform unit may be called a transform block (TB). A prediction block or prediction unit may mean a specific area in the form of a block within a picture, and may include an array of prediction samples. In addition, a transform block or a transform unit may mean a specific area in a block form within a picture, and may include an array of transform coefficients or residual samples.

The prediction unit 110 may perform a prediction on a block to be processed (hereinafter, referred to as a current block) and generate a predicted block including prediction samples of the current block. The unit of prediction performed by the prediction unit 110 may be a coding block, a transform block, or a prediction block.

The prediction unit 110 may determine whether intra prediction or inter prediction is applied to the current block. As an example, the prediction unit 110 may determine whether intra prediction or inter prediction is applied on a CU basis.

In the case of intra prediction, the prediction unit 110 may derive a prediction sample for the current block based on reference samples outside the current block in the picture to which the current block belongs (hereinafter, referred to as the current picture). In this case, the prediction unit 110 may (i) derive the prediction sample based on the average or interpolation of neighboring reference samples of the current block, and (ii) the neighbor reference of the current block. The prediction sample may be derived based on a reference sample present in a specific (prediction) direction with respect to the prediction sample among the samples. In case of (i), it may be called non-directional mode or non-angle mode, and in case of (ii), it may be called directional mode or angular mode. In intra prediction, the prediction mode may have, for example, 33 directional prediction modes and at least two non-directional modes. The non-directional mode may include a DC prediction mode and a planner mode (Planar mode). The prediction unit 110 may determine the prediction mode applied to the current block by using the prediction mode applied to the neighboring block.

In the case of inter prediction, the prediction unit 110 may derive the prediction sample for the current block based on the sample specified by the motion vector on the reference picture. The prediction unit 110 may apply one of a skip mode, a merge mode, and a motion vector prediction (MVP) mode to derive a prediction sample for the current block. In the skip mode and the merge mode, the prediction unit 110 may use the motion information of the neighboring block as the motion information of the current block. In the skip mode, unlike the merge mode, the difference (residual) between the prediction sample and the original sample is not transmitted. In the MVP mode, the motion vector of the current block may be derived using the motion vector of the neighboring block as a motion vector predictor.

In the case of inter prediction, the neighboring block may include a spatial neighboring block existing in the current picture and a temporal neighboring block present in the reference picture. A reference picture including the temporal neighboring block may be called a collocated picture (colPic). The motion information may include a motion vector and a reference picture index. Information such as prediction mode information and motion information may be encoded (entropy) and output in the form of a bitstream.

When the motion information of the temporal neighboring block is used in the skip mode and the merge mode, the highest picture on the reference picture list may be used as the reference picture. Reference pictures included in a reference picture list may be sorted based on a difference in a picture order count (POC) between a current picture and a corresponding reference picture. The POC corresponds to the display order of the pictures and may be distinguished from the coding order.

The subtraction unit 121 generates a residual sample which is a difference between the original sample and the prediction sample. When the skip mode is applied, residual samples may not be generated as described above.

The transform unit 122 generates transform coefficients by transforming the residual sample in units of transform blocks. The transform unit 122 may perform the transform according to the size of the transform block and the prediction mode applied to the coding block or the prediction block that spatially overlaps the transform block. For example, if intra prediction is applied to the coding block or the prediction block that overlaps the transform block, and the transform block is a 4 × 4 residual array, the residual sample is configured to perform a discrete sine transform (DST) transform kernel. The residual sample may be transformed using a discrete cosine transform (DCT) transform kernel.

The quantization unit 123 may quantize the transform coefficients to generate quantized transform coefficients.

The reordering unit 124 rearranges the quantized transform coefficients. The reordering unit 124 may reorder the quantized transform coefficients in the form of a block into a one-dimensional vector form through a coefficient scanning method. Although the reordering unit 124 has been described in a separate configuration, the reordering unit 124 may be part of the quantization unit 123.

The entropy encoding unit 130 may perform entropy encoding on the quantized transform coefficients. Entropy encoding may include, for example, encoding methods such as exponential Golomb, context-adaptive variable length coding (CAVLC), context-adaptive binary arithmetic coding (CABAC), and the like. The entropy encoding unit 130 may encode information necessary for video reconstruction other than the quantized transform coefficient (for example, a value of a syntax element) together or separately. Entropy encoded information may be transmitted or stored in units of network abstraction layer (NAL) units in the form of bitstreams.

The inverse quantization unit 125 inverse quantizes the quantized values (quantized transform coefficients) in the quantization unit 123, and the inverse transformer 126 inverse transforms the inverse quantized values in the inverse quantization unit 125 to generate a residual sample. Create

The adder 140 reconstructs the picture by combining the residual sample and the predictive sample. The residual sample and the predictive sample may be added in units of blocks to generate a reconstructed block. Although the adder 140 has been described in a separate configuration, the adder 140 may be part of the predictor 110. On the other hand, the adder 140 may be called a restoration unit or a restoration block generation unit.

The filter unit 150 may apply a deblocking filter and / or a sample adaptive offset to the reconstructed picture. Through deblocking filtering and / or sample adaptive offset, the artifacts of the block boundaries in the reconstructed picture or the distortion in the quantization process can be corrected. The sample adaptive offset may be applied on a sample basis and may be applied after the process of deblocking filtering is completed. The filter unit 150 may apply an adaptive loop filter (ALF) to the reconstructed picture. ALF may be applied to the reconstructed picture after the deblocking filter and / or sample adaptive offset is applied.

The memory 160 may store reconstructed pictures (decoded pictures) or information necessary for encoding / decoding. Here, the reconstructed picture may be a reconstructed picture after the filtering process is completed by the filter unit 150. The stored reconstructed picture may be used as a reference picture for (inter) prediction of another picture. For example, the memory 160 may store (reference) pictures used for inter prediction. In this case, pictures used for inter prediction may be designated by a reference picture set or a reference picture list.

Referring to FIG. 2, the video decoding apparatus 200 may include an entropy decoding unit 210, a residual processor 220, a predictor 230, an adder 240, a filter 250, and a memory 260. It may include. Here, the residual processor 220 may include a rearrangement unit 221, an inverse quantization unit 222, and an inverse transform unit 223.

When a bitstream including video information is input, the video decoding apparatus 200 may restore video in response to a process in which video information is processed in the video encoding apparatus.

For example, the video decoding apparatus 200 may perform video decoding using a processing unit applied in the video encoding apparatus. Thus, the processing unit block of video decoding may be, for example, a coding unit, and in another example, a coding unit, a prediction unit, or a transform unit. The coding unit may be split along the quad tree structure and / or binary tree structure from the largest coding unit.

The prediction unit and the transform unit may be further used in some cases, in which case the prediction block is a block derived or partitioned from the coding unit and may be a unit of sample prediction. At this point, the prediction unit may be divided into subblocks. The transform unit may be divided along the quad tree structure from the coding unit, and may be a unit for deriving a transform coefficient or a unit for deriving a residual signal from the transform coefficient.

The entropy decoding unit 210 may parse the bitstream and output information necessary for video reconstruction or picture reconstruction. For example, the entropy decoding unit 210 decodes information in a bitstream based on a coding method such as exponential Golomb coding, CAVLC, or CABAC, quantized values of syntax elements necessary for video reconstruction, and residual coefficients. Can be output.

More specifically, the CABAC entropy decoding method receives a bin corresponding to each syntax element in a bitstream, and decodes syntax element information and decoding information of neighboring and decoding target blocks or information of symbols / bins decoded in a previous step. The context model may be determined using the context model, the probability of occurrence of a bin may be predicted according to the determined context model, and arithmetic decoding of the bin may be performed to generate a symbol corresponding to the value of each syntax element. have. In this case, the CABAC entropy decoding method may update the context model by using the information of the decoded symbol / bin for the context model of the next symbol / bean after determining the context model.

The information related to the prediction among the information decoded by the entropy decoding unit 210 is provided to the prediction unit 230, and the residual value on which the entropy decoding has been performed by the entropy decoding unit 210, that is, the quantized transform coefficient, is used as a reordering unit ( 221 may be input.

The reordering unit 221 may rearrange the quantized transform coefficients in a two-dimensional block form. The reordering unit 221 may perform reordering in response to coefficient scanning performed by the encoding apparatus. Here, the rearrangement unit 221 has been described in a separate configuration, but the rearrangement unit 221 may be part of the inverse quantization unit 222.

The inverse quantization unit 222 may dequantize the quantized transform coefficients based on the (inverse) quantization parameter and output the transform coefficients. In this case, information for deriving a quantization parameter may be signaled from the encoding apparatus.

The inverse transform unit 223 may inversely transform transform coefficients to derive residual samples.

The prediction unit 230 may perform prediction on the current block and generate a predicted block including prediction samples for the current block. The unit of prediction performed by the prediction unit 230 may be a coding block, a transform block, or a prediction block.

The prediction unit 230 may determine whether to apply intra prediction or inter prediction based on the information about the prediction. In this case, a unit for determining which of intra prediction and inter prediction is to be applied and a unit for generating a prediction sample may be different. In addition, the unit for generating a prediction sample in inter prediction and intra prediction may also be different. For example, whether to apply inter prediction or intra prediction may be determined in units of CUs. In addition, for example, in inter prediction, a prediction mode may be determined and a prediction sample may be generated in PU units, and in intra prediction, a prediction mode may be determined in PU units and a prediction sample may be generated in TU units.

In the case of intra prediction, the prediction unit 230 may derive the prediction sample for the current block based on the neighbor reference samples in the current picture. The prediction unit 230 may derive the prediction sample for the current block by applying the directional mode or the non-directional mode based on the neighbor reference samples of the current block. In this case, the prediction mode to be applied to the current block may be determined using the intra prediction mode of the neighboring block.

In the case of inter prediction, the prediction unit 230 may derive the prediction sample for the current block based on the sample specified on the reference picture by the motion vector on the reference picture. The prediction unit 230 may apply any one of a skip mode, a merge mode, and an MVP mode to derive a prediction sample for the current block. In this case, motion information required for inter prediction of the current block provided by the video encoding apparatus, for example, information about a motion vector, a reference picture index, and the like may be obtained or derived based on the prediction information.

In the skip mode and the merge mode, the motion information of the neighboring block may be used as the motion information of the current block. In this case, the neighboring block may include a spatial neighboring block and a temporal neighboring block.

The prediction unit 230 may construct a merge candidate list using motion information of available neighboring blocks, and may use information indicated by the merge index on the merge candidate list as a motion vector of the current block. The merge index may be signaled from the encoding device. The motion information may include a motion vector and a reference picture. When the motion information of the temporal neighboring block is used in the skip mode and the merge mode, the highest picture on the reference picture list may be used as the reference picture.

In the skip mode, unlike the merge mode, the difference (residual) between the prediction sample and the original sample is not transmitted.

In the MVP mode, the motion vector of the current block may be derived using the motion vector of the neighboring block as a motion vector predictor. In this case, the neighboring block may include a spatial neighboring block and a temporal neighboring block.

For example, when the merge mode is applied, a merge candidate list may be generated by using a motion vector of a reconstructed spatial neighboring block and / or a motion vector corresponding to a Col block, which is a temporal neighboring block. In the merge mode, the motion vector of the candidate block selected from the merge candidate list is used as the motion vector of the current block. The information about the prediction may include a merge index indicating a candidate block having an optimal motion vector selected from candidate blocks included in the merge candidate list. In this case, the prediction unit 230 may derive the motion vector of the current block by using the merge index.

As another example, when the Motion Vector Prediction (MVP) mode is applied, a motion vector predictor candidate list may be generated using a motion vector of a reconstructed spatial neighboring block and / or a motion vector corresponding to a Col block, which is a temporal neighboring block. Can be. That is, the motion vector of the reconstructed spatial neighboring block and / or the Col vector, which is a temporal neighboring block, may be used as a motion vector candidate. The prediction information may include a prediction motion vector index indicating an optimal motion vector selected from the motion vector candidates included in the list. In this case, the prediction unit 230 may select the predicted motion vector of the current block from the motion vector candidates included in the motion vector candidate list using the motion vector index. The prediction unit of the encoding apparatus may obtain a motion vector difference (MVD) between the motion vector of the current block and the motion vector predictor, and may encode the output vector in a bitstream form. That is, MVD may be obtained by subtracting the motion vector predictor from the motion vector of the current block. In this case, the prediction unit 230 may obtain a motion vector difference included in the information about the prediction, and derive the motion vector of the current block by adding the motion vector difference and the motion vector predictor. The prediction unit may also obtain or derive a reference picture index or the like indicating a reference picture from the information about the prediction.

The adder 240 may reconstruct the current block or the current picture by adding the residual sample and the predictive sample. The adder 240 may reconstruct the current picture by adding the residual sample and the predictive sample in block units. Since the residual is not transmitted when the skip mode is applied, the prediction sample may be a reconstruction sample. Although the adder 240 has been described in a separate configuration, the adder 240 may be part of the predictor 230. On the other hand, the adder 240 may be called a restoration unit or a restoration block generation unit.

The filter unit 250 may apply the deblocking filtering sample adaptive offset, and / or ALF to the reconstructed picture. In this case, the sample adaptive offset may be applied in units of samples and may be applied after deblocking filtering. ALF may be applied after deblocking filtering and / or sample adaptive offset.

The memory 260 may store reconstructed pictures (decoded pictures) or information necessary for decoding. Here, the reconstructed picture may be a reconstructed picture after the filtering process is completed by the filter unit 250. For example, the memory 260 may store pictures used for inter prediction. In this case, pictures used for inter prediction may be designated by a reference picture set or a reference picture list. The reconstructed picture can be used as a reference picture for another picture. In addition, the memory 260 may output the reconstructed picture in an output order.

Meanwhile, in the case of inter prediction, in order to derive the motion information of the current block, not only the motion information of the neighboring block (ie, the spatial neighboring block) spatially adjacent to the current block, but also the neighboring block (ie, the temporal neighboring block) of the already decoded reference picture The motion information candidate list may be configured based on the motion information of the " The motion information may include a motion vector and a reference picture index, and the motion information candidate list may indicate a merge candidate list or a motion vector predictor (MVP) candidate list. Meanwhile, a duplicate check process may be performed on the motion information candidates added to the motion information candidate list to remove the duplicate motion information candidates from the motion information candidate list. The motion information candidate list may include motion information candidates having a predetermined number of candidates.

Meanwhile, when a skip mode or a merge mode is applied to the current block, a merge candidate list may be configured as described above, and the merge candidate list may include a spatial candidate, a temporal candidate, an affinity candidate, and ATMVP (Advanced Temporal Motion). Vector Predictor), STMVP (Spatial Temporal Motion Vector Predictor), combined candidate, and / or zero vector may be included as merge candidates. Here, the spatial candidate may indicate a merge candidate including motion information of spatial neighboring blocks of the current block, and the temporal candidate may indicate a merge candidate including motion information of the temporal neighboring blocks of the current block.

In the case of inter prediction in an existing coding system, only motion information of spatial neighboring blocks adjacent to the current block may be used to derive motion information of the current block. Accordingly, the present invention proposes a method of searching for motion information in a wider area which is already decoded, and not limited to adjacent neighboring blocks to derive motion information of the current block. Through this, more various motion information may be used as a candidate of motion information of the current block, and an effect of improving prediction accuracy may be generated. In addition, the present invention proposes a method of limiting the area that can be referred to in order to properly consider memory saving and performance improvement.

Hereinafter, a block, a small block, or a smallest block described in each drawing may mean an N × N pixel unit, and N may be an integer of 1 or more. For example, when N = 1, the block may mean one pixel, and when N = 4, the block may mean a 4 × 4 block (16 pixels).

3 exemplarily shows spatial neighboring blocks that can be used to derive a spatial candidate for the current block. Referring to FIG. 3, a position of a neighboring block capable of deriving motion information of the current block based on the current block 300 may be defined. One small block shown in FIG. 3 may represent a sub block, and the size of the sub block may be defined between an encoding device (or an encoding device) and a decoding device (or a decoding device), or a high level syntax ( It can be derived variably based on the size related information of the sub-block signaled through high level syntax. Referring to FIG. 3, the spatial neighboring blocks of the current block may include 49 spatial neighboring blocks, which may include spatial neighboring blocks adjacent to five current blocks and spatial neighboring blocks not adjacent to 44 current blocks. Can be.

For example, when the size of the sub block is nxn and the x component of the top-left sample position of the current block is 0 and the y component is 0, the first neighboring block is coordinates (-n, 7n). Block 2 containing a sample of coordinates (7n, -n), block 3 containing a sample of coordinates (8n, -n), and block 4 The neighboring block is a block containing samples of (-n, 8n) coordinates, the neighboring block 5 may be a block containing samples of (-n, -n) coordinates, and the neighboring block 6 is (-5n, 4n) may be a block containing a sample of coordinates, a block around 7 may be a block containing a sample of (4n, -4n) coordinates, and a block of 8 is a sample of (-5n, 0) coordinates The surrounding block # 9 may be a block containing samples of (0, -4n) coordinates; the peripheral block # 10 may be a block containing samples of (-5n, 7n) coordinates; , Block 11 may be a block containing samples of (7n, -4n) coordinates, block 12 is a block containing samples of (-5n, -4n) coordinates, block 13 is May be a block containing samples of (-5n, 11n) coordinates, a neighboring block 14 may be a block containing samples of (11n, -4n) coordinates, and a 15th neighboring block is (-n, 11n) May be a block containing a sample of coordinates, a block around 16 may be a block containing a sample of (11n, -n) coordinates, and a block of around 17 contains a sample of (-9n, 4n) coordinates Block around, block 18 may be a block containing samples of (4n, -8n) coordinates, block 19 is a block containing samples of (-9n, 0) coordinates, and Block around can be a block containing samples of (0, -8n) coordinates, block 21 is a block containing samples of (-9n, 7n) coordinates, block 22 is (7n) , -8 n) may be a block containing a sample of coordinates, a block around 23 may be a block containing a sample of (-9n, -8n) coordinates, and a block of around 24 is a sample of (-9n, 15n) coordinates May be a block including the neighboring block 25 may be a block including a sample of (15n, -8n) coordinates, and the neighboring block 26 is a block containing a sample of the (-n, 15n) coordinates , Block 27 may be a block containing samples of (15n, -n) coordinates, block 28 is a block containing samples of (-13n, 4n) coordinates, and block 29 is nearby. May be a block containing a sample of (4n, -12n) coordinates, a neighboring block 30 may be a block containing a sample of (-13n, 0) coordinates, and a neighboring block 31 is (0, -12n ) May be a block containing a sample of coordinates, and a neighboring block 32 may be a block containing a sample of (-13n, 7n) coordinates, and a neighboring block 33 is a sample of (7n, -12n) coordinates. The neighboring block can be a block containing samples of (-13n, -12n) coordinates, and the neighboring block 35 can be a block containing samples of (-13n, 19n) coordinates. And, block 36, can be a block containing samples of (19n, -12n) coordinates, block 37, can be a block containing samples of (-n, 19n) coordinates, block 38, and May be a block containing a sample of (19n, -n) coordinates, a neighboring block 39 may be a block containing a sample of (-17n, 4n) coordinates, and a neighboring block 40 is (4n, -16n ) May be a block containing a sample of coordinates, and the neighboring block 41 may be a block containing a sample of (-17n, 0) coordinates, and the neighboring block 42 includes a sample of (0, -16n) coordinates And the neighboring block 43 may be a block including samples of (-17n, 7n) coordinates, and the neighboring block 44 is a block containing samples of (7n, -16n) coordinates. And the surrounding block 45 can be a block containing samples of (-17n, -16n) coordinates, and the surrounding block 46 can be a block containing samples of (-17n, 23n) coordinates, and number 47 The neighboring block may be a block containing samples of (23n, -16n) coordinates, the neighboring block 48 may be a block containing samples of (-n, 23n) coordinates, and the neighboring block 49 is (23n, n) may be a block containing a sample of coordinates. On the other hand, for example, the size of the current block may be WxH, W may be 8n, H may be 8n.

In addition, referring to FIG. 3, a number written in each of the neighboring blocks may indicate a motion information search order of the neighboring block. That is, motion information of the neighboring blocks may be derived as motion information candidates (eg, merge candidates) of the current block in the search order. As shown in FIG. 3, motion information of a plurality of neighboring blocks may be used to derive motion information of the current block. That is, more various motion information may be configured as motion information candidates for the current block based on the motion information of a plurality of neighboring blocks, thereby improving the accuracy of prediction. In addition, although the above-described embodiment describes the merge mode as an example, even when the AMVP mode is applied to the current block, the motion information candidate list may be configured based on the plurality of neighboring blocks shown in FIG. 3. That is, the above motion information candidate list may indicate a merge candidate list or an MVP candidate list, and the motion information candidate may indicate a merge candidate or an MVP candidate. In addition, the spatial candidate may represent a spatial merge candidate or a spatial MVP candidate.

In addition, a method of deriving motion information of the current block based on spatial neighboring blocks different from the above-described embodiment may be proposed.

Referring to FIG. 4, a position of a neighboring block that may be referred to may be defined in order to construct a motion information candidate list including various motion information as motion information candidates. Referring to FIG. 4, a position of a neighboring block capable of deriving motion information of the current block based on the current block 400 may be defined. Referring to FIG. 4, the spatial neighboring blocks of the current block may include 27 spatial neighboring blocks. In addition, the spatial neighboring blocks adjacent to the five current blocks used in the existing block as well as the 22 current blocks may not be spatially adjacent. It may include peripheral blocks.

For example, when the size of the current block is WxH and the x component of the top-left sample position of the current block is 0 and the y component is 0, the neighboring block 1 is (-1, H-1 ) Is a block containing a sample of coordinates, and a neighboring block 2 is a block containing a sample of (W-1, -1) coordinates, and a neighboring block 3 is a block containing a sample of (W, -1) coordinates. The neighboring block 4 is a block containing a sample of (-1, H) coordinates, the neighboring block 5 may be a block containing a sample of (-1, -1) coordinates, and the neighboring block 6 is May be a block containing a sample of (-W-1, H-1) coordinates, and the neighboring block 7 may be a block containing a sample of (W-1, -H-1) coordinates, and around 8th The block may be a block containing a sample of (W, -H-1) coordinates, the neighboring block 9 may be a block containing a sample of (-W-1, H) coordinates, and the neighboring block 10 is The number of blocks containing samples of (-1, -H-1) coordinates Neighboring block 11 may be a block containing a sample of (-W-1, -1) coordinates, and a neighboring block 12 is a block containing a sample of (-W-1, 2H) coordinates, , Block 13 may be a block containing samples of (2W, -H-1) coordinates, and block 14 may be a block containing samples of (-W-1, -H-1) coordinates. And the neighboring block 15 may be a block containing a sample of (-2W-1, H-1) coordinates, and the peripheral block of 16 is a block containing a sample of (W-1, -2H-1) coordinates And the surrounding block 17 may be a block containing a sample of (W, -2H-1) coordinates, and the surrounding block 18 may be a block containing a sample of (-2W-1, H) coordinates. And the neighboring block 19 may be a block containing samples of (-1, -2H-1) coordinates, and the peripheral block of 20 may be a block containing samples of (-2W-1, -1) coordinates. And the neighboring block 21 may be a block including samples of (2W, -2H-1) coordinates, and 22 The neighboring block may be a block containing samples of (-2W-1, 2H) coordinates, the neighboring block 23 may be a block containing samples of (-W-1, -2H-1) coordinates, and 24 Block around may be a block containing a sample of coordinates (-2W-1, -H-1), block 25 is a block containing a sample of coordinates (3W, -2H-1), Peripheral block 26 may be a block containing samples of (-2W-1, 3H) coordinates, and block 27 may be a block containing samples of (-2W-1, -2H-1) coordinates. .

Referring to FIG. 4, a number written in each of the neighboring blocks may indicate a search order of motion information of the neighboring block. That is, motion information of the neighboring blocks may be derived as motion information candidates (eg, merge candidates) of the current block in the search order. The encoding device / decoding device may search the motion information of the neighboring blocks in the search order shown in FIG. 4, and use it as motion information or a motion vector predictor (MVP) in addition to the motion information candidate list for the current block. Can be. Also, as proposed in this embodiment, even when the motion information candidate list is configured, a pruning check process may be performed in the same manner as the configuration of the existing motion information candidate list. Here, the pruning check process may represent a process of checking whether the motion information is duplicated. That is, the encoding device / decoding device may determine whether the motion information of the neighboring block overlaps with the motion information candidate derived in the above order. When the motion information is overlapped, the motion information is a motion information candidate for the current block. May not be derived. Although the above-described embodiment describes the merge mode as an example, even when the AMVP mode is applied to the current block, the motion information candidate list may be configured based on the plurality of neighboring blocks shown in FIG. 4. That is, the above motion information candidate list may indicate a merge candidate list or an MVP candidate list, and the motion information candidate may indicate a merge candidate or an MVP candidate. In addition, the spatial candidate may represent a spatial merge candidate or a spatial MVP candidate.

5 shows another example of spatial neighboring blocks that can be used to derive a spatial candidate for the current block. Referring to FIG. 5, the spatial neighboring blocks of the current block are left neighboring blocks A ₁ , upper neighboring blocks B ₁ , right upper corner neighboring blocks B ₀ , and lower left corners used for existing motion information candidates. The peripheral block A ₀ and the upper left corner peripheral block B ₂ may be included. In addition, the spatial neighboring blocks of the current block may include neighboring blocks that are not adjacent to the current block derived based on the neighboring block adjacent to the current block. For example, a left neighboring block and an upper neighboring block, which are criteria for fetching motion information, may be defined. Referring to FIG. 5, the left peripheral block and the upper peripheral block may be defined as the left peripheral block A ₁ and the upper peripheral block B ₁ . Then, the encoding device / decoding device moves in the x-axis direction (horizontal) in the left peripheral block A ₁ and in the y-axis direction (vertical) in the upper peripheral block until a specific distance is reached. Tracing may be performed in a motion information storage unit (eg, a block of 4 × 4 size) until a specific distance is reached. Accordingly, the spatial peripheral blocks are peripheral blocks H ₁ to peripheral blocks H _N located on the left side of the left peripheral block A ₁ and peripheral blocks V ₁ to peripheral blocks located on the upper side of the upper peripheral block B ₁ . It may include V _N. The distance between the peripheral block H _N in the left peripheral block A ₁ may be the specific distance, and the distance between the peripheral block V _N in the upper peripheral block B ₁ may be the specific distance. Meanwhile, the specific distance may be preset. The encoding device / decoding device may search motion information of the neighboring blocks shown in FIG. 5, and may use it as motion information or a motion vector predictor (MVP) in addition to the motion information candidate list for the current block. More various motion information may be configured as motion information candidates for the current block based on motion information of a plurality of neighboring blocks, thereby improving accuracy of prediction. Although the above-described embodiment describes the merge mode as an example, even when the AMVP mode is applied to the current block, the motion information candidate list may be configured based on the plurality of neighboring blocks shown in FIG. 5. That is, the above motion information candidate list may indicate a merge candidate list or an MVP candidate list, and the motion information candidate may indicate a merge candidate or an MVP candidate. In addition, the spatial candidate may represent a spatial merge candidate or a spatial MVP candidate.

6 shows another example of spatial neighboring blocks that can be used to derive a spatial candidate for the current block. Referring to FIG. 6, the spatial neighboring blocks of the current block include a left neighboring block A, an upper neighboring block B, a right upper corner neighboring block C, and a lower left corner neighboring block used for a candidate for existing motion information. D), the upper left corner peripheral block E may be included. In addition, the spatial neighboring blocks may include neighboring blocks that are not adjacent to the current block derived based on neighboring blocks adjacent to the current block. Peripheral blocks that are not adjacent to the current block include peripheral blocks located on the left side of the left peripheral block A, peripheral blocks located on the upper side of the upper peripheral block B, and right upper corner peripheral block C. Peripheral blocks positioned at an upper side of the peripheral block, peripheral blocks positioned at a left side of the lower left corner peripheral block D, and peripheral blocks positioned at an upper left diagonal direction of the upper left corner peripheral block E; Can be.

For example, the encoding device / decoding device moves in an upward direction by a specific offset with respect to the upper right corner peripheral block C and the upper peripheral block B in units of 32x32 size, while B (i, j Motion information of the neighboring block at the position C) and the neighboring block at the position C (i, j) can be collected and moved in a diagonal direction (upper left diagonal direction) by a specific offset with respect to the upper left corner peripheral block (E). The motion information of the neighboring block at the position E (i, j) may be collected, and A (i is moved by a specific offset in the left direction with respect to the left peripheral block A and the lower left corner peripheral block D block. j) collect motion information of the neighboring block at the position and the neighboring block at the position D (i, j), and add the collected motion information as the motion information candidate of the current block to the motion information candidate list. . Here, the specific offset may be defined as 16, or may be freely defined within a limited range. Also, neighboring blocks not adjacent to the current block may be derived within a search range. The search range may be predefined. Referring to FIG. 6, when the x component of the top-left sample position of the current block is 0 and the y component is 0, the search range may be set to (-96, -96) coordinates.

For example, when the size of the current block is WxH, and the x component of the top-left sample position of the current block is 0 and the y component is 0, the left peripheral block A is (-1, H -1) a block containing a sample of coordinates, the upper peripheral block (B) is a block containing a sample of (W-1, -1) coordinates, and the right upper corner peripheral block (C) is (W, -1) a block containing a sample of coordinates, the lower left corner peripheral block (D) is a block containing a sample of (-1, H) coordinates, and the upper left corner peripheral block (E) is (-1) , -1) may be a block including a sample of coordinates.

Also, neighboring blocks positioned to the left of the left neighboring block A may include neighboring blocks A ₁ to neighboring blocks A _N , the specific offset is n, the size of the current block is WxH, and the current block When the x component of the top-left sample position of 0 is 0 and the y component is 0, the neighboring block A ₁ is a block containing a sample of (-1-n, H-1) coordinates, a neighboring block A ₂ Is a block containing a sample of (-1-2n, H-1) coordinates, ... The peripheral block A _N may be a block containing a sample of (-1-N * n, H-1) coordinates .

In addition, the neighboring blocks located above the upper neighboring block B may include neighboring blocks B ₁ to neighboring blocks B _N , the specific offset is n, the size of the current block is WxH, and the current block When the x component of the top-left sample position of is 0 and the y component is 0, the neighboring block B ₁ is a block containing a sample of (W-1, -1-n) coordinates, a neighboring block B ₂ May be a block including a sample of (W-1, -1-2n) coordinates, and the neighboring block B _N may be a block including a sample of (W-1, -1-N * n) coordinates. .

In addition, the neighboring blocks located above the upper right corner peripheral block C may include neighboring blocks C ₁ to neighboring blocks C _N , the specific offset is n, and the size of the current block is WxH, When the x component of the top-left sample position of the current block is 0 and the y component is 0, the neighboring block C ₁ is a block containing a sample of (W, -1-n) coordinates, a neighboring block C ₂ May be a block including a sample of (W, -1-2n) coordinates, and the neighboring block C _N may be a block including a sample of (W, -1-N * n) coordinates.

In addition, neighboring blocks positioned to the left of the lower left corner peripheral block D may include neighboring blocks D ₁ to neighboring blocks D _N , the specific offset is n, and the size of the current block is WxH, If the x component of the top-left sample position of the current block is 0 and the y component is 0, the neighboring block D ₁ is a block containing a sample of (-1-n, H) coordinates, a neighboring block D ₂ Is a block containing a sample of (-1-2n, H) coordinates, ... The neighboring block D _N may be a block containing a sample of (-1-N * n, H) coordinates.

In addition, the neighboring blocks located in the upper left target direction of the upper left corner peripheral block E may include peripheral blocks E ₁ to neighboring blocks E _N , the specific offset is n, and the size of the current block is If WxH and the x component of the top-left sample position of the current block is 0 and the y component is 0, the neighboring block E ₁ includes samples of (-1-n, -1-n) coordinates. Block, neighboring block E ₂ is a block containing samples of (-1-2n, -1-2n) coordinates, ... said neighboring block E _N is (-1-N * n, -1-N * n) It may be a block containing a sample of coordinates.

The encoding device / decoding device may search for motion information of the neighboring blocks shown in FIG. 6, and may use the motion information or a motion vector predictor (MVP) in addition to the motion information candidate list for the current block. More various motion information may be configured as motion information candidates for the current block based on the motion information of a plurality of neighboring blocks, thereby improving accuracy of prediction. Although the above-described embodiment describes the merge mode as an example, even when the AMVP mode is applied to the current block, the motion information candidate list may be configured based on the plurality of neighboring blocks shown in FIG. 6. That is, the above motion information candidate list may indicate a merge candidate list or an MVP candidate list, and the motion information candidate may indicate a merge candidate or an MVP candidate. In addition, the spatial candidate may represent a spatial merge candidate or a spatial MVP candidate.

Meanwhile, as in the above-described embodiments, a plurality of neighboring blocks may be used to derive motion information about the current block. However, when deriving the motion information of the current block based on a plurality of neighboring blocks, the amount of memory required for performing the decoding process (ie, an increase in the line buffer) and the computational complexity of the decoding process are increased. Since the amount of bits allocated to information for indicating a candidate selected from a plurality of candidates may increase, selecting an appropriate number of neighboring blocks for the current block and deriving a motion information candidate list based on the selected neighboring blocks Coding efficiency can be improved more.

Accordingly, the present invention proposes a method of selecting a neighboring block used to derive a motion information candidate list of the current block among a plurality of neighboring blocks. The present invention proposes embodiments of a condition for selecting a neighboring block as described below, whereby a neighboring block that satisfies one or a combination of a plurality of conditions disclosed in the embodiments described below is included in the current block. It can be used to derive a motion information candidate list.

For example, a neighboring block adjacent to the current block or a neighboring block located within 1 sample from the boundary of the current block among the neighboring blocks may be selected, and the motion of the current block is based on the motion information of the selected neighboring block. An information candidate may be derived to construct a motion information candidate list for the current block. In this way, the line buffer required for the decoding process can be saved.

In the description of the present invention, derivation of neighboring blocks may be referred to as selection of neighboring blocks, and derivation and selection may be used interchangeably. In addition, the neighboring block may include a neighboring block adjacent to the current block and a non-adjacent block not adjacent to the current block, and the block may include all if not called a neighboring block or a non-adjacent block.

Here, the positions of the above-described neighboring blocks may be based on a case using a raster-scan order or a similar order. Therefore, when using a different scan order, the positions of the neighboring blocks may vary.

For example, the scan order may be set from the lower right side to the upper left direction. Or scan order is (Right-> Left-Down-Up), (Down-> Up, Right-> Left), (Right-> Left-> Zig-Zag) and (Down-> Up-> Left) Zigzag). I.e. (right-> lower-> right-> left), (right-> right-> lower-> left), (right-> lower-> left-> right) and (right-> right-> top-left- Lower left), etc., but is not limited thereto.

Referring to FIG. 7, the motion information candidate list for predicting motion information of the current block 700 may be configured based on the spatial neighboring blocks of the current block, and the spatial neighboring blocks are the lower right region and the lower side of the current block. It may be included in at least one of the region, the lower left region, the right region, and the upper right region. Here, the lower right region may include at least one block located at the lower right side of the current block, the lower region may include at least one block located at the lower side of the current block, and the lower left region may be at the lower left of the current block. It may include at least one block located on the side, the right region may include at least one block located on the right side of the current block, the right upper region may include at least one block located on the right side of the current block Can be. Also, blocks in each region may or may not be adjacent to the current block. That is, it may be a neighboring block located within a predetermined distance from the boundary of the current block.

For example, the motion information candidate list for motion information prediction of the current block 800 may be configured based on the spatial neighboring blocks of the current block, and the spatial neighboring blocks are located within 1 sample from the boundary of the current block. It may also include a block. In this case, when the scan order is as shown in FIG. 7, blocks located within one sample from the boundary of the current block may appear as shown in FIG. 8, and a motion information candidate list may be configured based on the information of these blocks. Alternatively, the spatial neighboring blocks of the current block for constructing the motion information candidate list may include these blocks.

According to an embodiment, a method of selecting a neighboring block used to derive a motion information candidate list of the current block among the plurality of neighboring blocks described with reference to FIGS. 3 to 6 is used when another scan order described with reference to FIG. 7 is used. It may be modified and applied as appropriate. That is, the neighboring blocks described with reference to FIGS. 3 to 6 may be located on the lower left side, the left side, the upper left side, the upper side and the upper right side with respect to the current block. However, when another scan order is used, the neighboring blocks refer to the current block. It can be located on the upper right side, right side, lower right side, lower side and lower left side. In other words, the distance from the current block may be the same but the direction from the current block may be reversed.

9 shows an example of an available range of neighboring blocks for the current block. Here, the peripheral block may be referred to as a peripheral reference block.

For example, a neighboring block included in the same upper block as the current block 900 among the neighboring blocks may be selected, and the motion information candidate of the current block is derived based on the motion information of the selected neighboring block. A motion information candidate list for the current block may be constructed. An upper block including the current block may be referred to as a current upper block.

For example, the upper block may be referred to as a maximum coding unit or a largest coding unit as shown in FIG. 9. For example, an upper block may be referred to as a coding tree unit (CTU), and in this case, a CTU including the current block may be represented as a current CTU.

That is, a neighboring block included in the current higher block among the neighboring blocks may be selected, and a motion information candidate for the current block is derived by deriving a motion information candidate of the current block based on the motion information of the selected neighboring block. Lists can be constructed.

Referring to FIG. 9, neighboring blocks that may be used for motion information candidates include a left neighboring block A ₁ , an upper neighboring block B ₁ , a right upper corner neighboring block B ₀ , and a lower left corner of the current block 900. It may include a side corner peripheral block (A ₀ ), the upper left corner peripheral block (B ₂ ), the left peripheral block, the upper peripheral block, the upper right corner peripheral block, the lower left corner peripheral block and the upper left corner peripheral block It may be included in the same upper block as the current block.

Also, for example, a neighboring block included in the current upper block among the neighboring blocks, a neighboring block included in a left upper neighboring block of the current upper block, and a neighboring block included in a left upper neighboring upper block of the current upper block And / or a neighboring block included in an upper neighboring upper block of the current upper block may be selected, and the motion information for the current block is derived by deriving a motion information candidate of the current block based on the motion information of the selected neighboring block. The candidate list can be constructed.

For example, a neighboring block included in a specific region among the neighboring blocks may be selected, and a motion information candidate list for the current block is derived by deriving a motion information candidate of the current block based on the motion information of the selected neighboring block. Can be configured. Here, the specific region may indicate an area of 96x96 size or an area within a 96 sample distance from the upper left sample position based on the upper left sample position of the current block. In other words, the specific region may indicate a 96 × 96 size region centering on the upper left sample position of the current block or an area within a 96 sample distance from the upper left sample position of the current block. However, since the specific area may be set differently, the specific area is not limited to the area of the size and the area within the sample distance.

For example, referring to FIG. 10, a specific area may be set as Max Range 0, Max Range 1 and Max Range 2, which may be set to predetermined values at the encoder / decoder. have. Alternatively, the encoder may determine the rate-distortion comparison and transmit the determined value to the decoder. The decoder may obtain information about the specific region based on the determined value received from the encoder. Here, Max Range 0 may be four times the size of the current block, and may be a range in which the current block is located at the bottom right side. Max Range 1 may be 9 times the size of the current block, and may be a range in which the current block is located at the bottom right. Max Range 2 may be 16 times the size of the current block, and may be a range in which the current block is located at the bottom right.

In addition, as an example, a neighboring block included in a specific region among the neighboring blocks may be selected, and the motion information of the current block is derived by deriving a motion information candidate of the current block based on the motion information of the selected neighboring block. The candidate list can be constructed. Here, the specific region may indicate an area of two maximum coding unit sizes centered on the upper left sample position of the current block. Here, the maximum coding unit may refer to a CTU.

Also, as an example, when constructing a motion information candidate list for motion information prediction, a maximum coding unit may refer to neighboring blocks within a reference range determined based on the number. For example, the reference range may be determined by (width or width of maximum coding units) x (number of maximum coding units). That is, the reference range may be determined based on the size of the maximum coding unit and the number of maximum coding units. Here, the maximum coding unit may refer to a CTU. The number of maximum coding units may mean the number of maximum coding units in the current picture.

Also, for example, a neighboring block included in a specific region indicated by a specific motion vector among the neighboring blocks may be selected, and the motion information candidate of the current block is derived based on the motion information of the selected neighboring block. The motion information candidate list for the block may be constructed. Here, the specific region may indicate a region of a specific size, and the specific motion vector may be derived as a motion vector having a maximum absolute value among the motion vectors of neighboring blocks adjacent to the current block.

For example, when constructing a motion information candidate list for motion information prediction, the motion information candidate list may be limited to neighboring blocks within a range of a specific size with respect to a position indicated by a motion vector of a block adjacent to the current block. Here, the motion vector of the adjacent block may mean a motion vector having the largest absolute value among the motion vectors of the blocks adjacent to the current block.

For example, referring to FIG. 11, the specific size may mean a range of (p, q) in the vertical / horizontal direction with respect to the position indicated by the motion vector. That is, the specific region may be a region having a height of 2p and a width of 2q based on the position indicated by the motion vector. In this case, (p, q) may be determined based on at least one of the size of the current block, the size of the largest coding unit, and the size of the neighboring block. However, the specific size may be a predetermined value, but is not limited thereto.

For example, when the upper left corner block E ₀ among the adjacent blocks of the current block 1100 has a motion vector having the largest absolute value, the height is 2p around the position (x, y) indicated by the motion vector, An area of width 2q may be determined, and a block within the determined area may be selected to derive motion information candidates.

Also, for example, a neighboring block included in a specific region indicated by a specific motion vector among the neighboring blocks may be selected, and the motion information candidate of the current block is derived based on the motion information of the selected neighboring block. The motion information candidate list for the block may be constructed. Here, the specific region may represent a region of a specific size, and the specific motion vector may be derived as an average value of motion vectors of neighboring blocks adjacent to the current block.

Also, for example, a specific region may be determined based on a position indicated by the average of motion vectors of neighboring blocks adjacent to the current block, and a neighboring block in the specific region may be selected to derive motion information candidates of the current block. Can be. As described above, the specific region may indicate a region of a specific size, and the specific size may mean a range of (p, q) in the vertical / horizontal direction with respect to the position indicated by the motion vector. In other words, the average motion vector of the neighboring blocks may be used instead of the motion vector having the largest absolute value among the motion vectors of the neighboring blocks adjacent to the current block. That is, in FIG. 11, average motion vectors of A ₀ , B ₀ , C ₀ , D _0, and E ₀ may be used.

For example, a neighboring block included in a specific region indicated by a specific motion vector among the neighboring blocks may be selected, and a motion information candidate of the current block is derived based on the motion information of the selected neighboring block to the current block. The motion information candidate list may be configured. Here, the specific region may indicate a region of a specific size, and the specific motion vector may be derived as a motion vector of a specific neighboring block among neighboring blocks adjacent to the current block. On the other hand, if the specific neighboring block is not available (for example, when the specific neighboring block is encoded / decoded based on the intra prediction mode), the specific motion vector may be derived as a zero vector, or a specific neighbor A neighboring block encoded / decoded based on inter prediction in the order of searching for a block may be derived as the specific neighboring block, and the derived motion vector of the specific neighboring block may be derived as the specific motion vector.

That is, it may be determined whether a specific block is coded in the intra prediction mode (S1200). When the specific block is coded in the intra prediction mode, the search may be performed until a specific block coded using an 0 vector or an inter mode is coded. It may be performed (S1210). Subsequently, a specific range can be set based on the position indicated by the motion vector of the specific block coded in the inter mode (S1220), and the motion information candidate list of the current block can be constructed using the motion information of the neighboring block within the specific range. There is (S1230).

In addition, as an example, a neighboring block having motion information with respect to a specific reference picture among the neighboring blocks may be selected, and a motion information candidate of the current block is derived based on the motion information of the selected neighboring block. A motion information candidate list may be constructed for the. Here, the specific reference picture may be derived as a reference picture that is referred to the most among reference pictures for neighboring blocks adjacent to the current block.

Also, for example, a neighboring block having motion information about a reference picture of a specific distance from the current picture among the neighboring blocks may be selected, and the motion information candidate of the current block is selected based on the motion information of the selected neighboring block. The motion information candidate list for the current block may be constructed. Here, the specific distance may be derived as a distance between a current picture and a reference picture that is most referenced among reference pictures for neighboring blocks adjacent to the current block. On the other hand, the distance between the pictures may represent a picture order count (POC) difference. That is, the specific distance may indicate a difference between the POC of the reference picture and the POC of the current picture.

Also, for example, a neighboring block having motion information about a reference picture of the closest distance in the display order from the current picture among the neighboring blocks may be selected, and based on the motion information of the selected neighboring block, the neighboring block may be selected. A motion information candidate list for the current block may be constructed by deriving a motion information candidate. Here, the reference picture of the closest distance in the display order may represent a reference picture having the smallest difference from the display order of the current picture among the reference pictures for neighboring blocks adjacent to the current block.

In addition, as an example, when constructing a motion information candidate list for motion information prediction, only a motion vector of a neighboring block referring to a reference picture of the closest distance in the display order with the current picture may be used. That is, a neighboring block referring to a reference picture having the smallest difference between the current picture included in the current block and a picture order count (POC) may be used.

In addition, as an example, neighboring blocks of the current block through high level syntax such as a video parameter set (VPS), a sequence parameter set (SPS), a picture parameter set (PPS), a slice header, and the like. The information about may be signaled, the neighboring block for the current block may be derived based on the information on the neighboring block of the current block, and the motion of the current block based on the derived motion information of the neighboring block. An information candidate may be derived to construct a motion information candidate list for the current block. For example, the information on the neighboring block of the current block may include information about a CTU offset from the current block, a specific range, and / or a position of a neighboring block to designate a range. Here, the specific range may be defined in units of samples.

The method disclosed in FIG. 13 may be performed by the encoding apparatus disclosed in FIG. 1. Specifically, for example, S1300 to S1330 of FIG. 13 may be performed by the prediction unit of the encoding apparatus, and S1340 may be performed by the entropy encoding unit of the encoding apparatus. In addition, although not shown, a process of deriving a residual sample for the current block based on the original sample and the prediction sample for the current block may be performed by a subtractor of the encoding apparatus, The generating of the information about the residual on the basis of the current block may be performed by a converter of the encoding apparatus. The encoding of the information on the residual and the prediction of the current block may be performed. It may be performed by the entropy encoding unit of the encoding device.

The encoding apparatus derives neighboring blocks of the current block (S1300). That is, the neighboring blocks for the motion information candidate list of the current block among the neighboring blocks of the current block may be derived or selected. The encoding apparatus may determine the prediction mode of the current block. For example, the encoding apparatus may apply inter prediction to the current block. The encoding apparatus may select neighboring blocks for the motion information candidate list of the current block among the neighboring blocks of the current block. Meanwhile, the motion information candidate list may represent a merge candidate list or an MVP candidate list.

For example, the neighboring blocks may include non-adjacent blocks that are not adjacent to the current block. However, according to an exemplary embodiment, adjacent blocks may be included.

For example, the non-adjacent block may be derived based on a motion vector of a block adjacent to the current block, a maximum coding unit including the current block, or a current picture including the current block.

For example, neighboring blocks are blocks located in at least one of a lower left region, a lower region, a lower right region, a right region, and an upper right region of the current block when the scanning order is set from the lower right side to the upper left direction. Or a non-adjacent block. Here, the scan order may be set from the lower right side to the upper left direction. Or scan order is (Right-> Left-Down-Up), (Down-> Up, Right-> Left), (Right-> Left-> Zig-Zag) and (Down-> Up-> Left) Zigzag). I.e. (right-> lower-> right-> left), (right-> right-> lower-> left), (right-> lower-> left-> right) and (right-> right-> top-left- Lower left), etc., but is not limited thereto. Here, the lower right region may include at least one block located at the lower right side of the current block, the lower region may include at least one block located at the lower side of the current block, and the lower left region may be at the lower left of the current block. It may include at least one block located on the side, the right region may include at least one block located on the right side of the current block, the right upper region may include at least one block located on the right side of the current block Can be. Also, blocks in each region may or may not be adjacent to the current block. That is, it may be a non-adjacent block located within a predetermined distance from the boundary of the current block.

For example, neighboring blocks may include a block or a non-adjacent block located within the largest coding unit that includes the current block. Alternatively, the neighboring blocks may include a non-adjacent block located in any one of a left peripheral maximum coding unit, a left upper peripheral maximum coding unit, and an upper peripheral maximum coding unit of the maximum coding unit including the current block. . Here, the maximum coding unit may refer to a higher block or a coding tree unit (CTU) of the current block. In this case, the maximum coding unit including the current block may be referred to as a current CTU, and the left peripheral maximum coding unit, the upper left peripheral maximum coding unit, and the upper peripheral maximum coding unit of the maximum coding unit including the current block are the current CTU. It can be expressed as the left peripheral CTU, the upper left peripheral CTU and the upper peripheral CTU of.

For example, neighboring blocks may include non-adjacent blocks located in an area within a specific sample distance with respect to the upper left sample position of the current block. Here, the specific sample distance may be 96 sample distances. Alternatively, neighboring blocks may include blocks or non-adjacent blocks located in a region of a specific size with respect to the upper left sample position of the current block. Here, the specific size may be 96x96 size.

For example, neighboring blocks may include blocks or non-adjacent blocks located within a max range, the maximum range being one of four, nine and sixteen times the size of the current block, The current block may be located at the lower right side within the maximum range. That is, the maximum range may be set as Max Range 0, Max Range 1, and Max Range 2, whereby the maximum range may indicate a specific region. Alternatively, the maximum range or specific area may be predetermined. Here, Max Range 0 may have a range of 4 times the size of the current block, Max Range 1 may have a range of 9 times the current block, and Max Range 2 may have a range of 16 times the current block. have. More detailed description has been given above with reference to FIG. 10.

For example, the neighboring blocks may include a block or a non-adjacent block located within a reference range, and the reference range may be determined based on the maximum coding unit size and the number of maximum coding units. Here, the maximum coding unit size may be determined based on the width or width of the maximum coding unit, and the maximum coding unit may refer to a higher block or CTU of the current block. In addition, the number of maximum coding units may be the number of maximum coding units included in the current picture, but is not limited thereto.

For example, neighboring blocks may include a block or non-adjacent block located within a specific area centered on a position indicated by a specific motion vector, wherein the specific motion vector is derived from motion vectors of blocks adjacent to the current block. The size of the specific region may be determined based on at least one of the size of the current block, the size of the largest coding unit, and the size of the neighboring block. Alternatively, the size of the specific region may be predetermined. Here, the specific motion vector may be derived as a motion vector of the maximum absolute value among the motion vectors of blocks adjacent to the current block. Alternatively, it may be derived as an average value or an average motion vector of motion vectors of blocks adjacent to the current block. Referring to FIG. 11, the specific size may mean a range of (p, q) in the vertical / horizontal direction with respect to the position indicated by the motion vector. That is, the specific region may be a region having a height of 2p and a width of 2q based on the position indicated by the motion vector. In this case, (p, q) may be determined based on at least one of the size of the current block, the size of the largest coding unit, and the size of the neighboring block. For example, if the upper left corner block E ₀ of the neighboring block of the current block has a motion vector having the largest absolute value, the height is 2p and the width is 2q around the position (x, y) indicated by the motion vector. The phosphorus region may be determined and blocks within the determined region may be selected or derived to derive motion information candidates.

For example, neighboring blocks may include a block or a non-adjacent block that references a reference picture having a smallest difference in picture order count (POC) from a current picture included in the current block. Here, the POC may indicate a display order, and the reference picture having the smallest difference between the current picture and the POC may mean a reference picture that is closest in display order to the current picture. Alternatively, the reference picture may mean a reference picture having the smallest difference from the display order of the current picture.

The encoding apparatus constructs the motion information candidate list based on the derived neighboring blocks (S1310). The encoding apparatus may construct the motion information candidate list based on the derived or selected neighboring blocks. The encoding apparatus may derive motion information of the selected neighboring blocks as motion information candidates of the current block, and construct the motion information candidate list including the motion information candidates. In addition, the encoding apparatus may derive the motion information derived by combining the motion information of the selected neighboring blocks as the motion information candidate of the current block, and configure the motion information candidate list including the motion information candidate. Meanwhile, the motion information candidate list may indicate a merge candidate list or an MVP candidate list, and the motion candidate may indicate a merge candidate or an MVP candidate.

The encoding apparatus derives the motion information of the current block based on the motion information candidate list (S1320). The encoding apparatus may select a specific motion information candidate from the motion information candidates of the motion information candidate list, and derive the selected motion information candidate as motion information for the current block. The encoding apparatus may generate and encode index information indicating the selected motion information candidate among the motion information candidates of the motion information candidate list. In addition, the encoding apparatus may derive the selected motion information candidate as the MVP for the current block and derive the motion information for the current block based on the MVP. In this case, the encoding apparatus may generate and encode a motion vector difference (MVD) based on the motion vector of the MVP and the motion information. Meanwhile, the index information may indicate a merge index or an MVP index.

The encoding apparatus generates a predicted block of the current block based on the motion information (S1330). That is, the prediction of the current block may be performed based on the motion information. A prediction block of the current block may be derived based on the motion information, and a reconstruction block may be derived based on the prediction block. In detail, the encoding apparatus may derive a reference block within a reference picture based on the motion information. The motion information may include a motion vector and a reference picture index. The encoding apparatus may derive the reference picture indicated by the reference picture index among the reference pictures of the reference picture list as the reference picture of the current block, and convert the block indicated by the motion vector in the reference picture into the reference block of the current block. Can be derived. The encoding apparatus may generate a prediction sample based on the reference block.

In addition, the encoding apparatus may generate a residual sample based on the original sample and the generated prediction sample. The encoding apparatus may generate information about the residual based on the residual sample. The information about the residual may include transform coefficients related to the residual sample. The encoding apparatus may derive the reconstructed sample based on the prediction sample and the residual sample. That is, the encoding apparatus may derive the reconstructed sample by adding the prediction sample and the residual sample. In addition, the encoding apparatus may encode the information about the residual and output the bitstream. The bitstream may be transmitted to a decoding apparatus via a network or a storage medium.

The encoding apparatus encodes image information including information on prediction of the current block (S1340). The encoding apparatus may encode and output the video information including the information on the prediction of the current block in the form of a bitstream. The bitstream may be transmitted to a decoding apparatus via a network or a storage medium. For example, the encoding apparatus may determine the prediction mode of the current block, and generate information indicating the prediction mode. Also, for example, the information about the prediction of the current block may include information about the motion information candidate list. The information on the motion information candidate list may include information indicating the specific area. The specific area may indicate an area in which the selected neighboring blocks are located. The information indicating the specific area may include information indicating the size of the specific area and / or information indicating the location of the specific area. The information on the motion information candidate list may include the CTU offset information. The information on the prediction may include index information indicating the selected motion information candidate among motion information candidates of the motion information candidate list. The information on the prediction of the current block may include a merge flag indicating whether a merge mode is applied to the current block. In addition, the encoding apparatus may generate information about the residual based on the residual sample. The image information may include information about the residual, and the information about the residual may include transform coefficients related to the residual sample. The encoding device may encode the information about the residual and output the encoded information about the residual. The bitstream may be transmitted to a decoding apparatus via a network or a storage medium.

The method disclosed in FIG. 14 may be performed by the decoding apparatus disclosed in FIG. 2. Specifically, for example, S1400 to S1430 of FIG. 14 may be performed by the prediction unit of the decoding apparatus. In addition, although not shown, a process of acquiring image information including information on prediction of a current block and information on residual through a bitstream may be performed by an entropy decoding unit of the decoding apparatus. The process of deriving the residual sample for the current block based on the dual information may be performed by an inverse transform unit of the decoding apparatus, and the process of generating a reconstructed picture based on the prediction sample and the residual sample may be performed. It may be performed by an adder of the decoding apparatus.

The decoding apparatus derives neighboring blocks of the current block (S1400). In other words, the decoding apparatus may derive or select neighboring blocks for the motion information candidate list of the current block among neighboring blocks of the current block. The decoding apparatus may determine the prediction mode of the current block based on the information about the prediction of the current block. The decoding apparatus may apply inter prediction to the current block. The decoding apparatus may select neighboring blocks for the motion information candidate list of the current block among the neighboring blocks of the current block. Meanwhile, the motion information candidate list may represent a merge candidate list or an MVP candidate list.

The decoding apparatus configures the motion information candidate list based on the derived neighboring blocks (S1410). The decoding apparatus may construct the motion information candidate list based on the selected or derived neighboring blocks. The decoding apparatus may derive the motion information of the selected neighboring blocks as motion information candidates of the current block, and construct the motion information candidate list including the motion information candidates. In addition, the decoding apparatus may derive the motion information derived by combining the motion information of the selected neighboring blocks as the motion information candidate of the current block, and configure the motion information candidate list including the motion information candidate. Meanwhile, the motion information candidate list may indicate a merge candidate list or an MVP candidate list, and the motion candidate may indicate a merge candidate or an MVP candidate.

The decoding apparatus derives the motion information of the current block based on the motion information candidate list (S1420). The decoding apparatus may select a specific motion information candidate among the motion information candidates of the motion information candidate list, and derive the selected motion information candidate as motion information for the current block. For example, the decoding apparatus may obtain index information through the bitstream, and may derive the motion information candidate indicated by the index information among the motion information candidates of the motion information candidate list as the motion information for the current block. . Alternatively, the decoding apparatus may obtain index information and a motion vector difference (MVD) through a bitstream, and among the motion information candidates of the motion information candidate list, the motion information candidate indicated by the index information may be selected as an MVP for the current block. Motion Vector Predictor), and may be derived as motion information for the current block based on the MVP and the MVD. The index information may indicate a merge index or an MVP index.

The decoding apparatus generates a predicted block of the current block based on the motion information (S1430). That is, the prediction of the current block may be performed based on the motion information. A prediction block of the current block may be derived based on the motion information, and a reconstruction block may be derived based on the prediction block. In detail, the decoding apparatus may derive a reference block within a reference picture based on the motion information. The motion information may include a motion vector and a reference picture index. The decoding apparatus may derive the reference picture indicated by the reference picture index among the reference pictures of the reference picture list as the reference picture of the current block, and convert the block indicated by the motion vector in the reference picture as the reference block of the current block. Can be derived. The decoding apparatus may generate a prediction sample based on the reference block, and may directly use the prediction sample as a reconstruction sample according to a prediction mode, or generate a reconstruction sample by adding a residual sample to the prediction sample. . If there is a residual sample for the current block, the decoding apparatus may obtain information about the residual for the current block from the bitstream. The information about the residual may include transform coefficients regarding the residual sample. The decoding apparatus may derive the residual sample (or residual sample array) for the current block based on the residual information. The decoding apparatus may generate a reconstructed sample based on the prediction sample and the residual sample, and may derive a reconstructed block or a reconstructed picture based on the reconstructed sample. Thereafter, as described above, the decoding apparatus may apply an in-loop filtering procedure, such as a deblocking filtering and / or SAO procedure, to the reconstructed picture in order to improve subjective / objective picture quality as necessary.

According to the present invention described above, in order to derive the motion information of the current block, the motion information can be searched in a wider area that has already been decoded, and not limited to adjacent neighboring blocks. It can be used as a candidate for motion information to improve prediction accuracy.

In addition, according to the present invention, it is possible to select neighboring blocks suitable for the current block among the neighboring blocks based on a specific condition, and derive a motion information candidate list based on the selected neighboring blocks. Memory bandwidth can be saved, and coding efficiency can be improved by improving prediction performance.

In the above-described embodiment, the methods are described based on a flowchart as a series of steps or blocks, but the present invention is not limited to the order of steps, and any steps may occur in a different order or simultaneously from other steps as described above. have. In addition, those skilled in the art will appreciate that the steps shown in the flowcharts are not exclusive and that other steps may be included or one or more steps in the flowcharts may be deleted without affecting the scope of the present invention.

The above-described method according to the present invention may be implemented in software, and the encoding device and / or the decoding device according to the present invention may perform image processing of, for example, a TV, a computer, a smartphone, a set-top box, a display device, and the like. It can be included in the device.

When embodiments of the present invention are implemented in software, the above-described method may be implemented as a module (process, function, etc.) for performing the above-described function. The module may be stored in memory and executed by a processor. The memory may be internal or external to the processor and may be coupled to the processor by various well known means. The processor may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, and / or data processing devices. The memory may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium and / or other storage device.

15 schematically shows the structure of a content streaming system.

That is, the embodiments described in the present invention may be implemented and performed on a processor, a microprocessor, a controller or a chip. For example, the functional units shown in each drawing may be implemented and performed on a computer, processor, microprocessor, controller, or chip.

In addition, the decoding apparatus and encoding apparatus to which the present invention is applied include a multimedia broadcasting transmitting and receiving device, a mobile communication terminal, a home cinema video device, a digital cinema video device, a surveillance camera, a video chat device, a real time communication device such as video communication, and mobile streaming. Devices, storage media, camcorders, video on demand (VoD) service providers, over the top video (OTT) devices, internet streaming service providers, 3D (3D) video devices, video telephony video devices, and medical video devices It may be included and used to process a video signal or a data signal. For example, the OTT video device may include a game console, a Blu-ray player, an internet access TV, a home theater system, a smartphone, a tablet PC, a digital video recorder (DVR), and the like.

In addition, the processing method to which the present invention is applied can be produced in the form of a program executed by a computer, and can be stored in a computer-readable recording medium. Multimedia data having a data structure according to the present invention can also be stored in a computer-readable recording medium. The computer readable recording medium includes all kinds of storage devices and distributed storage devices in which computer readable data is stored. The computer-readable recording medium may be, for example, a Blu-ray disc (BD), a universal serial bus (USB), a ROM, a PROM, an EPROM, an EEPROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, and an optical disc. It may include a data storage device. The computer-readable recording medium also includes media embodied in the form of a carrier wave (for example, transmission over the Internet). In addition, the bitstream generated by the encoding method may be stored in a computer-readable recording medium or transmitted through a wired or wireless communication network. In addition, an embodiment of the present invention may be implemented as a computer program product by program code, which may be performed on a computer by an embodiment of the present invention. The program code may be stored on a carrier readable by a computer.

In addition, the content streaming system to which the present invention is applied may largely include an encoding server, a streaming server, a web server, a media storage, a user device, and a multimedia input device.

The encoding server compresses content input from multimedia input devices such as a smart phone, a camera, a camcorder, etc. into digital data to generate a bitstream and transmit the bitstream to the streaming server. As another example, when multimedia input devices such as smart phones, cameras, camcorders, etc. directly generate a bitstream, the encoding server may be omitted. The bitstream may be generated by an encoding method or a bitstream generation method to which the present invention is applied, and the streaming server may temporarily store the bitstream in the process of transmitting or receiving the bitstream.

The streaming server transmits the multimedia data to the user device based on the user's request through the web server, and the web server serves as a medium for informing the user of what service. When a user requests a desired service from the web server, the web server delivers it to a streaming server, and the streaming server transmits multimedia data to the user. In this case, the content streaming system may include a separate control server. In this case, the control server plays a role of controlling a command / response between devices in the content streaming system.

The streaming server may receive content from a media store and / or an encoding server. For example, when the content is received from the encoding server, the content may be received in real time. In this case, in order to provide a smooth streaming service, the streaming server may store the bitstream for a predetermined time.

Examples of the user device include a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), navigation, a slate PC, Tablet PCs, ultrabooks, wearable devices, such as smartwatches, glass glasses, head mounted displays, digital TVs, desktops Computer, digital signage, and the like. Each server in the content streaming system may be operated as a distributed server, in which case data received from each server may be distributed.

Claims

In the image decoding method performed by the decoding apparatus,

Deriving neighboring blocks of the current block;

Constructing the motion information candidate list based on the derived neighboring blocks;

Deriving motion information of the current block based on the motion information candidate list; And

Generating a predicted block of the current block based on the motion information;

The neighboring blocks include non-adjacent blocks that are not adjacent to the current block,

And wherein the non-adjacent block is derived based on a motion vector, a maximum coding unit including the current block, or a current picture including the current block.
The method of claim 1,

The neighboring blocks are non-adjacent blocks located in at least one of a lower left area, a lower area, a lower right area, a right area, and an upper right area of the current block when the scanning order is set from the lower right side to the upper left direction. Image decoding method comprising a.
The method of claim 1,

And the neighboring blocks include the non-adjacent block located within a maximum coding unit in which the current block is included.
The method of claim 1,

The neighboring blocks may include the non-adjacent block located in any one of a left peripheral maximum coding unit, a left upper peripheral maximum coding unit, and an upper peripheral maximum coding unit of the maximum coding unit including the current block. , Video decoding method.
The method of claim 1,

And wherein the neighboring blocks include the non-adjacent block located in an area within a specific sample distance with respect to the upper left sample position of the current block.
The method of claim 1,

The neighboring blocks include the non-adjacent block located within a max range,

And wherein the maximum range is one of four, nine, and sixteen times the size of the current block, wherein the current block is located at the bottom right in the maximum range.
The method of claim 1,

The peripheral blocks include the non-adjacent block located within a reference range,

And the reference range is determined based on a maximum coding unit size and the number of maximum coding units.
The method of claim 1,

The neighboring blocks include the non-adjacent block located within a specific area about a position indicated by a specific motion vector,

The specific motion vector is derived from motion vectors of blocks adjacent to the current block,

And the size of the specific region is determined based on at least one of a size of the current block, a size of a maximum coding unit, and a size of a neighboring block.
The method of claim 1,

And the neighboring blocks include the non-adjacent block referring to a reference picture having a smallest difference in picture order count (POC) from a current picture included in the current block.
In the video encoding method performed by the encoding device,

Deriving neighboring blocks of the current block;

Constructing the motion information candidate list based on the derived neighboring blocks;

Deriving motion information of the current block based on the motion information candidate list;

Generating a predicted block of the current block based on the motion information; And

Generating, encoding, and outputting prediction information about the current block;

The neighboring blocks include non-adjacent blocks that are not adjacent to the current block,

And wherein the non-adjacent block is derived based on a motion vector, a maximum coding unit including the current block, or a current picture including the current block.
The method of claim 10,

The neighboring blocks are non-adjacent blocks located in at least one of a lower left area, a lower area, a lower right area, a right area, and an upper right area of the current block when the scanning order is set from the lower right side to the upper left direction. Image encoding method comprising a.
The method of claim 10,

And the neighboring blocks include the non-contiguous block located within a maximum coding unit in which the current block is included.
The method of claim 10,

The neighboring blocks may include the non-adjacent block located in any one of a left peripheral maximum coding unit, a left upper peripheral maximum coding unit, and an upper peripheral maximum coding unit of the maximum coding unit including the current block. , Video encoding method.
The method of claim 10,

And the neighboring blocks include the non-adjacent block located in an area within a specific sample distance with respect to the upper left sample position of the current block.
A decoding apparatus for performing an image decoding method,

An entropy decoding unit for obtaining prediction information on the current block; And

Deriving neighboring blocks of the current block, constructing the motion information candidate list based on the derived neighboring blocks, deriving motion information of the current block based on the motion information candidate list, and based on the motion information A prediction unit generating a predicted block of the current block,

The neighboring blocks include non-adjacent blocks that are not adjacent to the current block,

And wherein the non-adjacent block is derived based on a motion vector, a maximum coding unit including the current block, or a current picture including the current block.